index
int64
0
4.29k
question
stringlengths
13
192
answer
stringlengths
3
3.15k
relevant_passage_ids
stringlengths
8
1.57k
id
int64
100
4.72k
context
stringlengths
2
156k
4,078
Is neurofilament light marker for disease?
Yes, Serum neurofilament light chain (sNfL) is a marker of neuroaxonal injury leading to numerous diseases such as frontotemporal dementia (FTD) and Multiple sclerosis (MS).
[32306372, 34602928, 31961243, 32255388, 34375485]
4,482
Frontotemporal dementia (FTD) is the second most frequent dementia, after Alzheimer's, in patients under the age of 65. It encompasses clinical entities characterized by behavioral, language, and executive control dysfunction. Neurofilament light chain (NfL) is a new, non-disease specific, widely studied biomarker indicative of axonal injury and degeneration. Various studies have previously explored the role of NfL in the diagnostic process, monitoring, and prognosis of dementia. The current systematic review and meta-analysis include all the available data concerning the role of NfL in frontotemporal dementia and its use as a potential biomarker in differentiating patients with FTD from (a) healthy individuals, (b) Alzheimer's dementia, (c) Dementia with Lewy bodies, (d) Motor Neuron disease, (e) Parkinsonian syndromes, and (f) psychiatric disorders. We also analyze the utility of NfL in distinguishing specific FTD subgroups. Neurofilament light chain has a potential role in differentiating patients with frontotemporal dementia from healthy controls, patients with Alzheimer's dementia, and psychiatric disorders. Higher NfL levels were also noted in patients with semantic primary progressive aphasia (PPA) when compared with behavioral FTD and non-fluent PPA patients. Further studies exploring the use of NfL in frontotemporal dementia are needed. BACKGROUND: Increased blood brain barrier (BBB) permeability, CNS inflammation and neuroaxonal damage are pathological hallmarks in early multiple sclerosis (MS). OBJECTIVE: To investigate the associations of neurofilament light chain (NfL) levels with measures of BBB integrity and central nervous system (CNS) inflammation in MS during the first demyelinating event. METHODS: Blood and cerebrospinal fluid (CSF) were obtained from 142 MS (McDonald 2017) treatment-naive patients from the SET study (63% female; age: 29.7 ± 7.9 years) following the disease onset. NfL, albumin, immunoglobulin G (IgG), and immunoglobulin M (IgM) levels were measured in CSF and blood samples. Albumin quotient was computed as a marker of BBB integrity. Immune cell subset counts in CSF were measured using flow cytometry. MS risk factors, such as Human leukocyte antigen DRB1 locus gene (HLA DRB1)*1501, anti-Epstein-Barr virus (EBV) antibodies, and 25-hydroxy vitamin D3, were also measured. RESULTS: Higher serum NfL (sNfL) levels were associated with higher albumin quotient (p < 0.001), CSF CD80+ (p = 0.012), and CD80+ CD19+ (p = 0.015) cell frequency. sNfL levels were also associated with contrast-enhancing and T2 lesions on brain magnetic resonance imaging (MRI; all p ⩽ 0.001). Albumin quotient was not associated with any of the MS risk factors assessed. sNfL levels were associated with anti-EBV viral capsid antigen (VCA) IgG levels (p = 0.0026). CONCLUSION: sNfL levels during the first demyelinating event of MS are associated with greater impairment of BBB integrity, immune cell extravasation, and brain lesion activity on MRI. BACKGROUND AND PURPOSE: Neurofilament light chain (NfL) has recently been proposed as a promising biomarker in frontotemporal dementia (FTD). We investigated the correlation of both cerebrospinal fluid (CSF) and serum NfL with detailed neuropsychological data and cognitive decline in a cohort of sporadic and familial FTD. METHODS: CSF and serum NfL, as well as conventional CSF Alzheimer's disease (AD) biomarkers (Aβ42, t-Tau, p-Tau181), were determined in 63 FTD patients (30 sporadic-FTD, 20 with progranulin (GRN) mutations [FTD-GRN], 13 with chromosome 9 open reading frame 72 [C9orf72] expansions [C9orf72-FTD]), 37 AD patients, and 31 neurologic controls. Serum NfL was also quantified in 37 healthy individuals. Correlations between baseline CSF and serum NfL levels, standardized neuropsychological tests, and the rate of cognitive decline in FTD patients were assessed. RESULTS: CSF and serum NfL presented with significantly higher levels in FTD than in AD patients and both control groups. Within FTD subtypes, genetic cases, and particularly FTD-GRN, had higher CSF and serum NfL levels. Significant correlations between NfL levels and overall cognitive function, abstract reasoning (CSF and serum), executive functions, memory, and language (serum) were found. A relationship between increased baseline CSF and serum NfL and a decay in cognitive performance over time was also observed. CONCLUSIONS: Our findings highlight the potential of serum NfL as a useful surrogate end point of disease severity in upcoming targeted treatments.
4,079
Is resistance training usually associated with increasing muscle hypertrophy?
Traditional resistance exercises have been widely used to promote muscle strength and hypertrophy.
[29608833, 31268995, 34052876, 31254797, 28280974, 31009427, 32740889, 8153497, 3057312, 11173673, 14766764, 25911469, 28315193, 31161403, 17166396, 28346813, 1864770, 18796867, 10932036, 20560706, 8681927, 28663372, 24188499, 8792025, 24751198, 21445603, 19196907, 31482093, 32162291, 12392444]
4,483
Mannarino, P, Matta, T, Lima, J, Simão, R, and Freitas de Salles, B. Single-Joint Exercise Results in Higher Hypertrophy of Elbow Flexors Than Multijoint Exercise. J Strength Cond Res 35(10): 2677-2681, 2021-Recent data suggest that single-joint exercises are unnecessary to maximize the resistance training (RT) results in novice to advanced individuals. However, the present literature is still inconsistent on this topic and controversy arises. The aim of this study was to compare the effects of the unilateral dumbbell row (DR) (multiple-joint) vs. unilateral biceps curl (BC) (single-joint) exercises on strength and elbow flexors muscle thickness (MT). Ten untrained men were assigned to an 8-week RT program for elbow flexors, one arm performing DR and the other performing BC in a within-subject design. After a familiarization, pretraining MT was measured using an ultrasound (US) technique, and strength was tested using 10 repetition maximum (10RM) tests. After pretesting, 8 weeks of RT (4-6 sets, 8-12 repetitions to concentric failure, 2 sessions per week) was performed. Post-testing was conducted in the same order as pretesting 48 and 72 hours after the last session. Single-joint BC exercise resulted in higher hypertrophy of elbow flexors (11.06%) than the DR (5.16%) multijoint exercise after 8 weeks of RT (p = 0.009). The 10RM improvement was higher for DR in DR-trained arm, whereas 10RM for BC was higher in BC-trained arm. The single-joint exercise resulted in higher hypertrophy of the elbow flexors than multijoint exercise after 8 weeks of RT, whereas strength improvements were greater in accordance with specificity of RT exercise. Therefore, in RT prescription for elbow flexors hypertrophy, single-joint exercises such as BC should be emphasized. BACKGROUND: While traditional resistance exercises have been widely used to promote muscle strength and hypertrophy in the elderly, few studies have reported the use of a functional approach in which common patterns for daily activities are considered the primary stimulus. OBJECTIVE: Investigate whether functional training has similar effects the traditional on body composition and muscle strength components in physically active older women. METHODS: Forty-seven older women completed a randomized and crossover clinical trial, distributed in three groups: Functional or Traditional Training (FUNCT/TRAD: n = 32; 65.28 ± 4.96 years) and Stretching Group (STRETCH: n = 15; 64.40 ± 3.68 years). Maximal dynamic strength was verified with the 1 repetition maximum (RM) test in the leg press and rowing machines. Muscular power was analyzed using 50% of the maximum load, speed was determined using a linear encoder, and isometric strength was analyzed with hand and lumbar dynamometers. ANOVA for repeated measures was applied for comparisons. RESULTS: The FUNCT showed a significant decrease in fat percentage (p = 0.015, 3.51%) and the TRAD a significant increase in lean mass (p = 0.008, 2.92%). Both FUNCT and TRAD generated significant increases in all components of muscle strength compared to baseline whereas STRETCH showed declines in these variables. No statistically significant differences were observed between the experimental groups in body composition. CONCLUSION: Functional and traditional training are equally efficient in improving strength components in physically active older women and, therefore, they may be complementary to combat some of the deleterious effects of senescence. This trial was registered at Brazilian Registry of Clinical Trials (RBR-9Y8KJQ). Franco, CMC, Carneiro, MAS, de Sousa, JFR, Gomes, GK, and Orsatti, FL. Influence of high- and low-frequency resistance training on lean body mass and muscle strength gains in untrained men. J Strength Cond Res 35(8): 2089-2094, 2021-The aim of this study was to investigate whether high-frequency resistance training (HFRT) performs better in lean body mass (LBM) and muscle strength gains when compared with low-frequency resistance training (LFRT). Eighteen untrained males (height: 1.76 ± 0.05 m, body mass: 78.3 ± 13.5 kg, and age: 22.1 ± 2.2 years) were randomly allocated into HFRT (n = 9) and LFRT (n = 9). Muscle strength {1 repetition maximum (RM) (bench press [BP] and unilateral leg extension [LE])} and LBM (DXA) were assessed at before and after 8 weeks of training. Both groups performed 7 whole-body resistance exercises, standardized to 10 sets per week, 8-12 maximal repetitions, and 90-120 seconds of rest in a 5-day resistance training routine. The LFRT performed a split-body routine, training each specific muscle group once a week. The HFRT performed a total-body routine, training all muscle groups every session and progressed from a training frequency of once per week to a training frequency of 5 times per week. Lean body mass increased without differences between groups (HFRT = 1.0 kg vs. LFRT = 1.5 kg; p = 0.377). Similarly, 1RM increased without differences between groups (right LE, HFRT = 21.2 kg vs. LFRT = 19.7 kg, p = 0.782; BP, HFRT = 7.1 kg vs. LFRT = 4.5 kg, p = 0.293). These findings suggest that in young untrained men, progressing from a training frequency of once per week to a training frequency of 5 times per week with equated volume produces similar gains in LBM and muscle strength as a constant training frequency of once per week, over an 8-week training period. Skeletal muscle tissue is sensitive to the acute and chronic stresses associated with resistance training. These responses are influenced by the structure of resistance activity (i.e. frequency, load and recovery) as well as the training history of the individuals involved. There are histochemical and biochemical data which suggest that resistance training alters the expression of myosin heavy chains (MHCs). Specifically, chronic exposure to bodybuilding and power lifting type activity produces shifts towards the MHC I and IIb isoforms, respectively. However, it is not yet clear which training parameters trigger these differential expressions of MHC isoforms. Interestingly, many programmes undertaken by athletes appear to cause a shift towards the MHC I isoform. Increments in the cross-sectional area of muscle after resistance training can be primarily attributed to fibre hypertrophy. However, there may be an upper limit to this hypertrophy. Furthermore, significant fibre hypertrophy appears to follow the sequence of fast twitch fibre hypertrophy preceding slow twitch fibre hypertrophy. Whilst some indirect measures of fibre number in living humans suggest that there is no interindividual variation, postmortem evidence suggests that there is. There are also animal data arising from investigations using resistance training protocols which suggest that chronic exercise can increase fibre number. Furthermore, satellite cell activity has been linked to myotube formation in the human. However, other animal models (i.e. compensatory hypertrophy) do not support the notion of fibre hyperplasia. Even if hyperplasia does occur, its effect on the cross-sectional area of muscle appears to be small. Phosphagen and glycogen metabolism, whilst important during resistance activity appear not to normally limit the performance of resistance activity. Phosphagen and related enzyme adaptations are affected by the type, structure and duration of resistance training. Whilst endogenous glycogen reserves may be increased with prolonged training, typical isotonic training for less than 6 months does not seem to increase glycolytic enzyme activity. Lipid metabolism may be of some significance in bodybuilding type activity. Thus, not surprisingly, oxidative enzyme adaptations appear to be affected by the structure and perhaps the modality of resistance training. The dilution of mitochondrial volume and endogenous lipid densities appears mainly because of fibre hypertrophy. Heavy resistance training is associated with increased body weight, lean body mass, and muscle cross-sectional area. The increased muscle cross-sectional area is mainly brought about by hypertrophy of individual muscle fibers. There is a greater increase in the area of fast twitch fibers compared to slow twitch fibers. In addition, long-term heavy resistance training may produce fiber proliferation. Mitochondrial volume density decreases in proportion to muscle hypertrophy in response to training. Typically, no capillary neoformation occurs during strength training. Therefore, capillary density decreases consequent to heavy resistance training. It appears, though, that bodybuilders, relying on a high repetition training system, in contrast to Olympic weight- and power lifters, display a small increase in number of capillaries per fiber. Enzyme activities, reflecting oxidative potential; decrease during long-term heavy resistance training, resulting in muscle hypertrophy. Although glycogen storage capacity is enhanced in strength trained athletes, enzyme activities reflecting anaerobic metabolism do not increase in response to heavy resistance exercise. In the past decade strength training has been investigated extensively as a means of reversing the muscle mass loss that occurs with aging (sarcopenia). High intensity resistance training (HIRT) has led to increased protein synthesis, along with muscle hypertrophy measured at the whole body, whole muscle, and muscle fibre levels, in older adults. Typically, the strength increments associated with HIRT have been much larger than the hypertrophic response. However, most HIRT periods have been quite short. Less is known about the long-term hypertrophic response to HIRT in older adults. In order to lessen the effects of sarcopenia, HIRT should continue over the long term in older adults, to improve functional performance and health. Muscle hypertrophy is the product of increased drive through protein synthetic pathways and the incorporation of newly divided satellite cells. Gains in muscle mass and strength can be achieved through exercise regimens that include resistance training. Increased insulin-like growth factor-I (IGF-I) can also promote hypertrophy through increased protein synthesis and satellite cell proliferation. However, it is not known whether the combined effect of IGF-I and resistance training results in an additive hypertrophic response. Therefore, rats in which viral administration of IGF-I was directed to one limb were subjected to ladder climbing to test the interaction of each intervention on muscle mass and strength. After 8 wk of resistance training, a 23.3% increase in muscle mass and a 14.4% increase in peak tetanic tension (P(o)) were observed in the flexor hallucis longus (FHL). Viral expression of IGF-I without resistance training produced a 14.8% increase in mass and a 16.6% increase in P(o) in the FHL. The combined interventions produced a 31.8% increase in muscle mass and a 28.3% increase in P(o) in the FHL. Therefore, the combination of resistance training and overexpression of IGF-I induced greater hypertrophy than either treatment alone. The effect of increased IGF-I expression on the loss of muscle mass associated with detraining was also addressed. FHL muscles treated with IGF-I lost only 4.8% after detraining, whereas the untreated FHL lost 8.3% muscle mass. These results suggest that a combination of resistance training and overexpression of IGF-I could be an effective measure for attenuating the loss of training-induced adaptations. The aim of the study was to determine whether it is possible to improve both maximum and rapid force production using resistance training that is typically used to induce muscle hypertrophy in previously untrained older men. Subjects (60-72 years) performed 20 weeks of "hypertrophic" resistance training twice weekly (n = 27) or control (n = 11). Maximum dynamic and isometric leg press, as well as isometric force over 0-100 ms, and maximum concentric power tests were performed pre- and post-intervention. Muscle activity was assessed during these tests by surface electromyogram of the vastus lateralis and medialis muscles. Muscle hypertrophy was assessed by panoramic ultrasound of the vastus lateralis. The intervention group increased their maximum isometric (from 2268 ± 544 to 2538 ± 701 N) and dynamic force production (from 137 ± 24 to 165 ± 29 kg), and these changes were significantly different to control (isometric 12 ± 16 vs. 1 ± 9 %; dynamic 21 ± 12 vs. 2 ± 4 %). No within- or between-group differences were observed in rapid isometric force or concentric power. Relative increases in vastus lateralis cross-sectional area trended to be statistically greater in the intervention group (10 ± 8 vs. 3 ± 6 %, P = 0.061). It is recommendable that resistance training programs for older individuals integrate protocols emphasizing maximum force/muscle hypertrophy and rapid force production in order to induce comprehensive health-related and functionally important improvements in this population. The possible muscular strength, hypertrophy, and muscle power benefits of resistance training under environmental conditions of hypoxia are currently being investigated.Nowadays, resistance training in hypoxia constitutes a promising new training strategy for strength and muscle gains. The main mechanisms responsible for these effects seem to be related to increased metabolite accumulation due to hypoxia. However, no data are reported in the literature to describe and compare the efficacy of the different hypertrophic resistance training strategies in hypoxia.Moreover, improvements in sprinting, jumping, or throwing performance have also been described at terrestrial altitude, encouraging research into the speed of explosive movements at altitude. It has been suggested that the reduction in the aerodynamic resistance and/or the increase in the anaerobic metabolism at higher altitudes can influence the metabolic cost, increase the take-off velocities, or improve the motor unit recruitment patterns, which may explain these improvements. Despite these findings, the applicability of altitude conditions in improving muscle power by resistance training remains to be clarified.This review examines current knowledge regarding resistance training in different types of hypoxia, focusing on strategies designed to improve muscle hypertrophy as well as power for explosive movements. It has been proposed that protein supplementation during resistance exercise training enhances muscle hypertrophy. The degree of hypertrophy during training is controlled in part through the activation of satellite cells and myonuclear accretion. PURPOSE: This study aimed to determine the efficacy of protein supplementation (and the type of protein) during traditional resistance training on myofiber cross-sectional area, satellite cell content, and myonuclear addition. METHODS: Healthy young men participated in supervised whole-body progressive resistance training 3 d·wk for 12 wk. Participants were randomized to one of three groups ingesting a daily 22-g macronutrient dose of soy-dairy protein blend (PB, n = 22), whey protein isolate (WP, n = 15), or an isocaloric maltodextrin placebo (MDP, n = 17). Lean mass, vastus lateralis myofiber-type-specific cross-sectional area, satellite cell content, and myonuclear addition were assessed before and after resistance training. RESULTS: PB and the pooled protein treatments (PB + WP = PRO) exhibited a greater whole-body lean mass %change compared with MDP (P = 0.057 for PB) and (P = 0.050 for PRO), respectively. All treatments demonstrated similar leg muscle hypertrophy and vastus lateralis myofiber-type-specific cross-sectional area (P < 0.05). Increases in myosin heavy chain I and II myofiber satellite cell content and myonuclei content were also detected after exercise training (P < 0.05). CONCLUSION: Protein supplementation during resistance training has a modest effect on whole-body lean mass as compared with exercise training without protein supplementation, and there was no effect on any outcome between protein supplement types (blend vs whey). However, protein supplementation did not enhance resistance exercise-induced increases in myofiber hypertrophy, satellite cell content, or myonuclear addition in young healthy men. We propose that as long as protein intake is adequate during muscle overload, the adaptations in muscle growth and function will not be influenced by protein supplementation. We conducted a 12-wk resistance training program in elderly women [mean age 69 +/- 1.0 (SE) yr] to determine whether increases in muscle strength are associated with changes in cross-sectional fiber area of the vastus lateralis muscle. Twenty-seven healthy women were randomly assigned to either a control or exercise group. The program was satisfactorily completed and adequate biopsy material obtained from 6 controls and 13 exercisers. After initial testing of baseline maximal strength, exercisers began a training regimen consisting of seven exercises that stressed primary muscle groups of the lower extremities. No active intervention was prescribed for the controls. Increases in muscle strength of the exercising subjects were significant compared with baseline values (28-115%) in all muscle groups. No significant strength changes were observed in the controls. Cross-sectional area of type II muscle fibers significantly increased in the exercisers (20.1 +/- 6.8%, P = 0.02) compared with baseline. In contrast, no significant change in type II fiber area was observed in the controls. No significant changes in type I fiber area were found in either group. We conclude that a program of resistance exercise can be safely carried out by elderly women, such a program significantly increases muscle strength, and such gains are due, at least in part, to muscle hypertrophy. This paper was prepared in partial fulfillment for Doctoral Degree in Physical Therapy at Texas Woman's University in Houston, TX. Resistance training is frequently used in rehabilitation to improve musculoskeletal function. The increased ability of skeletal muscle to generate force following resistance training results from two important changes: 1) the adaptation of the muscle fiber, and 2) the extent to which the motor unit can activate the muscle (neural adaption). The purpose of this article is to provide a review of research investigating the effects of resistance training on muscle fibers and on nervous system input. Muscle fiber adaptations caused by resistance training include increased cross-sectional area of the muscle (hypertrophy, hyperplasia, or both), selective hypertrophy of fast twitch fibers, decreased or maintained mitochondrial number and capillary density of muscle, and possible changes in energy sources. Changes in nervous system input resulting from resistance training include recruitment of an increased number and firing rate of motor units, increased reflex potentiation, and improved synchronization. An understanding of the adaptations occurring in muscle in response to resistance training provides a fundamental basis for which appropriate clinical exercise training programs can be developed for the rehabilitation of patients. J Orthop Sports Phys Ther 1990;12(6):248-255. Chronic resistance training induces increases in muscle fibre cross-sectional area (CSA), otherwise known as hypertrophy. This is due to an increased volume percentage of myofibrillarproteins within a given fibre. The exact time-course for muscle fibre hypertrophy is not well-documented but appears to require at least 6-7 weeks of regular resistive training at reasonably high intensity before increases in fibre CSA are deemed significant. Proposed training-induced changes in neural drive are hypothesized to increase strength due to increased synchrony of motor unit firing, reducedant agonist muscle activity, and/or a reduction in any bilateral strength deficit. Nonetheless, increases in muscle protein synthesis were observed following an isolated bout of resistance exercise. In addition, muscle balance was positive, following resistance exercise when amino acids were infused/ingested. This showed that protein accretion occurred during the postexercise period. The implications of this hypothesis for training-induced increases in strength are discussed. In resistance training, it has been empirically accepted that muscle hypertrophy is developed by low intensity and high volume training, while muscle strength and power are developed by high intensity and low volume training. The purpose of the present study was to investigate the influence of two different modes of resistance training on isokinetic strength and muscle cross-sectional area (CSA) in females. Eleven females, who had no experience in resistance training, participated in this study and were randomly divided into two groups. The former consisted of 4-5 sets of 15-20 RM (repetition maximum) with sufficient rest between sets (Group H), while the latter consisted of 8-9 sets of 4-6R M with 90 s of rest between sets (Group S). The former was assumed to be appropriate for muscle hypertrophy and the latter muscle strength, respectively. All subjects completed isotonic knee extension exercise three times a week for 8 weeks. Measurements were made on quadriceps muscle cross-sectional area (CSA) and isokinetic torques at 0, 60, 180, and approximately 300 degrees before training, at the fifth week and the end of training period. Muscle CSA was defined as the sum of CSA measured at 30, 50 and 70% of femur length. After training, muscle CSA had significantly increased in both groups: 3.3 +/- 0.7% (p < .05) for group H and 3.6 +/- 1.1% (p < .05) for group S, respectively. While the changes in isokinetic torque were 43.4 +/- 47.5% (p < .05) for group H and 27.4 +/- 31.3% (p < .05) for group S, respectively. In both groups the percentage changes of the isokinetic strength were significantly higher than those of the CSA. No significant difference in these variables were found between the two groups. These results suggest that during the early phase of resistance training two different modes of resistance training may have similar effects on muscle CSA and isokinetic strength in untrained females. Resistance training of healthy young men typically results in muscle hypertrophy and a shift in vastus lateralis composition away from type IIx fibers to an increase in IIa fiber content. Our previous studies of 8 wk of resistance training found that many metabolic syndrome men and women paradoxically increased IIx fibers with a decrease in IIa fibers. To confirm the hypothesis that obese subjects might have muscle remodeling after resistance training very different from healthy lean subjects, we subjected a group of nine obese male volunteers to progressive resistance training for a total of 16 wk. In these studies, weight loss was discouraged so that muscle changes would be attributed to the training alone. Detailed assessments included comparisons of histological examinations of needle biopsies of vastus lateralis muscle pretraining and at 8 and 16 wk. Prolonging the training from 8 to 16 wk resulted in increased strength, improved body composition, and more muscle fiber hypertrophy, but euglycemic clamp-quantified insulin responsiveness did not improve. Similar to prior studies, muscle fiber composition shifted toward more fast-twitch type IIx fibers (23 to 42%). Eight weeks of resistance training increased the muscle expression of phosphorylated Akt2 and mTOR. Muscle GLUT4 expression increased, although insulin receptor and IRS-1 expression did not change. We conclude that resistance training of prediabetic obese subjects is effective at changing muscle, resulting in fiber hypertrophy and increased type IIx fiber content, and these changes continue up to 16 wk of training.NEW & NOTEWORTHY Obese, insulin-resistant men responded to 16 wk of progressive resistance training with muscle hypertrophy and increased strength and a shift in muscle fiber composition toward fast-twitch, type IIx fibers. Activation of muscle mTOR was increased by 8 wk but did not increase further at 16 wk despite continued augmentation of peak power and rate of force generation. BACKGROUND: Resistance training in combination with practical blood flow restriction (pBFR) is thought to stimulate muscle hypertrophy by increasing muscle activation and muscle swelling. Most previous studies used the KAATSU device; however, little long-term research has been completed using pBFR. OBJECTIVE: To investigate the effects of pBFR on muscle hypertrophy. METHODS: Twenty college-aged male participants with a minimum of 1 year of resistance training experience were recruited for this study. Our study consisted of a randomized, crossover protocol consisting of individuals either using pBFR for the elbow flexors during the first 4 weeks (BFR-HI) or the second 4 weeks (HI-BFR) of an 8-week resistance training programme. Direct ultrasound-determined bicep muscle thickness was assessed collectively at baseline and at the end of weeks 4 and 8. RESULTS: There were no differences in muscle thickness between groups at baseline (P = 0·52). There were time (P<0·01, ES = 0·99) but no condition by time effects (P = 0·58, ES = 0·80) for muscle thickness in which the combined values of both groups increased on average from week 0 (3·66 ± 0·06) to week 4 (3·95 ± 0·05) to week 8 (4·11 ± 0·07). However, both the BFR-HI and HI-BFR increased significantly from baseline to week 4 (6·9% and 8·6%, P<0·01) and from weeks 4 to 8 (4·1%, 4·0%, P<0·01), respectively. CONCLUSION: The results of this study suggest that pBFR can stimulate muscle hypertrophy to the same degree to that of high-intensity resistance training. High-intensity resistance (HIR) training has been associated with muscle hypertrophy and decreased microvascular density that might produce a blood flow limitation. The effect of HIR training on lower leg maximal blood flow and minimum vascular resistance (Rmin) during reactive hyperemia were investigated in 7 healthy males. The gastrocnemius-soleus muscles of one leg were trained using maximal isokinetic concentric contractions for 4 weeks; the nontrained leg was the control. Lower leg blood flow was measured by venous occlusion plethysmography. Lower leg muscle volume was determined using magnetic resonance imaging. Peak isokinetic torque increased in both the trained (T) and nontrained (NT) legs (p < .05). Lower leg muscle volume increased by 2% in the T leg only (p < .05). In the T leg, maximal blood flow decreased and Rmin increased (p < .05); no hemodynamic change was detected in the NT leg. It is concluded that HIR training of the calf muscles is associated with a decrease in hyperemia-induced blood flow; thereby, indicating a blood flow limitation to the calf muscles. Low-intensity blood flow restricted (LI-BFR) resistance training has been shown to produce comparable increases in muscle hypertrophy to traditional high-intensity (HI) resistance training. However, a comparison of the acute vascular responses between the two types of exercise has not been made. The purpose of this study is to compare the acute vascular responses of HI, low-intensity (LI), and LI-BFR resistance exercise. Using a randomized, cross-over design, 11 young (28 ± 5 years) males completed three acute resistance exercise bouts (HI, LI and LI-BFR). Before (Pre), and starting at 15- and 45-min after each exercise bout, large (LAEI) and small (SAEI) artery compliance and calf blood flow were assessed. Calf blood flow was normalized per unit pressure as calf vascular conductance (CVC). Repeated measures (condition × time) ANOVA revealed a main time effect for LAEI and a main condition effect for SAEI. LAEI increased following exercise but returned to baseline at 45-min post. SAEI was greater during the HI condition compared to the LI or LI-BFR conditions. There was a significant condition × time interaction for CVC. CVC was elevated at 15- and 45-min post during the HI condition and at 15-min following the LI condition. CVC was not altered following the LI-BFR condition. These results suggest that HI, LI, and LI-BFR resistance exercise cause similar acute increases in large artery compliance but HI causes greater increases in small artery compliance and calf vascular conductance than LI or LI-BFR resistance exercise. We determined muscle fiber type-specific hypertrophy and changes in satellite cell (SC) content following a 12-week resistance training program in 13 healthy, elderly men (72 +/- 2 years). Leg strength and body composition (dual-energy X-ray absorptiometry and computed tomography) were assessed, and muscle biopsy samples were collected. Leg strength increased 25%-30% after training (p < .001). Leg lean mass and quadriceps cross-sectional area increased 6%-9% (p < .001). At baseline, mean fiber area and SC content were smaller in the Type II versus Type I muscle fibers (p < .01). Following training, Type II muscle fiber area increased from 5,438 +/- 319 to 6,982 +/- 503 microm(2) (p < .01). Type II muscle fiber SC content increased from 0.048 +/- 0.003 to 0.084 +/- 0.008 SCs per fiber (p < .001). No changes were observed in the Type I muscle fibers. In older adults, skeletal muscle tissue is still capable of inducing SC proliferation and differentiation, resulting in Type II muscle fiber hypertrophy. Resistance training is commonly prescribed to enhance strength/power qualities and is achieved via improved neuromuscular recruitment, fiber type transition, and/ or skeletal muscle hypertrophy. The rate and amount of muscle hypertrophy associated with resistance training is influenced by a wide array of variables including the training program, plus training experience, gender, genetic predisposition, and nutritional status of the individual. Various dietary interventions have been proposed to influence muscle hypertrophy, including manipulation of protein intake, specific supplement prescription, and creation of an energy surplus. While recent research has provided significant insight into optimization of dietary protein intake and application of evidence based supplements, the specific energy surplus required to facilitate muscle hypertrophy is unknown. However, there is clear evidence of an anabolic stimulus possible from an energy surplus, even independent of resistance training. Common textbook recommendations are often based solely on the assumed energy stored within the tissue being assimilated. Unfortunately, such guidance likely fails to account for other energetically expensive processes associated with muscle hypertrophy, the acute metabolic adjustments that occur in response to an energy surplus, or individual nuances like training experience and energy status of the individual. Given the ambiguous nature of these calculations, it is not surprising to see broad ranging guidance on energy needs. These estimates have never been validated in a resistance training population to confirm the "sweet spot" for an energy surplus that facilitates optimal rates of muscle gain relative to fat mass. This review not only addresses the influence of an energy surplus on resistance training outcomes, but also explores other pertinent issues, including "how much should energy intake be increased," "where should this extra energy come from," and "when should this extra energy be consumed." Several gaps in the literature are identified, with the hope this will stimulate further research interest in this area. Having a broader appreciation of these issues will assist practitioners in the establishment of dietary strategies that facilitate resistance training adaptations while also addressing other important nutrition related issues such as optimization of fuelling and recovery goals. Practical issues like the management of satiety when attempting to increase energy intake are also addressed. It is universally accepted that resistance training promotes increases in muscle strength and hypertrophy in younger and older populations. Although less investigated, studies largely suggest resistance training results in lower skeletal muscle mitochondrial volume; a phenomenon which has been described as a "dilution of the mitochondrial volume" via resistance training. While this phenomenon is poorly understood, it is likely a result of muscle fiber hypertrophy outpacing mitochondrial biogenesis. Critically, there is no evidence to suggest resistance training promotes a net loss in mitochondria. Further, given the numerous reports suggesting resistance training does not decrease and may even increase VO2max in previously untrained individuals, it is plausible certain aspects of mitochondrial function may be enhanced with resistance training, and this area warrants further research consideration. Finally, there are emerging data suggesting resistance training may affect mitochondrial dynamics. The current review will provide an in-depth discussion of these topics and posit future research directions which can further our understanding of how resistance training may affect skeletal muscle mitochondrial physiology. Resistance training (RT) is a popular method of conditioning to enhance sport performance as well as an effective form of exercise to attenuate the age-mediated decline in muscle strength and mass. Although the benefits of RT on skeletal muscle morphology and function are well established, its effect on left ventricular (LV) morphology remains equivocal. Some investigations have found that RT is associated with an obligatory increase in LV wall thickness and mass with minimal alteration in LV internal cavity dimension, an effect called concentric hypertrophy. However, others report that short- (<5 years) to long-term (>18 years) RT does not alter LV morphology, arguing that concentric hypertrophy is not an obligatory adaptation secondary to this form of exertion. This disparity between studies on whether RT consistently results in cardiac hypertrophy could be caused by: (i) acute cardiopulmonary mechanisms that minimise the increase in transmural pressure (i.e. ventricular pressure minus intrathoracic pressure) and LV wall stress during exercise; (ii) the underlying use of anabolic steroids by the athletes; or (iii) the specific type of RT performed. We propose that when LV geometry is altered after RT, the pattern is usually concentric hypertrophy in Olympic weightlifters. However, the pattern of eccentric hypertrophy (increased LV mass secondary to an increase in diastolic internal cavity dimension and wall thickness) is not uncommon in bodybuilders. Of particular interest, nearly 40% of all RT athletes have normal LV geometry, and these athletes are typically powerlifters. RT athletes who use anabolic steroids have been shown to have significantly higher LV mass compared with drug-free sport-matched athletes. This brief review will sort out some of the factors that may affect the acute and chronic outcome of RT on LV morphology. In addition, a conceptual framework is offered to help explain why cardiac hypertrophy is not always found in RT athletes.
4,080
What is known about FANK1?
Fank1 encodes a protein containing a fibronectin type III domain in the amino terminus and five ankyrin repeats in its carboxyl terminus. FANK1 displays a high degree of sequence conservation in 11 vertebrate species during evolution. Bioinformatic and experimental analyses revealed that Fank1 was exclusively expressed in the testis in both mice and humans. Consistent with its nuclear localization, a gene ontology analysis suggests that FANK1 has a DNA binding activity and thus may function as a transcription factor.
[17604233, 20978819, 31086747, 24369145]
4,486
In our effort to identify testis-specific genes we found Fank1, which encodes a protein containing a fibronectin type III domain in the amino terminus and five ankyrin repeats in its carboxyl terminus. FANK1 displays a high degree of sequence conservation in 11 vertebrate species during evolution. Bioinformatic and experimental analyses revealed that Fank1 was exclusively expressed in the testis in both mice and humans. Fank1 mRNA was expressed in mid to late pachytene spermatocytes as well as spermatids in steps 1-14. FANK1 protein was localized in the nuclei of the same cells within the seminiferous epithelium. Consistent with its nuclear localization, a gene ontology analysis suggests that FANK1 has a DNA binding activity and thus may function as a transcription factor. Given the highly restricted expression of FANK1, it may have a role in regulating gene expression in the transition from the meiotic phase to the haploid phase during spermatogenesis. Regulation of apoptosis at various stages of differentiation plays an important role in spermatogenesis. Therefore, the identification and characterisation of highly expressed genes in the testis that are involved in apoptosis is of great value to delineate the mechanism of spermatogenesis. Here, we reported that Fank1, a novel gene highly expressed in testis, functioned as an anti-apoptotic protein that activated the activator protein 1 (AP-1) pathway. We found that Jab1 (Jun activation domain-binding protein 1), a co-activator of AP-1, specifically interacted with Fank1. Reporter analyses showed that Fank1 activated AP-1 pathway in a Jab1-dependent manner. Fank1 overexpression also increased the expression and activation of endogenous c-Jun. Further study showed that Fank1 inhibited cell apoptosis by upregulating and activating endogenous c-Jun and its downstream target, Bcl-3. This process was shown to be Jab1 dependent. Taken together, our results indicated that by interacting with Jab1, Fank1 could suppress cell apoptosis by activating the AP-1-induced anti-apoptotic pathway. BACKGROUND: The fibronectin type 3 and ankyrin repeat domains 1 gene, Fank1, is an ancient, evolutionarily conserved gene present in vertebrates. Short-hairpin RNA (shRNA)-based knockdown transgenic mice have oligospermia caused by an increase in apoptotic germ cells. In this study, we investigated the in vivo function of Fank1. METHODS: In this study, we generated Fank1-knockout mice using the CRISPR/Cas9 system. We then investigated the phenotype and in vivo function of Fank1. Testes and epididymis tissues were analyzed by histological and immunofluorescence staining. Apoptotic cells were analyzed in terminal deoxynucleotidyl transferase dUTP nick end-labeling assays. Fertility and sperm counts were also evaluated. The GTEx database were used to assess gene expression quantitative trait loci and mRNA expression of candidate genes and genes neighboring single nucleotide polymorphisms was analyzed by quantitative RT-PCR. RESULTS: In contrast to the Fank1-knockdown model, no significant changes in epididymal sperm content and the number of apoptotic cells were observed in Fank1-/- homozygotes. In addition, a different pattern of Dusp1, Klk1b21 and Klk1b27 mRNA expression was detected in Fank1-knockout testis. These results reveal differences in the molecular changes between Fank1-knockdown mice and Fank1-knockout mice and provide a basic resource for population genetics studies.
4,081
Please list the drugs associated with Drug-Induced Hypophosphatemia.
Drug induced hypophosphatemia can occur with iron therapy as well a treatment with ferric carboxymaltose, elotuzumab, cemiplimab, Temsirolimus, capecitabine, panobinostat, bendamustine, ofatumumab, carboplatin and etoposide (BOCE)
[33638305, 33146052, 33051909, 17117416, 8069002, 26939882, 2108845, 31776845, 27613487, 20356849, 32730387, 34534708, 33146741, 33563894, 33237342, 32337119]
4,487
BACKGROUND: Temsirolimus is an mTOR antagonist with proven anticancer efficacy. Preclinical data suggest greater anticancer effect when mTOR inhibitors are combined with cytotoxic chemotherapy. We performed a Phase I assessment of the combination of temsirolimus and capecitabine in patients with advanced solid tumors. METHODS: Patients were enrolled in an alternating dose escalation of temsirolimus (at 15 or 25 mg IV weekly) and capecitabine (at 750, 1000, and 1250 mg/m2 twice daily) in separate Q2-week and Q3-week cohorts. At the recommended Phase II doses (RP2Ds) of temsirolimus and capecitabine (Q2), seven patients were also treated with oxaliplatin (85 mg/m2 , day 1) to determine triplet combination safety and efficacy. RESULTS: Forty-five patients were enrolled and 41 were evaluable for dose-limiting toxicities (DLTs). The most common adverse events (AEs) were mucositis, fatigue, and thrombocytopenia. The most common grade 3/4 AEs were hypophosphatemia and anemia. Five patients had DLTs, including hypophosphatemia, mucositis, and thrombocytopenia. The RP2Ds were temsirolimus 25 mg +capecitabine 1000 mg/m2 (Q2); and temsirolimus 25 mg +capecitabine 750 mg/m2 (Q3). Of the 38 patients evaluable for response, one had a partial response (PR) and 19 had stable disease (SD). The overall disease control rate was 52%. Five of the 20 patients with SD/PR maintained disease control for >6 months. CONCLUSIONS: The combination of temsirolimus and capecitabine is safe on both a Q2-week and a Q3-week schedule. The combination demonstrated promising evidence of disease control in this highly refractory population and could be considered for testing in disease-specific phase II trials. Administration of intravenous ferric carboxymaltose (FCM) for iron-deficient patients suffering heart failure with reduced ejection fraction (HFrEF) has been associated with transient hypophosphatemia. We sought to investigate and model the effect of intravenous FCM on phosphate levels in iron-deficient patients with HFrEF. In this single-center retrospective study, serum phosphate levels, recorded for clinical reasons, were collected out to 60 days following intravenous FCM. Hypophosphatemia was defined as a nadir serum phosphate level <0.64 mmol/L. This was further categorized as severe (0.4 to <0.64 mmol/L) and extreme (<0.4 mmol/L). Factors associated with hypophosphatemia and change in serum phosphate over time were explored. Of 173 patients included, 47 (27%) experienced hypophosphatemia, 44 (25%) were classified as severe, and 3 (2%) extreme. Risk of hypophosphatemia was increased for patients with a creatinine clearance between 60 and <90 mL/min (odds ratio, 2.3; 95% confidence interval, 1.0-5.5), while <60 mL/min was protective. The median time to nadir in patients who experienced hypophosphatemia was 8 (interquartile range, 4-16) days, with a return to baseline levels at 6 weeks. Biochemically relevant hypophosphatemia is common following a single dose of intravenous FCM. The median time to nadir was 8 days, and creatinine clearance may influence phosphate levels following intravenous FCM. These observations support the need to increase awareness among clinicians administering intravenous FCM to iron-deficient patients with HFrEF. Imatinib is the drug of first choice for most patients with chronic phase chronic myeloid leukemia (CML). Although it is generally well tolerated, a number of hematological and nonhematological side-effects have been described. We report here that imatinib induces hypophosphatemia in a high proportion of our series of CML patients previously treated with interferon alpha, and that this previously unreported side effect is associated with response. OBJECTIVE: To provide an outline of the drugs and nutritional therapy that could contribute to the development of hypophosphatemia in the critically ill patient. DATA SOURCES: Computerized abstracting services, references to primary literature articles, and review publications were screened for references to drug- or nutrition-related hypophosphatemia. STUDY SELECTION: Studies primarily describing responses in adults were selected. Animal research is described that illustrates findings in humans. DATA EXTRACTION: Information was abstracted from the findings of individual case reports and clinical trials. DATA SYNTHESIS: Data are organized by mechanism of possible effect on serum phosphate concentration. No reference is made to drugs that do not have an effect on phosphate metabolism. CONCLUSIONS: Hypophosphatemia can have significant effects that would hinder recovery of the critically ill patient. Antacids, catecholamines, beta-adrenergic agonists, sodium bicarbonate, and acetazolamide are commonly used therapeutic agents that could contribute significantly to the development of hypophosphatemia. Provision of nutrition to the chronically malnourished individual or chronic administration of phosphate-depleted parenteral nutrition could produce symptoms associated with hypophosphatemia. Other drugs could have a mild effect on lowering serum phosphate concentrations, but would be unlikely to produce symptoms unless combined with other etiologies of hypophosphatemia. The use of anticancer drugs is beneficial for patients with malignancies but is frequently associated with the occurrence of electrolyte disorders, which can be hazardous and in many cases fatal. The review presents the electrolyte abnormalities that can occur with the use of anticancer drugs and provides the related mechanisms. Platinum-containing anticancer drugs induce hypomagnesemia, hypokalemia and hypocalcemia. Moreover, platinum-containing drugs are associated with hyponatremia, especially when combined with large volumes of hypotonic fluids aiming to prevent nephrotoxicity. Alkylating agents have been linked with the occurrence of hyponatremia [due to syndrome of inappropriate antidiuretic hormone secretion (SIADH)] and Fanconi's syndrome (hypophosphatemia, aminoaciduria, hypouricemia and/or glucosuria). Vinca alkaloids are associated with hyponatremia due to SIADH. Epidermal growth factor receptor monoclonal antibody inhibitors induce hypomagnesemia, hypokalemia and hypocalcemia. Other, monoclonal antibodies, such as cixutumumab, cause hyponatremia due to SIADH. Tyrosine kinase inhibitors are linked to hyponatremia and hypophosphatemia. Mammalian target of rapamycin inhibitors induce hyponatremia (due to aldosterone resistance), hypokalemia and hypophosphatemia. Other drugs such as immunomodulators or methotrexate have been also associated with hyponatremia. The administration of estrogens at high doses, streptozocin, azacitidine and suramin may induce hypophosphatemia. Finally, the drug-related tumor lysis syndrome is associated with hyperphosphatemia, hyperkalemia and hypocalcemia. The prevention of electrolyte derangements may lead to reduction of adverse events during the administration of anticancer drugs. Serum phosphorus levels (Ps), dietary intake of phosphorus, and renal phosphate handling indexes were evaluated in 158 patients with chronic obstructive pulmonary disease (COPD) of varying degrees of severity; moreover, skeletal muscle phosphorus content (Pm) was measured in muscle samples obtained by quadriceps femoris needle biopsy in 14 of the same patients. Hypophosphatemia (Ps less than or equal to 2.5 mg/dl) was found in 34 (21.5 percent) of 158 patients without differences between groups of COPD patients presenting increasing severity of respiratory illness. No relationship was found between serum levels and dietary intake of phosphorus; hypophosphatemia was associated with low renal phosphate threshold (TmPO4/GFR) values in 31 (91 percent) of 34 patients. The prevalence of hypophosphatemia was significantly higher among COPD patients taking one or more drugs commonly used in COPD and known as negatively influencing renal phosphate handling: xanthine derivatives, corticosteroids, loop diuretics, and beta 2-adrenergic bronchodilators. Short-term administration of therapeutic doses of these drugs in COPD patients previously not taking any drug reduced TmPO4/GFR values; phosphaturic effect of short-term theophylline administration on renal phosphate handling was additive to that of long-term assumption of the drug. Muscle phosphorus content was both reduced in COPD patients as compared with control subjects and significantly correlated to serum phosphorus levels and to TmPO4/GFR values. The present investigation revealed a high prevalence of hypophosphatemia among COPD patients as well as a defect in renal phosphate reabsorption secondary, at least in part, to pharmacologic therapy. Moreover, it also suggests that in COPD patients muscle phosphorus content is likely to be reduced in presence of hypophosphatemia. Phosphate is actively involved in many important biochemical pathways, such as energy and nucleic acid metabolism, cellular signaling, and bone formation. Hypophosphatemia, defined as serum phosphate levels below 2.5 mg/dL (0.81 mmol/L), is frequently observed in the course of treatment with commonly used drugs, such as diuretics, bisphosphonates, antibiotics, insulin, and antacids. Furthermore, this undesired effect may complicate the use of several novel medications, including teriparatide, denosumab, parenteral iron, and antiviral and antineoplastic agents. This review addresses drug-associated hypophosphatemia, focusing on underlying mechanisms and the most recent knowledge on this topic, in order to increase the insight of clinicians, with reference to early diagnosis and appropriate management. INTRODUCTION: Tenofovir disoproxil fumarate (TDF) -containing regimens have been associated with nephrotoxicity and hypophosphatemia in HIV-infected patients. The objective of this study was to assess the possible risk factors for hypophosphatemia and evaluate the relationship between fractional excretion of filtered phosphate (FePi) and hypophosphatemia in TDF users. PATIENT AND METHODS: Patients were enrolled in a prospective cohort study between January 2011 and December 2014. We classified experienced HIV-infected patients (individuals maintained on antiretroviral therapy (ART) for 6 months or more) and naïve patients into 3 treatment groups: TDF-containing ART (group 1), non-TDF-containing ART (never received TDF or had not received TDF in the past 6 months; group 2) and naive to antiretroviral therapy (group 3). Specimens from each individual were assessed for serum phosphate, serum creatinine, urine phosphate, and urine creatinine. Multivariable logistic regression was performed to control for the following variables measured at baseline: eGFR, age, sex, sexual orientation, injection drug use (IDUs), HIV-RNA viral load, and CD4 cell count. RESULTS: The frequency of hypophosphatemia in groups 1, 2, and 3 was 20.2%, 7.2%, and 14.6%, respectively (P = 0.002). FePi above 10% also was significantly associated with hypophosphatemia (P = 0.003; adjusted odds ratio = 2.54). Patients with elevated CD4 cell counts (>500 cells/μL) exhibited a lower risk of hypophosphatemia (P = 0.002; adjusted odds ratio = 0.35). CONCLUSIONS: Hypophosphatemia is a multifactorial etiology; FePi was confirmed as a suggested method to predict the risk of hypophosphatemia in TDF users. Clinical Trial Number: TYGH103011. Hypophosphatemia (serum phosphorus concentration <2.5 mg/dl, 0.8 mmol/l), although rare in the general population, is commonly observed in hospitalized patients and may be associated with drug therapy. In fact, hypophosphatemia frequently develops in the course of treatment with drugs used in every-day clinical practice including diuretics and bisphosphonates. Proper diagnostic approach of patients with low serum phosphorus concentrations should involve a detailed medical history with special attention to the recent use of medications. The clinical manifestations of drug-induced hypophosphatemia are usually mild but might also be severe and potentially life-threatening. This review aims at a thorough understanding of the underlying pathophysiological mechanisms and risk factors of drug therapy-related hypophosphatemia thus allowing prevention and effective intervention strategies. Contemporary intravenous iron formulations allow administration of high doses of elemental iron and enable correction of total iron deficit in one or two infusions. An important but underappreciated complication of certain formulations is hypophosphatemia caused by increased secretion of the phosphaturic hormone, fibroblast growth factor 23 (FGF23). The pathophysiology of FGF23-induced hypophosphatemia due to certain intravenous iron formulations has been recently investigated in prospective clinical trials. To reach the correct diagnosis, clinicians must recognize the typical clinical manifestations of intravenous iron-induced hypophosphatemia and identify a specific pattern of biochemical changes (hyperphosphaturic hypophosphatemia triggered by high FGF23 that causes low 1,25 (OH)2 vitamin D, hypocalcemia and secondary hyperparathyroidism). Physicians and patients should be aware of hypophosphatemia as a common complication of intravenous iron therapy and monitor serum phosphate concentrations in patients receiving repeated doses of specific intravenous iron formulations. Symptoms of hypophosphatemia are associated with severity and duration. Persistent hypophosphatemia can occur with iron therapy and can cause debilitating diseases including myopathy, osteomalacia and fractures. This review summarizes the current understanding of the iron-phosphate axis as well as complications of intravenous iron-induced hypophosphatemia. Additional therapeutic options are needed for relapsed and refractory multiple myeloma (RRMM). We present data from a phase 1b, open-label, dose-escalation study (NCT01965353) of 20 patients with RRMM (median age: 63 years [range: 50-77]) and a median of four prior regimens (range: 2-14); 85% had refractory disease (lenalidomide [80%]; bortezomib [75%]; lenalidomide and bortezomib [50%]). Patients received a median of six cycles (range: 1-74) of panobinostat (10 or 15 mg), lenalidomide 15 mg, bortezomib 1 mg/m2, and dexamethasone 20 mg (pano-RVd). Median follow-up was ~14 months. Six dose-limiting toxicities were reported (mostly hematological); maximum tolerated dose of panobinostat (primary endpoint) was 10 mg. Most common adverse events (AEs) were diarrhea (60%) and peripheral neuropathy (60%); all grade 1/2. Grade 3/4 AEs occurred in 80% of patients and included decreased neutrophil (45%), platelet (25%) and white blood cell (25%) counts, anemia (25%) and hypophosphatemia (25%). No treatment-related discontinuations or mortality occurred. In evaluable patients (n = 18), overall response rate was 44%, and clinical benefit rate was 61%. Median duration of response was 9.2 months; progression-free survival was 7.4 months; overall survival was not reached. Pano-RVd proved generally well-tolerated and demonstrated potential to overcome lenalidomide and/or bortezomib resistance. The purpose of this single-center retrospective study was to determine the incidence of decreased blood phosphorus levels and hypophosphatemia among multiple myeloma (MM) patients treated with elotuzumab. Hypophosphatemia, which is defined as a serum phosphorus concentration < 2.5 mg/dL, leads to complications ranging from muscle weakness and disorientation to seizures and heart failure. A total of 23 MM patients receiving care in a clinic specializing in treatment of MM from July 2018 to March 2020 and treated with an elotuzumab-containing therapy were evaluated, and 9 were investigated for this study. Elotuzumab was given at 10 mg/kg weekly for the first two treatment cycles (28 days/cycle), followed by 10 mg/kg every other week for all subsequent cycles. Four different elotuzumab combination therapies were administered: 1) elotuzumab and dexamethasone 2) elotuzumab, lenalidomide and dexamethasone 3) elotuzumab, pomalidomide and dexamethasone and 4) elotuzumab, carfilzomib, pomalidomide, and dexamethasone. Phosphorous levels were determined at a median of every 13 days at intervals ranging from once weekly to once monthly until a phosphate supplement was prescribed to the patient or when elotuzumab treatment was discontinued. We found that regardless of elotuzumab combination therapy, all patients treated showed decreased phosphorus levels after initiating elotuzumab treatment with reductions ranging from 12.5% to 44.1% below baseline. Six participants (67%) demonstrated an average serum phosphorus at or below 2.5 mg/dL after starting elotuzumab therapy. This retrospective study suggests that hypophosphatemia commonly occurs among MM patients receiving elotuzumab-containing therapies.
4,082
Is Algenpantucel-L effective for pancreatic cancer?
No. In phase 3 clinical trial Algenpantucel-L immunotherapy did not improve survival in patients with borderline resectable or locally advanced unresectable pancreatic cancer receiving SOC neoadjuvant chemotherapy and chemoradiation.
[33630475, 23229886]
4,488
OBJECTIVES: To compare the efficacy and safety of algenpantucel-L [HyperAcute-Pancreas algenpantucel-L (HAPa); IND# 12311] immunotherapy combined with standard of care (SOC) chemotherapy and chemoradiation to SOC chemotherapy and chemoradiation therapy alone in patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma (PDAC). SUMMARY BACKGROUND DATA: To date, immunotherapy has not been shown to benefit patients with borderline resectable or locally advanced unresectable PDAC. HAPa is a cancer vaccine consisting of allogeneic pancreatic cancer cells engineered to express the murine α(1,3)GT gene. METHODS: A multicenter, phase 3, open label, randomized (1:1) trial of patients with borderline resectable or locally advanced unresectable PDAC. Patients received neoadjuvant SOC chemotherapy (FOLFIRINOX or gemcitabine/nab-paclitaxel) followed by chemoradiation (standard group) or the same standard neoadjuvant regimen combined with HAPa immunotherapy (experimental group). The primary outcome was overall survival. RESULTS: Between May 2013 and December 2015, 303 patients were randomized from 32 sites. Median (interquartile range) overall survival was 14.9 (12.2-17.8) months in the standard group (N = 158) and 14.3 (12.6-16.3) months in the experimental group (N = 145) [hazard ratio (HR) 1.02, 95% confidence intervals 0.66-1.58; P = 0.98]. Median progression-free survival was 13.4 months in the standard group and 12.4 months in the experimental group (HR 1.33, 95% confidence intervals 0.72-1.78; P = 0.59). Grade 3 or higher adverse events occurred in 105 of 140 patients (75%) in the standard group and in 115 of 142 patients (81%) in the experimental group (P > 0.05). CONCLUSIONS: Algenpantucel-L immunotherapy did not improve survival in patients with borderline resectable or locally advanced unresectable PDAC receiving SOC neoadjuvant chemotherapy and chemoradiation. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01836432. BACKGROUND: Despite continued investigation, limited progress has been made in the adjuvant treatment of resected pancreatic cancer. Novel or targeted therapies are needed. METHODS: Multi-institutional, open-label, dose-finding, phase 2 trial evaluating the use of algenpantucel-L (NewLink Genetics Corporation, Ames, IA) immunotherapy in addition to chemotherapy and chemoradiotherapy in the adjuvant setting for resected pancreatic cancer (ClinicalTrials.gov identifier, NCT00569387). The primary outcome was 12-month disease-free survival. Secondary outcomes included overall survival and toxicity. RESULTS: Seventy patients were treated with gemcitabine and 5-fluorouracil-based chemoradiotherapy as well as algenpantucel-L (mean 12 doses, range 1-14). After a median follow-up of 21 months, the 12-month disease-free survival was 62 %, and the 12-month overall survival was 86 %. The most common adverse events were injection site pain and induration. CONCLUSIONS: The addition of algenpantucel-L to standard adjuvant therapy for resected pancreatic cancer may improve survival. A multi-institutional, phase 3 study is ongoing (ClinicalTrials.gov identifier, NCT01072981).
4,083
What is the most frequent evolution (next stage) when Aortic intramural hematoma (IMH) is not treated?
Aortic intramural hematoma (IMH) evolves very dynamically in the short-term to regression, dissection, or aortic rupture
[25087203, 15710757, 29274600, 12874185, 32668075, 29945807, 32652687, 25512883, 10567317, 10585078, 19793400, 15066238]
4,490
Aortic intramural hematoma (IMH) is an acute aortic syndrome characterized by bleeding into the media of the aortic wall without intimal disruption or the classic flap formation. Its natural history is variable and still poorly understood, so strategies for therapeutic management are not fully established. In some cases there is partial or complete regression of the hematoma under medical treatment, but most progress to dissection, aneurysmal dilatation or aortic rupture. The authors present the case of a 44-year-old hypertensive male patient admitted with a diagnosis of IMH of the descending aorta. Despite initial symptom resolution and optimal medical therapy, the IMH evolved to a pseudoaneurysm, which was successfully treated by an endovascular approach. INTRODUCTION: Aortic intramural hematoma (IMH) is described as "dissection without intimal tear" due to rupture of vasa vasorum, which results in bleeding within the tunica media in the absence of intimal disruption or blood flow communication. The aim of our study is to validate perioperative evidence of intimal entry tear in patients with IMH and to suggest that this entity may represent a part of a disease and not a separate disease. PRESENTATION OF CASES: We report two patients admitted to our institution with sudden onset thoracic pain. A CT scan showed an aneurysm of the ascending aorta complicated by type A IMH. The patients underwent open operation. Surgical set-up has included right axillary artery as arterial inflow, no cross-clamp before hypothermic circulatory arrest and Kazui protocol for selective antegrade cerebral perfusion. We found no evidence of intimal flap, but we identified an intimal tear in both patients. A hemiarch procedure associated with root replacement, using two-grafts techniques was performed in both cases. The postoperative course was uneventful and the patients were discharged home. DISCUSSION: Recent data are emerging from the radiologic literature about the evidence of intimal lesions in IMH, but surgical reports are scant. The evidence of intimal tears contributes to consider as questionable the etiological role of vasa vasorum and it may justify updates in the management. CONCLUSION: We consider that IMH may represent a part of a disease (aortic dissection), depicted by radiological images in a specific single instant of its clinical evolution. BACKGROUND: Aortic intramural hematoma (IMH) evolves very dynamically in the short-term to regression, dissection, or aortic rupture. The aim of the present study was to assess the long-term clinical and morphological evolution of medically treated IMH. METHODS AND RESULTS: Fifty of 68 consecutive patients with aortic IMH monitored clinically and by imaging techniques at 3, 6, and 12 months and annually thereafter were prospectively studied. Mean follow-up was 45+/-31 months. In the first 6 months, total IMH regression was observed in 14 and progression to aortic dissection in 18 patients; in 14 of these, the dissection was localized, and 12 later developed pseudoaneurysm. At the end of follow-up, the IMH had regressed completely without dilatation in 17 patients (34%), progressed to classical dissection in 6 (12%), evolved to fusiform aneurysm in 11 (22%), evolved to saccular aneurysm in 4 (8%), and evolved to pseudoaneurysm in 12 (24%). Evolution to dissection was related to echolucency (P<0.02) and to longitudinal extension of IMH (P<0.01). Multivariate analysis showed an independent association between regression and smaller maximum aortic diameter and between aneurysm formation and atherosclerotic ulcerated plaque and absence of echolucent areas in IMH. CONCLUSIONS: The most frequent long-term evolution of IMH is to aortic aneurysm or pseudoaneurysm. Complete regression without changes in aorta size is observed in one third of cases, and progression to classical dissection is less common. A normal aortic diameter in the acute phase is the best predictor of IMH regression without complications, and absence of echolucent areas and atherosclerotic ulcerated plaque are associated with evolution to aortic aneurysm. Type B acute aortic dissection (AAD) and intramural hematoma (IMH) can both present as potentially catastrophic lesions of the descending aorta. IMH is distinguished from AAD by the absence of an intimal tear and flap. With short-term outcomes being similar to type B AAD, IMH is treated identically to AAD in the corresponding segment of the aorta. While all patients with any acute aortic syndrome of the descending aorta receive prompt anti-impulse therapy, thoracic endovascular aortic repair (TEVAR) is reserved for patients presenting with certain complications, namely malperfusion, rupture, or periaortic hematoma. Technical aspects of TEVAR for IMH include maximal endograft oversizing of 10% with 20 mm landing zones of the healthy aorta, revascularization of the left subclavian artery when covered, use of cerebrospinal fluid drainage with extensive coverage, and restoration of branch vessel perfusion. With respect to disease evolution, IMH may progress to classic AD, frank rupture, or aneurysmal dilation; yet, IMH may also regress and be completely resorbed. However, since the natural history of IMH is unpredictable, TEVAR is being used more aggressively to improve long-term survival, rates of secondary reintervention, and positive aortic remodeling. Much remains unknown for acute type B IMH, including the use of prophylactic TEVAR for stable uncomplicated presentations, as well as the optimal timing of intervention and certain technical aspects of TEVAR. As such, IMH remains a diagnostic and therapeutic challenge for cardiovascular surgeons. BACKGROUND: Intramural hematomas (IMHs) are reported to dynamically evolve into different clinical outcomes ranging from regression to aortic rupture, but no practice guidelines are available in China. OBJECTIVE: To determine the evolution of IMHs after long-term follow-up and to identify the predictive factors of IMH outcomes in the Chinese population. METHODS: A total of 123 IMH patients with clinical and imaging follow-up data were retrospectively studied. The primary endpoints were aortic disease-related death, aortic dissection, penetrating aortic ulcer (PAU), thickening of the aortic hematoma and aortic complications requiring surgical or endovascular treatment. RESULTS: All 123 IMH patients were monitored clinically. The follow-up duration ranged from 1.4 to 107 months (median, 20 months). Thirty-nine patients had type A IMH, and 84 had type B. The multivariate analysis showed that a baseline MAD ≥ 44.75 mm (2.9% vs 61.4%, P < 0.001) and acute PAUs (2.9% vs 34.1%, P = 0.008) were independent predictors of aorta-related events. CONCLUSIONS: Medication and short-term imaging are recommended for Chinese IMH patients with a hematoma thickness < 10.45 mm and a baseline MAD < 44.75 mm. Rigorous medical observation should also be performed during the acute phase of IMH. Within the spectrum of acute aortic syndromes, intramural hematoma (IMH) is a distinct lesion that is characterized by crescentic or circumferential thickening of the aortic wall in the absence of an intimal defect. The reported incidence of IMH among all type A acute aortic syndromes ranges from 3.5% to 28.3%. As compared with acute aortic dissection, IMH is a disease of the elderly, and it tends to have reduced rates of malperfusion syndromes, aortic insufficiency, and root dilation, yet also tends to have increased rates of pericardial effusion, cardiac tamponade, and periaortic hematoma. With respect to natural history, IMH may progress to classic dissection, frank rupture, or aneurysmal dilation; yet, IMH may also regress and be completely resorbed. However, studies disagree over the rates of progression or regression; as such, few studies agree on the short-term and long-term prognosis associated with IMH. American and European guidelines advocate emergent surgery for all acutely presenting type A IMH. At a minimum, supracoronary replacement of the aorta with hemiarch reconstruction is the preferred extent of operative repair to reduce rates of long-term reintervention for disease progression. However, valve and/or root procedures may be necessary proximally, while total arch reconstruction or hybrid procedures for the descending aorta may be necessary distally. Much remains unknown for IMH, including the ideal extent of aortic repair, risk-stratification for elderly patients, and the optimal treatment paradigm for stable, uncomplicated IMH. As such, IMH remains a diagnostic and therapeutic challenge for the cardiovascular surgeon. Thoracic aortic dissection (AD) is one of the most common aortic emergencies. It can be fatal if not promptly diagnosed and treated. Intramural hematoma (IMH) of the aorta is recognized as distinct from classic (double-barreled) AD. IMH also frequently leads to aortic emergency, which can be fatal unless rapidly diagnosed and treated. Recently, thoracic endovascular aortic repair (TEVAR) has been used for the treatment of complications caused by AD. TEVAR is also a viable option for the treatment of complicated IHM. In this article, we review the details of TEVAR as treatment options for AD and IMH, including the indications for TEVAR, imaging, and follow-up. BACKGROUND: It has been reported that early surgery should be required for patients with type A aortic intramural hematoma (IMH) because it tends to develop classic aortic dissection or rupture. However, the anatomic features of type A IMH that develops dissection or rupture are unknown. The purpose of this study was to investigate the predictors of progression or regression of type A IMH by computed tomography (CT). METHODS AND RESULTS: Twenty-two consecutive patients with type A IMH were studied by serial CT images. Aortic diameter and aortic wall thickness of the ascending aorta were estimated in CT images at 3 levels on admission and at follow-up (mean 37 days). We defined patients who showed increased maximum aortic wall thickness in the follow-up CT (n=9) or died of rupture (n=1) as the progression group (n=10). The other 12 patients, who all showed decreased maximum wall thickness, were categorized as the regression group. In the progression group, the maximum aortic diameter in the initial CT was significantly greater than that in the regression group (55+/-6 vs 47+/-3 mm, P=0.001). A Cox regression analysis revealed that the maximum aortic diameter was the strongest predictor for progression of type A IMH. We considered the optimal cutoff value to be 50 mm for the maximum aortic diameter to predict progression (positive predictive value 83%, negative predictive value 100%). CONCLUSIONS: Maximum aortic diameter estimated by the initial CT images is predictive for progression of type A IMH. This review article is written so as to present the pathophysiology, the symptomatology and the ways of diagnosis and treatment of a rather rare aortic disease called Intra-Mural Haematoma (IMH). Intramural haematoma is a quite uncommon but potentially lethal aortic disease that can strike as a primary occurrence in hypertensive and atherosclerotic patients to whom there is spontaneous bleeding from vasa vasorum into the aortic wall (media) or less frequently, as the evolution of a penetrating atherosclerotic ulcer (PAU). IMH displays a typical of dissection progress, and could be considered as a precursor of classic aortic dissection. IMH enfeebles the aortic wall and may progress to either outward rupture of the aorta or inward disruption of the intima layer, which ultimately results in aortic dissection. Chest and back acute penetrating pain is the most commonly noticed symptom at patients with IMH. Apart from a transesophageal echocardiography (TEE), a tomographic imaging such as a chest computed tomography (CT), a magnetic resonance (MRI) and most lately a multy detector computed tomography (MDCT) can ensure a quick and accurate diagnosis of IMH. Similar to type A and B aortic dissection, surgery is indicated at patients with type-A IMH, as well as at patients with a persistent and/or recurrent pain. For any other patient (with type-B IMH without an incessant pain and/or without complications), medical treatment is suggested, as applied in the case of aortic dissection. The outcome of IMH in ascending aorta (type A) appears favourable after immediate (emergent or urgent) surgical intervention, but according to international bibliography patients with IMH of the descending aorta (type B) show similar mortality rates to those being subjected to conservative medical or surgical treatment. Endovascular surgery and stent-graft placement is currently indicated in type B IMH.
4,084
Which drugs are included in the Qtern pill?
Qtern pill includes saxagliptin and dapagliflozin. It is indicated in the EU for the improvement of glycaemic control in adults with type 2 diabetes mellitus.
[28884600, 29176433, 32454718, 28176222]
4,491
OBJECTIVE: To review the pharmacology, pharmacokinetics, efficacy, safety, and place in therapy of the fixed-dose combination (FDC) product, QTERN (dapagliflozin/saxagliptin) tablets. DATA SOURCES: Searches of MEDLINE (1946 to July 1, 2017) were conducted using the keywords QTERN, saxagliptin, and dapagliflozin. Additional data were obtained from the prescribing information, the product dossier, and Clinicaltrials.gov . STUDY SELECTION AND DATA EXTRACTION: All English language articles related to pharmacology, pharmacokinetics, efficacy, or safety of the combination therapy in human subjects were reviewed. DATA SYNTHESIS: The pharmacokinetics of saxagliptin and dapagliflozin were not affected significantly when administered as an FDC product. Saxagliptin may suppress the increased secretion of glucagon associated with dapagliflozin. The combination dapagliflozin/saxagliptin has been studied as add-on therapy to metformin in patients with uncontrolled type 2 diabetes mellitus (T2DM). The difference in hemoglobin A1C (A1C) between saxagliptin + dapagliflozin + metformin (triple therapy) and saxagliptin + metformin was -0.59 (95% CI = -0.81 to -0.37, P < 0.0001), and the difference between triple therapy and dapagliflozin + metformin was -0.27 (95% CI = -0.48 to -0.05, P = 0.0166). The combination was well tolerated when added to metformin. CONCLUSION: QTERN (dapagliflozin/saxagliptin) tablets are a reasonable option for patients with T2DM not controlled on metformin, but cost, insurance coverage, and a lackluster reduction in A1C will likely limit its use until more data regarding its effects on complications of diabetes and cardiovascular outcomes become available. Author information: (1)Geoffrey Mospan is an assistant professor of pharmacy at Wingate University School of Pharmacy, Wingate, N.C. Cortney Mospan is an assistant professor of pharmacy at Wingate University School of Pharmacy, Wingate, N.C. Shayna Vance is a 4th year PharmD candidate at Wingate University School of Pharmacy, Wingate, N.C. Alyssa Bradshaw is a 4th year PharmD candidate at Wingate University School of Pharmacy, Wingate, N.C. Kalyn Meosky is a 4th year PharmD candidate at Wingate University School of Pharmacy, Wingate, N.C. Kirklin Bowles is a 4th year PharmD candidate at Wingate University School of Pharmacy, Wingate, N.C. OBJECTIVES: The fixed dose combination of saxagliptin and dapagliflozin is a recently approved antidiabetic medication. It is marketed under the brand name Qtern. The aim of this study was to develop a simple, rapid, sensitive, and validated isocratic reversed phase-high performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of saxagliptin and dapagliflozin in human plasma using linagliptin as internal standard as per US-Food and Drug Administration guidelines. MATERIALS AND METHODS: The method was performed on a Waters 2695 HPLC equipped with a quaternary pump. The analyte separation was achieved using an Eclipse XDB C18 (150 × 4.6 mm × 5 µm) column with a mobile phase consisting of 0.1% ortho phosphoric acid and acetonitrile (50:50) with pH adjusted to 5.0 at 1 mL/min flow rate. RESULTS: The analyte was detected at 254 nm. The retention time of the internal standard, saxagliptin, and dapagliflozin was 2.746, 5.173, and 7.218 min, respectively. The peaks were found to be free of interference. The method was validated over a dynamic linear range of 0.01 to 0.5 μg/mL and 0.05 to 2 μg/mL for saxagliptin and dapagliflozin, respectively, with a correlation coefficient of 0.998. The precision and accuracy of samples of six replicate measurements at lower limits of quantification level were within the limits. The analytes were found to be stable in human plasma at -28°C for 37 days. CONCLUSION: The stability, sensitivity, specificity, and reproducibility of this method make it appropriate for the determination of saxagliptin and dapagliflozin in human plasma.
4,085
List SLE-related autoantibodies.
Serum autoantibodies analyzed included lupus anticoagulant (LAC), anticardiolipine (aCL) IgG and IgM (first 3 also grouped into antiphospholipid autoantibodies (aPL)), anti-dsDNA, anti-SSA, anti-SSB, anti-RNP, and anti-Sm (the latter 5 grouped into SLE-related autoantibodies). Diagnostic panels comprising anti-RPLP2, anti-SNRPC and anti-PARP1, and anti-RPLP2, anti-PARP1, anti-MAK16 and anti- RPL7A were selected.
[29141377, 29156741, 30526327, 11093143, 31899518]
4,492
Objective: To analyze the clinical significance of anti- ubiquitin C-terminal hydrolase L1(UCHL-1)autoantibodies in neuropsychiatric systemic lupus erythematosus (NPSLE). Methods: Autoantibodies in cerebrospinal fluid specimen of 56 inpatients were detected by using indirect enzyme-linked immunosorbent assay (ELISA) and the fullmedical history and clinical manifestations were analyzed retrospectively. Results: The levels of anti-UCHL-1 autoantibodies in NPSLE group were significant higher than that in other controls (P<0.05). The positive rate of anti-UCHL-1 autoantibodies in NPSLE group was 23.7% (9/38), which was higher than that in the control groups (0%). A significant difference of anti-UCHL-1 autoantibodies was observed in the patients with blood system involvement (P=0.012). The positive rates of anti-UCHL autoantibodies in the patients with negative SLE related autoantibodies including AnuA, anti-dsDNA, Acl, anti-nRNP, anti-rRNP and anti-Smantibody negative were 41.7%, 29.4%, 29.2%, 25.9%, 25.0%, 25.0%, respectively.The levels of anti-UCHL-1 autoantibodies had a positive correlation with 24-hours proteinuria (r=0.361, P=0.039). Conclusion: Anti-UCHL-1 autoantibodies had promising value in the diagnosis of neuropsychiatric systemic lupus erythematosus. Systemic lupus erythematosus (SLE) is a common autoimmune disease. Many autoantibodies are closely associated with SLE. However, the specific epitopes recognized and bound by these autoantibodies are still unclear. This study screened the binding epitopes of SLE-related autoantibodies using a high-throughput screening method. Epitope prediction on 12 SLE-related autoantigens was performed using the Immune Epitope Database and Analysis Resource (IEDB) software. The predicted epitopes were synthesized into peptides and developed into a peptide array. Serum IgG from 50 SLE patients and 25 healthy controls was detected using the peptide array. The results were then validated using an enzyme-linked immunosorbent assay (ELISA). The diagnostic efficiency of each epitope was analyzed using a ROC curve. Seventy-three potential epitopes were screened for using the IEDB software after the epitopes on the 12 SLE-related autoantigens were analyzed. Peptide array screening revealed that the levels of the autoantibodies recognized and bound by 4 peptide antigens were significantly upregulated in the serum of SLE patients (P < 0.05). The ELISA results showed that the 4 antigens with significantly increased serum autoantibodies levels in SLE patients were acidic ribosomal phosphoprotein (P0)-4, acidic ribosomal phosphoprotein (P0)-11, DNA topoisomerase 1 (full length)-1, and U1-SnRNP 68/70 KDa-1 (P < 0.05), and the areas under the ROC curve for diagnosing SLE on the basis of these peptides were 0.91, 0.90, 0.93, and 0.91, respectively. Many autoantibodies specifically expressed in the serum of patients with SLE can be detected by specific peptide fragments and may be used as markers in clinical auxiliary diagnoses. The association of anti-nuclear antigen (ANA) and anti-cardiolipin (CL) antibodies is often observed during systemic lupus erythematosus (SLE) or the primary anti-phospholipid syndrome, thereby raising the possibility of a relationship between these two autoantibody populations. To determine whether ANA and anti-CL antibodies can overlap, we derived, from a male (NZW x BXSB)F1 mouse, 14 hybridomas selected based on their capacities to react with CL and to label HEp-2 cell nuclei. Four of these anti-CL were IgG and bound to CL and phosphatidylserine in a cofactor-dependent manner and reacted strongly with nucleosomes. Variable region sequence analysis indicated that these four monoclonal antibodies (mAb) were derived from three independent B cell clones that used recurrent heavy and/or light chain immunoglobulin rearrangements, as assessed by comparison with each other and prototypic anti-CL mAb previously derived from different lupus mouse strains. These results indicate that anti-CL mAb can have overlapping cross-reactivities with nucleosomes, thereby defining a new category of SLE-related autoantibodies characterized by their capacities to recognize distinct supramolecular complexes, formed by the association of an anionic structure and a protein, that exert a strong selective pressure on autoreactive B cell clones. OBJECTIVE: Clinical diagnosis of SLE is currently challenging due to its heterogeneity. Many autoantibodies are associated with SLE and are considered potential diagnostic markers, but systematic screening and validation of such autoantibodies is lacking. This study aimed to systematically discover new autoantibodies that may be good biomarkers for use in SLE diagnosis. METHODS: Sera from 15 SLE patients and 5 healthy volunteers were analysed using human proteome microarrays to identify candidate SLE-related autoantibodies. The results were validated by screening of sera from 107 SLE patients, 94 healthy volunteers and 60 disease controls using focussed arrays comprised of autoantigens corresponding to the identified candidate antibodies. Logistic regression was used to derive and validate autoantibody panels that can discriminate SLE disease. Extensive ELISA screening of sera from 294 SLE patients and 461 controls was performed to validate one of the newly discovered autoantibodies. RESULTS: A total of 31, 11 and 18 autoantibodies were identified to be expressed at significantly higher levels in the SLE group than in the healthy volunteers, disease controls and healthy volunteers plus disease control groups, respectively, with 25, 7 and 13 of these differentially expressed autoantibodies being previously unreported. Diagnostic panels comprising anti-RPLP2, anti-SNRPC and anti-PARP1, and anti-RPLP2, anti-PARP1, anti-MAK16 and anti- RPL7A were selected. Performance of the newly discovered anti-MAK16 autoantibody was confirmed by ELISA. Some associations were seen with clinical characteristics of SLE patients, such as disease activity with the level of anti-PARP1 and rash with the level of anti-RPLP2, anti-MAK16 and anti- RPL7A. CONCLUSION: The combined autoantibody panels identified here show promise for the diagnosis of SLE and for differential diagnosis of other major rheumatic immune diseases.
4,086
What is nephropathic cystinosis?
Nephropathic cystinosis is a rare autosomal recessive lysosomal storage disorder characterized by abnormal accumulation of intracellular cystine in various tissues including the brain, kidneys, bones, and eyes.
[9286148, 10556299, 28793998, 34237326, 25526929, 12795432, 11528232, 28629674, 29905968, 26565940, 10625078, 20865335, 25811383, 32564281, 24077756, 31548351, 11516611, 19705160, 15583946, 25345100, 27181776, 10210897, 31361240, 29806685, 33975805, 31570786, 8644713, 12204010, 25071085, 14610675, 33575541, 10673275, 7494397]
4,493
Infantile nephropathic cystinosis is a rare, autosomal recessive disease caused by a defect in the transport of cystine across the lysosomal membrane and characterized by early onset of renal proximal tubular dysfunction. Late-onset cystinosis, a rarer form of the disorder, is characterized by onset of symptoms between 12 and 15 years of age. We previously characterized the cystinosis gene, CTNS, and identified pathogenic mutations in patients with infantile nephropathic cystinosis, including a common, approximately 65 kb deletion which encompasses exons 1-10. Structure predictions suggested that the gene product, cystinosin, is a novel integral lysosomal membrane protein. We now examine the predicted effect of mutations on this model of cystinosin. In this study, we screened patients with infantile nephropathic cystinosis, those with late-onset cystinosis and patients whose phenotype does not fit the classical definitions. We found 23 different mutations in CTNS; 14 are novel mutations. Out of 25 patients with infantile nephropathic cystinosis, 12 have two severely truncating mutations, which is consistent with a loss of functional protein, and 13 have missense or in-frame deletions, which would result in disruption of transmembrane domains and loss of protein function. Mutations found in two late-onset patients affect functionally unimportant regions of cystinosin, which accounts for their milder phenotype. For three patients, the age of onset of cystinosis was <7 years but the course of the disease was milder than the infantile nephropathic form. This suggests that the missense mutations found in these individuals allow production of functional protein and may also indicate regions of cystinosin which are not functionally important. BACKGROUND AND OBJECTIVES: Infantile nephropathic cystinosis is a severe disease that occurs due to mutations in the cystinosis gene, and it is characterized by progressive dysfunction of multiple organs; >100 cystinosis gene mutations have been identified in multiple populations. Our study aimed to identify the clinical characteristics and spectrum of cystinosis gene mutations in Turkish pediatric patients with cystinosis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We identified the clinical characteristics and spectrum of cystinosis gene mutations in Turkish patients with cystinosis in a multicenter registry that was established for data collection. The data were extracted from this registry and analyzed. RESULTS: In total, 136 patients (75 men and 61 women) were enrolled in the study. The most common clinical findings were growth retardation, polyuria, and loss of appetite. None of the patients had the 57-kb deletion, but seven novel mutations were identified. The most common mutations identified were c.681G>A (p.Glu227Glu; 31%), c.1015G>A (p.Gly339Arg; 22%), and c.18_21 del (p.Thr7Phefs*7; 14%). These mutations were associated with earlier age of disease onset than the other mutations. To understand the effects of these allelic variants on clinical progression, the mutations were categorized into two major groups (missense versus deletion/duplication/splice site). Although patients with missense mutations had a better eGFR at the last follow-up visit, the difference was not significant. Patients in whom treatment began at age <2 years old had later onset of ESRD (P=0.02). Time to ESRD did not differ between the patients with group 1 and group 2 mutations. CONCLUSIONS: The most common cystinosis gene mutations identified in Turkey were c.681G>A (p.Glu227Glu), c.1015G>A (p.Gly339Arg), and c.18_21 del (p.Thr7Phefs*7). Patients with less severe cystinosis gene mutations tend to have better kidney outcome. Author information: (1)Department of Pediatric Subspecialties, Division of Nephrology, Bambino Gesù Children's Hospital-IRCCS, Rome, Italy. Electronic address: francesco.emma@opbg.net. (2)Renal Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK. (3)Department of Pediatric Nephrology, Children's Hospital RoMed Clinics Rosenheim, Rosenheim, Germany. (4)Department of Pediatric Nephrology, Hacettepe University School of Medicine, Ankara, Turkey. (5)Department of Pediatric Subspecialties, Division of Nephrology, Bambino Gesù Children's Hospital-IRCCS, Rome, Italy. (6)Division of Pediatric Nephrology, Hospital Universitari Vall d' Hebron, Barcelona, Spain. (7)Renal Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK; Department of Renal Medicine, University College London, London, UK. (8)Department of Pediatric Nephrology and Development and Regeneration, University Hospitals Leuven, Leuven, Belgium. (9)Department of Pediatrics II, University Hospital Essen, University of Duisburg-Essen, Essen, Germany. (10)Department of Paediatric Nephrology, Birmingham Women's and Children's Hospital NHS Trust, Birmingham, UK. (11)Department of Pediatric Nephrology, Hacettepe University School of Medicine, Ankara, Turkey; Nephrogenetic Laboratory, Hacettepe University School of Medicine, Ankara, Turkey. (12)Paris Descartes University, Imagine Institute, Inserm U1163, Paris, France; Adult Nephrology and Transplantation, Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Necker Hospital, Paris, France. (13)Department of Pediatric Nephrology, Robert Debré Hospital, University of Paris, Paris, France. (14)Department of Paediatric Nephrology, University Hospital of Lille, Lille, France. (15)Hospices Civils de Lyon, Centre de Référence Maladies Rénales Rares, Lyon, France. (16)Department of Pediatric Nephrology, Pediatric Hepatology and Pediatric Transplantation, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. (17)Department of Pediatric Nephrology, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, the Netherlands. (18)Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands. (19)Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany. (20)Clinical Pathways and Epidemiology Unit, Medical Direction, Bambino Gesù Children's Hospital-IRCCS, Rome, Italy. (21)Paris Descartes University, Imagine Institute, Laboratory of Hereditary Kidney Diseases, INSERM UMR 1163, Paris, France; Department of Genetics, AP-HP, Hôpital Necker-Enfants Malades, Paris, France. (22)Division of Nephrology, Cliniques Universitaires Saint-Luc, UCLouvain, Brussels, Belgium; Mechanisms of Inherited Kidney Disorders Group, University of Zurich, Zurich, Switzerland. (23)Pediatric Nephrology, Hôpital Necker-Enfants Malades, Paris University, Paris, France. BACKGROUND: Nephropathic cystinosis is characterized by an accumulation of cystine crystals within most body tissues. Renal transplantation and oral cysteamine have improved the general prognosis of the disease, and ocular manifestations are now the most common complication. This long-term follow-up study describes the sequence of ocular manifestations in patients with nephropathic cystinosis treated with oral and topical cysteamine. METHODS: Data were recorded for all patients with cystinosis examined between 1980 and 2000. For each patient, photophobia and visual acuity were evaluated and slit-lamp and fundus examinations were performed. For some patients, an electroretinogram was also performed. RESULTS: Twenty-nine patients were observed during this period. They received oral and topical cysteamine. Photophobia and loss of visual acuity generally began by 10 years of age but were severe only after 15 years of age. Peripheral corneal epithelial infiltration appeared in the first few years of life. Infiltration evolved toward the depth and center of the cornea during the second decade of life. Retinopathy was present in 51.7% of the patients, with 3 cases of maculopathy and 3 cases of flattening on electroretinogram. CONCLUSIONS: Photophobia and corneal infiltration, although generally severe after 15 years of age, could be treated with topical cysteamine and corneal transplantation. Retinal infiltration, previously described as frequent and potentially blinding, is currently observed in only half of these patients, with mild visual impairment. This could be related to the treatment with oral cysteamine reaching the retinal vascularization. Nephropathic cystinosis is an autosomal recessive lysosomal disease in which cystine cannot exit the lysosome to complete its degradation in the cytoplasm, thus accumulating in tissues. Some patients develop a distal myopathy involving mainly hand muscles. Myopathology descriptions from only 5 patients are available in the literature. We present a comprehensive clinical, pathological and genetic description of 3 patients from 2 families with nephropathic cystinosis. Intrafamiliar variability was detected in one family in which one sibling developed a severe distal myopathy while the other sibling did not show any signs of skeletal muscle involvement. One of the patients was on treatment with Cysteamine for over 12 years but still developed the usual complications of nephropathic cystinosis in his twenties. Novel pathological findings consisting in sarcoplasmic deposits reactive for slow myosin were identified. Three previously known and one novel mutation are reported. Nephropathic cystinosis should be included in the differential diagnosis of distal myopathies in those with early renal failure. Novel clinical and pathological features are reported here contributing to the characterization of the muscle involvement in nephropathic cystinosis. Nephropathic cystinosis is a rare lysosomal storage disorder. Patients present in the first year of life with renal Fanconi syndrome that evolves to progressive chronic kidney disease (CKD). Despite the multiple risk factors for bone disease, the frequency and severity of skeletal disorders in nephropathic cystinosis have not been described. We performed systematic bone and mineral evaluations of subjects with cystinosis seen at the NIH (n = 30), including history and physical examination, serum and urine biochemistries, DXA, vertebral fracture assessment, skeletal radiographs, and renal ultrasound. Additionally, histomorphometric analyses are reported on six subjects seen at the UCLA Bone and Mineral Metabolism Clinic. In NIH subjects, mean age was 20 years (range, 5 to 44 years), 60% were CKD stages G1 to G4, and 40% had a renal transplant. Mean bone mineral density (BMD) Z-scores were decreased in the femoral neck, total hip, and 1/3 radius (p < 0.05). Low bone mass at one or more sites was present in 46% of subjects. Twenty-seven percent of subjects reported one or more long bone fractures. Thirty-two percent of subjects had incidental vertebral fractures, which were unrelated to transplant status. Long-bone deformity/bowing was present in 64%; 50% had scoliosis. Diffuse osteosclerosis was present in 21% of evaluated subjects. Risk factors included CKD, phosphate wasting, hypercalciuria, secondary hyperparathyroidism, hypovitaminosis D, male hypogonadism, metabolic acidosis, and glucocorticoid/immunosuppressive therapy. Sixty-one percent of the non-transplanted subjects had ultrasonographic evidence of nephrocalcinosis or nephrolithiasis. Histomorphometric analyses showed impaired mineralization in four of six studied subjects. We conclude that skeletal deformities, decreased bone mass, and vertebral fractures are common and relevant complications of nephropathic cystinosis, even before renal transplantation. Efforts to minimize risk factors for skeletal disease include optimizing mineral metabolism and hormonal status, combined with monitoring for nephrocalcinosis/nephrolithiasis. © 2018 This article is a U.S. Government work and is in the public domain in the USA. OBJECTIVE: Nephropathic cystinosis is an autosomal recessive lysosomal storage disorder that is characterised by the accumulation of the amino acid cystine in several body tissues due to a mutation in the CTNS gene, which encodes the cystinosin protein. The aim of this study was to sequence the coding exons of the CTNS gene in five different Jordanian families and one family from Sudan with nephropathic cystinosis. METHODS: Probands initially presented with Fanconi syndrome symptoms. An eye examination showed the accumulation of cystine crystals in the cornea by the age of 2 years, suggesting cystinosis. All of the coding exons and flanking intronic sequences and the promoter region of the CTNS gene were amplified using polymerase chain reaction and subjected to sequencing. RESULTS: None of the probands in this study carried the European 57-kb deletion in the CTNS gene. Seven variants in the coding and promoter sequence of the CTNS gene were identified in the probands of this study. Two of these variants were a CTNS mutation that was previously identified in a heterozygous genotype in two different patients of European descendant. The two mutations were c.829dupA in exon 10 and c.890G>A in exon 11. The proband of family 2 was compound-heterozygous for the two mutations. CONCLUSION: This study is the first molecular study of infantile nephropathic cystinosis in Jordan. We successfully identified the causative CTNS mutations in Jordanian families. The results provide a basis for the early detection of the disease using molecular tools in a highly consanguineous Jordanian population. Ocular nonnephropathic cystinosis, a variant of the classic nephropathic type of cystinosis, is an autosomal recessive lysosomal storage disorder characterized by photophobia due to corneal cystine crystals but absence of renal disease. We determined the molecular basis for ocular cystinosis in four individuals. All had mutations in the cystinosis gene CTNS, indicating that ocular cystinosis is allelic with classic nephropathic cystinosis. The ocular cystinosis patients each had one severe mutation and one mild mutation, the latter consisting of either a 928 G-->A (G197R) mutation or an IVS10-3 C-->G splicing mutation resulting in the insertion of 182 bp of IVS10 into the CTNS mRNA. The mild mutations appear to allow for residual CTNS mRNA production, significant amounts of lysosomal cystine transport, and lower levels of cellular cystine compared with those in nephropathic cystinosis. The lack of kidney involvement in ocular cystinosis may be explained by two different mechanisms. On the one hand (e.g. the G197R mutation), significant residual cystinosin activity may be present in every tissue. On the other hand (e.g. the IVS 10-3 C-->G mutation), substantial cystinosin activity may exist in the kidney because of that tissue's specific expression of factors that promote splicing of a normal CTNS transcript. Each of these mechanisms could result in minimally reduced lysosomal cystine transport in the kidneys. Nephropathic cystinosis is a rare, inherited metabolic disease caused by functional defects of cystinosin associated with mutations in the CTNS gene. The mechanisms underlying the phenotypic alterations associated with this disease are not well known. In this study, gene expression profiles in peripheral blood of nephropathic cystinosis patients (N = 7) were compared with controls (N = 7) using microarray technology. In unsupervised hierarchical clustering analysis, cystinosis samples co-clustered, and 1,604 genes were significantly differentially expressed between both groups. Gene ontology analysis revealed that differentially expressed genes in cystinosis were enriched in cell organelles such as mitochondria, lysosomes, and endoplasmic reticulum (p ≤ 0.030). The majority of the differentially regulated genes were involved in oxidative phosphorylation, apoptosis, mitochondrial dysfunction, endoplasmic reticulum stress, antigen processing and presentation, B-cell-receptor signaling, and oxidative stress (p ≤ 0.003). Validation of selected genes involved in apoptosis and oxidative phosphorylation was performed by quantitative real-time polymerase chain reaction (PCR). Electron microscopy and confocal imaging of cystinotic renal proximal tubular epithelial cells further confirmed anomalies in the cellular organelles and pathways identified by microarray analysis. Further analysis of these genes and pathways may offer critical insights into the clinical spectrum of cystinosis patients and ultimately lead to novel links for targeted therapy. Cystinosis is an autosomal recessive lysosomal storage disorder caused by CTNS gene mutations. The CTNS gene encodes the protein cystinosin, which transports free cystine from lysosomes to cytoplasm. In cases of cystinosin deficiency, free cystine accumulates in lysosomes and forms toxic crystals that lead to tissue and organ damage. Since CTNS gene mutations were first described, many variations have been identified that vary according to geographic region, although the phenotype remains the same. Cystinosis is a hereditary disease that can be treated with the cystine-depleting agent cysteamine. Cysteamine slows organ deterioration, but cannot treat renal Fanconi syndrome or prevent eventual kidney failure; therefore, novel treatment modalities for cystinosis are of great interest to researchers. The present review aims to highlight the geographic differences in cystinosis-specifically in terms of its genetic aspects, clinical features, management, and long-term complications. Nephropathic cystinosis is an autosomal recessive lysosomal storage disorder in which intracellular cystine accumulates. It is caused by mutations in the CTNS gene. Clinical manifestations include renal tubular Fanconi syndrome in the first year of life, rickets, hypokalaemia, polyuria, dehydration and acidosis, growth retardation, hypothyroidism, photophobia and renal glomerular deterioration. Late complications include myopathy, pancreatic insufficiency and retinal blindness. Skeletal manifestations described in these patients include failure to thrive, osteomalacia, rickets and short stature. This paper describes progressive bony abnormalities in three unrelated patients with nephropathic cystinosis that have not been reported previously. BACKGROUND: Deletions or inactivating mutations of the cystinosin gene CTNS lead to cystine accumulation and crystals at acidic pH in patients with nephropathic cystinosis, a rare lysosomal storage disease and the main cause of hereditary renal Fanconi syndrome. Early use of oral cysteamine to prevent cystine accumulation slows progression of nephropathic cystinosis but it is a demanding treatment and not a cure. The source of cystine accumulating in kidney proximal tubular cells and cystine's role in disease progression are unknown. METHODS: To investigate whether receptor-mediated endocytosis by the megalin/LRP2 pathway of ultrafiltrated, disulfide-rich plasma proteins could be a source of cystine in proximal tubular cells, we used a mouse model of cystinosis in which conditional excision of floxed megalin/LRP2 alleles in proximal tubular cells of cystinotic mice was achieved by a Cre-LoxP strategy using Wnt4-CRE. We evaluated mice aged 6-9 months for kidney cystine levels and crystals; histopathology, with emphasis on swan-neck lesions and proximal-tubular-cell apoptosis and proliferation (turnover); and proximal-tubular-cell expression of the major apical transporters sodium-phosphate cotransporter 2A (NaPi-IIa) and sodium-glucose cotransporter-2 (SGLT-2). RESULTS: Wnt4-CRE-driven megalin/LRP2 ablation in cystinotic mice efficiently blocked kidney cystine accumulation, thereby preventing lysosomal deformations and crystal deposition in proximal tubular cells. Swan-neck lesions were largely prevented and proximal-tubular-cell turnover was normalized. Apical expression of the two cotransporters was also preserved. CONCLUSIONS: These observations support a key role of the megalin/LRP2 pathway in the progression of nephropathic cystinosis and provide a proof of concept for the pathway as a therapeutic target. Nephropathic cystinosis is characterized clinically by generalized proximal renal tubular dysfunction, renal Fanconi Syndrome and progressive renal failure. Glomerular-proximal tubule disconnection has been noted in renal biopsies from patients with nephropathic cystinosis. In vitro studies performed in cystinotic fibroblasts and renal proximal tubular cells support a role for apoptosis of the glomerulotubular junction, and we have further extended these studies to human native cystinotic kidney specimens. We performed semi-quantitative analysis of tubular density in kidney biopsies from patients with nephropathic cystinosis and demonstrated a significant reduction (p=0.0003) in the number of proximal tubules in the kidney tissue of patients with cystinosis compared to normal kidneys and kidneys with other causes of renal injury; this reduction appears to be associated with the over-expression of caspase-4. This study provides the first quantitative evidence of a loss of proximal tubules in nephropathic cystinosis and suggests a possible role of caspase-4 in the apoptotic loss of proximal tubular cells. Further work is needed to elucidate if this injury mechanism may be causative for the progression of renal functional decline in nephropathic cystinosis. Nephropathic cystinosis is a rare lysosomal storage disorder caused by mutations in the CTNS gene ncoding the lysosomal cystine transporter cystinosin. Cystinosin deficiency leads to accumulation of cystine in the lysosomes of cells throughout the body and deregulation of endocytosis, trafficking of intracellular vesicles and related cell signalling processes. One of the early features of the disease is renal Fanconi syndrome characterized by polyuria, proteinuria and urinary loss of various solutes. Later in life, extrarenal complications become apparent, and decline of kidney function leads to the development of end-stage renal disease. Modern therapy of the disease is based on treatment with cystine-lowering drug cysteamine, which helps to postpone the disease progression and development of extra-renal pathologies, but offers no cure for the Fanconi syndrome. Besides the improvement of cystine-lowering therapy based on new formulations of cysteamine, further development of therapy is necessary. Some steps forward were done in the recent years, including studies of cell signalling abnormalities in cystinosis and development of stem cell and gene therapy approaches. Author information: (1)Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA; Division of Kidney Diseases, Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA. Electronic address: c-langman@northwestern.edu. (2)Department of Pediatrics, University of California, San Diego, La Jolla, California, USA. (3)Department of Pediatrics, Division of Pediatric Nephrology, Robert Debré University Hospital, Paris, France. (4)Department of Nephrology and Urology, Istituto di Ricovero e Cura a Carattere Scientifico Bambino Gesù Children's Hospital, Rome, Italy. (5)Department of Pediatrics, McGill University, Montreal Children's Hospital, Montreal, Québec, Canada. (6)Department of Nephrology, Queen Elizabeth Hospital, Birmingham, UK. (7)Department of Pediatrics, Alberta Children's Hospital, Calgary, Alberta, Canada. (8)University Paris Descartes, Paris, France; Department of Biochemistry B, Necker-Enfants Malades Hospital, Paris, France. (9)Department of Nephrology-Transplantation, Necker Hospital, Assistance Publique Hôpitaux de Paris, Paris Descartes University, Paris, France. (10)Department of Pediatrics, Center of Pediatric Nephrology and Transplantation, Cairo University, Cairo, Egypt. (11)Department of Pediatric Genetics, University of Michigan, Ann Arbor, Michigan, USA. (12)Department of Pediatric Nephrology, University Hospitals Leuven, Belgium; Department of Development and Regeneration, Katholieke Universiteit Leuven, Belgium. Electronic address: elena.levtchenko@uzleuven.be. Nephropathic cystinosis is a rare autosomal recessive lysosomal disease characterized by accumulation of pathognomonic cystine crystals in renal and other tissues of the body. Cystinosis is caused by mutant cystinosin, the cystine transport protein located in lysosomal membranes, leading to systemic deposits of cystine and resultant end organ damage. Cystinosis is rarer in Asians than Caucasians with only a handful of cases reported from India to date. Due to its extreme rarity and clinically insidious presentation in contrast to the infantile form, the diagnosis of juvenile nephropathic cystinosis is frequently delayed or overlooked. Moreover, routine processing and sectioning of paraffin embedded tissues dissolves cystine crystals, making it difficult to diagnose this condition on light microscopic examination alone, mandating electron microscopic (EM) analysis of renal biopsies for an accurate diagnosis of this condition. We describe a case of juvenile nephropathic cystinosis presenting with uveitis and photophobia in a 17-year-old Indian male, diagnosed after EM examination of the patient's renal biopsy for evaluation of nephrotic syndrome. While highlighting the diagnostic utility of EM, we describe a few histopathologic clues which can prompt inclusion of EM analysis of renal biopsies in this setting. Nephropatic cystinosis (NC) is a rare disease associated with pathogenic variants in the CTNS gene, with a common variant that consists of a 57kb-deletion involving CTNS. Patients with NC that are treated with cysteamine improve their life quality and expectancy. We report a 12-month-old girl with a poor growth rate since the 4th month of life. She was admitted to the Hospital with acute kidney injury, severe dehydration and metabolic acidosis. She was treated with volume restorative and bicarbonate. Proximal tubulopathy and Fanconi's syndrome was diagnosed. Medical treatment improved renal function that was stabilized in stage 4 chronic kidney disease (CKD). Since infantile NC was suspected, CTNS genetic analysis was considered. Genomic DNA was isolated from peripheral blood to perform PCR for exons 3-12 in CTNS gene and for the specific 57kb-deletion PCR. Afterwards, variant segregation analysis was performed in the familiar trio. The genetic analysis showed that the patient was homozygous for the common 57kb-deletion encompassing CTNS that had been inherited from her asymptomatic heterozygous parents. The molecular confirmation allowed genetic counselling for parents and facilitated the access to cysteamine. Oral treatment with cysteamine resulted in improvement of renal function to CKD stage 3. After 16 months of treatment the patient shows metabolic stability and mild recovery of height. Ophthalmologic follow-up detected ocular cystine crystals 12 months after diagnosis, starting cysteamine drops. Nephropathic cystinosis is a severe, monogenic systemic disorder that presents early in life and leads to progressive organ damage, particularly affecting the kidneys. It is caused by mutations in the CTNS gene, which encodes the lysosomal transporter cystinosin, resulting in intralysosomal accumulation of cystine. Recent studies demonstrated that the loss of cystinosin is associated with disrupted autophagy dynamics, accumulation of distorted mitochondria, and increased oxidative stress, leading to abnormal proliferation and dysfunction of kidney cells. We discuss these molecular mechanisms driving nephropathic cystinosis. Further, we consider how unravelling molecular mechanisms supports the identification and development of new strategies for cystinosis by the use of small molecules, biologicals, and genetic rescue of the disease in vitro and in vivo. The autosomal recessive lysosomal storage disorder, nephropathic cystinosis is characterized by impaired transport of free cystine out of lysosomes. The gene responsible for cystinosis, CTNS, consists of 12 exons and encodes a 55 kDa putative lysosomal membrane protein, called cystinosin. Up to now more than 55 different CTNS mutations have been described in cystinosis. We have analyzed the mutation pattern in a population of 40 cystinosis patients from 35 families of German and Swiss origin. CTNS mutations in 68 out of 70 alleles were identified. The common 57-kb deletion accounted for 65% of the alleles. In five patients we found a known GACT deletion at position 18-21. In two patients we identified a nucleotide substitution at codon 339 and one patient showed a CG insertion at position 697-698. In five patients we observed a G insertion at position 926-927. Moreover, five novel mutations including two deletions involving exon 3 (61-61+2delGGT) and exon 6 (280delG), two insertions in exon 6 (292-293insA) and exon 7 (684insCACTT) and one nucleotide substitution in exon 11 (923G>T) have been identified. These data provide a basis for routine molecular diagnosis of cystinosis in the central European population, especially in cystinosis patients of German and Swiss origin. Nephropathic cystinosis, characterized by accumulation of cystine in the lysosomes, is caused by mutations in CTNS. The molecular and cellular mechanisms underlying proximal tubular dysfunction and progressive renal failure in nephropathic cystinosis are largely unclear, and increasing evidence supports the notion that cystine accumulation alone is not responsible for the end organ injury in cystinosis. We previously identified clusterin as potentially involved in nephropathic cystinosis. Here, we studied the expression of clusterin in renal proximal tubular epithelial cells obtained from patients with nephropathic cystinosis. The cytoprotective secretory form of clusterin, as evaluated by Western blot analysis, was low or absent in cystinosis cells compared with normal primary cells. Confocal microscopy revealed elevated levels of intracellular clusterin in cystinosis cells. Clusterin in cystinosis cells localized to the nucleus and cytoplasm and showed a filamentous and punctate aggresome-like pattern compared with diffuse cytoplasmic staining in normal cells. In kidney biopsy samples from patients with nephropathic cystinosis, clusterin protein expression was mainly limited to the proximal tubular cells. Furthermore, expression of clusterin overlapped with the expression of apoptotic proteins (apoptosis-inducing factor and cleaved caspase-3) and autophagy proteins (LC3 II and p62). Silencing of the clusterin gene resulted in a significant increase in cell viability and attenuation of apoptosis in cystinosis cells. Results of this study identify clusterin as a pivotal factor in the cell injury mechanism of nephropathic cystinosis and provide evidence linking cellular stress and injury to Fanconi syndrome and progressive renal injury in nephropathic cystinosis. Nephropathic cystinosis is an autosomal recessive lysosomal storage disorder in which intracellular cystine accumulates due to impaired transport out of lysosomes. The clinical manifestations include renal tubular Fanconi syndrome in the 1st year of life, with hypophosphatemic rickets, hypokalemia, polyuria, dehydration and acidosis, growth retardation, hypothyroidism, photophobia, renal glomerular deterioration by 10 years of age, and late complications such as myopathy, pancreatic insufficiency, and retinal blindnesss. The cystinosis gene, CTNS, codes for cystinosin, a 367 amino acid protein with seven transmembrane domains. More than 50 CTNSmutations have been identified, but approximately 50% of Northern European patients have a 57257-bp deletion which removes the first nine exons of CTNS. The mainstay of cystinosis therapy is oral cysteamine (Cystagon). This aminothiol can lower intracellular cystine content by 95%, and has proven efficacy in delaying renal glomerular deterioration, enhancing growth, preventing hypothyroidism, and lowering muscle cystine content. Its early and diligent use is critical; in one study, for every month of treatment prior to 3 years of age, 14 months' worth of later renal function were preserved. Several examples of individual patients treated early and having preserved renal function and normal growth are available. Newborn screening using a chip containing cDNA to detect common CTNSmutations may allow diagnosis and treatment in the first weeks of life. CONCLUSIONS: Early diagnosis and treatment of nephropathic cystinosis can change the course of this disease. Cystinosis is a rare autosomal recessive lysosomal storage disorder characterized by abnormal accumulation of intracellular cystine in various tissues including the brain, kidneys, bones, and eyes. Infantile nephropathic cystinosis is the most severe phenotype of cystinosis that has been associated with a wide spectrum of ocular features. In this report, the author describes a posterior segment spectral-domain optical coherence tomography (SD-OCT) finding that has not been previously reported in a case of nephropathic cystinosis. Nephropathic cystinosis is an autosomal recessive disorder caused by the defective transport of cystine out of lysosomes. Recently, the causative gene (CTNS) was identified and presumed to encode an integral membrane protein called cystinosin. Many of the disease-associated mutations in CTNS are deletions, including one >55 kb in size that represents the most common cystinosis allele encountered to date. In an effort to determine the precise genomic organization of CTNS and to gain sequence-based insight about the DNA within and flanking cystinosis-associated deletions, we mapped and sequenced the region of human chromosome 17p13 encompassing CTNS. Specifically, a bacterial artificial chromosome (BAC)-based physical map spanning CTNS was constructed by sequence-tagged site (STS)-content mapping. The resulting BAC contig provided the relative order of 43 STSs. Two overlapping BACs, which together contain all of the CTNS exons as well as extensive amounts of flanking DNA, were selected and subjected to shotgun sequencing. A total of 200,237 bp of contiguous, high-accuracy sequence was generated. Analysis of the resulting data revealed a number of interesting features about this genomic region, including the long-range organization of CTNS, insight about the breakpoints and intervening DNA associated with the common cystinosis-causing deletion, and structural information about five genes neighboring CTNS (human ortholog of rat vanilloid receptor subtype 1 gene, CARKL, TIP-1, P2X5, and HUMINAE). In particular, sequence analysis detected the presence of a novel gene (CARKL) residing within the most common cystinosis-causing deletion. This gene encodes a previously unknown protein that is predicted to function as a carbohydrate kinase. Interestingly, both CTNS and CARKL are absent in nearly half of all cystinosis patients (i.e., those homozygous for the common deletion). [The sequence data described in this paper have been submitted to the GenBank data library under accession nos. AF168787 and AF163573.] Nephropathic cystinosis is an autosomal recessive inborn error of metabolism characterized by the lysosomal storage of the disulphide amino acid cystine. It produces a variety of clinical manifestations including failure to thrive, the renal Fanconi syndrome, eye findings, and end-stage renal disease. A variety of phenotypes are known; however, the molecular defect underlying any of the forms has not yet been identified. Therapy of cystinosis with cysteamine averts the otherwise inevitable renal failure, but systemic therapy does not improve the corneal keratopathy. A number of presentations in this review detail approaches to gene identification, systemic therapy with cysteamine, measurement of cystine, and pathophysiological effects at the cellular and clinical level.
4,087
Which drugs are included in the Contrave pill?
Contrave® is an adjunct pharmacotherapy for obesity that contains bupropion (BUP) and naltrexone (NTX).
[34745784, 29151591, 25395816, 28130024, 26313898, 22860172, 25661549, 25258511, 20509712, 29408463, 30991059, 19777400, 27773782, 26679384, 26957883, 26105116, 19885278]
4,494
Erythroderma is a rare, potentially life-threatening presentation of psoriasis that can be triggered by medication reactions. Bupropion is indicated for major depressive disorder (Wellbutrin®, GlaxoSmithKline, Research Triangle Park, NC), smoking cessation (Zyban®, GlaxoSmithKline, Research Triangle Park, NC), and weight loss (when in formulation with naltrexone ER; Contrave®, Orixegen Therapeutics, La Jolla, CA). Bupropion can exacerbate psoriasis, however, this is an under-recognized side effect of the medication, particularly in the United States. We report a case of bupropion-induced erythrodermic psoriasis in a 62-year-old female who was prescribed the medication for depression. Due to the common comorbidities of depression, obesity, and tobacco abuse in psoriatic patients, all for which treatment with bupropion is indicated, it is important for physicians to be aware of the potential for a life-threatening medication reaction in this patient population. OBJECTIVE: Obesity is now the most prevalent chronic disease in the United States, which amounts to an estimated $147 billion in health care spending annually. The Affordable Care Act (ACA) enacted in 2010 included provisions for private and public health insurance plans that expanded coverage for lifestyle/behavior modification and bariatric surgery for the treatment of obesity. Pharmacotherapy, however, has not been included despite their evidence-based efficacy. We set out to investigate the coverage of Food and Drug Administration-approved medications for obesity within Medicare, Medicaid and ACA-established marketplace health insurance plans. METHODS: We examined coverage for phentermine, diethylpropion, phendimetrazine, Benzphentamine, Lorcaserin, Phentermine/Topiramate (Qysmia), Liraglutide (Saxenda) and Buproprion/Naltrexone (Contrave) among Medicare, Medicaid and marketplace insurance plans in 34 states. RESULTS: Among 136 marketplace health insurance plans, 11% had some coverage for the specified drugs in only nine states. Medicare policy strictly excludes drug therapy for obesity. Only seven state Medicaid programs have drug coverage. CONCLUSIONS: Obesity requires an integrated approach to combat its public health threat. Broader coverage of pharmacotherapy can make a significant contribution to fighting this complex and chronic disease. BACKGROUND: We report a case of erythrodermic pustular psoriasis associated with initiation of bupropion/naltrexone (Contrave®; Orexigen Therapeutics, La Jolla, CA) in a patient with no history of psoriasis. CASE REPORT: A 55-year-old woman was transferred to our tertiary medical center from a community hospital for possible Stevens-Johnson syndrome 3 weeks after initiation of bupropion/naltrexone. The patient was admitted to the burn unit for wound treatment and hydration. She received intravenous cyclosporine during the admission that resulted in acute kidney injury and the therapy was discontinued. The skin biopsy ruled out Stevens-Johnson syndrome and was more consistent with generalized pustular psoriasis. After discharge, the patient followed up with her dermatologist. She was diagnosed with acute generalized and erythrodermic psoriasis and the patient was restarted on cyclosporine 100 mg twice a day. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Few case reports of bupropion-induced generalized pustular psoriasis and erythrodermic psoriasis in patients with a history of psoriasis have been reported. To our knowledge, acute generalized erythrodermic pustular psoriasis associated with bupropion/naltrexone has not been reported in a patient without history of psoriasis. Due to increases in obesity and increases in prescribing of bupropion/naltrexone SR, health care providers should be aware of this possible severe adverse reaction. Contrave is an investigational fixed-dose combination drug of naltrexone and bupropion currently in Phase III clinical trials for the treatment of obesity. Orexigen Therapeutics, Inc. has demonstrated efficacy of their product and is currently addressing FDA safety concerns and deciding future actions. In March 2010, Orexigen(R) Therapeutics submitted a new drug application (NDA) for approval of naltrexone sustained release (SR)/bupropion SR (Contrave(R)) for the treatment of obesity in the US. The tablet contains naltrexone SR 32 mg and bupropion SR 360 mg. The drug has been tested in four randomized, double-blind, placebo-controlled, phase III trials and the co-primary endpoints were met in each case. This review discusses the key development milestones and clinical trial program to date. Contrave® is an adjunct pharmacotherapy for obesity that contains bupropion (BUP) and naltrexone (NTX). To further explore the psychopharmacology of this drug combination, male Sprague-Dawley rats were implanted with subcutaneous osmotic mini-pumps releasing: 40 mg/kg/day BUP, 4 mg/kg/day NTX, or 40 + 4 mg/kg/day BUP and NTX (BN). During 12 days of exposure, the animals were tested on operant intraoral self-administration (IOSA) of high fructose corn syrup (HFCS) on continuous (FR1) and progressive ratio (PR) schedules, on home cage drinking of HFCS, and on HFCS taste reactivity. Locomotion activity was also assessed. At the conclusion of the study, mRNA expression of genes involved in reward processing, appetite and mood were quantified. It was found that BN produced effects that could largely be ascribed to either BUP or NTX independently. More specifically, BN-induced reductions of HFCS IOSA on a FR1 schedule and home cage drinking, as well as alterations of MOR and POMC mRNA in the nucleus accumbens core and hypothalamus respectively, were attributable to NTX; while alterations of hippocampal BDNF mRNA was attributable to BUP. But, there was also some evidence of drug synergy: only BN caused persistent reductions of HFCS IOSA and drinking; BN produced the least gain of body weight; and only BN-treated rats displayed altered D2R mRNA in the caudate-putamen. Taken together, these observations support the use of BUP + NTX as a mean to alter consumption of sugars and reducing their impact on brain systems involved in reward, appetite and mood. A fixed dose combination of bupropion (BPP) and naltrexone (NTX), Contrave®, is an FDA approved pharmacotherapy for the treatment of obesity. A recent study found that combining BPP with low-dose NTX reduced alcohol drinking in alcohol-preferring male rats. To explore potential pharmacological effects of the BPP + NTX combination on alcohol drinking, both male and female C57Bl/6J mice were tested on one-week drinking-in-the dark (DID) and three-week intermittent access (IA) models. Neuronal proopiomelanocortin (POMC) enhancer knockout (nPE-/-) mice with hypothalamic-specific deficiency of POMC, and its bioactive peptides melanocyte stimulating hormone and beta-endorphin, were used as a genetic control for the effects of the BPP + NTX. A single administration of BPP + NTX (10 mg/kg + 1 mg/kg) decreased alcohol intake after DID in C57Bl/6J males, but not females. Also in C57Bl/6J males, BPP + NTX reduced intake of the caloric reinforcer sucrose, but not the non-caloric reinforcer saccharin. In contrast, BPP + NTX had no effect on alcohol DID in nPE-/- males. Pretreatment with the selective melanocortin 4 receptor (MC4R) antagonist HS014 reversed the anti-dipsogenic effect of BPP + NTX on alcohol DID in C57Bl/6J males. In the 3-week chronic IA model, single or repeated administrations for four days of BPP + NTX reduced alcohol intake and preference in C57Bl/6J males only. The behavioral measures observed in C57Bl/6J mice provide clear evidence that BPP + NTX profoundly reduced alcohol drinking in males, but the doses tested were not effective in females. Furthermore, our results suggest a hypothalamic POMC/MC4R-dependent mechanism for the observed BPP + NTX effects on alcohol drinking in male mice. Contrave(®) is a combination of naltrexone hydrochloride extended release and bupropion hydrochloride extended release for the treatment of obesity, and is used with lifestyle modification. Its safety and efficacy were assessed in four randomized, double-blind, placebo-controlled, 56-week Phase III clinical trials in 4536 adult subjects: COR-1, COR-II, COR-BMOD and COR-DM. All four studies demonstrated statistically significant and clinically meaningful weight loss following up to 52 weeks of treatment with naltrexone/bupropion compared with placebo. The average weight loss from baseline across the four studies was approximately 11-22 lbs (5-9 kg). Results show the efficacy of Contrave for weight loss, as well as significant improvements in cardiometabolic markers. This review focuses on the four studies, their outcomes and the mechanism of action of Contrave. Naltrexone/Bupropion ER (Contrave): Newly Approved Treatment Option for Chronic Weight Management in Obese Adults. Oral naltrexone extended-release/bupropion extended-release (naltrexone ER/bupropion ER; Contrave(®), Mysimba(™)) is available as an adjunct to a reduced-calorie diet and increased physical activity in adults with an initial body mass index (BMI) of ≥ 30 kg/m(2) (i.e. obese) or a BMI of ≥ 27 kg/m(2) (i.e. overweight) in the presence of at least one bodyweight-related comorbidity, such as type 2 diabetes mellitus, hypertension or dyslipidaemia. In 56-week phase III trials in these patient populations, oral naltrexone ER/bupropion ER 32/360 mg/day was significantly more effective than placebo with regard to percentage bodyweight reductions from baseline and the proportion of patients who achieved bodyweight reductions of ≥ 5 and ≥ 10%. Significantly greater improvements in several cardiometabolic risk factors were also observed with naltrexone ER/bupropion ER versus placebo, as well as greater improvements in glycated haemoglobin levels in obese or overweight adults with type 2 diabetes. Naltrexone ER/bupropion ER was generally well tolerated in phase III trials, with nausea being the most common adverse event. Thus, naltrexone ER/bupropion ER 32/360 mg/day as an adjunct to a reduced-calorie diet and increased physical activity, is an effective and well tolerated option for chronic bodyweight management in obese adults or overweight adults with at least one bodyweight-related comorbidity.
4,088
When is lorlatinib used?
Lorlatinib is a third-generation ALK inhibitor that can overcome the largest number of acquired ALK resistance mutations, including the solvent-front mutation G1202R.
[34589977, 34585621, 34548910]
4,495
Treatment of advanced stage anaplastic lymphoma kinase (ALK) positive non-small cell lung cancer (NSCLC) with ALK tyrosine kinase inhibitors (TKIs) has been shown to be superior to standard platinum-based chemotherapy. However, secondary progress of disease frequently occurs under ALK inhibitor treatment. The clinical impact of re-biopsies for treatment decisions beyond secondary progress is, however, still under debate. Here, we report on two novel subsequent polyclonal on- and off-target resistance mutations in a patient with ALK-fused NSCLC under ALK inhibitor treatment. A 63-year-old male patient with an advanced stage EML4-ALK fused pulmonary adenocarcinoma was initially successfully treated with the second-generation ALK inhibitor alectinib and upon progressions subsequently with brigatinib, lorlatinib and chemoimmunotherapy (CIT). Progress to alectinib was associated with a so far undescribed ALK mutation (p.A1200_G1201delinsW) which was, however, tractable by brigatinib. An off-target KRAS-mutation (p.Q61K) occurred in association with subsequent progression under second-line TKI treatment. Third-line lorlatinib showed limited efficacy but chemoimmunotherapy resulted in disappearance of the KRAS mutant clone and clinical tumor control for another eight months. In conclusion, we suggest molecular profiling of progressive tumor disease also for ALK-positive NSCLC to personalize treatment in a subgroup of ALK-positive patients.
4,089
Ladybird homeobox (Lbx) transcription factors regulate the development of what body systems/organs?
Ladybird homeobox (Lbx) transcription factors have crucial functions in muscle and nervous system development in many animals
[18541024, 33786818, 12588966, 28843494, 24721834, 18056427, 16378763, 22077099, 15136145, 34411410, 9716535, 9342040, 19216761, 25035933]
4,496
BACKGROUND: Lbx/ladybird genes originated as part of the metazoan cluster of Nk homeobox genes. In all animals investigated so far, both the protostome genes and the vertebrate Lbx1 genes were found to play crucial roles in neural and muscle development. Recently however, additional Lbx genes with divergent expression patterns were discovered in amniotes. Early in the evolution of vertebrates, two rounds of whole genome duplication are thought to have occurred, during which 4 Lbx genes were generated. Which of these genes were maintained in extant vertebrates, and how these genes and their functions evolved, is not known. RESULTS: Here we searched vertebrate genomes for Lbx genes and discovered novel members of this gene family. We also identified signature genes linked to particular Lbx loci and traced the remnants of 4 Lbx paralogons (two of which retain Lbx genes) in amniotes. In teleosts, that have undergone an additional genome duplication, 8 Lbx paralogons (three of which retain Lbx genes) were found. Phylogenetic analyses of Lbx and Lbx-associated genes show that in extant, bony vertebrates only Lbx1- and Lbx2-type genes are maintained. Of these, some Lbx2 sequences evolved faster and were probably subject to neofunctionalisation, while Lbx1 genes may have retained more features of the ancestral Lbx gene. Genes at Lbx1 and former Lbx4 loci are more closely related, as are genes at Lbx2 and former Lbx3 loci. This suggests that during the second vertebrate genome duplication, Lbx1/4 and Lbx2/3 paralogons were generated from the duplicated Lbx loci created during the first duplication event. CONCLUSION: Our study establishes for the first time the evolutionary history of Lbx genes in bony vertebrates, including the order of gene duplication events, gene loss and phylogenetic relationships. Moreover, we identified genetic hallmarks for each of the Lbx paralogons that can be used to trace Lbx genes as other vertebrate genomes become available. Significantly, we show that bony vertebrates only retained copies of Lbx1 and Lbx2 genes, with some Lbx2 genes being highly divergent. Thus, we have established a base on which the evolution of Lbx gene function in vertebrate development can be evaluated. Homeobox-containing (Hox) genes play important roles in development, particularly in the development of neurons and sensory organs, and in specification of body plan. The Hmx gene family is a new class of homeobox-containing genes defined by a conserved homeobox region and a characteristic pattern of expression in the central nervous system that is more rostral than that of the Hox genes. To date, three closely related members of the Hmx family, Hmx1, Hmx2, and Hmx3, have been described. All three Hmx genes are expressed in the craniofacial region of developing embryos. Here we show, for the first time, the expression of the transcription factor Hmx3 in postnatally developing salivary glands. Hmx3 protein is expressed in a cell type-specific manner in rat salivary glands. Hmx3 is present in both the nuclei and cytoplasm of specific groups of duct cells of the submandibular, parotid, and sublingual glands. Hmx3 expression increases during postnatal development of the submandibular gland. The duct cells show increasing concentrations of Hmx3 protein with progressive development of the submandibular gland. In contrast, the acinar cells of the three salivary glands do not exhibit detectable levels of Hmx3 protein. The migration of limb myogenic precursors from limb level somites to their ultimate site of differentiation in the limb is a paradigmatic example of a set of dynamic and orchestrated migratory cell behaviours. The homeobox containing transcription factor ladybird homeobox 1 (Lbx1) is a central regulator of limb myoblast migration, null mutations of Lbx1 result in severe disruptions to limb muscle formation, particularly in the distal region of the limb in mice (Gross et al., 2000). As such Lbx1 has been hypothesized to control lateral migration of myoblasts into the distal limb anlage. It acts as a core regulator of the limb myoblast migration machinery, controlled by Pax3. A secondary role for Lbx1 in the differentiation and commitment of limb musculature has also been proposed (Brohmann et al., 2000; Uchiyama et al., 2000). Here we show that lateral migration, but not differentiation or commitment of limb myoblasts, is controlled by the phosphorylation of three adjacent serine residues of LBX1. Electroporation of limb level somites in the chick embryo with a dephosphomimetic form of Lbx1 results in a specific defect in the lateral migration of limb myoblasts. Although the initial delamination and migration of myoblasts is unaffected, migration into the distal limb bud is severely disrupted. Interestingly, myoblasts undergo normal differentiation independent of their migratory status, suggesting that the differentiation potential of hypaxial muscle is not regulated by the phosphorylation state of LBX1. Furthermore, we show that FGF8 and ERK mediated signal transduction, both critical regulators of the developing limb bud, have the capacity to induce the phosphorylation of LBX1 at these residues. Overall, this suggests a mechanism whereby the phosphorylation of LBX1, potentially through FGF8 and ERK signalling, controls the lateral migration of myoblasts into the distal limb bud. Author information: (1)Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, USA. (2)Laboratory for Bone and Joint Diseases, Center for Integrative Medical Sciences, RIKEN, Tokyo, Japan. (3)Laboratory for Medical Science Mathematics, Center for Integrative Medical Sciences, RIKEN, Yokohama, Japan. (4)Seay Center for Musculoskeletal Research, Texas Scottish Rite Hospital for Children, Dallas, USA School of Biotechnology, SMVDU, Katra, India. (5)Laboratory for Bone and Joint Diseases, Center for Integrative Medical Sciences, RIKEN, Tokyo, Japan Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan. (6)Laboratory for Statistical Analysis, Center for Integrative Medical Sciences, Riken, Yokohama, Japan. (7)Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan. (8)Department of Orthopedic Surgery, Texas Scottish Rite Hospital for Children, Dallas, USA Department of Orthopaedics, University of Texas Southwestern Medical Center at Dallas, Dallas, USA. (9)Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China Joint Scoliosis Research Center, The Chinese University of Hong Kong and Nanjing University, Hong Kong, China. (10)Functional Genomics and Biostatistical Computing Laboratory, Shenzhen Research Institute of the Chinese University of Hong Kong, Hong Kong, China Department of Chemical Pathology, the Chinese University of Hong Kong, Shatin, Hong Kong SAR, China. (11)Department of Biochemistry, University of Hong Kong, Hong Kong, China. (12)Department of Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China. (13)Department of Orthopedics, The Memorial Hospital of Sun Yat-Sen University, Guangzhou, China. (14)Department of Spine Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China. (15)Department of Psychiatry, University of Hong Kong, Hong Kong, China. (16)Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong, China. (17)Seay Center for Musculoskeletal Research, Texas Scottish Rite Hospital for Children, Dallas, USA Department of Orthopaedics, University of Texas Southwestern Medical Center at Dallas, Dallas, USA Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, USA McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center at Dallas, Dallas, USA. Ladybird (Lbx) homeodomain transcription factors function in neural and muscle development--roles conserved from Drosophila to vertebrates. Lbx expression in mice specifies neural cell types, including dorsally located interneurons and association neurons, within the neural tube. Little, however, is known about the regulation of vertebrate lbx family genes. Here we describe the expression pattern of three zebrafish ladybird genes via mRNA in situ hybridization. Zebrafish lbx genes are expressed in distinct but overlapping regions within the developing neural tube, with strong expression within the hindbrain and spinal cord. The Hox family of transcription factors, in cooperation with cofactors such as Pbx and Meis, regulate hindbrain segmentation during embryogenesis. We have identified a novel regulatory interaction in which lbx1 genes are strongly downregulated in Pbx-depleted embryos. Further, we have produced a transgenic zebrafish line expressing dTomato and EGFP under the control of an lbx1b enhancer--a useful tool to acertain neuron location, migration, and morphology. Using this transgenic strain, we have identified a minimal neural lbx1b enhancer that contains key regulatory elements for expression of this transcription factor. In Drosophila, neurons and glial cells are produced by neural precursor cells called neuroblasts (NBs), which can be individually identified. Each NB generates a characteristic cell lineage specified by a precise spatiotemporal control of gene expression within the NB and its progeny. Here we show that the homeobox genes ladybird early and ladybird late are expressed in subsets of cells deriving from neuroblasts NB 5-3 and NB 5-6 and are essential for their correct development. Our analysis revealed that ladybird in Drosophila, like their vertebrate orthologous Lbx1 genes, play an important role in cell fate specification processes. Among those cells that express ladybird are NB 5-6-derived glial cells. In ladybird loss-of-function mutants, the NB 5-6-derived exit glial cells are absent while overexpression of these genes leads to supernumerary glial cells of this type. Furthermore, aberrant glial cell positioning and aberrant spacing of axonal fascicles in the nerve roots observed in embryos with altered ladybird function suggest that the ladybird genes might also control directed cell movements and cell-cell interactions within the developing Drosophila ventral nerve cord. Ladybird homeobox (Lbx) transcription factors have crucial functions in muscle and nervous system development in many animals. Amniotes have two Lbx genes, but only Lbx1 is expressed in spinal cord. In contrast, teleosts have three lbx genes and we show here that zebrafish lbx1a, lbx1b, and lbx2 are expressed by distinct spinal cell types, and that lbx1a is expressed in dI4, dI5, and dI6 interneurons, as in amniotes. Our data examining lbx expression in Scyliorhinus canicula and Xenopus tropicalis suggest that the spinal interneuron expression of zebrafish lbx1a is ancestral, whereas lbx1b has acquired a new expression pattern in spinal cord progenitor cells. lbx2 spinal expression was probably acquired in the ray-finned lineage, as this gene is not expressed in the spinal cords of either amniotes or S. canicula. We also show that the spinal function of zebrafish lbx1a is conserved with mouse Lbx1. In zebrafish lbx1a mutants, there is a reduction in the number of inhibitory spinal interneurons and an increase in the number of excitatory spinal interneurons, similar to mouse Lbx1 mutants. Interestingly, the number of inhibitory spinal interneurons is also reduced in lbx1b mutants, although in this case the number of excitatory interneurons is not increased. lbx1a;lbx1b double mutants have a similar spinal interneuron phenotype to lbx1a single mutants. Taken together these data suggest that lbx1b and lbx1a may be required in succession for correct specification of dI4 and dI6 spinal interneurons, although only lbx1a is required for suppression of excitatory fates in these cells. In the mesoderm of Drosophila embryos, a defined number of cells segregate as progenitors of individual body wall muscles. Progenitors and their progeny founder cells display lineage-specific expression of transcription factors but the mechanisms that regulate their unique identities are poorly understood. Here we show that the homeobox genes ladybird early and ladybird late are expressed in only one muscle progenitor and its progeny: the segmental border muscle founder cell and two precursors of adult muscles. The segregation of the ladybird-positive progenitor requires coordinate action of neurogenic genes and an interplay of inductive Hedgehog and Wingless signals from the overlying ectoderm. Unlike so far described progenitors but similar to the neuroblasts, the ladybird-positive progenitor undergoes morphologically asymmetric division. We demonstrate that the ectopic ladybird expression is sufficient to change the identity of a subset of progenitor/founder cells and to generate an altered pattern of muscle precursors. When ectopically expressed, ladybird transforms the identity of neighbouring, Krüppel-positive progenitors leading to the formation of giant segmental border muscles and supernumerary precursors of lateral adult muscles. In embryos lacking ladybird gene function, specification of two ladybird-expressing myoblast lineages is affected. The segmental border muscles do not form or have abnormal shapes and insertion sites while the number of lateral precursors of adult muscles is dramatically reduced. Altogether our results provide new insights into the genetic control of diversification of muscle precursors and indicate a further similarity between the myogenic and neurogenic pathways. The embryonic heart precursors of Drosophila are arranged in a repeated pattern of segmental units. There is growing evidence that the development of individual elements of this pattern depends on both mesoderm intrinsic patterning information and inductive signals from the ectoderm. In this study, we demonstrate that two homeobox genes, ladybird early and ladybird late, are involved in the cardiogenic pathway in Drosophila. Their expression is specific to a subset of cardioblast and pericardial cell precursors and is critically dependent on mesodermal tinman function, epidermal Wingless signaling and the coordinate action of neurogenic genes. Negative regulation by hedgehog is required to restrict ladybird expression to two out of six cardioblasts in each hemisegment. Overexpression of ladybird causes a hyperplasia of heart precursors and alters the identity of even-skipped-positive pericardial cells. Loss of ladybird function leads to the opposite transformation, suggesting that ladybird participates in the determination of heart lineages and is required to specify the identities of subpopulations of heart cells. We find that both early Wingless signaling and ladybird-dependent late Wingless signaling are required for proper heart formation. Thus, we propose that ladybird plays a dual role in cardiogenesis: (i) during the early phase, it is involved in specification of a segmental subset of heart precursors as a component of the cardiogenic tinman-cascade and (ii) during the late phase, it is needed for maintaining wingless activity and thereby sustaining the heart pattern process. These events result in a diversification of heart cell identities within each segment. BACKGROUND: Skeletal muscle differentiation requires assembly of contractile proteins into organized myofibrils. The Drosophila ladybird homeobox gene (lad) functions in founder cells of the segmental border muscle to promote myoblast fusion and muscle shaping. Tetrapods have two homologous genes (Lbx). Lbx1 functions in migration and/or proliferation of hypaxial myoblasts, whereas the function of Lbx2 is poorly understood. RESULTS: To elucidate the role of Lbx in vertebrate myogenesis, we examined Lbx function in zebrafish. Zebrafish lbx2 transcripts appear in newly formed paraxial mesoderm and become restricted to adaxial cells, precursors of slow muscle. Slow muscles lose lbx2 expression as they differentiate, while a subset of differentiating fast muscle cells transiently expresses lbx2. Fin and hyoid muscle express lbx2 later. In contrast, lbx1b expression first appears lateral to the somites at late segmentation stages and is later restricted to fin muscle. Morpholino knockdown of Lbx1b and Lbx2 suppresses hypaxial muscle development. Moreover, knockdown of Lbx2 results in malformation of muscle fibers and reduced fusion of fast precursors, although no obvious effects on induction or specification are observed. Expression of myofilament genes, including actin and myosin, requires the engrailed repressor domain of Lbx2. CONCLUSION: Our results elucidate a new function of Lbx2 as a regulator of myofibril formation. Homeobox genes are an evolutionarily conserved class of transcription factors that are critical for development of many organ systems, including the brain and eye. During retinogenesis, homeodomain-containing transcription factors, which are encoded by homeobox genes, play essential roles in the regionalization and patterning of the optic neuroepithelium, specification of retinal progenitors and differentiation of all seven of the retinal cell classes that derive from a common progenitor. Homeodomain transcription factors control retinal cell fate by regulating the expression of target genes required for retinal progenitor cell fate decisions and for terminal differentiation of specific retinal cell types. The essential role of homeobox genes during retinal development is demonstrated by the number of human eye diseases, including colobomas and anophthalmia, which are attributed to homeobox gene mutations. In the following review, we highlight the role of homeodomain transcription factors during retinogenesis and regulation of their gene targets. Understanding the complexities of vertebrate retina development will enhance our ability to drive differentiation of specific retinal cell types towards novel cell-based replacement therapies for retinal degenerative diseases.
4,091
When is the protein OAS1 activated?
OAS1 is a IFN-stimulated gene. Antiviral response.
[34082434, 34873989, 34826092, 34108012, 33307546]
4,498
The female reproductive tract (FRT) is a major site of HIV sexual transmission. As the outermost layer of cells in the FRT, the human cervical epithelial cells (HCEs) have direct contact with HIV or infected cells. Our early work showed that supernatant (SN) from TLR3-activated HCEs contain the antiviral factors that could potently inhibit HIV replication in macrophages. However, it remains to be determined how HCEs transport the anti-HIV factors to macrophages. This follow-up study examined the role of exosomes in HCE-mediated anti-HIV activity. We found that TLR3 activation of HCEs resulted in the release of exosomes that contained multiple IFN-stimulated genes (ISGs: ISG56, OAS1, MxA, and Mx2) and the HIV restriction microRNAs (miR-28, miR-29 family members, miR-125b, miR-150, miR-382, miR-223, miR-20a, and miR-198). The depletion of exosomes from SN of TLR3-activated HCEs diminished HCE-mediated anti-HIV activity in macrophages, indicating that HCE-derived exosomes are responsible for transporting the antiviral molecules to macrophages. These in vitro findings suggest a novel antiviral mechanism by which HCEs participate in the FRT innate immunity against HIV infection. Further in vivo studies are necessary in order to develop an exosome-based delivery system for prevention and treatment of HIV infection through sexual transmission. The innate immune system has an important role in developing the initial resistance to virus infection, and the ability of oligoadenylate synthetase to overcome viral evasion and enhance innate immunity is already established in humans. In the present study, we have tried to explore the molecular and structural variations present in Sahiwal (indigenous) and crossbred (Frieswal) cattle to identify the molecular mechanism of action of OAS1 gene in activation of innate immune response. The significant changes in structural alignment in terms of orientation of loops, shortening of β-sheets and formation of 3-10 α-helix was noticed in Sahiwal and Frieswal cattle. Further, it has been observed that OAS1 from Sahiwal had better binding with APC and DTP ligand than Frieswal OAS1. A remarkable change was seen in orientation at the nucleoside base region of both the ligands, which are bound with OAS1 protein from Frieswal and Sahiwal cattle. The Molecular Dynamic study of apo and ligand complex structures was provided more insight towards the stability of OAS1 from both cattle. This analysis displayed that the Sahiwal cattle protein has more steady nature throughout the simulation and has better binding towards Frieswal in terms of APC and DTP binding. Thus, OAS1 protein is the potential target for explaining the innate immune response in Sahiwal than Frieswal.Communicated by Ramaswamy H. Sarma. BACKGROUND: Transposable elements (TEs) are repetitive sequences of viral origin that compose almost half of the human genome. These elements are tightly controlled within cells, and if activated, they can cause changes in both gene regulation and immune viral responses that have been associated with several chronic inflammatory diseases in humans. As oxidants are potent activators of TEs, and because oxidative injury is a major risk factor in relation to idiopathic pulmonary fibrosis (IPF), we hypothesized that TEs might be involved in the regulation of gene expression and so contribute to inflammation in cases of IPF. IPF is a fatal lung disease that involves the gradual replacement of the alveolar tissue with fibrotic scars as well as the accumulation of inflammatory cells in the lower respiratory tract. Although IPF is known to occur as a result of the complex interaction between age, environmental risk factors (i.e., oxidative stress) and genetics, the relative contributions of these factors to the disease remain unclear. To determine whether TEs are associated with IPF, we compared the transcriptional profiles of the genes and TEs of lung cells obtained from both healthy donors and IPF patients. RESULTS: We quantified TE and gene expression levels using a published bulk RNA-seq dataset containing 24 subjects (16 donors and eight IPF patients), including three lung-cell types per subject, as well as an scRNA-seq dataset concerning 16 subjects (eight donors and eight IPF patients). We found evidence of TE dysregulation in the alveolar type II lung cells and alveolar macrophages of the IPF patients. In addition, the activation of the LINE1 family of elements in IPF is associated with the increased expression of TE cellular regulators (MOV10, IFI16, SAMHD1, and APOBECG3), interferon-stimulating genes (ISG15, IFI6, IFI27, IFI44, and OAS1), chemokines (CX3CL1 and CXCL9), and interleukins (IL15RA). We also propose that TE derepression might be involved in the regulation of previously reported IPF candidate genes (MUC5B, CHL1, SPP1, and MMP7). CONCLUSION: Based on our findings, we propose that TE derepression plays an important role in the regulation of gene expression and can also prompt both the recruitment of inflammatory processes and the disruption of the immunological balance, which can lead to chronic inflammation in IPF. Collaborators: Millar J, Nichol A, Walsh T, Shankar-Hari M, Ponting C, Meikle J, Finernan P, Mcmaster E, Law A, Baillie JK, Paterson T, Wackett T, Armstrong R, Clark R, Coutts A, Donnelly L, Gilchrist T, Hafezi K, Macgillivray L, Maclean A, McCafferty S, Morrice K, Weaver J, Boz C, Golightly A, Ward M, Mal H, Szoor-McElhinney H, Brown A, Hendry R, Stenhouse A, Cullum L, Law D, Law S, Law R, Swets M, Day N, Taneski F, Duncan E, Parkinson N, Collier D, Wood S, Zak A, Borra C, Matharu M, May P, Alldis Z, Mitchelmore O, Bowles R, Easthope A, Bibi F, Lancoma-Malcolm I, Gurasashvili J, Pheby J, Shiel J, Bolton M, Patel M, Taylor M, Zongo O, Ebano P, Harding P, Astin-Chamberlain R, Choudhury Y, Cox A, Kallon D, Burton M, Hall R, Blowes S, Prime Z, Biddle J, Prysyazhna O, Newman T, Tierney C, Kassam J, Shankar-Hari M, Ostermann M, Campos S, Bociek A, Lim R, Grau N, Jones TO, Whitton C, Marotti M, Arbane G, Bonner S, Hugill K, Reid J, Welters I, Waugh V, Williams K, Shaw D, Roman JF, Martinez ML, Johnson E, Waite A, Johnston B, Hamilton D, Mulla S, McPhail M, Smith J, Baillie JK, Barclay L, Hope D, McCulloch C, McQuillan L, Clark S, Singleton J, Priestley K, Rea N, Callaghan M, Campbell R, Andrew G, Marshall L, McKechnie S, Hutton P, Bashyal A, Davidson N, Summers C, Polgarova P, Stroud K, Pathan N, Elston K, Agrawal S, Battle C, Newey L, Rees T, Harford R, Brinkworth E, Williams M, Murphy C, White I, Croft M, Bandla N, Gellamucho M, Tomlinson J, Turner H, Davies M, Quinn A, Hussain I, Thompson C, Parker H, Bradley R, Griffiths R, Scriven J, Nilsson A, Bates M, Dasgin J, Gill J, Puxty A, Cathcart S, Salutous D, Turner L, Duffy K, Puxty K, Joseph A, Herdman-Grant R, Simms R, Swain A, Naranjo A, Crowe R, Sollesta K, Loveridge A, Baptista D, Morino E, Davey M, Golden D, Jones J, Moreno Cuesta J, Haldeos A, Bakthavatsalam D, Vincent R, Elhassan M, Xavier K, Ganesan A, Purohit D, Abdelrazik M, Morgan J, Akeroyd L, Bano S, Lawton T, Warren D, Bromley M, Sellick K, Gurr L, Wilkinson B, Nagarajan V, Szedlak P, Cupitt J, Stoddard E, Benham L, Preston S, Laha S, Slawson N, Bradshaw Z, Brown J, Caswell M, Melling S, Bamford P, Faulkner M, Cawley K, Jeffrey H, London E, Sainsbury H, Nagra I, Nasir F, Dunmore C, Jones R, Abraheem A, Al-Moasseb M, Girach R, Padden G, Egan J, Brantwood C, Alexander P, Bradley-Potts J, Allen S, Felton T, Manna S, Farnell-Ward S, Leaver S, Queiroz J, Maccacari E, Dawson D, Delgado CC, Saluzzio RP, Ezeobu O, Ding L, Sicat C, Kanu R, Durrant G, Texeira J, Harrison A, Samakomva T, Scriven J, Willis H, Hopkins B, Thrasyvoulou L, Jackson M, Zaki A, Tibke C, Bennett S, Woodyatt W, Kent A, Goodwin E, Brandwood C, Clark R, Smith L, Rooney K, Thomson N, Rodden N, Hughes E, McGlynn D, Clark C, Clark P, Abel L, Sundaram R, Gemmell L, Brett M, Hornsby J, MacGoey P, Price R, Digby B, O'Neil P, McConnell P, Henderson P, Henderson S, Sim M, Kennedy-Hay S, McParland C, Rooney L, Baxter N, Pogson D, Rose S, Daly Z, Brimfield L, Phull MK, Hussain M, Pogreban T, Rosaroso L, Salciute E, Grauslyte L, Brealey D, Raith E, MacCallum N, Bercades G, Hass I, Smyth D, Reyes A, Martir G, Clement ID, Webster K, Hays C, Gulati A, Hodgson L, Margarson M, Gomez R, Baird Y, Thirlwall Y, Folkes L, Butler A, Meadows E, Moore S, Raynard D, Fox H, Riddles L, King K, Kimber S, Hobden G, McCarthy A, Cannons V, Balagosa I, Chadbourn I, Gardner A, Horner D, McLaughlanv D, Charles B, Proudfoot N, Marsden T, McMorrow L, Blackledge B, Pendlebury J, Harvey A, Apetri E, Basikolo C, Catlow L, Doonan R, Knowles K, Lee S, Lomas D, Lyons C, Perez J, Poulaka M, Slaughter M, Slevin K, Taylor M, Thomas V, Walker D, Harris J, Drummond A, Tully R, Dearden J, Philbin J, Munt S, Rishton C, O'Connor G, Mulcahy M, Dobson E, Cuttler J, Edward M, Norris J, Hanson K, Poole A, Rose A, Sloan B, Buckley S, Brooke H, Smithson E, Charlesworth R, Sandhu R, Thirumaran M, Wagstaff V, Suarez JC, Kaliappan A, Vertue M, Nicholson A, Riches J, Solesbury A, Kittridge L, Forsey M, Maloney G, Cole J, Davies M, Davies R, Hill H, Thomas E, Williams A, Duffin D, Player B, Radhakrishnan J, Gibson S, Lyle A, McNeela F, Patel B, Gummadi M, Sloane G, Dormand N, Salmi S, Farzad Z, Cristiano D, Liyanage K, Thwaites V, Varghese M, Meredith M, Mills G, Willson J, Harrington K, Lenagh B, Cawthron K, Masuko S, Raithatha A, Bauchmuller K, Wiles M, Ahmad N, Barker J, Jackson Y, Kibutu F, Bird S, Watson G, Martin J, Bevan E, Brown CW, Trodd D, English K, Bell G, Wilcox L, Katary A, Gopal S, Lake V, Harris N, Metherell S, Radford E, Scriven J, Moore F, Bancroft H, Daglish J, Sangombe M, Carmody M, Rhodes J, Bellamy M, Garg A, Kuravi A, Virgilio E, Ranga P, Butler J, Botfield L, Dexter C, Fletcher J, Shanmugasundaram P, Hambrook G, Burn I, Manso K, Thornton D, Tebbutt J, Penn R, Hulme J, Hussain S, Maqsood Z, Joseph S, Colley J, Hayes A, Ahmed C, Haq R, Clamp S, Kumar R, Purewal M, Baines B, Frise M, Jacques N, Coles H, Caterson J, Rai SG, Brunton M, Tilney E, Keating L, Walden A, Antcliffe D, Brett S, Gordon A, Templeton M, Rojo R, Banach D, Arias SS, Fernandez Z, Coghlan P, Williams D, Jardine C, Bewley J, Sweet K, Grimmer L, Johnson R, Garland Z, Gumbrill B, Phillips C, Ortiz-Ruiz de Gordoa L, Peasgood E, Tridente A, Shuker K, Greer S, Lynch C, Pothecary C, Roche L, Deacon B, Turner K, Singh J, Howe GS, Paul P, Gill M, Wynter I, Ratnam V, Shelton S, Naisbitt J, Melville J, Baruah R, Morrison S, McGregor A, Parris V, Mpelembue M, Srikaran S, Dennis C, Sukha A, Williams A, Verlander M, Holding K, Riches K, Downes C, Swan C, Rostron A, Roy A, Woods L, Cornell S, Wakinshaw F, Creagh-Brown B, Blackman H, Salberg A, Smith E, Donlon S, Mtuwa S, Michalak-Glinska N, Stone S, Beazley C, Pristopan V, Nikitas N, Lankester L, Wells C, Raj AS, Fletcher K, Khade R, Tsinaslanidis G, MacMahon M, Fowler S, McGregor A, Coventry T, Stewart R, Wren L, Mwaura E, Mew L, Rose A, Scaletta D, Williams F, Inweregbu K, Nicholson A, Lancaster N, Cunningham M, Daniels A, Harrison L, Hope S, Jones S, Crew A, Wray G, Matthews J, Crawley R, Carter J, Birkinshaw I, Ingham J, Scott Z, Pearson H, Howard K, Joy R, Roche S, Clark M, Purvis S, Morrison A, Strachan D, Taylor M, Clements S, Black K, Parmar C, Altabaibeh A, Simpson K, Mostoles L, Gilbert K, Ma L, Alvaro A, Thomas M, Faulkner B, Worner R, Hayes K, Gendall E, Blakemore H, Borislavova B, Goff E, Vuylsteke A, Mwaura L, Zamikula J, Garner L, Mitchell A, Mepham S, Cagova L, Fofano A, Holcombe H, Praman K, Szakmany T, Heron AE, Cherian S, Cutler S, Roynon-Reed A, Randell G, Convery K, Stammers K, Fottrell-Gould D, Hudig L, Keshet-Price J, Peters M, O'Neill L, Ray S, Belfield H, McHugh T, Jones G, Akinkugbe O, Tomas A, Abaleke E, Beech E, Meghari H, Yussuf S, Bamford A, Hairsine B, Dooks E, Farquhar F, Packham S, Bates H, McParland C, Armstrong L, Kaye C, Allan A, Medhora J, Liew J, Botello A, Anderson F, Cusack R, Golding H, Prager K, Williams T, Leggett S, Golder K, Male M, Jones O, Criste K, Marani M, Anumakonda V, Amin V, Karthik K, Kausar R, Anastasescu E, Reid K, Smith M, Hormis A, Walker R, Collier D, Duncan T, Uriel A, Ustianowski A, T-Michael H, Bruce M, Connolly K, Smith K, Partridge R, Griffin D, Mupudzi M, Muchenje N, Martin D, Filipe H, Eastgate C, Jackson C, Gratrix A, Foster L, Martinson V, Stones E, Abernathy C, Parkinson P, Reed A, Prendergast C, Rogers P, Woodruff M, Shokkar R, Kaul S, Barron A, Collins C, Beavis S, Whileman A, Dale K, Hawes J, Pritchard K, Gascoyne R, Stevenson L, Jha R, Lim L, Krishnamurthy V, Parker R, Turner-Bone I, Wilding L, Reddy A, Whiteley S, Wilby E, Howcroft C, Aspinwall A, Charlton S, Ogg B, Menzies D, Pugh R, Allan E, Lean R, Davies F, Easton J, Qiu X, Kumar S, Darlington K, Houston G, O'Brien P, Geary T, Allan J, Meikle A, Hughes G, Balasubramaniam M, Latham S, McKenna E, Flanagan R, Sathe S, Davies E, Roche L, Chablani M, Kirkby A, Netherton K, Archer S, Yates B, Ashbrook-Raby C, Cole S, Casey M, Cabrelli L, Chapman S, Hutcheon A, Whyte C, Almaden-Boyle C, Pattison N, Cruz C, Vochin A, Kent H, Thomas A, Murdoch S, David B, Penacerrada M, Lubimbi G, Bastion V, Wulandari R, Lorusso R, Valentine J, Clarke D, Serrano-Ruiz A, Hierons S, Eckbad C, Ramos L, Demetriou C, Mitchard S, White K, White N, Pitts S, Branney D, Frankham J, Watters M, Langton H, Prout R, Page V, Varghes T, Cowton A, Kay A, Potts K, Birt M, Kent M, Wilkinson A, Jude EB, Turner V, Savill H, McCormick J, Clark M, Coulding M, Siddiqui S, Mercer O, Rehman H, Potla D, Capps N, Donaldson D, Jones J, Button H, Martin T, Hard K, Agasou A, Tonks L, Arden T, Boyle P, Carnahan M, Strickley J, Adams C, Childs D, Rikunenko R, Leigh M, Breekes M, Wilcox R, Bowes A, Tiveran H, Hurford F, Summers J, Carter A, Hussain Y, Ting L, Javaid A, Motherwell N, Moore H, Millward H, Jose S, Schunki N, Noakes A, Clulow C, Sadera G, Jacob R, Jones C, Blunt M, Coton Z, Curgenven H, Ally SM, Beaumont K, Elsaadany M, Fernandes K, Ali Mohamed Ali I, Rangarajan H, Sarathy V, Selvanayagam S, Vedage D, White M, Smith M, Truman N, Chukkambotla S, Keith S, Cockerill-Taylor J, Ryan-Smith J, Bolton R, Springle P, Dykes J, Thomas J, Khan M, Hijazi MT, Massey E, Croston G, Reschreiter H, Camsooksai J, Patch S, Jenkins S, Humphrey C, Wadams B, Msiska M, Adanini O, Attwood B, Parsons P, Tatham K, Jhanji S, Black E, Dela Rosa A, Howle R, Thomas B, Bemand T, Raobaikady R, Saha R, Staines N, Daniel A, Finn J, Hutter J, Doble P, Shovelton C, Pawley C, Kannan T, Hill M, Combes E, Monnery S, Joefield T, Popescu M, Thankachen M, Oblak M, Little J, McIvor S, Brady A, Whittle H, Prady H, Chan R, Ahmed A, Morris A, Gibson C, Gordon E, Keenan S, Quinn H, Benyon S, Marriott S, Zitter L, Park L, Baines K, Lyons M, Holland M, Keenan N, Young M, Garrioch S, Dawson J, Tolson M, Scholefield B, Bi R, Richardson N, Schumacher N, Cosier T, Millen G, Higham A, Simpson K, Turki S, Allen L, Crisp N, Hazleton T, Knight A, Deery J, Price C, Turney S, Tilbey S, Beranova E, Wright D, George L, Twiss S, Cowton A, Wadd S, Postlethwaite K, Gondo P, Masunda B, Kayani A, Hadebe B, Whiteside J, Campbell R, Clarke N, Donnison P, Trim F, Leadbitter I, Butcher D, O'Sullivan S, Purewal B, Bell S, Rivers V, O'Leary R, Birch J, Collins E, Anderson S, Hammerton K, Andrews E, Higham A, Burns K, Edmond I, Salutous D, Todd A, Donnachie J, Turner P, Prentice L, Symon L, Runciman N, Auld F, Halkes M, Mercer P, Thornton L, Debreceni G, Wilkins J, Brown A, Crickmore V, Subramanian G, Marshall R, Jennings C, Latif M, Bunni L, Spivey M, Bean S, Burt K, Linnett V, Ritzema J, Sanderson A, McCormick W, Bokhari M, Kapoor R, Loader D, Ayers A, Harrison W, North J, Belagodu Z, Paramsothy R, Olufuwa O, Gherman A, Fuller B, Stuart C, Kelsall O, Davis C, Wild L, Wood H, Thrush J, Durie A, Austin K, Archer K, Anderson P, Vigurs C, Thorpe C, Thomas A, Knights E, Boyle N, Price A, Kubisz-Pudelko A, Wood D, Lewis A, Board S, Pippard L, Perry J, Beesley K, Rattray A, Taylor M, Lee E, Lennon L, Douglas K, Bell D, Boyle R, Glass L, Nauman Akhtar M, Dent K, Potoczna D, Pearson S, Horsley E, Spencer S, Phillips C, Mullan D, Skinner D, Gaylard J, Ortiz-Ruiz de Gordoa L, Barber R, Hewitt C, Hilldrith A, Shepardson S, Wills M, Jackson-Lawrence K, Gupta A, Easthope A, Timlick E, Gorman C, Otahal I, Gales A, Coetzee S, Sell C, Raj M, Peiu M, Parris V, Quaid S, Watson E, Elliott K, Mallinson J, Chandler B, Turnbull A, Quinn A, Finch C, Holl C, Cooper J, Evans A, Khaliq W, Collins A, Gude ET, Love N, van Koutrik L, Hunt J, Kaye D, Fisher E, Brayne A, Tuckey V, Jackson P, Parkin J, Brealey D, Raith E, Tariq A, Houlden H, Tucci A, Hardy J, Moncur E, Highgate J, Cowley A, Mitra A, Stead R, Behan T, Burnett C, Newton M, Heeney E, Pollard R, Hatton J, Patel A, Kasipandian V, Allibone S, Genetu RM, Otahal I, O'Brien L, Omar Z, Perkins E, Davies K, Tetla D, Pothecary C, Deacon B, Shelley B, Irvine V, Williams S, Williams P, Birch J, Goodsell J, Tutton R, Bough L, Winter-Goodwin B, Kitson R, Pinnell J, Wilson A, Nortcliffe T, Wood T, Home M, Holdroyd K, Robinson M, Hanson K, Shaw R, Greig J, Brady M, Haigh A, Matupe L, Usher M, Mellor S, Dale S, Gledhill L, Shaw L, Turner G, Kelly D, Anwar B, Riley H, Sturgeon H, Ali A, Thomis L, Melia D, Dance A, Humphreys S, Frost I, Gopal V, Godden J, Holden A, Swann S, Smith T, Clapham M, Poultney U, Harper R, Rice P, Khaliq W, Reece-Anthony R, Gurung B, Moultrie S, Odam M, Mayer A, Bellini A, Pickard A, Bryant J, Roe N, Sowter J, Butcher D, Lang K, Taylor J, Barry P, Hobrok M, Tench H, Wolf-Roberts R, McGuinness H, Loosley R, Hawcutt D, Rad L, O'Malley L, Saunderson P, Seddon G, Anderson T, Rogers N, Ruddy J, Harkins M, Taylor M, Beith C, McAlpine A, Ferguson L, Grant P, MacFadyen S, McLaughlin M, Baird T, Rundell S, Glass L, Welsh B, Hamill R, Fisher F, Smith T, Gregory J, Brown A, Campbell A, Smuts S, Kenneth Baillie J, Carson G, Alex B, Bach B, Barclay WS, Bogaert D, Chand M, Cooke GS, Docherty AB, Dunning J, da Silva Filipe A, Fletcher T, Green CA, Harrison EM, Hiscox JA, Ho AYW, Horby PW, Ijaz S, Khoo S, Klenerman P, Lim WS, Mentzer AJ, Merson L, Meynert AM, Noursadeghi M, Moore SC, Palmarini M, Paxton WA, Pollakis G, Price N, Rambaut A, Robertson DL, Sancho-Shimizu V, Scott JT, de Silva T, Sigfrid L, Solomon T, Sriskandan S, Stuart D, Tedder RS, Thomson EC, Thompson AAR, Thwaites RS, Turtle LCW, Zambon M, Hardwick H, Donohue C, Lyons R, Norman L, Pius R, Drake TM, Fairfield CJ, Knight SR, Mclean KA, Murphy D, Shaw CA, Dalton J, Girvan M, Saviciute E, Roberts S, Harrison J, Marsh L, Connor M, Halpin S, Jackson C, Gamble C, Leeming G, Wham M, Greenhalf W, Shaw V, McDonald S, Keating S, Ganna A, Sulem P, van Heel DA, Cordioli M, Sveinbjornsson G, Niemi MEK, Shelton JF, Shastri AJ, Ye C, Weldon CH, Filshtein-Sonmez T, Coker D, Symons A, Esparza-Gordillo J, Aslibekyan S, Auton A, Krieger JE, Marques E, Jannes CE, Mari F, Daga S, Baldassarri M, Benetti E, Furini S, Fallerini C, Fava F, Valentino F, Doddato G, Giliberti A, Tita R, Amitrano S, Bruttini M, Croci S, Meloni I, Pinto AM, Frullanti E, Mencarelli MA, Rizzo CL, Montagnani F, Di Sarno L, Tommasi A, Palmieri M, Emiliozzi A, Fabbiani M, Rossetti B, Zanelli G, Bargagli E, Bergantini L, D'Alessandro M, Cameli P, Bennet D, Anedda F, Marcantonio S, Scolletta S, Franchi F, Mazzei MA, Guerrini S, Conticini E, Cantarini L, Frediani B, Tacconi D, Spertilli C, Feri M, Donati A, Scala R, Guidelli L, Spargi G, Corridi M, Nencioni C, Croci L, Caldarelli GP, Spagnesi M, Piacentini P, Bandini M, Desanctis E, Cappelli S, Canaccini A, Verzuri A, Anemoli V, Ognibene A, Vaghi M, D'Arminio Monforte A, Merlini E, Mondelli MU, Mantovani S, Ludovisi S, Girardis M, Venturelli S, Sita M, Cossarizza A, Antinori A, Vergori A, Rusconi S, Siano M, Gabrieli A, Riva A, Francisci D, Schiaroli E, Scotton PG, Andretta F, Panese S, Scaggiante R, Gatti F, Parisi SG, Castelli F, Quiros-Roldan ME, Magro P, Zanella I, Della Monica M, Piscopo C, Capasso M, Russo R, Andolfo I, Iolascon A, Fiorentino G, Carella M, Castori M, Merla G, Aucella F, Raggi P, Marciano C, Perna R, Bassetti M, Di Biagio A, Sanguinetti M, Masucci L, Valente S, Mandalà M, Giorli A, Salerni L, Zucchi P, Parravicini P, Menatti E, Baratti S, Trotta T, Giannattasio F, Coiro G, Lena F, Coviello DA, Mussini C, Bosio G, Martinelli E, Mancarella S, Tavecchia L, Crotti L, Picchiotti N, Gori M, Gabbi C, Sanarico M, Ceri S, Pinoli P, Raimondi F, Biscarini F, Stella A.
4,092
Does Amblyopia affect the eye?
Amblyopia, also called lazy eye, is a disorder of sight in which the brain fails to process inputs from one eye and over time favors the other eye. It results in decreased vision in an eye that otherwise typically appears normal
[22883843, 34499336, 31852024, 457357, 34679448, 9698332, 29687838, 28346616, 31161888, 7799459, 31833253, 22789926, 12913328, 18025648, 20671288, 20826682, 20922043, 31281344, 21870913, 31712066, 2062534, 14680777, 34682200, 31453915, 26917086, 25637856, 29905124, 24386790, 19146342, 3278568, 6853107, 21061879, 19195640, 23894908]
4,499
OBJECTIVE: To confirm if using a neutral density filter (NDF) affects eyes with strabismic amblyopia differently compared to fellow non-amblyopic eyes, and to determine if a similar effect could be observed when using a NDF during peripheral visual field testing. DESIGN: Prospective controlled case series. PARTICIPANTS: 19 subjects with strabismic amblyopia with visual acuities between 20/400 and 20/40 in their affected eyes were recruited to the study. Fellow non-amblyopic eyes served as the control group. METHODS: Visual acuity in both eyes was assessed using a projected Snellen eye chart with two NDFs (0.4 and 3.0 densities). Visual fields were assessed using a Humphrey perimeter using one NDF (0.4 density). Best corrected visual acuity and visual fields were also recorded. RESULTS: When using a 3.0 NDF, visual acuity was reduced in all eyes (p < 0.0001). When using a 0.4 NDF, visual acuity was significantly improved in eyes with strabismic amblyopia compared to unfiltered conditions (p = 0.0011). There was no significant effect by NDFs on visual field testing in eyes with strabismic amblyopia or fellow non-amblyopic eyes. CONCLUSIONS: Neutral density filters affect eyes with strabismic amblyopia differently than they do non-amblyopic eyes. A significant improvement in visual acuity of eyes with strabismic amblyopia was observed when using a 0.4 NDF compared to non-amblyopic eyes. Visual acuity was reduced in amblyopic as well as non-amblyopic eyes when viewing through a 3.0 NDF. No significant change in visual fields was observed when using a 0.4 NDF in amblyopic or non-amblyopic eyes. Amblyopia is the most common cause of monocular visual impairment in children, with a prevalence of 2-3%. Not only is visual acuity reduced in one eye but binocular vision is affected, fellow eye deficits may be present, eye-hand coordination and reading can be affected, and self-perception may be diminished. New technologies for preschool vision screening hold promise for accessible, early, and accurate detection of amblyopia. Together with recent advances in our theoretical understanding of amblyopia and technological advances in amblyopia treatment, we anticipate improved visual outcomes for children affected by this very common eye condition. This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors. BACKGROUND: The role of optometrists in paediatric visual assessment must compliment the role of other eye-care practitioners at all levels of care. This study was undertaken to determine if optometrists in Ghana screen, diagnose and manage paediatric ocular conditions (for example, strabismus, amblyopia), and further assessed if optometrists in Ghana have the requisite paediatric instrumentation in their practices. METHODS: This was a cross-sectional descriptive survey involving optometrists in both public and private eye-care sectors in Ghana. A paediatric visual assessment questionnaire was sent to all registered optometrists in Ghana. The contents of the questionnaire evaluated areas of vision assessment, refraction, and previous diagnosis and management, which were matched with practice characteristics such as location, type of practice and type of employment. Chi-squared statistic was used to test associations between variables. RESULTS: Responses were obtained from 140 optometrists out of the 326 registered optometrists, representing a response rate of 46 per cent. Overall, less than half of respondents (64 which represents 46 per cent) assessed themselves as practising full-scope paediatric eye care. These self-assessment views were more common among optometrists at the regional level (111: 79.3 per cent), followed by the district (20: 14.3 per cent) and sub-district levels (nine: 6.4 per cent) (χ2 = 4.774, p < 0.05), but was not influenced by type of employment, type of practice and level of training (p > 0.05). In addition, the study revealed that many respondents were more likely to assess pre-schoolers' visual acuity (VA) (121: 96.0 per cent), do refraction (109: 88.6 per cent) and perform binocular vision (BV) assessment (93: 76.9 per cent) compared to the toddlers' VA (72: 55.4 per cent), refraction (57: 46 per cent) and BV assessment (68: 56.2 per cent). CONCLUSION: Full-scope paediatric eye care services among optometrists in Ghana is limited. The contrast sensitivity function of both eyes of subjects with functional amblyopia has been measured. A clinically significant difference was found between the amblyopic and the normal eye. It appears that the functionally amblyopic eye takes more information from the peripheral parts of the stimulus than does the normal eye. The sensitivity of the normal eye increases linearly with increasing width of the stimulus to show a knee at a certain number of grating lines, whereafter the sensitivity remains constant. The sensitivity of the amblyopic eye initially rises much faster than that of the normal eye with increasing stimulus width. In the amblyopic eye, there is no definite linear relationship between width of stimulus and the contrast sensitivity and no definite knee in the curve at which maximum sensitivity is reached. There is no consensus on whether amblyopia affects the retinal vascular plexus and morphology. Previous studies focused on the differences between amblyopic patients and normal controls without evaluating amblyopic eyes after patching. To evaluate differences in the superficial vascular density of amblyopic eyes, normal eyes, and amblyopic eyes reaching normal BCVA after patch therapy, OCTA was used. All patients underwent a comprehensive ophthalmological examination, including visual acuity, refraction, ocular motility tests, and anterior and posterior segment examination. OCTA was performed by an expert physician using the Zeiss Cirrus 5000-HD-OCT Angioplex (Carl Zeiss, Meditec, Inc., Dublin, OH, USA). OCTA scans were performed using a 3 × 3 mm2 and 6 × 6 mm2 fovea-centered image setting. The mean outer macular vessel density in the previously amblyopic group was 19.15 ± 0.51%. This was statistically significantly higher than in both the amblyopic group (18.70 ± 1.14%) and the normal controls (18.18 ± 1.40%) (p = 0.014). The previously amblyopic group also significantly differed from both normal controls and amblyopic eyes with regards to the inner (p = 0.011), outer (p = 0.006), and full (p = 0.003) macular perfusion. Finally, linear regression analysis revealed that BCVA was linearly correlated to outer perfusion in amblyopic (p = 0.003) and ex amblyopic eyes (p < 0.001). Considering the cross-sectional nature of our study, from our results, we can only hypothesize a possible correlation between light stimulation and retinal vasculature development. However, further longitudinal studies are needed to support this hypothesis. OBJECTIVE: Amblyopia or lazy eye is a common visual problem affecting children that cannot correct with lenses. Nitric oxide synthase (NOS) is a critical enzyme that regulates the activity of nitric oxide (NO), a key signaling molecule with multiple roles in many tissues. Among its many activities, NOS has been proposed to be required for normal eye development and altered NOS expression can lead to perturbations in eye development and vision. MATERIALS AND METHODS: To examine the potential role of neuronal NOS (nNOS) in vision loss, we generated a model of monocular deprivation amblyopia in rats. After suturing one eye, we examined several parameters of neural activity and nNOS expression in the retina 7, 14 and 28 days later. RESULTS: We found the rapid and progressive loss of neural activity in the retina of sutured eyes compared to non-treated and control eyes. The sutured eyes also showed decreased expression of nNOS at the protein and mRNA levels, indicating a strong correlation between nNOS expression and retina activity. CONCLUSIONS: These data suggest a potential role for nNOS activity in vision loss, opening potential avenues for therapeutic intervention. Unilateral amblyopia is a visual disorder that arises after selective disruption of visual input to one eye during critical periods of development. In the clinic, amblyopia is understood as poor visual acuity in an eye that was deprived of pattern vision early in life. By its nature, however, amblyopia has an adverse effect on the development of a binocular visual system and the interactions between signals from two eyes. Visual functions aside from visual acuity are impacted, and many studies have indicated compromised sensitivity in the fellow eye even though it demonstrates normal visual acuity. While these fellow eye deficits have been noted, no overarching theory has been proposed to describe why and under what conditions the fellow eye is impacted by amblyopia. Here, we consider four explanations that may account for decreased fellow eye sensitivity: the fellow eye is adversely impacted by treatment for amblyopia; the maturation of the fellow eye is delayed by amblyopia; fellow eye sensitivity is impacted for visual functions that rely on binocular cortex; and fellow eye deficits reflect an adaptive mechanism that works to equalize the sensitivity of the two eyes. To evaluate these ideas, we describe five visual functions that are commonly reported to be deficient in the amblyopic eye (hyperacuity, contrast sensitivity, spatial integration, global motion, and motion-defined form), and unify the current evidence for fellow eye deficits. Further research targeted at exploring fellow eye deficits in amblyopia will provide us with a broader understanding of normal visual development and how amblyopia impacts the developing visual system. 1. Sometimes called "lazy eye," amblyopia is poor vision in an eye that did not develop normal sight during early childhood. Amblyopia is common, affecting approximately 2 or 3 out of every 100 people. The best time to correct amblyopia is during infancy or early childhood. 2. Amblyopia has three major causes: strabismus (misaligned eyes), unequal focus (refractive error), and cloudiness in the normally clear eye tissues. 3. To correct amblyopia, a child must be made to use the weak eye. This is usually done by patching or covering the strong eye. Amblyopia cannot be cured by treating the cause alone; the weaker eye must be made stronger in order to see normally. Although postmortem morphological changes in the lateral geniculate nucleus (LGN) have been reported in human amblyopia, LGN function during monocular viewing by amblyopic eyes has not been documented in humans. We used functional magnetic resonance imaging (fMRI) to study monocular visual activation of the LGN in a patient with anisometropic amblyopia. Four normal subjects, a patient with optic neuritis and a patient with anisometropic amblyopia were studied with fMRI at 1.5 T during monocular checkerboard stimulation. Activated areas in the LGN and visual cortex were identified after data processing (motion correction and spatial normalization) with SPM99. In the 4 normal subjects, comparable activation of the LGN and visual cortex was obtained by stimulation of either the right or left eye. In the patient with unilateral optic neuritis, activation of the LGN and visual cortex was markedly decreased when the affected eye was stimulated. Similarly, decreased activation of the LGN as well as the visual cortex by the affected eye was demonstrated in the patient with anisometropic amblyopia. Our preliminary results suggest that activation of the LGN is diminished during monocular viewing by affected eyes in anisometropic amblyopia. fMRI appears to be a feasible method to study LGN activity in human amblyopia. We compared the optic nerve head topography and retinal nerve fiber layer (RNFL) thickness of the strabismic and anisometropic amblyopic eyes with the normal fellow eyes and age-matched controls and concluded that, although amblyopia is a functional visual loss, RNFL thickness and optic nerve head topographic changes in strabismic and anisometropic amblyopic eyes may be affected by amblyopia. Further histopathological and clinic confirmations are needed. PURPOSE: To investigate, using optical coherence tomography (OCT), whether retinal nerve fiber layer thickness (RNFLT) is affected in amblyopic eyes. METHODS: Using OCT (Stratus OCT™ [Carl Zeiss, Dublin, CA]), the RNFLT was measured in 26 patients with persistent unilateral amblyopia and in 25 patients with recovered unilateral amblyopia. The RNFLT was compared between the affected and fellow eyes in patients with persistent amblyopia and in those with recovered amblyopia, and between the amblyopic eyes of patients with persistent amblyopia and the previously amblyopic eyes of patients with recovered amblyopia. RESULTS: In patients with persistent amblyopia and in those with recovered amblyopia, the affected eyes were significantly more hyperopic than the fellow eyes. The average (±standard deviation) RNFLT measured 105.5 ± 14.0 μm for the persistently amblyopic eyes; this value did not significantly differ from that of the fellow eyes (105.2 ± 13.0 μm) or the previously amblyopic eyes of recovered amblyopia (107.1 ± 11.7 μm). Also, logistic regression analysis adjusting for refraction showed no significant difference in the RNFLT between the persistently amblyopic eyes and the previously amblyopic eyes. CONCLUSIONS: Our results indicate that there is no significant change in the RNFLT in amblyopic eyes. Amblyopia is a neurodevelopmental visual disorder arising from decorrelated binocular experience during the critical periods of development. The hallmark of amblyopia is reduced visual acuity and impairment in binocular vision. The consequences of amblyopia on various sensory and perceptual functions have been studied extensively over the past 50 years. Historically, relatively fewer studies examined the impact of amblyopia on visuomotor behaviours; however, research in this area has flourished over the past 10 years. Therefore, the aim of this review paper is to provide a comprehensive review of current knowledge about the effects of amblyopia on eye movements, upper limb reaching and grasping movements, as well as balance and gait. Accumulating evidence indicates that amblyopia is associated with considerable deficits in visuomotor behaviour during amblyopic eye viewing, as well as adaptations in behaviour during binocular and fellow eye viewing in adults and children. Importantly, due to amblyopia heterogeneity, visuomotor development in children and motor skill performance in adults may be significantly influenced by the etiology and clinical features, such as visual acuity and stereoacuity. Studies with larger cohorts of children and adults are needed to disentangle the unique contribution of these clinical characteristics to the development and performance of visuomotor behaviours. Visual processing is thought to involve initial local analyses that are subsequently integrated globally to derive functional representations of structure that extends over large areas of visual space. Amblyopia is a common deficit in spatial vision that could be based on either unreliable local estimates of image structure, irregularities in global image integration or a combination of errors at both these stages. The purpose of this study was to quantify the integration of local spatial information in amblyopia with global orientation discrimination and inter-ocular matching tasks. Stimuli were composed of pseudo-random arrays of highly visible and resolvable features (Gabor patches) whose local orientation and position were drawn from global distributions whose mean and variance statistics were systemically varied. Global orientation discrimination thresholds in both the amblyopic and fellow eye were elevated. The orientational and positional variances perceived by the amblyopic eye were matched by stimuli with higher variances perceived in the fellow eye. It would appear that amblyopes are able to integrate orientation information across visual space but the global representation of local structure shows greater variability compared to normal. It is this increased spatial uncertainty that underlies the spatial deficit in amblyopia. Amblyopia is a reduced best-corrected visual acuity of one or both eyes that cannot be attributed to a structural abnormality; it is a functional reduction in the vision of an eye caused by disuse during a critical period of visual development. It is considered the leading cause of visual defects in children. With early diagnosis and treatment, children with amblyopia can significantly improve their vision. However, if it is neglected and not treated during childhood, unfortunately, it permanently decreases vision. Therefore, prevention, detection, and treatment largely depend on parents. This article explores parents' perspectives on amblyopia and routine examination of their children's eyes. A cross-sectional study used an electronic questionnaire consisting of five main sections to assess the level of awareness of amblyopia among parents. As a result, a total of 325 participants were included in our analysis. 209 (64.3%) were mothers, and 116 (35/7%) were fathers. The age groups were 35-50 years of age (61.5%), 20-34 years (23.4%), and older than 50 years (15%). Participants with a history of amblyopia numbered 23 (7.1%), and 39 had an amblyopic child (12%). A good awareness level of amblyopia among parents was found in only 10 (3%) participants, a fair awareness level in 202 (62%), and 113 (35%) participants were classified as having a poor awareness level of amblyopia. Only 13.8% of the parents took their children for yearly routine eye exams, while the majority (72%) took their children only if they had a complaint, and 14.2% took them for eye checkups only before school entry. In conclusion, parents' awareness of amblyopia in Tabuk City, KSA, was low. In addition, a limited proportion of parents reported consistently taking their children for routine eye exams. Therefore, raising awareness should be considered in public education regarding the disease. Amblyopia is defined as a loss of letter recognition visual acuity in the affected eye; however, studies in both nonhuman primates and man have shown that other important aspects of vision, including color, motion, and contour perception, are also abnormal. The anatomical changes that occur in the lateral geniculate nucleus and visual cortex following monocular visual deprivation affect both eyes and follow very different patterns with deprivation that begins at different ages and differ markedly in the magnocellular and parvocellular pathways. The interactions between the eyes and the requirements for recovery are very different following onset at different ages and differ for magnocellular and parvocellular pathways. Electrophysiological and psychophysical studies in man show different patterns of change in patients with strabismic amblyopia of early and late onset and abnormalities of color and motion processing that affect both amblyopic and fellow eyes and differ with age of onset. Abnormal visual experience also has more general effects on development, with amblyopic children showing abnormalities of eye-hand coordination when using either their amblyopic or fellow eyes, and abnormalities of reading. Differential effects of abnormal visual experience and treatment on magnocellular and parvocellular pathways may account for some of the visual deficits and treatment failures seen in amblyopia. Amblyopia is a developmental disorder resulting in poor vision in one eye. The mechanism by which input to the affected eye is prevented from reaching the level of awareness remains poorly understood. We recorded simultaneously from large populations of neurons in the supragranular layers of areas V1 and V2 in 6 macaques that were made amblyopic by rearing with artificial strabismus or anisometropia, and 1 normally reared control. In agreement with previous reports, we found that cortical neuronal signals driven through the amblyopic eyes were reduced, and that cortical neurons were on average more strongly driven by the non-amblyopic than by the amblyopic eyes. We analyzed multiunit recordings using standard population decoding methods, and found that visual signals from the amblyopic eye, while weakened, were not degraded enough to explain the behavioral deficits. Thus additional losses must arise in downstream processing. We tested the idea that under monocular viewing conditions, only signals from neurons dominated by - rather than driven by - the open eye might be used. This reduces the proportion of neuronal signals available from the amblyopic eye, and amplifies the interocular difference observed at the level of single neurons. We conclude that amblyopia might arise in part from degradation in the neuronal signals from the amblyopic eye, and in part from a reduction in the number of signals processed by downstream areas. Amblyopia is a developmental disorder that affects the spatial vision of one or both eyes in the absence of an obvious organic cause; it is associated with a history of abnormal visual experience during childhood. Subtypes have been defined based on the purported etiology, namely, strabismus (misaligned eyes) and/or anisometropia (unequal refractive error). Here we consider the usefulness of these subclassifications. Amblyopia or "lazy eye" represents a disorder of the visual system characterized by poor vision in an eye that is otherwise physically normal. Anisometropia, the condition in which the two eyes have an unequal refractive error, is considered the second most common cause of amblyopia. The purpose of this study is to determine the efficiency of HTS Amblyopia iNet Software by studying the progress of visual acuity, contrast sensitivity and stereopsis vision in anisometropic amblyopic children. 5 patients (age: 5-13 years), treated with HTS Amblyopia iNet Software at OftaTotal Clinic from Sibiu, between 2010-2013, participated in this clinical trial. Initially, visual acuity ranged from 0.25 to 0.8, contrast sensitivity from 1.35 to 1.65 Log. Unit. and 1 patient presented stereoscopic vision. After treatment, visual acuity ranged from 0.8 to 1, contrast sensitivity from 1.35 to 1.95 Log. Unit., also all patients presented stereoscopic vision. HTS Amblyopia iNet Software represents an effective modern approach in the treatment of anisometropic amblyopia. Amblyopia is a disorder of visual acuity in one eye, thought to arise from suppression by the other eye during development of the visual cortex. In the attentional blink, the second of two targets (T2) in a Rapid Serial Visual Presentation (RSVP) stream is difficult to detect and identify when it appears shortly but not immediately after the first target (T1). We investigated the attentional blink seen through amblyopic eyes and found that it was less finely tuned in time than when the 12 amblyopic observers viewed the stimuli with their preferred eyes. T2 performance was slightly better through amblyopic eyes two frames after T1 but worse one frame after T1. Previously (A. V. Popple & D. M. Levi, 2007), we showed that when the targets were red letters in a stream of gray letters (or vice versa), normal observers frequently confused T2 with the letters before and after it (neighbor errors). Observers viewing through their amblyopic eyes made significantly fewer neighbor errors and more T2 responses consisting of letters that were never presented. In normal observers, T1 (on the rare occasions when it was reported incorrectly) was often confused with the letter immediately after it. Viewing through their amblyopic eyes, observers with amblyopia made more responses to the letter immediately before T1. These results suggest that childhood suppression of the input from amblyopic eyes disrupts attentive processing. We hypothesize reduced connectivity between monocularly tuned lower visual areas, subcortical structures that drive foveal attention, and more frontal regions of the brain responsible for letter recognition and working memory. Perhaps when viewing through their amblyopic eyes, the observers were still processing the letter identity of a prior distractor when the color flash associated with the target was detected. After T1, unfocused temporal attention may have bound together erroneously the features of succeeding letters, resulting in the appearance of letters that were not actually presented. These findings highlight the role of early (monocular) visual processes in modulating the attentional blink, as well as the role of attention in amblyopic visual deficits. Amblyopia, commonly known as "lazy eye," is a frequent but preventable cause of decreased vision. An anatomically normal eye, free from organic disease, has reduced vision compared with the other eye. Ptosis of the eyelids, strabismus, certain refractive disorders and other abnormalities may precede amblyopia. If discovered early enough, usually before the age of five, amblyopia can often be reversed. Experimental amblyopia in animal models causes a reduction of cell sizes in lateral geniculate nucleus (LGN) laminae connected with the amblyopic eye. However, direct evidence that the human amblyopic visual system is affected in a similar manner has been lacking. Histologic study of the LGNs from a patient with ophthalmologically confirmed anisometropic amblyopia shows a decrease of cell sizes in the parvocellular layers innervated by the amblyopic eye. This decrease was more pronounced in laminae receiving crossed fibers. To our knowledge this is the first report about structural alterations in the afferent visual pathway of a human amblyope and the data reaffirm the validity of the monkey model for further study of the basic mechanisms in amblyopia. Amblyopia is defined as reduced and uncorrectable vision in a structurally normal eye. Early detection of amblyopia is very important. This can be accomplished through screening programs designed to identify amblyopia risk factors. Testing can be performed by trained teachers, technicians, school nurses and pediatricians as well as by eye care professionals. Once a child is identified as having an amblyopia risk factor it is crucial that the parents follow up with a pediatric ophthalmologist for a comprehensive examination. Amblyopia is the leading cause of monocular vision loss in the United States for adults under the age of 40. Amblyopia is amenable to therapy and is cost effective to treat. It is believed that earlier therapy for amblyopia provides better outcomes, but treatment has been shown effective even in some older children. In this paper, studies are cited regarding treatment of amblyopia. PURPOSE: To learn whether electrophysiological changes indicating amblyopia occur even in the absence of clinically recognizable amblyopia. DESIGN: Prospective study. METHODS: Four consecutive infants between 7 and 19 months of age with unilateral periocular vascular lesions that intermittently obstructed vision in the affected eye and no clinical evidence of amblyopia were evaluated. No child had anisometropia greater than 0.50 diopter in the greatest meridian or strabismus. Sweep visual evoked potential vernier acuity was measured under monocular viewing conditions with the fellow eye tested as the control. RESULTS: Response amplitudes and acuity thresholds were significantly diminished in the affected eyes. A phase analysis showed slowing of the response in the affected eyes compared with the control eyes. CONCLUSIONS: An amblyopia-like effect on vernier acuity occurred in infants with unilateral periocular vascular birthmarks when the lesion caused intermittent occlusion of the eye. Whether long-term effects will occur is unknown, but children with no clinically apparent amblyopia in the setting of a vascular mark or other cause of intermittent occlusion of the visual axis should be followed, since these electrophysiology findings suggest amblyopia may be present. Amblyopia is characterised by decrease in vision in one or both eyes as a result of processing defect in the visual pathways of the brain. It is considered an irreversible process if detected in the adult age group. This study was conducted from July 1 to December 31, 2010, at Shifa Foundation Community Health Centre, Islamabad, to determine if anisometropic amblyopia detected in adults can be reversed. A total of 15 adults, 11 (73.33%) males and 4 (26.66%) females, were managed for anisometropic amblyopia. All the patients were prescribed full cycloplegic correction in the anisometropic eye simultaneously with part-time occlusion therapy. Success was defined as visual acuity of 6/18 or better at the end of the therapy. All patients were required to complete a structured questionnaire regarding their experiences with the therapy. Reversal of amblyopia was observed in 11 (73.33%) patients who felt more confident about performing tasks for which they had earlier considered themselves unsuitable. Poor compliance was responsible for not producing the desired outcome in 4 (26.66%) patients. Anisometropic amblyopia in adults is reversible with dedicated efforts on behalf of both the ophthalmologist and the patient.
4,093
Which drugs are included in the Lonsurf combination pill?
Lonsurf is an oral fixed dose combination of trifluridine and tipiracil that is used for cancer treatment.
[32891715, 30445951, 32801768, 27568360, 27431756, 34207352, 26197742, 31489588, 26609205, 34034550, 28315543, 31002008, 33294265, 33468799]
4,500
BACKGROUND: Trifluridine/tipiracil (TAS-102, Lonsurf®), a novel oral anti-tumor agent combining an anti-neoplastic thymidine-based nucleoside analogue (trifluridine, FTD) with a thymidine phosphorylase inhibitor (tipiracil hydrochloride, TPI) presents a new treatment option for metastatic colorectal cancer (mCRC) patients refractory or intolerant to standard therapies. FTD/TPI was approved in the European Union (EU) in April 2016 and launched on the German market in August 15, 2016. METHODS: We investigated the characteristics of patients (pts) with mCRC treated with FTD/TPI at 118 centers in Germany from January 12 to August 14, 2016 and analyzed the safety in a clinical real-world setting. RESULTS: In Germany, a total of 226 mCRC patients were included into a compassionate-use-program (CUP) and received FTD/TPI. For 45.5% of patients (n = 101), 253 adverse events (AE) were documented, most of them drug-related (n = 135). From January 12 (2016) to March 2 (2017), 124 serious adverse events (SAE) were reported (74 drug related). The most common serious adverse drug reactions (SADR) were leukopenia (12 events), neutropenia (8 events), anemia (7 events), diarrhea and nausea (5 events each) (observation period January 12 2016 to October 7 2016). In total, 122 patients (54%) discontinued FTD/TPI treatment, mostly due to progression (n = 75) followed by AEs (n = 21), deaths (n = 16), and non-specified reasons (n = 16). Interestingly, 12 patients with ECOG PS ≥2 achieved up to 3 cycles of FTD/TPI and in this patient population only 3 treatment discontinuations due to AEs were documented and the safety profile was comparable to the entire population. CONCLUSION: The patient characteristics as well as the safety profile of FTD/TPI documented in the German CUP were consistent with those reported in the pivotal trial RECOURSE without unexpected safety signals. Trifluridine/tipiracil or TAS-102 (Taiho Oncology, Lonsurf®, Princeton, NJ, USA) is a combination tablet of trifluridine, a thymidine-based nucleoside analog, and tipiracil, a thymidine phosphorylase inhibitor, in a 1:0.5 molar ratio. This drug was first approved for use in metastatic colorectal cancer patients. Recently, the U S Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have granted approval of trifluridine/tipiracil for treatment of metastatic gastric and gastroesophageal junction adenocarcinoma in patients following at least two lines of chemotherapy including fluoropyrimidine and platinum chemotherapy agents, as well as taxanes or irinotecan. This approval was granted after the findings from first a Phase II trial (EPOC1201) investigating trifluridine/tipiracil, and later a global Phase III trial (TAGS trial) that compared trifluridine/tipiracil vs placebo with best supportive care. Both trials primarily utilized trifluridine/tipiracil at a dose of 35 mg/m2 twice daily. In the EPOC1201 trial, the primary end point of disease control rate was greater than 50% after eight weeks of therapy. The most common grade three or four adverse event was neutropenia; additional toxicities included leukopenia, anemia, and anorexia. In the TAGS trial, overall survival in patients treated with trifluridine/tipiracil (5.7 months) was significantly improved as compared to the placebo-controlled group (3.6 months). Treatment with trifluridine/tipiracil not only did not impair quality of life but also tended to reduce the risk of deterioration of quality of life. The results of these studies along with the subsequent FDA and EMA approval have generated an important breakthrough in regard to treatment options for patients with refractory metastatic gastric or gastroesophageal junction adenocarcinoma. Trifluridine/tipiracil (Lonsurf(®)) is a novel, orally active, antimetabolite agent comprised of trifluridine, a thymidine-based nucleoside analogue, and tipiracil, a potent thymidine phosphorylase inhibitor. Trifluridine is incorporated into DNA via phosphorylation, ultimately inhibiting cell proliferation. Tipiracil increases systemic exposure of trifluridine when coadministered. Trifluridine/tipiracil has recently been approved for the treatment of adult patients with metastatic colorectal cancer (mCRC) who are refractory to or are not considered candidates for, current standard chemotherapy and biological therapy in the EU and USA and in unresectable advanced or recurrent CRC in Japan. The approved regimen of oral twice-daily trifluridine/tipiracil (35 mg/m(2) twice daily on days 1-5 and 8-12 of each 28-day cycle) significantly improved overall survival and progression-free survival and was associated with a significantly higher disease control rate than placebo when added to best supportive care in the multinational, pivotal phase III trial (RECOURSE) and a phase II Japanese trial. Trifluridine/tipiracil was associated with an acceptable tolerability profile, with adverse events generally being managed with dose reductions, temporary interruptions in treatment or administration of granulocyte-colony stimulating factor. The most common grade 3-4 adverse events (≥10 %) were anaemia, neutropenia, thrombocytopenia and leukopenia. In conclusion, trifluridine/tipiracil is a useful additional treatment option for the management of mCRC in patients who are refractory to, or are not considered candidates for, currently available therapies. Within the past several years, no chemotherapy has been sufficient to increase the overall survival of patients with chemorefractory colorectal cancer. TAS-102 (Lonsurf) is an oral fluoropyrimidine that is formed by the combination of 2 active drugs: trifluridine (a nucleoside analog) and tipiracil hydrochloride (a thymidine phosphorylase inhibitor). This drug extended the median overall survival by approximately 2 months compared with placebo in a randomized phase III trial composed of Asian and non-Asian patients with refractory (or intolerant) metastatic colorectal cancer. The clinical development of TAS-102 began approximately a decade ago and included 2 pivotal randomized studies, which are discussed in this review. This drug has just been approved in Japan, and as soon as possible, it will be marketed in Western countries as well; it will therefore become the standard of care for this patient population. The optimal combination of TAS-102 with other agents, as well as the mechanism of resistance to this regimen should be defined in the near future. Trifluridine/tipiracil (Lonsurf®) is a fixed-dose combination tablet comprising trifluridine, an antineoplastic nucleoside analogue, and tipiracil, a thymidine phosphorylase inhibitor. Trifluridine/tipiracil has recently been granted an additional indication in the USA for the treatment of metastatic gastric cancer, including gastroesophageal junction adenocarcinoma, in patients who have been previously treated with at least two systemic treatment regimens, and has received a positive opinion for this indication in the EU. In the large pivotal phase III TAGS trial, trifluridine/tipiracil plus best supportive care (BSC) significantly prolonged overall survival (OS; primary endpoint) compared with placebo plus BSC in this patient group. Progression-free survival (PFS) and the disease control rate were also improved with trifluridine/tipiracil relative to placebo. Health-related quality of life was not adversely affected by the addition of trifluridine/tipiracil to BSC and time to deterioration of Eastern Cooperative Oncology Group (ECOG) performance status was significantly delayed. The most common adverse events were mainly haematological (neutropenia, leucopenia and anaemia) and gastrointestinal (nausea, vomiting and diarrhoea), and were generally manageable with dosage modifications and/or supportive care. Adverse events ≥ Grade 3 were most frequently haematological in nature. Thus, trifluridine/tipiracil provides a valuable and much needed treatment option for patients with metastatic gastric or gastroesophageal junction adenocarcinoma that has progressed on at least two prior therapies. Evolocumab (Repatha) for patients with hypercholesterolemia whose condition has not been controlled by statins and other therapies; trifluridine/tipiracil (Lonsurf) for metastatic colorectal cancer; and blood coagulation factor VIII (Nuwiq) for adults and children with hemophilia A. In the RECOURSE trial which lead to its accreditation, Lonsurf (trifluridine/tipiracil) was shown to extend progression free survival (PFS) by 1.8 months in metastatic colorectal cancer. This Trust audit aims to assess the average quantity of cycles of Lonsurf received by participants and the length of time it extends PFS. Similarly, to identify how many participants required a dose-reduction or experienced toxicities which necessitated supportive therapies. Quantitative data was collected retrospectively from all participants who had received ≥1 cycle of Lonsurf from The Clatterbridge Cancer Centre (CCC) from 2016 until June 2020. Participant electronic patient records were accessed to identify toxicity grading, length of treatment received, the date progression was identified, if dose reductions were applied and if supportive therapies were administered. Lonsurf extends PFS in patients with metastatic colorectal cancer at CCC by 3.0 months (95% CI: 2.73-3.27) and average treatment length was 2.4 months. However, 78 participants (41.5%) received a dose reduction due to toxicities. A total of 955 toxicities were recorded by participants; the most commonly reported toxicities irrespective of grade were fatigue (33.8%), diarrhoea (13.8%) and nausea (12.3%). The most common grade ≥3 toxicities were constipation and infection. The most frequently utilised supportive therapies were loperamide (49.6%) and domperidone (49.1%). Granulocyte colony stimulating factor (GCSF) was required by patients on 5 occasions (0.3%) in total. Lonsurf extends median PFS in patients with metastatic colorectal cancer by 3.0 months. The most common grade ≥3 toxicities which necessitated supportive therapies or a dose reduction were gastrointestinal and infection. BACKGROUND: Treatment-related adverse events (AEs) are common in patients with metastatic colorectal cancer (mCRC) receiving chemotherapy. These AEs may affect patient adherence, particularly with completely oral regimens, such as trifluridine/tipiracil (TAS-102, Lonsurf®), an antimetabolite agent for patients with mCRC refractory or intolerant to standard therapies. . OBJECTIVES: This article reviews strategies for promoting adherence and educating patients and caregivers about oral therapy with trifluridine/tipiracil. . METHODS: Recommended strategies for managing AEs are reviewed, with a focus on the most common AEs reported in patients with mCRC receiving trifluridine/tipiracil in clinical trials. . FINDINGS: Oncology nurses play an important role in educating and counseling patients regarding treatment and its potential side effects. Among patients with mCRC refractory or intolerant to standard therapies, trifluridine/tipiracil was found to have a favorable safety profile. It is associated with hematologic AEs as well as a low incidence of nausea, diarrhea, vomiting, anorexia, and fatigue. Background: The treatment options for patients with therapy refractory metastatic colorectal cancer (mCRC) are sparse. TAS-102 (FTD/TPI) is a new oral anti-tumour agent composed of a nucleoside analogue, trifluridine, and a thymidine phosphorylase inhibitor, tipiracil, indicated for patients with mCRC who are refractory to standard therapies. This study summarizes published and unpublished experience with FTD/TPI in clinical practice settings. Patients and methods: The Medline/PubMed, Embase and Cochrane Library databases were searched to identify observational studies on FTD/TPI monotherapy for mCRC. Papers describing use of FTD/TPI monotherapy outside clinical trials in series of patients evaluable for effectiveness were eligible. The outcomes of interest were median progression free survival (mPFS), median overall survival (mOS) as well as mean PFS time restricted to six months (PFS6m) and mean OS time restricted to one year (OS1y). Results of the pooled analyses of observational studies were compared to the results of the Japanese phase II trial and the two phase III trials, RECOURSE and TERRA. Results: Seven published and two unpublished studies with 1008 patients from 64 centres were included for analysis. The pooled mPFS was 2.2 months (95% CI 2.1 to 2.3 months), and the pooled mOS was 6.6 months (95% CI 6.1 to 7.1 months). PFS6m was 2.9 months (95% CI 2.6 to 3.1 months) and OS1y was 6.8 (95% CI 6.0 to 7.5) months. While these results all reflect RECOURSE, the pooled mOS is lower than in the phase II trial and the OS1y is inferior to both the phase II trial and TERRA. Conclusion: This systematic review and a meta-analysis indicates that in real life settings, the survival benefit of FTD/TPI monotherapy in patients with therapy refractory mCRC reflects the outcomes in RECOURSE but is inferior to outcomes in the two Asian efficacy trials. What is already known TAS 102 (Lonsurf) is an oral fixed dose combination of trifluridine (FTD) and tipiracil (TPI) indicated as salvage-line treatment in patients with therapy refractory metastatic colorectal cancer (mCRC). A Japanese phase II trial and two phase III trials, RECOURSE and TERRA, demonstrated that FTD/TPI prolonged overall survival. What this study adds This systematic review and meta-analysis of real life data from 64 sites indicates that the effectiveness in daily clinical practice settings of FTD/TPI monotherapy in late stage mCRC reflects the outcomes in RECOURCE but is inferior to the outcomes in the Japanese phase II trial and TERRA. TAS-102/Lonsurf is a new oral anti-tumor drug consisting of trifluridine and tipiracil in a 1:0.5 molar ratio. Lonsurf has been approved globally, including US, Europe Union, and China, to treat patients with advanced colorectal cancer. Ongoing clinical trials are currently conducted for the treatment of other solid cancers. However, the therapeutic potential of TAS-102 in hematological malignancies has not been explored. In this study, we investigate the therapeutic efficacy of TAS-102 in multiple myeloma both in vitro and in vivo. We demonstrate that TAS-102 treatment inhibits tumor cell proliferation in six human myeloma cell lines with IC50 values in a range from 0.64 to 9.10 μM. Dot blotting and immunofluorescent staining show that trifluridine is predominately incorporated into genomic DNAs of myeloma cells. TAS-102 treatment induces myeloma cell apoptosis through cell cycle arrest in G1 phase and activation of cGAS-STING signaling in myeloma cells. In the human myeloma xenograft models, TAS-102 treatment reduces tumor progression and prolongs mouse survival. TAS-102 has shown its efficacies in the drug-resistant myeloma cells, and the combination of TAS-102 and bortezomib has a synergistic anti-myeloma activity. Our preclinical studies indicate that TAS-102 is a potential novel agent for myeloma therapy. TAGS trial revealed the efficacy and safety of trifluridine/tipiracil(Lonsurf®)treatment in patients with metastatic gastric cancer following gastrectomy. Here, we successfully treated 38 months survival case after recurrences following radical gastrectomy for advanced adenocarcinoma of esophago-gastric junction using historical recommended chemotherapy regimens and trifluridine/tipiracil as a fifth-line chemotherapy. Trifluridine/tipiracil therapy contributed to effective and safety treatment even in late-line chemotherapy for recurrent gastric cancer.
4,094
What is the correlation of Cathepsin L and COVID-19?
Cathepsin L (CTSL) is a kind of the SARS-entry-associated CoV-2's proteases, which plays a key role in the virus's entry into the cell and subsequent infection
[34807310, 34575910, 34527703]
4,501
INTRODUCTION: Cathepsin L (CTSL) is a kind of the SARS-entry-associated CoV-2's proteases, which plays a key role in the virus's entry into the cell and subsequent infection. We investigated the association between the expression level of CTSL and overall survival in Glioblastoma multiforme (GBM) patients, to better understand the possible route and risks of new coronavirus infection for patients with GBM. METHODS: The expression level of CTSL in GBM was analyzed using TCGA and CGGA databases. The relationship between CTSL and immune infiltration levels was analyzed by means of the TIMER database. The impact of CTSL inhibitors on GBM biological activity was tested. RESULTS: The findings revealed that GBM tissues had higher CTSL expression levels than that of normal brain tissues, which was associated with a significantly lower survival rate in GBM patients. Meanwhile, the expression level of CTSL negatively correlated with purity, B cell and CD8+ T cell in GBM. CTSL inhibitor significantly reduced growth and induced mitochondrial apoptosis. CONCLUSION: According to the findings, CTSL acts as an independent prognostic factor and can be considered as promising therapeutic target for GBM. The ongoing pandemic illustrates limited therapeutic options for controlling SARS-CoV-2 infections, calling a need for additional therapeutic targets. The viral spike S glycoprotein binds to the human receptor angiotensin-converting enzyme 2 (ACE2) and then is activated by the host proteases. Based on the accessibility of the cellular proteases needed for SARS-S activation, SARS-CoV-2 entrance and activation can be mediated by endosomal (such as cathepsin L) and non-endosomal pathways. Evidence indicates that in the non-endosomal pathway, the viral S protein is cleaved by the furin enzyme in infected host cells. To help the virus enter efficiently, the S protein is further activated by the serine protease 2 (TMPRSS2), provided that the S has been cleaved by furin previously. In this review, important roles for host proteases within host cells will be outlined in SARS-CoV-2 infection and antiviral therapeutic strategies will be highlighted. Although there are at least five highly effective vaccines at this time, the appearance of the new viral mutations demands the development of therapeutic agents. Targeted inhibition of host proteases can be used as a therapeutic approach for viral infection.
4,095
Is autism thought to be related to the Arginine Vasopressin Peptide (AVP)?
Differences in vasopressin levels in individuals suffering from the autism spectrum disorders have been demonstrated.
[28283809, 31043522, 32650534, 31571878, 17174726, 27974283, 28258508, 23413037, 15098001, 26200852, 21150165, 32341146, 21453499]
4,502
An accumulating body of evidence indicates a tight relationship between the endocrine system and abnormal social behavior. Two evolutionarily conserved hypothalamic peptides, oxytocin and arginine-vasopressin, because of their extensively documented function in supporting and regulating affiliative and socio-emotional responses, have attracted great interest for their critical implications for autism spectrum disorders (ASD). A large number of controlled trials demonstrated that exogenous oxytocin or arginine-vasopressin administration can mitigate social behavior impairment in ASD. Furthermore, there exists long-standing evidence of severe socioemotional dysfunctions after hypothalamic lesions in animals and humans. However, despite the major role of the hypothalamus for the synthesis and release of oxytocin and vasopressin, and the evident hypothalamic implication in affiliative behavior in animals and humans, a rather small number of neuroimaging studies showed an association between this region and socioemotional responses in ASD. This review aims to provide a critical synthesis of evidences linking alterations of the hypothalamus with impaired social cognition and behavior in ASD by integrating results of both anatomical and functional studies in individuals with ASD as well as in healthy carriers of oxytocin receptor (OXTR) genetic risk variant for ASD. Current findings, although limited, indicate that morphofunctional anomalies are implicated in the pathophysiology of ASD and call for further investigations aiming to elucidate anatomical and functional properties of hypothalamic nuclei underlying atypical socioemotional behavior in ASD. BACKGROUND: Dysregulation of the vasopressin (AVP) system has been implicated in the pathogenesis of autistic spectrum disorder (ASD). Apelin is a recently discovered neuropeptide that could counteract AVP actions and whose receptors are colocalized with vasopressin in hypothalamic magnocellular neurons. Aims of the present study were to investigate circulating levels of apelin in patients with ASD and to assess their correlation with plasma AVP concentrations. METHODS: Plasma levels of apelin and AVP were measured in a total of 18 patients with ASD and 21 age- and gender-matched healthy comparison subjects. The Childhood Autism Rating Scale (CARS) was used to assess the severity of autistic symptoms. RESULTS: Significantly reduced levels of apelin (p < 0.001) and elevated concentrations of AVP (p = 0.02) were found in ASD patients as compared to controls. Additionally, a significant inverse correlation between apelin and AVP levels was found within the ASD group (r = -0.61; p = 0.007), but not in healthy participants (r = -0.26; p = 0.25). Multivariate linear regression analysis showed that only AVP concentrations independently predicted apelin values in ASD individuals (beta = -0.42, t = 2.63, p = 0.014). No correlation was seen between apelin levels and CARS scores (r = -0.10; p = 0.68). CONCLUSIONS: Our findings of a significantly reduced peripheral level of apelin coupled with elevated AVP point to a subtle but definite vasopressinergic dysfunction in autism that could play a role in the etiopathophysiology of this disorder in humans. Autism Spectrum Disorders (ASD) are characterized by: social and communication impairments, and by restricted repetitive behaviors. The aim of the present paper is to review abnormalities of oxytocin (OXT) and related congenital malformations in ASD. A literature search was conducted in the PubMed database up to 2016 for articles related to the pathomechanism of ASD, abnormalities of OXT and the OXT polymorphism in ASD. The pathomechanism of ASD has yet to be. The development of ASD is suggested to be related to abnormalities of the oxytocin-arginin-vasopressin system. Previous results suggest that OXT and arginine vasopressin (AVP) may play a role in the etiopathogenesis of ASD. Dysfunction of brain-derived arginine-vasopressin (AVP) systems may be involved in the etiology of autism spectrum disorder (ASD). Certain regions such as the hypothalamus, amygdala, and hippocampus are known to contain either AVP neurons or terminals and may play an important role in regulating complex social behaviors. The present study was designed to investigate the concomitant changes in autistic behaviors, circulating AVP levels, and the structure and functional connectivity (FC) of specific brain regions in autistic children compared with typically developing children (TDC) aged from 3 to 5 years. The results showed: (1) children with ASD had a significantly increased volume in the left amygdala and left hippocampus, and a significantly decreased volume in the bilateral hypothalamus compared to TDC, and these were positively correlated with plasma AVP level. (2) Autistic children had a negative FC between the left amygdala and the bilateral supramarginal gyri compared to TDC. The degree of the negative FC between amygdala and supramarginal gyrus was associated with a higher score on the clinical autism behavior checklist. (3) The degree of negative FC between left amygdala and left supramarginal gyrus was associated with a lowering of the circulating AVP concentration in boys with ASD. (4) Autistic children showed a higher FC between left hippocampus and right subcortical area compared to TDC. (5) The circulating AVP was negatively correlated with the visual and listening response score of the childhood autism rating scale. These results strongly suggest that changes in structure and FC in brain regions containing AVP may be involved in the etiology of autism. There has been intensified interest in the neuropeptides oxytocin (OT) and arginine vasopressin (AVP) in autism spectrum disorders (ASD) given their role in affiliative and social behavior in animals, positive results of treatment studies using OT, and findings that genetic polymorphisms in the AVP-OT pathway are present in individuals with ASD. Nearly all such studies in humans have focused only on males. With this preliminary study, we provide basic and novel information on the involvement of OT and AVP in autism, with an investigation of blood plasma levels of these neuropeptides in 75 preadolescent and adolescent girls and boys ages 8-18: 40 with high-functioning ASD (19 girls, 21 boys) and 35 typically developing children (16 girls, 19 boys). We related neuropeptide levels to social, language, repetitive behavior, and internalizing symptom measures in these individuals. There were significant gender effects: Girls showed higher levels of OT, while boys had significantly higher levels of AVP. There were no significant effects of diagnosis on OT or AVP. Higher OT values were associated with greater anxiety in all girls, and with better pragmatic language in all boys and girls. AVP levels were positively associated with restricted and repetitive behaviors in girls with ASD but negatively (nonsignificantly) associated with these behaviors in boys with ASD. Our results challenge the prevailing view that plasma OT levels are lower in individuals with ASD, and suggest that there are distinct and sexually dimorphic mechanisms of action for OT and AVP underlying anxiety and repetitive behaviors. Autism Res 2013, 6: 91-102. © 2013 International Society for Autism Research, Wiley Periodicals, Inc. Impaired reciprocal social interaction is one of the core features of autism. While its determinants are complex, one biomolecular pathway that clearly influences social behavior is the arginine-vasopressin (AVP) system. The behavioral effects of AVP are mediated through the AVP receptor 1a (AVPR1a), making the AVPR1a gene a reasonable candidate for autism susceptibility. We tested the gene's contribution to autism by screening its exons in 125 independent autistic probands and genotyping two promoter polymorphisms in 65 autism affected sibling pair (ASP) families. While we found no nonconservative coding sequence changes, we did identify evidence of linkage and of linkage disequilibrium. These results were most pronounced in a subset of the ASP families with relatively less severe impairment of language. Thus, though we did not demonstrate a disease-causing variant in the coding sequence, numerous nontraditional disease-causing genetic abnormalities are known to exist that would escape detection by traditional gene screening methods. Given the emerging biological, animal model, and now genetic data, AVPR1a and genes in the AVP system remain strong candidates for involvement in autism susceptibility and deserve continued scrutiny. Oxytocin (OT) and arginine-vasopressin (AVP) are 2 peptides that are produced in the brain and released via the pituitary gland to the peripheral blood, where they have diverse physiological functions. In the last 2 decades it has become clear that these peptides also play a central role in the modulation of mammalian social behavior by their actions within the brain. Several lines of evidence suggest their involvement in autism spectrum disorder (ASD), which is known to be associated with impaired social cognition and behavior. Recent clinical trials using OT administration to autistic patients have reported promising results. Here, we aim to describe the main data that suggest a connection between these peptides and ASD. Following a short illustration of several major topics in ASD biology we will (a) briefly describe the oxytocinergic and vasopressinergic systems in the brain, (b) discuss a few compelling cases manifesting the involvement of OT and AVP in mammalian social behavior, (c) describe data supporting the role of these peptides in human social cognition and behavior, and (d) discuss the possibility of the involvement of OT and AVP in ASD etiology, as well as the prospect of using these peptides as a treatment for ASD patients. BACKGROUND: Arginine vasopressin (AVP) has been hypothesized to play a role in aetiology of autism based on a demonstrated involvement in the regulation of social behaviours. The arginine vasopressin receptor 1A gene (AVPR1A) is widely expressed in the brain and is considered to be a key receptor for regulation of social behaviour. Moreover, genetic variation at AVPR1A has been reported to be associated with autism. Evidence from non-human mammals implicates variation in the 5'-flanking region of AVPR1A in variable gene expression and social behaviour. METHODS: We examined four tagging single nucleotide polymorphisms (SNPs) (rs3803107, rs1042615, rs3741865, rs11174815) and three microsatellites (RS3, RS1 and AVR) at the AVPR1A gene for association in an autism cohort from Ireland. Two 5'-flanking region polymorphisms in the human AVPR1A, RS3 and RS1, were also tested for their effect on relative promoter activity. RESULTS: The short alleles of RS1 and the SNP rs11174815 show weak association with autism in the Irish population (P = 0.036 and P = 0.008, respectively). Both RS1 and RS3 showed differences in relative promoter activity by length. Shorter repeat alleles of RS1 and RS3 decreased relative promoter activity in the human neuroblastoma cell line SH-SY5Y. CONCLUSIONS: These aligning results can be interpreted as a functional route for this association, namely that shorter alleles of RS1 lead to decreased AVPR1A transcription, which may proffer increased susceptibility to the autism phenotype.
4,096
Are there any tools that could predict protein structure considering amino acid sequence?
Yes. Tools such as Jpred, Jnet, Porter 4.0 and PSIPRED Workbench have been developed that predict protein structure based solely on its amino acid sequence, whereas the recently updated Jnet algorithm provides a three-state (alpha-helix, beta-strand and coil) prediction of secondary structure at an accuracy of 81.5%.
[18463136, 26519323, 33999203, 17888742, 21780007, 20066664, 15980586, 19433514, 23772049, 31388850, 15215441, 34265844, 18757875, 31251384, 31063641, 15978619, 19046975]
4,503
Protein tertiary structure prediction algorithms aim to predict, from amino acid sequence, the tertiary structure of a protein. In silico protein structure prediction methods have become extremely important, as in vitro-based structural elucidation is unable to keep pace with the current growth of sequence databases due to high-throughput next-generation sequencing, which has exacerbated the gaps in our knowledge between sequences and structures.Here we briefly discuss protein tertiary structure prediction, the biennial competition for the Critical Assessment of Techniques for Protein Structure Prediction (CASP) and its role in shaping the field. We also discuss, in detail, our cutting-edge web-server method IntFOLD2-TS for tertiary structure prediction. Furthermore, we provide a step-by-step guide on using the IntFOLD2-TS web server, along with some real world examples, where the IntFOLD server can and has been used to improve protein tertiary structure prediction and aid in functional elucidation. Author information: (1)TUM (Technical University of Munich) Department of Informatics, Bioinformatics & Computational Biology - i12, Boltzmannstr 3, 85748 Garching/Munich, Germany. (2)TUM Graduate School CeDoSIA, Boltzmannstr 11, 85748 Garching, Germany. (3)Luxembourg Centre For Systems Biomedicine (LCSB), University of Luxembourg, Campus Belval, House of Biomedicine II, 6 avenue du Swing, L-4367 Belvaux, Luxembourg. (4)ELIXIR Luxembourg (ELIXIR-LU) Node, University of Luxembourg, Campus Belval, House of Biomedicine II, 6 avenue du Swing, L-4367 Belvaux, Luxembourg. (5)Department of Otolaryngology Head & Neck Surgery, The Ninth People's Hospital & Ear Institute, School of Medicine & Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai Jiao Tong University, Shanghai, China. (6)Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany. (7)The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel. (8)Department of Biochemistry & Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978 Tel Aviv, Israel. (9)Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA. (10)Roche Polska Sp. z o.o., Domaniewska 39B, 02-672 Warsaw, Poland. (11)Garvan Institute of Medical Research, Sydney, Australia. (12)Department of Data Sciences, Dana-Farber Cancer Institute, Boston, MA 02215, USA. (13)Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA. (14)Broad Institute of MIT and Harvard, Boston, MA 02142, USA. (15)HSWT (Hochschule Weihenstephan Triesdorf | University of Applied Sciences), Department of Bioengineering Sciences, Am Hofgarten 10, 85354 Freising, Germany. (16)Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. (17)BIPS, Poblacion Baco, Mindoro, Philippines. (18)Quantitative and Computational Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. (19)School of Biological Sciences, Seoul National University, Seoul, South Korea. (20)Artificial Intelligence Institute, Seoul National University, Seoul, South Korea. (21)Institute for Advanced Study (TUM-IAS), Lichtenbergstr. 2a, 85748 Garching/Munich, Germany. (22)TUM School of Life Sciences Weihenstephan (WZW), Alte Akademie 8, Freising, Germany. PreSSAPro is a software, available to the scientific community as a free web service designed to provide predictions of secondary structures starting from the amino acid sequence of a given protein. Predictions are based on our recently published work on the amino acid propensities for secondary structures in either large but not homogeneous protein data sets, as well as in smaller but homogeneous data sets corresponding to protein structural classes, i.e. all-alpha, all-beta, or alpha-beta proteins. Predictions result improved by the use of propensities evaluated for the right protein class. PreSSAPro predicts the secondary structure according to the right protein class, if known, or gives a multiple prediction with reference to the different structural classes. The comparison of these predictions represents a novel tool to evaluate what sequence regions can assume different secondary structures depending on the structural class assignment, in the perspective of identifying proteins able to fold in different conformations. The service is available at the URL http://bioinformatica.isa.cnr.it/PRESSAPRO/. A wealth of in silico tools is available for protein motif discovery and structural analysis. The aim of this chapter is to collect some of the most common and useful tools and to guide the biologist in their use. A detailed explanation is provided for the use of Distill, a suite of web servers for the prediction of protein structural features and the prediction of full-atom 3D models from a protein sequence. Besides this, we also provide pointers to many other tools available for motif discovery and secondary and tertiary structure prediction from a primary amino acid sequence. The prediction of protein intrinsic disorder and the prediction of functional sites and SLiMs are also briefly discussed. Given that user queries vary greatly in size, scope and character, the trade-offs in speed, accuracy and scale need to be considered when choosing which methods to adopt. For naturally occurring proteins, similar sequence implies similar structure. Consequently, multiple sequence alignments (MSAs) often are used in template-based modeling of protein structure and have been incorporated into fragment-based assembly methods. Our previous homology-free structure prediction study introduced an algorithm that mimics the folding pathway by coupling the formation of secondary and tertiary structure. Moves in the Monte Carlo procedure involve only a change in a single pair of phi,psi backbone dihedral angles that are obtained from a Protein Data Bank-based distribution appropriate for each amino acid, conditional on the type and conformation of the flanking residues. We improve this method by using MSAs to enrich the sampling distribution, but in a manner that does not require structural knowledge of any protein sequence (i.e., not homologous fragment insertion). In combination with other tools, including clustering and refinement, the accuracies of the predicted secondary and tertiary structures are substantially improved and a global and position-resolved measure of confidence is introduced for the accuracy of the predictions. Performance of the method in the Critical Assessment of Structure Prediction (CASP8) is discussed. Rational peptide design and large-scale prediction of peptide structure from sequence remain a challenge for chemical biologists. We present PEP-FOLD, an online service, aimed at de novo modelling of 3D conformations for peptides between 9 and 25 amino acids in aqueous solution. Using a hidden Markov model-derived structural alphabet (SA) of 27 four-residue letters, PEP-FOLD first predicts the SA letter profiles from the amino acid sequence and then assembles the predicted fragments by a greedy procedure driven by a modified version of the OPEP coarse-grained force field. Starting from an amino acid sequence, PEP-FOLD performs series of 50 simulations and returns the most representative conformations identified in terms of energy and population. Using a benchmark of 25 peptides with 9-23 amino acids, and considering the reproducibility of the runs, we find that, on average, PEP-FOLD locates lowest energy conformations differing by 2.6 A Calpha root mean square deviation from the full NMR structures. PEP-FOLD can be accessed at http://bioserv.rpbs.univ-paris-diderot.fr/PEP-FOLD. SUMMARY: Protein secondary structure and solvent accessibility predictions are a fundamental intermediate step towards protein structure and function prediction. We present new systems for the ab initio prediction of protein secondary structure and solvent accessibility, Porter 4.0 and PaleAle 4.0. Porter 4.0 predicts secondary structure correctly for 82.2% of residues. PaleAle 4.0's accuracy is 80.0% for prediction in two classes with a 25% accessibility threshold. We show that the increasing training set sizes that come with the continuing growth of the Protein Data Bank keep yielding prediction quality improvements and examine the impact of protein resolution on prediction performances. AVAILABILITY: Porter 4.0 and PaleAle 4.0 are freely available for academic users at http://distillf.ucd.ie/porterpaleale/. Up to 64 kb of input in FASTA format can be processed in a single submission, with predictions now being returned to the user within a single web page and, optionally, a single email. Predicting the three-dimensional structure of proteins is a long-standing challenge of computational biology, as the structure (or lack of a rigid structure) is well known to determine a protein's function. Predicting relative solvent accessibility (RSA) of amino acids within a protein is a significant step towards resolving the protein structure prediction challenge especially in cases in which structural information about a protein is not available by homology transfer. Today, arguably the core of the most powerful prediction methods for predicting RSA and other structural features of proteins is some form of deep learning, and all the state-of-the-art protein structure prediction tools rely on some machine learning algorithm. In this article we present a deep neural network architecture composed of stacks of bidirectional recurrent neural networks and convolutional layers which is capable of mining information from long-range interactions within a protein sequence and apply it to the prediction of protein RSA using a novel encoding method that we shall call "clipped". The final system we present, PaleAle 5.0, which is available as a public server, predicts RSA into two, three and four classes at an accuracy exceeding 80% in two classes, surpassing the performances of all the other predictors we have benchmarked. Knowledge of the detailed structure of a protein is crucial to our understanding of the biological functions of that protein. The gap between the number of solved protein structures and the number of protein sequences continues to widen rapidly in the post-genomics era due to long and expensive processes for solving structures experimentally. Computational prediction of structures from amino acid sequence has come to play a key role in narrowing the gap and has been successful in providing useful information for the biological research community. We have developed a prediction pipeline, PROSPECT-PSPP, an integration of multiple computational tools, for fully automated protein structure prediction. The pipeline consists of tools for (i) preprocessing of protein sequences, which includes signal peptide prediction, protein type prediction (membrane or soluble) and protein domain partition, (ii) secondary structure prediction, (iii) fold recognition and (iv) atomic structural model generation. The centerpiece of the pipeline is our threading-based program PROSPECT. The pipeline is implemented using SOAP (Simple Object Access Protocol), which makes it easier to share our tools and resources. The pipeline has an easy-to-use user interface and is implemented on a 64-node dual processor Linux cluster. It can be used for genome-scale protein structure prediction. The pipeline is accessible at http://csbl.bmb.uga.edu/protein_pipeline. Proteins are essential to life, and understanding their structure can facilitate a mechanistic understanding of their function. Through an enormous experimental effort1-4, the structures of around 100,000 unique proteins have been determined5, but this represents a small fraction of the billions of known protein sequences6,7. Structural coverage is bottlenecked by the months to years of painstaking effort required to determine a single protein structure. Accurate computational approaches are needed to address this gap and to enable large-scale structural bioinformatics. Predicting the three-dimensional structure that a protein will adopt based solely on its amino acid sequence-the structure prediction component of the 'protein folding problem'8-has been an important open research problem for more than 50 years9. Despite recent progress10-14, existing methods fall far short of atomic accuracy, especially when no homologous structure is available. Here we provide the first computational method that can regularly predict protein structures with atomic accuracy even in cases in which no similar structure is known. We validated an entirely redesigned version of our neural network-based model, AlphaFold, in the challenging 14th Critical Assessment of protein Structure Prediction (CASP14)15, demonstrating accuracy competitive with experimental structures in a majority of cases and greatly outperforming other methods. Underpinning the latest version of AlphaFold is a novel machine learning approach that incorporates physical and biological knowledge about protein structure, leveraging multi-sequence alignments, into the design of the deep learning algorithm. MOTIVATION: Predictions of protein local structure, derived from sequence alignment information alone, provide visualization tools for biologists to evaluate the importance of amino acid residue positions of interest in the absence of X-ray crystal/NMR structures or homology models. They are also useful as inputs to sequence analysis and modeling tools, such as hidden Markov models (HMMs), which can be used to search for homology in databases of known protein structure. In addition, local structure predictions can be used as a component of cost functions in genetic algorithms that predict protein tertiary structure. We have developed a program (predict-2nd) that trains multilayer neural networks and have applied it to numerous local structure alphabets, tuning network parameters such as the number of layers, the number of units in each layer and the window sizes of each layer. We have had the most success with four-layer networks, with gradually increasing window sizes at each layer. RESULTS: Because the four-layer neural nets occasionally get trapped in poor local optima, our training protocol now uses many different random starts, with short training runs, followed by more training on the best performing networks from the short runs. One recent addition to the program is the option to add a guide sequence to the profile inputs, increasing the number of inputs per position by 20. We find that use of a guide sequence provides a small but consistent improvement in the predictions for several different local-structure alphabets. AVAILABILITY: Local structure prediction with the methods described here is available for use online at http://www.soe.ucsc.edu/compbio/SAM_T08/T08-query.html. The source code and example networks for PREDICT-2ND are available at http://www.soe.ucsc.edu/~karplus/predict-2nd/ A required C++ library is available at http://www.soe.ucsc.edu/~karplus/ultimate/ The PSIPRED Workbench is a web server offering a range of predictive methods to the bioscience community for 20 years. Here, we present the work we have completed to update the PSIPRED Protein Analysis Workbench and make it ready for the next 20 years. The main focus of our recent website upgrade work has been the acceleration of analyses in the face of increasing protein sequence database size. We additionally discuss any new software, the new hardware infrastructure, our webservices and web site. Lastly we survey updates to some of the key predictive algorithms available through our website. Prediction of protein secondary structure is an important step towards elucidating its three dimensional structure and its function. This is a challenging problem in bioinformatics. Segmental semi Markov models (SSMMs) are one of the best studied methods in this field. However, incorporating evolutionary information to these methods is somewhat difficult. On the other hand, the systems of multiple neural networks (NNs) are powerful tools for multi-class pattern classification which can easily be applied to take these sorts of information into account. To overcome the weakness of SSMMs in prediction, in this work we consider a SSMM as a decision function on outputs of three NNs that uses multiple sequence alignment profiles. We consider four types of observations for outputs of a neural network. Then profile table related to each sequence is reduced to a sequence of four observations. In order to predict secondary structure of each amino acid we need to consider a decision function. We use an SSMM on outputs of three neural networks. The proposed SSMM has discriminative power and weights over different dependency models for outputs of neural networks. The results show that the accuracy of our model in predictions, particularly for strands, is considerably increased.
4,097
Which proteins does p110α interact with?
p110α interacts with p85α and RAS proteins.
[34884613, 24229705, 24367658, 30683915, 24229709, 26122737, 23086038, 25003191]
4,504
Attribution of specific roles to the two ubiquitously expressed PI 3-kinase (PI3K) isoforms p110α and p110β in biological functions they have been implicated, such as in insulin signalling, has been challenging. While p110α has been demonstrated to be the principal isoform activated downstream of the insulin receptor, several studies have provided evidence for a role of p110β. Here we have used isoform-selective inhibitors to estimate the relative contribution of each of these isoforms in insulin signalling in adipocytes, which are a cell type with essential roles in regulation of metabolism at the systemic level. Consistent with previous genetic and pharmacological studies, we found that p110α is the principal isoform activated downstream of the insulin receptor under physiological conditions. p110α interaction with Ras enhanced the strength of p110α activation by insulin. However, this interaction did not account for the selectivity for p110α over p110β in insulin signalling. We also demonstrate that p110α is the principal isoform activated downstream of the β-adrenergic receptor (β-AR), another important signalling pathway in metabolic regulation, through a mechanism involving activation of the cAMP effector molecule EPAC1. This study offers further insights in the role of PI3K isoforms in the regulation of energy metabolism with implications for the therapeutic application of selective inhibitors of these isoforms. Glutathione S-transferases P1 (GSTP1) is a phase II detoxifying enzyme and increased expression of GSTP1 has been linked with acquired resistance to anti-cancer drugs. However, most anticancer drugs are not good substrates for GSTP1, suggesting that the contribution of GSTP1 to drug resistances might not be dependent on its capacity to detoxify chemicals or drugs. In the current study, we found a novel mechanism by which GSTP1 protects human breast cancer cells from adriamycin (ADR)-induced cell death and contributes to the drug resistance. GSTP1 protein level is very low in human breast cancer cell line MCF-7 but is high in ADR-resistant MCF-7/ADR cells. Under ADR treatment, MCF-7/ADR cells showed a higher autophagy level than MCF-7 cells. Overexpression of GSTP1 in MCF-7 cells by using the DNA transfection vector enhanced autophagy and down-regulation of GSTP1 through RNA interference in MCF-7/ADR cells decreased autophagy. When autophagy was prevented, GSTP1-induced ADR resistance reduced. We found that GSTP1 enhanced autophagy level in MCF-7 cells through interacting with p110α subunit of phosphatidylinositol-3-kinase (PI3K) and then inhibited PI3K/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) activity. Proline123, leucine160, and glutamine163, which located in C terminal of GSTP1, are essential for GSTP1 to interact with p110α, and the following autophagy and drug resistance regulation. Taken together, our findings demonstrate that high level of GSTP1 maintains resistance of breast cancer cells to ADR through promoting autophagy. These new molecular insights provide an important contribution to our better understanding the effect of GSTP1 on the resistance of tumors to chemotherapy. Phosphatidylinositol 3-kinase (PI3K) α is a heterodimeric lipid kinase that catalyzes the conversion of phosphoinositol-4,5-bisphosphate to phosphoinositol-3,4,5-trisphosphate. The PI3Kα signaling pathway plays an important role in cell growth, proliferation, and survival. This pathway is activated in numerous cancers, where the PI3KCA gene, which encodes for the p110α PI3Kα subunit, is mutated. Its mutation often results in gain of enzymatic activity; however, the mechanism of activation by oncogenic mutations remains unknown. Here, using computational methods, we show that oncogenic mutations that are far from the catalytic site and increase the enzymatic affinity destabilize the p110α-p85α dimer. By affecting the dynamics of the protein, these mutations favor the conformations that reduce the autoinhibitory effect of the p85α nSH2 domain. For example, we determined that, in all of the mutants, the nSH2 domain shows increased positional heterogeneity as compared with the wild-type, as demonstrated by changes in the fluctuation profiles computed by normal mode analysis of coarse-grained elastic network models. Analysis of the interdomain interactions of the wild-type and mutants at the p110α-p85α interface obtained with molecular dynamics simulations suggest that all of the tumor-associated mutations effectively weaken the interactions between p110α and p85α by disrupting key stabilizing interactions. These findings have important implications for understanding how oncogenic mutations change the conformational multiplicity of PI3Kα and lead to increased enzymatic activity. This mechanism may apply to other enzymes and/or macromolecular complexes that play a key role in cell signaling. Phosphoinositide 3-kinase (PI3K) mediates insulin actions by relaying signals from insulin receptors (IRs) to downstream targets. The p110α catalytic subunit of class IA PI3K is the primary insulin-responsive PI3K implicated in insulin signaling. We demonstrate here a new mode of spatial regulation for the p110α subunit of PI3K by PAQR3 that is exclusively localized in the Golgi apparatus. PAQR3 interacts with p110α, and the intracellular targeting of p110α to the Golgi apparatus is reduced by PAQR3 downregulation and increased by PAQR3 overexpression. Insulin-stimulated PI3K activity and phosphoinositide (3,4,5)-triphosphate production are enhanced by Paqr3 deletion and reduced by PAQR3 overexpression in hepatocytes. Deletion of Paqr3 enhances insulin-stimulated phosphorylation of AKT and glycogen synthase kinase 3β, but not phosphorylation of IR and IR substrate-1 (IRS-1), in hepatocytes, mouse liver, and skeletal muscle. Insulin-stimulated GLUT4 translocation to the plasma membrane and glucose uptake are enhanced by Paqr3 ablation. Furthermore, PAQR3 interacts with the domain of p110α involved in its binding with p85, the regulatory subunit of PI3K. Overexpression of PAQR3 dose-dependently reduces the interaction of p85α with p110α. Thus, PAQR3 negatively regulates insulin signaling by shunting cytosolic p110α to the Golgi apparatus while competing with p85 subunit in forming a PI3K complex with p110α.
4,098
Which is the protein-membrane interface of the Cholesterol-regulated Start protein 4 protein (STARD4)?
L124 is the protein-membrane interface of the Cholesterol-regulated Start protein 4 protein (STARD4).
[26168008]
4,505
The steroidogenic acute regulatory protein-related lipid transfer (START) domain family is defined by a conserved 210-amino acid sequence that folds into an α/β helix-grip structure. Members of this protein family bind a variety of ligands, including cholesterol, phospholipids, sphingolipids, and bile acids, with putative roles in nonvesicular lipid transport, metabolism, and cell signaling. Among the soluble START proteins, STARD4 is expressed in most tissues and has previously been shown to transfer sterol, but the molecular mechanisms of membrane interaction and sterol binding remain unclear. In this work, we use biochemical techniques to characterize regions of STARD4 and determine their role in membrane interaction and sterol binding. Our results show that STARD4 interacts with anionic membranes through a surface-exposed basic patch and that introducing a mutation (L124D) into the Omega-1 (Ω1) loop, which covers the sterol binding pocket, attenuates sterol transfer activity. To gain insight into the attenuating mechanism of the L124D mutation, we conducted structural and biophysical studies of wild-type and L124D STARD4. These studies show that the L124D mutation reduces the conformational flexibility of the protein, resulting in a diminished level of membrane interaction and sterol transfer. These studies also reveal that the C-terminal α-helix, and not the Ω1 loop, partitions into the membrane bilayer. On the basis of these observations, we propose a model of STARD4 membrane interaction and sterol binding and release that requires dynamic movement of both the Ω1 loop and membrane insertion of the C-terminal α-helix.
4,099
What causes the "worst headache" of a patient's life?
This is a classic description of a subarachnoid hemorrhage (SAH). The gold standard for the diagnostic evaluation of a SAH remains non-contrast head computed tomography (CT) followed by lumbar puncture if the CT is negative.
[22338211, 17929738, 28434443, 27741994, 9737490]
4,506
BACKGROUND: Headache is the most common presenting symptom of subarachnoid hemorrhage (SAH), ranging from mild headache to the "worst headache of my life". As headache is often non-specific, patients may not seek immediate medical attention, though prompt medical and surgical management is expected to improve clinical outcomes. In this study, we explore the independent association between duration from onset of symptoms to presentation at an emergency department (ED) and clinical outcomes after SAH. METHODS: Participants with a primary diagnosis of nontraumatic SAH were identified from consecutive patients at 11 regional stroke centres participating in the Registry of the Canadian Stroke Network (RCSN, 2003-2005). Hunt and Hess score (H+H), and modified Rankin Scale (mRS) at discharge were collected on SAH cases by trained nurse-abstractors. For analysis, patients were categorized into patients with mild-moderate dependency (mRS 0-3) and those with severe dependence or death (mRS 4-6) at hospital discharge. Multivariable regression analyses were used to determine the association between 'time to presentation' and clinical outcomes, independent of comorbidities. RESULTS: Of 721 SAH patients included in the RCSN, 642 (89.0%) had the interval between 'time last seen normal' and time of ED presentation recorded. Mean duration from symptom onset to ED arrival was 27.04 hours (+/- 2.02). One hundred and sixty-six patients (25.9%) presented to the ED more than 24 hours after onset of symptoms. On multivariable analysis, there was no association between time to presentation and severe disability or death at hospital discharge (OR 1.0 [95% CI 0.95-1.01]); 30-day mortality (OR 1.0 [95% CI 0.91-1.02]; or six-month mortality (OR 1.0 [95% CI 1.0-1.02]). Increasing H+H score and age were significantly associated with increased odds of death and severe dependence at hospital discharge. CONCLUSIONS: In this observational study, duration from symptom onset to hospital presentation was not independently associated with death or severe disability at hospital discharge following SAH. Age and H+H score were independent predictors of clinical outcome after non-traumatic SAH. Aneurysmal subarachnoid hemorrhage (SAH) is a neurological emergency with high risk of neurological decline and death. Although the presentation of a thunderclap headache or the worst headache of a patient's life easily triggers the evaluation for SAH, subtle presentations are still missed. The gold standard for diagnostic evaluation of SAH remains noncontrast head computed tomography (CT) followed by lumbar puncture if the CT is negative for SAH. Management of patients with SAH follows standard resuscitation of critically ill patients with the emphasis on reducing risks of rebleeding and avoiding secondary brain injuries. STUDY OBJECTIVE: This study investigated the hypothesis that modern computed tomographic (CT) imaging is sufficient to exclude subarachnoid hemorrhage (SAH) in patients with severe headache. METHODS: All 38,730 adult patients who presented to Hermann Hospital in Houston, Texas, during a 16-month period were prospectively screened to detect those with "the worst headache of my life." Two neuroradiologists blinded to the study hypothesis interpreted the CT scans. Patients with negative scans underwent comprehensive cerebrospinal fluid (CSF) analysis including cell count in first and last tubes, visual and spectrophotometric detection of xanthochromia, and CSF D-dimer assay. RESULTS: A chief complaint of headache was elicited in 455 patients, and 107 of these had "worst headache" and were enrolled in the study. CT-confirmed SAH was found in 18 of the 107 (17%). Only 2 patients (2.5%, 95% confidence interval, .3% to 8.8%) had SAH detected by CSF analysis among those with negative CT imaging result. CSF spectrophotometric detection was the most sensitive test for blood. Three patients with less than 6 red blood cells in tube 1 had positive spectrophotometric results, but in all 3, tube 4 was negative on spectrophotometric analysis, suggesting a high false-positive rate. CONCLUSION: Modern CT imaging is sufficient to exclude 97.5% of SAH in patients presenting to the ED with "worst headache" symptoms.
4,100
Which are the types of cancer that c-Myc is associated with?
The types of cancer that c-Myc is associates with are breast cancer, non-small-cell lung cancer and pancreatic ductal adenocarcinoma.
[20697349, 30226440, 24646303, 3670047, 3332004, 20737197, 29263157, 28623290, 1493439, 15929079, 31144531, 2227545, 26954716, 25306215, 18190704, 28160502, 28741879, 19174520, 8353142, 33390842, 30224636]
4,507
Background: c-Myc is overexpressed in different types of cancer, including thyroid cancer, and has been considered undruggable. There is evidence showing that MLN8237, a type of aurora A kinase (AURKA) inhibitor, destabilizes c-Myc proteins in liver cancer cells through disruption of the c-Myc/AURKA complex. However, the role of MLN8237 in thyroid cancer remains largely unclear. The aims of this study were to test the therapeutic potential of MLN8237 in thyroid cancer, and to analyze determinant factors affecting the response of thyroid cancer cells to MLN8237 and clarify the corresponding mechanism. Methods: The phenotypic effects of MLN8237 in thyroid cancer cells were evaluated through a series of in vitro and in vivo experiments, and the mechanism of c-Myc affecting MLN8237 response were explored using Western blot, ubiquitination, and cycloheximide chase assays. Results: The data show that the levels of c-Myc protein were strongly associated with MLN8237 cellular response in thyroid cancer cells. Only the cells with high c-Myc expression exhibited growth inhibition upon MLN8237 treatment. However, MLN8237 barely affected the growth of those with low c-Myc expression. Mechanistically, MLN8237 dramatically promoted proteasomal degradation of c-Myc proteins through disruption of the c-Myc/AURKA complex in the cells with high c-Myc expression. A similar antitumor activity of MLN8237 was also found in xenograft tumor models. Conclusions: The data demonstrate that c-Myc is a major determinant for MLN8237 responsiveness in thyroid cancer cells. Thus, indirectly targeting c-Myc by MLN8237 may be an effective strategy for thyroid cancer overexpressing c-Myc. CONTEXT: c-Myc plays a key role in glioma cancer stem cell maintenance. A drug delivery system, nanoparticles loading plasmid DNAs inserted with siRNA fragments targeting c-Myc gene (NPs-c-Myc-siRNA-pDNAs), for the treatment of glioma, has not previously been reported. OBJECTIVE: NPs-c-Myc-siRNA-pDNAs were prepared and evaluated in vitro. MATERIALS AND METHODS: Three kinds of c-Myc-siRNA fragments were separately synthesized and linked with empty siRNA expression vectors in the mole ratio of 3:1 by T4 DNA ligase. The linked products were then separately transfected into Escherichia coli. DH5α followed by extraction with Endofree plasmid Mega kit (Qiagen, Hilden, Germany) obtained c-Myc-siRNA-pDNAs. Finally, the recombinant c-Myc-siRNA3-pDNAs, generating the highest transfection efficiency and the greatest apoptotic ability, were chosen for encapsulation into NPs by the double-emulsion solvent-evaporation procedure, followed by stability, transfection efficiency, as well as qualitative and quantitative apoptosis evaluation. RESULTS: NPs-c-Myc-siRNA3-pDNAs were obtained with spherical shape in uniform size below 150 nm, with the zeta potential about -18 mV, the encapsulation efficiency and loading capacity as 76.3 ± 5.4% and 1.91 ± 0.06%, respectively. The stability results showed that c-Myc-siRNA3-pDNAs remained structurally and functionally stable after encapsulated into NPs, and NPs could prevent the loaded c-Myc-siRNA3-pDNAs from DNase degradation. The transfection efficiency of NPs-c-Myc-siRNA3-pDNAs was proven to be positive. Furthermore, NPs-c-Myc-siRNA3-pDNAs produced significant apoptosis with the apoptotic rate at 24.77 ± 5.39% and early apoptosis cells observed. DISCUSSION AND CONCLUSION: Methoxy-poly-(ethylene-glycol)-poly-(lactide-co-glycolide) nanoparticles (MPEG-PLGA-NPs) are potential delivery carriers for c-Myc-siRNA3-pDNAs. DNAs from 253 fresh human tumors of 38 different types were hybridized with 17 different oncogene probes. The analysis demonstrated unique associations between amplification of specific oncogenes and specific types of tumors. In a large number of cases it was determined that amplified oncogenes occurred in 10 to 20% of tumors with the following specific associations: c-myc in adenocarcinomas, squamous carcinomas and sarcomas but not hematologic malignancies; c-erbB2 in adenocarcinomas, particularly breast cancers; c-erbB1 in squamous carcinomas; N-myc in neuroblastomas. A small number of cases suggested other specific associations: amplified c-myb in breast cancers; amplified c-ras-Ha and c-ras-Ki in ovarian carcinomas. In addition, there was a correlation between amplification of c-myc and the clinical stage of adenocarcinomas, and amplification of c-erbB2 and the clinical stage and lymph node involvement of breast cancers. Molecular and cell biologic studies of a large number of lung cancer cell lines of all histologic types have revealed several mechanisms active in the pathogenesis of these cells. Small cell lung cancer (also called "oat cell" lung cancer) has a deletion involving chromosome region 3p(14-23) that is confirmed by DNA restriction fragment length polymorphisms analysis (studies done in collaboration with Dr. Susan Naylor). Several lung cancers of both small cell and non-small cell type (including adeno- and squamous cell lung cancer) express the proto-oncogenes c-, N-, or L-myc, and in some cases more than one of these family members. N-myc appears restricted in its expression to the small cell lung cancer type while c-myc and L-myc can be expressed in both small cell and non-small cell lung cancers. Many lung cancers of all histologic types also express large amounts of p53, which are not correlated with the amount or type of myc gene product expressed. In small cell lung cancer, high levels of myc gene expression are usually associated with gene amplification, and not uncommonly there is rearrangement of some of the amplified copies. In non-small cell lung cancer, expression without amplification or rearrangement of myc genes is seen. In contrast, high level expression of p53 is not associated with gene amplification in any lung cancer type. In addition, to these proto-oncogenes acting at a presumed nuclear locus, there is increased expression of various ras family members and the c-raf-1 proto-oncogene (in collaboration with Dr. Ulf Rapp). Lung cancer cells in tissue culture can grow in medium without serum and few or no other growth factors added. Thus, it appears that lung cancer cells can produce their own growth factors which can act in an "autocrine" fashion. The best characterized example of this is gastrin releasing peptide (GRP, also called bombesin) produced by small cell lung cancer. In at least some small cell lung cancers, interference with GRP action by specific monoclonal antibodies results in inhibition of tumor cell growth in culture and in nude mouse xenografts. Thus, constitutively expressed GRP gene may function as a cellular oncogene under certain circumstances in small cell lung cancer. Based on these observations we are proposing to test monoclonal anti-GRP antibodies in patients. The upregulation or mutation of C-MYC has been observed in gastric, colon, breast, and lung tumors and in Burkitt's lymphoma. However, little is known about the role C-MYC plays in gastric adenocarcinoma. In the present study, we intended to investigate the influence of C-MYC on the growth, proliferation, apoptosis, invasion, and cell cycle of the gastric cancer cell line SGC7901 and the gastric cell line HFE145. C-MYC cDNA was subcloned into a constitutive vector PCDNA3.1 followed by transfection in normal gastric cell line HFE145 by using liposome. Then stable transfectants were selected and appraised. Specific inhibition of C-MYC was achieved using a vector-based siRNA system which was transfected in gastric cancer cell line SGC7901. The apoptosis and cell cycles of these clones were analyzed by using flow cytometric assay. The growth and proliferation were analyzed by cell growth curves and colony-forming assay, respectively. The invasion of these clones was analyzed by using cell migration assay. The C-MYC stable expression clones (HFE-Myc) and C-MYC RNAi cells (SGC-MR) were detected and compared with their control groups, respectively. HFE-Myc grew faster than HFE145 and HFE-PC (HFE145 transfected with PCDNA3.1 vector). SGC-MR1, 2 grew slower than SGC7901 and SGC-MS1, 2 (SGC7901 transfected with scrambled control duplexes). The cell counts of HFE-Myc in the third, fourth, fifth, sixth, and seventh days were significantly more than those of control groups (P < 0.05). Those of SGC-MR1, 2 in the fourth, fifth, sixth, and seventh days were significantly fewer than those of control groups (P < 0.05). Cell cycle analysis showed that proportions of HFE-Myc and SGC-MR cells in G0-G1 and G2-M were different significantly with their control groups, respectively (P < 0.05). The apoptosis rate of HFE-Myc was significantly higher than those of control groups (P < 0.05). Results of colony-forming assay showed that the colony formation rate of HFE-Myc was higher than those of control groups; otherwise, the rate of SGC-MR was lower than those of their control groups (P < 0.05). The results of cell migration assay showed that there were no significant differences between experimental groups and control groups (P > 0.05). In conclusion, C-MYC can promote the growth and proliferation of normal gastric cells, and knockdown of C-MYC can restrain the growth and proliferation of gastric cancer cells. It can induce cell apoptosis and help tumor cell maintain malignant phenotype. But it can have not a detectable influence on the ability of invasion of gastric cancer cells. The transcription factor gene MYC is important in breast cancer, and its mRNA is maintained at a high level even in the absence of gene amplification. The mechanism(s) underlying increased MYC mRNA expression is unknown. Here, we demonstrate that MYC mRNA was stabilized upon estrogen stimulation of estrogen receptor-positive breast cancer cells via SRC-dependent effects on a recently described RNA-binding protein, IMP1 with an N-terminal deletion (ΔN-IMP1). We also show that loss of the tumor suppressor p53 increased MYC mRNA levels even in the absence of estrogen stimulation. However, in cells with wild-type p53, SRC acted to overcome p53-mediated inhibition of estrogen-stimulated cell cycle entry and progression. SRC thus promotes cell proliferation in two ways: by stabilizing MYC mRNA and by inhibiting p53 function. Since estrogen receptor-positive breast cancers typically express wild-type p53, these studies establish a rationale for p53 status to be predictive for effective SRC inhibitor treatment in this subtype of breast cancer. Previously, we cloned a new gene termed 'tongue cancer resistance-associated protein 1' (TCRP1), which modulates tumorigenesis, enhances cisplatin (cDDP) resistance in cancers, and may be a potential target for reversing drug resistance. However, the mechanisms for regulating TCRP1 expression remain unclear. Herein, we combined bioinformatics analysis with luciferase reporter assay and ChIP assay to determine that c-Myc could directly bind to TCRP1 promoter to upregulate its expression. TCRP1 upregulation in multidrug resistant tongue cancer cells (Tca8113/PYM) and cisplatin-resistant A549 lung cancer cells (A549/DDP) was accompanied by c-Myc upregulation, compared to respective parental cells. In tongue and lung cancer cells, siRNA-mediated knockdown of c-Myc led to decrease TCRP1 expression, whereas overexpression c-Myc did the opposite. Moreover, TCRP1 knockdown attenuated chemoresistance resulting from c-Myc overexpression, but TCRP1 overexpression impaired the effect of c-Myc knockdown on chemosensitivity. Additionally, in both human tongue and lung cancer tissues, c-Myc protein expression positively correlated with TCRP1 protein expression and these protein levels were associated with worse prognosis for patients. Combined, these findings suggest that c-Myc could transcriptionally regulate TCRP1 in cell lines and clinical samples and identified the c-Myc-TCRP1 axis as a negative biomarker of prognosis in tongue and lung cancers. The function of c-myc in physiology is only partially known. Its product has DNA binding properties and plays a role in the control of proliferation and differentiation. In general, increased c-myc expression leads to proliferation and abolishment of differentiation. The involvement of c-myc in mouse plasmacytomas and human Burkitt's lymphoma is well known: due to chromosomal translocation c-myc comes under the influence of regulatory elements of immunoglobulin genes, leading to increased expression of the gene and proliferation of the cells. In man, the chromosomal translocations may occur within the increased pool of (pre) B-cells due to Epstein Barr virus (EBV) and malaria infection with subsequent immunosuppression. Apart from these early (primary?) events in lymphomagenesis, c-myc is also often involved in tumour progression, probably by a similar mechanism. Different types of c-myc involvement are associated with specific types of lymphoma: there are differences between endemic, sporadic and ileocecal Burkitt's lymphoma as well as between those and primary extranodal large cell lymphoma and large cell lymphoma which has progressed. These differences are associated with the differentiation of the involved lymphoid cells and may point to the stage of differentiation in which the oncogenic event occurred. c-MYC is a multifaceted protein that regulates cell proliferation, differentiation and apoptosis. Its crucial role in diverse cancers has been demonstrated in several studies. Here, we analysed the influence of the rare c-MYC Asn11Ser polymorphism on familial breast cancer risk by performing a case-control study with a Polish (cases n = 349; controls n = 441) and a German (cases n = 356; controls n = 655) study population. All cases have been tested negative for mutations in the BRCA1 and BRCA2 genes. A joint analysis of the Polish and the German study population revealed a 54% increased risk for breast cancer associated with the heterozygous Asn11Ser variant (OR = 1.54, 95% CI 1.05-2.26, p = 0.028). The breast cancer risk associated with this genotype increases above the age of 50 years (OR = 2.24, 95% CI 1.20-4.21, p = 0.012). The wild-type amino acid Asn of this polymorphism is located in the N-terminal MYC transactivation domain and is highly conserved not only among most diverse species but also in the N-MYC homologue. Due to the pivotal role of c-MYC in diverse tumours, this variant might affect the genetic susceptibility of other cancers as well. Aim: To investigate whether plasma C-MYC level could be an indicator in clinical progression of breast cancer. Materials & methods: Plasma level of C-MYC expression was detected by quantitative real time PCR and the level of c-myc protein in breast cancer tissues was detected by immunohistochemistry. The expression level of C-MYC mRNA in supernatant of cancer cells culture was measured compared with the nonbreast cancer cells. Results: Plasma C-MYC level was significantly higher in patients with breast cancer than that in the controls, which associated with clinical stages, lymph node status, etc. Receiver operating characteristic curve analysis showed the sensitivity and specificity of plasma C-MYC level for diagnosis of breast cancer were 63.6 and 81.8%, respectively. The expression of c-myc protein in breast cancer tissues was associated with plasma C-MYC level, even C-MYC level in supernatant of cancer cells was elevated. Conclusion: Plasma C-MYC level might be a potential indicator in progression of breast cancer. BACKGROUND: MYC is amplified in approximately 15% of breast cancers (BCs) and is associated with poor outcome. c-MYC protein is multi-faceted and participates in many aspects of cellular function and is linked with therapeutic response in BCs. We hypothesised that the functional role of c-MYC differs between molecular subtypes of BCs. METHODS: We therefore investigated the correlation between c-MYC protein expression and other proteins involved in different cellular functions together with clinicopathological parameters, patients' outcome and treatments in a large early-stage molecularly characterised series of primary invasive BCs (n=1106) using immunohistochemistry. The METABRIC BC cohort (n=1980) was evaluated for MYC mRNA expression and a systems biology approach utilised to identify genes associated with MYC in the different BC molecular subtypes. RESULTS: High MYC and c-MYC expression was significantly associated with poor prognostic factors, including grade and basal-like BCs. In luminal A tumours, c-MYC was associated with ATM (P=0.005), Cyclin B1 (P=0.002), PIK3CA (P=0.009) and Ki67 (P<0.001). In contrast, in basal-like tumours, c-MYC showed positive association with Cyclin E (P=0.003) and p16 (P=0.042) expression only. c-MYC was an independent predictor of a shorter distant metastases-free survival in luminal A LN+ tumours treated with endocrine therapy (ET; P=0.013). In luminal tumours treated with ET, MYC mRNA expression was associated with BC-specific survival (P=0.001). In ER-positive tumours, MYC was associated with expression of translational genes while in ER-negative tumours it was associated with upregulation of glucose metabolism genes. CONCLUSIONS: c-MYC function is associated with specific molecular subtypes of BCs and its overexpression confers resistance to ET. The diverse mechanisms of c-MYC function in the different molecular classes of BCs warrants further investigation particularly as potential therapeutic targets. BACKGROUND: Pancreatic ductal adenocarcinoma (PDA) is frequently driven by oncogenic KRAS(KRAS*) mutations. We developed a mouse model of KRAS*-induced PDA and, based on genetic results demonstrating that KRAS* tumorigenicity depends on Myc activity, we evaluated the therapeutic potential of an orally administered anti-Myc drug. METHODS: We tested the efficacy of Mycro3, a small-molecule inhibitor of Myc-Max dimerization, in the treatment of mouse PDA (n = 9) and also of xenografts of human pancreatic cancer cell lines (NOD/SCID mice, n = 3-12). Tumor responses to the drug were evaluated by PET/CT imaging, and histological, immunohistochemical, molecular and microarray analyses. The Student's t test was used for differences between groups. All statistical tests were two-sided. RESULTS: Transgenic overexpression of KRAS* in the pancreas resulted in pancreatic intraepithelial neoplasia in two-week old mice, which developed invasive PDA a week later and became moribund at one month. However, this aggressive form of pancreatic tumorigenesis was effectively prevented by genetic ablation of Myc specifically in the pancreas. We then treated moribund, PDA-bearing mice daily with the Mycro3 Myc-inhibitor. The mice survived until killed at two months. PET/CT image analysis (n = 5) demonstrated marked shrinkage of PDA, while immunohistochemical analyses showed an increase in cancer cell apoptosis and reduction in cell proliferation (treated/untreated proliferation index ratio: 0.29, P < .001, n = 3, each group). Tumor growth was also drastically attenuated in Mycro3-treated NOD/SCID mice (n = 12) carrying orthotopic or heterotopic xenografts of human pancreatic cancer cells (eg, mean tumor weight ± SD of treated heterotopic xenografts vs vehicle-treated controls: 15.2±5.8 mg vs 230.2±43.9 mg, P < .001). CONCLUSION: These results provide strong justification for eventual clinical evaluation of anti-Myc drugs as potential chemotherapeutic agents for the treatment of PDA. It has been reported that miR-376a is involved in the formation and progression of several types of cancer. However, the expression and function of miR-376a is still unknown in non-small cell lung carcinomas (NSCLC). In this study, the expression of miR-376a in NSCLC tissues and cell lines were examined by real-time PCR, the effects of miR-376a on cell proliferation, apoptosis and invasion were evaluated in vitro. Luciferase reporter assay was performed to identify the targets of miR-376a. The results showed that miR-376a was significantly downregulated in NSCLC tissues and cell lines. Restoration of miR-376a in NSCLC cell line A549 significantly inhibited cell proliferation, increased cell apoptosis and suppressed cell invasion, compared with control-transfected A549 cells. Luciferase reporter assay showed that c-Myc, an oncogene that regulating cell survival, angiogenesis and metastasis, was a direct target of miR-376a. Over-expression of miR-376a decreased the mRNA and protein levels of c-Myc in A549 cells. In addition, upregulation of c-Myc inhibited miR-376a-induced inhibition of cell proliferation and invasion in A549 cells. Therefore, our results indicate a tumor suppressor role of miR-376a in NSCLC by targeting c-Myc. miR-376a may be a promising therapeutic target for NSCLC. The MYC family of cellular oncogenes includes c-Myc, N-myc, and L-myc, which encode transcriptional regulators involved in the control of cell proliferation and death. Accordingly, these genes become aberrantly activated and expressed in specific types of cancers. For example, c-Myc translocations occur frequently in human B lymphoid tumors, while N-myc gene amplification is frequent in human neuroblastomas. The observed association between aberrations in particular MYC family genes and specific subsets of malignancies might reflect, at least in part, tissue-specific differences in expression or function of a given MYC gene. Since c-Myc and N-myc share substantial functional redundancy, another factor that could influence tumor-specific gene activation would be mechanisms that target aberrations (e.g., translocations) in a given MYC gene in a particular tumor progenitor cell type. We have previously shown that mice deficient for the DNA Ligase4 (Lig4) nonhomologous DNA end-joining factor and the p53 tumor suppressor routinely develop progenitor (pro)-B cell lymphomas that harbor translocations leading to c-Myc amplification. Here, we report that a modified allele in which the c-Myc coding sequence is replaced by N-myc coding sequence (NCR allele) competes well with the wild-type c-Myc allele as a target for oncogenic translocations and amplifications in the Lig4/p53-deficient pro-B cell lymphoma model. Tumor onset, type, and cytological aberrations are similar in tumors harboring either the wild-type c-Myc gene or the NCR allele. Our results support the notion that particular features of the c-Myc locus select it as a preferential translocation/amplification target, compared to the endogenous N-myc locus, in Lig4/p53-deficient pro-B cell lymphomas. Pancreatic adenocarcinoma is a highly malignant cancer that often involves a deregulation of c-Myc. It has been shown that c-Myc plays a pivotal role in the regulation of a variety of physiological processes and is involved in early neoplastic development, resulting in poor progression. Hence, suppression of c-Myc overexpression is a potential strategy for pancreatic cancer therapy. CUDC-907 is a novel dual-acting inhibitor of phosphoinositide 3-kinase (PI3K) and histone deacetylase (HDAC). It has shown potential efficiency in patients with lymphoma, multiple myeloma, or thyroid cancer, as well as in solid tumors with c-Myc alterations, but the evidence is lacking for how CUDC-907 regulates c-Myc. In this study, we investigated the effect of CUDC-907 on human pancreatic cancer cells in vitro and in vivo. Our results showed that CUDC-907 potently inhibited the proliferation of 9 pancreatic cancer cell lines in vitro with IC50 values ranging from 6.7 to 54.5 nM. Furthermore, we revealed the antitumor mechanism of CUDC-907 in Aspc-1, PANC-1, and Capan-1 pancreatic cancer cells: it suppressed the HDAC6 subunit, thus downregulating c-Myc protein levels, which was a mode of action distinct from the existing mechanisms. Consistently, the extraordinary antitumor activity of CUDC-907 accompanied by downregulation of c-Myc and Ki67 expression in tumor tissue was observed in a human pancreatic cancer Aspc-1 xenograft nude mouse model in vivo. Our results suggest that CUDC-907 can be a valuable therapeutic option for treating pancreatic adenocarcinoma.
4,101
Which pathways are involved in cellular senescence?
Cellular senescence requires signal transduction, and the two most important signaling pathways are the P16Ink4a/Rb (retinoblastoma protein) pathway and the P19Arf/P53/P21Cip1 pathway, which interact but independently regulate the process of the cells cycle.
[29608137, 15743671, 33855023]
4,508
Cellular senescence is a program activated by normal cells in response to various types of stress. These include telomere uncapping, DNA damage, oxidative stress, oncogene activity and others. Senescence can occur following a period of cellular proliferation or in a rapid manner in response to acute stress. Once cells have entered senescence, they cease to divide and undergo a series of dramatic morphologic and metabolic changes. Cellular senescence is thought to play an important role in tumor suppression and to contribute to organismal aging, but a detailed description of its physiologic occurrence in vivo is lacking. Recent studies have provided important insights regarding the manner by which different stresses and stimuli activate the signaling pathways leading to senescence. These studies reveal that a population of growing cells may suffer from a combination of different physiologic stresses acting simultaneously. The signaling pathways activated by these stresses are funneled to the p53 and Rb proteins, whose combined levels of activity determine whether cells enter senescence. Here we review recent advances in our understanding of the stimuli that trigger senescence, the molecular pathways activated by these stimuli, and the manner by which these signals determine the entry of a population of cells into senescence. Cellular senescence is a stable cell cycle arrest that can be triggered in normal cells in response to various intrinsic and extrinsic stimuli, as well as developmental signals. Senescence is considered to be a highly dynamic, multi-step process, during which the properties of senescent cells continuously evolve and diversify in a context dependent manner. It is associated with multiple cellular and molecular changes and distinct phenotypic alterations, including a stable proliferation arrest unresponsive to mitogenic stimuli. Senescent cells remain viable, have alterations in metabolic activity and undergo dramatic changes in gene expression and develop a complex senescence-associated secretory phenotype. Cellular senescence can compromise tissue repair and regeneration, thereby contributing toward aging. Removal of senescent cells can attenuate age-related tissue dysfunction and extend health span. Senescence can also act as a potent anti-tumor mechanism, by preventing proliferation of potentially cancerous cells. It is a cellular program which acts as a double-edged sword, with both beneficial and detrimental effects on the health of the organism, and considered to be an example of evolutionary antagonistic pleiotropy. Activation of the p53/p21WAF1/CIP1 and p16INK4A/pRB tumor suppressor pathways play a central role in regulating senescence. Several other pathways have recently been implicated in mediating senescence and the senescent phenotype. Herein we review the molecular mechanisms that underlie cellular senescence and the senescence associated growth arrest with a particular focus on why cells stop dividing, the stability of the growth arrest, the hypersecretory phenotype and how the different pathways are all integrated.
4,102
Which disease phenotype has the worst prognosis in Duchenne Muscular Dystrophy?
A strong association between the risk of cognitive disability and the involvement of groups of DMD isoforms was found. In particular, improvements in the correlation of FSIQ with mutation location were identified when a new classification system for mutations affecting the Dp140 isoform was implemented.
[1865568, 34342696, 32791185, 21178099, 20098710, 15637982]
4,509
The clinical course and prognosis of Duchenne muscular dystrophy (DMD) was compared in patients with deletions of the gene for dystrophin (cDMD) and those without such deletions. A total of 24 patients was followed for at least 2 yrs. At age 12 the rating of the activities of daily life (ADL) and disease stage were less favorable in those patients with deletions of the gene for cDMD. At age 14, no difference in ADL and disease stage was observed between the two groups. The percent vital capacity was lower in those patients with the cDMD deficit. When the prognosis was evaluated by multivariate analysis of the data obtained at age 12, the percent of patients predicted as dying before the age of 20 was 40% for those without the cDMD deficit but 76% for those who were cDMD defective. None of the cDMD defective patients lived longer than 20 yrs, whereas 5 of 14 patients without the cDND deficit survived longer than 20 yrs. Disorders such as cardiac and respiratory failure were also seen more frequently in the cDND defective patients. These results suggest that patients with Duchenne muscular dystrophy with defective cDMD have more severe disease than those without cDMD deficit. Neuromuscular diseases (NMD) encompass a broad spectrum of diseases with variable type of cardiac involvement and there is lack of clinical data on Cardiovascular Magnetic Resonance (CMR) phenotypes or even prognostic value of CMR in NMD. We explored the diagnostic and prognostic value of CMR in NMD-related cardiomyopathies. The study included retrospective analysis of a cohort of 111 patients with various forms of NMD; mitochondrial: n = 14, Friedreich's ataxia (FA): n = 27, myotonic dystrophy: n = 27, Becker/Duchenne's muscular dystrophy (BMD/DMD): n = 15, Duchenne's carriers: n = 6, other: n = 22. Biventricular volumes and function and myocardial late gadolinium enhancement (LGE) pattern and extent were assessed by CMR. Patients were followed-up for the composite clinical endpoint of death, heart failure development or need for permanent pacemaker/intracardiac defibrillator. The major NMD subtypes, i.e. FA, mitochondrial, BMD/DMD, and myotonic dystrophy had significant differences in the incidence of LGE (56%, 21%, 62% & 30% respectively, chi2 = 9.86, p = 0.042) and type of cardiomyopathy phenotype (chi2 = 13.8, p = 0.008), extent/pattern (p = 0.006) and progression rate of LGE (p = 0.006). In survival analysis the composite clinical endpoint differed significantly between NMD subtypes (p = 0.031), while the subgroup with LGE + and LVEF < 50% had the worst prognosis (Log-rank p = 0.0034). We present data from a unique cohort of NMD patients and provide evidence on the incidence, patterns, and the prognostic value of LGE in NMD-related cardiomyopathy. LGE is variably present in NMD subtypes and correlates with LV remodelling, dysfunction, and clinical outcomes in patients with NMD. BACKGROUND: Duchenne muscular dystrophy (DMD) is a fatal progressive muscle-wasting disease caused by mutations in the DMD gene. Dilated cardiomyopathy is the leading cause of death in DMD; therefore, further understanding of this complication is essential to reduce morbidity and mortality. METHODS: A common null variant (R577X) in the ACTN3 gene, which encodes α-actinin-3, has been studied in association with muscle function in healthy individuals; however it has not yet been examined in relationship to the cardiac phenotype in DMD. In this study, we determined the ACTN3 genotype in 163 patients with DMD and examined the correlation between ACTN3 genotypes and echocardiographic findings in 77 of the 163 patients. RESULTS: The genotypes 577RR(RR), 577RX(RX) and 577XX(XX) were identified in 13 (17%), 44 (57%) and 20 (26%) of 77 patients, respectively. We estimated cardiac involvement-free survival rate analyses using Kaplan-Meier curves. Remarkably, the left ventricular dilation (> 55 mm)-free survival rate was significantly lower in patients with the XX null genotype (P < 0.01). The XX null genotype showed a higher risk for LV dilation (hazard ratio 9.04). CONCLUSIONS: This study revealed that the ACTN3 XX null genotype was associated with a lower left ventricular dilation-free survival rate in patients with DMD. These results suggest that the ACTN3 genotype should be determined at the time of diagnosis of DMD to improve patients' cardiac outcomes. OBJECTIVE: Duchenne muscular dystrophy (DMD) is the most common single-gene lethal disorder. Substantial patient-patient variability in disease onset and progression and response to glucocorticoids is seen, suggesting genetic or environmental modifiers. METHODS: Two DMD cohorts were used as test and validation groups to define genetic modifiers: a Padova longitudinal cohort (n = 106) and the Cooperative International Neuromuscular Research Group (CINRG) cross-sectional natural history cohort (n = 156). Single nucleotide polymorphisms to be genotyped were selected from mRNA profiling in patients with severe vs mild DMD, and genome-wide association studies in metabolism and polymorphisms influencing muscle phenotypes in normal volunteers were studied. RESULTS: Effects on both disease progression and response to glucocorticoids were observed with polymorphism rs28357094 in the gene promoter of SPP1 (osteopontin). The G allele (dominant model; 35% of subjects) was associated with more rapid progression (Padova cohort log rank p = 0.003), and 12%-19% less grip strength (CINRG cohort p = 0.0003). CONCLUSIONS: Osteopontin genotype is a genetic modifier of disease severity in Duchenne dystrophy. Inclusion of genotype data as a covariate or in inclusion criteria in DMD clinical trials would reduce intersubject variance, and increase sensitivity of the trials, particularly in older subjects. BACKGROUND: A significant component of the variation in cognitive disability that is observed in Duchenne muscular dystrophy (DMD) is known to be under genetic regulation. In this study we report correlations between standardised measures of intelligence and mutational class, mutation size, mutation location and the involvement of dystrophin isoforms. METHODS AND RESULTS: Sixty two male subjects were recruited as part of a study of the cognitive spectrum in boys with DMD conducted at the Sydney Children's Hospital (SCH). All 62 children received neuropsychological testing from a single clinical psychologist and had a defined dystrophin gene (DMD) mutation; including DMD gene deletions, duplications and DNA point mutations. Full Scale Intelligence Quotients (FSIQ) in unrelated subjects with the same mutation were found to be highly correlated (r = 0.83, p = 0.0008), in contrast to results in previous publications. In 58 cases (94%) it was possible to definitively assign a mutation as affecting one or more dystrophin isoforms. A strong association between the risk of cognitive disability and the involvement of groups of DMD isoforms was found. In particular, improvements in the correlation of FSIQ with mutation location were identified when a new classification system for mutations affecting the Dp140 isoform was implemented. SIGNIFICANCE: These data represent one of the largest studies of FSIQ and mutational data in DMD patients and is among the first to report on a DMD cohort which has had both comprehensive mutational analysis and FSIQ testing through a single referral centre. The correlation between FSIQ results with the location of the dystrophin gene mutation suggests that the risk of cognitive deficit is a result of the cumulative loss of central nervous system (CNS) expressed dystrophin isoforms, and that correct classification of isoform involvement results in improved estimates of risk. About 60% of both Duchenne's muscular dystrophy (DMD) and Becker's muscular dystrophy (BMD) is due to deletions of dystrophin gene. For cases with deletion mutations the "reading frame" hypothesis predicts that deletions which result in disruption of the translation reading frame prevent production of stable protein and are associated with DMD. In contrast, intragenic deletions that involve exons encoding an integral number of triplet codons maintain proper reading frame. The resulting abnormal proteins are stable and partially functional, resulting in a milder and more variable BMD phenotype. To test the validity of this theory,we analyzed 40 patients-19 independent deletions at the DMD/BMD locus. Clinical/molecular correlations based on the altera-tions of the reading frame were valid in 69.2% of cases. After exclusion of: --2 patients with del 3-6 (with no consistent clinical expression); --1 DMD patient with large in-frame deletion; --2 patients that were too young to be classified; --4 patients in whom it was impossible to identify the extent of deletion (del 47 and del 44-45), the correlation between deletion and clinical severity was as predicted in 92.4% of cases. The present data should be useful in establishing the prognosis in individual patients even in sporadic cases with no affected relatives.
4,103
What links developmental pathways to ALS?
A direct link between developmental pathways and ALS is not described. However, cytoskeletal proteins such as KIF5A are implicated in ALS, and the cytoskeletal protein N-cadherin is involved in plasticity of the cerebral cortex. Development depends on connections of the sympathetic nervous system, involving mechanisms such as axon growth, neuron survival, and dendrite growth. BACE1, which is involved in Alzheimer's disease, is also implicated in axonal regeneration.
[30524706, 20832291, 33835400, 34599308, 31233613, 27428653, 31176720, 32236823]
4,510
Plasticity of the cerebral cortex following a modification of the sensorimotor experience takes place in several steps that can last from few hours to several months. Among the mechanisms involved in the dynamic modulation of the cerebral cortex in adults, it is commonly proposed that short-term plasticity reflects changes in synaptic connections. Here, we were interested in the time-course of synaptic plasticity taking place in the somatosensory primary cortex all along a 14-day period of sensorimotor perturbation (SMP), as well as during a recovery phase up to 24 h. Activation and expression level of pre- (synapsin 1, synaptophysin, synaptotagmin 1) and postsynaptic (AMPA and NMDA receptors) proteins, postsynaptic density scaffold proteins (PSD-95 and Shank2), and cytoskeletal proteins (neurofilaments-L and M, β3-tubulin, synaptopodin, N-cadherin) were determined in cortical tissue enriched in synaptic proteins. During the SMP period, most changes were observed as soon as D7 in the presynaptic compartment and were followed, at D14, by changes in the postsynaptic compartment. These changes persisted at least until 24 h of recovery. Proteins involved in synapse structure (scaffolding, adhesion, cytoskeletal) were mildly affected and almost exclusively at D14. We concluded that experience-dependent reorganization of somatotopic cortical maps is accompanied by changes in synaptic transmission with a very close time-course. Amyotrophic lateral sclerosis (ALS) is an adult onset disease but with an increasingly recognized preclinical prodrome. A wide spectrum of investigative approaches has identified loss of inhibitory function at the heart of ALS. In developing an explanation for the onset of ALS, it remains a consideration that ALS has its origins in neonatal derangement of the γ-aminobutyric acid (GABA)-ergic system, with delayed conversion from excitatory to mature inhibitory GABA and impaired excitation/inhibition balance. If this is so, the resulting chronic excitotoxicity could marginalize cortical network functioning very early in life, laying the path for neurodegeneration. The possibility that adult-onset neurodegenerative conditions might have their roots in early developmental derangements is worthy of consideration, particularly in relation to current models of disease pathogenesis. Unraveling the very early molecular events will be crucial in developing a better understanding of ALS and other adult neurodegenerative disorders. Muscle Nerve, 2019. Modeling amyotrophic lateral sclerosis (ALS) with human induced pluripotent stem cells (iPSCs) aims to reenact embryogenesis, maturation and aging of spinal motor neurons (spMNs) in vitro. As the maturity of spMNs grown in vitro compared to spMNs in vivo remains largely unaddressed, it is unclear to what extent this in vitro system captures critical aspects of spMN development and molecular signatures associated with ALS. Here, we compared transcriptomes among iPSC-derived spMNs, fetal spinal tissues and adult spinal tissues. This approach produced a maturation scale revealing that iPSC-derived spMNs were more similar to fetal spinal tissue than to adult spMNs. Additionally, we resolved gene networks and pathways associated with spMN maturation and aging. These networks enriched for pathogenic familial ALS genetic variants and were disrupted in sporadic ALS spMNs. Altogether, our findings suggest that developing strategies to further mature and age iPSC-derived spMNs will provide more effective iPSC models of ALS pathology.
4,104
Is thalidomide used as an immunomodulatory drug nowadays?
Yes.
[28154372, 1605898, 15718159, 20617746, 17168659, 31187860, 28571559, 12412207, 12190008, 29285050, 21048383, 16305990, 22233815, 29920472, 15709921, 11734114, 20223727, 12789488, 17369076, 12803319, 15327481]
4,511
The sedative thalidomide was withdrawn from the market 30 years ago because of its teratogenic and neurotoxic adverse effects. The compound was later discovered to be extremely effective in the treatment of erythema nodosum leprosum, a complication of lepromatous leprosy. This effect is probably due to a direct influence on the immune system, because thalidomide possesses no antibacterial activity. The compound is presently used as an experimental drug in the treatment of a variety of diseases with an autoimmune character, including recurrent aphthosis of nonviral and nonfungal origin in human immunodeficiency virus (HIV) patients. This article reviews the most important chemical and pharmacokinetic properties of thalidomide. The possible mechanisms of the nonsedative effects of thalidomide with respect to the safety of its use in HIV patients are discussed. Because the mechanism of the immunomodulatory effect of thalidomide is unknown, the possibility that the administration of this compound will accelerate the deterioration of the immunological status of HIV patients cannot be excluded. Clinical evidence suggests that thalidomide may aggravate the condition of patients with preexisting peripheral neuropathy. Hypersensitivity reactions to thalidomide may occur more frequently in HIV patients than in other patient groups. Because of the teratogenic activity of thalidomide, reliable contraception must be provided to female patients of childbearing age. Before the introduction of thalidomide therapy to an HIV patient presenting with oral ulcers, a fungal or viral origin of the lesions should be excluded. Thalidomide should not be used in patients with preexisting HIV-related peripheral polyneuropathy, polyradiculopathy or encephalopathy. In patients experiencing a complete remission, the discontinuation of thalidomide treatment and its reintroduction in the case of a relapse are preferable to maintenance therapy. Thalidomide is a drug with bad reputation from the 1960's as it appeared to be teratogenic by causing foetal anomalies. However, in the beginning of 1990s it was shown very antiangiogenic. Its immunological effects were known already from earlier studies. Nowadays its use is accepted in myeloma therapy. It is also used in many study protocols, e.g. in pediatric patients with brainstem tumors. Thalidomide should be used very cautiously for fertile patients because of its teratogenity. Other adverse effects are tiredness, obstipation, thrombosis, and polyneuropathy. Thalidomide is an immunomodulatory agent; although its mechanisms of action are not fully understood, many authors have described its anti-inflammatory and immunosuppressive properties. More interestingly, thalidomide has shown the ability to suppress tumor necrosis factor alpha (TNF alpha) production and to modify the expression of TNF alpha induced adhesion molecules on endothelial cells and on human leukocytes. Thalidomide has been used in several diseases (i.e. dermatological, autoimmune, gastrointestinal). In this review we focus specifically on the use of this drug in disorders with rheumatological features such as lupus erythematosus, rheumatoid arthritis and Still's disease, ankylosing spondylitis, and Behçet's disease. Despite its well known side effects, first of all peripheral nerve involvement and teratogenesis, which can be avoided by following strict guidelines, thalidomide could represent an alternative drug in some rheumatological conditions, particularly in patients who show resistance, contraindication or toxicity with other conventional treatments. Thalidomide was withdrawn from the market in the early sixties because of its teratogenic effects. Despite forty years of research, the mechanism of thalidomide embryopathy has remained unsolved. Thalidomide has various immunomodulatory effects. Thalidomide inhibits TNF alpha production, has T-cell costimulatory properties and modulates the expression of cell surface molecules on leukocytes in vivo. Thalidomide also has anti-angiogenic activity in vivo. Angiogenesis plays an important role in the pathogenesis of both solid tumours and hematologic malignancies such as multiple myeloma and lymphoma. In clinical studies, thalidomide has been used as an inhibitor of angiogenesis. Erythema nodosum leprosum is the only registered indication for the use of thalidomide in the United States of America. Thalidomide is also effective in the treatment of chronic graft-versus-host disease, mucocutaneous lesions in Behçet's syndrome and HIV infections, and multiple myeloma. The US Food and Drug Administration approved thalidomide and its analogues for the treatment of erythema nodosum leprosum, in spite of the notoriety of reports of severe birth defects in the middle of the last century. As immunomodulatory drugs, thalidomide and its analogues have been used to effectively treat various diseases. In the present review, preclinical data about the effects of thalidomide and its analogues on the immune system are integrated, including the effects of cytokines on transdifferentiation, the anti-inflammatory effect, immune cell function regulation and angiogenesis. The present review also investigates the latest developments of thalidomide as a therapeutic option for the treatment of idiopathic pulmonary fibrosis, skin fibrosis, and ophthalmopathies. Thalidomide was developed in the 1950s as a sedative drug and withdrawn in 1961 because of its teratogenic effects, but has been rediscovered as an immuno-modulatory drug. It has been administered successfully for the treatment of erythema nodosum leprosum, aphthous ulceration and cachexia in HIV disease, inflammatory bowel diseases, and several malignant diseases. The suppressive effect of thalidomide on the activation of the nuclear transcription factor NF-κB may explain these effects of thalidomide. NF-κB is retained in the cytoplasm with IκBα, and is activated by a wide variety of inflammatory stimuli including TNF, IL-1 and endotoxin followed by its translocation to the nucleus. Angiogenesis and organogenesis also require gene transcription and signal translocation. The findings shed new light on the anti-inflammatory properties of thalidomide and suggest pharmaceutical actions of thalidomide via interference of transcription mechanism. I reviewed the effects of thalidomide on auto-inflammatory diseases of childhood. After nearly decades of extinction as a sedative and antiemetic, thalidomide reemerged as the parent compound of a novel and promising class of therapeutics termed the immunomodulatory drugs (IMiDs). The analogues of thalidomide, CC-5013 (lenalidomide, Revlimid) and CC-4047 (Actimid) are more potent regulators of cellular immune and cytokine response while lacking some of the dose limiting side effects of the parent compound, such as neurologic toxicity. Preclinical data will be reviewed that outlines these drugs' effects on tumor necrosis alpha, interleukin 12, angiogenesis, and T-cell function. The evolution of the use of thalidomide as a therapeutic for diseases such as multiple myeloma and myelodysplastic syndrome and the promising initial results of the new IMiDs will be reviewed. Thalidomide is a drug that, since its development, has made history in the world of medicine--having been withdrawn and now has returned with a boom as an anticancer and immunomodulatory drug. However, its mode of action in various diseases (i.e. different types of hematologic malignancies, solid tumors) as well as in various infections (i.e. pneumonia, tuberculosis, HIV infection etc.) and related inflammatory conditions is not well understood. As the immune system plays an important role in the pathogenesis of both infection-related as well as noninfectious (i.e. cancer) inflammatory diseases, much research has been done in the past few years to discover and design better immunomodulatory agents. Such immunomodulatory agents should be able to target the immune system in such a way that host suffers minimum damage and normal function of the immune system remains intact. In the present review an attempt is made to highlight the immunomodulatory action of thalidomide in various pathologic conditions. Multiple myeloma (MM) is a disease of unknown, complex etiology that affects primarily older adults. The course of the disease and the patients' survival time are very heterogeneous, but over the last decade, clear progress in the treatment of this incurable disease has been observed. Therapeutics that have proven to be highly effective include the immunomodulatory drug thalidomide and its newer analogs, lenalidomide and pomalidomide, as well as the proteasome inhibitors bortezomib and carfilzomib. However, the administration of some of the treatments, e.g., thalidomide or bortezomib, has also been associated with the occurrence of a serious and common adverse effect, drug-induced peripheral neuropathy. The mechanism of the development of the peripheral neuropathy is poorly understood. Nevertheless, one of its potential causes could be inadequate concentrations of crucial trophic factors, including neurotrophic and/or angiogenic factors, which are responsible for the proliferation, differentiation, survival and death of neuronal and nonneuronal cells. It has been more than three decades since the withdrawal of thalidomide from the marketplace. Thalidomide is attracting growing interest because of its reported immunomodulatory and anti-inflammatory properties. Current evidence indicates that thalidomide reduces the activity of the inflammatory cytokine tumor necrosis factor-alpha by accelerating the degradation of its messenger RNA. Thalidomide inhibits angiogenesis. Recently, thalidomide was approved for sale in the United States for the treatment of erythema nodosum leprosum, an inflammatory complication of Hansen's disease. Thalidomide has been used successfully in several other dermatologic disorders, including aphthous stomatitis, Behcet's syndrome, chronic cutaneous systemic lupus erythematosus, and graft-versus-host disease, the apparent shared characteristic of which is immune dysregulation. Many recent studies have evaluated thalidomide in patients with HIV infection, in which this drug is an efficacious agent against oral aphthous ulcers, HIV-associated wasting syndrome, HIV-related diarrhea, and Kaposi's sarcoma. Only in the last several years has thalidomide been aggressively investigated for its antiangiogenic potential and immunomodulatory properties in various tumor types. Current research on thalidomide in oncology covers investigation in a wide range of both solid tumors and hematologic malignancies. It is now recognized that all cases of multiple myeloma (MM) are preceded by the premalignant condition of monoclonal gammopathy of undetermined significance (MGUS). Although patients with MGUS are generally asymptomatic and currently managed by "watch and wait," the identification of high-risk patients whose disease will progress more rapidly to smoldering MM (SMM) and MM aids in timely intervention. The immunomodulatory agents thalidomide and lenalidomide and the proteasome inhibitor bortezomib are now routine components of MM therapy in both first-line and relapsed/ refractory settings. These targeted agents are used in various combinations with chemotherapy for the treatment of both transplantation-ineligible and transplantation-eligible patients. More recently, a trend toward evaluation of 3- and 4-drug multiagent combinations before transplantation and prolongation of primary therapy has generated new treatment paradigms. Ultimately, the physician's choice of therapy and treatment strategy requires consideration of regimen-associated toxicities and integration of the patient's risk, comorbid status, and response and tolerability of previous treatment regimens. Particular attention needs to be paid to baseline and/or treatment-emergent peripheral neuropathy, thrombotic risk, changes in renal function, and bone health. Despite recent advances, all patients with MM eventually relapse, and efforts to identify novel synergistic combinations and new agents are ongoing. This review highlights challenges in the clinic and newer approaches under evaluation for the treatment and/or management of patients with MGUS, SMM, and MM. Thalidomide was introduced as a sedative and antiemetic agent to the European market in the late 1950s. However, it soon became clear that a hitherto unheard-of incidence of severe birth defects was due to the maternal use of thalidomide and the drug was withdrawn from the market. Despite its teratogenesis, thalidomide is currently being rediscovered because of its known spectrum of anticachectic, antiemetic, mildly hypnotic, anxiolytic, anti-inflammatory, antiangiogenic, and analgesic properties. The mechanism of action of thalidomide is probably based on its immunomodulatory effect, namely the suppression of production of tumor necrosis factor alpha and the modulation of interleukins. A striking but not well-known finding is the effectiveness of thalidomide as an analgesic or analgesic adjuvant. During the early era of thalidomide use, the drug was shown to enhance the analgesic efficacy of a combined treatment with acetylsalicylic acid, phenacetin, and caffeine (APC) by testing "normal volunteers, using electrical stimulation of teeth." The combination of thalidomide and APC was superior to other combinations (APC alone, APC and codeine) with respect to both the total analgesic effect and the duration of this analgesic effect. In 1965 thalidomide was found to be effective in treating the painful subcutaneous manifestations of the leprosy-associated erythema nodosum leprosum, a condition for which it eventually was approved by the United States Food and Drug Administration in 1998. In an animal model of neuropathic pain (chronic constriction injury), thalidomide was shown to reduce both mechanical allodynia and thermal hyperalgesia. Recent studies documented the analgesic efficacy of thalidomide in treating painful mucocutaneous aphthous ulcers associated with HIV syndrome and Behcet's disease.However, to date there are no recent clinical trials that are specifically designed to explore the analgesic potential of thalidomide. In view of the current basic research and clinical findings,we suggest to investigate the potential benefits of thalidomide in severe pain conditions that respond poorly to common pain management approaches such as neuropathic pain, postherpetic neuralgia, or central pain phenomena. Because its mechanism of action is distinct from that of other drugs such as steroids, thalidomide offers the possibility of a combined treatment with other agents with nonoverlapping toxicities. We conclude that thalidomide, when used properly,may enrich the therapeutic regimen in the management of some pain-related conditions. Over the past 50 years, thalidomide has been a target of active investigation in both malignant and inflammatory conditions. Although initially developed for its sedative properties, decades of investigation have identified a multitude of biological effects that led to its classification as an immunomodulatory drug (IMiD). In addition to suppression of tumor necrosis factor-alpha (TNF-alpha), thalidomide effects the generation and elaboration of a cascade of pro-inflammatory cytokines that activate cytotoxic T-cells even in the absence of co-stimulatory signals. Furthermore, vascular endothelial growth factor (VEGF) and beta fibroblast growth factor (bFGF) secretion and cellular response are suppressed by thalidomide, thus antagonizing neoangiogenesis and altering the bone marrow stromal microenvironment in hematologic malignancies. The thalidomide analogs, lenalidomide (CC-5013; Revlimid) and CC-4047 (Actimid), have enhanced potency as inhibitors of TNF-alpha and other inflammatory cytokines, as well as greater capacity to promote T-cell activation and suppress angiogenesis. Both thalidomide and lenalidomide are effective in the treatment of multiple myeloma and myelodysplastic syndromes for which the Food and Drug Administration granted recent approval. Nonetheless, each of these IMiDs remains the subject of active investigation in solid tumors, hematologic malignancies, and other inflammatory conditions. This review will explore the pharmacokinetic and biologic effects of thalidomide and its progeny compounds. Thalidomide has recently shown considerable promise in the treatment of a number of conditions, such as leprosy and cancer. Its effectiveness in the clinic has been ascribed to wide-ranging properties, including anti-TNF-alpha, T-cell costimulatory and antiangiogenic activity. Novel compounds with improved immunomodulatory activity and side effect profiles are also being evaluated. These include selective cytokine inhibitory drugs (SelCIDs), with greatly improved TNF-alpha inhibitory activity, and immunomodulatory drugs (IMiDs) that are structural analogs of thalidomide, with improved properties. A third group recently identified within the SelCID group, with phosphodiesterase type 4-independent activity, is in the process of being characterized in laboratory studies. This review describes the emerging immunological properties of thalidomide, from a historical context to present-day clinical applications, most notably in multiple myeloma but also in other cancers, inflammatory disease, and HIV. We also describe the laboratory studies that have led to the characterization and development of SelCIDs and IMiDs into potentially clinically relevant drugs. Early trial data suggest that these novel immunomodulatory compounds may supercede thalidomide to become established therapies, particularly in certain cancers. Further evidence is required, however, to correlate the clinical efficacy of these compounds with their known immunomodulatory, antiangiogenic, and antitumor properties.
4,105
Does p85α homodimerize?
p110α-free p85α homodimerizes
[21984976, 33127913, 26222500, 26475863]
4,512
The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. We elucidate a p110α-independent role of homodimerized p85α in the positive regulation of PTEN stability and activity. p110α-free p85α homodimerizes via two intermolecular interactions (SH3:proline-rich region and BH:BH) to selectively bind unphosphorylated activated PTEN. As a consequence, homodimeric but not monomeric p85α suppresses the PI3K pathway by protecting PTEN from E3 ligase WWP2-mediated proteasomal degradation. Further, the p85α homodimer enhances the lipid phosphatase activity and membrane association of PTEN. Strikingly, we identified cancer patient-derived oncogenic p85α mutations that target the homodimerization or PTEN interaction surface. Collectively, our data suggest the equilibrium of p85α monomer-dimers regulates the PI3K pathway and disrupting this equilibrium could lead to disease development.
4,106
Which are the components that evaluate druglikeness?
Lipinski's rule states that, in general, an orally active drug has no more than one violation of the following criteria: No more than 5 hydrogen bond donors (the total number of nitrogen–hydrogen and oxygen–hydrogen bonds) No more than 10 hydrogen bond acceptors (all nitrogen or oxygen atoms) A molecular mass less than 500 daltons An octanol-water partition coefficient (log P) that does not exceed 5
[33217892, 26771590, 22778837, 11259830, 11300855, 31817628, 21480669, 21142079]
4,513
In the present work, the anti-inflammatory and antiasthmatic potential of biseugenol, isolated as the main component from n-hexane extract from leaves of Nectandra leucantha and chemically prepared using oxidative coupling from eugenol, was evaluated in an experimental model of mixed-granulocytic asthma. Initially, in silico studies of biseugenol showed good predictions for drug-likeness, with adherence to Lipinski's rules of five (RO5), good Absorption, Distribution, Metabolism and Excretion (ADME) properties and no alerts for Pan-Assay Interference Compounds (PAINS), indicating adequate adherence to perform in vivo assays. Biseugenol (20 mg·kg-1) was thus administered intraperitoneally (four days of treatment) and resulted in a significant reduction in both eosinophils and neutrophils of bronchoalveolar lavage fluid in ovalbumin-sensitized mice with no statistical difference from dexamethasone (5 mg·kg-1). As for lung function parameters, biseugenol (20 mg·kg-1) significantly reduced airway and tissue damping in comparison to ovalbumin group, with similar efficacy to positive control dexamethasone. Airway hyperresponsiveness to intravenous methacholine was reduced with biseugenol but was inferior to dexamethasone in higher doses. In conclusion, biseugenol displayed antiasthmatic effects, as observed through the reduction of inflammation and airway hyperresponsiveness, with similar effects to dexamethasone, on mixed-granulocytic ovalbumin-sensitized mice. The chemical structure of a drug determines its physicochemical properties, further determines its ADME/Tox properties, and ultimately affects its pharmacological activity. Medicinal chemists can regulate the pharmacological activity of drug molecules by modifying their structure. Ring systems and functional groups are important components of a drug. The proportion of non-hydrocarbon atoms among non-hydrogen atoms reflects the heavy atoms proportion of a drug. The three factors have considerable potential for the assessment of the drug-like properties of organic molecules. However, to the best of our knowledge, there have been no studies to systematically analyze the simultaneous effects of the number of aromatic and non-aromatic rings, the number of some special functional groups and the proportion of heavy atoms on the drug-like properties of an organic molecule. To this end, the numbers of aromatic and non-aromatic rings, the numbers of some special functional groups and the heavy atoms proportion of 6891 global approved small drugs have been comprehensively analyzed. We first uncovered three important structure-related criteria closely related to drug-likeness, namely: (1) the best numbers of aromatic and non-aromatic rings are 2 and 1, respectively; (2) the best functional groups of candidate drugs are usually -OH, -COOR and -COOH in turn, but not -CONHOH, -SH, -CHO and -SO3H. In addition, the -F functional group is beneficial to CNS drugs, and -NH2 functional group is beneficial to anti-infective drugs and anti-cancer drugs; (3) the best R value intervals of candidate drugs are in the range of 0.05-0.50 (preferably 0.10-0.35), and R value of the candidate CNS drugs should be as small as possible in this interval. We envision that the three chemical structure-related criteria may be applicable in a prospective manner for the identification of novel candidate drugs and will provide a theoretical foundation for designing new chemical entities with good drug-like properties. Combinatorial chemistry needs focused molecular diversity applied to the druglike chemical space (drugspace). A drugspace map can be obtained by systematically applying the same conventions when examining the chemical space, in a manner similar to the Mercator convention in geography: Rules are equivalent to dimensions (e.g., longitude and latitude), while structures are equivalent to objects (e.g., cities and countries). Selected rules include size, lipophilicity, polarizability, charge, flexibility, rigidity, and hydrogen bond capacity. For these, extreme values were set, e.g., maximum molecular weight 1500, calculated negative logarithm of the octanol/water partition between -10 and 20, and up to 30 nonterminal rotatable bonds. Only S, N, O, P, and halogens were considered as elements besides C and H. Selected objects include a set of "satellite" structures and a set of representative drugs ("core" structures). Satellites, intentionally placed outside drugspace, have extreme values in one or several of the desired properties, while containing druglike chemical fragments. ChemGPS (chemical global positioning system) is a tool that combines these predefined rules and objects to provide a global drugspace map. The ChemGPS drugspace map coordinates are t-scores extracted via principal component analysis (PCA) from 72 descriptors that evaluate the above-mentioned rules on a total set of 423 satellite and core structures. Global ChemGPS scores describe well the latent structures extracted with PCA for a set of 8599 monocarboxylates, a set of 45 heteroaromatic compounds, and for 87 alpha-amino acids. ChemGPS positions novel structures in drugspace via PCA-score prediction, providing a unique mapping device for the druglike chemical space. ChemGPS scores are comparable across a large number of chemicals and do not change as new structures are predicted, making this tool a well-suited reference system for comparing multiple libraries and for keeping track of previously explored regions of the chemical space. Adequate bioavailability is one of the essential properties for an orally administered drug. Lipinski and others have formulated simplified rules in which compounds that satisfy selected physiochemical properties, for example, molecular weight (MW) ≤ 500 or the logarithm of the octanol-water partition coefficient, log P(o/w) < 5, are anticipated to likely have pharmacokinetic properties appropriate for oral administration. However, these schemes do not simultaneously consider the combination of the physiochemical properties, complicating their application in a more automated fashion. To overcome this, we present a novel method to select compounds with a combination of physicochemical properties that maximize bioavailability and druglikeness based on compounds in the World Drug Index database. In the study four properties, MW, log P(o/w), number of hydrogen bond donors, and number of hydrogen acceptors, were combined into a 4-dimensional (4D) histogram, from which a scoring function was defined on the basis of a 4D dependent multivariate Gaussian model. The resulting equation allows for assigning compounds a bioavailability score, termed 4D-BA, such that chemicals with higher 4D-BA scores are more likely to have oral druglike characteristics. The descriptor is validated by applying the function to drugs previously categorized in the Biopharmaceutics Classification System, and examples of application of the descriptor are given in the context of previously published studies targeting heme oxygenase and SHP2 phosphatase. The approach is anticipated to be useful in early lead identification studies in combination with clustering methods to maximize chemical and structural diversity when selecting compounds for biological assays from large database screens. It may also be applied to prioritize synthetically feasible chemical modifications during lead compound optimization.
4,107
Do angiotensin-converting-enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) increase the likelihood of severe COVID-19?
No. Patients receiving angiotensin-converting-enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) should continue treatment with these agents if there is no other reason for discontinuation. Despite speculation that patients with COVID-19 who are receiving these agents may be at increased risk for adverse outcomes, accumulating evidence does not support an association of ACE inhibitors and ARBs with more severe disease. In addition, stopping these agents in some patients can exacerbate comorbid cardiovascular or kidney disease and increase mortality.
[33222020, 32348166, 33085063, 32685191, 32242182, 32579597, 33614350, 32558877, 33891615, 33981731, 34611496, 32422062, 34599472, 32875060, 33504565, 33842874, 32651067, 32474043, 33748156, 32918209, 33038021, 32587982, 33095513, 32485082, 32611676, 32320478, 34155486, 32965603, 32737124, 33201001, 33210357, 32514935, 33658619, 32757246, 33231487]
4,514
Association of renin-angiotensin system inhibitors with risk of death in patients with hypertension (HTN) and coronavirus disease 2019 (COVID-19) is not well characterized. The aim of this study was to evaluate the outcomes of patients with HTN and COVID-19 with respect to different chronic antihypertensive drug intake. We performed a retrospective, observational study from a large cohort of patients with HTN and with a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection admitted to the Emergency Rooms (ER) of the Piacenza Hospital network from February 21, 2020 to March 20, 2020. There were 1050 patients admitted to the ERs of the Piacenza Hospital network with COVID-19. HTN was present in 590 patients [median age, 76.2 years (IQR 68.2-82.6)]; 399 (66.1%) patients were male. Of them, 248 patients were chronically treated with ACEi, 181 with ARBs, and 161 with other drugs (O-drugs) including beta blockers, diuretics and calcium-channel inhibitors. With respect to the antihypertensive use, there was no difference between comorbid conditions. During a follow-up of 38 days (IQR 7.0-46.0), 256 patients (43.4%) died, without any difference stratifying for antihypertensive drugs. Of them, 107 (43.1%) were in ACEi group vs 67 (37%) in ARBs group vs 82 (50.7%) in O-drugs group, (log-rank test: p = 0.066). In patients with HTN and COVID-19, neither ACEi nor ARBs were independently associated with mortality. After adjusting for potential confounders in risk prediction, the rate of death was similar. Our data confirm Specialty Societal recommendations, suggesting that treatment with ACEIs or ARBs should not be discontinued because of COVID-19. Targeting the renin-angiotensin system is proposed to affect mortality due to coronavirus disease 2019 (COVID-19). We aimed to compare the mortality rates in COVID-19 patients who received angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEIs/ARBs) and those who did not. In this retrospective cohort study, mortality was considered as the main outcome measure. All underlying diseases were assessed by the chronic use of medications related to each condition. We defined two main groups based on the ACEIs/ARBs administration. A logistic regression model was designed to define independent predictors of mortality as well as a Cox regression analysis. In total, 2553 patients were included in this study. The mortality frequency was higher in patients with a history of underlying diseases (22.4% vs 12.7%, P value < 0.001). The mortality rate in patients who received ACEIs/ARBs were higher than non-receivers (29.3% vs. 19.5%, P value = 0.013, OR = 1.3, 95% CI 1.1, 1.7) in the univariate analysis. However, the use of ACEIs/ARBs was a protective factor against mortality in the model when adjusted for underlying conditions, length of stay, age, gender, and ICU admission (P value < 0.001, OR = 0.5, 95% CI 0.3, 0.7). The Kaplan-Meier curve showed an overall survival of approximately 85.7% after a 120-day follow-up. ACEIs/ARBs are protective factors against mortality in COVID-19 patients with HTN, and these agents can be considered potential therapeutic options in this disease. The survival probability is higher in ACEIs/ARBs receivers than non-receivers. There is current debate concerning the use of angiotensin-converting enzyme (ACE) inhibitors or angiotensin II type 1 receptor blockers (ARBs), for hypertension management, during COVID-19 infection. Specifically, the suggestion has been made that ACE inhibitors or ARBs could theoretically contribute to infection via increasing ACE2 receptor expression and hence increase viral load. The ACE2 receptor is responsible for binding the SAR-CoV2 viral spike and causing COVID-19 infection. What makes the argument somewhat obtuse for ACE inhibitors or ARBs is that ACE2 receptor expression can be increased by compounds that activate or increase the expression of SIRT1. Henceforth common dietary interventions, vitamins and nutrients may directly or indirectly influence the cellular expression of the ACE2 receptor. There are many common compounds that can increase the expression of the ACE2 receptor including Vitamin C, Metformin, Resveratrol, Vitamin B3 and Vitamin D. It is important to acknowledge that down-regulation or blocking the cellular ACE2 receptor will likely be pro-inflammatory and may contribute to end organ pathology and mortality in COVID-19. In conclusion from the perspective of the ACE2 receptor, COVID-19 prevention and treatment are distinctly different. This letter reflects on this current debate and suggests angiotensin-converting enzyme inhibitors and ARBs are likely beneficial during COVID-19 infection for hypertensive and normotensive patients. AIMS: This retrospective case-control study was aimed at identifying potential independent predictors of severe/lethal COVID-19, including the treatment with Angiotensin-Converting Enzyme inhibitors (ACEi) and/or Angiotensin II Receptor Blockers (ARBs). METHODS AND RESULTS: All adults with SARS-CoV-2 infection in two Italian provinces were followed for a median of 24 days. ARBs and/or ACEi treatments, and hypertension, diabetes, cancer, COPD, renal and major cardiovascular diseases (CVD) were extracted from clinical charts and electronic health records, up to two years before infection. The sample consisted of 1603 subjects (mean age 58.0y; 47.3% males): 454 (28.3%) had severe symptoms, 192 (12.0%) very severe or lethal disease (154 deaths; mean age 79.3 years; 70.8% hypertensive, 42.2% with CVD). The youngest deceased person aged 44 years. Among hypertensive subjects (n = 543), the proportion of those treated with ARBs or ACEi were 88.4%, 78.7% and 80.6% among patients with mild, severe and very severe/lethal disease, respectively. At multivariate analysis, no association was observed between therapy and disease severity (Adjusted OR for very severe/lethal COVID-19: 0.87; 95% CI: 0.50-1.49). Significant predictors of severe disease were older age (with AORs largely increasing after 70 years of age), male gender (AOR: 1.76; 1.40-2.23), diabetes (AOR: 1.52; 1.05-2.18), CVD (AOR: 1.88; 1.32-2.70) and COPD (AOR: 1.88; 1.11-3.20). Only gender, age and diabetes also predicted very severe/lethal disease. CONCLUSION: No association was found between COVID-19 severity and treatment with ARBs and/or ACEi, supporting the recommendation to continue medication for all patients unless otherwise advised by their physicians. Objective In this study, we aimed to compare the severity and outcomes in hypertensive patients presenting with coronavirus disease 2019 (COVID-19) who were taking angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) and those who were on other antihypertensive drugs. Methods This retrospective cohort study involved 182 hypertensive patients who presented with COVID-19 infection. The study population comprised 91 patients who were taking ACEIs/ARBs (group A) and 91 patients who were taking other antihypertensive drugs such as β-blockers (BBs), calcium channel blockers (CCBs), or thiazides (group B). All patients were provided the same type of treatment for the management of COVID-19. We recorded the data related to demographic and anthropometric variables as well as clinical symptoms during the treatment period. Disease severity and hospital mortality were the primary study endpoints. Results There was no significant difference in COVID-19-related outcomes between the groups except for the severity of lung infiltration on chest X-rays. There were 37 (41.1%) patients having >50% lung infiltration in group A and 53 (58.2%) in group B (p-value: 0.02). Severe disease was diagnosed in 37 (40.7%) patients in group A compared to 39 (42.7%) patients in group B (p-value: 0.76). In-hospital mortality was noted in 17 (18.7%) patients in group A and 22 (24.2%) patients in group B (p-value: 0.36). Conclusion Based on our results, we did not find any significant association between the use of ACEIs/ARBs and either the severity of COVID-19 infection necessitating admission to ICU or in-hospital mortality. IMPORTANCE: It has been hypothesized that angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) may make patients more susceptible to coronavirus disease 2019 (COVID-19) and to worse outcomes through upregulation of the functional receptor of the virus, angiotensin-converting enzyme 2. OBJECTIVE: To examine whether use of ACEI/ARBs was associated with COVID-19 diagnosis and worse outcomes in patients with COVID-19. DESIGN, SETTING, AND PARTICIPANTS: To examine outcomes among patients with COVID-19, a retrospective cohort study using data from Danish national administrative registries was conducted. Patients with COVID-19 from February 22 to May 4, 2020, were identified using ICD-10 codes and followed up from day of diagnosis to outcome or end of study period (May 4, 2020). To examine susceptibility to COVID-19, a Cox regression model with a nested case-control framework was used to examine the association between use of ACEI/ARBs vs other antihypertensive drugs and the incidence rate of a COVID-19 diagnosis in a cohort of patients with hypertension from February 1 to May 4, 2020. EXPOSURES: ACEI/ARB use was defined as prescription fillings 6 months prior to the index date. MAIN OUTCOMES AND MEASURES: In the retrospective cohort study, the primary outcome was death, and a secondary outcome was a composite outcome of death or severe COVID-19. In the nested case-control susceptibility analysis, the outcome was COVID-19 diagnosis. RESULTS: In the retrospective cohort study, 4480 patients with COVID-19 were included (median age, 54.7 years [interquartile range, 40.9-72.0]; 47.9% men). There were 895 users (20.0%) of ACEI/ARBs and 3585 nonusers (80.0%). In the ACEI/ARB group, 18.1% died within 30 days vs 7.3% in the nonuser group, but this association was not significant after adjustment for age, sex, and medical history (adjusted hazard ratio [HR], 0.83 [95% CI, 0.67-1.03]). Death or severe COVID-19 occurred in 31.9% of ACEI/ARB users vs 14.2% of nonusers by 30 days (adjusted HR, 1.04 [95% CI, 0.89-1.23]). In the nested case-control analysis of COVID-19 susceptibility, 571 patients with COVID-19 and prior hypertension (median age, 73.9 years; 54.3% men) were compared with 5710 age- and sex-matched controls with prior hypertension but not COVID-19. Among those with COVID-19, 86.5% used ACEI/ARBs vs 85.4% of controls; ACEI/ARB use compared with other antihypertensive drugs was not significantly associated with higher incidence of COVID-19 (adjusted HR, 1.05 [95% CI, 0.80-1.36]). CONCLUSIONS AND RELEVANCE: Prior use of ACEI/ARBs was not significantly associated with COVID-19 diagnosis among patients with hypertension or with mortality or severe disease among patients diagnosed as having COVID-19. These findings do not support discontinuation of ACEI/ARB medications that are clinically indicated in the context of the COVID-19 pandemic. Author information: (1)Department of Population Health Sciences, Division of Health System Innovation and Research, University of Utah School of Medicine, Salt Lake City, UT, United States of America. (2)Department of Medicine, Renal-Electrolyte and Hypertension Division, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States of America. (3)Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America. (4)George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT, United States of America. (5)Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States of America. (6)Department of Medicine, Division of Cardiology, University of Utah School of Medicine, Salt Lake City, UT, United States of America. (7)Department of Pediatrics, Section of Nephrology, Brenner Children's Hospital, Wake Forest School of Medicine, Winston Salem, NC, United States of America. (8)Division of Public Health Sciences, Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston Salem, NC, United States of America. (9)Department of Medicine, Division of Cardiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America. (10)Department of Pharmacotherapy and Translational Research, University of Florida College of Pharmacy, Gainesville, FL, United States of America. (11)Department of Medicine, University of Florida, College of Medicine, Gainesville, FL, United States of America. (12)Institute for Health Research, Kaiser Permanente Colorado, Aurora, CO, United States of America. (13)Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD. (14)Department of Public Health; University of Massachusetts Lowell, Lowell, MA, United States of America. (15)Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, United States of America. (16)Department of Medicine, Division of Cardiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America. (17)Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States of America. (18)MedStar Washington Hospital Center, Washington, DC, United States of America. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) share a target receptor with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The use of ACEIs/ARBs may cause angiotensin-converting enzyme 2 receptor upregulation, facilitating the entry of SARS-CoV-2 into host cells. There is concern that the use of ACEIs/ARBs could increase the risks of severe COVID-19 and mortality. The impact of discontinuing these drugs in patients with COVID-19 remains uncertain. We aimed to assess the association between the use of ACEIs/ARBs and the risks of mortality and severe disease in patients with COVID-19. A systematic search was performed in PubMed, EMBASE, Cochrane Library, and MedRxiv.org from December 1, 2019, to June 20, 2020. We also identified additional citations by manually searching the reference lists of eligible articles. Forty-two observational studies including 63,893 participants were included. We found that the use of ACEIs/ARBs was not significantly associated with a reduction in the relative risk of all-cause mortality [odds ratio (OR) = 0.87, 95% confidence interval (95% CI) = 0.75-1.00; I 2 = 57%, p = 0.05]. We found no significant reduction in the risk of severe disease in the ACEI subgroup (OR = 0.95, 95% CI = 0.88-1.02, I 2 = 50%, p = 0.18), the ARB subgroup (OR = 1.03, 95% CI = 0.94-1.13, I 2 = 62%, p = 0.48), or the ACEI/ARB subgroup (OR = 0.83, 95% CI = 0.65-1.08, I 2 = 67%, p = 0.16). Moreover, seven studies showed no significant difference in the duration of hospitalization between the two groups (mean difference = 0.33, 95% CI = -1.75 to 2.40, p = 0.76). In conclusion, the use of ACEIs/ARBs appears to not have a significant effect on mortality, disease severity, or duration of hospitalization in COVID-19 patients. On the basis of the findings of this meta-analysis, there is no support for the cessation of treatment with ACEIs or ARBs in patients with COVID-19. INTRODUCTION: There is significant interest in the use of angiotensin converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) in coronavirus disease 2019 (COVID-19) and concern over potential adverse effects since these medications upregulate the severe acute respiratory syndrome coronavirus 2 host cell entry receptor ACE2. Recent studies on ACE-I and ARB in COVID-19 were limited by excluding outpatients, excluding patients by age, analyzing ACE-I and ARB together, imputing missing data, and/or diagnosing COVID-19 by chest computed tomography without definitive reverse transcription polymerase chain reaction (RT-PCR), all of which are addressed here. METHODS: We performed a retrospective cohort study of 1023 COVID-19 patients diagnosed by RT-PCR at Stanford Hospital through April 8, 2020 with a minimum follow-up time of 14 days to investigate the association between ACE-I or ARB use with outcomes. RESULTS: Use of ACE-I or ARB medications was not associated with increased risk of hospitalization, intensive care unit admission, or death. Compared to patients with charted past medical history, there was a lower risk of hospitalization for patients on ACE-I (odds ratio (OR) 0.43; 95% confidence interval (CI) 0.19-0.97; P = 0.0426) and ARB (OR 0.39; 95% CI 0.17-0.90; P = 0.0270). Compared to patients with hypertension not on ACE-I or ARB, patients on ARB medications had a lower risk of hospitalization (OR 0.09; 95% CI 0.01-0.88; P = 0.0381). CONCLUSIONS: These findings suggest that the use of ACE-I and ARB is not associated with adverse outcomes and may be associated with improved outcomes in COVID-19, which is immediately relevant to care of the many patients on these medications. BACKGROUND: The role of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-receptor blockers (ARBs) in coronavirus disease 2019 (COVID-19) susceptibility, severity, and treatment is unclear. PURPOSE: To evaluate, on an ongoing basis, whether use of ACEIs or ARBs either increases risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or is associated with worse COVID-19 disease outcomes, and to assess the efficacy of these medications for COVID-19 treatment. DATA SOURCES: MEDLINE (Ovid) and Cochrane Database of Systematic Reviews from 2003 to 4 May 2020, with planned ongoing surveillance for 1 year; the World Health Organization database of COVID-19 publications and medRxiv.org through 17 April 2020; and ClinicalTrials.gov to 24 April 2020, with planned ongoing surveillance. STUDY SELECTION: Observational studies and trials in adults that examined associations and effects of ACEIs or ARBs on risk for SARS-CoV-2 infection and COVID-19 disease severity and mortality. DATA EXTRACTION: Single-reviewer abstraction confirmed by another reviewer, independent evaluation by 2 reviewers of study quality, and collective assessment of certainty of evidence. DATA SYNTHESIS: Two retrospective cohort studies found that ACEI and ARB use was not associated with a higher likelihood of receiving a positive SARS-CoV-2 test result, and 1 case-control study found no association with COVID-19 illness in a large community (moderate-certainty evidence). Fourteen observational studies, involving a total of 23 565 adults with COVID-19, showed consistent evidence that neither medication was associated with more severe COVID-19 illness (high-certainty evidence). Four registered randomized trials plan to evaluate ACEIs and ARBs for treatment of COVID-19. LIMITATION: Half the studies were small and did not adjust for important confounding variables. CONCLUSION: High-certainty evidence suggests that ACEI or ARB use is not associated with more severe COVID-19 disease, and moderate-certainty evidence suggests no association between use of these medications and positive SARS-CoV-2 test results among symptomatic patients. Whether these medications increase the risk for mild or asymptomatic disease or are beneficial in COVID-19 treatment remains uncertain. PRIMARY FUNDING SOURCE: None. (PROSPERO: registration number pending). BACKGROUND: The association of ACE inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) with disease severity of patients with COVID-19 is still unclear. We conducted a systematic review and meta-analysis to investigate if ACEI/ARB use is associated with the risk of mortality and severe disease in patients with COVID-19. METHODS: We searched all available clinical studies that included patients with confirmed COVID-19 who could be classified into an ACEI/ARB group and a non-ACEI/ARB group up until 4 May 2020. A meta-analysis was performed, and primary outcomes were all-cause mortality and severe disease. RESULTS: ACEI/ARB use did not increase the risk of all-cause mortality both in meta-analysis for 11 studies with 12 601 patients reporting ORs (OR=0.52 (95% CI=0.37 to 0.72), moderate certainty of evidence) and in 2 studies with 8577 patients presenting HRs. For 12 848 patients in 13 studies, ACEI/ARB use was not related to an increased risk of severe disease in COVID-19 (OR=0.68 (95% CI=0.44 to 1.07); I2=95%, low certainty of evidence). CONCLUSIONS: ACEI/ARB therapy was not associated with increased risk of all-cause mortality or severe manifestations in patients with COVID-19. ACEI/ARB therapy can be continued without concern of drug-related worsening in patients with COVID-19. Publisher: INTRODUCTION: Les antagonistes des récepteurs de l'angiotensine (ARA) et/ou les inhibiteurs de l'enzyme de conversion de l'angiotensine (IECA) feraient varier la mortalité liée à la COVID-19, mais il est possible que les méta-analyses actuelles qui combinaient les résultats bruts et ajustés soient invalidées du fait que les comorbidités sont plus fréquentes chez les utilisateurs d'ARA/IECA. MÉTHODES: Nous avons effectué des recherches dans les bases de données PubMed/MEDLINE/Embase pour trouver des études de cohorte et des méta-analyses qui portent sur la mortalité associée à un traitement préexistant par ARA/IECA chez les patients hospitalisés atteints de la COVID-19. Nous avons utilisé la métarégression à effets aléatoires pour calculer les rapports de cotes regroupés de mortalité ajustés en fonction du déséquilibre de l’âge, du sexe, et de la prévalence des maladies cardiovasculaires, de l'hypertension, du diabète sucré et de l'insuffisance rénale chronique entre les utilisateurs et les non-utilisateurs d'ARA/IECA dans le cadre de l’étude durant la synthèse des données. RÉSULTATS: Dans les 30 études portant sur 17 281 patients, 22 %, 68 %, 25 % et 11 % avaient respectivement une maladie cardiovasculaire, de l'hypertension, le diabète sucré et de l'insuffisance rénale chronique. L'utilisation des ARA/IECA a été associée à une mortalité significativement plus faible après avoir tenu compte des facteurs confusionnels potentiels (rapport de cotes 0,77 [intervalle de confiance à 95 % : 0,62, 0,96]). En revanche, la méta-analyse sur l'utilisation des ARA/IECA n'a pas été associée de façon significative à la mortalité lorsque toutes les études ont été combinées sans ajustement sur les facteurs confusionnels (0,87 [intervalle de confiance à 95 % : 0,71, 1,08]). CONCLUSIONS: L'utilisation des ARA/IECA a été associée à la diminution de la mortalité au sein des cohortes de patients atteints de la COVID-19 après l'ajustement en fonction de l’âge, du sexe, des maladies cardiovasculaires, de l'hypertension, du diabète et de l'insuffisance rénale chronique. Les méta-analyses non ajustées peuvent ne pas permettre de déterminer si les ARA/IECA sont associés à la mortalité liée à la COVID-19 en raison du biais d'indication. INTRODUCCIÓN: Existe controversia respecto al uso de los inhibidores de la enzima convertidora de angiotensina (IECA) o los bloqueadores de los receptores tipo I de la angiotensina II (ARA-II) para el tratamiento de la hipertensión arterial en COVID-19. Se ha sugerido que estos fármacos podrían tanto aumentar como reducir el riesgo de COVID-19 grave. PACIENTES Y MÉTODO: Estudio de cohortes retrospectivo de pacientes consecutivos de un área sanitaria, con hipertensión e infección por SARS-CoV-2. Variable de resultados: ingreso hospitalario por COVID-19 grave. RESULTADOS: Fueron diagnosticados 539 sujetos por infección por SARS-CoV-2. De estos, 157 (29,1%) eran hipertensos y se incluyeron en el estudio. Se ingresaron 69 (43,9%) pacientes por COVID-19 grave. En el análisis multivariante, la edad más elevada, la diabetes y la miocardiopatía hipertensiva se relacionaron con el riesgo de ingreso hospitalario. El tratamiento con ARA-II se asoció con un riesgo significativamente más bajo de ingreso (HR: 0,29, IC 95%: 0,10-0,88). Una tendencia similar, aunque no significativa, se encontró para los IECA. CONCLUSIÓN: el tratamiento con ARA-II o IECA no se asoció con una peor evolución clínica en pacientes hipertensos consecutivos infectados por SARS-CoV-2. Introduction: Corona Virus disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. The aim of this study was to investigate the impact of being on an Angiotensin-Converting Enzyme Inhibitors (ACEI) and/or Angiotensin Receptor Blockers (ARB) on hospital admission, on the following COVID-19 outcomes: disease severity, ICU admission, and mortality. Methods: The charts of all patients consecutively diagnosed with COVID-19 from the 24th of February to the 16th of June of the year 2020 in Jaber Al-Ahmed Al-Sabah hospital in Kuwait were checked. All related patient information and clinical data was retrieved from the hospitals electronic medical record system. The primary outcome was COVID-19 disease severity defined as the need for Intensive Care Unit (ICU) admission. Secondary outcome was mortality. Results: A total of 4,019 COVID-19 patients were included, of which 325 patients (8.1%) used ACEI/ARB, users of ACEI/ARB were found to be significantly older (54.4 vs. 40.5 years). ACEI/ARB users were found to have more co-morbidities; diabetes (45.8 vs. 14.8%) and hypertension (92.9 vs. 13.0%). ACEI/ARB use was found to be significantly associated with greater risk of ICU admission in the unadjusted analysis [OR, 1.51 (95% CI: 1.04-2.19), p = 0.028]. After adjustment for age, gender, nationality, coronary artery disease, diabetes and hypertension, ICU admission was found to be inversely associated with ACEI use [OR, 0.57 (95% CI: 0.34-0.88), p = 0.01] and inversely associated with mortality [OR, 0.56 (95% CI: 0.33-0.95), p = 0.032]. Conclusion: The current evidence in the literature supports continuation of ACEI/ARB medications for patients with co-morbidities that acquire COVID-19 infection. Although, the protective effects of such medications on COVID-19 disease severity and mortality remain unclear, the findings of the present study support the use of ACEI/ARB medication. INTRODUCTION: The use of renin-angiotensin system (RAS) inhibitors, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), was alleged to cause a more severe course of novel coronavirus disease 2019 (COVID-19). METHODS: We systematically reviewed the published studies to assess the association of RAS inhibitors with mortality as well as disease severity in COVID-19 patients. A systematic literature search was performed to retrieve relevant original studies investigating mortality and severity (severe/critical disease) in COVID-19 patients with and without exposure to RAS inhibitors. RESULTS: A total of 59 original studies were included for qualitative synthesis. Twenty-four studies that reported adjusted effect sizes (24 studies reported mortality outcomes and 16 studies reported disease severity outcomes), conducted in RAS inhibitor-exposed and unexposed groups, were pooled in random-effects models to estimate overall risk. Quality assessment of studies revealed that most of the studies included were of fair quality. The use of an ACEI/ARB in COVID-19 patients was significantly associated with lower odds (odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.56-0.95; n = 18,749) or hazard (hazard ratio [HR] = 0.75, 95% CI 0.60-0.95; n = 26,598) of mortality compared with non-use of ACEI/ARB. However, the use of an ACEI/ARB was non-significantly associated with lower odds (OR = 0.91, 95% CI 0.75-1.10; n = 7446) or hazard (HR = 0.73, 95% CI 0.33-1.66; n = 6325) of developing severe/critical disease compared with non-use of an ACEI/ARB. DISCUSSION: Since there was no increased risk of harm, the use of RAS inhibitors for hypertension and other established clinical indications can be maintained in COVID-19 patients. Some have hypothesized that the use of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin-receptor blockers (ARB) may modify susceptibility to coronavirus disease-2019 (COVID-19) in humans. Thus, we conducted two meta-analyses to investigate the effect of ACEI and ARB on mortality and susceptibility to COVID-19. Pubmed and EMBASE were searched through June 2020 to identify clinical trials that investigated the testing positive and in-hospital mortality rates for COVID-19 for those who were treated with ACEI and/or ARB and for those who were not treated with ACEI or ARB. The first analysis investigated the testing positive rate of COVID-19. The second analysis investigated the in-hospital mortality rate for patients with COVID-19. Three eligible studies for the first analysis and 14 eligible studies for the second analysis were identified. The first analysis demonstrated that the use of ACEI or ARB did not affect the testing positive rates (odds ratio [OR] [confidence interval [CI]] = 0.96 [0.88-1.04]; p = .69, OR [CI] = 0.99 [0.91-1.08]; p = 0.35, respectively). The second analysis showed that the use of ACEI and/or ARB did not affect in-hospital mortality (risk ratio [RR] 95% [CI]] = 0.88 [0.64-1.20], p = 0.42). The subgroup analysis by limiting studies of patients with hypertension showed ACEI and/or ARB use was associated with a significant reduction of in-hospital mortality compared with no ACEI or ARB use (RR [CI] = 0.66 [0.49-0.89], p = 0.004). Our analysis demonstrated that ACEI and/or ARB use was associated neither with testing positive rates of COVID-19 nor with mortality of COVID-19 patients. Author information: (1)Division of Population Health and Genomics, University of Dundee, UK. (2)Observational Health Data Analytics, Janssen Research and Development, Titusville, NJ, USA. (3)Department of Biomedical Informatics, Ajou University School of Medicine, Suwon, Korea. (4)Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, Australia. (5)Real World Solutions, IQVIA, Cambridge, MA, USA. (6)Fundació Institut Universitari per a la recerca a l'Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Barcelona, Spain. (7)Department of Veterans Affairs, Salt Lake City, UT, USA. (8)University of Utah School of Medicine, Salt Lake City, UT, USA. (9)Department of Biomedical Informatics, Columbia University, New York, USA. (10)The Hyve, Utrecht, Netherlands. (11)Translational Discovery, Bill & Melinda Gates Medical Research Institute, Seattle, WA, USA. (12)Geriatric Research Education, and Clinical Care Center, Tennessee Valley Healthcare System VA, Nashville, TN. (13)Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA. (14)Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA. (15)School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. (16)Medication Safety Research Chair, King Saud University, Riyadh, Saudi Arabia. (17)Tufts Medical Center, Tufts University, Boston, MA, USA. (18)Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, Netherlands. (19)Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Oxford University, Oxford, UK. (20)School of Public Health, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. (21)Melbourne School of Public Health, The University of Melbourne, Victoria, Australia. (22)Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK. (23)Section of Cardiovascular Medicine, Department of Medicine, Yale University, New Haven, CT, USA. (24)Department of Biostatistics, UCLA Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, USA. (25)Department of Computational Medicine, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA, USA. Renin-angiotensin-aldosterone system (RAAS) inhibitors, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are one of the most prescribed antihypertensive medications. Previous studies showed RAAS inhibitors increase the expression of ACE2, a cellular receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which provokes a concern that the use of ACEI and ARB in hypertensive individuals might lead to increased mortality and severity of coronavirus disease 2019 (COVID-19). To further investigate the effects of ACEI/ARB on COVID-19 patients, we systematically reviewed relevant studies that met predetermined inclusion criteria in search of PubMed, Embase, Cochrane Library databases, medRxiv, and bioRxiv. The search strategy included clinical data published through October 12, 2020. Twenty-six studies involving 8104 hypertensive patients in ACEI/ARB-treated group and 8203 hypertensive patients in non-ACEI/ARB-treated group were analyzed. Random-effects meta-analysis showed ACEI/ARB treatment was significantly associated with a lower risk of mortality in hypertensive COVID-19 patients (odds ratio [OR] = 0.624, 95% confidence interval [CI] = 0.457-0.852, p = .003, I2 = 74.3%). Meta-regression analysis showed that age, gender, study site, Newcastle-Ottawa Scale scores, comorbidities of diabetes, coronary artery disease, chronic kidney disease, or cancer has no significant modulating effect of ACEI/ARB treatment on the mortality of hypertensive COVID-19 patients (all p > .1). In addition, the ACEI/ARB treatment was associated with a lower risk of ventilatory support (OR = 0.682, 95% CI = 0.475-1.978, p = .037, I2 = 0.0%). In conclusion, these results suggest that ACEI/ARB medications should not be discontinued for hypertensive patients in the context of COVID-19 pandemic. Concerns have been raised regarding the safety of angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in patients with coronavirus disease of 2019 (COVID-19), based on the hypothesis that such medications may raise expression of ACE2, the receptor for severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). We conducted a literature review of studies (n = 12) in experimental animals and human subjects (n = 12) and evaluated the evidence regarding the impact of administration of ACEIs and ARBs on ACE2 expression. We prioritized studies that assessed ACE2 protein expression data, measured directly or inferred from ACE2 activity assays. The findings in animals are inconsistent with respect to an increase in ACE2 expression in response to treatment with ACEIs or ARBs. Control/sham animals show little to no effect in the plurality of studies. Those studies that report increases in ACE2 expression tend to involve acute injury models and/or higher doses of ACEIs or ARBs than are typically administered to patients. Data from human studies overwhelmingly imply that administration of ACEIs/ARBs does not increase ACE2 expression. Available evidence, in particular, data from human studies, does not support the hypothesis that ACEI/ARB use increases ACE2 expression and the risk of complications from COVID-19. We conclude that patients being treated with ACEIs and ARBs should continue their use for approved indications. OBJECTIVE: Although recent evidence suggests no increased risk of severe COVID-19 outcomes associated with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) use, the relationship is less clear among patients with hypertension and diverse racial/ethnic groups. This study evaluates the risk of hospitalization and mortality among patients with hypertension and COVID-19 in a large US integrated healthcare system. METHODS: Patients with hypertension and COVID-19 (between March 1- September 1, 2020) on ACEIs or ARBs were compared with patients on other frequently used antihypertensive medications. RESULTS: Among 14,129 patients with hypertension and COVID-19 infection (mean age 60 years, 48% men, 58% Hispanic), 21% were admitted to the hospital within 30 days of COVID-19 infection. Of the hospitalized patients, 24% were admitted to intensive care units, 17% required mechanical ventilation, and 10% died within 30 days of COVID-19 infection. Exposure to ACEIs or ARBs prior to COVID-19 infection was not associated with an increased risk of hospitalization or all-cause mortality (rate ratios for ACEIs vs other antihypertensive medications ​= ​0.98, 95% CI: 0.88, 1.08; ARBs vs others ​= ​1.00, 95% CI: 0.90, 1.11) after applying inverse probability of treatment weights. These associations were consistent across racial/ethnic groups. Use of ACEIs or ARBs during hospitalization was associated with a lower risk of all-cause mortality (odds ratios for ACEIs or ARBs vs others ​= ​0.50, 95% CI: 0.34, 0.72). CONCLUSION: Our study findings support continuation of ACEI or ARB use for patients with hypertension during the COVID-19 pandemic and after COVID-19 infection. Considerable concern has emerged for the potential harm in the use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor inhibitors (ARBs) in COVID-19 patients, given that ACEIs and ARBs may increase the expression of ACE2 receptors that represent the way for coronavirus 2 to entry into the cell and cause severe acute respiratory syndrome. Assess the effect of ACEI/ARBs on outcome in COVID-19 patients. Hospital-based prospective study. A total of 431 patients consecutively presenting at the Emergency Department and found to be affected by COVID-19 were assessed. Relevant clinical and laboratory variables were recorded, focusing on the type of current anti hypertensive treatment. Outcome variables were NO, MILD, SEVERE respiratory distress (RD) operationally defined and DEATH. Hypertension was the single most frequent comorbidity (221/431 = 51%). Distribution of antihypertensive treatment was: ACEIs 77/221 (35%), ARBs 63/221 (28%), OTHER than ACEIs or ARBs 64/221 (29%). In 17/221 (8%) antihypertensive medication was unknown. The proportion of patients taking ACEIs, ARBs or OTHERs who developed MILD or SEVERE RD was 43/77 (56%), 33/53 (52%), 39/64 (61%) and 19/77 (25%), 16/63 (25%) and 16/64 (25%), respectively, with no statistical difference between groups. Despite producing a RR for SEVERE RD of 2.59 (95% CI 1.93-3.49), hypertension was no longer significant in a logistic regression analysis that identified age, CRP and creatinine as the sole independent predictors of SEVERE RD and DEATH. ACEIs and ARBs do not promote a more severe outcome of COVID-19. There is no reason why they should be withheld in affected patients. BACKGROUND: Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are known to increase the expression of angiotensin converting enzyme 2 receptor, which has been shown to be the receptor for the acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2). AREAS OF UNCERTAINTY: Based on these observations, speculations raised the concerns that ACEIs/ARBs users would be more susceptible to SARS-CoV-2 infection and would be at higher risk for severe COVID-19 disease and death. Therefore, we systematically reviewed the literature and performed a meta-analysis of the association between prior use of ACEIs and ARBs and mortality due to COVID-19 disease. DATA SOURCES: A comprehensive search of several databases from November 2019 to June 18, 2020 was conducted. The databases included Ovid MEDLINE(R) and Epub Ahead of Print, In-Process and Other Non-Indexed Citations and Daily, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, Web of Science, and Scopus. Medrxiv.org was also searched for unpublished data. THERAPEUTIC ADVANCES: Nine studies with a total of 18,833 patients infected with SARS-CoV-2 met our eligibility criteria. Prior use of ACEIs and/or ARBs was associated with reduced mortality among SARS-CoV-2-infected patients, with a pooled adjusted relative risk (aRR) from 6 studies of 0.63, 95% confidence interval (CI) (0.42-0.94) (I 2 = 65%). Three studies reported separately on ACEIs or ARBs and their association with survival among SARS-CoV-2-infected patients, with a pooled adjusted relative risk of 0.78, 95% CI (0.58-1.04) (I 2 = 0%) and 0.97, 95% CI (0.73-1.30) (I 2 = 0%) respectively. The results of sensitivity analyses were consistent with the main analysis. CONCLUSION: Our meta-analysis suggests that use of ACEIs/ARBs is associated with a decreased risk of death among SARS-CoV-2-infected patients. This finding provides a reassurance to the public not to stop prescribed ACEIs/ARBs because of fear of severe COVID-19. BACKGROUND: COVID-19 is caused by the coronavirus SARS-CoV-2, which uses angiotensin-converting enzyme 2 (ACE-2) as a receptor for cellular entry. It is theorized that ACE inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) may increase vulnerability to SARS-CoV-2 by upregulating ACE-2 expression, but ACE-I/ARB discontinuation is associated with clinical deterioration. OBJECTIVE: To determine whether ACE-I and ARB use is associated with acute kidney injury (AKI), macrovascular thrombosis and in-hospital mortality. METHODS: A retrospective, single-centre study of 558 hospital inpatients with confirmed COVID-19 admitted from 1 March to 30 April 2020, followed up until 24 May 2020. AKI and macrovascular thrombosis were primary end-points, and in-hospital mortality was a secondary end-point. RESULTS: AKI occurred in 126 (23.1%) patients, 34 (6.1%) developed macrovascular thrombi, and 200 (35.9%) died. Overlap propensity score-weighted analysis showed no significant effect of ACE-I/ARB use on the risk of occurrence of the specified end-points. On exploratory analysis, severe chronic kidney disease (CKD) increases odds of macrovascular thrombi (OR: 8.237, 95% CI: 1.689-40.181, P = 0.009). The risk of AKI increased with advancing age (OR: 1.028, 95% CI: 1.011-1.044, P = 0.001) and diabetes (OR: 1.675, 95% CI: 1.065-2.633, P = 0.025). Immunosuppression was associated with lower risk of AKI (OR: 0.160, 95% CI: 0.029-0.886, P = 0.036). Advancing age, dependence on care, male gender and eGFR < 60 mL min-1 /1.73 m2 increased odds of in-hospital mortality. CONCLUSION: We did not identify an association between ACE-I/ARB use and AKI, macrovascular thrombi or mortality. This supports the recommendations of the European and American Societies of Cardiology that ACE-Is and ARBs should not be discontinued during the COVID-19 pandemic. Angiotensin-converting enzyme (ACE) inhibitors (ACEIs) and angiotensin II type‑1 receptor blockers (ARBs) are among the most widely prescribed drugs for the treatment of arterial hypertension, heart failure and chronic kidney disease. A number of studies, mainly in animals and not involving the lungs, have indicated that these drugs can increase expression of angiotensin-converting enzyme 2 (ACE2). ACE2 is the cell entry receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19) that is currently battering the globe. This has led to the hypothesis that use of ACEIs and ARBs may increase the risk of developing severe COVID-19. In this point of view paper, possible scenarios regarding the impact of ACEI/ARB pharmacotherapy on COVID-19 are discussed in relation to the currently available evidence. Although further research on the influence of blood-pressure-lowering drugs, including those not targeting the renin-angiotensin system, is warranted, there are presently no compelling clinical data showing that ACEIs and ARBs increase the likelihood of contracting COVID-19 or worsen the outcome of SARS-CoV‑2 infections. Thus, unless contraindicated, use of ACEIs/ARBs in COVID-19 patients should be continued in line with the recent recommendations of medical societies. BACKGROUND: Speculations whether treatment with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin II receptor blockers (ARB) predisposes to severe coronavirus disease 2019 (COVID-19) or worsens its outcomes. This study assessed the association of ACE-I/ARB therapy with the development of severe COVID-19. METHODS: This multi-center, prospective study enrolled patients hospitalized for COVID-19 and receiving one or more antihypertensive agents to manage either hypertension or cardiovascular disease. ACE-I/ARB therapy associations with severe COVID-19 on the day of hospitalization, intensive care unit (ICU) admission, mechanical ventilation and in-hospital death on follow-up were tested using a multivariate logistic regression model adjusted for age, obesity, and chronic illnesses. The composite outcome of mechanical ventilation and death was examined using the adjusted Cox multivariate regression model. RESULTS: Of 338 enrolled patients, 245 (72.4%) were using ACE-I/ARB on the day of hospital admission, and 197 continued ACE-I/ARB therapy during hospitalization. Ninety-eight (29%) patients had a severe COVID-19, which was not significantly associated with the use of ACE-I/ARB (OR 1.17, 95% CI 0.66-2.09; P = .57). Prehospitalization ACE-I/ARB therapy was not associated with ICU admission, mechanical ventilation, or in-hospital death. Continuing ACE-I/ARB therapy during hospitalization was associated with decreased mortality (OR 0.22, 95% CI 0.073-0.67; P = .008). ACE-I/ARB use was not associated with developing the composite outcome of mechanical ventilation and in-hospital death (HR 0.95, 95% CI 0.51-1.78; P = .87) versus not using ACE-I/ARB. CONCLUSION: Patients with hypertension or cardiovascular diseases receiving ACE-I/ARB therapy are not at increased risk for severe COVID-19 on admission to the hospital. ICU admission, mechanical ventilation, and mortality are not associated with ACE-I/ARB therapy. Maintaining ACE-I/ARB therapy during hospitalization for COVID-19 lowers the likelihood of death. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT4357535.
4,108
Which small molecules inhibit the c-Myc/Max dimerization?
Mycros are the first inhibitors of c-Myc/Max dimerization, which have been demonstrated to inhibit DNA binding of c-Myc with preference over other dimeric transcription factors in vitroMost Myc inhibitors prevent the association between Myc and its obligate heterodimerization partner Max via their respective bHLH-ZIP domainsPreviously we showed that two c-Myc-Max inhibitors, 10058-F4 and 10074-G5, bound to distinct ID regions of the monomeric c-Myc bHLHZip domainWe tested the efficacy of Mycro3, a small-molecule inhibitor of Myc-Max dimerizationIn a fluorescence polarization screen for the MYC-MAX interaction, we have identified a novel small-molecule inhibitor of MYC, KJ-Pyr-9, from a Kröhnke pyridine libraryWe have previously demonstrated that the small molecule 10058-F4, known to bind to the c-MYC bHLHZip dimerization domain and inhibiting the c-MYC/MAX interaction, also interferes with the MYCN/MAX dimerization in vitro and imparts anti-tumorigenic effects in neuroblastoma tumor models with MYCN overexpressionWe developed a series of small-molecule MYC inhibitors that engage MYC inside cells, disrupt MYC/MAX dimers, and impair MYC-driven gene expression.Inhibition of MYC/MAX dimerization by a small-molecule antagonist (IIA6B17) has been shown to interfere with MYC-induced transformation of chick embryo fibroblasts, suggesting that the functional inhibitors of the MYC family of oncoproteins have potential as therapeutic agents.
[23801058, 19114306, 20801893, 18288422, 24859015, 17046567, 25306215, 19432426, 25114221, 24976143, 31679823, 26474287, 30880155, 16873022]
4,515
The c-Myc (Myc) oncoprotein is a high-value therapeutic target given that it is deregulated in multiple types of cancer. However, potent small molecule inhibitors of Myc have been difficult to identify, particularly those whose mechanism relies on blocking the association between Myc and its obligate heterodimerization partner, Max. We have recently reported a structure-activity relationship study of one such small molecule, 10074-G5, and generated an analog, JY-3-094, with significantly improved ability to prevent or disrupt the association between recombinant Myc and Max proteins. However, JY-3094 penetrates cells poorly. Here, we show that esterification of a critical para-carboxylic acid function of JY-3-094 by various blocking groups significantly improves cellular uptake although it impairs the ability to disrupt Myc-Max association in vitro. These pro-drugs are highly concentrated within cells where JY-3-094 is then generated by the action of esterases. However, the pro-drugs are also variably susceptible to extracellular esterases, which can deplete extracellular reservoirs. Furthermore, while JY-3-094 is retained by cells for long periods of time, much of it is compartmentalized within the cytoplasm in a form that appears to be less available to interact with Myc. Our results suggest that persistently high extracellular levels of pro-drug, without excessive susceptibility to extracellular esterases, are critical to establishing and maintaining intracellular levels of JY-3-094 that are sufficient to provide for long-term inhibition of Myc-Max association. Analogs of JY-3-094 appear to represent promising small molecule Myc inhibitors that warrant further optimization. Inhibition of MYC/MAX dimerization by a small-molecule antagonist (IIA6B17) has been shown to interfere with MYC-induced transformation of chick embryo fibroblasts, suggesting that the functional inhibitors of the MYC family of oncoproteins have potential as therapeutic agents. In the present study, a functional MYC reporter gene assay has been developed, using a luciferase gene construct under the control of the ornithine decarboxylase (ODC) gene promoter. This luciferase gene construct has been stably transfected into the MYCN amplified neuroblastoma cell line (NGP) and MYCC-overexpressed neuroepithelioma cell line (NB100). After exposure of the cell lines to IIA6B17 for 24 h, a significant reduction of luciferase activity was only observed in the NB100 cells, with IC50 values of approximately 28+/-9 microM, indicating that IIA6B17 has cell line-specific activity which may be selective for individual members of the MYC family. Members of the MYC family are the most frequently deregulated oncogenes in human cancer and are often correlated with aggressive disease and/or poorly differentiated tumors. Since patients with MYCN-amplified neuroblastoma have a poor prognosis, targeting MYCN using small molecule inhibitors could represent a promising therapeutic approach. We have previously demonstrated that the small molecule 10058-F4, known to bind to the c-MYC bHLHZip dimerization domain and inhibiting the c-MYC/MAX interaction, also interferes with the MYCN/MAX dimerization in vitro and imparts anti-tumorigenic effects in neuroblastoma tumor models with MYCN overexpression. Our previous work also revealed that MYCN-inhibition leads to mitochondrial dysfunction resulting in accumulation of lipid droplets in neuroblastoma cells. To expand our understanding of how small molecules interfere with MYCN, we have now analyzed the direct binding of 10058-F4, as well as three of its analogs; #474, #764 and 10058-F4(7RH), one metabolite C-m/z 232, and a structurally unrelated c-MYC inhibitor 10074-G5, to the bHLHZip domain of MYCN. We also assessed their ability to induce apoptosis, neurite outgrowth and lipid accumulation in neuroblastoma cells. Interestingly, all c-MYC binding molecules tested also bind MYCN as assayed by surface plasmon resonance. Using a proximity ligation assay, we found reduced interaction between MYCN and MAX after treatment with all molecules except for the 10058-F4 metabolite C-m/z 232 and the non-binder 10058-F4(7RH). Importantly, 10074-G5 and 10058-F4 were the most efficient in inducing neuronal differentiation and lipid accumulation in MYCN-amplified neuroblastoma cells. Together our data demonstrate MYCN-binding properties for a selection of small molecules, and provide functional information that could be of importance for future development of targeted therapies against MYCN-amplified neuroblastoma. OBJECTIVE: The protooncogene c-Myc plays an important role in the control of cell proliferation, apoptosis, and differentiation, and its aberrant expression is frequently seen in multiple human cancers, including acute myeloid leukemia (AML). As c-Myc heterodimerizes with Max to transactivate downstream target genes in leukemogenesis. Inhibition of the c-Myc/Max heterodimerization by the recently identified small-molecule compound, 10058-F4, might be a novel antileukemic strategy. MATERIALS AND METHODS: HL-60, U937, and NB4 cells and primary AML cells were used to examine the effects of 10058-F4 on apoptosis and myeloid differentiation. RESULTS: We showed that 10058-F4 arrested AML cells at G0/G1 phase, downregulated c-Myc expression and upregulated CDK inhibitors, p21 and p27. Meanwhile, 10058-F4 induced apoptosis through activation of mitochondrial pathway shown by downregulation of Bcl-2, upregulation of Bax, release of cytoplasmic cytochrome C, and cleavage of caspase 3, 7, and 9. Furthermore, 10058-F4 also induced myeloid differentiation, possibly through activation of multiple transcription factors. Similarly, 10058-F4-induced apoptosis and differentiation could also be observed in primary AML cells. CONCLUSION: Our study has shown that inhibition of c-Myc/Max dimerization with small-molecule inhibitors affects multiple cellular activities in AML cells and represents a potential antileukemic approach. BACKGROUND: Pancreatic ductal adenocarcinoma (PDA) is frequently driven by oncogenic KRAS(KRAS*) mutations. We developed a mouse model of KRAS*-induced PDA and, based on genetic results demonstrating that KRAS* tumorigenicity depends on Myc activity, we evaluated the therapeutic potential of an orally administered anti-Myc drug. METHODS: We tested the efficacy of Mycro3, a small-molecule inhibitor of Myc-Max dimerization, in the treatment of mouse PDA (n = 9) and also of xenografts of human pancreatic cancer cell lines (NOD/SCID mice, n = 3-12). Tumor responses to the drug were evaluated by PET/CT imaging, and histological, immunohistochemical, molecular and microarray analyses. The Student's t test was used for differences between groups. All statistical tests were two-sided. RESULTS: Transgenic overexpression of KRAS* in the pancreas resulted in pancreatic intraepithelial neoplasia in two-week old mice, which developed invasive PDA a week later and became moribund at one month. However, this aggressive form of pancreatic tumorigenesis was effectively prevented by genetic ablation of Myc specifically in the pancreas. We then treated moribund, PDA-bearing mice daily with the Mycro3 Myc-inhibitor. The mice survived until killed at two months. PET/CT image analysis (n = 5) demonstrated marked shrinkage of PDA, while immunohistochemical analyses showed an increase in cancer cell apoptosis and reduction in cell proliferation (treated/untreated proliferation index ratio: 0.29, P < .001, n = 3, each group). Tumor growth was also drastically attenuated in Mycro3-treated NOD/SCID mice (n = 12) carrying orthotopic or heterotopic xenografts of human pancreatic cancer cells (eg, mean tumor weight ± SD of treated heterotopic xenografts vs vehicle-treated controls: 15.2±5.8 mg vs 230.2±43.9 mg, P < .001). CONCLUSION: These results provide strong justification for eventual clinical evaluation of anti-Myc drugs as potential chemotherapeutic agents for the treatment of PDA. Deregulation of the c-Myc transcription factor is involved in many types of cancer, making this oncoprotein an attractive target for drug discovery. One approach to its inhibition has been to disrupt the dimeric complex formed between its basic helix-loop-helix leucine zipper (bHLHZip) domain and a similar domain on its dimerization partner, Max. As monomers, bHLHZip proteins are intrinsically disordered (ID). Previously we showed that two c-Myc-Max inhibitors, 10058-F4 and 10074-G5, bound to distinct ID regions of the monomeric c-Myc bHLHZip domain. Here, we use circular dichroism, fluorescence polarization, and NMR to demonstrate the presence of an additional binding site located between those for 10058-F4 and 10074-G5. All seven of the originally identified Myc inhibitors are shown to bind to one of these three discrete sites within the 85-residue bHLHZip domain of c-Myc. These binding sites are composed of short contiguous stretches of amino acids that can selectively and independently bind small molecules. Inhibitor binding induces only local conformational changes, preserves the overall disorder of c-Myc, and inhibits dimerization with Max. NMR experiments further show that binding at one site on c-Myc affects neither the affinity nor the structural changes taking place upon binding to the other sites. Rather, binding can occur simultaneously and independently on the three identified sites. Our results suggest the widespread existence of peptide regions prone to small-molecule binding within ID domains. A rational and generic approach to the inhibition of protein-protein interactions involving ID proteins may therefore be possible through the targeting of ID sequence. In a fluorescence polarization screen for the MYC-MAX interaction, we have identified a novel small-molecule inhibitor of MYC, KJ-Pyr-9, from a Kröhnke pyridine library. The Kd of KJ-Pyr-9 for MYC in vitro is 6.5 ± 1.0 nM, as determined by backscattering interferometry; KJ-Pyr-9 also interferes with MYC-MAX complex formation in the cell, as shown in a protein fragment complementation assay. KJ-Pyr-9 specifically inhibits MYC-induced oncogenic transformation in cell culture; it has no or only weak effects on the oncogenic activity of several unrelated oncoproteins. KJ-Pyr-9 preferentially interferes with the proliferation of MYC-overexpressing human and avian cells and specifically reduces the MYC-driven transcriptional signature. In vivo, KJ-Pyr-9 effectively blocks the growth of a xenotransplant of MYC-amplified human cancer cells. c-Myc is a basic helix-loop-helix-leucine zipper (bHLH-ZIP) transcription factor that is responsible for the transcription of a wide range of target genes involved in many cancer-related cellular processes. Over-expression of c-Myc has been observed in, and directly contributes to, a variety of human cancers including those of the hematopoietic system, lung, prostate and colon. To become transcriptionally active, c-Myc must first dimerize with Myc-associated factor X (Max) via its own bHLH-ZIP domain. A proven strategy towards the inhibition of c-Myc oncogenic activity is to interfere with the structural integrity of the c-Myc-Max heterodimer. The small molecule 10074-G5 is an inhibitor of c-Myc-Max dimerization (IC50 =146 μM) that operates by binding and stabilizing c-Myc in its monomeric form. We have identified a congener of 10074-G5, termed 3jc48-3 (methyl 4'-methyl-5-(7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)-[1,1'-biphenyl]-3-carboxylate), that is about five times as potent (IC50 =34 μM) at inhibiting c-Myc-Max dimerization as the parent compound. 3jc48-3 exhibited an approximate twofold selectivity for c-Myc-Max heterodimers over Max-Max homodimers, suggesting that its mode of action is through binding c-Myc. 3jc48-3 inhibited the proliferation of c-Myc-over-expressing HL60 and Daudi cells with single-digit micromolar IC50 values by causing growth arrest at the G0 /G1 phase. Co-immunoprecipitation studies indicated that 3jc48-3 inhibits c-Myc-Max dimerization in cells, which was further substantiated by the specific silencing of a c-Myc-driven luciferase reporter gene. Finally, 3jc48-3's intracellular half-life was >17 h. Collectively, these data demonstrate 3jc48-3 to be one of the most potent, cellularly active and stable c-Myc inhibitors reported to date. Author information: (1)Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA. (2)Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA. (3)Center for Developmental Therapeutics, Northwestern University, Evanston, IL 60208, USA. (4)Division of Reproductive Science in Medicine, Department of OB/GYN, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA. (5)Division of Reproductive Science in Medicine, Department of OB/GYN, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago IL 60611, USA. (6)Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago IL 60611, USA. (7)Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208, USA; The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago IL 60611, USA. (8)Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA. Electronic address: sarki.abdulkadir@northwestern.edu. Author information: (1)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, MA 02142, USA. (2)Division of Oncology, Departments of Medicine and Pathology Stanford School of Medicine, Stanford, CA 94305, USA. (3)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. (4)Department of Molecular and Human Genetics and Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA. (5)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Kronos Bio, Inc., Cambridge, MA 02139, USA. (6)Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. (7)Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. (8)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; BioMicro Center, Massachusetts Institute of Technology, Cambridge, MA 02142, USA. (9)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA. (10)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, USA. (11)Department of Molecular and Human Genetics and Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX 77030, USA. (12)David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; MIT Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. Electronic address: koehler@mit.edu.
4,109
Which models are used for predicting disease progression in Duchenne Muscular Dystrophy?
Longitudinal changes in biomarkers were modeled with a cumulative distribution function using a nonlinear mixed-effects approach.
[31960231, 28643370, 34877803, 30571821, 32184340, 22248373, 6863354]
4,516
The 6-minute walk test (6MWT) is used as a clinical endpoint to evaluate drug efficacy in Duchenne Muscular Dystrophy (DMD) trials. A model was developed using digitized 6MWT data that estimated two slopes and two intercepts to characterize 6MWT improvement during development and 6MWT decline. Mean baseline 6MWT was 362 (±87) meters. The model predicted an improvement at a rate of 20 meters/year (95% confidence interval (CI) = 9.4-30) up until 10 years old (95% CI = 6.78-13.1), and then a decline at a rate of 85 meters/year (95% CI = 72-98). Interpatient slope variability for improvement and decline were similar at 21.9 percentage of coefficient of variation (%CV) and 23.3%CV, respectively. Model simulations using age demographics from a previous DMD natural history study could reasonably predict the trend in improvement and decline in the 6MWT. This model can be used to quantitate individual patient trajectories, identify prognostic factors for disease progression, and evaluate drug effect. Early clinical trials of therapies to treat Duchenne muscular dystrophy (DMD), a fatal genetic X-linked pediatric disease, have been designed based on the limited understanding of natural disease progression and variability in clinical measures over different stages of the continuum of the disease. The objective was to inform the design of DMD clinical trials by developing a disease progression model-based clinical trial simulation (CTS) platform based on measures commonly used in DMD trials. Data were integrated from past studies through the Duchenne Regulatory Science Consortium founded by the Critical Path Institute (15 clinical trials and studies, 1505 subjects, 27,252 observations). Using a nonlinear mixed-effects modeling approach, longitudinal dynamics of five measures were modeled (NorthStar Ambulatory Assessment, forced vital capacity, and the velocities of the following three timed functional tests: time to stand from supine, time to climb 4 stairs, and 10 meter walk-run time). The models were validated on external data sets and captured longitudinal changes in the five measures well, including both early disease when function improves as a result of growth and development and the decline in function in later stages. The models can be used in the CTS platform to perform trial simulations to optimize the selection of inclusion/exclusion criteria, selection of measures, and other trial parameters. The data sets and models have been reviewed by the US Food and Drug Administration and the European Medicines Agency; have been accepted into the Fit-for-Purpose and Qualification for Novel Methodologies pathways, respectively; and will be submitted for potential endorsement by both agencies. INTRODUCTION: Duchenne muscular dystrophy (DMD) leads to a progressive deterioration of the mus cle function and premature death. There are no longitudinal studies on the course of this pathology in Chile. OBJECTIVE: To determine survival between the years 1993-2013, divided into two periods (1993-2002 and 2003-2013), and the effect of social determinants in patients with DMD admitted in Teleton Institutes of Chile (TI). PATIENTS AND METHOD: Prospective follow-up study in a clinical series of 462 patients with DMD. The information was obtained by searching for patients with DMD in OLAP cube (Online Analytical Processing). From the clinical records of the TI of Santiago, the variables corresponding to the diagnostic method, stage of DMD described in terms of muscle de terioration and function according to Swinyard classification were recorded; existence and type of tests that conclude the diagnosis and, in the cases reported, the existence of family history. Kaplan Meier survival analysis was applied, where global survival was defined between birth and age of death. The determinant factors analyzed were estimated through the Cox-Snell's proportional risk model. RESULTS: Survival at 20 years of age from TI entry was 51.7% (CI95%: 45.1-57.8), 48.5% in the period 1993-2002 and 72.8% between 2003-2013. The percentage of survival at the same age according to socioeconomic status (SES) was 82% in high SES, 67% in middle SES, and 42% in low SES, with a statistically significant difference between high and middle SES in relation to extreme poverty. Ac cording to country areas, the survival was close to 75 % at 17 years of age. CONCLUSIONS: The survival information from patients with DMD from childhood to adult life is valuable for predicting the clinical course of the disease with the current medical care. There is evidence of improvement in the probability of survival at the age of 20 and marked inequity according to the socioeconomic variable. OBJECTIVE: To quantify disease progression in individuals with Duchenne muscular dystrophy (DMD) using magnetic resonance biomarkers of leg muscles. METHODS: MRI and magnetic resonance spectroscopy (MRS) biomarkers were acquired from 104 participants with DMD and 51 healthy controls using a prospective observational study design with patients with DMD followed up yearly for up to 6 years. Fat fractions (FFs) in vastus lateralis and soleus muscles were determined with 1H MRS. MRI quantitative T2 (qT2) values were measured for 3 muscles of the upper leg and 5 muscles of the lower leg. Longitudinal changes in biomarkers were modeled with a cumulative distribution function using a nonlinear mixed-effects approach. RESULTS: MRS FF and MRI qT2 increased with DMD disease duration, with the progression time constants differing markedly between individuals and across muscles. The average age at half-maximal muscle involvement (μ) occurred 4.8 years earlier in vastus lateralis than soleus, and these measures were strongly associated with loss-of-ambulation age. Corticosteroid treatment was found to delay μ by 2.5 years on average across muscles, although there were marked differences between muscles with more slowly progressing muscles showing larger delay. CONCLUSIONS: MRS FF and MRI qT2 provide sensitive noninvasive measures of DMD progression. Modeling changes in these biomarkers across multiple muscles can be used to detect and monitor the therapeutic effects of corticosteroids on disease progression and to provide prognostic information on functional outcomes. This modeling approach provides a method to transform these MRI biomarkers into well-understood metrics, allowing concise summaries of DMD disease progression at individual and population levels. CLINICALTRIALSGOV IDENTIFIER: NCT01484678. We used biochemical and clinical variables to develop a method to predict the expected duration of independent walking following surgery and bracing in patients with Duchenne muscular dystrophy. Data from the records of fifty patients were analyzed by linear and multiple regression. The most useful factors, applied in combination, in predicting the duration of walking ability after bracing were: percentage of residual muscle strength, vital capacity, creatinine coefficient, motivation of the patient at the time of bracing, and decrease in creatinine coefficient in the two years prior to bracing. This system uses readily available variables to predict the response to bracing in patients with Duchenne muscular dystrophy. Improvement in the criteria for the selection of patients for surgery and bracing is important in view of the economic cost as well as the demands on the time and energy of these children and their parents.
4,110
What links muscle cellular pathways to ALS?
Changes to muscle cellular pathways may occur downstream of motor neuron pathology in ALS. Genetic changes to pathways that are important to muscle function may also be causal of the disease. In addition, changes to the muscle may be responsible for motor neuron death. Pathological changes occur in muscle before disease onset and independent from MN degeneration, and the muscle may release toxic elements, such as via extracellular vesicle secretion. Muscle metabolism and mitochondrial activity, RNA processing, tissue-resident stem cell function responsible for muscle regeneration, and proteostasis that regulates muscle mass in adulthood, are all deregulated in ALS. There may also be a link between motor neuron death, the immune system, and muscle cells, as muscle-resident glial cells have been shown to activate upon nerve injury. Muscle-restricted expression of a localized insulin-like growth factor Igf-1 isoform maintained muscle integrity and enhanced satellite cell activity in SOD1(G93A) transgenic mice.
[34137441, 19889637, 25602021, 26041991, 22996383, 33661767, 26775178, 32986860, 29765840, 15657392, 34357138, 30682329, 27195289, 34018075, 20007902, 34776863]
4,517
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by loss of both upper and lower motor neurons (MNs). The main clinical features of ALS are motor function impairment, progressive muscle weakness, muscle atrophy and, ultimately, paralysis. Intrinsic skeletal muscle deterioration plays a crucial role in the disease and contributes to ALS progression. Currently, there are no effective treatments for ALS, highlighting the need to obtain a deeper understanding of the molecular events underlying degeneration of both MNs and muscle tissue, with the aim of developing successful therapies. Muscle tissue is enriched in a group of microRNAs called myomiRs, which are effective regulators of muscle homeostasis, plasticity and myogenesis in both physiological and pathological conditions. After providing an overview of ALS pathophysiology, with a focus on the role of skeletal muscle, we review the current literature on myomiR network dysregulation as a contributing factor to myogenic perturbations and muscle atrophy in ALS. We argue that, in view of their critical regulatory function at the interface between MNs and skeletal muscle fiber, myomiRs are worthy of further investigation as potential molecular targets of therapeutic strategies to improve ALS symptoms and counteract disease progression. Accumulation of abnormal protein inclusions is implicated in motor neuron degeneration in amyotrophic lateral sclerosis (ALS). Autophagy, an intracellular process targeting misfolded proteins and damaged organelles for lysosomal degradation, plays crucial roles in survival and diseased conditions. Efforts were made to understand the role of autophagy in motor neuron degeneration and to target autophagy in motor neuron for ALS treatment. However, results were quite contradictory. Possible autophagy defects in other cell types may also complicate the results. Here, we examined autophagy activity in skeletal muscle of an ALS mouse model G93A. Through overexpression of a fluorescent protein LC3-RFP, we found a basal increase in autophagosome formation in G93A muscle during disease progression when the mice were on a regular diet. As expected, an autophagy induction procedure (starvation plus colchicine) enhanced autophagy flux in skeletal muscle of normal mice. However, in response to the same autophagy induction procedure, G93A muscle showed significant reduction in the autophagy flux. Immunoblot analysis revealed that increased cleaved caspase-3 associated with apoptosis was linked to the cleavage of several key proteins involved in autophagy, including Beclin-1, which is an essential molecule connecting autophagy and apoptosis pathways. Taking together, we provide the evidence that the cytoprotective autophagy pathway is suppressed in G93A skeletal muscle and this suppression may link to the enhanced apoptosis during ALS progression. The abnormal autophagy activity in skeletal muscle likely contributes muscle degeneration and disease progression in ALS. Mutations in Cu/Zn superoxide dismutase (SOD1) are one of the genetic causes of Amyotrophic Lateral Sclerosis (ALS). Although the primary symptom of ALS is muscle weakness, the link between SOD1 mutations, cellular dysfunction and muscle atrophy and weakness is not well understood. The purpose of this study was to characterize cellular markers of ER stress in skeletal muscle across the lifespan of G93A*SOD1 (ALS-Tg) mice. Muscles were obtained from ALS-Tg and age-matched wild type (WT) mice at 70d (pre-symptomatic), 90d and 120-140d (symptomatic) and analyzed for ER stress markers. In white gastrocnemius (WG) muscle, ER stress sensors PERK and IRE1α were upregulated ~2-fold at 70d and remained (PERK) or increased further (IRE1α) at 120-140d. Phospho-eIF2α, a downstream target of PERK and an inhibitor of protein translation, was increased by 70d and increased further to 12.9-fold at 120-140d. IRE1α upregulation leads to increased splicing of X-box binding protein 1 (XBP-1) to the XBP-1s isoform. XBP-1s transcript was increased at 90d and 120-140d indicating activation of IRE1α signaling. The ER chaperone/heat shock protein Grp78/BiP was upregulated 2-fold at 70d and 90d and increased to 6.1-fold by 120-140d. The ER-stress-specific apoptotic signaling protein CHOP was upregulated 2-fold at 70d and 90d and increased to 13.3-fold at 120-140d indicating progressive activation of an apoptotic signal in muscle. There was a greater increase in Grp78/BiP and CHOP in WG vs. the more oxidative red gastrocnemius (RG) ALS-Tg at 120-140d indicating greater ER stress and apoptosis in fast glycolytic muscle. These data show that the ER stress response is activated in skeletal muscle of ALS-Tg mice by an early pre-symptomatic age and increases with disease progression. These data suggest a mechanism by which myocellular ER stress leads to reduced protein translation and contributes to muscle atrophy and weakness in ALS. INTRODUCTION: Amyotrophic lateral sclerosis (ALS), a degenerative disorder of the central nervous system, manifests as progressive weakening of muscles. The diagnosis and prognosis of ALS are often unclear, so useful biomarkers are needed. METHODS: Total proteins were extracted from muscle samples from 36 ALS, 17 spinal muscular atrophy (SMA), and 36 normal individuals. The expression levels of 134 proteins and phosphoproteins were assessed using protein pathway array analysis. RESULTS: Seventeen proteins were differentially expressed between ALS and normal muscle, and 9 proteins were differentially expressed between ALS and SMA muscle. The low-level expression of Akt and Factor XIIIB correlates with unfavorable survival, and the risk score calculated based on these proteins predicts the survival of each individual patient. CONCLUSIONS: Some proteins could be selected as clinically useful biomarkers. Specifically, Akt and Factor XIIIB were found to be promising biomarkers for estimating prognosis in ALS. Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor dysfunction and loss of large motor neurons in the spinal cord and brain stem. While much research has focused on mechanisms of motor neuron cell death in the spinal cord, degenerative processes in skeletal muscle and neuromuscular junctions (NMJs) are also observed early in disease development. Although recent studies support the potential therapeutic benefits of targeting the skeletal muscle in ALS, relatively little is known about inflammation and glial responses in skeletal muscle and near NMJs, or how these responses contribute to motor neuron survival, neuromuscular innervation, or motor dysfunction in ALS. We recently showed that human mesenchymal stem cells modified to release glial cell line-derived neurotrophic factor (hMSC-GDNF) extend survival and protect NMJs and motor neurons in SOD1(G93A) rats when delivered to limb muscles. In this study, we evaluate inflammatory and glial responses near NMJs in the limb muscle collected from a rat model of familial ALS (SOD1(G93A) transgenic rats) during disease progression and following hMSC-GDNF transplantation. Muscle samples were collected from pre-symptomatic, symptomatic, and end-stage animals. A significant increase in the expression of microglial inflammatory markers (CD11b and CD68) occurred in the skeletal muscle of symptomatic and end-stage SOD1(G93A) rats. Inflammation was confirmed by ELISA for inflammatory cytokines interleukin-1 β (IL-1β) and tumor necrosis factor-α (TNF-α) in muscle homogenates of SOD1(G93A) rats. Next, we observed active glial responses in the muscle of SOD1(G93A) rats, specifically near intramuscular axons and NMJs. Interestingly, strong expression of activated glial markers, glial fibrillary acidic protein (GFAP) and nestin, was observed in the areas adjacent to NMJs. Finally, we determined whether ex vivo trophic factor delivery influences inflammation and terminal Schwann cell (TSC) response during ALS. We found that intramuscular transplantation of hMSC-GDNF tended to exhibit less inflammation and significantly maintained TSC association with NMJs. Understanding cellular responses near NMJs is important to identify suitable cellular and molecular targets for novel treatment of ALS and other neuromuscular diseases. Amyotrophic lateral sclerosis (ALS) is an adult onset disorder characterized by progressive neuromuscular junction (NMJ) dismantling and degeneration of motor neurons leading to atrophy and paralysis of voluntary muscles responsible for motion and breathing. Except for a minority of patients harbouring genetic mutations, the origin of most ALS cases remains elusive. Peripheral tissues, and particularly skeletal muscle, have lately demonstrated an active contribution to disease pathology attracting a growing interest for these tissues as therapeutic targets in ALS. In this sense, molecular mechanisms essential for cell and tissue homeostasis have been shown to be deregulated in the disease. These include muscle metabolism and mitochondrial activity, RNA processing, tissue-resident stem cell function responsible for muscle regeneration, and proteostasis that regulates muscle mass in adulthood. This review aims to compile scientific evidence that demonstrates the role of skeletal muscle in ALS pathology and serves as reference for development of novel therapeutic strategies targeting this tissue to delay disease onset and progression. LINKED ARTICLES: This article is part of a themed issue on Neurochemistry in Japan. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.6/issuetoc. From early description by Charcot, the classification of the Amyotrophic Lateral Sclerosis (ALS) is evolving from a subtype of Motor Neuron (MN) Disease to be considered rather a multi-systemic, non-cell autonomous and complex neurodegenerative disease. In the last decade, the huge amount of knowledge acquired has shed new insights on the pathological mechanisms underlying ALS from different perspectives. However, a whole vision on the multiple dysfunctional pathways is needed with the inclusion of information often excluded in other published revisions. We propose an integrative view of ALS pathology, although centered on the synaptic failure as a converging and crucial player to the etiology of the disease. Homeostasis of input and output synaptic activity of MNs has been proved to be severely and early disrupted and to definitively contribute to microcircuitry alterations at the spinal cord. Several cells play roles in synaptic communication across the MNs network system such as interneurons, astrocytes, microglia, Schwann and skeletal muscle cells. Microglia are described as highly dynamic surveying cells of the nervous system but also as determinant contributors to the synaptic plasticity linked to neuronal activity. Several signaling axis such as TNFα/TNFR1 and CX3CR1/CX3CL1 that characterize MN-microglia cross talk contribute to synaptic scaling and maintenance, have been found altered in ALS. The presence of dystrophic and atypical microglia in late stages of ALS, with a decline in their dynamic motility and phagocytic ability, together with less synaptic and neuronal contacts disrupts the MN-microglia dialogue, decreases homeostatic regulation of neuronal activity, perturbs "on/off" signals and accelerates disease progression associated to impaired synaptic function and regeneration. Other hotspot in the ALS affected network system is the unstable neuromuscular junction (NMJ) leading to distal axonal degeneration. Reduced neuromuscular spontaneous synaptic activity in ALS mice models was also suggested to account for the selective vulnerability of MNs and decreased regenerative capability. Synaptic destabilization may as well derive from increased release of molecules by muscle cells (e.g. NogoA) and by terminal Schwann cells (e.g. semaphorin 3A) conceivably causing nerve terminal retraction and denervation, as well as inhibition of re-connection to muscle fibers. Indeed, we have overviewed the alterations on the metabolic pathways and self-regenerative capacity presented in skeletal muscle cells that contribute to muscle wasting in ALS. Finally, a detailed footpath of pathologic changes on MNs and associated dysfunctional and synaptic alterations is provided. The oriented motivation in future ALS studies as outlined in the present article will help in fruitful novel achievements on the mechanisms involved and in developing more target-driven therapies that will bring new hope in halting or delaying disease progression in ALS patients. Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by a selective degeneration of motor neurons, atrophy, and paralysis of skeletal muscle. Although a significant proportion of familial ALS results from a toxic gain of function associated with dominant SOD1 mutations, the etiology of the disease and its specific cellular origins have remained difficult to define. Here, we show that muscle-restricted expression of a localized insulin-like growth factor (Igf) -1 isoform maintained muscle integrity and enhanced satellite cell activity in SOD1(G93A) transgenic mice, inducing calcineurin-mediated regenerative pathways. Muscle-specific expression of local Igf-1 (mIgf-1) isoform also stabilized neuromuscular junctions, reduced inflammation in the spinal cord, and enhanced motor neuronal survival in SOD1(G93A) mice, delaying the onset and progression of the disease. These studies establish skeletal muscle as a primary target for the dominant action of inherited SOD1 mutation and suggest that muscle fibers provide appropriate factors, such as mIgf-1, for neuron survival. Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder that leads to progressive degeneration of motor neurons (MNs) and severe muscle atrophy without effective treatment. Most research on ALS has been focused on the study of MNs and supporting cells of the central nervous system. Strikingly, the recent observations of pathological changes in muscle occurring before disease onset and independent from MN degeneration have bolstered the interest for the study of muscle tissue as a potential target for delivery of therapies for ALS. Skeletal muscle has just been described as a tissue with an important secretory function that is toxic to MNs in the context of ALS. Moreover, a fine-tuning balance between biosynthetic and atrophic pathways is necessary to induce myogenesis for muscle tissue repair. Compromising this response due to primary metabolic abnormalities in the muscle could trigger defective muscle regeneration and neuromuscular junction restoration, with deleterious consequences for MNs and thereby hastening the development of ALS. However, it remains puzzling how backward signaling from the muscle could impinge on MN death. This review provides a comprehensive analysis on the current state-of-the-art of the role of the skeletal muscle in ALS, highlighting its contribution to the neurodegeneration in ALS through backward-signaling processes as a newly uncovered mechanism for a peripheral etiopathogenesis of the disease. Amyotrophic lateral sclerosis (ALS) is a devastating neuromuscular disease characterized by motor neuron loss and prominent skeletal muscle wasting. Despite more than one hundred years of research efforts, the pathogenic mechanisms underlying neuromuscular degeneration in ALS remain elusive. While the death of motor neuron is a defining hallmark of ALS, accumulated evidences suggested that in addition to being a victim of motor neuron axonal withdrawal, the intrinsic skeletal muscle degeneration may also actively contribute to ALS disease pathogenesis and progression. Examination of spinal cord and muscle autopsy/biopsy samples of ALS patients revealed similar mitochondrial abnormalities in morphology, quantity and disposition, which are accompanied by defective mitochondrial respiratory chain complex and elevated oxidative stress. Detailing the molecular/cellular mechanisms and the role of mitochondrial dysfunction in ALS relies on ALS animal model studies. This review article discusses the dysregulated mitochondrial Ca2+ and reactive oxygen species (ROS) signaling revealed in live skeletal muscle derived from ALS mouse models, and a potential role of the vicious cycle formed between the dysregulated mitochondrial Ca2+ signaling and excessive ROS production in promoting muscle wasting during ALS progression. Muscle weakness is considered the pivotal sign of amyotrophic lateral sclerosis (ALS). Knowledge about the skeletal muscle degeneration/regeneration process and the myogenic potential is limited in ALS patients. Therefore, we investigate these processes in a time course perspective by analysing skeletal muscle biopsies from ALS patients collected before and after a 12-week period of normal daily activities and compare these with healthy age-matched control tissue. We do this by evaluating mRNA and protein (immunohistochemical) markers of regeneration, neurodegeneration, myogenesis, cell cycle regulation, and inflammation. Our results show morphological changes indicative of active denervation and reinnervation and an increase in small atrophic fibres. We demonstrate differences between ALS and controls in pathways controlling skeletal muscle homeostasis, cytoskeletal and regenerative markers, neurodegenerative factors, myogenic factors, cell cycle determinants, and inflammatory markers. Our results on Pax7 and MyoD protein expression suggest that proliferation and differentiation of skeletal muscle stem cells are affected in ALS patients, and the myogenic processes cannot overcome the denervation-induced wasting. The prominent causes for motor neuron diseases like ALS are demyelination, immune dysregulation, and neuroinflammation. Numerous research studies indicate that the downregulation of IGF-1 and GLP-1 signaling pathways plays a significant role in the progression of ALS pathogenesis and other neurological disorders. In the current review, we discussed the dysregulation of IGF-1/GLP-1 signaling in neurodegenerative manifestations of ALS like a genetic anomaly, oligodendrocyte degradation, demyelination, glial overactivation, immune deregulation, and neuroexcitation. In addition, the current review reveals the IGF-1 and GLP-1 activators based on the premise that the restoration of abnormal IGF-1/GLP-1 signaling could result in neuroprotection and neurotrophic effects for the clinical-pathological presentation of ALS and other brain diseases. Thus, the potential benefits of IGF-1/GLP-1 signal upregulation in the development of disease-modifying therapeutic strategies may prevent ALS and associated neurocomplications. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by loss of motor neurons, denervation of target muscles, muscle atrophy, and paralysis. Understanding ALS pathogenesis may require a fuller understanding of the bidirectional signaling between motor neurons and skeletal muscle fibers at neuromuscular synapses. Here, we show that a key regulator of this signaling is miR-206, a skeletal muscle-specific microRNA that is dramatically induced in a mouse model of ALS. Mice that are genetically deficient in miR-206 form normal neuromuscular synapses during development, but deficiency of miR-206 in the ALS mouse model accelerates disease progression. miR-206 is required for efficient regeneration of neuromuscular synapses after acute nerve injury, which probably accounts for its salutary effects in ALS. miR-206 mediates these effects at least in part through histone deacetylase 4 and fibroblast growth factor signaling pathways. Thus, miR-206 slows ALS progression by sensing motor neuron injury and promoting the compensatory regeneration of neuromuscular synapses. Amyotrophic lateral sclerosis (ALS) is a terminalneurodegenerative disease. Clinical and molecular observations suggest that ALS pathology originates at a single site and spreads in an organized and prion-like manner, possibly driven by extracellular vesicles. Extracellular vesicles (EVs) transfer cargo molecules associated with ALS pathogenesis, such as misfolded and aggregated proteins and dysregulated microRNAs (miRNAs). However, it is poorly understood whether altered levels of circulating extracellular vesicles or their cargo components reflect pathological signatures of the disease. In this study, we used immuno-affinity-based microfluidic technology, electron microscopy, and NanoString miRNA profiling to isolate and characterize extracellular vesicles and their miRNA cargo from frontal cortex, spinal cord, and serum of sporadic ALS (n = 15) and healthy control (n = 16) participants. We found larger extracellular vesicles in ALS spinal cord versus controls and smaller sized vesicles in ALS serum. However, there were no changes in the number of extracellular vesicles between cases and controls across any tissues. Characterization of extracellular vesicle-derived miRNA cargo in ALS compared to controls identified significantly altered miRNA levels in all tissues; miRNAs were reduced in ALS frontal cortex and spinal cord and increased in serum. Two miRNAs were dysregulated in all three tissues: miR-342-3p was increased in ALS, and miR-1254 was reduced in ALS. Additional miRNAs overlapping across two tissues included miR-587, miR-298, miR-4443, and miR-450a-2-3p. Predicted targets and pathways associated with the dysregulated miRNAs across the ALS tissues were associated with common biological pathways altered in neurodegeneration, including axon guidance and long-term potentiation. A predicted target of one identified miRNA (N-deacetylase and N-sulfotransferase 4; NDST4) was likewise dysregulated in an in vitro model of ALS, verifying potential biological relevance. Together, these findings demonstrate that circulating extracellular vesicle miRNA cargo mirror those of the central nervous system disease state in ALS, and thereby offer insight into possible pathogenic factors and diagnostic opportunities.
4,111
For what known mutations is KRAS gene considered to be oncogenic?
G12C, G12V, G12D and G12A are all observed mutations of the KRAS oncogene.
[20385028, 25359494, 33618059, 31309326, 11668624, 22232209, 29650325, 25941399, 33709341, 19440799, 32308773, 25065594, 31289513, 31332011, 29453361, 20846262, 20034871, 23572025, 32956987, 31827279, 22329297, 26701267, 33325140, 33860195, 30199525, 25257576, 34369256, 22247021, 9612526, 32176377, 34822010, 26970110]
4,518
BACKGROUND: Mutational analysis of the KRAS gene has recently been established as a complementary in vitro diagnostic tool for the identification of patients with colorectal cancer who will not benefit from anti-epidermal growth factor receptor (EGFR) therapies. Assessment of the mutation status of KRAS might also be of potential relevance in other EGFR-overexpressing tumors, such as those occurring in breast cancer. Although KRAS is mutated in only a minor fraction of breast tumors (5%), about 60% of the basal-like subtype express EGFR and, therefore could be targeted by EGFR inhibitors. We aimed to study the mutation frequency of KRAS in that subtype of breast tumors to provide a molecular basis for the evaluation of anti-EGFR therapies. METHODS: Total, genomic DNA was obtained from a group of 35 formalin-fixed paraffin-embedded, triple-negative breast tumor samples. Among these, 77.1% (27/35) were defined as basal-like by immunostaining specific for the established surrogate markers cytokeratin (CK) 5/6 and/or EGFR. KRAS mutational status was determined in the purified DNA samples by Real Time (RT)-PCR using primers specific for the detection of wild-type KRAS or the following seven oncogenic somatic mutations: Gly12Ala, Gly12Asp, Gly12Arg, Gly12Cys, Gly12Ser, Gly12Val and Gly13Asp. RESULTS: We found no evidence of KRAS oncogenic mutations in all analyzed tumors. CONCLUSIONS: This study indicates that KRAS mutations are very infrequent in triple-negative breast tumors and that EGFR inhibitors may be of potential benefit in the treatment of basal-like breast tumors, which overexpress EGFR in about 60% of all cases. Although all KRas (protein that in humans is encoded by the KRas gene) point mutants are considered to have a similar prognostic capacity, their transformation and tumorigenic capacities vary widely. We compared the metastatic efficiency of KRas G12V (Kirsten rat sarcoma viral oncogene homolog with valine mutation at codon 12) and KRas G13D (Kirsten rat sarcoma viral oncogene homolog with aspartic mutation at codon 13) oncogenes in an orthotopic colorectal cancer (CRC) model. Following subcutaneous preconditioning, recombinant clones of the SW48 CRC cell line [Kras wild-type (Kras WT)] expressing the KRas G12V or KRas G13D allele were microinjected in the mouse cecum. The percentage of animals developing lymph node metastasis was higher in KRas G12V than in KRas G13D mice. Microscopic, macroscopic, and visible lymphatic foci were 1.5- to 3.0-fold larger in KRas G12V than in KRas G13D mice (P < 0.05). In the lung, only microfoci were developed in both groups. KRas G12V primary tumors had lower apoptosis (7.0 ± 1.2 vs. 7.4 ± 1.0 per field, P = 0.02), higher tumor budding at the invasion front (1.2 ± 0.2 vs. 0.6 ± 0.1, P = 0.04), and a higher percentage of C-X-C chemokine receptor type 4 (CXCR4)-overexpressing intravasated tumor emboli (49.8 ± 9.4% vs. 12.8 ± 4.4%, P < 0.001) than KRas G13D tumors. KRas G12V primary tumors showed Akt activation, and β5 integrin, vascular endothelial growth factor A (VEGFA), and Serpine-1 overexpression, whereas KRas G13D tumors showed integrin β1 and angiopoietin 2 (Angpt2) overexpression. The increased cell survival, invasion, intravasation, and specific molecular regulation observed in KRas G12V tumors is consistent with the higher aggressiveness observed in patients with CRC expressing this oncogene. Mutation in the gene that encodes Kirsten rat sarcoma viral oncogene homolog (KRAS) is the most common oncogenic driver in advanced non-small cell lung cancer, occurring in approximately 30% of lung adenocarcinomas. Over 80% of oncogenic KRAS mutations occur at codon 12, where the glycine residue is substituted by different amino acids, leading to genomic heterogeneity of KRas-mutant tumors. The KRAS glycine-to-cysteine mutation (G12C) composes approximately 44% of KRAS mutations in non-small cell lung cancer, with mutant KRasG12C present in approximately 13% of all patients with lung adenocarcinoma. Mutant KRas has been an oncogenic target for decades, but no viable therapeutic agents were developed until recently. However, advances in KRas molecular modeling have led to the development and clinical testing of agents that directly inhibit mutant KRasG12C. These agents include sotorasib (AMG-510), adagrasib (MRTX-849), and JNJ-74699157. In addition to testing for known actionable oncogenic driver alterations in EGFR, ALK, ROS1, BRAF, MET exon 14 skipping, RET, and NTRK and for the expression of programmed cell-death protein ligand 1, pathologists, medical oncologists, and community practitioners will need to incorporate routine testing for emerging biomarkers such as MET amplification, ERBB2 (alias HER2), and KRAS mutations, particularly KRAS G12C, considering the promising development of direct inhibitors of KRasG12C protein. We previously reported the occurrence of novel dinucleotide mutations of the K-RAS gene (KRAS2) in 2% of pancreatic tumors sampled, but it remained unknown whether these were functional mutations that convert the proto-oncogene to an oncogene, or unselected mutations that might inactivate protein function. In the current study, the functionality of these rare mutations was quantitated via a mitogen-activated protein kinase (MAPK) pathway-specific transactivational reporter system. Pathway activation by dinucleotide mutant proteins was comparable to that of the common G12V mutant K-Ras protein. Current allele-specific technologies often employed to detect K-RAS mutations in clinical tumor samples produce false results when dinucleotide mutations are present. Therefore, it is advisable to consider dinucleotide KRAS2 mutants in the strategic design of mutational screens used to assay clinical tumor samples. Hum Mutat 18:357, 2001. Pancreatic cancer is almost invariably associated with mutations in the KRAS gene, most commonly KRASG12D, that result in a dominant-active form of the KRAS GTPase. However, how KRAS mutations promote pancreatic carcinogenesis is not fully understood, and whether oncogenic KRAS is required for the maintenance of pancreatic cancer has not been established. To address these questions, we generated two mouse models of pancreatic tumorigenesis: mice transgenic for inducible KrasG12D, which allows for inducible, pancreas-specific, and reversible expression of the oncogenic KrasG12D, with or without inactivation of one allele of the tumor suppressor gene p53. Here, we report that, early in tumorigenesis, induction of oncogenic KrasG12D reversibly altered normal epithelial differentiation following tissue damage, leading to precancerous lesions. Inactivation of KrasG12D in established precursor lesions and during progression to cancer led to regression of the lesions, indicating that KrasG12D was required for tumor cell survival. Strikingly, during all stages of carcinogenesis, KrasG12D upregulated Hedgehog signaling, inflammatory pathways, and several pathways known to mediate paracrine interactions between epithelial cells and their surrounding microenvironment, thus promoting formation and maintenance of the fibroinflammatory stroma that plays a pivotal role in pancreatic cancer. Our data establish that epithelial KrasG12D influences multiple cell types to drive pancreatic tumorigenesis and is essential for tumor maintenance. They also strongly support the notion that inhibiting KrasG12D, or its downstream effectors, could provide a new approach for the treatment of pancreatic cancer. BACKGROUND: Somatic mutations have been related to the highest incidence of metastatic disease and different treatment responses. The molecular cause of prostate cancer (PC) is still unclear; however, its progression involves alterations in oncogenes and tumor suppressor genes as well as somatic mutations such as the ones in PIK3CA gene. A high percentage of PC is considered sporadic, which means that the damage to the genes occurs by chance after birth (mainly somatic mutations will drive the cancer event). However, little is known about somatic mutations in PC development. MATERIALS AND METHODS: We evaluated prostate biopsies in the main somatic mutations genes (PIK3CA, TP53, EGFR, KIT, KRAS, PTEN, and BRAF) among individuals with PSA values>4ng/ml (n = 125), including affected and unaffected PC subjects. RESULTS: Mutations in KIT gene are related to aggressive PC: TNM stages II to III, Gleason score ≥ 7 and D'Amico risk (P = 0.037, 0.040, and 0.017). However, there are no statistical significant results when more than 3 somatic mutations are presented in the same individual. In relation to environmental factors (smoking, diet, alcohol intake, or workplace exposure) there are no significant differences in the effect of environmental exposure and the somatic mutation presence. The most prevalent mutations among patients with PC are c.1621A>C (rs3822214) in KIT, c.38G>C (rs112445441) in KRAS and c.733G>A (rs28934575) in TP53 genes. KRAS, KIT, and TP53 genes are the most prevalent ones in patients with PC. CONCLUSIONS: Somatic alterations predisposing to chromosomal rearrangements in PC remain largely undefined. We show that KIT, KRAS, and TP53 genes have a higher presence among patients with PC and that mutations in KIT gene are related to an aggressive PC. However, we did not find any environmental effect in somatic mutations among PC individuals. Activating mutations in the KRAS gene (Kirsten rat sarcoma 2 viral oncogene homolog gene) are commonly seen across the various solid organ and hematolymphoid neoplasms. With the likelihood of the mutation specific KRAS inhibitor entering clinical practice, the present studies profiled the landscape of these mutations in the Indian population to add to databases and posit the clinical utility of its emerging inhibitors. This study included 489 formalin fixed paraffin-embedded (FFPE) tissue samples from consecutive patients during a 5-year period (2015-2019). The clinical records were obtained from the medical record archives of the institution. Library preparation was done using the Oncomine Assay™. Sequencing was performed using the Ion PGM Hi-Q Sequencing Kit on the Ion Torrent Personal Genome Machine (Ion PGM) as well as on Ion Torrent S5 sequencer using the S5 sequencing kit. Ion Torrent Suite™ Browser version 5.10 and Ion Reporter™ version 5.10 were used for data analysis. A total of 50 cases with KRAS mutations were observed occurring most commonly in the codons 12 and 13. The G12D mutation was the most commonly encountered subtype in our cohort (21/50), whereas the G12C mutation was observed in 5 cases, and interestingly, this mutation was only seen in patients with non-small cell lung carcinoma (NSCLC). In the largest cohort from Indian subcontinent reporting spectrum of KRAS mutations in human cancers, an incidence of 11% was observed across all cancer types. Therapies targeting the G12C mutations can benefit up to 20% KRAS-mutated NSCLC. Building databases of spectrum of KRAS mutations in different populations across diverse cancer types is the anticipatory step to this end. BACKGROUND: Mutations of KRAS are known to occur in periampullary and ampullary adenomas and carcinomas. However, nothing is known about NRAS, HRAS, BRAF, and PIK3CA mutations in these tumors. While oncogenic BRAF contributes to the tumorigenesis of both pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasms/carcinomas (IPMN/IPMC), PIK3CA mutations were only detected in IPMN/IPMC. This study aimed to elucidate possible roles of BRAF and PIK3CA in the development of ampullary and periampullary adenomas and carcinomas. METHODS: Mutations of BRAF, NRAS, HRAS, KRAS, and PIK3CA were evaluated in seven adenomas, seven adenomas with carcinoma in situ, and 21 adenocarcinomas of the periampullary duodenal region and the ampulla of Vater. Exons 1 of KRAS; 2 and 3 of NRAS and HRAS; 5, 11, and 15 of BRAF; and 9 and 20 of PIK3CA were examined by direct genomic sequencing. RESULTS: In total, we identified ten (28.6%) KRAS mutations in exon 1 (nine in codon 12 and one in codon 13), two missense mutations of BRAF (6%), one within exon 11 (G469A), and one V600E hot spot mutation in exon 15 of BRAF. BRAF mutations were present in two of five periampullary tumors. All mutations appear to be somatic since the same alterations were not detected in the corresponding normal tissues. CONCLUSION: Our data provide evidence that oncogenic properties of KRAS and BRAF but not NRAS, HRAS, and PIK3CA contribute to the tumorigenesis of periampullary and ampullary tumors; BRAF mutations occur more frequently in periampullary than ampullary neoplasms. Rationale: KRAS is one of the most frequently mutated oncogenes in cancers. The protein's picomolar affinity for GTP/GDP and smooth protein structure resulting in the absence of known allosteric regulatory sites makes its genomic-level activating mutations a difficult but attractive target. Methods: Two CRISPR systems, genome-editing CRISPR/SpCas9 and transcription-regulating dCas9-KRAB, were developed to deplete the KRAS G12S mutant allele or repress its transcription, respectively, with the goal of treating KRAS-driven cancers. Results: SpCas9 and dCas9-KRAB systems with a sgRNA targeting the mutant allele blocked the expression of the mutant KRAS gene, leading to an inhibition of cancer cell proliferation. Local adenoviral injections using SpCas9 and dCas9-KRAB systems suppressed tumor growth in vivo. The gene-depletion system (SpCas9) performed more effectively than the transcription-suppressing system (dCas9-KRAB) on tumor inhibition. Application of both Cas9 systems to wild-type KRAS tumors did not affect cell proliferation. Furthermore, through bioinformatic analysis of 31555 SNP mutations of the top 20 cancer driver genes, the data showed that our mutant-specific editing strategy could be extended to a reference list of oncogenic mutations with high editing potentials. This pipeline could be applied to analyze the distribution of PAM sequences and survey the best alternative targets for gene editing. Conclusion: We successfully developed both gene-depletion and transcription-suppressing systems to specifically target an oncogenic KRAS mutant allele that led to significant tumor regression. These findings show the potential of CRISPR-based strategies for the treatment of tumors with driver gene mutations. Somatic activation of the KRAS proto-oncogene is evident in almost all pancreatic cancers, and appears to represent an initiating event. These mutations occur primarily at codon 12 and less frequently at codons 13 and 61. Although some studies have suggested that different KRAS mutations may have variable oncogenic properties, to date there has been no comprehensive functional comparison of multiple KRAS mutations in an in vivo vertebrate tumorigenesis system. We generated a Gal4/UAS-based zebrafish model of pancreatic tumorigenesis in which the pancreatic expression of UAS-regulated oncogenes is driven by a ptf1a:Gal4-VP16 driver line. This system allowed us to rapidly compare the ability of 12 different KRAS mutations (G12A, G12C, G12D, G12F, G12R, G12S, G12V, G13C, G13D, Q61L, Q61R and A146T) to drive pancreatic tumorigenesis in vivo. Among fish injected with one of five KRAS mutations reported in other tumor types but not in human pancreatic cancer, 2/79 (2.5%) developed pancreatic tumors, with both tumors arising in fish injected with A146T. In contrast, among fish injected with one of seven KRAS mutations known to occur in human pancreatic cancer, 22/106 (20.8%) developed pancreatic cancer. All eight tumorigenic KRAS mutations were associated with downstream MAPK/ERK pathway activation in preneoplastic pancreatic epithelium, whereas nontumorigenic mutations were not. These results suggest that the spectrum of KRAS mutations observed in human pancreatic cancer reflects selection based on variable tumorigenic capacities, including the ability to activate MAPK/ERK signaling. The 3 human RAS genes, KRAS, NRAS, and HRAS, encode 4 different RAS proteins which belong to the protein family of small GTPases that function as binary molecular switches involved in cell signaling. Activating mutations in RAS are among the most common oncogenic drivers in human cancers, with KRAS being the most frequently mutated oncogene. Although KRAS is an excellent drug discovery target for many cancers, and despite decades of research, no therapeutic agent directly targeting RAS has been clinically approved. Using structure-based drug design, we have discovered BI-2852 (1), a KRAS inhibitor that binds with nanomolar affinity to a pocket, thus far perceived to be "undruggable," between switch I and II on RAS; 1 is mechanistically distinct from covalent KRASG12C inhibitors because it binds to a different pocket present in both the active and inactive forms of KRAS. In doing so, it blocks all GEF, GAP, and effector interactions with KRAS, leading to inhibition of downstream signaling and an antiproliferative effect in the low micromolar range in KRAS mutant cells. These findings clearly demonstrate that this so-called switch I/II pocket is indeed druggable and provide the scientific community with a chemical probe that simultaneously targets the active and inactive forms of KRAS. Lung cancer, like other cancers, is considered to develop through the accumulation of genetic alterations. Mutation of the KRAS gene is one of the most important events in carcinogenesis of the lung. The KRAS gene, belonging to the RAS gene family, encodes a membrane-bound 21-kd guanosine triphosphate (GTP)-binding protein. Single point mutations in this protein result in continuous activation to transmit excessive signals, promoting a variety of biological events. In lung cancers, the mutations concentrate at codon 12 and mostly affect adenocarcinomas (ADCs). They also affect atypical adenomatous hyperplasia, the precursor of ADCs. Therefore, mutation of the KRAS gene is suggested to confer a growth advantage to airway epithelial cells enabling them to expand clonally early in the development of ADCs. The mutation is also a reliable marker of an unfavorable response to certain molecular-targeting therapies. Furthermore, patients with ADCs affected by mutations have been reported to exhibit a significantly higher risk of postoperative disease recurrence. Thus, the significance of KRAS gene mutations has been investigated extensively. However, not all the details emerged. In this review, particulars that have been established are introduced, and important issues remaining to be resolved are discussed, with special reference to carcinogenesis of the lung. OBJECTIVES: The efficacy of anti- programmed cell death 1 (PD-1)/PD-1 ligand (PD-L1) immune checkpoint inhibitors remains controversial in patients with KRAS mutation. In addition, whether and how KRAS gene and its mutant subtypes might influence immunity has not been clarified yet. Here we examine some important biomarkers for the efficacy of immunotherapy in specific KRAS subtypes. MATERIALS AND METHODS: We conducted a bioinformatics analysis on somatic mutations data, transcriptome sequencing data and proteomic data from The Cancer Genome Atlas (TCGA) database. CIBERSORT was used to provide an estimation of the abundances of immune cells using gene expression data. RESULTS: From a cohort of 567 patients with lung adenocarcinoma (LUAD) based on TCGA, the overall mutation rate of KRAS was 26.29 %, including KRAS/TP53 co-mutation rate of 9.7 %. We observed increased Tumor mutation burden (TMB) in KRAS mutant group compared with wild type, while no difference in PD-L1 expression and immune cell infiltration. More importantly, TP53 and KRAS/TP53 co-mutation group not only significantly increased tumor mutation burden, but also had higher PD-L1 protein level and immune cell infiltration. We further focused on influence of KRAS mutant subtype on immune biomarker. The most prevalent mutant subtype of KRAS in lung adenocarcinoma was G12C(9.88 %,56/567), followed by G12 V(5.82 %,33/567), G12D(3.00 %,17/567), G12A(3.00 %,17/567), respectively. Among them, G12D mutation appeared to be a special mutant subtype with an obviously lower TMB. This low mutation load was more significant when co-mutation with TP53. Besides, our results also revealed significantly decreased expressions of PD-L1 protein level and immune cell infiltration (activated CD4 memory T cell, helper T cell, M1 macrophage and NK cell) in KRAS G12D/TP53 mutant group. CONCLUSION: KRAS G12D/TP53 co-mutation drives immune suppression and might be a negative predictive biomarker for anti-PD-1/PD-L1 immune checkpoint inhibitors in patients with lung adenocarcinoma. Activation of KRAS oncogene has been implicated in colorectal carcinogenesis. KRAS mutations can be detected in more than 30% of all patients with colorectal cancer (CRC). Most recently, regimens that include anti-epidermal growth factor receptor (EGFR) targeted antibodies, cetuximab and panitumumab, for metastatic CRC have been developed. Several recent studies have shown that patients with KRAS mutations in codons 12 and 13 in metastatic CRC do not benefit from anti-EGFR therapy. With the aim to determine KRAS status as predictive biomarker, 7 known mutations ofKRAS gene in codons 12 or 13 on 44 CRC samples were tested. After DNA extraction from paraffin-embedded tumor tissue blocks, KRAS mutations were analysed using quantitative real-time PCR with internationally certified method, for the first time in Croatia. Mutations were detected in 12 tumor samples: five patients with Gly12Val (GGT>GTT), three with Gly12Asp (GGT>GAT), two patients with Gly13Asp (GGC>GAC), one patient with Gly12Ser (GGT>AGT) and one with Gly12Cys (GGT>TGT) mutation in tumor. Our data about KRAS mutational status in the sample of Croatian population diagnosed with CRC have shown that incidence of KRAS mutation is 27%, which is consistent with results already reported worldwide. The final result must be a proper selection of the correct therapy with EGFR inhibitors for the patients with CRC which is critical for improving clinical outcomes, unnecessary toxicities, side effects and financial cost. Although clinical data suggest remarkable promise for targeting programmed cell death protein-1 (PD-1) and ligand (PD-L1) signaling in non-small-cell lung cancer (NSCLC), it is still largely undetermined which subtype of patients will be responsive to checkpoint blockade. In the present study, we explored whether PD-L1 was regulated by mutant Kirsten rat sarcoma viral oncogene homolog (KRAS), which is frequently mutated in NSCLC and results in poor prognosis and low survival rates. We verified that PD-L1 levels were dramatically increased in KRAS mutant cell lines, particularly in NCI-H441 cells with KRAS G12V mutation. Overexpression of KRAS G12V remarkably elevated PD-L1 messenger RNA and protein levels, while suppression of KRAS G12V led to decreased PD-L1 levels in NCI-H441 cells. Consistently, higher levels of PD-L1 were observed in KRAS-mutated tissues as well as tumor tissues-derived CD4+ and CD8+ T cells using a tumor xenograft in B-NDG mice. Mechanically, both in vitro and in vivo assays found that KRAS G12V upregulated PD-L1 via regulating the progression of epithelial-to-mesenchymal transition (EMT). Moreover, pembrolizumab activated the antitumor activity and decreased tumor growth with KRAS G12V mutated NSCLC. This study demonstrates that KRAS G12V mutation could induce PD-L1 expression and promote immune escape via transforming growth factor-β/EMT signaling pathway in KRAS-mutant NSCLC, providing a potential therapeutic approach for NSCLC harboring KRAS mutations. Oncogenic mutations in the KRAS gene are well-established drivers of cancer. While the recently developed KRASG12C inhibitors offer a targeted KRAS therapy and have shown success in the clinic, KRASG12C represents only 11% of all KRAS mutations. Current therapeutic approaches for all other KRAS mutations are both indirect and nonmutant-selective, largely focusing on inhibition of downstream KRAS effectors such as MAP kinases. Inhibition of KRAS downstream signaling results in a system-wide down-modulation of the respective targets, raising concerns about systemic cell toxicity. Here, we describe a custom short interfering RNA oligonucleotide (EFTX-D1) designed to preferentially bind mRNA of the most commonly occurring KRAS missense mutations in codons 12 and 13. We determined that EFTX-D1 preferentially reduced the mutant KRAS sequence versus wild-type at the levels of both transcription and translation and reversed oncogenic KRAS-induced morphologic and growth transformation. Furthermore, EFTX-D1 significantly impaired the proliferation of several KRAS mutant cancer cell lines in 2-D as well as 3-D assays. Taken together, our data indicate a novel use of RNA interference to target oncogenic KRAS-driven cancers specifically. A mutated KRAS protein is frequently observed in human cancers. Traditionally, the oncogenic properties of KRAS missense mutants at position 12 (G12X) have been considered as equal. Here, by assessing the probabilities of occurrence of all KRAS G12X mutations and KRAS dynamics we show that this assumption does not hold true. Instead, our findings revealed an outstanding mutational bias. We conducted a thorough mutational analysis of KRAS G12X mutations and assessed to what extent the observed mutation frequencies follow a random distribution. Unique tissue-specific frequencies are displayed with specific mutations, especially with G12R, which cannot be explained by random probabilities. To clarify the underlying causes for the nonrandom probabilities, we conducted extensive atomistic molecular dynamics simulations (170 μs) to study the differences of G12X mutations on a molecular level. The simulations revealed an allosteric hydrophobic signaling network in KRAS, and that protein dynamics is altered among the G12X mutants and as such differs from the wild-type and is mutation-specific. The shift in long-timescale conformational dynamics was confirmed with Markov state modeling. A G12X mutation was found to modify KRAS dynamics in an allosteric way, which is especially manifested in the switch regions that are responsible for the effector protein binding. The findings provide a basis to understand better the oncogenic properties of KRAS G12X mutants and the consequences of the observed nonrandom frequencies of specific G12X mutations. Colorectal cancer (CRC) is one of the most important causes of morbidity and mortality in the developed world and is gradually more frequent in the developing world including Saudi Arabia. According to the Saudi Cancer Registry report 2015, CRC is the most common cancer in men (14.9%) and the second most prevalent cancer. Oncogenic mutations in the KRAS gene play a central role in tumorigenesis and are mutated in 30-40% of all CRC patients. To explore the prevalence of KRAS gene mutations in the Saudi population, we collected 80 CRC tumor tissues and sequenced the KRAS gene using automated sequencing technologies. The chromatograms presented mutations in 26 patients (32.5%) in four different codons, that is, 12, 13, 17, and 31. Most of the mutations were identified in codon 12 in 16 patients (61.5% of all mutations). We identified a novel mutation c.51 G>A in codon 17, where serine was substituted by arginine (S17R) in four patients. We also identified a very rare mutation, c.91 G>A, in which glutamic acid was replaced by lysine (E31K) in three patients. In conclusion, our findings further the knowledge about KRAS mutations in different ethnic groups is indispensable to fully understand their role in the development and progression of CRC. BACKGROUND: In certain non-small cell lung cancer (NSCLC) populations, codon 12 mutations of the KRAS oncogene comprising mostly G-T transversions have diagnostic and prognostic value. However, it is not known if these findings are applicable to all populations of lung cancer patients. AIMS: To examine for KRAS codon 12 mutations in Australian NSCLC patients. METHODS: Tumour samples and corresponding normal lung tissue from 108 Australian patients with NSCLC undergoing curative resection were studied for mutations of KRAS codon 12 using a sensitive PCR assay. Mutations were confirmed by DNA sequencing and correlated with histological subtype, tumour stage, the presence of nodal metastases and survival. RESULTS: Eleven KRAS codon 12 mutations were detected in 108 NSCLCs, with most (8/11) occurring in the adenocarcinoma subtype (17% prevalence), but were not associated with adverse outcome or clinico-pathological features. G-T transversions were surprisingly infrequent (37% of adenocarcinoma mutations). CONCLUSIONS: These data add to the evidence suggesting geographical differences in the spectrum and significance of KRAS codon 12 mutational genotypes in NSCLC. While these may be due to genetic variation and/or differences in carcinogen exposure, there is a need for larger population based studies before this potentially important biomarker can be recommended universally for optimising lung cancer management. The RAS genes, which include H, N, and KRAS, comprise the most frequently mutated family of oncogenes in cancer. Mutations in KRAS - such as the G12C mutation - are found in most pancreatic, half of colorectal and a third of lung cancer cases and is thus responsible for a substantial proportion of cancer deaths. Consequently, KRAS has been the subject of exhaustive drug-targeting efforts over the past 3-4 decades. These efforts have included targeting the KRAS protein itself but also its posttranslational modifications, membrane localization, protein-protein interactions and downstream signalling pathways. Most of these strategies have failed and no KRAS-specific drugs have yet been approved. However, for one specific mutation, KRASG12C , there is light on the horizon. MRTX849 was recently identified as a potent, selective and covalent KRASG12C inhibitor that possesses favourable drug-like properties. MRTX849 selectively modifies the mutant cysteine residue in GDP-bound KRASG12C and inhibits GTP-loading and downstream KRAS-dependent signalling. The drug inhibits the in vivo growth of multiple KRASG12C -mutant cell line xenografts, causes tumour regression in patient-derived xenograft models and shows striking responses in combination with other agents. It has also produced objective responses in patients with mutant-specific lung and colorectal cancer. In this review, we discuss the history of RAS drug-targeting efforts, the discovery of MRTX849, and how this drug provides an exciting and long-awaited opportunity to selectively target mutant KRAS in patients. INTRODUCTION: KRAS was one of the earliest human oncogenes to be described and is one of the most commonly mutated genes in different human cancers, including colorectal cancer. Despite KRAS mutants being known driver mutations, KRAS has proved difficult to target therapeutically, necessitating a comprehensive understanding of the molecular mechanisms underlying KRAS-driven cellular transformation. OBJECTIVES: To investigate the metabolic signatures associated with single copy mutant KRAS in isogenic human colorectal cancer cells and to determine what metabolic pathways are affected. METHODS: Using NMR-based metabonomics, we compared wildtype (WT)-KRAS and mutant KRAS effects on cancer cell metabolism using metabolic profiling of the parental KRAS G13D/+ HCT116 cell line and its isogenic, derivative cell lines KRAS +/- and KRAS G13D/-. RESULTS: Mutation in the KRAS oncogene leads to a general metabolic remodelling to sustain growth and counter stress, including alterations in the metabolism of amino acids and enhanced glutathione biosynthesis. Additionally, we show that KRASG13D/+ and KRASG13D/- cells have a distinct metabolic profile characterized by dysregulation of TCA cycle, up-regulation of glycolysis and glutathione metabolism pathway as well as increased glutamine uptake and acetate utilization. CONCLUSIONS: Our study showed the effect of a single point mutation in one KRAS allele and KRAS allele loss in an isogenic genetic background, hence avoiding confounding genetic factors. Metabolic differences among different KRAS mutations might play a role in their different responses to anticancer treatments and hence could be exploited as novel metabolic vulnerabilities to develop more effective therapies against oncogenic KRAS.
4,112
Which proteins does the p85α interact with?
p85α interacts with itself, with p110α and with p110d
[29740032, 29300353, 26222500, 21057544, 21266249, 16219545, 24657164, 28205613, 30651929, 21827948, 16135792, 26122737, 29494137, 20348926]
4,519
Calmodulin (CaM) and phosphatidylinositide-3 kinase (PI3Kα) are well known for their multiple roles in a series of intracellular signaling pathways and in the progression of several human cancers. Crosstalk between CaM and PI3Kα has been an area of intensive research. Recent experiments have shown that in adenocarcinoma, K-Ras4B is involved in the CaM-PI3Kα crosstalk. Based on experimental results, we have recently put forward a hypothesis that the coordination of CaM and PI3Kα with K-Ras4B forms a CaM-PI3Kα-K-Ras4B ternary complex, which leads to the formation of pancreatic ductal adenocarcinoma. However, the mechanism for the CaM-PI3Kα crosstalk is unresolved. Based on molecular modeling and molecular dynamics simulations, here we explored the potential interactions between CaM and the c/nSH2 domains of p85α subunit of PI3Kα. We demonstrated that CaM can interact with the c/nSH2 domains and the interaction details were unraveled. Moreover, the possible modes for the CaM-cSH2 and CaM-nSH2 interactions were uncovered and we used them to construct a complete CaM-PI3Kα complex model. The structural model of CaM-PI3Kα interaction not only offers a support for our previous ternary complex hypothesis, but also is useful for drug design targeted at CaM-PI3Kα protein-protein interactions. The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. We elucidate a p110α-independent role of homodimerized p85α in the positive regulation of PTEN stability and activity. p110α-free p85α homodimerizes via two intermolecular interactions (SH3:proline-rich region and BH:BH) to selectively bind unphosphorylated activated PTEN. As a consequence, homodimeric but not monomeric p85α suppresses the PI3K pathway by protecting PTEN from E3 ligase WWP2-mediated proteasomal degradation. Further, the p85α homodimer enhances the lipid phosphatase activity and membrane association of PTEN. Strikingly, we identified cancer patient-derived oncogenic p85α mutations that target the homodimerization or PTEN interaction surface. Collectively, our data suggest the equilibrium of p85α monomer-dimers regulates the PI3K pathway and disrupting this equilibrium could lead to disease development. Inducible acetylation of p53 at lysine residues has a great impact on regulating the transactivation of this protein, which is associated with cell growth arrest and/or apoptosis under various stress conditions. However, the factor(s) for regulating p53 acetylation remains largely unknown. In the current study, we have shown that p85α, the regulatory subunit of phosphatidylinositol-3-kinase, has a critical role in mediating p53 acetylation and promoter-specific transactivation in the ultraviolet B (UVB) response. Depletion of p85α in mouse embryonic fibroblasts significantly impairs UVB-induced apoptosis, as well as p53 transactivation and acetylation at Lys370 (Lys373 of human p53); however, the accumulation, nuclear translocation and phosphorylation of p53 are not affected. Interestingly, p85α binds to p300, promotes the p300-p53 interaction and the subsequent recruitment of the p53/p300 complex to the promoter region of the specific p53 target gene in response to UVB irradiation. Moreover, ablation of p53 acetylation at Lys370 by site-directed mutagenesis dramatically suppresses UVB-induced expression of the specific p53-responsive gene as well as cell apoptosis. Therefore, we conclude that p85α is a novel regulator of p53-mediated response under certain stress conditions, and targeting the p85α-dependent p53 pathway may be promising for cancer therapy. The endoplasmic reticulum (ER) consists of an interconnected, membranous network that is the major site for the synthesis and folding of integral membrane and secretory proteins. Within the ER lumen, protein folding is facilitated by molecular chaperones and a variety of enzymes that ensure that polypeptides obtain their appropriate, tertiary conformation (Dobson, C. M. (2004). Principles of protein folding, misfolding and aggregation. Semin. Cell Dev. Biol. 15, 3-16; Ni, M., and Lee, A. S. (2007). ER chaperones in mammalian development and human diseases. FEBS Lett. 581, 3641-3651.). Physiological conditions that increase protein synthesis or stimuli that disturb the processes by which proteins obtain their native conformation, create an imbalance between the protein-folding demand and capacity of the ER. This results in the accumulation of unfolded or improperly folded proteins in the ER lumen and a state of ER stress. The cellular response, referred to as the unfolded protein response (UPR), results in activation of three linked signal transduction pathways: PKR-like kinase (PERK), inositol requiring 1 α (IRE1α), and activating transcription factor 6α (ATF6α) (Ron, D., and Walter, P. (2007). Signal integration in the endoplasmic reticulum unfolded protein response. Nat. Rev. Mol. Cell. Biol. 8, 519-529; Schroder, M., and Kaufman, R. (2005). ER stress and the unfolded protein response. Mutat. Res./Fundam. Mol. Mech. Mutagen. 569, 29-63.). Collectively, the combined actions of these signaling cascades serve to reduce ER stress through attenuation of translation to reduce protein synthesis and through activation of transcriptional programs that ultimately serve to increase ER protein-folding capacity. Recently, we and Park et al. have characterized a novel function for the p85α and p85β subunits as modulators of the UPR by virtue of their ability to facilitate the nuclear entry of XBP-1s following induction of ER stress (Park, S. W., Zhou, Y., Lee, J., Lu, A., Sun, C., Chung, J., Ueki, K., and Ozcan, U. (2010). Regulatory subunits of PI3K, p85alpha and p85 beta, interact with XBP1 and increase its nuclear translocation. Nat. Med. 16, 429-437; Winnay, J. N., Boucher, J., Mori, M. A., Ueki, K., and Kahn, C. R. (2010). A regulatory subunit of phosphoinositide 3-kinase increases the nuclear accumulation of X-box-binding protein-1 to modulate the unfolded protein response. Nat. Med. 16, 438-445.). This chapter describes the recently elucidated role for the regulatory subunits of PI 3-kinase as modulators of the UPR and provides methods to measure UPR pathway activation. Phosphoinositide 3-kinase (PI3K) activity is important for regulating cell growth, survival, and motility. We report here the identification of bromodomain-containing protein 7 (BRD7) as a p85α-interacting protein that negatively regulates PI3K signaling. BRD7 binds to the inter-SH2 (iSH2) domain of p85 through an evolutionarily conserved region located at the C terminus of BRD7. Via this interaction, BRD7 facilitates nuclear translocation of p85α. The BRD7-dependent depletion of p85 from the cytosol impairs formation of p85/p110 complexes in the cytosol, leading to a decrease in p110 proteins and in PI3K pathway signaling. In contrast, silencing of endogenous BRD7 expression by RNAi increases the steady-state level of p110 proteins and enhances Akt phosphorylation after stimulation. These data suggest that BRD7 and p110 compete for the interaction to p85. The unbound p110 protein is unstable, leading to the attenuation of PI3K activity, which suggests how BRD7 could function as a tumor suppressor. It has been reported that p21-activated kinase 4 (PAK4) is amplified in pancreatic cancer tissue. PAK4 is a member of the PAK family of serine/threonine kinases, which act as effectors for several small GTPases, and has been specifically identified to function downstream of HGF-mediated c-Met activation in a PI3K dependent manner. However, the functionality of PAK4 in pancreatic cancer and the contribution made by HGF signalling to pancreatic cancer cell motility remain to be elucidated. We now find that elevated PAK4 expression is coincident with increased expression levels of c-Met and the p85α subunit of PI3K. Furthermore, we demonstrate that pancreatic cancer cells have a specific motility response to HGF both in 2D and 3D physiomimetic organotypic assays; which can be suppressed by inhibition of PI3K. Significantly, we report a specific interaction between PAK4 and p85α and find that PAK4 deficient cells exhibit a reduction in Akt phosphorylation downstream of HGF signalling. These results implicate a novel role for PAK4 within the PI3K pathway via interaction with p85α. Thus, PAK4 could be an essential player in PDAC progression representing an interesting therapeutic opportunity. Phosphoinositide 3-kinase δ is upregulated in lymphocytic leukemias. Because the p85-regulatory subunit binds to any class IA subunit, it was assumed there is a single universal p85-mediated regulatory mechanism; however, we find isozyme-specific inhibition by p85α. Using deuterium exchange mass spectrometry (DXMS), we mapped regulatory interactions of p110δ with p85α. Both nSH2 and cSH2 domains of p85α contribute to full inhibition of p110δ, the nSH2 by contacting the helical domain and the cSH2 via the C terminus of p110δ. The cSH2 inhibits p110β and p110δ, but not p110α, implying that p110α is uniquely poised for oncogenic mutations. Binding RTK phosphopeptides disengages the SH2 domains, resulting in exposure of the catalytic subunit. We find that phosphopeptides greatly increase the affinity of the heterodimer for PIP2-containing membranes measured by FRET. DXMS identified regions decreasing exposure at membranes and also regions gaining exposure, indicating loosening of interactions within the heterodimer at membranes. The p85alpha subunit of phosphatidylinositol 3-kinase (PI-3k) forms a complex with a protein network associated with oncogenic fusion tyrosine kinases (FTKs) such as BCR/ABL, TEL/ABL, TEL/JAK2, TEL/PDGFbetaR, and NPM/ALK, resulting in constitutive activation of the p110 catalytic subunit of PI-3k. Introduction of point mutations in the N-terminal and C-terminal SH2 domain and SH3 domain of p85alpha, which disrupt their ability to bind phosphotyrosine and proline-rich motifs, respectively, abrogated their interaction with the BCR/ABL protein network. The p85alpha mutant protein (p85mut) bearing these mutations was unable to interact with BCR/ABL and other FTKs, while its binding to the p110alpha catalytic subunit of PI-3k was intact. In addition, binding of Shc, c-Cbl, and Gab2, but not Crk-L, to p85mut was abrogated. p85mut diminished BCR/ABL-dependent activation of PI-3k and Akt kinase, the downstream effector of PI-3k. This effect was associated with the inhibition of BCR/ABL-dependent growth of the hematopoietic cell line and murine bone marrow cells. Interestingly, the addition of interleukin-3 (IL-3) rescued BCR/ABL-transformed cells from the inhibitory effect of p85mut. SCID mice injected with BCR/ABL-positive hematopoietic cells expressing p85mut survived longer than the animals inoculated with BCR/ABL-transformed counterparts. In conclusion, we have identified the domains of p85alpha responsible for the interaction with the FTK protein network and transduction of leukemogenic signaling. Phosphatidylinositol 3-kinase (PI3K) α is a heterodimeric lipid kinase that catalyzes the conversion of phosphoinositol-4,5-bisphosphate to phosphoinositol-3,4,5-trisphosphate. The PI3Kα signaling pathway plays an important role in cell growth, proliferation, and survival. This pathway is activated in numerous cancers, where the PI3KCA gene, which encodes for the p110α PI3Kα subunit, is mutated. Its mutation often results in gain of enzymatic activity; however, the mechanism of activation by oncogenic mutations remains unknown. Here, using computational methods, we show that oncogenic mutations that are far from the catalytic site and increase the enzymatic affinity destabilize the p110α-p85α dimer. By affecting the dynamics of the protein, these mutations favor the conformations that reduce the autoinhibitory effect of the p85α nSH2 domain. For example, we determined that, in all of the mutants, the nSH2 domain shows increased positional heterogeneity as compared with the wild-type, as demonstrated by changes in the fluctuation profiles computed by normal mode analysis of coarse-grained elastic network models. Analysis of the interdomain interactions of the wild-type and mutants at the p110α-p85α interface obtained with molecular dynamics simulations suggest that all of the tumor-associated mutations effectively weaken the interactions between p110α and p85α by disrupting key stabilizing interactions. These findings have important implications for understanding how oncogenic mutations change the conformational multiplicity of PI3Kα and lead to increased enzymatic activity. This mechanism may apply to other enzymes and/or macromolecular complexes that play a key role in cell signaling. Calmodulin (CaM) is a calcium sensor protein that directly interacts with the dual-specificity (lipid and protein) kinase PI3Kα through the SH2 domains of the p85 regulatory subunit. In adenocarcinomas, the CaM interaction removes the autoinhibition of the p110 catalytic subunit of PI3Kα, leading to activation of PI3Kα and promoting cell proliferation, survival, and migration. Here we demonstrate that the cSH2 domain of p85α engages its two CaM-binding motifs in the interaction with the N- and C-lobes of CaM as well as the flexible central linker, and our nuclear magnetic resonance experiments provide structural details. We show that in response to binding CaM, cSH2 exposes its tryptophan residue at the N-terminal region to the solvent. Because of the flexible nature of both CaM and cSH2, multiple binding modes of the interactions are possible. Binding of CaM to the cSH2 domain can help release the inhibition imposed on the p110 subunit, similar to the binding of the phosphorylated motif of RTK, or phosphorylated CaM (pCaM), to the SH2 domains. Amino acid sequence analysis shows that CaM-binding motifs are common in SH2 domains of non-RTKs. We speculate that CaM can also activate these kinases through similar mechanisms. Despite the fact that X-box binding protein-1 (XBP-1) is one of the main regulators of the unfolded protein response (UPR), the modulators of XBP-1 are poorly understood. Here, we show that the regulatory subunits of phosphotidyl inositol 3-kinase (PI3K), p85alpha (encoded by Pik3r1) and p85beta (encoded by Pik3r2) form heterodimers that are disrupted by insulin treatment. This disruption of heterodimerization allows the resulting monomers of p85 to interact with, and increase the nuclear translocation of, the spliced form of XBP-1 (XBP-1s). The interaction between p85 and XBP-1s is lost in ob/ob mice, resulting in a severe defect in XBP-1s translocation to the nucleus and thus in the resolution of endoplasmic reticulum (ER) stress. These defects are ameliorated when p85alpha and p85beta are overexpressed in the liver of ob/ob mice. Our results define a previously unknown insulin receptor signaling pathway and provide new mechanistic insight into the development of ER stress during obesity.
4,113
Computational tools for predicting allosteric pathways in proteins
CorrSite identifies potential allosteric ligand-binding sites based on motion correlation analyses between cavities.
[32737291, 25340971, 20161451, 24803851, 27580047, 29750256, 27254668, 33844527, 28282132, 23842804, 23742907, 30688063]
4,520
Allostery is a universal phenomenon that couples the information induced by a local perturbation (effector) in a protein to spatially distant regulated sites. Such an event can be described in terms of a large scale transmission of information (communication) through a dynamic coupling between structurally rigid (minimally frustrated) and plastic (locally frustrated) clusters of residues. To elaborate a rational description of allosteric coupling, we propose an original approach - MOdular NETwork Analysis (MONETA) - based on the analysis of inter-residue dynamical correlations to localize the propagation of both structural and dynamical effects of a perturbation throughout a protein structure. MONETA uses inter-residue cross-correlations and commute times computed from molecular dynamics simulations and a topological description of a protein to build a modular network representation composed of clusters of residues (dynamic segments) linked together by chains of residues (communication pathways). MONETA provides a brand new direct and simple visualization of protein allosteric communication. A GEPHI module implemented in the MONETA package allows the generation of 2D graphs of the communication network. An interactive PyMOL plugin permits drawing of the communication pathways between chosen protein fragments or residues on a 3D representation. MONETA is a powerful tool for on-the-fly display of communication networks in proteins. We applied MONETA for the analysis of communication pathways (i) between the main regulatory fragments of receptors tyrosine kinases (RTKs), KIT and CSF-1R, in the native and mutated states and (ii) in proteins STAT5 (STAT5a and STAT5b) in the phosphorylated and the unphosphorylated forms. The description of the physical support for allosteric coupling by MONETA allowed a comparison of the mechanisms of (a) constitutive activation induced by equivalent mutations in two RTKs and (b) allosteric regulation in the activated and non-activated STAT5 proteins. Our theoretical prediction based on results obtained with MONETA was validated for KIT by in vitro experiments. MONETA is a versatile analytical and visualization tool entirely devoted to the understanding of the functioning/malfunctioning of allosteric regulation in proteins - a crucial basis to guide the discovery of next-generation allosteric drugs. Allostery can occur by way of subtle cooperation among protein residues (e.g., amino acids) even in the absence of large conformational shifts. Dynamical network analysis has been used to model this cooperation, helping to computationally explain how binding to an allosteric site can impact the behavior of a primary site many ångstroms away. Traditionally, computational efforts have focused on the most optimal path of correlated motions leading from the allosteric to the primary active site. We present a program called Weighted Implementation of Suboptimal Paths (WISP) capable of rapidly identifying additional suboptimal pathways that may also play important roles in the transmission of allosteric signals. Aside from providing signal redundancy, suboptimal paths traverse residues that, if disrupted through pharmacological or mutational means, could modulate the allosteric regulation of important drug targets. To demonstrate the utility of our program, we present a case study describing the allostery of HisH-HisF, an amidotransferase from T. maritima thermotiga. WISP and its VMD-based graphical user interface (GUI) can be downloaded from http://nbcr.ucsd.edu/wisp. Allostery is the phenomenon in which a ligand binding at one site affects other sites in the same macromolecule. Allostery has important roles in many biological processes. Theoretically, all nonfibrous proteins are potentially allosteric. However, few allosteric proteins have been validated, and the identification of novel allosteric sites remains a challenge. The motion of residues and subunits underlies protein function; therefore, we hypothesized that the motions of allosteric and orthosteric sites are correlated. We utilized a data set of 24 known allosteric sites from 23 monomer proteins to calculate the correlations between potential ligand-binding sites and corresponding orthosteric sites using a Gaussian network model (GNM). Most of the known allosteric site motions showed high correlations with corresponding orthosteric site motions, whereas other surface cavities did not. These high correlations were robust when using different structural data for the same protein, such as structures for the apo state and the orthosteric effector-binding state, whereas the contributions of different frequency modes to motion correlations depend on the given protein. The high correlations between allosteric and orthosteric site motions were also observed in oligomeric allosteric proteins. We applied motion correlation analysis to predict potential allosteric sites in the 23 monomer proteins, and some of these predictions were in good agreement with published experimental data. We also performed motion correlation analysis to identify a novel allosteric site in 15-lipoxygenase (an enzyme in the arachidonic acid metabolic network) using recently reported activating compounds. Our analysis correctly identified this novel allosteric site along with two other sites that are currently under experimental investigation. Our study demonstrates that the motions of allosteric sites are highly correlated with the motions of orthosteric sites. Our correlation analysis method provides new tools for predicting potential allosteric sites. While the pervasiveness of allostery in proteins is commonly accepted, we further show the generic nature of allosteric mechanisms by analyzing here transmembrane ion-channel viroporin 3a and RNA-dependent RNA polymerase (RdRp) from SARS-CoV-2 along with metabolic enzymes isocitrate dehydrogenase 1 (IDH1) and fumarate hydratase (FH) implicated in cancers. Using the previously developed structure-based statistical mechanical model of allostery (SBSMMA), we share our experience in analyzing the allosteric signaling, predicting latent allosteric sites, inducing and tuning targeted allosteric response, and exploring the allosteric effects of mutations. This, yet incomplete list of phenomenology, forms a complex and unique allosteric territory of protein function, which should be thoroughly explored. We propose a generic computational framework, which not only allows one to obtain a comprehensive allosteric control over proteins but also provides an opportunity to approach the fragment-based design of allosteric effectors and drug candidates. The advantages of allosteric drugs over traditional orthosteric compounds, complemented by the emerging role of the allosteric effects of mutations in the expansion of the cancer mutational landscape and in the increased mutability of viral proteins, leave no choice besides further extensive studies of allosteric mechanisms and their biomedical implications. Allosteric mechanism of proteins is essential in biomolecular signaling. An important aspect underlying this mechanism is the communication pathways connecting functional residues. Here, a Monte Carlo (MC) path generation approach is proposed and implemented to define likely allosteric pathways through generating an ensemble of maximum probability paths. The protein structure is considered as a network of amino acid residues, and inter-residue interactions are described by an atomistic potential function. PDZ domain structures are presented as case studies. The analysis for bovine rhodopsin and three myosin structures are also provided as supplementary case studies. The suggested pathways and the residues constituting the pathways are maximally probable and mostly agree with the previous studies. Overall, it is demonstrated that the communication pathways could be multiple and intrinsically disposed, and the MC path generation approach provides an effective tool for the prediction of key residues that mediate the allosteric communication in an ensemble of pathways and functionally plausible residues. The MCPath server is available at http://safir.prc.boun.edu.tr/clbet_server. Allostery, or allosteric regulation, is the phenomenon in which protein functional activity is altered by the binding of an effector at an allosteric site that is topographically distinct from the orthosteric, active site. As one of the most direct and efficient ways to regulate protein function, allostery has played a fundamental role in innumerable biological processes of all living organisms, including enzyme catalysis, signal transduction, cell metabolism, and gene transcription. It is thus considered as "the second secret of life". The abnormality of allosteric communication networks between allosteric and orthosteric sites is associated with the pathogenesis of human diseases. Allosteric modulators, by attaching to structurally diverse allosteric sites, offer the potential for differential selectivity and improved safety compared with orthosteric drugs that bind to conserved orthosteric sites. Harnessing allostery has thus been regarded as a novel strategy for drug discovery. Despite much progress having been made in the repertoire of allostery since the turn of the millennium, the identification of allosteric drugs for therapeutic targets and the elucidation of allosteric mechanisms still present substantial challenges. These challenges are derived from the difficulties in the identification of allosteric sites and mutations, the assessment of allosteric protein-modulator interactions, the screening of allosteric modulators, and the elucidation of allosteric mechanisms in biological systems. To address these issues, we have developed a panel of allosteric services for specific allosteric applications over the past decade, including (i) the creation of the Allosteric Database, with the aim of providing comprehensive allosteric information such as allosteric proteins, modulators, sites, pathways, etc., (ii) the construction of the ASBench benchmark of high-quality allosteric sites for the development of computational methods for predicting allosteric sites, (iii) the development of Allosite and AllositePro for the prediction of the location of allosteric sites in proteins, (iv) the development of the Alloscore scoring function for the evaluation of allosteric protein-modulator interactions, (v) the development of Allosterome for evolutionary analysis of query allosteric sites/modulators within the human proteome, (vi) the development of AlloDriver for the prediction of allosteric mutagenesis, and (vii) the development of AlloFinder for the virtual screening of allosteric modulators and the investigation of allosteric mechanisms. Importantly, we have validated computationally predicted allosteric sites, mutations, and modulators in the real cases of sirtuin 6, casein kinase 2α, phosphodiesterase 10A, and signal transduction and activation of transcription 3. Furthermore, our developed allosteric methods have been widely exploited by other users around the world for allosteric research. Therefore, these allosteric services are expected to expedite the discovery of allosteric drugs and the investigation of allosteric mechanisms.
4,114
What are the classic signs of a basilar skull fracture?
Basilar skull fractures are fractures of the lower part of the skull. The four classic signs are: 1. Periorbital ecchymosis (“raccoon eyes”). 2. Postauricular ecchymosis (Battle sign). 3. CSF otorrhea or rhinorrhea (leakage of CSF, which is clear in appearance, from the ears or nose). 4. Hemotympanum (blood behind the eardrum).
[2759776, 30216260, 24095269, 9800356, 717321, 1788430, 22951125, 19392601, 34236447]
4,521
In this paper we are reporting a retrospective study of patients under 18 years of age managed at the Los Angeles County/University of Southern California Medical Center from January 1979 through December 1987 with the diagnosis of basilar skull fracture. Sixty-two patients with basilar skull fractures were admitted during that 7 1/2 year period. The most common etiology was pedestrain versus vehicle accidents (42%), followed by falls (27%), vehicle accidents (23%), and being hit by an object (8%). The most common physical findings were hemotympanum (58%) and bleeding in the ear canals (47%). Thirty-four percent of the patients complained of hearing loss. Cerebrospinal fluid otorrhea was noted in 16 patients (26%), while only 1 patient had cerebrospinal fluid rhinorrhea. Facial nerve paralysis was present in 8 patients (13%). Vestibular symptoms were rare. Sixty-three percent of the patients had the diagnosis confirmed by radiography. The clinical presentation, complications, management and outcome of basilar skull fractures in the pediatric population are discussed. Although clinical signs for the diagnosis of basilar skull fracture (BSF) are ambiguous, they are widely used to make decisions on initial interventions involving trauma patients. We aimed to assess the performance of early and late (within 48 hr posttrauma) signs for BSF diagnosis and to verify the correlation between the presence of these signs and head injury severity. We conducted a prospectively designed follow-up study at a referral hospital for trauma care in Sao Paulo, Brazil, and performed structured observations for 48 hr post-blunt head injury in patients aged 12 years or older. The following signs of BSF were considered: raccoon eyes, Battle's sign, otorrhea, and rhinorrhea. Among the 136 enrolled patients (85.3% male; mean age 40 ± 21.4 years), 28 patients (20.6%) had BSF. The clinical signs for the early or late detection of BSF had low accuracy (55.9% vs. 43.4%), specificity (52.8% vs. 30.5%), and positive predictive value (25.7% vs. 27.1%). However, the presence of these signs was correlated to head injury severity, indicated by the Glasgow Coma Scale (p = .041) and Maximum Abbreviated Injury Scale-Head region (p = .002). In view of the low accuracy of these signs, resulting low clinical value of their presence, and their high sensitivity in the late stage, the study results contraindicate the value of BSF signs for making decisions about using the nasal route for the introduction of catheters and tubes in initial trauma care. Forty-six cases of basilar skull fractures in children were reviewed to determine the incidence of CNS infection following injury and the possible value of antimicrobial chemoprophylaxis. The clinical course of the children who were treated with antibiotics was compared with that of patients who received no antimicrobial therapy. Included in the study were patients with hemotympanum alone or with hemotympanum plus additional clinical or roentgenographic signs of basilar skull fracture; patients with tympanic membrane perforation without otorrhea but with blood in the auditory canal; and children with either otorrhea or rhinorrhea. Acute, delayed, or recurrent infection of the CNS did not develop in any of the patients. This study is the first of its kind presented in children. It would seem on the basis of the present series that the systematic use of antibiotic prophylaxis in children with hemotympanum following basilar skull fractures is unwarranted and that children with other signs of basilar skull fractures may have an equally small risk of meningitis following injury. A prospective study was performed on 4,262 consecutive patients who had had skull examinations for recent head trauma. Clinical signs and symptoms and patient history were correlated with skull fractures and intracranial sequelae as identified on CT studies, in order to evaluate the predictive value of each clinical finding and to identify high-yield referral criteria. Ninety-seven skull fractures (3%) and 32 intracranial sequelae (0.7%) were observed. All the intracranial complications were observed in patients with fractures and with altered consciousness of some degrees (Glasgow Coma Scale score less than 13). Most patients were asymptomatic (41%) or showed "low risk" symptoms (29%): among them, neither fractures nor complications were observed. High-risk clinical signs, mainly expressing basilar fractures (as rhinorrhea, otorrhea, focal neurologic signs, retroauricular hematoma) demonstrated high predictive value (100%) for intracranial sequelae. Other "moderate risk" findings for intracranial injury--i.e. loss of consciousness at any time, antegrade or retrograde amnesia, multiple trauma, and possible skull penetration--showed a high correlation with skull fractures and a slightly lower one with intracranial sequelae. The most predictive finding for brain injury was the depressed level of consciousness: brain injuries were never observed in fully conscious patients; in altered consciousness with GCS 15-13 we observed 4% of skull fractures with no sequelae; at GCS values 12-9, 61% of skull fractures and 20% of sequelae were present, whereas at GCS less than 8, 100% of complicated fracture were observed. The finding of skull fracture showed 33% of predictivity for brain damage, which was, however, always associated with "high or moderate risk" clinical signs. Therefore, the authors suggest some guidelines for the management of patients with recent head trauma, including referral criteria for X-rays or CT studies, based on signs and symptoms with high, intermediate and low risk of developing intracranial sequelae. A 56-year-old woman presented with retrograde amnesia and confusion at the Emergency Department after falling down the stairs. Physical examination revealed a bilateral periorbital hematoma (raccoon eyes) and bilateral retroauricular ecchymosis, both strongly indicative of a basilar skull fracture. Publisher: KLINISCHES PROBLEM: Bei Schädelbasisfrakturen handelt es sich um Frakturen des unteren Abschnitts des Hirnschädels. Sie machen ca. 20 % aller Schädelfrakturen aus und werden vor allem durch Hochranztraumen und Stürze aus großer Höhe verursacht. Sie können in Abhängigkeit ihrer genauen Lokalisation in frontobasale, laterobasale und frontolaterale Frakturen unterteilt werden. Mögliche klinische Zeichen sind das Vorliegen einer Rhino- und Otoliquorrhoe, Monokel- und Brillenhämatome, retroaurikuläre Ekchymose (sog. Battle-Zeichen) sowie Hirnnervenausfälle. Ferner kann es bei den Felsenbeinfrakturen zu einer Schallleitungsstörung, Schallempfindungsstörung sowie zu Schwindel und Übelkeit aufgrund eines möglichen Ausfalls des Labyrinths kommen. EMPFEHLUNGEN FüR DIE PRAXIS: Bei klinischen Zeichen auf Vorliegen einer Schädelbasisfraktur, neurologischen Ausfällen oder eingeschränktem Bewusstsein (GCS < 15) sollte eine Computertomographie (CT) zum Ausschluss einer Schädelbasisfraktur und begleitenden Pathologien erfolgen. Zusätzlich sollte bei Verdacht auf eine Gefäßverletzung eine CT-Angiographie erfolgen. Die Therapie erfolgt in der Regel interdisziplinär und richtet sich insbesondere nach den begleitenden Verletzungen und möglichen Komplikationen. Häufig ist ein rein konservatives Vorgehen mit engmaschigen Kontrollen (u. a. mit Bildgebung) ausreichend. Ein operatives Vorgehen dient der Behandlung von möglichen Komplikationen, wie z. B. ausgeprägte intrazerebrale Blutungen.
4,115
Which biomarkers are currently used for Duchenne Muscular Dystrophy?
MRI measurements can be used as biomarkers of disease severity in ambulant patients with DMD. malate dehydrogenase 2 as candidate prognostic biomarker for Duchenne muscular dystrophy
[27854211, 32476037, 26963343, 28252048, 21479190, 31892637, 32695843, 31881125, 34533053, 32791870, 34439489, 26091074, 29554116, 23945935, 28821969, 24813925, 30499689, 27778157, 27979502, 32390640, 25150707, 26594036, 31838454, 24460924]
4,522
BACKGROUND: Duchenne Muscular Dystrophy (DMD) is a severe, progressive, neuromuscular disorder of childhood. While a number of serum factors have been identified as potential biomarkers of DMD, none, as yet, are proteins within the dystrophin-associated glycoprotein (DAG) complex. OBJECTIVE: We have developed an immobilized serum ELISA assay to measure the expression of a constitutively cleaved and secreted component of the DAG complex, the N-terminal domain of α dystroglycan (αDG-N), and assayed relative expression in serum from muscular dystrophy patients and normal controls. METHODS: ELISAs of immobilized patient or mouse serum and Western blots were used to assess αDG-N expression. RESULTS: Immobilization of diluted serum on ELISA plates was important for this assay, as methods to measure serum αDG-N in solution were less robust. αDG-N ELISA signals were significantly reduced in DMD serum (27±3% decrease, n = 9, p < 0.001) relative to serum from otherwise normal controls (n = 38), and calculated serum αDG-N concentrations were reduced in DMD relative to normal (p < 0.01) and Becker Muscular Dystrophy (n = 11, p < 0.05) patient serum. By contrast, ELISA signals from patients with Inclusion Body Myositis were not different than normal (4±3% decrease, n = 8, p = 0.99). αDG-N serum signals were also significantly reduced in utrophin-deficient mdx mice as compared to mdx and wild type mice. CONCLUSIONS: Our results are the first demonstration of a component of the DAG complex as a potential serum biomarker in DMD. Such a serum measure could be further developed as a tool to help reflect overall muscle DAG complex expression or stability. Despite promising therapeutic avenues, there is currently no effective treatment for Duchenne muscular dystrophy (DMD), a lethal monogenic disorder caused by the loss of the large cytoskeletal protein, dystrophin. A highly promising approach to therapy, applicable to all DMD patients irrespective to their genetic defect, is to modulate utrophin, a functional paralogue of dystrophin, able to compensate for the primary defects of DMD restoring sarcolemmal stability. One of the major difficulties in assessing the effectiveness of therapeutic strategies is to define appropriate outcome measures. In the present study, we utilised an aptamer based proteomics approach to profile 1,310 proteins in plasma of wild-type, mdx and Fiona (mdx overexpressing utrophin) mice. Comparison of the C57 and mdx sera revealed 83 proteins with statistically significant >2 fold changes in dystrophic serum abundance. A large majority of previously described biomarkers (ANP32B, THBS4, CAMK2A/B/D, CYCS, CAPNI) were normalised towards wild-type levels in Fiona animals. This work also identified potential mdx markers specific to increased utrophin (DUS3, TPI1) and highlights novel mdx biomarkers (GITR, MYBPC1, HSP60, SIRT2, SMAD3, CNTN1). We define a panel of putative protein mdx biomarkers to evaluate utrophin based strategies which may help to accelerate their translation to the clinic. OBJECTIVE: To assess the evidence of a relationship between muscle MRI and disease severity in Duchenne muscular dystrophy (DMD). METHODS: We conducted a systematic review of studies that analyzed correlations between MRI measurements and motor function in patients with DMD. PubMed, Cochrane, Scopus, and Web of Science were searched using relevant keywords and inclusion/exclusion criteria (January 1, 1990-January 31, 2019). We evaluated article quality using the Joanna Briggs Institute scale. Information regarding the samples included, muscles evaluated, MRI protocols and motor function tests used was collected from each article. Correlations between MRI measurements and motor function were reported exhaustively. RESULTS: Seventeen of 1,629 studies identified were included. Most patients included were ambulant with a mean age of 8.9 years. Most studies evaluated lower limb muscles. Moderate to excellent correlations were found between MRI measurements and motor function. The strongest correlations were found for quantitative MRI measurements such as fat fraction or mean T2. Correlations were stronger for lower leg muscles such as soleus. One longitudinal study reported that changes in soleus mean T2 were highly correlated with changes in motor function. CONCLUSION: The findings of this systematic review showed that MRI measurements can be used as biomarkers of disease severity in ambulant patients with DMD. Guidelines are proposed to help clinicians choose the most appropriate MRI measurements and muscles to evaluate. Studies exploring upper limb muscles, other stages of the disease, and sensitivity of measurements to change are needed. Recently, several promising treatments have emerged for neuromuscular disorders, highlighting the need for robust biomarkers for monitoring therapeutic efficacy and maintenance of the therapeutic effect. Several studies have proposed circulating and tissue biomarkers, but none of them has been validated to monitor acute and long-term drug response. We previously described how the myostatin (MSTN) level is naturally downregulated in several neuromuscular diseases, including Duchenne muscular dystrophy (DMD). Here, we show that the dystrophin-deficient Golden Retriever muscular dystrophy (GRMD) dog model also presents an intrinsic loss of Mstn production in muscle. The abnormally low levels of Mstn observed in the GRMD dog puppies at 2 months were partially rescued at both mRNA and protein level after adeno-associated virus (AAV)-microdystrophin treatment in a dose-dependent manner. These results show that circulating Mstn is a robust and reliable quantitative biomarker, capable of measuring a therapeutic response to pharmaco-gene therapy in real time in the neuromuscular system, as well as a quantitative means for non-invasive follow-up of a therapeutic effect. Moreover, a 2-year follow-up also suggests that Mstn could be a longitudinal monitoring tool to follow maintenance or decrease of the therapeutic effect. BACKGROUND: Duchenne muscular dystrophy (DMD) is a fatal disease for which no cure is available. Clinical trials have shown to be largely underpowered due to inter-individual variability and noisy outcome measures. The availability of biomarkers able to anticipate clinical benefit is highly needed to improve clinical trial design and facilitate drug development. METHODS: In this study, we aimed to appraise the value of protein biomarkers to predict prognosis and monitor disease progression or treatment outcome in patients affected by DMD. We collected clinical data and 303 blood samples from 157 DMD patients in three clinical centres; 78 patients contributed multiple blood samples over time, with a median follow-up time of 2 years. We employed linear mixed models to identify biomarkers that are associated with disease progression, wheelchair dependency, and treatment with corticosteroids and performed survival analysis to find biomarkers whose levels are associated with time to loss of ambulation. RESULTS: Our analysis led to the identification of 21 proteins whose levels significantly decrease with age and nine proteins whose levels significantly increase. Seven of these proteins are also differentially expressed in non-ambulant patients, and three proteins are differentially expressed in patients treated with glucocorticosteroids. Treatment with corticosteroids was found to partly counteract the effect of disease progression on two biomarkers, namely, malate dehydrogenase 2 (MDH2, P = 0.0003) and ankyrin repeat domain 2 (P = 0.0005); however, patients treated with corticosteroids experienced a further reduction on collagen 1 serum levels (P = 0.0003), especially following administration of deflazacort. A time to event analysis allowed to further support the use of MDH2 as a prognostic biomarker as it was associated with an increased risk of wheelchair dependence (P = 0.0003). The obtained data support the prospective evaluation of the identified biomarkers in natural history and clinical trials as exploratory biomarkers. CONCLUSIONS: We identified a number of serum biomarkers associated with disease progression, loss of ambulation, and treatment with corticosteroids. The identified biomarkers are promising candidate prognostic and surrogate biomarkers, which may support drug developers if confirmed in prospective studies. The serum levels of MDH2 are of particular interest, as they correlate with disease stage and response to treatment with corticosteroids, and are also associated with the risk of wheelchair dependency and pulmonary function. Aim: Evaluate the utility of glutamate dehydrogenase (GLDH) and cardiac troponin I as safety biomarkers, and creatine kinase and muscle injury panel as muscle health biomarkers in Duchenne muscular dystrophy. Patients & methods: Data were collected during a Phase II trial of domagrozumab. Results: GLDH was a more specific biomarker for liver injury than alanine aminotransferase. Cardiac troponin I elevations were variable and not sustained, limiting its applicability as a biomarker. Muscle injury panel biomarkers were no more informative than creatine kinase as a muscle health biomarker. Conclusion: Results support the use of GLDH as a specific biomarker for liver injury in patients with Duchenne muscular dystrophy. Clinical trial registration: ClinicalTrials.gov, NCT02310763. PURPOSE: Duchenne muscular dystrophy (DMD) is currently the most commonly diagnosed form of muscular dystrophy due to mutations in the dystrophin gene. However, its pathological process remains unknown and there is a lack of specific molecular biomarkers. The aim of our study is to explore key regulatory connections underlying the progression of DMD. MATERIALS AND METHODS: The gene expression profile dataset GSE38417 of DMD was obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between DMD patients and healthy controls were screened using geo2R, followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway enrichment analyses. Then a protein-protein interaction (PPI) network and sub-network of modules were constructed. To investigate the regulatory network underlying DMD, a global triple network including miRNAs, mRNAs and transcription factors (TFs) was constructed. RESULTS: A total of 1811 DEGs were found between the DMD and control groups, among which HERC5, SKP2 and FBXW5 were defined as hub genes with a degree of connectivity >35 in the PPI network. Furthermore, the five TFs ZNF362, ATAT1, SPI1, TCF12 and ABCF2, as well as the eight miRNAs miR-124a, miR-200b/200c/429, miR-19a/b, miR-23a/b, miR-182, miR-144, miR-498 and miR-18a/b were identified as playing crucial roles in the molecular pathogenesis of DMD. CONCLUSIONS: This paper provides a comprehensive perspective on the miRNA-TF-mRNA co-regulatory network underlying DMD, although the bioinformatic findings need further validation in future studies. Author information: (1)Research Center in Technology and Design Assistance of Jalisco State (CIATEJ, AC), National Council of Science and Technology (CONACYT), Guadalajara 44270, Mexico. monica207383614@gmail.com. (2)National Medical Centre \"20 de Noviembre\", Institute for Social Security of State Workers, Mexico City 03100, Mexico. elfroy77_@hotmail.com. (3)National Medical Centre \"20 de Noviembre\", Institute for Social Security of State Workers, Mexico City 03100, Mexico. wicho_unam@hotmail.com. (4)National Institute of Rehabilitation, Mexico City 14389, Mexico. bgodiaz@gmail.com. (5)Faculty of Medicine, National Autonomous University of Mexico, Mexico City 04510, Mexico. guilleavila2000@yahoo.com. (6)Research Center in Technology and Design Assistance of Jalisco State (CIATEJ, AC), National Council of Science and Technology (CONACYT), Guadalajara 44270, Mexico. ialvarez@ciatej.mx. (7)Studies Section of Postgraduate and Research, School of Medicine, National Polytechnic Institute, Mexico City 11340, Mexico. rmcoralv@gmail.com. (8)National Medical Centre \"20 de Noviembre\", Institute for Social Security of State Workers, Mexico City 03100, Mexico. p.mondragonteran@gmail.com. (9)National Institute of Rehabilitation, Mexico City 14389, Mexico. rescobarmex@gmail.com. (10)Asociación de Distrofia Muscular de Occidente A.C., Guadalajara 44380, Mexico. dranoemigarcia@gmail.com. (11)Mexican Institute of Social Security-CMNO, Guadalajara 44340, Mexico. dranoemigarcia@gmail.com. (12)Faculty of Medicine, Autonomous University of Guadalajara, Guadalajara 45129, Mexico. avc200180@yahoo.com.mx. (13)National Medical Centre \"20 de Noviembre\", Institute for Social Security of State Workers, Mexico City 03100, Mexico. rolasil@yahoo.com.mx. (14)National Medical Centre \"20 de Noviembre\", Institute for Social Security of State Workers, Mexico City 03100, Mexico. lblhmedgen@gmail.com. OBJECTIVE: To provide evidence for quantitative magnetic resonance (qMR) biomarkers in Duchenne muscular dystrophy by investigating the relationship between qMR measures of lower extremity muscle pathology and functional endpoints in a large ambulatory cohort using a multicenter study design. METHODS: MR spectroscopy and quantitative imaging were implemented to measure intramuscular fat fraction and the transverse magnetization relaxation time constant (T2) in lower extremity muscles of 136 participants with Duchenne muscular dystrophy. Measures were collected at 554 visits over 48 months at one of three imaging sites. Fat fraction was measured in the soleus and vastus lateralis using MR spectroscopy, while T2 was assessed using MRI in eight lower extremity muscles. Ambulatory function was measured using the 10m walk/run, climb four stairs, supine to stand, and six minute walk tests. RESULTS: Significant correlations were found between all qMR and functional measures. Vastus lateralis qMR measures correlated most strongly to functional endpoints (|ρ| = 0.68-0.78), although measures in other rapidly progressing muscles including the biceps femoris (|ρ| = 0.63-0.73) and peroneals (|ρ| = 0.59-0.72) also showed strong correlations. Quantitative MR biomarkers were excellent indicators of loss of functional ability and correlated with qualitative measures of function. A VL FF of 0.40 was an approximate lower threshold of muscle pathology associated with loss of ambulation. DISCUSSION: Lower extremity qMR biomarkers have a robust relationship to clinically meaningful measures of ambulatory function in Duchenne muscular dystrophy. These results provide strong supporting evidence for qMR biomarkers and set the stage for their potential use as surrogate outcomes in clinical trials. Extracellular microRNAs (miRNAs) are promising biomarkers of the inherited muscle wasting condition Duchenne muscular dystrophy, as they allow non-invasive monitoring of either disease progression or response to therapy. In this study, serum miRNA profiling reveals a distinct extracellular miRNA signature in dystrophin-deficient mdx mice, which shows profound dose-responsive restoration following dystrophin rescue. Extracellular dystrophy-associated miRNAs (dystromiRs) show dynamic patterns of expression that mirror the progression of muscle pathology in mdx mice. Expression of the myogenic miRNA, miR-206 and the myogenic transcription factor myogenin in the tibialis anterior muscle were found to positively correlate with serum dystromiR levels, suggesting that extracellular miRNAs are indicators of the regenerative status of the musculature. Similarly, extracellular dystromiRs were elevated following experimentally-induced skeletal muscle injury and regeneration in non-dystrophic mice. Only a minority of serum dystromiRs were found in extracellular vesicles, whereas the majority were protected from serum nucleases by association with protein/lipoprotein complexes. In conclusion, extracellular miRNAs are dynamic indices of pathophysiological processes in skeletal muscle. Diagnosis of muscular dystrophies is currently based on invasive methods requiring muscle biopsies or blood tests. The aim of the present study was to identify urinary biomarkers as a diagnostic tool for muscular dystrophies. Here, the urinary proteomes of Duchenne muscular dystrophy (DMD) patients and healthy donors were compared with a bottom-up proteomic approach. Label-free analysis of more than 1100 identified proteins revealed that 32 of them were differentially expressed between healthy controls and DMD patients. Among these 32 proteins, titin showed the highest fold change between healthy subjects and DMD patients. Interestingly, most of the sequenced peptides belong to the N-terminal and C-terminal parts of titin, and the presence of the corresponding fragments in the urine of DMD patients was confirmed by Western blot analysis. Analysis of a large cohort of DMD patients and age-matched controls (a total of 104 individuals aged from 3 to 20 years) confirmed presence of the N-ter fragment in all but two patients. In two DMD patients aged 16 and 20 years this fragment was undetectable and two healthy controls of 16 and 19 years with serum CK >800 IU/L demonstrated a low level of the fragment. N- and C-terminal titin fragments were also detected in urine from patients with other muscular dystrophies such as Becker muscular dystrophy and Limb-girdle muscular dystrophy (type 1D, 2D and 2J) but not in neurogenic spinal muscular atrophy. They were also present in urine of dystrophin-deficient animal models (GRMD dogs and mdx mice). Titin is the first urinary biomarker that offers the possibility to develop a simple, non-invasive and easy-to-use test for pre-screening of muscular dystrophies, and may also prove to be useful for the non-invasive follow up of DMD patients under treatment. Duchenne muscular dystrophy (DMD) is a fatal inherited genetic disorder that results in progressive muscle weakness and ultimately loss of ambulation, respiratory failure and heart failure. Cardiac MRI (MRI) plays an increasingly important role in the diagnosis and clinical care of boys with DMD and associated cardiomyopathies. Conventional cardiac MRI biomarkers permit measurements of global cardiac function and presence of fibrosis, but changes in these measures are late manifestations. Emerging MRI biomarkers of myocardial function and structure include the estimation of rotational mechanics and regional strain using MRI tagging; T1-mapping; and T2-mapping, a marker of inflammation, edema and fat. These emerging biomarkers provide earlier insights into cardiac involvement in DMD, improving patient care and aiding the evaluation of emerging therapies. Circulating microRNAs (miRs/miRNAs) are being used as non-invasive biomarkers for diagnosis, prognosis and efficiency of clinical trials. However, to exploit their potential it is necessary to improve and standardize their detection. In a previous study, we identified two microRNAs, miR-30c and miR-181a, that appear to be key regulators of muscular dystrophy. We hypothesized that they could represent useful biomarkers of Duchenne and Becker muscular dystrophies (DMD and BMD). The objective of this study was to assess the absolute levels of miR-30c and miR-181a in sera of DMD and BMD patients using digital PCR (a robust technique for precise and direct quantification of small amounts of nucleic acids without standard curves and external references), and investigate the correlation between miR-30c and miR-181a expressions and several clinical parameters. Our results show that the serum levels of miR-30c and miR-181a increased 7- and 6-fold respectively in DMD patients (n = 21, 2-14 years, ambulant), and 7-fold in BMD patients (n = 5, 9-15 years) compared to controls (n = 22, 2-14 years). No association between miRNA levels and age or corticosteroid treatment was detected in DMD. However, there was a trend towards higher levels of miR-30c in DMD patients with better preserved motor function according to various motor scales and timed tests. We demonstrate that digital PCR is a useful technique for accurate absolute quantification of microRNAs in sera of DMD/BMD patients. We propose miR-30c and miR-181a as reliable serum diagnostic biomarkers for DMD and BMD and miR-30c as a potential novel biomarker to assess disease severity in DMD. BACKGROUND: Duchenne Muscular Dystrophy is a severe, incurable disorder caused by mutations in the dystrophin gene. The disease is characterized by decreased muscle function, impaired muscle regeneration and increased inflammation. In a clinical context, muscle deterioration, is evaluated using physical tests and analysis of muscle biopsies, which fail to accurately monitor the disease progression. OBJECTIVES: This study aims to confirm and asses the value of blood protein biomarkers as disease progression markers using one of the largest longitudinal collection of samples. METHODS: A total of 560 samples, both serum and plasma, collected at three clinical sites are analyzed using a suspension bead array platform to assess 118 proteins targeted by 250 antibodies in microliter amount of samples. RESULTS: Nine proteins are confirmed as disease progression biomarkers in both plasma and serum. Abundance of these biomarkers decreases as the disease progresses but follows different trajectories. While carbonic anhydrase 3, microtubule associated protein 4 and collagen type I alpha 1 chain decline rather constantly over time, myosin light chain 3, electron transfer flavoprotein A, troponin T, malate dehydrogenase 2, lactate dehydrogenase B and nestin plateaus in early teens. Electron transfer flavoprotein A, correlates with the outcome of 6-minutes-walking-test whereas malate dehydrogenase 2 together with myosin light chain 3, carbonic anhydrase 3 and nestin correlate with respiratory capacity. CONCLUSIONS: Nine biomarkers have been identified that correlate with disease milestones, functional tests and respiratory capacity. Together these biomarkers recapitulate different stages of the disorder that, if validated can improve disease progression monitoring. Creatine kinase has been utilized as a diagnostic marker for Duchenne muscular dystrophy (DMD), but it correlates less well with the DMD pathological progression. In this study, we hypothesized that muscle-specific microRNAs (miR-1, -133, and -206) in serum may be useful for monitoring the DMD pathological progression, and explored the possibility of these miRNAs as potential non-invasive biomarkers for the disease. By using real-time quantitative reverse transcription-polymerase chain reaction in a randomized and controlled trial, we detected that miR-1, -133, and -206 were significantly over-expressed in the serum of 39 children with DMD (up to 3.20 ± 1.20, 2(-ΔΔCt) ): almost 2- to 4-fold enriched in comparison to samples from the healthy controls (less than 1.15 ± 0.34, 2(-ΔΔCt) ). To determine whether these miRNAs were related to the clinical features of children with DMD, we analyzed the associations compared to creatine kinase. There were very good inverse correlations between the levels of these miRNAs, especially miR-206, and functional performances: high levels corresponded to low muscle strength, muscle function, and quality of life. Moreover, by receiver operating characteristic curves analyses, we revealed that these miRNAs, especially miR-206, were able to discriminate DMD from controls. Thus, miR-206 and other muscle-specific miRNAs in serum are useful for monitoring the DMD pathological progression, and hence as potential non-invasive biomarkers for the disease. There has been a long-standing need for reliable, non-invasive biomarkers for Duchenne muscular dystrophy (DMD). We found that the levels of muscle-specific microRNAs, especially miR-206, in the serum of DMD were 2- to 4-fold higher than in the controls. High levels corresponded to low muscle strength, muscle function, and quality of life (QoL). These miRNAs were able to discriminate DMD from controls by receiver operating characteristic (ROC) curves analyses. Thus, miR-206 and other muscle-specific miRNAs are useful as non-invasive biomarkers for DMD.
4,116
What links lipid metabolism pathways to ALS?
Dysregulation of lipid metabolism is observed early in the spinal cord of the SOD1 ALS mouse model, and abnormal levels of cholesterol and other lipids are observed in the blood and CNS of ALS patients. In addition, higher blood high density lipoprotein and apolipoprotein A1 levels are associated with reduced risk of developing ALS.
[33905537, 31848577, 31562633, 33113361, 28870551, 24600344, 33544228, 33332650, 32656815, 29410613, 33707063, 34518331, 34502460, 20362558, 31406145, 30767689, 34782793, 34623437, 29904341, 32962914, 34343139, 34469619, 32927603, 26483191]
4,523
Nucleocytosolic transport, a membrane process, is impaired in motor neurons in amyotrophic lateral sclerosis (ALS). This study analyzes the nuclear lipidome in motor neurons in ALS and examines molecular pathways linked to the major lipid alterations. Nuclei were obtained from the frozen anterior horn of the lumbar spinal cord of ALS patients and age-matched controls. Lipidomic profiles of this subcellular fraction were obtained using liquid chromatography and mass spectrometry. We validated the mechanisms behind presumable lipidomic changes by exploring ALS surrogate models including human motor neurons (derived from ALS lines and controls) subjected to oxidative stress, the hSOD-G93A transgenic mice, and samples from an independent cohort of ALS patients. Among the differential lipid species, we noted 41 potential identities, mostly belonging to phospholipids (particularly ether phospholipids, as plasmalogens), as well as diacylglycerols and triacylglycerides. Decreased expression of alkyldihydroxyacetonephosphate synthase (AGPS)-a critical peroxisomal enzyme in plasmalogen synthesis-is found in motor neuron disease models; this occurs in parallel with an increase in the expression of sterol carrier protein 2 (SCP2) mRNA in ALS and Scp2 levels in G93A transgenic mice. Further, we identified diminished expression of diacylglycerol-related enzymes, such as phospholipase C βI (PLCβI) and protein kinase CβII (PKCβII), linked to diacylglycerol metabolism. Finally, lipid droplets were recognized in the nuclei, supporting the identification of triacylglycerides as differential lipids. Our results point to the potentially pathogenic role of altered composition of nuclear membrane lipids and lipids in the nucleoplasm in the anterior horn of the spinal cord in ALS. Overall, these data support the usefulness of subcellular lipidomics applied to neurodegenerative diseases. Author information: (1)Department of Biostatistics and Health Informatics, King's College London, London, UK; Maurice Wohl Clinical Neuroscience Institute, King's College London, Department of Basic and Clinical Neuroscience, London, UK; National Institute for Health Research Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust and King's College London, London, UK. Electronic address: alfredo.iacoangeli@kcl.ac.uk. (2)Institute for Molecular Bioscience, The University of Queensland, Brisbane, Brisbane QLD 4072, Australia. (3)Maurice Wohl Clinical Neuroscience Institute, King's College London, Department of Basic and Clinical Neuroscience, London, UK. (4)National Institute for Health Research Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust and King's College London, London, UK; Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK. (5)Centre for Motor Neuron Disease Research, Macquarie University, Sidney NSW 2109, Australia. (6)Centre for Healthy Brain Ageing, School of Psychiatry, UNSW Medicine, University of New South Wales, Sydney NSW, Australia; Neuroscience Research Australia, Randwick NSW, Australia. (7)Fiona Stanley Hospital, 11 Robin Warren Drive, Murdoch Perth WA 6150, Australia; Notre Dame University, 32 Mouat Street, Fremantle WA 6160, Australia; Murdoch University, 90 South Street, Murdoch WA 6150, Australia. (8)Calvary Health Care Bethlehem, Parkdale VIC 3195, Australia. (9)ANZAC Research Institute, Concord Repatriation General Hospital, Sydney NSW 2139, Australia. (10)Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK. (11)Centre for Clinical Research, The University of Queensland, Brisbane QLD, Australia; Queensland Brain Institute, The University of Queensland, Brisbane QLD, Australia. (12)Centre for Clinical Research, The University of Queensland, Brisbane QLD, Australia; Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane QLD, Australia. (13)Brain and Mind Centre, The University of Sydney, Sydney NSW, Australia. (14)Flinders Medical Centre, Bedford Park SA 5042, Australia. (15)Centre for Healthy Brain Ageing, School of Psychiatry, UNSW Medicine, University of New South Wales, Sydney NSW, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Sydney NSW Australia. (16)Department of Biostatistics and Health Informatics, King's College London, London, UK; National Institute for Health Research Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust and King's College London, London, UK; Institute of Health Informatics, University College London, London, UK. (17)Maurice Wohl Clinical Neuroscience Institute, King's College London, Department of Basic and Clinical Neuroscience, London, UK; Department of Neurology and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Milan, Italy. (18)Centre for Clinical Research, The University of Queensland, Brisbane QLD, Australia; Queensland Brain Institute, The University of Queensland, Brisbane QLD, Australia; Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane QLD, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane QLD, Australia. (19)Institute for Molecular Bioscience, The University of Queensland, Brisbane, Brisbane QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane QLD, Australia. (20)Centre for Clinical Research, The University of Queensland, Brisbane QLD, Australia; Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane QLD, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane QLD, Australia. (21)Maurice Wohl Clinical Neuroscience Institute, King's College London, Department of Basic and Clinical Neuroscience, London, UK; King's College Hospital, Bessemer Road, London SE5 9RS, UK. INTRODUCTION: Converging evidence highlights that lipid metabolism plays a key role in ALS pathophysiology. Dyslipidemia has been described in ALS patients and may be protective but peripheral lipoprotein subclasses have never been studied. MATERIAL AND METHODS: We collected sera from 30 ALS patients and 30 gender and age-matched controls. We analyzed 11 distinct lipoprotein subclasses by linear polyacrylamide gel electrophoresis (Lipoprint, Quantimetrix Corporation, USA). We also measured lipoprotein (a), apolipoprotein B, and apolipoprotein E levels. RESULTS: ALS patients had significant higher total cholesterol, HDL-cholesterol, and LDL-cholesterol levels than controls (p<0.0001, p=0.0007, and p=0.0065, respectively). The LDL-1 subfraction concentration was higher (1.03±0.41 vs. 0.71±0.28mmol/L; p=0.0006) and the IDL-B subfraction lower (6.5±2% vs. 8.0±2%; p=0.001) in ALS patients than controls. DISCUSSION: Our preliminary work confirmed the association between ALS and dyslipidemia. The low IDL-B levels may explain the hepatic steatosis frequently reported in ALS. The high levels of the cholesterol-rich LDL-1 subfraction is consistent with previously reported hypercholesterolemia. CONCLUSION: This study describes, for the first time, the distribution of serum lipoproteins in ALS patients, with low IDL-B and high LDL-1 subfraction level. Motor neuron diseases (MNDs) are characterized by selective death of motor neurons and include mainly adult-onset amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Neurodegeneration is not the single pathogenic event occurring during disease progression. There are multiple lines of evidence for the existence of defects in lipid metabolism at peripheral level. For instance, hypermetabolism is well characterized in ALS, and dyslipidemia correlates with better prognosis in patients. Lipid metabolism plays also a role in other MNDs. In SMA, misuse of lipids as energetic nutrients is described in patients and in related animal models. The composition of structural lipids in the central nervous system is modified, with repercussion on membrane fluidity and on cell signaling mediated by bioactive lipids. Here, we review the main epidemiologic and mechanistic findings that link alterations of lipid metabolism and motor neuron degeneration, and we discuss the rationale of targeting these modifications for therapeutic management of MNDs. AIM: Peroxisomes play a key role in lipid metabolism, and peroxisome defects have been associated with neurodegenerative diseases such as X-adrenoleukodystrophy and Alzheimer's disease. This study aims to elucidate the contribution of peroxisomes in lipid alterations of area 8 of the frontal cortex in the spectrum of TDP43-proteinopathies. Cases of frontotemporal lobar degeneration-TDP43 (FTLD-TDP), manifested as sporadic (sFTLD-TDP) or linked to mutations in various genes including expansions of the non-coding region of C9ORF72 (c9FTLD), and of sporadic amyotrophic lateral sclerosis (sALS) as the most common TDP43 proteinopathies, were analysed. METHODS: We used transcriptomics and lipidomics methods to define the steady-state levels of gene expression and lipid profiles. RESULTS: Our results show alterations in gene expression of some components of peroxisomes and related lipid pathways in frontal cortex area 8 in sALS, sFTLD-TDP and c9FTLD. Additionally, we identify a lipidomic pattern associated with the ALS-FTLD-TDP43 proteinopathy spectrum, notably characterised by down-regulation of ether lipids and acylcarnitine among other lipid species, as well as alterations in the lipidome of each phenotype of TDP43 proteinopathy, which reveals commonalities and disease-dependent differences in lipid composition. CONCLUSION: Globally, lipid alterations in the human frontal cortex of the ALS-FTLD-TDP43 proteinopathy spectrum, which involve cell membrane composition and signalling, vulnerability against cellular stress and possible glucose metabolism, are partly related to peroxisome impairment. The world's population aging progression renders age-related neurodegenerative diseases to be one of the biggest unsolved problems of modern society. Despite the progress in studying the development of pathology, finding ways for modifying neurodegenerative disorders remains a high priority. One common feature of neurodegenerative diseases is mitochondrial dysfunction and overproduction of reactive oxygen species, resulting in oxidative stress. Although lipid peroxidation is one of the markers for oxidative stress, it also plays an important role in cell physiology, including activation of phospholipases and stimulation of signaling cascades. Excessive lipid peroxidation is a hallmark for most neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and many other neurological conditions. The products of lipid peroxidation have been shown to be the trigger for necrotic, apoptotic, and more specifically for oxidative stress-related, that is, ferroptosis and neuronal cell death. Here we discuss the involvement of lipid peroxidation in the mechanism of neuronal loss and some novel therapeutic directions to oppose it. Lipids are a fundamental class of organic molecules implicated in a wide range of biological processes related to their structural diversity, and based on this can be broadly classified into five categories; fatty acids, triacylglycerols (TAGs), phospholipids, sterol lipids and sphingolipids. Different lipid classes play major roles in neuronal cell populations; they can be used as energy substrates, act as building blocks for cellular structural machinery, serve as bioactive molecules, or a combination of each. In amyotrophic lateral sclerosis (ALS), dysfunctions in lipid metabolism and function have been identified as potential drivers of pathogenesis. In particular, aberrant lipid metabolism is proposed to underlie denervation of neuromuscular junctions, mitochondrial dysfunction, excitotoxicity, impaired neuronal transport, cytoskeletal defects, inflammation and reduced neurotransmitter release. Here we review current knowledge of the roles of lipid metabolism and function in the CNS and discuss how modulating these pathways may offer novel therapeutic options for treating ALS. The endoplasmic reticulum (ER) and mitochondria connect at multiple contact sites to form a unique cellular compartment, termed the 'mitochondria-associated ER membranes' (MAMs). MAMs are hubs for signalling pathways that regulate cellular homeostasis and survival, metabolism, and sensitivity to apoptosis. MAMs are therefore involved in vital cellular functions, but they are dysregulated in several human diseases. Whilst MAM dysfunction is increasingly implicated in the pathogenesis of neurodegenerative diseases, its role in amyotrophic lateral sclerosis (ALS) is poorly understood. However, in ALS both ER and mitochondrial dysfunction are well documented pathophysiological events. Moreover, alterations to lipid metabolism in neurons regulate processes linked to neurodegenerative diseases, and a link between dysfunction of lipid metabolism and ALS has also been proposed. In this review we discuss the structural and functional relevance of MAMs in ALS and how targeting MAM could be therapeutically beneficial in this disorder. BACKGROUND: Premorbid body mass index, physical activity, diabetes and cardiovascular disease have been associated with an altered risk of developing amyotrophic lateral sclerosis (ALS). There is evidence of shared genetic risk between ALS and lipid metabolism. A very large prospective longitudinal population cohort permits the study of a range of metabolic parameters and the risk of subsequent diagnosis of ALS. METHODS: The risk of subsequent ALS diagnosis in those enrolled prospectively to the UK Biobank (n=502 409) was examined in relation to baseline levels of blood high and low density lipoprotein (HDL, LDL), total cholesterol, total cholesterol:HDL ratio, apolipoproteins A1 and B (apoA1, apoB), triglycerides, glycated haemoglobin A1c (HbA1c) and creatinine, plus self-reported exercise and body mass index. RESULTS: Controlling for age and sex, higher HDL (HR 0.84, 95% CI 0.73 to 0.96, p=0.010) and apoA1 (HR 0.83, 95% CI 0.72 to 0.94, p=0.005) were associated with a reduced risk of ALS. Higher total cholesterol:HDL was associated with an increased risk of ALS (HR 1.17, 95% CI 1.05 to 1.31, p=0.006). In models incorporating multiple metabolic markers, higher LDL or apoB was associated with an increased risk of ALS, in addition to a lower risk with higher HDL or apoA. Coronary artery disease, cerebrovascular disease and increasing age were also associated with an increased risk of ALS. CONCLUSIONS: The association of HDL, apoA1 and LDL levels with risk of ALS contributes to an increasing body of evidence that the premorbid metabolic landscape may play a role in pathogenesis. Understanding the molecular basis for these changes will inform presymptomatic biomarker development and therapeutic targeting. Amyotrophic lateral sclerosis (ALS) is a multifactorial and complex fatal degenerative disorder. A number of pathological mechanisms that lead to motor neuron death have been identified, although there are many unknowns in the disease aetiology of ALS. Alterations in lipid metabolism are well documented in the progression of ALS, both at the systemic level and in the spinal cord of mouse models and ALS patients. The origin of these lipid alterations remains unclear. This study aims to identify early lipid metabolic pathways altered before systemic metabolic symptoms in the spinal cord of mouse models of ALS. To do this, we performed a transcriptomic analysis of the spinal cord of SOD1G93A mice at an early disease stage, followed by a robust transcriptomic meta-analysis using publicly available RNA-seq data from the spinal cord of SOD1 mice at early and late symptomatic disease stages. The meta-analyses identified few lipid metabolic pathways dysregulated early that were exacerbated at symptomatic stages; mainly cholesterol biosynthesis, ceramide catabolism, and eicosanoid synthesis pathways. We present an insight into the pathological mechanisms in ALS, confirming that lipid metabolic alterations are transcriptionally dysregulated and are central to ALS aetiology, opening new options for the treatment of these devastating conditions. Amyotrophic lateral sclerosis (ALS) is one of the most common adult-onset neurodegenerative diseases, with progressive paralysis and muscle atrophy. The exact pathogenic mechanism remains unknown, but recent evidence suggests that differential gene expression and gene splicing may play a significant role. We used Affymetrix GeneChip Mouse Exon 1.0 ST Array to investigate the expression profiling of lumbar spinal cord samples from SOD1-G93A transgenic mice, the widely used animal model of ALS. The de-regulated genes analyzed either from the expression level or from the alternative splicing level both showed overlapping GO categories and pathway mapping. Our findings indicate that cell adhesion, immune-inflammation response and lipid metabolism all play important roles in the onset of ALS. Detailed analysis by RT-PCR of key genes confirmed the experimental results of microarrays. These results suggest a multi-factor mechanism in ALS development. Amyotrophic lateral sclerosis (ALS) is characterized by progressive loss of upper and lower motor neurons leading to muscle paralysis and death. While a link between dysregulated lipid metabolism and ALS has been proposed, lipidome alterations involved in disease progression are still understudied. Using a rodent model of ALS overexpressing mutant human Cu/Zn-superoxide dismutase gene (SOD1-G93A), we performed a comparative lipidomic analysis in motor cortex and spinal cord tissues of SOD1-G93A and WT rats at asymptomatic (~70 days) and symptomatic stages (~120 days). Interestingly, lipidome alterations in motor cortex were mostly related to age than ALS. In contrast, drastic changes were observed in spinal cord of SOD1-G93A 120d group, including decreased levels of cardiolipin and a 6-fold increase in several cholesteryl esters linked to polyunsaturated fatty acids. Consistent with previous studies, our findings suggest abnormal mitochondria in motor neurons and lipid droplets accumulation in aberrant astrocytes. Although the mechanism leading to cholesteryl esters accumulation remains to be established, we postulate a hypothetical model based on neuroprotection of polyunsaturated fatty acids into lipid droplets in response to increased oxidative stress. Implicated in the pathology of other neurodegenerative diseases, cholesteryl esters appear as attractive targets for further investigations. Author information: (1)Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA. (2)Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. (3)The Robert Packard Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA. (4)Department of Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA, USA. (5)Department of Biochemistry, College of Medicine, Dong-A University, Busan, Korea. (6)Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Korea. (7)The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA. (8)Department of Biology, San Diego State University, San Diego, CA, USA. (9)Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon, Korea. (10)Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany. (11)School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea. (12)Jeonbuk Branch Institute, Korea Institute of Toxicology, Jeongeup, Republic of Korea. (13)Department of Biomedical Science, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Republic of Korea. (14)Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, MD, USA. (15)Department of Biochemistry, College of Medicine, Dong-A University, Busan, Korea. ybhong@dau.ac.kr. (16)Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Korea. ybhong@dau.ac.kr. (17)Department of Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, Los Angeles, CA, USA. heoh@usc.edu. (18)Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA. glee48@jhmi.edu. (19)Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. glee48@jhmi.edu. (20)The Robert Packard Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA. glee48@jhmi.edu. (21)The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA. glee48@jhmi.edu. Age-associated neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD) and Alzheimer's disease (AD) are an unmet health need, with significant economic and societal implications, and an ever-increasing prevalence. Membrane lipid rafts (MLRs) are specialised plasma membrane microdomains that provide a platform for intracellular trafficking and signal transduction, particularly within neurons. Dysregulation of MLRs leads to disruption of neurotrophic signalling and excessive apoptosis which mirrors the final common pathway for neuronal death in ALS, PD and AD. Sphingomyelinase (SMase) and phospholipase (PL) enzymes process components of MLRs and therefore play central roles in MLR homeostasis and in neurotrophic signalling. We review the literature linking SMase and PL enzymes to ALS, AD and PD with particular attention to attractive therapeutic targets, where functional manipulation has been successful in preclinical studies. We propose that dysfunction of these enzymes is upstream in the pathogenesis of neurodegenerative diseases and to support this we provide new evidence that ALS risk genes are enriched with genes involved in ceramide metabolism (P=0.019, OR = 2.54, Fisher exact test). Ceramide is a product of SMase action upon sphingomyelin within MLRs, and it also has a role as a second messenger in intracellular signalling pathways important for neuronal survival. Genetic risk is necessarily upstream in a late age of onset disease such as ALS. We propose that manipulation of MLR structure and function should be a focus of future translational research seeking to ameliorate neurodegenerative disorders. ALS patients exhibit dyslipidemia, hypermetabolism and weight loss; in addition, cellular energetics deficits have been detected prior to denervation. Although evidence that metabolism is altered in ALS is compelling, the mechanisms underlying metabolic dysregulation and the contribution of altered metabolic pathways to disease remain poorly understood. Here we use a Drosophila model of ALS based on TDP-43 that recapitulates hallmark features of the disease including locomotor dysfunction and reduced lifespan. We performed a global, unbiased metabolomic profiling of larvae expressing TDP-43 (wild-type, TDPWT or disease-associated mutant, TDPG298S) and identified several lipid metabolism associated alterations. Among these, we found a significant increase in carnitine conjugated long-chain fatty acids and a significant decrease in carnitine, acetyl-carnitine and beta-hydroxybutyrate, a ketone precursor. Taken together these data suggest a deficit in the function of the carnitine shuttle and reduced lipid beta oxidation. To test this possibility we used a combined genetic and dietary approach in Drosophila. Our findings indicate that components of the carnitine shuttle are misexpressed in the context of TDP-43 proteinopathy and that genetic modulation of CPT1 or CPT2 expression, two core components of the carnitine shuttle, mitigates TDP-43 dependent locomotor dysfunction, in a variant dependent manner. In addition, feeding medium-chain fatty acids or beta-hydroxybutyrate improves locomotor function, consistent with the notion that bypassing the carnitine shuttle deficit is neuroprotective. Taken together, our findings highlight the potential contribution of the carnitine shuttle and lipid beta oxidation in ALS and suggest strategies for therapeutic intervention based on restoring lipid metabolism in motor neurons. Lipids play an important role in the central nervous system (CNS). They contribute to the structural integrity and physical characteristics of cell and organelle membranes, act as bioactive signalling molecules, and are utilised as fuel sources for mitochondrial metabolism. The intricate homeostatic mechanisms underpinning lipid handling and metabolism across two major CNS cell types; neurons and astrocytes, are integral for cellular health and maintenance. Here, we explore the various roles of lipids in these two cell types. Given that changes in lipid metabolism have been identified in a number of neurodegenerative diseases, we also discuss changes in lipid handling and utilisation in the context of amyotrophic lateral sclerosis (ALS), in order to identify key cellular processes affected by the disease, and inform future areas of research. PURPOSE OF REVIEW: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease targeting upper and lower motor neurons, inexorably leading to an early death. Defects in energy metabolism have been associated with ALS, including weight loss, increased energy expenditure, decreased body fat mass and increased use of lipid nutrients at the expense of carbohydrates. We review here recent findings on impaired energy metabolism in ALS, and its clinical importance. RECENT FINDINGS: Hypothalamic atrophy, as well as alterations in hypothalamic peptides controlling energy metabolism, have been associated with metabolic derangements. Recent studies showed that mutations causing familial ALS impact various metabolic pathways, in particular mitochondrial function, and lipid and carbohydrate metabolism, which could underlie these metabolic defects in patients. Importantly, slowing weight loss, through high caloric diets, is a promising therapeutic strategy, and early clinical trials indicated that it might improve survival in at least a subset of patients. More research is needed to improve these therapeutic strategies, define pharmacological options, and refine the population of ALS patients that would benefit from these approaches. SUMMARY: Dysfunctional energy homeostasis is a major feature of ALS clinical picture and emerges as a potential therapeutic target. Energy metabolism and redox state are strictly linked; energy metabolism is a source of reactive oxygen species (ROS) that, in turn, regulate the flux of metabolic pathways. Moreover, to assure redox homeostasis, metabolic pathways and antioxidant systems are often coordinately regulated. Several findings show that superoxide dismutase 1 (SOD1) enzyme has effects that go beyond its superoxide dismutase activity and that its functions are not limited to the intracellular compartment. Indeed, SOD1 is secreted through unconventional secretory pathways, carries out paracrine functions and circulates in the blood bound to lipoproteins. Striking experimental evidence links SOD1 to the redox regulation of metabolism. Important clues are provided by the systemic effects on energy metabolism observed in mutant SOD1-mediated amyotrophic lateral sclerosis (ALS). The purpose of this review is to analyze in detail the involvement of SOD1 in redox regulation of metabolism, nutrient sensing, cholesterol metabolism and regulation of mitochondrial respiration. The scientific literature on the relationship between ALS, mutated SOD1 and metabolism will also be explored, in order to highlight the metabolic functions of SOD1 whose biological role still presents numerous unexplored aspects that deserve further investigation. Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset disease characterized by upper and lower motor neuron degeneration, muscle wasting and paralysis. Growing evidence suggests a link between changes in lipid metabolism and ALS. Here, we used UPLC/TOF-MS to survey the lipidome in SOD1(G86R) mice, a model of ALS. Significant changes in lipid expression were evident in spinal cord and skeletal muscle before overt neuropathology. In silico analysis also revealed appreciable changes in sphingolipids including ceramides and glucosylceramides (GlcCer). HPLC analysis showed increased amounts of GlcCer and downstream glycosphingolipids (GSLs) in SOD1(G86R) muscle compared with wild-type littermates. Glucosylceramide synthase (GCS), the enzyme responsible for GlcCer biosynthesis, was up-regulated in muscle of SOD1(G86R) mice and ALS patients, and in muscle of wild-type mice after surgically induced denervation. Conversely, inhibition of GCS in wild-type mice, following transient peripheral nerve injury, reversed the overexpression of genes in muscle involved in oxidative metabolism and delayed motor recovery. GCS inhibition in SOD1(G86R) mice also affected the expression of metabolic genes and induced a loss of muscle strength and morphological deterioration of the motor endplates. These findings suggest that GSLs may play a critical role in ALS muscle pathology and could lead to the identification of new therapeutic targets.
4,117
What is the multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19?
Multisystem inflammatory syndrome in children (MIS-C) is a well described and documented condition that is associated with the active or recent COVID-19 infection. A similar presentation in adults is termed as Multisystem inflammatory syndrome in Adults (MIS-A). Multisystem inflammatory syndrome in children (MIS-C) is a novel, life-threatening hyperinflammatory condition that develops in children a few weeks after infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This disease has created a diagnostic challenge due to overlap with Kawasaki disease (KD) and KD shock syndrome. The majority of patients with MIS-C present with the involvement of at least four organ systems, and all have evidence of a marked inflammatory state. Most patients show an increase in the level of at least four inflammatory markers (C-reactive protein, neutrophil count, ferritin, procalcitonin, fibrinogen, interleukin-6, and triglycerides). Therapy is primarily with immunomodulators, suggesting that the disease is driven by post-infectious immune dysregulation. Most patients, even those with severe cardiovascular involvement, recover without sequelae. Since coronary aneurysms have been reported, echocardiographic follow-up is needed.
[34107136, 34507521, 33872261, 33743370, 32755212, 34203277, 34509326, 34246424, 34087834, 33841438, 34881206, 34880708, 33190340, 33445833, 33463127, 32923992, 32631771, 34553691, 33011038, 34472807, 32966765, 32946801, 34116467, 33679227]
4,524
OBJECTIVE: Although the initial reports of COVID-19 cases in children described that children were largely protected from severe manifestations, clusters of paediatric cases of severe systemic hyperinflammation and shock related to severe acute respiratory syndrome coronavirus 2 infection began to be reported in the latter half of April 2020. A novel syndrome called "multisystem inflammatory syndrome in children" (MIS-C) shares common clinical features with other well-defined syndromes, including Kawasaki disease, toxic shock syndrome and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. Our objective was to develop a protocol for the evaluation, treatment and follow-up of patients with MIS-C. METHODS: The protocol was developed by a multidisciplinary team. We convened a multidisciplinary working group with representation from the departments of paediatric critical care, cardiology, rheumatology, surgery, gastroenterology, haematology, immunology, infectious disease and neurology. Our protocol and recommendations were based on the literature and our experiences with multisystem inflammatory syndrome in children. After an agreement was reached and the protocol was implemented, revisions were made on the basis of expert feedback. CONCLUSION: Children may experience acute cardiac decompensation or other organ system failure due to this severe inflammatory condition. Therefore, patients with severe symptoms of MIS-C should be managed in a paediatric intensive care setting, as rapid clinical deterioration may occur. Therapeutic approaches for MIS-C should be tailored depending on the patients' phenotypes. Plasmapheresis may be useful as a standard treatment to control hypercytokinemia in cases of MIS-C with severe symptoms. Long-term follow-up of patients with cardiac involvement is required to identify any sequelae of MIS-C. Multisystem inflammatory syndrome in children (MIS-C) is a novel, life-threatening hyperinflammatory condition that develops in children a few weeks after infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This disease has created a diagnostic challenge due to overlap with Kawasaki disease (KD) and KD shock syndrome. The majority of patients with MIS-C present with the involvement of at least four organ systems, and all have evidence of a marked inflammatory state. Most patients show an increase in the level of at least four inflammatory markers (C-reactive protein, neutrophil count, ferritin, procalcitonin, fibrinogen, interleukin-6, and triglycerides). Therapy is primarily with immunomodulators, suggesting that the disease is driven by post-infectious immune dysregulation. Most patients, even those with severe cardiovascular involvement, recover without sequelae. Since coronary aneurysms have been reported, echocardiographic follow-up is needed.Further study is needed to create uniform diagnostic criteria, therapy, and follow-up protocols. The coronavirus disease 2019 (COVID-19) pandemic has impacted the health of children worldwide. Although overall mortality from COVID-19 in children remains low, an associated multisystem inflammatory disorder has emerged. The disorder has been recognized and named multisystem inflammatory syndrome in children (MIS-C) by the World Health Organization and the Centers for Disease Control and Prevention. This comprehensive review describes the epidemiology, pathophysiology, signs and symptoms, other potential diagnoses, and treatments relevant to MIS-C. The review also includes patient and family education and anticipatory guidance, and discusses nursing implications for nurses working in various roles and settings, including direct care, research, and public health. The coronavirus disease 2019 (COVID-19) pandemic has caused widespread mortality and morbidity. Though children are largely spared from severe illness, a novel childhood hyperinflammatory syndrome presumed to be associated with and subsequent to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has emerged with potentially severe outcomes. Multisystem inflammatory disorder in children (MIS-C) most commonly affects young, school-aged children and is characterized by persistent fever, systemic hyperinflammation, and multisystem organ dysfunction. While uncommon and generally treatable, MIS-C presents potentially life-altering medical sequelae, complicated by a dearth of information regarding its etiology, pathophysiology, and long-term outcomes. The severity of MIS-C may warrant the need for increased awareness and continued COVID-19 mitigation efforts, particularly until potential factors conferring a predisposition to MIS-C can be clarified through additional research. Well-informed guidelines will be critical as the school year progresses. In this article, current knowledge on MIS-C is reviewed and the potential implications of this novel syndrome are discussed from a public health perspective. Myocardial infarctions (MI) have been reported in adults with COVID-19. Although MIs are rare in children with COVID-19, cardiac involvement is still possible. In this case report, we present an adolescent with recent COVID-19 infection who presented with an ECG initially suggestive of myocardial infarction (MI). We describe how to differentiate between myocardial infarctions and myopericarditis. A 15-year-old boy, with a history of COVID-19 infection a month prior, presented to the emergency department with fever, abdominal pain, diarrhea, and chest pain. On ECG, he was found to have focal ST-segment elevations in V3 through V6. Given the immediate concern for MI, an emergent echocardiogram was done and showed normal left ventricular systolic function with no regional dyskinesia and normal coronary artery diameters. A repeat ECG showed diffuse ST elevations in the inferior leads and T-wave inversions on V5 and V6, confirming the diagnosis of myopericarditis. In conclusion, multisystem-inflammatory syndrome in children associated with COVID-19 (MIS-C) is a new entity describing a post-infectious inflammatory response in children with prior COVID-19 exposure. Cardiac involvement can include myopericarditis. Initial ECGs may show ST-changes suggestive of MI. However, serial ECGs and echocardiograms can differentiate between MI and myocarditis/myopericarditis. Even with COVID-19, MIs are extremely rare in children, and it is important to be aware of MIS-C and its cardiac complications. El síndrome inflamatorio multisistémico pediátrico vinculado a la COVID-19 (SIM-PedS) es, según la Organización Mundial de la Salud, un nuevo síndrome descrito en pacientes menores de 19 años con historia previa de exposición a SARS-CoV-2. La presentación inicial de este síndrome se caracteriza por fiebre persistente que asocia debilidad, dolor abdominal, vómitos y/o diarrea. Menos frecuentemente los pacientes pueden presentar también erupción cutánea y conjuntivitis. El cuadro clínico tiene expresividad y evolución variables, por lo que algunos pacientes pediátricos afectados pueden empeorar rápidamente, desarrollando desde hipotensión y shock cardiogénico a daño multiorgánico. Los hallazgos analíticos característicos del síndrome consisten en elevación de marcadores inflamatorios y disfunción cardíaca. Los hallazgos radiológicos más frecuentes son cardiomegalia, derrame pleural, signos de insuficiencia cardíaca, ascitis y cambios inflamatorios en la fosa ilíaca derecha. En la pandemia actual por COVID-19 es necesario que el radiólogo conozca las características clínico-analíticas y radiológicas de este síndrome para realizar un correcto diagnóstico. Most of the reports about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children reported mild-to-moderate disease manifestations. However, recent reports explored a rare pediatric multisystem syndrome possibly associated with SARS-CoV-2 infection termed multisystem inflammatory syndrome in children (MIS-C).The study prospectively enrolled 5 patients with clinical and laboratory evidence of MIS-C associated with SARS-CoV-2 infection. They were admitted to the pediatric intensive care unit (PICU). Their clinical presentation, laboratory, and outcome were described.All patients shared similar clinical presentations such as persistent documented fever for more than 3 days, respiratory symptoms, gastrointestinal involvement, and increased inflammatory markers (CRP, ESR, and ferritin). Three patients had concurrent positive coronavirus disease 2019 (COVID-19) infection, and the other 2 patients had contact with suspected COVID-19 positive patients. They were all managed in the PICU and received intravenous immunoglobulin, systemic steroid, and hydroxychloroquine. The hospital stays ranged between 3 and 21 days. One patient died due to severe multiorgan failures and shock, and the other 4 patients were discharged with good conditions.Pediatric patients with SARS-CoV-2 are at risk for MIS-C. MIS-C has a spectrum of clinical and laboratory presentations, and the clinicians need to have a high index of suspicion for the diagnosis and should initiate its early treatment to avoid unfavorable outcomes. Long-term follow-up studies will be required to explore any sequelae of MIS-C, precisely the cardiovascular complications. BACKGROUND: SARS-CoV-2 occurs in the majority of children as COVID-19, without symptoms or with a paucisymptomatic respiratory syndrome, but a small proportion of children develop the systemic Multi Inflammatory Syndrome (MIS-C), characterized by persistent fever and systemic hyperinflammation, with some clinical features resembling Kawasaki Disease (KD). OBJECTIVE: With this study we aimed to shed new light on the pathogenesis of these two SARS-CoV-2-related clinical manifestations. METHODS: We investigated lymphocyte and dendritic cells subsets, chemokine/cytokine profiles and evaluated the neutrophil activity mediators, myeloperoxidase (MPO), and reactive oxygen species (ROS), in 10 children with COVID-19 and 9 with MIS-C at the time of hospital admission. RESULTS: Patients with MIS-C showed higher plasma levels of C reactive protein (CRP), MPO, IL-6, and of the pro-inflammatory chemokines CXCL8 and CCL2 than COVID-19 children. In addition, they displayed higher levels of the chemokines CXCL9 and CXCL10, mainly induced by IFN-γ. By contrast, we detected IFN-α in plasma of children with COVID-19, but not in patients with MIS-C. This observation was consistent with the increase of ISG15 and IFIT1 mRNAs in cells of COVID-19 patients, while ISG15 and IFIT1 mRNA were detected in MIS-C at levels comparable to healthy controls. Moreover, quantification of the number of plasmacytoid dendritic cells (pDCs), which constitute the main source of IFN-α, showed profound depletion of this subset in MIS-C, but not in COVID-19. CONCLUSIONS: Our results show a pattern of immune response which is suggestive of type I interferon activation in COVID-19 children, probably related to a recent interaction with the virus, while in MIS-C the immune response is characterized by elevation of the inflammatory cytokines/chemokines IL-6, CCL2, and CXCL8 and of the chemokines CXCL9 and CXL10, which are markers of an active Th1 type immune response. We believe that these immunological events, together with neutrophil activation, might be crucial in inducing the multisystem and cardiovascular damage observed in MIS-C. Multisystem inflammatory syndrome in children (MIS-C) is a rare and critical condition that affects children following exposure to severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection, leading to multiorgan dysfunction and shock. MIS-C has been reported from different parts of the world but rarely from Arab countries. In this report, we describe a 15-year-old Arab boy who was admitted to the ICU during the surge of Coronavirus transmission in Syria with a clinical picture consistent with MIS-C, including high-grade fever, gastrointestinal symptoms, rash, multiorgan dysfunction, and shock. Laboratory profile showed significant elevation of inflammatory markers, negative SARS-CoV-2 RT-PCR testing but positive serologic testing for SARS-CoV-2. The patient received intravenous immunoglobulins (IVIG) and glucocorticoids with remarkable cardiac improvement and significant alleviation in inflammatory markers. To our knowledge, this is the first reported case of MIS-C from Syria, which adds to the epidemiological data about this new syndrome. BACKGROUND: : Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) is an emerging condition that was first identified in paediatrics at the onset of the COVID-19 pandemic. The condition is also known as pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (PIMS-TS or PIMS), and multiple definitions have been established for this condition that share overlapping features with Kawasaki Disease and toxic shock syndrome. METHODS: : A review was conducted to identify literature describing the epidemiology of MIS-C, published up until March 9, 2021. A database established at the Public Health Agency of Canada with COVID-19 literature was searched for articles referencing MIS-C, PIMS or Kawasaki Disease in relation to COVID-19. RESULTS: : A total of 195 out of 988 articles were included in the review. The median age of MIS-C patients was between seven and 10 years of age, although children of all ages (and adults) can be affected. Multisystem inflammatory syndrome in children disproportionately affected males (58% patients), and Black and Hispanic children seem to be at an elevated risk for developing MIS-C. Roughly 62% of MIS-C patients required admission to an intensive care unit, with one in five patients requiring mechanical ventilation. Between 0% and 2% of MIS-C patients died, depending on the population and available interventions. CONCLUSION: : Multisystem inflammatory syndrome in children can affect children of all ages. A significant proportion of patients required intensive care unit and mechanical ventilation and 0%-2% of cases resulted in fatalities. More evidence is needed on the role of race, ethnicity and comorbidities in the development of MIS-C. AIM: This study determined the influence of the COVID-19 pandemic on the occurrence of multisystem inflammatory syndrome in children (MIS-C) and compared the main characteristics of MIS-C and Kawasaki disease (KD). METHODS: We included patients aged up to 18 years of age who were diagnosed with MIS-C or KD in a paediatric university hospital in Paris from 1 January 2018 to 15 July 2020. Clinical, laboratory and imaging characteristics were compared, and new French COVID-19 cases were correlated with MIS-C cases in our hospital. RESULTS: There were seven children with MIS-C, from 6 months to 12 years of age, who were all positive for the virus that causes COVID-19, and 40 virus-negative children with KD. Their respective characteristics were as follows: under 5 years of age (14.3% vs. 85.0%), paediatric intensive care unit admission (100% vs. 10.0%), abdominal pain (71.4% vs. 12.5%), myocardial dysfunction (85.7% vs. 5.0%), shock syndrome (85.7% vs. 2.5%) and mean and standard deviation C-reactive protein (339 ± 131 vs. 153 ± 87). There was a strong lagged correlation between the rise and fall in MIS-C patients and COVID-19 cases. CONCLUSION: The rise and fall of COVID-19 first wave mirrored the MIS-C cases. There were important differences between MIS-C and KD. The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been spreading worldwide since December 2019. Hundreds of cases of children and adolescents with Kawasaki disease (KD)-like hyperinflammatory illness have been reported in Europe and the United States during the peak of the COVID-19 pandemic with or without shock and cardiac dysfunction. These patients tested positive for the polymerase chain reaction or antibody test for SARS-CoV-2 or had a history of recent exposure to COVID-19. Clinicians managing such patients coined new terms for this new illness, such as COVID-19-associated hyperinflammatory response syndrome, pediatric inflammatory multisystem syndrome temporally associated with COVID-19, or COVID-19-associated multisystem inflammatory syndrome in children (MIS-C). The pathogenesis of MIS-C is unclear; however, it appears similar to that of cytokine storm syndrome. MIS-C shows clinical features similar to KD, but differences between them exist with respect to age, sex, and racial distributions and proportions of patients with shock or cardiac dysfunction. Recommended treatments for MIS-C include intravenous immunoglobulin, corticosteroids, and inotropic or vasopressor support. For refractory patients, monoclonal antibody to interleukin-6 receptor (tocilizumab), interleukin-1 receptor antagonist (anakinra), or monoclonal antibody to tumor necrosis factor (infliximab) may be recommended. Patients with coronary aneurysms require aspirin or anticoagulant therapy. The prognosis of MIS-C seemed favorable without sequelae in most patients despite a reported mortality rate of approximately 1.5%. The prevalence of multisystem inflammatory syndrome in children (MIS-C) has increased since the coronavirus disease 2019 (COVID-19) pandemic started. This study was aimed to describe clinical manifestation and outcomes of MIS-C associated with COVID-19. This systematic review and meta-analysis were conducted on all available literature until July 3rd, 2020. The screening was done by using the following keywords: ("novel coronavirus" Or COVID-19 or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus) and ("MIS-C" or "multisystem inflammatory" or Kawasaki). Data on gender, ethnicity, clinical presentations, need for mechanical ventilation or admission to intensive care unit (ICU), imaging, cardiac complications, and COVID-19 laboratory results were extracted to measure the pooled estimates. Out of 314 found articles, 16 articles with a total of 600 patients were included in the study, the most common presentation was fever (97%), followed by gastrointestinal symptoms (80%), and skin rashes (60%) as well as shock (55%), conjunctivitis (54%), and respiratory symptoms (39%). Less common presentations were neurologic problems (33%), and skin desquamation (30%), MIS-C was slightly more prevalent in males (53.7%) compared to females (46.3%). The findings of this meta-analysis on current evidence found that the common clinical presentations of COVID-19 associated MIS-C include a combination of fever and mucocutaneous involvements, similar to atypical Kawasaki disease, and multiple organ dysfunction. Due to the relatively higher morbidity and mortality rate, it is very important to diagnose this condition promptly. BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome, is a new dangerous childhood disease that is temporally associated with coronavirus disease 2019 (COVID-19). We aimed to describe the typical presentation and outcomes of children diagnosed with this hyperinflammatory condition. METHODS: We conducted a systematic review to communicate the clinical signs and symptoms, laboratory findings, imaging results, and outcomes of individuals with MIS-C. We searched four medical databases to encompass studies characterizing MIS-C from January 1st, 2020 to July 25th, 2020. Two independent authors screened articles, extracted data, and assessed risk of bias. This review was registered with PROSPERO CRD42020191515. FINDINGS: Our search yielded 39 observational studies (n = 662 patients). While 71·0% of children (n = 470) were admitted to the intensive care unit, only 11 deaths (1·7%) were reported. Average length of hospital stay was 7·9 ± 0·6 days. Fever (100%, n = 662), abdominal pain or diarrhea (73·7%, n = 488), and vomiting (68·3%, n = 452) were the most common clinical presentation. Serum inflammatory, coagulative, and cardiac markers were considerably abnormal. Mechanical ventilation and extracorporeal membrane oxygenation were necessary in 22·2% (n = 147) and 4·4% (n = 29) of patients, respectively. An abnormal echocardiograph was observed in 314 of 581 individuals (54·0%) with depressed ejection fraction (45·1%, n = 262 of 581) comprising the most common aberrancy. INTERPRETATION: Multisystem inflammatory syndrome is a new pediatric disease associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is dangerous and potentially lethal. With prompt recognition and medical attention, most children will survive but the long-term outcomes from this condition are presently unknown. FUNDING: Parker B. Francis and pilot grant from 2R25-HL126140. Funding agencies had no involvement in the study. OBJECTIVE: To differentiate severe/critical coronavirus disease 2019 (COVID-19) infection from multisystem inflammatory syndrome in children (MIS-C). METHODS: Single-center chart review comparing characteristics of children with MIS-C and 'severe/critical' COVID-19 infection. Multivariate logistic regression was performed to create predictive models for predicting MIS-C. RESULTS: Of 68 patients, 28 (41.2%) had MIS-C while 40 (58.8%) had severe/critical COVID-19 infection. MIS-C patients had a higher prevalence of fever, mucocutaneous, cardiac and gastrointestinal involvement and a lower prevalence of respiratory symptoms (P<0.05). Significantly lower hemoglobin, platelet count, serum electrolytes, and significantly elevated inflammatory and coagulation markers were observed in MIS-C cohort. Upon multivariate logistic regression, the best model included C-reactive protein (CRP), platelet count, gastrointestinal and mucocutaneus involvement and absence of respiratory involvement (performance of 0.94). CRP>40 mg/L with either platelet count <150x109 or mucocutaneous involvement had specificity of 97.5% to diagnose MIS-C. CONCLUSION: Elevated CRP, thrombocytopenia and mucocutaneous involvement at presentation are helpful in differentiating MIS-C from severe COVID-19. The varied spectrum of presentation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is intriguing. Multisystem inflammatory syndrome in children (MIS-C) is a well described and documented condition that is associated with the active or recent COVID-19 infection. A similar presentation in adults is termed as Multisystem inflammatory syndrome in Adults (MIS-A). With only very limited cases reported from the west, MIS-A is considered a rare and serious complication of COVID-19. However, it is not as uncommon as we think. Many cases go undiagnosed for lack of COVID -19 like symptoms and unawareness among treating clinicians about this newer clinical entity. Further, antibody testing and inflammatory markers are not easily available in many of the Indian hospitals especially in rural India where the second wave had been intense, thereby making it difficult for the diagnosis of MIS-A. Also, there is no clear treatment guideline for MIS-A unlike MIS-C where the treatment protocol is well laid out. Awareness about MIS-A among treating clinicians can thus help in further evaluation and increased identification of the syndrome at the early stages thereby helping in the early institution of treatment. Our tertiary COVID care hospital in South India which has handled about 5200 cases of COVID-19 is been able to identify 04 cases of MIS-A proving that this clinical entity is not as rare as it is thought but lacks reporting and prompt identification. Here we describe 04 cases of MIS-A and strive to bring in the various aspects of it, including the clinical presentation, laboratory markers, diagnostic criteria and treatment considerations in this post second wave of the COVID-19 pandemic in India. Author information: (1)Science for Life Laboratory, Department of Women's and Children Health, Karolinska Institutet, Stockholm 17165, Sweden. (2)Research Unit of Congenital and Perinatal Infections, Bambino Gesù Children's Hospital, Rome 00165, Italy; Chair of Pediatrics, Department of Systems Medicine, University of Rome "Tor Vergata", Rome 00133, Italy. (3)Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm 17176, Sweden. (4)Research Unit of Congenital and Perinatal Infections, Bambino Gesù Children's Hospital, Rome 00165, Italy. (5)Research Unit of Congenital and Perinatal Infections, Bambino Gesù Children's Hospital, Rome 00165, Italy; Academic Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome 00165, Italy. (6)Center for Regenerative Medicine, Department of Medicine, Karolinska Institutet, Stockholm 14186, Sweden. (7)Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm 17176, Sweden; Department of Immunology, Genetics and Pathology, Uppsala University and Department of Clinical Genetics, Uppsala University Hospital, Uppsala 75185, Sweden. (8)Academic Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome 00165, Italy. (9)Chair of Pediatrics, Department of Systems Medicine, University of Rome "Tor Vergata", Rome 00133, Italy; Academic Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome 00165, Italy. (10)Department of Medicine (Solna), Karolinska University Hospital, Karolinska Institutet, Stockholm 17176, Sweden; Science for life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala 75237, Sweden. Electronic address: nils.landegren@ki.se. (11)Research Unit of Congenital and Perinatal Infections, Bambino Gesù Children's Hospital, Rome 00165, Italy; Chair of Pediatrics, Department of Systems Medicine, University of Rome "Tor Vergata", Rome 00133, Italy. Electronic address: paolo.palma@opbg.net. (12)Science for Life Laboratory, Department of Women's and Children Health, Karolinska Institutet, Stockholm 17165, Sweden; Pediatric Rheumatology, Karolinska University Hospital, Stockholm 17164, Sweden. Electronic address: petter.brodin@ki.se. OBJECTIVE: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease (COVID-19) is a rare and challenging diagnosis requiring early treatment. The diagnostic criteria involve clinical, laboratory, and complementary tests. This review aims to draw pediatrician attention to this diagnosis, suggesting early treatment strategies, and proposing a pediatric emergency care flowchart. SOURCES: The PubMed/MEDLINE/WHO COVID-19 databases were reviewed for original and review articles, systematic reviews, meta-analyses, case series, and recommendations from medical societies and health organizations published through July 3, 2020. The reference lists of the selected articles were manually searched to identify any additional articles. SUMMARY OF THE FINDINGS: COVID-19 infection is less severe in children than in adults, but can present as MIS-C, even in patients without comorbidities. There is evidence of an exacerbated inflammatory response with potential systemic injury, and it may present with aspects similar to those of Kawasaki disease, toxic shock syndrome, and macrophage activation syndrome. MIS-C can develop weeks after COVID-19 infection, suggesting an immunomediated cause. The most frequent clinical manifestations include fever, gastrointestinal symptoms, rash, mucous membrane changes, and cardiac dysfunction. Elevated inflammatory markers, lymphopenia, and coagulopathy are common laboratory findings. Supportive treatment and early immunomodulation can control the intense inflammatory response and reduce complications and mortality. CONCLUSIONS: MIS-C associated with COVID-19 is serious, rare, and potentially fatal. The emergency department pediatrician must recognize and treat it early using immunomodulatory strategies to reduce systemic injury. Further studies are needed to identify the disease pathogenesis and establish the most appropriate treatment. BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a dangerous pediatric complication of COVID-19. OBJECTIVE: The purpose of this review article is to provide a summary of the diagnosis and management of MIS-C with a focus on management in the acute care setting. DISCUSSION: MIS-C is an inflammatory syndrome which can affect nearly any organ system. The most common symptoms are fever and gastrointestinal symptoms, though neurologic and dermatologic findings are also well-described. The diagnosis includes a combination of clinical and laboratory testing. Patients with MIS-C will often have elevated inflammatory markers and may have an abnormal electrocardiogram or echocardiogram. Initial treatment involves resuscitation with careful assessment for cardiac versus vasodilatory shock using point-of-care ultrasound. Treatment should include intravenous immunoglobulin, anticoagulation, and consideration of corticosteroids. Interleukin-1 and/or interleukin-6 blockade may be considered for refractory cases. Aspirin is recommended if there is thrombocytosis or Kawasaki disease-like features on echocardiogram. Patients will generally require admission to an intensive care unit. CONCLUSION: MIS-C is a condition associated with morbidity and mortality that is increasingly recognized as a potential complication in pediatric patients with COVID-19. It is important for emergency clinicians to know how to diagnose and treat this disorder.
4,118
What datasets are available related to Duchenne Muscular Dystrophy?
Using data from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) Five sources of RWD/NHD were contributed by Universitaire Ziekenhuizen Leuven, DMD Italian Group, The Cooperative International Neuromuscular Research Group, ImagingDMD, and the PRO-DMD-01 study (n = 430 patients, in total).
[28807723, 28859693, 25338682, 32611643, 26356412, 32791870, 23382369, 34776418, 30448867, 32692451, 33918694, 21836521, 22639722, 34877803, 28739181, 19394035, 34682100, 26981371, 24634239]
4,525
BACKGROUND: Duchenne muscular dystrophy (DMD) is the most common disease in children caused by mutations in the DMD gene, and DMD and Becker muscular dystrophy (BMD) are collectively called dystrophinopathies. Dystrophinopathies show a complex mutation spectrum. The importance of mutation databases, with clinical phenotypes and protein studies of patients, is increasingly recognized as a reference for genetic diagnosis and for the development of gene therapy. METHODS: We used the data from the Japanese Registry of Muscular Dystrophy (Remudy) compiled during from July 2009 to March 2017, and reviewed 1497 patients with dystrophinopathies. RESULTS: The spectrum of identified mutations contained exon deletions (61%), exon duplications (13%), nonsense mutations (13%), small deletions (5%), small insertions (3%), splice-site mutations (4%), and missense mutations (1%). Exon deletions were found most frequently in the central hot spot region between exons 45-52 (42%), and most duplications were detected in the proximal hot spot region between exons 3-25 (47%). In the 371 patients harboring a small mutation, 194 mutations were reported and 187 mutations were unreported. CONCLUSIONS: We report the largest dystrophinopathies mutation dataset in Japan from a national patient registry, "Remudy". This dataset provides a useful reference to support the genetic diagnosis and treatment of dystrophinopathy. BACKGROUND: Gene expression analysis is powerful for investigating the underlying mechanisms of Duchenne muscular dystrophy (DMD). Previous studies mainly neglected co-expression or transcription factor (TF) information. Here we integrated TF information into differential co-expression analysis (DCEA) to explore new understandings of DMD pathogenesis. METHODS: Using two microarray datasets from Gene Expression Omnibus (GEO) database, we firstly detected differentially expressed genes (DEGs) and pathways enriched with DEGs. Secondly, we constructed differentially regulated networks to integrate the TF-to-target information and the differential co-expression genes. RESULTS: A total of 454 DEGs were detected and both KEGG pathway and ingenuity pathway analysis revealed that pathways enriched with aberrantly regulated genes are mostly involved in the immune response processes. DCEA results generated 610 pairs of DEGs regulated by at least one common TF, including 78 pairs of co-expressed DEGs. A network was constructed to illustrate their relationships and a subnetwork for DMD related molecules was constructed to show genes and TFs that may play important roles in the secondary changes of DMD. Among the DEGs which shared TFs with DMD, six genes were co-expressed with DMD, including ATP1A2, C1QB, MYOF, SAT1, TRIP10, and IFI6. CONCLUSION: Our results may provide a new understanding of DMD and contribute potential targets for future therapeutic tests. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_210. PURPOSE OF REVIEW: This review aims to describe the benefits and limitations of using the Duchenne Connect patient registry to provide information particularly in regard to active treatment choices in Duchenne muscular dystrophy and their impact on disease progression. RECENT FINDINGS: Clinical trials and natural history studies are difficult for rare diseases like Duchenne muscular dystrophy. Using an online patient self-report survey model, Duchenne Connect provides relevant data that are difficult to gather in other ways. Validation of the overall dataset is supported by comparable mutational spectrum relative to other cohorts and demonstrated beneficial effect of corticosteroid use in prolonging ambulation. These types of analyses are provocative and allow multivariate analyses across the breadth of patient and physician medication and supplement practices. Because the data are self-reported and online, the barrier to participation is low and great potential exists for novel directions of further research in a highly participatory forum. SUMMARY: Patient registries for Duchenne and Becker muscular dystrophy (DBMD) are powerful tools for monitoring patient outcomes, comparing treatment options, and relating information between patients, researchers, and clinicians. Duchenne Connect is an online patient self-report registry for individuals with DBMD that facilitates aggregation of treatment modalities, outcomes, and genotype data and has played a vital role in furthering DBMD research, particularly in the USA, in a highly participatory and low-cost manner. PURPOSE: Duchenne muscular dystrophy (DMD) is currently the most commonly diagnosed form of muscular dystrophy due to mutations in the dystrophin gene. However, its pathological process remains unknown and there is a lack of specific molecular biomarkers. The aim of our study is to explore key regulatory connections underlying the progression of DMD. MATERIALS AND METHODS: The gene expression profile dataset GSE38417 of DMD was obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between DMD patients and healthy controls were screened using geo2R, followed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway enrichment analyses. Then a protein-protein interaction (PPI) network and sub-network of modules were constructed. To investigate the regulatory network underlying DMD, a global triple network including miRNAs, mRNAs and transcription factors (TFs) was constructed. RESULTS: A total of 1811 DEGs were found between the DMD and control groups, among which HERC5, SKP2 and FBXW5 were defined as hub genes with a degree of connectivity >35 in the PPI network. Furthermore, the five TFs ZNF362, ATAT1, SPI1, TCF12 and ABCF2, as well as the eight miRNAs miR-124a, miR-200b/200c/429, miR-19a/b, miR-23a/b, miR-182, miR-144, miR-498 and miR-18a/b were identified as playing crucial roles in the molecular pathogenesis of DMD. CONCLUSIONS: This paper provides a comprehensive perspective on the miRNA-TF-mRNA co-regulatory network underlying DMD, although the bioinformatic findings need further validation in future studies. OBJECTIVE: To review current approaches for obtaining patient data in Duchenne muscular dystrophy (DMD) and consider how monitoring and comparing outcome measures across DMD clinics could facilitate standardized and improved patient care. METHODS: We reviewed annual standardized data from cystic fibrosis (CF) clinics and DMD care guidelines and consensus statements; compared current approaches to obtain DMD patient data and outcome measures; and considered the best method for implementing public reporting of outcomes, to drive improvements in health care delivery. RESULTS: Current methods to monitor DMD patient information (MD STARnet, DuchenneConnect, and TREAT-NMD) do not yet provide patients with comparative outcome data. The CF patient registry allows for reporting of standard outcomes across clinics and is associated with improved CF outcomes. A similar patient registry is under development for the Muscular Dystrophy Association (MDA) clinic network. Suggested metrics for quality care include molecular diagnosis, ambulatory status and age at loss of ambulation, age requiring ventilator support, and survival. CONCLUSIONS: CF longevity has increased by almost 33% from 1986 to 2010, in part due to a CF patient registry that has been stratified by individual care centers since 1999, and publically available since 2006. Implementation of outcome reporting for MDA clinics might promote a similar benefit to patients with DMD. Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) phenotypes are used to describe disease progression in affected individuals. However, considerable heterogeneity has been observed across and within these two phenotypes, suggesting a spectrum of severity rather than distinct conditions. Characterizing the phenotypes and subphenotypes aids researchers in the design of clinical studies and clinicians in providing anticipatory guidance to affected individuals and their families. Using data from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet), we used K-means cluster analysis to group phenotypically similar males with pediatric-onset dystrophinopathy. We identified four dystrophinopathy clusters: Classical BMD, Classical DMD, late ambulatory DMD, and severe DMD. The clusters that we identified align with both 'classical' and 'non-classical' dystrophinopathy described in the literature. Individuals with dystrophinopathies have heterogenous clinical presentations that cluster into phenotypically similar groups. Use of clinically-derived phenotyping may provide a clearer understanding of disease trajectories, reduce variability in study results, and prevent exclusion of certain cohorts from analysis. Findings from studying subphenotypes may ultimately improve our ability to predict disease progression. A retrospective study in which we reviewed the hospital files of a subset of 7 patients with Duchenne muscular dystrophy participating in the open-label phase I/II PRO051-02 study in Leuven. The objective of this study was to describe in detail the injection site reactions in these children treated with drisapersen (PRO-051), a 2'-O-methyl phosphorothioate RNA antisense oligonucleotide, that induces exon 51 skipping in Duchenne muscular dystrophy. Antisense oligonucleotides, restoring the reading frame by skipping of exons, have become a potential treatment of Duchenne muscular dystrophy and other monogenetic diseases. Erythema followed by hyperpigmentation, fibrosis, and calcification were seen at the injection sites in all children. Ulcerations, which were difficult to heal, occurred in 5 of 7 children. Progression still occurred after switching to intravenous administration of drisapersen or even after stopping therapy. Systemic reactions included a reversible proteinuria and α1-microglobulinuria. Moreover, hypotrichosis was a common feature.Conclusion: Subcutaneous administration of drisapersen causes severe and progressive injection site effects. What is known: • Antisense oligonucleotides offer the possibility to convert Duchenne muscular dystrophy to the less severe Becker type. This can potentially be achieved by targeting and skipping specific exons of the Duchenne muscular dystrophy gene to restore the disrupted reading frame and to induce the production of a semi functional dystrophin protein. • Drisapersen is such an antisense oligonucleotides which can be administered subcutaneously. Its use has been tested extensively in the escalating dose pilot study (PRO051-02). What is new: • This report describes the injection site reactions caused by this type of agent in detail which has never been done before. We therefore reviewed the hospital files of 7 patients with Duchenne muscular dystrophy participating in the phase I/II open-label, escalating dose pilot study (PRO051-02) with drisapersen. • Severe side effects starting with erythema, hyperpigmentation, and later fibrosis, calcification, and difficult to treat ulcerations developed in all patients, and these continued to progress even after cessation of drisapersen. We discuss some possible underlying mechanisms. The exact mechanism however is still not known. AIM: To investigate the differences in attainment of developmental milestones between young males with Duchenne muscular dystrophy (DMD) and young males from the general population. METHOD: As part of the case-control 4D-DMD study (Detection by Developmental Delay in Dutch boys with Duchenne Muscular Dystrophy), data on developmental milestones for 76 young males with DMD and 12 414 young males from a control group were extracted from the health care records of youth health care services. The characteristics of DMD were acquired from questionnaires completed by parents. Logistic regression analyses were performed with milestone attainment (yes/no) as the dependent variable and DMD (yes/no) as the independent variable, with and without adjustment for age at visit. RESULTS: The mean number of available milestones was 43 (standard deviation [SD]=13, range: 1-59) in the DMD group and 40 (SD=15, range: 1-60) in the control group. The presence of developmental delay was evident at 2 to 3 months of age, with a higher proportion of young males with DMD failing to attain milestones of gross/fine motor activity, adaptive behaviour, personal/social behaviour, and communication (range age-adjusted odds ratios [ORs]=2.3-4.0, p<0.01). Between 12 and 36 months of age, differences in the attainment of developmental milestones concerning gross motor activity increased with age (range age-adjusted ORs=10.3-532, p<0.001). We also found differences in developmental milestones concerning fine motor activity, adaptive behaviour, personal/social behaviour, and communication between 12 and 48 months of age (range age-adjusted ORs=2.5-9.7, p<0.01). INTERPRETATION: We found delays in the attainment of motor and non-motor milestones in young males with DMD compared to the control group. Such delays were already evident a few months after birth. Developmental milestones that show a delay in attainment have the potential to aid the earlier diagnosis of DMD. PURPOSE: To determine whether sociodemographic factors are associated with delays at specific steps in the diagnostic process of Duchenne and Becker muscular dystrophy. METHODS: We examined abstracted medical records for 540 males from population-based surveillance sites in Arizona, Colorado, Georgia, Iowa, and western New York. We used linear regressions to model the association of three sociodemographic characteristics with age at initial medical evaluation, first creatine kinase measurement, and earliest DNA analysis while controlling for changes in the diagnostic process over time. The analytical dataset included 375 males with information on family history of Duchenne and Becker muscular dystrophy, neighborhood poverty levels, and race/ethnicity. RESULTS: Black and Hispanic race/ethnicity predicted older ages at initial evaluation, creatine kinase measurement, and DNA testing (P < 0.05). A positive family history of Duchenne and Becker muscular dystrophy predicted younger ages at initial evaluation, creatine kinase measurement and DNA testing (P < 0.001). Higher neighborhood poverty was associated with earlier ages of evaluation (P < 0.05). CONCLUSIONS: Racial and ethnic disparities in the diagnostic process for Duchenne and Becker muscular dystrophy are evident even after adjustment for family history of Duchenne and Becker muscular dystrophy and changes in the diagnostic process over time. Black and Hispanic children are initially evaluated at older ages than white children, and the gap widens at later steps in the diagnostic process. Early clinical trials of therapies to treat Duchenne muscular dystrophy (DMD), a fatal genetic X-linked pediatric disease, have been designed based on the limited understanding of natural disease progression and variability in clinical measures over different stages of the continuum of the disease. The objective was to inform the design of DMD clinical trials by developing a disease progression model-based clinical trial simulation (CTS) platform based on measures commonly used in DMD trials. Data were integrated from past studies through the Duchenne Regulatory Science Consortium founded by the Critical Path Institute (15 clinical trials and studies, 1505 subjects, 27,252 observations). Using a nonlinear mixed-effects modeling approach, longitudinal dynamics of five measures were modeled (NorthStar Ambulatory Assessment, forced vital capacity, and the velocities of the following three timed functional tests: time to stand from supine, time to climb 4 stairs, and 10 meter walk-run time). The models were validated on external data sets and captured longitudinal changes in the five measures well, including both early disease when function improves as a result of growth and development and the decline in function in later stages. The models can be used in the CTS platform to perform trial simulations to optimize the selection of inclusion/exclusion criteria, selection of measures, and other trial parameters. The data sets and models have been reviewed by the US Food and Drug Administration and the European Medicines Agency; have been accepted into the Fit-for-Purpose and Qualification for Novel Methodologies pathways, respectively; and will be submitted for potential endorsement by both agencies. Individuals with Duchenne muscular dystrophy (DMD) often exhibit delayed motor and cognitive development, including delayed onset of ambulation. Data on age when loss of independent ambulation occurs are well established for DMD; however, age at onset of walking has not been well described. We hypothesize that an effective medication given in early infancy would advance the age when walking is achieved so that it is closer to age-matched norms, and that this discrete event could serve as the primary outcome measure in a clinical trial. This study examined three data sets, Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet); Dutch Natural History Survey (DNHS); and Parent Project Muscular Dystrophy (PPMD). The distribution of onset of ambulation in DMD (mean ± SD) and median age, in months, at the onset of ambulation was 17.3 (±5.5) and 16.0 in MD STARnet, 21.8 (±7.1) and 20.0 in DNHS, and 16.1 (±4.4) and 15 in PPMD. Age of ambulation in these data sets were all significantly later (P <0.001) than the corresponding age for typically developing boys, 12.1 (±1.8). A hypothetical clinical trial study design and power analyses are presented based on these data. BACKGROUND: Therapeutic trials are critical to improving outcomes for individuals diagnosed with Duchenne muscular dystrophy (DMD). Understanding predictors of clinical trial participation could maximize enrollment. METHODS: Data from six sites (Colorado, Iowa, Piedmont region North Carolina, South Carolina, Utah, and western New York) of the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) were analyzed. Clinical trial participation and individual-level clinical and sociodemographic characteristics were obtained from medical records for the 2000-2015 calendar years. County-level characteristics were determined from linkage of the most recent county of residence identified from medical records and publicly available federal datasets. Fisher's exact and Wilcoxon two-sample tests were used with statistical significance set at one-sided p-value (<0.05) based on the hypothesis that nonparticipants had fewer resources. RESULTS: Clinical trial participation was identified among 17.9% (MD STARnet site: 3.7-27.3%) of 358 individuals with DMD. Corticosteroids, tadalafil, and ataluren (PTC124) were the most common trial medications recorded. Fewer non-Hispanic blacks or Hispanics than non-Hispanic whites participated in clinical trials. Trial participants tended to reside in counties with lower percentages of non-Hispanic blacks. Conclusion: Understanding characteristics associated with clinical trial participation is critical for identifying participation barriers and generalizability of trial results. MD STARnet is uniquely able to track clinical trial participation through surveillance and describe patterns of participation.
4,119
What links immune response pathways to ALS?
Microglia, which are the primary immune cells of the central nervous system, are strongly implicated in ALS, their activation being correlated with various clinical features, and inflammatory microglial responses being correlated withe disease progression. The immune response may be implicated in other ways with ALS molecular pathology. such as through inflammatory regulation and circulating interleukins. It is possible the T cell receptor signalling and activation is involved. It is also possible that the innate / non-specific immune system is involved - i.e. immune protection against foreign substances, viruses, and bacteria.
[20406178, 25344935, 24170856, 33918092, 32594542, 27308305, 29568058, 34402459, 27812125, 25889790]
4,526
The immune system has been found to be involved with positive and negative effects in the nervous system of amyotrophic lateral sclerosis (ALS) patients. In general, T cells, B cells, NK cells, mast cells, macrophages, dendritic cells, microglia, antibodies, complement and cytokines participate in limiting damage. Several mechanisms of action, such as production of neurotrophic growth factors and interaction with neurons and glial cells, have been shown to preserve these latter from injury and stimulate growth and repair. The immune system also participates in proliferation of neural progenitor stem cells and their migration to sites of injury and this activity has been documented in various neurologic disorders including traumatic injury, ischemic and hemorrhagic stroke, multiple sclerosis, infection, and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease and ALS). Many therapies have been shown to stimulate the protective and regenerative aspects of the immune system in humans, such as intravenous immunoglobulins, and other experimental interventions such as vaccination, minocycline, antibodies and neural stem cells, have shown promise in animal models of ALS. Consequently, several immunosuppressive and immunomodulatory therapies have been tried in ALS, generally with no success, in particular intravenous immunoglobulins. The multiple aspects of the immune response in ALS are beginning to be appreciated, and their potential as pharmacologic targets in neurologic disease is being explored. The immune system is inextricably linked with many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), a devastating neuromuscular disorder affecting motor cell function with an average survival of 3 years from symptoms onset. In ALS, there is a dynamic interplay between the resident innate immune cells, that is, microglia and astrocytes, which may become progressively harmful to motor neurons. Although innate and adaptive immune responses are associated with progressive neurodegeneration, in the early stages of ALS immune activation pathways are primarily considered to be beneficial promoting neuronal repair of the damaged tissues, though a harmful effect of T cells at this stage of disease has also been observed. In addition, although auto-antibodies against neuronal antigens are present in ALS, it is unclear whether these arise as a primary or secondary event to neuronal damage, and whether the auto-antibodies are indeed pathogenic. Understanding how the immune system contributes to the fate of motor cells in ALS may shed light on the triggers of disease as well as on the mechanisms contributing to the propagation of the pathology. Immune markers may also act as biomarkers while pathways involved in immune action may be targets of new therapeutic strategies. Here, we review the modalities by which the immune system senses the core pathological process in motor neuron disorders, focusing on tissue-specific immune responses in the neuromuscular junction and in the neuroaxis observed in affected individuals and in animal models of ALS. We elaborate on existing data on the immunological fingerprint of ALS that could be used to identify clues on the disease origin and patterns of progression. Accumulating evidence from mice expressing ALS-causing mutations in superoxide dismutase (SOD1) has implicated pathological immune responses in motor neuron degeneration. This includes microglial activation, lymphocyte infiltration, and the induction of C1q, the initiating component of the classic complement system that is the protein-based arm of the innate immune response, in motor neurons of multiple ALS mouse models expressing dismutase active or inactive SOD1 mutants. Robust induction early in disease course is now identified for multiple complement components (including C1q, C4, and C3) in spinal cords of SOD1 mutant-expressing mice, consistent with initial intraneuronal C1q induction, followed by global activation of the complement pathway. We now test if this activation is a mechanistic contributor to disease. Deletion of the C1q gene in mice expressing an ALS-causing mutant in SOD1 to eliminate C1q induction, and complement cascade activation that follows from it, is demonstrated to produce changes in microglial morphology accompanied by enhanced loss, not retention, of synaptic densities during disease. C1q-dependent synaptic loss is shown to be especially prominent for cholinergic C-bouton nerve terminal input onto motor neurons in affected C1q-deleted SOD1 mutant mice. Nevertheless, overall onset and progression of disease are unaffected in C1q- and C3-deleted ALS mice, thus establishing that C1q induction and classic or alternative complement pathway activation do not contribute significantly to SOD1 mutant-mediated ALS pathogenesis in mice. Motor Neuron Disease (MND) is a fatal neurodegenerative condition, which is characterized by the selective loss of the upper and lower motor neurons. At the sites of motor neuron injury, accumulation of activated microglia, the primary immune cells of the central nervous system, is commonly observed in both human post mortem studies and animal models of MND. Microglial activation has been found to correlate with many clinical features and importantly, the speed of disease progression in humans. Both anti-inflammatory and pro-inflammatory microglial responses have been shown to influence disease progression in humans and models of MND. As such, microglia could both contribute to and protect against inflammatory mechanisms of pathogenesis in MND. While murine models have characterized the microglial response to MND, these studies have painted a complex and often contradictory picture, indicating a need for further characterization in humans. This review examines the potential role microglia play in MND in human and animal studies. Both the pro-inflammatory and anti-inflammatory responses will be addressed, throughout the course of disease, followed by the potential of microglia as a target in the development of disease-modifying treatments for MND. OBJECTIVE: To evaluate the combined blood expression of neuromuscular and inflammatory biomarkers as predictors of disease progression and prognosis in amyotrophic lateral sclerosis (ALS). METHODS: Logistic regression adjusted for markers of the systemic inflammatory state and principal component analysis were carried out on plasma levels of creatine kinase (CK), ferritin, and 11 cytokines measured in 95 patients with ALS and 88 healthy controls. Levels of circulating biomarkers were used to study survival by Cox regression analysis and correlated with disease progression and neurofilament light chain (NfL) levels available from a previous study. Cytokines expression was also tested in blood samples longitudinally collected for up to 4 years from 59 patients with ALS. RESULTS: Significantly higher levels of CK, ferritin, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β, IL-2, IL-8, IL-12p70, IL-4, IL-5, IL-10, and IL-13 and lower levels of interferon (IFN)-γ were found in plasma samples from patients with ALS compared to controls. IL-6, TNF-α, and IFN-γ were the most highly regulated markers when all explanatory variables were jointly analyzed. High ferritin and IL-2 levels were predictors of poor survival. IL-5 levels were positively correlated with CK, as was TNF-α with NfL. IL-6 was strongly associated with CRP levels and was the only marker showing increasing expression towards end-stage disease in the longitudinal analysis. CONCLUSIONS: Neuromuscular pathology in ALS involves the systemic regulation of inflammatory markers mostly active on T-cell immune responses. Disease stratification based on the prognostic value of circulating inflammatory markers could improve clinical trials design in ALS. Author information: (1)Department of Neuroscience and Pathobiology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan. (2)Laboratory for Motor Neuron Disease, RIKEN Brain Science Institute, Wako, Japan. (3)Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, Japan. (4)Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Wako, Japan. (5)Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Tokyo, Japan. (6)Division of Pharmacology, Faculty of Pharmacy, Keio University, Tokyo, Japan. (7)Department of Mucosal Immunology, School of Medicine, Chiba University, Chiba, Japan. (8)Division of Innate Immune Regulation, International Research and Development Center for Mucosal Vaccines, Institute of Medical Science, The University of Tokyo, Tokyo, Japan. (9)Laboratory of Host Defense, World Premier International Immunology Frontier Research Center, and Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan. (10)Department of Cellular and Molecular Neuropathology, Juntendo University Graduate School of Medicine, Tokyo, Japan. (11)Department of Neuroscience and Pathobiology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan. kojiyama@riem.nagoya-u.ac.jp. (12)Laboratory for Motor Neuron Disease, RIKEN Brain Science Institute, Wako, Japan. kojiyama@riem.nagoya-u.ac.jp. (13)Department of Neuroscience and Pathobiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. kojiyama@riem.nagoya-u.ac.jp. PURPOSE OF REVIEW: Neuroinflammation is an important mediator of the pathogenesis of disease in amyotrophic lateral sclerosis (ALS). Genetic mutations such as C9orf72 have begun to define the numerous cell autonomous pathways that initiate motor neuron injury. Yet, it is the signalling to surrounding glia and peripherally derived immune cells that initiates the noncell autonomous inflammatory process and promotes self-propagating motor neuron cell death. The purpose of this review is to explore the systemic immune/inflammatory contributions to the pathogenesis of ALS: what are the peripheral pro-inflammatory signatures, what initiates their presence and do they represent potential therapeutic targets. RECENT FINDINGS: In ALS, motor neuron cell death is initiated by multiple cell autonomous pathways leading to misfolded proteins, oxidative stress, altered mitochondria, impaired autophagy and altered RNA metabolism, which collectively promote noncell autonomous inflammatory reactivity. The resulting disease is characterized by activated microglia and astrocytes as well as peripherally derived pro-inflammatory innate and adaptive immune cells. In this unrelenting disorder, circulating blood monocytes and natural killer cells are pro-inflammatory. Furthermore, regulatory T lymphocytes are dysfunctional, and pro-inflammatory cytokines and acute phase proteins are elevated. SUMMARY: The collective dysregulation of cells and cytokines in patients with ALS accurately reflect increased disease burdens, more rapid progression rates and reduced survival times, reinforcing the concept of ALS as a disorder with extensive systemic pro-inflammatory responses. These increased systemic pro-inflammatory immune constituents provide potentially meaningful therapeutic targets. Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by damage of motor neurons. Recent reports indicate that inflammatory responses occurring within the central nervous system contribute to the pathogenesis of ALS. We aimed to investigate disease-specific gene expression associated with neuroinflammation by conducting transcriptome analysis on fibroblasts from three patients with sporadic ALS and three normal controls. Several pathways were found to be upregulated in patients with ALS, among which the toll-like receptor (TLR) and NOD-like receptor (NLR) signaling pathways are related to the immune response. Genes-toll-interacting protein (TOLLIP), mitogen-activated protein kinase 9 (MAPK9), interleukin-1β (IL-1β), interleukin-8 (IL-8), and chemokine (C-X-C motif) ligand 1 (CXCL1)-related to these two pathways were validated using western blotting. This study validated the genes that are associated with TLR and NLR signaling pathways from different types of patient-derived cells. Not only fibroblasts but also induced pluripotent stem cells (iPSCs) and neural rosettes from the same origins showed similar expression patterns. Furthermore, expression of TOLLIP, a regulator of TLR signaling pathway, decreased with cellular aging as judged by changes in its expression through multiple passages. TOLLIP expression was downregulated in ALS cells under conditions of inflammation induced by lipopolysaccharide. Our data suggest that the TLR and NLR signaling pathways are involved in pathological innate immunity and neuroinflammation associated with ALS and that TOLLIP, MAPK9, IL-1β, IL-8, and CXCL1 play a role in ALS-specific immune responses. Moreover, changes of TOLLIP expression might be associated with progression of ALS. BACKGROUND: The peripheral immune system is implicated in modulating microglial activation, neurodegeneration and disease progression in amyotrophic lateral sclerosis (ALS). Specifically, there is reduced thymic function and regulatory T cell (Treg) number in ALS patients and mutant superoxide dismutase 1 (SOD1) mice, while passive transfer of Tregs ameliorates disease in mutant SOD1 mice. Here, we assessed the effects of augmenting endogenous CD4+ T cell number by stimulating the thymus using surgical castration on the phenotype of transgenic SOD1(G93A) mice. METHOD: Male SOD1(G93A) mice were castrated or sham operated, and weight loss, disease onset and progression were examined. Thymus atrophy and blood CD4+, CD8+ and CD4+ FoxP3+ T cell numbers were determined by fluorescence activated cell sorting (FACS). Motor neuron counts, glial cell activation and androgen receptor (AR) expression in the spinal cord were investigated using immunohistochemistry and Western blotting. Differences between castrated and sham mice were analysed using an unpaired t test or one-way ANOVA. RESULTS: Castration significantly increased thymus weight and total CD4+ T cell numbers in SOD1(G93A) mice, although Tregs levels were not affected. Despite this, disease onset and progression were similar in castrated and sham SOD1(G93A) mice. Castration did not affect motor neuron loss or astrocytic activation in spinal cords of SOD1(G93A) mice; however, microglial activation was reduced, specifically M1 microglia. We also show that AR is principally expressed in spinal motor neurons and progressively downregulated in spinal cords of SOD1(G93A) mice from disease onset which is further enhanced by castration. CONCLUSIONS: These results demonstrate that increasing thymic function and CD4+ T cell number by castration confers no clinical benefit in mutant SOD1 mice, which may reflect an inability to stimulate neuroprotective Tregs. Nonetheless, castration decreases M1 microglial activation in the spinal cord without any clinical improvement and motor neuron rescue, in contrast to other approaches to suppress microglia in mutant SOD1 mice. Lastly, diminished AR expression in spinal motor neurons, which links to another motor neuron disorder, spinal bulbar muscular atrophy (SBMA), may contribute to ALS pathogenesis and suggests a common disease pathway in ALS and SBMA mediated by disruption of AR signalling in motor neurons.
4,120
Which vitamin deficiencies may present with neurologic signs or symptoms?
Many vitamin deficiencies have been described as a cause of neurologic signs and symptoms. For instance, vitamin B12 deficiency can cause several types of neurological manifestations, such as subacute combined degeneration of the spinal cord, ataxia, peripheral polyneuropathy, optic nerve neuropathy, and cognitive disorders. In addition, vitamin B1 (Thiamine) and B6 (Pyridoxine) deficiency can both cause peripheral neuropathy. Specifically, vitamin B1 deficiency can also cause confusion, ophthalmoplegia, nystagmus, and ataxia in the context of beriberi and Wernicke's encephalopathy. Finally, vitamin A deficiency has been described to cause retinal change-related visual defects and subsequent vision loss.
[3714053, 23697293, 20402062, 6301966, 1648656, 22525460, 24365342, 6164769, 24115632, 22450609, 20640946, 32228659, 9012278, 3722679, 28331457, 33961285, 26385097, 22303049, 28771404, 33231056, 33343698, 15142228, 31094486, 31193945, 31838171, 21590622, 31490402, 6308196, 31837157, 23834987, 8682350, 9527151]
4,527
We describe nine patients with fat malabsorption in whom a spectrum of vitamin E deficiency was present. Early deficiency was generally asymptomatic, and intermediate deficiency produced some impairment. Ataxia, weakness, reflex changes, impaired vision, and pigment retinopathy were associated with chronic, advanced deficiency. In the last group, delayed central somatosensory conduction and amplitude reduction of the electroretinogram were present. In adults, a severe vitamin E deficiency state existed for more than 5 years before producing measurable neurologic damage. The clinical picture is less homogeneous than previously suggested, and electrophysiologic abnormalities need not predate clinical dysfunction. We report herein our interesting case series of 15 infants admitting with neurological symptoms who were found to have vitamin B12 deficiency. Infants who were admitted to our hospital between 2004 and 2007 with neurological symptoms and were found to have vitamin B12 deficiency were included in this study. Data regarding clinical and laboratory features were obtained. Of 15 infants, 9 were boys (60%) and 6 were girls (40%). The mean age was 11.7 months. Anorexia, pallor, hypotonia, and neurodevelopmental retardation were present in all infants. Seizures and tremor were observed in 46.6% (7/15) and 33% (5/15) of patients, respectively. Seizures were generalized tonic-clonic in 4 patients, generalized tonic in 1 patient and focal in 2 patients. Four patients had tremor on admission and 1 patient had occurrence after vitamin B12 treatment. Vitamin B12 deficiency may lead to serious neurological deficits in addition to megaloblastic anemia. Persistent neurological damage can be prevented with early diagnosis and treatment. We believe that a thorough clinical and neurological assessment might prevent failure to notice rare but possible vitamin B12 deficiency in infants with neurological deficits and neurodevelopmental retardation. Thirteen children, aged 10 months to 20 years, presenting with chronic cholestasis from the first month of life and with low serum levels of vitamins A and/or E, have been investigated for neurological and ophthalmological symptoms. Clinical findings consisted of 4 types: peripheral neuropathy; cerebellar dysfunction; abnormalities of eye movement, and retinal degenerative changes. The results of electrophysiological and morphological studies of muscle and nerves were consistent with neurono-axonal degeneration. Electrical abnormalities of the retina, especially a decrease of the b wave of electroretinogram, appear to be the first sign of the syndrome, allowing early detection. Evidence for vitamin deficiency (E or E+A) suggests substitutive parenteral treatment in such patients. We reviewed 153 episodes of cobalamin deficiency involving the nervous system that occurred in 143 patients seen over a recent 17-year period at 2 New York City hospitals. Pernicious anemia was the most common underlying cause of the deficiency. Neurologic complaints, most commonly paresthesias or ataxia, were the first symptoms of Cbl deficiency in most episodes. The median duration of symptoms before diagnosis and treatment with vitamin B12 was 4 months, although long delays in diagnosis occurred in some patients. Diminished vibratory sensation and proprioception in the lower extremities were the most common objective findings. A wide variety of neurologic symptoms and signs were encountered, however, including ataxia, loss of cutaneous sensation, muscle weakness, diminished or hyperactive reflexes, spasticity, urinary or fecal incontinence, orthostatic hypotension, loss of vision, dementia, psychoses, and disturbances of mood. Multiple neurologic syndromes were often seen in a single patient. In 42 (27.4%) of the 153 episodes, the hematocrit was normal, and in 31 (23.0%), the mean corpuscular volume was normal. Neutropenia and thrombocytopenia were unusual even in anemic patients. In nonanemic patients in whom diagnosis was delayed, neurologic progression frequently occurred although the hematocrit remained normal. In 27 episodes, the serum cobalamin concentration was only moderately decreased (in the range of 100-200 pg/ml) and in 2 the serum level was normal. Neurologic impairment, as assessed by a quantitative severity score, was judged to be mild in 99 episodes, moderate in 39 and severe in 15. Severity of neurologic dysfunction before treatment was clearly related to the duration of symptoms prior to diagnosis. In addition, the hematocrit correlated significantly with severity, independent of the longer duration of symptoms in nonanemic patients. Four patients experienced transient neurologic exacerbations soon after beginning treatment with cyanocobalamin, with subsequent recovery. Followup evaluation was adequate to assess the neurologic response to vitamin B12 therapy in 121 episodes. All patients responded, and in 57 (47.1%), recovery was complete, with no remaining symptoms or findings on examination. The severity score was reduced by 50% or greater after treatment in 91% of the episodes. Residual long-term moderate or severe neurologic disability was noted following only 7 (6.3%) episodes. The extent of neurologic involvement after treatment was strongly related to that before therapy as well as to the duration of symptoms. The percent improvement over baseline neurologic status after treatment was inversely related to duration of symptoms and hematocrit. Some evidence of response was always seen during the first 3 months of treatment.(ABSTRACT TRUNCATED AT 400 WORDS) The activities of the red blood cell enzymes transketolase, glutathione reductase, and glutamic oxaloacetate transaminase were measured with and without in vitro addition of their respective coenzyme components thiamine, riboflavin, and pyridoxine in a group of patients with neurological disorders which may have been caused by malnutrition, intestinal malabsorption, hepatic failure or neoplasms arising outside the nervous system. The incidence of thiamine deficiency was 31%, of riboflavin deficiency 22% and of pyridoxine deficiency 6%. Alcoholics in particular suffered from deficiencies of vitamin B 1, and B 2. There was a correlation of vitamin B 1 and B 2 deficiency and signs of a cerebellar and/or brainstem lesion. The most frequent symptoms in this connection were gait disturbances and oculomotor signs like spontaneous and gaze nystagmus, disturbed eye tracking, diminished optokinetic nystagmus, decreased ability to suppress vestibular nystagmus by fixation. These signs hardly ever occurred in alcoholic patients who showed no deficiency of vitamin B 1, B 2 or B 6. Whenever they do appear, a vitamin B supplementation has to be performed in order to prevent the manifestation of Wernicke's encephalopathy, cerebral or cerebellar atrophy. Alcoholics showed the same incidence of polyneuropathy, whether they suffered from a deficiency of B vitamins or not. Deficiencies of vitamin B 1, B 2 or B 6 were also found in patients with intestinal malabsorption and polyneuropathy, diabetic polyneuropathy, optic atrophy, myelopathy and cerebellar ataxia of unknown etiology, neurological manifestations of neoplasms arising outside the nervous system, B 12 myeloencephalopathy and Thévenard's syndrome. Vitamin B12 deficiency is a common cause of neuropsychiatric symptoms in elderly persons. Malabsorption accounts for the majority of cases. Vitamin B12 deficiency has been associated with neurologic, cognitive, psychotic, and mood symptoms, as well as treatment-resistance. Clinician awareness should be raised to accurately diagnose and treat early deficiencies to prevent irreversible structural brain damage, because current practice can be ineffective at identifying cases leading to neuropsychiatric sequelae. This clinical review focuses on important aspects of the recognition and treatment of vitamin B12 deficiency and neuropsychiatric manifestations of this preventable illness in elderly patients. Nearly two thirds of American adults are either overweight or obese. Accordingly, bariatric surgery experienced explosive growth during the past decade. Current estimates place the worldwide volume of bariatric procedures at greater than 300,000 cases annually. Micronutrient deficiencies are well-described following bariatric surgery, and they may present with devastating and sometimes irreversible neurologic manifestations. Clinical symptoms range from peripheral neuropathy to encephalopathy, and are most commonly caused by thiamine, copper, and B(12) deficiencies. It is well known that the neurologic manifestations of vitamin B12 deficiency can occur in the absence of anemia. The authors recently observed two elderly patients who presented to a chronic care institution with the diagnosis of dementia, and in both individuals low serum B12 levels were found in conjunction with abnormal Schilling tests. In neither of these two patients was there anemia or macrocytosis. After receiving parenteral B12 injections there was improvement noted in cognitive functions as well as in activities of daily living. The authors are reporting these patients to alert clinicians to the fact that pernicious anemia in the elderly can first present with low serum B12 levels and neurologic abnormalities in the absence of anemia or macrocytosis. BACKGROUND: Vision loss resulting from thiamine deficiency is a recognized complication of bariatric surgery. Most patients with such vision loss have Wernicke encephalopathy with characteristic changes seen on neuroimaging. Other patients may have retinal hemorrhages, optic disc edema, and peripheral neuropathy without Wernicke encephalopathy. The risk for thiamine deficiency is potentiated by the presence of prolonged vomiting. CASE REPORT: A 37-year-old female presented with abrupt onset of vision loss and peripheral neuropathy following bariatric surgery. She had a history of prolonged vomiting postoperatively. Examination of the posterior segment of the eye revealed optic disc edema and large retinal hemorrhages bilaterally. Metabolic workup demonstrated thiamine deficiency. She responded quickly to parenteral thiamine therapy with recovery of normal vision and resolution of ophthalmologic findings. CONCLUSION: Patients who undergo bariatric surgery and have a thiamine deficiency can present with visual symptoms and ophthalmologic findings only visible by fundoscopy prior to developing more severe and potentially irreversible complications from the vitamin deficiency. Early detection of intraocular changes resulting from thiamine deficiency and initiation of therapy could prevent more devastating neurologic manifestations. Our case supports the consideration of a prospective study aimed at determining the true incidence of ocular and visual changes such as retinal hemorrhage, optic disc edema, and peripapillary telangiectasia in patients following bariatric surgery. BACKGROUND: Nutritional visual defects are apparently uncommon nowadays in developed nations. Retinal change-related visual defects caused by hypovitaminoses may be underdiagnosed. AIM OF THE STUDY: To investigate the retinal structural and functional changes in a patient with multivitamin deficiency before and during vitamin supplementation. METHODS: A 51-year-old female had been on vegetarian diet as a child, and on restrict vegan diet during the last 2 years, developing severe bilateral deterioration of visual function and polyneuropathy. Blood test revealed low levels of vitamin A, B6 and D. The patient underwent examinations with optical coherence tomography (OCT), computerized visual field examination (VF), electroretinography (ERG), visual evoked potentials (VEP) and neurography before and after vitamin supplementation. RESULTS: Visual acuity (VA) was 20/1000 and VF examination showed central scotoma in both eyes. Color vision was significantly affected. Full-field ERG showed normal rod and cone function, but a clearly reduced central peak was registered in multifocal ERG (mf-ERG), indicating impaired fovea function. VEP showed delayed latency and low amplitude of P100 in both eyes. Neurography showed sensory polyneuropathy. OCT showed significant thinning of macular ganglion cell plus inner plexiform layer (GCIPL) with rapid progression. Retinal nerve fiber layer (RNFL) was preserved and normal, which is in contrast to neuroinflammatory conditions. After 2.5 years of multivitamin supplementation, the visual functions were improved. GCIPL thickness was stable without further deterioration. CONCLUSIONS: Multivitamin deficiency results in progressive thinning of GCIPL with severe visual deterioration. In contrast to neuroinflammation, RNFL is preserved and normal. Stabilized GCIPL during vitamin supplementation was associated with improved visual function. OCT provides a sensitive and objective measure for differential diagnosis, monitoring retinal change and response to therapy. BACKGROUND: Vitamin B12 deficiency is often diagnosed with hematological manifestations of megaloblastic macrocytic anemia, which is usually the initial presentation. Neurological symptoms are often considered to be late manifestations and usually occur after the onset of anemia. Sub acute combined cord degeneration, which is a rare cause of myelopathy is however the commonest neurological manifestation of vitamin B12 deficiency. CASE PRESENTATION: We present a case of a 66 year old Sinhalese Sri Lankan female, who is a strict vegetarian, presenting with one month's history suggestive of Sub-acute combined cord degeneration in the absence of haematological manifestations of anaemia. Her Serum B12 levels were significantly low, after which she was treated with hydroxycobalamine supplementation, showing marked clinical improvement of symptoms, with normalization of serum B12 levels. Hence, the diagnosis of vitamin B12 deficiency was confirmed retrospectively. CONCLUSION: Vitamin B12 deficiency could rarely present with neurological manifestations in the absence of anaemia. Therefore a high index of suspicion is necessary for the early diagnosis and prompt treatment in order to reverse neurological manifestations, as the response to treatment is inversely proportionate to the severity and duration of the disease. Long lists of psychiatric illness or symptoms have been documented to be caused by vitamin B12 deficiency. We describe an atypical case of a young adult who presented with predominant negative symptoms followed by neurological symptoms consistent with vitamin B12 deficiency. The symptoms showed complete remission after vitamin B12 supplementation. The uniqueness of this case is that vitamin B12 deficiency presented with predominant negative symptoms without other psychotic and manic symptoms, which has not been reported previously. Jitteriness and tremors in the newborn period typically precipitate an extensive, invasive, and expensive search for the etiology. Vitamin D deficiency has not been historically included in the differential of tremors. We report a shivering, jittery newborn who was subjected to a battery of testing, with the only biochemical abnormality being vitamin D deficiency. A second case had chin tremors and vitamin D deficiency. Review of our patients suggests that shudders, shivers, jitteriness, or tremors may be the earliest sign of vitamin D deficiency in the newborn. Neonates who present with these signs should be investigated for vitamin D deficiency. Publisher: El déficit de vitamina B12 es una de las complicaciones más importantes que puede producir el vegetarianismo. Los lactantes hijos de madres vegetarianas tienen riesgo aumentado de deficiencia y de presentar compromiso neurológico irreversible si esta no se identifica y corrige adecuadamente. Se describe el caso de un lactante de un mes y veinte días que consultó por episodios paroxísticos de mecanismo epileptógeno, en el cual los estudios complementarios permitieron identificar un déficit de vitamina B12 como causa de estos. Tras la confirmación diagnóstica, se instauró el tratamiento con vitamina B12 intramuscular, con remisión completa de los síntomas, buena evolución posterior y desarrollo psicomotor sin alteraciones. Teniendo en cuenta las tendencias alimentarias actuales, es necesario incorporar, en la práctica clínica habitual, la anamnesis nutricional materna detallada para detectar precozmente el riesgo de déficit de esta vitamina y prevenirlo. Hyperemesis gravidarum is a complication of pregnancy associated with severe nausea and vomiting that can lead to fluid-electrolyte imbalances and nutritional deficiencies. Wernicke's encephalopathy is a neurologic manifestation of acute thiamine (vitamin B1) deficiency. We describe a case of hyperemesis gravidarum presenting with gait ataxia and nystagmus which led to a diagnosis of Wernicke's encephalopathy. Vitamin B(12) deficiency (B(12)D) has a wide variety of neurological symptoms and signs. However, cerebellar dysfunction and cranial neuropathies other than optic neuropathy have been rarely reported. Herein, we describe two cases of unusual neurological manifestations of B(12)D. One patient showed prominent hoarseness with vocal cord paralysis, myelopathy, and peripheral neuropathy. The other had gait disturbance, lateral gaze limitation and cerebellar dysfunction in addition to the typical manifestations of subacute combined degeneration. Vitamin B(12) deficiency can rarely affect cerebellum and cranial nerves other than optic nerve. The review discusses thesteps of vitamin B12 metabolism and its role in maintaining of neurological functions. The term "vitamin B12 (cobalamin)" refers to several substances (cobalamins) of a very similar structure. Cobalamin enters the body with animal products. On the peripherу cobalamin circulates only in binding with proteins transcobalamin I and II (complex cobalamin-transcobalamin II is designated as "holotranscobalamin"). Holotranscobalamin is absorbed by different cells, whereas transcobalamin I-binded vitamin B12 - only by liver and kidneys. Two forms of cobalamin were identified as coenzymes of cellular reactions which are methylcobalamin (in cytoplasm) and hydroxyadenosylcobalamin (in mitochondria). The main causes of cobalamin deficiency are related to inadequate intake of animal products, autoimmune gastritis, pancreatic insufficiency, terminal ileum disease, syndrome of intestinal bacterial overgrowth. Relative deficiency may be seen in excessive binding of vitamin B12 to transcobalamin I. Cobalamin deficiency most significantly affects functions of blood, nervous system and inflammatory response. Anemia occurs in 13-15% of cases; macrocytosis is an early sign. The average size of neutrophils and monocytes is the most sensitive marker of megaloblastic hematopoiesis. The demands in vitamin B12 are particularly high in nervous tissue. Hypovitaminosis is accompanied by pathological lesions both in white and gray brain matter. Several types of neurological manifestations are described: subacute combined degeneration of spinal cord (funicular myelinosis), sensomotor polyneuropathy, optic nerve neuropathy, cognitive disorders. The whole range of neuropsychiatric disorders with vitamin B12 deficiency has not been studied well enough. Due to certain diagnostic difficulties they are often regarded as "cryptogenic", "reactive", "vascular» origin. Normal or decreased total plasma cobalamin level could not a reliable marker of vitamin deficiency. In difficult cases the content of holotranscobalamin, methylmalonic acid / homocysteine, and folate in the blood serum should be investigated besides carefully analysis of clinical manifestations. RATIONALE: There have been a few reported cases of subacute combined degeneration (SCD) associated with vitamin E deficiency, but the period of intestinal malabsorption was more than several years. We present a rare case of acute onset SCD that occurred in a relatively short period of several weeks with vitamin E deficiency related to small bowel obstruction. PATIENT CONCERNS: A 50-year-old woman had abdominal pain. A small bowel obstruction was suspected and conservative treatment was performed. She underwent bowel surgery after 2 weeks without any improvement. Following the operation, she was in a state of reduced consciousness. She was treated in an intensive care unit. Her consciousness level gradually recovered to alert in a week, but other symptoms such as ataxia, weakness on limbs, severe dysarthria, and dysphagia occurred. Since then, she had spent nearly 6 weeks in a bed-ridden state without improving. DIAGNOSIS: SCD associated with vitamin E deficiency was confirmed by laboratory investigations, electrophysiologic test, and whole spine magnetic resonance imaging scans. INTERVENTIONS: For vitamin E supplementation, she was administered a dose of 1200 mg/d. Physical therapy was focused on strengthening exercise, balance, and walker gait training. Occupational therapy was focused on activities of daily living training and dysphagia rehabilitation. OUTCOMES: After 6 weeks, her muscle strengths and functional level were substantially improved. The vitamin E level was recovered to normal range. LESSONS: This case suggests that if neurological symptoms occur in patients with intestinal obstruction, clinicians need to consider a deficiency of micronutrients such as vitamin E and vitamin B12. Patients with short clinical courses suffer less neurological damage and achieve faster recovery. Vitamin E malabsorption and deficiency during chronic childhood cholestasis has been associated with a progressive ataxic neurologic syndrome. Hyporeflexia, the first sign of neurologic dysfunction, may begin prior to age 2 years, but severe symptoms do not develop until age 5 to 10 years. To establish the age of onset of neuropathologic lesions, we prospectively evaluated four young children with severe cholestasis. Malabsorption and deficiency of vitamin E were documented by low serum vitamin E concentrations, low serum vitamin E to total serum lipids ratios, elevated hydrogen peroxide hemolysis, and impaired absorption of a pharmacologic dose of alpha-tocopherol. Abnormal neurologic findings in two patients were limited to areflexia, ptosis, mild truncal ataxia, and hypotonia; two patients had minimal signs of neurologic dysfunction. Sural nerve histology at age 6 to 25 months revealed a degenerative axonopathy involving large-caliber myelinated fibers, but without quantitative axonal loss. Muscle histology and histochemistry tests yielded normal results. Our study suggests that neurologic injury may occur during the first two years of life in vitamin E-deficient children with cholestatic hepatobiliary disease, obligating aggressive attempts at correcting this deficiency state at a very young age. Children deficient in vitamin E have various neurologic symptoms. 2 cases representing different mechanisms of this vitamin deficiency are reported. A 15-year-old boy with fat malabsorption due to cystic fibrosis who was diagnosed as being vitamin E deficient (< 0.5 mg/l), had typical neuropathies. On the other hand, a 12-year-old Beduin girl had isolated vitamin E deficiency, as well as neurological symptoms suggestive of Friedrich's ataxia. Vitamin E supplementation by intramuscular injection in the first case and per os in the second led to significant improvement in neurological symptoms. Ataxia with vitamin E deficiency is an autosomal recessive condition associated with a defect in the a-tocopherol transfer protein. Clinically it manifests as a progressive ataxia with a phenotype resembling that of Friedreich's ataxia. There is some evidence that progression of neurological symptoms is prevented by vitamin E therapy. A patient is described who was given a clinical diagnosis of Friedreich's ataxia. Molecular genetic analysis showed the absence of the frataxin gene expansion. Subsequent vitamin E assay showed deficiency and a diagnosis of ataxia with vitamin E deficiency was made. It is recommended that all patients with ataxia of unknown cause should have vitamin E deficiency excluded. When a diagnosis of Friedreich's ataxia is considered patients should have frataxin analysis in addition. Further, neurologists should be aware that ataxia with vitamin E deficiency may present as "mutation negative" Friedreich's ataxia.
4,121
Which are the uses of deep learning models in Duchenne Muscular Dystrophy?
Deep Learning of Ultrasound Imaging for Evaluating Ambulatory Function of Individuals with Duchenne Muscular Dystrophy.
[28582264, 31397906, 34071811, 32858918]
4,528
BACKGROUND: Children with physical impairments are at a greater risk for obesity and decreased physical activity. A better understanding of physical activity pattern and energy expenditure (EE) would lead to a more targeted approach to intervention. OBJECTIVE: This study focuses on studying the use of machine-learning algorithms for EE estimation in children with disabilities. A pilot study was conducted on children with Duchenne muscular dystrophy (DMD) to identify important factors for determining EE and develop a novel algorithm to accurately estimate EE from wearable sensor-collected data. METHODS: There were 7 boys with DMD, 6 healthy control boys, and 22 control adults recruited. Data were collected using smartphone accelerometer and chest-worn heart rate sensors. The gold standard EE values were obtained from the COSMED K4b2 portable cardiopulmonary metabolic unit worn by boys (aged 6-10 years) with DMD and controls. Data from this sensor setup were collected simultaneously during a series of concurrent activities. Linear regression and nonlinear machine-learning-based approaches were used to analyze the relationship between accelerometer and heart rate readings and COSMED values. RESULTS: Existing calorimetry equations using linear regression and nonlinear machine-learning-based models, developed for healthy adults and young children, give low correlation to actual EE values in children with disabilities (14%-40%). The proposed model for boys with DMD uses ensemble machine learning techniques and gives a 91% correlation with actual measured EE values (root mean square error of 0.017). CONCLUSIONS: Our results confirm that the methods developed to determine EE using accelerometer and heart rate sensor values in normal adults are not appropriate for children with disabilities and should not be used. A much more accurate model is obtained using machine-learning-based nonlinear regression specifically developed for this target population. INTRODUCTION: Golden retriever muscular dystrophy (GRMD) is a spontaneous X-linked canine model of Duchenne muscular dystrophy that resembles the human condition. Muscle percentage index (MPI) is proposed as an imaging biomarker of disease severity in GRMD. METHODS: To assess MPI, we used MRI data acquired from nine GRMD samples using a 4.7 T small-bore scanner. A machine learning approach was used with eight raw quantitative mapping of MRI data images (T1m, T2m, two Dixon maps, and four diffusion tensor imaging maps), three types of texture descriptors (local binary pattern, gray-level co-occurrence matrix, gray-level run-length matrix), and a gradient descriptor (histogram of oriented gradients). RESULTS: The confusion matrix, averaged over all samples, showed 93.5% of muscle pixels classified correctly. The classification, optimized in a leave-one-out cross-validation, provided an average accuracy of 80% with a discrepancy in overestimation for young (8%) and old (20%) dogs. DISCUSSION: MPI could be useful for quantifying GRMD severity, but careful interpretation is needed for severe cases. A significant percentage of Duchenne muscular dystrophy (DMD) cases are caused by premature termination codon (PTC) mutations in the dystrophin gene, leading to the production of a truncated, non-functional dystrophin polypeptide. PTC-suppressing compounds (PTCSC) have been developed in order to restore protein translation by allowing the incorporation of an amino acid in place of a stop codon. However, limitations exist in terms of efficacy and toxicity. To identify new compounds that have PTC-suppressing ability, we selected and clustered existing PTCSC, allowing for the construction of a common pharmacophore model. Machine learning (ML) and deep learning (DL) models were developed for prediction of new PTCSC based on known compounds. We conducted a search of the NCI compounds database using the pharmacophore-based model and a search of the DrugBank database using pharmacophore-based, ML and DL models. Sixteen drug compounds were selected as a consensus of pharmacophore-based, ML, and DL searches. Our results suggest notable correspondence of the pharmacophore-based, ML, and DL models in prediction of new PTC-suppressing compounds.
4,122
What is "long-COVID"?
"Long-COVID" is a complex condition where the affected individuals do not recover for several weeks or months following the onset of symptoms suggestive of COVID-19, and the symptoms are not explained by an alternative diagnosis. Persistent physical symptoms following acute COVID-19 are common and typically include fatigue, dyspnea, chest pain, and cough. Headache, joint pain, myalgias, and loss of smell have also been reported. Common psychological and cognitive symptoms include poor concentration, cognitive impairment/confusion, insomnia, and overall reduced quality of life.
[33786465, 34580069, 34068009, 33172844, 34533807, 34485849, 34163217, 33532785, 33892403, 34319569, 34024217, 34709019, 34276671]
4,529
Large numbers of people are being discharged from hospital following COVID-19 without assessment of recovery. In 384 patients (mean age 59.9 years; 62% male) followed a median 54 days post discharge, 53% reported persistent breathlessness, 34% cough and 69% fatigue. 14.6% had depression. In those discharged with elevated biomarkers, 30.1% and 9.5% had persistently elevated d-dimer and C reactive protein, respectively. 38% of chest radiographs remained abnormal with 9% deteriorating. Systematic follow-up after hospitalisation with COVID-19 identifies the trajectory of physical and psychological symptom burden, recovery of blood biomarkers and imaging which could be used to inform the need for rehabilitation and/or further investigation. We aimed this systematic review to analyze and review the currently available published literature related to long COVID, understanding its pattern, and predicting the long-term effects on survivors. We thoroughly searched the databases for relevant articles till May 2021. The research articles that met our inclusion and exclusion criteria were assessed and reviewed by two independent researchers. After preliminary screening of the identified articles through title and abstract, 249 were selected. Consequently, 167 full-text articles were assessed and reviewed based on our inclusion criteria and thus 20 articles were regarded as eligible and analyzed in the present analysis. All the studies included adult population aged between 18 and above 60 years. The median length of hospital stay of the COVID-19 patients during the acute infection phase ranged from 8 days to 17 days. The most common prevalent long-term symptoms in COVID-19 patients included persistent fatigue and dyspnea in almost all of the studies. Other reported common symptoms included: shortness of breath, cough, joint pain, chest pain or tightness, headache, loss of smell/taste, sore throat, diarrhea, loss of memory, depression, anxiety. Associated cardiovascular events included arrhythmias, palpitations and hypotension, increased HR, venous thromboembolic diseases, myocarditis, and acute/decompensated heart failure as well. Among neurological manifestations headache, peripheral neuropathy symptoms, memory issues, concentration, and sleep disorders were most commonly observed with varying frequencies. Mental health issues affecting mental abilities, mood fluctuations namely anxiety and depression, and sleep disorders were commonly seen. Further, diarrhea, vomiting, digestive disorders, and Loss of appetite or weight loss are common gastrointestinal manifestations. Therefore, appropriate clinical evaluation is required in long COVID cases which in turn may help us to identify the risk factors, etiology, and to my help, we treat them early with appropriate management strategies. Our objective was to mine Reddit to discover long-COVID symptoms self-reported by users, compare symptom distributions across studies, and create a symptom lexicon. We retrieved posts from the /r/covidlonghaulers subreddit and extracted symptoms via approximate matching using an expanded meta-lexicon. We mapped the extracted symptoms to standard concept IDs, compared their distributions with those reported in recent literature and analyzed their distributions over time. From 42 995 posts by 4249 users, we identified 1744 users who expressed at least 1 symptom. The most frequently reported long-COVID symptoms were mental health-related symptoms (55.2%), fatigue (51.2%), general ache/pain (48.4%), brain fog/confusion (32.8%), and dyspnea (28.9%) among users reporting at least 1 symptom. Comparison with recent literature revealed a large variance in reported symptoms across studies. Temporal analysis showed several persistent symptoms up to 15 months after infection. The spectrum of symptoms identified from Reddit may provide early insights about long-COVID. COVID-19 is an ongoing pandemic with many challenges that are now extending to its intriguing long-term sequel. 'Long-COVID-19' is a term given to the lingering or protracted illness that patients of COVID-19 continue to experience even in their post-recovery phase. It is also being called 'post-acute COVID-19', 'ongoing symptomatic COVID-19', 'chronic COVID-19', 'post COVID-19 syndrome', and 'long-haul COVID-19'. Fatigue, dyspnea, cough, headache, brain fog, anosmia, and dysgeusia are common symptoms seen in Long-COVID-19, but more varied and debilitating injuries involving pulmonary, cardiovascular, cutaneous, musculoskeletal and neuropsychiatric systems are also being reported. With the data on Long-COVID-19 still emerging, the present review aims to highlight its epidemiology, protean clinical manifestations, risk predictors, and management strategies. With the re-emergence of new waves of SARS-CoV-2 infection, Long-COVID-19 is expected to produce another public health crisis on the heels of current pandemic. Thus, it becomes imperative to emphasize this condition and disseminate its awareness to medical professionals, patients, the public, and policymakers alike to prepare and augment health care facilities for continued surveillance of these patients. Further research comprising cataloging of symptoms, longer-ranging observational studies, and clinical trials are necessary to evaluate long-term consequences of COVID-19, and it warrants setting-up of dedicated, post-COVID care, multi-disciplinary clinics, and rehabilitation centers. BACKGROUND AND AIMS: Long COVID is the collective term to denote persistence of symptoms in those who have recovered from SARS-CoV-2 infection. METHODS: WE searched the pubmed and scopus databases for original articles and reviews. Based on the search result, in this review article we are analyzing various aspects of Long COVID. RESULTS: Fatigue, cough, chest tightness, breathlessness, palpitations, myalgia and difficulty to focus are symptoms reported in long COVID. It could be related to organ damage, post viral syndrome, post-critical care syndrome and others. Clinical evaluation should focus on identifying the pathophysiology, followed by appropriate remedial measures. In people with symptoms suggestive of long COVID but without known history of previous SARS-CoV-2 infection, serology may help confirm the diagnosis. CONCLUSIONS: This review will helps the clinicians to manage various aspects of Long COVID. Long COVID or post-COVID-19 syndrome first gained widespread recognition among social support groups and later in scientific and medical communities. This illness is poorly understood as it affects COVID-19 survivors at all levels of disease severity, even younger adults, children, and those not hospitalized. While the precise definition of long COVID may be lacking, the most common symptoms reported in many studies are fatigue and dyspnoea that last for months after acute COVID-19. Other persistent symptoms may include cognitive and mental impairments, chest and joint pains, palpitations, myalgia, smell and taste dysfunctions, cough, headache, and gastrointestinal and cardiac issues. Presently, there is limited literature discussing the possible pathophysiology, risk factors, and treatments in long COVID, which the current review aims to address. In brief, long COVID may be driven by long-term tissue damage (e.g. lung, brain, and heart) and pathological inflammation (e.g. from viral persistence, immune dysregulation, and autoimmunity). The associated risk factors may include female sex, more than five early symptoms, early dyspnoea, prior psychiatric disorders, and specific biomarkers (e.g. D-dimer, CRP, and lymphocyte count), although more research is required to substantiate such risk factors. While preliminary evidence suggests that personalized rehabilitation training may help certain long COVID cases, therapeutic drugs repurposed from other similar conditions, such as myalgic encephalomyelitis or chronic fatigue syndrome, postural orthostatic tachycardia syndrome, and mast cell activation syndrome, also hold potential. In sum, this review hopes to provide the current understanding of what is known about long COVID. More than one year since its emergence, corona virus disease 2019 (COVID-19) is still looming large with a paucity of treatment options. To add to this burden, a sizeable subset of patients who have recovered from acute COVID-19 infection have reported lingering symptoms, leading to significant disability and impairment of their daily life activities. These patients are considered to suffer from what has been termed as "chronic" or "long" COVID-19 or a form of post-acute sequelae of COVID-19, and patients experiencing this syndrome have been termed COVID-19 long-haulers. Despite recovery from infection, the persistence of atypical chronic symptoms, including extreme fatigue, shortness of breath, joint pains, brain fogs, anxiety and depression, that could last for months implies an underlying disease pathology that persist beyond the acute presentation of the disease. As opposed to the direct effects of the virus itself, the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is believed to be largely responsible for the appearance of these lasting symptoms, possibly through facilitating an ongoing inflammatory process. In this review, we hypothesize potential immunological mechanisms underlying these persistent and prolonged effects, and describe the multi-organ long-term manifestations of COVID-19.
4,123
Are functional tests a good biomarker for Duchenne Muscular Dystrophy?
North Star Ambulatory Assessment is practical and reliable. allow assessment of high-functioning boys with Duchenne muscular dystrophy.
[31546754, 34155911, 22699538, 31879850, 29167533, 30180785, 22974002, 8347064, 30688316, 30404418, 16102988, 29742798, 31009620, 21800026, 21954141, 28084836, 24762862, 32390640, 32022138, 29174526]
4,530
Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder caused by out of frame mutations in the dystrophin gene. The hallmark symptoms of the condition include progressive degeneration of skeletal muscle, cardiomyopathy, and respiratory dysfunction. The most recent advances in therapeutic strategies for the treatment of DMD involve exon skipping or administration of minidystrophin, but these strategies are not yet universally available, nor have they proven to be a definitive cure for all DMD patients. Early diagnosis and tracking of symptom progression of DMD usually relies on creatine kinase tests, evaluation of patient performance in various ambulatory assessments, and detection of dystrophin from muscle biopsies, which are invasive and painful for the patient. While the current research focuses primarily on restoring functional dystrophin, accurate and minimally invasive methods to detect and track both symptom progression and the success of early DMD treatments are not yet available. In recent years, several groups have identified miRNA signature changes in DMD tissue samples, and a number of promising studies consistently detected changes in circulating miRNAs in blood samples of DMD patients. These results could potentially lead to non-invasive detection methods, new molecular approaches to treating DMD symptoms, and new methods to monitor of the efficacy of the therapy. In this review, we focus on the role of circulating miRNAs in DMD and highlight their potential both as a biomarker in the early detection of disease and as a therapeutic target in the prevention and treatment of DMD symptoms. Aim: Using baseline data from a clinical trial of domagrozumab in Duchenne muscular dystrophy, we evaluated the correlation between functional measures and quantitative MRI assessments of thigh muscle. Patients & methods: Analysis included timed functional tests, knee extension/strength and North Star Ambulatory Assessment. Patients (n = 120) underwent examinations of one thigh, with MRI sequences to enable measurements of muscle volume (MV), MV index, mean T2 relaxation time via T2-mapping and fat fraction. Results: MV was moderately correlated with strength assessments. MV index, fat fraction and T2-mapping measures had moderate correlations (r ∼ 0.5) to all functional tests, North Star Ambulatory Assessment and age. Conclusion: The moderate correlation between functional tests, age and baseline MRI measures supports MRI as a biomarker in Duchenne muscular dystrophy clinical trials. Trial registration: ClinicalTrials.gov, NCT02310763; registered 4 November 2014. OBJECTIVE: Evaluate muscle force and motor function in patients with Duchenne muscular dystrophy (DMD) in a period of six months. METHOD: Twenty children and adolescents with diagnosis of DMD were evaluated trough: measurement of the strength of the flexors and extensors of the shoulder, elbow, wrist, knee and ankle through the Medical Research Council (MRC), and application of the Motor Function Measure (MFM). The patients were evaluated twice within a six-month interval. RESULTS: Loss of muscle strength was identified in the MRC score for upper proximal members (t=-2.17, p=0.04). In the MFM, it was noted significant loss in the dimension 1 (t=-3.06, p=0.006). Moderate and strong correlations were found between the scores for muscular strength and the MFM dimensions. CONCLUSION: The MFM scale was a useful instrument in the follow up of patients with DMD. Moreover, it is a more comprehensive scale to assess patients and very good for conducting trials to evaluate treatment. As the drug development pipeline for Duchenne muscular dystrophy (DMD) rapidly advances, clinical trial outcomes need to be optimized. Effective assessment of disease burden, natural history progression, and response to therapy in clinical trials for Duchenne muscular dystrophy are critical factors for clinical trial success. By choosing optimal biomarkers to better assess therapeutic efficacy, study costs and sample size requirements can be reduced. Currently, functional measures continue to serve as the primary outcome for the majority of DMD clinical trials. Quantitative measures of muscle health, including magnetic resonance imaging and spectroscopy, electrical impedance myography, and ultrasound, sensitively identify diseased muscle, disease progression, and response to a therapeutic intervention. Furthermore, such non-invasive techniques have the potential to identify disease pathology prior to onset of clinical symptoms. Despite robust supportive evidence, non-invasive quantitative techniques are still not frequently utilized in clinical trials for Duchenne muscular dystrophy. Non-invasive quantitative techniques have demonstrated the ability to quantify disease progression and potential response to therapeutic intervention, and should be used as a supplement to current standard functional measures. Such methods have the potential to significantly accelerate the development and approval of therapies for DMD. Becker muscular dystrophy (BMD) is a neuromuscular disorder allelic to Duchenne muscular dystrophy (DMD), caused by in-frame mutations in the dystrophin gene, and characterized by a clinical progression that is both milder and more heterogeneous than DMD. Muscle magnetic resonance imaging (MRI) has been proposed as biomarker of disease progression in dystrophinopathies. Correlation with clinically meaningful outcome measures such as North Star Ambulatory Assessment (NSAA) and 6 minute walk test (6MWT) is paramount for biomarker qualification. In this study, 51 molecularly confirmed BMD patients (aged 7-69 years) underwent muscle MRI and were evaluated with functional measures (NSAA and 6MWT) at the time of the MRI, and subsequently after one year. We confirmed a pattern of fatty substitution involving mainly the hip extensors and most thigh muscles. Severity of muscle fatty substitution was significantly correlated with specific DMD mutations: in particular, patients with an isolated deletion of exon 48, or deletions bordering exon 51, showed milder involvement. Fat infiltration scores correlated with baseline functional measures, and predicted changes after 1 year. We conclude that in BMD, skeletal muscle MRI not only strongly correlates with motor function, but also helps in predicting functional deterioration within a 12-month time frame. OBJECTIVE: To investigate the effects of lower limb flexibility on the functional performance of children with Duchenne muscular dystrophy. METHODS: Thirty children, whose functional levels were at 1 or 2 according to the Brooke Lower Extremity Functional Classification Scale, were included in this study. The flexibilities of the hamstrings, hip flexors, tensor fascia latae, and gastrocnemius muscles were evaluated in the children's dominant lower limbs. The children's functional performance was assessed using 6-minute walk tests and timed performance tests. The correlations between the flexibilities of the lower limb muscles and the performance tests were examined. RESULTS: The flexibilities of the lower extremity muscles were found to be correlated to the 6-minute walk tests and the timed performance tests. The flexibility of the hamstrings (r = -.825), the gastrocnemius muscles (r = .545), the hip flexors (r = .481), and the tensor fascia latae (r = .445) were found to be correlated with functional performance as measured by the 6-minute walk tests (P < .05). DISCUSSION: The results of the current study indicate that the flexibility of the lower limbs has an effect on functional performance in the early stages of Duchenne muscular dystrophy. More research is needed to determine the functional effects of flexibility on performance by adding long-term flexibility exercises to the physiotherapy programs of children with Duchenne muscular dystrophy. BACKGROUND: The aim of this study was to perform a longitudinal assessment using Quantitative Muscle Testing (QMT) in a cohort of ambulant boys affected by Duchenne muscular dystrophy (DMD) and to correlate the results of QMT with functional measures. This study is to date the most thorough long-term evaluation of QMT in a cohort of DMD patients correlated with other measures, such as the North Star Ambulatory Assessment (NSAA) or three 6-min walk test (6MWT). METHODS: This is a single centre, prospective, non-randomised, study assessing QMT using the Kin Com(®) 125 machine in a study cohort of 28 ambulant DMD boys, aged 5 to 12 years. This cohort was assessed longitudinally over a 12 months period of time with 3 monthly assessments for QMT and with assessment of functional abilities, using the NSAA and the 6MWT at baseline and at 12 months only. QMT was also used in a control group of 13 healthy age-matched boys examined at baseline and at 12 months. RESULTS: There was an increase in QMT over 12 months in boys below the age of 7.5 years while in boys above the age of 7.5 years, QMT showed a significant decrease. All the average one-year changes were significantly different than those experienced by healthy controls. We also found a good correlation between quantitative tests and the other measures that was more obvious in the stronger children. CONCLUSION: Our longitudinal data using QMT in a cohort of DMD patients suggest that this could be used as an additional tool to monitor changes, providing additional information on segmental strength. Eighteen boys with Duchenne muscular dystrophy (DMD) were assessed for their ability to perform tasks involving wrist and hand function. Each subject was assessed using the Jebsen Test of Hand Function, range of motion measurements, and muscle strength tests. Writing and simulated page turning were performed successfully by boys in all age groups. Boys over age 15 had difficulty completing simulated feeding and picking up large and small objects. The muscle strength of the wrist extensors and the radial deviation range of motion at the wrist were found to be strongly correlated with six of the seven tasks assessed. These two clinical assessments appear to be good indicators of overall wrist and hand function. Life expectancy with DMD is increasing with advances in respiratory care making preservation of wrist and hand function, the major activity remaining with advanced disease, increasingly important. While the number of new treatment options tested in patients with Duchenne muscular dystrophy (DMD) is increasing, there is still no defining of the most reliable assessments regarding therapeutic efficacy. We present clinical and radiological outcome measures used in ambulatory patients participating in our trial "Treatment with L-citrulline and metformin in Duchenne muscular dystrophy". The motor function measure is a validated test in patients with neuromuscular disorders that consists of 32 items and assesses all three dimensions of motor performance including standing and transfer (D1 subscore), axial and proximal motor function (D2 subscore), and distal motor function (D3 subscore). The test shows high intra- and inter-rater variability but only when strictly following guidelines of the materials, examination steps, and calculation of scores. The 6-minute walk test, timed 10-meter walk/run test, and supine-up time are commonly used timed functional tests that also sufficiently monitor changes in muscle function; however, they strongly depend on patient collaboration. Quantitative MRI is an objective and sensitive biomarker to detect subclinical changes, though the examination costs may be a reason for its limited use. In this study, a high correlation between all clinical assessments and quantitative MRI scans was found. The combinational use of these methods provides a better understanding about disease progression; however, longitudinal studies are needed to validate their reliability. OBJECTIVE: Duchenne muscular dystrophy, an X-linked genetic disease, leads to progressive muscle weakness mainly in the lower limbs. Motor function tests help to monitor disease progression. Can low-cost, simple assessments help in the diagnostic suspicion of Duchenne muscular dystrophy? The authors aim to define the sensitivity of time to rise from the floor, time to walk 10meters, and time to run 10meters, evaluating them as eventual diagnostic screening tools. METHODS: This is an analytical, observational, retrospective (1998-2015), and prospective study (2015-2018). Cases were recruited from the database of the pediatric neurology department and the healthy, from child care consultations, with normal gait development (up to 15 months) and without other comorbidities (neuromuscular, pulmonary, heart diseases) from the same university hospital. RESULTS: 128 Duchenne muscular dystrophy patients and 344 healthy children were analyzed, equally distributed in age groups. In Duchenne muscular dystrophy, there is a progressive increase in the means of the times to perform the motor tests according to the age group, which accelerates very abruptly after 7 years of age. Healthy children acquire maximum motor capacity at 6 years and stabilize their times. The time to rise showed a p-value <0.05 and a strong association (effect size [ES] >0.8) in all age groups (except at 12 years), with time to walk 10 meters from 9 years, and with time to run 10 meters , from 5 years. The 100% sensitivity points were defined as follows: time to rise, at 2s; time to walk 10 meters, 5s; time to run 10 meters, 4s. CONCLUSIONS: Time to rise is a useful and simple tool in the screening of neuromuscular disorders such as Duchenne muscular dystrophy, a previously incurable disease with new perspectives for treatment. OBJECTIVE: To describe the involvement of lower leg muscles in boys with Duchenne muscular dystrophy (DMD) by using MR imaging (MRI) and spectroscopy (MRS) correlated to indices of functional status. SUBJECTS AND METHODS: Nine boys with DMD (mean age, 11 years) and eight healthy age- and BMI-matched boys (mean age, 13 years) prospectively underwent lower leg MRI, 1H-MRS of tibialis anterior (TA) and soleus (SOL) for lipid fraction measures, and 31P-MRS for pH and high-energy phosphate measures. DMD subjects were evaluated using the Vignos lower extremity functional rating, and tests including 6 min walk test (6MWT) and 10 m walk. RESULTS: DMD subjects had highest fatty infiltration scores in peroneal muscles, followed by medial gastrocnemius and soleus. Compared to controls, DMD boys showed higher intramuscular fat (P = 0.04), lipid fractions of TA and SOL (P = 0.02 and 0.003, respectively), pH of anterior compartment (P = 0.0003), and lower phosphocreatine/inorganic phosphorus ratio of posterior compartment (P = 0.02). The Vignos rating correlated with TA (r = 0.79, P = 0.01) and SOL (r = 0.71, P = 0.03) lipid fractions. The 6MWT correlated with fatty infiltration scores of SOL (r = -0.76, P = 0.046), medial (r = -0.80, P = 0.03) and lateral (r = -0.84, P = 0.02) gastrocnemius, intramuscular fat (r = -0.80, P = 0.03), and SOL lipid fraction (r = -0.89, P = 0.007). Time to walk 10 m correlated with anterior compartment pH (r = 0.78, P = 0.04). CONCLUSION: Lower leg muscles of boys with DMD show a distinct involvement pattern and increased adiposity that correlates with functional status. Lower leg MRI and 1H-MRS studies may help to noninvasively demonstrate the severity of muscle involvement. BACKGROUND AND PURPOSE: The aims of this study were to develop a clinical assessment scale to measure functional ability in ambulant boys with Duchenne muscular dystrophy and to determine the reliability of the scale in multiple centres in the UK. METHODS: Focus groups and workshops were held with experienced paediatric neuromuscular physiotherapists to determine scale content. A manual was prepared with accompanying videos, and training sessions were conducted. A total of 17 physiotherapists from participating centres used the videos to determine inter-rater reliability. Five determined the intra-rater reliability. RESULTS: Strength of agreement for these groups based on total subject scores was very good (0.95 and ≥ 0.93 for consistency and absolute agreement, respectively). Test-retest ability was high, with perfect agreement between occasions for all but two items of the scale. CONCLUSIONS: Our study indicates that the North Star Ambulatory Assessment is practical and reliable. It takes only 10 minutes to perform and incorporates both universally used timed tests as well as levels of activities, which allow assessment of high-functioning boys with Duchenne muscular dystrophy. PURPOSE: Duchenne muscular dystrophy can lead to upper extremity limitations, pain and stiffness. In a previous study, these domains have been investigated using extensive questionnaires, which are too time-consuming for clinical practice. This study aimed at gaining insight into the underlying dimensions of these questionnaires, and to construct a short questionnaire that can be used for clinical assessment. METHODS: Exploratory factor analysis was performed on the responses of 213 participants to a web-based survey to find the underlying dimensions in the Capabilities of Upper Extremity questionnaire, the ABILHAND questionnaire, and questionnaires regarding pain and stiffness. Based on these underlying dimensions, a stepwise approach was formulated. In addition, construct validity of the factors was investigated. RESULTS: In total, 14 factors were identified. All had high internal consistency (Cronbach's alpha >0.89) and explained 80-88% of the variance of the original questionnaires. Construct validity was supported, because participants in the early ambulatory stage performed significantly better (p< 0.001) than participants in the late non-ambulatory stage. CONCLUSION: The factors identified from the set of questionnaires provide a valid representation of upper extremity function, pain and stiffness in Duchenne muscular dystrophy. Based on the factor commonalities, the Upper Limb Short Questionnaire was formulated. Implications for Rehabilitation New insights into the underlying dimensions of upper extremity function, pain and stiffness in Duchenne muscular dystrophy are gained. Fourteen factors, with good internal consistency and construct validity, are identified regarding upper extremity function, pain and stiffness in Duchenne muscular dystrophy. Based on these factors, the Upper Limb Short Questionnaire is presented. The Upper Limb Short Questionnaire can be used as an identifier of arm-hand limitations and the start of more thorough clinical investigation. BACKGROUND: Duchenne Muscular Dystrophy is a severe, incurable disorder caused by mutations in the dystrophin gene. The disease is characterized by decreased muscle function, impaired muscle regeneration and increased inflammation. In a clinical context, muscle deterioration, is evaluated using physical tests and analysis of muscle biopsies, which fail to accurately monitor the disease progression. OBJECTIVES: This study aims to confirm and asses the value of blood protein biomarkers as disease progression markers using one of the largest longitudinal collection of samples. METHODS: A total of 560 samples, both serum and plasma, collected at three clinical sites are analyzed using a suspension bead array platform to assess 118 proteins targeted by 250 antibodies in microliter amount of samples. RESULTS: Nine proteins are confirmed as disease progression biomarkers in both plasma and serum. Abundance of these biomarkers decreases as the disease progresses but follows different trajectories. While carbonic anhydrase 3, microtubule associated protein 4 and collagen type I alpha 1 chain decline rather constantly over time, myosin light chain 3, electron transfer flavoprotein A, troponin T, malate dehydrogenase 2, lactate dehydrogenase B and nestin plateaus in early teens. Electron transfer flavoprotein A, correlates with the outcome of 6-minutes-walking-test whereas malate dehydrogenase 2 together with myosin light chain 3, carbonic anhydrase 3 and nestin correlate with respiratory capacity. CONCLUSIONS: Nine biomarkers have been identified that correlate with disease milestones, functional tests and respiratory capacity. Together these biomarkers recapitulate different stages of the disorder that, if validated can improve disease progression monitoring. Duchenne muscular dystrophy (DMD) usually affects men. However, women are also affected in rare instances. Approximately 8% of female DMD carriers have muscle weakness and cardiomyopathy. The early identification of functional and motor impairments can support clinical decision making. OBJECTIVE: To investigate the motor and functional impairments of 10 female patients with dystrophinopathy diagnosed with clinical, pathological, genetic and immunohistochemical studies. METHODS: A descriptive study of a sample of symptomatic female carriers of DMD mutations. The studied variables were muscular strength and functional performance. RESULTS: The prevalence was 10/118 (8.4%) symptomatic female carriers. Deletions were found in seven patients. The age of onset of symptoms in female carriers of DMD was quite variable. Pseudohypertrophy of calf muscles, muscular weakness, compensatory movements and longer timed performance on functional tasks were observed in most of the cases. Differently from males with DMD, seven female patients showed asymmetrical muscular weakness. The asymmetric presentation of muscle weakness was frequent and affected posture and functionality in some cases. The functional performance presents greater number of compensatory movements. Time of execution of activities was not a good biomarker of functionality for this population, because it does not change in the same proportion as the number of movement compensations. CONCLUSION: Clinical manifestation of asymmetrical muscle weakness and compensatory movements, or both can be found in female carriers of DMD mutations, which can adversely affect posture and functional performance of these patients. Author information: (1)Division of Pediatric Neurology, University of Basel Children's Hospital, Basel, Switzerland; Department of Neurology, University of Basel Hospital, Basel, Switzerland. (2)Division of Pediatric Neurology, University of Basel Children's Hospital, Basel, Switzerland; Division of Neurology, Medical University Clinic, Kantonsspital Baselland, Bruderholz, Switzerland. (3)Division of Pediatric Neurology, University of Basel Children's Hospital, Basel, Switzerland; Division of Pediatric Neurology, Lausanne University Hospital, Lausanne, Switzerland; Division of Pediatric Neurology, University of Berne Hospital, Berne, Switzerland. (4)Division of Pediatric Neurology, University of Basel Children's Hospital, Basel, Switzerland. (5)Department of Pediatrics, Kaiser Franz Josef Hospital, Vienna, Austria. (6)Laboratoire de Génétique Médicale, INSERM 1112, Faculté de Médecine, Strasbourg, France. (7)Division of Pediatric Neurology, Lausanne University Hospital, Lausanne, Switzerland. (8)Division of Pediatric Neurology, University of Berne Hospital, Berne, Switzerland. (9)Division of Pediatric Neurology, Children's Hospital, Aarau, Switzerland. (10)Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland. (11)Department of Clinical Research, Clinical Trial Unit, University of Basel Hospital, Basel, Switzerland. (12)Division of Pediatric Neurology, University of Basel Children's Hospital, Basel, Switzerland; Department of Neurology, University of Basel Hospital, Basel, Switzerland; Division of Neurology, Medical University Clinic, Kantonsspital Baselland, Bruderholz, Switzerland. Electronic address: dirk.fischer@ukbb.ch.
4,124
What is the most sensitive test for the diagnosis of multiple sclerosis?
These results support previous conclusions that MRI is the most sensitive test for detecting white matter asymptomatic lesions, and the most predictive for the diagnosis of CDMS.
[10919200, 1449838, 8164014, 3208208, 20003089, 6830166, 7629529, 2795066, 16400831]
4,531
Magnetic resonance is the most sensitive para-clinical method available for the diagnosis of multiple sclerosis since it shows changes in 95% of the patients with clinically definite multiple sclerosis. However, little correlation has been found, in different studies, between the parameters of magnetic resonance and the degree of neurological disability. The development and gradual application of new techniques of magnetic resonance, which permit specific detection of the lesions with the greatest degree of nerve dysfunction, permits improvement in the use of this technique for study of the natural history of the disease and thus to monitor patients given new treatments. The relation between the results of 7 biological markers (cells, total protein, albumin, IgG, IgG ratio, Tibbling ratio, and Tourtellotte's formula) and 4 paraclinical tests (PEV, PEATC, CT and MR) in 236 patients with multiple sclerosis (MS) not selected by the localization of symptoms were studied. One hundred forty-one had clinically defined MS, 22 had defined MS supported by a laboratory and 68 had clinically probable MS. The existence of a relation between PEV and MRI abnormality and the increase in the concentration and the ratios of intrathecal IgG synthesis and the degree of certainty of disease diagnosis was demonstrated. The most sensitive test was MRI (93%) followed by VEP (83%) and BAEP (60%) and the sensitivity of the study with high resolution CT including 59 patients explored by double enhancement and delayed cut off was very low (33%). It was considered that for the lack of a specific diagnostic test the use of biological markers PEV and MR constituted a necessary aid in the diagnosis of MS. The sensitivities and predictive values of visual, somatosensory, and brain auditory evoked potentials (EPs), cerebrospinal fluid oligoclonal banding (CSF-OB) and magnetic resonance imaging (MRI) were evaluated for the early diagnosis of clinically definite multiple sclerosis (CDMS). Paraclinical evidence of asymptomatic lesions allows a diagnosis of CDMS. Eighty-two patients in whom MS was suspected but diagnosis of CDMS was not possible entered the study prospectively. Paraclinical examinations were performed at entry. Patients were examined and underwent EPs every 6 months, and MRI yearly. After a mean follow-up of 2.9 years, 28 patients (34%) had developed CDMS (McDonald-Halliday criteria). The initial MRI was strongly suggestive of MS in 19 of these (68%), while 27 (96%) had at least one MS-like abnormality in the initial MRI. CSF-OB and EPs had lower sensitivities. CDMS developed during follow-up in 19 of the 36 patients (53%) who had an initial MRI strongly suggestive of MS but in only 1 of the 25 who had normal MRI when first studied. These results support previous conclusions that MRI is the most sensitive test for detecting white matter asymptomatic lesions, and the most predictive for the diagnosis of CDMS. Magnetic resonance imaging (MRI) has been shown to be a good method of visualizing the lesions in MS. We have studied several applications of MRI to the evaluation of patients and experimental models. In diagnosis, MRI is the most sensitive test for the demonstration of dissemination of lesions in space. Pathological correlation studies show that MRI reliably measures the extent of chronic demyelination. Experimental studies show that MRI detects acute inflammatory lesions and measures their evolution. MRI also is a reliable measure of the extent of the MS process, serial MRI scans detect evidence of disease activity in MS not always disclosed by clinical evaluation. MRI will have an enormous future impact on the evaluation of patients in clinical studies and in understanding the evolution of pathological processes. Magnetic resonance imaging (MRI) is a sensitive paraclinical test for diagnosis and assessment of disease progression in multiple sclerosis (MS) and is often used to evaluate therapeutic efficacy. The formation of new T2-hyperintense MRI lesions is commonly used to measure disease activity, but lacks specificity because edema, inflammation, gliosis, and axonal loss all contribute to T2 lesion formation. As the role of neurodegeneration in the pathophysiology of MS has become more prominent, the formation and evolution of chronic or persistent Tl-hypointense lesions (black holes) have been used as markers of axonal loss and neuronal destruction to measure disease activity. Despite the use of various detection methods, including advanced imaging techniques such as magnetization transfer imaging and magnetic resonance spectroscopy, correlation of persistent black holes with clinical outcomes in patients with MS remains uncertain. Furthermore, although axonal loss and neuronal tissue destruction are known to contribute to irreversible disability in patients with MS, there are limited data on the effect of therapy on longitudinal change in Tl-hypointense lesion volume. Measurement of black holes in clinical studies may elucidate the underlying pathophysiology of MS and may be an additional method of evaluating therapeutic efficacy. The results of cerebrospinal fluid agarose gel electrophoresis in 300 consecutive patients were correlated with neurological examinations and diagnoses, other cerebrospinal fluid studies, and the results of evoked potential examinations. The presence of oligoclonal bands was the most sensitive test for multiple sclerosis (MS); bands were present in from 100% (11/11) of patients with definite MS to 82% (27/33) of those with possible MS (classified by McAlpine criteria). The visual evoked response was the next most sensitive study. Thirty-eight patients without MS or related disorders had bands in the IgG region. Three patients had plasma cell dyscrasias. Seven patients had thick single bands. Single bands did not correlate with chronic polyneuropathy but appeared to be an artifact of storage. Twenty-eight patients had active neurological disease, including cerebral infarction (in 5), viral infection (in 4), remote effect of carcinoma (in 4), and acute and chronic polyneuropathies (in 6). In acute illnesses (i.e., vascular insults), repeat electrophoresis showed disappearance of bands. In continually active disease, bands persisted. These results indicate that the presence of oligoclonal bands provides sensitive supporting evidence for the diagnosis of MS but that bands may be present in other disorders, including those not directly related to infection or abnormal immune response. The data suggest that oligoclonal bands may represent an immune response to neurological injury that is prominent in disorders with a particularly intense or continuous antigenic stimulus. The yield of paraclinical tests was evaluated in a prospective study of 189 consecutive patients referred for suspected multiple sclerosis (142 patients with multiple sclerosis, 47 non-multiple sclerosis patients on discharge). Patients were first classified according to the Poser criteria by the clinical findings. Subsequently, the results of paraclinical tests (cranial MRI, visually evoked potentials (VEPs), somatosensory evoked potentials by tibial nerve stimulation (SSEPs), motor evoked potentials (MEPs), and analysis of CSF for oligoclonal banding and IgG-index (CSF)) were taken into account. The percentage of reclassified patients (reclassification sensitivity, RS) was always lower than the percentage of abnormal results (diagnostic sensitivity, DS), and the divergence of RS v DS differed between the tests (60% v 84% in MRI, 31% v 77% in CSF, 29% v 37% in VEPs, 20% v 68% in MEPs, and 12% v 46% in SSEPs respectively). False reclassifications of non-multiple sclerosis patients to multiple sclerosis would have occurred with all tests (MRI: six of 47 patients, (reclassification specificity 88%); CSF: one (98%); VEPs: two (96%); MEPs: two (96%); SSEPs: four (91%); P < 0.05). Although MRI had superior diagnostic capacity, 57 of the 142 patients with multiple sclerosis were not reclassified by the MRI result, 12 of whom were reclassified by CSF and 18 by one of the evoked potential (EP) studies. Of the 98 patients not reclassified by CSF, 53 were reclassified by MRI and 39 by EPs. The results suggest that for the evaluation of paraclinical tests in suspected multiple sclerosis, comparison of diagnostic sensitivities is inappropriate. In general, a cranial MRI contributes most to the diagnosis; however, due to its comparatively low specificity and its considerable number of negative results, EP or CSF studies are often useful to establish the diagnosis of multiple sclerosis. Magnetic resonance imaging (MRI) has recently been recognised as the most sensitive method with which to detect clinically silent lesions in patients affected by multiple sclerosis. Visually guided horizontal saccadic eye movements (SEM) were studied, together with MRI, in 57 multiple sclerosis patients. A very similar sensitivity was found for both MRI (78.2%) and SEM analysis (76.3%). Significant associations between peak saccadic velocity and brain stem signs and between saccadic latency and visual signs were observed. There is no single test that is diagnostic of MS, including MRI. The lesions detected with MRI are pathologically nonspecific. The principles of MS diagnosis are based on showing dissemination of white matter lesions in space and time. MRI is the most sensitive method for revealing asymptomatic dissemination of lesions in space and time. The pattern and evolution of MRI lesions, in the appropriate clinical setting, has made MRI abnormalities invaluable criteria for the early diagnosis of MS. The first important role for MRI in the diagnosis of MS allows for an early diagnosis of MS for CIS patients using the IP diagnostic criteria, including MRI for dissemination in space (DIS) and time (DIT). The sensitivity of diagnosing MS within the first year after a single attack is 94%, with a specificity of 83%. The MRI evidence required to support the diagnosis varies, depending on the strength of the clinical findings. Allowing a new MRI lesion to substitute for a clinical attack doubles the number of CIS patients who can be diagnosed as having MS within 1 year of symptom onset. Increasing the sensitivity of the test with more lenient criteria, as recommended by the AAN subcommittee, can result in decreased specificity. The second important role for MRI in the diagnostic work-up of suspected MS patients is to rule out alternative diagnoses obvious on MRI, such as spinal stenosis and most brain tumors. Characteristic lesions that favor MS include Dawson Fingers, ovoid lesions, corpus callosum lesions, and asymptomatic spinal cord lesions. However, other white matter diseases can have similar appearances on MRI. Persistent gadolinium enhancement greater than three months, lesions with mass effect, and meningeal enhancement suggest other disorders. A standardized MRI protocol for brain and spinal cord is crucial for comparing across studies or between centers. T2W MRI cannot distinguish between acute and chronic lesions. Gadolinium provides useful information about new lesion activity and is helpful in ruling out alternative diagnoses such as neoplasm, vascular malformations, and leptomeningeal disease. A single gadolinium-enhanced MRI can potentially provide evidence for dissemination in space and time. Spinal cord imaging is equally valuable to rule out spinal stenosis or tumor, and for detecting asymptomatic lesions when brain imaging is nondiagnostic in patients suspected of having MS. Precise criteria may be too suggestive that MS can be diagnosed by MRI and a negative MRI at the time of CIS does not rule out MS. MRI evidence plays a supportive role in what is ultimately a clinical diagnosis of MS, in the appropriate clinical situation, and always at the exclusion of alternative diagnoses.
4,125
Define pseudotumor cerebri. How is it treated?
Benign intracranial hypertension (BIH) is characterized by an elevation of the intracranial pressure not associated with an intracranial process or hydrocephaly, and with normal cerebrospinal fluid (CSF) contents. The elevation of the intracranial pressure is isolated; therefore, diseases such as cerebral venous thrombosis or dural fistulas should not be considered as etiologies of BIH. The exact definition of BIH remains debated, and other terms such as "pseudotumor cerebri" or "idiopathic intracranial hypertension" are often used in the literature. The management of patients with BIH depends mainly on the presence and severity of ocular symptoms and signs on which the prognostic of the disease is based. Repeated lumbar punctures associated with acetazolamide and weight loss are usually efficient enough. However a surgical treatment (optic nerve sheath fenestration or lumboperitoneal shunt) is required when appropriate medical management does not prevent progressive alteration of vision (visual loss or visual field defect), or when the patients complains of severe, refractory headaches. Careful follow-up with repeated formal visual field testing may help preventing a devastating visual loss in these patients.
[20721668, 8721925, 10532364, 23265564, 15010717, 23136035, 10529973, 16388155, 27128512, 11524298, 7049034, 1614156, 25449933, 2347863, 29393752, 11240545, 33717740, 26444398, 32736880, 11680122, 3799419]
4,532
INTRODUCTION: Pseudotumor cerebri is a condition characterized by raised intracranial pressure, normal CSF contents, and normal brain with normal or small ventricles on imaging studies. It affects predominantly obese women of childbearing age; however, its incidence seems to be increasing among adolescent and children. While among older children the clinical picture is similar to that of adults, younger children present demographic and clinical peculiarities. Different diagnostic criteria for adults and pre-pubertal children have been proposed. Etiology and pathogenesis are still unclear, particular concerning the role of obstruction to venous outflow. METHODS: An extensive literature review concerning all the aspects of pseudotumor cerebri has been performed, both among adults and pre-pubertal children. CONCLUSION: Pseudotumor cerebri is an avoidable cause of visual loss, both in adults and children. Few diagnostic measures are usually sufficient to determine the correct diagnosis. Since pseudotumor cerebri is a diagnosis of exclusion, the differential diagnosis work out is of special importance. Modern neuroimaging techniques, especially magnetic resonance imaging and magnetic resonance venography may clarify the role of obstruction to venous outflow in each case. Various therapeutic options are available: medical, surgical, and endovascular procedures may be used to prevent irreversible visual loss. Treatment is usually effective, and most patients will experience complete resolution of symptoms without persistent deficits. Pseudotumour cerebri is the name of a syndrome characterized by headache and papilloedema, with normal cerebral CT/MR studies and CSF with a high pressure and normal laboratory findings. We describe four patients who fulfilled the diagnostic criteria of this condition (including normal 0.5T MR studies). They all had cerebral angiograms showing minor abnormalities localized to the level of the superior longitudinal sinus. All improved on treatment with anticoagulants and steroids. In view of these findings we consider that in cases of pseudotumour cerebri without a clear aetiological factor, an angio MR study should be done, or if this technique is not available, a cerebral angiogram should be done, to exclude cerebral venous drainage defects. PURPOSE: Demographic and outcome data in the era of modern neuroimaging are needed to describe pseudotumor cerebri in children. METHODS: We reviewed the medical records of children less than 18 years old who were diagnosed with pseudotumor cerebri between 1977 and 1997. We defined pseudotumor cerebri as (1) increased intracranial pressure, (2) normal or small ventricles, and (3) normal cerebrospinal fluid composition. The condition might be idiopathic or the result of a nontumor etiology. RESULTS: Thirty-seven patients had an initial diagnosis of pseudotumor cerebri. Two patients were subsequently diagnosed with a central nervous system malignancy and were excluded from further analysis. The remaining 35 patients included 10 patients with idiopathic pseudotumor cerebri and 25 patients with disorders reported to be associated with pseudotumor cerebri. The mean age was 10.6 years with a range of 3 to 17 years. Twenty patients (57%) were female and 13 patients (37%) were obese. At presentation 4 patients had a visual acuity less than 20/40 in the best eye and 10 patients had visual field deficits. Seventeen patients (49%) had cranial nerve deficits, all of which resolved with normalization of the intracranial pressure. Follow-up data were obtained on 30 patients. Only one patient had a final visual acuity less than 20/40 in the best eye, whereas six patients had residual visual field deficits. Ten patients (33%) had optic nerve atrophy. CONCLUSIONS: There was no gender predominance, and associated etiologic factors were common in these children with pseudotumor cerebri. Permanent visual loss occurs in some children with pseudotumor cerebri. Quantitative perimetry and optic nerve examination were more sensitive than visual acuity determination in detecting damage to the visual sensory system. In rare instances the patient diagnosed with pseudotumor cerebri will be found after extended follow-up to harbor an intracranial neoplasm. Pseudotumor cerebri, or benign intracranial hypertension, is characterized by intracranial hypertension of unknown etiology typically in obese women <45 years of age, and can be disabling secondary to headaches and visual disturbances. Medical management includes pharmaceuticals that reduce cerebrospinal fluid (CSF) production and lumbar punctures that reduce the CSF volume, both aimed at reducing intracranial pressure. When medical management fails, surgical CSF diverting procedures are indicated. Recently it has been demonstrated that dural sinus stenosis or thrombosis can be responsible for this disease and treated with endovascular venous stent placement. The intent of this educational manuscript is to review the clinical presentation of pseudotumor cerebri patients and discuss the medical, surgical, and endovascular treatment options for this disease. After reading this paper, the reader should be able to: (1) understand the pathophysiological basis of pseudotumor cerebri, (2) describe its presenting signs and symptoms, and (3) discuss the medical, surgical, and endovascular treatment options. Pseudotumor cerebri is an idiopathic disorder characterized by papilledema and elevated intracranial pressure without a mass lesion. Most patients are female and young and are either overweight or have a history of recent weight gain. Other disease states, such as systemic lupus erythematosus, and drugs, such as tetracycline, have also been associated with the development of pseudotumor cerebri. The mechanism is unclear, but is likely related to decreased cerebrospinal fluid (CSF) resorption. Almost all patients have headache, but the greatest morbidity of the disorder is visual loss related to optic disc swelling. Common radiographic findings in pseudotumor cerebri include an empty sella, dilation of the optic nerve sheaths and elevation of the optic disc. The CSF, aside from elevated opening pressure, is normal without evidence of infection or inflammation. Treatment of patients with no or mild to moderate visual loss is primarily medical, with acetazolamide as the first-line agent. Acetazolamide decreases CSF production. Furosemide and corticosteroids are secondary choices. Optic nerve surgery is reserved for patients with severe visual loss or progression in visual deficits despite medical management. Idiopathic intracranial hypertension (IIH, pseudotumor cerebri) is a syndrome of elevated intracranial pressure of unknown cause that occurs predominantly in obese women of childbearing age. It is a diagnosis of exclusion and, therefore, other causes of increased intracranial pressure must be sought with history, imaging, and cerebrospinal fluid examination before the diagnosis can be made. IIH produces symptoms and signs of increased intracranial pressure, including papilledema. If untreated, papilledema can cause progressive irreversible visual loss and optic atrophy. The treatment approach depends on the severity and time course of symptoms and visual loss, as determined by formal visual field testing. The main goals of treatment are alleviation of symptoms, including headache, and preservation of vision. All overweight IIH patients should be encouraged to enter a weight-management program with a goal of 5-10 % weight loss, along with a low-salt diet. When there is mild visual loss, medical treatment with acetazolamide should be initiated. Other medical treatments can be added or substituted when acetazolamide is insufficient as monotherapy or poorly tolerated. When visual loss is more severe or rapidly progressive, surgical interventions, such as optic nerve sheath fenestration or cerebrospinal fluid shunting, may be required to prevent further irreversible visual loss. The choice of intervention depends on the relative severity of symptoms and visual loss, as well as local expertise. At present, the role of transverse venous sinus stenting remains unclear. Although there are no evidence-based data to guide therapy, there is an ongoing randomized double-blind placebo-controlled treatment trial, investigating diet and acetazolamide therapy for IIH. Pseudotumor cerebri is an unusual syndrome of increased intracranial pressure without a space-occupying mass. Many associations are known, but the pathogenesis remains a mystery. The diagnosis and treatment of pseudotumor cerebri are often challenging. Because it is not rare, neurosurgeons, neurologists, and ophthalmologists frequently work in concert to manage these patients. This article reviews the diagnostic criteria and differential diagnosis of pseudotumor cerebri. The medical and surgical treatments currently employed in this disorder are discussed. Pseudotumor cerebri is a clinical syndrome characterized by raised intracranial pressure with normal ventricular size, anatomy and position. Headache, vomiting and diplopia are the most common symptoms. Signs include those of raised intracranial pressure including papilledema and absence of focal neurological signs. A secondary cause is identifiable in 50% of children; the most common predisposing conditions are otitis media, viral infection and medications. Management is mainly directed towards identifying and treating the cause and measures to reduce the raised intracranial pressure. Though it is mostly a self limited condition, optic atrophy and blindness can occur. Oculomotor nerve palsy is very rarely associated with pseudotumor cerebri. We report a unique case of pseudotumor cerebri who had left Oculomotor palsy with sparing of the pupillary fibres, which resolved following treatment with oral acetazolamide. Pseudotumor cerebri is a central nervous disorder with elevated intracranial pressure that is most common among young obese women. It presents with headache, transient visual obscurations and loss of central vision. Papilledema and visual field defects are frequent. Acetazolamid can be used for treatment. If medical treatment is not successful, optic nerve sheath decompression is recommended. Three patients were treated medically and there were treated surgically. Both methods stabilized or improved visual fields and central vision. AIMS: The aim was to identify Pseudotumor cerebri treatment options and assess their efficacy. SETTING AND DESIGN: Review article. MATERIALS AND METHODS: Existing literature and the authors' experience were reviewed. RESULTS: Treatment options range from observation to surgical intervention. Weight loss and medical treatment may be utilized in cases without vision loss or in combination with surgical treatment. Cerebrospinal fluid shunting procedures and/or optic nerve sheath decompression is indicated for severe vision loss or headache unresponsive to medical management. The recent use of endovascular stenting of transverse sinus stenoses has also demonstrated benefit in patients with pseudotumor cerebri. CONCLUSION: While each treatment form may be successful individually, a multimodal approach is typically utilized with treatments selected on a case-by-case basis. OBJECTIVE Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, is a complex and difficult-to-manage condition that can lead to permanent vision loss and refractory headaches if untreated. Traditional treatment options, such as unilateral ventriculoperitoneal (VP) or lumboperitoneal (LP) shunt placement, have high complication and failure rates and often require multiple revisions. The use of bilateral proximal catheters has been hypothesized as a method to improve shunt survival. The use of stereotactic technology has improved the accuracy of catheter placement and may improve treatment of IIH, with fewer complications and greater shunt patency time. METHODS The authors performed a retrospective chart review for all patients with IIH who underwent stereotactic placement of biventriculoperitoneal (BVP) shunt catheters from 2008 to 2016 at their institution. Bilateral proximal catheters were Y-connected to a Strata valve with a single distal catheter. We evaluated clinical, surgical, and ophthalmological variables and outcomes. RESULTS Most patients in this series of 34 patients (mean age 34.4 ± 8.2 years, mean body mass index 38.7 ± 8.3 kg/m2; 91.2% were women) undergoing 41 shunt procedures presented with headache (94.1%) and visual deficits (85.3%). The mean opening pressure was 39.6 ± 9.0 cm H2O. In addition, 50.0% had undergone previous unilateral shunt placement, and 20.6% had undergone prior optic nerve sheath fenestration. After BVP shunt placement, there were no cases of proximal catheter obstruction and only a single case of valve obstruction at 41.9 months, with a mean follow-up of 24.8 ± 20.0 months. Most patients showed improvement in their headache (82.4%), subjective vision (70.6%), and papilledema (61.5% preoperatively vs 20.0% postoperatively, p = 0.02) at follow-up. Additional primary complications included 4 patients with migration of their distal catheters out of the peritoneum (twice in 1 patient), and an infection of the distal catheter after catheter dislodgment. The proximal obstructive shunt complication rate in this series (2.9%) was lower than that with LP (53.5%) or unilateral VP (37.8%) shunts seen in the literature. CONCLUSIONS This small series suggests that stereotactic placement of BVP shunt catheters appears to improve shunt survival rates and presenting symptoms in patients with IIH. Compared with unilateral VP or LP shunts, the use of BVP shunts may be a more effective and more functionally sustained method for the treatment of IIH. Pseudotumor cerebri, or idiopathic intracranial hypertension (IIH), is a syndrome of elevated intracranial pressure (ICP) of unknown etiology that occurs predominantly in obese women of childbearing age. Pseudotumor cerebri literally means "false brain tumor". It is a "diagnosis of exclusion" therefore a complete work-up to rule out life-threatening causes for increased ICP must be performed through a comprehensive history, complete physical examination, diagnostic imaging, and cerebrospinal fluid (CSF) analysis before the diagnosis can be made. The authors present the case of a young woman with headache, and near blindness due to pseudotumor cerebri. The presentation, diagnosis, and treatment options are discussed. Pseudotumor cerebri or benign intracranial hypertension is a syndrome of raised intracranial pressure without obvious explanation. Most patients are obese women at childbearing age. Symptoms and signs usually include headache, nausea, vomiting, edema of the papilla, visual obscurations and rarely palsy of the nervus abducens. The prognosis is generally good, but progressive visual loss and eventual blindness are major risks. We report the case of a 21-year-old non-obese young woman who developed pseudotumor cerebri while taking minocycline for acne therapy. Identical symptoms occurred upon inadvert rechallenge with minocycline for the second time.
4,126
What is pseudodementia?
Depression can cause some clinical symptoms and signs of dementia, classically in older adults. This type of "dementia" is called pseudodementia and is typically reversible with treatment.
[9658274, 453349, 12910854, 7316680, 30319082, 3911280, 2204977, 4050642, 6342420, 21995351, 32318620, 23979551]
4,533
BACKGROUND: The literature was reviewed to abstract items which were claimed to distinguish organic dementia from pseudodementia. Their discriminating powers were tested in a prospective study. Eighteen of these items were selected to create a questionnaire which should distinguish organic dementia from pseudodementia. The gold standard was the final diagnosis given by a consultant psychiatrist 12-14 months later. METHOD: One hundred and twenty-eight patients referred to our service with a differential diagnosis of depressive pseudodementia were screened using a checklist of 44 characteristic features (in the form of questions with 'yes' or 'no' answers) which were claimed in the literature of differentiate between organic dementia and depressive pseudodementia. This checklist covers the areas of history, clinical data, insight and performance. RESULTS: Forty points (questions) out of the 44 in the checklist showed significant discriminating power to differentiate dementia from depressive pseudodementia (p < 0.01). A principal component and factor analysis was performed from which 18 questions were extracted. The shortened questionnaire was able to classify (43/44 cases) 98% of dementia cases and (60/63) 95% of depression correctly. A new definition has been introduced for 'pseudodementia' as a syndrome of reversible subjective or objective cognitive problems caused by non-organic disorder. Thus depressive pseudodementia may be classified into two subtypes. Type I is a group of patients who have depressive symptoms with subject complaint of dysmnesia without measurable intellectual deficits. Type II is a group of patients who have depressive symptoms and show poor cognitive performance based on poor concentration not due to organic disorder. Pseudodementia is the syndrome in which dementia is mimicked or caricatured by functional psychiatric disorders. The author describes 10 patients with pseudodementia and compares its clinical features with those of true dementia. The syndrome occurred in patients with various psychiatric diagnoses, but a striking feature in most patients was marked dependency. The recognition of this clinical syndrome should obviate the need for many neurological diagnostic studies and lead to earlier and more effective psychiatric treatment. Specific symptoms of depression in aged subjects are presented in the paper. Cognitive dysfunctions in elder depressive patients (so called pseudodementia) as well as comorbidity of dementia with depression are special diagnostic problems. Both etiopathogenetic and clinical issues are discussed. Depression and a number of other psychiatric conditions can impair cognition and give the appearance of neurodegenerative disease. Collectively, this group of disorders is known as 'pseudodementia' and are important to identify given their potential reversibility with treatment. Despite considerable interest historically, the longitudinal outcomes of patients with pseudodementia remain unclear. We conducted a systematic review of longitudinal studies of pseudodementia. Bibliographic databases were searched using a wide range of search terms. Two reviewers independently assessed papers for inclusion, rated study quality, and extracted data. The search identified 18 studies with follow-up varying from several weeks to 18 years. Overall, 284 patients were studied, including 238 patients with depression, 18 with conversion disorder, 14 with psychosis, and 11 with bipolar disorder. Irrespective of diagnosis, 33% developed irreversible dementia at follow-up, 53% no longer met criteria for dementia, and 15% were lost to follow-up. Considerable variability was identified, with younger age at baseline, but not follow-up duration, associated with better outcomes. ECT and pharmacological interventions were also reported to be beneficial, though findings were limited by the poor quality of the studies. Overall, the findings suggest that pseudodementia may confer an increased risk of irreversible dementia in older patients. The findings also indicate, however, that a significant proportion improve, while many remain burdened with their psychiatric condition, independent of organic dementia. The findings support the clinical value of the construct and the need for its re-examination in light of developments in neuroimaging, genomics, other investigative tools, and trial methodology. Despite the increased attention that the syndrome of pseudodementia is receiving, several important questions regarding diagnostic criteria and accuracy, etiology, and even the appropriateness of the term itself remain unanswered. The author reviews the literature on this topic, including published case reports. On the basis of the available data, it appears that there may be at least two categories of pseudodementia and that the cognitive impairment associated with depressive illness is more appropriately viewed as a depression-induced organic mental disorder. Directions for future research are suggested. Dementia has a wide range of reversible causes. Well known among these is depression, though other psychiatric disorders can also impair cognition and give the appearance of neurodegenerative disease. This phenomenon has been known historically as "pseudodementia." Although this topic attracted significant interest in the 1980s and 1990s, research on the topic has waned. In this paper, we consider reasons for this decline, including objections to the term itself and controversy about its distinctness from organic dementia. We discuss limitations in the arguments put forward and existing research, which, crucially, does not support inevitable progression. We also discuss other neglected masquerades, such as of pseudodementia itself ("pseudo-pseudodementia") and depression ("pseudodepression"). Based on this reappraisal, we argue that these terms, while not replacing modern diagnostic criteria, remain relevant as they highlight unique groups of patients, potential misdiagnosis, and important, but neglected, areas of research.
4,127
Should acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) be used when providing supportive care for COVID-19?
Nonsteroidal anti-inflammatory drugs (NSAIDs) have been theorized to cause harm in patients with COVID-19, but clinical data are limited. Given the uncertainty, acetaminophen is the preferred antipyretic agent for most patients rather than NSAIDs. If NSAIDs are needed, the lowest effective dose is recommended.
[33824640, 32805057, 32256706, 33197762, 34318916, 33997800, 33135113, 32447629, 32460369, 32505846, 33658615, 34339037]
4,534
Despite our growing knowledge about the COVID pandemic, not much concern has been focused upon the effective pain management in pediatric patients suffering from this SARS CoV2 virus. Symptoms with pain like myalgia (10%-40%), sore throat (5%-30%), headache (14%-40%) and abdominal pain (10%) are common in children suffering from COVID. (3-5) We conducted a systematic review regarding analgesia for COVID positive pediatric patients. Cochrane, PubMed, and Google scholar databases were searched for relevant literature. Owing to the novel status of COVID-19 with limited literature, we included randomized controlled trials (RCTs), observational studies, case series and case reports in the descending order of consideration. Articles in languages other than English, abstract only articles and non-scientific commentaries were excluded. The Primary outcome was evaluation of pain related symptoms and best strategies for their management. Our review revealed that a multidisciplinary approach starting from non-pharmacological techniques like drinking plenty of water, removing triggers like inadequate sleep, specific foods and psychotherapy including distraction, comfort and cognitive behavioural strategies should be used. Pharmacological approaches like acetaminophen, NSAIDS, spasmolytics etc. can be used if non-pharmacological therapy is inadequate. As per the current strength of evidence, acetaminophen and ibuprofen can be safely administered for pain management in children with COVID-19. Undertreated pain is a significant contributor to increased morbidity and poor prognosis. Integration of evidence based non-pharmacotherapies in the multidisciplinary pain management will contribute towards improved functioning, early recovery and better quality care for pediatric patients suffering from COVID. AIMS: In light of the recent safety concerns relating to NSAID use in COVID-19, we sought to evaluate cardiovascular and respiratory complications in patients taking NSAIDs during acute lower respiratory tract infections. METHODS: We carried out a systematic review of randomised controlled trials and observational studies. Studies of adult patients with short-term NSAID use during acute lower respiratory tract infections, including bacterial and viral infections, were included. Primary outcome was all-cause mortality. Secondary outcomes were cardiovascular, renal and respiratory complications. RESULTS: In total, eight studies including two randomised controlled trials, three retrospective and three prospective observational studies enrolling 44 140 patients were included. Five of the studies were in patients with pneumonia, two in patients with influenza, and one in a patient with acute bronchitis. Meta-analysis was not possible due to significant heterogeneity. There was a trend towards a reduction in mortality and an increase in pleuro-pulmonary complications. However, all studies exhibited high risks of bias, primarily due to lack of adjustment for confounding variables. Cardiovascular outcomes were not reported by any of the included studies. CONCLUSION: In this systematic review of NSAID use during acute lower respiratory tract infections in adults, we found that the existing evidence for mortality, pleuro-pulmonary complications and rates of mechanical ventilation or organ failure is of extremely poor quality, very low certainty and should be interpreted with caution. Mechanistic and clinical studies addressing the captioned subject are urgently needed, especially in relation to COVID-19. Given the current SARS-CoV-2 (COVID-19) pandemic, the availability of reliable information for clinicians and patients is paramount. There have been a number of reports stating that non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids may exacerbate symptoms in COVID-19 patients. Therefore, this review aimed to collate information available in published articles to identify any evidence behind these claims with the aim of advising clinicians on how best to treat patients. This review found no published evidence for or against the use of NSAIDs in COVID-19 patients. Meanwhile, there appeared to be some evidence that corticosteroids may be beneficial if utilised in the early acute phase of infection, however, conflicting evidence from the World Health Organisation surrounding corticosteroid use in certain viral infections means this evidence is not conclusive. Given the current availability of literature, caution should be exercised until further evidence emerges surrounding the use of NSAIDs and corticosteroids in COVID-19 patients. The pathogenesis of Coronavirus disease 2019 is still obscure and the need for exploration of possible mechanisms to suggest drugs based on knowledge should never be delayed. In this manuscript, we present a novel theory to explain the pathogenesis of COVID-19; lymphocyte distraction theory upon which the author has used, in a preprinted protocol, non-steroidal anti-inflammatory drugs (NSAIDs); diclofenac potassium, ibuprofen and ketoprofen, successfully to treat COVID-19 patients. Furthermore, we agree with a recommendation that glucocorticoids should not be used routinely for COVID-19 patients and suggested to be beneficial only for patients with late acute respiratory distress syndrome. A clinical proof of ibuprofen safety in COVID-19 has been published by other researchers and we suggest that early administration of NSAIDs, including ibuprofen, in COVID-19 is not only safe but it might also prevent COVID-19 complications and this manuscript explains some of the suggested associated protective mechanisms. Collaborators: Baillie JK, Semple MG, Openshaw PJ, Carson G, Alex B, Bach B, Barclay WS, Bogaert D, Chand M, Cooke GS, da Silva Filipe A, de Silva T, Docherty AB, Dunning J, Fletcher T, Green CA, Harrison EM, Hiscox JA, Ho AY, Horby PW, Ijaz S, Khoo S, Klenerman P, Law A, Lim WS, Mentzer AJ, Merson L, Meynert AM, Moore SC, Noursadeghi M, Palmarini M, Paxton WA, Pollakis G, Price N, Rambaut A, Robertson DL, Russell CD, Sancho-Shimizu V, Scott JT, Sigfrid L, Solomon T, Sriskandan S, Stuart D, Summers C, Tedder RS, Thompson AAR, Thomson EC, Thwaites RS, Turtle LC, Zambon M, Donohue C, Griffiths F, Hardwick H, Lyons R, Oosthuyzen W, Drake TM, Fairfield CJ, Knight SR, Mclean KA, Murphy D, Norman L, Pius R, Shaw CA, Connor M, Dalton J, Gamble C, Girvan M, Halpin S, Harrison J, Jackson C, Marsh L, Roberts S, Saviciute E, Clohisey S, Hendry R, Law A, Leeming G, Scott-Brown J, Wham M, Greenhalf W, McDonald S, Shaw V, Keating S, Ahmed KA, Armstrong JA, Ashworth M, Asiimwe IG, Bakshi S, Barlow SL, Booth L, Brennan B, Bullock K, Carlucci N, Cass E, Catterall BW, Clark JJ, Clarke EA, Cole S, Cooper L, Cox H, Davis C, Dincarslan O, Doce Carracedo A, Dunn C, Dyer P, Elliott A, Evans A, Finch L, Fisher LW, Flaherty L, Foster T, Garcia-Dorival I, Greenhalf W, Gunning P, Hartley C, Holmes A, Jensen RL, Jones CB, Jones TR, Khandaker S, King K, Kiy RT, Koukorava C, Lake A, Lant S, Latawiec D, Lavelle-Langham L, Lefteri D, Lett L, Livoti LA, Mancini M, Massey H, Maziere N, McDonald S, McEvoy L, McLauchlan J, Metelmann S, Miah NS, Middleton J, Mitchell J, Moore SC, Murphy EG, Penrice-Randal R, Pilgrim J, Prince T, Reynolds W, Ridley PM, Sales D, Shaw VE, Shears RK, Small B, Subramaniam KS, Szemiel A, Taggart A, Tanianis-Hughes J, Thomas J, Trochu E, van Tonder L, Wilcock E, Zhang JE, MacLean A, McCafferty S, Morrice K, Murphy L, Wrobel N, Adeniji K, Agranoff D, Agwuh K, Ail D, Aldera EL, Alegria A, Angus B, Ashish A, Atkinson D, Bari S, Barlow G, Barnass S, Barrett N, Bassford C, Basude S, Baxter D, Beadsworth M, Bernatoniene J, Berridge J, Best N, Bothma P, Brittain-Long R, Bulteel N, Burden T, Burtenshaw A, Caruth V, Chadwick D, Chadwick D, Chambler D, Chee N, Child J, Chukkambotla S, Clark T, Collini P, Cosgrove C, Cupitt J, Cutino-Moguel MT, Dark P, Dawson C, Dervisevic S, Donnison P, Douthwaite S, DuRand I, Dushianthan A, Dyer T, Evans C, Eziefula C, Fegan C, Finn A, Fullerton D, Garg S, Garg S, Garg A, Gkrania-Klotsas E, Godden J, Goldsmith A, Graham C, Hardy E, Hartshorn S, Harvey D, Havalda P, Hawcutt DB, Hobrok M, Hodgson L, Hormis A, Jacobs M, Jain S, Jennings P, Kaliappan A, Kasipandian V, Kegg S, Kelsey M, Kendall J, Kerrison C, Kerslake I, Koch O, Koduri G, Koshy G, Laha S, Laird S, Larkin S, Leiner T, Lillie P, Limb J, Linnett V, Little J, Lyttle M, MacMahon M, MacNaughton E, Mankregod R, Masson H, Matovu E, McCullough K, McEwen R, Meda M, Mills G, Minton J, Mirfenderesky M, Mohandas K, Mok Q, Moon J, Moore E, Morgan P, Morris C, Mortimore K, Moses S, Mpenge M, Mulla R, Murphy M, Nagarajan T, Nagel M, Nelson M, O'Shea MK, Ostermann M, Otahal I, Pais M, Panchatsharam S, Papakonstantinou D, Papineni P, Paraiso H, Patel B, Pattison N, Pepperell J, Peters M, Phull M, Pintus S, Post F, Price D, Prout R, Rae N, Reschreiter H, Reynolds T, Richardson N, Roberts M, Roberts D, Rose A, Rousseau G, Ryan B, Saluja T, Sarah S, Shah A, Shankar-Hari M, Shanmuga P, Sharma A, Shawcross A, Singh Pooni J, Sizer J, Smith R, Snelson C, Spittle N, Staines N, Stambach T, Stewart R, Subudhi P, Szakmany T, Tatham K, Thomas J, Thompson C, Thompson R, Tridente A, Tupper-Carey D, Twagira M, Ustianowski A, Vallotton N, Vincent-Smith L, Visuvanathan S, Vuylsteke A, Waddy S, Wake R, Walden A, Welters I, Whitehouse T, Whittaker P, Whittington A, Wijesinghe M, Williams M, Wilson L, Winchester S, Wiselka M, Wolverson A, Wooton DG, Workman A, Yates B, Young P. Concern about the appropriate role of nonsteroidal anti-inflammatory drugs (NSAIDs) in COVID-19 speculate that NSAIDs, in particular ibuprofen, may upregulate the entry point for the virus, the angiotensin-converting enzyme (ACE) 2 receptors and increase susceptibility to the virus or worsen symptoms in existing disease. Adverse outcomes with COVID-19 have been linked to cytokine storm but the most effective way to address exaggerated inflammatory response is complex and unclear. The Expert Working Group on the Commission of Human Medicines in the UK and other organizations have stated that there is insufficient evidence to establish a link between ibuprofen and susceptibility to or exacerbation of COVID-19. NSAID use must also be categorized by whether the drugs are relatively low-dose over-the-counter oral products taken occasionally versus higher-dose or parenteral NSAIDs. Even if evidence emerged arguing for or against NSAIDs in this setting, it is unclear if this evidence would apply to all NSAIDs at all doses in all dosing regimens. Paracetamol (acetaminophen) has been proposed as an alternative to NSAIDs but there are issues with liver toxicity at high doses. There are clearly COVID-19 cases where NSAIDs should not be used, but there is no strong evidence that NSAIDs must be avoided in all patients with COVID-19; clinicians must weigh these choices on an individual basis. BACKGROUND: Since there is still no definitive conclusion regarding which non-steroidal anti-inflammatory drugs (NSAIDs) are most effective and safe in viral respiratory infections, we decided to evaluate the efficacy and safety of various NSAIDs in viral respiratory infections so that we can reach a conclusion on which NSAID is best choice for coronavirus disease 2019 (COVID-19). METHODS: A search was performed in Medline (via PubMed), Embase and CENTRAL databases until 23 March 2020. Clinical trials on application of NSAIDs in viral respiratory infections were included. RESULTS: Six clinical trials were included. No clinical trial has been performed on COVID-19, Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome infections. Studies show that ibuprofen and naproxen not only have positive effects in controlling cold symptoms, but also do not cause serious side effects in rhinovirus infections. In addition, it was found that clarithromycin, naproxen and oseltamivir combination leads to decrease in mortality rate and duration of hospitalisation in patients with pneumonia caused by influenza. CONCLUSION: Although based on existing evidence, NSAIDs have been effective in treating respiratory infections caused by influenza and rhinovirus, since there is no clinical trial on COVID-19 and case-reports and clinical experiences are indicative of elongation of treatment duration and exacerbation of the clinical course of patients with COVID-19, it is recommended to use substitutes such as acetaminophen for controlling fever and inflammation and be cautious about using NSAIDs in management of COVID-19 patients until there are enough evidence. Naproxen may be a good choice for future clinical trials.
4,128
Is there a way to distinguish COVID-19 clinically from other respiratory illnesses, particularly influenza?
No, the clinical features of COVID-19 overlap substantially with influenza and other respiratory viral illnesses. There is no way to distinguish among them without testing.
[32903584, 34016193, 33742041, 32856744, 32445165, 33537361, 32542934, 33135801, 32881022]
4,535
COVID-19 is a pandemic viral disease with catastrophic global impact. This disease is more contagious than influenza such that cluster outbreaks occur frequently. If patients with symptoms quickly underwent testing and contact tracing, these outbreaks could be contained. Unfortunately, COVID-19 patients have symptoms similar to other common illnesses. Here, we hypothesize the order of symptom occurrence could help patients and medical professionals more quickly distinguish COVID-19 from other respiratory diseases, yet such essential information is largely unavailable. To this end, we apply a Markov Process to a graded partially ordered set based on clinical observations of COVID-19 cases to ascertain the most likely order of discernible symptoms (i.e., fever, cough, nausea/vomiting, and diarrhea) in COVID-19 patients. We then compared the progression of these symptoms in COVID-19 to other respiratory diseases, such as influenza, SARS, and MERS, to observe if the diseases present differently. Our model predicts that influenza initiates with cough, whereas COVID-19 like other coronavirus-related diseases initiates with fever. However, COVID-19 differs from SARS and MERS in the order of gastrointestinal symptoms. Our results support the notion that fever should be used to screen for entry into facilities as regions begin to reopen after the outbreak of Spring 2020. Additionally, our findings suggest that good clinical practice should involve recording the order of symptom occurrence in COVID-19 and other diseases. If such a systemic clinical practice had been standard since ancient diseases, perhaps the transition from local outbreak to pandemic could have been avoided. We conducted a retrospective chart review examining the demographics, clinical history, physical findings, and comorbidities of patients with influenza and patients with coronavirus disease 2019 (COVID-19). Older patients, male patients, patients reporting fever, and patients with higher body mass indexes (BMIs) were more likely to have COVID-19 than influenza. Coronavirus disease 2019 (COVID-19) has spread in more than 100 countries and regions around the world, raising grave global concerns. COVID-19 has a similar pattern of infection, clinical symptoms, and chest imaging findings to influenza pneumonia. In this retrospective study, we analysed clinical and chest CT data of 24 patients with COVID-19 and 79 patients with influenza pneumonia. Univariate analysis demonstrated that the temperature, systolic pressure, cough and sputum production could distinguish COVID-19 from influenza pneumonia. The diagnostic sensitivity and specificity for the clinical features are 0.783 and 0.747, and the AUC value is 0.819. Univariate analysis demonstrates that nine CT features, central-peripheral distribution, superior-inferior distribution, anterior-posterior distribution, patches of GGO, GGO nodule, vascular enlargement in GGO, air bronchogram, bronchiectasis within focus, interlobular septal thickening, could distinguish COVID-19 from influenza pneumonia. The diagnostic sensitivity and specificity for the CT features are 0.750 and 0.962, and the AUC value is 0.927. Finally, a multivariate logistic regression model combined the variables from the clinical variables and CT features models was made. The combined model contained six features: systolic blood pressure, sputum production, vascular enlargement in the GGO, GGO nodule, central-peripheral distribution and bronchiectasis within focus. The diagnostic sensitivity and specificity for the combined features are 0.87 and 0.96, and the AUC value is 0.961. In conclusion, some CT features or clinical variables can differentiate COVID-19 from influenza pneumonia. Moreover, CT features combined with clinical variables had higher diagnostic performance. As coronavirus disease 2019 (COVID-19) crashed into the influenza season, clinical characteristics of both infectious diseases were compared to make a difference. We reported 211 COVID-19 patients and 115 influenza patients as two separate cohorts at different locations. Demographic data, medical history, laboratory findings, and radiological characters were summarized and compared between two cohorts, as well as between patients at the intensive care unit (ICU) andnon-ICU within the COVID-19 cohort. For all 326 patients, the median age was 57.0 (interquartile range: 45.0-69.0) and 48.2% was male, while 43.9% had comorbidities that included hypertension, diabetes, bronchitis, and heart diseases. Patients had cough (75.5%), fever (69.3%), expectoration (41.1%), dyspnea (19.3%), chest pain (18.7%), and fatigue (16.0%), etc. Both viral infections caused substantial blood abnormality, whereas the COVID-19 cohort showed a lower frequency of leukocytosis, neutrophilia, or lymphocytopenia, but a higher chance of creatine kinase elevation. A total of 7.7% of all patients possessed no abnormal sign in chest computed tomography (CT) scans. For both infections, pulmonary lesions in radiological findings did not show any difference in their location or distribution. Nevertheless, compared to the influenza cohort, the COVID-19 cohort presented more diversity in CT features, where certain specific CT patterns showed significantly more frequency, including consolidation, crazy paving pattern, rounded opacities, air bronchogram, tree-in-bud sign, interlobular septal thickening, and bronchiolar wall thickening. Differentiable clinical manifestations and CT patterns may help diagnose COVID-19 from influenza and gain a better understanding of both contagious respiratory illnesses. Coronavirus disease 2019 (COVID-19) is currently causing a pandemic and will likely persist in endemic form in the foreseeable future. Physicians need to correctly approach this new disease, often representing a challenge in terms of differential diagnosis. Although COVID-19 lacks specific signs and symptoms, we believe internists should develop specific skills to recognize the disease, learning its 'semeiotic'. In this review article, we summarize the key clinical features that may guide in differentiating a COVID-19 case, requiring specific testing, from upper respiratory and/or influenza-like illnesses of other aetiology. We consider two different clinical settings, where availability of the different diagnostic strategies differs widely: outpatient and inpatient. Our reasoning highlights how challenging a balanced approach to a patient with fever and flu-like symptoms can be. At present, clinical workup of COVID-19 remains a hard task to accomplish. However, knowledge of the natural history of the disease may aid the internist in putting common and unspecific symptoms into the correct clinical context. OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a global pandemic in early 2020 with rapidly evolving approaches to diagnosing the clinical illness called coronavirus disease (COVID-19). The primary objective of this scoping review is to synthesize current research of the diagnostic accuracy of history, physical examination, routine laboratory tests, real-time reverse transcription-polymerase chain reaction (rRT-PCR), immunology tests, and computed tomography (CT) for the emergency department (ED) diagnosis of COVID-19. Secondary objectives included a synopsis of diagnostic biases likely with current COVID-19 research as well as corresponding implications of false-negative and false-positive results for clinicians and investigators. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Scoping Review (PRISMA-ScR)-adherent synthesis of COVID-19 diagnostic accuracy through May 5, 2020, was conducted. The search strategy was designed by a medical librarian and included studies indexed by PubMed and Embase since January 2020. RESULTS: A total of 1,907 citations were screened for relevance. Patients without COVID-19 are rarely reported, so specificity and likelihood ratios were generally unavailable. Fever is the most common finding, while hyposmia and hypogeusia appear useful to rule in COVID-19. Cough is not consistently present. Lymphopenia is the mostly commonly reported laboratory abnormality and occurs in over 50% of COVID-19 patients. rRT-PCR is currently considered the COVID-19 criterion standard for most diagnostic studies, but a single test sensitivity ranges from 60% to 78%. Multiple reasons for false-negatives rRT-PCR exist, including sample site tested and disease stage during which sample was obtained. CT may increase COVID-19 sensitivity in conjunction with rRT-PCR, but guidelines for imaging patients most likely to benefit are emerging. IgM and IgG serology levels are undetectable in the first week of COVID-19, but sensitivity (range = 82% to 100%) and specificity (range = 87% to 100%) are promising. Whether detectable COVID-19 antibodies correspond to immunity remains unanswered. Current studies do not adhere to accepted diagnostic accuracy reporting standards and likely report significantly biased results if the same tests were to be applied to general ED populations with suspected COVID-19. CONCLUSIONS: With the exception of fever and disorders of smell/taste, history and physical examination findings are unhelpful to distinguish COVID-19 from other infectious conditions that mimic SARS-CoV-2 like influenza. Routine laboratory tests are also nondiagnostic, although lymphopenia is a common finding and other abnormalities may predict severe disease. Although rRT-PCR is the current criterion standard, more inclusive consensus-based criteria will likely emerge because of the high false-negative rate of PCR tests. The role of serology and CT in ED assessments remains undefined.
4,129
What is the incubation period for COVID-19?
For COVID-19, the mean incubation period was 6.0 days globally but near 7.0 days in the mainland of China, which will help identify the time of infection and make disease control decisions. The Delta VOC yielded a significantly shorter incubation period (4.0 vs. 6.0 days), higher viral load (20.6 vs. 34.0, cycle threshold of the ORF1a/b gene), and a longer duration of viral shedding in pharyngeal swab samples (14.0 vs. 8.0 days) compared with the wild-type strain.
[33643779, 32661509, 33548553, 33773195, 34423821, 33998486, 34535192, 34541481, 34886835, 32801208, 33362233, 34368314, 33832511, 33915459, 34485577, 33748041, 33706702, 33024342, 34579681, 32627172, 32848488, 33818217, 34117868, 33035373, 32594928, 34131198]
4,536
AIM: This study aims to conduct a review of the existing literature about incubation period for COVID-19, which can provide insights to the transmission dynamics of the disease. METHODS: A systematic review followed by meta-analysis was performed for the studies providing estimates for the incubation period of COVID-19. The heterogeneity and bias in the included studies were tested by various statistical measures, including I2 statistic, Cochran's Q test, Begg's test and Egger's test. RESULTS: Fifteen studies with 16 estimates of the incubation period were selected after implementing the inclusion and exclusion criteria. The pooled estimate of the incubation period is 5.74 (5.18, 6.30) from the random effects model. The heterogeneity in the selected studies was found to be 95.2% from the I2 statistic. There is no potential bias in the included studies for meta-analysis. CONCLUSION: This review provides sufficient evidence for the incubation period of COVID-19 through various studies, which can be helpful in planning preventive and control measures for the disease. The pooled estimate from the meta-analysis is a valid and reliable estimate of the incubation period for COVID-19. OBJECTIVE: The aim of this study was to explore any age-related change in the incubation period of COVID-19, specifically any difference between older (aged ≥65 years) and younger adults. METHODS: Based on online data released officially by 21 Chinese cities from January 22 to February 15, 2020, the incubation period of COVID-19 patients who had travelled to Hubei was studied according to age. Previous studies were reviewed and compared. RESULTS: The study recruited 136 COVID-19 patients who had travelled to Hubei during January 5-31, 2020, stayed for 1-2 days, and returned with symptom onset during January 10-February 6, 2020. The median age was 50.5 years (range 1-86 years), and 22 patients (16.2%) were aged ≥65 years. The age-stratified incubation period was U-shaped with higher values at extremes of age. The median COVID-19 incubation period was 8.3 (90% confidence interval [CI], 7.4-9.2) days for all patients, 7.6 (90% CI, 6.7-8.6) days for younger adults, and 11.2 (90% CI, 9.0-13.5) days for older adults. The 5th/25th/75th/90th percentiles were 2.3/5.3/11.3/14.2 days for all, 2.0/5.0/10.5/13.2 days for younger adults, and 3.1/7.8/14.4/17.0 days for older adults. There were 11 published studies on COVID-19 incubation periods up to March 30, 2020, reporting means of 1.8-7.2 days, and medians of 4-7.5 days, but there was no specific study on the effect of age on incubation period. One study showed that severe COVID-19 cases, which included more elderly patients, had longer incubation periods. CONCLUSION: Based on 136 patients with a travel history to Hubei, the epicenter of COVID-19, the COVID-19 incubation period was found to be longer in older adults. This finding has important implications for diagnosis, prevention, and control of COVID-19. Author information: (1)Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington, IN, USA. Electronic address: kejima@iu.edu. (2)Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan. (3)Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington, IN, USA. (4)Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan; Department of Applied Biological Science, Tokyo University of Science, Noda, Japan. (5)National Center for Global Health and Medicine, Tokyo, Japan. (6)Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan; Department of Applied Biological Science, Tokyo University of Science, Noda, Japan; MIRAI, JST, Saitama, Japan; Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan. (7)International Research Center for Neurointelligence, The University of Tokyo, Tokyo, Japan. (8)Graduate School of Medicine, Hokkaido University, Hokkaido, Japan. (9)Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan; MIRAI, JST, Saitama, Japan; Institute for the Advanced Study of Human Biology (ASHBi), Kyoto University, Kyoto, Japan; NEXT-Ganken Program, Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan; Science Groove Inc., Fukuoka, Japan. Electronic address: iwamishingo@gmail.com. BACKGROUND: Coronavirus disease 2019 (COVID-19) has caused a heavy disease burden globally. The impact of process and timing of data collection on the accuracy of estimation of key epidemiological distributions are unclear. Because infection times are typically unobserved, there are relatively few estimates of generation time distribution. METHODS: We developed a statistical framework to jointly estimate generation time and incubation period from human-to-human transmission pairs, accounting for sampling biases. We applied the framework on 80 laboratory-confirmed human-to-human transmission pairs in China. We further inferred the infectiousness profile, serial interval distribution, proportions of presymptomatic transmission, and basic reproduction number (R0) for COVID-19. RESULTS: The estimated mean incubation period was 4.8 days (95% confidence interval [CI], 4.1-5.6), and mean generation time was 5.7 days (95% CI, 4.8-6.5). The estimated R0 based on the estimated generation time was 2.2 (95% CI, 1.9-2.4). A simulation study suggested that our approach could provide unbiased estimates, insensitive to the width of exposure windows. CONCLUSIONS: Properly accounting for the timing and process of data collection is critical to have correct estimates of generation time and incubation period. R0 can be biased when it is derived based on serial interval as the proxy of generation time. ANTECEDENTES Y OBJETIVO: El período de incubación de la COVID-19 ayuda a determinar la duración óptima del período de cuarentena y a crear modelos predictivos de curvas de incidencia. Se han reportado resultados variables en recientes estudios y, por ello, el objetivo de esta revisión sistemática es proporcionar una estimación más precisa del período de incubación de la COVID-19. MÉTODOS: Se realizó una búsqueda bibliográfica en las bases de datos de Pubmed, Scopus/EMBASE y la Cochrane Library, incluyendo todos los estudios observacionales y experimentales que reportaban un período de incubación y que se habían publicado entre el 1 de enero y el 21 de marzo de 2020. Se estimó la media y el percentil 95 del período de incubación mediante metaanálisis, teniendo en cuenta la heterogeneidad entre los estudios y el análisis con variables moderadoras. RESULTADOS: Se incluyeron siete estudios (n = 792) en el metaanálisis. La heterogeneidad (I2 83,0%, p < 0,001) disminuyó significativamente cuando se tuvo en cuenta la calidad del estudio y el modelo estadístico utilizado como variables moderadoras (I2 15%). El período medio de incubación oscilaba entre 5,6 (IC 95%: 5,2 a 6,0) y 6,7 días (IC 95%: 6,0 a 7,4), según el modelo estadístico utilizado. El percentil 95 fue de 12,5 días cuando la edad media de los pacientes era de 60 años, aumentando un día por cada 10 años de edad. CONCLUSIÓN: Según los datos publicados sobre el período de incubación de la COVID-19, el tiempo medio entre la exposición y la aparición de los síntomas clínicos depende del modelo estadístico utilizado y el percentil 95, de la edad media de los pacientes. Se recomienda registrar el sexo y la edad en la recogida de los datos para poder analizar los posibles patrones diferenciales. BACKGROUND: The incubation period is a crucial index of epidemiology in understanding the spread of the emerging Coronavirus disease 2019 (COVID-19). In this study, we aimed to describe the incubation period of COVID-19 globally and in the mainland of China. METHODS: The searched studies were published from December 1, 2019 to May 26, 2021 in CNKI, Wanfang, PubMed, and Embase databases. A random-effect model was used to pool the mean incubation period. Meta-regression was used to explore the sources of heterogeneity. Meanwhile, we collected 11 545 patients in the mainland of China outside Hubei from January 19, 2020 to September 21, 2020. The incubation period fitted with the Log-normal model by the coarseDataTools package. RESULTS: A total of 3235 articles were searched, 53 of which were included in the meta-analysis. The pooled mean incubation period of COVID-19 was 6.0 days (95% confidence interval [CI] 5.6-6.5) globally, 6.5 days (95% CI 6.1-6.9) in the mainland of China, and 4.6 days (95% CI 4.1-5.1) outside the mainland of China (P = 0.006). The incubation period varied with age (P = 0.005). Meanwhile, in 11 545 patients, the mean incubation period was 7.1 days (95% CI 7.0-7.2), which was similar to the finding in our meta-analysis. CONCLUSIONS: For COVID-19, the mean incubation period was 6.0 days globally but near 7.0 days in the mainland of China, which will help identify the time of infection and make disease control decisions. Furthermore, attention should also be paid to the region- or age-specific incubation period. BACKGROUND: A novel variant of SARS-CoV-2, the Delta variant of concern (VOC, also known as lineage B.1.617.2), is fast becoming the dominant strain globally. We reported the epidemiological, viral, and clinical characteristics of hospitalized patients infected with the Delta VOC during the local outbreak in Guangzhou, China. METHODS: We extracted the epidemiological and clinical information pertaining to the 159 cases infected with the Delta VOC across seven transmission generations between May 21 and June 18, 2021. The whole chain of the Delta VOC transmission was described. Kinetics of viral load and clinical characteristics were compared with a cohort of wild-type infection in 2020 admitted to the Guangzhou Eighth People's Hospital. FINDINGS: There were four transmission generations within the first ten days. The Delta VOC yielded a significantly shorter incubation period (4.0 vs. 6.0 days), higher viral load (20.6 vs. 34.0, cycle threshold of the ORF1a/b gene), and a longer duration of viral shedding in pharyngeal swab samples (14.0 vs. 8.0 days) compared with the wild-type strain. In cases with critical illness, the proportion of patients over the age of 60 was higher in the Delta VOC group than in the wild-type strain (100.0% vs. 69.2%, p = 0.03). The Delta VOC had a higher risk than wild-type infection in deterioration to critical status (hazards ratio 2.98 [95%CI 1.29-6.86]; p = 0.01). INTERPRETATION: Infection with the Delta VOC is characterized by markedly increased transmissibility, viral loads and risk of disease progression compared with the wild-type strain, calling for more intensive prevention and control measures to contain future outbreaks. FUNDING: National Grand Program, National Natural Science Foundation of China, Guangdong Provincial Department of Science and Technology, Guangzhou Laboratory. BACKGROUND: COVID-19 patients with long incubation period were reported in clinical practice and tracing of close contacts, but their epidemiological or clinical features remained vague. METHODS: We analyzed 11,425 COVID-19 cases reported between January-August, 2020 in China. The accelerated failure time model, Logistic and modified Poisson regression models were used to investigate the determinants of prolonged incubation period, as well as their association with clinical severity and transmissibility, respectively. RESULT: Among local cases, 268 (10.2%) had a prolonged incubation period of > 14 days, which was more frequently seen among elderly patients, those residing in South China, with disease onset after Level I response measures administration, or being exposed in public places. Patients with prolonged incubation period had lower risk of severe illness (ORadjusted = 0.386, 95% CI: 0.203-0.677). A reduced transmissibility was observed for the primary patients with prolonged incubation period (50.4, 95% CI: 32.3-78.6%) than those with an incubation period of ≤14 days. CONCLUSIONS: The study provides evidence supporting a prolonged incubation period that exceeded 2 weeks in over 10% for COVID-19. Longer monitoring periods than 14 days for quarantine or persons potentially exposed to SARS-CoV-2 should be justified in extreme cases, especially for those elderly. OBJECTIVES: The aim of this study was to conduct a rapid systematic review and meta-analysis of estimates of the incubation period of COVID-19. DESIGN: Rapid systematic review and meta-analysis of observational research. SETTING: International studies on incubation period of COVID-19. PARTICIPANTS: Searches were carried out in PubMed, Google Scholar, Embase, Cochrane Library as well as the preprint servers MedRxiv and BioRxiv. Studies were selected for meta-analysis if they reported either the parameters and CIs of the distributions fit to the data, or sufficient information to facilitate calculation of those values. After initial eligibility screening, 24 studies were selected for initial review, nine of these were shortlisted for meta-analysis. Final estimates are from meta-analysis of eight studies. PRIMARY OUTCOME MEASURES: Parameters of a lognormal distribution of incubation periods. RESULTS: The incubation period distribution may be modelled with a lognormal distribution with pooled mu and sigma parameters (95% CIs) of 1.63 (95% CI 1.51 to 1.75) and 0.50 (95% CI 0.46 to 0.55), respectively. The corresponding mean (95% CIs) was 5.8 (95% CI 5.0 to 6.7) days. It should be noted that uncertainty increases towards the tail of the distribution: the pooled parameter estimates (95% CIs) resulted in a median incubation period of 5.1 (95% CI 4.5 to 5.8) days, whereas the 95th percentile was 11.7 (95% CI 9.7 to 14.2) days. CONCLUSIONS: The choice of which parameter values are adopted will depend on how the information is used, the associated risks and the perceived consequences of decisions to be taken. These recommendations will need to be revisited once further relevant information becomes available. Accordingly, we present an R Shiny app that facilitates updating these estimates as new data become available. OBJECTIVE: To estimate the incubation period of Vietnamese confirmed COVID-19 cases. METHODS: Only confirmed COVID-19 cases who are Vietnamese and locally infected with available data on date of symptom onset and clearly defined window of possible SARS-CoV-2 exposure were included. We used three parametric forms with Hamiltonian Monte Carlo method for Bayesian Inference to estimate incubation period for Vietnamese COVID-19 cases. Leave-one-out Information Criterion was used to assess the performance of three models. RESULTS: A total of 19 cases identified from 23 Jan 2020 to 13 April 2020 was included in our analysis. Average incubation periods estimated using different distribution model ranged from 6.0 days to 6.4 days with the Weibull distribution demonstrated the best fit to the data. The estimated mean of incubation period using Weibull distribution model was 6.4 days (95% credible interval (CrI): 4.89-8.5), standard deviation (SD) was 3.05 (95%CrI 3.05-5.30), median was 5.6, ranges from 1.35 to 13.04 days (2.5th to 97.5th percentiles). Extreme estimation of incubation periods is within 14 days from possible infection. CONCLUSION: This analysis provides evidence for an average incubation period for COVID-19 of approximately 6.4 days. Our findings support existing guidelines for 14 days of quarantine of persons potentially exposed to SARS-CoV-2. Although for extreme cases, the quarantine period should be extended up to three weeks. BACKGROUND: As a highly contagious disease, coronavirus disease 2019 (COVID-19) is wreaking havoc around the world due to continuous spread among close contacts mainly via droplets, aerosols, contaminated hands or surfaces. Therefore, centralized isolation of close contacts and suspected patients is an important measure to prevent the transmission of COVID-19. At present, the quarantine duration in most countries is 14 d due to the fact that the incubation period of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is usually identified as 1-14 d with median estimate of 4-7.5 d. Since COVID-19 patients in the incubation period are also contagious, cases with an incubation period of more than 14 d need to be evaluated. CASE SUMMARY: A 70-year-old male patient was admitted to the Department of Respiratory Medicine of The First Affiliated Hospital of Harbin Medical University on April 5 due to a cough with sputum and shortness of breath. On April 10, the patient was transferred to the Fever Clinic for further treatment due to close contact to one confirmed COVID-19 patient in the same room. During the period from April 10 to May 6, nucleic acid and antibodies to SARS-CoV-2 were tested 7 and 4 times, respectively, all of which were negative. On May 7, the patient developed fever with a maximum temperature of 39℃, and his respiratory difficulties had deteriorated. The results of nucleic acid and antibody detection of SARS-CoV-2 were positive. On May 8, the nucleic acid and antibody detection of SARS-CoV-2 by Heilongjiang Provincial Center for Disease Control were also positive, and the patient was diagnosed with COVID-19 and reported to the Chinese Center for Disease Control and Prevention. CONCLUSION: This case highlights the importance of the SARS-CoV-2 incubation period. Further epidemiological investigations and clinical observations are urgently needed to identify the optimal incubation period of SARS-CoV-2 and formulate rational and evidence-based quarantine policies for COVID-19 accordingly. BACKGROUND: The aim of our study was to determine through a systematic review and meta-analysis the incubation period of COVID-19. It was conducted based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Criteria for eligibility were all published population-based primary literature in PubMed interface and the Science Direct, dealing with incubation period of COVID-19, written in English, since December 2019 to December 2020. We estimated the mean of the incubation period using meta-analysis, taking into account between-study heterogeneity, and the analysis with moderator variables. RESULTS: This review included 42 studies done predominantly in China. The mean and median incubation period were of maximum 8 days and 12 days respectively. In various parametric models, the 95th percentiles were in the range 10.3-16 days. The highest 99th percentile would be as long as 20.4 days. Out of the 10 included studies in the meta-analysis, 8 were conducted in China, 1 in Singapore, and 1 in Argentina. The pooled mean incubation period was 6.2 (95% CI 5.4, 7.0) days. The heterogeneity (I2 77.1%; p < 0.001) was decreased when we included the study quality and the method of calculation used as moderator variables (I2 0%). The mean incubation period ranged from 5.2 (95% CI 4.4 to 5.9) to 6.65 days (95% CI 6.0 to 7.2). CONCLUSIONS: This work provides additional evidence of incubation period for COVID-19 and showed that it is prudent not to dismiss the possibility of incubation periods up to 14 days at this stage of the epidemic. Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, was first reported in December 2019 in Wuhan, Hubei province, China. It is now known as a pandemic and a global crisis due to rapid human-to-human transmission with the vast expansion that has affected almost all countries. The primary source of the disease is still unknown, but it is possible that the virus was transmitted through bat to an intermediate host and then to humans. The main and early symptoms of COVID-19 infection are fatigue, fever, dry cough, myalgia, and dyspnea. The incubation period of the disease is about 2-14 days, which is one of the important parameters for planning to prevent disease outbreak. PT-polymerase chain reaction test is used to diagnose the disease; chest computed tomography scan, chest X-ray, blood tests, and symptoms are also very helpful in diagnosing the disease. There is a strong emphasis on controlling infections and hand hygiene to prevent the transmission of the disease. There is not enough knowledge about this disease yet, and there are no specific vaccines or medications available to prevent and treat this disease. The current review study uses articles indexed on databases of Embase, Elsevier, PubMed, and World Health Organization and Centers for Disease Control and Prevention, and keywords of coronavirus, COVID-19, acute respiratory distress syndrome and China. SARS-CoV-2, a member of the family coronaviridae, has triggered a lethal pandemic termed coronavirus disease 2019 (COVID-19). Pediatric patients, mainly from families with a cluster of infection or a history of exposure to epidemic areas, get infected via direct contacts or air-borne droplets. Children (aged below 18 years) are susceptible to COVID-19, with an average incubation period of about 6.5 days. Most cases present asymptomatic or common cold symptoms such as fever, cough, and myalgia or fatigue, which is milder than adult patients. Besides, most abnormal laboratory and radiologic findings in children with COVID-19 are non-specific. Since no specific chemotherapeutic agents have been approved for children, timely preventive methods could effectively forestall the transmission of SARS-CoV-2. To date, mostly studied cases have been adults with COVID-19, whereas data on pediatrics patients remain poorly defined. We herein conducted a literature review for papers published in PubMed and medRxiv (preprints) between December 2019 and December 2020 that reported on pediatrics patients (aged below 18 years) with a confirmed COVID-19 diagnosis. In this review, we summarized and discussed the pathogenesis, epidemiology, and clinical management of COVID-19 in pediatrics patients to improve our understanding of this new disease in children. BACKGROUND: Understanding the epidemiological parameters that determine the transmission dynamics of COVID-19 is essential for public health intervention. Globally, a number of studies were conducted to estimate the average serial interval and incubation period of COVID-19. Combining findings of existing studies that estimate the average serial interval and incubation period of COVID-19 significantly improves the quality of evidence. Hence, this study aimed to determine the overall average serial interval and incubation period of COVID-19. METHODS: We followed the PRISMA checklist to present this study. A comprehensive search strategy was carried out from international electronic databases (Google Scholar, PubMed, Science Direct, Web of Science, CINAHL, and Cochrane Library) by two experienced reviewers (MAA and DBK) authors between the 1st of June and the 31st of July 2020. All observational studies either reporting the serial interval or incubation period in persons diagnosed with COVID-19 were included in this study. Heterogeneity across studies was assessed using the I2 and Higgins test. The NOS adapted for cross-sectional studies was used to evaluate the quality of studies. A random effect Meta-analysis was employed to determine the pooled estimate with 95% (CI). Microsoft Excel was used for data extraction and R software was used for analysis. RESULTS: We combined a total of 23 studies to estimate the overall mean serial interval of COVID-19. The mean serial interval of COVID-19 ranged from 4. 2 to 7.5 days. Our meta-analysis showed that the weighted pooled mean serial interval of COVID-19 was 5.2 (95%CI: 4.9-5.5) days. Additionally, to pool the mean incubation period of COVID-19, we included 14 articles. The mean incubation period of COVID-19 also ranged from 4.8 to 9 days. Accordingly, the weighted pooled mean incubation period of COVID-19 was 6.5 (95%CI: 5.9-7.1) days. CONCLUSIONS: This systematic review and meta-analysis showed that the weighted pooled mean serial interval and incubation period of COVID-19 were 5.2, and 6.5 days, respectively. In this study, the average serial interval of COVID-19 is shorter than the average incubation period, which suggests that substantial numbers of COVID-19 cases will be attributed to presymptomatic transmission. BACKGROUND: Factors associated with the incubation period of COVID-19 are not fully known. The aim of this study was to estimate the incubation period of COVID-19 using epidemiological contact tracing data, and to explore whether there were different incubation periods among different age gr1oups. METHODS: We collected contact tracing data in a municipality in Hubei province during the full outbreak period of COVID-19. The exposure periods were inferred from the history of travel in Wuhan and/or history of exposure to confirmed cases. The incubation periods were estimated using parametric accelerated failure time models accounting for interval censoring of exposures. RESULTS: The incubation period of COVID-19 follows a Weibull distribution and has a median of 5.8 days with a bootstrap 95% CI: 5.4-6.7 days. Of the symptomatic cases, 95% showed symptoms by 14.3 days (95% CI: 13.0-15.7), and 99% showed symptoms by 18.7 days (95% CI: 16.7-20.9). The incubation periods were not found significantly different between male and female. Elderly cases had significant longer incubation periods than young age cases (HR 1.49 with 95% CI: 1.09-2.05). The median incubation period was estimated at 4.0 days (95% CI: 3.5-4.4) for cases aged under 30, 5.8 days (95% CI: 5.6-6.0) for cases aged between 30 and 59, and 7.7 days (95% CI: 6.9-8.4) for cases aged greater than or equal to 60. CONCLUSION: The current practice of a 14-day quarantine period in many regions is reasonable for any age. Older people infected with SARS-CoV2 have longer incubation period than that of younger people. Thus, more attention should be paid to asymptomatic elderly people who had a history of exposure. The COVID-19 pandemic has been causing serious disasters to mankind. The incubation period is a key parameter for epidemic control and also an important basis for epidemic prediction, but its distribution law remains unclear. This paper analyzed the epidemiological information of 787 confirmed non-Wuhan resident cases, and systematically studied the characteristics of the incubation period of COVID-19 based on the interval-censored data estimation method. The results show that the incubation period of COVID-19 approximately conforms to the Gamma distribution with a mean value of 7.8 (95%CI:7.4-8.5) days and a median value of 7.0 (95%CI:6.7-7.3) days. The incubation period was positively correlated with age and negatively correlated with disease severity. Female cases presented a slightly higher incubation period than that of males. The proportion of infected persons who developed symptoms within 14 days was 91.6%. These results are of great significance to the prevention and control of the COVID-19 pandemic. Incubation period is an important parameter to inform quarantine period and to study transmission dynamics of infectious diseases. We conducted a systematic review and meta-analysis on published estimates of the incubation period distribution of coronavirus disease 2019, and showed that the pooled median of the point estimates of the mean, median and 95th percentile for incubation period are 6.3 days (range, 1.8-11.9 days), 5.4 days (range, 2.0-17.9 days), and 13.1 days (range, 3.2-17.8 days), respectively. Estimates of the mean and 95th percentile of the incubation period distribution were considerably shorter before the epidemic peak in China compared to after the peak, and variation was also noticed for different choices of methodological approach in estimation. Our findings implied that corrections may be needed before directly applying estimates of incubation period into control of or further studies on emerging infectious diseases. We compared clinical symptoms, laboratory findings, radiographic signs and outcomes of COVID-19 and influenza to identify unique features. Depending on the heterogeneity test, we used either random or fixed-effect models to analyse the appropriateness of the pooled results. Overall, 540 articles included in this study; 75,164 cases of COVID-19 (157 studies), 113,818 influenza type A (251 studies) and 9266 influenza type B patients (47 studies) were included. Runny nose, dyspnoea, sore throat and rhinorrhoea were less frequent symptoms in COVID-19 cases (14%, 15%, 11.5% and 9.5%, respectively) in comparison to influenza type A (70%, 45.5%, 49% and 44.5%, respectively) and type B (74%, 33%, 38% and 49%, respectively). Most of the patients with COVID-19 had abnormal chest radiology (84%, p < 0.001) in comparison to influenza type A (57%, p < 0.001) and B (33%, p < 0.001). The incubation period in COVID-19 (6.4 days estimated) was longer than influenza type A (3.4 days). Likewise, the duration of hospitalization in COVID-19 patients (14 days) was longer than influenza type A (6.5 days) and influenza type B (6.7 days). Case fatality rate of hospitalized patients in COVID-19 (6.5%, p < 0.001), influenza type A (6%, p < 0.001) and influenza type B was 3%(p < 0.001). The results showed that COVID-19 and influenza had many differences in clinical manifestations and radiographic findings. Due to the lack of effective medication or vaccine for COVID-19, timely detection of this viral infection and distinguishing from influenza are very important. A novel coronavirus disease, designated as COVID-19, has become a pandemic worldwide. This study aims to estimate the incubation period and serial interval of COVID-19. We collected contact tracing data in a municipality in Hubei province during a full outbreak period. The date of infection and infector-infectee pairs were inferred from the history of travel in Wuhan or exposed to confirmed cases. The incubation periods and serial intervals were estimated using parametric accelerated failure time models, accounting for interval censoring of the exposures. Our estimated median incubation period of COVID-19 is 5.4 days (bootstrapped 95% confidence interval (CI) 4.8-6.0), and the 2.5th and 97.5th percentiles are 1 and 15 days, respectively; while the estimated serial interval of COVID-19 falls within the range of -4 to 13 days with 95% confidence and has a median of 4.6 days (95% CI 3.7-5.5). Ninety-five per cent of symptomatic cases showed symptoms by 13.7 days (95% CI 12.5-14.9). The incubation periods and serial intervals were not significantly different between male and female, and among age groups. Our results suggest a considerable proportion of secondary transmission occurred prior to symptom onset. And the current practice of 14-day quarantine period in many regions is reasonable. We propose a novel model based on a set of coupled delay differential equations with fourteen delays in order to accurately estimate the incubation period of COVID-19, employing publicly available data of confirmed corona cases. In this goal, we separate the total cases into fourteen groups for the corresponding fourteen incubation periods. The estimated mean incubation period we obtain is 6.74 days (95% Confidence Interval(CI): 6.35 to 7.13), and the 90th percentile is 11.64 days (95% CI: 11.22 to 12.17), corresponding to a good agreement with statistical supported studies. This model provides an almost zero-cost computational complexity to estimate the incubation period.
4,130
What is Guillain-Barre syndrome (GBS)?
Guillain-Barré syndrome (GBS) is an acute immune mediated neuropathy, polyradiculoneuritis, characterized by rapid onset of symmetric extremity muscle paralysis, areflexia and albuminocytological dissociation in the cerebrospinal fluid (CSF). Recently, the heterogeneity of GBS has been noticed with definition of several GBS variants. The diagnosis of GBS includes clinical, electrophysiological and laboratory (CSF) criteria.
[34434441, 30895887, 12690329, 26793497, 24511391, 31639842, 19202218, 28968363, 26560944, 23087283, 32537271, 23431480, 12134330, 15168961, 24872655, 16708185, 8478553, 12415961, 15018590, 23642721, 32192609, 9365863, 15921641, 16206698, 30069105, 20508277, 33002998, 23117942, 24731000]
4,537
Guillain-Barre Syndrome is a well described acute demyelinating polyradiculoneuropathy with a likely autoimmune basis characterized by progressive ascending muscle paralysis. Classically, GBS is attributed to antecedent upper respiratory and gastrointestinal infections. We present the first case of GBS after Robotically Assisted Laparoscopic Prostatectomy using the daVinci(®) Surgical System. Guillain-Barré syndrome (GBS) was first described in 1916 (Guillain G, 1916) and is approaching its 100th anniversary. Our knowledge of the syndrome has hugely expanded since that time. Once originally considered to be only demyelinating in pathology we now recognise both axonal and demyelinating subtypes. Numerous triggering or antecedent events including infections are recognised and GBS is considered an immunological response to these. GBS is now considered to be a clinical syndrome of an acute inflammatory neuropathy encompassing a number of subtypes with evidence of different immunological mechanisms. Some of these are clearly understood while others remain to be fully elucidated. Complement fixing antibodies against peripheral nerve gangliosides alone and in combination are increasingly recognised as an important mechanism of nerve damage. New antibodies against other nerve antigens such as neurofascin have been recently described. Research databases have been set up to look at factors associated with prognosis and the influence of intravenous immunoglobulin (IvIg) pharmacokinetics in therapy. Exciting new studies are in progress to examine a possible role for complement inhibition in the treatment of the syndrome. Guillain-Barre syndrome (GBS) is the leading cause of acute paralysis that can potentially affect all of the human population. GBS is believed to be an immune-mediated disease, possibly triggered by a recent infection, and driven by an immune attack targeting the peripheral nervous system. GBS can be divided into several subtypes depending on the phenotype, pathophysiology, and neurophysiological features. Unfortunately, morbidity and mortality rates are still high despite the current understanding of the pathophysiology and available treatment options. Additional research is still needed to shed more light into the pathogenesis for a better understanding and treatment of this condition. Acute Inflammatory Demyelinating Polyneuropathy--Guillain-Barre syndrome (GBS) affects spinal roots, peripheral and cranial nerves. Various clinical variants of GBS have been described. Isolated cranial nerve involvement without prominent signs of GBS is considered as rare variant of this disease. The aim of the study was to identify clinical characteristics of various forms of GBS particularly in rare variants of the disease. 57 patients with GBS were evaluated based on clinical and electrophysiological data. The following forms of GBS were revealed: 27 had acute inflammatory demyelinating polyradiculoneuropathy, 9--acute motor axonal neuropathy, 12--acute motor and sensory axonal neuropathy, 5--Fisher syndrome and 3--facial diplegia (rare clinical variant). 50 patients were graded 3 or more according to Hughes functional grading scale. Seasonal preponderance was found in spring (March-May) and autumn (September-November). 23 patients received IVIG and 34 were treated by plasma exchange within two weeks after onset. Follow up study revealed: 46 recovered satisfactory, 8 were persistently disabled, 3 died during admission to hospital. Guillain-Barre syndrome showed seasonal distribution and high frequency of axonal forms. Intravenous immunoglobulin therapy was more effective than plasma exchange. Poor outcomes were likely due to severe condition (required mechanical ventilation) and axonal forms. It is crucial to timely identify rare variants of GBS which recover with appropriate treatment. PURPOSE OF REVIEW: This article reviews the current state of Guillain-Barré syndrome (GBS), including its clinical presentation, evaluation, pathophysiology, and treatment. RECENT FINDINGS: GBS is an acute/subacute-onset polyradiculoneuropathy typically presenting with sensory symptoms and weakness over several days, often leading to quadriparesis. Approximately 70% of patients report a recent preceding upper or lower respiratory tract infection or gastrointestinal illness. Approximately 30% of patients require intubation and ventilation because of respiratory failure. Nerve conduction studies in the acute inflammatory demyelinating polyradiculoneuropathy (AIDP) form of GBS typically show evidence for a multifocal demyelinating process, including conduction block or temporal dispersion in motor nerves. Sural sparing is a common phenomenon when testing sensory nerves. CSF analysis commonly shows an elevated protein, but this elevation may not be present until the third week of the illness. Patients with AIDP are treated with best medical management and either IV immunoglobulin (IVIg) or plasma exchange. SUMMARY: GBS is a common form of acute quadriparesis; a high level of suspicion is needed for early diagnosis. With appropriate therapy, most patients make a very good to complete recovery. Guillain-Barré syndrome (GBS) is an acute self-limited polyneuropathy named after Guillain, Barré, and Strohl, who first reported it in 1916. GBS was considered a demyelinating disease until the 1980s, when the acute axonal type of GBS was first reported. Since then, acute inflammatory demyelinating polyneuropathy and acute motor axonal neuropathy have been considered the two main subtypes of GBS. Autoimmunity underlies the pathogenesis of GBS. The presence of antibodies against various glycolipids in the acute-phase sera from patients with GBS has frequently been reported since the late 1980s. The effectiveness of plasmapheresis and intravenous immunoglobulin therapy has been established since the mid-1980s. However, severe or refractory cases still occur and further investigation is necessary for the development of novel treatments that are effective for such cases. Guillain-Barre syndrome (GBS) is a postinfectious, autoimmune disorder which, apart from limb weakness, is characterised by cranial nerve involvement. Bilateral facial nerve palsy is the most common pattern of cranial nerve involvement in GBS. However, unilateral facial palsy, although uncommon, can be seen in GBS. We report a rare case of unilateral facial palsy in GBS and importance of electrophysiological tests including blink study in such cases has been emphasised. Objective Guillain Barre syndrome (GBS) is an autoimmune-mediated, acute, symmetrical, flaccid paralysis. Guillain Barre syndrome has different electrophysiological types that carry prognostic significance and tend to differ between adults and children. This study aims to compare the clinical outcome of Guillain Barre syndrome in Pakistani children based on their electrophysiological types to help in understanding and predicting the prognosis. Study design Observational comparative study Place & duration The pediatric department, Shifa International Hospital, Islamabad; all patients with Guillain Barre syndrome seen between 2012 and 2019 Method All children aged one to 16 years in whom Guillain Barre syndrome was diagnosed based on clinical history, examination, and electrophysiological findings. Institutional review board (IRB) approval was taken and data entered on the designed questionnaire. Chi-square and non-parametric tests were applied for significant association. Results Twenty-three children were included in the study. Of these, 14 were males (60.9%) while the mean age was 5.8 (+4.5) years. Acute inflammatory demyelinating polyneuropathy (AIDP) was found to be the predominant type (9; 39.1%) followed by acute motor and sensory axonal neuropathy (AMSAN) (6; 26.1%), Acute motor axonal neuropathy (AMAN) was diagnosed in four (17.4%) patients. Six (26.1%) patients needed mechanical ventilation and 10 patients (43.5%) required intensive care unit (ICU) care. The majority of the patients (18; 78.3%) received intravenous immunoglobulin (IVIG). Conclusion The study highlights varied electrophysiological types of GBS in Pakistani children, which differ in predominance from previous studies. However, various indicators of poor outcomes that are highlighted in adults, including the older age group, need for mechanical ventilation, and electrophysiological evidence of axonal degeneration, were not significant predictors of outcome in children. OBJECTIVE: To review about this disorder, with emphasis on the intensive care of severe Guillain Barr syndrome (GBS). DEVELOPMENT: GBS is an acute immune mediated inflammatory polyneuropathy that may lead to quadriparesis, ventilatory failure, and autonomic dysfunction but also to many general medical problems that have great bearing on outcome. Therefore severe GBS patients require admission into an intensive care unit (ICU), where in addition to the disorders mentioned before, other complications can arise. The neurologist who plans to deal comprehensively with these patients must be familiar with therapy for infections, nutrition, fluid management, and selected aspects of pulmonary medicine as well as the indications for and complications of plasma exchange and gammaglobulin infusion. CONCLUSIONS: With modern intensive care support, the outcome is excellent (>80% recovery), although in many cases a persistent residual paresis occurs. Because GBS is largely self limited, the skill daily cares of these patients in an ICU contributes as much, or more, to the overall outcome of an individual patient as do specific immune therapies. Guillain-Barré syndrome (GBS) is an autoimmune acute peripheral neuropathy. Frequently a flu-like episode or a gastroenteritis precede GBS, and the cross-reactivity between microbial and neural antigens partly explains the pathophysiology of the disease and the possible detection of antiganglioside antibodies. The weakness reaches its nadir in 2-4 weeks: the patients may be chair- or bed-bound, may need artificial ventilation and frequently experience dysautonomic dysfunction; 5-15% of the patients die and more patients are left with a disabling motor deficit and/or fatigue. Electrophysiology and cerebrospinal fluid evaluation support the diagnosis. The treatment of GBS is multidisciplinary, and both plasma exchange and high dose immunoglobulin (IVIg) are effective in reducing both the severity of the disease and the residual deficits. Finally, steroids are not effective in GBS. Guillain-Barré syndrome (GBS) is a complicated degenerative disorder which can be chronic or acute in nature. Its etiology is unclear although it has been associated with both cell- and humoral-mediated autoimmune mechanisms. Pathophysiologic effects of the disease include inflammation, demyelination of peripheral nerves, loss of granular bodies and degeneration of the basement membrane of the Schwann cell. This results in ascending paralysis and loss of cranial nerve function. Manifestations may be acute or chronic, and temporary or permanent, depending upon the degree of neuronal destruction. Due to the pervasive nature of GBS, nursing care is a challenge. Assessment of motor, respiratory and cardiac function is of key importance. Total care of the patient focuses on risks related to impaired mobility and ineffective airway clearance. Psychosocial care and patient education are also integral components of care. Guillain-Barré syndrome (GBS) is clinically defined as an acute peripheral neuropathy causing limb weakness that progresses over a time period of days or, at the most, up to 4 weeks. GBS occurs throughout the world with a median annual incidence of 1.3 cases per population of 100 000, with men being more frequently affected than women. GBS is considered to be an autoimmune disease triggered by a preceding bacterial or viral infection. Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus and Mycoplasma pneumoniae are commonly identified antecedent pathogens. In the acute motor axonal neuropathy (AMAN) form of GBS, the infecting organisms probably share homologous epitopes to a component of the peripheral nerves (molecular mimicry) and, therefore, the immune responses cross-react with the nerves causing axonal degeneration; the target molecules in AMAN are likely to be gangliosides GM1, GM1b, GD1a and GalNAc-GD1a expressed on the motor axolemma. In the acute inflammatory demyelinating polyneuropathy (AIDP) form, immune system reactions against target epitopes in Schwann cells or myelin result in demyelination; however, the exact target molecules in the case of AIDP have not yet been identified. AIDP is by far the most common form of GBS in Europe and North America, whereas AMAN occurs more frequently in east Asia (China and Japan). The prognosis of GBS is generally favourable, but it is a serious disease with a mortality of approximately 10% and approximately 20% of patients are left with severe disability. Treatment of GBS is subdivided into: (i) the management of severely paralysed patients with intensive care and ventilatory support; and (ii) specific immunomodulating treatments that shorten the progressive course of GBS, presumably by limiting nerve damage. High-dose intravenous immunoglobulin (IVIg) therapy and plasma exchange aid more rapid resolution of the disease. The predominant mechanisms by which IVIg therapy exerts its action appear to be a combined effect of complement inactivation, neutralisation of idiotypic antibodies, cytokine inhibition and saturation of Fc receptors on macrophages. Corticosteroids alone do not alter the outcome of GBS. Guillain-Barré syndrome (GBS) is characterized by rapidly evolving ascending weakness, mild sensory loss, and hyporeflexia or areflexia. Acute inflammatory demyelinating polyneuropathy was the first to be recognized over a century ago and is the most common form of GBS. Axonal motor and sensorimotor variants have been described in the last three decades and are mediated by molecular mimicry targeting peripheral nerve motor axons. Other rare phenotypic variants have been recently described with pure sensory variant, restricted autonomic manifestations, and the pharyngeal-cervical-brachial pattern. It is important to recognize GBS and its variants because of the availability of equally effective therapies in the form of plasmapheresis and intravenous immunoglobulins. Guillain-Barre syndrome (GBS) is a life-threatening immune-mediated acute inflammatory polyneuropathy and is associated with various antecedent infections. Its association with tuberculosis is very uncommon with only a handful of cases being reported in the literature. It's association with tuberculous meningitis is even more scarce with only one case reported in literature till date. We report a 40-year-old lady with GBS associated with tuberculous meningitis. GBS was confirmed with clinical examination and nerve conduction studies. Acute Guillain-Barre syndrome (GBS) is a demyelinating polyneuropathy which responds readily to plasma exchange (PEX). According to the North American Acute GBS PEX study there is a 50% or more reduction in the recovery time if PEX is initiated early in the course of the disease. Demyelinating antibodies are usually IgM. IgA antibodies require prolonged PEX. Patients with predominant IgG antibodies have chronic inflammatory demyelinating polyneuropathy (CIDP), which requires an even longer course of PEX, over weeks to months or years. We reviewed records of 73 patients with the initial diagnosis of GBS treated with PEX. Among these patients, 55 had classic GBS, three had the Miller-Fisher variant, two had CIDP, and 13 had demyelinating-like polyneuropathies associated with other conditions including malignancy, vaccine-related myelitis, steroid-induced myopathy, polymyositis, botulism, gram-negative sepsis, Sjogren's, and AIDS. Hughes grading system was used. Patients were graded 3 to 5, with grade 3 patients being unable to walk 5 m without support, grade 4 patients being bed or chair bound, and grade 5 patients being ventilator dependent. Of 60 unassociated (GBS) demyelinating cases receiving a mean of 6.5 PEX procedures, 13 (21%) were intubated early in the treatment, with four (6%) remaining ventilator dependent post-PEX. Of 51 non-intubated patients, 15 became ambulatory post-PEX. Patients with the Miller-Fisher variant showed improvement within 6 hours of PEX initiation. We did not investigate correlation of GBS with infection; however, we did observe a rise in CMV titer among 15% of the 58 patients with acute GBS. Considering our results we believe that intensive PEX on a daily basis for a few days is necessary for severely affected individuals. We advise five to nine procedures at consultation unless early, rapid recovery occurs. Guillain-Barré syndrome (GBS) is an autoimmune disease that leads to an axonal demyelination and/or degeneration of peripheral nerves through molecular mimicry. The usual pattern is an ascending areflexic motor paralysis with a distinct cerebral-spinal fluid (CSF) showing elevated protein level without accompanying pleocytosis. Diagnosis is essentially clinical, but the CSF studies and electrodiagnostic features may help confirming the diagnosis. Prognosis is usually good, with complete recovery in 80-85% of the cases. However, 10% will remain with permanent neurological damage and about 5% will die. Immunomodulation is the goal treatment, but supportive care is of the utmost importance in the treatment and prevention of complications. The purpose of this work was to review all GBS diagnosed between 1st January 1997 and 31st December 2001, in patients 18 or older admitted to Hospital Pedro Hispano (Portugal). During the 5-year study period, 62446 patients were admitted to hospital, of which 15 with GBS. Thirteen had a good evolution: 10 with total recovery over a period of a maximum of six months; one remain with serious neurological damage at 2 years of evolution and the remaining one died with a pure motor form of GBS (both had a previous gastrointestinal infection). The results of this review are in accordance with what is described in the literature, regarding incidence, epidemiological data and clinical behaviour. Guillain-Barré syndrome (GBS) is an acute immune mediated neuropathy, polyradiculoneuritis, characterized by rapid onset of symmetric extremity muscle paralysis, areflexia and albuminocytological dissociation in the cerebrospinal fluid (CSF). Recently, the heterogeneity of GBS has been noticed with definition of several GBS variants. The axonal GBS associated with anti-GM1 antibodies is the most important variant with the specific role of Campylobacterjejuni (CJ) in the induction of the disease. The role of our study was to determine the frequency of antecedent infection with CJ in the population of our patients with GBS, the association with anti-GM1 antibodies and the distribution of these antibodies within clinical forms of the disease. The diagnosis of GBS has been established in 17 patients according to clinical, electrophysiological and laboratory (CSF) criteria. The serum antibodies to 63 kDa flagellar protein isolated from CJ serotype 0:19 were determined by ELISA and Western blot and serum anti-GM1 antibodies by ELISA. In relation to the disability score two patients were ambulatory, five were ambulatory with support, seven were bedridden and two patients needed respirator. Five (29%) patients had pure motor, while 12 (71%) had sensorimotor GBS. The cranial nerves were involved in 11 (65%) and 9 (53%) patients had autonomic dysfunction. Electromyoneurography showed primary axonal, predominantly motor neuropathy in 6 (35%) and demyelinating sensorimotor neuropathy in 11 (65%) patients. The CSF protein content ranged from 0.47 to 3.88 g/L. The antecedent infection with CJ was shown by serum antibodies to CJ flagellar protein in 12 (71%) patients. Fifteen (88%) patients had IgG anti-GM1 antibodies. Twelve (71%) patients had both antibodies. In relation to the clinical form, anti-CJ antibodies were found in 8 (73%) out of 11 patients with demyelinating GBS and in 4 (66.6%) out of 6 patients with axonal GBS. The high titer of anti-GM1 antibodies was found in all patients (100%) with axonal and in 9 (82%) out of 11 patients with demyelinating GBS. The association of IgG anti-CJ and IgG anti-GM1 antibodies was found in 4 (66.6%) out of 6 patients with axonal and in 8 (73%) out of 11 patients with demyelinating GBS. The main features of our patients with GBS were high frequency of antecedent infection with CJ, unusually frequent association with anti-GM1 antibodies, and equally frequent association of anti-CJ and anti-GM1 antibodies in both, axonal and demyelinating GBS. Guillain-Barre syndrome (GBS) is an autoimmune polyradiculoneuropathy usually preceded by respiratory tract or gastrointestinal infection. The pathogenesis in GBS is based on molecular mimicry mechanism. Hansen's disease is common in India and is the most common infectious cause of neuropathy. We describe a 42-year-old man who was being treated for borderline tuberculoid leprosy and developed Type 1 lepra reaction followed by GBS and responded to plasmapheresis. Lepra reaction may lead to exposure of neural antigens, resulting in autoimmune mechanism and demyelination of peripheral nerves. Guillain-Barré syndrome (GBS) is an autoimmune and post-infectious immune disease. The syndrome includes several pathological subtypes, the most common of which is a multifocal demyelinating disorder of the peripheral nerves. In the present review, the main clinical aspects and the basic features of GBS are discussed along with approaches to diagnosis and treatment. Furthermore, the pathophysiology of GBS is reviewed, with an emphasis on the production of symptoms and the course of the disease. Guillain-Barré syndrome (GBS) is an acute inflammatory polyradiculoneuropathy, which has various clinical presentations and both axonal and demyelinating forms. The original description of "ascending paralysis" encompasses the most common varieties: the primary demyelinating form, acute inflammatory demyelinating polyneuropathy (AIDP), and some of the axonal forms, acute motor axonal neuropathy (AMAN) and acute motor and sensory axonal neuropathy (AMSAN). However, there are now well-documented acute "monophasic" polyneuropathies that have a different clinical phenomenology than that described originally by Guillain, Barré, and Strohl: Miller Fisher syndrome, pure sensory neuropathy/neuronopathy, pandysautonomia, and oropharyngeal variant. Here the authors review both typical GBS (AIDP, AMAN, and AMSAN), and variant syndromes with a focus on clinical and diagnostic features, pathologic findings, pathogenesis, and treatment. Guillain-Barré syndrome (GBS) is an autoimmune polyneuropathy which presents with acute onset and rapid progression of flaccid, hyporeflexi quadriparesis. Both sensory and autonomic nerve involvement is seen. GBS has various subtypes that vary in their pathophysiology. The pathogenesis involves an immune response triggered by a preceding event which may be an infection, immunisation or surgical procedure. Clinical diagnosis has been largely the primary diagnosing criterion for GBS along with electrodiagnosis, which has several pitfalls and is supported by ancillary testing of cerebrospinal fluid (CSF) analysis and Nerve Conduction Studies. Measurement of anti-ganglioside antibodies is also an effective tool in its diagnosis. Further understanding of pathophysiology and better diagnostic methods are required for better management of GBS.
4,131
Is lumbar puncture the first test that should be performed on a patient with increased intracranial pressure?
No. A lumbar puncture is contraindicated in any patient with signs of increased intracranial pressure because it may precipitate cerebral herniation and death. For this reason, a computed tomography (CT) or magnetic resonance imaging (MRI) scan is done first. When the findings of the scan are normal, a lumbar puncture can be performed, if needed.
[21541088, 11985377, 3550721, 10608260, 2277190, 28965126, 3520526, 5763958, 25685562, 21129599]
4,538
OBJECTIVE: To assess the usage of cranial computed tomography (CT) in patients admitted with meningitis. DESIGN: Retrospective study. SETTING: Heart of England NHS foundation trust, a teaching hospital in the West Midlands. PARTICIPANTS: Two groups of adult patients admitted with meningitis between April 2001 and September 2004 and from September 2006 until September 2009. MAIN OUTCOME MEASURES: The numbers of patients having cranial CT and lumbar puncture and whether any complications had arisen following lumbar puncture. The appropriateness of the CT request according to local criteria. RESULTS: A total of 111 patients were admitted in the initial time period and 47 patients in the second time period. In the first group, 67 patients underwent CT (61%), compared with 36 patients (80%) in the second group. There were eight abnormal scans (12%) in the initial group including three patients with radiological features of cerebral oedema. Of these patients, one underwent lumbar puncture and had no neurological sequelae. In the second group, there were five abnormal scans (14%) with one presenting a contraindication for lumbar puncture due to mild ventricular dilatation. A lumbar puncture was performed in this patient without complication. All patients with abnormal scans had clinical features to suggest raised intracranial pressure. CT scan requests were considered inappropriate in 26% of patients in the initial study period and 56% of patients in the second study period. CONCLUSION: More patients with meningitis are undergoing CT and the number of inappropriate requests are increasing. There are few abnormal CT scans presenting a contraindication for lumbar puncture and the majority of these patients usually have clinical signs to suggest raised intracranial pressure. Death following lumbar puncture (LP) is feared by physicians. Many opinions are found in literature on the question whether computed cranial tomography (CT) should be performed before LP, to prevent herniation. These opinions are mainly based on retrospective studies and pathophysiological reasoning. In this review the difficulties in the decision whether we should perform CT before LP are discussed. It is explained that the concept of "raised intracranial pressure" is confusing, and that the less ambiguous terms "brain shift" and "raised CSF pressure" should be used instead. Brain shift is a contraindication to LP, whether CSF pressure is raised or not, and whether papilloedema is present or not. Subsequently, recommendations are offered for indications to perform CT before LP, grouped according to the safety and clinical utility of LP. Examination of cerebrospinal fluid remains a mainstay of the diagnosis of many acute central nervous system illnesses, including meningitis, encephalitis, and polyneuropathies such as Guillain-Barré syndrome. Although generally considered innocuous, there may be considerable danger when lumbar puncture is performed in the presence of increased intracranial pressure, especially when a mass lesion is present. We review the literature surrounding the danger of lumbar puncture when intracranial pressure is increased and discuss our approach to the problem in lieu of the advent of computerized tomographic scanning. CSF evaluation is the single most important aspect of the laboratory diagnosis of meningitis. Analysis of the CSF abnormalities produced by bacterial, mycobacterial, and fungal infections may greatly facilitate diagnosis and direct initial therapy. Basic studies of CSF that should be performed in all patients with meningitis include measurement of pressure, cell count and white cell differential; determination of glucose and protein levels; Gram's stain; and culture. In bacterial meningitis, Limulus lysate assay and tests to identify bacterial antigens may allow rapid diagnosis. Where there is strong suspicion of tuberculous or fungal meningitis, CSF should also be submitted for acid-fast stain, India ink preparation, and cryptococcal antigen; unless contraindicated by increased intracranial pressure, large volumes (up to 40-50 mL) should be obtained for culture. If a history of residence in the Southwest is elicited, complement-fixing antibodies to Coccidioides immitis should also be ordered. Newer tests based on immunologic methods or gene amplification techniques hold great promise for diagnosis of infections caused by organisms that are difficult to culture or present in small numbers. Despite the great value of lumbar puncture in the diagnosis of meningitis, injudicious use of the procedure may result in death from brain herniation. Lumbar puncture should be avoided if focal neurologic findings suggest concomitant mass lesion, as in brain abscess, and lumbar puncture should be approached with great caution if meningitis is accompanied by evidence of significant intracranial hypertension. Institution of antibiotic therapy for suspected meningitis should not be delayed while neuroradiologic studies are obtained to exclude abscess or while measures are instituted to reduce intracranial pressure. Serious complications (catastrophes) resulting from diverse neurological diagnostic procedures can be caused by erroneous indication and omission, as well as by delay and erroneous execution or interpretation. Headache, caused by cerebrospinal fluid (CSF) hypotension, is a frequent complication of lumbar puncture; hematic patch is a therapeutic option for severe cases. The most serious complication is cerebral herniation and, for its prevention, computed tomography (CT) or cerebral magnetic resonance imaging (MRI) must always be performed before lumbar puncture: a lesion with evident mass effect is a contraindication. Some cases of minor subarachnoid hemorrhages can produce sentinel headache: when the findings of CT scans are normal, lumbar puncture must be performed for diagnosis and prevention of a catastrophic recurrence. Edrophonium testing can be complicated with bradycardia and/or asystole. The lack of indication of this procedure is a cause of under-diagnosis of myasthenia gravis, especially in older people. Electromyography produces few complications (rare cases of paraspinal hematomas and pneumothorax). Ultrasound, CT angiography and MR angiography examinations have decreased the indications for cerebral angiography, whose main complications -in addition to contrast reactions, hemorrhage and infection at the injection site- are neurological deficits caused by vascular dissection or atheromatous embolus. Video-electroencephalogram (EEG) recording with medication suppression can be used in the presurgical evaluation of epilepsy, which can precipitate repeated seizures with the risk of injuries and status epilepticus. The possible complications of studies performed with invasive electrodes are infections and intracranial hemorrhages. Cerebral biopsy is indicated when treatable disease is suspected but the therapeutic options (radiotherapy, chemotherapy) have potential serious adverse effects. Furthermore, cerebral biopsy can aggravate previous neurological deficits or produce new deficits. Genetic testing is not indicated in healthy children when an untreatable disease is suspected. In adults, genetic testing is appropriate in selected cases, but detailed previous information should be gathered and the possibility of triggering serious emotional reactions should always be considered.
4,132
What laboratory abnormalities are commonly seen in patients with COVID-19?
Common laboratory abnormalities among patients with COVID-19 include: 1. Elevated inflammatory markers (e.g., ferritin, C-reactive protein, and erythrocyte sedimentation rate). 2. Elevated aminotransaminase levels (i.e., AST, ALT). 3. Elevated lactate dehydrogenase (LDH) levels. 4. Lymphopenia, leucocytosis. Abnormalities in coagulation testing (e.g., increased D-Dimers, decreased platelets), elevated procalcitonin levels, and elevated troponin levels have also been reported. The degree of these abnormalities tends to correlate with disease severity.
[32877961, 34258956, 33986318, 32352401, 33482780, 32721958, 33726761, 34383402, 33407543, 33522493, 33548996, 32336069, 33973190, 33210948, 34374346, 32542934, 32449374, 33936225, 32501877, 32656888, 32344313]
4,539
Coronavirus disease 2019 (COVID-19) is the third known animal coronavirus, after severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome coronavirus (MERS-CoV). The mean age of the infected patients was estimated to be between 50 and 69 years old. Accordingly, the COVID-19 mortality rate was calculated as 15%. In this regard, the essential component of prevention and planning is knowledge of laboratory and demographic findings among COVID-19 patients; therefore, the present study was conducted to investigate laboratory and demographic findings among these patients worldwide. This systematic review was performed on the articles published in English between January 1, 2019 and May 4, 2020, using MeSH-compliant keywords such as "COVID-19", "Laboratory, coronavirus disease-19 testing", and " demography " in international databases (PubMed, and web of science Scopus). Thereafter, the articles relevant to laboratory and demographic findings among COVID-19 patients were included in the final review. Reviewing the included articles showed changes in the mean lymphocytes count ranged from 0.7 to 39 in hospital or severe cases. Moreover, Leukopenia was not observed in patients with thrombocytopenia. In addition, C-reactive protein (CRP), leukocytes, D-dimer, FDP, FIB, neutrophils, AST, serum creatinine, t-troponin, troponin I, and blood bilirubin levels showed increasing trends in most studies conducted on COVID-19 patients. Notably, the elevated LDH level was more common among children than adults. According to the results of the present study, and by considering the clinical characteristics of COVID-19 patients on the one hand, and considering the changes in laboratory samples such as lymphocytes and other blood markers due to the damaged myocardial, hepatic, and renal tissues on the other hand, it is recommended to confirm the diagnosis of this infection by evaluating the patients' blood samples using other diagnostic methods like lung scan. Prognostic markers are needed to understand the disease course and severity in patients with Covid-19. There is evidence that Covid-19 causes gastrointestinal symptoms and abnormalities in liver enzymes. We aimed to determine if hepatobiliary laboratory data could predict disease severity in patients with Covid-19. In this retrospective, single institution, cohort study that analyzed patients admitted to a community academic hospital with the diagnosis of Covid-19, we found that elevations of Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT) and Alkaline Phosphatase (AP) at any time during hospital admission increased the odds of ICU admission by 5.12 (95% CI: 1.55-16.89; p = 0.007), 4.71 (95% CI: 1.51-14.69; p = 0.01) and 4.12 (95% CI: 1.21-14.06, p = 0.02), respectively. Hypoalbuminemia found at the time of admission to the hospital was associated with increased mortality (p = 0.02), hypotension (p = 0.03), and need for vasopressors (p = 0.02), intubation (p = 0.01) and hemodialysis (p = 0.002). Additionally, there was evidence of liver injury: AST was significantly elevated above baseline in patients admitted to the ICU (54.2 ± 15.70 U/L) relative to those who were not (9.2 ± 4.89 U/L; p = 0.01). Taken together, this study found that hypoalbuminemia and abnormalities in hepatobiliary laboratory data may be prognostic factors for disease severity in patients admitted to the hospital with Covid-19. BACKGROUND: COVID-19 is a systemic viral infection which mainly targets the human respiratory system with many secondary clinical manifestations especially affecting the hematopoietic system and haemostasis. Few studies have highlighted the prognostic value of blood findings such as lymphopenia, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, LDH, CRP, cardiac troponin, low-density lipoproteins and chest radiographic abnormality. A study of progressions of blood and radiological results may help to identify patients at high risk of severe outcomes. This systematic review aimed to assess the temporal progression of blood and radiology findings of patients with COVID-19. METHODS: Comprehensive systematic literature search was conducted on Medline, Embase and Cochrane databases to identify articles published for peripheral blood investigation and radiological results of COVID-19 patients. RESULTS: A total of 27 studies were included in this review. The common laboratory features reported include lymphopenia, elevated levels of C-reactive proteins and lactate dehydrogenase. For radiological signs, ground-glass opacifications, consolidations, and crazy paving patterns were frequently reported. There is a correlation between lymphocyte count, neutrophil count and biomarkers such as C-reactive proteins and lactate dehydrogenase; at a later phase of the disease (more than 7 days since onset of symptoms), lymphopenia worsens while neutrophil count, C-reactive protein levels and lactate dehydrogenase levels increase. Frequencies of ground-glass opacifications and ground-glass opacifications with consolidations decrease at a later phase of the disease while that of consolidation and crazy paving pattern rises as the disease progresses. More extensive lung involvement was also seen more frequently in the later phases. CONCLUSION: The correlation between temporal progression and the reported blood and radiological results may be helpful to monitor and evaluate disease progression and severity. Coronavirus disease 2019 (COVID-19) is affecting millions of patients worldwide. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which belongs to the family Coronaviridae, with 80% genomic similarities to SARS-CoV. Lymphopenia was commonly seen in infected patients and has a correlation to disease severity. Thrombocytopenia, coagulation abnormalities, and disseminated intravascular coagulation were observed in COVID-19 patients, especially those with critical illness and non-survivors. This pandemic has caused disruption in communities and hospital services, as well as straining blood product supply, affecting chemotherapy treatment and haematopoietic stem cell transplantation schedule. In this article, we review the haematological manifestations of the disease and its implication on the management of patients with haematological disorders. BACKGROUND: Abnormal laboratory findings are common in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this systematic review was to investigate the effect of the level of some laboratory factors (C-reactive protein (CRP), creatinine, leukocyte count, hemoglobin, and platelet count) on the severity and outcome of coronavirus disease 2019 (COVID-19). METHODS: We searched PubMed, Web of Science, Scopus, and Google Scholar. We collected the articles published before May 26, 2020. We gathered the laboratory factors in groups of patients with COVID-19, and studied the relation between level of these factors with severity and outcome of the disease. RESULTS: Mean CRP level, creatinine, hemoglobin, and the leukocytes count in the critically ill patients were significantly higher than those of the other groups (non-critical patients); mean CRP = 54.81 mg/l, mean creatinine = 86.82 μmol/l, mean hemoglobin = 144.05 g/l, and mean leukocyte count = 7.41 × 109. The lymphocyte count was higher in patients with mild/moderate disease (mean: 1.32 × 109) and in the invasive ventilation group (mean value of 0.72 × 109), but it was considerably lower than those of the other two groups. The results showed that the platelet count was higher in critically ill patients (mean value of 205.96 × 109). However, the amount was lower in the invasive ventilation group compared with the other groups (mean level = 185.67 × 109). CONCLUSION: With increasing disease severity, the leukocyte count and the level of CRP increase significantly and the lymphocyte count decreases. There seems to be a significant relation between platelet level, hemoglobin, and creatinine level with severity of the disease. However, more studies are required to confirm this. BACKGROUND: The aim of this study was to investigate changes in some laboratory parameters in response to four independent variables (COVID-19, diabetes, gender, and age) using univariate and multivariate analysis. METHODS: We measured WBC (neutrophil and lymphocytes), RBC and platelet counts, and hemoglobin, lactate dehydrogenase, C-reactive protein, IL-2, IL-4, and vitamin D3 levels in 30 hospitalized patients with severe COVID-19 and in 30 healthy people in terms of COVID-19. The population was divided into groups based on each of the variables of age, gender, COVID-19, and type 2 diabetes. Then they were subjected to univariate and multivariate analysis of logistic regression. RESULTS: Based on CBC data, leukocytosis (in 70% of COVID-19 patients, 61.1% of diabetic patients, and 70.9 ± 18 years old), neutrophilia (in 73.3% of patients with COVID-19, 61.1% of diabetic patients, and 66 ± 18.6 years old), neutropenia (in 6.7% of patients with COVID-19, 27.8% of diabetic patients, and 33.6 ± 12.7 years old), lymphocytosis (10% of patients with COVID-19, 33.3% of diabetic patients, and 35.4 ± 15.5 years old), and lymphocytopenia (in 76.7% of patients with COVID-19, 66.7% of diabetic patients, and 67.1 ± 18.8 years old) were observed in the population. The elderly and those with COVID-19 had significant abnormal RBC and platelet counts. Increased LDH and CRP levels and abnormal hemoglobin level were related to elderly, COVID-19, and diabetes conditions. Although the levels of IL-2 and -4 were significant in patients with COVID-19 and elderly; however, the changes were not significant in diabetic patients. Changes in serum vitamin D levels were not significant in any of the sub-groups. CONCLUSIONS: We showed that leukocytosis, neutrophilia, lymphocytopenia, abnormal counts of RBCs and platelets, the elevated levels of LDH and CRP, and abnormal hemoglobin levels in blood are considered as poor prognostic factors for COVID-19. Coronavirus disease 2019 (COVID-19) pandemic continues devastating effects on healthcare systems. Such a crisis calls for an urgent need to develop a risk stratification tool. The present chapter aimed to identify laboratory and clinical correlates of adverse outcomes in patients with COVID-19. To this end, we conducted a systematic evaluation of studies that investigated laboratory abnormalities in patients with COVID-19 and compared i. patients with a severe form of disease and patients with a non-severe form of the disease, ii. patients who were in critical condition and patients who were not in critical condition, and iii. patients who survived and patients who died. We included 54 studies in the data synthesis. Compared to patients with a non-severe form of COVID-19, patients who had a severe form of disease revealed higher values for white blood cells (WBC), polymorphonuclear leukocytes (PMN), total bilirubin, alanine aminotransferase (ALT), creatinine, troponin, procalcitonin, lactate dehydrogenase (LDH), and D-dimer. By contrast, platelet count, lymphocyte count, and albumin levels were decreased in patients with a severe form of COVID-19. Also, patients with a severe phenotype of disease were more likely to have diabetes, chronic heart disease, chronic obstructive pulmonary disease (COPD), cerebrovascular disease, hypertension, chronic kidney disease (CKD), and malignancy. Compared to patients who survived, patients who died had higher WBC, PMN, total bilirubin, ALT, procalcitonin, IL-6, creatinine, PT, lymphocyte count, platelet count, and albumin. Also, non-survivors revealed a higher prevalence of diabetes, chronic heart disease, COPD, cerebrovascular disease, and CKD. Meta-analyses identified several laboratory parameters that might help the prediction of severe, critical, and lethal phenotypes of COVID-19. These parameters correlate with the immune system function, inflammation, coagulation, and liver and kidney function. BACKGROUND: Clinical observations demonstrated that COVID-19 related pneumonia is often accompanied by hematological and coagulation abnormalities including lymphopenia, thrombocytopenia, and prolonged prothrombin time. The evaluation of laboratory findings including coagulation and inflammation parameters may represent a promising approach for early determination of COVID-19 severity. METHODS AND MATERIALS: In the present study, we aimed to identify laboratory parameters present upon admission in patients with COVID-19 related viral pneumonia and associated with an early in-hospital development of refractory respiratory failure or severe acute respiratory distress syndrome requiring treatment in an intensive care unit. We investigated differences in the C-reactive protein (CRP) and fibrinogen levels, prothrombin time (PT) and international normalized ratio (INR) between COVID-19 patients who had been transferred to an ICU within two weeks after admission (n = 82) and COVID-19 patients with stable course of the disease (n = 74). RESULTS: Multiple comparisons showed statistically significantly prolonged PT on admission in ICU-transferred COVID-19 patients (14.15 sec, median, CI 95% 13.4 ÷ 14.9) compared to the stable COVID-19 patients (13.25 sec, median, CI 95% 12.9 ÷ 13.6) (p-value = .0005). CRP levels upon admission were statistically significantly higher in ICU-transferred COVID-19 patients (132 mg/L, median, CI95% 113 ÷ 159) compared to the stable COVID-19 patients (51 mg/L, median, CI95% 33 ÷ 72) (p-value < .0001). On-admission fibrinogen and INR levels did not statistically significantly differ between ICU-transferred COVID-19 patients and stable COVID-19 patients. CONCLUSION: We suggest that CRP and PT levels present on admission in COVID-19 patients may be used as early prognostic markers of severe pneumonia requiring transfer to ICU. BACKGROUND: Laboratory parameter abnormalities are commonly observed in COVID-19 patients; however, their clinical significance remains controversial. We assessed the prevalence, characteristics, and clinical impact of laboratory parameters in COVID-19 patients hospitalized in Daegu, Korea. METHODS: We investigated the clinical and laboratory parameters of 1,952 COVID-19 patients on admission in nine hospitals in Daegu, Korea. The average patient age was 58.1 years, and 700 (35.9%) patients were men. The patients were classified into mild (N=1,612), moderate (N=294), and severe (N=46) disease groups based on clinical severity scores. We used chi-square test, multiple comparison analysis, and multinomial logistic regression to evaluate the correlation between laboratory parameters and disease severity. RESULTS: Laboratory parameters on admission in the three disease groups were significantly different in terms of hematologic (Hb, Hct, white blood cell count, lymphocyte%, and platelet count), coagulation (prothrombin time and activated partial thromboplastin time), biochemical (albumin, aspartate aminotransferase, alanine aminotransferase, lactate, blood urea nitrogen, creatinine, and electrolytes), inflammatory (C-reactive protein and procalcitonin), cardiac (creatinine kinase MB isoenzyme and troponin I), and molecular virologic (Ct value of SARS-CoV-2 RdRP gene) parameters. Relative lymphopenia, prothrombin time prolongation, and hypoalbuminemia were significant indicators of COVID-19 severity. Patients with both hypoalbuminemia and lymphopenia had a higher risk of severe COVID-19. CONCLUSIONS: Laboratory parameter abnormalities on admission are common, are significantly associated with clinical severity, and can serve as independent predictors of COVID-19 severity. Monitoring the laboratory parameters, including albumin and lymphocyte count, is crucial for timely treatment of COVID-19. OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a global pandemic in early 2020 with rapidly evolving approaches to diagnosing the clinical illness called coronavirus disease (COVID-19). The primary objective of this scoping review is to synthesize current research of the diagnostic accuracy of history, physical examination, routine laboratory tests, real-time reverse transcription-polymerase chain reaction (rRT-PCR), immunology tests, and computed tomography (CT) for the emergency department (ED) diagnosis of COVID-19. Secondary objectives included a synopsis of diagnostic biases likely with current COVID-19 research as well as corresponding implications of false-negative and false-positive results for clinicians and investigators. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Scoping Review (PRISMA-ScR)-adherent synthesis of COVID-19 diagnostic accuracy through May 5, 2020, was conducted. The search strategy was designed by a medical librarian and included studies indexed by PubMed and Embase since January 2020. RESULTS: A total of 1,907 citations were screened for relevance. Patients without COVID-19 are rarely reported, so specificity and likelihood ratios were generally unavailable. Fever is the most common finding, while hyposmia and hypogeusia appear useful to rule in COVID-19. Cough is not consistently present. Lymphopenia is the mostly commonly reported laboratory abnormality and occurs in over 50% of COVID-19 patients. rRT-PCR is currently considered the COVID-19 criterion standard for most diagnostic studies, but a single test sensitivity ranges from 60% to 78%. Multiple reasons for false-negatives rRT-PCR exist, including sample site tested and disease stage during which sample was obtained. CT may increase COVID-19 sensitivity in conjunction with rRT-PCR, but guidelines for imaging patients most likely to benefit are emerging. IgM and IgG serology levels are undetectable in the first week of COVID-19, but sensitivity (range = 82% to 100%) and specificity (range = 87% to 100%) are promising. Whether detectable COVID-19 antibodies correspond to immunity remains unanswered. Current studies do not adhere to accepted diagnostic accuracy reporting standards and likely report significantly biased results if the same tests were to be applied to general ED populations with suspected COVID-19. CONCLUSIONS: With the exception of fever and disorders of smell/taste, history and physical examination findings are unhelpful to distinguish COVID-19 from other infectious conditions that mimic SARS-CoV-2 like influenza. Routine laboratory tests are also nondiagnostic, although lymphopenia is a common finding and other abnormalities may predict severe disease. Although rRT-PCR is the current criterion standard, more inclusive consensus-based criteria will likely emerge because of the high false-negative rate of PCR tests. The role of serology and CT in ED assessments remains undefined. The Coronavirus Disease (COVID-19) pandemic first broke out in December 2019 in Wuhan, China, and has now spread worldwide. Laboratory findings have been only partially described in some observational studies. To date, more comprehensive systematic reviews of laboratory findings on COVID-19 are missing. We performed a systematic review with a meta-analysis to assess laboratory findings in patients with COVID-19. Observational studies from three databases were selected. We calculated pooled proportions and 95% confidence interval (95% CI) using the random-effects model meta-analysis. A total of 1106 articles were identified from PubMed, Web of Science, CNKI (China), and other sources. After screening, 28 and 7 studies were selected for a systematic review and a meta-analysis, respectively. Of the 4,663 patients included, the most prevalent laboratory finding was increased C-reactive protein (CRP; 73.6%, 95% CI 65.0-81.3%), followed by decreased albumin (62.9%, 95% CI 28.3-91.2%), increased erythrocyte sedimentation rate (61.2%, 95% CI 41.3-81.0%), decreased eosinophils (58.4%, 95% CI 46.5-69.8%), increased interleukin-6 (53.1%, 95% CI 36.0-70.0%), lymphopenia (47.9%, 95% CI 41.6-54.9%), and increased lactate dehydrogenase (LDH; 46.2%, 95% CI 37.9-54.7%). A meta-analysis of seven studies with 1905 patients showed that increased CRP (OR 3.0, 95% CI: 2.1-4.4), lymphopenia (OR 4.5, 95% CI: 3.3-6.0), and increased LDH (OR 6.7, 95% CI: 2.4-18.9) were significantly associated with severity. These results demonstrated that more attention is warranted when interpreting laboratory findings in patients with COVID-19. Patients with elevated CRP levels, lymphopenia, or elevated LDH require proper management and, if necessary, transfer to the intensive care unit. BACKGROUND: In the context of the COVID-19 outbreak of worldwide, we aim to analyze the laboratory risk factors of in-hospital death in patients with severe COVID-19. METHODS: All ≥18-year-old patients with confirmed severe COVID-19 admitted to Tongji Hospital (Wuhan, China) from February 3 to February 20, 2020, were retrospectively enrolled and followed up until March 20, 2020. Epidemiological, clinical, laboratory, and treatment data were collected and explored the risk factors associated with in-hospital death. RESULTS: A total of 73 severe patients were enrolled in the study, of whom 20 (27%) patients died in hospital during the average 28 days of follow-up period. The median age of non-survivors was significantly older than survivors (69 [64-76.5] years vs 64 [56-71.3] years, P = .033) and 15 (75%) patients were males. The laboratory abnormalities of non-survivors mainly presented in serious inflammation response and multiple organ failure, with high levels of cytokines and deranged coagulation parameters. Multivariable regression showed that neutrophil count greater than 4.47 × 109 /L (OR, 58.35; 95%CI: 2.16-1571.69; P = .016), hypersensitivity C-reactive protein greater than 86.7 mg/L (OR, 14.90; 95%CI: 1.29-171.10; P = .030), creatine kinase greater than 101 U/L (OR, 161.62; 95%CI: 6.45-4045.20; P = .002), and blood urea nitrogen greater than 6.7 mmol/L (OR, 11.18; 95%CI: 1.36-91.62; P = .024) were risk factors for in-hospital death. CONCLUSION: The risk factors of neutrophil count, hypersensitivity C-reactive protein, creatine kinase, and blood urea nitrogen could help clinicians to early identify COVID-19 severe patients with poor outcomes on admission. Virus direct attack and cytokine storm play a major role in the death of COVID-19.
4,133
Do only changes in coding regions of MEF2C cause developmental disorders?
No. Non-coding region variants upstream of MEF2C cause severe developmental disorder through three distinct loss-of-function mechanisms.
[34022131]
4,540
Author information: (1)Institute of Biomedical and Clinical Science, University of Exeter Medical School, Royal Devon & Exeter Hospital, Exeter EX2 5DW, UK. (2)National Heart & Lung Institute and MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, UK; Cardiovascular Research Centre, Royal Brompton & Harefield Hospitals NHS Trust, London SW3 6NP, UK. (3)Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain. (4)Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK. (5)National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK. (6)Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. (7)European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Cambridge CB10 1SD, UK. (8)Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield S10 2TH, UK; Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, Sheffield S10 2TH, UK. (9)Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University Hospitals NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK; Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK. (10)Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University Hospitals NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK. (11)Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK. (12)Department of Pediatrics, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA. (13)UCD Academic Centre on Rare Diseases, School of Medicine and Medical Sciences, University College Dublin, and Clinical Genetics, Temple Street Children's University Hospital, Dublin D01 XD99, Ireland. (14)West Midlands Regional Clinical Genetics Service and Birmingham Health Partners, Birmingham Women's and Children's Hospitals NHS Foundation Trust, Birmingham B4 6NH, UK. (15)Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA. (16)All Wales Medical Genomics Service, NHS Wales Cardiff and Vale University Health Board, Institute of Medical Genetics, University Hospital of Wales, Cardiff CF14 4AY, UK. (17)Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7LE, UK. (18)Department of Neurology, University of Kansas School of Medicine-Salina Campus, Salina, KS 67401, USA. (19)National Heart & Lung Institute and MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, UK. (20)GeneDx, Gaithersburg, MD 20877, USA. (21)Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK; East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK. (22)Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), 28029 Madrid, Spain. (23)Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK. Electronic address: nwhiffin@well.ox.ac.uk.
4,134
Which factor is inhibited by Milvexian?
Milvexian is a small molecule, active-site inhibitor of factor XIa (FXIa) being developed to prevent and treat thrombotic events.
[34558200, 34780683, 34494428, 34752670]
4,541
Milvexian (BMS-986177/JNJ-70033093) is a small molecule, active-site inhibitor of factor XIa (FXIa) being developed to prevent and treat thrombotic events. The safety, tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of milvexian were assessed in a two-part, double-blind, placebo-controlled, sequential single ascending dose (SAD) and multiple ascending dose (MAD) study in healthy adults. Participants in SAD panels (6 panels of 8 participants; n = 48) were randomized (3:1) to receive milvexian (4, 20, 60, 200, 300, or 500 mg) or placebo. The 200- and 500-mg panels investigated the pharmacokinetic impact of a high-fat meal. Participants in MAD panels (7 panels of 8 participants; n = 56) were randomized (3:1) to receive milvexian (once- or twice-daily) or placebo for 14 days. All milvexian dosing regimens were safe and well-tolerated, with only mild treatment-emergent adverse events and no clinically significant bleeding events. In SAD panels, maximum milvexian plasma concentration occurred 3 h postdose in all fasted panels. The terminal half-life (T1/2 ) ranged from 8.3 to 13.8 h. In fasted panels from 20 to 200 mg, absorption was dose-proportional; results at higher doses (300 and 500 mg) were consistent with saturable absorption. Food increased milvexian bioavailability in a dose-dependent fashion. In MAD panels, steady-state milvexian plasma concentration was reached within 3 and 6 dosing days with once- and twice-daily dosing, respectively. Renal excretion was less than 20% in all panels. Prolongation of activated partial thromboplastin time was observed and was directly related to drug exposure. These results suggest that the safety, tolerability, PK, and PD properties of milvexian are suitable for further clinical development. BACKGROUND: Factor XIa inhibitors for the prevention and treatment of venous and arterial thromboembolism may be more effective and result in less bleeding than conventional anticoagulants. Additional data are needed regarding the efficacy and safety of milvexian, an oral factor XIa inhibitor. METHODS: In this parallel-group, phase 2 trial, we randomly assigned 1242 patients undergoing knee arthroplasty to receive one of seven postoperative regimens of milvexian (25 mg, 50 mg, 100 mg, or 200 mg twice daily or 25 mg, 50 mg, or 200 mg once daily) or enoxaparin (40 mg once daily). The primary efficacy outcome was venous thromboembolism (which was a composite of asymptomatic deep-vein thrombosis, confirmed symptomatic venous thromboembolism, or death from any cause). The principal safety outcome was bleeding. RESULTS: Among the patients receiving milvexian twice daily, venous thromboembolism developed in 27 of 129 (21%) taking 25 mg, in 14 of 124 (11%) taking 50 mg, in 12 of 134 (9%) taking 100 mg, and in 10 of 131 (8%) taking 200 mg. Among those receiving milvexian once daily, venous thromboembolism developed in 7 of 28 (25%) taking 25 mg, in 30 of 127 (24%) taking 50 mg, and in 8 of 123 (7%) taking 200 mg, as compared with 54 of 252 patients (21%) taking enoxaparin. The dose-response relationship with twice-daily milvexian was significant (one-sided P<0.001), and the 12% incidence of venous thromboembolism with twice-daily milvexian was significantly lower than the prespecified benchmark of 30% (one-sided P<0.001). Bleeding of any severity occurred in 38 of 923 patients (4%) taking milvexian and in 12 of 296 patients (4%) taking enoxaparin; major or clinically relevant nonmajor bleeding occurred in 1% and 2%, respectively; and serious adverse events were reported in 2% and 4%, respectively. CONCLUSIONS: Postoperative factor XIa inhibition with oral milvexian in patients undergoing knee arthroplasty was effective for the prevention of venous thromboembolism and was associated with a low risk of bleeding. (Funded by Bristol Myers Squibb and Janssen Research and Development; AXIOMATIC-TKR ClinicalTrials.gov number, NCT03891524.). Factor XIa (FXIa) is an enzyme in the coagulation cascade thought to amplify thrombin generation but has a limited role in hemostasis. From preclinical models and human genetics, an inhibitor of FXIa has the potential to be an antithrombotic agent with superior efficacy and safety. Reversible and irreversible inhibitors of FXIa have demonstrated excellent antithrombotic efficacy without increased bleeding time in animal models (Weitz, J. I., Chan, N. C. Arterioscler. Thromb. Vasc. Biol. 2019, 39 (1), 7-12). Herein, we report the discovery of a novel series of macrocyclic FXIa inhibitors containing a pyrazole P2' moiety. Optimization of the series for (pharmacokinetic) PK properties, free fraction, and solubility resulted in the identification of milvexian (BMS-986177/JNJ-70033093, 17, FXIa Ki = 0.11 nM) as a clinical candidate for the prevention and treatment of thromboembolic disorders, suitable for oral administration. BACKGROUND: Milvexian (BMS-986177/JNJ-70033093) is an orally bioavailable factor XIa (FXIa) inhibitor currently in phase 2 clinical trials. OBJECTIVES: To evaluate in vitro properties and in vivo characteristics of milvexian. METHODS: In vitro properties of milvexian were evaluated with coagulation and enzyme assays, and in vivo profiles were characterized with rabbit models of electrolytic-induced carotid arterial thrombosis and cuticle bleeding time (BT). RESULTS: Milvexian is an active-site, reversible inhibitor of human and rabbit FXIa (Ki 0.11 and 0.38 nM, respectively). Milvexian increased activated partial thromboplastin time (APTT) without changing prothrombin time and potently prolonged plasma APTT in humans and rabbits. Milvexian did not alter platelet aggregation to ADP, arachidonic acid, or collagen. Milvexian was evaluated for in vivo prevention and treatment of thrombosis. For prevention, milvexian 0.063 + 0.04, 0.25 + 0.17, and 1 + 0.67 mg/kg+mg/kg/h preserved 32 ± 6*, 54 ± 10*, and 76 ± 5%* of carotid blood flow (CBF) and reduced thrombus weight by 15 ± 10*, 45 ± 2*, and 70 ± 4%*, respectively (*p < .05; n = 6/dose). For treatment, thrombosis was initiated for 15 min and CBF decreased to 40% of control. Seventy-five minutes after milvexian administration, CBF averaged 1 ± 0.3, 39 ± 10, and 66 ± 2%* in groups treated with vehicle and milvexian 0.25 + 0.17 and 1 + 0.67 mg/kg+mg/kg/h, respectively (*p < .05 vs. vehicle; n = 6/group). The combination of milvexian 1 + 0.67 mg/kg+mg/kg/h and aspirin 4 mg/kg/h intravenous did not increase BT versus aspirin monotherapy. CONCLUSIONS: Milvexian is an effective antithrombotic agent with limited impact on hemostasis, even when combined with aspirin in rabbits. This study supports inhibition of FXIa with milvexian as a promising antithrombotic therapy with a wide therapeutic window.
4,135
What is Granzyme B?
Granzyme B is a serine protease that is secreted by Natural Killer (NK) cells and cytotoxic T lymphocytes during a cellular immune response and can induce apoptosis.
[32079690, 32302642, 32324629, 32608278, 34549432, 34509050]
4,542
Granzyme B is known to be a serine protease contained in granules of cytotoxic T cells. We have previously reported an influence of granzyme B expression in T regulatory cells (Tregs) on the risk of acute graft versus host disease (GVHD) onset. However, it is still unknown if conventional T cells (Tcon) use the granzyme B pathway as a mechanism of alloimmunity. We hypothesized that granzyme B in Tcon may affect recurrence within the first 6 months after allogeneic transplantation (allo-HSCT). A total of 65 patients with different hematological malignancies were included in this study. Blood samples were collected on day +30 after allo-HSCT. The percentage of granzyme B positive conventional T cells in patients who developed relapse in the first 6 months after allo-HSCT was 11.3 (4.5-35.3) compared to the others in continuous complete remission-1.3 (3.65-9.7), р = 0.011. The risk of relapse after allo-HSCT was in 3.9 times higher in patients with an increased percentage of granzyme B positive conventional T cells. The findings demonstrated that the percentage of granzyme B positive conventional T cells on day +30 after allo-HSCT could be a predictable marker of relapse within the first 6 months after allo-HSCT. Kawasaki disease (KD) is a systemic vasculitis of unknown etiology which predominantly affects medium- and small-sized muscular arteries. Histopathologic studies of KD vasculitis lesions have demonstrated characteristic T cell infiltration and an abundance of CD8 T cells; however, the contribution of cytotoxic lymphocytes to KD vasculitis lesions has not been identified. Here, we histopathologically and immunohistochemically examined infiltrating inflammatory cells, particularly cytotoxic protein-positive cells, such as granzyme B cells and TIA-1 cells, in KD vasculitis lesions. Three autopsy specimens with acute-phase KD were observed and contained 24 vasculitis lesions affecting medium-sized muscular arteries, excluding pulmonary arteries. Infiltrating neutrophils in vasculitis lesions were evaluated by hematoxylin and eosin staining, and monocytes/macrophages and lymphocytes were evaluated by immunohistochemistry. The predominant cells were CD163 monocytes/macrophages and CD3 T cells. CD8 T cells, granzyme B cells, and TIA-1 cells were also observed, but CD56 natural killer cells were rare. To the best of our knowledge, the current study is the first histopathologic report confirming the infiltration of inflammatory cells with cytotoxic proteins in vasculitis lesions in patients with KD. Cytotoxic T cells may play a role in the development of vasculitis lesions in KD patients. To date, the mechanisms of inflammation have been poorly studied in fish of commercial interest, due to the lack of development of appropriate experimental models. The current study evaluated a local inflammation triggered by a polymeric carrageenin mixture (a mucopolysaccharide derived from the red seaweed Chondrus crispus) in the skin of gilthead seabream (Sparus aurata). Fish were injected subcutaneously with phosphate-buffered saline (as control) or λ/κ-carrageenin (1%), and skin samples from the injection sites were collected 1.5, 3 and 6 hr post-injection, processed for inclusion in paraplast and stained with haematoxylin-eosin, Alcian blue or periodic acid-Schiff. Furthermore, immunohistochemistry and expression analyses of several cells' markers and proinflammatory genes were also analysed in samples of the injected sites. Microscopic results indicated an increased number of skin mucus-secreting cells and acidophilic granulocytes in the skin of fish studied at 1.5 hr and 3 hr post-injection with carrageenin, respectively, with respect to the data obtained in control fish. Otherwise, both the gene expression of the non-specific cytotoxic cell marker (granzyme B, grb) and the proinflammatory cytokine (interleukin-1β, il-1β) were up-regulated at 1.5 hr in the skin of fish injected with carrageenin compared with the control fish, whilst the gene expression of acidophilic granulocyte markers (NADPH oxidase subunit Phox22 and Phox40, phox22 and phox40) was up-regulated at 3 and 6 hr in the carrageenin group, compared with the control group. In addition, the gene expression of myeloperoxidase (mpo) was also up-regulated at 6 hr in the skin of fish injected with carrageenin in comparison with control samples. The present results indicate the chronological participation of two important immune cells involved in the resolution of the inflammation in the skin of gilthead seabream. BACKGROUND: Immune checkpoint inhibitors (ICI) therapies have demonstrated significant benefit in the treatment of many tumors including high grade urothelial cancer (HGUC) of the bladder. However, variability in patients' clinical responses highlights the need for biomarkers to aid patient stratification. ICI relies on an intact host immune response. In this context, we hypothesize that key players in the antitumor immune response such as markers of activated cytotoxic T lymphocytes (CD8, granzyme-B) and immune suppression (FOXP3) may help to identify patients who will derive the greatest therapeutic benefit from ICI. A major obstacle for deployment of such a strategy is the limited quantities of tumor-derived biopsy material. Therefore, in this technical study, we develop a multiplex biomarker with digital workflow. We explored the (1) concordance of conventional single stain results using digital image analysis, and (2) agreement between digital scoring versus manual analysis. METHODS: (1) For concordance study of single and multiplex stains, triplicate core tissue microarrays of 207 muscle invasive, HGUC of bladder had sequential 4-micron sections cut and stained with CD8, FOXP3 and granzyme-B. An inhouse developed tri-chromogen multiplex immunohistochemistry (m-IHC) assay consisting of CD8 (green), granzyme B (brown), and FOXP3 (red) was used to stain the next sequential tissue section. (2) Agreement between manual and digital analysis was performed on 19 whole slide sections of HGUC cystectomy specimens. All slides were scanned using Aperio ScanScope AT Digital Scanner at 40X. Quantitative digital image analysis was performed using QuPath version 0.2.3 open-source software. Scores from triplicate cores were averaged for each HGUC specimen for each marker. Intraclass correlation coefficients were used to compare percent positive cells between the single- and multi-plex assays. Lin's concordance correlation coefficients were used for manual versus digital analysis. RESULTS AND CONCLUSIONS: m-IHC offers significant advantages in characterizing the host immune microenvironment particularly in limited biopsy tissue material. Utilizing a digital image workflow resulted in significant concordance between m-IHC and individual single stains (p < 0.001 for all assessments). Moderate to good agreements were achieved between manual and digital scoring. Our technical work demonstrated potential uses of multiplex marker in assessing the host immune status and could be used in conjunction with PD-L1 as a predictor of response to ICI therapy.
4,136
Is CircRNA produced by back splicing of exon, intron or both, forming exon or intron circRNA?
Human transcriptome contains a large number of circular RNAs (circRNAs) that are mainly produced by back splicing of pre-mRNA.
[33662561, 34313732, 34179306, 29116363, 29322444, 33649838, 32751504, 34160816, 28265491, 27365365, 31931031, 33614648]
4,543
Protein-coding and noncoding genes in eukaryotes are typically expressed as linear messenger RNAs, with exons arranged colinearly to their genomic order. Recent advances in sequencing and in mapping RNA reads to reference genomes have revealed that thousands of genes express also covalently closed circular RNAs. Many of these circRNAs are stable and contain exons, but are not translated into proteins. Here, we review the emerging understanding that both, circRNAs produced by co- and posttranscriptional head-to-tail "backsplicing" of a downstream splice donor to a more upstream splice acceptor, as well as circRNAs generated from intronic lariats during colinear splicing, may exhibit physiologically relevant regulatory functions in eukaryotes. We describe how circRNAs impact gene expression of their host gene locus by affecting transcriptional initiation and elongation or splicing, and how they partake in controlling the function of other molecules, for example by interacting with microRNAs and proteins. We conclude with an outlook how circRNA dysregulation affects disease, and how the stability of circRNAs might be exploited in biomedical applications. CircRNAs are a subclass of lncRNAs that have been found to be abundantly present in a wide range of species, including humans. CircRNAs are generally produced by a noncanonical splicing event called backsplicing that is dependent on the canonical splicing machinery, giving rise to circRNAs classified into three main categories: exonic circRNA, circular intronic RNA, and exon-intron circular RNA. Notably, circRNAs possess functional importance and display their functions through different mechanisms of action including sponging miRNAs, or even being translated into functional proteins. In addition, circRNAs also have great potential as biomarkers, particularly in cancer, thanks to their high stability, tissue type and developmental stage specificity, and their presence in biological fluids, which make them promising candidates as noninvasive biomarkers. In this chapter, we describe the most commonly used techniques for the study of circRNAs as cancer biomarkers, including high-throughput techniques such as RNA-Seq and microarrays, and other methods to analyze the presence of specific circRNAs in patient samples. Circular RNAs (circRNAs) belong to a recently re-discovered species of RNA that emerge during RNA maturation through a process called back-splicing. A downstream 5' splice site is linked to an upstream 3' splice site to form a circular transcript instead of a canonical linear transcript. Recent advances in next-generation sequencing (NGS) have brought circRNAs back into the focus of many scientists. Since then, several studies reported that circRNAs are differentially expressed across tissue types and developmental stages, implying that they are actively regulated and not merely a by-product of splicing. Though functional studies have shown that some circRNAs could act as miRNA-sponges, the function of most circRNAs remains unknown. To expand our understanding of possible roles of circular RNAs, we propose a new pipeline that could fully characterizes candidate circRNA structure from RNAseq data-FUCHS: FUll CHaracterization of circular RNA using RNA-Sequencing. Currently, most computational prediction pipelines use back-spliced reads to identify circular RNAs. FUCHS extends this concept by considering all RNA-seq information from long reads (typically >150 bp) to learn more about the exon coverage, the number of double break point fragments, the different circular isoforms arising from one host-gene, and the alternatively spliced exons within the same circRNA boundaries. This new knowledge will enable the user to carry out differential motif enrichment and miRNA seed analysis to determine potential regulators during circRNA biogenesis. FUCHS is an easy-to-use Python based pipeline that contributes a new aspect to the circRNA research. In mammals, many classes of noncoding RNAs (ncRNAs) are expressed at a much higher level in the brain than in other organs. Recent studies have identified a new class of ncRNAs called circular RNAs (circRNAs), which are produced by back-splicing and fusion of either exons, introns, or both exon-intron into covalently closed loops. The circRNAs are also highly enriched in the brain and increase continuously from the embryonic to the adult stage. Although the functional significance and mechanism of action of circRNAs are still being actively explored, they are thought to regulate the transcription of their host genes and sequestration of miRNAs and RNA binding proteins. Some circRNAs are also shown to have translation potential to form peptides. The expression and abundance of circRNAs seem to be spatiotemporally maintained in a normal brain. Altered expression of circRNAs is also thought to mediate several disorders, including brain-tumor growth, and acute and chronic neurodegenerative disorders by affecting mechanisms such as angiogenesis, neuronal plasticity, autophagy, apoptosis, and inflammation. This review discusses the involvement of various circRNAs in brain development and CNS diseases. A better understanding of the circRNA function will help to develop novel therapeutic strategies to treat CNS complications. Circular RNAs (circRNAs) are an evolutionarily conserved novel class of non-coding endogenous RNAs (ncRNAs) found in the eukaryotic transcriptome, originally believed to be aberrant RNA splicing by-products with decreased functionality. However, recent advances in high-throughput genomic technology have allowed circRNAs to be characterized in detail and revealed their role in controlling various biological and molecular processes, the most essential being gene regulation. Because of the structural stability, high expression, availability of microRNA (miRNA) binding sites and tissue-specific expression, circRNAs have become hot topic of research in RNA biology. Compared to the linear RNA, circRNAs are produced differentially by backsplicing exons or lariat introns from a pre-messenger RNA (mRNA) forming a covalently closed loop structure missing 3' poly-(A) tail or 5' cap, rendering them immune to exonuclease-mediated degradation. Emerging research has identified multifaceted roles of circRNAs as miRNA and RNA binding protein (RBP) sponges and transcription, translation, and splicing event regulators. CircRNAs have been involved in many human illnesses, including cancer and neurodegenerative disorders such as Alzheimer's and Parkinson's disease, due to their aberrant expression in different pathological conditions. The functional versatility exhibited by circRNAs enables them to serve as potential diagnostic or predictive biomarkers for various diseases. This review discusses the properties, characterization, profiling, and the diverse molecular mechanisms of circRNAs and their use as potential therapeutic targets in different human malignancies.
4,137
How does condensin affect the function of topoisomeraseII?
Condensin prevents deleterious anaphase bridges during chromosome segregation by promoting sister chromatid decatenation.
[14600262, 22236810, 24062159, 23133392, 17360754]
4,544
Assembly of compact mitotic chromosomes and resolution of sister chromatids are two essential processes for the correct segregation of the genome during mitosis. Condensin, a five-subunit protein complex, is thought to be required for chromosome condensation. However, recent genetic analysis suggests that condensin is only essential to resolve sister chromatids. To study further the function of condensin we have depleted DmSMC4, a subunit of the complex, from Drosophila S2 cells by dsRNA-mediated interference. Cells lacking DmSMC4 assemble short mitotic chromosomes with unresolved sister chromatids where Barren, a non-SMC subunit of the complex is unable to localise. Topoisomerase II, however, binds mitotic chromatin after depletion of DmSMC4 but it is no longer confined to a central axial structure and becomes diffusely distributed all over the chromatin. Furthermore, cell extracts from DmSMC4 dsRNA-treated cells show significantly reduced topoisomerase II-dependent DNA decatenation activity in vitro. Nevertheless, DmSMC4-depleted chromosomes have centromeres and kinetochores that are able to segregate, although sister chromatid arms form extensive chromatin bridges during anaphase. These chromatin bridges do not result from inappropriate maintenance of sister chromatid cohesion by DRAD21, a subunit of the cohesin complex. Moreover, depletion of DmSMC4 prevents premature sister chromatid separation, caused by removal of DRAD21, allowing cells to exit mitosis with chromatin bridges. Our results suggest that condensin is required so that an axial chromatid structure can be organised where topoisomerase II can effectively promote sister chromatid resolution. The compaction of chromatin that occurs when cells enter mitosis is probably the most iconic process of dividing cells. Mitotic chromosomal compaction or 'condensation' is functionally linked to resolution of chromosomal intertwines, transcriptional shut-off and complete segregation of chromosomes. At present, understanding of the molecular events required to convert interphase chromatin into mitotic chromosomes is limited. Here, we review recent advances in the field, focusing on potential chromosomal compaction mechanisms and their importance to chromosome segregation. We propose a model of how metaphase chromosomes could be shaped based on the enzymatic activities of condensin and topoisomerase II in overwinding and relaxation of the DNA fiber during mitosis. We suggest that condensin overwinding is an important requirement for intertwine resolution by topoisomerase II and, together with the inhibition of transcription, contributes to cytological mitotic chromosome appearance or 'condensation'. The condensin complex is a key determinant of mitotic chromosome architecture. In addition, condensin promotes resolution of sister chromatids during anaphase, a function that is conserved from prokaryotes to human. Anaphase bridges observed in cells lacking condensin are reminiscent of chromosome segregation failure after inactivation of topoisomerase II (topo II), the enzyme that removes catenanes persisting between sister chromatids following DNA replication. Circumstantial evidence has linked condensin to sister chromatid decatenation but, because of the difficulty of observing chromosome catenation, this link has remained indirect. Alternative models for how condensin facilitates chromosome resolution have been put forward. Here, we follow the catenation status of circular minichromosomes of three sizes during the Saccharomyeces cerevisiae cell cycle. Catenanes are produced during DNA replication and are for the most part swiftly resolved during and following S-phase, aided by sister chromatid separation. Complete resolution, however, requires the condensin complex, a dependency that becomes more pronounced with increasing chromosome size. Our results provide evidence that condensin prevents deleterious anaphase bridges during chromosome segregation by promoting sister chromatid decatenation. Fragile sites are loci of recurrent chromosome breakage in the genome. They are found in organisms ranging from bacteria to humans and are implicated in genome instability, evolution, and cancer. In budding yeast, inactivation of Mec1, a homolog of mammalian ATR, leads to chromosome breakage at fragile sites referred to as replication slow zones (RSZs). RSZs are proposed to be homologous to mammalian common fragile sites (CFSs) whose stability is regulated by ATR. Perturbation during S phase, leading to elevated levels of stalled replication forks, is necessary but not sufficient for chromosome breakage at RSZs or CFSs. To address the nature of additional event(s) required for the break formation, we examined involvement of the currently known or implicated mechanisms of endogenous chromosome breakage, including errors in replication fork restart, premature mitotic chromosome condensation, spindle tension, anaphase, and cytokinesis. Results revealed that chromosome breakage at RSZs is independent of the RAD52 epistasis group genes and of TOP3, SGS1, SRS2, MMS4, or MUS81, indicating that homologous recombination and other recombination-related processes associated with replication fork restart are unlikely to be involved. We also found spindle force, anaphase, or cytokinesis to be dispensable. RSZ breakage, however, required genes encoding condensin subunits (YCG1, YSC4) and topoisomerase II (TOP2). We propose that chromosome break formation at RSZs following Mec1 inactivation, a model for mammalian fragile site breakage, is mediated by internal chromosomal stress generated during mitotic chromosome condensation. Previous studies of Epstein-Barr virus (EBV) replication focused mainly on the viral and cellular factors involved in replication compartment assembly and controlling the cell cycle. However, little is known about how EBV reorganizes nuclear architecture and the chromatin territories. In EBV-positive nasopharyngeal carcinoma NA cells or Akata cells, we noticed that cellular chromatin becomes highly condensed upon EBV reactivation. In searching for the possible mechanisms involved, we found that transient expression of EBV BGLF4 kinase induces unscheduled chromosome condensation, nuclear lamina disassembly, and stress fiber rearrangements, independently of cellular DNA replication and Cdc2 activity. BGLF4 interacts with condensin complexes, the major components in mitotic chromosome assembly, and induces condensin phosphorylation at Cdc2 consensus motifs. BGLF4 also stimulates the decatenation activity of topoisomerase II, suggesting that it may induce chromosome condensation through condensin and topoisomerase II activation. The ability to induce chromosome condensation is conserved in another gammaherpesvirus kinase, murine herpesvirus 68 ORF36. Together, these findings suggest a novel mechanism by which gammaherpesvirus kinases may induce multiple premature mitotic events to provide more extrachromosomal space for viral DNA replication and successful egress of nucleocapsid from the nucleus.
4,138
Which signaling pathway does LY294002 inhibit?
LY294002, can block the PI3K/AKT signaling pathway.
[34820336]
4,545
Internal tandem duplications (ITD) mutation within FMS-like tyrosine kinase 3 (FLT3), the most frequent mutation happens in almost 20% acute myeloid leukemia (AML) patients, always predicts a poor prognosis. As a small molecule tyrosine kinase inhibitor, sorafenib is clinically used for the treatment of advanced renal cell carcinoma (RCC), hepatocellular carcinoma (HCC), and differentiated thyroid cancer (DTC), with its preclinical and clinical activity demonstrated in the treatment of Fms-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutant AML. Even though it shows a rosy future in the AML treatment, the short response duration remains a vital problem that leads to treatment failure. Rapid onset of drug resistance is still a thorny problem that we cannot overlook. Although the mechanisms of drug resistance have been studied extensively in the past years, there is still no consensus on the exact reason for resistance and without effective therapeutic regimens established clinically. My previous work reported that sorafenib-resistant FLT3-ITD mutant AML cells displayed mitochondria dysfunction, which rendered cells depending on glycolysis for energy supply. In my present one, we further illustrated that losing the target protein FLT3 and the continuously activated PI3K/Akt signaling pathway may be the reason for drug resistance, with sustained activation of PI3K/AKT signaling responsible for the highly glycolytic activity and adenosine triphosphate (ATP) generation. PI3K inhibitor, LY294002, can block PI3K/AKT signaling, further inhibit glycolysis to disturb ATP production, and finally induce cell apoptosis. This finding would pave the way to remedy the FLT3-ITD mutant AML patients who failed with FLT3 targeted therapy.
4,139
Is METTL1 overexpression associated with better patient survival?
No. METTL1 is frequently amplified and overexpressed in cancers and is associated with poor patient survival.
[34352207]
4,546
Author information: (1)Stem Cell Program, Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA. (2)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK; Milner Therapeutics Institute, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; Storm Therapeutics Ltd., Moneta Building (B280), Babraham Research Campus, Cambridge CB22 3AT, UK. (3)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK. (4)Department of Pathology, Cancer Center, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA. (5)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK; Karaiskakio Foundation, Nicandrou Papamina Avenue, 2032 Nicosia, Cyprus. (6)Division of Newborn Medicine and Epigenetics Program, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA. (7)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK; Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK. (8)Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, USA. (9)Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA. (10)Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK. (11)Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA. (12)Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK. (13)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK; Karaiskakio Foundation, Nicandrou Papamina Avenue, 2032 Nicosia, Cyprus; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK. (14)Department of Pathology, Cancer Center, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Harvard Initiative for RNA Medicine, Boston, MA 02115, USA. (15)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK; Milner Therapeutics Institute, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK. Electronic address: kt404@cam.ac.uk. (16)Stem Cell Program, Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Harvard Initiative for RNA Medicine, Boston, MA 02115, USA. Electronic address: rgregory@enders.tch.harvard.edu.
4,140
List monoclonal antibodies included in the REGEN-COV.
REGEN-COV is a combination of the monoclonal antibodies casirivimab and imdevimab. It has been shown to markedly reduce the risk of hospitalization or death among high-risk persons with coronavirus disease 2019.
[34393218, 34716907, 34347950, 34159343, 34159344, 34463470, 34587383, 34673689]
4,547
Regulatory authorities, including the US Food and Drug Administration (FDA), have accelerated diagnostic and therapeutic approvals during the coronavirus disease 2019 (COVID-19) pandemic. Accelerated clinical development and approvals have resulted in vaccine programs for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, some individuals remain at high risk for the progression of COVID-19. In the US, the FDA has given Emergency Use Authorization (EUA) for two neutralizing therapeutic monoclonal antibody 'cocktails,' casirivimab and imdevimab (REGEN-COV), bamlanivimab and etesevimab, and one monotherapy, bamlanivimab, for prophylactic post-exposure therapy in individuals at high risk of progressing to severe COVID-19. Preclinical and clinical studies showed consistent effectiveness of REGEN-COV against current variants of SARS-CoV-2. On 21st November 2020, the FDA approved an initial EUA for REGEN-COV to treat mild to moderate COVID-19 in adults and in children 12 years or older with exposure to SARS-CoV-2 at high risk for progression to severe COVID-19. On 30th July 2021, the FDA updated its EUA for REGEN-COV for emergency use as post-exposure prophylactic to prevent COVID-19 progression in adults and children aged 12 years or older. This Editorial aims to provide an update on accelerated regulatory authorization for post-exposure prophylactic neutralizing monoclonal antibodies to SARS-CoV-2 for individuals at high risk for COVID-19. Collaborators: Warshoff N, Moreiras L, Altamirano D, Ellington D, Faikih F, Smith W, Gibson R, Buckner K, Rosen R, Sapp A, Kohli A, McIntyre V, Sachdeva Y, McFarland A, Gibson D, Kim K, Ahn J, Neinchel L, Paryani N, Mottola A, Day E, Navarro M, Victoria R, Victoria X, Uong R, Sampson M, Polk C, Leonard M, McCurdy L, Medaris LA, Shahid Z, Davidson L, Nazir J, Lee J, Elliott A, Sathyanaryan S, Oberoi M, Siddiqui M, Arsad M, Bruning K, Hosek S, Oyedele T, Sarda V, Mercon M, Stephenson K, Barouch D, Juelg B, Tan CS, Zash R, Collier AR, Ansel J, Jaegle K, Roque-Guerrero L, Gomez Ramirez A, Capote J, Paz G, Paasche-Orlow M, Dedier J, Vadgama S, Patak R, Chronos N, Hefty C, Borger J, Momodu I, Carswell L, King B, Starr R, Syndergaard S, Patel N, Patel R, Sattar R, Mohseni R, Unger J, De Jesus-Maranan S, Casaclang C, Seep M, Brown C, Whatley J, Levinson D, Alvi S, James N, Ahmed A, Koilpillai R, Cassady S, Cox J, Torres E, Krainson J, Rosenthal MJ, Winnie M, Plemons J, Verma O, Leggett R, Reyes R, Beck K, Poliquin B, Mussaji M, Shah J, Sutton D, Pereira E, Gloria R, Kelly S, Dennis-Saltz A, Sheikh-Ali M, Saikali E, Magee J, Goldfaden R, Boghara H, Patel S, Eichelbaum B, Anderson D, Su S, Akhavan A, Kirby D, Venglik J, Mayer K, Khan T, Gelman M, Fakih FA, Fakih FM, Layish D, Alvarado F, Diaz J, Focil A, Rosas G, Correa S, Bogseth M, Patel B, Tarshis G, Grablin K, Simonelli P, Martin S, Sharma A, Chen A, Dhaubhadel P, Khan S, Naik S, Penupolu S, Sivarajah T, Kwon TS, Saladi L, Raiszadeh F, Myint KT, Kyaw A, Dowie D, O'Reilly R, Varghese L, Bratu S, Assallum H, Weerasinghe AT, Ayinla R, Mannheimer S, Morrison E, Franks J, Avelino Loquere J, Rosario O, Low A, Villacrucis J, Skolnick A, Minkowitz H, Leiman D, Price T, Krasko A, Wiener I, Reed L, Lin O, Ramesh M, Alangaden G, Saggar S, Birch T, De La Rosa B, Neyra K, Kunwar E, Kingsley J, Pixler A, McBride V, Aberg J, Cespedes M, Abrams-Downey A, Kojic E, Lugo L, Liu S, Salomon N, Perlman D, Altman D, Rahman F, Osorio G, Mathew J, Koshy S, Mazo D, Cossarini F, Middleton S, Jen A, Reategui Schwarz EM, Trevino M, DeVries B, Menon V, Kasubhai M, Venugopal U, Pillai A, Oulds F, Hong M, Harper W, Eckert L, Wadeson D, Cohen L, Chua J, Kottilil S, Husson J, Baddley J, Wilkerson RG, Narayanan S, Eke U, Noe M, Malave Sanchez M, Kim A, Robbins G, Siedner M, Gandhi R, Hysell K, Lazarus J, Yonker L, Arduino R, Vigil KJ, Perez-Perez R, Bello CJ, Arce-Nunez E, Acosta J, Arronte JL, Meissner E, Flume P, Goodwin A, Jandhyala D, Nadig N, Jeanfreau R, Jeanfreau S, Tortorich S, Akula S, Matherne P, Gaddy D, Mikhail M, Annamalai R, Nguyen H, Nayani N, Ramchandra M, Mehta P, Horne J, Hassan G, Oguchi G, Onyema J, Ramgopal M, Jacobs B, Cason L, Trodglen A, Streinu A, Manolache D, Streinu-Cercel A, Sandulescu O, Blanaru A, Stoica M, Andone AM, Dospinoiu D, Serban S, Patru L, Buhuara C, Dorobantu R, Motoi M, Daramus I, Bihoi G, Ghita A, Miron V, Spataru G, Nyaku A, Swaminathan S, Chang T, Traylor R, Gordon L, McDivitt J, Castro L, Young D, Carson G, Kottkamp A, Mulligan MJ, Bershteyn A, Raabe V, Davis T, Olson M, Brill S, Malvestutto C, Koletar S, Saigal T, Sobhanie M, Doraiswamy V, Hassan MA, Young J, DeJesus E, Rolle CP, Hinestrosa F, Cruz D, Wilder T, Garrett J, Skipper S, Dandillaya R, Ananth K, Frank I, Koenig H, Donaghy E, Dunbar D, Killion J, Amin R, Basener S, Lowry T, Cannon K, Chadwick M, Galvez O, Castillo F, Jefferies J, Arnold S, Thacker A, Cordasco E, Zeno B, Holmes H, Lee H, Gaibu N, Cojocaru V, Seremet A, Iacob S, Usatii R, Ghicavii N, Coltuclu A, Bujor O, Mylonakis E, Farmakiotis D, Tashima K, Ryback N, Ruane P, Wolfe P, Trinidad K, Moy J, Shah R, Sindhura B, Sha B, Savant M, Hsiao F, Yee E, Gordillo M, Bhattacharyya R, Tallapragada S, Artau A, Larkin J, Mercado R, Milam M, Kraitman N, Lowry M, Temple S, Offner L, Loutfi R, Voelker K, Frank M, Grant A, Sims J 3rd, Vasquez M, Degazon K, Asuncion K, Andrews J, Subramanian A, Singh U, Maldonado Y, Khosla C, Olivera E, Abreu M, Fatakia A, Miller M, Clinton K, Reiss G, Edupuganti S, Rouphael N, Kelley C, Phadke V, Grimsley Ackerley C, Collins M, Miller L, Hatlen T, Chung M, Cantos Lucio V, Del Rio C, Lennox J, Kandiah S, Moran C, Sheth A, Rebolledo P, Gopalsamy N, Bhamidipati D, Osiyemi O, Menajovsky-Chaves JA, Campbell C, Strand A, Klein A, Poutsiaka D, Viau Colindres R, Chow B, Thorpe C, Hopkins M, Chow J, Kohli R, Caro J, Griffiths J, Boucher H, Perry W, Kogelman L, Golan Y, Vindenes T, Mendoza C, Mostafavi S, Cano Guerra CA, Dabenigno P, Malla B, Fusco D, Drouin A, Denson J, Zifodya J, Bojanowski C, Dietrich M, Drury S, Herrick J, Novak R, Patel M, Acloque G, Martinez A, Sethi S, Clemency B, Kunadharaju R, Parthasarathy S, Rischard F, Cohen S, Thompson G, Nguyen H, Crabtree S, Fichtenbaum C, Huaman M, Robertson J, Simoes E, Campbell T, Ramanan P, Dunlevy H, Benamu E, Baduashvili A, Krsak M, Johnson S, Chauhan L, Fredregil E, Economos S, Kleiner G, Abbo L, Shukla B, Gebbia J, Rodriguez M, Leuck AM, Abassi M, Pullen M, Lloveras JL, Mena L, Shimose Ciudad L, Lin J, Wohl D, Hurt C, Fischer W 2nd, Tompkins K, Kim K, Lakshmi S, Somboonwit C, Wilson J, Oxner A, Vasey T, Guerra L, Petri W, Dykstra K, Morrissey M, Cesko L, Shin J, Warren C, Sasson J, Marie C, Shirley DA, Carpenter R, Madden G, Donigan D, Sutton M, Edwards C, Brooks E, Wade R, Simmons S, Pinnata J, Barnabas R, Karuna S, Collier AC, McElrath J, Maenza J, Shapiro A, Stankiewicz-Karita H, Chu H, Church C, Hartman W, Connor J, Striker R, Philley J, Devine M, Yates R, Hickerson S, Kalams S, Wilson G, Donnenberg M, de Wit M, Erb D, DeLaCruz L, Channa S, Henn S, Coleman M, MacLaren L, Goldstein D, Eggleston A, Koebele C, McKenzie M, Deese T, Thomas B, Tsakiris L, Blank S, Mirenda R, Martin A, Gharat G, Kokaram C, Wray K, Partap C, Arzamasova U, Louissaint K, Fernandez M, Chani A, Adepoju A, Mahmood A, Mortagy A, Dupljak A, Baum A, Brown A, Froment A, Hooper A, Margiotta A, Bombardier A, Islam A, Smith A, Dhillon A, McMillian A, Breazna A, Aslam A, Carpentino B, Kowal B, Siliverstein B, Horel B, Zhu B, Musser B, Bush B, Head B, Snow B, Zhu B, Debray C, Phillips C, Simiele C, Lee C, Nienstedt C, Trbovic C, Chan C, Elliott C, Fish C, Ni C, Polidori C, Enciso C, Caira C, Powell C, Kyratsous CA, Baum C, McDonald C, Leigh C, Pan C, Wolken D, Manganello D, Liu D, Stein D, Weinreich DM, Hassan D, Gulabani D, Fix D, Leonard D, Sarda D, Bonhomme D, Kennedy D, Darcy D, Barron D, Hughes D, Rofail D, Kaur D, Ramesh D, Bianco D, Cohen D, Forleo Neto E, Jean-Baptiste E, Bukhari E, Doyle E, Bucknam E, Labriola-Tomkins E, Nanna E, O'Keefe EH, Gasparino E, Fung E, Isa F, To FY, Herman G, Yancopoulos GD, Bellingham G, Sumner G, Moggan G, Power G, Zeng H, Mariveles H, Gonzalez H, Kang H, Noor H, Minns I, Heirman I, Peszek I, Donohue J, Rusconi J, Austin J, Parrino J, Yo J, McDonnell J, Hamilton JD, Boarder J, Wei J, Yu J, Malia J, Tucciarone J, Tyler-Gale J, Davis JD, Strein J, Cohen J, Meyer J, Ursino J, Im J, Tramaglini J, Wolken J, Potter K, Scacalossi K, Naidu K, Browning K, Rutkowski K, Yau K, Woloshin K, Lewis-Amezcua K, Turner K, Dornheim K, Chiu K, Mohan K, McGuire K, Macci K, Ringleben K, Mohammadi K, Foster K, Knighton L, Lipsich L, Darling L, Boersma L, Cowen L, Hersh L, Jackson L, Purcell L, Sherpinsky L, Lai L, Faria L, Geissler L, Boppert L, Fiske L, Dickens M, Mancini M, Leigh MC, O'Brien M, Batchelder M, Klinger M, Partridge M, Tarabocchia M, Wong M, Rodriguez M, Albizem M, O'Byrne M, Braunstein N, Sarkar N, Stahl N, Deitz N, Memblatt N, Shah N, Kumar N, Herrera O, Adedoyin O, Yellin O, Snodgrass P, Floody P, D'Ambrosio P, Gao P, Hou P, Hearld P, Li Q, Kitchenoff R, Ali R, Iyer R, Chava R, Alaj R, Pedraza R, Hamlin R, Hosain R, Gorawala R, White R, Yu R, Fogarty R, Dass SB, Bollini S, Ganguly S, DeCicco S, Patel S, Cassimaty S, Somersan-Karakaya S, McCarthy S, Henkel S, Ali S, Geila Shapiro S, Kim S, Nossoughi S, Bisulco S, Elkin S, Long S, Sivapalasingam S, Irvin S, Wilt S, Min T, Constant T, Devins T, DiCioccio T, Norton T, Bernardo T, Chuang TC, Wei V, Nuce V, Battini V, Caldwell W, Gao X, Chen X, Tian Y, Khan Y, Zhao Y, Kim Y, Dye B, Hurt CB, Burwen DR, Barouch DH, Burns D, Brown E, Bar KJ, Marovich M, Clement M, Cohen MS, Sista N, Barnabas RV, Zwerski S. IMPORTANCE: Easy-to-administer antiviral treatments may be used to prevent progression from asymptomatic infection to COVID-19 and to reduce viral carriage. OBJECTIVE: Evaluate the efficacy and safety of subcutaneous casirivimab and imdevimab antibody combination (REGEN-COV) to prevent progression from early asymptomatic SARS-CoV-2 infection to COVID-19. DESIGN: Randomized, double-blind, placebo-controlled, phase 3 study that enrolled asymptomatic close contacts living with a SARS-CoV-2-infected household member (index case). Participants who were SARS-CoV-2 RT-qPCR-positive at baseline were included in the analysis reported here. SETTING: Multicenter trial conducted at 112 sites in the United States, Romania, and Moldova. PARTICIPANTS: Asymptomatic individuals ≥12 years of age were eligible if identified within 96 hours of collection of the index case's positive SARS-CoV-2 test sample. INTERVENTIONS: A total of 314 asymptomatic, SARS-CoV-2 RT-qPCR-positive individuals living with an infected household contact were randomized 1:1 to receive a single dose of subcutaneous REGEN-COV 1200mg (n=158) or placebo (n=156). MAIN OUTCOMES AND MEASURES: The primary endpoint was the proportion of participants who developed symptomatic COVID-19 during the 28-day efficacy assessment period. The key secondary efficacy endpoints were the number of weeks of symptomatic SARS-CoV-2 infection and the number of weeks of high viral load (>4 log10 copies/mL). Safety was assessed in all treated participants. RESULTS: Subcutaneous REGEN-COV 1200mg significantly prevented progression from asymptomatic to symptomatic disease compared with placebo (31.5% relative risk reduction; 29/100 [29.0%] vs 44/104 [42.3%], respectively; P=.0380). REGEN-COV reduced the overall population burden of high-viral load weeks (39.7% reduction vs placebo; 48 vs 82 total weeks; P=.0010) and of symptomatic weeks (45.3% reduction vs placebo; 89.6 vs 170.3 total weeks; P=.0273), the latter corresponding to an approximately 5.6-day reduction in symptom duration per symptomatic participant. Six placebo-treated participants had a COVID-19-related hospitalization or ER visit versus none for those receiving REGEN-COV. The proportion of participants receiving placebo who had ≥1 treatment-emergent adverse events was 48.1% compared with 33.5% for those receiving REGEN-COV, including events related (39.7% vs 25.8%, respectively) or not related (16.0% vs 11.0%, respectively) to COVID-19. CONCLUSIONS AND RELEVANCE: Subcutaneous REGEN-COV 1200mg prevented progression from asymptomatic SARS-CoV-2 infection to COVID-19, reduced the duration of high viral load and symptoms, and was well tolerated. TRIAL REGISTRATION: ClinicalTrials.gov Identifier, NCT04452318. BACKGROUND: Casirivimab and imdevimab (REGEN-COV™) markedly reduces risk of hospitalization or death in high-risk individuals with Covid-19. Here we explore the possibility that subcutaneous REGEN-COV prevents SARS-CoV-2 infection and subsequent Covid-19 in individuals at high risk of contracting SARS-CoV-2 by close exposure in a household with a documented SARS-CoV-2-infected individual. METHODS: Individuals ≥12 years were enrolled within 96 hours of a household contact being diagnosed with SARS-CoV-2 and randomized 1:1 to receive 1200 mg REGEN-COV or placebo via subcutaneous injection. The primary efficacy endpoint was the proportion of participants without evidence of infection (SARS-CoV-2 RT-qPCR-negative) or prior immunity (seronegative) who subsequently developed symptomatic SARS-CoV-2 infection during a 28-day efficacy assessment period. RESULTS: Subcutaneous REGEN-COV significantly prevented symptomatic SARS-CoV-2 infection compared with placebo (81.4% risk reduction; 11/753 [1.5%] vs. 59/752 [7.8%], respectively; P<0.0001), with 92.6% risk reduction after the first week (2/753 [0.3%] vs. 27/752 [3.6%], respectively). REGEN-COV also prevented overall infections, either symptomatic or asymptomatic (66.4% risk reduction). Among infected participants, the median time to resolution of symptoms was 2 weeks shorter with REGEN-COV vs. placebo (1.2 vs. 3.2 weeks, respectively), and the duration of time with high viral load (>104 copies/mL) was lower (0.4 vs. 1.3 weeks, respectively). REGEN-COV was generally well tolerated. CONCLUSIONS: Administration of subcutaneous REGEN-COV prevented symptomatic Covid-19 and asymptomatic SARS-CoV-2 infection in uninfected household contacts of infected individuals. Among individuals who became infected, REGEN-COV reduced the duration of symptomatic disease, decreased maximal viral load, and reduced the duration of detectable virus.(ClinicalTrials.gov number, NCT04452318.). The emergency use authorization for REGEN-COV (a combination of two monoclonal antibodies, casirivimab and imdevimab) has been revised to include postexposure prophylaxis of COVID-19 in adults and children 12 years of age and older who, if they become COVID-19 positive, are at high risk for severe disease.Prophylaxis with REGEN-COV is not a substitute for vaccination against COVID-19.
4,141
Which disease is caused by mutations in the gene PRF1?
The presence of mutations in PRF1, UNC13D, STX11 and STXBP2 genes in homozygosis or compound heterozygosis results in immune deregulation. Most such cases lead to clinical manifestations of haemophagocytic lymphohistiocytosis (HLH).
[29216683, 34339548, 33869605, 31865540]
4,548
BACKGROUND: Familial hemophagocytic lymphohistiocytosis (FHL) is a primary immunodefici-ency disease caused by gene defects. The onset of FHL in adolescents and adults may lead clinicians to ignore or even misdiagnose the disease. To the best of our knowledge, this is the first report to detail the clinical features of type 2 FHL (FHL2) with compound heterozygous perforin (PRF1) defects involving the c.163C>T mutation, in addition to correlation analysis and a literature review. CASE SUMMARY: We report a case of a 27-year-old male patient with FHL2, who was admitted with a persistent fever and pancytopenia. Through next-generation sequencing technology of hemophagocytic lymphohistiocytosis (HLH)-related genes, we found compound heterozygous mutations of PRF1: c.65delC (p.Pro22Argfs*29) (frameshift mutation, paternal) and c.163C>T (p.Arg55Cys) (missense mutation, maternal). Although he did not receive hematopoietic stem cell transplantation, the patient achieved complete remission after receiving HLH-2004 treatment protocol. To date, the patient has stopped taking drugs for 15 mo, is in a stable condition, and is under follow-up observation. CONCLUSION: The delayed onset of FHL2 may be related to the PRF1 mutation type, pathogenic variation pattern, triggering factors, and the temperature sensitivity of some PRF1 mutations. For individual, the detailed reason for the delay in the onset of FHL warrants further investigation. Author information: (1)Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Jeffrey Model Foundation Excellence Center, Barcelona, Catalonia, Spain. (2)Immune Regulation and Immunotherapy Group, CIBBIM-Nanomedicine, Vall d'Hebron Institut de Recerca, Universitat Autonoma de Barcelona, Barcelona, Spain. (3)Functional Unit of Clinical Immunology and Primary Immunodeficiencies, Allergy and Clinical Immunology Department, Hospital Sant Joan de Déu, University of Barcelona, Pediatric Research Institute Sant Joan de Déu, Barcelona, Spain. (4)Research Unit in Translational Bioinformatics in Neurosciences, Universitat Autònoma de Barcelona, Barcelona, Spain. (5)Hematology Department, Hospital Sant Joan de Déu, Universitat de Barcelona, Barcelona, Spain. (6)Institut de Recerca Hospital Sant Joan de Déu Barcelona, Barcelona, Spain. (7)Diagnostic Immunology Research Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Catalonia, Spain. (8)Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona (UAB), Barcelona, Catalonia, Spain. (9)Genetics Department, Hospital Universitari Vall d'Hebron (HUVH), Barcelona, Catalonia, Spain. (10)Institut Catala per la Recerca i Estudis Avançats (ICREA), Barcelona, Spain. (11)Immune Regulation and Immunotherapy Group, CIBBIM-Nanomedicine, Vall d'Hebron Institut de Recerca, Universitat Autonoma de Barcelona, Barcelona, Spain. joan.sayos@vhir.org. (12)Institut de Recerca Vall hebron (VHIR), Immune Regulation and Immunotherapy Group, Edifici Mediterrania, Lab 09, Planta baixa, Passeig Vall d'Hebron 119-129, 08035, Barcelona, Spain. joan.sayos@vhir.org. (13)Immunology Division, Hospital Universitari Vall d'Hebron (HUVH), Jeffrey Model Foundation Excellence Center, Barcelona, Catalonia, Spain. mmartinez@vhebron.net. (14)Diagnostic Immunology Research Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Catalonia, Spain. mmartinez@vhebron.net. (15)Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona (UAB), Barcelona, Catalonia, Spain. mmartinez@vhebron.net.
4,142
What protein is encoded by the GRN gene?
Loss-of-function mutations in the gene encoding for the protein progranulin (PGRN), GRN, are one of the major genetic abnormalities involved in frontotemporal lobar degeneration.
[30862089, 33433870, 32507413, 33433878, 33636385, 26652843, 34433069, 31626287, 31962288, 24709683, 33028409, 24503614, 29744576, 32929860, 22277331, 29053785, 23383391, 31864418, 31291241, 20946666, 28778989, 28828399]
4,549
Neurodegenerative diseases such as Alzheimer's disease have proven resistant to new treatments. The complexity of neurodegenerative disease mechanisms can be highlighted by accumulating evidence for a role for a growth factor, progranulin (PGRN). PGRN is a glycoprotein encoded by the GRN/Grn gene with multiple cellular functions, including neurotrophic, anti-inflammatory and lysosome regulatory properties. Mutations in the GRN gene can lead to frontotemporal lobar degeneration (FTLD), a cause of dementia, and neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Both diseases are associated with loss of PGRN function resulting, amongst other features, in enhanced microglial neuroinflammation and lysosomal dysfunction. PGRN has also been implicated in Alzheimer's disease (AD). Unlike FTLD, increased expression of PGRN occurs in brains of human AD cases and AD model mice, particularly in activated microglia. How microglial PGRN might be involved in AD and other neurodegenerative diseases will be discussed. A unifying feature of PGRN in diseases might be its modulation of lysosomal function in neurons and microglia. Many experimental models have focused on consequences of PGRN gene deletion: however, possible outcomes of increasing PGRN on microglial inflammation and neurodegeneration will be discussed. We will also suggest directions for future studies on PGRN and microglia in relation to neurodegenerative diseases. Numerous kindreds with familial frontotemporal lobar degeneration have been linked to mutations in microtubule-associated protein tau (MAPT) or progranulin (GRN) genes. While there are many similarities in the clinical manifestations and associated neuroimaging findings, there are also distinct differences. In this review, we compare and contrast the demographic/inheritance characteristics, histopathology, pathophysiology, clinical aspects, and key neuroimaging findings between those with MAPT and GRN mutations. Loss-of-function mutations in the gene encoding for the protein progranulin (PGRN), GRN, are one of the major genetic abnormalities involved in frontotemporal lobar degeneration. However, genetic variations, mainly missense, in GRN have also been linked to other neurodegenerative diseases. We found 12 different pathogenic/likely pathogenic variants in 21 patients identified in a cohort of Italian patients affected by various neurodegenerative disorders. We detected the p.Thr272SerfsTer10 as the most frequent, followed by the c.1179+3A>G variant. We characterized the clinical phenotype of 12 patients from 3 pedigrees carrying the c.1179+3A>G variant, demonstrated the pathogenicity of this mutation, and detected other rarer variants causing haploinsufficiency (p.Met1?, c.709-2A>T, p.Gly79AspfsTer39). Finally, by applying bioinformatics, neuropathological, and biochemical studies, we characterized 6 missense/synonymous variants (p.Asp94His, p.Gly117Asp, p.Ala266Pro, p.Val279Val, p.Arg298His, p.Ala505Gly), including 4 previously unreported. The designation of variants is crucial for genetic counseling and the enrollment of patients in clinical studies. It has been more than a decade since heterozygous loss-of-function mutations in the progranulin gene (GRN) were first identified as an important genetic cause of frontotemporal lobar degeneration (FTLD). Due to the highly diverse biological functions of the progranulin (PGRN) protein, encoded by GRN, multiple possible disease mechanisms have been proposed. Early work focused on the neurotrophic properties of PGRN and its role in the inflammatory response. However, since the discovery of homozygous GRN mutations in patients with a lysosomal storage disorder, investigation into the possible roles of PGRN and its proteolytic cleavage products granulins, in lysosomal function and dysfunction, has taken center stage. In this chapter, we summarize the GRN mutational spectrum and its associated phenotypes followed by an in-depth discussion on the possible disease mechanisms implicated in FTLD-GRN. We conclude with key outstanding questions which urgently require answers to ensure safe and successful therapy development for GRN mutation carriers. The granulin protein (also known as, and hereafter referred to as, progranulin) is a secreted glycoprotein that contributes to overall brain health. Heterozygous loss-of-function mutations in the gene encoding the progranulin protein (Granulin Precursor, GRN) are a common cause of familial frontotemporal dementia (FTD). Gene therapy approaches that aim to increase progranulin expression from a single wild-type allele, an area of active investigation for the potential treatment of GRN-dependent FTD, will benefit from the availability of a mouse model that expresses a genomic copy of the human GRN gene. Here we report the development and characterization of a novel mouse model that expresses the entire human GRN gene in its native genomic context as a single copy inserted into a defined locus (Hprt) in the mouse genome. We show that human and mouse progranulin are expressed in a similar tissue-specific pattern, suggesting that the two genes are regulated by similar mechanisms. Human progranulin rescues a phenotype characteristic of progranulin-null mice, the exaggerated and early deposition of the aging pigment lipofuscin in the brain, indicating that the two proteins are functionally similar. Longitudinal behavioural and neuropathological analyses revealed no significant differences between wild-type and human progranulin-overexpressing mice up to 18 months of age, providing evidence that long-term increase of progranulin levels is well tolerated in mice. Finally, we demonstrate that human progranulin expression can be increased in the brain using an antisense oligonucleotide that inhibits a known GRN-regulating micro-RNA, demonstrating that the transgene is responsive to potential gene therapy drugs. Human progranulin-expressing mice represent a novel and valuable tool to expedite the development of progranulin-modulating therapeutics. GRN, the gene coding for the progranulin (PGRN) protein, was recognized as a gene linked to frontotemporal lobar degeneration (FTLD). The first mutations identified were null mutations giving rise to haploinsufficiency. Missense mutations were subsequently detected, but only a small subset has been functionally investigated. We identified missense mutations (C105Y, A199V, and R298H) in FTLD cases with family history and/or with low plasma PGRN levels. The aim of this study was to determine their pathogenicity. We performed functional studies, analyzing PGRN expression, secretion, and cleavage by elastase. GRN C105Y affected both secretion and elastase cleavage, likely representing a pathogenic mutation. GRN A199V did not alter the physiological properties of PGRN and GRN R298H produced only moderate effects on PGRN secretion, indicating that their pathogenicity is uncertain. In the absence of strong segregation data and neuropathological examinations, genetic, biomarker, and functional studies can be applied to an algorithm to assess the likelihood of pathogenicity for a mutation. This information can improve our understanding of the complex mechanisms by which GRN mutations lead to FTLD. Mutations in the GRN gene coding for progranulin (PGRN) are responsible for many cases of familial frontotemporal lobar degeneration (FTLD) with TAR DNA-binding protein 43 (TDP-43)-positive inclusions (FTLD-TDP). GRN mutations create null alleles resulting in decreased progranulin protein or haploinsufficiency. FTLD-TDP with GRN mutations is characterized by lentiform neuronal intranuclear inclusions that are positive for TDP-43 in affected brain regions. In this study, by stably expressed short hairpin RNA, we established a neuroblastoma cell line with decreased PGRN level. This cell line reveals TDP-43-positive intranuclear inclusions. In addition, replacement with purified PGRN protein restores normal TDP-43 nuclear distribution. This cell model can be valuable for the study of the role of PGRN in the pathogenesis in FTLD-TDP. Understanding of frontotemporal lobar degeneration, the underlying pathology most often linked to the clinical diagnosis of frontotemporal dementia, is rapidly increasing. Mutations in 7 known genes (MAPT, GRN, C9orf72, VCP, CHMP2B, and, rarely, TARDBP and FUS) are associated with frontotemporal dementia, and the pathologic classification of frontotemporal lobar degeneration has recently been modified to reflect these discoveries. Mutations in one of these genes (GRN), which encodes progranulin, have been implicated in up to a quarter of cases of frontotemporal lobar degeneration with TDP-43 (TAR DNA-binding protein 43)-positive inclusions; currently, there are more than 60 known pathogenic mutations of the gene. We present the clinical, pathologic, and genetic findings on 6 cases from 4 families, 5 of which were shown to have a novel GRN c.708+6_+9delTGAG mutation. Single nucleotide polymorphisms (SNPs) in TMEM106B encoding the lysosomal type II transmembrane protein 106B increase the risk for frontotemporal lobar degeneration (FTLD) of GRN (progranulin gene) mutation carriers. Currently, it is unclear if progranulin (PGRN) and TMEM106B are synergistically linked and if a gain or a loss of function of TMEM106B is responsible for the increased disease risk of patients with GRN haploinsufficiency. We therefore compare behavioral abnormalities, gene expression patterns, lysosomal activity, and TDP-43 pathology in single and double knockout animals. Grn-/- /Tmem106b-/- mice show a strongly reduced life span and massive motor deficits. Gene expression analysis reveals an upregulation of molecular signature characteristic for disease-associated microglia and autophagy. Dysregulation of maturation of lysosomal proteins as well as an accumulation of ubiquitinated proteins and widespread p62 deposition suggest that proteostasis is impaired. Moreover, while single Grn-/- knockouts only occasionally show TDP-43 pathology, the double knockout mice exhibit deposition of phosphorylated TDP-43. Thus, a loss of function of TMEM106B may enhance the risk for GRN-associated FTLD by reduced protein turnover in the lysosomal/autophagic system. Progranulin, a secreted glycoprotein, is encoded in humans by the single GRN gene. Progranulin consists of seven and a half, tandemly repeated, non-identical copies of the 12 cysteine granulin motif. Many cellular processes and diseases are associated with this unique pleiotropic factor that include, but are not limited to, embryogenesis, tumorigenesis, inflammation, wound repair, neurodegeneration and lysosome function. Haploinsufficiency caused by autosomal dominant mutations within the GRN gene leads to frontotemporal lobar degeneration, a progressive neuronal atrophy that presents in patients as frontotemporal dementia. Frontotemporal dementia is an early onset form of dementia, distinct from Alzheimer's disease. The GRN-related form of frontotemporal lobar dementia is a proteinopathy characterized by the appearance of neuronal inclusions containing ubiquitinated and fragmented TDP-43 (encoded by TARDBP). The neurotrophic and neuro-immunomodulatory properties of progranulin have recently been reported but are still not well understood. Gene delivery of GRN in experimental models of Alzheimer's- and Parkinson's-like diseases inhibits phenotype progression. Here we review what is currently known concerning the molecular function and mechanism of action of progranulin in normal physiological and pathophysiological conditions in both in vitro and in vivo models. The potential therapeutic applications of progranulin in treating neurodegenerative diseases are highlighted. Progranulin is a growth factor involved in the regulation of multiple processes including tumorigenesis, wound repair, development, and inflammation. The recent discovery that mutations in the gene encoding for progranulin (GRN) cause frontotemporal lobar degeneration (FTLD), and other neurodegenerative diseases leading to dementia, has brought renewed interest in progranulin and its functions in the central nervous system. GRN null mutations cause protein haploinsufficiency, leading to a significant decrease in progranulin levels that can be detected in plasma, serum and cerebrospinal fluid (CSF) of mutation carriers. The dosage of circulating progranulin sped up the identification of GRN mutations thus favoring genotype-phenotype correlation studies. Researchers demonstrated that, in GRN null mutation carriers, the shortage of progranulin invariably precedes clinical symptoms and thus mutation carriers are "captured" regardless of their disease status. GRN is a particularly appealing gene for drug targeting, in the way that boosting its expression may be beneficial for mutation carriers, preventing or delaying the onset of GRN-related neurodegenerative diseases. Physiological regulation of progranulin expression level is only partially known. Progranulin expression reflects mutation status and, intriguingly, its levels can be modulated by some additional factor (i.e. genetic background; drugs). Thus, factors increasing the production and secretion of progranulin from the normal gene are promising potential therapeutic avenues. In conclusion, peripheral progranulin is a nonintrusive highly accurate biomarker for early identification of mutation carriers and for monitoring future treatments that might boost the level of this protein. Progranulin (PGRN) is a protein encoded by the GRN gene with multiple identified functions including as a neurotrophic factor, tumorigenic growth factor, anti-inflammatory cytokine and regulator of lysosomal function. A single mutation in the human GRN gene resulting in reduced PGRN expression causes types of frontotemporal lobar degeneration resulting in frontotemporal dementia. Prosaposin (PSAP) is also a multifunctional neuroprotective secreted protein and regulator of lysosomal function. Interactions of PGRN and PSAP affect their functional properties. Their roles in Alzheimer's disease (AD), the leading cause of dementia, have not been defined. In this report, we examined in detail the cellular expression of PGRN in middle temporal gyrus samples of a series of human brain cases (n = 45) staged for increasing plaque pathology. Immunohistochemistry showed PGRN expression in cortical neurons, microglia, cerebral vessels and amyloid beta (Aβ) plaques, while PSAP expression was mainly detected in neurons and Aβ plaques, and to a limited extent in astrocytes. We showed that there were increased levels of PGRN protein in AD cases and corresponding increased levels of PSAP. Levels of PGRN and PSAP protein positively correlated with amyloid beta (Aβ), with PGRN levels correlating with phosphorylated tau (serine 205) levels in these samples. Although PGRN colocalized with lysosomal-associated membrane protein-1 in neurons, most PGRN associated with Aβ plaques did not. Aβ plaques with PGRN and PSAP deposits were identified in the low plaque non-demented cases suggesting this was an early event in plaque formation. We did not observe PGRN-positive neurofibrillary tangles. Co-immunoprecipitation studies of PGRN from brain samples identified only PSAP associated with PGRN, not sortilin or other known PGRN-binding proteins, under conditions used. Most PGRN associated with Aβ plaques were immunoreactive for PSAP showing a high degree of colocalization of these proteins that did not change between disease groups. As PGRN supplementation has been considered as a therapeutic approach for AD, the possible involvement of PGRN and PSAP interactions in AD pathology needs to be further considered. Loss-of-function mutations in GRN cause frontotemporal dementia (FTD) with transactive response DNA-binding protein of 43 kD (TDP-43)-positive inclusions and neuronal ceroid lipofuscinosis (NCL). There are no disease-modifying therapies for either FTD or NCL, in part because of a poor understanding of how mutations in genes such as GRN contribute to disease pathogenesis and neurodegeneration. By studying mice lacking progranulin (PGRN), the protein encoded by GRN, we discovered multiple lines of evidence that PGRN deficiency results in impairment of autophagy, a key cellular degradation pathway. PGRN-deficient mice are sensitive to Listeria monocytogenes because of deficits in xenophagy, a specialized form of autophagy that mediates clearance of intracellular pathogens. Cells lacking PGRN display reduced autophagic flux, and pathological forms of TDP-43 typically cleared by autophagy accumulate more rapidly in PGRN-deficient neurons. Our findings implicate autophagy as a novel therapeutic target for GRN-associated NCL and FTD and highlight the emerging theme of defective autophagy in the broader FTD/amyotrophic lateral sclerosis spectrum of neurodegenerative disease.
4,143
What is the difference in the roles of Tcf1 and Tcf3 during development?
Τhere are opposing effects of Tcf3 and Tcf1 in the control of Wnt stimulation of embryonic stem cell self-renewal. In contrast to β-catenin-dependent functions described for Tcf1 the known embryonic functions for Tcf3 are consistent with β-catenin-independent repressor activity. Wnt signal stimulation reduces the level of Tcf3, and increases those of Tcf1 (also known as Tcf7) and Lef1, positive mediators of Wnt signaling.
[22573616, 24832538, 21685894]
4,550
The canonical Wnt/β-catenin signaling pathway classically functions through the activation of target genes by Tcf/Lef-β-catenin complexes. In contrast to β-catenin-dependent functions described for Tcf1, Tcf4 and Lef1, the known embryonic functions for Tcf3 in mice, frogs and fish are consistent with β-catenin-independent repressor activity. In this study, we genetically define Tcf3-β-catenin functions in mice by generating a Tcf3ΔN knock-in mutation that specifically ablates Tcf3-β-catenin. Mouse embryos homozygous for the knock-in mutation (Tcf3(ΔN/ΔN)) progress through gastrulation without apparent defects, thus genetically proving that Tcf3 function during gastrulation is independent of β-catenin interaction. Tcf3(ΔN/ΔN) mice were not viable, and several post-gastrulation defects revealed the first in vivo functions of Tcf3-β-catenin interaction affecting limb development, vascular integrity, neural tube closure and eyelid closure. Interestingly, the etiology of defects indicated an indirect role for Tcf3-β-catenin in the activation of target genes. Tcf3 directly represses transcription of Lef1, which is stimulated by Wnt/β-catenin activity. These genetic data indicate that Tcf3-β-catenin is not necessary to activate target genes directly. Instead, our findings support the existence of a regulatory circuit whereby Wnt/β-catenin counteracts Tcf3 repression of Lef1, which subsequently activates target gene expression via Lef1-β-catenin complexes. We propose that the Tcf/Lef circuit model provides a mechanism downstream of β-catenin stability for controlling the strength of Wnt signaling activity during embryonic development. During mouse neocortical development, the Wnt-β-catenin signaling pathway plays essential roles in various phenomena including neuronal differentiation and proliferation of neural precursor cells (NPCs). Production of the appropriate number of neurons without depletion of the NPC population requires precise regulation of the balance between differentiation and maintenance of NPCs. However, the mechanism that suppresses Wnt signaling to prevent premature neuronal differentiation of NPCs is poorly understood. We now show that the HMG box transcription factor Tcf3 (also known as Tcf7l1) contributes to this mechanism. Tcf3 is highly expressed in undifferentiated NPCs in the mouse neocortex, and its expression is reduced in intermediate neuronal progenitors (INPs) committed to the neuronal fate. We found Tcf3 to be a repressor of Wnt signaling in neocortical NPCs in a reporter gene assay. Tcf3 bound to the promoter of the proneural bHLH gene Neurogenin1 (Neurog1) and repressed its expression. Consistent with this, Tcf3 repressed neuronal differentiation and increased the self-renewal activity of NPCs. We also found that Wnt signal stimulation reduces the level of Tcf3, and increases those of Tcf1 (also known as Tcf7) and Lef1, positive mediators of Wnt signaling, in NPCs. Together, these results suggest that Tcf3 antagonizes Wnt signaling in NPCs, thereby maintaining their undifferentiated state in the neocortex and that Wnt signaling promotes the transition from Tcf3-mediated repression to Tcf1/Lef1-mediated enhancement of Wnt signaling, constituting a positive feedback loop that facilitates neuronal differentiation. The co-occupancy of Tcf3 with Oct4, Sox2 and Nanog on embryonic stem cell (ESC) chromatin indicated that Tcf3 has been suggested to play an integral role in a poorly understood mechanism underlying Wnt-dependent stimulation of mouse ESC self-renewal of mouse ESCs. Although the conventional view of Tcf proteins as the β-catenin-binding effectors of Wnt signalling suggested Tcf3-β-catenin activation of target genes would stimulate self-renewal, here we show that an antagonistic relationship between Wnt3a and Tcf3 on gene expression regulates ESC self-renewal. Genetic ablation of Tcf3 replaced the requirement for exogenous Wnt3a or GSK3 inhibition for ESC self-renewal, demonstrating that inhibition of Tcf3 repressor is the necessary downstream effect of Wnt signalling. Interestingly, both Tcf3-β-catenin and Tcf1-β-catenin interactions contributed to Wnt stimulation of self-renewal and gene expression, and the combination of Tcf3 and Tcf1 recruited Wnt-stabilized β-catenin to Oct4 binding sites on ESC chromatin. This work elucidates the molecular link between the effects of Wnt and the regulation of the Oct4/Sox2/Nanog network.
4,144
What is disrupted by ALS- and FTD-associated missense mutations in TBK1?
ALS- and FTD-associated missense mutations in TBK1 differentially disrupt mitophagy.
[34099552]
4,552
TANK-binding kinase 1 (TBK1) is a multifunctional kinase with an essential role in mitophagy, the selective clearance of damaged mitochondria. More than 90 distinct mutations in TBK1 are linked to amyotrophic lateral sclerosis (ALS) and fronto-temporal dementia, including missense mutations that disrupt the abilities of TBK1 to dimerize, associate with the mitophagy receptor optineurin (OPTN), autoactivate, or catalyze phosphorylation. We investigated how ALS-associated mutations in TBK1 affect Parkin-dependent mitophagy using imaging to dissect the molecular mechanisms involved in clearing damaged mitochondria. Some mutations cause severe dysregulation of the pathway, while others induce limited disruption. Mutations that abolish either TBK1 dimerization or kinase activity were insufficient to fully inhibit mitophagy, while mutations that reduced both dimerization and kinase activity were more disruptive. Ultimately, both TBK1 recruitment and OPTN phosphorylation at S177 are necessary for engulfment of damaged mitochondra by autophagosomal membranes. Surprisingly, we find that ULK1 activity contributes to the phosphorylation of OPTN in the presence of either wild-type or kinase-inactive TBK1. In primary neurons, TBK1 mutants induce mitochondrial stress under basal conditions; network stress is exacerbated with further mitochondrial insult. Our study further refines the model for TBK1 function in mitophagy, demonstrating that some ALS-linked mutations likely contribute to disease pathogenesis by inducing mitochondrial stress or inhibiting mitophagic flux. Other TBK1 mutations exhibited much less impact on mitophagy in our assays, suggesting that cell-type-specific effects, cumulative damage, or alternative TBK1-dependent pathways such as innate immunity and inflammation also factor into the development of ALS in affected individuals.
4,145
What is Morel–Lavallée lesion?
Morel-Lavallée lesion is a closed degloving soft-tissue injury that results in the accumulation of a hemolymphatic fluid between the skin/superficial fascia and the deep fascia.
[33508615, 25785224, 33310472, 26965645, 30652431, 33217297, 33936913, 25114393, 32335518, 27579812, 23332912, 33775030, 26506679, 30547132, 26023620, 32257483, 17351119, 34401233, 23739602, 24161364, 33792213, 24639319, 32716145, 33438963, 20463988, 30025335, 22266744]
4,553
INTRODUCTION AND IMPORTANCE: A Morel-Lavallee lesion is a closed degloving injury due to traumatic separation of the hypodermis from underlying fascia. Accumulation of hemolymphatic fluid that occurs is a potential habitat for bacteria. Management options include percutaneous aspiration, open debridement, or a non-surgical approach, each with recurrence risk. In the event of recurrence, sclerotherapy is used. In this case report, after reviewing povidone iodine's efficacy in treating seromas, we used it as a sclerosant for recurrent Morel-Lavallee lesion as the more established options were unavailable in our setting. CASE PRESENTATION: A 49-year-old with no known comorbid presented following a motor traffic accident, with left lateral thigh swelling. He was stable systematically, with a tense, tender left lateral thigh swelling and intact neurovascular assessment distally. X-ray and computed tomography ruled out skeletal and vascular injuries. Magnetic resonance imaging revealed a 580 ml type 1 Morell-Lavallee lesion. Open surgical debridement was done to drain and debride the lesion. He developed two recurrences that necessitated percutaneous aspiration. Doxycycline and talc sclerosants were considered; however, due to their unavailability, povidone iodine was used. It is now five months post-intervention without increased pain, recurrence, or wound complications. CLINICAL DISCUSSION: Recurrence is hypothesized to be due to the persistence of fluid loculations, unobliterated dead space, and pseudocyst formation. Sclerotherapy stimulates inflammation that results in fibrosis of the cavity walls causing its obliteration. Doxycycline, the most studied sclerosant in Morel-Lavallée lesion has an efficacy of 95.7%. CONCLUSION: The current report is the first successful use of povidone iodine for sclerotherapy of recurring Morel-Lavallée lesions. Based on povidone iodine experiences as a sclerosant, it is associated with increased analgesic requirements. We cautiously propose its use as an alternative in settings where talc powder and doxycycline powder are unavailable. INTRODUCTION: Morel-Lavallée lesion (MLL) is a posttraumatic closed degloving soft tissue injury, in which the subcutaneous tissues are separated from the underlying fascia. Surgical treatment is recommended if conservative management fails. The conventional surgical treatment for the lesion is surgical drainage and debridement. PRESENTATION OF CASE: A 51-year-old male patient presented with swelling of the right thigh incurred during a traffic accident. The lesion was diagnosed with MLL. The MLL was successfully treated with a minimally invasive arthroscopic treatment after failure of conservative treatment. The arthroscopic treatment was chosen because of the patient's comorbidity that posed a risk of surgical wound complications. In addition, negative pressure wound therapy (NPWT) was performed postoperatively to ensure healing and to prevent recurrence of the lesion. The patient was successfully treated and the healing of the lesion was also confirmed with MRI. DISCUSSION: In a patient with a risk of wound complications due to a comorbidity, this minimally invasive arthroscopic treatment is useful. In addition, NPWT was used to ensure healing and to prevent recurrence. Although the use of NPWT combined with endoscopic treatment has not been reported, additional NPWT reported in this case may be helpful to ensure healing. CONCLUSION: In case of MLL with a risk of surgical complications, the arthroscopic treatment is a reasonable method and achieves the goal of an open surgical debridement without increased morbidity. INTRODUCTION: Soft tissue injuries are a common presenting complaint seen in the emergency department following trauma. However, internal degloving injuries are not commonly seen by the emergency provider. CASE REPORT: A 57-year-old male presented with right lower extremity pain, bruising, and swelling after a low-speed bicycle accident five days prior. Physical examination revealed an edematous and ecchymotic right lower extremity extending from the mid-thigh distally. Computed tomography of the thigh demonstrated a hyperdense foci within the fluid collection suggesting internal hemorrhage and internal de-gloving suggestive of a Morel-Lavallée lesion. DISCUSSION: The Morel-Lavallée lesion is a post-traumatic soft tissue injury that occurs as a result of shearing forces that create a potential space for the collection of blood, lymph, and fat. First described in 1853 by French physician Maurice Morel-Lavallée, this internal degloving injury can serve as a nidus of infection if not treated appropriately. Magnetic resonance imaging has become the diagnostic modality of choice due to its high resolution of soft tissue injuries. Treatment has been focused on either conservative management or surgical debridement after consultation with a surgeon. CONCLUSION: The emergency physician should consider Morel-Lavallée lesions in patients with a traumatic hematoma formation to avoid complications that come from delayed diagnosis. Morel-Lavallée lesions are post-traumatic, closed degloving injuries occurring deep to subcutaneous plane due to disruption of capillaries resulting in an effusion containing hemolymph and necrotic fat. Magnetic resonance imaging (MRI) is the modality of choice in the evaluation of Morel-Lavallée lesion. Early diagnosis and management is essential as any delay in diagnosis or missed lesion will lead to the effusion becoming infected or leading to extensive skin necrosis. The Morel-Lavallée lesion is a closed soft-tissue degloving injury commonly associated with high-energy trauma. The thigh, hip, and pelvic region are the most commonly affected locations. Timely identification and management of a Morel-Lavallée lesion is crucial because distracting injuries in the polytraumatized patient can result in a missed or delayed diagnosis. Bacterial colonization of these closed soft-tissue injuries has resulted in their association with high rates of perioperative infection. Recently, MRI has been used to characterize and classify these lesions. Definitive management is dictated by the size, location, and age of the injury and ranges from percutaneous drainage to open débridement and irrigation. Chronic lesions may lead to the development of pseudocysts and contour deformities of the extremity. A Morel-Lavallée lesion (MLL) is a posttraumatic soft-tissue injury characterized by an accumulation of blood, lymph, and other physiologic breakdown products between subcutaneous tissue and underlying fascia. It was first described as occurring over the proximal lateral thigh, but it has since been documented at various anatomic locations. Diagnosis is typically made by careful physical examination and a radiographic analysis, most commonly with magnetic resonance imaging (MRI). Recently, musculoskeletal ultrasound (US) has been recognized as a useful adjunct to and potential replacement for MRI in the diagnosis and monitoring of an MLL. We present a case report of a patient with an MLL of the knee. We obtained magenetic resonance (MRI) and US images at the time of diagnosis, and follow-up US images during convalescence. By doing so, we were able to identify several key sonographic findings of an MLL at this location and compare them with MRI. Although there have been several published reports to date that describe the use of musculoskeletal US in the diagnosis of MLL, this is the first of which we are aware that does so at the knee. Morel-Lavallée lesion is a post-traumatic degloving cyst, usually filled with blood, lymph or necrotic tissue, which mostly develops in the area around greater trochanter. Early diagnosis and prompt treatment is essential to prevent further complications, such as compression of surrounding structures. X-rays have limited use and magnetic resonance imaging (MRI) is the modality of choice in diagnosing the lesion. We report a case of a 35-year female presenting with left thigh pain after a fall from motorcycle almost 21/2 years ago. Ultrasound and MRI confirmed the presence of Morel-Lavallée lesion involving the left pelvis and upper thigh. Given the chronicity of lesion and extensive tissue involvement, the patient underwent surgical excision of the lesion with favourable long-term outcomes. In this case report and literature review, we discuss the pathophysiology, clinical presentation, radiological findings and management options for Morel-Lavallée lesion. Key Words: Morel-Lavallée lesion, Post-traumatic cyst, Degloving Injury, Tangential cyst. Morel-Lavallée Lesion (MLL) is a posttraumatic, closed degloving injury where the skin and superficial fascia get separated from deep fascia (fascialata) in the trochanteric region and upper thigh, hence creating a potential space. Similar lesions at other locations (e.g., abdominal wall and lumbar regions) have been described as Morel-Lavallée effusion, hematoma, or extravasation. Injury to an area with rich vascular and lymphatic supply leads to filling of this space with blood, lymph, fat, and necrotic debris. MLL usually presents as painful fluctuant swelling in the anterolateral portion o fthe upper thigh. Many of these maybe missed at initial evaluation and present weeks to months after the initial trauma. The Morel-Lavallée lesion (MLL) is a closed degloving injury caused by traumatic separation of the subcutaneous tissue from the underlying fascia, without a break in the overlying skin. We present two cases that demonstrate a previously unrecognised association of the MLL with thoracolumbar spine fractures. The lesion is frequently missed, or its significance is overlooked, on initial evaluation. Awareness of this injury should allow tailored strategies to decrease the high risk of wound complications. Morel-lavallee lesion (MLL) represents post traumatic subcutaneous cyst generally overlying bony prominences like greater trochanter, lower back, knee and scapula. A 51-year-old man presented with a swelling in left thigh since six years which was insidious in onset, gradually progressive in size and not associated with pain, fever or discharge. There was no history of trauma or any associated constitutional symptoms. Since there was no history of trauma recalled by the patient the clinical dilemma was between soft tissue sarcoma and cold abscess. We report a case of slow growing painless mass lesion of thigh, diagnosed on Magnetic Resonance Imaging (MRI) as morel lavallee lesion and describe its salient imaging features with treatment options. Morel-Lavallée lesion (MLL) is a degloving injury in soft tissues caused by shear force accompanying trauma. Even if it is a small lacrimal wound at the initial visit, there is a range of skin necrosis which is not suitable for it. As a cause of the injury, a shearing force was applied over a wide range, and penetrating blood vessel damage to the skin occurred, resulting in skin necrosis. Attention is required. BACKGROUND: The Morel-Lavallee lesion is a closed degloving injury most commonly described in the region of the hip joint after blunt trauma. It also occurs in the knee as a result of shearing trauma during football and is a distinct lesion from prepatellar bursitis and quadriceps contusion. PURPOSE: To review the authors' experience with Morel-Lavallee lesion of the knee in the elite contact athlete to construct a diagnostic and treatment algorithm. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-seven knees in 24 players were identified from 1 National Football League team's annual injury database as having sustained a Morel-Lavallee lesion between 1993 and 2006. Their charts were retrospectively reviewed. RESULTS: The most common mechanism of injury was a shearing blow on the playing surface (81%). The most common motion deficit was active flexion (41%). The mean time for resolution of the fluid collection and achievement of full active flexion was 16.3 days. The mean number of practices missed was 1.5. The mean number of games missed was 0.1. Fourteen knees (52%) were treated successfully with compression wrap, cryotherapy, and motion exercises. Thirteen knees (48%) were treated with at least 1 aspiration, and 6 knees (22%) were treated with multiple aspirations for recurrent serosanguineous fluid collections. In 3 cases (11%), the Morel-Lavallee lesion was successfully treated with doxycycline sclerodesis after 3 aspirations failed to resolve the recurrent fluid collections; return to play was immediate thereafter in each case. CONCLUSION: In football, Morel-Lavallee lesion of the knee usually occurs from a shearing blow from the playing field. Diagnosis is confirmed when examination reveals a large suprapatellar area of palpable fluctuance. Elite athletes are typically able to return to practice and game play long before complete resolution of the lesion. Recurrent fluid collections can occur, necessitating aspiration in approximately half the cases for successful treatment. Recalcitrant fluid collections can be safely and expeditiously treated with doxycycline sclerodesis. The Morel-Lavallée lesion is a closed internal soft-tissue degloving injury. About 15.7% of Morel-Lavallée lesions occur in the knee region. Morel-Lavallée lesions are considered chronic when the lesion contains a capsule. The capsule prevents resorption of the fluid content, and the lesion will recur when using conservative treatment alone. Surgical debridement with resection of the capsule is a more definitive treatment option, but it may induce wound complications. In this Technical Note, the technical details of endoscopic resection of chronic Morel-Lavallée lesion of the knee are discussed. This minimally invasive technique has the advantage of better cosmetic results and fewer wound complications. BACKGROUND: The Morel-Lavallée lesion is a post-traumatic collection of fluid arising after a 'closed degloving injury' has caused the separation of the skin and subcutis from the underlying muscular fascia. It usually occurs in the trochanteric region or proximal thigh. CASE DESCRIPTION: A 36-year-old obese man was referred to the emergency department by his general practitioner for fever and pain in the right lower abdominal quadrant. Blood testing revealed elevated infection parameters. As appendicitis was suspected, a CT scan of the abdomen was performed. This revealed a Morel-Lavallée lesion, which he had sustained 9 months earlier when he had been hit by a car while riding his bicycle. A rapid recovery ensued after ultrasound-guided percutaneous drainage and treatment with antibiotics. CONCLUSION: A Morel-Lavallée lesion, which could manifest even months later, should be considered after any traumatic injury. Ultrasound, CT and MRI are useful tools for proper diagnosis. There is no consensus about treatment in either the acute or the chronic phase to date. BACKGROUND CONTEXT: The Morel-Lavallée lesion occurs from a compression and shear force that usually separates the skin and subcutaneous tissue from the underlying muscular fascia. A dead space is created that becomes filled with blood, liquefied fat, and lymphatic fluid from the shearing of vasculature and lymphatics. If not treated appropriately, these lesions can become infected, cause tissue necrosis, or form chronic seromas. PURPOSE: To review appropriate identification and treatment of Morel-Lavallée lesions in spinopelvic dissociation patients. STUDY DESIGN: Uncontrolled case series. METHODS: Retrospective review of medical records. No funding was received in support of this study. The authors report no conflicts of interest. RESULTS: We present four cases of patients with traumatic spinopelvic dissociation. All had concomitant lumbosacral Morel-Lavallée lesions. All four trauma patients suffered traumatic spinopelvic dissociation with concomitant lumbosacral Morel-Lavallée lesions. Appropriate treatment included irrigation and debridement, drainage, antibiotics, and vacuum-assisted wound closure. CONCLUSIONS: Our series reflects an association of Morel-Lavallée lesion in spinopelvic dissociation trauma patients. Possibly, the rotatory injury that occurs at the spinopelvic junction creates a shear force to form the Morel-Lavallée lesion. When presented with a spinopelvic dissociation patient, one should be prepared to treat a Morel-Lavallée lesion. Postoperative seroma is a common complication of many surgical procedures in which anatomical dead space has been created. A particular case of lesion in which seroma occurs is the Morel-Lavallée lesion (MLL), which is an uncommon closed soft-tissue degloving injury that develops after high-energy trauma or crush injury where shearing forces separate the subcutaneous tissue from the underlying fascia. The diagnostic evaluation begins with an adequate history and physical examination, followed by instrumental research with ultrasonography, computed tomography, and magnetic resonance imaging. Postoperative seromas and MLLs share a similar pathology and natural evolution as both injuries, once chronic, develop a pseudobursa; thus, the authors think that the same treatment algorithm may be suitable for both the lesions. Several strategies for the treatment of post-surgical and post-traumatic seromas have been described in the literature, ranging from conservative measures for acute and small injuries to surgical management and sclerotherapy for chronic and large ones. Despite some seromas resolving with conventional management, lesion recurrence is a matter of concern. The authors present their experience in the treatment of both post-surgical and post-traumatic chronic seromas not responsive to conservative treatments by surgical drainage of the seroma, capsulectomy, and application of vacuum-assisted closure therapy to allow granulation tissue formation, dead spaces obliteration, and wound healing. Primary wound closure with closed suction drain placement and an elastic compression bandaging are finally performed. From 2014 to 2019, a total of 15 patients (9 females and 6 males) were treated for recurrent chronic seromas with the proposed surgical approach. Five cases were MLLs, while 10 cases were postoperative seromas. The patients were between 33 and 79 years old, and they were followed up at 4 weeks and 3 and 6 months after surgery. All 15 patients with chronic seromas not responsive to conservative treatment showed a complete resolution of the lesions with the proposed treatment approach with no evidence of lesion recurrence, proving its effectiveness. The Morel-Lavallée lesion (MLL) is a posttraumatic close degloving injury, which is often underdiagnosed at first. Patients with MLLs usually present with tender and enlarging soft tissue swelling with fluctuation, decreased skin sensation, ecchymosis, or even skin necrosis hours to days after the inciting injury. The lesion can lead to intractable morbidity if it remains untreated. There is no consensus regarding the treatment for MLL at present. Here, we report an MLL in the pretibial region of a 43-year-old woman who experienced a low-energy contusion in a motorbike accident. The pretibial lesion was diagnosed using sonography and fine-needle aspiration. We successfully treated the patient by performing percutaneous debridement via a small incision and injections of fibrin after conservative treatment failed. The method we herein propose achieved the goal of open surgical debridement, providing faster recovery and a high degree of patient comfort. We reviewed the available pertinent literature and propose our own treatment protocol with the aim to establish common therapies ofMLL. A Morel-Lavallée lesion is a relatively rare condition involving a closed, degloving injury to the pelvis, resulting in a blood-filled cystic cavity created by separation of the subcutaneous tissue from the underlying fascia. This injury typically occurs following high-speed trauma. We describe a case that occurred in a professional American football player who was treated with percutaneous decompression and evacuation of the hematoma. The player returned to playing football at the professional level 22 days after the injury without residual deformity or disability. INTRODUCTION: The Morel-Lavallée lesion is an infrequently described, post-traumatic closed de-gloving wound that results from separation of the skin and subcutaneous tissues from the underlying deep fascia as a result of shearing forces that tear perforating vessels and lymphatics. This condition is rare in children and to our knowledge it represents the youngest case of Morel-Lavallée lesion yet reported. PRESENTATION OF CASE: We report on a twelve-month-old girl who presented after a motor vehicle accident with a tender fluctuant mass of the back and buttocks. Computed tomography revealed a large but discrete fluid collection between the subcutaneous fat and the deep fascial planes, extending from the posterior thoracic paraspinal soft tissues to the right gluteal region. A diagnosis of Morel-Lavallée lesion was made. This patient was managed with serial ultrasound-guided percutaneous drainage and compression bandages. The patient did well and was subsequently discharged. There was no recurrence of the lesion on follow-up. DISCUSSION: The Morel-Lavallée lesion is a rare consequence of abrupt high impact trauma. There is no accepted management approach and a variety of conservative as well as surgical options exist. Goals of management include drainage, debridement and meticulous dead space management to prevent recurrence. CONCLUSION: The Morel-Lavallée lesion is a rare finding in children involved in high impact trauma and prompt intervention is crucial to prevent complications. Image-guided drainage is a rational management approach with excellent outcomes.
4,146
What is known about the protein patatin?
Patatin, the major protein found in potatoes, was purified and shows several isoforms. The essential amino acid content of patatin was ashighas 76%, indicating that it is a valuable protein source. Patatin was an O-linked glycoprotein that contained fucose monosaccharides, as well as mannose, rhamnose, glucose, galactose, xylose, and arabinose. Patatin had a fucosylated glycan structural feature, which strongly bound AAL (Aleuria aurantia Leukoagglutinin), a known fucose binding lectin. Moreover, thelipid metabolism regulatory effects of patatin on the fat catabolism, fat absorption, and inhibition of lipase activity were measured after high-fat feeding of zebrafish larvae. Results revealed that 37.0 μg/mL patatin promoted 23% lipid decomposition metabolism. Meanwhile patatin could inhibite lipase activity and fat absorption, whose effects accounted for half that of a positive control drug. Our findings suggest that patatin, a fucosylated glycoprotein, could potentially be used as a naturalactiveconstituent with anti-obesity effects.
[34509145, 33272761]
4,554
Potato patatin is considered a valuable plant protein by the food industry for its exceptional functional properties and nutritional value. Nonetheless, it has not been widely used due to its low abundance in potatoes and high cost. Pichia pastoris was utilized for expression of patatin to overcome agricultural limitations. Biochemical and biophysical characterization of Patatin-B2 (rPatB2) and Patatin-17 (rPat17) is described. rPatB2 and rPat17 had higher zeta potential and superior solubility at various pH conditions in comparison with commercial patatin, whereas particle size distribution was similar. Inflection temperatures were higher than potato isolated patatins. Antioxidant capacity of rPatB2 and rPat17 was similar to that of commercial patatin and the specific enzymatic activity of rPatB2 was 5-fold higher than rPat17 and patatins isolated from potato. Results indicate yeast-derived patatin properties are comparable to patatins from potatoes, suggesting their potential use in various plant-based products such as meat and dairy analogues.
4,147
What is the mode of action of primaquine?
Primaquine (PQ) not only eliminates P. falciparum gametocytes but also kills liver dormant forms of P. vivax and P. ovale.
[1657920, 28289025, 34546758, 1475854, 34216464, 34257648, 34474834, 31217011, 698128, 4625625, 10501629]
4,555
The lysosomotropic amine primaquine has previously been shown to inhibit both secretory and recycling processes of cells in culture. We have used a cell-free assay that reconstitutes glycoprotein transport through the Golgi apparatus to investigate the mechanism of action of primaquine. In this assay, primaquine inhibits protein transport at a half-maximal concentration of 50 microM, similar to the concentration previously reported to disrupt protein secretion in cultured cells. Kinetic analysis of primaquine inhibition indicates that its point of action is at an early step in the vesicular transport mechanism. Primaquine does not inhibit the fusion of vesicles already attached to their target membranes. Primaquine irreversibly inactivates the membranes that form transport vesicles (donor), but not the membranes that are the destination of those vesicles (acceptor). Morphological data indicate that primaquine inhibits the budding of vesicles from the donor membranes. Once formed, the vesicles are refractile to primaquine action, and their attachment to and fusion with acceptor membranes proceeds unimpeded. In addition to illuminating the mechanism of action of primaquine, this study suggests that the selective action of this agent will make it a useful tool in the study of the formation of transport vesicles. Hemolytic toxicity caused by primaquine (PQ) is a high-risk condition that hampers the wide use of PQ to treat liver-stage malaria. This study demonstrated that phospholipid-free small unilamellar vesicles (PFSUVs) composed of Tween80 and cholesterol could encapsulate and deliver PQ to the hepatocytes with reduced exposure to the red blood cells (RBCs). Nonionic surfactant (Tween80) and cholesterol-forming SUVs with a mean diameter of 50 nm were fabricated for delivering PQ. Drug release/retention, drug uptake by RBCs, pharmacokinetics, and liver uptake of PFSUVs-PQ were evaluated in invitro and invivo models in comparison to free drugs. Additionally, the stress effect on RBCs induced by free PQ and PFSUVs-PQ was evaluated by examining RBC morphology. PFSUVs provided >95% encapsulation efficiency for PQ at a drug-to-lipid ratio of 1:20 (w/w) and stably retained the drug in the presence of serum. When incubated with RBCs, PQ uptake in the PFSUVs group was reduced by 4- to 8-folds compared to free PQ. As a result, free PQ induced significant RBC morphology changes, while PFSUVs-PQ showed no such adverse effect. Intravenously (i.v.) delivered PFSUVs-PQ produced a comparable plasma profile as free PQ, given i.v. and orally, while the liver uptake was increased by 4.8 and 1.6-folds, respectively, in mice. Within the liver, PFSUVs selectively targeted the hepatocytes, with no significant blood or liver toxicity in mice. PFSUVs effectively targeted PQ to the liver and reduced RBC uptake compared to free PQ, leading to reduced RBC toxicity. PFSUVs exhibited potential in improving the efficacy of PQ for treating liver-stage malaria. It has been shown elsewhere that the epidermal growth factor (EGF) in A431 cells can recycle in receptor-bound state (Teslenko et al., 1987; Sorkin et al., 1989, 1991). Present study deals with the action of primaquine, a lysosomotropic agent, on EGF-receptor complexes (EGF-RC). By the method of indirect immunofluorescence with anti-EGF-R monoclonal antibody it is found that following a 1 h incubation of cells at 37 degrees C in the presence of EGF a bright staining of endosomes appears in the intranuclear region, while after incubation of the cells at 4 degrees only margins of cells are stained. Such a pattern of fluorescence is peculiar of endocytosis in A431 cells. When the cells were incubated in the presence of a 0.3 mM primaquine for 1 h, the immunostaining is changed: bright compact spot in the para-Golgi region appeared. The effect of primaquine is reversible. When the cells after preincubation with EGF were incubated in the absence of EGF for 3 h at 37 degrees C, the staining of cell margins could be observed again, demonstrating the recycling of EGF-RC. Under similar conditions of cell incubation, but in the presence of primaquine, the staining of the para-Golgi region was not changed. In the experiments with 125I-EGF it was shown that intracellular accumulations of 125I-EGF were maintained when the cells were incubated in the presence of 0.3 mM primaquine. It is concluded that primaquine inhibits the recycling of EGF-R in A431 cells. BACKGROUND: The effect of primaquine in preventing Plasmodium vivax relapses from dormant stages is well established. For Plasmodium ovale, the relapse characteristics and the use of primaquine is not as well studied. We set to evaluate the relapsing properties of these 2 species, in relation to primaquine use among imported malaria cases in a nonendemic setting. METHODS: We performed a nationwide retrospective study of malaria diagnosed in Sweden 1995-2019, by reviewing medical records of 3254 cases. All episodes of P. vivax (n = 972) and P. ovale (n = 251) were selected for analysis. RESULTS: First time relapses were reported in 80/857 (9.3%) P. vivax and 9/220 (4.1%) P. ovale episodes, respectively (P < .01). Without primaquine, the risk for relapse was higher in P. vivax, 20/60 (33.3%), compared to 3/30 (10.0%) in P. ovale (hazard ratio [HR] 3.5, 95% confidence interval [CI] 1.0-12.0). In P. vivax, patients prescribed primaquine had a reduced risk of relapse compared to episodes without relapse preventing treatment, 7.1% vs 33.3% (HR 0.2, 95% CI .1-.3). In P. ovale, the effect of primaquine on the risk of relapse did not reach statistical significance, with relapses seen in 2.8% of the episodes compared to 10.0% in patients not receiving relapse preventing treatment (HR 0.3, 95% CI .1-1.1). CONCLUSIONS: The risk of relapse was considerably lower in P. ovale than in P. vivax infections indicating different relapsing features between the two species. Primaquine was effective in preventing P. vivax relapse. In P. ovale, relapse episodes were few, and the supportive evidence for primaquine remains limited. Primaquine (PQ) not only eliminates P. falciparum gametocytes but also kills liver dormant forms of P. vivax and P. ovale. Owing to these unique therapeutic properties, it is an essential drug. Although PQ has been used for over 70 years, its toxicological database has gaps such as the absence of studies on its reproductive and developmental toxicity and kinetics in pregnancy. This study investigated the transplacental transfer of PQ and the effects of intrauterine exposure on the postnatal growth, survival, and neurobehavioral development of the offspring. PQ kinetics and transplacental transfer were investigated in rats treated orally (40 mg.kg·bw-1) on gestation day (GD) 21. PQ was analyzed by high-performance liquid chromatography with diode array ultraviolet detection. To evaluate effects of intrauterine exposure on postnatal development, dams were treated orally with PQ (20 mg.kg·bw-1·d-1) or water (controls) on GD 0-21. Postnatal survival, body weight gain, somatic maturation, and reflex acquisition were evaluated. The open field test (OF) was conducted on PND 25. PQ concentration in the fetal plasma was nearly half that in maternal plasma. Except for increase in pregnancy loss, no effects of PQ were noted at term pregnancy and first days of life. Prenatal PQ did not affect postnatal weight gain nor did it impair somatic and neurologic development of the offspring. Pups born to PQ-treated dams showed reduced exploration and enhanced emotionality in the OF. PQ given in pregnancy, at doses greater than those recommended for malaria therapy, may affect pup postnatal survival and emotional behavior. Malaria is the most common parasitic disease around the world, especially in tropical and sub-tropical regions. This parasitic disease can have a rapid and severe evolution. It is transmitted by female anopheline mosquitoes. There is no reliable vaccine or diagnostic test against malaria; instead, Artesunate is used for the treatment of severe malaria and Artemisinin is used for uncomplicated falciparum malaria. However, these treatments are not efficient against severe malaria and improvements are needed. Primaquine (PQ) is one of the most widely used antimalarial drugs. It is the only available drug to date for combating the relapsing form of malaria. Nevertheless, it has severe side effects. Particle drug-delivery systems present the ability to enhance the therapeutic properties of drugs and decrease their side effects. Here, we report the development of Polymeric Primaquine Microparticles (PPM) labeled with 99mTc for therapeutic strategy against malaria infection. The amount of primaquine encapsulated into the PPM was 79.54%. PPM presented a mean size of 929.47 ± 37.72 nm, with a PDI of 0.228 ± 0.05 showing a homogeneous size for the microparticles and a monodispersive behavior. Furthermore, the biodistribution test showed that primaquine microparticles have a high liver accumulation. In vivo experiments using mice show that the PPM treatments resulted in partial efficacy and protection against the development of the parasite compared to free Primaquine. These results suggest that microparticles drug delivery systems of primaquine could be a possible approach for malaria prevention and treatment. BACKGROUND: The challenge in anti-malarial chemotherapy is based on the emergence of resistance to drugs and the search for medicines against all stages of the life cycle of Plasmodium spp. as a therapeutic target. Nowadays, many molecules with anti-malarial activity are reported. However, few studies about the cellular and molecular mechanisms to understand their mode of action have been explored. Recently, new primaquine-based hybrids as new molecules with potential multi-acting anti-malarial activity were reported and two hybrids of primaquine linked to quinoxaline 1,4-di-N-oxide (PQ-QdNO) were identified as the most active against erythrocytic, exoerythrocytic and sporogonic stages. METHODS: To further understand the anti-malarial mode of action (MA) of these hybrids, hepg2-CD81 were infected with Plasmodium yoelii 17XNL and treated with PQ-QdNO hybrids during 48 h. After were evaluated the production of ROS, the mitochondrial depolarization, the total glutathione content, the DNA damage and proteins related to oxidative stress and death cell. RESULTS: In a preliminary analysis as tissue schizonticidals, these hybrids showed a mode of action dependent on peroxides production, but independent of the activation of transcription factor p53, mitochondrial depolarization and arrest cell cycle. CONCLUSIONS: Primaquine-quinoxaline 1,4-di-N-oxide hybrids exert their antiplasmodial activity in the exoerythrocytic phase by generating high levels of oxidative stress which promotes the increase of total glutathione levels, through oxidation stress sensor protein DJ-1. In addition, the role of HIF1a in the mode of action of quinoxaline 1,4-di-N-oxide is independent of biological activity. Four amphipathic drugs, primaquine, propranolol, chlorpromazine and tetracaine, were used to cause endocytosis in glucose-depleted red cells, and the relative reduction of membrane surfaces was measured by the toluidine blue (TB) method. The TB measurements correlated well with the observed electron microscopic alterations. In vitro blood storage studies indicated loss of cell membrane during storage correlated with decreasing uptake of TB by the red cells. Regeneration of cellular ATP with adenosine did not always restore TB uptake by the cells. Loss of red blood cell membrane either by exocytosis or endocytosis may occur during normal in vivo or in vitro ageing, and may be increased in pathological states or by the action of drugs. The growth of a strain of Bacillus megaterium was prevented by a minimal inhibitory concentration of primaquine of 52 mug/ml or 2 x 10(-4)m. When exponentially growing cultures received the drug at 6 x 10(-4)m, the rate of growth was drastically reduced and no further growth occurred after 15 min of exposure. At this concentration, primaquine was bactericidal, causing a 50% reduction in the viable population after one doubling time of 45 min. Supplying primaquine to cultures 30 min after adding radioactive-labeled phenylalanine, thymidine, uracil, or diaminopimelic acid produced an immediate and complete inhibition of protein biosynthesis but no inhibition of deoxyribonucleic acid biosynthesis for at least 15 min, and caused the formation of ribonucleic acid and cell wall polymer to proceed linearly at rates similar to those established prior to the addition of drug. This pattern of inhibition of macromolecular biosyntheses suggests that the major in vivo action of primaquine in B. megaterium is to block protein synthesis. The cytoadherence of four Plasmodium falciparum malaria isolates (FCR-3, RSA-14, 15 and 17) to monocytes was used as a measure of the expression of monocyte receptors after the monocytes had been exposed to seven antimalarial drugs. Quinine, chloroquine, primaquine, pyrimethamine, artemesinin, mefloquine and proguanil all down-regulated the expression of monocyte receptors by 40% or greater at the therapeutic concentrations of each drug. Each malaria isolate had a unique adherence profile for drug induced changes in monocytes. Each drug appeared to alter the expression of more than one monocyte receptor. The most effective drugs were quinine, pyrimethamine and palludrin and the least effective were artemether and mefloquine. The results suggest a previously undetected immunomodulatory action of antimalarial drugs.
4,148
Which databases are devoted to 3D genome interactions?
3DIV is a 3D-genome Interaction Viewer and database. The 3D Genome Browser is a web-based browser for visualizing 3D genome organization and long-range chromatin interactions. GMOL is an Interactive Tool for 3D Genome Structure Visualization. 3Disease Browser is a Web server for integrating 3D genome and disease-associated chromosome rearrangement data. The 3DGD is a database of genome 3D structure, that currently holds Hi-C data on four species, for easy accessing and visualization of chromatin 3D structure data.
[27734896, 30286773, 29106613, 24526713, 26868282]
4,556
Chromosomal rearrangement (CR) events have been implicated in many tumor and non-tumor human diseases. CR events lead to their associated diseases by disrupting gene and protein structures. Also, they can lead to diseases through changes in chromosomal 3D structure and gene expression. In this study, we search for CR-associated diseases potentially caused by chromosomal 3D structure alteration by integrating Hi-C and ChIP-seq data. Our algorithm rediscovers experimentally verified disease-associated CRs (polydactyly diseases) that alter gene expression by disrupting chromosome 3D structure. Interestingly, we find that intellectual disability may be a candidate disease caused by 3D chromosome structure alteration. We also develop a Web server (3Disease Browser, http://3dgb.cbi.pku.edu.cn/disease/) for integrating and visualizing disease-associated CR events and chromosomal 3D structure. Author information: (1)Bioinformatics and Genomics Program, The Pennsylvania State University, University Park, State College, PA, 16802, USA. (2)Department of Biochemistry and Molecular Biology, College of Medicine, The Pennsylvania State Hershey, Hershey, PA, 17033, USA. (3)Department of Computer and Information Science, University of Pennsylvania, Philadelphia, PA, 19104, USA. (4)Department of Genetics, The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63108, USA. (5)Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA. (6)Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599, USA. (7)Department of Computer Science, University of North Carolina, Chapel Hill, NC, 27599, USA. (8)Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA. (9)Center for Computational Biology and Bioinformatics, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, State College, PA, 16802, USA. (10)Department of Genetics, The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63108, USA. twang@genetics.wustl.edu. (11)Bioinformatics and Genomics Program, The Pennsylvania State University, University Park, State College, PA, 16802, USA. fyue@hmc.psu.edu. (12)Department of Biochemistry and Molecular Biology, College of Medicine, The Pennsylvania State Hershey, Hershey, PA, 17033, USA. fyue@hmc.psu.edu. Three-dimensional (3D) chromatin structure is an emerging paradigm for understanding gene regulation mechanisms. Hi-C (high-throughput chromatin conformation capture), a method to detect long-range chromatin interactions, allows extensive genome-wide investigation of 3D chromatin structure. However, broad application of Hi-C data have been hindered by the level of complexity in processing Hi-C data and the large size of raw sequencing data. In order to overcome these limitations, we constructed a database named 3DIV (a 3D-genome Interaction Viewer and database) that provides a list of long-range chromatin interaction partners for the queried locus with genomic and epigenomic annotations. 3DIV is the first of its kind to collect all publicly available human Hi-C data to provide 66 billion uniformly processed raw Hi-C read pairs obtained from 80 different human cell/tissue types. In contrast to other databases, 3DIV uniquely provides normalized chromatin interaction frequencies against genomic distance dependent background signals and a dynamic browsing visualization tool for the listed interactions, which could greatly advance the interpretation of chromatin interactions. '3DIV' is available at http://kobic.kr/3div. Author information: (1)Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, P. R. China, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, National Center for Protein Science, Shanghai 333 Haike Road, Pudong District, Shanghai 201210 and Shanghai Center for Bioinformation Technology, 1278 Keyuan Road, Shanghai 201203, P. R. ChinaKey Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, P. R. China, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, National Center for Protein Science, Shanghai 333 Haike Road, Pudong District, Shanghai 201210 and Shanghai Center for Bioinformation Technology, 1278 Keyuan Road, Shanghai 201203, P. R. China. (2)Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, P. R. China, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, National Center for Protein Science, Shanghai 333 Haike Road, Pudong District, Shanghai 201210 and Shanghai Center for Bioinformation Technology, 1278 Keyuan Road, Shanghai 201203, P. R. China.
4,149
Is there an association between pyostomatitis vegetans and Crohn's disease?
Yes. Pyostomatitis vegetans (PV) is a rare condition characterized by pustules that affect the oral mucosa. It is a highly specific marker for inflammatory bowel disease and its correct recognition may lead to the diagnosis of ulcerative colitis or Crohn's disease.
[8426722, 28639684, 9528646, 12890215, 21305742, 19552719, 31035024, 9747282, 27830291, 2037493, 24379574, 28209014, 19242389, 27433081, 26864508, 27377117, 28958141]
4,559
Oral features of Crohn's disease include ulcers, lip fissuring, cobblestone plaques, angular cheilitis, polypoid lesions, and perioral erythema. Pyostomatitis vegetans is a rare eruption of the oral mucosa characterized by tiny yellow pustules. It is considered a marker for inflammatory bowel disease. We describe a 45-year-old woman with a 6-month history of painful sores in her mouth, diarrhea, weight loss, and cutaneous lesions. Oral examination revealed cobblestone plaques and indentation on the tongue and friable vegetating pustules on the labial commissures. Staphylococcus simulans was isolated from the pustules. Laboratory studies revealed leucocytosis, eosinophilia, and low hemoglobin and zinc levels. Histologic study of the labial lesions revealed hyperplastic epithelium with intraepithelial clefts that contain eosinophils and neutrophils. Tongue lesions showed chronic inflammation with noncaseating granulomas. Later, colonoscopy and biopsy demonstrated Crohn's disease of the anorectal region. Pyostomatitis vegetans lesions regressed after oral zinc supplementation. Prednisone treatment resulted in healing of the tongue lesions. In our patient, pyostomatitis vegetans appeared to be related to zinc deficiency that may have been caused by malabsorption. The pathogenetic interrelationship between pyostomatitis vegetans and Crohn's disease is discussed. Pyostomatitis vegetans is a disease of the gingiva and the oral mucosa with noticeable, uncommon morphology. Clinical characteristics of this rare disease and considerations regarding differential diagnosis are described. Pyostomatitis vegetans is frequently associated with chronic inflammatory bowel diseases and can, thus, give a diagnostic hint at an existing ulcerative colitis or Crohn’s disease. A therapy plan for pyostomatitis vegetans is presented, which led to remission using local treatment only. The follow-up examination after one year showed that the treatment outcome had remained stable. An unexpected clinical appearance of the gingiva with small, pale pink thickenings after therapy and at follow-up is portrayed. HISTORY AND CLINICAL FINDINGS: A 27-year-old man was referred to the dermatological out-patient clinic because of inflammatory changes in the oral mucosa of unknown cause. 5 months earlier he had been diagnosed as having Crohn's disease of the terminal ileum. On both sides of the buccal mucosa there were rough erythematous vegetations and disseminated miliary abscesses, which extended to the labial gingiva and the soft palate. Further physical examination was unremarkable. INVESTIGATIONS: Several inflammatory parameters were increased: C-reactive protein 100 mg/l, erythrocyte sedimentation rate 55/88 mm, eosinophilic cationic protein 35.8 ng/ml (normal range 2.3-16 ng/ml). White cell count was normal (7,25/nl), with a lymphocytopenia of 11.9%. There was no eosinophilia. Haemoglobin was reduced to 11.6 g/dl and the platelets raised to 526/nl. Smears of the oral mucosa showed no fungal, viral or bacterial infection. Biopsy revealed leucocytic microabscesses in the epithelium, granulation tissue and flat ulcerations with adjoining superficial necrotic zones. DIAGNOSIS, TREATMENT AND COURSE: The clinical and histological picture as well as the association with Crohn's disease (CD) suggested pyostomatitis vegetans (PV). The PV was treated with disinfectant mouth washes which improved the subjective findings. Budesonide was given for CD. CONCLUSION: PV is a rare and usually isolated condition, but it can also occur in association with a chronic gastrointestinal disease such as ulcerative colitis and Crohn's disease. The diagnosis of PV indicates a thorough gastroenterological investigation. A 35-year-old woman with severe fistulizing Crohn's disease presented with pyostomatitis vegetans affecting both the mouth and the vulva. The coalescing pustules transformed within several days into vegetating lesions on areas of inflammation. Microbial assessments revealed no pathogenic agent. Histology showed neutrophilic microabscesses, but no granulomas. Three injections of infliximab and maintenance therapy with methotrexate resulted in rapid and complete regression of both the pyostomatitis vegetans and the Crohn's disease. Infliximab and methotrexate may be a promising treatment for the rare cases of pyostomatitis vegetans associated with Crohn's disease. Pyostomatitis vegetans (PV) is a rare, chronic mucocutaneous disorder associated with inflammatory bowel disease (IBD). Oral lesions of PV are distinct and present as multiple white or yellow pustules with an erythematous base that coalesce and undergo necrosis to form a typical "snail tracks" appearance. Two cases of PV associated with IBD--one with Crohn's disease (CD) and the other with ulcerative colitis (UC) are reported. In the first case, adalimumab therapy brought the oral and gastrointestinal manifestations to complete remission. In the second case, the remission was achieved with systemic steroid therapy, but the disease relapsed after therapy discontinuation. Azathioprine was added leading to sustained remission of PV. Because of persistent active intestinal manifestation of UC, in spite of immunosuppressive therapy, infliximab was introduced. With the therapy remission of intestinal manifestation of UC was achieved as well. Our cases confirm previously reported good experience with immunomodulators and biologics in the treatment of PV. But, before using them we have to exclude an infectious etiology of oral lesions. Inflammatory bowel disease (IBD) comprises two chronic, tissue-destructive, clinical entities: Crohn's disease (CD) and ulcerative colitis (UC), both immunologically based. Bowel symptoms are predominant, but extra-intestinal complications may occur, including involvement of the oral cavity. Oral involvement during IBD includes several types of lesions: the most common are aphthae; uncommon lesions include, among others, pyostomatitis vegetans and granulomatous lesions of CD. Starting with a presentation of six patients with oral manifestations, which were crucial for the final diagnosis of IBD, a review on the subject is presented. Oral involvement in IBD may be previous or simultaneous to the gastrointestinal symptoms. However, in the majority of cases, bowel disease precedes the onset of oral lesions by months or years. In many patients, the intestinal symptoms may be minimal and can go undetected; thus, most authors believe that the bowel must be thoroughly examined in all patients with suspected IBD even in the absence of specific symptoms. Usually, the clinical course of oral lesions is parallel to the activity of IBD; therefore, oral manifestations are a good cutaneous marker of IBD. BACKGROUND: Pyostomatitis-pyodermatitis vegetans is an uncommon condition associated with chronic inflammatory bowel disease in 75% of the cases, usually hemorrhagic rectocolitis. CASE REPORT: A 48-year-old man was referred for recent development of pustulous lesions of the lips and buccal mucosa and weight loss. He complained of abdominal pain and intermittent diarrhea which had persisted for more than one year. During the last three months, a pseudotumoral plaque with a pustulous rim had developed over the two distal phalanxes of the right middle finger in association with ungueal lysis and nodular, vegetating and crusted lesions on the lateral aspect of the left arm. Small pustules covered the entire buccal mucosa excepting the tongue and the glans forming a typical snail trace aspect. Bacterial and mycological samples were negative. The histology reports for skin and mucosa were similar: epithelial hyperplasia, intra- and subepithelial granulocyte micro-abscesses and polymorphous infiltration of the superficial derma with numerous neutrophils and eosinophils. There was a discrete interkeratinocytic fluorescence at direct immunofluorescence but indirect immunofluorescence was negative. Anti-desmogleine 1 immunolabeling showed typical normal skin uptake and immunotransfer was negative. Digestive tract endoscopy and histopathology examination of the bowel specimens confirmed the diagnosis of Crohn's disease. Clinical manifestations improved dramatically with prednisone. DISCUSSION: This case of pyostomatitis-pyodermatitis vegetans involved several aspects rarely reported in the literature: a) the cutaneomucosal signs were inaugural; b) the association with Crohn's disease; c) the presence of lesions to the genital mucosa; d) the unusual localization of the inaugural skin manifestations. This clinical entity has now been clearly distinguished from pemphigus vegetans. There was however a long debate on the similar clinical, histological and even immunological expressions. We suggest that pyostomatitis-pyodermatitis vegetans belongs to the spectrum of neutrophilic dermatoses and other authors even propose it is a clinical form of pyoderma gangrenosum. BACKGROUND: Over recent decades, both the incidence and prevalence of chronic inflammatory bowel disease have continued to rise in industrialized countries; the disease is frequently associated with extracutaneous involvement and comorbidity. OBJECTIVES: The purpose of this work was to investigate the frequency and specificity of mucocutaneous manifestations in Crohn's disease (CD) and ulcerative colitis (UC). MATERIALS AND METHODS: An extensive search in peer-reviewed journals via PubMed was performed; presented is a summary and analysis of various studies and data, including data of patients treated at our department. RESULTS: CD and UC are frequently associated with mucocutaneous symptoms; however, primary/specific disease-associations are exclusively seen in CD patients. These include peri-anal and -stomal fistulas and ulcerations, "metastatic" Crohn's disease as well as oral granulomatous disease. Moreover, in both CD and UC, there occur several other inflammatory skin conditions such as erythema nodosum, pyoderma gangrenosum, hidradenitis suppurativa, chronic oral aphthous disease, Sweet syndrome, pyostomatitis vegetans, and bowel-associated dermatosis-arthritis syndrome. Malnutrition syndromes (zinc and vitamin deficiencies) are only rarely observed. CONCLUSION: On skin and oral/genital mucous membranes various different inflammatory manifestations may be observed during the course of CD or UC. However, most data about a direct pathogenic relationship of the gastrointestinal and dermatologic disorders are quite heterogeneous or even contradictory. Nevertheless, knowledge of these conditions and their possible association with CD and UC could be crucial for early diagnosis and initiation of an appropriate therapy and thus be essential to prevent secondary tissue damage. Pyostomatitis vegetans is a rare disease of the oral cavity with characteristic clinical and histopathological findings. Its importance lies in its high correlation with inflammatory diseases of the intestinal tract. The present case report and a review of the literature are taken as a basis to discuss the disease as an entity. Pyostomatitis vegetans is a specific marker for ulcerative colitis and Crohn's disease. Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis, not only affect the intestinal tract but also have an extraintestinal involvement within the oral cavity. These oral manifestations may assist in the diagnosis and the monitoring of disease activity, whilst ignoring them may lead to an inaccurate diagnosis and useless and expensive workups. Indurated tag-like lesions, cobblestoning, and mucogingivitis are the most common specific oral findings encountered in CD cases. Aphthous stomatitis and pyostomatitis vegetans are among non-specific oral manifestations of IBD. In differential diagnosis, side effects of drugs, infections, nutritional deficiencies, and other inflammatory conditions should also be considered. Treatment usually involves managing the underlying intestinal disease. In severe cases with local symptoms, topical and/or systemic steroids and immunosuppressive drugs might be used. Pyostomatitis vegetans is a very rare oral manifestation with unknown pathogenesis. Skin and other mucous membrane involvement may be seen. This lesion has strong association with Inflammatory Bowel Disease (IBD) and may be the first sign of it. The management of Pyostomatitis vegetans is usually based on the management of underlying bowel disease. We present a case of Pyostomatitis vegetans involving gingiva and oral mucosa with no skin lesion which led to the diagnosis of Crohn's disease to emphasize important role of dentists in diagnosis of rare oral lesions and management of patients' systemic disease. The incidence of inflammatory bowel diseases (IBD) - Crohn's disease (CD) and ulcerative colitis (UC) - has been increasing on a global scale, and progressively, more gastroenterologists will be included in the diagnosis and treatment of IBD. Although IBD primarily affects the intestinal tract, extraintestinal manifestations of the disease are often apparent, including in the oral cavity, especially in CD. Specific oral manifestations in patients with CD are as follows: indurate mucosal tags, cobblestoning and mucogingivitis, deep linear ulcerations and lip swelling with vertical fissures. The most common non-specific manifestations, such as aphthous stomatitis and angular cheilitis, occur in both diseases, while pyostomatitis vegetans is more pronounced in patients with UC. Non-specific lesions in the oral cavity can also be the result of malnutrition and drugs. Malnutrition, followed by anemia and mineral and vitamin deficiency, affects the oral cavity and teeth. Furthermore, all of the drug classes that are applied to the treatment of inflammatory bowel diseases can lead to alterations in the oral cavity due to the direct toxic effects of the drugs on oral tissues, as well as indirect immunosuppressive effects with a risk of developing opportunistic infections or bone marrow suppression. There is a higher occurrence of malignant diseases in patients with IBD, which is related to the disease itself and to the IBD-related therapy with a possible oral pathology. Treatment of oral lesions includes treatment of the alterations in the oral cavity according to the etiology together with treatment of the primary intestinal disease, which requires adequate knowledge and a strong cooperation between gastroenterologists and specialists in oral medicine.
4,150
Is serotonin transported by platelets?
Yes, platelets transport serotonin.
[31570504, 32876809, 34662506, 31624776, 32901992]
4,560
The serotonergic system, serotonin (5HT), serotonin transporter (SERT), and serotonin receptors (5HT-x), is an evolutionarily ancient system that has clear physiological advantages to all life forms from bacteria to humans. This review focuses on the role of platelet/plasma serotonin and the cardiovascular system with minor references to its significant neurotransmitter function. Platelets transport and store virtually all plasma serotonin in dense granules. Stored serotonin is released from activated platelets and can bind to serotonin receptors on platelets and cellular components of the vascular wall to augment aggregation and induce vasoconstriction or vasodilation. The vascular endothelium is critical to the maintenance of cardiovascular homeostasis. While there are numerous ligands, neurological components, and baroreceptors that effect vascular tone it is proposed that serotonin and nitric oxide (an endothelium relaxing factor) are major players in the regulation of systemic blood pressure. Signals not fully defined, to date, that direct serotonin binding to one of the 15 identified 5HT receptors versus the transporter, and the role platelet/plasma serotonin plays in regulating hypertension within the cardiovascular system remain important issues to better understand many diseases and to develop new drugs. Also, expanded research of these pathways in lower life-forms may serve as important model systems to further our understanding of the evolution and mechanisms of action of serotonin. Autism spectrum disorder (ASD) is a clinically heterogeneous neurodevelopmental disorder that is caused by gene-environment interactions. To improve its diagnosis and treatment, numerous efforts have been undertaken to identify reliable biomarkers for autism. None of them have delivered the holy grail that represents a reproducible, quantifiable, and sensitive biomarker. Though blood platelets are mainly known to prevent bleeding, they also play pivotal roles in cancer, inflammation, and neurological disorders. Platelets could serve as a peripheral biomarker or cellular model for autism as they share common biological and molecular characteristics with neurons. In particular, platelet-dense granules contain neurotransmitters such as serotonin and gamma-aminobutyric acid. Molecular players controlling granule formation and secretion are similarly regulated in platelets and neurons. The major platelet integrin receptor αIIbβ3 has recently been linked to ASD as a regulator of serotonin transport. Though many studies revealed associations between platelet markers and ASD, there is an important knowledge gap in linking these markers with autism and explaining the altered platelet phenotypes detected in autism patients. The present review enumerates studies of different biomarkers detected in ASD using platelets and highlights the future needs to bring this research to the next level and advance our understanding of this complex disorder. Calcification, fibrosis, and chronic inflammation are the predominant features of calcific aortic valve disease, a life-threatening condition. Drugs that induce serotonin (5-hydroxytryptamine [5-HT]) are known to damage valves, and activated platelets, which carry peripheral serotonin, are known to promote calcific aortic valve stenosis. However, the role of 5-HT in valve leaflet pathology is not known. We tested whether serotonin mediates inflammation-induced matrix mineralization in valve cells. Real-time reverse transcription-polymerase chain reaction analysis showed that murine aortic valve interstitial cells (VICs) expressed both serotonin receptor types 2A and 2B (Htr2a and Htr2b). Although Htr2a expression was greater at baseline, Htr2b expression was induced several-fold more than Htr2a in response to the pro-calcific tumor necrosis factor-α (TNF-α) treatment. 5-HT also augmented TNF-α-induced osteoblastic differentiation and matrix mineralization of VIC, but 5-HT alone had no effects. Inhibition of serotonin receptor type 2B, using specific inhibitors or lentiviral knockdown in VIC, attenuated 5-HT effects on TNF-α-induced osteoblastic differentiation and mineralization. 5-HT treatment also augmented TNF-α-induced matrix metalloproteinase-3 expression, which was also attenuated by Htr2b knockdown. Htr2b expression in aortic roots and serum levels of peripheral 5-HT were also greater in the hyperlipidemic Apoe-/- mice than in control normolipemic mice. These findings suggest a new role for serotonin signaling in inflammation-induced calcific valvulopathy.
4,151
Proteins in the karyopherin family (Kaps) are associated with what cellular process?
Nuclear translocation of large proteins is mediated through specific protein carriers, collectively named karyopherins (importins, exportins and adaptor proteins)
[19117056, 26947076, 33571591, 33482249, 32023817, 33681296, 11777942, 21347375, 22357553, 32474299, 31487436, 17116750, 34034774, 11309407, 33728352, 11735022, 10385521, 15367670, 9391096, 33300986, 21029754]
4,561
The karyopherin (Kap) family of nuclear transport factors facilitates macromolecular transport through nuclear pore complexes (NPCs). The binding of Kaps to their cargos can also regulate, both temporally and spatially, the interactions of the cargo protein with interacting partners. Here, we show that the essential yeast Kap, Kap121, binds Dam1 and Duo1, components of the microtubule (MT)-associated Dam1 complex required for linking dynamic MT ends with kinetochores (KTs). Like mutations in the Dam1 complex, loss of Kap121 function compromises the formation of normal KT-MT attachments during mitosis. We show that the stability of the Dam1 complex in vivo is dependent on its association with Kap121. Furthermore, we show that the Kap121/Duo1 complex is maintained in the presence of RanGTP but Kap121 is released by the cooperative actions of RanGTP and tubulin. We propose that Kap121 stabilizes the Dam1 complex and participates in escorting it to spindle MTs. Karyopherins mediate the macromolecular transport between the cytoplasm and the nucleus and participate in cancer progression. However, the role and mechanism of importin-11 (IPO11), a member of the karyopherin family, in glioma progression remain undefined. Effects of IPO11 on glioma progression were detected using CCK-8, colony formation assay, flow cytometry analysis, caspase-3 activity assay, and Transwell invasion assay. Western blot analysis was used to detect the expression of active caspase-3, active caspase-7, active caspase-9, N-cadherin, Vimentin, E-cadherin, β-catenin, and c-Myc. The activity of Wnt/β-catenin pathway was evaluated by the T-cell factor/lymphoid enhancer factor (TCF/LEF) transcription factor reporter assay. Results showed that IPO11 knockdown inhibited proliferation and reduced colony number in glioma cells. IPO11 silencing promoted the apoptotic rate, increased expression levels of active caspase-3, caspase-7, and caspase-9, and enhanced caspase-3 activity. Moreover, IPO11 silencing inhibited glioma cell invasion by suppressing epithelial-to-mesenchymal transition (EMT). Mechanistically, IPO11 knockdown inactivated the Wnt/β-catenin pathway. β-Catenin overexpression abolished the effects of IPO11 silencing on the proliferation, apoptosis, and invasion in glioma cells. Furthermore, IPO11 silencing blocked the malignant phenotypes and repressed the Wnt/β-catenin pathway in vivo. In conclusion, IPO11 knockdown suppressed the malignant phenotypes of glioma cells by inactivating the Wnt/β-catenin pathway. BACKGROUND: Nuclear translocation of large proteins is mediated through specific protein carriers, collectively named karyopherins (importins, exportins and adaptor proteins). Cargo proteins are recognized by importins through specific motifs, known as nuclear localization signals (NLS). However, only the NLS recognized by importin α and transportin (M9 NLS) have been identified so far METHODS: An unsupervised in silico approach was used, followed by experimental validation. RESULTS: We identified the sequence EKRKI(E/R)(K/L/R/S/T) as an NLS signal for importin 7 recognition. This sequence was validated in the breast cancer cell line T47D, which expresses importin 7. Finally, we verified that importin 7-mediated nuclear protein transport is affected by cargo protein phosphorylation. CONCLUSIONS: The NLS sequence for importin 7 was identified and we propose this approach as an identification method of novel specific NLS sequences for β-karyopherin family members. GENERAL SIGNIFICANCE: Elucidating the complex relationships of the nuclear transporters and their cargo proteins may help in laying the foundation for the development of novel therapeutics, targeting specific importins, with an immediate translational impact. In eukaryotic cells, nucleocytoplasmic trafficking of macromolecules is largely mediated by Karyopherin β/Importin (KPNβ or Impβ) nuclear transport factors, and they import and export cargo proteins or RNAs via the nuclear pores across the nuclear envelope, consequently effecting the cellular signal cascades in response to pathogen attack and environmental cues. Although achievements on understanding the roles of several KPNβs have been obtained from model plant Arabidopsis thaliana, comprehensive analysis of potato KPNβ gene family is yet to be elucidated. In our genome-wide identifications, a total of 13 StKPNβ (Solanum tuberosum KPNβ) genes were found in the genome of the doubled monoploid S. tuberosum Group Phureja DM1-3. Sequence alignment and conserved domain analysis suggested the presence of importin-β N-terminal domain (IBN_N, PF08310) or Exporin1-like domain (XpoI, PF08389) at N-terminus and HEAT motif at the C-terminal portion in most StKPNβs. Phylogenetic analysis indicated that members of StKPNβ could be classified into 16 subgroups in accordance with their homology to human KPNβs, which was also supported by exon-intron structure, consensus motifs, and domain compositions. RNA-Seq analysis and quantitative real-time PCR experiments revealed that, except StKPNβ3d and StKPNβ4, almost all StKPNβs were ubiquitously expressed in all tissues analyzed, whereas transcriptional levels of several StKPNβs were increased upon biotic/abiotic stress or phytohormone treatments, reflecting their potential roles in plant growth, development or stress responses. Furthermore, we demonstrated that silencing of StKPNβ3a, a SA- and H2O2-inducible KPNβ genes led to increased susceptibility to environmental challenges, implying its crucial roles in plant adaption to abiotic stresses. Overall, our results provide molecular insights into StKPNβ gene family, which will serve as a strong foundation for further functional characterization and will facilitate potato breeding programs. Nucleocytoplasmic transport occurs through the nuclear pore complex (NPC), which in yeast is a ~50 MDa complex consisting of ~30 different proteins. Small molecules can freely exchange through the NPC, but macromolecules larger than ~40 kDa must be aided across by transport factors, most of which belong to a related family of proteins termed karyopherins (Kaps). These transport factors bind to the disordered phenylalanine-glycine (FG) repeat domains in a family of NPC proteins termed FG nups, and this specific binding allows the transport factors to cross the NPC. However, we still know little in terms of the molecular and kinetic details regarding how this binding translates to selective passage of transport factors across the NPC. Here we show that the specific interactions between Kaps and FG nups are strongly modulated by the presence of a cellular milieu whose proteins appear to act as very weak competitors that nevertheless collectively can reduce Kap/FG nup affinities by several orders of magnitude. Without such modulation, the avidities between Kaps and FG nups measured in vitro are too tight to be compatible with the rapid transport kinetics observed in vivo. We modeled the multivalent interactions between the disordered repeat binding sites in the FG nups and multiple cognate binding sites on Kap, showing that they should indeed be sensitive to even weakly binding competitors; the introduction of such competition reduces the availability of these binding sites, dramatically lowering the avidity of their specific interactions and allowing rapid nuclear transport. Nuclear import of proteins relies on nuclear import receptors called importins/karyopherins (Kaps), whose functions were reported in yeasts, fungi, plants, and animal cells, including cell cycle control, morphogenesis, stress sensing/response, and also fungal pathogenecity. However, limited is known about the physiological function and regulatory mechanism of protein import in the rice-blast fungus Magnaporthe oryzae. Here, we identified an ortholog of β-importin in M. oryzae encoded by an ortholog of KAP119 gene. Functional characterisation of this gene via reverse genetics revealed that it is required for vegetative growth, conidiation, melanin pigmentation, and pathogenicity of M. oryzae. The mokap119Δ mutant was also defective in formation of appressorium-like structure from hyphal tips. By affinity assay and liquid chromatography-tandem mass spectrometry, we identified potential MoKap119-interacting proteins and further verified that MoKap119 interacts with the cyclin-dependent kinase subunit MoCks1 and mediates its nuclear import. Transcriptional profiling indicated that MoKap119 may regulate transcription of infection-related genes via MoCks1 regulation of MoSom1. Overall, our findings provide a novel insight into the regulatory mechanism of M. oryzae pathogenesis likely by MoKap119-mediated nuclear import of the cyclin-dependent kinase subunit MoCks1. Many cargoes destined for nuclear import carry nuclear localization signals that are recognized by karyopherins (Kaps). We present methods to quantitate import rates and measure Kap and cargo concentrations in single yeast cells in vivo, providing new insights into import kinetics. By systematically manipulating the amounts, types, and affinities of Kaps and cargos, we show that import rates in vivo are simply governed by the concentrations of Kaps and their cargo and the affinity between them. These rates fit to a straightforward pump-leak model for the import process. Unexpectedly, we deduced that the main limiting factor for import is the poor ability of Kaps and cargos to find each other in the cytoplasm in a background of overwhelming nonspecific competition, rather than other more obvious candidates such as the nuclear pore complex and Ran. It is likely that most of every import round is taken up by Kaps and nuclear localization signals sampling other cytoplasmic proteins as they locate each other in the cytoplasm. BACKGROUND: Karyopherin α-2 (KPNA2) is a member of karyopherin family, which is proved to be responsible for the import or export of cargo proteins. Studies have determined that KPNA2 is associated with the development and prognosis of various cancers, yet the role of KPNA2 in ovarian carcinoma and its potential molecular mechanisms remains unclear. MATERIALS AND METHODS: The expression and prognosis of KPNA2 in ovarian cancer was investigated using GEPIA and Oncomine analyses. Mutations of KPNA2 in ovarian cancer were analyzed by cBioPortal database. The prognostic value of KPNA2 expression was evaluated by our own ovarian carcinoma samples using RT-qPCR. Subsequently, the cell growth, migration and invasion of ovarian cancer cells were investigated by CCK-8 and transwell assay, respectively. The protein levels of KPNA2 and KIF4A were determined by western blot. RESULTS: We obtained the following important results. (1) KPNA2 and KIF4A wereoverexpressed in ovairan cancer tissues and cells. (2) Among patients with ovarian cancer, overexpressed KPNA2 was associated with lower survival rate. (3) Mutations (R197* and S140F) in KPNA2 will have some influences on protein structure, and then may cause protein function abnormal. (4) KPNA2 konckdown inhibited proliferation, migration, invasion, as well as the expression of KIF4A. CONCLUSION: KPNA2, as a tumorigenic gene in ovarian cancer, accelerated tumor progression by up-regulating KIF4A, suggesting that KPNA2 might be a hopeful indicator of treatment and poor prognosis. The first step in the assembly of new chromatin is the cell cycle-regulated synthesis and nuclear import of core histones. The core histones include H2A and H2B, which are assembled into nucleosomes as heterodimers. We show here that the import of histone H2A and H2B is mediated by several members of the karyopherin (Kap; importin) family. An abundant complex of H2A, H2B, and Kap114p was detected in cytosol. In addition, two other Kaps, Kap121p and Kap123p, and the histone chaperone Nap1p were isolated with H2A and H2B. Nap1p is not necessary for the formation of the Kap114p-H2A/H2B complex or for import of H2A and H2B. We demonstrate that both histones contain a nuclear localization sequence (NLS) in the amino-terminal tail. Fusions of the NLSs to green fluorescent protein were specifically mislocalized to the cytoplasm in kap mutant strains. In addition, we detected a specific mislocalization in a kap95 temperature-sensitive strain, suggesting that this Kap is also involved in the import of H2A and H2B in vivo. Importantly, we show that Kap114p, Kap121p, and Kap95 interact directly with both histone NLSs and that RanGTP inhibits this association. These data suggest that the import of H2A and H2B is mediated by a network of Kaps, in which Kap114p may play the major role. Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies and is known for its high resistance and low response to treatment. Tumor immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Karyopherin alpha 2 (KPNA2), a member of the nuclear transporter family, is elevated in multiple human cancers and accelerates carcinogenesis. However, the specific role of KPNA2 in PDAC remains unclear. In this study, we found that expression of KPNA2 was significantly upregulated in PDAC compared to adjacent nontumor tissue and its high expression was correlated with poor survival outcome by analyzing the GEO datasets. Similar KPNA2 expression pattern was also found in both human patient samples and KPC mouse models through IHC staining. Although KPNA2 knockdown failed to impair the vitality and migration ability of PDAC cells in vitro, the in vivo tumor growth was significantly impeded and the expression of immune checkpoint ligand PD-L1 was reduced by silencing KPNA2. Furthermore, we uncovered that KPNA2 modulated the expression of PD-L1 by mediating nuclear translocation of STAT3. Collectively, our data suggested that KPNA2 has the potential to serve as a promising biomarker for diagnosis in PDAC. Human karyopherin alpha2 (KPNA2), a member of the karyopherin alpha family, plays a key role in the nuclear import of proteins with a classical nuclear localization signal (NLS). KPNA2, as part of a karyopherin alpha-beta heterodimer, directly binds to the NLS of proteins and functions as an adaptor that binds NLS-containing proteins via karyopherin beta to the nuclear pore complex. The NLS protein-receptor complex is translocated through the pore by an energy-dependent mechanism. Recently, we have identified and mapped the gene for KPNA2 in close proximity to a translocation breakpoint within 17q23-q24 associated with Russell-Silver syndrome (RSS). Therefore, we considered KPNA2 as a positional candidate gene for this heterogeneous disorder. RSS is mainly characterized by pre- and postnatal growth retardation, lateral asymmetry, and other dysmorphic features. Here, we present the genomic organization of the human KPNA2 gene with 11 exons spanning approximately 10 kb on chromosome 17q23-q24. Screening for mutations within all exons and adjacent intronic sequences from 31 unrelated RSS patients revealed three single nucleotide polymorphisms (SNPs) in exons 1, 5, and 7, and five SNPs in introns 1, 4 (2 SNPs), 8, and 9, respectively. No disease-related mutation was identified by comparing the sequence data of the RSS patients with their clinically normal parents and controls. Binding of the TATA-binding protein (TBP) to the promoter is the first and rate limiting step in the formation of transcriptional complexes. We show here that nuclear import of TBP is mediated by a new karyopherin (Kap) (importin) family member, Kap114p. Kap114p is localized to the cytoplasm and nucleus. A complex of Kap114p and TBP was detected in the cytosol and could be reconstituted using recombinant proteins, suggesting that the interaction was direct. Deletion of the KAP114 gene led to specific mislocalization of TBP to the cytoplasm. We also describe two other potential minor import pathways for TBP. Consistent with other Kaps, the dissociation of TBP from Kap114p is dependent on RanGTP. However, we could show that double stranded, TATA-containing DNA stimulates this RanGTP-mediated dissociation of TBP, and is necessary at lower RanGTP concentrations. This suggests a mechanism where, once in the nucleus, TBP is preferentially released from Kap114p at the promoter of genes to be transcribed. In this fashion Kap114p may play a role in the intranuclear targeting of TBP. In yeast there are at least 14 members of the beta-karyopherin protein family that govern the movement of a diverse set of cargoes between the nucleus and cytoplasm. Knowledge of the cargoes carried by each karyopherin and insight into the mechanisms of transport are fundamental to understanding constitutive and regulated transport and elucidating how they impact normal cellular functions. Here, we have focused on the identification of nuclear import cargoes for the essential yeast beta-karyopherin, Kap121p. Using an overlay blot assay and coimmunopurification studies, we have identified 30 putative Kap121p cargoes. Among these were Nop1p and Sof1p, two essential trans-acting protein factors required at the early stages of ribosome biogenesis. Characterization of the Kap121p-Nop1p and Kap121p-Sof1p interactions demonstrated that, in addition to lysine-rich nuclear localization signals (NLSs), Kap121p recognizes a unique class of signals distinguished by the abundance of arginine and glycine residues and consequently termed rg-NLSs. Kap104p is also known to recognize rg-NLSs, and here we show that it compensates for the loss of Kap121p function. Sof1p is also transported by Kap121p; however, its import can be mediated by a piggyback mechanism with Nop1p bridging the interaction between Sof1p and Kap121p. Together, our data elucidate additional levels of complexity in these nuclear transport pathways. The alpha- and beta-karyopherins (Kaps), also called importins, mediate the nuclear transport of proteins. All alpha-Kaps contain a central domain composed of eight approximately 40 amino acid, tandemly arranged, armadillo-like (Arm) repeats. The number and order of these repeats have not changed since the common origin of fungi, plants, and mammals. Phylogenetic analysis suggests that the various alpha-Kaps fall into two groups, alpha1 and alpha2. Whereas animals encode both types, the yeast genome encodes only an alpha1-Kap. The beta-Kaps are characterized by 14-15 tandemly arranged HEAT motifs. We show that the Arm repeats of alpha-Kaps and the HEAT motifs of beta-Kaps are similar, suggesting that the alpha-Kaps and beta-Kaps (and for that matter, all Arm and HEAT repeat-containing proteins) are members of the same protein superfamily. Phylogenetic analysis indicates that there are at least three major groups of beta-Kaps, consistent with their proposed cargo specificities. We present a model in which an alpha-independent beta-Kap progenitor gave rise to the alpha-dependent beta-Kaps and the alpha-Kaps. The transport of histones from the cytoplasm to the nucleus of the cell, through the nuclear membrane, is a cellular process that regulates the supply of new histones in the nucleus and is key for DNA replication and transcription. Nuclear import of histones is mediated by proteins of the karyopherin family of nuclear transport receptors. Karyopherins recognize their cargos through linear motifs known as nuclear localization/export sequences or through folded domains in the cargos. Karyopherins interact with nucleoporins, proteins that form the nuclear pore complex, to promote the translocation of their cargos into the nucleus. When binding to histones, karyopherins not only function as nuclear import receptors but also as chaperones, protecting histones from non-specific interactions in the cytoplasm, in the nuclear pore and possibly in the nucleus. Studies have also suggested that karyopherins might participate in histones deposition into nucleosomes. In this review we describe structural and biochemical studies from the last two decades on how karyopherins recognize and transport the core histone proteins H3, H4, H2A and H2B and the linker histone H1 from the cytoplasm to the nucleus, which karyopherin is the major nuclear import receptor for each of these histones, the oligomeric state of histones during nuclear import and the roles of post-translational modifications, histone-chaperones and RanGTP in regulating these nuclear import pathways. Proteins in the karyopherin-β family mediate the majority of macromolecular transport between the nucleus and the cytoplasm. Eleven of the 19 known human karyopherin-βs and 10 of the 14S. cerevisiae karyopherin-βs mediate nuclear import through recognition of nuclear localization signals or NLSs in their cargos. This receptor-mediated process is essential to cellular viability as proteins are translated in the cytoplasm but many have functional roles in the nucleus. Many known karyopherin-β-cargo interactions were discovered through studies of the individual cargos rather than the karyopherins, and this information is thus widely scattered in the literature. We consolidate information about cargos that are directly recognized by import-karyopherin-βs and review common characteristics or lack thereof among cargos of different import pathways. Knowledge of karyopherin-β-cargo interactions is also critical for the development of nuclear import inhibitors and the understanding of their mechanisms of inhibition. This article is part of a Special Issue entitled: Regulation of Signaling and Cellular Fate through Modulation of Nuclear Protein Import.
4,152
What percentage of human genes have no introns?
About 3% of human genes have no introns. URL_0
[21914464, 11333024, 16469316, 26415210, 22732409]
4,562
Intronless genes (IGs) fraction varies between 2.7 and 97.7% in eukaryotic genomes. Although many databases on exons and introns exist, there was no curated database for such genes which allowed their study in a concerted manner. Such a database would be useful to identify the functional features and the distribution of these genes across the genome. Here, a new database of IGs in eukaryotes based on GenBank data was described. This database, called IGD (Intronless Gene Database), is a collection of gene sequences that were annotated and curated. The current version of IGD contains 687 human intronless genes with their protein and CDS sequences. Some features of the entries are given in this paper. Data was extracted from GenBank release 183 using a Perl script. Data extraction was followed by a manual curation step. Intronless genes were then analyzed based on their RefSeq annotation and Gene Ontology functional class. IGD represents a useful resource for retrieval and in silico study of intronless genes. IGD is available at http://www.bioinfo-cbs.org/igd with comprehensive help and FAQ pages that illustrate the main uses of this resource. Nonsense-mediated decay (NMD), also called mRNA surveillance, is an evolutionarily conserved pathway that degrades mRNAs that prematurely terminate translation. To date, the pathway in mammalian cells has been shown to depend on the presence of a cis-acting destabilizing element that usually consists of an exon-exon junction generated by the process of pre-mRNA splicing. Whether or not mRNAs that derive from naturally intronless genes, that is, mRNAs not formed by the process of splicing, are also subject to NMD has yet to be investigated. The possibility of NMD is certainly reasonable considering that mRNAs of Saccharomyces cerevisiae are subject to NMD even though most derive from naturally intronless genes. In fact, mRNAs of S. cerevisiae generally harbor a loosely defined splicing-independent destabilizing element that has been proposed to function in NMD analogously to the spliced exon-exon junction of mammalian mRNAs. Here, we demonstrate that nonsense codons introduced into naturally intronless genes encoding mouse heat shock protein 70 or human histone H4 fail to elicit NMD. Failure is most likely because each mRNA lacks a cis-acting destabilizing element, because insertion of a spliceable intron a sufficient distance downstream of a nonsense codon within either gene is sufficient to elicit NMD. Using computational approaches we have identified 2017 expressed intronless genes in the mouse genome. Evolutionary analysis reveals that 56 intronless genes are conserved among the three domains of life--bacteria, archea and eukaryotes. These highly conserved intronless genes were found to be involved in essential housekeeping functions. About 80% of expressed mouse intronless genes have orthologs in eukaryotic genomes only, and thus are specific to eukaryotic organisms. 608 of these genes have intronless human orthologs and 302 of these orthologs have a match in OMIM database. Investigation into these mouse genes will be important in generating mouse models for understanding human diseases. Nucleosomes, the basic units of chromatin, are involved in transcription regulation and DNA replication. Intronless genes, which constitute 3 percent of the human genome, differ from intron-containing genes in evolution and function. Our analysis reveals that nucleosome positioning shows a distinct pattern in intronless and intron-containing genes. The nucleosome occupancy upstream of transcription start sites of intronless genes is lower than that of intron-containing genes. In contrast, high occupancy and well positioned nucleosomes are observed along the gene body of intronless genes, which is perfectly consistent with the barrier nucleosome model. Intronless genes have a significantly lower expression level than intron-containing genes and most of them are not expressed in CD4+ T cell lines and GM12878 cell lines, which results from their tissue specificity. However, the highly expressed genes are at the same expression level between the two types of genes. The highly expressed intronless genes require a higher density of RNA Pol II in an elongating state to compensate for the lack of introns. Additionally, 5' and 3' nucleosome depleted regions of highly expressed intronless genes are deeper than those of highly expressed intron-containing genes. Intronless genes (IGs) constitute approximately 3% of the human genome. Human IGs are essentially different in evolution and functionality from the IGs of unicellular eukaryotes, which represent the majority in their genomes. Functional analysis of IGs has revealed a massive over-representation of signal transduction genes and genes encoding regulatory proteins important for growth, proliferation, and development. IGs also often display tissue-specific expression, usually in the nervous system and testis. These characteristics translate into IG-associated diseases, mainly neuropathies, developmental disorders, and cancer. IGs represent recent additions to the genome, created mostly by retroposition of processed mRNAs with retained functionality. Processing, nuclear export, and translation of these mRNAs should be hampered dramatically by the lack of splice factors, which normally tightly cover mature transcripts and govern their fate. However, natural IGs manage to maintain satisfactory expression levels. Different mechanisms by which IGs solve the problem of mRNA processing and nuclear export are discussed here, along with their possible impact on reporter studies.
4,153
What are the currently FDA approved monoclonal antibodies for myeloma?
The US Food and Drug Administration approved MoAbs, include belantamab mafodotin, daratumumab, elotuzumab, and isatuximab.
[34549911]
4,563
In the past several years, there have been significant advances in the therapeutic arsenal of agents used to treat multiple myeloma (MM). Despite these advances, MM remains incurable. One of the most recent therapeutic advances is the development of targeted monoclonal antibodies (MoAbs). The MoAbs have significantly improved disease response rates, and extended survival in MM patients. In this review, we highlight the current US Food and Drug Administration approved MoAbs, namely, belantamab mafodotin, daratumumab, elotuzumab, and isatuximab. The mechanisms of action and pivotal clinical trials that led to US Food and Drug Administration approval of these agents and their current therapeutic use in the management of patients with MM are discussed in detail. Lastly, we describe several novel MoAbs under clinical investigation with potential for approval in the future.
4,154
What is caused by biallelic variants in PCDHGC4?
Biallelic variants in PCDHGC4 cause a novel neurodevelopmental syndrome with progressive microcephaly, seizures, and joint anomalies.
[34244665]
4,564
Author information: (1)Cologne Center for Genomics (CCG), University of Cologne and University Hospital Cologne, Cologne, Germany. (2)Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany. (3)Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad, Pakistan. (4)Department of Neuromuscular Disorders, UCL Institute of Neurology, London, UK. (5)Department of Medical Genetics, Ankara Bilkent City Hospital, Ankara, Turkey. (6)Aix Marseille Univ, INSERM, MMG, Marseille, France. (7)Assistance Publique-Hôpitaux de Marseille, Hôpital La Timone Enfants, Département de Génétique Médicale, Marseille, France. (8)Genetics of Learning Disability Service, Hunter Genetics, Waratah, NSW, Australia. (9)Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK. (10)Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK. (11)Department of Pediatrics, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia. (12)Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany. (13)Paediatric Genetic and Metabolic Service, Tawam Hospital, Al Ain, United Arab Emirates. (14)Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan. (15)Pakistan Science Foundation (PSF), Islamabad, Pakistan. (16)Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada. (17)University Institute of Biochemistry and Biotechnology (UIBB), PMAS-Arid Agriculture University, Rawalpindi, Pakistan. (18)Neurochemicalbiology and Genetics Laboratory (NGL), Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad, Pakistan. (19)Centre for Biotechnology and Microbiology, University of Swat, Swat, Pakistan. (20)Assistance Publique-Hôpitaux de Marseille, APHM, Hôpital Timone Enfants, Service de Neurologie Pédiatrique, Marseille, France. (21)T.Y. Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Sydney, Australia. (22)Specialty of Child and Adolescent Health and Discipline of Genomic Medicine, The Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, Australia. (23)Department of Clinical Genetics, The Children's Hospital at Westmead, Sydney, Australia. (24)National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK. (25)CENTOGENE GmbH, Rostock, Germany. (26)Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre (THRC), Eberhard Karls University Tübingen, Tübingen, Germany. (27)Department of Bioinformatics & Biotechnology, Faculty of Basic and Applied Sciences, International Islamic University, Islamabad, Pakistan. (28)Department of Pediatric Neurology, Children's Hospital and Institute of Child Health, Lahore, Pakistan. (29)Development and Behavioural Pediatrics Department, Institute of Child Health and The Children Hospital, Lahore, Pakistan. (30)Pediatric Neurology Department, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. (31)Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London, UK. (32)Innovative Medical Research Center, Mashhad Branch, Islamic Azad University, Mashhad, Iran. (33)Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine, University Hospital Cologne, Cologne, Germany. (34)Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany. (35)Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. (36)Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia. (37)Cologne Center for Genomics (CCG), University of Cologne and University Hospital Cologne, Cologne, Germany. mhussain@uni-koeln.de. (38)Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany. mhussain@uni-koeln.de. (39)Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine, University Hospital Cologne, Cologne, Germany. mhussain@uni-koeln.de. (40)Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany. goekhan.yigit@med.uni-goettingen.de. (#)Contributed equally
4,155
Is Sotrovimab effective for COVID-19?
Yes. Among high-risk patients with mild-to-moderate Covid-19, sotrovimab reduced the risk of disease progression.
[34819468, 34531332, 34706189, 34556486]
4,565
The Food and Drug Administration has granted emergency use authorization to sotrovimab for the treatment of mild to moderate COVID-19 in patients at increased risk for progression to severe illness.Sotrovimab is a monoclonal antibody that works directly against the spike protein of SARS-CoV-2 to block its attachment and entry into a human cell. BACKGROUND: Many recent studies have investigated the role of drug interventions for coronavirus disease 2019 (COVID-19) infection. However, an important question has been raised about how to select the effective and secure medications for COVID-19 patients. The aim of this analysis was to assess the efficacy and safety of the various medications available for severe and non-severe COVID-19 patients based on randomized placebo-controlled trials (RPCTs). METHODS: We did an updated network meta-analysis. We searched the databases from inception until July 31, 2021, with no language restrictions. We included RPCTs comparing 49 medications and placebo in the treatment of severe and non-severe patients (aged 18 years or older) with COVID-19 infection. We extracted data on the trial and patient characteristics, and the following primary outcomes: all-cause mortality, the ratios of virological cure, and treatment-emergent adverse events. Odds ratio (OR) and their 95% confidence interval (CI) were used as effect estimates. RESULTS: From 3,869 publications, we included 61 articles related to 73 RPCTs (57 in non-severe COVID-19 patients and 16 in severe COVID-19 patients), comprising 20,680 patients. The mean sample size was 160 (interquartile range 96-393) in this study. The median duration of follow-up drugs intervention was 28 days (interquartile range 21-30). For increase in virological cure, we only found that proxalutamide (OR 9.16, 95% CI 3.15-18.30), ivermectin (OR 6.33, 95% CI 1.22-32.86), and low dosage bamlanivimab (OR 5.29, 95% CI 1.12-24.99) seemed to be associated with non-severe COVID-19 patients when compared with placebo, in which proxalutamide seemed to be better than low dosage bamlanivimab (OR 5.69, 95% CI 2.43-17.65). For decrease in all-cause mortality, we found that proxalutamide (OR 0.13, 95% CI 0.09-0.19), imatinib (OR 0.49, 95% CI 0.25-0.96), and baricitinib (OR 0.58, 95% CI 0.42-0.82) seemed to be associated with non-severe COVID-19 patients; however, we only found that immunoglobulin gamma (OR 0.27, 95% CI 0.08-0.89) was related to severe COVID-19 patients when compared with placebo. For change in treatment-emergent adverse events, we only found that sotrovimab (OR 0.21, 95% CI 0.13-0.34) was associated with non-severe COVID-19 patients; however, we did not find any medications that presented a statistical difference when compared with placebo among severe COVID-19 patients. CONCLUSION: We conclude that marked variations exist in the efficacy and safety of medications between severe and non-severe patients with COVID-19. It seems that monoclonal antibodies (e.g., low dosage bamlanivimab, baricitinib, imatinib, and sotrovimab) are a better choice for treating severe or non-severe COVID-19 patients. Clinical decisions to use preferentially medications should carefully consider the risk-benefit profile based on efficacy and safety of all active interventions in patients with COVID-19 at different levels of infection. OBJECTIVE: To evaluate the efficacy and safety of antiviral antibody therapies and blood products for the treatment of novel coronavirus disease 2019 (covid-19). DESIGN: Living systematic review and network meta-analysis, with pairwise meta-analysis for outcomes with insufficient data. DATA SOURCES: WHO covid-19 database, a comprehensive multilingual source of global covid-19 literature, and six Chinese databases (up to 21 July 2021). STUDY SELECTION: Trials randomising people with suspected, probable, or confirmed covid-19 to antiviral antibody therapies, blood products, or standard care or placebo. Paired reviewers determined eligibility of trials independently and in duplicate. METHODS: After duplicate data abstraction, we performed random effects bayesian meta-analysis, including network meta-analysis for outcomes with sufficient data. We assessed risk of bias using a modification of the Cochrane risk of bias 2.0 tool. The certainty of the evidence was assessed using the grading of recommendations assessment, development, and evaluation (GRADE) approach. We meta-analysed interventions with ≥100 patients randomised or ≥20 events per treatment arm. RESULTS: As of 21 July 2021, we identified 47 trials evaluating convalescent plasma (21 trials), intravenous immunoglobulin (IVIg) (5 trials), umbilical cord mesenchymal stem cells (5 trials), bamlanivimab (4 trials), casirivimab-imdevimab (4 trials), bamlanivimab-etesevimab (2 trials), control plasma (2 trials), peripheral blood non-haematopoietic enriched stem cells (2 trials), sotrovimab (1 trial), anti-SARS-CoV-2 IVIg (1 trial), therapeutic plasma exchange (1 trial), XAV-19 polyclonal antibody (1 trial), CT-P59 monoclonal antibody (1 trial) and INM005 polyclonal antibody (1 trial) for the treatment of covid-19. Patients with non-severe disease randomised to antiviral monoclonal antibodies had lower risk of hospitalisation than those who received placebo: casirivimab-imdevimab (odds ratio (OR) 0.29 (95% CI 0.17 to 0.47); risk difference (RD) -4.2%; moderate certainty), bamlanivimab (OR 0.24 (0.06 to 0.86); RD -4.1%; low certainty), bamlanivimab-etesevimab (OR 0.31 (0.11 to 0.81); RD -3.8%; low certainty), and sotrovimab (OR 0.17 (0.04 to 0.57); RD -4.8%; low certainty). They did not have an important impact on any other outcome. There was no notable difference between monoclonal antibodies. No other intervention had any meaningful effect on any outcome in patients with non-severe covid-19. No intervention, including antiviral antibodies, had an important impact on any outcome in patients with severe or critical covid-19, except casirivimab-imdevimab, which may reduce mortality in patients who are seronegative. CONCLUSION: In patients with non-severe covid-19, casirivimab-imdevimab probably reduces hospitalisation; bamlanivimab-etesevimab, bamlanivimab, and sotrovimab may reduce hospitalisation. Convalescent plasma, IVIg, and other antibody and cellular interventions may not confer any meaningful benefit. SYSTEMATIC REVIEW REGISTRATION: This review was not registered. The protocol established a priori is included as a data supplement. FUNDING: This study was supported by the Canadian Institutes of Health Research (grant CIHR- IRSC:0579001321). READERS' NOTE: This article is a living systematic review that will be updated to reflect emerging evidence. Interim updates and additional study data will be posted on our website (www.covid19lnma.com).
4,156
Is Otolin-1 a matrix protein?
Yes, otolin-1 is a otoconia matrix protein.
[28498270, 20856818, 18410381, 29076638]
4,566
OBJECTIVE: To test the hypothesis that age-related demineralization of otoconia will result in an age-related increase in blood levels of otoconia matrix protein, otolin-1. STUDY DESIGN: Cross-sectional observational clinical trial. SETTING: Clinical research center. PATIENTS: Seventy nine men and women ranging in age from 22 to 95 years old. INTERVENTIONS: Diagnostic. MAIN OUTCOME MEASURES: Blood levels of otolin-1 in relation to age. RESULTS: Levels of otolin-1 of subjects divided into four age groups (1: 20-30 [n = 20], 2: 50-65 [n = 20], 3: 66-80 [n = 20], 4: 81-95 [n = 19] years old) demonstrated an increasing trend with age. The difference between otolin levels of groups 2 and 3, as well as, (p = 0.04) and 2 and 4 (p = 0.031) were statistically significant, but there was no significant difference between the two oldest groups. CONCLUSIONS: Otolin-1 blood levels are significantly higher in patients older than 65 years of age. This is consistent with previous scanning electron microscopy findings of age-related otoconia degeneration and increased prevalence of benign paroxysmal positional vertigo (BPPV) with age. Normative data provided here can serve as important reference values against which levels from BPPV patients can be compared with further evaluate otolin-1 as a circulatory biomarker for otoconia degeneration. BACKGROUND: The mammalian otoconial membrane is a dense extracellular matrix containing bio-mineralized otoconia. This structure provides the mechanical stimulus necessary for hair cells of the vestibular maculae to respond to linear accelerations and gravity. In teleosts, Otolin is required for the proper anchoring of otolith crystals to the sensory maculae. Otoconia detachment and subsequent entrapment in the semicircular canals can result in benign paroxysmal positional vertigo (BPPV), a common form of vertigo for which the molecular basis is unknown. Several cDNAs encoding protein components of the mammalian otoconia and otoconial membrane have recently been identified, and mutations in these genes result in abnormal otoconia formation and balance deficits. PRINCIPAL FINDINGS: Here we describe the cloning and characterization of mammalian Otolin, a protein constituent of otoconia and the otoconial membrane. Otolin is a secreted glycoprotein of ∼70 kDa, with a C-terminal globular domain that is homologous to the immune complement C1q, and contains extensive posttranslational modifications including hydroxylated prolines and glycosylated lysines. Like all C1q/TNF family members, Otolin multimerizes into higher order oligomeric complexes. The expression of otolin mRNA is restricted to the inner ear, and immunohistochemical analysis identified Otolin protein in support cells of the vestibular maculae and semi-circular canal cristae. Additionally, Otolin forms protein complexes with Cerebellin-1 and Otoconin-90, two protein constituents of the otoconia, when expressed in vitro. Otolin was also found in subsets of support cells and non-sensory cells of the cochlea, suggesting that Otolin is also a component of the tectorial membrane. CONCLUSION: Given the importance of Otolin in lower organisms, the molecular cloning and biochemical characterization of the mammalian Otolin protein may lead to a better understanding of otoconial development and vestibular dysfunction. In the biomineralization processes, proteins are thought to control the polymorphism and morphology of the crystals by forming complexes of structural and mineral-associated proteins. To identify such proteins, we have searched for proteins that may form high-molecular-weight (HMW) aggregates in the matrix of fish otoliths that have aragonite and vaterite as their crystal polymorphs. By screening a cDNA library of the trout inner ear using an antiserum raised against whole otolith matrix, a novel protein, named otolith matrix macromolecule-64 (OMM-64), was identified. The protein was found to have a molecular mass of 64 kDa, and to contain two tandem repeats and a Glu-rich region. The structure of the protein and that of its DNA are similar to those of starmaker, a protein involved in the polymorphism control in the zebrafish otoliths [Söllner C, Burghammer M, Busch-Nentwich E, Berger J, Schwarz H, Riekel C & Nicolson T (2003) Science302, 282-286]. (45)Ca overlay analysis revealed that the Glu-rich region has calcium-binding activity. Combined analysis by western blotting and deglycosylation suggested that OMM-64 is present in an HMW aggregate with heparan sulfate chains. Histological observations revealed that OMM-64 is expressed specifically in otolith matrix-producing cells and deposited onto the otolith. Moreover, the HMW aggregate binds to the inner ear-specific short-chain collagen otolin-1, and the resulting complex forms ring-like structures in the otolith matrix. Overall, OMM-64, by forming a calcium-binding aggregate that binds to otolin-1 and forming matrix protein architectures, may be involved in the control of crystal morphology during otolith biomineralization.
4,157
List the drug targets of Faricimab?
Faricimab, a bispecific antibody that inhibits VEGF-A and Ang-2.
[32729888, 34511878, 32729897, 30905643, 32785136, 33471572, 34188445, 32342814, 31513439]
4,567
Conflict of interest statement: AK: Consultant: Adverum, Aerpio, Allergan, Chengdu Kanghong, DORC, Genentech, Inc., Kato, Kodiak, Novartis, Gemini, Graybug, Gyroscope, Opthea, Oxurion, PolyPhotonix, Recens Medical, Regenxbio, Roche Research support: Adverum, Alkahest, Allegro, Allergan, Chengdu Kanghong, Gemini, Genentech, Inc., Gyroscope, Iveric Bio, NGM, Neurotech, Kodiak, Novartis, Opthea, Oxurion, Regenxbio, Recens Medical, Roche Lecture fees: Allergan, Genentech, Novartis CD: Consultant: Genentech, Roche, Regeneron, Novartis, IvericBio Research support: Genentech, Roche, Regeneron, Novartis, IvericBio, Kodiak, Adverum, Gyroscope Lecture fees: Novartis, DORC CYW: Consultant: Allergan/AbbVie, Alcon, Alimera Sciences, Novartis, Regeneron, REGENXBIO, Genentech, DORC DE: Consultant: Genentech, Regeneron, Allergan, Novartis, Notal Vision, EyePoint, Gyroscope, Kodiak, RecensMedical, DORC, IvericBio, Apellis, KKR, Regenxbio, Bausch & Lomb Research support: AsclepiX, Genentech, Bayer, Novartis, Alimera, Opthea, Ocular Therapeutix, EyePoint, Mylan, Chengdu, Gemini, Gyroscope, Kodiak, NGM, RecensMedical, Alkahest, Ionis, IvericBio, Regenxbio Lecture fees: Genentech, Bayer, Allergan, Novartis, EyePoint, DORC, Apellis Equity/Stockholder: Clearside, US Retina, Hemera Biopharmaceuticals, Boston Image Reading Center, Network Eye Founder: Network Eye RPS: Consultant: Regeneron, Genentech, Alcon, Novartis, Asclepix, Gyroscope, Bausch and Lomb. Research support: Apellis, NGM Biopharma The authors report no other conflicts of interest in this work. This review summarizes the latest findings in the literature of Angiopoietin-2 (Ang-2), Tyrosine-protein kinase receptor (Tie-2) complex, and faricimab along with their involvement for the treatment of retinal vascular diseases in various clinical trials. In ischemic diseases, such as diabetic retinopathy, Ang-2 is upregulated, deactivating Tie-2, resulting in vascular leakage, pericyte loss, and inflammation. Recombinant Angiopeotin-1 (Ang-1), Ang-2-blocking molecules, and inhibitors of vascular endothelial protein tyrosine phosphatase (VE-PTP) decrease inflammation-associated vascular leakage, showing therapeutic effects in diabetes, atherosclerosis, and ocular neovascular diseases. In addition, novel studies show that angiopoietin-like proteins may play an important role in cellular metabolism leading to retinal vascular diseases. Current therapeutic focus combines Ang-Tie targeted drugs with other anti-angiogenic or immune therapies. Clinical studies have identified faricimab, a novel bispecific antibody designed for intravitreal use, to simultaneously bind and neutralize Ang-2 and VEGF-A for treatment of diabetic eye disease. By targeting both Ang-2 and vascular endothelial growth factor-A (VEGF-A), faricimab displays an improved and sustained efficacy over longer treatment intervals, delivering superior vision outcomes for patients with diabetic macular edema and reducing the treatment burden for patients with neovascular age-related macular degeneration and diabetic macular edema. Phase 2 results have produced promising outcomes with regard to efficacy and durability. Faricimab is currently being evaluated in global Phase 3 studies. INTRODUCTION: Intravitreal antivascular endothelial growth factor (VEGF) drugs represent the first-line treatment option for wet age-related macular degeneration (w-AMD) and diabetic macular edema (DME); however, the frequent injection intervals have illuminated to the necessity for new molecules allowing a more prolonged treatment regimen. Faricimab is a promising bispecific drug targeting VEGF-A and the Ang-Tie/pathway. Phase II STAIRWAY and AVENUE Trials showed its clinical efficacy for the treatment of w-AMD, while the phase II BOULEVARD Trial revealed its superiority to monthly ranibizumab in the management of DME with a monthly treatment regimen. The agents are awaiting approval for the treatment of w-AMD and DME. AREAS COVERED: This article presents an overview of w-AMD and diabetic retinopathy and examines the progress of Faricimab through clinical trials. It offers insights on where Faricimab may be placed in the future market of anti-VEGF treatments and discusses the role of Ang/Tie pathway as a potential additive weapon for the treatment of w-AMD, DME, and retinal vein occlusion (RVO). EXPERT OPINION: The possibility of administering faricimab with more prolonged treatment intervals represents an important advantage to decrease the treatment burden and improve patient compliance. Further phase III trials should provide more evidence on clinical efficacy. Introduction: The Tie-2/Angiopoietin pathway is a therapeutic target for the treatment of neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME). Activation of Tie-2 receptor via Ang-1 maintains vascular stability to limit exudation. Ang-2, a competitive antagonist to Ang-1, and VE-PTP, an endothelial-specific phosphatase, interfere with the Tie-2-Ang-1 axis, resulting in vascular leakage. Areas covered: Faricimab, a bispecific antibody that inhibits VEGF-A and Ang-2, is in phase 3 trials for nAMD and DME. Nesvacumab is an Ang-2 inhibitor; when coformulated with aflibercept, it failed to show benefit over aflibercept monotherapy in achieving visual gains in phase 2 studies of nAMD and DME. ARP-1536 is an intravitreally administered VE-PTP inhibitor undergoing preclinical studies. AKB-9778 is a subcutaneously administered VE-PTP inhibitor that, when combined with monthly ranibizumab, reduced DME more effectively than ranibizumab monotherapy in a phase 2 study. AKB-9778 monotherapy did not reduce diabetic retinopathy severity score compared to placebo. AXT107, currently in the preclinical phase, promotes conversion of Ang-2 into a Tie-2 agonist and blocks signaling through VEGFR2 and other receptor tyrosine-kinases. Expert opinion: Tie-2/Angiopoietin pathway modulators show promise to reduce treatment burden and improve visual outcomes in nAMD and DME, with potential to treat cases refractory to current treatment modalities.
4,158
What induces downstream of gene (DoG) readthrough transcription?
Stress-induced transcriptional readthrough generates very long downstream of gene containing transcripts (DoGs), which may explain up to 20% of intergenic transcription. Massive induction of transcriptional readthrough generates downstream of gene-containing transcripts (DoGs) in cells under stress condition. Ca2+ signaling mediates reduced transcription termination in response to certain stress conditions. This reduction allows readthrough transcription, generating a highly inducible and diverse class of downstream of gene containing transcripts (DoGs) that we have recently described.
[26861889, 29548296, 9343185, 29945683, 28928151, 29147672, 30089468]
4,568
Previous studies demonstrated that massive induction of transcriptional readthrough generates downstream of gene-containing transcripts (DoGs) in cells under stress condition. Here, we analyzed TSS-seq (transcription start site sequencing) data from the DBTSS database. We investigated TSS tags at the end of gene for all pan-stress and untreated-cell DoGs, in comparison with expression-matched non-DoGs. We observed significantly more TSS tags at the end of pan-stress and untreated-cell DoG genes than non-DoG genes, even though their TSS tags in the promoter is the same. Importantly, the median value of TSS tags at gene end normalized to gene promoter is significantly higher than the median expression ratio of short DoG to host gene and of long DoG to host gene. Our results indicate that downstream overlapping long non-coding RNAs derived from the TSS at the gene end may be an important source of DoGs. In cells productively infected with adenovirus type 5, transcription is not terminated between the E1a gene and the adjacent downstream E1b gene. Insertion of the mouse beta(maj)-globin transcription termination sequence (GGT) into the E1a coding region dramatically reduces early, but not late, E1b expression (E. Falck-Pedersen, J. Logan, T. Shenk, and J. E. Darnell, Jr., Cell 40:897-905, 1985). In the study described herein, we showed that base substitution mutations in the globin DNA that specifically relieved transcription termination also restored early E1b promoter activity in cis, establishing that maximal early E1b expression requires readthrough transcription originating from the adjacent upstream gene. To identify potential targets of readthrough activation, a series of recombinant viruses with double mutations was constructed. Each double-mutant virus strain had the transcription termination sequences in the first exon of E1a and a deletion within the transcription control region of E1b. Early E1b expression from the double-mutant strains was more defective than that from strains containing either mutation alone, indicating that the deleted regions (positions -362 to -35) are not the target for readthrough activation. Two findings suggested that a cis-dominant property of early viral templates is important for readthrough activation. First, the early E1b defect caused by the GGT insertion was not complemented in trans by factors present in late-infected cells. Second, restoration of E1b transcription at late times occurred concurrently with viral DNA replication. Readthrough activation may help convert virion DNA into a transcriptionally competent template prior to DNA replication and late transcription. Naturally occurring stress-induced transcriptional readthrough is a recently discovered phenomenon, in which stress conditions lead to dramatic induction of long transcripts as a result of transcription termination failure. In 2015, we reported the induction of such downstream of gene (DoG) containing transcripts upon osmotic stress in human cells, while others observed similar transcripts in virus-infected and cancer cells. Using the rigorous methodology Cap-Seq, we demonstrated that DoGs result from transcriptional readthrough, not de novo initiation. More recently, we presented a genome-wide comparison of NIH3T3 mouse cells subjected to osmotic, heat, and oxidative stress and concluded that massive induction of transcriptional readthrough is a hallmark of the mammalian stress response. In their recent letter, Huang and Liu in contrast claim that DoG transcripts result from novel transcription initiation near the ends of genes. Their conclusions rest on analyses of a publicly available transcription start site (TSS-Seq) dataset from unstressed NIH3T3 cells. Here, we present evidence that this dataset identifies not only true transcription start sites, TSSs, but also 5'-ends of numerous snoRNAs, which are generally processed from introns in mammalian cells. We show that failure to recognize these erroneous assignments in the TSS-Seq dataset, as well as ignoring published Cap-Seq data on TSS mapping during osmotic stress, have led to misinterpretation by Huang and Liu. We conclude that, contrary to the claims made by Huang and Liu, TSS-Seq reads near gene ends cannot explain the existence of DoGs, nor their stress-mediated induction. Rather it is, as we originally demonstrated, transcriptional readthrough that leads to the formation of DoGs. The calcium ion (Ca2+) is a key intracellular signaling molecule with far-reaching effects on many cellular processes. One of the most important such Ca2+ regulated processes is transcription. A body of literature describes the effect of Ca2+ signaling on transcription initiation as occurring mainly through activation of gene-specific transcription factors by Ca2+-induced signaling cascades. However, the reach of Ca2+ extends far beyond the first step of transcription. In fact, Ca2+ can regulate all phases of transcription, with additional effects on transcription-associated events such as alternative splicing. Importantly, Ca2+ signaling mediates reduced transcription termination in response to certain stress conditions. This reduction allows readthrough transcription, generating a highly inducible and diverse class of downstream of gene containing transcripts (DoGs) that we have recently described. BACKGROUND: Recent studies have described a widespread induction of transcriptional readthrough as a consequence of various stress conditions in mammalian cells. This novel phenomenon, initially identified from analysis of RNA-seq data, suggests intriguing new levels of gene expression regulation. However, the mechanism underlying naturally occurring transcriptional readthrough, as well as its regulatory consequences, still remain elusive. Furthermore, the readthrough response to stress has thus far not been investigated outside of mammalian species, and the occurrence of readthrough in many physiological and disease conditions remains to be explored. RESULTS: To facilitate a wider investigation into transcriptional readthrough, we created the DoGFinder software package, for the streamlined identification and quantification of readthrough transcripts, also known as DoGs (Downstream of Gene-containing transcripts), from any RNA-seq dataset. Using DoGFinder, we explore the dependence of DoG discovery potential on RNA-seq library depth, and show that stress-induced readthrough induction discovery is robust to sequencing depth, and input parameter settings. We further demonstrate the use of the DoGFinder software package on a new publically available RNA-seq dataset, and discover DoG induction in human PME cells following hypoxia - a previously unknown readthrough inducing stress type. CONCLUSIONS: DoGFinder will enable users to explore, in a few simple steps, the readthrough phenomenon in any condition and organism. DoGFinder is freely available at https://github.com/shalgilab/DoGFinder .
4,160
Is AGO2 related to cytokinesis?
Yes. AGO2 localizes to cytokinetic protrusions in a p38-dependent manner and is needed for accurate cell division.
[34117353]
4,570
Argonaute 2 (AGO2) is an indispensable component of the RNA-induced silencing complex, operating at the translational or posttranscriptional level. It is compartmentalized into structures such as GW- and P-bodies, stress granules and adherens junctions as well as the midbody. Here we show using immunofluorescence, image and bioinformatic analysis and cytogenetics that AGO2 also resides in membrane protrusions such as open- and close-ended tubes. The latter are cytokinetic bridges where AGO2 colocalizes at the midbody arms with cytoskeletal components such as α-Τubulin and Aurora B, and various kinases. AGO2, phosphorylated on serine 387, is located together with Dicer at the midbody ring in a manner dependent on p38 MAPK activity. We further show that AGO2 is stress sensitive and important to ensure the proper chromosome segregation and cytokinetic fidelity. We suggest that AGO2 is part of a regulatory mechanism triggered by cytokinetic stress to generate the appropriate micro-environment for local transcript homeostasis.
4,161
Hampton’s hump is characteristic to which disease?
Hampton’s hump is characteristic to pulmonary embolism.
[26521192, 24862753, 8372182]
4,571
We discuss a case of a 20-year-old woman presenting with chest pain found to have a Hampton's hump on chest x-ray and corresponding wedge infarct on computed tomographic scan. Contrary to our suspicion that this febrile and tachycardic patient had a pulmonary embolism, she was later determined to have a septic embolus secondary to endocarditis. We highlight the difficulties in diagnosing certain cases of endocarditis in the emergency department, as well as the difficulties in distinguishing septic emboli from pulmonary emboli,especially with plain radiographs. A 56-year-old man presented to the Accident and Emergency Department with pleuritic chest pain of sudden onset. He gave a history of short-distance air travel ten days earlier. Chest radiograph showed a peripheral-based opacity in the right lower zone, which was not seen in a previous study done three months ago, suggestive of Hampton's hump. The D-dimer level was raised. Computed tomography pulmonary angiography confirmed the diagnosis of pulmonary embolism in a right lower lobe segmental branch, with adjacent collapsed lung, consistent with lung infarction. The patient was started on heparin injection with significant relief of his symptoms. The clinical and imaging features of pulmonary embolism are described, with emphasis on the historical radiographic signs and the current dual-energy computed tomography innovations.
4,162
What is the activity of Indoleamine 2,3-dioxygenase 1.
Indoleamine 2,3-dioxygenase 1 (IDO1), a known immunosuppressive enzyme that catalyzes the rate-limiting step in the oxidation of tryptophan (Trp) to kynurenine (Kyn), has received increasing attention as an attractive immunotherapeutic target for cancer therapy.
[34535017, 34752953, 34520819, 34557196]
4,572
The contribution of the bone marrow (BM) immune microenvironment to acute myeloid leukemia (AML) development is well-known, but its prognostic significance is still elusive. Indoleamine 2,3-dioxygenase 1 (IDO1), which is negatively regulated by the BIN1 proto-oncogene, is an interferon-γ-inducible mediator of immune tolerance. With the aim to develop a prognostic IDO1-based immune gene signature, biological and clinical data of 982 patients with newly diagnosed, nonpromyelocytic AML were retrieved from public datasets and analyzed using established computational pipelines. Targeted transcriptomic profiles of 24 diagnostic BM samples were analyzed using the NanoString's nCounter platform. BIN1 and IDO1 were inversely correlated and individually predicted overall survival. PLXNC1, a semaphorin receptor involved in inflammation and immune response, was the IDO1-interacting gene retaining the strongest prognostic value. The incorporation of PLXNC1 into the 2-gene IDO1-BIN1 score gave rise to a powerful immune gene signature predicting survival, especially in patients receiving chemotherapy. The top differentially expressed genes between IDO1lowand IDO-1high and between PLXNC1lowand PLXNC1high cases further improved the prognostic value of IDO1 providing a 7- and 10-gene immune signature, highly predictive of survival and correlating with AML mutational status at diagnosis. Taken together, our data indicate that IDO1 is pivotal for the construction of an immune gene signature predictive of survival in AML patients. Given the emerging role of immunotherapies for AML, our findings support the incorporation of immune biomarkers into current AML classification and prognostication algorithms. Indoleamine 2,3-dioxygenase 1 (IDO1), a known immunosuppressive enzyme that catalyzes the rate-limiting step in the oxidation of tryptophan (Trp) to kynurenine (Kyn), has received increasing attention as an attractive immunotherapeutic target for cancer therapy. Up to now, eleven small-molecule IDO1 inhibitors have entered clinical trials for the treatment of cancers. In addition, proteolysis targeting chimera (PROTAC) based degraders also provide prospects for cancer therapy. Herein we present a comprehensive overview of the medicinal chemistry strategies and potential therapeutic applications of IDO1 inhibitors in nonclinical trials and IDO1-PROTAC degraders. Author information: (1)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 19110700091@fudan.edu.cn. (2)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 16210700110@fudan.edu.cn. (3)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 18110700076@fudan.edu.cn. (4)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 17110700017@fudan.edu.cn. (5)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 17110700084@fudan.edu.cn. (6)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 18210700067@fudan.edu.cn. (7)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 17210700070@fudan.edu.cn. (8)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: 17210700113@fudan.edu.cn. (9)Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Siping Road 1239, Shanghai, 200092, China. Electronic address: kuangcx@tongji.edu.cn. (10)Department of Pharmacology, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China. Electronic address: liuhr@fudan.edu.cn. (11)State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Songhu Road 2005, Shanghai, 200438, China. Electronic address: yangqing68@fudan.edu.cn. Immune escape is an early phenomenon in cancer development/progression. Indoleamine 2,3-dioxygenase 1 (IDO1) is a normal endogenous mechanism of acquired peripheral immune tolerance and may therefore be tumor-promoting. This study investigated the clinical relevance of IDO1 expression by immune cells in the lymph nodes and blood and of the serum kynurenine/tryptophan (Kyn/Trp) ratio in 65 systemic treatment naïve stage I-III melanoma patients. Blood samples were collected within the first year of diagnosis. Patients had a median follow-up of 61 months. High basal IDO1 expression in peripheral monocytes and low IFNγ-induced IDO1 upregulation correlated with worse outcome independent from disease stage. Interestingly studied factors were not interrelated. During follow-up, the risk of relapse was 9% (2/22) in the subgroup with high IFNγ-induced IDO1 upregulation in monocytes. In contrast, if IDO1 upregulation was low, relapse occurred in 30% (3/10) of patients with low basal IDO1 expression in monocytes and in 61.5% (8/13) in the subgroup with high basal IDO1 expression in monocytes (Log-Rank test, p=0.008). This study reveals some immune features in the blood of early stage melanoma that may be of relevance for disease outcome. These may offer a target for sub-stratification and early intervention.
4,163
What is the purpose of Macropinocytosis?
Macropinocytosis is an endocytic process, which involves the engulfment of extra-cellular content in vesicles known as macropinosomes.
[34755081, 27647881, 30333835, 14732047, 30617109, 29085336, 27352861, 32745890, 31924779, 25096879, 11029048, 17760832, 10321993, 30725454, 10678991, 30966999, 30400219, 30967003, 30967006, 30967007, 30967008, 30967009, 33520357, 32756454, 27503856, 11890548, 15533943]
4,573
Macropinocytosis refers to the non-specific uptake of extracellular fluid, which plays ubiquitous roles in cell growth, immune surveillance, and virus entry. Despite its widespread occurrence, it remains unclear how its initial cup-shaped plasma membrane extensions form without any external solid support, as opposed to the process of particle uptake during phagocytosis. Here, by developing a computational framework that describes the coupling between the bistable reaction-diffusion processes of active signaling patches and membrane deformation, we demonstrated that the protrusive force localized to the edge of the patches can give rise to a self-enclosing cup structure, without further assumptions of local bending or contraction. Efficient uptake requires a balance among the patch size, magnitude of protrusive force, and cortical tension. Furthermore, our model exhibits cyclic cup formation, coexistence of multiple cups, and cup-splitting, indicating that these complex morphologies self-organize via a common mutually-dependent process of reaction-diffusion and membrane deformation. Macropinocytosis has received increasing attention in recent years for its various roles in nutrient acquisition, immune surveillance, and virus and cancer pathologies. In most cases macropinocytosis is initiated by the sudden increase in an external stimulus such as a growth factor. This "induced" form of macropinocytosis has been the subject of much of the work addressing its mechanism and function over the years. An alternative, "constitutive" form of macropinocytosis restricted to primary innate immune cells also exists, although its mechanism has remained severely understudied. This mini-review focuses on the very recent advances that have shed new light on the initiation, formation and functional relevance of constitutive macropinocytosis in primary innate immune cells. An emphasis is placed on how this new understanding of constitutive macropinocytosis is helping to define the sentinel function of innate immune cells including polarized macrophages and dendritic cells. Macropinocytosis is a form of endocytosis that accompanies cell surface ruffling. It is distinct in many ways from the better characterized micropinocytosis, which includes clathrin-coated vesicle endocytosis and small uncoated vesicles. Because macropinosomes are relatively large, they provide an efficient route for non-selective endocytosis of solute macromolecules. This route may facilitate MHC-class-II-restricted antigen presentation by dendritic cells. Because the ruffling that leads to macropinocytosis is regulated, it has been exploited by some pathogenic bacteria as a novel route for entry into cells. Macropinocytosis is an actin-driven process of large-scale and non-specific fluid uptake used for feeding by some cancer cells and the macropinocytosis model organism Dictyostelium discoideum In Dictyostelium, macropinocytic cups are organized by 'macropinocytic patches' in the plasma membrane. These contain activated Ras, Rac and phospholipid PIP3, and direct actin polymerization to their periphery. We show that a Dictyostelium Akt (PkbA) and an SGK (PkbR1) protein kinase act downstream of PIP3 and, together, are nearly essential for fluid uptake. This pathway enables the formation of larger macropinocytic patches and macropinosomes, thereby dramatically increasing fluid uptake. Through phosphoproteomics, we identify a RhoGAP, GacG, as a PkbA and PkbR1 target, and show that it is required for efficient macropinocytosis and expansion of macropinocytic patches. The function of Akt and SGK in cell feeding through control of macropinosome size has implications for cancer cell biology. Macropinocytosis is a means by which eukaryotic cells ingest extracellular liquid and dissolved molecules. It is widely conserved amongst cells that can take on amoeboid form and, therefore, appears to be an ancient feature that can be traced back to an early stage of evolution. Recent advances have highlighted how this endocytic process can be subverted during pathology - certain cancer cells use macropinocytosis to feed on extracellular protein, and many viruses and bacteria use it to enter host cells. Prion and prion-like proteins can also spread and propagate from cell to cell through macropinocytosis. Progress is being made towards using macropinocytosis therapeutically, either to deliver drugs to or cause cell death by inducing catastrophically rapid fluid uptake. Mechanistically, the Ras signalling pathway plays a prominent and conserved activating role in amoebae and in mammals; mutant amoebae with abnormally high Ras activity resemble tumour cells in their increased capacity for growth using nutrients ingested through macropinocytosis. This Commentary takes a functional and evolutionary perspective to highlight progress in understanding and use of macropinocytosis, which is an ancient feeding process used by single-celled phagotrophs that has now been put to varied uses by metazoan cells and is abused in disease states, including infection and cancer. Macropinocytosis is an evolutionarily-conserved, large-scale, fluid-phase form of endocytosis that has been ascribed different functions including antigen presentation in macrophages and dendritic cells, regulation of receptor density in neurons, and regulation of tumor growth under nutrient-limiting conditions. However, whether macropinocytosis regulates the expansion of non-transformed mammalian cells is unknown. Here we show that primary mouse and human T cells engage in macropinocytosis that increases in magnitude upon T cell activation to support T cell growth even under amino acid (AA) replete conditions. Mechanistically, macropinocytosis in T cells provides access of extracellular AA to an endolysosomal compartment to sustain activation of the mechanistic target of rapamycin complex 1 (mTORC1) that promotes T cell growth. Our results thus implicate a function of macropinocytosis in mammalian cell growth beyond Ras-transformed tumor cells via sustained mTORC1 activation. Macropinocytosis is exploited by many pathogens for entry into cells. Coronaviruses (CoVs) such as severe acute respiratory syndrome (SARS) CoV and Middle East respiratory syndrome CoV are important human pathogens; however, macropinocytosis during CoV infection has not been investigated. We demonstrate that the CoVs SARS CoV and murine hepatitis virus (MHV) induce macropinocytosis, which occurs late during infection, is continuous, and is not associated with virus entry. MHV-induced macropinocytosis results in vesicle internalization, as well as extended filopodia capable of fusing with distant cells. MHV-induced macropinocytosis requires fusogenic spike protein on the cell surface and is dependent on epidermal growth factor receptor activation. Inhibition of macropinocytosis reduces supernatant viral titers and syncytia but not intracellular virus titers. These results indicate that macropinocytosis likely facilitates CoV infection through enhanced cell-to-cell spreading. Our studies are the first to demonstrate virus use of macropinocytosis for a role other than entry and suggest a much broader potential exploitation of macropinocytosis in virus replication and host interactions. Importance: Coronaviruses (CoVs), including severe acute respiratory syndrome (SARS) CoV and Middle East respiratory syndrome CoV, are critical emerging human pathogens. Macropinocytosis is induced by many pathogens to enter host cells, but other functions for macropinocytosis in virus replication are unknown. In this work, we show that CoVs induce a macropinocytosis late in infection that is continuous, independent from cell entry, and associated with increased virus titers and cell fusion. Murine hepatitis virus macropinocytosis requires a fusogenic virus spike protein and signals through the epidermal growth factor receptor and the classical macropinocytosis pathway. These studies demonstrate CoV induction of macropinocytosis for a purpose other than entry and indicate that viruses likely exploit macropinocytosis at multiple steps in replication and pathogenesis. Macropinocytosis results from the closure of lamellipodia generated by membrane ruffling, thereby reflecting cortical actin dynamics. Both transformation of Rat-1 fibroblasts by v-Src or K-Ras and stable transfection for expression of dominant-positive, wild-type phosphoinositide 3-kinase (PI3K) regulatory subunit p85 alpha constitutively led to stress fiber disruption, cortical actin recruitment, extensive ruffling, and macropinosome formation, as measured by a selective acceleration of fluid-phase endocytosis. These alterations closely correlated with activation of PI3K and phosphatidylinositol-specific phospholipase C (PI-PLC), as assayed by 3-phosphoinositide synthesis in situ and in vitro and inositol 1, 4,5 trisphosphate steady-state levels, respectively; they were abolished by stable transfection of v-Src-transformed cells for dominant-negative truncated p85 alpha expression and by pharmacological inhibitors of PI3K and PI-PLC, indicating a requirement for both enzymes. Whereas PI3K activation resisted PI-PLC inhibition, PI-PLC activation was abolished by a PI3K inhibitor and dominant-negative transfection, thus placing PI-PLC downstream of PI3K. Together, these data suggest that permanent sequential activation of both PI3K and PI-PLC is necessary for the dramatic reorganization of the actin cytoskeleton in oncogene-transformed fibroblasts, resulting in constitutive ruffling and macropinocytosis. Macropinocytosis defines a series of events initiated by extensive plasma membrane reorganization or ruffling to form an external macropinocytic structure that is then enclosed and internalized. The process is constitutive in some organisms and cell types but in others it is only pronounced after growth factor stimulation. Internalized macropinosomes share many features with phagosomes and both are distinguished from other forms of pinocytic vesicles by their large size, morphological heterogeneity and lack of coat structures. A paucity of information is available on other distinguishing features for macropinocytosis such as specific marker proteins and drugs that interfere with its mechanism over other endocytic processes. This has hampered efforts to characterize the dynamics of this pathway and to identify regulatory proteins that are expressed in order to allow it to proceed. Upon internalization, macropinosomes acquire regulatory proteins common to other endocytic pathways, suggesting that their identities as unique structures are short-lived. There is however less consensus regarding the overall fate of the macropinosome cargo or its limiting membrane and processes such as fusion, tubulation, recycling and regulated exocytosis have all been implicated in shaping the macropinosome and directing cargo traffic. Macropinocytosis has also been implicated in the internalization of cell penetrating peptides that are of significant interest to researchers aiming to utilize their translocation abilities to deliver therapeutic entities such as genes and proteins into cells. This review focuses on recent findings on the regulation of macropinocytosis, the intracellular fate of the macropinosome and discusses evidence for the role of this pathway as a mechanism of entry for cell penetrating peptides. Macropinocytosis has emerged as an important nutrient supply pathway that sustains cell growth of cancer cells within the nutrient-poor tumor microenvironment. By internalizing extracellular fluid through this bulk endocytic pathway, albumin is supplied to the cancer cells, which, after degradation, serves as an amino acid source to meet the high nutrient demands of these highly proliferating cells. Here, we describe a streamlined protocol for visualization and quantitation of macropinosomes in adherent cancer cells grown in vitro. The determination of the "macropinocytic index" provides a tool for measuring the extent to which this internalization pathway is utilized within the cancer cells and allows for comparison between different cell lines and treatments. The protocol provided herein has been optimized for reproducibility and is readily adaptable to multiple conditions and settings. Gonococcal entry into primary human urethral epithelial cells (HUEC) can occur by macropinocytosis. Scanning and transmission electron microscopy revealed lamellipodia surrounding gonococci, and confocal laser scanning microscopy analysis showed organisms colocalized with M(r) 70,000 fluorescein isothiocyanate-labeled dextran within the cells. Phosphoinositide 3-kinase inhibitors and an actin polymerization inhibitor prevented macropinocytic entry of gonococci into HUEC. Macropinocytosis is a prevalent and essential pathway in macrophages where it contributes to anti-microbial responses and innate immune cell functions. Cell surface ruffles give rise to phagosomes and to macropinosomes as multi-functional compartments that contribute to environmental sampling, pathogen entry, plasma membrane turnover and receptor signalling. Rapid, high resolution, lattice light sheet imaging demonstrates the dynamic nature of macrophage ruffling. Pathogen-mediated activation of surface and endosomal Toll-like receptors (TLRs) in macrophages upregulates macropinocytosis. Here, using multiple forms of imaging and microscopy, we track membrane-associated, fluorescently-tagged Rab8a expressed in live macrophages, using a variety of cell markers to demonstrate Rab8a localization and its enrichment on early macropinosomes. Production of a novel biosensor and its use for quantitative FRET analysis in live cells, pinpoints macropinosomes as the site for TLR-induced activation of Rab8a. We have previously shown that TLR signalling, cytokine outputs and macrophage programming are regulated by the GTPase Rab8a with PI3 Kγ as its effector. Finally, we highlight another effector, the phosphatase OCRL, which is located on macropinosomes and interacts with Rab8a, suggesting that Rab8a may operate on multiple levels to modulate phosphoinositides in macropinosomes. These findings extend our understanding of macropinosomes as regulatory compartments for innate immune function in macrophages. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'. In tumour cells, macropinocytosis functions as an amino acid supply route and supports cancer cell survival and proliferation. Initially demonstrated in oncogenic KRAS-driven models of pancreatic cancer, macropinocytosis triggers the internalization of extracellular proteins via discrete endocytic vesicles called macropinosomes. The incoming protein cargo is targeted for lysosome-dependent degradation, causing the intracellular release of amino acids. These protein-derived amino acids support metabolic fitness by contributing to the intracellular amino acid pools, as well as to the biosynthesis of central carbon metabolites. In this way, macropinocytosis represents a novel amino acid supply route that tumour cells use to survive the nutrient-poor conditions of the tumour microenvironment. Macropinocytosis has also emerged as an entry mechanism for a variety of nanomedicines, suggesting that macropinocytosis regulation in the tumour setting can be harnessed for the delivery of anti-cancer therapeutics. A slew of recent studies point to the possibility that macropinocytosis is a pervasive feature of many different tumour types. In this review, we focus on the role of this important uptake mechanism in a variety of cancers and highlight the main molecular drivers of macropinocytosis in these malignancies. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'. Macropinosome formation occurs as a localized sequence of biochemical activities and associated morphological changes, which may be considered a form of signal transduction leading to the construction of an organelle. Macropinocytosis may also convey information about the availability of extracellular nutrients to intracellular regulators of metabolism. Consistent with this idea, activation of the metabolic regulator mechanistic target of rapamycin complex-1 (mTORC1) in response to acute stimulation by growth factors and extracellular amino acids requires internalization of amino acids by macropinocytosis. This suggests that macropinocytosis is necessary for mTORC1-dependent growth of metazoan cells, both as a route for delivery of amino acids to sensors associated with lysosomes and as a platform for growth factor-dependent signalling to mTORC1 via phosphatidylinositol 3-kinase (PI3K) and the Akt pathway. Because the biochemical signals required for the construction of macropinosomes are also required for cell growth, and inhibition of macropinocytosis inhibits growth factor signalling to mTORC1, we propose that signalling by growth factor receptors is organized into stochastic, structure-dependent cascades of chemical reactions that both build a macropinosome and stimulate mTORC1. More generally, as discrete units of signal transduction, macropinosomes may be subject to feedback regulation by metabolism and cell dimensions. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'. In macropinocytosis, cells take up micrometre-sized droplets of medium into internal vesicles. These vesicles are acidified and fused to lysosomes, their contents digested and useful compounds extracted. Indigestible contents can be exocytosed. Macropinocytosis has been known for approaching 100 years and is described in both metazoa and amoebae, but not in plants or fungi. Its evolutionary origin goes back to at least the common ancestor of the amoebozoa and opisthokonts, with apparent secondary loss from fungi. The primary function of macropinocytosis in amoebae and some cancer cells is feeding, but the conserved processing pathway for macropinosomes, which involves shrinkage and the retrieval of membrane to the cell surface, has been adapted in immune cells for antigen presentation. Macropinocytic cups are large actin-driven processes, closely related to phagocytic cups and pseudopods and appear to be organized around a conserved signalling patch of PIP3, active Ras and active Rac that directs actin polymerization to its periphery. Patches can form spontaneously and must be sustained by excitable kinetics with strong cooperation from the actin cytoskeleton. Growth-factor signalling shares core components with macropinocytosis, based around phosphatidylinositol 3-kinase (PI3-kinase), and we suggest that it evolved to take control of ancient feeding structures through a coupled growth factor receptor. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'. Macropinocytosis is an evolutionarily conserved form of endocytosis that mediates non-selective uptake of extracellular fluid and the solutes contained therein. In mammalian cells, macropinocytosis is initiated by growth factor-mediated activation of the Ras and PI3-kinase signalling pathways. In malignant cells, oncogenic activation of growth factor signalling sustains macropinocytosis cell autonomously. Recent studies of cancer metabolism, discussed here, have begun to define a role for macropinocytosis as a nutrient uptake route. Macropinocytic cancer cells ingest macromolecules in bulk and break them down in the lysosome to support metabolism and macromolecular synthesis. Thereby, macropinocytosis allows cells to tap into the copious nutrient stores of extracellular macromolecules when canonical nutrients are scarce. These findings demonstrate that macropinocytosis promotes metabolic flexibility and resilience, which enables cancer cells to survive and grow in nutrient-poor environments. Implications for physiological roles of growth factor-stimulated macropinocytosis in cell metabolism and its relationship with other nutrient uptake pathways are considered. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'. Macropinocytosis-the large-scale, non-specific uptake of fluid by cells-is used by Dictyostelium discoideum amoebae to obtain nutrients. These cells form circular ruffles around regions of membrane defined by a patch of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and the activated forms of the small G-proteins Ras and Rac. When this ruffle closes, a vesicle of the medium is delivered to the cell interior for further processing. It is accepted that PIP3 is required for efficient macropinocytosis. Here, we assess the roles of Ras and Rac in Dictyostelium macropinocytosis. Gain-of-function experiments show that macropinocytosis is stimulated by persistent Ras activation and genetic analysis suggests that RasG and RasS are the key Ras proteins involved. Among the activating guanine exchange factors (GEFs), GefF is implicated in macropinocytosis by an insertional mutant. The individual roles of Rho family proteins are little understood but activation of at least some may be independent of PIP3. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'. Previously, we reported that fluid-phase endocytosis of native LDL by PMA-activated human monocytederived macrophages converted these macrophages into cholesterol-enriched foam cells (Kruth, H. S., Huang, W., Ishii, I., and Zhang, W. Y. (2002) J. Biol. Chem. 277, 34573-34580). Uptake of fluid by cells can occur either by micropinocytosis within vesicles (<0.1 microm diameter) or by macropinocytosis within vacuoles ( approximately 0.5-5.0 microm) named macropinosomes. The current investigation has identified macropinocytosis as the pathway for fluid-phase LDL endocytosis and determined signaling and cytoskeletal components involved in this LDL endocytosis. The phosphatidylinositol 3-kinase inhibitor, LY294002, which inhibits macropinocytosis but does not inhibit micropinocytosis, completely blocked PMA-activated macrophage uptake of fluid and LDL. Also, nystatin and filipin, inhibitors of micropinocytosis from lipid-raft plasma membrane domains, both failed to inhibit PMA-stimulated macrophage cholesterol accumulation. Time-lapse video phase-contrast microscopy and time-lapse digital confocal-fluorescence microscopy with fluorescent DiI-LDL showed that PMA-activated macrophages took up LDL in the fluid phase by macropinocytosis. Macropinocytosis of LDL depended on Rho GTPase signaling, actin, and microtubules. Bafilomycin A1, the vacuolar H+-ATPase inhibitor, inhibited degradation of LDL and caused accumulation of undegraded LDL within macropinosomes and multivesicular body endosomes. LDL in multivesicular body endosomes was concentrated >40-fold over its concentration in the culture medium consistent with macropinosome shrinkage by maturation into multivesicular body endosomes. Macropinocytosis of LDL taken up in the fluid phase without receptor-mediated binding of LDL is a novel endocytic pathway that generates macrophage foam cells. Macropinocytosis in macrophages and possibly other vascular cells is a new pathway to target for modulating foam cell formation in atherosclerosis.
4,164
Which was the first species in which a de novo gene emergence ("gene birth") was reported?
New genes can arise through duplication of a pre-existing gene or de novo from non-coding DNA, providing raw material for evolution of new functions in response to a changing environment. A prime example is the independent evolution of antifreeze glycoprotein genes (afgps) in the Arctic codfishes and Antarctic notothenioids to prevent freezing.
[29216381, 29556078, 27358863, 28943376, 22722833, 28325876, 30346517, 24391509, 28642936, 27103098, 27056411, 25506301]
4,574
Accumulating evidence indicates that some protein-coding genes have originated de novo from previously non-coding genomic sequences. However, the processes underlying de novo gene birth are still enigmatic. In particular, the appearance of a new functional protein seems highly improbable unless there is already a pool of neutrally evolving peptides that are translated at significant levels and that can at some point acquire new functions. Here, we use deep ribosome-profiling sequencing data, together with proteomics and single nucleotide polymorphism information, to search for these peptides. We find hundreds of open reading frames that are translated and that show no evolutionary conservation or selective constraints. These data suggest that the translation of these neutrally evolving peptides may be facilitated by the chance occurrence of open reading frames with a favourable codon composition. We conclude that the pervasive translation of the transcriptome provides plenty of material for the evolution of new functional proteins. Novel protein-coding genes can arise either through re-organization of pre-existing genes or de novo. Processes involving re-organization of pre-existing genes, notably after gene duplication, have been extensively described. In contrast, de novo gene birth remains poorly understood, mainly because translation of sequences devoid of genes, or 'non-genic' sequences, is expected to produce insignificant polypeptides rather than proteins with specific biological functions. Here we formalize an evolutionary model according to which functional genes evolve de novo through transitory proto-genes generated by widespread translational activity in non-genic sequences. Testing this model at the genome scale in Saccharomyces cerevisiae, we detect translation of hundreds of short species-specific open reading frames (ORFs) located in non-genic sequences. These translation events seem to provide adaptive potential, as suggested by their differential regulation upon stress and by signatures of retention by natural selection. In line with our model, we establish that S. cerevisiae ORFs can be placed within an evolutionary continuum ranging from non-genic sequences to genes. We identify ~1,900 candidate proto-genes among S. cerevisiae ORFs and find that de novo gene birth from such a reservoir may be more prevalent than sporadic gene duplication. Our work illustrates that evolution exploits seemingly dispensable sequences to generate adaptive functional innovation. RNA-binding proteins (RBPs) control the fate of nearly every transcript in a cell. However, no existing approach for studying these posttranscriptional gene regulators combines transcriptome-wide throughput and biophysical precision. Here, we describe an assay that accomplishes this. Using commonly available hardware, we built a customizable, open-source platform that leverages the inherent throughput of Illumina technology for direct biophysical measurements. We used the platform to quantitatively measure the binding affinity of the prototypical RBP Vts1 for every transcript in the Saccharomyces cerevisiae genome. The scale and precision of these measurements revealed many previously unknown features of this well-studied RBP. Our transcribed genome array (TGA) assayed both rare and abundant transcripts with equivalent proficiency, revealing hundreds of low-abundance targets missed by previous approaches. These targets regulated diverse biological processes including nutrient sensing and the DNA damage response, and implicated Vts1 in de novo gene "birth." TGA provided single-nucleotide resolution for each binding site and delineated a highly specific sequence and structure motif for Vts1 binding. Changes in transcript levels in vts1Δ cells established the regulatory function of these binding sites. The impact of Vts1 on transcript abundance was largely independent of where it bound within an mRNA, challenging prevailing assumptions about how this RBP drives RNA degradation. TGA thus enables a quantitative description of the relationship between variant RNA structures, affinity, and in vivo phenotype on a transcriptome-wide scale. We anticipate that TGA will provide similarly comprehensive and quantitative insights into the function of virtually any RBP. The evolution of novel protein-coding genes from noncoding regions of the genome is one of the most compelling pieces of evidence for genetic innovations in nature. One popular approach to identify de novo genes is phylostratigraphy, which consists of determining the approximate time of origin (age) of a gene based on its distribution along a species phylogeny. Several studies have revealed significant flaws in determining the age of genes, including de novo genes, using phylostratigraphy alone. However, the rate of false positives in de novo gene surveys, based on phylostratigraphy, remains unknown. Here, I reanalyze the findings from three studies, two of which identified tens to hundreds of rodent-specific de novo genes adopting a phylostratigraphy-centered approach. Most putative de novo genes discovered in these investigations are no longer included in recently updated mouse gene sets. Using a combination of synteny information and sequence similarity searches, I show that ∼60% of the remaining 381 putative de novo genes share homology with genes from other vertebrates, originated through gene duplication, and/or share no synteny information with nonrodent mammals. These results led to an estimated rate of ∼12 de novo genes per million years in mouse. Contrary to a previous study (Wilson BA, Foy SG, Neme R, Masel J. 2017. Young genes are highly disordered as predicted by the preadaptation hypothesis of de novo gene birth. Nat Ecol Evol. 1:0146), I found no evidence supporting the preadaptation hypothesis of de novo gene formation. Nearly half of the de novo genes confirmed in this study are within older genes, indicating that co-option of preexisting regulatory regions and a higher GC content may facilitate the origin of novel genes. The rearrangement of pre-existing genes has long been thought of as the major mode of new gene generation. Recently, de novo gene birth from non-genic DNA was found to be an alternative mechanism to generate novel protein-coding genes. However, its functional role in human disease remains largely unknown. Here we show that NCYM, a cis-antisense gene of the MYCN oncogene, initially thought to be a large non-coding RNA, encodes a de novo evolved protein regulating the pathogenesis of human cancers, particularly neuroblastoma. The NCYM gene is evolutionally conserved only in the taxonomic group containing humans and chimpanzees. In primary human neuroblastomas, NCYM is 100% co-amplified and co-expressed with MYCN, and NCYM mRNA expression is associated with poor clinical outcome. MYCN directly transactivates both NCYM and MYCN mRNA, whereas NCYM stabilizes MYCN protein by inhibiting the activity of GSK3β, a kinase that promotes MYCN degradation. In contrast to MYCN transgenic mice, neuroblastomas in MYCN/NCYM double transgenic mice were frequently accompanied by distant metastases, behavior reminiscent of human neuroblastomas with MYCN amplification. The NCYM protein also interacts with GSK3β, thereby stabilizing the MYCN protein in the tumors of the MYCN/NCYM double transgenic mice. Thus, these results suggest that GSK3β inhibition by NCYM stabilizes the MYCN protein both in vitro and in vivo. Furthermore, the survival of MYCN transgenic mice bearing neuroblastoma was improved by treatment with NVP-BEZ235, a dual PI3K/mTOR inhibitor shown to destabilize MYCN via GSK3β activation. In contrast, tumors caused in MYCN/NCYM double transgenic mice showed chemo-resistance to the drug. Collectively, our results show that NCYM is the first de novo evolved protein known to act as an oncopromoting factor in human cancer, and suggest that de novo evolved proteins may functionally characterize human disease. The phenomenon of de novo gene birth from junk DNA is surprising, because random polypeptides are expected to be toxic. There are two conflicting views about how de novo gene birth is nevertheless possible: the continuum hypothesis invokes a gradual gene birth process, while the preadaptation hypothesis predicts that young genes will show extreme levels of gene-like traits. We show that intrinsic structural disorder conforms to the predictions of the preadaptation hypothesis and falsifies the continuum hypothesis, with all genes having higher levels than translated junk DNA, but young genes having the highest level of all. Results are robust to homology detection bias, to the non-independence of multiple members of the same gene family, and to the false positive annotation of protein-coding genes. De novo protein-coding gene origination is increasingly recognized as an important evolutionary mechanism. However, there remains a large amount of uncertainty regarding the frequency of these events and the mechanisms and speed of gene establishment. Here, we describe a rigorous search for cases of de novo gene origination in the great apes. We analyzed annotated proteomes as well as full genomic DNA and transcriptional and translational evidence. It is notable that results vary between database updates due to the fluctuating annotation of these genes. Nonetheless we identified 35 de novo genes: 16 human-specific; 5 human and chimpanzee specific; and 14 that originated prior to the divergence of human, chimpanzee, and gorilla and are found in all three genomes. The taxonomically restricted distribution of these genes cannot be explained by loss in other lineages. Each gene is supported by an open reading frame-creating mutation that occurred within the primate lineage, and which is not polymorphic in any species. Similarly to previous studies we find that the de novo genes identified are short and frequently located near pre-existing genes. Also, they may be associated with Alu elements and prior transcription and RNA-splicing at the locus. Additionally, we report the first case of apparent independent lineage sorting of a de novo gene. The gene is present in human and gorilla, whereas chimpanzee has the ancestral noncoding sequence. This indicates a long period of polymorphism prior to fixation and thus supports a model where de novo genes may, at least initially, have a neutral effect on fitness. Genomes contain a large number of unique genes which have not been found in other species. Although the origin of such "orphan" genes remains unclear, they are thought to be involved in species-specific adaptive processes. Here, we analyzed seven orphan genes (MoSPC1 to MoSPC7) prioritized based on in planta expressed sequence tag data in the rice blast fungus, Magnaporthe oryzae. Expression analysis using qRT-PCR confirmed the expression of four genes (MoSPC1, MoSPC2, MoSPC3 and MoSPC7) during plant infection. However, individual deletion mutants of these four genes did not differ from the wild-type strain for all phenotypes examined, including pathogenicity. The length, GC contents, codon adaptation index and expression during mycelial growth of the four genes suggest that these genes formed during the evolutionary history of M. oryzae. Synteny analyses using closely related fungal species corroborated the notion that these genes evolved de novo in the M. oryzae genome. In this report, we discuss our inability to detect phenotypic changes in the four deletion mutants. Based on these results, the four orphan genes may be products of de novo gene birth processes, and their adaptive potential is in the course of being tested for retention or extinction through natural selection.
4,166
Which type of cancer has been suggested as a strategy for potential small-molecule inhibition of METTL3?
Small-molecule inhibition of METTL3 is a strategy against myeloid leukaemia. Targeting of RNA-modifying enzymes represents a promising avenue for anticancer therapy.
[33902106]
4,576
Author information: (1)Milner Therapeutics Institute, University of Cambridge, Cambridge, UK. (2)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Cambridge, UK. (3)Storm Therapeutics Ltd, Cambridge, UK. (4)Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK. (5)Evotec (UK) Ltd, Abingdon, UK. (6)The Center for the Study of Hematological Malignancies/Karaiskakio Foundation, Nicosia, Cyprus. (7)Division of Virology, Department of Pathology, University of Cambridge, Cambridge, UK. (8)MRC Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Cambridge, UK. (9)The Gurdon Institute and Department of Pathology, University of Cambridge, Cambridge, UK. (10)Research Unit Apoptosis in Hematopoietic Stem Cells, Helmholtz Zentrum München, German Research Center for Environmental Health (HMGU), Munich, Germany. (11)German Consortium for Translational Cancer Research (DKTK), Munich, Germany. (12)Department of Pediatrics, Dr. von Hauner Children's Hospital, Ludwig Maximilians University München, Munich, Germany. (13)Storm Therapeutics Ltd, Cambridge, UK. oliver.rausch@stormtherapeutics.com. (14)Milner Therapeutics Institute, University of Cambridge, Cambridge, UK. kt404@cam.ac.uk. (15)Haematological Cancer Genetics, Wellcome Trust Sanger Institute, Cambridge, UK. kt404@cam.ac.uk. (16)Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK. kt404@cam.ac.uk. (17)The Gurdon Institute and Department of Pathology, University of Cambridge, Cambridge, UK. kt404@cam.ac.uk. (18)Milner Therapeutics Institute, University of Cambridge, Cambridge, UK. t.kouzarides@gurdon.cam.ac.uk. (19)The Gurdon Institute and Department of Pathology, University of Cambridge, Cambridge, UK. t.kouzarides@gurdon.cam.ac.uk. (#)Contributed equally
4,167
What is the mechanism of action of Lanifibranor?
Lanifibranor is peroxisome proliferator-activated receptor (PPAR) agonist.
[33987427, 30261763, 32613381, 33038502, 34488870, 32360434, 33278455, 34670042, 29446942]
4,577
Liver fibrosis is the excessive expression and accumulation of extracellular matrix proteins in the liver. Fibrotic scarring occurs as the consequence of chronic injury and inflammation. While the successful treatment of hepatitis B and C reduced the burden of liver disease related to viral hepatitis, non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH) are nowadays the leading causes of hepatic fibrosis worldwide. Although basic research activities have significantly advanced our understanding of the molecular disease pathogenesis, the present therapeutic options for fibrosis are still limited. In advanced disease stages, liver transplantation often remains the only curative treatment. This highlights the necessity of preventive strategies to avoid complications of fibrosis, particularly cirrhosis, portal hypertension and liver cancer. Lifestyle modifications (weight loss, exercise, healthy diet) are the basis for prevention and treatment of NAFLD-associated fibrosis. In the present review, we discuss recent advances in antifibrotic prevention and therapy. In particular, we review the current concepts for antifibrotic drug candidates in the treatment of NAFLD and NASH. While some compounds aim at reverting pathogenic liver metabolism, an alternative approach is to disconnect the injury (e.g., NAFLD) from inflammation and/or fibrosis. Investigational drugs typically target metabolic pathways, insulin resistance, hepatocyte death, inflammatory cell recruitment or activation, the gut-liver axis, matrix expression or matrix turnover. While several promising drug candidates failed in phase 2 or 3 clinical trials (including elafibranor, emricasan and selonsertib), promising results with the farnesoid X receptor agonist obeticholic acid, the pan-PPAR agonist lanifibranor and the chemokine receptor CCR2/CCR5 inhibitor cenicriviroc support the expectation of an effective pharmacological therapy for liver fibrosis in the near future. Tackling NAFLD-associated fibrosis from different directions by combinatorial drug treatment and effective lifestyle changes hold the greatest prospects. Background Non-alcoholic steatohepatitis (NASH), a multifactorial disease, can progress to hepatic fibrosis and cirrhosis. The Peroxysomal Proliferator-Activated Receptors, PPARα, β/δ and γ, play a central role in the regulation of glucose and lipid metabolism and of the inflammatory and fibrogenic pathways in liver and in other organs that all contribute to NASH pathogenesis. Lanifibranor (IVA337), a panPPAR agonist, by acting on these three different PPAR isotypes, combines pharmacological effects that could address the different components of the disease as demonstrated in preclinical models. Objectives NATIVE study (EudraCT: 2016-001979-70, NCT: NCT03008070) aims to assess the safety and the efficacy of a 24-week treatment with lanifibranor (800 and 1200 mg/day) in adult non-cirrhotic NASH patients. The primary efficacy endpoint is a 2-point reduction in the activity part of the Steatosis Activity Fibrosis (SAF) histological score (combining inflammation and ballooning) without worsening of fibrosis. Design NATIVE is a Phase 2b randomised, placebo-controlled, double-blind, parallel-assignment, dose-range study. Eligible adult patients with a confirmed histological diagnosis of NASH should have a SAF Activity score of 3 or 4 (>2) and a SAF Steatosis score ≥ 1. There is no specific criterion related to the fibrosis score except that patients with cirrhosis (F4) were excluded. Summary This study will evaluate the efficacy of a 24-week treatment of NASH with lanifibranor based on histological evaluations (SAF score) by biopsy. The number of responders according to the SAF Activity score-based definition from baseline to 24 weeks will be compared between groups and serves as primary endpoint. BACKGROUND: The TβRII∆k-fib transgenic (TG) mouse model of scleroderma replicates key fibrotic and vasculopathic complications of systemic sclerosis through fibroblast-directed upregulation of TGFβ signalling. We have examined peroxisome proliferator-activated receptor (PPAR) pathway perturbation in this model and explored the impact of the pan-PPAR agonist lanifibranor on the cardiorespiratory phenotype. METHODS: PPAR pathway gene and protein expression differences from TG and WT sex-matched littermate mice were determined at baseline and following administration of one of two doses of lanifibranor (30 mg/kg or 100 mg/kg) or vehicle administered by daily oral gavage up to 4 weeks. The prevention of bleomycin-induced lung fibrosis and SU5416-induced pulmonary hypertension by lanifibranor was explored. RESULTS: Gene expression data were consistent with the downregulation of the PPAR pathway in the TβRII∆k-fib mouse model. TG mice treated with high-dose lanifibranor demonstrated significant protection from lung fibrosis after bleomycin and from right ventricular hypertrophy following induction of pulmonary hypertension by SU5416, despite no significant change in right ventricular systolic pressure. CONCLUSIONS: In the TβRII∆k-fib mouse strain, treatment with 100 mg/kg lanifibranor reduces the development of lung fibrosis and right ventricular hypertrophy induced by bleomycin or SU5416, respectively. Reduced PPAR activity may contribute to the exaggerated fibroproliferative response to tissue injury in this transgenic model of scleroderma and its pulmonary complications. BACKGROUND: Management of nonalcoholic steatohepatitis (NASH) is an unmet clinical need. Lanifibranor is a pan-PPAR (peroxisome proliferator-activated receptor) agonist that modulates key metabolic, inflammatory, and fibrogenic pathways in the pathogenesis of NASH. METHODS: In this phase 2b, double-blind, randomized, placebo-controlled trial, patients with noncirrhotic, highly active NASH were randomly assigned in a 1:1:1 ratio to receive 1200 mg or 800 mg of lanifibranor or placebo once daily for 24 weeks. The primary end point was a decrease of at least 2 points in the SAF-A score (the activity part of the Steatosis, Activity, Fibrosis [SAF] scoring system that incorporates scores for ballooning and inflammation) without worsening of fibrosis; SAF-A scores range from 0 to 4, with higher scores indicating more-severe disease activity. Secondary end points included resolution of NASH and regression of fibrosis. RESULTS: A total of 247 patients underwent randomization, of whom 103 (42%) had type 2 diabetes mellitus and 188 (76%) had significant (moderate) or advanced fibrosis. The percentage of patients who had a decrease of at least 2 points in the SAF-A score without worsening of fibrosis was significantly higher among those who received the 1200-mg dose, but not among those who received the 800-mg dose, of lanifibranor than among those who received placebo (1200-mg dose vs. placebo, 55% vs. 33%, P = 0.007; 800-mg dose vs. placebo, 48% vs. 33%, P = 0.07). The results favored both the 1200-mg and 800-mg doses of lanifibranor over placebo for resolution of NASH without worsening of fibrosis (49% and 39%, respectively, vs. 22%), improvement in fibrosis stage of at least 1 without worsening of NASH (48% and 34%, respectively, vs. 29%), and resolution of NASH plus improvement in fibrosis stage of at least 1 (35% and 25%, respectively, vs. 9%). Liver enzyme levels decreased and the levels of the majority of lipid, inflammatory, and fibrosis biomarkers improved in the lanifibranor groups. The dropout rate for adverse events was less than 5% and was similar across the trial groups. Diarrhea, nausea, peripheral edema, anemia, and weight gain occurred more frequently with lanifibranor than with placebo. CONCLUSIONS: In this phase 2b trial involving patients with active NASH, the percentage of patients who had a decrease of at least 2 points in the SAF-A score without worsening of fibrosis was significantly higher with the 1200-mg dose of lanifibranor than with placebo. These findings support further assessment of lanifibranor in phase 3 trials. (Funded by Inventiva Pharma; NATIVE ClinicalTrials.gov number, NCT03008070.). Here, we describe the identification and synthesis of novel indole sulfonamide derivatives that activate the three peroxisome proliferator activated receptor (PPAR) isoforms. Starting with a PPARα activator, compound 4, identified during a high throughput screening (HTS) of our proprietary screening library, a systematic optimization led to the discovery of lanifibranor (IVA337) 5, a moderately potent and well balanced pan PPAR agonist with an excellent safety profile. In vitro and in vivo, compound 5 demonstrated strong activity in models that are relevant to nonalcoholic steatohepatitis (NASH) pathophysiology suggesting therapeutic potential for NASH patients.
4,168
Summarize the function of DEAH helicase DHX36 and its role in G-quadruplex-dependent processes.
DEAH-Box helicase 36 (DHX36), a member of the large DExD/H box helicase family, enzymatically unwinds both G4 DNA and G4 RNA. RNA helicases of the DEAH/RHA family form a large and conserved class of enzymes that remodel RNA protein complexes (RNPs) by translocating along the RNA
[34862880, 29269411, 25653156, 33021960, 33857358, 33857359, 29899445, 34025941, 30910870, 27797375]
4,579
Single-stranded DNA (ssDNA) and RNA regions that include at least four closely spaced runs of three or more consecutive guanosines strongly tend to fold into stable G-quadruplexes (G4s). G4s play key roles as DNA regulatory sites and as kinetic traps that can inhibit biological processes, but how G4s are regulated in cells remains largely unknown. Here, we developed a kinetic framework for G4 disruption by DEAH-box helicase 36 (DHX36), the dominant G4 resolvase in human cells. Using tetramolecular DNA and RNA G4s with four to six G-quartets, we found that DHX36-mediated disruption is highly efficient, with rates that depend on G4 length under saturating conditions (kcat) but not under subsaturating conditions (kcat/Km ). These results suggest that a step during G4 disruption limits the kcat value and that DHX36 binding limits kcat/Km Similar results were obtained for unimolecular DNA G4s. DHX36 activity depended on a 3' ssDNA extension and was blocked by a polyethylene glycol linker, indicating that DHX36 loads onto the extension and translocates 3'-5' toward the G4. DHX36 unwound dsDNA poorly compared with G4s of comparable intrinsic lifetime. Interestingly, we observed that DHX36 has striking 3'-extension sequence preferences that differ for G4 disruption and dsDNA unwinding, most likely arising from differences in the rate-limiting step for the two activities. Our results indicate that DHX36 disrupts G4s with a conventional helicase mechanism that is tuned for great efficiency and specificity for G4s. The dependence of DHX36 on the 3'-extension sequence suggests that the extent of formation of genomic G4s may not track directly with G4 stability. RNA helicases of the DEAH/RHA family form a large and conserved class of enzymes that remodel RNA protein complexes (RNPs) by translocating along the RNA. Driven by ATP hydrolysis, they exert force to dissociate hybridized RNAs, dislocate bound proteins or unwind secondary structure elements in RNAs. The sub-cellular localization of DEAH-helicases and their concomitant association with different pathways in RNA metabolism, such as pre-mRNA splicing or ribosome biogenesis, can be guided by cofactor proteins that specifically recruit and simultaneously activate them. Here we review the mode of action of a large class of DEAH-specific adaptor proteins of the G-patch family. Defined only by their eponymous short glycine-rich motif, which is sufficient for helicase binding and stimulation, this family encompasses an immensely varied array of domain compositions and is linked to an equally diverse set of functions. G-patch proteins are conserved throughout eukaryotes and are even encoded within retroviruses. They are involved in mRNA, rRNA and snoRNA maturation, telomere maintenance and the innate immune response. Only recently was the structural and mechanistic basis for their helicase enhancing activity determined. We summarize the molecular and functional details of G-patch-mediated helicase regulation in their associated pathways and their involvement in human diseases. DHX36 is a eukaryotic DEAH/RHA family helicase that disrupts G-quadruplex structures (G4s) with high specificity, contributing to regulatory roles of G4s. Here we used a DHX36 truncation to examine the roles of the 13-amino acid DHX36-specific motif (DSM) in DNA G4 recognition and disruption. We found that the DSM promotes G4 recognition and specificity by increasing the G4 binding rate of DHX36 without affecting the dissociation rate. Further, for most of the G4s measured, the DSM has little or no effect on the G4 disruption step by DHX36, implying that contacts with the G4 are maintained through the transition state for G4 disruption. This result suggests that partial disruption of the G4 from the 3' end is sufficient to reach the overall transition state for G4 disruption, while the DSM remains unperturbed at the 5' end. Interestingly, the DSM does not contribute to G4 binding kinetics or thermodynamics at low temperature, indicating a highly modular function. Together, our results animate recent DHX36 crystal structures, suggesting a model in which the DSM recruits G4s in a modular and flexible manner by contacting the 5' face early in binding, prior to rate-limiting capture and disruption of the G4 by the helicase core. Guanine-rich nucleic acid sequences challenge the replication, transcription, and translation machinery by spontaneously folding into G-quadruplexes, the unfolding of which requires forces greater than most polymerases can exert1,2. Eukaryotic cells contain numerous helicases that can unfold G-quadruplexes 3 . The molecular basis of the recognition and unfolding of G-quadruplexes by helicases remains poorly understood. DHX36 (also known as RHAU and G4R1), a member of the DEAH/RHA family of helicases, binds both DNA and RNA G-quadruplexes with extremely high affinity4-6, is consistently found bound to G-quadruplexes in cells7,8, and is a major source of G-quadruplex unfolding activity in HeLa cell lysates 6 . DHX36 is a multi-functional helicase that has been implicated in G-quadruplex-mediated transcriptional and post-transcriptional regulation, and is essential for heart development, haematopoiesis, and embryogenesis in mice9-12. Here we report the co-crystal structure of bovine DHX36 bound to a DNA with a G-quadruplex and a 3' single-stranded DNA segment. We show that the N-terminal DHX36-specific motif folds into a DNA-binding-induced α-helix that, together with the OB-fold-like subdomain, selectively binds parallel G-quadruplexes. Comparison with unliganded and ATP-analogue-bound DHX36 structures, together with single-molecule fluorescence resonance energy transfer (FRET) analysis, suggests that G-quadruplex binding alone induces rearrangements of the helicase core; by pulling on the single-stranded DNA tail, these rearrangements drive G-quadruplex unfolding one residue at a time. Because of high stability and slow unfolding rates of G-quadruplexes (G4), cells have evolved specialized helicases that disrupt these non-canonical DNA and RNA structures in an ATP-dependent manner. One example is DHX36, a DEAH-box helicase, which participates in gene expression and replication by recognizing and unwinding parallel G4s. Here, we studied the molecular basis for the high affinity and specificity of DHX36 for parallel-type G4s using all-atom molecular dynamics simulations. By computing binding free energies, we found that the two main G4-interacting subdomains of DHX36, DSM and OB, separately exhibit high G4 affinity but they act cooperatively to recognize two distinctive features of parallel G4s: the exposed planar face of a guanine tetrad and the unique backbone conformation of a continuous guanine tract, respectively. Our results also show that DSM-mediated interactions are the main contributor to the binding free energy and rely on making extensive van der Waals contacts between the GXXXG motifs and hydrophobic residues of DSM and a flat guanine plane. Accordingly, the sterically more accessible 5'-G-tetrad allows for more favorable van der Waals and hydrophobic interactions which leads to the preferential binding of DSM to the 5'-side. In contrast to DSM, OB binds to G4 mostly through polar interactions by flexibly adapting to the 5'-terminal guanine tract to form a number of strong hydrogen bonds with the backbone phosphate groups. We also identified a third DHX36/G4 interaction site formed by the flexible loop missing in the crystal structure. Long non-coding RNAs (lncRNAs) are frequently dysregulated in a variety of human cancers. However, their biological roles in these cancers remain incompletely understood. In this study, we analyze the gene expression profiles of colon cancer tissues and identify a previously unannotated lncRNA, FLJ39051, that we term GSEC (G-quadruplex-forming sequence containing lncRNA), as a lncRNA that is upregulated in colorectal cancer. We further demonstrate that knockdown of GSEC results in the reduction of colon cancer cell motility. We also show that GSEC binds to the DEAH box polypeptide 36 (DHX36) RNA helicase via its G-quadruplex-forming sequence and inhibits DHX36 G-quadruplex unwinding activity. Moreover, knockdown of DHX36 restores the reduced migratory activity of colon cancer cells caused by GSEC knockdown. These results suggest that GSEC plays an important role in colon cancer cell migration by inhibiting the function of DHX36 via its G-quadruplex structure.
4,169
What is the function of the YY1 transcriptional regulator?
The ubiquitous transcription factor Yin Yang 1 (YY1) is known to have a fundamental role in normal biologic processes such as embryogenesis, differentiation, replication, and cellular proliferation. YY1 is a transcription factor that can activate or repress transcription of a variety of genes and is involved in several developmental processes. YY1 overexpression and/or activation is associated with unchecked cellular proliferation, resistance to apoptotic stimuli, tumorigenesis and metastatic potential. YY1, in addition to its regulatory roles in normal biologic processes, may possess the potential to act as an initiator of tumorigenesis and may thus serve as both a diagnostic and prognostic tumor marker; furthermore, it may provide an effective target for antitumor chemotherapy and/or immunotherapy.
[16314846, 12411495, 16822951, 8276234, 26981420, 18542060, 18046414, 22570637, 9696045, 24575094, 15955096, 9359867, 26892542]
4,580
The ubiquitous transcription factor Yin Yang 1 (YY1) is known to have a fundamental role in normal biologic processes such as embryogenesis, differentiation, replication, and cellular proliferation. YY1 exerts its effects on genes involved in these processes via its ability to initiate, activate, or repress transcription depending upon the context in which it binds. Mechanisms of action include direct activation or repression, indirect activation or repression via cofactor recruitment, or activation or repression by disruption of binding sites or conformational DNA changes. YY1 activity is regulated by transcription factors and cytoplasmic proteins that have been shown to abrogate or completely inhibit YY1-mediated activation or repression; however, these mechanisms have not yet been fully elucidated. Since expression and function of YY1 are known to be intimately associated with progression through phases of the cell cycle, the physiologic significance of YY1 activity has recently been applied to models of tumor biology. The majority of the data are consistent with the hypothesis that YY1 overexpression and/or activation is associated with unchecked cellular proliferation, resistance to apoptotic stimuli, tumorigenesis and metastatic potential. Studies involving hematopoetic tumors, epithelial-based tumors, endocrine organ malignancies, hepatocellular carcinoma, and retinoblastoma support this hypothesis. Molecular mechanisms that have been investigated include YY1-mediated downregulation of p53 activity, interference with poly-ADP-ribose polymerase, alteration in c-myc and nuclear factor-kappa B (NF-kappaB) expression, regulation of death genes and gene products, and differential YY1 binding in the presence of inflammatory mediators. Further, recent findings implicate YY1 in the regulation of tumor cell resistance to chemotherapeutics and immune-mediated apoptotic stimuli. Taken together, these findings provide strong support of the hypothesis that YY1, in addition to its regulatory roles in normal biologic processes, may possess the potential to act as an initiator of tumorigenesis and may thus serve as both a diagnostic and prognostic tumor marker; furthermore, it may provide an effective target for antitumor chemotherapy and/or immunotherapy. To explore mechanisms for specificity of function within the family of E2F transcription factors, we have identified proteins that interact with individual E2F proteins. A two-hybrid screen identified RYBP (Ring1- and YY1-binding protein) as a protein that interacts specifically with the E2F2 and E2F3 family members, dependent on the marked box domain in these proteins. The Cdc6 promoter contains adjacent E2F- and YY1-binding sites, and both are required for promoter activity. In addition, YY1 and RYBP, in combination with either E2F2 or E2F3, can stimulate Cdc6 promoter activity synergistically, dependent on the marked box domain of E2F3. Using chromatin immunoprecipitation assays, we show that both E2F2 and E2F3, as well as YY1 and RYBP, associate with the Cdc6 promoter at G(1)/S of the cell cycle. In contrast, we detect no interaction of E2F1 with the Cdc6 promoter. We suggest that the ability of RYBP to mediate an interaction between E2F2 or E2F3 and YY1 is an important component of Cdc6 activation and provides a basis for specificity of E2F function. YY1 is a transcription factor that can activate or repress transcription of a variety of genes and is involved in several developmental processes. YY1 is a repressor of transcription in differentiated H9C2 cells and in neonatal cardiac myocytes but an activator of transcription in undifferentiated H9C2 cells. We now present a detailed analysis of the functional domains of YY1 when it is acting as a repressor or an activator and identify the mechanism whereby its function is regulated in the differentiation of H9C2 cells. We show that histone deacetylase 5 (HDAC5) is localized to the cytoplasm in undifferentiated H9C2 cells and that this localization is dependent on Ca(2+)/calmodulin-dependent kinase IV (CaMKIV) and/or protein kinase D (PKD). In differentiated cells, HDAC5 is nuclear and interacts with YY1. Finally, we show that HDAC5 localization in differentiated cells is dependent on phosphatase 2A (PP2A). Our results suggest that a signaling mechanism that involves CaMKIV/PKD and PP2A controls YY1 function through regulation of HDAC5 and is important in the maintenance of muscle differentiation. The assembly of multicomponent complexes at promoters, enhancers, and silencers likely entails perturbations in the path of the DNA helix. We present evidence that YY1, a ubiquitously expressed DNA-binding protein, regulates the activity of the c-fos promoter primarily through an effect on DNA structure. YY1 binds to and induces a phased DNA bend at three sites in this promoter. By use of a truncated c-fos promoter activity containing a single functional YY1 site, we show that YY1 represses promoter activity but that repression does not appear to be an intrinsic property of the protein in this context. Moreover, when the orientation of the YY1 site is reversed, YY1 activates the same promoter. Repression by YY1 is also alleviated by changing the relative phasing of factor-binding sites on either side of YY1. We conclude that the principal function of YY1 in this promoter is to bend DNA to regulate contact between other proteins. Thus, YY1 represents a new class of transcription factors that influences promoter function by affecting promoter structure rather than by directly contacting the transcriptional machinery. We provide evidence that the product of the male sex determination gene SRY may also belong to this class of structural factors. We showed earlier that p300/CBP plays an important role in G1 progression by negatively regulating c-Myc and thereby preventing premature G1 exit. Here, we have studied the mechanism by which p300 represses c-Myc and show that in quiescent cells p300 cooperates with histone deacetylase 3 (HDAC3) to repress transcription. p300 and HDAC3 are recruited to the upstream YY1-binding site of the c-Myc promoter resulting in chromatin deacetylation and repression of c-Myc transcription. Consistent with this, ablation of p300, YY1 or HDAC3 expression results in chromatin acetylation and induction of c-Myc. These three proteins exist as a complex in vivo and form a multiprotein complex with the YY1-binding site in vitro. The C-terminal region of p300 is both necessary and sufficient for the repression of c-Myc. These and other results suggest that in quiescent cells the C-terminal region of p300 provides corepressor function and facilitates the recruitment of p300 and HDAC3 to the YY1-binding site and represses the c-Myc promoter. This corepressor function of p300 prevents the inappropriate induction of c-Myc and S phase. Transcriptional complexes that contain peroxisome-proliferator-activated receptor coactivator (PGC)-1alpha control mitochondrial oxidative function to maintain energy homeostasis in response to nutrient and hormonal signals. An important component in the energy and nutrient pathways is mammalian target of rapamycin (mTOR), a kinase that regulates cell growth, size and survival. However, it is unknown whether and how mTOR controls mitochondrial oxidative activities. Here we show that mTOR is necessary for the maintenance of mitochondrial oxidative function. In skeletal muscle tissues and cells, the mTOR inhibitor rapamycin decreased the gene expression of the mitochondrial transcriptional regulators PGC-1alpha, oestrogen-related receptor alpha and nuclear respiratory factors, resulting in a decrease in mitochondrial gene expression and oxygen consumption. Using computational genomics, we identified the transcription factor yin-yang 1 (YY1) as a common target of mTOR and PGC-1alpha. Knockdown of YY1 caused a significant decrease in mitochondrial gene expression and in respiration, and YY1 was required for rapamycin-dependent repression of those genes. Moreover, mTOR and raptor interacted with YY1, and inhibition of mTOR resulted in a failure of YY1 to interact with and be coactivated by PGC-1alpha. We have therefore identified a mechanism by which a nutrient sensor (mTOR) balances energy metabolism by means of the transcriptional control of mitochondrial oxidative function. These results have important implications for our understanding of how these pathways might be altered in metabolic diseases and cancer. Studies of coat color mutants have greatly contributed to the discovery of genes that regulate melanocyte development and function. Here, we generated Yy1 conditional knockout mice in the melanocyte-lineage and observed profound melanocyte deficiency and premature gray hair, similar to the loss of melanocytes in human piebaldism and Waardenburg syndrome. Although YY1 is a ubiquitous transcription factor, YY1 interacts with M-MITF, the Waardenburg Syndrome IIA gene and a master transcriptional regulator of melanocytes. YY1 cooperates with M-MITF in regulating the expression of piebaldism gene KIT and multiple additional pigmentation genes. Moreover, ChIP-seq identified genome-wide YY1 targets in the melanocyte lineage. These studies mechanistically link genes implicated in human conditions of melanocyte deficiency and reveal how a ubiquitous factor (YY1) gains lineage-specific functions by co-regulating gene expression with a lineage-restricted factor (M-MITF)-a general mechanism which may confer tissue-specific gene expression in multiple lineages. During B cell development, long-distance DNA interactions are needed for V(D)J somatic rearrangement of the immunoglobulin (Ig) loci to produce functional Ig genes, and for class switch recombination (CSR) needed for antibody maturation. The tissue-specificity and developmental timing of these mechanisms is a subject of active investigation. A small number of factors are implicated in controlling Ig locus long-distance interactions including Pax5, Yin Yang 1 (YY1), EZH2, IKAROS, CTCF, cohesin, and condensin proteins. Here we will focus on the role of YY1 in controlling these mechanisms. YY1 is a multifunctional transcription factor involved in transcriptional activation and repression, X chromosome inactivation, Polycomb Group (PcG) protein DNA recruitment, and recruitment of proteins required for epigenetic modifications (acetylation, deacetylation, methylation, ubiquitination, sumoylation, etc.). YY1 conditional knock-out indicated that YY1 is required for B cell development, at least in part, by controlling long-distance DNA interactions at the immunoglobulin heavy chain and Igκ loci. Our recent data show that YY1 is also required for CSR. The mechanisms implicated in YY1 control of long-distance DNA interactions include controlling non-coding antisense RNA transcripts, recruitment of PcG proteins to DNA, and interaction with complexes involved in long-distance DNA interactions including the cohesin and condensin complexes. Though common rearrangement mechanisms operate at all Ig loci, their distinct temporal activation along with the ubiquitous nature of YY1 poses challenges for determining the specific mechanisms of YY1 function in these processes, and their regulation at the tissue-specific and B cell stage-specific level. The large numbers of post-translational modifications that control YY1 functions are possible candidates for regulation. Fe65 is an adaptor protein that interacts with the Alzheimer beta-amyloid precursor protein and is expressed mainly in the neurons of several regions of the nervous system. The FE65 gene has a TATA-less promoter that drives an efficient transcription in cells showing a neuronal phenotype, whereas its efficiency is poor in non-neuronal cells. A short sequence encompassing the transcription start site contains sufficient information to drive the transcription in neuronal cells but not in non-neural cells. Electrophoretic mobility-shift assays performed with rat brain nuclear extracts showed that three major DNA-protein complexes, named BI, BII and BIII, are formed by the FE65 minimal promoter. The proteins present in complexes BI and BII were purified from bovine brain; internal microsequencing of the purified proteins demonstrated that they corresponded to the previously isolated single-stranded-DNA-binding protein Pur alpha, abundantly expressed in the brain. In Chinese hamster ovary (CHO) cells, where the efficiency of FE65 promoter is very low, transient expression of Pur alpha increased the transcription efficiency of the FE65 minimal promoter. By using oligonucleotide competition and a specific antibody we demonstrated that the transcription factor YY1 is responsible for the formation of complex BIII. Also in this case, the transient expression of the YY1 cDNA in CHO cells resulted in an increased transcription from the FE65 minimal promoter. The absence of any co-operative effect when CHO cells were co-transfected with both YY1 and Pur alpha cDNA species suggests that two different transcription regulatory mechanisms could have a role in the regulation of the FE65 gene. Regulatory T (T(reg)) cells are essential for maintenance of immune homeostasis. Foxp3 is the key transcription factor for T(reg)-cell differentiation and function; however, molecular mechanisms for its negative regulation are poorly understood. Here we show that YY1 expression is lower in T(reg) cells than T(conv) cells, and its overexpression causes a marked reduction of Foxp3 expression and abrogation of suppressive function of Treg cells. YY1 is increased in T(reg) cells under inflammatory conditions with concomitant decrease of suppressor activity in dextran sulfate-induced colitis model. YY1 inhibits Smad3/4 binding to and chromatin remodelling of the Foxp3 locus. In addition, YY1 interrupts Foxp3-dependent target gene expression by physically interacting with Foxp3 and by directly binding to the Foxp3 target genes. Thus, YY1 inhibits differentiation and function of T(reg) cells by blocking Foxp3.
4,170
Which CYP genes' expression is decreased at the in vivo level following pomegranate juice consumption?
It was found that pomegranate juice consumption decreased total hepatic CYP content as well as the expression of CYP1A2 and CYP3A.
[18158835]
4,581
Beneficial health effects have recently been claimed for pomegranate juice. In vitro and in vivo studies have demonstrated its anti-atherosclerotic capacity, chemoprevention and chemotherapy of prostate cancer, and antiproliferative, apoptotic, and antioxidant activity, among others. On the other hand, there is a complex interplay between tumor initiation, promotion, and progression and xenobiotic biotranformation. This led us to investigate the effect of pomegranate juice consumption on cytochrome P450 (CYP) activity and expression. For this purpose, male mice consumed this fruit juice for 4 weeks, and pentobarbital-induced sleeping time and total hepatic CYP content, activity, and expression were evaluated. Moreover, the activity of CYP isoform 2E1 and expression of the main CYP isoforms, namely, CYP1A1/2, CYP2E1, and CYP3A, were also assessed. It was found that pomegranate juice consumption decreased total hepatic CYP content as well as the expression of CYP1A2 and CYP3A. Prevention of procarcinogen activation through CYP activity/expression inhibition may be involved in pomegranate juice's effect on tumor initiation, promotion, and progression.
4,171
Class-defining mutations in which genes drive FLT3-ITD-mutant AML?
Advances in cancer genomics have revealed genomic classes of acute myeloid leukemia (AML) characterized by class-defining mutations, such as chimeric fusion genes or in genes such as NPM1, MLL, and CEBPA. These class-defining mutations frequently synergize with internal tandem duplications in FLT3 (FLT3-ITDs) to drive leukemogenesis.
[33956058]
4,582
Advances in cancer genomics have revealed genomic classes of acute myeloid leukemia (AML) characterized by class-defining mutations, such as chimeric fusion genes or in genes such as NPM1, MLL, and CEBPA. These class-defining mutations frequently synergize with internal tandem duplications in FLT3 (FLT3-ITDs) to drive leukemogenesis. However, ∼20% of FLT3-ITD-positive AMLs bare no class-defining mutations, and mechanisms of leukemic transformation in these cases are unknown. To identify pathways that drive FLT3-ITD mutant AML in the absence of class-defining mutations, we performed an insertional mutagenesis (IM) screening in Flt3-ITD mice, using Sleeping Beauty transposons. All mice developed acute leukemia (predominantly AML) after a median of 73 days. Analysis of transposon insertions in 38 samples from Flt3-ITD/IM leukemic mice identified recurrent integrations at 22 loci, including Setbp1 (20/38), Ets1 (11/38), Ash1l (8/38), Notch1 (8/38), Erg (7/38), and Runx1 (5/38). Insertions at Setbp1 led exclusively to AML and activated a transcriptional program similar, but not identical, to those of NPM1-mutant and MLL-rearranged AMLs. Guide RNA targeting of Setbp1 was highly detrimental to Flt3ITD/+/Setbp1IM+, but not to Flt3ITD/+/Npm1cA/+, AMLs. Also, analysis of RNA-sequencing data from hundreds of human AMLs revealed that SETBP1 expression is significantly higher in FLT3-ITD AMLs lacking class-defining mutations. These findings propose that SETBP1 overexpression collaborates with FLT3-ITD to drive a subtype of human AML. To identify genetic vulnerabilities of these AMLs, we performed genome-wide CRISPR-Cas9 screening in Flt3ITD/+/Setbp1IM+ AMLs and identified potential therapeutic targets, including Kdm1a, Brd3, Ezh2, and Hmgcr. Our study gives new insights into epigenetic pathways that can drive AMLs lacking class-defining mutations and proposes therapeutic approaches against such cases.
4,172
Belzutifan has shown effectiveness for which diseases?
Belzutifan is the small-molecule HIF 2 alpha inhibitor that has demonstrated significant efficacy in the von Hippel-Lindau disease related renal cell carcinomas, hemangioblastomas, and pancreatic neuroendocrine tumors while demonstrating an acceptable safety profile
[34613603, 34590859, 33931436, 34818478, 34482771, 33945366, 34479868]
4,583
Belzutifan (Welireg™) is an oral small molecule inhibitor of hypoxia-inducible factor (HIF)-2α being developed by Peloton Therapeutics for the treatment of solid tumours, including renal cell carcinoma (RCC) with clear cell histology (ccRCC) and von Hippel-Lindau (VHL) disease-associated RCC. In August 2021, belzutifan received its first approval in the USA for the treatment of patients with VHL disease who require therapy for associated RCC, central nervous system (CNS) haemangioblastomas or pancreatic neuroendocrine tumours (pNET), not requiring immediate surgery. Clinical studies of belzutifan (as monotherapy or combination therapy) in other indications, including ccRCC, pNET and phaeochromocytoma/paraganglioma, are also underway in various countries. This article summarizes the milestones in the development of belzutifan leading to this first approval for certain VHL disease-associated tumours. BACKGROUND: Patients with von Hippel-Lindau (VHL) disease have a high incidence of renal cell carcinoma owing to VHL gene inactivation and constitutive activation of the transcription factor hypoxia-inducible factor 2α (HIF-2α). METHODS: In this phase 2, open-label, single-group trial, we investigated the efficacy and safety of the HIF-2α inhibitor belzutifan (MK-6482, previously called PT2977), administered orally at a dose of 120 mg daily, in patients with renal cell carcinoma associated with VHL disease. The primary end point was objective response (complete or partial response) as measured according to the Response Evaluation Criteria in Solid Tumors, version 1.1, by an independent central radiology review committee. We also assessed responses to belzutifan in patients with non-renal cell carcinoma neoplasms and the safety of belzutifan. RESULTS: After a median follow-up of 21.8 months (range, 20.2 to 30.1), the percentage of patients with renal cell carcinoma who had an objective response was 49% (95% confidence interval, 36 to 62). Responses were also observed in patients with pancreatic lesions (47 of 61 patients [77%]) and central nervous system hemangioblastomas (15 of 50 patients [30%]). Among the 16 eyes that could be evaluated in 12 patients with retinal hemangioblastomas at baseline, all (100%) were graded as showing improvement. The most common adverse events were anemia (in 90% of the patients) and fatigue (in 66%). Seven patients discontinued treatment: four patients voluntarily discontinued, one discontinued owing to a treatment-related adverse event (grade 1 dizziness), one discontinued because of disease progression as assessed by the investigator, and one patient died (of acute toxic effects of fentanyl). CONCLUSIONS: Belzutifan was associated with predominantly grade 1 and 2 adverse events and showed activity in patients with renal cell carcinomas and non-renal cell carcinoma neoplasms associated with VHL disease. (Funded by Merck Sharp and Dohme and others; MK-6482-004 ClinicalTrials.gov number, NCT03401788.). BACKGROUND: The 2021 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium represents an unmissable event for oncologists who deal with renal cell carcinoma (RCC). AIM AND RESULTS: This article describes the main acquisitions of RCC management, including the advent of a new combo (pembrolizumab+lenvatinib) as first-line therapy, the confirmation of an OS advantage of ICI plus VEGFR-TKI combinations over sunitinib at longer follow-up, the persistent benefit from these combinations in particular subgroups (clear cell mRCC tumors with sarcomatoid differentiation), and possible new approaches in subsequent lines of therapy (including the HIF-2α inhibitor belzutifan). CONCLUSIONS: This 2021 ASCO Genitourinary Cancer Symposium laid the foundations for further knowledge development necessary for an increasingly personalized management of mRCC. In a first, the FDA has approved an inhibitor of hypoxia-inducible factor-2α. The drug is also the first approved to treat von Hippel-Lindau disease-associated renal cell carcinoma, central nervous system hemangioblastomas, and pancreatic neuroendocrine tumors.
4,173
Where are the PUX proteins found?
PUX proteins specifically associate with the nucleoskeleton underneath the INM.
[32601292, 34141135]
4,584
In plants, AAA-adenosine triphosphatase (ATPase) Cell Division Control Protein 48 (CDC48) uses the force generated through ATP hydrolysis to pull, extract, and unfold ubiquitylated or sumoylated proteins from the membrane, chromatin, or protein complexes. The resulting changes in protein or RNA content are an important means for plants to control protein homeostasis and thereby adapt to shifting environmental conditions. The activity and targeting of CDC48 are controlled by adaptor proteins, of which the plant ubiquitin regulatory X (UBX) domain-containing (PUX) proteins constitute the largest family. Emerging knowledge on the structure and function of PUX proteins highlights that these proteins are versatile factors for plant homeostasis and adaptation that might inspire biotechnological applications.
4,174
Are Tregs CD4(+)CD25(+) regulatory T cells a positive regulator of the immune response?
CD4(+)CD25(+) regulatory T cells (Tregs) are negative regulators of the immune system that induce and maintain immune tolerance.
[16393984, 19816193, 18205702, 23635849, 21386770, 22749847, 17368474, 23983771, 16020508, 17234458, 24754976, 16809644, 24483245, 20843956, 18032693, 21655351, 27109178, 22899644, 34495808, 19005268, 23531479, 17407195, 17826781, 25113439, 17848162, 20384869, 19543397, 15778406, 24095986, 21597299, 18580479]
4,585
CD4+ T cells naturally expressing CD25 molecules (natural T regulatory cells (Tregs)) have a role in maintaining self tolerance and in regulating responses to infectious agents, transplantation Ags, and tumor Ags. CD4+ Tregs induced from CD4+CD25- precursors (induced Tregs) also regulate immune responses in the periphery. However, which of these Tregs is a major impediment in generating antitumor CTL responses is not clear. We show that although the CD4+CD25+ subsets isolated from peripheral blood-derived lymphocytes do suppress the proliferation of CD4+CD25- effector T cells, they do not suppress the activation and expansion of the self but melanoma-associated, melanoma Ag-reactive T cell 1 (MART-1)27-35-specific CD8+ T cells stimulated by the respective peptide-loaded matured dendritic cells in vitro. The CD4+CD25- counterparts, in contrast, lead to the generation of CD25+ glucocorticoid-inducible TNFR+-Forkhead/winged helix transcription factor+ populations and efficiently suppress the activation and expansion of the MART-127-35 epitope-specific CTLs. Our data suggest that when CTL precursors are optimally stimulated, natural Tregs are not a formidable constraint toward generating a robust antitumor CTL response, but induced Tregs could be. The immunosuppressive effects of CD4+ CD25 high regulatory T cells (Tregs) interfere with antitumor immune responses in cancer patients. Here, we present a novel class of engineered human interleukin (IL)-2 analogs that antagonizes the IL-2 receptor, for inhibiting regulatory T cell suppression. These antagonists have been engineered for high affinity to the alpha subunit of the IL-2 receptor and very low affinity to either the beta or gamma subunit, resulting in a signaling-deficient IL-2 analog that sequesters the IL-2 receptor alpha subunit from wild type IL-2. Two variants, "V91R" and "Q126T" with residue substitutions that disrupt the beta and gamma subunit binding interfaces, respectively, have been characterized in both a T cell line and in human primary Tregs. These mutants retain their high affinity binding to IL-2 receptor alpha subunit, but do not activate STAT5 phosphorylation or stimulate T cell growth. The 2 mutants competitively antagonize wild-type IL-2 signaling through the IL-2 receptor with similar efficacy, with inhibition constants of 183 pM for V91R and 216 pM for Q126T. Here, we present a novel approach to CD25-mediated Treg inhibition, with the use of an engineered human IL-2 analog that antagonizes the IL-2 receptor. It is well established that CD4CD25 regulatory T cells (Tregs) downregulate inflammatory immune responses and help to maintain immune homeostasis. Recent reports have shown that ligation of germline encoded pattern recognition receptors such as Toll-like receptors can stimulate Tregs and therefore implicate Tregs in the pathophysiology of sepsis and other inflammatory diseases. In this report, we show that injection of lipopolysaccharide (LPS) leads to expansion of CD4CD25FoxP3 Tregs, suggesting that these cells may play an important role in immune regulation in LPS-induced acute inflammation. Indeed, genetic or immunological inhibition of Treg function using mice lacking functional Tregs (CD25 KO mice) or anti-CD25 monoclonal antibody (anti-CD25 mAb), respectively, led to acute death in an otherwise nonlethal LPS challenge. This was accompanied by exaggerated production of proinflammatory cytokines. Strikingly, adoptive transfer of CD4CD25 Tregs to CD25 KO mice before LPS challenge rescues mice from death. Unlike LPS, depletion of Tregs followed by concanavalin A (Con A) challenge does not result in mortality, suggesting that Treg depletion does not globally influence all models of acute inflammation. We authenticate our findings by showing that depletion of Tregs leads to mortality in a nonlethal Escherichia coli challenge accompanied by elevated serum levels of proinflammatory cytokines. Collectively, our results indicate that in addition to regulation of LPS-induced acute inflammation, Tregs help to improve bacterial clearance and promote survival in an acute model of bacterial infection. BACKGROUND: Because CD4CD25Foxp3 regulatory T cells (Tregs) are essential for the maintenance of self-tolerance, significant interest surrounds the developmental cues for thymic-derived natural Tregs (nTregs) and periphery-generated adaptive Tregs (aTregs). In the transplant setting, the allograft may play a role in the generation of alloantigen-specific Tregs, but this role remains undefined. We examined whether the immune response to a transplant allograft results in the peripheral generation of aTregs. METHODS: To identify generation of aTregs, purified graft-reactive CD4CD25 T cells were adoptively transferred to mice-bearing skin allograft. To demonstrate that aTregs are necessary for tolerance, DBA/2 skin was transplanted onto C57BL/6-RAG-1-deficient recipients adoptively transferred with purified sorted CD4CD25 T cells; half of the recipients undergo tolerance induction treatment. RESULTS: By tracking adoptively transferred cells, we show that purified graft-reactive CD4CD25 T lymphocytes up-regulate Foxp3 in mice receiving skin allografts in the absence of any treatment. Interestingly, cotransfer of antigen-specific nTregs suppresses the up-regulation of Foxp3 by inhibiting the proliferation of allograft-responsive T cells. In vitro data are consistent with our in vivo data-Foxp3 cells are generated on antigen activation, and this generation is suppressed on coculture with antigen-specific nTregs. Finally, blocking aTreg generation in grafted, rapamycin-treated mice disrupts alloantigen-specific tolerance induction. In contrast, blocking aTreg generation in grafted mice treated with nondepleting anti-CD4 plus anti-CD40L antibodies does not disrupt graft tolerance. CONCLUSIONS: We conclude that graft alloantigen stimulates the de novo generation of aTregs, and this generation may represent a necessary step in some but not all protocols of tolerance induction. Accumulating evidence has demonstrated that naturally occurring CD4(+)CD25(+) regulatory T cells (Tregs) are critical for maintenance of immunological tolerance and have been shown to be important in regulating the immune responses in many diseases. Curcumin, a phytochemical obtained from the rhizome of the plant Curcuma longa, has achieved the potential therapeutic interest to numerous immune-related disorders. However, the effect and mechanism of curcumin on Tregs remain largely elusive. In the present study, curcumin inhibition of the suppressive activity of CD4(+)CD25(+) regulatory T cells appears to be dependent on three categories: inhibiting cell-cell contact by down-regulation of CTLA-4, suppressing inhibitory cytokine secretion and decreasing the ability to consume IL-2 and/or suppress IL-2 production. In addition, Foxp3 expression was also reduced on Tregs after curcumin stimulation. Moreover, we found that nuclear translocation of p65 and c-Rel, which is critical for Foxp3 and CD25 expressions, was markedly decreased in Tregs with curcumin stimulation. Based on the role of curcumin in the suppressive activity of Tregs, it may be feasible to use curcumin as an immunotherapy for Treg-related diseases, such as tumors and sepsis. CD4(+)CD25(+) regulatory T cells (Tregs) are considered to play a key role as suppressors of immune mediated reactions. The analysis of Treg function in patients with autoimmune, allergic or oncogenic diseases has emerged over the past years. In the present study we describe a CFSE based protocol to measure Treg mediated suppression of CD4(+) T cells. Measuring Treg suppressive capacity towards proliferation of anti-CD3 Ab stimulated CD4(+)CD25(-) T cells in coculture experiments by means of a CFSE based and a classical [(3)H]thymidine incorporation assay gave similar results, provided that CD4(+)CD25(+) T cells were anergic. However, when CD4(+)CD25(+) T cells proliferated upon mitogenic stimulation, data obtained by the CFSE assay allowed the detection of a significant Treg suppression whereas this was clearly underestimated using the [(3)H]thymidine assay. In addition, an indirect CFSE based method was developed to analyze antigen specific responses of total CD4(+) T cells and Treg depleted CD4(+) T cells (i.e. CD4(+)CD25(-) T cells). Our results indicate that, in healthy individuals, CD4(+) T cell responses against the multiple sclerosis (MS) auto-antigens, myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG), were increased in Treg depleted CD4(+) T cells as compared to total CD4(+) T cells. Our initial data suggest that Tregs in MS patients show an impaired suppression of myelin reactive T cells when compared to healthy controls. Moreover, this experimental setup permits the measurement of cytokine production of the antigen proliferated CFSE(low) T cells by additional flow cytometric analyses. In conclusion, the described CFSE based Treg suppression assay is a valuable tool to study suppressor T cells in (auto)immune disorders. CD4+CD25+ regulatory T cells (Tregs) are essential negative regulators of immune responses. Here, we examined the signaling properties of human Tregs, using CD4+CD25+ Treg and CD4+CD25- control (Tcont) cell lines generated from cord blood. Treg cell lines were markedly hyporesponsive to stimulation with dendritic cells and with anti-CD3/CD28-coated beads. Hyporesponsiveness was reversed by exogenous interleukin-2 (IL-2). T-cell receptor (TCR)-CD3/CD28-mediated activation of Rap1 and Akt was retained in Tregs, but activation of Ras, mitogenactivated protein kinase 1/2 (MEK1/2), and extracellular signal-regulated kinase 1/2 (Erk1/2) was impaired. Tregs were blocked from cell cycle progression due to decrease of cyclin E and cyclin A and increase of p27kip1 (p27kip cyclin dependent kinase inhibitor). IL-2 induced sustained increase of cyclin E and cyclin A and prevented up-regulation of p27kip1. Tregs had high susceptibility to apoptosis that was reversed by IL-2, which correlated with activation of Erk1/2, up-regulation of Bcl-x(L) (B-cell CLL/lymphoma 2-like nuclear gene encoding mitochondrial protein, transcript variant 2), and phosphorylation of Bad (Bcl2 antagonist of cell death) at Ser112. Thus, Tregs share biochemical characteristics of anergy, including abortive activation of Ras-MEK-Erk, increased activation of Rap1, and increased expression of p27kip1. In addition, our results indicate that TCR-CD3/CD28-mediated and IL-2 receptor-mediated signals converge at the level of MEK-Erk kinases to regulate Treg survival and expansion and suggest that manipulation of the MEK-Erk axis may represent a novel strategy for Treg expansion for immunotherapy. CD4(+)CD25(+) regulatory T cells (Treg) play a central role in the prevention of autoimmunity and in the control of immune responses by down-regulating the function of effector CD4(+) or CD8(+) T cells. The role of Treg in Mycobacterium tuberculosis infection and persistence is inadequately documented. Therefore, the current study was designed to determine whether CD4(+)CD25(+)FoxP3(+) regulatory T cells may modulate immunity against human tuberculosis (TB). Our results indicate that the number of CD4(+)CD25(+)FoxP3(+) Treg increases in the blood or at the site of infection in active TB patients. The frequency of CD4(+)CD25(+)FoxP3(+) Treg in pleural fluid inversely correlates with local MTB-specific immunity (p<0.002). These CD4(+)CD25(+)FoxP3(+) T lymphocytes isolated from the blood and pleural fluid are capable of suppressing MTB-specific IFN-gamma and IL-10 production in TB patients. Therefore, CD4(+)CD25(+)FoxP3(+) Treg expanded in TB patients suppress M. tuberculosis immunity and may therefore contribute to the pathogenesis of human TB. The immune system has evolved numerous mechanisms of peripheral T cell immunoregulation, including a network of regulatory T (Treg) cells, to modulate and down-regulate immune responses at various times and locations and in various inflammatory circumstances. Amongst these, naturally occurring CD4(+)CD25(+) Treg cells (nTreg) represent a major lymphocyte population engaged in the dominant control of self-reactive T responses and maintaining tolerance in several models of autoimmunity. CD4(+)CD25(+) Treg cells differentiate in the normal thymus as a functionally distinct subpopulation of T cells bearing a broad T cell receptor repertoire, endowing these cells with the capacity to recognize a wide range of self and nonself antigen specificities. The generation of CD4(+)CD25(+) Treg cells in the immune system is genetically controlled, influenced by antigen recognition, and various signals, in particular, cytokines such as interleukin-2 and transforming growth factor-beta1, control their activation, expansion, and suppressive effector activity. Functional abrogation of these cells in vivo or genetic defects that affect their development or function unequivocally promote the development of autoimmune and other inflammatory diseases in animals and humans. Recent progress has shed light on our understanding of the cellular and molecular basis of CD4(+)CD25(+) Treg cell-mediated immune regulation. This article discusses the relative contribution of CD4(+)CD25(+) nTreg cells in the induction of immunologic self-tolerance and provides a comprehensive overview of recent finding regarding the functional properties and effector mechanism of these cells, as revealed from various in vitro and in vivo models. α7 Nicotinic acetylcholine receptor (α7 nAChR) has been found in several non-neuronal cells and is described as an important regulator of cellular function. Naturally occurring CD4(+)CD25(+) regulatory T cells (Tregs) are essential for the active suppression of autoimmunity. The present study investigated whether naturally occurring Tregs expressed α7 nAChR and investigated the functionary role of this receptor in controlling suppressive activity of these cells. We found that CD4(+)CD25(+) Tregs from naive C57BL/6J mice positively expressed α7 nAChR, and its activation by nicotine enhanced the suppressive capacity of Tregs. Nicotine stimulation up-regulated the expression of cytotoxic T-lymphocyte-associated antigen (CTLA)-4 and forkhead/winged helix transcription factor p3 (Foxp3) on Tregs but had no effect on the production of interleukin (IL)-10 and transforming growth factor-β1 by Tregs. In the supernatants of CD4(+)CD25(+) Tregs/CD4(+)CD25(-) T-cell cocultures, we observed a decrease in the concentration of IL-2 in nicotine-stimulated groups, but nicotine stimulation had no effect on the ratio of IL-4/interferon (IFN)-γ, which partially represented T-cell polarization. The above-mentioned effects of nicotine were reversed by a selective α7 nAChR antagonist, α-bungarotoxin. In addition, the ratio of IL-4/IFN-γ was increased by treatment with α-bungarotoxin. We conclude that nicotine might increase Treg-mediated immune suppression of lymphocytes via α7 nAChR. The effect is related to the up-regulation of CTLA-4 as well as Foxp3 expression and decreased IL-2 secretion in CD4(+)CD25(+) Tregs/CD4(+)CD25(-) T-cell coculture supernatants. α7 nAChR seems to be a critical regulator for immunosuppressive function of CD4(+)CD25(+) Tregs. CD4(+)CD25(+) regulatory T cells (Tregs) are potent modulators of immune responses. The transcriptional program distinguishing Tregs from the CD4(+)CD25(-) Th cells is unclear. NFAT, a key transcription factor, is reported to interact with forkhead box p3, allowing inhibitory and activating signals in T cells. In the current study, we hypothesize that distinctive NFAT regulation in Tregs as compared with Th cells, may contribute to specific functions of these cells. Tregs express basal levels of cytoplasmic NFATc1 and NFATc2. In contrast to Th cells, anti-CD3-mediated T cell activation did not induce nuclear translocation of NFATc1 or NFATc2 in Tregs. This effect was associated with altered regulation for NFAT in Tregs that included reduced calcium flux, diminished calcineurin activation, and increased activity of glycogen synthase kinase-3beta, a negative regulatory kinase for NFAT in Tregs relative to Th cells. These data suggested that NFAT inhibition in Th cells may induce regulatory function. Indeed, pharmacologically mediated NFAT inhibition induced Th cells to function as Tregs, an effect that was mediated by induction of membrane-bound TGF-beta on Th cells. Collectively, these data suggest that maintaining NFAT at basal levels is a part of the transcriptional program required for Tregs. CD25(High) CD4+ regulatory T cells (Treg cells) have been described as key players in immune regulation, preventing infection-induced immune pathology and limiting collateral tissue damage caused by vigorous anti-parasite immune response. In this review, we summarize data obtained by the investigation of Treg cells in different clinical forms of Chagas' disease. Ex vivo immunophenotyping of whole blood, as well as after stimulation with Trypanosoma cruzi antigens, demonstrated that individuals in the indeterminate (IND) clinical form of the disease have a higher frequency of Treg cells, suggesting that an expansion of those cells could be beneficial, possibly by limiting strong cytotoxic activity and tissue damage. Additional analysis demonstrated an activated status of Treg cells based on low expression of CD62L and high expression of CD40L, CD69, and CD54 by cells from all chagasic patients after T. cruzi antigenic stimulation. Moreover, there was an increase in the frequency of the population of Foxp3+ CD25(High)CD4+ cells that was also IL-10+ in the IND group, whereas in the cardiac (CARD) group, there was an increase in the percentage of Foxp3+ CD25(High) CD4+ cells that expressed CTLA-4. These data suggest that IL-10 produced by Treg cells is effective in controlling disease development in IND patients. However, in CARD patients, the same regulatory mechanism, mediated by IL-10 and CTLA-4 expression is unlikely to be sufficient to control the progression of the disease. These data suggest that Treg cells may play an important role in controlling the immune response in Chagas' disease and the balance between regulatory and effector T cells may be important for the progression and development of the disease. Additional detailed analysis of the mechanisms on how these cells are activated and exert their function will certainly give insights for the rational design of procedure to achieve the appropriate balance between protection and pathology during parasite infections. Not all T cells are effector cells of the anti-tumor immune system. One of the subpopulations of CD4+ T cells that express CD25+ and the transcription factor FOXP3, known as Regulator T cells (TReg), plays an essential role in maintaining tolerance and immune homeostasis preventing autoimmune diseases, minimalize chronic inflammatory diseases by enlisting various immunoregulatory mechanisms. The balance between effector T cells (Teff) and regulator T cells is crucial in determining the outcome of an immune response. Regarding tumors, activation or expansion of TReg cells reduces anti-tumor immunity. TReg cells inhibit the activation of CD4+ and CD8+ T cells and suppress anti-tumor activity in the tumor microenvironment. In addition, TReg cells also promote tumor angiogenesis both directly and indirectly to ensure oxygen and nutrient transport to the tumor. There is accumulating evidence showing a positive result that removing or suppressing TReg cells increases anti-tumor immune response. However, depletion of TReg cells will cause autoimmunity. One strategy to improve or restore tumor immunity is targeted therapy on the dominant effector TReg cells in tumor tissue. Various molecules such as CTLA-4, CD4, CD25, GITR, PD-1, OX40, ICOS are in clinical trials to assess their role in attenuating TReg cells' function. OBJECTIVES: CD4CD25 regulatory T cells (Tregs) play a key role in the prevention of various inflammatory and autoimmune disorders by suppressing immune responses. The beneficial effect of statins on myocardial ischemia-reperfusion injury (IRI) depends in part on their immunomodulatory and anti-inflammatory mechanisms. We aimed to determine whether Tregs contribute to statin-induced cardioprotection against myocardial IRI. METHODS: Thirty-two rats were divided into four groups: sham, ischemia-reperfusion (IR), rosuvastatin (RSV)/IR, and mevalonic acid (MVA)+RSV/IR. Myocardial IR was induced by a 30-min coronary occlusion, followed by a 48-h reperfusion. RSV (5 mg/kg) was administered intravenously 18 h before IR. The rats were killed after 48-h reperfusion. Serum cardiac troponin I (cTnI) was measured by ELISA, infiltration of inflammatory cells in myocardium by hematoxylin and eosin staining, expression of FoxP3 protein by western blotting, accumulation of Tregs in myocardium by immunohistochemical examination, and infarct size by TTC staining. RESULTS: Significant elevation in serum cTnI, enlarged infarct size, and marked infiltration of inflammatory cells in myocardium were observed in the IR group. The administration of RSV significantly reduced the serum cTnI level, attenuated the accumulation of inflammatory cells, decreased infarct size, and increased the FoxP3 expression and Treg accumulation in myocardium compared with the IR group. The combination of RSV and MVA pretreatment partially abolished the anti-inflammatory and infarct size-limiting effects and completely reversed Treg accumulation in myocardium induced by RSV. The accumulation of inflammatory cells was negatively correlated with FoxP3 expression and Treg accumulation in the ischemic myocardium. CONCLUSION: RSV pretreatment was associated with more Treg accumulation, less inflammatory response, and myocardial injury, suggesting that such cardioprotection against IRI was partially mediated by Treg-negative modulation of inflammation response, probably through the HMG-CoA reductase pathway. Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are in widespread use due to their LDL reducing properties and concomitant improvement of clinical outcome in patients with and without preexisting atherosclerosis. Considerable evidence suggests that immune mediated mechanisms play a dominant role in the beneficial effects of statins. Naturally occurring CD4(+)CD25(+) regulatory T cells (Tregs) have a key role in the prevention of various inflammatory and autoimmune disorders by suppressing immune responses. We tested the hypothesis that statins influence the circulating number and the functional properties of Tregs. We studied the effects of in vivo and in vitro statin treatment of human and murine mononuclear cells on the number of Tregs and the expression level of their master transcription regulator, Foxp3. Atorvastatin, but not mevastatin nor pravastatin, treatment of human peripheral blood mononuclear cells (PBMCs) increased the number of CD4(+)CD25(high) cells, and CD4(+)CD25(+)Foxp3(+) cells. These Tregs, induced by atorvastatin, expressed high levels of Foxp3, which correlated with an increased regulatory potential. Furthermore, co-culture studies revealed that atorvastatin induced CD4(+)CD25(+)Foxp3(+) Tregs were derived from peripheral CD4(+)CD25(-)Foxp3(-) cells. Simvastatin and pravastatin treatment in hyperlipidemic subjects increased the number of Tregs. In C57BL/6 mice however, no effect of statins on Tregs was evident. In conclusion, statins appear to significantly influence the peripheral pool of Tregs in humans. This finding may shed light on the mechanisms governing the plaque stabilizing properties of statins. BACKGROUND: Alteration of regulatory T cells (Tregs) may contribute to ineffective suppression of proinflammatory cytokines in type 1 diabetes. AIM: We determined the percentage of Tregs expressing CD62L or tumor necrosis factor receptor type 2 (TNFR2) in 70 young type 1 diabetic patients compared with 30 controls and assessed their relation to inflammation, glycemic control and micro-vascular complications. METHODS: High-sensitivity C-reactive protein (hs-CRP), hemoglobin A1c (HbA1c), tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) were assessed with flow cytometric analysis of Tregs, Tregs expressing CD62L or TNFR2. RESULTS: The percentage of CD4(+)CD25(high) T cells and CD4(+)CD25(high)CD62L(high) cells were significantly decreased while CD4(+)CD25(high)TNFR2(+) T cells were elevated in patients with micro-vascular complications than those without and controls (p<0.001). ROC curve revealed that the cutoff values of Tregs, Tregs expressing CD62L and Tregs expressing TNFR2 (7.46%, 24.2% and 91.9%, respectively) could detect micro-vascular complications. Significant negative correlations were observed between Tregs expressing CD62L and disease duration, FBG, HbA1c, urinary albumin excretion and hs-CRP, whereas, positive correlations were found between Tregs expressing TNFR2 and these variables (p<0.05). TNF-α was significantly increased while IL-10 was decreased among patients with micro-vascular complications than those without (p<0.05). CONCLUSIONS: Alteration in the frequency of Tregs and Tregs expressing CD62L or TNFR2 in type 1 diabetes is associated with increased inflammation, poor glycemic control and risk of micro-vascular complications. Regulatory CD4(+) CD25(+) T (Treg) cells with the ability to suppress host immune responses against self- or non-self antigens play important roles in the processes of autoimmunity, transplant rejection, infectious diseases and cancers. The proper regulation of CD4(+) CD25(+) Treg cells is thus critical for optimal immune responses. Toll-like receptor (TLR)-mediated recognition of specific structures of invading pathogens initiates innate as well as adaptive immune responses via antigen-presenting cells (APCs). Interestingly, new evidence suggests that TLR signalling may directly or indirectly regulate the immunosuppressive function of CD4(+) CD25(+) Treg cells in immune responses. TLR signalling may shift the balance between CD4(+) T-helper cells and Treg cells, and subsequently influence the outcome of the immune response. This immunomodulation pathway may therefore have potential applications in the treatment of graft rejection, autoimmune diseases, infection diseases and cancers. CD4(+)CD25(+) regulatory T cells (Tregs) are critical for the peripheral immune tolerance. Understanding the signals for the generation of Tregs is important for the clinical immunotherapy, but only limited progress has been made on obtaining enough peripheral Tregs. The aim of this study was to evaluate the role of trichosanthin (Tk) extracted from Chinese medicinal herb Trichosanthes kirilowi on the function of Tregs in vitro and in vivo. We reported here that Tk is needed for the expansion of freshly isolated CD4(+)CD25(+)Tregs (nTregs) into Tk-expanded CD4(+)CD25(+)Tregs (Tk-Tregs) through up-regulating CD25 and Foxp3 expression. The dose-response analyses indicated that 100 ng/ml Tk was the most appropriate dose. The result of real-time PCR showed that Tk-Tregs expressed 1.5-fold higher levels of Foxp3 than those observed in nTregs. Tk-Tregs markedly suppressed activation of effector T cells at a suppressor/responder ratio of 1:1, 1:2, 1:4, 1:8 or 1:16, and their effect was dose dependent. Moreover, Tk-Tregs secreted more immunosuppressive cytokines interleukin (IL)-10 and transforming growth factor (TGF)-beta1 after stimulating with antigen and antigen-presenting cells (APC). Transwell experiments showed that not only cell-to-cell contact but also soluble cytokines were involved in suppressive mechanism of Tk-Tregs. And Tk-Tregs were more efficient in suppressing CD25(-)T cell response to specific antigen than to irrelative antigen. Most importantly, it was revealed for the first time that Tk-Tregs could prolong the survival duration of mice with acute graft-versus-host disease (aGVHD). In conclusion, the study suggests a possible therapeutic potential of Tk-Tregs for clinical treatment on aGVHD. BACKGROUND: Regulatory T cells (Tregs) are essential in the control of tolerance. Evidence implicates Tregs in human autoimmune conditions. Here we investigated their role in systemic sclerosis (SSc). METHODS/PRINCIPAL FINDINGS: Patients were subdivided as having limited cutaneous SSc (lcSSc, n = 20) or diffuse cutaneous SSc (dcSSc, n = 48). Further subdivision was made between early dcSSc (n = 24) and late dcSSc (n = 24) based upon the duration of disease. 26 controls were studied for comparison. CD3+ cells were isolated using FACS and subsequently studied for the expression of CD4, CD8, CD25, FoxP3, CD127, CD62L, GITR, CD69 using flow cytometry. T cell suppression assays were performed using sorted CD4CD25(high)CD127(-) and CD4CD25(low)CD127(high) and CD3(+) cells. Suppressive function was correlated with CD69 surface expression and TGFbeta secretion/expression. The frequency of CD4(+)CD25(+) and CD25(high)FoxP3(high)CD127(neg) T cells was highly increased in all SSc subgroups. Although the expression of CD25 and GITR was comparable between groups, expression of CD62L and CD69 was dramatically lower in SSc patients, which correlated with a diminished suppressive function. Co-incubation of Tregs from healthy donors with plasma from SSc patients fully abrogated suppressive activity. Activation of Tregs from healthy donors or SSc patients with PHA significantly up regulated CD69 expression that could be inhibited by SSc plasma. CONCLUSIONS/SIGNIFICANCE: These results indicate that soluble factors in SSc plasma inhibit Treg function specifically that is associated with altered Treg CD69 and TGFbeta expression. These data suggest that a defective Treg function may underlie the immune dysfunction in systemic sclerosis. Immune activation during chronic HIV infection is a strong clinical predictor of death and may mediate CD4(+) T cell depletion. Regulatory T cells (Tregs) are CD4(+)CD25(bright)CD62L(high) cells that actively down-regulate immune responses. We asked whether loss of Tregs during HIV infection mediates immune activation in a cross-sectional study of 81 HIV-positive Ugandan volunteers. We found that Treg number is strongly correlated with both CD4(+) and CD8(+) T cell activation. In multivariate modeling, this relationship between Treg depletion and CD4(+) T cell activation was stronger than any other clinical factor examined, including viral load and absolute CD4 count. Tregs appear to decline at different rates compared with other CD4(+) T cells, resulting in an increased regulator to helper ratio in many patients with advanced disease. We hypothesize that this skewing may contribute to T cell effector dysfunction. Our findings suggest Tregs are a major contributor to the immune activation observed during chronic HIV infection.
4,175
Is Mediator present at super enhancers?
Yes. Super enhancers are clusters of enhancers that are densely occupied by the master regulator and mediator.
[28839111, 28978570, 27376235, 26416749, 25955728, 23582322, 25547603, 23582323, 25263550]
4,586
Super-enhancers are characterized by high levels of Mediator binding and are major contributors to the expression of their associated genes. They exhibit high levels of local chromatin interactions and a higher order of local chromatin organization. On the other hand, lncRNAs can localize to specific DNA sites by forming a RNA:DNA:DNA triplex, which in turn can contribute to local chromatin organization. In this paper, we characterize a new class of lncRNAs called super-lncRNAs that target super-enhancers and which can contribute to the local chromatin organization of the super-enhancers. Using a logistic regression model based on the number of RNA:DNA:DNA triplex sites a lncRNA forms within the super-enhancer, we identify 442 unique super-lncRNA transcripts in 27 different human cell and tissue types; 70% of these super-lncRNAs were tissue restricted. They primarily harbor a single triplex-forming repeat domain, which forms an RNA:DNA:DNA triplex with multiple anchor DNA sites (originating from transposable elements) within the super-enhancers. Super-lncRNAs can be grouped into 17 different clusters based on the tissue or cell lines they target. Super-lncRNAs in a particular cluster share common short structural motifs and their corresponding super-enhancer targets are associated with gene ontology terms pertaining to the tissue or cell line. Super-lncRNAs may use these structural motifs to recruit and transport necessary regulators (such as transcription factors and Mediator complexes) to super-enhancers, influence chromatin organization, and act as spatial amplifiers for key tissue-specific genes associated with super-enhancers. A number of studies have recently demonstrated that super-enhancers, which are large cluster of enhancers typically marked by a high level of acetylation of histone H3 lysine 27 and mediator bindings, are frequently associated with genes that control and define cell identity during normal development. Super-enhancers are also often enriched at cancer genes in various malignancies. The identification of such enhancers would pinpoint critical factors that directly contribute to pathogenesis. In this study, we performed enhancer profiling using primary leukemia samples from adult T-cell leukemia/lymphoma (ATL), which is a genetically heterogeneous intractable cancer. Super-enhancers were enriched at genes involved in the T-cell activation pathway, including IL2RA/CD25, CD30, and FYN, in both ATL and normal mature T cells, which reflected the origin of the leukemic cells. Super-enhancers were found at several known cancer gene loci, including CCR4, PIK3R1, and TP73, in multiple ATL samples, but not in normal mature T cells, which implicated those genes in ATL pathogenesis. A small-molecule CDK7 inhibitor, THZ1, efficiently inhibited cell growth, induced apoptosis, and downregulated the expression of super-enhancer-associated genes in ATL cells. Furthermore, enhancer profiling combined with gene expression analysis identified a previously uncharacterized gene, TIAM2, that was associated with super-enhancers in all ATL samples, but not in normal T cells. Knockdown of TIAM2 induced apoptosis in ATL cell lines, whereas overexpression of this gene promoted cell growth. Our study provides a novel strategy for identifying critical cancer genes. Super-enhancers (SEs), which are composed of large clusters of enhancers densely loaded with the Mediator complex, transcription factors and chromatin regulators, drive high expression of genes implicated in cell identity and disease, such as lineage-controlling transcription factors and oncogenes. BRD4 and CDK7 are positive regulators of SE-mediated transcription. By contrast, negative regulators of SE-associated genes have not been well described. Here we show that the Mediator-associated kinases cyclin-dependent kinase 8 (CDK8) and CDK19 restrain increased activation of key SE-associated genes in acute myeloid leukaemia (AML) cells. We report that the natural product cortistatin A (CA) selectively inhibits Mediator kinases, has anti-leukaemic activity in vitro and in vivo, and disproportionately induces upregulation of SE-associated genes in CA-sensitive AML cell lines but not in CA-insensitive cell lines. In AML cells, CA upregulated SE-associated genes with tumour suppressor and lineage-controlling functions, including the transcription factors CEBPA, IRF8, IRF1 and ETV6 (refs 6-8). The BRD4 inhibitor I-BET151 downregulated these SE-associated genes, yet also has anti-leukaemic activity. Individually increasing or decreasing the expression of these transcription factors suppressed AML cell growth, providing evidence that leukaemia cells are sensitive to the dosage of SE-associated genes. Our results demonstrate that Mediator kinases can negatively regulate SE-associated gene expression in specific cell types, and can be pharmacologically targeted as a therapeutic approach to AML. The HSA21 encoded Single-minded 2 (SIM2) transcription factor has key neurological functions and is a good candidate to be involved in the cognitive impairment of Down syndrome. We aimed to explore the functional capacity of SIM2 by mapping its DNA binding sites in mouse embryonic stem cells. ChIP-sequencing revealed 1229 high-confidence SIM2-binding sites. Analysis of the SIM2 target genes confirmed the importance of SIM2 in developmental and neuronal processes and indicated that SIM2 may be a master transcription regulator. Indeed, SIM2 DNA binding sites share sequence specificity and overlapping domains of occupancy with master transcription factors such as SOX2, OCT4 (Pou5f1), NANOG or KLF4. The association between SIM2 and these pioneer factors is supported by co-immunoprecipitation of SIM2 with SOX2, OCT4, NANOG or KLF4. Furthermore, the binding of SIM2 marks a particular sub-category of enhancers known as super-enhancers. These regions are characterized by typical DNA modifications and Mediator co-occupancy (MED1 and MED12). Altogether, we provide evidence that SIM2 binds a specific set of enhancer elements thus explaining how SIM2 can regulate its gene network in neuronal features.
4,177
What is caused by biallelic variants in SPATA5L1?
Biallelic variants in SPATA5L1 lead to intellectual disability, spastic-dystonic cerebral palsy, epilepsy, and hearing loss.
[34626583]
4,588
Author information: (1)Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. (2)Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ 85016, USA; Departments of Child Health, Neurology, Cellular, and Molecular Medicine and Program in Genetics, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, USA. (3)Department of Neuromuscular Disorders, Institute of Neurology, University College London, Queen Square, WC1N 3BG London, UK. (4)Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, 81675 Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, 85764 Neuherberg, Germany. (5)CSIRO Health and Biosecurity, The Australian e-Health Research Centre, Brisbane, QLD 4029, Australia. (6)Pediatric Neuroradiology Division, Pediatric Radiology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ 85016, USA; University of Arizona College of Medicine, Phoenix, AZ 85004, USA; Mayo Clinic, Scottsdale, AZ 85259, USA. (7)Neurology Department, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia. (8)Department of Medical Genomics, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia. (9)Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA, USA. (10)Department of Computer Science, City University of Hong Kong, Kowloon 999077, Hong Kong. (11)Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Center for Data Driven Discovery in Biomedicine, Children's Hospital of Philadelphia, Philadelphia, PA 19146, USA. (12)Department of Bone and Osteogenesis Imperfecta, Kennedy Krieger Institute, Baltimore, MD 21205, USA. (13)Center for Autism and Related Disorders, Kennedy Krieger Institute, Baltimore, MD 21211, USA. (14)Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA. (15)University of Massachusetts Medical School - Baystate, Baystate Children's Hospital, Springfield, MA 01107, USA. (16)Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. (17)Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, 81675 Munich, Germany. (18)Centre of Child and Adolescent Medicine, Department of Pediatric Neurology and Metabolic Medicine, Heidelberg University Hospital, 69120 Heidelberg, Germany. (19)Department of Child Neurology and Metabolic Medicine, Center for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany. (20)Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD 21205, USA. (21)Dor Yeshorim, Committee for Prevention of Jewish Genetic Diseases, New York, NY 11211, USA. (22)Dor Yeshorim, Committee for Prevention of Jewish Genetic Diseases, Jerusalem 9054020, Israel. (23)Department of Child Neurology, Justus-Liebig-University Giessen, 35392 Giessen, Germany. (24)Department of Neurology, South Kazakhstan Medical Academy, Shymkent 160001, Kazakhstan. (25)Clinical Genetics, Royal Devon & Exeter NHS Foundation Trust, EX1 2ED Exeter, UK. (26)Clinical Pharmacology, William Harvey Research Institute, Charterhouse Square, School of Medicine and Dentistry Queen Mary University of London, London EC1M 6BQ, UK. (27)Penn State Health Children's Hospital, Hershey, PA 17033, USA. (28)Department of Clinical Neurosciences, John Van Geest Cambridge Centre for Brain Repair, University of Cambridge School of Clinical Medicine, CB2 0PY Cambridge, UK. (29)Inonu University, Faculty of Medicine, Turgut Ozal Research Center, Department of Paediatric Neurology, 44280 Malatya, Turkey. (30)Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, 35340 Izmir, Turkey; Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylul University, 35340 Izmir, Turkey. (31)Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, 35340 Izmir, Turkey; Department of Medical Biology, Faculty of Medicine, Dokuz Eylul University, 35220 Izmir, Turkey. (32)Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital, and Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada. (33)Università Cattolica Sacro Cuore, Facoltà di Medicina e Chirurgia, Dipartimento Scienze della Vita e Sanità Pubblica, 00168 Roma, Italy; Fondazione Policlinico A. Gemelli IRCCS, Sezione di Medicina Genomica, 00168 Roma, Italy. (34)Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Naples, Italy. (35)Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Naples, Italy; Department of Precision Medicine, University of Campania "Luigi Vanvitelli," 80138 Naples, Italy. (36)Department of Neuropediatrics, Jena University Hospital, 07747 Jena, Germany. (37)Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tuebingen, Germany. (38)Institute of Systems Motor Science, University of Lübeck, 23538 Lübeck, Germany. (39)Department of Paediatric and Adolescent Medicine, St Joseph Hospital, 12101 Berlin, Germany. (40)University Children's Hospital Oldenburg, Department of Neuropaediatric and Metabolic Diseases, 26133 Oldenburg, Germany. (41)Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany; Junior Research Group, Genetics of Childhood Brain Malformations, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany. (42)Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, 26129 Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, 26129 Oldenburg, Germany. (43)Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy. (44)GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA. (45)Unit of Child Neuropsichiatry, Department of Clinical and Surgical Neurosciences and Rehabilitation, IRCCS Giannina Gaslini, Genoa 16147, Italy. (46)Australian Regenerative Medicine Institute, Monash University, Clayton, VIC 3168, Australia. (47)Pediatric Neurology and Muscular Diseases Unit, IRRCS Istituto Giannina Gaslini, 16148 Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16142 Genoa, Italy. (48)Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16142 Genoa, Italy; Unit of Medical Genetics, IRRCS Istituto Giannina Gaslini, 16147 Genoa, Italy. (49)Departments of Pediatrics and Medicine, Columbia University, New York, NY 10032, USA. (50)Department of Neurology, Cook Children's Medical Center, Fort Worth, TX 76104, USA; Department of Pediatrics, University of North Texas Health Science Center, Fort Worth, TX 76107, USA. (51)Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5006, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia. (52)Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5006, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia; South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia. (53)Brain and Mitochondrial Research Group, Murdoch Children's Research Institute, Melbourne Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, NSW 2006, Australia. (54)Yale Center for Genome Analysis, Yale University, New Haven, CT 06520, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA. (55)Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. (56)Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. (57)Department of Paediatrics, Monash University, Melbourne, VIC 3168, Australia. (58)Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany. (59)Department of Otolaryngology - Head and Neck Surgery, Tübingen Hearing Research Centre, Eberhard Karls University Tübingen, 72076 Tübingen, Germany. (60)Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA. (61)Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tuebingen, Germany; Centre for Rare Diseases, University of Tübingen, 72074 Tuebingen, Germany. (62)Department of Paediatrics, Adolescent Medicine and Neonatology, Munich Clinic, Schwabing Hospital and Technical University of Munich, School of Medicine, 80804 Munich, Germany. (63)Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD 21201, USA; Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA. Electronic address: sriazuddin@som.umaryland.edu. (64)Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ 85016, USA; Departments of Child Health, Neurology, Cellular, and Molecular Medicine and Program in Genetics, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, USA. Electronic address: kruerm@arizona.edu.
4,178
A combination of which two drugs was tested in the IMbrave150 trial?
IMbrave150 trial tested a combination of atezolizumab and bevacizumab for advanced hepatocellular carcinoma.
[33139264, 34245216, 34522691, 34377156, 34051880, 34798793, 33442538, 33213161, 34189869, 34167423, 33663220, 34853653, 34771637, 32984090, 32349374, 33549983]
4,589
AIM: A clinical trial (IMbrave150) indicated the efficacy and safety of atezolizumab plus bevacizumab for patients with unresectable hepatocellular carcinoma (HCC). In this study, we evaluated this therapeutic combination in a real-world setting, with a focus on patients who did not meet the IMbrave150 eligibility criteria. METHODS: In this multicenter study, patients with unresectable HCC treated with atezolizumab plus bevacizumab between October 2020 and May 2021 were screened. In patients who did not meet IMbrave150 eligibility criteria, treatment responses and safety at 6 and 12 weeks were evaluated. RESULTS: Atezolizumab plus bevacizumab was initiated in 64 patients, including 46 patients (71.9%) who did not meet IMbrave150 eligibility criteria. Most of these patients had a history of systemic therapy (44/46). The objective response rate and disease control rate observed using Response Evaluation Criteria in Solid Tumors 1.1 were 5.2% and 82.8% at 6 weeks and 10.0% and 84.0% at 12 weeks, respectively; these rates were similar between patients who met and did not meet the IMbrave150 criteria. Ten patients experienced progressive disease (PD) at 6 weeks. Portal vein tumor thrombosis was significantly associated with PD (p = 0.039); none of the 15 patients with hepatitis B virus-related HCC experienced PD (p = 0.050). The most common adverse events of grade 3 or higher were aspartate aminotransferase elevation (n = 8, 13.8%) and the safety profile was similar between patients who met and did not meet the IMbrave150 criteria. CONCLUSION: Most patients treated with atezolizumab plus bevacizumab did not meet the IMbrave150 criteria; however, the combination therapy showed good safety and efficacy at the early treatment phase. Portal vein involvement is considered one of the most fearful complications of hepatocellular carcinoma (HCC). Portal vein tumor thrombosis (PVTT) is associated with aggressive tumor biology (high grade), high tumor burden (number and size of lesions), high levels of serum markers (AFP), poor liver function (deranged LFT), and poor performance status of patients. The Barcelona Clinic Liver Cancer staging system places HCC patients with PVTT in advanced stage (BCLC Stage-C). This group contains a fairly heterogeneous patient population, previously considered candidates for palliative systemic therapy with sorafenib. However, this provided modest overall survival (OS) benefit. The results of a recent Phase III (IMbrave150) trial favor the combination of atezolizumab and bevacizumab over sorafenib as a standard of care in advanced unresectable HCC. While only lenvatinib proved to be non-inferior against sorafenib in a phase III (REFLECT trial), regorafenib (RESORCE trial), ramucirumab (REACH-2), and cabozantinib (CELESTIAL) have been approved second-line therapy in phase III clinical trials. Recently, the data on the prospect of other modalities in the management of HCC with PVTT is mounting with favorable results. Targeting multiple pathways in the HCC cascade using a combination of drugs and other modalities such as RT, TACE, TARE, and HAIC appear effective for systemic and loco-regional control. The quest for the ideal combination therapy and the sequence set is still widely unanswered and prospective trials are lacking. With the armament of available therapeutic options and the advances and refinements in the delivery system, down-staging patients to make them eligible for curative resection has been reported. In a rapidly evolving treatment landscape, performing surgery when appropriate, in the form of LR and even LT to achieve cure does not seem farfetched. Likewise, adjuvant therapy and prompt management of the recurrences holds the key to prolong OS and DFS. This review discusses the management options of HCC patients with PVTT. In light of positive efficacy and safety findings from the IMbrave150 trial of atezolizumab plus bevacizumab, this novel combination has become the preferred first-line standard of care for patients with unresectable hepatocellular carcinoma (HCC). Several additional trials are ongoing that combine an immune checkpoint inhibitor with another agent such as a multiple kinase inhibitor or antiangiogenic agent. Therefore, the range of first-line treatment options for unresectable HCC is likely to increase, and healthcare providers need succinct information about the use of such combinations, including their efficacy and key aspects of their safety profiles. Here, we review efficacy and safety data on combination immunotherapies and offer guidance on monitoring and managing adverse events, especially those associated with atezolizumab plus bevacizumab. Because of their underlying liver disease and high likelihood of portal hypertension, patients with unresectable HCC are at particular risk of gastrointestinal bleeding, and this risk may be exacerbated by treatments that include antiangiogenic agents. Healthcare providers also need to be alert to the risks of proteinuria and hypertension, colitis, hepatitis, and reactivation of hepatitis B or C virus infection. They should also be aware of the possibility of rarer but potentially life-threatening adverse events such as pneumonitis and cardiovascular events. Awareness of the risks associated with these therapies and knowledge of adverse event monitoring and management will become increasingly important as the therapeutic range broadens in unresectable HCC. INTRODUCTION: The treatment algorithm of advanced hepatocellular carcinoma (HCC) has evolved since the introduction of immunotherapy. The IMbrave150 trial set atezolizumab-bevacizumab as a new standard-of-care first-line treatment for unresectable HCC patients. However, for patients with intermediate or advanced stage with portal vein thrombosis but without distant metastases, 90Yttrium transarterial radioembolization (90Y-TARE) is considered the treatment of choice. AREAS COVERED: We discuss the main evidence regarding the use of 90Y-TARE in HCC, the recent progress of immunotherapy in this tumor, and the preclinical rationale of combining VEGF blockade with the other two treatment strategies. EXPERT OPINION: HCC has an extremely heterogeneous tumor immune microenvironment. This may explain the inconsistent outcomes obtained with immune-checkpoint inhibitors. The identification of patients who could benefit most from immunotherapy is crucial; however, reliable markers of response are lacking. Radiation therapy and VEGF inhibition have an established synergism with immunotherapy, mainly linked to enhanced antigen presentation and reduced immunosuppressive immune infiltrate. Combining an immune-checkpoint inhibitor with VEGF blockade and 90Y-TARE might hence overcome primary resistances observed when each of these treatments is administerd alone. Systemic therapy for hepatocellular carcinoma (HCC) has changed markedly since the introduction of the molecular targeted agent sorafenib in 2007. Sorafenib increased the available treatment options for patients with extrahepatic spread and vascular invasion and improved survival in patients with advanced HCC; however, various shortcomings such as low response rates and relatively high toxicity (e.g., hand-foot skin reaction) prompted concerted efforts aimed at developing new molecular targeted agents to provide more treatment options and second-line agents for patients with disease progression or intolerance to sorafenib. Despite many attempts to develop new drugs between 2007 and 2016, all first-line and second-line clinical trials conducted during this period failed. However, between 2017 and 2019, 4 drugs (lenvatinib as a first-line agent and regorafenib, cabozantinib, and ramucirumab as second-line agents) emerged in quick succession from clinical trials and became available for clinical use. In addition, nivolumab and pembrolizumab were approved as second-line agents after sorafenib. A recent phase III trial (IMbrave150) showed that combination immunotherapy with atezolizumab plus bevacizumab increases overall survival compared with sorafenib therapy; Food and Drug Agency already approved this combination therapy, and worldwide approval is expected soon. This review describes the recent advances in systemic therapy and the use of tyrosine kinase inhibitors (sorafenib, lenvatinib, regorafenib, and cabozantinib), monoclonal antibodies (ramucirumab and bevacizumab), and immune checkpoint inhibitors (nivolumab, pembrolizumab, and atezolizumab) in elderly patients and the similarity of their efficacy and safety profiles to those in the general population. Hepatocellular carcinoma remains a serious global disease. Its incidence is increasing. Standard procedures have been developed for each stage. The complexity of this disease shows that the selection of patients in stage 0/A for different types of surgical treatment is very complicated. Treatment methods of stage B, especially locoregional treatment represented by TACE (transarterial chemoembolization or radioembolization of TARE), radiofrequency ablation and others, move freely to lower and higher stages as adjunctive therapy. Lenvatinib can replace TACE with equal efficacy in cases where locoregional treatment cannot be used. Until 2016, the only systemic treatment option for stage C was sorafenib. Lenvatinib became a second-line drug to show non-inferiority to sorafenib in OS. Retrospective analyzes revealed that patients who responded to the treatment with lenvatinib or sorafenib had a median survival of over 22 months. Sequential treatment with sorafenib and regorafenib in the RESOURCE study with a median survival of more than 24 months was similar. Ramucirumab was effective only in patients with high AFP levels. The study demonstrated the importance of selecting patients according to prognostic factors (extrahepatic spread and vascular invasion). Second-line cabozantinib has shown the same benefit as regorafenib. In the second line, immunotherapy represented by anti PD-1 antibodies nivolumab and pembrolizumab was used. Sequential administration after sorafenib prolonged the median overall survival of about 22 months. We currently have sorafenib and lenvatinib in the first line, regorafenib, cabozantinib, ramucirumab (AFP 400 &#956;g/L), pembrolizumab and nivolumab in the second line. The possibilities of monotherapy have been exhausted. The discovery of a synergistic effect of angiogenesis inhibitors, which convert a cold tumor into a hot one and facilitate the efficacy of anti-PD-1 / anti-PDL-1 antibodies, has led to a highly effective combination therapy. In study IMbrave150, the combination of atezolizumab and bevacizumab was successfully used compared to sorafenib in the first-line treatment. Additional studies are currently underway using other tyrosin kinase inhibitors - regorafenib, lenvatinib and cabozantinib - in combination with nivolumab, ipilimumab and pembrolizumab. This development of treatment at all stages evoked with renewed urgency the need to find a suitable way to search for the early stages of HCC and to create a more effective system for selecting patients for the most appropriate treatment. Introduction: The treatment of unresectable hepatocellular carcinoma (HCC) has radically changed after the approval of the combination of atezolizumab plus bevacizumab as first-line treatment. A strong preclinical rationale exists to support the combination of bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody (mAb), and atezolizumab, an anti-programmed death ligand 1 mAb. The efficacy of the combination was first assessed in the phase Ib GO30140 study, and the combination was then proven superior to the prior standard of care, sorafenib, in the phase III IMbrave150 trial.Areas covered: This article focuses on the mechanism of action of atezolizumab and bevacizumab, their synergistic action, and the two clinical trials leading to approval. We also collected the body of post-hoc analyses and meta-analyses to help guide the decision-making process in terms of patient selection and subsequent treatments.Expert opinion: Atezolizumab plus bevacizumab are the current standard of care for first-line treatment of unresectable or metastatic HCC and treatment-naïve patient should be treated with the combination, unless contraindications to the drugs. Since all the available agents for further lines of treatment have been approved for sorafenib-pretreated patients, prospective trials, post-hoc analyses, and real-world data assessing valid treatment sequencing are strongly needed. Atezolizumab plus bevacizumab combination therapy was approved worldwide for use in 2020. A 30% objective response rate with 8% complete response (CR) was achieved in a phase 3 IMbrave150 trial. Here, the change in the treatment strategy for hepatocellular carcinoma (HCC) using atezolizumab plus bevacizumab combination therapy is reviewed. The phase 3 IMbrave150 clinical trial was successful because of the direct antitumor effect of bevacizumab, which shifted the suppressive immune microenvironment to a responsive immune microenvironment, in addition to its synergistic effects when combined with atezolizumab. The analysis of CR cases was effective in patients with poor conditions, particularly tumor invasion in the main portal trunk (Vp4), making the combination therapy a breakthrough for HCC treatment. The response rate of the combination therapy was 44% against intermediate-stage HCC. Such a strong tumor-reduction effect paves the way for curative conversion (ABC conversion) therapy and, therefore, treatment strategies for intermediate-stage HCC may undergo a significant shift in the future. As these treatment strategies are effective in maintaining liver function, even in elderly patients, the transition frequency to second-line treatments could also be improved. These strategies may be effective against nonalcoholic steatohepatitis-related hepatocellular carcinoma and WNT/β-catenin mutations to a certain degree. For over a decade, sorafenib remained the only systemic agent with proven clinical efficacy for patients with advanced hepatocellular carcinoma (HCC). Recent years have seen a proliferation of agents. In the first line, lenvatinib was found to be non-inferior to sorafenib in terms of overall survival (OS), with significantly better progression-free survival and objective response rate. Meanwhile, encouraging efficacy signals were observed in phase I/II studies of immune checkpoint inhibitors as monotherapy in HCC. Although subsequent phase III trials failed to demonstrate statistically significant benefit in OS, other clinically meaningful outcomes were observed, including long-term disease control with a favorable toxicity profile. In addition, a synergistic response has been postulated based on the interplay between antiangiogenic molecular targeted agents and immunotherapy. On this basis, interest has turned toward combination strategies of immunotherapy with these standard-of-care medications in the hope of improving treatment efficacy for advanced HCC, while maintaining tolerable safety profiles. Indeed, preliminary results from phase I studies of lenvatinib plus pembrolizumab and atezolizumab plus bevacizumab have proved favorable, prompting phase III investigations in the frontline setting, and for atezolizumab plus bevacizumab, these positive findings have been substantiated by recent reporting of phase III data from IMbrave150. In this review, we will present the currently available data on combination therapy atezolizumab plus bevacizumab in advanced HCC, and compare these findings to other promising combination treatments, most notably that of lenvatinib plus pembrolizumab.
4,179
Is ALS a heritable disease?
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder of the motor system. The etiology is still unknown and the pathogenesis remains unclear. ALS is familial in the 10% of cases with a Mendelian pattern of inheritance.
[31959876, 33027627, 34587215, 32391572, 34025336]
4,590
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease. The majority of cases are sporadic (sALS), while the most common inherited form is due to C9orf72 mutation (C9ALS). A high burden of inclusion pathology is seen in glia (including oligodendrocytes) in ALS, especially in C9ALS. Myelin basic protein (MBP) messenger RNA (mRNA) must be transported to oligodendrocyte processes for myelination, a possible vulnerability for normal function. TDP43 is found in pathological inclusions in ALS and is a component of mRNA transport granules. Thus, TDP43 aggregation could lead to MBP loss. Additionally, the hexanucleotide expansion of mutant C9ALS binds hnRNPA2/B1, a protein essential for mRNA transport, causing potential further impairment of hnRNPA2/B1 function, and thus myelination. Using immunohistochemistry for p62 and TDP43 in human post-mortem tissue, we found a high burden of glial inclusions in the prefrontal cortex, precentral gyrus, and spinal cord in ALS, which was greater in C9ALS than in sALS cases. Double staining demonstrated that the majority of these inclusions were in oligodendrocytes. Using immunoblotting, we demonstrated reduced MBP protein levels relative to PLP (a myelin component that relies on protein not mRNA transport) and neurofilament protein (an axonal marker) in the spinal cord. This MBP loss was disproportionate to the level of PLP and axonal loss, suggesting that impaired mRNA transport may be partly responsible. Finally, we show that in C9ALS cases, the level of oligodendroglial inclusions correlates inversely with levels of hnRNPA2/B1 and the number of oligodendrocyte precursor cells. We conclude that there is considerable oligodendrocyte pathology in ALS, which at least partially reflects impairment of mRNA transport. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. Amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disease involving the upper and lower motor neurons of the spinal cord, brainstem, and cerebral cortex. At least 30 genes have been implicated in familial ALS (fALS) and sporadic ALS (sALS). Kaneb et al. (2015) first carried out a large-scale sequencing study in ALS patients and identified two loss-of-function (LOF) variants in the GLE1 gene. The LOF mutation-induced disruption of RNA metabolism through the haploinsufficiency mechanism is implicated in ALS pathogenesis. A total of 628 ALS patients and 522 individuals without neurodegenerative disorders were enrolled in this study to explore the GLE1 gene contribution to ALS in the Chinese population. All 16 exons and the flanking intron of GLE1 were screened by Sanger sequencing. In total, we identified seven rare GLE1 coding variants, including one novel nonsense mutation and six rare missense mutations in 628 ALS patients. The frequency of GLE1 LOF mutations was 0.16% (1/628) among Chinese sALS patients, implying that it is an uncommon genetic determinant of ALS in Chinese patients. Additionally, the rare missense variants in the hCG1-binding domain of GLE1 impairing the distribution of the hGle1B isoform at the nuclear pore complex (NPC) region may be involved in the pathogenesis of ALS.
4,180
What is ARNIL?
Long noncoding RNA (lncRNA) antisense noncoding RNA in the INK4 locus (ANRIL) is involved in several human cancers.
[28251886]
4,591
Long noncoding RNA (lncRNA) antisense noncoding RNA in the INK4 locus (ANRIL) is involved in several human cancers. However, the role of ANRIL in renal cell carcinoma (RCC) remains unclear. This study aimed to explore whether, and how, ANRIL affects the progression of RCC. First, the expression of ANRIL in clinical tumor tissues and four kinds of RCC cell lines was evaluated. After transfection, cell viability, colony number, apoptosis, migration, and invasion were assessed. The expression of proteins related to apoptosis, epithelial-to-mesenchymal transition (EMT), and the β-catenin signaling pathway was then assessed. In addition, the effect of IWR-endo (β-catenin inhibitor) on cell viability, migration, and invasion, as well as β-catenin expression, was also evaluated. The results showed that ANRIL was highly expressed in RCC tissues and RCC cell lines. ANRIL significantly promoted cell proliferation, migration, invasion, and EMT but inhibited cell apoptosis. Additionally, the expression levels of β-catenin, Ki-67, glycogen synthase kinase 3β (GSK-3β), phosphorylated GSK-3β, T-cell transcription factor 4 (TCF-4), and leukemia enhancer factor 1 (LEF-1) were all markedly upregulated by ANRIL. The effect of ARNIL silencing was opposite to that of ANRIL overexpression. The effect of ARNIL on proliferation, migration, and invasion of RCC cells was found to be reversed by IWR-endo. In conclusion, ANRIL, which is highly expressed in RCC, acted as a carcinogen in RCC cells through the activation of the β-catenin pathway.
4,181
What is the indication of CPX-351?
CPX-351 has been approved by the US FDA and the EMA for the treatment of adults with newly diagnosed therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes.
[34256819]
4,592
BACKGROUND: CPX-351 (United States: Vyxeos®; Europe: Vyxeos® Liposomal), a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a synergistic 1:5 molar ratio, is approved by the US FDA and the EMA for the treatment of adults with newly diagnosed therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes. In a pivotal phase 3 study that evaluated 309 patients aged 60 to 75 years with newly diagnosed high-risk/secondary acute myeloid leukemia, CPX-351 significantly improved median overall survival versus conventional 7 + 3 chemotherapy (cytarabine continuous infusion for 7 days plus daunorubicin for 3 days), with a comparable safety profile. A Quality-adjusted Time Without Symptoms of disease or Toxicity (Q-TWiST) analysis of the phase 3 study was performed to compare survival quality between patients receiving CPX-351 versus conventional 7 + 3 after 5 years of follow-up. METHODS: Patients were randomized 1:1 between December 20, 2012 and November 11, 2014 to receive induction with CPX-351 or 7 + 3. Survival time for each patient was partitioned into 3 health states: TOX (time with any grade 3 or 4 toxicity or prior to remission), TWiST (time in remission without relapse or grade 3 or 4 toxicity), and REL (time after relapse). Within each treatment arm, Q-TWiST was calculated by adding the mean time spent in each health state weighted by its respective quality-of-life, represented by health utility. The relative Q-TWiST gain, calculated as the difference in Q-TWiST between treatment arms divided by the mean survival of the 7 + 3 control arm, was determined in order to evaluate results in the context of other Q-TWiST analyses. RESULTS: The relative Q-TWiST gain with CPX-351 versus 7 + 3 was 53.6% in the base case scenario and 39.8% among responding patients. Across various sensitivity analyses, the relative Q-TWiST gains for CPX-351 ranged from 48.0 to 57.6%, remaining well above the standard clinically important difference threshold of 15% for oncology. CONCLUSIONS: This post hoc analysis demonstrates that CPX-351 improved quality-adjusted survival, further supporting the clinical benefit in patients with newly diagnosed high-risk/secondary acute myeloid leukemia. Trial registration This trial was registered on September 28, 2012 at www.clinicaltrials.gov as NCT01696084 ( https://clinicaltrials.gov/ct2/show/NCT01696084 ) and is complete.