SARS-CoV-2 infection of the pancreas promotes thrombofibrosis and is associated with new-onset diabetes

Evidence suggests an association between severe acute respiratory syndrome-cornavirus-2 (SARS-CoV-2) infection and the occurrence of new-onset diabetes. We examined pancreatic expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), the cell entry factors for SARS-CoV-2, using publicly available single-cell RNA sequencing data sets, and pancreatic tissue from control male and female nonhuman primates (NHPs) and humans. We also examined SARS-CoV-2 immunolocalization in pancreatic cells of SARS-CoV-2-infected NHPs and patients who had died from coronavirus disease 2019 (COVID-19). We report expression of ACE2 in pancreatic islet, ductal, and endothelial cells in NHPs and humans. In pancreata from SARS-CoV-2-infected NHPs and COVID-19 patients, SARS-CoV-2 infected ductal, endothelial, and islet cells. These pancreata also exhibited generalized fibrosis associated with multiple vascular thrombi. Two out of 8 NHPs developed new-onset diabetes following SARS-CoV-2 infection. Two out of 5 COVID-19 patients exhibited new-onset diabetes at admission. These results suggest that SARS-CoV-2 infection of the pancreas may promote acute and especially chronic pancreatic dysfunction that could potentially lead to new-onset diabetes

Regional expression of HOXA4 along the aorta and its potential role in human abdominal aortic aneurysms

<p>Abstract</p> <p>Background</p> <p>The infrarenal abdominal aorta exhibits increased disease susceptibility relative to other aortic regions. Allograft studies exchanging thoracic and abdominal segments showed that regional susceptibility is maintained regardless of location, suggesting substantial roles for embryological origin, tissue composition and site-specific gene expression.</p> <p>Results</p> <p>We analyzed gene expression with microarrays in baboon aortas, and found that members of the HOX gene family exhibited spatial expression differences. <it>HOXA4 </it>was chosen for further study, since it had decreased expression in the abdominal compared to the thoracic aorta. Western blot analysis from 24 human aortas demonstrated significantly higher HOXA4 protein levels in thoracic compared to abdominal tissues (<it>P </it>< 0.001). Immunohistochemical staining for HOXA4 showed nuclear and perinuclear staining in endothelial and smooth muscle cells in aorta. The <it>HOXA4 </it>transcript levels were significantly decreased in human abdominal aortic aneurysms (AAAs) compared to age-matched non-aneurysmal controls (<it>P </it>< 0.00004). Cultured human aortic endothelial and smooth muscle cells stimulated with INF-γ (an important inflammatory cytokine in AAA pathogenesis) showed decreased levels of HOXA4 protein (<it>P </it>< 0.0007).</p> <p>Conclusions</p> <p>Our results demonstrated spatial variation in expression of HOXA4 in human aortas that persisted into adulthood and that downregulation of <it>HOXA4 </it>expression was associated with AAAs, an important aortic disease of the ageing population.</p

Expression of SARS-CoV-2 Entry Factors in the Pancreas of Normal Organ Donors and Individuals with COVID-19

This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Diabetes is associated with increased mortality from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Given literature suggesting a potential association between SARS-CoV-2 infection and diabetes induction, we examined pancreatic expression of angiotensin-converting enzyme 2 (ACE2), the key entry factor for SARS-CoV-2 infection. Specifically, we analyzed five public scRNA-seq pancreas datasets and performed fluorescence in situ hybridization, western blotting, and immunolocalization for ACE2 with extensive reagent validation on normal human pancreatic tissues across the lifespan, as well as those from coronavirus disease 2019 (COVID-19) cases. These in silico and ex vivo analyses demonstrated prominent expression of ACE2 in pancreatic ductal epithelium and microvasculature, but we found rare endocrine cell expression at the mRNA level. Pancreata from individuals with COVID-19 demonstrated multiple thrombotic lesions with SARS-CoV-2 nucleocapsid protein expression that was primarily limited to ducts. These results suggest SARS-CoV-2 infection of pancreatic endocrine cells, via ACE2, is an unlikely central pathogenic feature of COVID-19-related diabetes.We thank the families of the organ donors and autopsy subjects for the gift of tissues. We also thank Jill K. Gregory, CMI (Icahn School of Medicine at Mount Sinai, New York, NY) for preparing the graphical abstract. These efforts were supported by NIH P01 AI042288 and UC4 DK108132 (M.A.A.); JDRF (M.A.A.); NIH R01 DK122160 (M.C.-T.); NIH R01 AI134971 and P30 DK020541 (D.H.); JDRF 3-PDF-2018-575-A-N (V.V.D.H.); R01 DK093954 , R21 DK119800-01A1 , UC4 DK104166 , and U01 DK127786 (C.E.-M.); VA Merit Award I01BX001733 (C.E.-M.); Imaging Core of NIH/ NIDDK P30 DK097512 (C.E.-M.); gifts from the Sigma Beta Sorority , the Ball Brothers Foundation , and the George and Frances Ball Foundation (C.E.-M.); the Network for Pancreatic Organ Donors with Diabetes ( nPOD ; RRID: SCR_014641 ) ( 5-SRA-2018-557-Q-R ); and The Leona M. & Harry B. Helmsley Charitable Trust ( 2018PG-T1D053 ). The authors also wish to acknowledge the Islet and Physiology Core of the Indiana Diabetes Research Center ( P30DK097512 ). The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication

Heat stress activates AKT via focal adhesion kinase-mediated pathway in neonatal rat ventricular myocytes

Heat stress (HS)-induced cardioprotection is associated with increased paxillin localization to the membrane fraction of neonatal rat ventricular myocytes (NRVM). The purpose of this study was 1) to examine the subcellular signaling pathways activated by HS; 2) to determine whether myocardial stress organizes and activates an integrated survival pathway; and 3) to investigate potential downstream cytoprotective proteins activated by HS. After HS, NRVM were subjected to chemical inhibitors (CI) designed to simulate ischemia by inhibiting both glycolysis and mitochondrial respiration. Protein kinase B (AKT) expression (wild type) was increased selectively with an adenoviral vector. Cell signaling was analyzed with Western blot analysis, while oncosis/apoptosis was assayed by measuring Trypan blue exclusion and/or terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining, respectively. HS increased phosphorylation of focal adhesion kinase (FAK) at tyrosine 397 but did not adversely affect the viability of NRVM before CI. HS increased association between FAK and phosphatidylinositol 3-kinase as well as causing a significant increase in AKT activity. Increased expression of wild-type AKT protected myocytes from both oncotic and apoptotic cell death. Increased expression of a FAK inhibitor, FRNK, reduced AKT phosphorylation in response to HS both at time 0 and after 10 min of CI compared with myocytes expressing empty virus. We conclude that myocardial stress activates cytoskeleton-based signaling pathways that are associated with protection from lethal cell injury