scholarly journals Persistent Infection of Human Pancreatic Islets by Coxsackievirus B Is Associated with Alpha Interferon Synthesis in β Cells

2000 ◽  
Vol 74 (21) ◽  
pp. 10153-10164 ◽  
Author(s):  
Wassim Chehadeh ◽  
Julie Kerr-Conte ◽  
François Pattou ◽  
Gunar Alm ◽  
Jean Lefebvre ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Islet Cells ◽  
Human Islets ◽  
Adult Brain ◽  
Viral Rna ◽  
Alpha Interferon ◽  
Β Cells ◽  
Human Pancreatic Islets ◽  
Reverse Transcription Pcr ◽  
Vp1 Capsid Protein

ABSTRACT The interactions of coxsackievirus B3 (CVB3), CVB4E2 (diabetogenic), and CVB4JBV (nondiabetogenic) strains with human pancreatic islets from eight adult brain-dead donors were investigated. Persistent replication of viruses in human islets was proved by detection of viral RNA by in situ hybridization, VP1 capsid protein by immunofluorescence (IF) staining, negative-strand viral RNA by reverse transcription-PCR in extracted RNA from islets, and release of infectious particles up to 30 days after infection without obvious cytolysis. By double IF staining, glucagon-containing α cells and insulin-containing β cells were shown to be susceptible to CVB. The persistence of CVB3 and CVB4 in islet cells was associated with the chronic synthesis of alpha interferon (IFN-α), as evidenced by the detection of IFN-α mRNA and immunoreactive IFN-α with antiviral activity. By double IF staining, IFN-α was detected in insulin-producing β cells only. Experiments with neutralizing anti-coxsackievirus and adenovirus receptor (CAR) antibodies provided evidence that CAR was expressed by α and β cells and that it played a role in the infection of these cells with CVB and the consecutive IFN-α expression in β cells. The viral replication and the expression of IFN-α in islets were not restricted to the CVB4E2 diabetogenic strain and did not depend on the genetic background of the host. The neutralization of endogenous IFN-α significantly enhanced the CVB replication in islet cells and resulted in rapid destruction of islets. Thus, human β cells can harbor a persistent CVB infection, and CVB-induced IFN-α plays a role in the initiation and/or maintenance of chronic CVB infection in human islets.

scholarly journals Asymmetrical distribution of δ and PP cells in human pancreatic islets

2016 ◽  
Vol 229 (2) ◽  
pp. 123-132 ◽  
Author(s):  
Charlotte Barbieux ◽  
Géraldine Parnaud ◽  
Vanessa Lavallard ◽  
Estelle Brioudes ◽  
Jérémy Meyer ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pancreatic Islets ◽  
Islet Cells ◽  
Human Islets ◽  
Human Pancreatic Islets ◽  
Asymmetrical Distribution ◽  
Computerized Morphometry ◽  
Vascular Channels ◽  
Type 2 Diabetic

The aim of this study was to evaluate the location of PP and δ cells in relation to the vascularization within human pancreatic islets. To this end, pancreas sections were analysed by immunofluorescence using antibodies against endocrine islet and endothelial cells. Staining in different islet areas corresponding to islet cells adjacent or not to peripheral or central vascular channels was quantified by computerized morphometry. As results, α, PP and δ cells were preferentially found adjacent to vessels. In contrast to α cells, which were evenly distributed between islet periphery and intraislet vascular channels, PP and δ cells had asymmetric and opposite distributions: PP staining was higher and somatostatin staining was lower in the islet periphery than in the area around intraislet vascular channels. Additionally, frequencies of PP and δ cells were negatively correlated in the islets. No difference was observed between islets from the head and the tail of the pancreas, and from type 2 diabetic and non-diabetic donors. In conclusion, the distribution of δ cells differs from that of PP cells in human islets, suggesting that vessels at the periphery and at the centre of islets drain different hormonal cocktails.

scholarly journals Using single-nucleus RNA-sequencing to interrogate transcriptomic profiles of archived human pancreatic islets

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Giorgio Basile ◽  
Sevim Kahraman ◽  
Ercument Dirice ◽  
Hui Pan ◽  
Jonathan M. Dreyfuss ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Rna Sequencing ◽  
Islet Cells ◽  
Strong Association ◽  
Cell Types ◽  
Human Islets ◽  
Human Islet ◽  
Human Pancreatic Islets ◽  
Single Nucleus ◽  
Type Gene

Abstract Background Human pancreatic islets are a central focus of research in metabolic studies. Transcriptomics is frequently used to interrogate alterations in cultured human islet cells using single-cell RNA-sequencing (scRNA-seq). We introduce single-nucleus RNA-sequencing (snRNA-seq) as an alternative approach for investigating transplanted human islets. Methods The Nuclei EZ protocol was used to obtain nuclear preparations from fresh and frozen human islet cells. Such preparations were first used to generate snRNA-seq datasets and compared to scRNA-seq output obtained from cells from the same donor. Finally, we employed snRNA-seq to obtain the transcriptomic profile of archived human islets engrafted in immunodeficient animals. Results We observed virtually complete concordance in identifying cell types and gene proportions as well as a strong association of global and islet cell type gene signatures between scRNA-seq and snRNA-seq applied to fresh and frozen cultured or transplanted human islet samples. Conclusions We propose snRNA-seq as a reliable strategy to probe transcriptomic profiles of freshly harvested or frozen sources of transplanted human islet cells especially when scRNA-seq is not ideal.

scholarly journals The direct effects of the angiotensin-converting enzyme inhibitors, zofenoprilat and enalaprilat, on isolated human pancreatic islets

2006 ◽  
Vol 154 (2) ◽  
pp. 355-361 ◽  
Author(s):  
Roberto Lupi ◽  
Silvia Del Guerra ◽  
Marco Bugliani ◽  
Ugo Boggi ◽  
Franco Mosca ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Secretion ◽  
Pancreatic Islets ◽  
Ace Inhibitors ◽  
High Glucose ◽  
Ace Inhibitor ◽  
Human Islets ◽  
Converting Enzyme ◽  
Β Cells ◽  
Human Pancreatic Islets

Objective: Data from prospective studies suggest a significant reduction in the risk of new diabetes from drug therapies containing angiotensin-converting enzyme (ACE) inhibitors. Since the renin–angiotensin system (RAS) has been found locally in several tissues and cells, including pancreatic islets, we hypothesized that the positive metabolic effects of ACE inhibitors may be due to a beneficial action of these compounds on insulin-secreting β-cells. Design and methods: Isolated human pancreatic islets were studied after 24 h of incubation with 22.2 mmol/l glucose, with or without the presence in the incubation medium of 0.5–6.0 mmol/l zofenoprilat or enalaprilat, ACE inhibitor drugs which differ by the presence of a sulphydryl or a carboxyl group in their structural formula. Functional and molecular studies were then performed to assess insulin secretion, redox balance, mRNA and protein expression. Results: Angiotensinogen, ACE and angiotensin type 1 receptor mRNA expression increased in islets cultured in high glucose; this was similarly prevented by the presence of either ACE inhibitor. As expected, preculture of human islets in high glucose determined a marked reduction in insulin secretion which was associated with enhanced oxidative stress, as shown by increased nitrotyrosine concentrations, and enhanced expression of protein kinase C β and NADPH oxidase. The presence of either of the ACE inhibitors counteracted several of the deleterious effects of high glucose exposure, including reduction of insulin secretion and increased oxidative stress; zofenoprilat showed significantly more marked effects. Conclusions: These results showed that: (a) RAS molecules are present in human islets and their expression is sensitive to glucose concentration, (b) ACE inhibitors, and in particular zofenoprilat, protect human islets from glucotoxicity and (c) the effects of ACE inhibition are associated with decreased oxidative stress. Together, these findings provide evidence that the possible beneficial effects of ACE inhibitors in human diabetes are due, at least in part, to a protective action on pancreatic β-cells.

scholarly journals Combinatorial transcription factor profiles predict mature and functional human islet α and β cells

2021 ◽  
Author(s):  
Shristi Shrestha ◽  
Diane C. Saunders ◽  
John T. Walker ◽  
Joan Camunas-Soler ◽  
Xiao-Qing Dai ◽  
...  
Keyword(s):  
Islet Cells ◽  
Hormone Secretion ◽  
Developmental State ◽  
Human Islets ◽  
Glucose Sensing ◽  
Pancreatic Tissue ◽  
Β Cells ◽  
Cellular Processes ◽  
Normal Human ◽  
Multiple Donors

ABSTRACTIslet-enriched transcription factors (TFs) exert broad control over cellular processes in pancreatic α and β cells and changes in their expression are associated with developmental state and diabetes. However, the implications of heterogeneity in TF expression across islet cell populations are not well understood. To define this TF heterogeneity and its consequences for cellular function, we profiled >40,000 cells from normal human islets by scRNA-seq and stratified α and β cells based on combinatorial TF expression. Subpopulations of islet cells co-expressing ARX/MAFB (α cells) and MAFA/MAFB (β cells) exhibited greater expression of key genes related to glucose sensing and hormone secretion relative to subpopulations expressing only one or neither TF. Moreover, all subpopulations were identified in native pancreatic tissue from multiple donors. By Patch-seq, MAFA/MAFB co-expressing β cells showed enhanced electrophysiological activity. Thus, these results indicate combinatorial TF expression in islet α and β cells predicts highly functional, mature subpopulations.

Des-Acyl Ghrelin Fragments and Analogues Promote Survival of Pancreatic β-Cells and Human Pancreatic Islets and Prevent Diabetes in Streptozotocin-Treated Rats

2012 ◽  
Vol 55 (6) ◽  
pp. 2585-2596 ◽  
Author(s):  
Riccarda Granata ◽  
Fabio Settanni ◽  
Michel Julien ◽  
Rita Nano ◽  
Gabriele Togliatto ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Human Pancreatic Islets ◽  
Acyl Ghrelin

Metformin, but not leptin, regulates AMP-activated protein kinase in pancreatic islets: impact on glucose-stimulated insulin secretion

2004 ◽  
Vol 286 (6) ◽  
pp. E1023-E1031 ◽  
Author(s):  
Isabelle Leclerc ◽  
Wolfram W. Woltersdorf ◽  
Gabriela da Silva Xavier ◽  
Rebecca L. Rowe ◽  
Sarah E. Cross ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Insulin Secretion ◽  
Protein Kinase ◽  
Pancreatic Islets ◽  
Human Islets ◽  
Β Cells ◽  
Min6 Cells ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase

Metformin, a drug widely used in the treatment of type 2 diabetes, has recently been shown to act on skeletal muscle and liver in part through the activation of AMP-activated protein kinase (AMPK). Whether metformin or the satiety factor leptin, which also stimulates AMPK in muscle, regulates this enzyme in pancreatic islets is unknown. We have recently shown that forced increases in AMPK activity inhibit insulin secretion from MIN6 cells (da Silva Xavier G, Leclerc I, Varadi A, Tsuboi T, Moule SK, and Rutter GA. Biochem J 371: 761–774, 2003). Here, we explore whether 1) glucose, metformin, or leptin regulates AMPK activity in isolated islets from rodent and human and 2) whether changes in AMPK activity modulate insulin secretion from human islets. Increases in glucose concentration from 0 to 3 and from 3 to 17 mM inhibited AMPK activity in primary islets from mouse, rat, and human, confirming previous findings in insulinoma cells. Incubation with metformin (0.2–1 mM) activated AMPK in both human islets and MIN6 β-cells in parallel with an inhibition of insulin secretion, whereas leptin (10–100 nM) was without effect in MIN6 cells. These studies demonstrate that AMPK activity is subject to regulation by both glucose and metformin in pancreatic islets and clonal β-cells. The inhibitory effects of metformin on insulin secretion may therefore need to be considered with respect to the use of this drug for the treatment of type 2 diabetes.

scholarly journals Palmitate Activates Autophagy in INS-1E β-Cells and in Isolated Rat and Human Pancreatic Islets

PLoS ONE ◽  
2012 ◽  
Vol 7 (5) ◽  
pp. e36188 ◽  
Author(s):  
Luisa Martino ◽  
Matilde Masini ◽  
Michela Novelli ◽  
Pascale Beffy ◽  
Marco Bugliani ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
Β Cells ◽  
Human Pancreatic Islets ◽  
Isolated Rat

scholarly journals Expression Pattern of 12-Lipoxygenase in Human Islets With Type 1 Diabetes and Type 2 Diabetes

2015 ◽  
Vol 100 (3) ◽  
pp. E387-E395 ◽  
Author(s):  
Wojciech J. Grzesik ◽  
Joseph L. Nadler ◽  
Yui Machida ◽  
Jerry L. Nadler ◽  
Yumi Imai ◽  
...  
Keyword(s):  
Outcome Measure ◽  
Islet Cells ◽  
Human Islets ◽  
Β Cells ◽  
Β Cell ◽  
Diabetes Development ◽  
12 Lipoxygenase ◽  
Type 2 Diabetic

Context: Inflammation in the pancreas can cause β-cell stress, leading to diabetes development. Access to human pancreas tissues via the Network for Pancreatic Organ Donors with Diabetes (nPOD) has allowed characterization of pathways leading to this inflammation. Objective: 12-Lipoxygenase (12-LO) induces inflammation and has been implicated in diabetes development. Our goal was to determine expression of 12-LO in human islets from control, autoantibody-positive, type 1 diabetic, and type 2 diabetic nPOD pancreas donors. Design: Pancreas tissues from nPOD donors were examined by immunohistochemistry and immunofluorescence for islet expression of 12-LO in different subsets of islet cells. Participants: Donor pancreas samples were obtained from nPOD based on disease status (control, n = 7; autoantibody-positive, n = 8; type 1 diabetic, n = 17; or type 2 diabetic donors, n = 15). Main Outcome Measure: Determination of 12-LO expression within human islets served as the main outcome measure, including distinguishing which types of islet cells expressed 12-LO. Results: Islets from control participants (nondiabetic) lacked islet expression of 12-LO. Of donors in the other groups, 25% to 37% expressed islet 12-LO with a clear inverse relation between the numbers of β-cells and 12-LO+ cells within islets of 12-LO+ cases. 12-LO expression was not seen within macrophages, endothelial cells, α-cells, or β-cells, but only within cells expressing low levels of pancreatic polypeptide (PP) and increased levels of vimentin. Conclusions: 12-LO expression colocalizes within a specific type of islet PP+ cell under prediabetic and diabetic conditions. The costaining of PP and vimentin suggests that 12-LO participates in the process leading to β-cell dedifferentiation in the islet.

scholarly journals Unraveling the role of the ghrelin gene peptides in the endocrine pancreas

2010 ◽  
Vol 45 (3) ◽  
pp. 107-118 ◽  
Author(s):  
Riccarda Granata ◽  
Alessandra Baragli ◽  
Fabio Settanni ◽  
Francesca Scarlatti ◽  
Ezio Ghigo
Keyword(s):  
Pancreatic Islets ◽  
Cell Biology ◽  
Islet Cell ◽  
Endocrine Pancreas ◽  
Islet Cells ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Islet Cell ◽  
Ghrelin Gene

The ghrelin gene peptides include acylated ghrelin (AG), unacylated ghrelin (UAG), and obestatin (Ob). AG, mainly produced by the stomach, exerts its central and peripheral effects through the GH secretagogue receptor type 1a (GHS-R1a). UAG, although devoid of GHS-R1a-binding affinity, is an active peptide, sharing with AG many effects through an unknown receptor. Ob was discovered as the G-protein-coupled receptor 39 (GPR39) ligand; however, its physiological actions remain unclear. The endocrine pancreas is necessary for glucose homeostasis maintenance. AG, UAG, and Ob are expressed in both human and rodent pancreatic islets from fetal to adult life, and the pancreas is the major source of ghrelin in the perinatal period. GHS-R1a and GPR39 expression has been shown in β-cells and islets, as well as specific binding sites for AG, UAG, and Ob. Ghrelin colocalizes with glucagon in α-islet cells, but is also uniquely expressed in ε-islet cells, suggesting a role in islet function and development. Indeed, AG, UAG, and Ob regulate insulin secretion in β-cells and isolated islets, promote β-cell proliferation and survival, inhibit β-cell and human islet cell apoptosis, and modulate the expression of genes that are essential in pancreatic islet cell biology. They even induce β-cell regeneration and prevent diabetes in streptozotocin-treated neonatal rats. The receptor(s) mediating their effects are not fully characterized, and a signaling crosstalk has been suggested. The present review summarizes the newest findings on AG, UAG, and Ob expression in pancreatic islets and the role of these peptides on β-cell development, survival, and function.

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