bluuebunny/crossref_metadata_2025_split huggingface dataset:
ICAM‐1: a novel mechanism by which the inflammatory response augments myogenesis (1102.10)
Authors: Goh Qingnian , Dearth Christopher , Awadia Sahezeel , Garcia‐Mata Rafael , Corbett Jacob , Pizza Francis 
Published: June 2021

Recent investigations by our laboratory demonstrated that skeletal muscle cell expression of intercellular adhesion molecule‐1 (ICAM‐1), an important protein of the inflammatory response, augmented events of myogenesis in which myotubes are forming, adding nuclei, aligning, fusing, synthesizing proteins, and hypertrophying. Our current work extended these findings by incorporating pharmacological tools with an in vitro approach to discern underlying mechanisms associated with ICAM‐1 mediated myogenesis. Antibody neutralization revealed the extracellular domain of ICAM‐1 to be fundamentally important in augmenting homotypic adhesion of myoblasts, leading to myotube formation and myonuclear accretion. In contrast, inhibition of the cytoplasmic domain of ICAM‐1 with a cell permeable peptide revealed its critical role in augmenting both myotube formation and myonuclear accretion, as well as myotube alignment and fusion, rates of protein synthesis, and overall myotube size. Peptide inhibition further demonstrated that the signal transducing function of the ICAM‐1 cytoplasmic domain augmented events of myogenesis through mechanisms involving increased Rho GTPase (Rac1 and cdc42) and Akt/p70s6k activity. Taken together, our findings extend knowledge of the immunobiology of skeletal muscle cells by revealing a novel mechanism through which the inflammatory response facilitates myogenesis.Grant Funding Source: This research was supported by the ACSM Foundation Doctoral Student Research Grant(Q Goh)
The effect of lipid concentration on myosin heavy chain isoform expression in cultured Weddell seal skeletal muscle cells (1102.26)
Authors: Garcia Teresa , Kanatous Shane 
Published: June 2021

Prior studies have shown that myoglobin expression is increased when muscle cells are exposed to hypoxia and a second stimulus such as exercise. Aerobic muscle fibers expressing either Type I or IIA myosin heavy chains (MHC) have more myoglobin than other fiber types, and changes in the expression of myoglobin are usually attributed to a change in fiber type. Recently, De Miranda et al. (2012) showed that cultured Weddell seal skeletal muscle cells grown in normoxic conditions experienced an increase in myoglobin expression in response to increased lipid concentration in the culture media. The objective of this study was to determine if increasing lipid in the media would affect the expression of MHC that would underlie the increase in myoglobin expression. Weddell seal cells from primary culture were proliferated in normoxic conditions for seven days in growth media supplemented with either 2.5% or 5.0% lipid, and both treatments were differentiated for seven days in either hypoxic (0.5% oxygen) or normoxic (21% oxygen) environments. Cells were homogenized, and protein was separated via gel electrophoresis and stained with Coomassie. A difference in the presence of MHC isoforms was not detected between the 2.5% and 5.0% treatment groups, in either oxygen condition. We conclude that lipid may be acting independent of changes in MHC via another undescribed pathway to increase myoglobin expression.Grant Funding Source: Supported by Colorado State University
Effect of 17β estradiol on statin‐induced apoptosis (1102.38)
Authors: Bielman Marie , Barlas Kyle , Hoffman Carl , Ball Karen 
Published: June 2021

We have previously studied the effects of estrogen (E) on statin‐induced myotoxicity with E providing no apparent protection. In our studies E was added simultaneously with the statins, possibly explaining the lack of E effect. The anti‐apoptotic effect of E has been shown to be tightly linked to induction of hsp27. The purpose of this study was to establish the dependence of an anti‐apoptotic effect on prior E exposure. C2C12 cells were cultured in growth media (GM) and plated in 6‐well plates. After plates reached approximately 70% confluence, cells were exposed to one of six treatments: control (GM), E (10‐8 M 17β Estradiol), SS (10‐4 M Simvastatin), or three different treatments of E + SS (no E pretreatment; 45 min E pretreatment; or 45 minute E pretreatment with continued E+SS). After 24‐48 hours exposure, cells were DAPI‐stained and apoptotic nuclei were quantified. Data was analyzed by 1‐way ANOVA; p<0.05. As in previous studies, SS induced apoptosis with a significant increase in condensed nuclei (33.8% +/‐ 11.7% vs 6.2% +/‐ 2.6% in GM). Addition of E had no effect under any of the three E+SS conditions (45.4% +/‐ 15.6%, 34.9% +/‐ 14.5%, 35.5% +/‐ 15.4%). These results further support our earlier findings that question the ability of E to protect against statin‐induced toxicity. Pre‐treatment with E, known to induce hsp27, had no impact on the response to SS. Further studies are needed to explain the discrepancy between these data and E effects in other models of apoptosis.Grant Funding Source: NSF STEP Grant
Phosphorylation of nNOSα promotes muscle cell differentiation (1102.40)
Authors: Kar Rekha , Masters Bettie , Roman Linda 
Published: June 2021

Nitric Oxide (NO), produced by the nitric oxide synthases (NOS), regulates muscle cell structure and function. Neuronal NOS (nNOS) is the predominant isoform of NOS expressed in skeletal muscle, and exists as several splice variants, including nNOSα, µ and β. As opposed to myotubes, which mostly express nNOS µ, myoblasts predominantly express nNOSα. Phosphorylation of NOSs has been shown to regulate their activity, and studies from our group showed that nNOSµ is phosphorylated in response to insulin in skeletal muscle. To explore the effect of phosphorylation of nNOSα on muscle cell differentiation, we generated C2C12 myoblast cell lines stably expressing IRES‐EGFP, IRES‐EGFP‐nNOSα, or IRES‐EGFP‐nNOSα S1412E (a phosphomimetic mutation). Differentiation was induced in all these stable cell lines by serum starvation, and was evaluated by morphological and immunoblot analyses. The phosphomimetic of nNOSα (S1412E) greatly stimulated the differentiation of myoblasts to myotubes in comparison to the vector only or the nNOSα‐expressing C2C12 myoblasts, as revealed by phase contrast microscopy and by the increased expression of myosin heavy chain (mYHC), a marker of differentiation, suggesting a critical regulation of muscle cell differentiation by nNOSα phosphorylation at this particular residue. Recombinant nNOSα S1412E showed no apparent increase in NO production, compared to nNOSα WT, suggesting that phosphorylation at this site in nNOSα promotes differentiation through alternate protein‐protein interactions, translocation or other signaling pathways. Future studies will involve distinguishing the distinct roles played by various nNOS splice variants and phosphorylation events in muscle cell differentiation.Grant Funding Source: Supported by NIH #HL07446 and GM052419
Indomethacin increases organ damage and heat stroke mortality in mice (1104.13)
Authors: Leon Lisa , Dineen Shauna , Plamper Mark 
Published: June 2021

The effect of non‐steroidal anti‐inflammatory drugs (NSAIDs) on the progression of organ damage during heat stroke (HS) recovery is unknown. We examined the effect of oral indomethacin (INDO; 5 mg/kg) on core temperature (Tc; ±0.1°, radiotelemetry), organ (kidney, liver) gene expression of IL‐6 and lipocalin2 (LCN2; an injury biomarker), and survival of male C57BL/6J mice (23.7±0.5g; 6‐9 mice/group) at Tc,Max (42.4°C), 3h and 24h of HS recovery. INDO had no effect on Tc during heat exposure or recovery. INDO caused ~50% increase in HS mortality, which was associated with increased gut hemorrhaging. In HS survivors, kidney IL‐6 (4‐ to 38‐fold) and LCN2 (6‐ to 9‐fold) expression was increased throughout recovery and INDO potentiated these responses (5‐ to 280‐fold and 20‐ to 56‐fold, respectively; P<0.05). Liver IL‐6 (2‐to 4‐fold) and LCN2 (14‐ to 16‐fold) expression was lower than the kidney, but these responses were also potentiated by INDO (IL‐6: 3‐17‐fold; LCN2: 20‐ to 120‐fold; P<0.05). Plasma LCN2 was increased by INDO in non‐heated control and HS mice at 24h of recovery indicating an effect of the drug alone on organ damage. NSAIDs are known to cause gut bleeding, but these studies suggest there is a heat‐NSAIDs interaction that exacerbates the toxic effects of this drug. Plasma LCN2 may be a sensitive biomarker of organ damage in our model. Author views not official US Army or DoD policy.Grant Funding Source: DoD Medical Research and Materiel Command
Acute heat stress responses of mice with sickle cell trait (1104.18)
Authors: Chen Yifan , Islam Aminul 
Published: June 2021

It has been a long standing controversy about whether individuals with sickle cell trait (SCT) are vulnerable to injury or even sudden death during physical activity in hot climates. Experimental studies assessing susceptibility of SCT to heat stress are lacking. Our objective was to examine whether transgenic SCT mice had an altered thermoregulatory response to heat exposure. All SCT mice (n =16) and majority of age‐ and gender‐matched normal mice (29 of 45) completed two separate heat tests (2 hr each at 39.5 degree C) without severe hyperthermia (42.4 degree C). SCT mice had a significantly lower body weight than normal mice (n = 19) with similar peak core temperature (Tc). There was no difference in weight loss between SCT and normal mice during heat exposure. No significant correlations between peak Tc and body weight were found among SCT or normal mice. Compared to their normal counterparts, both non‐heat exposed (n = 9) and heat exposed SCT mice had significantly higher levels of heat shock protein 72 (HSP72) in various tissues, slightly lower hematocrit values, but similar plasma lactate dehydrogenase concentrations. No differences in plasma inflammatory and redox makers were found between SCT and normal mice following heat exposure. We conclude that SCT mice reveal neither thermoregulatory dysfunction nor increased oxidative/inflammatory stress when exposed to moderate heat. The physiological significance of increased tissue HSP72 remains to be determined.Grant Funding Source: Supported by The Office of Naval Research Grant N0001411MP2002 and USU Intramural Grant R091EH
Electric fans mitigate cardiovascular and thermal strain during extreme heat events (1104.5)
Authors: Ravanelli Nicholas , Jay Ollie 
Published: June 2021

Extreme heat events (EHEs) increase mortality rates due to heat related illness and are known to exacerbate underlying health conditions. Current international health guidelines warn against the fan use when ambient temperature exceeds 35°C; however no evidence exists supporting or refuting their use during EHEs. Our aim was to evaluate the critical environmental limits for cardiovascular and thermal strain with (F) and without (NF) a fan (v=4.0 m•s‐1) at an ambient temperature (Ta) of 36°C and 42°C in 4 separate trials. Six males (23.8 ± 3.5 y) sat in a climatic chamber regulated at either 36°C or 42°C while ambient water vapor pressure (Pa) was raised by 0.3 kPa every 7.5 min from 1.6 to 5.6 kPa. Heart rate (HR), esophageal temperature (Tes), and whole body sweat loss (WBSL) were measured. The critical Pa (Pa_crit) at which an upward inflection of HR was observed was significantly higher with F at both 36°C (F: 5.1±0.2 kPa; NF: 3.9±0.4 kPa, P<0.001) and 42°C (F: 4.4±0.4 kPa; NF: 3.2±0.4 kPa; P=0.01). Likewise, the Pa_crit for an upward inflection of Tes was significantly higher with F at 42°C (F: 4.8±0.1 kPa; NF: 4.1±0.4 kPa; P=0.01). However, WBSL was significantly greater with F at 42°C (F: 877±23 g; NF: 540±125 g, P=0.005) and 36°C (F: 391±23 g; NF: 353±32 g, P=0.02). Thus, contrary to current guidelines, fans mitigate cardiovascular and thermal strain at Ta values as high as 42°C, but necessitate a greater fluid intake.Grant Funding Source: Supported by NSERC
Effects of hindlimb unloading and radiation on vasodilator responses in skeletal muscle arteries (1106.18)
Authors: Ghosh Payal , Stabley John , Kilar Cody , Behnke Bradley , Alwood Joshua , Shirazi Yasaman , Globus Ruth , Delp Michael 
Published: June 2021

Long‐term spaceflight leads to extensive changes to the microvasculature as a result of weightlessness, which may be compounded by the effects of radiation exposure. The purpose of this study was to assess the individual and combined effects of hindlimb unloading (HU) and radiation (Rad) on vasodilator responses in the skeletal muscle microcirculation.Adult male C57BL/6 mice were randomized to one of four groups: control, HU (tail suspension for 10‐11 days), Rad (100cGy of 150MeV protons and 20cGy of 800MeV 56Fe), and HU‐Rad. Gastrocnemius feed arteries were isolated, cannulated and pressurized for in vitro study. Endothelium‐dependent (ACh, 10‐9‐10‐4 M) and ‐independent (Dea‐NONOate, 10‐9‐10‐4 M) vasodilator responses were evaluated. NOS and COX inhibitors (L‐NAME and Indomethacin) were used to determine which endothelium‐dependent signaling pathways were altered.In all treatment groups endothelium‐dependent and ‐independent vasodilator responses were significantly impaired compared to controls (max ACh dilation: 91Â±2%). ACh‐induced vasodilation was less in the HU‐Rad (68Â±3%) group than in HU (79Â±1%) or Rad (80Â±2%) alone. Independent and simultaneous treatment with L‐NAME and indomethacin reduced vasodilation and eliminated group differences. Dea‐NONOate‐induced vasodilation was reduced to a greater degree in the Rad and HU‐Rad groups.These findings suggest that the combination of insults experienced during spaceflight lead to significant impairment of vasodilatory function, mediated through endothelium‐dependent reductions in NOS signaling and vascular smooth muscle dysfunction.Grant Funding Source: Supported by NSBRI, NCC 9‐58‐44
Transcriptome‐wide RNA sequencing analysis of rat skeletal muscle feed arteries: impact of exercise training in obesity (1106.23)
Authors: Padilla Jaume , Jenkins Nathan , Thorne Pamela , Martin Jeffrey , Rector R , Davis J , Laughlin M 
Published: June 2021

We employed next generation RNA sequencing (RNA‐Seq) technology to determine the extent to which exercise alters global gene expression in skeletal muscle feed arteries and aortic endothelial cells (AEC) of obese OLETF rats. Transcriptional profiles of the soleus and gasctrocnemius muscle feed arteries (SFA and GFA, respectively) and AEC‐enriched samples from rats that underwent an endurance exercise training program(EndEx; n=12), interval sprint training program (IST; n=12), or remained sedentary (Sed; n=12) were examined. In response to EndEx, there were 39 upregulated and 20 downregulated genes in SFA and 1 upregulated and 1 downregulated gene in GFA (FDR < 10%). In response to IST, there were 305 upregulated and 324 downregulated genes in SFA and 101 upregulated and 66 downregulated genes in GFA, with an overlap of 32 genes between arteries. Furthermore, in AEC, there were 183 up‐regulated and 141 downregulated genes with EndEx and 71 upregulated and 69 downregulated genes with IST, with an overlap of 35 between exercise programs. Only expression of two genes (i.e., Tubb2b and Slc9a3r2) was altered (i.e., increased) by exercise in all three arteries. The finding that both EndEx and IST produced greater transcriptional changes in the SFA compared to the GFA is intriguing when considering the fact that treadmill exercise is associated with greater relative increases in blood flow to the gastrocnemius muscle compared to the soleus muscle.Grant Funding Source: NIH RO1HL036088
Anillin regulates cell‐cell junction integrity by organizing junctional accumulation of RhoA‐GTP, F‐actin, and Myosin‐2 (1109.17)
Authors: Miller Ann , Reyes Ciara , Jin Meiyan , Arnold Torey , Breznau Elaina , Espino Rhogelyn , Goryachev Andrew 
Published: June 2021

Anillin is a scaffolding protein that organizes and stabilizes actomyosin contractile rings and was previously thought to function primarily in cytokinesis. Using Xenopus laevis embryos as a model system to examine Anillin’s role in the intact vertebrate epithelium, we find that a population of Anillin surprisingly localizes to epithelial cell‐cell junctions throughout the cell cycle, whereas it was previously thought to be nuclear during interphase. Further, we show that Anillin plays a critical role in regulating cell‐cell junction integrity. Both tight junctions and adherens junctions are disrupted when Anillin is knocked down, leading to abnormal intercellular spaces and increased permeability to fluorescent dextran. Further, fluorescence recover after photobleaching (FRAP) studies show that Anillin perturbation affects the dynamics of the tight junction protein ZO‐1. Anillin interacts with RhoA, F‐actin, and Myosin‐2, all of which regulate cell‐cell junction structure and function. When Anillin is knocked down, active RhoA (RhoA‐GTP), F‐actin, and Myosin‐2 are misregulated at junctions. Indeed, while overall accumulation of RhoA‐GTP is reduced when Anillin is depleted, increased dynamic “flares” of RhoA‐GTP are observed at cell‐cell junctions. Junctional accumulation of F‐actin and Myosin‐2 are also reduced when Anillin is depleted. We propose that Anillin is required for proper RhoA‐GTP distribution at cell‐cell junctions in order to maintain a robust apical actomyosin belt, which is required for cell‐cell junction integrity. These results reveal a novel role for Anillin in regulating epithelial cell‐cell junctions.Grant Funding Source: Supported by R00GM089765, start‐up funds, NSF Predoc Fellowships & T32GM007315 to C.R. and E.B.
The kinase WNK1 is a powerful inhibitor of the K+:Cl‐ cotransporters (1109.6)
Authors: Melo Zesergio , Murillo Adrián , Chávez‐Canales María , Vázquez Norma , Hadchouel Juliette , Gamba Gerardo , Mercado Adriana 
Published: June 2021

The K+:Cl‐ cotransporters (KCC1‐4) belong to the SLC12 family of electroneutral cation‐chloride cotransporters that translocate ions outside the cells to regulate cell volume and intracellular chloride concentration. We previously shown that WNK3 and WNK4 inhibit the activity of KCCs and the elimination of kinase activity turned them into a powerful activators of all KCCs. WNK1 is a ubiquitously expressed kinase that produces two distinct hereditary diseases: pseudohypoaldosteronism type II and hereditary sensory neuropathy 2. Its effect on the regulation of KCCs activity is yet unknown. In the present study, we show using Xenopus laevis oocytes as expression system, that activation of all four KCCs by cell swelling was prevented by coinjection with the various WNK1 isoforms cRNA. The negative effect of WNK1 on the KCCs is kinase dependent, as it was not present when the kinase dead WNK1‐D368A was used. Elimination of the SPAK binding site (WNK1‐F316A) or the HQ motif of WNK1 (required for WNK to WNK interaction; WNK1‐HQ) prevented the inhibitory effect of WNK1 on KCCs, suggesting that interaction between WNK1 monomers and with SPAK is required. In contrast to the kinase dead WNK3, the kinase dead WNK1‐D368A had no effect on the KCCs activity in isotonic conditions. Altogether, our data support that under hypotonic conditions KCCs are regulated by WNK1 and this modulation requires SPAK binding sites in the kinase.Grant Funding Source: SEP‐CONACyT 165815 GG, 132503 AM
The velocity of pellet propulsion in guinea pig distal colon is differentially modified by short‐chain fatty acids (1110.8)
Authors: Hurst Norm , Kendig Derek , Murthy Karnam , Grider John 
Published: June 2021

INTRODUCTION: Short‐chain fatty acids (SCFAs) are produced by commensurate bacteria in the colon. The type and concentration of SCFAs depend on dietary intake of carbohydrate and fiber. While most fermentation occurs in proximal colon, unabsorbed SCFAs entering the distal colon are likely to modify propulsion initiated by fecal pellet‐induced distension. AIM: To determine the effect of SCFAs on pellet propulsion in distal colon. METHODS: The distal colon was removed from guinea pig and placed in an organ bath containing Kreb’s buffer. Following equilibration, video tracking software was used to measure the velocity of propulsion of a clay pellet placed in the orad end of a segment. Pellets propulsion was repeated during intraluminal perfusion of Kreb’s buffer containing individual SCFAs at 30 mM caudad to the pellet at 0.1 ml/min. RESULTS: The mean velocity of pellet propulsion in the absence of SCFAs was 1.5 ± 0.2 mm/sec. Luminal perfusion with 30 mM sodium butyrate increased the velocity of pellet propulsion by 30 ± 4% (p<0.05) whereas luminal perfusion with 30 mM sodium propionate decreased velocity of pellet propulsion by 75 ± 8%. Conclusion: Propionate had opposing effects to butyrate on the velocity of propulsion of artificial clay fecal pellets in the guinea pig distal colon. These studies suggest that the movement of feces in the colon depends not only on distension but also on the chemical (i.e. dietary) composition of the feces and the microbiota.Grant Funding Source: Supported by DK34153
Mesenchymal stem cells isolated from the bone marrow of mice with gastritis induce epithelial‐mesenchymal transition of gastric organoids (1119.5)
Authors: Turner Jacob , Feng Rui , Donnelly Jessica , Schumacher Michael , Zavros Yana 
Published: June 2021

Background: Bone marrow‐derived MSCs exhibit characteristics that are reminiscent of a cancer‐associated fibroblast (CAF) phenotype in response to chronic gastritis, (Donnelly et al., 2013, Dig. Dis. and Sci.). Although it is well documented that MSCs migrate to the site of gastric inflammation, the precise role of these cells in cancer development is largely unknown. Hypothesis: MSCs, transformed to a CAF phenotype, induce epithelial‐mesenchymal transition (EMT) of the gastric epithelium. Methods: MSCs were isolated from the bone marrow of either uninflamed C57BL/6 mice (B6 MSCs) or gastrin‐deficient mice exhibiting chronic gastritis (GKO MSCs). B6 MSCs or GKO MSCs were then co‐cultured in transwells using mouse‐derived fundic gland gastric organoids. Gene expression changes were measured by qRT‐PCR in both MSCs and organoids. Results: Compared to B6 MSCs, GKO MSCs exhibited increased expression of IL‐6, TGFβ, VEGF, alpha smooth muscle actin (αSMA), gremlin1 and components of the Hedgehog signaling pathway. Organoids co‐cultured with B6 MSCs appeared as epithelial spheroids with strong E cadherin expression. In co‐culture with GKO MSCs, organoids exhibited a budding phenotype with decreased expression of E cadherin and increased expression of αSMA, Zeb1/2, TWIST1/2, N‐cadherin and VEGF. Conclusion: MSCs isolated from mice with chronic gastritis induce EMT of the gastric epithelium.Grant Funding Source: 119072‐RSG‐10‐167‐01‐MPC (Y. Zavros)
DNA methylation differences in CD16+ cells between normal weight and obese women of childbearing age (1120.11)
Authors: Hohos Natalie , Park Hea Jin , Shade Deanna , Hausman Dorothy , Meagher Richard , Smith Alicia , Della‐Fera Mary Anne , Bailey Lynn , Baile Clifton 
Published: June 2021

It is well established that DNA cytosine methylation epialleles (CG vs 5MeCG) alter the expression of obesity related genes. The current study examined differences in 5MeCG in CD16+ cells isolated from blood using antibody‐bound magnetic beads in normal weight (BMI 18.5‐24.9 kg/m2; n = 12) and obese (BMI > 30 kg/m2; n = 6) women (18‐35y). 5MeCG was measured across > 485,000 CG sites using the HumanMethylation450 BeadChip (Illumina©). 16,969 CG sites were differentially methylated in obese as compared to normal weight women (p < 0.05). 65.4% of these sites had decreased methylation. Six of these CG’s remained associated (p < 10‐7) after adjustment for multiple testing (False Discovery Rate < 0.05), including sites in CRYGB, CDH5, and VASH1. Our results have potential implications in obesity and CDH5 has been shown previously to have differential methylation in peripheral blood leukocytes in obese (Wang et al. doi: 10.1186/1741‐7015‐8‐87). Continued analysis will further examine these methylation differences.Grant Funding Source: Supported by a grant from the UGA Obesity Initiative and the GRA Eminent Scholar Endowment (CAB)