Expression data from human pancreatic islets
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE38642 | GEO | 2012/07/05
SECONDARY ACCESSION(S): PRJNA168302
REPOSITORIES: GEO
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Project description:Close to 50 genetic loci have been associated with type 2 diabetes (T2D), but they explain only 15% of the heritability. In an attempt to identify additional T2D genes, we analyzed global gene expression in human islets from 63 donors. Islets from cadaver donors (54 non-diabetic and 9 diabetic) 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.
2012-07-05 | E-GEOD-38642 | biostudies-arrayexpress
Project description:We have studied the impact of T2D on open chromatin in human pancreatic islets. We used assay for transposase-accessible chromatin using sequencing (ATAC-seq) to profile open chromatin in islets from T2D and non-diabetic donors. We identified ATAC-seq peaks representing open chromatin regions in islets of non-diabetic and diabetic donors. The majority of ATAC-seq peaks mapped near transcription start sites. Additionally, peaks were enriched in enhancer regions and in regions where islet-specific TFs bind. Islet ATAC-seq peaks overlap with SNPs associated with T2D and with additional SNPs in LD with known T2D SNPs. There was enrichment of open chromatin regions near highly expressed genes in human islets.
2019-04-06 | GSE129383 | GEO
Project description:In this study, we achieved integrated transcriptomic and proteomic profiles of GK islets in a time-course fashion at different stages of T2D. Subsequent bioinformatics analysis revealed the chronological order of T2D-related molecular events during the deterioration of pancreatic islets. Our large quantitative dataset provide a valuable resource to obtain a comprehensive picture of the mechanisms responsible for islet dysfunction and to identify potential interventions to prevent beta-cell failure in human T2D.
2017-06-02 | PXD004709 | Pride
Project description:A gene co-expression network analysis has been conducted to identify T2D-associated gene modules. Donors 1-48 were used for the initial analysis and donors 49-80 for the replication and were normalized separately in this study Islets from cadaver donors (57 non-diabetic and 20 diabetic) 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.
2012-10-23 | E-GEOD-41762 | biostudies-arrayexpress
Project description:Little is known about the contribution of the epigenome to the pathophysiology of type 2 diabetes (T2D). Here we have used genome-wide DNA methylation profiling to obtain the first comprehensive DNA methylation data set for human T2D pancreatic islets. Therefore, we analyzed the methylation profile of 27,578 CpG sites affiliated to more than 14,000 genes in 16 samples of pancreatic islets, 11 normal and 5 type 2-diabetic. Keywords: DNA methylation Keywords: Methylation profiling by array We measured the methylation status of the 27,578 CpG sites (Human Methylation27 DNA BeadChip array) in genomic DNA obtained from pnacreatic islets of 11 non-diabetic and 5 type-2-diabetic male human donors to identify genes that are differentially methylated in T2D.
2012-04-22 | E-GEOD-21232 | biostudies-arrayexpress
Project description:Genetic studies have identified ≥240 loci associated with type 2 diabetes (T2D), yet most of these loci lie in non-coding regions, masking the underlying molecular mechanisms. Recent studies investigating gene expression in pancreatic islets have provided key insights into the molecular drivers of T2D pathophysiology through comprehensive genetic and genomic analyses. However, similar studies investigating microRNA (miRNA) expression remain limited. Here, we present the largest genetic and genomic analysis of miRNA expression in human islets to date, spanning 63 participants. We characterize the genetic regulation of miRNA expression by decomposing the expression of highly heritable miRNAs into cis- and trans- genetic components and mapping cis loci associated with miRNA expression (miRNA-eQTLs). We find (a) 81 heritable miRNAs, which we show are primarily regulated by trans-acting genetic effects, and (b) 5 miRNA-eQTLs. To evaluate the impact of miRNA expression on T2D, we use several different strategies to nominate T2D-associated miRNAs. First, we colocalize miRNA-eQTLs with genetic studies of T2D and several T2D-related traits and identify one miRNA, miR-1908, that shares genetic signals for blood glucose and HbA1c. Next, we intersect miRNA seed regions with credible set SNPs from T2D and T2D-related genetic studies and find 46 miRNAs that may have altered binding and function due to disrupted seed regions. Finally, we perform differential expression analysis and identify 38 miRNAs associated with either T2D status, body mass index, sex, or a polygenic score for HbA1c levels. To validate identified miRNAs, we perform chromatin run-on sequencing and confirm differential transcription of T2D-associated miRNAs.
2023-01-29 | GSE196797 | GEO
Project description:Here we harnessed the potential of expression arrays in 89 human pancreatic islet donors (different levels of blood glucose (HbA1c)) to identify genes regulated in this relevant tissue for type 2 diabetes (T2D). 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.
2014-07-17 | E-GEOD-50397 | biostudies-arrayexpress
Project description:Recent advances in the understanding of the genetics of type 2 diabetes (T2D) susceptibility have focused attention on the regulation of transcriptional activity within the pancreatic beta-cell. MicroRNAs (miRNAs) represent an important component of regulatory control, and have proven roles in the development of human disease and control of glucose homeostasis. We set out to establish the miRNA profile of human pancreatic islets and of enriched beta-cell populations, and to explore their potential involvement in T2D susceptibility. We used Illumina small RNA sequencing to profile the miRNA fraction in three preparations each of primary human islets and of enriched beta-cells generated by fluorescence-activated cell sorting. In total, 366 miRNAs were found to be expressed (i.e. >100 cumulative reads) in islets and 346 in beta-cells; of the total of 384 unique miRNAs, 328 were shared. A comparison of the islet-cell miRNA profile with those of 15 other human tissues identified 40 miRNAs predominantly expressed (i.e. >50% of all reads seen across the tissues) in islets. Several highly-expressed islet miRNAs, such as miR-375, have established roles in the regulation of islet function, but others (e.g. miR-27b-3p, miR-192-5p) have not previously been described in the context of islet biology. As a first step towards exploring the role of islet-expressed miRNAs and their predicted mRNA targets in T2D pathogenesis, we looked at published T2D association signals across these sites. We found evidence that predicted mRNA targets of islet-expressed miRNAs were globally enriched for signals of T2D association (p-values <0.01, q-values <0.1). At six loci with genome-wide evidence for T2D association (AP3S2, KCNK16, NOTCH2, SCL30A8, VPS26A, and WFS1) predicted mRNA target sites for islet-expressed miRNAs overlapped potentially causal variants. In conclusion, we have described the miRNA profile of human islets and beta-cells and provide evidence linking islet miRNAs to T2D pathogenesis. Examination of the miRNA profiles in 3 preparations of isolated pancreatic islets and 3 preparations of FACS-enriched pancreatic beta-cells
2013-06-07 | E-GEOD-47720 | biostudies-arrayexpress
Project description:Type-2 diabetes (T2D) is a complex metabolic disorder that affects hundreds of millions of people world-wide and is a growing public health concern. Despite recent advances in T2D research, the etiology of this disease and the mechanisms underlying the metabolic defects remain poorly understood. While obesity is thought to be the main cause for the rising prevalence of T2D, obesity alone cannot explain differences in the trends of T2D among different geographical regions and populations. Growing evidence suggests that environmental exposures to toxic and diabetogenic substances must play important roles. Inorganic arsenic (iAs) is a naturally occurring toxic metalloid. Hundreds of millions of people worldwide are exposed to unsafe levels of iAs in drinking water and food. iAs is a potent carcinogen, but iAs exposure has also been linked to increase risk of T2D. While the link between iAs exposure and T2D is well-established, the mechanisms underlying the diabetogenic effects of iAs exposure remain unclear. Results of our previously published and ongoing studies suggest that pancreatic islets are a primary target for iAs and its metabolites and that impaired insulin secretion by islets is the mechanism by which iAs exposure leads to diabetes. The proposed project will use metabolomics to identify metabolic pathways in β-cells that are targeted by iAs and its metabolites, monomethyl-As (MAs) and dimethyl-As (DMAs). The metabolomics data combined with results of our ongoing mechanistic studies will provide a comprehensive picture of the metabolic dysfunction leading to the development of diabetes in individuals exposed to iAs and of the molecular mechanisms that underlie this dysfunction. Identifying the affected pathways and mechanisms will ultimately help to improve strategies for prevention and/or treatment of T2D associated with chronic exposure to iAs.
2020-01-30 | ST001314 | MetabolomicsWorkbench
Project description:The antisense non-coding RNA in the INK locus (ANRIL), which originates from the CDKN2A/B (INK4-ARF) locus, has been identified as a hotspot for genetic variants associated with cardiometabolic disease including coronary artery disease (CAD) and Type 2 diabetes (T2D). We recently found that ANRIL abundance in human pancreatic islets was increased in donors carrying certain T2D risk-SNPs, and that a T2D risk-SNP located within exon2 of ANRIL conferred reduced beta cell proliferation index, pointing to a role for ANRIL in the regulation of T2D pathogenicity via an impact on insulin secretory capacity. Recent studies in other cell types have found that the balance between linear and circular species of ANRIL is linked to the regulation of cardiovascular disease phenotypes. Less is known about circular ANRIL expression in diabetes-relevant cell types and how their abundance might influence the risk of T2D. Herein, we use high-throughput and divergent primer sequencing of circular RNA in human pancreatic islet cells to quantify and characterize circular isoforms of ANRIL. We identified several circular ANRIL isoforms that are more abundant than linear ANRIL and whose expression was correlated across dozens of individuals. Back-splicing did not occur with equal probability at all ANRIL splice sites. Rather, some specific splice sites were found to have a higher propensity to be involved in back-splicing and are weakly enriched for sequence features known to promote back-splicing. Finally, we found that islets from carriers of the T2D risk allele at rs564398 in exon 2 of ANRIL had a higher ratio of circular ANRIL relative to linear ANRIL compared to protective-allele carriers, and that higher circular:linear ANRIL ratio was associated with a decreased beta cell proliferation index. Together, our study points to the combined involvement of both linear and circular ANRIL species in T2D phenotypes and opens the door for future studies to understand the molecular mechanisms by which ANRIL impacts cellular function in human pancreatic islets.
2022-05-11 | GSE192541 | GEO