bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptional profiling of skeletal muscle during hypertrophy in the absence of satellite cell participation reveals muscle‐specific diversity and satellite cell dependent signaling networks
Authors: Englund Davis A. , Figueiredo Vandre , dungan cory , Murach Kevin , Peck Bailey , Dupont Alec , McCarthy John , Peterson Charlotte 
Published: April 2020

The role of satellite cells (muscle stem cells) during hypertrophic growth remains to be fully elucidated. Previous findings are limited due to the mode of mechanical overload and a relatively narrow analysis of downstream effectors influenced by satellite cell depletion. The current study was designed to determine how the absence of satellite cells influences the transcriptome‐wide response and phenotypic adaptation to short‐ and long‐term periods of muscle growth in the oxidative soleus and the glycolytic/oxidative plantaris. We administered vehicle (SC+) or tamoxifen (SC−) to adult (6 months old) female Pax7‐DTA mice for 5 consecutive days to effectively deplete satellite cells. Following a 2‐week washout period, mice were subjected to progressive weighted wheel running (PoWeR) for 4 or 8 weeks or served as sedentary (locked running wheel) controls. After 4 and 8 weeks of PoWeR satellite cell and myonuclear density were significantly increased only in the muscles of SC+ mice. While muscle fiber size increased in both groups, growth was blunted at 4 and 8 weeks in the soleus and at 8 weeks in the plantaris of SC− mice. Further, measures of collagen demonstrate impaired extracellular matrix remodeling during muscle adaptation at both time points in the absence of satellite cells. RNA‐sequencing of the soleus and plantaris revealed muscle‐specific differences in the response to PoWeR as well as a dysregulated transcriptional profile during growth in the absence of satellite cells. These findings indicate satellite cells are required for optimal muscle growth and likely play a role in coordinating an efficacious transcriptional response for adaptations to exercise. We plan to further interrogate these findings at the myonuclear level via single‐nuclear sequencing, enabling a more targeted and fiber type‐specific analysis of signaling cascades dysregulated in the absence of satellite cell participation.Support or Funding InformationSupported by AG060701 and AG049806 to CAP and JJM, AR071753 to KAM and TL1 TR001997 to DAE
3D‐printing of Stem Cells and Stromal Cells to Prime for Vascularization and Regeneration
Authors: Peirce-Cottler Shayn 
Published: April 2020

Implanted engineered constructs intended for regenerating tissues face the immediate challenge of recruiting a microvasculature for the delivery of oxygen and nutrients, the trafficking of immune cells, and the regulation of interstitial fluid. The microcirculation is a hierarchical network of interconnected vessels that achieves this diverse range of functionality through its different components: arterioles, capillaries, and venules. The lumenized and branched structure of the microcirculation requires proper positioning of different cell types ‐‐ endothelial cells with an abluminal coating of pericytes and vascular smooth muscle cells ‐‐ and the establishment of a basement membrane between them. Spatially and temporally‐regulated molecular cues drive the cell‐to‐cell interactions that coordinate the assembly of these complex networks. Our lab combines computational modeling with 3D‐bioprinting to understand how microvessels assemble in vivo and to design and pattern them in vitro. We identified a sub‐population of cells in the stromal vascular fraction of adipose tissue that is capable of supporting capillaries and neo‐capillaries, much like native pericytes. We have developed techniques to exploit their use in murine models of diabetes, where angiogenesis is dysregulated and wound healing is delayed. Applications of our approach also include skeletal muscle regeneration and pancreatic islet re‐implantation.Support or Funding InformationUniversity of Virginia Center for Advanced Biomanufacturing University of Virginia School of Medicine Pinn Scholars
The Use of Surface Anatomy in Emergency Interventional Procedures: A Mixed Methods Analysis Comparing the Procedural Approaches of Clinicians
Authors: Fillmore Erin , Leech Caroline , Tunstall Richard 
Published: April 2020

A good knowledge of surface anatomy forms an essential part of safe and effective clinical practice for many healthcare specialties. Understanding and using surface anatomy is key to interpreting normal anatomy on medical images and being able to describe the location, appearance and relationships of palpable anatomical structures. It is the definition of usable anatomy. However, evidence shows that even though clinicians rank surface anatomy as an essential aspect of anatomy needed to succeed in training, the way in which qualified clinicians use surface anatomical landmarks for common procedures varies greatly. This two‐phase sequential explanatory mixed methods study explored how practising emergency medicine and surgical clinicians, at various levels of qualification, use surface anatomy in order to perform a cricothyroidotomy, thoracostomy and/or thoracotomy. It examined what surface anatomy is used, how it is used, why it was used, and explored clinicians’ perceptions of the importance of surface anatomy in performing these procedures. Using this case study example, the findings illustrate that inconsistencies exist in the use and application of surface anatomy in practice. It highlights the need to more fully understand how surface anatomy is being used across specialities, across procedures and across levels of training. Finally, this study has shown there is a need for improved applied training in landmarking for core procedures that require a comprehensive knowledge of surface anatomy. Only in understanding the most common misconceptions and inconsistencies in surface anatomy’s use and application, can current guidelines help shape future teaching of the subject.Support or Funding InformationNone
Determining the effects of Wnt signaling in the alleviation of cholestasis via the promotion of hepatocyte transdifferentiation
Authors: Kosar Karis , Nejak-Bowen Kari , Li Qin 
Published: April 2020

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease characterized by bile duct inflammation and fibrosis, resulting in end‐stage liver disease and reduced life expectancy. Therefore, an effective treatment for PSC is needed. Hepatocytes exhibit remarkable plasticity and are known to be capable of transdifferentiating into cholangiocytes in models of biliary injury, which could create de novo ducts, repair damaged cholangiocytes, or contribute to bile detoxification. Previous studies utilizing in vitro organoid cultures and genetic mouse models found that β‐catenin and downstream targets are upregulated in hepatic organoid cultures, and mice expressing excess β‐catenin in the liver had an increased number of hepatocytes expressing cholangiocyte markers compared to wild type (WT) when subjected to cholestatic injury. These findings led to the hypothesis that Wnt/ß‐catenin signaling drives hepatocyte‐to‐cholangiocyte transdifferentiation during biliary injury. To test this hypothesis, we utilized lineage tracing in hepatic organoid cultures and TG mice expressing a mutated non‐degradable form of β‐catenin (S45D) in liver. We show that hepatocytes transdifferentiate to cholangiocytes in organoid cultures, and the cholangiocytes present are not from native contaminating cholangiocytes. We determined that TG mice fed DDC diet, which induces bile stasis, have: 1) improved serum ALP over time, indicating less biliary injury; 2) increased bile output compared to WT mice fed DDC diet; and 3) bile ducts populated with hepatocyte‐derived cholangiocytes. Through these studies we demonstrate that Wnt/ß‐catenin signaling catalyzes hepatocyte‐to‐cholangiocyte transdifferentiation, and activation of this pathway alleviates cholestasis in mouse models of PSC.Support or Funding InformationNIH grant 1R01DK103775NIH training grant T32EB0010216NIH grant 1F31DK118802‐01
Activation of Nogo‐B receptor expression ameliorates type 2 diabetes in mice by improving insulin sensitivity
Authors: Chen Yi , Li Qi , Duan Yajun , Yang Xiaoxiao , Chen Yuanli , Han Jihong 
Published: April 2020

Reduction of insulin resistance/improvement of insulin sensitivity is the most effective treatment for type 2 diabetes (T2D). We previously reported Nogo‐B receptor (NGBR) is a specific negative regulator for liver X receptor alpha (LXRα)‐dependent hepatic lipogenesis, indicating NGBR may play an important role in hepatic lipid metabolism. However, it remains unknown if NGBR is involved in glucose metabolism and insulin sensitivity. Herein, we report the role of NGBR expression in insulin resistance and T2D development.In vitro, the role of NGBR in insulin sensitivity was analyzed by NGBR knockdown/overexpression in hepatic cell line. The pathophysiological role of NGBR in insulin sensitivity was analyzed in high‐fat diet (HFD)/streptozotocin (STZ)‐induced diabetic mice infected with recombinant adenovirus expressing NGBR by tail vein injection. We found inhibition of NGBR expression by siRNA decreased insulin sensitivity, and attenuated adiponectin‐activated AMPKa phosphorylation in hepatocytes. Reciprocally, NGBR overexpression enhanced insulin response. In vivo, NGBR overexpression was observed in mouse liver after infection of recombinant adenovirus expressing NGBR. Associated with NGBR overexpression, blood glucose was reduced while insulin sensitivity/glucose homeostasis was enhanced. NGBR overexpression also decreased triglyceride and NEFA levels in both liver and serum, and attenuated the injury in pancreatic islets. Furthermore, genes related to ER stress and mitochondrial functions in skeletal muscles and inflammation in adipose tissues were improved by hepatic NGBR overexpression. In conclusion, our study implicates the importance of understanding the role of hepatic NGBR in insulin sensitivity and treatment of T2D.
Renal sympathetic denervation attenuates congestive heart failure in angiotensin II‐dependent hypertension: studies with Ren‐2 transgenic hypertensive rats with aorto‐caval fistula
Authors: Honetschlagerova Zuzana , Melenovsky Vojtech 
Published: April 2020

ObjectiveWe hypothesized that renal denervation (RDN) attenuates the progression of aorto‐caval fistula (ACF)‐induced heart failure (HF) and the development of renal dysfunction in Ren‐2 transgenic rats (TGR), a model of ANG II‐dependent hypertension.MethodsRDN (severing renal nerve fibers, followed by phenol application) was done one week after creation of ACF; the follow‐up period was 70 days. The animals studied were: 1) Sham‐operated TGR (initial n = 8); 2) Sham‐operated TGR + RDN (n = 9); 3) ACF TGR (n = 31); 4) ACF TGR + RDN (n = 34). In separate groups (n = 8 in each), three weeks after induction of ACF, renal artery blood flow (RBF, Transonic probe) responses were determined to intrarenal ANG II (2 and 8 ng), norepinephrine (NE) (20 and 40 ng) and acetylcholine (Ach) (10 and 40 ng).ResultsUntreated ACF TGR began to die 3 weeks after induction of ACF and the final survival rate was 10% (3 from 31). RDN substantially improved the final survival rate to 50% (17 from 34). Basal RBF was significantly lower in ACF TGR than in sham‐operated TGR (6.9 ± 0.4 vs. 10.1 ± 0.5 ml.min−1.g−1, p<0.05) and RDN did not alter it in any group. Both doses of ANG II decreased RBF more in ACF TGR than in sham‐operated TGR (−17 ± 2% vs. −9 ± 2% and −42 ± 3% vs. −25 ± 2%, p<0.05 in both cases) and RDN increased RBF responsiveness to ANG II in ACF TGR (to −29 ± 3% and to −74 ± 3%, p<0.05 in both cases) as well as in sham‐operated TGR (to −21 ± 3% and −42 ± 3%, p<0.05). Intrarenal NE comparably decreased RBF in ACF TGR and sham‐operated TGR, and RDN increased RBF responsiveness in both groups. Intrarenal Ach increased RBF significantly more in ACF TGR than in sham‐operated TGR (+24 ± 2% vs. +11 ± 2% and +26 ± 2% vs. +13 ± 2%, p<0.05 in both cases) and RDN did not alter it in any group.ConclusionThe results show that RDN significantly improved survival rate in ACF TGR, however this beneficial effect was not associated with improvement of reduced RBF or with attenuation of exaggerated renal vascular responsiveness to ANG II.Support or Funding InformationSupported by the Ministry of Health of the Czech Republic grant No. NV‐18‐02‐00053 awarded to L.Č. All rights reserved. Supported by MH CZ ‐ DRO („Institute for Clinical and Experimental Medicine – IKEM, IN 00023001“).
Stress‐Induced Cardiomyopathy Following Exertional Heat Stroke in Mice
Authors: Laitano Orlando , Garcia Christian K. , Mattingly Alex J. , Robinson Gerard P. , Murray Kevin O. , King Michelle , Ingram Brian , Ramamoorthy Sivapriya , Leon Lisa R. , Clanton Thomas L. 
Published: April 2020

INTRODUCTIONApparent return to homeostasis may not be the end of concerns for exertional heat stroke (EHS) victims. It is well known that patients with cardiovascular diseases are more prone to develop heat related illnesses due to impaired thermoregulation. Epidemiological data suggest EHS exposure is associated with a ~2.5 times higher risk of long‐sterm cardiovascular disease in humans. However, whether EHS results in cardiovascular disorders remains unknown.OBJECTIVETo determine the potential of EHS to contribute to development of a stress‐induced cardiomyopathy using a preclinical mouse model of EHS.METHODSMale and female C57bl/6J mice underwent forced wheel running for 1.5–3 h in a 37.5°C/40% relative humidity environmental chamber until symptom limitation, characterized by central nervous system dysfunction at peak core temperatures of 42.2 ± 0.3 °C. Sham exercise control mice ran for the same duration as EHS mice at 22.5°C. Myocardial and plasma samples (n = 8/group) were obtained between 30 min −14 d recovery, analyzed using metabolomics/lipidomics platforms and compared to sham exercise controls. Data are presented as fold‐change from control.RESULTSFemales ran ~40% longer than males (121.16 ± 22 vs. 189.25 ± 35 min; P < 0.05), with a ~51% greater heat load (240 vs.160°C·min; P < 0.05). The immediate recovery period revealed an acute energy substrate crisis characterized by a ~0.5‐fold decrease in plasma lactate, pyruvate, glucose and fructose at 3 h post EHS (P < 0.05) from which both sexes recovered within 24 h. At 9–14 d post EHS, the myocardium of female mice developed ~0.5‐fold elevations (P < 0.05) in free fatty acids, ceramides, and diacylglycerols. Moreover, glycolysis shifted towards the pentose phosphate and glycerol‐3P dehydrogenase pathways. Tricarboxylic acid cycle metabolites revealed bottlenecks in substrate flow and build‐up of intermediate metabolites. These changes are consistent with cardiac metabolic dysfunction observed in chronic heart failure patients. Males exhibited only late stage reductions in acylcarnitines and elevations in acetylcarnitine.CONCLUSIONSWe demonstrate that the myocardium of female mice is vulnerable to a slowly emerging metabolic disorder following EHS that may lead to long‐term cardiovascular complications. If these abnormalities persist over time, it raises the possibility that untoward outcomes of severe EHS exposure could emerge later in life. Lack of similar findings in males may reflect their reduced time of heat exposure.Support or Funding InformationDOD Grant BA180078. The opinions or assertions contained herein are the private views of the author(s) and are not to be construed as official or reflecting the views of the Army or the DoD.
HNF4 paralogue gene expression and function in the kissing bug Rhodnius prolixus
Authors: de Oliveira Fernanda Almeida , Musselman Laura Palanker , Gondim Katia Calp , Majerowicz David 
Published: April 2020

HNF4 is a transcription factor and member of the nuclear receptor superfamily, proteins that play important roles in development and metabolism. HNF4 is a key gene in the adaptation to fasting and regulates many genes involved in lipid oxidation and mobilization. Mammalian genomes contain two paralogues named HNF4 alpha and HNF4 gamma, but most insect genomes have only one HNF4 gene. After the publication of the Rhodnius prolixus genome, we noticed there were two paralogous HNF4 genes known as RpHNF4.1 and RpHNF4.2. Currently, little is known about HNF4 function in the kissing bug R. prolixus, so study of HNF4 paralogues may provide unique insight into the metabolism and physiology of this important vector for Chagas Disease. A qPCR analysis reveled different patterns of expression of these two genes in different R. prolixus organs, with RpHNF4.1 expressed mainly in ovaries while RpHNF4.2 is the main form expressed in fat body, midgut and flight muscle, suggesting they may have different functions. Drosophila melanogaster is a useful insect model organism with genetic tools that can be used to test the conserved functions of the HNF4 paralogues from R. prolixus. Because R. prolixus has a long life cycle and few genetic tools, we are constructing D. melanogaster transgenic flies to conditionally express each gene in wild‐type and dHNF4 null mutant backgrounds. Loss of dHNF4 in these flies produces adult lethality and these animals acumulate triacylglycerol in the fat body and have low expression of genes involved in the beta oxidation pathway as larvae. Using the GAL4‐UAS system, we aim to generate flies expressing only RpHNF4.1 or RpHNF4.2 without the interference of dHNF4. With these constructs, we will be able to evaluate alterations and possible rescue of the lifespan and lipid metabolism pathway independently for each R. prolixus HNF4 gene. This data may shed some light in their individual physiological roles and suggest new lines of investigation on the lipid metabolism of the Chagas desease vector. Ultimately, a better understanding of conserved features of HNF4 paralogues may provide new molecular targets for obesity treatment in other organisms.Support or Funding InformationThe first author is a Fulbright Scholar at Binghamton University. Special thanks to the Fulbright Comission Brazil. CAPES, CNPq and FAPERJ.
Evidence for a novel interaction between key enzymes in the lipid biosynthesis pathway in S. cerevisiae
Authors: Greenwood Brianna , Stuart David 
Published: April 2020

Lipids are essential for energy storage and integrity of membranes in organisms ranging from humans to yeast. The biological properties of triglycerides and other lipids are determined by their composition and the order of assembly. Previous research has demonstrated that acyl‐CoA molecules are delivered to the enzymes involved in lipid biosynthesis in a specific order. It has been proposed that this ordered assembly is achieved by means of a membrane‐bound lipid synthesis complex in which the key enzymes interact through specific protein‐protein contacts. Preliminary data from yeast two‐hybrid and coimmunoprecipitation studies have revealed specific protein‐protein interactions between lipid synthesizing enzymes. Interactions were found between Ole1, the main desaturase in yeast, and Dga1, the terminal enzyme in the triglyceride synthesis pathway, as well as between Ole1 and Slc1, a protein that acylates lysophosphatidic acid. Future research aims to determine the other proteins in complex with Ole1 with a biotin ligase proximity assay and direct interactors via in vitro studies. This research is revealing the architecture of the enzyme complex and how it controls lipid synthesis and composition. Investigating the lipid biosynthesis complex will have implications for a wide variety of applied research, from treating lipid dysregulation in humans to biofuel production by microbes.Support or Funding InformationNSERC, BioIndustrial Innovates Canada, Alberta Innovates Biofutures, University of Alberta Faculty of Medicine and Dentistry
Contribution of Kir4.1/Kir5.1 Channels to the Control of ENaC‐Mediated Apical Sodium Transport in the Cortical Collecting Duct
Authors: Isaeva Elena , Palygin Oleg , Shalygin Alexey , Bohovyk Ruslan , Fedoriuk Mykhailo , Klemens Christine , El-Meanawy Ashraf , Denton Jerod , Staruschenko Alexander 
Published: April 2020

Recent studies using genetically modified animal models reveal that inwardly rectifying potassium channels Kir4.1 and Kir5.1, encoded by Kcnj10 and Kcnj16 genes, play an essential role in determining plasma potassium level and regulating blood pressure. Moreover, we have revealed recently that the deletion of Kcnj16 gene in Dahl salt‐sensitive (SS) rats has the profound effect on the blood pressure and renal damage. These data uncover a new potential target for the treatment of salt‐induced hypertension. Protein products of Kcnj10 and Kcnj16 are localized to the basolateral membrane of distal nephron segments forming functional homomeric (Kir4.1) and heteromeric (Kir4.1/Kir5.1) potassium channels that play an essential role in establishing a negative basolateral membrane potential and recycling K+ ions moved into the cytosol by the Na+/K+‐ATPase. In the present study we examined the effect of pharmacological inhibition of Kir4.1 and Kir4.1/Kir5.1 channels on sodium transport through the epithelial Na+ channel (ENaC) in the cortical collecting duct (CCD) cells. We have reported recently that Kir4.1 inhibitor nortriptyline (100 μM), but not fluoxetine (100 μM) inhibited whole‐cell potassium currents recorded from native principal CCD cells. First we examined whether fluoxetine and nortriptyline have different selectivity in targeting Kir4.1 and Kir4.1/Kir5.1 expressed in Chinese hamster ovary (CHO) cells. Single channel analysis revealed that application of 100 μM of amitriptyline produces a significant decrease in NPo of Kir4.1/Kir5.1 but does not affect Kir4.1 current activity, whereas fluoxetine selectively inhibits Kir4.1. Next we examined whether selective inhibition of Kir4.1 and Kir4.1/Kir5.1 affects an apical sodium transport via ENaC. We showed that amitriptyline, but not fluoxetine reduced (IC50=15.0 μM) the amiloride‐sensitive short‐circuit current (ISC) measured in polarized epithelial mCCDcl1 cells. In control experiments, application of amitriptyline did not directly affect ENaC activity overexpressed in CHO cells. Using different concentrations of recently developed Kir4.1 inhibitor, VU0134992, and patch‐clamp studies of single‐channel activity on mCCD cell line and native rodent and human CCD tubules, we confirmed that inhibition of Kir4.1/Kir5.1 channel but not Kir4.1 produces suppressive effect on ENaC activity. In summary, inhibition of Kir4.1/Kir5.1 channels in CCD cells indirectly reduces apical sodium conductance through ENaC, demonstrating the importance of basolateral potassium channels in the control of sodium reabsorption in distal nephron.Support or Funding InformationNational Institutes of Health grants R01 DK120821 (to J.D. and A.S.), R56 DK121750 (to O.P.), and R35 HL135749 (to A.S.)