bluuebunny/crossref_metadata_2025 huggingface dataset:
Selectively upregulated microRNAs in pulmonary artery smooth muscle cells from patients with idiopathic pulmonary arterial hypertension
Authors: Pohl Nicole M. , Makino Ayako , Yuan Jason X.‐J.
Published: June 2021

Pulmonary vascular remodeling is a major cause for the elevated pulmonary vascular resistance in patients with idiopathic pulmonary arterial hypertension (IPAH). Downregulated voltage‐gated K+ (Kv) channels and upregulated TRPC channels have been demonstrated in pulmonary artery smooth muscle cells (PASMC) from IPAH patients. It is, however, unclear how these changes are regulated. microRNAs (miRNAs) are small noncoding RNAs that act as important regulators by post‐transcrptionally modulating protein expression. To determine if the phenotypic changes seen in IPAH‐PASMC could be due to miRNA regulation, we analyzed and compared miRNA expression through the application of a cancer‐related miRNA PCR microarray from SABiosciences. Among 89 miRNAs screened, 6 were significantly upregulated (e.g. miR‐222; its expression level is 3.5 fold higher in IPAH‐PASMC than in normal PASMC). Using bioinformatics to predict miRNA targets, we identified multiple potential targets including Kv channels (e.g., KNCA1, KCNC4, KCNH7, KCNK3, KCNJ2) and Ca2+‐activated K+ (KCa) channels (e.g., KCNMA1), as well as other targets that have been associated with ion channel function and regulation. We are now validating the importance of these miRNAs in IPAH‐PASMC and anticipate discovering how the observed molecular changes in Kv/KCa channels in IPAH PASMC might be regulated by miRNAs. NIH grants: HL 066012 and HL 098053.
Angiotensin II stimulates neural stem cell proliferation through Nox4‐generated superoxide
Authors: Topchiy Elena , Panzhinskiy Evgeniy , Das Mita , Zawada Michael
Published: June 2021

How reactive oxygen species (ROS) affect neural stem cell (NSC) self‐renewal is poorly understood, but might be important for normal development and during neurodegenerative conditions. We investigated whether production of superoxide via activation of NADPH oxidase (Nox) affects NSC proliferation. In the vascular smooth muscle cells, angiotensin II (Ang II) activates Nox‐driven superoxide generation to induce proliferation. We hypothesized that Ang II activates one of the Nox isoforms to regulate NSC self‐renewal. In a murine neural stem cell line, C17.2, Ang II (100nM) stimulated superoxide production detected by dihydroethidium (DHE) fluorescence. Ang II increased proliferation and an antioxidant N‐acetyl‐cysteine blocked Ang II‐induced increase in cell numbers. Confocal microscopy using DHE and a mitochondrial marker (MitoTracker) revealed that C17.2 cells contain two sources of ROS: mitochondrial and extramitochondrial, indicating that Nox might be involved. Nox4 was found to be constitutively expressed and Ang II increased protein levels of Nox4. SiRNA targeting Nox4 reduced Nox4 expression and attenuated Ang II‐induced ROS production and proliferation. Our findings suggest that Ang II‐induced proliferation of NSCs requires Nox4‐generated superoxide production. This mechanism might be important for normal and stress‐ or disease‐modified neurogenesis. Support: AA016654 and HL64917.
Role of brain nitric oxide in cardiovascular control of tegu lizards
Authors: Bicego Kenia C , Dantonio Valter , Toledo Ana G , Gargaglioni Luciane H , Abe Augusto S , Andrade Denis O
Published: June 2021

The aim of the present study was to determine if nitric oxide (NO) acting on the brain of the tegu lizard Tupinambis merianae presents an inhibitory effect on arterial blood pressure (ABP) and heart rate (HR) by reducing the sympathetic activity dependent on α adrenergic receptors. A guide cannula was implanted into brain lateral ventricle for injections of L‐NMMA (non selective NO synthase inhibitor) or mCSF (mock cerebrospinal fluid). A catheter was inserted into the femoral artery for ABP record and another one in the femoral vein for injections of α1‐adrenergic antagonist (prazosin) and agonist (phenylephrine) or saline. Experiments were conducted during spring (activity) and winter (hibernation) at 24–27°C to abolish temperature effect on ABP and HR. Basal ABP (mmHg) and HR (bpm) were, respectively: 35.2 ± 3.2 and 10.4 ± 1.5 (winter); 31.6 ± 1.5 and 11.8 ± 1.0 (spring). No seasonal variation of the basal values was observed. L‐NMMA increased ABP and HR in both seasons (P< 0.05), an effect that was more prominent during spring. The pre‐treatment with prazosin inhibited the hypertensive and taquicardic effects of L‐NMMA in both seasons. The effectiveness of prazosin was confirmed by the blockade of phenylephrine effects. We conclude that NO seems to act on the brain of tegus as a hypotensive agent via a mechanism dependent on α adrenergic receptors in the periphery. Supported by FAPESP and CNPq.
The A2A adenosine receptor rescues the UPS deficiency of Huntington's disease via a PKA‐dependent pathway
Authors: Chern Yijuang , Lin Jiun‐Tsai , Lai Hsing‐Lin
Published: June 2021

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by a CAG trinucleotide expansion of the Huntingtin (HTT) gene. The normal Htt gene has 35 or fewer repeats in the N‐terminal region, while expansions of longer than 36 convert Htt into a toxic protein and evokes HD pathogenesis. Effective removal of mutant Htt has thus become one of the most challenging aspects of drug development for HD. The A2A adenosine receptor (A2AR) is a G protein‐coupled receptor that is expressed in many brain areas including the striatum. The main signal transduction activated by A2AR is the cAMP/protein kinase A (PKA)‐mediated pathway. We previously demonstrated that in an HD transgenic mouse model (R6/2), daily administration of CGS21680 (CGS), an agonist of A2AR, attenuated several major symptoms of HD. In the present study, we show that CGS ameliorated the impaired activity of the ubiquitin‐proteasome system (UPS) in striatal neurons and striatal synaptosome fractions of R6/2 mice. This function of CGS was blocked by an antagonist of A2AR and an inhibitor of protein kinase A (PKA), suggesting that it was mediated by A2AR in a PKA‐dependent manner. Our study collectively suggests that the UPS is a potential drug target for HD, and might have an important impact on the development of therapeutic interventions for HD.
The Change of Physical Fitness and Quality of Life on the Elderly People Using Exercise Programs in Leisure‐Welfare Facility
Authors: Jin Haeng Mi , Kwon Jin Sook , Park In Sook , Lim Ho Nam , Kim Jung Eun
Published: June 2021

The purpose of this study was to examine the change of physical fitness and quality of life on the elderly people with using exercise programs in leisure‐welfare facility, and to identify the correlations among physical fitness and quality of life. The study was conducted with 78 seniors participating in exercise programs (EP), 36 seniors with sedentary work program (SWP), and 44 seniors who are not exercising (NE). The exercise program was conducted with 14 wks, 2 times per wk with low impact silver healthy dance program. The changes of the groups' physical fitness and quality of life were analyzed before and after the exercise program. After participating in programs, the flexibilities of lower body and physical strength of lower body in EP group and SWP group were significantly increased compared to NE group. But there was no difference in balance among three groups. EP group presented significantly higher quality of life than the other groups. In addition, as the quality of life was increased, the overall physical fitness was also increased. In conclusion, the elderly people who participated in the exercise program significantly increased their physical fitness and quality of life, therefore, we can consider that the low impact regular exercise program could improve elderly people's physical fitness and the quality of life.
Dietary Cholesterol Affects Skeletal Muscle Protein Synthesis Following Acute Resistance Exercise
Authors: Lee Chang Woock , Lee Teak V , Chen Vincent CW , Bui Steve , Riechman Steven E
Published: June 2021

We have previously shown that high cholesterol (CL) intake resulted in greater lean mass gains in elderly men and women after 12 weeks of resistance training. However, little is known about the effects of CL on protein synthesis rates in skeletal muscle. We examined the effects of CL consumption on muscle protein synthesis in response to acute bouts of high intensity resistance exercise (RE).

Two groups of 20–28 year old, healthy, untrained adults underwent 10 days of either high CL (HC: 14mg/kg lean/day, ~800mg/day, n=8) or low CL (LC: 3.5mg/kg lean/day, <200mg/day, n=7) diet followed by acute bouts of high intensity unilateral leg exercises (leg press & extension: 5 sets, reps to failure, 85% of max strength, emphasis on eccentric contraction) where one leg was exercised while the other leg served as the non‐exercise control. Biopsies were taken from vastus lateralis muscle 22h after exercise and cumulative myofibrillar protein synthesis (FSR) was measured using 2H2O as a tracer.

A significant difference in FSR (relative to control) was observed between the groups (HC: 94.6±23% vs. LC: −65.4±25%, p<0.01) with ANCOVA analysis (covariates: exercise history, lean mass, & degree of muscle soreness after RE). Our data suggest that CL may affect the anabolic response to RE possibly through its effect on membrane stability, inflammatory response, and lipid rafts/cell signaling.
Platelet inhibition with clopidogrel augments cutaneous reactive hyperemia
Authors: Dahmus Jessica D , Bruning Rebecca S , Manning Keefe B. , Holowatz Lacy A.
Published: June 2021

Platelet inhibition through the administration of aspirin (ASA) or clopidogrel are widely‐used methods for the primary and secondary prevention of atherothrombotic disease. ASA and clopidogrel inhibit platelet function through different mechanisms and attenuate reflex cutaneous vasodilation (VD). We hypothesized that systemic ASA and clopidogrel would attenuate shear‐induced cutaneous VD. Five healthy men and women (55±3 years) were given systemic ASA (81mg), clopidogrel (75mg), or placebo for 7 days in a double‐blind fashion with 2 weeks of washout between treatments. A reactive hyperemia protocol was performed to assess shear‐induced cutaneous VD. Skin blood flow (SkBF) was measured using laser‐Doppler flowmetry (LDF). Cutaneous vascular conductance was calculated (CVC=LDF/MAP) and normalized to max (%CVCmax: 43°C). Clopidogrel augmented the SkBF area under the curve with reactive hyperemia (AUCclopidogrel = 4111.1 ± 381.2 vs. AUCplacebo = 3559.0 ± 259.0 %CVCmax·s; p<0.05) but there was no change with ASA (AUCASA = 3373.7 ± 567.3 %CVCmax·s). Clopidogrel had a similar effect on the total hyperemic response (THRclopidogrel = 2280± 358 vs. THRplacebo = 1765 ± 212 %CVCmax·s; p=0.05). Contrary to our hypothesis, clopidogrel augmented cutaneous reactive hyperemia, suggesting that platelet ADP‐receptor inhibition may improve cutaneous shear‐induced VD.

Supported by NIH grant 1R21HL098645‐01
Wingless homolog Wnt11 suppresses bacterial invasion and inflammation in intestinal epithelial cells
Authors: Sun Jun , Liu Xingyin , Wu Shaoping , Xia Yinglin , Li Xi Emma
Published: June 2021

The Wnt pathway controls cell fate during development and homeostasis in self‐renewing tissues. Wnt signaling is involved in the activation of proinflammatory mediators in inflammatory disorders. However, these studies are focus on the responses of the monocytes to the inflammatory cytokines. How Wnt modulates the host responses to bacteria is unexplored. We reported here that Wnt11 expression was elevated after Salmonella infection in intestinal epithelia cells. We further demonstrated that pathogenic bacteria Salmonella regulate Wnt11 expression and location in vivo. Moreover, we found less Salmonella invasion in the cells with Wnt11 overexpression comparing to the normal cells. Whereas IL‐8 in the Wnt11 transfected cells was undetectable, it was easily detectable in the cells with low level of Wnt11. Inhibition of Wnt led to higher IL‐8 expression comparing to the normal cells after Salmonella infection. Functionally, Wnt11 overexpression inhibited the Salmonella‐induced apoptosis and suppressed the inflammatory NF‐kappaB and JNK activities. AvrA is a bacterial protein that stabilizing beta‐catenin, the down‐stream of Wnt. We found that Wnt11 expression and transcriptional activity were regulated by Salmonella AvrA. Overall, Wnt11 is a novel and important contributor to intestinal homeostasis and host defense.

This work was supported by the National Institutes of Health (DK075386‐0251, R03DK089010‐01), the American Cancer Society (RSG‐09‐075‐01‐MBC), and the IDEAL award from the New York State's Empire State Stem Cell Board (N09G‐279) to Jun Sun.
Modulation of K2P3.1 (TASK‐1) and K2P9.1 (TASK‐3) by reactive oxygen species
Authors: Kim Donghee , Papreck Justin R.
Published: June 2021

Reactive oxygen species (ROS) may mediate hypoxia‐induced vasoconstriction of the pulmonary arteries and excitation of O2‐sensitive cells. In these cells, TASKs contribute to the background K+ current that is inhibited by hypoxia. To determine the role of ROS in hypoxic inhibition of TASK, we studied the effects of hydrogen peroxide (H2O2) and superoxide radical on TASKs expressed in HeLa cells. H2O2 applied to inside‐out, but outside‐out, patches activated TASK‐1, TASK‐3 and TASK‐1/3 heteromer starting at ~16 mM. H2O2 did not affect other K2P channels (TREK‐2, TASK‐2, TALK‐2, TRESK). Dithiothreitol and MTSEA had no effect on basal TASK activity, and did not block the H2O2‐induced increase in channel activity. H2O2 increased the activity of TASK mutant in which the C‐terminus of TASK‐3 was replaced with that of TREK‐2. Xanthine/xanthine oxidase mixture used to generate superoxide radical showed no effect on TASKs from either side of the membrane, but activated TASK‐2 from the extracellular side. In rat cerebellar granule neurons, adrenal chromaffin cells and carotid body glomus cells that express TASK‐like channels, intracellular H2O2 (>16 mM) activated the channels, similar to that observed with cloned TASKs. Although H2O2 is able to activate TASKs, the high [H2O2] required for this effect suggests that H2O2 is unlikely to act as a signal mediator for hypoxia.
The effects of heat treatment on AMPK activation in skeletal muscle in type 2 diabetic rats
Authors: Tsuzuki Takamasa , Kobayashi Hiroyuki , Naito Hisashi , Katamoto Shizuo
Published: June 2021

In previous study, heat treatment and AMPK activation by exercise improved glucose tolerance in rat.

PURPOSE

To determine the effects of heat treatment on AMPK activation in skeletal muscle in type 2 diabetic rats.

METHODS

Otsuka Long‐Evans Tokushima Fatty rat (OLETF: n=16, 305.3±11.4g), an accurate animal model for human type 2 diabetes, and their counter parts (LETO: n=8, 226.7±14.1g) were used. Sixteen OLETF rats were divided into two groups; Control (n=8: CON) and Heat treatment (n=8: HT). HT received a lower‐body heat treatment (41 °C for 20 min) using water bath under anesthesia once a week for twelve weeks. An intraperitoneal glucose tolerance test was performed for each group in week‐11. In week‐12, the soleus muscles were removed 48 h after the last heat treatment. Phospho‐AMPK and total‐AMPK in the muscle was determined by Western blot analysis.

RESULTS

At 120 min after glucose injection, blood glucose levels of CON and HT were significantly higher than LETO, whereas blood glucose level of HT was lower than CON. AMPK phosphorylation ratio in the soleus muscle of CON was significantly lower than LETO. However, heat treatment significantly increased AMPK phosphorylation ratio in HT compared with CON, and there was no significant difference between LETO and HT.

CONCLUSION

Our results indicate that weekly heat treatment for twelve weeks could increase AMPK activation in skeletal muscle in type 2 diabetic rats.
Time course of diaphragm function recovery after mechanical ventilation in an animal model
Authors: Thomas Debby , Maes Karen , Agten Anouk , Decramer Marc , Gayan‐Ramirez Ghislaine
Published: June 2021

Several studies have shown that controlled mechanical ventilation (CMV) results in rapid and severe diaphragmatic dysfunction. The recovery response of the diaphragm to normal function after mechanical ventilation is not known, although these data may have an impact on weaning from the ventilator. We examined the time‐course of diaphragm function recovery in an animal model of CMV.

Anesthetized rats were submitted to 24h of CMV followed by either 1h, 2h or 3h of spontaneous breathing (SB) or to 24–27h of CMV.

There were no differences in blood pressure, blood gases, body weight or muscle weights between the four groups. The in vitro diaphragm force‐frequency curve was similar in the CMV group and in the CMV groups followed by 1h or 2h of SB. Three hours of SB after CMV resulted in a significant improvement of the diaphragm force compared to all other groups. Diaphragm cross sectional area (CSA) of the type I and type IIa fibers was similar in all groups, while the CSA of the type IIx/b fibers was significant increased in the CMV + 3h SB group (+27%, p<0.05) compared to CMV. No differences were observed in the activity of calpain and caspase‐3 between the four groups.

These data show that reloading the diaphragm for 3h after CMV results in a significant improvement of the diaphragm force together with an increase in the CSA of the type IIx/b muscle fibers.

Supported by FWO‐Flanders G.0893.11 and AstraZeneca Pharmaceuticals
Species‐Specific Hsp70 and Hsp100 Teamwork in Thermotolerance and Protein Disaggregation
Authors: Miot Marika , Reidy Michael , Doyle Shannon , Hoskins Joel , Johnston Danielle , Masison Daniel , Wickner Sue
Published: June 2021

Cells possess molecular chaperones and proteases to counteract the toxic effects of environmental stresses. The chaperone Hsp104 in yeast and its homolog ClpB in E. coli possess the unique ability to solubilize and refold aggregated proteins in cooperation with the Hsp70/DnaK chaperone system. The action of Hsp104 and ClpB in promoting thermotolerance is species specific: Hsp104 cannot function in bacteria and ClpB cannot act in yeast. To determine the regions of Hsp104 and ClpB necessary for this specificity, we tested chimeras of Hsp104 and ClpB in vivo and in vitro. We show that the Hsp104 and ClpB middle‐domains dictate the species specificity of Hsp104/ClpB for cell survival at high temperature. In protein reactivation assays in vitro, we show that the region responsible for the specificity is within helix 2 and helix 3 of the middle‐domain. In a bacterial two‐hybrid assay, DnaK interacts with ClpB and with chimeras that have the ClpB middle domain. Our results suggest that the interaction between Hsp70/DnaK and helices 2 and 3 of the middle‐domain of Hsp104/ClpB determines the specificity required for protein disaggregation both in vivo and in vitro, as well as for cellular thermotolerance.
Sphingomyelinase promotes atrophy in C2C12 myotubes
Authors: Schwagerl Peter Jerome , Talbert Erin E. , Nguyen Linda M.‐D. , Powers Scott K. , Ferreira Leonardo F.
Published: June 2021

Chronic heart failure, sepsis, and cancer chemotherapy lead to skeletal muscle atrophy. In all these conditions, the activity of sphingomyelinase (SMase) in the plasma is elevated. SMase has been shown to activate proteolytic pathways in non‐muscle cells. We tested the hypothesis that exogenous SMase promotes atrophy in skeletal muscle cells. Differentiated C2C12 myotubes were exposed to SMase (0.5 U/ml) or vehicle every 24 hrs for 48 hrs. We used brightfield microscopy to acquire images for measurement of myotube width (3 images per well). All myotubes within each field of view were analyzed (total: SMase 112 and vehicle 101 myotubes). Myotube widths were compiled to provide an average per well (n = 3/group). Initial analysis showed that SMase decreased myotube width by ~25% (mean±SD; vehicle 25.3±2.4 μm, SMase 18.9±1.2 μm; P < 0.05). Our data suggests that SMase promotes skeletal muscle atrophy. This is consistent with activation of proteolytic pathways.

Funding support: NIH/NHLBI 1K99HL098453‐01
Induction of chronic non‐inflammatory widespread pain in rats increases sympathetic activity
Authors: de Melo Vitor Ulisses , Oliveira Larissa Resende , Macedo Fabricio Nunes , Barreto Andre Sales , Passos Daniel Badaue , dos Santos Marcio Roberto Viana , Sluka Kathleen A , DeSantana Josimari M , Santana‐Filho Valter J
Published: June 2021

Fibromyalgia (FM) is characterized by chronic non‐inflammatory widespread pain (CWP). Changes in sympathetic function occur in patients with FM. In attempt to elucidate the pathophysiology mechanisms of FM we used an animal model that mimics FM symptoms. We aimed to evaluate changes in the autonomic balance as well as baroreflex function in response to CWP induction in rats. 14 wistar male rats with (GSA, n=8) and without (GSN, n=6) the induction of CWP were used. CWP was induced by two injections of pH 4.0 saline into the gastrocnemius muscle. 24 hours after the second injection of acid or neutral saline the animals were instrumentated to record blood pressure (BP), analyze variability of pulse interval (IP) and BP, and analyze spontaneous barorefex sensibility (BRS). After induction of CWP, there was an increase in the oscillations (IP variability) at LF (11 ± 1.18), a decrease in the oscillations at HF (89 ± 1.18) which results in an increase in the LF/HF ratio (0.14 ± 0.02) when compared to controls (7 ± 0.4 LF; 93 ± 0.4 HF; 0.08 ± 0.00 LF/HF;). There was no difference in BP oscillations in LF between groups (50 ± 3.9% GSA vs 38 ± 5.5% GSN, p= 0.09). BRS was reduced when compared to controls (11,87 ± 1,42 mmHg/s GSA vs 17,45 ± 3,10 mmHg/s GSN, p= 0.04) Our results showed that induction of CWP in rats shifts the autonomic balance towards sympathetic tone as well as decrease the BRS, conditions that are also seen in humans with FM.
Expression of miRNAs targeting genes involved in baroreceptor sensory transduction differs in SHR vs. WKY rats
Authors: Lu Yongjun , Whiteis Carol A , Chapleau Mark W , Abboud Francois M
Published: June 2021

ASIC2 channels contribute to baroreceptor activity (Neuron 2009), and BK channels determine the excitability of baroreceptor neurons (J. Physiol 2007). We observed that ASIC2, BKα, kcna1, and kcnd2 were decreased whereas Atp1b1 and Atp1b2 were significantly increased in the nodose ganglia (NG) of SHR compared to WKY rats. Altered miRNAs suppress specific mRNAs and cause transcript degradation or translational repression. Based on the reported databases, we chose 84 miRNAs as putative inhibitors of the genes mentioned and contrasted their expression in NG of SHR and WKY rats (male, 12 weeks). Ten miRNAs (34c for ASIC2; 543 for ATP1b1; 144 for ATP1b2; 203 & 543 for BKα 7 b, 10b, 25, 34c & 144 for kcna1; 200c & 206 for kcnd2) were up‐regulated and 9 others (29a, 29c, 142‐3p, 181a‐1, 181c & 363 for ATP1b1; 410 for ATP1b2; 29a, 29c, 181a‐1 & 181c for BKα 32, 96 & 363 for kcna1; 324‐5p & 363 for kcnd2) were down‐regulated more than 4‐fold in SHR compared to WKY. The decreased ASIC2 may be explained by up‐regulated miR‐34c and the increased ATP1b1 may reflect the several down‐regulated miRNAs. However the presence of both up‐regulated and down‐regulated miRNAs does not allow us to define their roles in K+ channel expression in SHR. Nonetheless consideration of selected miRNAs as therapeutic targets for restoring baroreflex sensitivity and reducing blood pressure in hypertension deserves to be explored. (HL14388).
Attenuated regional vasodilatory effects of gastrointestinal hormones in obesity prone animals: implications for obesity‐related hypertension
Authors: How Jackie May Yen , Pumpa Talia Jane , Sartor Daniela Maria
Published: June 2021

Obese animals have reduced renal and splanchnic sympathoinhibitory responses to gastrointestinal hormones that may have implications for increased vascular resistance. Our aim was to determine whether the vasodilatory effects induced by gastric leptin and cholecystokinin (CCK) are also attenuated in obesity. Male Sprague‐Dawley rats were fed a medium high fat diet (MHFD; n=24) or a low fat diet (LFD; n=8) for 13 weeks. Based on weight gain, MHFD rats were stratified into obesity prone (OP; upper tertile; n=8) or obesity resistant (OR; lower tertile; n=8) groups. Baseline arterial pressure (AP) was recorded in isoflurane‐anesthetised rats and Doppler flow probes were attached to the renal and superior mesenteric (SM) arteries for measurement of vascular conductance (VC). CCK was administered intravenously (0.1‐4 μg/kg) and leptin (15 μg/kg) infused close to the coeliac artery. OP rats had elevated AP compared to both LFD and OR rats (P<0.05 for all). CCK increased renal VC in LFD and OR rats and this response was blunted in OP rats (0.5‐4 μg/kg; P<0.05 for all). Leptin significantly increased renal VC in LFD compared to OP rats (P<0.05). In the SM artery, CCK increased VC in LFD animals, and this response was attenuated in OP rats (1–2 μg/kg; P<0.05 for all). Reduced vasodilatory effects of gut hormones may contribute to elevated vascular resistance associated with obesity‐related hypertension.
Angiopoietin‐1 but not angiopoietin‐2 induces IL‐8 synthesis and release from human neutrophils
Authors: Neagoe Paul‐Eduard , Dumas Elizabeth , Hajjar Fadi , Sirois Martin G
Published: June 2021

Angiopoietins (Ang1 and Ang2) can promote neutrophil chemotactic activities by activating Tie2 receptor. Moreover, pretreatment with Ang1 or Ang2 enhances the chemotactic effect of interleukin‐8 (IL‐8). We wanted to assess if angiopoietins can promote IL‐8 protein synthesis and release from human neutrophils. Only a treatment with Ang1 at 10−8 M induced a significant increase of IL‐8 protein synthesis (3.6‐fold) and release (5.5‐fold), whereas the combination of Ang1 and Ang2 induced the same effect as Ang1 alone. Moreover, IL‐8 mRNA production was also increased (4.7‐fold) as compared to PBS. Cycloheximide, a protein synthesis inhibitor, reduced Ang1‐mediated IL‐8 protein synthesis and release by up to 96 and 92% respectively, whereas IL‐8 mRNA was increased by up to 18‐fold compared to PBS‐treated neutrophils. Actinomycin D, an mRNA synthesis inhibitor, reduced Ang1‐mediated IL‐8 mRNA and protein synthesis only within the first hour of treatment by 54 and 52% respectively. Using specific kinase inhibitors, we observed that Ang1‐driven IL‐8 mRNA and protein increase is p42/44 MAPK dependent and independent from p38 MAPK and PI3K activity. In summary, Ang1 (10−8 M) induces IL‐8 mRNA synthesis, as well as IL‐8 protein synthesis and release, through the activation of p42/44 MAPK. This work was supported by the Canadian Institutes of Health Research and the Heart and Stroke Foundation of Quebec.
CNS Relaxin activates spinally projecting and vasopressin containing cells in the hypothalamic paraventricular nucleus
Authors: Brown Randall Joseph , Coldren Kevin , King T. Luise , Kline David D. , Hasser Eileen M. , Heesch Cheryl M.
Published: June 2021

Relaxin (RLX), an ovarian hormone which is secreted in pregnancy, activates the subfornical organ (SFO) and hypothalamic regions associated with control of blood volume and sympathetic nerve activity (SNA). The current experiments phenotyped cells in the paraventricular nucleus (PVN) which are activated by RLX. Carotid and femoral artery and vein catheters were implanted in female virgin rats. Spinally projecting cells were retrogradely labeled by microinjection of fluorogold (FG) or cholera toxin‐b (CTb) (90nl) into the intermediolateral cell column. After 5 days human RLX 2 (1μg/hr) or saline (Sal, 1ml/hr) was infused (1.5 hr) into the forebrain circulation (intra‐carotid artery, ica) of conscious rats. RLX (n=3) increased mean arterial pressure (MAP, 9±2 mmHg) while Sal (n=5) had no effect (+1 ± 1mmHg). Rats were euthanized, perfused with 4% paraformaldehyde, brains sectioned (30 μm), and Fos‐, CTb‐, and vasopressin (VP‐) immunoreactivity (IR) were evaluated. Following RLX, cells in the lateral margins of the SFO expressed Fos‐IR, consistent with activation of PVN projecting neurons. Forty ±11% of VP‐IR cells (bregma −1.8mm) and 36±7% of spinally projecting cells (bregma −2.12mm) were activated (Fos‐IR) by ica RLX. In contrast, Fos‐IR was minimal in Sal treated rats. These data provide an anatomical substrate for a role of RLX in the adaptations in regulation of VP and SNA in pregnancy. HL091164(CMH)
Tubuloglomerular feedback control of glomerular filtration rate is preserved in connexin 40‐deficient mice
Authors: Oppermann Mona , Castrop Hayo , Eisner Christoph , Schnermann Jurgen
Published: June 2021

The gap junctional protein connexin 40 (Cx40) is highly expressed in the extraglomerular mesangium connecting the tubular epithelium at the macula densa and the afferent arteriole. Participation of Cx40 in juxtaglomerular communication is suggested by the finding that the expression of renin and the localization of renin‐expressing cells are greatly abnormal in Cx40‐deficient mice. In the present experiments we have therefore used wild type and Cx40−/− mice to determine the role of connexin 40 in tubuloglomerular feedback (TGF). Stop flow pressure (Psf) assessed by micropuncture fell from 40.0±1.7 to 34.5±1.7 mmHg in C57Bl/6 wild type mice, and from 31.3±1.0 to 26.9±0.9 mmHg in Cx40−/− mice. Psf changes of 5.5±0.5 mmHg in wild type and of 4.4±0.5 in Cx40−/− mice were not significantly different (p=0.125). Psf values were significantly lower in Cx40−/− than wild type mice at all flow rates. Arterial blood pressure was not different between wild type and Cx40−/− mice. Glomerular filtration rate (GFR) of conscious mice was lower in Cx40−/− than wild types and this difference increased with aging. We conclude that TGF responsiveness is well maintained in the absence of connexin 40 suggesting that coupling through this dominant mesangial protein is not required for tubulo‐vascular communication. Renal vascular resistance appears to be elevated in Cx40−/− mice, perhaps a consequence of the elevated plasma renin levels.
Collecting Duct‐Specific Knockout of Adenylyl Cyclase Type VI Causes Urinary Concentration Defect in Mice
Authors: Roos Karl , Strait Kevin A , Kohan Donald E
Published: June 2021

Adenylyl cyclase VI (AC6) has been implicated in arginine vasopressin (AVP)‐stimulated renal water reabsorption. To evaluate the AC6 role we generated mice with collecting duct (CD)‐specific KO of AC6 using the Cre/lox system. KO and floxed controls were studied on normal water, chronically water loaded, and water deprived for 18 hours, ± DDAVP clamp 25ng/hr. Food, water intake, body weight, urine volume and osmolality, and inner medullary collecting duct (IMCD) AVP stimulated cAMP levels were measured. Baseline urine osmolality (Uosm) was reduced (1427±91 KO vs. 1938±189 mOsm/L con, p<0.04). After 18 hr water deprivation, Uosm was also reduced (2271±160 KO vs. 2777±108 mOsm/L con, p<0.02). There was no change with chronic water loading. With DDAVP infusion there was no difference in Uosm with normal conditions, or chronic water loading. With water deprivation Uosm decreased (3142±50 KO vs 3332±63 mOsm/L con p=0.032). There was no difference in urine volume or fluid intake. In acutely isolated IMCD AVP stimulated cAMP accumulation was reduced (0.09±0.015 KO vs. 0.16±0.015 pmol/μg con p=0.016). Thus, AC6 plays an important role in AVP stimulated water reabsorption and cAMP accumulation in CD.
Putative Arginine Kinase
Authors: Rajkovic Andrei , Fraga Dean
Published: June 2021

A recent genome blast conducted by Fraga et al. has revealed the possibility of an arginine kinase in several proteobacteria. This study was undertaken to characterize the putative arginine kinase discovered in Myxococcus Xanthus. Arginine kinases serve to catalyze the transfer of a high‐energy phosphoryl group from ATP to the specific guanidino compound arginine. Arginine kinase belongs to a family of proteins known as phosphagen kianses, which are widely distributed and conserved enzymes amongst metazoan and some protozoan organisms, but are rarely found in bacteria. Ross Ellington has extensively reviewed the role of this enzyme and suggests phosphagen kinases play a vital role in energy homeostasis. Myxococcus Xanthus has a complex development cycle forming fruiting bodies upon starvation that give rise to spores. The development cycle is mediated through a complex signaling pathway that may potentially require a significant amount of energy to initiate. To test this hypothesis the putative arginine kinase gene was knocked out of Myxococcus Xanthus by homologous recombination and subjected to a series of phenotypic assays measuring its responses to ionic and osmotic stress. In the development assays without ionic or osmotic stress the knock out (KO) strain was unable to develop, or formed aberrant fruiting bodies. Interestingly, the KO strain was rescued when the development assay contained either .3M KCl or .3M sucrose. Another phenotypic assay subjected the WT and the KO strain to ionic and osmotic stress during the vegetative stage. Doubling times were measured and the KO strain had a considerably higher generation time than the WT. This suggests the possibility that the putative arginine kinase is involved in energy regulation or may be involved in a development pathway.
Cloning and Purification of GST1 in Leishmania tarentolae
Authors: Addy Nicole , Osei‐Owusu Nana , Currington Rashalai , Hearne Jennifer
Published: June 2021

Leishmaniasis afflicts nearly 12 million of the world's population. The causative agent is the Leishmania parasite which, in contrast to other eukaryotes, lacks a complete heme biosynthetic pathway; therefore, they must acquire heme exogenously. Here, we suggest that one mechanism of heme sequestration may be accomplished through its coordination with glutathione (GSH) via membrane associated proteins in eicosanoid and glutathione metabolism (MAPEG), which are members of the glutathione transferase (GST) superfamily. In Macaca fascicularis microsomal prostaglandin E synthase type 2 (mPGES‐2), a MAPEG GST, binds to GSH. This enzyme‐glutathione complex then has the potential to form a coordination bond with heme. Therefore, it is hypothesized that there is an enzyme similar to mPGES‐2 which scavenges free heme in promastigote Leishmania. Consequently, the GST superfamily member gene, resembling mPGES‐2, was identified using genomic searches. The L. tarentolae gene was cloned, facilitating the biophysical and biochemical characterization of the enzyme in relation to its heme binding capabilities. Identification of this gene provides the first evidence of a GST superfamily member in Leishmania. This will be achieved through multiple spectroscopic techniques. Since Leishmania lack a complete heme biosynthetic pathway, the exploitation of its heme dependency is a key target for drug discovery.
O‐GlcNAc levels modulate adipocytokine transcription
Authors: Wollaston‐Hayden Edith E. , Harris Ruth B. , Wells Lance
Published: June 2021

Increased flux through the hexosamine biosynthetic pathway and the corresponding increase in intracellular glycosylation of proteins via O‐GlcNAc is sufficient to induce insulin resistance (IR) in multiple systems. Previously, our group used shotgun proteomics to identify multiple rodent adipocytokines whose levels are modulated upon the induction of IR by indirectly and directly modulating O‐GlcNAc levels. We have validated the relative levels of several of these adipocytokines using immunoblotting. Since adipocytokines levels are regulated primarily at the level of transcription and O‐GlcNAc alters the function of many transcription factors, we hypothesized that elevated O‐GlcNAc levels on key transcription factors are modulating adipocytokine expression. Here, we show that upon the elevation of O‐GlcNAc levels and the induction of IR in mature 3T3‐F442a adipocytes, the steady‐state transcript levels of multiple adipocytokines, as measured by quantitative RT‐PCR, reflect the modulation observed at the protein level. We have gone on to validate the adipocytokine transcript levels in mouse models of diabetes. Using inguinal fat pads from the severely IR db/db mouse model and the mildly IR diet‐induced mouse model, we have confirmed that the adipocytokines regulated by O‐GlcNAc modulation in cell culture are likewise modulated in the whole animal upon a shift to IR.

R01DK075069(LW)
CLINICAL ANATOMY OF THE PRETENDINOUS BANDS IN DUPUYTREN'S DISEASE
Authors: MATUSZ Petru L. , BRATU Tiberiu , GALOSI Lucian , PRILIPCEANU Georgeana , NODITI Gheorghe
Published: June 2021

The special clinical aspect of Dupuytren's disease is characterized by thickening and contracture of the fibrous pretendinous bands on the palmar surface of the hand and fingers. There are also presented firm nodules and atrophic grooves or pits in the pits in the skin of the palm of the hand. We analyzed the frequency of location of the contracture of the fibrous pretendinous bands, on one consecutive series of 200 cases. Only 2.5% of the cases were female. The bilaterality of Dupuytren's disease was evident in 53% of the cases. 26.5% of single affected hands were right and 20.5% were left. A percent of 73.5% of cases showed only one fibrous pretendinous band; 26.5% of cases showed association of two or three fibrous pretendinous band. The whole study material revealed the location of the fibrous pretendinous band as follows: 0.5% thumb; 1% index finger;15% middle finger; 87% ring finger and 25.5% little finger. The most common combination of affected fingers are in: 16.5% ring finger and little finger; 75% middle finger and ring finger; 2.5% middle finger, ring finger and little finger; 0.5% thumb and index finger. These data are important for the hand surgery. (Supported by CNMP 62054/2008).
Morphometric and genetic characterization of scorpion species from Colima, Mexico
Authors: Gutiérrez María Teresa Romero , Hernández Verónica Quintero , Delgado Jaime Bolaños , Carrera Francisco Mendoza , Enciso Iván Delgado , Possani Lourival , Velazquez Laura Leticia Valdez
Published: June 2021

Centruroides genus causes the highest number of deaths by scorpion sting in Mexico, the taxonomic situation for some species of this genus still not clear. The objective was the morphometric and genetic classification of specimens from Colima comparing experimental sequences with nucleotide sequences reported in Genbank. Scorpion specimens were collected in Colima, they were classificated by taxonomic keys, DNA was extracted and a segment of cox1 gene of mitochondrial genome was amplified. 4 species were identified (Centruroides tecomanus, C. infamatus, C. elegans y Vaejovis intrepidus), C. tecomanus was the dominant species (58.9%). A sequence of 964 bp belonging to cox1 gene of C. tecomanus was determined. A‐T content of the sequence was 61.72%. We succeeded identifying 4 scorpion species by morphometric analysis and gene cox1 of C. tecomanus was sequenced, showing similarity to C. limpidus. Authors thank FRABA‐UdC for financial support.
Characteristic features of human catalytic light chain, 22F6, showing the suppression of influenza virus infection by the different way
Authors: Fujimoto Naoko , Hifumi Emi , Uda Taizo
Published: June 2021

We found unique human catalytic light chains in which #4 clone showed a substantial effect on the suppression of infectivity of influenza virus A type (H1N1). Interestingly, 22F6 clone also showed a unique characteristic to prevent from the infection of influenza virus by the quite different way.

Generally, in vitro assay, the virus and the antibody was first mixed and then the solution was incubated for one hour with MDCK cells in medium. Then, the plaques were counted for estimating the infection efficacy. In this study, we employed a new method in which only antibody was incubated with MDCK cells for one hour. After that, the medium solution containing the antibody was discarded and the well was washed out with the medium. Then the influenza virus dissolved in the medium without an antibody was put into the wells, followed by counting the number of plaques.

C179 monoclonal antibody has been used in world widely as a famous neutralizing mAb against influenza virus H1N1 and H2N2 types. For the general in vitro assay, the mAb could completely suppress the infection of the virus against MDCK cells as expected but not in our new method. #4 clone showed the similar result. Surprisingly, 22F6 clone could lower the infectivity of the virus in our method. Namely, the functional mechanism of 22F6 clone is quite different from the neutralizing activity of C179 mAb and the catalytic activity of #4 clone.
Stable isotope markers of sweetened beverage consumption: relationships with health outcomes in a Yup'ik Eskimo study population
Authors: Nash Sarah Heather , Bersamin Andrea , Kristal Alan R , Boyer Bert B , OˈBrien Diane M
Published: June 2021

The objective of this study was to develop and apply stable isotope markers of sugar sweetened beverage (SSB) intake in the Yup'ik Eskimo population of Southwest Alaska. Biomarkers of SSB intake are of interest in this population, which is experiencing a nutrition transition that includes increased consumption of sugars. The carbon isotope ratio (δ13C) is high in sweeteners based on corn or sugar cane, and has been associated with SSB intake in non‐Native US populations. We show that soft drink intake is associated with the δ13C values of RBC (r = 0.47), hair (r = 0.52) and plasma (r = 0.57) in a community‐based sample of 68 Yup'ik Eskimos. However, δ13C is also associated with traditional and commercial animal protein sources. Thus, this marker cannot be used as an indicator of SSB specifically, but indicates intake of market foods generally. We then examine the relationship between RBC δ13C and markers of chronic disease in a larger study population (n = 1003). In models adjusted for age, sex, BMI and marine intake, δ13C values were positively associated with fat mass, waist circumference, Apo‐A2, triglycerides, and diastolic blood pressure. They were negatively associated with ghrelin, LDL and HbA1c. We conclude that increased intake of market foods has a negative impact on chronic disease risk factors.

Grant Funding Source : NIH NCRR COBRE: P20 RR16430‐10, and NIH NIDDK R01DK07442
Development of an atlas of food photographs with visual references and evaluation study on its use for assisting to estimate food weight in dietary recall
Authors: Wang Zhixu , Sun Zhongqing , Zhong Chunmei , Wu Jieshu , Fan Ping , Li Zuwen
Published: June 2021

Objective

This project is aiming to generate a new photographic tool used for assisting dietary assessment.

Methods

About 200 most common food items were included to make illustrative pictures. In a picture, a series of 4–10 portions were put in a platform, with three set of visual references: lining up horizontally with sequence of portion size from small to large, background grid in centimeters, and well‐known articles for every person. A self‐controlled and a randomized controlled weight estimation experiment were carried out both upon the subjects of 200 urban residents and 200 young college students, without and with assistance of the food pictures.

Results

Total 659 food pictures were produced and compiled into a Food Atlas. The results from the evaluation experiments, both by the self‐controlled and the randomized controlled methods, indicated that estimation differences by urban residents had been reduced 7.3%~24.6% of actual weight when picture assistance. The young students gave 19.6%~33.0% more accurate estimations when assisted with the pictures than the controls.

Conclusion

The new developed food pictures could be used as an effective tool for assisting dietary recall.
Correction of eating habits and prevention of weight gain by nutrition education in Korean college students
Authors: Bu So Young
Published: June 2021

The purpose of this study was to investigate if the nutrition education through elective course work and nutrition counseling program in university can change eating habit and prevent weight gain in first‐year college students in Gyeongbuk area. Total of 98 participants enrolled the course work and received a series of lecture about obesity, weight management, concept of nutrition and food choices for 14 weeks. BMI and body composition including body fat were measured and pattern of 24h diet recall and questionnaires were collected at the beginning and end of coursework. Paired t test and Pearson correlations were utilized for analysis. Data showed that body weight and BMI in mild‐risk obese group whose percent body fat is in between 30–40% were significantly decreased (p=0.039) after nutrition education. In addition to anthropometric changes, general life habit including dietary habit of subject including the decrease of alcohol consumption, control of overeating, and utilization of nutrition knowledge (p<0.01) were significantly improved after the education. Total number of response to regular exercise was increased after the coursework but average frequency of exercise in each individual was not changed. These results suggest that academic incentives could be considered for improving lifestyle including nutritional behavior to prevent weight gain in first year college students.
Relationship between adipokines, lipid profile, and insulin sensitivity in older African Americans: Adiponectin as a potential cardioprotective mediator
Authors: Lemacks Jennifer Lynn , Ernst Jasminka Ilich , Ralston Penny A. , Coccia Catherine , Young-Clark Iris , Wickrama Kandauda , Harris Cynthia M.
Published: June 2021

Research examining endocrine communication involving leptin, adiponectin and obesity in African Americans (AAs) is sparse. Our objective was to examine relationships between lipid profile (HDL, LDL, TotalChol, TG, VLDL), insulin sensitivity (by QUICKI), and adipokines in 71 mid‐life/older African Americans enrolled in a church‐based health intervention project. Participants were (MEAN±SD) 59.5±10.1y old with BMI 34.9±9.2kg/m2, and 73% female. Log‐transformed variables were utilized in calculations and the data were analyzed using SPSS19.0. Pearson's correlations revealed association between adiponectin and HDL (r=0.26, p=0.03), TG (r=−0.32, p<0.01), and QUICKI (r=0.48, p<0.001); as well as leptin and LDL (r=−0.21, p=0.07) after controlling for BMI, age, and gender. Regression analysis revealed adiponectin to be a significant predictor of HDL (β=0.28, p<0.01) and TG (β=−0.36, p=0.001), after controlling for BMI, age, and gender. Adiponectin was also a significant predictor of QUICKI (β=0.24, p=0.01) after controlling for BMI, age, gender, insulin, and glucose levels. There were no relationships between leptin, lipid profile, and insulin sensitivity. Based on these results, adiponectin may have cardioprotective benefits as an endocrine mediator by improving insulin sensitivity and lipid profile in older AAs. Funded by: NIH Institute on Minority Health & Health Disparities (R24MD002807‐02)

Grant Funding Source : NIH
Muscle protein synthesis is suboptimal following a typical carbohydrate‐rich breakfast
Authors: Mamerow Madonna Marie , Mettler Joni A. , English Kirk L. , Layman Donald K. , Volpi Elena , Paddon-Jones Douglas
Published: June 2021

Most Americans generally consume a relatively small amount of dietary protein at breakfast, typically less than 10 grams, and favor carbohydrate‐rich breakfasts. Yet, some evidence suggests that approximately 25–30 g protein is needed to maximally stimulate muscle protein synthesis rates. The objective of this study examined the acute and sustained effects of a 30 g protein‐rich breakfast meal compared to the typical 10 g American breakfast. Healthy adult men and women (n=11, 38+/−2.98 y, BMI: 26.1+/− 1.1) participated in a 7‐day crossover feeding study with 30 day washout. Study diets were isoenergetic, with Diet 1 providing 30 g protein at each breakfast meal and Diet 2 providing 10 g. Stable isotope methodology with muscle biopsies and blood sampling was used to assess muscle protein synthesis. Day 1 results indicated that the 30 g protein breakfast enhanced muscle fractional synthesis rates to a greater extent than the 10 g protein breakfast and was sustained throughout day 7. In conclusion, compared to the typical carbohydrate‐rich American breakfast, consuming a moderate amount of protein (30 g) at breakfast may promote increased utilization of dietary protein and enhanced muscle synthesis in adults.