scholarly journals BET proteins are required for transcriptional activation of the senescent beta cell secretome in Type 1 Diabetes

2019 ◽  
Author(s):  
Peter J. Thompson ◽  
Ajit Shah ◽  
Charalampia-Christina Apostolopolou ◽  
Anil Bhushan
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Transcriptional Activation ◽  
Human Islets ◽  
Nod Mouse ◽  
Transcriptional Program ◽  
Protein Inhibition ◽  
Bet Protein

AbstractOBJECTIVEType 1 Diabetes (T1D) results from progressive loss of pancreatic beta cells due to autoimmune destruction. We recently reported that during the natural history of T1D in humans and the female nonobese diabetic (NOD) mouse model, beta cells acquire a senescence-associated secretory phenotype (SASP) that is a major driver of disease onset and progression, but the mechanisms that activate SASP in beta cells were not explored. The objective of this study was to identify transcriptional mechanisms of SASP activation in beta cells.METHODSWe used the female NOD mouse model of spontaneous autoimmune T1D and ex vivo experiments on NOD mouse and human islets to test the hypothesis that Bromodomain Extra-Terminal domain (BET) proteins activate the beta cell SASP transcriptional program.RESULTSHere we show that beta cell SASP is transcriptionally controlled by BET proteins, including BRD4. Chromatin analysis of key beta cell SASP genes in NOD islets revealed binding of BRD4 at active regulatory regions. BET protein inhibition in NOD islets diminished not only the transcriptional activation and secretion of SASP factors but also the non-cell autonomous activity. BET protein inhibition also decreased the extent of SASP induction in human islets exposed to DNA damage. The BET protein inhibitor iBET-762 prevented diabetes in NOD mice and also attenuated SASP in beta cells in vivo.CONCLUSIONSTaken together, our findings support a crucial role for BET proteins in the activation of the beta cell SASP transcriptional program. These studies suggest avenues for preventing T1D by transcriptional inhibition of SASP.

scholarly journals BET Proteins Are Required for Transcriptional Activation of the Senescent Islet Cell Secretome in Type 1 Diabetes

2019 ◽  
Vol 20 (19) ◽  
pp. 4776 ◽  
Author(s):  
Peter J. Thompson ◽  
Ajit Shah ◽  
Hara Apostolopolou ◽  
Anil Bhushan
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cells ◽  
Transcriptional Activation ◽  
Pancreatic Beta Cells ◽  
Islet Cells ◽  
Disease Onset ◽  
Protein Inhibition ◽  
Bet Protein

Type 1 diabetes (T1D) results from the progressive loss of pancreatic beta cells as a result of autoimmune destruction. We recently reported that during the natural history of T1D in humans and the female nonobese diabetic (NOD) mouse model, beta cells acquire a senescence-associated secretory phenotype (SASP) that is a major driver of disease onset and progression, but the mechanisms that activate SASP in beta cells were not explored. Here, we show that the SASP in islet cells is transcriptionally controlled by Bromodomain ExtraTerminal (BET) proteins, including Bromodomain containing protein 4 (BRD4). A chromatin analysis of key beta cell SASP genes in NOD islets revealed binding of BRD4 at active regulatory regions. BET protein inhibition in NOD islets diminished not only the transcriptional activation and secretion of SASP factors, but also the non-cell autonomous activity. BET protein inhibition also decreased the extent of SASP induction in human islets exposed to DNA damage. The BET protein inhibitor iBET-762 prevented diabetes in NOD mice and also attenuated SASP in islet cells in vivo. Taken together, our findings support a crucial role for BET proteins in the activation of the SASP transcriptional program in islet cells. These studies suggest avenues for preventing T1D by transcriptional inhibition of SASP.

scholarly journals Serum miR-204 is an early biomarker of type 1 diabetes-associated pancreatic beta-cell loss

2019 ◽  
Vol 317 (4) ◽  
pp. E723-E730 ◽  
Author(s):  
Guanlan Xu ◽  
Lance A. Thielen ◽  
Junqin Chen ◽  
Truman B. Grayson ◽  
Tiffany Grimes ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Cell Loss ◽  
Human Islets ◽  
Serum Samples ◽  
Early Biomarker

Pancreatic beta-cell death is a major factor in the pathogenesis of type 1 diabetes (T1D), but straightforward methods to measure beta-cell loss in humans are lacking, underlining the need for novel biomarkers. Using studies in INS-1 cells, human islets, diabetic mice, and serum samples of subjects with T1D at different stages, we have identified serum miR-204 as an early biomarker of T1D-associated beta-cell loss in humans. MiR-204 is a highly enriched microRNA in human beta-cells, and we found that it is released from dying beta-cells and detectable in human serum. We further discovered that serum miR-204 was elevated in children and adults with T1D and in autoantibody-positive at-risk subjects but not in type 2 diabetes or other autoimmune diseases and was inversely correlated with remaining beta-cell function in recent-onset T1D. Thus, serum miR-204 may provide a much needed novel approach to assess early T1D-associated human beta-cell loss even before onset of overt disease.

Beta-cell markers and autoantigen expression by a human insulinoma cell line: similarities to native beta cells

1996 ◽  
Vol 150 (1) ◽  
pp. 113-120 ◽  
Author(s):  
M G Cavallo ◽  
F Dotta ◽  
L Monetini ◽  
S Dionisi ◽  
M Previti ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Monoclonal Antibodies ◽  
Beta Cell ◽  
Cell Line ◽  
Beta Cells ◽  
Cell Markers ◽  
Insulinoma Cell ◽  
Insulinoma Cell Line ◽  
Human Insulinoma

Abstract In the present study we have evaluated the expression of different beta-cell markers, islet molecules and autoantigens relevant in diabetes autoimmunity by a human insulinoma cell line (CM) in order to define its similarities with native beta cells and to discover whether it could be considered as a model for studies on immunological aspects of Type 1 diabetes. First, the positivity of the CM cell line for known markers of neuroendocrine derivation was determined by means of immunocytochemical analysis using different anti-islet monoclonal antibodies including A2B5 and 3G5 reacting with islet gangliosides, and HISL19 binding to an islet glycoprotein. Secondly, the expression and characteristics of glutamic acid decarboxylase (GAD) and of GM2-1 ganglioside, both known to be islet autoantigens in diabetes autoimmunity and expressed by human native beta cells, were investigated in the CM cell line. The pattern of ganglioside expression in comparison to that of native beta cells was also evaluated. Thirdly, the binding of diabetic sera to CM cells reacting with islet cytoplasmic antigens (ICA) was studied by immunohistochemistry. The results of this study showed that beta cell markers identified by anti-islet monoclonal antibodies A2B5, 3G5 and HISL-19 are expressed by CM cells; similarly, islet molecules such as GAD and GM2-1 ganglioside are present and possess similar characteristics to those found in native beta cells; the pattern of expression of other gangliosides by CM cells is also identical to human pancreatic islets; beta cell autoantigen(s) reacting with antibodies present in islet cell antibodies (ICA) positive diabetic sera identified by ICA binding are also detectable in this insulinoma cell line. We conclude that CM cells show close similarities to native beta cells with respect to the expression of neuroendocrine markers, relevant beta cell autoantigens in Type 1 diabetes (GAD, GM2-1, ICA antigen), and other gangliosides. Therefore, this insulinoma cell line may be considered as an ideal model for studies aimed at investigating autoimmune phenomena occurring in Type 1 diabetes. Journal of Endocrinology (1996) 150, 113–120

scholarly journals Beta Cell Autophagy in the Pathogenesis of Type 1 Diabetes

2021 ◽  
Author(s):  
Charanya Muralidharan ◽  
Amelia K Linnemann
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Potential Role ◽  
Cell Dysfunction ◽  
Unconventional Secretion ◽  
Insulin Dependent

Type 1 diabetes is an insulin-dependent, autoimmune disease where the pancreatic beta cells are destroyed resulting in hyperglycemia. This multi-factorial disease involves multiple environmental and genetic factors, and has no clear etiology. Accumulating evidence suggests that early signaling defects within the beta cells may promote a change in the local immune mileu, contributing to autoimmunity. Therefore, many studies have been focused on intrinsic beta cell mechanisms that aid in restoration of cellular homeostasis under environmental conditions that cause dysfunction. One of these intrinsic mechanisms to promote homeostasis is autophagy, defects in which are clearly linked with beta cell dysfunction in the context of type 2 diabetes. Recent studies have now also pointed towards beta cell autophagy defects in the context of type 1 diabetes. In this perspectives review, we will discuss the evidence supporting a role for beta cell autophagy in the pathogenesis of type 1 diabetes, including a potential role for unconventional secretion of autophagosomes/lysosomes in the changing dialogue between the beta cell and immune cells.

scholarly journals Type 1 diabetes risk genes mediate pancreatic beta cell survival in response to proinflammatory cytokines

2021 ◽  
Author(s):  
Paola Benaglio ◽  
Han Zhu ◽  
Mei-Lin Okino ◽  
Jian Yan ◽  
Ruth Elgamal ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Cell Survival ◽  
Beta Cells ◽  
High Throughput ◽  
Proinflammatory Cytokines ◽  
Pancreatic Beta Cell ◽  
Regulatory Elements ◽  
A Genome

Beta cells intrinsically contribute to the pathogenesis of type 1 diabetes (T1D), but the genes and molecular processes that mediate beta cell survival in T1D remain largely unknown. We combined high throughput functional genomics and human genetics to identify T1D risk loci regulating genes affecting beta cell survival in response to the proinflammatory cytokines IL-1b, IFNg, and TNFa. We mapped 38,931 cytokine-responsive candidate cis-regulatory elements (cCREs) active in beta cells using ATAC-seq and single nuclear ATAC-seq (snATAC-seq), and linked cytokine-responsive beta cell cCREs to putative target genes using single cell co-accessibility and HiChIP. We performed a genome-wide pooled CRISPR loss-of-function screen in EndoC-betaH1 cells, which identified 867 genes affecting cytokine-induced beta cell loss. Genes that promoted beta cell survival and had up-regulated expression in cytokine exposure were specifically enriched at T1D loci, and these genes were preferentially involved in inhibiting inflammatory response, ubiquitin-mediated proteolysis, mitophagy and autophagy. We identified 2,229 variants in cytokine-responsive beta cell cCREs altering transcription factor (TF) binding using high-throughput SNP-SELEX, and variants altering binding of TF families regulating stress, inflammation and apoptosis were broadly enriched for T1D association. Finally, through integration with genetic fine mapping, we annotated T1D loci regulating beta cell survival in cytokine exposure. At the 16p13 locus, a T1D variant affected TF binding in a cytokine-induced beta cell cCRE that physically interacted with the SOCS1 promoter, and increased SOCS1 activity promoted beta cell survival in cytokine exposure. Together our findings reveal processes and genes acting in beta cells during cytokine exposure that intrinsically modulate risk of T1D.

Islet infiltration, cytokine expression and beta cell death in the NOD mouse, BB rat, Komeda rat, LEW.1AR1-iddm rat and humans with type 1 diabetes

Diabetologia ◽  
2013 ◽  
Vol 57 (3) ◽  
pp. 512-521 ◽  
Author(s):  
Anne Jörns ◽  
Tanja Arndt ◽  
Andreas Meyer zu Vilsendorf ◽  
Jürgen Klempnauer ◽  
Dirk Wedekind ◽  
...  
Keyword(s):  
Cell Death ◽  
Type 1 Diabetes ◽  
Beta Cell ◽  
Cytokine Expression ◽  
Nod Mouse ◽  
Bb Rat ◽  
Beta Cell Death

scholarly journals Oligofructose as an adjunct in treatment of diabetes in NOD mice

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Clement Chan ◽  
Colin M. Hyslop ◽  
Vipul Shrivastava ◽  
Andrea Ochoa ◽  
Raylene A. Reimer ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Insulin Sensitivity ◽  
Gut Microbiota ◽  
Beta Cell ◽  
Beta Cells ◽  
Adjunctive Therapy ◽  
Remission Rate ◽  
Beta Cell Proliferation ◽  
Autoimmune Attack

Abstract In type 1 diabetes, restoration of normoglycemia can be achieved if the autoimmune attack on beta cells ceases and insulin requirement is met by the residual beta cells. We hypothesize that an adjunctive therapy that reduces insulin demand by increasing insulin sensitivity will improve the efficacy of an immunotherapy in reversing diabetes. We tested the gut microbiota-modulating prebiotic, oligofructose (OFS), as the adjunctive therapy. We treated non-obese diabetic mice with an immunotherapy, monoclonal anti-CD3 antibody (aCD3), with or without concurrent dietary supplement of OFS. After 8 weeks of OFS supplement, the group that received both aCD3 and OFS (aCD3 + OFS) had a higher diabetes remission rate than the group that received aCD3 alone. The aCD3 + OFS group had higher insulin sensitivity accompanied by reduced lymphocytic infiltrate into the pancreatic islets, higher beta-cell proliferation rate, higher pancreatic insulin content, and secreted more insulin in response to glucose. The addition of OFS also caused a change in gut microbiota, with a higher level of Bifidobacterium and lower Clostridium leptum. Hence, our results suggest that OFS can potentially be an effective therapeutic adjunct in the treatment of type 1 diabetes by improving insulin sensitivity and beta-cell function, leading to improved glycemic control.

scholarly journals miRNA-375 a Sensor of Glucotoxicity Is Altered in the Serum of Children with Newly Diagnosed Type 1 Diabetes

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Lucien Marchand ◽  
Audrey Jalabert ◽  
Emmanuelle Meugnier ◽  
Kathleen Van den Hende ◽  
Nicole Fabien ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Cell Mass ◽  
Beta Cell Mass ◽  
Human Islets ◽  
Rt Pcr ◽  
Stem Loop ◽  
Cell Alterations ◽  
Established Role

Background.The use of miRNAs as biomarkers for Type 1 Diabetes (T1D) risk is attractive as T1D is usually diagnosed in front of acute symptoms. As miR-375 is highly expressed in the endocrine pancreas, we postulated that its circulating level might reflect beta cell alterations and might be altered in the blood of T1D patients recently diagnosed.Methods.Sera were obtained from 22 T1D children at onset of the disease, before subcutaneous insulin treatment, and from 10 nondiabetic pediatric controls. MiR-375 seric level was quantified by stem-loop RT-PCR-based assay. MiRNAs regulations in isolated human islets in response to high glucose concentrations were determined by TaqMan Low-Density Array.Results.The abundance of miR-375, among the 410 miRNAs detected in human islets, mirrored its well-established role in rodent islet biology. Upregulated miRNAs targeted genes involved in islet homeostasis and regulation of beta cell mass. Downregulated miRNAs, including miR-375, were involved in pancreas secretion and protein turnover. Seric level of miR-375 was lower in T1D children versus age-matched controls, without any correlations with HbA1c, glycaemia, and number of autoantibodies.Conclusion.Altered circulating level of miR-375 at onset of T1D might be a general biomarker of metabolic alterations and inflammation associated with the disease.

scholarly journals Investigation of the utility of the 1.1B4 cell as a model human beta cell line for study of persistent enteroviral infection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessica R. Chaffey ◽  
Jay Young ◽  
Kaiyven A. Leslie ◽  
Katie Partridge ◽  
Pouria Akhbari ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Cell Line ◽  
Beta Cells ◽  
Cell Cultures ◽  
Enteroviral Infection ◽  
Beta Cell Line ◽  
Human Beta Cells ◽  
Human Beta Cell

AbstractThe generation of a human pancreatic beta cell line which reproduces the responses seen in primary beta cells, but is amenable to propagation in culture, has long been an important goal in diabetes research. This is particularly true for studies focussing on the role of enteroviral infection as a potential cause of beta-cell autoimmunity in type 1 diabetes. In the present work we made use of a clonal beta cell line (1.1B4) available from the European Collection of Authenticated Cell Cultures, which had been generated by the fusion of primary human beta-cells with a pancreatic ductal carcinoma cell, PANC-1. Our goal was to study the factors allowing the development and persistence of a chronic enteroviral infection in human beta-cells. Since PANC-1 cells have been reported to support persistent enteroviral infection, the hybrid 1.1B4 cells appeared to offer an ideal vehicle for our studies. In support of this, infection of the cells with a Coxsackie virus isolated originally from the pancreas of a child with type 1 diabetes, CVB4.E2, at a low multiplicity of infection, resulted in the development of a state of persistent infection. Investigation of the molecular mechanisms suggested that this response was facilitated by a number of unexpected outcomes including an apparent failure of the cells to up-regulate certain anti-viral response gene products in response to interferons. However, more detailed exploration revealed that this lack of response was restricted to molecular targets that were either activated by, or detected with, human-selective reagents. By contrast, and to our surprise, the cells were much more responsive to rodent-selective reagents. Using multiple approaches, we then established that populations of 1.1B4 cells are not homogeneous but that they contain a mixture of rodent and human cells. This was true both of our own cell stocks and those held by the European Collection of Authenticated Cell Cultures. In view of this unexpected finding, we developed a strategy to harvest, isolate and expand single cell clones from the heterogeneous population, which allowed us to establish colonies of 1.1B4 cells that were uniquely human (h1.1.B4). However, extensive analysis of the gene expression profiles, immunoreactive insulin content, regulated secretory pathways and the electrophysiological properties of these cells demonstrated that they did not retain the principal characteristics expected of human beta cells. Our data suggest that stocks of 1.1B4 cells should be evaluated carefully prior to their use as a model human beta-cell since they may not retain the phenotype expected of human beta-cells.

scholarly journals Phase II multicentre, double-blind, randomised trial of ustekinumab in adolescents with new-onset type 1 diabetes (USTEK1D): trial protocol

BMJ Open ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. e049595
Author(s):  
John W Gregory ◽  
Kymberley Carter ◽  
Wai Yee Cheung ◽  
Gail Holland ◽  
Jane Bowen-Morris ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Research Ethics ◽  
Beta Cells ◽  
Beta Cell Function ◽  
Cell Function ◽  
Double Blind ◽  
C Peptide ◽  
New Onset

IntroductionMost individuals newly diagnosed with type 1 diabetes (T1D) have 10%–20% of beta-cell function remaining at the time of diagnosis. Preservation of residual beta-cell function at diagnosis may improve glycaemic control and reduce longer-term complications.Immunotherapy has the potential to preserve endogenous beta-cell function and thereby improve metabolic control even in poorly compliant individuals. We propose to test ustekinumab (STELARA), a targeted and well-tolerated therapy that may halt T-cell and cytokine-mediated destruction of beta-cells in the pancreas at the time of diagnosis.Methods and analysisThis is a double-blind phase II study to assess the safety and efficacy of ustekinumab in 72 children and adolescents aged 12–18 with new-onset T1D.Participants should have evidence of residual functioning beta-cells (serum C-peptide level >0.2nmol/L in the mixed-meal tolerance test (MMTT) and be positive for at least one islet autoantibody (GAD, IA-2, ZnT8) to be eligible.Participants will be given ustekinumab/placebo subcutaneously at weeks 0, 4 and 12, 20, 28, 36 and 44 in a dose depending on the body weight and will be followed for 12 months after dose 1.MMTTs will be used to measure the efficacy of ustekinumab for preserving C-peptide area under the curve at week 52 compared with placebo. Secondary objectives include further investigations into the efficacy and safety of ustekinumab, patient and parent questionnaires, alternative methods for measuring insulin production and exploratory mechanistic work.Ethics and disseminationThis trial received research ethics approval from the Wales Research Ethics Committee 3 in September 2018 and began recruiting in December 2018.The results will be disseminated using highly accessed, peer-reviewed medical journals and presented at conferences.Trial registration numberISRCTN14274380.

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