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.

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.

scholarly journals Type 1 Diabetes: Interferons and the Aftermath of Pancreatic Beta-Cell Enteroviral Infection

2020 ◽  
Vol 8 (9) ◽  
pp. 1419
Author(s):  
Pouria Akhbari ◽  
Sarah J Richardson ◽  
Noel G Morgan
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Pancreatic Beta Cells ◽  
Growth Regulation ◽  
Cell Function ◽  
Viral Infections ◽  
Pancreatic Beta Cell ◽  
Enteroviral Infection ◽  
Cellular Processes

Enteroviruses (EVs) have long been implicated in the pathogenesis of type 1 diabetes (T1D), and accumulating evidence has associated virus-induced autoimmunity with the loss of pancreatic beta cells in T1D. Inflammatory cytokines including interferons (IFN) form a primary line of defence against viral infections, and their chronic elevation is a hallmark feature of many autoimmune diseases. IFNs play a key role in activating and regulating innate and adaptive immune responses, and to do so they modulate the expression of networks of genes and transcription factors known generically as IFN stimulated genes (ISGs). ISGs in turn modulate critical cellular processes ranging from cellular metabolism and growth regulation to endoplasmic reticulum (ER) stress and apoptosis. More recent studies have revealed that IFNs also modulate gene expression at an epigenetic as well as post-transcriptional and post-translational levels. As such, IFNs form a key link connecting the various genetic, environmental and immunological factors involved in the initiation and progression of T1D. Therefore, gaining an improved understanding of the mechanisms by which IFNs modulate beta cell function and survival is crucial in explaining the pathogenesis of virally-induced T1D. This should provide the means to prevent, decelerate or even reverse beta cell impairment.

Vitamin D supplementation induces CatG-mediated CD4+ T cell inactivation and restores pancreatic beta-cell function in mice with type 1 diabetes

2021 ◽  
Author(s):  
Xiaoyang Lai ◽  
Xuyang Liu ◽  
Xia Cai ◽  
Fang Zou
Keyword(s):  
Vitamin D ◽  
Type 1 Diabetes ◽  
Beta Cell ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Β Cell Function

Type 1 diabetes (T1D) is a chronic autoimmune disease accompanied by the immune-mediated destruction of pancreatic β-cells. In this study, we aimed to explore the regulatory effects of Vitamin D (VD) supplementation on pancreatic β-cell function by altering the expression of bioinformatically identified cathepsin G (CatG) in T1D model mice. A T1D mouse model was established in non-obese diabetic (NOD) mice, and their islets were isolated and purified. Pancreatic mononuclear cells (MNCs) were collected, from which CD4+ T cells were isolated. The levels of interleukin (IL)-2, IL-10, tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ) in the supernatant of mouse pancreatic tissue homogenate were assessed using ELISA. Immunohistochemistry and TUNEL staining were conducted to evaluate the effects of VD supplementation on pancreatic tissues of T1D mice. The pancreatic beta-cell line MIN6 was used for in vitro substantiation of findings in vivo. VD supplementation reduced glucose levels and improved glucose tolerance in T1D mice. Further, VD supplementation improved pancreatic β-cell function and suppressed immunological and inflammatory reactions in the T1D mice. We documented overexpression of CatG in diabetes tissue samples, and then showed that VD supplementation normalized the islet immune microenvironment through down-regulating CatG expression in T1D mice. Experiments in vitro subsequently demonstrated that VD supplementation impeded CD4+ T activation by down-regulating CatG expression, and thereby enhanced pancreatic β-cell function. Results of the present study elucidated that VD supplementation can down-regulate the expression of CatG and inhibit CD4+ T cell activation, thereby improving β-cell function in T1D.

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.

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 Mediators and mechanisms of pancreatic beta-cell death in type 1 diabetes

2008 ◽  
Vol 52 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Pierre Pirot ◽  
Alessandra K. Cardozo ◽  
Décio L. Eizirik
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Map Kinases ◽  
Pancreatic Beta Cell ◽  
Insulin Deficiency ◽  
Beta Cell Destruction ◽  
Pro Inflammatory Cytokines

Type 1 diabetes mellitus (T1D) is characterized by severe insulin deficiency resulting from chronic and progressive destruction of pancreatic beta-cells by the immune system. The triggering of autoimmunity against the beta-cells is probably caused by environmental agent(s) acting in the context of a predisposing genetic background. Once activated, the immune cells invade the islets and mediate their deleterious effects on beta-cells via mechanisms such as Fas/FasL, perforin/granzyme, reactive oxygen and nitrogen species and pro-inflammatory cytokines. Binding of cytokines to their receptors on the beta-cells activates MAP-kinases and the transcription factors STAT-1 and NFkappa-B, provoking functional impairment, endoplasmic reticulum stress and ultimately apoptosis. This review discusses the potential mediators and mechanisms leading to beta-cell destruction in T1D.

scholarly journals Alpha cell dysfunction in early type 1 diabetes

2021 ◽  
Author(s):  
Nicolai Doliba ◽  
Andrea Rozo ◽  
Jeffrey Roman ◽  
Wei Qin ◽  
Daniel Traum ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Cell Function ◽  
Early Stage ◽  
Glucagon Secretion ◽  
Cell Loss ◽  
Human Islets ◽  
Alpha Cell ◽  
Acid Decarboxylase ◽  
Alpha Cell Function

Multiple islet autoantibodies (AAb) predict type 1 diabetes (T1D) and hyperglycemia within 10 years. By contrast, T1D develops in just ~15% of single AAb+ (generally against glutamic acid decarboxylase, GADA+) individuals; hence the single GADA+ state may represent an early stage of T1D amenable to interventions. Here, we functionally, histologically, and molecularly phenotype human islets from non-diabetic, GADA+ and T1D donors. Similar to the few remaining beta cells in T1D islets, GADA+ donor islets demonstrated a preserved insulin secretory response. By contrast, alpha cell glucagon secretion was dysregulated in both T1D and GADA+ islets with impaired glucose suppression of glucagon secretion. Single cell RNA sequencing (scRNASeq) of GADA+ alpha cells revealed distinct abnormalities in glycolysis and oxidative phosphorylation pathways and a marked downregulation of PKIB, providing a molecular basis for the loss of glucose suppression and the increased effect of IBMX observed in GADA+ donor islets. The striking observation of a distinct early defect in alpha cell function that precedes beta cell loss in T1D suggests that not only overt disease, but also the progression to T1D itself, is bihormonal in nature.

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