Expression microarray analysis of human pancreatic islets reveals CD59 function
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE54279 | GEO | 2014/03/02
SECONDARY ACCESSION(S): PRJNA236085
REPOSITORIES: GEO
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Project description:Pancreatic islets are central in type 2-diabetes development, which coincides with increased activity of innate immunity. Intriguingly, human pancreatic islets express many complement genes. The most highly expressed gene was the complement inhibitor CD59 that is GPI anchored to the cell membrane, which unexpectedly was found in high amounts intracellularly in beta cells. Silencing of CD59 strongly suppressed insulin secretion. Importantly, this suppression was unrelated to established CD59 functions, but rather depletion of intracellular CD59. Imaging experiments identified a distal site of inhibition in the exocytotic pathway, but prior to emptying of the insulin granules. Proximity Ligation Assays pin-pointed the mechanism to impaired turnover of exocytosis-regulating SNARE-proteins and CD59 was detected in complex with VAMP2 and syntaxin. CD59 was downregulated by 24-h glucose incubations in human islets, rat cell lines and in islets from three rodent diabetes models. Islets from cadaver donors were provided by the Nordic Islet Transplantation Programme (www.nordicislets.org), Uppsala University. The microarrays were performed using GeneChipM-BM-. Human Gene 1.0 ST whole transcript according to Affymetrix standard protocol.
2014-03-02 | E-GEOD-54279 | biostudies-arrayexpress
Project description:Defects in pancreatic islets and the progression of multi-tissue insulin resistance in combination with environmental factors are the main causes of type 2 diabetes (T2D). Mass spectrometry-based proteomics of five key-metabolic tissues on a cohort of 42 multi-organ donors provided deep coverage of the proteomes of pancreatic islets, visceral adipose tissue (VAT), liver, skeletal muscle and serum. Enrichment analysis of gene ontology (GO) terms built a tissue-specific map of the chronological order of altered biological processes across healthy controls (CTRL), pre-diabetes (PD) and T2D subjects. This unique dataset allowed us to explore alterations of entire biological pathways and individual proteins in multiple tissues. We confirmed the significant decrease of the citric acid cycle and the respiratory electron transport in VAT and muscle of T2D and we provided a thorough visual representation of the complete set of downregulated proteins. Importantly, we found widespread novel alterations in relevant biological pathways including the increase in hemostasis in pancreatic islets of PD, the increase in the complement cascade in liver and pancreatic islets of PD and the elevation in cholesterol biosynthesis in liver of T2D. Overall, our findings suggest inflammatory, immune and vascular impairments in pancreatic islets as potentially causal factors of insufficient insulin production and increased glucagon levels in the early stages of T2D. In contrast alterations in lipid metabolism and mitochondrial function in the liver and VAT/muscle, respectively, became evident later in manifest T2D. This first multi-tissue proteomic map indicates the temporal order of tissue-specific metabolic dysregulation in T2D development.
2022-10-12 | PXD027597 | Pride
Project description:Activating mutations in the KATP channel cause a rare genetic form of diabetes called neonatal diabetes. These mutations render the channel permanently open results in membrane hyperpolarisation of the pancreatic beta-cell. This prevents calcium influx and impairs insulin secretion. Mice expressing the human neonatal diabetes mutation Kir6.2-V59M specifically in pancreatic beta-cells are diabetic but do not display dyslipidaemia or insulin resistance. In this experiment, gene expression changes were analysed to explore the effect of high blood glucose per se on isolated pancreatic islets
2017-07-05 | E-MTAB-5086 | biostudies-arrayexpress
Project description:Wolfram syndrome, an autosomal recessive disorder characterized by juvenile-onset diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene. WFS1 encodes an endoplasmic reticulum resident transmembrane protein. The Wfs1-null mice exhibit progressive insulin deficiency and diabetes. The aim of the present study was to describe the insulin secretion and transcriptome of pancreatic islets in WFS1-deficient mice. WFS1-deficient (Wfs1KO) mice had considerably less pancreatic islets than heterozygous (Wfs1HZ) or wild-type (WT) mice. Wfs1KO pancreatic islets secreted less insulin after stimulation with 2 and 10 mM glucose and with tolbutamide solution compared to WT and Wfs1HZ islets, but not after stimulation with 20 mM glucose. Differences in proinsulin amount were not statistically significant although there was a trend that Wfs1KO had an increased level of proinsulin. After stimulation with 2 mM glucose solution the proinsulin/insulin ratio in Wfs1KO was significantly higher than that of WT and Wfs1HZ. RNA-seq from pancreatic islets found melastatin-related transient receptor potential subfamily member 5 protein gene (Trpm5) to be downregulated in WFS1-deficient mice. Functional annotation of RNA sequencing results showed that WFS1 deficiency influenced significantly the pathways related to tissue morphology, endocrine system development and function, molecular transport network. These findings suggest an interactive role of WFS1 and TRPM5 in insulin secretion. 12 samples: three genotypes, 4 individuals in each genotype
2015-02-14 | E-GEOD-65929 | biostudies-arrayexpress
Project description:The global prevalence of type 2 diabetes (T2D) is increasing, and it is contributing to the susceptibility to diabetes and its related epidemic in offspring. Although the impacts of paternal T2D on metabolism of offspring have been well established, the exact molecular and mechanistic basis that mediates these impacts remains largely unclear. Here we show that paternal T2D increases the susceptibility to diabetes in offspring through the gametic epigenetic alterations. Paternal T2D led to glucose intolerance and insulin resistance in offspring. Relative to controls, offspring of T2D fathers exhibited altered gene expression patterns in the pancreatic islets, with downregulation of several genes involved in glucose metabolism and insulin signaling pathway. Epigenomic profiling of offspring pancreatic islets revealed numerous changes in cytosine methylation depending on paternal T2D, including reproducible changes in methylation over several insulin signaling genes. Paternal T2D altered overall methylome patterns in sperm, with a large portion of differentially methylated genes overlapped with that of pancreatic islets in offspring. Our study revealed, for the first time, that T2D can be inherited transgenerationally through the mammalian germline by an epigenetic manner. Examination of the effect of paternal T2D on the DNA methylation in the pancreatic islets of offspring and in the sperm of father.
2013-01-02 | E-GEOD-43238 | biostudies-arrayexpress
Project description:Using an integrated approach to characterize the pancreatic tissue and isolated islets from a 33-year-old with 17 years of type 1 diabetes (T1D), we found donor islets contained β cells without insulitis and lacked glucose-stimulated insulin secretion despite a normal insulin response to cAMP-evoked stimulation. With these unexpected findings for T1D, we sequenced the donor DNA and found a pathogenic heterozygous variant in hepatocyte nuclear factor 1 alpha (HNF1A). In one of the first studies of human pancreatic islets with a disease-causing HNF1A variant associated with the most common form of monogenic diabetes, we found that HNF1A dysfunction leads to insulin-insufficient diabetes reminiscent of T1D by impacting the regulatory processes critical for glucose-stimulated insulin secretion and suggest a rationale for a therapeutic alternative to current treatment.
2018-09-22 | GSE120299 | GEO
Project description:The NF-κB pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic beta cell dysfunction in the metabolic syndrome. While canonical NF-κB signaling is well studied, there is little information on the divergent non-canonical NF-κB pathway in the context of pancreatic islet dysfunction in diabetes. Here, we demonstrate that pharmacological activation of the non-canonical NF-κB inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. Further, we identify NIK as a critical negative regulator of beta cell function as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of non-canonical NF-κB components p100 to p52, and accumulation of RelB. Tumor necrosis factor α (TNFα) and receptor activator of NF-κB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive beta cell intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the non-canonical NF-κB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to beta cell failure. These studies reveal that NIK contributes a central mechanism for beta cell failure in diet-induced obesity. We identify a role for Nuclear Factor inducing κB (NIK) in pancreatic beta cell failure. NIK activation disrupts glucose homeostasis in zebrafish in vivo and impairs glucose-stimulated insulin secretion in mouse and human islets in vitro. NIK activation also perturbs beta cell insulin secretion in a diet-induced obesity mouse model. These studies reveal that NIK contributes a central mechanism for beta cell failure in obesity. To uncover the role of NIK in pancreatic beta cells, we performed a gene expression microarray analysis comparing pancreatic islets with constitutive beta cell intrinsicNIK activation from the 16 week old mice (beta cell specific TRAF2 and TRAF2 knockout mice) to their controls (n=3 per group).
2015-06-18 | E-GEOD-68317 | biostudies-arrayexpress
Project description:Insulin-secreting β cells and glucagon-secreting α cells maintain physiological blood glucose levels, and their malfunction drives diabetes development. Using ChIP sequencing and RNA sequencing analysis, we determined the epigenetic and transcriptional landscape of human pancreatic α, β, and exocrine cells. We found that, compared with exocrine and β cells, differentiated α cells exhibited many more genes bivalently marked by the activating H3K4me3 and repressing H3K27me3 histone modifications. This was particularly true for β cell signature genes involved in transcriptional regulation. Remarkably, thousands of these genes were in a monovalent state in β cells, carrying only the activating or repressing mark. Our epigenomic findings suggested that α to β cell reprogramming could be promoted by manipulating the histone methylation signature of human pancreatic islets. Indeed, we show that treatment of cultured pancreatic islets with a histone methyltransferase inhibitor leads to colocalization of both glucagon and insulin and glucagon and insulin promoter factor 1 (PDX1) in human islets and colocalization of both glucagon and insulin in mouse islets. Thus, mammalian pancreatic islet cells display cell-type–specific epigenomic plasticity, suggesting that epigenomic manipulation could provide a path to cell reprogramming and novel cell replacement-based therapies for diabetes. Pancreatic islets were collected post-mortem from 6 human donors and subjected to FACS to separate populations of alpha, beta, and exocrine cells. Depending on the availability of resulting material, sorted islet cell populations were used for H3K4me3, H3K27me3 ChIP-seq, or RNA-seq analysis. All ChIP-seq samples have a corresponding input from the same sample.
2013-08-28 | E-GEOD-50386 | biostudies-arrayexpress
Project description:Insulin (INS) synthesis and secretion from pancreatic M-NM-2 cells are tightly regulated; their deregulation causes diabetes. Here we map INS-associated loci in human pancreatic islets by 4C and 3C techniques and show that the INS gene physically interacts with the SYT8 gene, located over 300 kb away. This interaction is elevated by glucose and accompanied by increases in SYT8 expression. Inactivation of the INS promoter by promoter-targeting siRNA reduces SYT8 gene expression. SYT8-INS interaction and SYT8 transcription are attenuated by CTCF depletion. Furthermore, SYT8 knockdown decreases insulin secretion in islets. These results reveal a non-redundant role for SYT8 in insulin secretion and indicate that the INS promoter acts from a distance to stimulate SYT8 transcription. This suggests a function for the INS promoter in coordinating insulin transcription and secretion through long-range regulation of SYT8 expression in human islets. Circular Chromosome Conformation Capture (4C)-Seq experiments to profile interactions of INS promoter in human pancreatic islets isolated from two donors: donor 1 and donor 2.
2011-02-22 | E-GEOD-25862 | biostudies-arrayexpress
Project description:Background: Tetraspanin-7 (Tspan7) is an islet autoantigen involved in autoimmune type 1 diabetes and known to regulate beta-cell L-type Ca2+ channel activity. However, the role of Tspan7 in pancreatic beta-cell function is not yet fully understood. Methods: Histological analyses were conducted using immunostaining. Whole-body metabolism was tested using glucose tolerance test. Islet hormone secretion was quantified using static batch incubation or dynamic perifusion. Beta-cell transmembrane currents, electrical activity and exocytosis were measured using whole-cell patch-clamping and capacitance measurements. Gene expression was studied using mRNA-sequencing and quantitative PCR. Results: Tspan7 is expressed in insulin-containing granules of pancreatic beta-cells. Tspan7-knockout mice (Tspan7 y/- mouse) exhibit reduced body weight and ad libitum plasma glucose but normal glucose tolerance. Tspan7y/- islets have normal insulin content and glucose- or tolbutamide-stimulated insulin secretion. Depolarisation-triggered Ca2+ current was enhanced in Tspan7y/- beta-cells, but beta-cell electrical activity and depolarisation-evoked exocytosis were unchanged suggesting that exocytosis was less sensitive to Ca2+. TSPAN7 knockdown (KD) in human pseudo-islets led to a significant reduction in high K+-stimulated insulin secretion. Transcriptomic analyses show that TSPAN7 KD in human pseudo-islets correlated with changes in genes involved in hormone secretion, apoptosis and ER stress. Consistent with rodent beta-cells, exocytotic Ca2+ sensitivity was reduced in a human beta cell line (EndoC-bH1) following Tspan7 KD. Conclusion: Tspan7 is involved in the regulation of Ca2+-dependent exocytosis in beta-cells. Its function is more significant in human beta-cells than their rodent counterparts
2022-10-10 | GSE213729 | GEO