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 The acquisition of an insulin-secreting phenotype by HGF-treated rat pancreatic ductal cells (ARIP) is associated with the development of susceptibility to cytokine-induced apoptosis

2005 ◽  
Vol 34 (2) ◽  
pp. 367-376 ◽  
Author(s):  
E Anastasi ◽  
C Santangelo ◽  
A Bulotta ◽  
F Dotta ◽  
B Argenti ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Pancreatic Beta Cells ◽  
Interleukin 1 ◽  
Pancreatic Beta Cell ◽  
Necrosis Factor Alpha ◽  
Ductal Cells ◽  
Pancreatic Ductal Cells ◽  
Induced Apoptosis

The elucidation of mechanisms regulating the regeneration and survival of pancreatic beta cells has fundamental implications in the cell therapy of type 1 diabetes. The present study had the following three aims: 1. to investigate whether pancreatic ductal epithelial cells can be induced to differentiate into insulin-producing cells by exposing them to hepatocyte growth factor (HGF); 2. to characterize some of the molecular events leading to their differentiation toward a beta-cell-like phenotype; 3. to evaluate the susceptibility of newly differentiated insulin-secreting cells to cytokine-induced apoptosis, a mechanism of beta-cell destruction occurring in type 1 diabetes. We demonstrated that HGF-treated rat pancreatic ductal cell line (ARIP) cells acquired the capability to transcribe the insulin gene and translate its counterpart protein. HGF-treated cells also exhibited a glucose-dependent capability to secrete insulin into the cultured medium. Expression analysis of some of the genes regulating pancreatic beta-cell differentiation revealed a time-dependent transcription of neurogenin-3 and Neuro-D in response to HGF. Finally, we determined the susceptibility to proinflammatory cytokine (PTh1)-induced apoptosis by incubating HGF-treated and untreated ARIP cells with a cocktail of interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ). Such treatment induced apoptotic death, as determined by the TUNEL technique, in about 40% of HGF-treated, insulin-secreting ARIP cells, while untreated ARIP cells were resistant to PTh1-induced apoptosis. In conclusion, we showed that HGF promotes the differentiation of ARIP cells into pancreatic beta-cell-like cells, and that the differentiation toward an insulin-secreting phenotype is associated with the appearance of susceptibility to cytokine-induced apoptosis.

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.

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.

scholarly journals Alpk1 Sensitizes Pancreatic Beta Cells to Cytokine-Induced Apoptosis via Upregulating TNF-α Signaling Pathway

2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Ding ◽  
Xi Luo ◽  
Yiting Tu ◽  
Xianlan Duan ◽  
Jia Liu ◽  
...  
Keyword(s):  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Pancreatic Beta Cell ◽  
Min6 Cells ◽  
Beta Cell Failure ◽  
Tnf Α ◽  
Induced Apoptosis ◽  
Pro Inflammatory Cytokines

Pancreatic beta cell failure is the hallmark of type 1 diabetes (T1D). Recent studies have suggested that pathogen recognizing receptors (PRRs) are involved in the survival, proliferation and function of pancreatic beta cells. So far, little is known about the role of alpha-protein kinase 1 (ALPK1), a newly identified cytosolic PRR specific for ADP-β-D-manno-heptose (ADP-heptose), in beta cell survival. In current study we aimed to fill the knowledge gap by investigating the role of Alpk1 in the apoptosis of MIN6 cells, a murine pancreatic beta cell line. We found that the expression of Alpk1 was significantly elevated in MIN6 cells exposed to pro-inflammatory cytokines, but not to streptozotocin, low-dose or high-dose glucose. Activation of Alpk1 by ADP heptose alone was insufficient to induce beta cell apoptosis. However, it significantly exacerbated cytokine-induced apoptosis in MIN6 cells. Mechanistic investigations showed that Alpk1 activation was potent to further induce the expression of tumor necrosis factor (TNF)-α and Fas after cytokine stimulation, possibly due to enhanced activation of the TIFA/TAK1/NF-κB signaling axis. Treatment of GLP-1 receptor agonist decreased the expression of TNF-α and Fas and improved the survival of beta cells exposed to pro-inflammatory cytokines and ADP heptose. In summary, our data suggest that Alpk1 sensitizes beta cells to cytokine-induced apoptosis by potentiating TNF-α signaling pathway, which may provide novel insight into beta cell failure and T1D development.

scholarly journals Partners in Crime: Beta-Cells and Autoimmune Responses Complicit in Type 1 Diabetes Pathogenesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Eliana Toren ◽  
KaLia S. Burnette ◽  
Ronadip R. Banerjee ◽  
Chad S. Hunter ◽  
Hubert M. Tse
Keyword(s):  
Type 1 Diabetes ◽  
Immune System ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Disease Etiology ◽  
Autoreactive T Cell ◽  
Beta Cell Heterogeneity ◽  
Beta Cell Response

Type 1 diabetes (T1D) is an autoimmune disease characterized by autoreactive T cell-mediated destruction of insulin-producing pancreatic beta-cells. Loss of beta-cells leads to insulin insufficiency and hyperglycemia, with patients eventually requiring lifelong insulin therapy to maintain normal glycemic control. Since T1D has been historically defined as a disease of immune system dysregulation, there has been little focus on the state and response of beta-cells and how they may also contribute to their own demise. Major hurdles to identifying a cure for T1D include a limited understanding of disease etiology and how functional and transcriptional beta-cell heterogeneity may be involved in disease progression. Recent studies indicate that the beta-cell response is not simply a passive aspect of T1D pathogenesis, but rather an interplay between the beta-cell and the immune system actively contributing to disease. Here, we comprehensively review the current literature describing beta-cell vulnerability, heterogeneity, and contributions to pathophysiology of T1D, how these responses are influenced by autoimmunity, and describe pathways that can potentially be exploited to delay T1D.

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 Long-RNA Sequencing and Ribosome Profiling of Inflamed Beta-Cells Reveal an Extensive Translatome Landscape

2021 ◽  
Author(s):  
Sofia Thomaidou ◽  
Roderick C. Slieker ◽  
Arno R. van der Slik ◽  
Jasper Boom ◽  
Flip Mulder ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Translation Initiation ◽  
Pancreatic Beta Cells ◽  
Ribosome Profiling ◽  
Central Tolerance ◽  
Autoreactive T Cell ◽  
Human Beta Cells

Type 1 diabetes is an autoimmune disease characterized by autoreactive T-cell mediated destruction of the insulin-producing pancreatic beta-cells. Increasing evidence suggest that the beta-cells themselves contribute to their own destruction by generating neo-antigens through the production of aberrant or modified proteins that escape central tolerance. We have recently demonstrated that ribosomal infidelity amplified by stress could lead to the generation of neoantigens in human beta-cells, emphasizing the participation of nonconventional translation events to autoimmunity, as occurring in cancer or virus-infected tissues. Using a transcriptome-wide profiling approach to map translation initiation start sites in human beta-cells under standard and inflammatory conditions, we identify a completely new set of polypeptides derived from non-canonical start sites and translation initiation within lncRNA. Our data underline the extreme diversity of the beta-cell translatome and may reveal new functional biomarkers for beta-cell distress, disease prediction and progression and therapeutic intervention in type 1 diabetes.

scholarly journals Neoepitopes in Type 1 Diabetes: Etiological Insights, Biomarkers and Therapeutic Targets

2021 ◽  
Vol 12 ◽  
Author(s):  
Teresa Rodriguez-Calvo ◽  
James D. Johnson ◽  
Lut Overbergh ◽  
Jessica L. Dunne
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cell ◽  
Therapeutic Targets ◽  
Biological Response ◽  
Peripheral Tolerance ◽  
Cellular Mechanisms

The mechanisms underlying type 1 diabetes (T1D) pathogenesis remain largely unknown. While autoantibodies to pancreatic beta-cell antigens are often the first biological response and thereby a useful biomarker for identifying individuals in early stages of T1D, their role in T1D pathogenesis is not well understood. Recognition of these antigenic targets by autoreactive T-cells plays a pathological role in T1D development. Recently, several beta-cell neoantigens have been described, indicating that both neoantigens and known T1D antigens escape central or peripheral tolerance. Several questions regarding the mechanisms by which tolerance is broken in T1D remain unanswered. Further delineating the timing and nature of antigenic responses could allow their use as biomarkers to improve staging, as targets for therapeutic intervention, and lead to a better understanding of the mechanisms leading to loss of tolerance. Multiple factors that contribute to cellular stress may result in the generation of beta-cell derived neoepitopes and contribute to autoimmunity. Understanding the cellular mechanisms that induce beta-cells to produce neoantigens has direct implications on development of therapies to intercept T1D disease progression. In this perspective, we will discuss evidence for the role of neoantigens in the pathogenesis of T1D, including antigenic responses and cellular mechanisms. We will additionally discuss the pathways leading to neoepitope formation and the cross talk between the immune system and the beta-cells in this regard. Ultimately, delineating the timing of neoepitope generation in T1D pathogenesis will determine their role as biomarkers as well as therapeutic targets.

scholarly journals Endoplasmic Reticulum-Mitochondria Crosstalk and Beta-Cell Destruction in Type 1 Diabetes

2021 ◽  
Vol 12 ◽  
Author(s):  
Saurabh Vig ◽  
Joost M. Lambooij ◽  
Arnaud Zaldumbide ◽  
Bruno Guigas
Keyword(s):  
Endoplasmic Reticulum ◽  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Beta Cell Destruction ◽  
Unfolded Protein ◽  
Cell Destruction ◽  
The Unfolded Protein Response ◽  
And Function

Beta-cell destruction in type 1 diabetes (T1D) results from the combined effect of inflammation and recurrent autoimmunity. In response to inflammatory signals, beta-cells engage adaptive mechanisms where the endoplasmic reticulum (ER) and mitochondria act in concert to restore cellular homeostasis. In the recent years it has become clear that this adaptive phase may trigger the development of autoimmunity by the generation of autoantigens recognized by autoreactive CD8 T cells. The participation of the ER stress and the unfolded protein response to the increased visibility of beta-cells to the immune system has been largely described. However, the role of the other cellular organelles, and in particular the mitochondria that are central mediator for beta-cell survival and function, remains poorly investigated. In this review we will dissect the crosstalk between the ER and mitochondria in the context of T1D, highlighting the key role played by this interaction in beta-cell dysfunctions and immune activation, especially through regulation of calcium homeostasis, oxidative stress and generation of mitochondrial-derived factors.

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