bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adipose tissue heparan sulfate proteoglycans – critical regulators of adipocyte metabolism and glucose homeostasis
Authors: Pessentheiner Ariane R. , Quach Anthony , Al-Azzam Norah , Liu Sihao , Downes Michael , Evans Ronald M. , Gordts Philip L.M.S. 
Published: April 2020

Heparan sulfate (HS) proteoglycans are important components of cells and the extracellular microenvironment. Interaction between growth factors and receptors is often modulated by the amount and degree of HS sulfation. We hypothesize that natural variation in HS composition on adipocytes serves as a rheostat for adipocyte function and impacts susceptibility to develop insulin resistance, type‐2 diabetes and obesity.We use mice with adipose tissue (AT) specific inactivation of the HS biosynthetic enzymes N‐acetylglucosamine‐N‐deacetylase‐N‐sulfotransferase 1 (Ndst1‐AKO) and Exostosin 1 (Ext1‐AKO) mediated by the Adipoq‐Cre driver. These models allow us to study the impact of HS sulfation and chain length, respectively, on adipocyte metabolism and systemic glucose homeostasis in the context of diet‐induced obesity.On a high fat diet both Ndst1‐AKO and Ext1‐AKO mice gain more weight compared to WT littermates and develop significant glucose intolerance and insulin resistance. A pyruvate tolerance test indicates that disturbed adipocyte‐HS significantly affects liver gluconeogenesis. Moreover, hepatic inflammation is elevated in Ndst1‐AKO mice compared to WT controls, indicating that adipocyte‐HS also influences the organ cross‐talk between AT and liver. Previously, it has been shown that fibroblast growth factor 1 (FGF1) is a potent insulin sensitizer with great therapeutic potential. FGF1 signaling depends on the presence of HS on the plasma membrane. We show that the insulin‐sensitizing effect of FGF1 is diminished in Ndst1‐AKO and Ext1‐AKO mice. However, the insulin sensitization response to FGF21, another metabolic active FGF without HS‐dependency, is unaffected by HS alterations in AT.Our data suggest that HS composition in AT regulates FGF1 sequestration and signaling, leading to metabolic complications upon diet‐induced obesity. In this context, our results underline the importance of HS composition in AT for signaling processes that are critical for glucose homeostasis.
p23 Co‐chaperone Protects Aryl Hydrocarbon Receptor (AHR) from the Autophagy‐Mediated Degradation
Authors: Yang Yujie , Chan William K. 
Published: April 2020

The aryl hydrocarbon receptor (AHR) is first discovered as a transcription factor in response to toxic compounds such as dioxins. It also plays important roles in organ development, immune responses, metabolisms and carcinogenesis. Without ligand activation, AHR resides in the cytosol and is accompanied by Hsp90, p23 and XAP2. AHR is degraded via the 26S proteasome after ligand activation. However, it is still unclear how basal AHR protein levels are regulated. We previously discovered that AHR protein levels are lower in p23 stable knockdown (p23KD) cell lines when there is no ligand treatment. Here we report that treatment of proteasome inhibitor MG132 could not restore AHR in p23KD HeLa cells while the autophagy inhibitor chloroquine increased AHR proteins levels to 2.5 to 3‐fold in p23KD HeLa cells and 2‐fold in WT HeLa cells. Similar results were observed when cells were treated with other autophagy inhibitors (bafilomycin A1 and 3MA). There was higher autophagic flux in p23KD HeLa cells than in WT HeLa cells. Results from the co‐immunoprecipitation experiment and proximity ligation assay showed interaction between AHR and LC3B (LC3B‐II), which is an important protein in macroautophagy. These results support that the AHR protein levels are regulated by autophagy and p23 can protect AHR from the autophagy‐mediated degradation. Additional data will be presented to address the mechanisms of basal AHR protein degradation via autophagy.Support or Funding InformationNIH R15ES023104
IL‐33/ST2L mediated ADAMTS10 activation regulate retinal endothelial cell sprouting and neovascularization in a murine model of hypoxia‐induced retinopathy
Authors: Singh Nikhlesh Kumar 
Published: April 2020

Pathological retinal neovascularization is a clinical manifestation of various proliferative retinopathies, including retinopathy of prematurity (ROP), diabetic retinopathy, and the wet form of macular degeneration. A characteristic feature of these conditions is the presence of hypoxic areas and over‐expression of the proangiogenic vascular endothelial growth factor (VEGF). Treatments of these neovascular diseases using laser or anti‐VEGF therapies not only induce various local and systemic side effects but also are only partially effective. Here, using a murine model of oxygen‐induced retinopathy, we found that either intravitreal injections of IL‐33 siRNA or genetic deletion of IL‐33 resulted in reduced neovascularization with no significant changes in the avascular area. These findings suggest a role for IL‐33 in pathological neovascularization with little or no effect on the normal retinal repair. Interestingly, we observed that along with IL‐33 activation, hypoxia also induces expression of ST2 transmembrane receptor (ST2L), both at mRNA and protein levels, with little or no effect on secretory ST2 (sST2) levels. Our in vitro experiments using human retinal microvascular endothelial cells as a model suggest the importance of IL‐33/ST2L‐signaling on endothelial cell migration, tube formation, and sprouting. Besides it, our in vitro and in vivo findings provide evidence that IL‐33/ST2L‐signaling via ADAMTS10 activation facilitates sprout formation and invasion of connective tissue through controlled degradation of extracellular matrix proteins (ECMs). These results strongly suggest that IL‐33/ST2L‐signaling plays a key role in retinal neovascularization and thus represents a new pharmacological target for the treatment of diseases where excessive neovascularization is the underlying pathology.Support or Funding InformationThe research is supported by NIH EY029709 grant..
Acute High Phosphate Intake Impairs Endothelial‐Dependent Vasodilation in Young Premenopausal Women
Authors: Stephens Brandi , Nandadeva Damsara , Kaur Jasdeep , Barbosa Thales C. , Fadel Paul J. 
Published: April 2020

In the United States, the growing abundance of processed foods has led to Americans consuming more than double the recommended dietary intake of inorganic phosphate (Pi). Chronic consumption of Pi is associated with a higher risk of cardiovascular disease in the general population; however, studies investigating underlying mechanisms are limited. Recently, our lab has reported an impairment in brachial artery flow‐mediated dilation (FMD) following acute high Pi consumption in young, healthy men. To our knowledge, the effect of acute high Pi on vascular function in women remains unknown. This becomes important, as previous longitudinal work suggests that women may be protected from the greater cardiovascular risk associated with high serum phosphorus. Therefore, the aim of this study was to determine the effect of acute high Pi consumption on vascular function in young, healthy women. Eight healthy premenopausal women ingested a high‐Pi drink containing 2,000 mg of phosphorus (23 ± 2 yrs; mean ± SEM). Heart rate (HR) (ECG) and arterial blood pressure (BP) (finger photoplethysmography and automated sphygmomanometer) were measured during a 10 min baseline. FMD was used to assess conduit artery endothelial function and microvascular function was quantified as reactive hyperemic velocity AUC following cuff release. In addition, Pulse Wave Velocity (PWV) was used to assess large artery stiffness. All measures were performed before (pre) and 60 min after (post) Pi drink consumption (a time period our lab has shown to elicit peak elevations in serum phosphate following Pi consumption). Resting mean arterial BP and HR were not different pre‐ vs. post‐ Pi consumption (BP= pre, 80 ± 1; post, 81 ± 2 mmHg; p=0.28; HR= pre, 62 ± 4; post, 62 ± 4 beats/min; p=0.64). In contrast, FMD was significantly attenuated post‐Pi consumption, (pre, 6.7 ± 0.5%; post, 4.8 ± 0.8%; p=0.04), whereas, reactive hyperemic velocity AUC remained unchanged (pre, 2590 ± 488 arbitrary units; post, 2056 ± 221 arbitrary units; p=0.30), indicating that acute high Pi consumption had no effect on microvascular function. In addition, PWV was also unaffected by acute high Pi (p=0.18). Collectively, our preliminary findings suggest that, similar to men, exposure to acute high Pi impairs conduit artery endothelial function, but not microvascular function, in young healthy women.Support or Funding InformationUniversity of Texas at Arlington College of Nursing and Health Innovation
miR‐23a and miR‐23b Are Putative Regulators of KDM6A Protein Expression in Epithelial Mesenchymal Transition
Authors: Kim Joelle , Johnson Kelsey , Taube Joseph 
Published: April 2020

Cancer cell metastasis is the leading cause of cancer patient mortality. Tumor progression of epithelial cancers is facilitated by epithelial‐mesenchymal transition (EMT) and mesenchymal‐epithelial transition (MET), reverse processes that enable invasive cellular behavior. A key regulator of EMT/MET is lysine (K)‐specific demethylase 6A (KDM6A), an enzyme involved in epithelial gene expression that is abundant in epithelial cell phenotypes. We have previously determined that KDM6A is not dynamically regulated at the transcription level; we now aim to investigate whether post‐transcriptional mechanisms modulate KDM6A expression patterns. KDM6A mRNA transcripts are potentially regulated by specific miRNAs that inhibit expression of KDM6A protein, influencing EMT and downstream cellular morphology.To identify miRNAs that likely target KDM6A, eight databases were utilized to compile a list of ~160 potential miRNAs predicted to bind at the KDM6A 3′ untranslated region (UTR). Top miRNA candidates were then selected by number of deep sequencing reads, observed amounts in breast cancer cell lines, and frequency in patient data. miR‐23a, ‐23b, ‐145, and ‐199a were determined as potential regulators of KDM6A. The miRNAs were quantified by performing miRNA‐specific RT‐qPCR on RNA collected from TGFβ‐induced EMT and MET at various timepoints. Of the four miRNA candidates, miR‐23a and ‐23b were identified as likely post‐transcriptional regulators of KDM6A, as their relative quantification levels follow expected patterns opposing KDM6A expression throughout EMT/MET.Future directions aim to determine whether experimental manipulation of miR‐23a/b alters KDM6A protein expression and whether predicted binding sites at the KDM6A 3′ UTR are required. Cloning the gene for miR‐23a/b into a mammalian expression vector to observe miRNA‐overexpression effects on KDM6A expression can clarify KDM6A’s potential role in metastatic activity and can introduce new targets for research in clinical applications.Support or Funding InformationInvestigation of KDM6A function is supported through funding from Susan G. Komen and Jack G. and Norma Jean Folmar.
Effects of Gravidity on Locust Jump Performance
Authors: Valachovic Abigail Corrine , Kirkton Scott David 
Published: April 2020

Among life‐history trade‐offs, the cost of reproduction has been well‐studied. An increase in body mass due to gravidity has been shown to negatively affect survival in vertebrates, but it has not been widely studied in invertebrates. Insects, especially American locusts (Schistocerca americana), are good models to study how life‐history changes affect locomotion. For our research, we collected non‐gravid and gravid female grasshoppers and conducted a five minute endurance jumping test. Non‐gravid females (n=20, mean weight= 2.25 g) had an average maximum jump distance of 189 cm over the first minute. Over the five minute trial, non‐gravid female jump frequency decreased by 7% and mean distance per jump decreased by 46%. In contrast, gravid females (n=12, mean weight= 2.7 g) in the first minute had an average maximum jump distance of 169 cm. Over the five minute trial, gravid female jump frequency decreased by 8% and the mean distance per jump decreased by 52%. Next, we added weights to additional groups of non‐gravid and gravid females to determine how additional mass affected jump performance. The weights were either 20% or 40% of the average group body mass (n=12 for weighted non‐gravid, n=8–10 for weighted gravid). During the five minute trial, jump frequency significantly decreased in weighted grasshoppers regardless of whether they were gravid or not. In addition, the mean distance per jump significantly decreased with weights in both non‐gravid (p<0.008) and gravid females (p<0.0405). Therefore, increased body mass reduced frequency and mean distance per jump during repeated jumping. These results support a trade‐off between gravidity and locomotory performance in American locusts.Support or Funding InformationUnion College Student and Faculty Research Fund
Metabolic RNA‐seq profiles from sporadic Alzheimer’s disease patients: Analysis of glycolytic and ketolytic pathways
Authors: Saito Erin , Miller Justin , Kauwe John S. , Bikman Benjamin T. 
Published: April 2020

Sporadic Alzheimer’s disease (AD) is a widespread neurodegenerative disorder that progressively impairs memory and behavior. Although much of AD research has centered on the aggregation of amyloid plaques and neurofibrillary tangles, recent research revealing a strong and consistent correlation with impaired glucose metabolism has placed the relevance of these classic AD phenotypes in disease etiology and progression into question. Here we determine whether impairments in glycolytic gene expression might be responsible for AD glucose metabolism dysfunction and examine ketolysis through differential gene expression in AD patients. RNA‐seq profiles of postmortem AD brains from several available datasets were used to compare glycolytic and ketolytic gene expression between AD patients and cognitive‐normal controls. Glycolytic and ketolytic RNA‐seq profiles were also analyzed from progressive supranuclear palsy (PSP) patients compared to cognitive‐normal controls to determine whether these impairments in metabolic function are specific to AD or common to tauopathies. Our analyses show widespread disruption of both glycolytic and ketolytic pathways in several regions of the brain relevant to memory formation in AD brains. These analyses provide further evidence that metabolism is impaired at multiple levels (i.e. substrate transport, glycolysis, ketolysis, etc.) in AD and that these impairments are characteristic of AD, not PSP.Support or Funding InformationR01AG11380, R01AG21136, R01AG31272, R01AG042611, RF1AG054052
Two weeks of severe food restriction has long‐term adverse effects on cardiac function three months after refeeding in female Fischer rats
Authors: De Souza Aline M.A. , De Almeida Jônathas F.Q. , West Crystal , Ji Hong , Sandberg Kathryn 
Published: April 2020

IntroductionSevere food restriction (sFR) is associated with acute cardiovascular dysfunction including long QT intervals, arrhythmias, hypotension, bradycardia and sometimes sudden cardiac death. Little, however, is known regarding the long‐term effects of sFR after these individuals have recovered their body weight (BW).MethodsThree‐month‐old female Fischer rats were divided into 2 groups and maintained on a control (CT; regular chow ad libitum, n=8) or sFR (60% reduction of daily food intake, n=8) diet. After 2 weeks on the sFR diet, all rats received regular chow ad libitum for three months (‐Refed). Thereafter, cardiac function was assessed in isolated hearts using Langendorff method before and after 30 minutes of ischemia‐reperfusion (I/R).ResultsAfter 14 days of the sFR diet, rats lost 18% of their BW. Mean arterial pressure (MAP) (p<0.05) and heart rate (HR) (p<0.05) were also reduced compared to CT rats. Although no differences in BW were detected between the CT‐Refed and sFR‐Refed rats, perfusion pressure was increased by approximately 17 mm Hg (p<0.05 by 2‐way ANOVA), left ventricular systolic and diastolic pressures were increased by approximately 17 and 15 mm Hg, respectively (p<0.05 by 2‐way‐ANOVA), and HR was reduced by approximately 81 bpm (p<0.05 by 2 way‐ANOVA) in sFR‐Refed compared to CT‐Refed hearts during I/R. In addition, the sFR‐Refed had 2‐fold more arrhythmias (%: CT‐Refed, 34 ± 8 vs sFR‐Refed, 68 ± 9; p<0.05) during I/R than CT‐Refed hearts.ConclusionDespite normalization of BW and basal MAP 3 months after refeeding, isolated hearts from animals subjected to sFR and refeeding had higher perfusion, left ventricular systolic and diastolic pressures and lower HR and were more susceptible to I/R‐induced arrhythmias than hearts from CT‐Refed rats. This study has clinical ramifications for individuals who engage in short term very low calorie dieting or have experienced inadequate food intake from other causes (e.g., very low food security, war, natural disasters) who may be at increased risk of developing cardiovascular disease.Support or Funding InformationNIH 1R01HL119380 (KS); AHA 19POST34380744 (AS)
mTORC1 is required for the lipidation and ER‐to‐Golgi transport of prechylomicrons in Caco‐2 cells
Authors: Moreau Regis , Wang Zhigang 
Published: April 2020

Dietary fats are efficiently digested and absorbed by enterocytes, assembled into triacylglycerol‐rich chylomicrons and finally secreted in a multistep process. The role of mTORC1 (mechanistic target of rapamycin complex 1) in the fate of absorbed lipids, their intracellular trafficking, triacylglycerol packaging in chylomicrons by enterocytes has not been previously studied. On the basis of our previous work in hepatocytes showing that mTORC1 positively regulate VLDL production, we hypothesized that intestinal mTORC1 supports the production and secretion of chylomicrons. Lentivirus mediated shRNA technology was used to knockdown (>90% down) mTORC1 signaling‐associated proteins, Raptor and TSC2, to create three Caco‐2 cell lines that exhibit basal (shScramble cells), low (shRaptor cells) or high (shTSC2 cells) mTORC1 activity. Chylomicron production was primed with the addition of 1.2 mM oleate/1.5% BSA complex to the apical side of ThinCert™ cell culture inserts. We found that knocking down Raptor disrupts triacylglycerol synthesis and chylomicron assembly. Knockdown of Raptor decreased the mRNA levels of APOB (−87%), MTTP (−94%), FASN (−76%), DGAT1 (−77%) and DGAT2 (−81%) compared with control shScramble cells. The cellular protein abundance of apoB (−89%), MTTP (−63%) and FASN (−80%), and the secretion of apoB100 (−51%), apoB48 (−66%) and triacylglycerols (−69%) were decreased compared with control shScramble cells. Rapamycin (a mTORC1 inhibitor) lowered the secretion of apoB100 and apoB48 in shScramble cells by 47% and 75%, respectively. Knockdown of Raptor decreased the gene expression of prechylomicron transport vesicle‐associated proteins VAMP7 (vesicle‐associated membrane protein 7) and SAR1B (secretion associated Ras related GTPase 1B) by 85% and 70%, respectively, compared with shScramble cells, suggesting that prechylomicron trafficking from the ER to the Golgi was repressed in the absence of Raptor. In conclusion, our studies revealed the critical role of mTORC1 in chylomicron metabolism. These findings have broad implications for the absorption of essential fatty acids and lipid‐soluble vitamins, for chylomicron retention disease, chylomicron overproduction and associated hypertriglyceridemia.Support or Funding InformationUSDA Hatch Act, USDA‐NIFA
Trehalose Does Not Improve Alcohol‐Impaired TFEB and Liver Injury in Mice
Authors: CHAO XIAOJUAN , Ni Hong-Min , Wang Shaogui , Ding Wen-Xing 
Published: April 2020

Alcoholic liver disease (ALD) is one of the major causes of chronic liver disease worldwide. We previously demonstrated that chronic plus acute alcohol binge (“Gao‐binge”) impaired hepatic transcription factor EB (TFEB), a master regulator of lysosomal biogenesis, resulted in insufficient autophagy that contributes to Gao‐binge alcohol‐induced liver injury in mice. Trehalose, a disaccharide, has been shown to activate TFEB and protects against diet‐induced non‐alcoholic fatty liver disease in mice. The aim of the present study was to investigate whether trehalose would reverse impaired TFEB and insufficient autophagy induced by Gao‐binge alcohol and in turn protect against Gao‐binge alcohol‐induced liver injury. We found that trehalose increased TFEB nuclear translocation, elevated levels of LC3‐II and lysosomal proteins in cultured AML12 cells and in mouse livers, confirming the activation of TFEB by trehalose. Surprisingly, trehalose failed to activate TFEB in Gao‐binge alcohol‐treated mouse livers. As a result, trehalose failed to protect against Gao‐binge alcohol‐induced liver injury and steatosis. However, Gao‐binge alcohol increased infiltration of hepatic neutrophils and levels of inflammatory cytokine gene expression, which were attenuated by trehalose, suggesting trehalose inhibits alcohol‐induced inflammation independent of TFEB activation. In conclusion, our results indicate that trehalose fails to improve the impaired TFEB and liver injury but ameliorates hepatic inflammation induced by Gao‐binge alcohol.Support or Funding InformationNIH R01 AA020518, R01 DK102142, U01 AA024733 AND P30GM118247 (W.X.D).
Cardiomyocyte Specific Knock‐out of Erythropoietin Has Adaptive Non‐Erythropoietic Effects on Cardiac Function: A Novel Cardiac Myokine
Authors: Alshamali Razan , Edgett Brittany , Romanova Nadya , Farquharson Laura , Savinova Iryna , Marrow Jade , Allwood Melissa , Brunt Keith , Simpson Jeremy 
Published: April 2020

IntroductionErythropoietin (EPO), in response to hypoxia, is produced by the kidney, which stimulates erythropoiesis in the bone marrow. While the kidney is regarded as the primary source of EPO, mainly in vitro expression has been shown from cells or tissues of the brain, liver, and reproductive organs. However, whether these organs are an endogenous extra‐renal source and their physiological significance is unknown. Interestingly, recombinant human EPO (rhEPO) confers cardiac cytoprotection and increases contractility. Albeit, this occurs using supra‐physiological doses of rhEPO. Whether the kidney is responsible for these effects remains to be elucidated. Therefore, the
primary objective of this research is to investigate the physiological relevance of endogenous cardiomyocyte EPO production. We
hypothesized that: 1) adult cardiomyoctes are a source of EPO production and 2) the loss of cardiomyocyte EPO expression leads to a decrease in contractility and an increase in susceptibility to ischemia‐reperfusion injury.MethodsCardiomyocyte‐specific deletion of EPO (EPOfl/fl‐CM) was obtained by injecting 8‐week old α‐MHC‐MerCreMer+/−: EPO fl/fl male mice with 20 mg/kg tamoxifen daily for 5 days. Left ventricular (LV) EPO expression was determined using qPCR analysis. Cardiac structure and function were assessed by echocardiography, invasive hemodynamics and the Langendorff, respectively. Hematocrit was measured from blood collected via saphenous vein. Data was obtained 8‐weeks post‐tamoxifen.ResultsParadoxically, EPOfl/fl‐CM mice exhibited a dramatic increase in whole heart EPO expression. Further, cardiac‐derived EPO confers inotropic, lusitropic and hypertrophic effects. Furthermore, in response to ischemia‐reperfusion injury, EPOfl/fl‐CM mice show profound cytoprotection. Importantly, we show that endogenous cardiac‐derived EPO is capable of improving cardiac function without affecting whole body Hct levels.ConclusionThe knock‐out of EPO from the cardiomyocyte leads to a reciprocal increase in LV EPO expression, whereby an alternate cell in the heart is over‐compensating for the loss of cardiomyocyte‐derived EPO. This study furthers our fundamental understanding of EPO biology and establishes it as a novel cardiac myokine, capable of increasing cardiac function and driving hypertrophy.Support or Funding InformationHeart and Stroke FoundationCanadian Institutes of Health Research