bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of VE‐PTP Scaffold in Stabilizing the Adherens Junction
Authors: Juettner Vanessa , Dan Arkaprava , Leckband Deborah , Komarova Yulia , Malik Asrar 
Published: November 2023

The Vascular Endothelial Protein Tyrosine Phosphatase (VE‐PTP) is an endothelial‐specific phosphatase that dephosphorylates multiple proteins including Vascular Endothelial (VE)‐cadherin, the main adhesion protein of adherens junctions (AJ). However, the role of VE‐PTP in stabilization of VE‐cadherin adhesion complexes remains unclear. VE‐cadherin establishes adhesion events through trans interactions with opposing VE‐cadherin molecules at AJs. In resting endothelial monolayers, it undergoes continues exchange between junctional and cytosolic pools. Using VE‐cadherin tagged with the photoconvertable protein Dendra2, we have demonstrated that VE‐PTP regulates steady‐state kinetics of VE‐cadherin at AJs in a phosphatase‐independent manner. Overexpression of wild‐type (WT) or phosphatase “dead” VE‐PTP mutant similarly decreased the VE‐cadherin dissociation rate from AJs as compared to control cells expressing empty vector. In agreement with these results, VE‐PTP depletion increased VE‐cadherin dissociation rate from AJs. Furthermore, treatment of the cells with the VE‐PTP phosphatase inhibitor, AKB‐9785, did not alter VE‐cadherin dynamics suggesting that VE‐PTP promoted stability of VE‐cadherin adhesion by decreasing VE‐cadherin dissociation rate in a phosphatase‐independent manner. Because Rac1 stabilizes AJs by reducing mechanical tension across VE‐cadherin adhesion, we analyzed junctional activity of Rac1 as well as the tension applied to VE‐cadherin using respective FRET biosensors. We observed that overexpression of VE‐PTP caused both Rac1 activation at AJs and reduction of tension across VE‐cadherin adhesion. Consistent with these results, VE‐PTP knockdown decreased Rac1 activity at AJs and increased stress at AJs determined using micropillar arrays. Cumulatively, our data suggest a scaffold role of VE‐PTP in regulating Rac1 activity at AJs. Future studies will further investigate the molecular mechanisms by which VE‐PTP activates Rac1.Support or Funding InformationFunding: National Institutes of Health grant R01 HL103922 to Y.A. Komarova, and T32 and RO1 HL45638 to A.B. Malik.
Critical Role of Vitamin D3 in Helicobacter pylori Eradication in Stomachs
Authors: Hu Wei 
Published: November 2023

Backgrounds and objectivesHelicobacter pylori (H. pylori) establishes a new and important field in clinical microbiology, as the bacterium was found to be a major cause of several severe gastric disorders, including chronic gastritis and peptic ulcers. It is also a risk factor for adenocarcinoma and gastric lymphoma. Antibiotic treatment is adopted as the first therapeutic approach for H. pylori eradication. However, with the prevalence of antibiotics usage, multidrug resistance (MDR) is found to be increasingly common and also critical in clinics in the past decades. Therefore, new strategies of drug treatment are urgently needed for patients with H. pylori infection. This study aimed at demonstrating the critical role of vitamin D3 in H. pylori eradication.MethodsPCR and immunostaning assay were used to determine the intracellular H. pylori level. Western blot assay was used to determine the autophagy‐related proteins level. Acridine Orange and GFP‐mCherry‐LC3 plasmid transfection were used to measure lysosomal acidification.ResultsWe found a promising effect of vitamin D3 in clearing H. pylori infection both in gastric epithelial cells and in animals. The action was found to be independent on cathelicidin expression which was activated by vitamin D3 and shown to have anti‐bacterial action. Importantly, it was demonstrated that vitamin D3 could revitalize the degradation function of lysosomes which was adversely affected by H. pylori in cells after infection. This restoring effect was accomplished by lysosomal acidification enhancement. Moreover, we also found that the therapeutic action was not acting through vitamin D receptor, instead it was mediated by a separate receptor, the PDIA3 inside the cell, following by activating the calcium channel TRPML3 in lysosomes, and the degradation function can be restored by vitamin D3 through PDIA3 receptor.ConclusionsOur studies revealed a novel and unique antibacterial pathway for Vitamin D3, which is different from the mechanisms of action for traditional antibiotics. Therefore, vitamin D3 could be a new therapeutic agent for bacterial infection and in particular those MDR bacteria in the future.Support or Funding InformationThis study was partly supported by the General Research Fund from the Hong Kong Research Grant Council (CUHK 463613) and the Health and Medical Research Fund from the Food and Health Bureau (13120062) in Hong Kong and the National Natural Science Foundation of China (No. 81473269).
Obesity‐Induced Mouse Prostatic Dysfunction is Improved by Chronic Treatment with Resveratrol: Implication of Oxidative Stress and Neuronal Growth Factor
Authors: Calmasini Fabiano Beraldi , Oliveira Mariana Gonçalves , Alexandre Eduardo Costa , Silva Fabio Henrique , Tavares Edith Bastos Gandra , Antunes Edson 
Published: November 2023

IntroductionThe worldwide incidence of obesity has increased dramatically in the past 25 years. Clinical studies indicate a strong correlation between obesity and genitourinary tract diseases, being benign prostatic hyperplasia (BPH) one of the most common prostatic disorders affecting obese individuals1,2. Recently, increased oxidative stress has been shown to play a pivotal role in BPH pathogenesis/progression3. In the present study we explored the effects of the polyphenol resveratrol, an antioxidant drug, on obesity‐induced prostatic dysfunctions.MethodsMale C57BL6/JUnib mice, fed for 12 weeks with either a standard chow or high‐fat diet to induce obesity were treated daily with resveratrol (100 mg/kg/day, gavage) from weeks 10–12 of diet. Concentration‐response curves to phenylephrine (PE; α1‐adrenoceptor agonist) and potassium chloride (KCl; depolarizing agent) as well as neurogenic contractions produced by electrical‐field stimulation (EFS; 1–32 Hz, 50 V, 10 s) were obtained. Stereological analysis, reactive‐oxygen species (ROS) levels, RT‐PCR for neuronal growth factor (NGF) and NADPH subunit gp91phox were all performed in the prostatic tissues in all groups.ResultsA significant increase (P<0.01) in the prostate smooth muscle contractions (PSM) to PE and KCl were observed in obese group compared with control animals. Likewise, EFS‐induced PSM contractions were higher in obese animals in all frequencies employed. Resveratrol fully restored the enhanced PSM contractions to PE, KCl and EFS in obese group. ROS levels were 87% higher (P<0.001) in prostate from obese mice. Moreover, mRNA expression for gp91phox was 57% higher (P<0.05) in prostate of obese mice. Resveratrol restored the augmented ROS production and gp91phox mRNA in obese mice, without affecting these parameters in the control group. In prostate from obese mice, the stereological analysis showed epithelial polyps formation and reduced lumen area whereas stromal and smooth muscle cells layer remained unchanged. A significant increase by about of 70% (P<0.01) in mRNA expression for NGF was also found in prostate of obese mice. Resveratrol significantly restored the NGF mRNA expression, and attenuated the epithelial alterations, without affecting the reduced luminal area.ConclusionA two‐week treatment with resveratrol is capable to reverse the prostatic dysfunctions in obesity mice. Resveratrol may be a good pharmacological option to prevent obesity‐associated prostatic dysfunctions.Support or Funding InformationFundação de Amparo à Pesquisa do Estado de São Paulo ‐ FAPESP (2016/01178‐6)
Drugging the Gut Microbiome for the Treatment of Alcohol‐Induced Liver Injury
Authors: Helsley Robert N. , Schugar Rebecca C. , Ferguson Daniel , Gromovsky Anthony D. , Neumann Chase , Wang Zeneng , Allende Daniela , Nagy Laura E. , Hazen Stanley L. , Brown Jonathan M. 
Published: November 2023

ObjectivesSustained alcohol abuse initiates a progressive disease pathogenesis involving simple steatosis, steatohepatitis, fibrosis, cirrhosis, and in some cases hepatocellular carcinoma. There is mounting evidence that microbes resident in the human intestine represent a key transmissible factor promoting inflammatory diseases including alcoholic liver disease (ALD). However, mechanisms by which gut microbiota synergize with excessive alcohol intake to promote ALD are poorly understood. We have recently revealed a metaorganismal pathway where nutrients in high fat foods can be metabolized by gut microbes to generate trimethylamine (TMA), which is subsequently metabolized by the host enzyme flavin‐containing monooxygenase 3 (FMO3) to produce the pro‐atherogenic metabolite trimethylamine‐N‐oxide (TMAO). Hepatic FMO3 mRNA levels are suppressed in alcoholics and breath levels of TMA correlate with the severity of alcoholic hepatitis. Thus, this study investigates whether pharmacological inhibition of gut microbe‐derived TMA production can blunt ethanol‐induced liver injuryMethods and ResultsWe first determined if ethanol feeding would alter circulating TMA and TMAO levels in mice. Acute (6% vol/vol Lieber DiCarli) and chronic (25 days Lieber DiCarli) isocaloric pair‐ and ethanol‐feeding elicited increases in both TMA and TMAO levels. We then employed a novel approach to block TMA production by using a small molecule inhibitor (CC08) targeting the gut microbial TMA‐producing enzyme CutC/D. CC08 treatment effectively abolished ethanol‐elicited increases in TMA and TMAO. In parallel, CC08 treated mice were completely protected against ethanol‐induced hepatic fat deposition, hepatocellular inflammation, and elevated alanine aminotransferase levels. Collectively, these results suggest inhibiting gut microbial production of TMA can blunt ethanol‐induced liver injury.ConclusionsOur results establish the TMA/TMAO pathway as an important regulator of ethanol‐induced liver injury. Inhibition of TMA production by utilizing small molecule inhibitors targeting the TMA lyase, such as CC08, may represent a novel therapeutic approach to combat ethanol‐induced liver injury.Support or Funding InformationP50 (AA024333‐01)
Role of Hypoxia‐Inducible‐Factor‐2α in Transcriptional Regulation of Heme Oxygenase‐1 in Hypoxic Cardiomyocytes
Authors: Eadie Ashley L. , Allwood Melissa A. , Platt Mathew J. , Huber Jason , Trivedi Purvi C. , Madhu Malav N. , Pulinilkunnil Thomas C. , Simpson Jeremy A. , Brunt Keith R. 
Published: November 2023

INTRODUCTIONThe heme metabolism pathway is a novel therapeutic target in the management of heart failure, with cytoprotection mediated through induction of heme oxygenase‐1 (HMOX1). However, translation of HMOX1‐targeted therapeutics to the clinic has not occurred. Understanding of heme bioavailability regulation in cardiomyocytes, particularly during hypoxia or heart failure, is incomplete. The molecular response to hypoxia is largely regulated by hypoxia inducible transcription factors (HIFs). HIF1α transcriptionally regulates HMOX1 in acute, severe hypoxia but the role of HIF2α in heme metabolism is unknown. A detailed understanding of the differences in molecular regulation between acute or chronic and severe or moderate hypoxia in cardiomyocytes is required.HYPOTHESISHypoxia‐inducible factor 2α (HIF2α) contains heme‐regulatory motifs that are sensitized by heme bioavailability at various degrees of hypoxia in cardiomyocytes to regulate the acute expression of HMOX1 in vitro and in experimental models of heart failure in vivo.METHODSAcute myocardial infarction (AMI)‐induced heart failure was modeled through permanent surgical ligation of the left anterior descending coronary artery in mice. Hypertensive heart failure was modeled through transverse aortic constriction (TAC). Expression of heme regulatory enzymes and hypoxia inducible factors were measured via Western Blot, qPCR and heme content assay. In vitro, hypoxia was established by incubating H9C2 and neonatal rat cardiomyocytes in an adjustable‐oxygen chamber. HIF1α and HIF2α were knocked down or overexpressed through adenoviral vectors. To investigate the role of heme bioavailability in HIF2α sensitization, cells were incubated with the heme surrogate, hemin.RESULTSIn vivo, heme levels were increased in both AMI and TAC‐induced heart failure progressively, however not due to increased heme synthesis enzymes. In vitro, HMOX1 was increased by HIF2α more than by HIF1α overexpression. This response was synergistically increased in heme‐replete hypoxia with HIF2α, but not HIF1α, overexpression.CONCLUSIONSWe have shown for the first time that HIF2α is a novel regulator of HMOX1. Further understanding of heme homeostasis in the heart is necessary to optimize therapeutic targeting of the heme metabolic pathway in heart failure. Further, we show that HIF2α has a distinct role from HIF1α as it is sensitive to heme bioavailability and not an exclusive oxygen sensor.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada
A transgenic mouse model to study a novel PRKAG2 mutation (K475E) causing infantile‐onset hypertrophic cardiomyopathy
Authors: XU YANCHUN , Liu Hong , Phornphutkul Chanika , Hardie Grahame , Dudley Samuel C , Padbury James F , Tseng Yi‐Tang 
Published: November 2023

BackgroundPRKAG2 encodes the γ2 subunit isoform of AMPK, a heterotrimeric enzyme with major roles in regulation of energy metabolism in response to cellular stress. Mutations in PRKAG2 have been implicated in hypertrophic cardiomyopathy (HCM). We identified a novel PRKAG2 mutation in a neonate with prenatal onset of HCM noted on a 27‐week prenatal ultrasound. Molecular testing for HCM revealed a de novo PRKAG2 mutation (K475E). We have demonstrated that overexpressing the K475E mutant in vitro leads to activation of cell growth pathway. We also have demonstrated that K475E mutation led to increases in cell size and area which can be reversed by rapamycin.ObjectiveTo developed transgenic mouse models to confirm K475E‐induced cardiac phenotype, determine the downstream signaling pathways involved, and test targeted therapy for K475E‐induced HCM using rapamycin.MethodsHuman WT and K475E DNA constructs were inserted into a pBluescript vector with the mouse α‐myosin heavy chain promoter. Transgenic mice with the cardiac‐specific overexpression of WT (TgWT) or the K475E mutation (TgK475E) were established by pronucleus microinjection. Survival curve and cardiac hypertrophy were examined and cardiac function changes were monitored by echocardiography.ResultsMale TgK475E mice were prone to sudden death with only 50% survived by 13‐week old. Hypertrophy in TgK475E mice was confirmed by their significant increases in heart weight/body weight and heart weight/tibial length ratios versus the non‐transgenic control and TgWT mice. Histology revealed large vacuoles and high glycogen content in TgK475E myocytes throughout the ventricles. Echocardiography confirmed that LV mass dramatically increased in TgK475E mice starting from 5 weeks of age. At 6‐week old, ejection fraction (EF) was more than 70% in TgK475E mice, which then decreased to less than 30% by 18‐week old. Fraction shortening (FS) in TgK475E mice showed similar trend. In contrast, EF and FS in non‐transgenic control and TgWT mice were not significantly changed. Compared to nontransgenic control and TgWT mice, Vd, Vs, LIVD (d) and LIVD (s) were all significantly increased in TgK475E mice starting at 7‐week of age. 4‐week Rapamycin treatment dramatically decreased the ratios of heart weight/body weight and heart weight/tibia length in TgK475E mice.ConclusionThese results indicate the transgenic mouse model reflects the early onset phenotype of the K475E mutation‐induced HCM. Targeted therapeutic strategy with mTOR inhibition is partially effective and should be studied further.Support or Funding InformationThis study was supported by NIH P30GM114750 (J.P., Y.‐T.T.) and Oh‐Zopfi Research Award, Women & Infant's Hospital (Y.‐T.T.). We thank the COBRE in Perinatal Biology Core and Kilguss Core Facility for the excellent molecular and microscopy supports.
Spontaneous Dystrophic Cardiac Calcinosis in C.B‐17 SCID Mice
Authors: Raghunathan Suchi , Reynolds Corey L. , Stewart M. David , Schwartz Robert J. , McConnell Bradley K 
Published: November 2023

Animal models have a pivotal role in biomedical research and contribute significantly to the study of human disease. C.B‐17 SCID mice which are homozygous for prkdscid mutation and have BALB/c background, have been used to support research in cancer, diabetes, obesity, cardiovascular diseases and many other areas. In the current study, we report severe cardiac calcinosis in C.B‐17 SCID male mice at 10 weeks of age, particularly the right ventricular myocardium. Dystrophic cardiac calcinosis is a characteristic of certain inbred strains of mice of which BALB/c background mice exhibit more susceptibility. It is characterized by myocardial injury, calcification and necrosis of the tissue. Here, we analyzed the ECG and echocardiogram of C.B‐17 SCID mice from two different colonies; Germantown, NY colony and Cambridge City, IN colony of Taconic Biosciences. Histological analysis was used to characterize the calcinotic lesions and fibrosis. At 10 weeks of age, 61% of the total C.B‐17 SCID mice from both colonies exhibited significant ventricular calcinosis, predominantly on the right ventricle. The frequency of calcinosis was more than 50% in the Cambridge City mouse colony and 25% in the Germantown mouse colony. The ECG recordings of unanesthetized mice did not exhibit any significant differences between calcinotic and non‐calcinotic mice from either colony. Cardiac function wall dimensions, derived from cardiac echocardiograms, also did not exhibit any significant difference between calcinotic and non‐calcinotic mice from either colonies. However, histology showed necrosis and calcium deposits within the myocardium. In conclusion, C.B‐17 SCID mice exhibit severe dystrophic cardiac calcinosis as early as 10 weeks of age. These strain of mice should be cautiously considered for other disease model studies where calcium homeostasis has a significant role to play.Support or Funding InformationUniversity of Houston
Post‐Infarct Remodeling in the Myocardium is Regulated by Hippo/YAP Signaling
Authors: Madhu Malav N. , Eadie Ashley L. , Aguiar Christie , Platt Mathew J. , Hassan Ansar , Simpson Jeremy A. , Brunt Keith R. 
Published: November 2023

BACKGROUNDVentricular remodeling is a complex process involving cell death, inflammation, fibrosis, cardiomyocyte hypertrophy. Recent studies show that Hippo/YAP signaling regulates cardiomyocyte growth and survival following ischemic injury in the myocardium. However, its role in ventricular remodeling is still poorly understood and may hold the potential for therapeutic targeting. In this study, we investigated the expression of Hippo/YAP signaling proteins in the mouse model of acute myocardial infarction.METHODSFor acute myocardial infarction (AMI), mice were sedated with ketamine (50mg/kg) and xylazine (5mg/kg), intubated, ventilated, and maintained with 2% isoflurane. Through a left thoracotomy, the left coronary artery was ligated 1 to 2 mm below the border of the left atrial appendage. Animals were sacrificed after 4 weeks post AMI and hearts were harvested and frozen at −80°C. Tissues were homogenized and subjected to western blot analysis.RESULTSImmunoblot analysis of heart tissues show increased expression of β‐MHC, a protein commonly associated with ventricular remodeling and hypertrophy, in 4 week AMI hearts compared to sham. We report a significant increase in Hippo pathway components like Mst1, Mst2, pMob1 and YAP binding protein such as 14‐3‐3 in 4 week AMI hearts compared to sham hearts. On the other hand, YAP expression was reduced in 4 week AMI group compared to control group.CONCLUSIONCollectively, our data suggest that the kinase cascade in Hippo/YAP pathway is activated resulting in YAP inactivation, which may contribute to ventricular remodeling following myocardial infarction.Support or Funding InformationNatural Sciences and Engineering Research Council of Canada
Clofibrate, a Unique Fibrate that Augments Cardiac Contractility Through a PPARa‐independent Mechanism
Authors: Ponnapureddy Rakesh , Gill Tarana , Kim Seo‐Hyun , Mirza Omer , Stone Jessica , Anderson Jon , Touchberry Chad , Wacker Michael 
Published: November 2023

BackgroundFibrates are a group of synthetic peroxisomal proliferator‐activated receptor alpha (PPARα) agonists that have been in clinical use for several decades for their hypolipidemic properties. Clofibrate is the pioneer drug in the class of fibrates which have been shown to reduce triglyceride levels and elevate HDL cholesterol levels through PPARα agonism. More recently, non‐genomic actions of fibrates have received attention. In our previous experiments, we have demonstrated that fibrates induced acute relaxation of mouse aorta through non‐PPARα mediated mechanisms. Clofibrate, in particular, has been shown to inhibit Na+/K+ ATPase (NKA) activity in the rat kidney. It is well known that the NKA pump also plays an important role in maintaining calcium homeostasis in cardiomyocytes and NKA pump inhibition results in increased cardiac contractility. However, the direct effects of fibrates on cardiac muscle have not been tested. The objective of this study was to determine if clofibrate alters cardiac contractility independent of stimulation of PPARa.MethodsLeft ventricular muscle strips were isolated from 12–16 week‐old male wild type (WT) and PPARa null mice at 1 Hz in an oxygenated organ bath. Contractile waveforms were analyzed after treatment with clofibrate, clofibrate ester, gemfibrozil, and Wyeth 14,643 and also compared to the well‐known NKA pump inhibitor ouabain.ResultsWe found that the effect of clofibrate on cardiac contractility in WT mice was concentration‐dependent with a 1.3 and 1.5‐fold increase above baseline at 2 and 20 μM concentrations, respectively (n= 7; P<0.05) and with no significant increase at 0.2 mM (P>0.05). The contractile response to clofibrate in PPARα deficient muscle strips was similar to WT with significant increases at 2 and 20 mM (n=7; P<0.05). Clofibrate ester, gemfibrozil and Wyeth 14,643, did not increase cardiac contractility (n=4; P>0.05). The change in contractile force of the muscle strips after administration of clofibrate was comparable to ouabain in WT mice (n=5; P<0.05).ConclusionsOur findings show that clofibrate uniquely augments cardiac contractility through a PPARα‐independent mechanism which was comparable to the effect produced by the NKA pump inhibitor ouabain. Based on these results, there may be a new mechanism of action for clofibrate in cardiac contractility and could be explored as a novel heart failure treatment strategy.