bluuebunny/crossref_metadata_2025 huggingface dataset:
Intravenous prostanoids in systemic sclerosis-associated pulmonary arterial hypertension: a single-centre experience
Authors: Vlachou Maria , Fayed Hossam , Dawson Adele , Reddecliffe Sally , Stevenson Alexander , Thomson Ross J , Schreiber Benjamin Emmanuel , Coghlan J Gerry
Published: June 2021

Objectives

The current study evaluates survival rates among SSc-associated pulmonary arterial hypertension (SSc-PAH) patients on i.v. prostanoids, and short-term impact of i.v. prostanoids on clinical and haemodynamic parameters.

Methods

Baseline demographics, invasive and non-invasive data, European Society of Cardiology (ESC) score and REVEAL score of 81 SSc-PAH patients (median age 61 years, interquartile range 54–67 years, 84% females) were prospectively recorded, from November 2006 till November 2020, before initiation of i.v. prostanoids, and at first formal reassessment. Survival data were retrieved from National Health Service Spine and hospital databases.

Results

Significant improvements in clinical and haemodynamic parameters in response to i.v. prostanoid therapy were documented. Functional class (FC) (16.6% improved by 1FC, P =0.041), mean pulmonary arterial pressure (−6.5 mmHg, P =0.036), pulmonary vascular resistance (−2.6 WU, P =0.012), cardiac index (Q/m2) (+0.7 l/min/m2, P =0.003) and mixed venous oxygen saturation (SvO2) (+3%, P =0.036) improved. Estimated survival for CTD-PAH patients on i.v. prostanoids was 64%, 31% and 18%, at 1 year, 3 years and 5 years, respectively. Independent baseline predictors of mortality were older age (HR: 1.043, 95% CI: 1.011–1.075, P =0.007), higher N-terminal pro-brain natriuretic peptide levels (HR: 2.191, 95% CI: 1.131–4.243, P =0.020), and lower SvO2 levels (HR: 0.962, 95% CI: 0.926–0.998, P =0.039). High ESC risk or high and very high REVEAL score was associated with significantly worse survival compared with patients with lower risk scores, both at baseline and when reassessed after a median of 6.5 months.

Conclusions

Survival among SSc-PAH patients on i.v. prostanoids remains poor, risk scoring at baseline and after 6.5 months of therapy improves prognostication.
The Pristimantis trachyblepharis species group, a clade of miniaturized frogs: description of four new species and insights into the evolution of body size in the genus
Authors: Zumel Daniel , Buckley David , Ron Santiago R
Published: June 2021

Species richness in the genus Pristimantis is underestimated due to the existence of morphologically cryptic species. This is worsened by the low sampling effort and the lack of studies using genetic markers. Here, we use molecular and morphological data to determine the phylogenetic relationships of a clade of Pristimantis distributed throughout montane tropical forests in the eastern Andes, from central Ecuador to northern Perú. We name this clade the Pristimantis trachyblepharis species group. Our results show that it comprises nine species, of which four are formally described and five are new. Four of these undescribed species are formally described here. The group is composed of miniaturized species, such as Pristimantis nanus sp. nov., currently the smallest known species of the genus and the smallest vertebrate in Ecuador. As a first approach to understanding the evolutionary origin and implications of body-size reduction in Pristimantis, we here study the phylogenetic signal and evolutionary trends of body size within the genus. We also provide the first record of P. aquilonaris in Ecuador and we show, for the first time, the phylogenetic position of P. albujai, P. aquilonaris, P. minimus and P. trachyblepharis, which are also members of the P. trachyblepharis species group.
Down‐regulation of MnSOD via Sirt1/FoxO3a complex increase oxidative stress with cardiac overexpression of Type 5 Adenylyl Cyclase
Authors: Lai Lo , Yan Lin , Hu Che‐Lin , Gao Shumin , Iwatsubo Kosaku , Ishikawa Yoshihiro , Sadoshima Junichi , Vatner Stephen F. , Vatner Dorothy E.
Published: June 2021

We examined the stress of chronic (7 days) isoproterenol (ISO) stimulation 60mg/kg/day in 3–5 month AC5 Tg mice and WT littermates. Over 30% Tg mice died after day 3 while none of the WT mice died (n=12/group). Oxidative stress induced by chronic ISO stimulation was detected by 8‐Hydroxy‐2′‐deoxyguanosine (8‐OHdG) staining and AC5 Tg hearts showed 27% more positive staining than WT. To further examine whether AC5 Tg mice are less tolerant to oxidative stress, we injected paraquat (PQ), an oxidative stress inducer, and again more positive 8‐OHdG staining was observed in AC5 Tg mice hearts than AC5 KO mice, while the anti‐oxidant MnSOD protein was 40% lower in AC5 Tg than WT. We further hypothesized that inhibition of AC5 activates Sirt1 and FoxO3a, key transcription regulators of MnSOD. Luciferase test showed 3 fold higher FoxO3a transcriptional activity in AC5 knockdown myocytes. Protein expression of MnSOD was 40% decreased in neonatal myocytes infected by both ad‐AC5‐shRNA and ad‐Sirt1‐shRNA compared with AC5 knockdown myocytes. These data suggest that AC5 inhibits the Sirt1/FoxO3a complex thus down‐regulating MnSOD expression, and consequently increasing oxidative stress.
Intranasal Theophylline: A Novel Method to Treat Patients with Smell Loss (Hyposmia)
Authors: Henkin Robert I. , Gouliouk Vasily , Schultz Mike , Minnick Laura
Published: June 2021

While the oral phosphodiesterase (PDE) inhibitor theophylline has proven useful in the treatment of hyposmia its efficacy has been limited by its side effects, its slow action to improve olfactory function requiring months of drug use and by development of drug resistance. To overcome these adverse effects an open label, single source clinical trial using intranasal theophylline was performed in 10 patients with hyposmia before and after both oral and intranasal theophylline. Intranasal theophylline was administered daily in each naris at a dose of 20μg of buffered drug through use of a clinically adapted syringe which delivered the drug into the mid‐upper nose. Patients were studied weekly for two weeks and then biweekly for four weeks. Both subjective and objective measurements of smell and taste function were obtained. After one week of intranasal drug eight of the 10 patients reported subjective improvement in both taste and smell function and appetite. Objective measurements with smell and taste function tests also improved in each of these patients. This improvement continued over the subsequent three weeks of the study. No side effects were experienced by any patient. Blood theophylline levels at the time of maximal smell and taste improvement were 0. After one week of discontinuing the intranasal drug two patients reported subjective diminution in smell function confirmed by objective smell and taste measurements whereas six patients maintained improvement for two months after intranasal theophylline was discontinued. This open label clinical trial suggests that intranasal theophylline is both safe and more effective than oral theophylline in the treatment of hyposmia.
The biological activity of proNGF is determined by the relative levels of TrkA and p75NTR receptors
Authors: Fahnestock Margaret , Ioannou Maria S. , Masoudi Raheleh
Published: June 2021

Nerve growth factor (NGF) regulates neuronal survival, differentiation and function and is found in CNS as the NGF precursor, proNGF. Whether proNGF is neurotrophic or apoptotic is controversial. NGF and proNGF bind the TrkA receptor which is responsible for cell survival and differentiation, and p75NTR, which can mediate apoptosis. ProNGF has a higher affinity for p75NTR while NGF has a higher affinity for TrkA. It is known that the ratio of TrkA to p75NTR can determine whether mature NGF signals cell survival or death. We show here that the ratio of TrkA to p75NTR also determines the fate of cells treated with proNGF. We used growth conditions, siRNA and knockouts to modulate TrkA levels in PC12 cells expressing both TrkA and p75NTR. We found that although proNGF is neurotrophic for cells expressing high levels of TrkA and moderate or low levels of p75NTR, proNGF induces apoptosis in cells expressing lower levels of TrkA and higher levels of p75NTR, while NGF is neurotrophic unless TrkA is eliminated. Thus, proNGF is more sensitive to relative TrkA/p75NTR levels than NGF. In conclusion, the biological activity of proNGF can be altered by modulating relative levels of TrkA and p75NTR, suggesting that proNGF is neurotrophic under normal circumstances, but that a shift in the balance between its two receptors, as occurs in neurodegenerative disease or injury, may alter proNGF signaling from cell survival to cell death. Support: Canadian Institutes of Health Research (CIHR) Grants MOP‐64382 and IAO‐94360 to MF, NSERC Scholarship to MSI, Ministry of Science of Iran Scholarship to RM.
Serine 575 accounts for difference in thiazide affinity between mammalian and flounder NCC
Authors: Castañeda‐Bueno Maria , Vazquez Norma , Hernandez Damian , Rodriguez‐Lobato Erika , Moreno Erika , Gamba Gerardo , Rodriguez‐Lobato Erika , Gamba Gerardo
Published: June 2021

Thiazide diuretics are recommended as the first line pharmacological therapy for the treatment of arterial hypertension. Little is known, however, about residues defining the binding and/or affinity for thiazide type diuretics into its protein target, the renal Na‐Cl cotransporter (NCC). We have previously shown that affinity for thiazides is higher in rat (rNCC) than in flounder (flNCC). A chimeric analysis approach between flNCC and rNCC showed that transmembrane regions (TM) 8–12 contain information defining the difference in metolazone affinity (Moreno et al. JBC 2006). In the present study, alignment analysis revealed that there are only 6 non‐conservative variations between flNCC and mammalian NCC in TM 8–12, located as follows: two in TM9, three in TM11, and one in TM12. We used site directed mutagenesis to generate rNCC containing flNCC residues and thiazide affinity was defined using Xenopus laevis oocytes in which wild type or mutant NCC activity was assessed by measuring 22Na+ uptake in the presence of increasing concentrations of metolazone. We observed that mutations in TM11 conferred rNCC an flNCC‐like affinity, which could be explained solely by the substitution of a single residue, the S575C. Supporting this observation, the substitution C576S conferred flNCC an rNCC‐like affinity. Interestingly, S575C mutation also rendered rNCC more active. Mutation of S575 in rNCC for other residues such as alanine, aspartate, and lysine did not alter metolazone affinity, suggesting that reduced affinity in flNCC could be due to the formation of a disulfide bond. We conclude that difference in metolazone affinity between rat and flounder NCC can be explained by a single residue.
Multidrug resistance P‐glycoprotein/ABCB1/MDR1 protects against apoptosis by reducing cellular ceramides (Cer) induced by cadmium (Cd)
Authors: Lee Wing‐Kee , Torchalski Blazej , Chakraborty Prabir K , Thévenod Frank
Published: June 2021

Cd damages the kidney by apoptosis, but chronic Cd exposure also leads to cancer. Previously, we showed Cd apoptosis mediated by ceramide‐calpain signaling (Lee, W.‐K., Am J Physiol Cell Physiol 2007), but also Cd‐induced upregulation of the multidrug resistance transporter P‐glycoprotein (MDR1) to promote kidney proximal tubule cell (PTC) survival (Thévenod, F., J Biol Chem 2000). The aim of the study was to investigate mechanisms of MDR1 dependent survival of Cd exposed cells. In MDR1 overexpressing kidney cells (MDR1‐MDCK), toxicity of 10–20 μM Cd and 10–50 μM C6 Cer (by MTT assay and nuclear staining) was significantly reduced by up to 75% and 60%, respectively, which was abolished by the MDR1 blocker PSC833. Electrical measurements (ECIS) of MDCK and MDR1‐MDCK monolayers ± Cd showed similar effects. Efflux of 109Cd was not enhanced in MDR1‐MDCK and unaffected by MDR1 inhibitors (PSC833, C219). A diacylglycerol kinase assay revealed lower basal total Cer levels in MDR1‐MDCK (0.31 ± 0.04 μM) than controls (0.49 ± 0.07 μM). Cer levels were increased by 67.2 ± 16.0% in MDCK but only a 21.9 ± 4.8% increase in MDR1‐MDCK by 3 h Cd. Furthermore, induction of MDR1 expression by Wnt signalling (transfection of β‐catenin and TCF4) reduced cell death by Cd in PTC. Rather than exporting Cd, MDR1 seems to confer its protective effects by reducing cellular Cer levels or by efflux of Cer metabolites.

Funded by DFG TH 345/10‐1 and TH 345/11‐1
Association of chronic kidney disease with mitochondrial dysfunction in the skeletal muscle
Authors: Yazdi Puya G. , Yang Jia‐Ying , Wang Ping H. , Vaziri Nasratola D.
Published: June 2021

Advanced chronic kidney disease (CKD) is associated with impaired exercise capacity, skeletal muscle dysfunction, and oxidative stress. Mitochondria are the primary source of production of energy and generation of reactive oxygen species (ROS). We hypothesized that skeletal muscle dysfunction and oxidative stress in CKD are, in part, due to impaired energy production and heightened ROS generation by mitochondria. Mitochondrial state 3 respiration (measured as the maximal rate of ADP conversion to ATP, using pyruvate and malate as substrates) and mitochondrial complex I enzyme activity were determined in the gastrocnemius muscle of male SD rats 14 weeks after 5/6 nephrectomy (CKD) or sham‐operation (control). The CKD group exhibited proteinuria, hypertension, azotemia, and reduced weight gain. This was associated with significant reduction (−39%) of state 3 mitochondrial respiration and a significant increase in the mitochondrial complex I enzyme activity. The latter is the first step in oxidative phosphorylation by catalyzing oxidation of reduced nicotinamide adenine dinucleotide (NADH→NAD+), a process which is linked to production of ROS. In conclusion, CKD results in impaired mitochondrial respiration, depressed energy production and increased ROS generation in the skeletal muscle. These events can simultaneously contribute to the reduction of exercise capacity and oxidative stress in CKD.
Evaluation of MRSA Detection By Genetic v/s Chromogenic v/s Conventional Methods in New Admission to SICU/TICU/NICU Units at Hamad Medical Corporation
Authors: Doiphode Sanjay , Thani Asma Al , Al‐Remaihi Hanan , Yagoob Aisha , Al‐Moklf Fatema
Published: June 2021

Methicillin‐resistant Staphylococcus aureus (MRSA) is usually acquired during exposure to hospitals and other healthcare facilities, and causes a variety of serious health care associated infections. The aim of this study is to evaluate, compare and detect MRSA using genetic, chromogenic and conventional methods in admission to SICU/TICU/NICU at Hamad Medical Corporation. A total of 30 specimens were collected from patients admitted to SICU/TICU/NICU and each specimen was performed in 4 different methods including 1‐ conventional method using: Mannitol salt agar (MSA), 2‐ chromogenic using CHROMagar and 2 genetic methods; 3‐Smart Cycler BD GeneOhm™ MRSA and 4‐ GeneXpert® MRSA Assay. The results indicated that MRSA was detected in 10% of the study population. The distribution of positive samples using MSA Vs CHROMagar Vs Gene OHM Vs GenXpert methods was as following: 28%, 18%, 27% and 27% respectively.

So we can conclude that traditional methods for screening of MRSA with the conventional and chromogenic methods are still useful to determine the type of MRSA and both methods are complementary to each others and introducing the genetic methods had a great advantage in solving problems facing the hospital with turnaround time.
Human Epidermal Neural Crest Stem Cells (hEPI‐NCSC)
Authors: Sieber‐Blum Maya , Clewes Oliver , Loughney Andrew , Murdoch Alison
Published: June 2021

EPI‐NCSC originate from the embryonic neural crest and reside in a postnatal location, the bulge of hair follicles. Here we report the characterization and directed differentiation of hEPI‐NCSC. Like mouse EPI‐NCSC, hEPI‐NCSC emigrate from bulge explants of human hair follicles. They are multipotent and express the neural crest stem cell signature genes, which we have determined for mouse EPI‐NCSC (Hu YF et al, 2006). hEPI‐NCSC can give rise to all major neural crest derivatives, including neurons, Schwann cells, bone/cartilage cells, smooth muscle cells, and melanoyctes. Like mouse EPI‐NCSC, hEPI‐NCSC express the iPS genes SOX2, MYC, KLF4, LIN28 at levels similar to human embryonic stem cells (hESC; H9 line). Unlike mouse EPI‐NCSC, hEPI‐NCSC also express Nanog at levels similar to hESC as determined by real‐time PCR. hEPI‐NCSC can be expanded ex‐vivo into millions of stem cells. They can undergo directed differentiation into several cell types, including dopaminergic neurons. In summary, hEPI‐NCSC are promising candidates for future cell‐based therapy and regenerative medicine. Supported by grant 22358 from the Medical Research Council (MSB) and grant K‐0903 from the Parkinson's Disease Society (MSB).
Fenofibrate (FEN), a peroxisome proliferator activated receptor alpha (PPAR α) agonist, decreases dietary fat absorption and alters triglyceride (TG) metabolism in enterocytes of mice
Authors: Uchida Aki , Slipchenko Mikhail N. , Cheng Ji‐Xin , Buhman Kimberly K.
Published: June 2021

FEN activates PPARα and lowers blood TG concentrations. The mechanism is complex and involves decreasing hepatic secretion of TG via increasing fatty acid oxidation (FAO) and increasing clearance of blood TG via lipolysis. We hypothesized that FEN may also lower blood TG conc. via altering dietary fat absorption and intestinal TG metabolism. We fed mice a high‐fat diet for 2 wks and then orally administered FEN (800 mg/kg bw/d) or vehicle (VEH) for 5 d and investigated TG metabolism in the small intestine. FEN effectively lowered fasting blood TG conc. compared to VEH (21±1 vs 27±2 mg/dL, P=0.02, n=7). Dietary fat absorption was lower in FEN compared to VEH mice as evidenced by fecal fat percent (10.7±0.6 vs 2.3±0.2% fat, P=0.003, n=4–5). Intestinal FAO was determined ex vivo by measuring the production of 3H2O from 3H‐oleate. FAO in FEN was 1.5 fold higher compared to VEH mice (P=0.03, n=11–12). TG storage was imaged by coherent anti‐Stokes Raman scattering microscopy. Very little to no TG storage was found in enterocytes of FEN compared to abundant TG storage in VEH mice. We determined TG secretion from enterocytes in chow fed mice orally administered FEN or VEH. We measured blood TG conc. before, 1, 2, and 3h post oil oral gavage. The AUC was interestingly, greater from FEN than VEH mice (P=0.045, n=7–10). These results confirm that FEN decreases dietary fat absorption and alters TG metabolism in enterocytes of mice.

Grant Funding Source: American Heart Association
The effect of a low glycemic index diet on gestational hyperglycemia: A pilot trial
Authors: Grant Shannan , Wolever Thomas MS , O'Connor Deborah L , Josse Robert G
Published: June 2021

The main objective of this study was to determine the effect of a low glycemic index (low‐GI) diet on fasting glucose, HbA1c and self monitored blood glucose (SMBG). Secondary outcomes included intervention feasibility, maternal weight gain and infant birth‐weight. Women (n=47) with gestational diabetes or impaired glucose tolerance of pregnancy were randomized to low‐GI (n=23) or control (n=24) diets and were followed from 28 weeks gestation until delivery. This study was conducted at St. Michael's Hospital, Toronto. Diet GI was significantly higher on control, 58 (95% CI:56,60) than low‐GI, 49 (47,51; p=0.001). Glycemic control improved in both groups (p<0.05) with no significant difference between groups. SMBG after breakfast was directly related to pre‐pregnancy BMI in the control but not the Low‐GI group (p=0.021). Mean infant birth weight on low‐GI was less than on control (not significant). Maternal weight gain was not significantly different between groups. Study foods were rated “good” by participants. Participants were willing to consume them post‐intervention. A low‐GI diet was accepted by participants and attenuated the relationship between pre‐pregnancy BMI and postprandial SMBG.
Australopithecus afarensis and the Evolution of the Human Cranial Base
Authors: Kimbel William , Rak Yoel
Published: June 2021

Differences in ape and human cranial base form are usually attributed to a combination of an enlarged brain, retracted face and upright locomotion in humans. Relative to the apes, the human foramen magnum is anteriorly inclined and, with the occipital condyles, is forwardly located on a broad, short and flexed base; the petrous bones are coronally rotated; the glenoid region is topographically complex; the nuchal lines low; and the nuchal plane horizontal. The proximate causes of these innovations are accessible through the fossil record, the only data source on the temporal pattern of trait evolution in the human lineage.

Australopithecus afarensis (3.7‐3.0 Ma) is the earliest hominin species in which the cranial base can be assessed comprehensively. It shows that in small‐brained, bipedal hominins the foramen magnum and occipital condyles are anterior, as in humans, but without the foramen's forward inclination. In some skulls this is associated with a short, broad base and an inferiorly rotated occipital – novelties shared with later australopiths and humans. In others, including a recently recovered female, a more primitive morphology is present: while the foramen and condyles reside anteriorly on a short base, the nuchal lines are high, the nuchal plane is steep, and the base is relatively narrow.

We explore implications for sexual dimorphism and functional integration in the hominin cranial base.
Nociceptive Sensory Neurons (NSNs) Promote Alveolar Macrophages' (AMs) Synthesis of Matrix Metalloproteinases (MMPs) during Cigarette Smoke (CS) via Releasing Substance P (SP)
Authors: Xu Junyang , Xu Fadi
Published: June 2021

CS up‐regulates AMs' MMP‐2, ‐9, and ‐12 expressions, contributing to the pathogenesis of COPD. Although SP released from NSNs' fibers in the lungs during CS is a key factor in producing pulmonary MMPs, its direct effect on AMs' synthesizing these MMPs is unknown. We asked if NSNs directly interact with AMs in promoting SP release and enhancing AMs' MMPs expression, especially during CS, in this study in vitro. AMs (MH‐S macrophages) and NSNs (50B11 neurons) were separate‐ or co‐cultured for 12 h without or with pretreatment of neurokinin 1 receptor (NK1R) antagonist (aprepitant and CP‐99,994) under control and CS condition, respectively. We found that: 1) under control, SP in supernatant and MMP‐12 rather than MMP‐2 and ‐9 in AMs were significantly higher in the co‐cultured preparation than the sum of the separate‐cultured preparations; 2) in the co‐cultured preparation, SP and MMP‐2, ‐9, and ‐12 expression were further increased by 4.5‐, 4.4‐, 8‐, and 2.4‐fold (P < 0.05), respectively, in 3 μg/ml CS‐treated preparation, compared to the control, with little change in the cells' viability; 3) MMPs were not detectable in NSNs at all conditions; and 4) NK1R antagonists strikingly reduced the CS's modulatory effects on the MMPs in the co‐cultured AMs by 30%–43%. Our results suggest an important role of SP in AMs' synthesis of MMPs induced by the interaction of NSNs and AMs, particularly during CS exposure.
Fatty acid intake and bone mineral density, structure and strength; measured by pQCT in young girls
Authors: Laudermilk Monica Janeene , Going Scott B , Thomson Cynthia A , Houtkooper Linda
Published: June 2021

Background

Diet may influence maximum growth rates and accrual of BMD during pre‐adolescence. In vivo, in vitro and human studies linking fat intake and bone status reveal biphasic effects dependent on fatty acid quantity and composition.

Objective

To assess the relationship of fatty acid intake and bone parameters in young girls.

Design

Cross‐sectional study of 363 girls age 8–12 y.

Methods

Girls completed the Harvard Youth/Adolescent Food Frequency Questionnaire. Bone parameters were measured by peripheral quantitative computed tomography (pQCT) in the non‐dominant leg.

Results

4th grade: Fat intake was a negative correlate of periosteal circumference, trabecular and cortical area, and bone strength. Polyunsaturated fat and ω6 were positive correlates of femur cortical density. Monounsaturated fat was a positive predictor of tibia trabecular area. 6th grade: ω6:ω3 intake was inversely associated with tibia trabecular and cortical area and periosteal circumference. ω6:ω3 was a negative correlate and predictor of femoral bone strength. Total fat, saturated fat, ω3 and ω6:ω3 predicted cortical densities, trabecular area, endosteal and periosteal circumferences of the tibia and femur.

Conclusion

Cross‐sectional fat intake is related to bone status measured by pQCT and can have a type dependent, regio‐specific impact that may vary through maturation. The Jump‐In study was funded by NIH: HD050775.

Grant Funding Source: NIH: HD050775
SNAT2 and LAT1 transporter abundance is developmentally regulated in skeletal muscle of neonatal pigs
Authors: Suryawan Agus , Gazzaneo María C. , Almonaci Rosemarie D. , Nguyen Hanh V. , Torrazza Roberto Murgas , Davis Teresa A.
Published: June 2021

Previously we demonstrated that the insulin‐ and amino acid–induced activation of the mammalian target of rapamycin complex 1 (mTORC1) is developmentally regulated in neonatal pigs. Recent studies have indicated an important role of the System A transporters (SNAT2 and SLC1A5) and the L transporter (LAT1) in intracellular accumulation of essential amino acids, such as leucine, and in mTORC1 activation. This study aimed to determine the effects of age and the post‐prandial rise in insulin and amino acids on the abundance and activation of SNAT2, SLC1A5 and LAT1. Overnight fasted 6‐ and 26‐day‐old pigs were infused for 2 h with saline, insulin, or amino acids to achieve fed levels. The abundance of SNAT2 and LAT1, but not SLC1A5, was significantly higher in muscle of 6‐ than in 26‐d‐old pigs. The activation of SNAT2, determined by transporter translocation to the plasma membrane, was unaffected by 2 hr infusion of amino acids or insulin. To determine the acute effects of feeding, SNAT2 activation was determined 0, 30, and 60 min after a complete meal. Feeding had no effect on SNAT2 activation at any time point suggesting that SNAT2 activation in vivo may be short‐lived. In conclusion, the elevated abundance of SNAT2 and LAT1 is likely to play a significant role in the enhanced amino acid‐induced activation of mTORC1 in neonatal pigs (Supported by NIH grants AR‐44474 and USDA/ARS 6250510000‐33).
Tart cherry intake reduces plasma and tissue inflammation in obesity‐prone rats
Authors: Seymour E Mitchell , Urcuyo‐Llanes Daniel , Bolling Steven F , Bennink Maurice R
Published: June 2021

Obesity involves chronic inflammation, which may contribute to cardiovascular disease Previous studies show that diet provision of anthocyanin‐rich extracts can reduce inflammation. Our group tested the dietary relevance of these findings using a whole‐foods approach with anthocyanin‐rich tart cherries. We compared the effects of tart cherry‐enriched diets in obesity‐prone Zucker Fatty rats fed a pair‐fed a higher fat diet (47% of kcal) supplemented with either 1% freeze‐dried tart cherry powder or 0.85% extra carbohydrate (1:1 glucose:fructose). After 90 days, cherry intake significantly reduced serum glucose, triglycerides, cholesterol, and plasma tumor necrosis factor‐α and interleukin‐6. Cherry intake also reduced body weight, total fat mass and abdominal fat pad weight while increasing lean body mass. In addition, cherry decreased abdominal fat pad NFκB activity, TNF‐α mRNA and TNF‐α protein. Finally, cherry intake reduced cardiac NFκB activity, TNF‐α mRNA and TNF‐α protein. In obese rats, tart cherry‐enriched diets reduce plasma inflammation, abdominal fat inflammation, and cardiac inflammation, known risk factors for cardiovascular disease.
Interleukin‐18 disrupts tight junctions in gastric and intestinal epithelial monolayers
Authors: Lapointe Tamia K , Hirota Christina L , Menard Daniel , MacNaughton Wallace K , Buret Andre G
Published: June 2021

Chronic inflammatory conditions of the gut including Helicobacter pylori gastritis and the inflammatory bowel diseases ulcerative colitis and Crohn's disease are characterized by compromised epithelial barrier function and tight junction alterations. Both conditions are associated with increased mucosal levels of the proinflammatory cytokine interleukin‐18 (IL‐18). The role of IL‐18 in epithelial barrier defects has yet to be investigated.

AIM

This study assessed the effect of IL‐18 on gastric and intestinal epithelial barrier structure and function.

RESULTS

Human gastric (HGE‐20) and colonic (Caco‐2) epithelial monolayers challenged with IL‐18 showed redistribution of tight junctional proteins claudin‐4 and occludin. This was accompanied by a matrix metalloproteinase‐9 independent decrease in claudin‐4 and occludin expression. Despite disrupting epithelial tight junction structure, IL‐18 treatment did not affect apical‐to‐basolateral fluxes of 3000MW FITC‐dextran, suggesting no effect of IL‐18 on transepithelial permeability to small molecules.

CONCLUSION

These findings demonstrate that IL‐18 disrupts epithelial barrier structure in gastric and intestinal monolayers without affecting transepithelial permeability. Future studies will assess the significance of IL‐18 ‐mediated tight junction disruption with respect to leukocyte transmigration across epithelia. Funded by CIHR.
PAF receptor deficiency results in increased PMA‐induced inflammation and augmented chemical carcinogenesis
Authors: Konger Raymond Lloyd , Kozman Amal , Sahu Ravi P , Travers Jeffrey B
Published: June 2021

Platelet activating factor (PAF) is a well known proinflammatory mediator. Previous studies have shown that PAF‐like ligands are formed by various oxidative stressors. Given that phorbol esters are potent inducers of both inflammation and oxidative stress, we sought to determine whether PAF acts as a mediator of topical phorbol ester–induced inflammation and subsequent neoplastic development. First, topical phorbol myristate acetate (PMA) induced the production of PAFR ligand in mouse skin. Next, relative to controls, mice lacking the PAFR (KO mice) exhibit an increase in chronic PMA application‐induced inflammation. This was seen as increased skin thickness, myeloperoxidase expression, and increased inflammatory cytokine/chemokine expression. Next, using a DMBA/PMA carcinogenesis protocol, we show that KO mice exhibit a two‐fold increase in tumor multiplicity along with an increase in squamous cell carcinomas (SCC) relative to benign papillomas (< 1% SCC in wildtype vs 32% SCCs in KO mice). The above data suggests that the PAF‐R may play a paradoxical role in suppressing inflammation associated with chronic PMA application, thus indicating a possible paradigm shift in our understanding of the role of PAF in regulating inflammation. Moreover, PAF may play an important protective role in cutaneous neoplastic development. Supported by the National Institutes of Health and the Prevent Cancer Foundation.
Molecular mechanism underlying LPS‐induced generation of reactive oxygen species in macrophages
Authors: Li Liwu , Maitra Urmila , Singh Neeraj , Gan Lu
Published: June 2021

The generation of reactive oxygen species (ROS) by host macrophages plays a critical role during the pathogenesis of diverse inflammatory diseases. Bacterial lipopolysaccharide (LPS) triggers the expression of ROS through multiple mechanisms including the activation and induction of NADPH oxidase, as well as the suppression of anti‐oxidative enzymes involved in ROS clearance. However, the underlying molecular mechanisms are poorly defined. The objective of this study is to systematically define the molecular mechanisms underlying the induction of ROS by LPS in macrophages. Using bone marrow derived macrophages (BMDM) harvested from wild type (WT) or IRAK‐1 (interleukin‐1 receptor associated kinase 1) deficient mice, we observed that LPS induced significantly less ROS in IRAK‐1−/− macrophages, indicating that IRAK‐1 is critically involved in the induction of ROS. Mechanistically, we observed that IRAK‐1 is required for LPS‐induced expression of NOX‐1, a key component of NADPH oxidase, via multiple transcription factors including p65/RelA, C/EBPβ and C/EBPδ. On the other hand, we demonstrated that IRAK‐1 associated with and activated small GTPase Rac1, a known activator of NOX‐1 oxidase enzymatic activity. IRAK‐1 forms a close complex with Rac1 via a poly‐proline motif within the variable region of IRAK‐1. On the other hand, we also observed that IRAK‐1 is required for LPS‐mediated suppression of PPARα and PGC‐1α, nuclear factors essential for the expression of anti‐oxidative enzymes such as GPX3 and catalase. Consequently, injection of LPS causes significantly less plasma lipid peroxidation in IRAK‐1−/− mice compared to wild type mice. Taken together, our study reveals IRAK‐1 as a novel component involved in the generation of ROS induced by LPS. This study is supported by a grant from NIH (R01 AI64414).
An Anatomical Comparative Study of Lower Limb Discrepancy and Scoliosis
Authors: Santoriello Lisa Marie , Aibinder William Reuben , Pagano Anthony , Márquez Samuel
Published: June 2021

Lower limb (LL) discrepancy (LLD) and Scoliosis (S) are two conditions found within the general population that afflict a variety of polytypic individuals. This study compares tibial, femoral, and total LL length among scoliotic (S) and non‐scoliotic (NS) donor bodies (n=22) representing an urban population. Seven of the individuals exhibited various degrees of scoliosis. Femoral length was measured from the lateral condyle to the greater trochanter. Tibial length was measured from the medial malleolus to the medial condyle. Individual components of the left and right LL were compared within and between the S and NS groups. T‐tests revealed no significant LLD difference (p < 0.05) between S and NS groups or within a pooled sample. Despite a lack of significant differences found between S and NS groups in each of their individual bony components of the LL, no individual in the pooled sample was identically symmetrical in femoral or total LL length. Only one individual presented with a left and right tibia of equal length measuring 36.6 centimeters. These results suggest that the presence of LLD transcends scoliotic condition and may be the anatomical norm for humans. The biomechanical response to LLD on gait and posture remains unresolved and requires further investigation.

Grant Funding Source: AAA
Molecular modulation of the alpha‐subunit VISIT‐DG sequence in the catalytic sites of Escherichia coli ATP synthase
Authors: Ahmad Zulfiqar , Brudecki Laura E
Published: June 2021

F1Fo‐ATP synthase is the smallest known biological nanomotor, found from bacteria to man. This enzyme is responsible for ATP synthesis by oxidative or photophosphorylation in membranes of bacteria, mitochondria, and chloroplasts. Thus, ATP synthase is the fundamental means of cell energy production in animals, plants, and almost all microorganisms. A typical 70 kg human with a relatively sedentary lifestyle will generate around 2.0 million kg of ATP from ADP and Pi (inorganic phosphate) in a 75‐year lifespan. Pi binding is a primary step in ATP synthesis by ATP synthase, so understanding the molecular basis of Pi binding is an important goal. X‐ray structures of the catalytic sites show the highly conserved α‐subunit VISIT‐DG sequence in close proximity to the conserved phosphate binding residues αR376, βR182, βK155, and βR246 in the phosphate binding subdomain. Lately, we found that αSer‐347 of VISIT‐DG sequence is an additional, important residue involved in phosphate‐binding and transition state stabilization. In contrast, αGly‐351, although strongly conserved and clearly important for function, appears not to play a direct role. Further, through mutagenic modulation and biochemical characterization of αVal‐345, αIle‐346, αIle‐348, αThr‐349, and αAsp‐350, we have been able to identify their direct/indirect role in Pi binding, in maintaining structural integrity of the Pi binding pocket, and in function.
Displaced Conformational Equilibrium in a Piezophilic Cytochrome P450
Authors: Sineva Elena V , Halpert James R , Davydov Dmitri R
Published: June 2021

Cytochromes P450 from piezophilic bacteria living at extreme pressures provide a powerful tool for exploration of the substrate‐dependent conformational transitions in the enzyme, which involve large changes in hydration and are thus pressure‐sensitive. Cytochrome P450 of a deep‐sea bacteria Photobacterium profundum SS9 was cloned and expressed in E. coli. Purified P450‐SS9 was found to be predominantly in the high‐spin state. The enzyme was found to bind various substrates including fatty acids and their derivatives. The spin equilibrium could be displaced by substrate binding to either high‐spin (HS) or low‐spin (LS), depending on the structure. In contrast to all cytochromes P450 studied up to date, hydrostatic pressure failed to displace the spin equilibrium completely to the LS state in the substrate‐free P450‐SS9. Similar behavior is observed in HS‐complexes, whereas the spin equilibrium in the LS‐complexes becomes pressure‐sensitive. We also probed the accessibility of the heme pocket with H2O2–dependent heme depletion. The rate of this process, which was very slow in the substrate‐free enzyme and in HS‐complexes, is dramatically increased in LS‐complexes. These findings provide evidence of large‐scale changes in the openness and degree of hydration of the active site that are involved in the substrate‐dependent spin transitions in the enzyme. (Supported by NIH grant GM054995)
Determining Structural Differences in the Dark and Light States of AppA using Vibrational and Ultrafast Fluorescence Spectroscopy
Authors: Haigney Allison L , Kondo Minako , Stelling Allison , Lukacs Andras , Bacher Adelbert , Tonge Peter , Meech Stephen
Published: June 2021

The blue light using flavin (BLUF) domain proteins are a novel class of photosensors that bind flavin noncovalently in order to sense and respond to high intensity blue (450 nm) light. The transcriptional antirepressor AppA, is a BLUF photosensor that utilizes a non‐covalently bound flavin chromophore which is unable to undergo large scale structural change upon light absorption. This is in contrast to most photoreceptors which undergo structural reformations such as trans/cis isomerization upon irradiation. It is of great interest to understand how the BLUF protein matrix senses and responds to flavin photoexcitation. Light absorption is thought to result in alterations in a hydrogen bonding network that surrounds the flavin chromophore on the picosecond time scale. The excited photochemistry of wild‐type AppA and several mutants of AppA in which the hydrogen bonding network has been altered, has been analyzed using ultrafast (100 fs) time resolved fluorescence spectroscopy and picosecond time resolved infrared spectroscopy. Reconstitution of the protein with isotopically‐labeled flavin has permitted unambiguous assignment of the ground and excited state modes associated with the flavin C2=O and C4=O groups, and together the data provide a more detailed understanding of the photoexcitation mechanism.
SRF, a novel anti‐cancer drug, inhibits microtubule polymerization and dynamics and induces hyperphosphorylation of Bcl‐2 in cancer cells
Authors: Choi Bo‐Hwa , Feng Lin , Amaravadhi Harikishore , Bharatham Nagakumar , Prakash Ravi , Yoon Ho Sup
Published: June 2021

Microtubules, major components of highly dynamic cytoskeletal fibers, are involved in several cellular functions, including cell division, signaling, and trafficking, making them a suitable target for the development of chemotherapeutic drugs against cancer. Our recent structure‐based drug design efforts led us to discover a novel drug named Suprafenacine (SRF) that binds to microtubules. SRF inhibits the polymerization of tubulin and causes G2/M phase arrest, and induces the phosphorylation of Bcl‐2 in cancer cells, which are blocked by the treatment of JNK inhibitor SP600125, suggesting that JNK plays an important role in this event. SRF exerts selective cytotoxic profile and induces preferential apoptosis in cancer cells. Moreover, SRF is shown to overcome drug resistance of cancer cells and leads to antitumor activity in a mouse xenograft model. Taken together, our data suggest that SRF is a novel microtubule‐targeting anti‐cancer compound that perturbs microtubule dynamics and subsequently influences Bcl‐2, a central player in apoptotic regulation. Ministry of Health of Singapore Grant NMRC/1177/2008
The Role of Non‐Synonymous ZnT2 Gene Polymorphisms in Cellular Zn Homeostasis in Mammary Epithelial Cells
Authors: Seo Young Ah , Kelleher Shannon L
Published: June 2021

ZnT2 plays a major role in Zn export from the mammary gland into milk. Recently, we determined that ZnT2 is associated with secretory vesicles reflecting its role in Zn secretion during lactation. Herein, we identified two distinct single‐nucleotide polymorphisms (SNPs) in ZnT2 (SNP1: rs35235055, leucine to proline (Leu23Pro); SNP2: rs35623192, arginine to cysteine (Arg340Cys). We examined the localization and function of each SNP in cells generated to express mutants‐ and wild type‐HA fusion proteins. SNP1 was localized to the lysosome while SNP2 was localized to the Golgi. This mislocalization suggest that role of ZnT2 in Zn secretion might be affected. Importantly, FluoZin‐3 fluorescence (indicator of labile vesicular zinc pools) was significantly higher in cells expressing SNP1 (+ 35%) and SNP2 (+25%) compared with cells overexpressing wild type ZnT2. Moreover, Zn secretion was significantly lower in cells expressing SNP1 (−49%) and SNP2 (−28%) compared with cells overexpressing wild type ZnT2. Furthermore, expression of SNP1 was associated with decreased cytoplasmic Zn levels (−66%), suggesting that SNP1 depleted total cellular Zn pools. Taken together, our data indicate that SNPs in ZnT2 may result in significant differences in cellular Zn homeostasis in humans and suggest that dysregulation of mammary gland Zn metabolism may be implicated in human health and disease. Supported by NIH #HD058614 to SLK.

Grant Funding Source: NIH
Effects of consumption of honey, sucrose and glucose on satiety and postprandial metabolism in healthy subjects
Authors: Nemoseck Tricia , Cholish Dana , Petrisko Yumi , Kern Mark
Published: June 2021

We recently demonstrated that consuming a 240‐kcal portion of honey produces an attenuated glycemic response in healthy adults compared to glucose but not sucrose and that honey reduces food intake compared to sucrose in rats. The purpose of this study was to compare the effects of consuming honey, sucrose and glucose at a greater energy load on satiety and plasma glucose, insulin and ghrelin. In a randomized, crossover design, 14 healthy subjects consumed 400‐kcal solutions containing honey, sucrose or glucose following a 10‐hr fast. Visual analog scales for satiety assessment and fingerprick blood samples were collected over a 2‐hr period. Satiety area under the curve (AUC) and plasma ghrelin area over the curve did not differ significantly among the sweeteners consumed. Intake of honey resulted in lower (p≤.05) plasma glucose and insulin AUCs (mean ± SEM: −33.3±6.1% and −11.1%±1.6%, respectively) than the AUCs induced by glucose consumption (p≤.05). Consumption of honey elicited lower (p≤.05) plasma glucose AUC (−16.4%±6.2%) compared to sucrose but resulted in similar insulin AUCs. These results suggest that at the given energy load, honey promotes a potentially healthier response than sucrose and glucose with regard to postprandial glucose metabolism. However, there appears to be no difference in satiating power among honey, sucrose and glucose.

Sponsored by a grant from the American Heart Association
Impact of a 16‐week behavioral weight loss program on diet quality
Authors: LEE EUNKYUNG , WEBBER KELLY H
Published: June 2021

Background

Behavioral weight loss programs are effective for short‐term weight loss but there is a lack of literature which deals with the impact of these programs on changes in diet quality that they may produce. The Healthy Eating Index (HEI)‐2005 was developed as a summary measure of diet quality by U.S. Department of Agriculture.

Objective

To explore changes in participants’ diet quality, as measured by the HEI‐2005, over the course of a 16‐week Internet behavioral weight loss program.

Design, Setting, and Participants

A single‐center randomized controlled trial conducted from August 2008 to December 2008 in Lexington, KY. Sixty‐six women whose mean (SD) age was 48.6 (10.8) years and body mass index was 31.8 (3.7) kg/m2 completed all dietary measures.

Interventions

Participants received two face‐to‐face group sessions with a dietitian, at baseline and 4‐weeks, in addition to 16 weekly behavioral weight loss lessons delivered via an Internet website.

Main Outcome Measures

Dietary intake was measured using the 2005 Block food frequency questionnaire.

Results

Participants showed a significant reduction in energy intake (1854.2±771.7 Vs 1372.9±423.7; p<0.001), and a significant increase in diet quality score as measured by the HEI‐2005 (52.5±10.3 Vs 56.2±10.9; p =0.0016).

Conclusion

Participation in an Internet behavioral weight loss program significantly improved diet quality in adult women.

Funding Disclosure: Funding for this study was provided by startup funds of the second author.
Obesity is higher in male than female adolescents in Guadalajara, Mexico
Authors: Vasquez‐Garibay Edgar Manuel , Gutierrez‐Ruvalcaba Clara Luz , Romero‐Velarde Enrique , Troyo‐Sanroman Rogelio
Published: June 2021

With the purpose to compare the prevalence of obesity in males and females adolescents in a high school from the metropolitan area of Guadalajara, Mexico, a cross sectional randomly design, with 105 males and 105 females of 12 to 16 years old were included. They were healthy and authorized consent was obtained. Variables included: age, gender, BMI, tricipital and sub scapular skin fold, percent of body fat (%BF) (Slaughter's equation) and bioelectrical impedance analysis (BIA). A student T test, chi square, OR (confidence intervals 95%) and the Pearson coefficient for the correlation between the %BF obtained by the Slaughter equation and BIA methods were obtained. Mean age was 13.9 and 13.5 years for males and females. The %BF by slaughter's equation and BIA was significantly higher in females (29.9 and 26.9% respectively) than males (24.4 and 15.4%), (p<0.001). BIA tended to significantly overestimate the %BF in males (p<0.01). Both methods were highly correlated in females (r = 0.807) and males (r = 0.856). Percentage of overweight was similar in males and females (22 vs. 20%); but, the percentage of obesity was significantly higher (p = 0.037) in males (11.4%) than in females (3.8%). The %BF was higher in females and the frequency of obesity was higher in males. BIA seemed to overestimate %BF in males, although there are high correlations between slaughter equation and BIA in both genders.
Effect of cinnamon on postprandial glucose
Authors: Wright Cynthia B. , Calder Sarah , Humphries Laura
Published: June 2021

Controlling blood glucose (BG) is important because type 2 diabetes is a common and increasing problem among Americans. Previous research on the impact of cinnamon on BG has produced conflicting results. The objective of the present study was to investigate the impact of cinnamon supplements on BG concentration among healthy young adults (mean age 22.6 ± 3.3 years). Baseline fasting BG was measured before participants consumed a meal containing 76.25 g of carbohydrate and cinnamon capsules (0, 2, 3, 4, or 5 g) each day of a five‐day trial. BG was also measured 30 and 60 minutes post‐meal. Cinnamon supplements decreased the peak concentration of the BG curve in males (p=0.040) and in those with a family history of diabetes (p=0.026). Additional research on the impact of cinnamon supplementation on postprandial BG among individuals diagnosed with type 2 diabetes is warranted before health claims are made.