ABSTRACT: Propargite, an environmental chemical, interacts with GWAS identified diabetes genes to impact human pancreatic β-cell death [propargite treatment]
Project description:Propargite, an environmental chemical, interacts with GWAS identified diabetes genes to impact human pancreatic β-cell death [PTPN2 knockout]
Project description:This paper describes the first time a high-content environmental chemicals screen using pancreatic β-like cells derived from human pluripotent stem cells (hPSCs), and discovered that a commonly used pesticide, propargite, induces pancreatic β-cell DNA damage and necrosis. More interestingly, we found out the genetic background of β-like cells affects their response to propargite-induced toxicity, based on isogenic hPSC platform, including for variants GWAS identified associated with T1D, since isogenic GSTT1-/- and PTPN2-/- pancreatic β-like cells are hypersensitive to propargite-induced β-cell death both in vitro and in vivo. In summary, our study identified an environmental chemical that contributes to the loss of β-cells and provides an innovative platform for using hPSC-derived cells to explore gene-environment interactions that impact diabetes disease progression.
Project description:This paper describes the first time a high-content environmental chemicals screen using pancreatic β-like cells derived from human pluripotent stem cells (hPSCs), and discovered that a commonly used pesticide, propargite, induces pancreatic β-cell DNA damage and necrosis. More interestingly, we found out the genetic background of β-like cells affects their response to propargite-induced toxicity, based on isogenic hPSC platform, including for variants GWAS identified associated with T1D, since isogenic GSTT1-/- and PTPN2-/- pancreatic β-like cells are hypersensitive to propargite-induced β-cell death both in vitro and in vivo. In summary, our study identified an environmental chemical that contributes to the loss of β-cells and provides an innovative platform for using hPSC-derived cells to explore gene-environment interactions that impact diabetes disease progression.
Project description:To identify effector genes of pancreatic beta cell failure, we integrated analyses of FoxO1 regulated genes with ChIPseq and RNAseq, super-enhancers, and human type 2 diabetes GWAS loci.
Project description:A robust system using disease relevant cells to systematically evaluate the role in diabetes for loci identified through genome wide association studies (GWAS) is urgently needed. Toward this goal, we created isogenic mutant human embryonic stem cell (hESC) lines in GWAS-identified candidate diabetes genes including CDKAL1, KCNQ1 and KCNJ11, and used directed differentiation to evaluate the function of derivative human beta-like cells. The mutations did not affect the generation of insulin+ cells, but impaired insulin secretion both in vitro and in vivo, coinciding with defective glucose homeostasis. CDKAL1-/- insulin+ cells also displayed hypersensitivity to lipotoxicity. A high-content chemical screen identified a candidate drug that rescued CDKAL1-/--specific defects by inhibiting the AP1 (FOS/JUN) pathway. These studies establish a platform using isogenic hESCs to evaluate the function of GWAS-identified loci, and identify a drug candidate that rescues gene-specific defects, paving the way to precision therapy of metabolic diseases.A robust system using disease relevant cells to systematically evaluate the role in diabetes for loci identified through genome wide association studies (GWAS) is urgently needed. Toward this goal, we created isogenic mutant human embryonic stem cell (hESC) lines in GWAS-identified candidate diabetes genes including CDKAL1, KCNQ1 and KCNJ11, and used directed differentiation to evaluate the function of derivative human beta-like cells. The mutations did not affect the generation of insulin+ cells, but impaired insulin secretion both in vitro and in vivo, coinciding with defective glucose homeostasis. CDKAL1-/- insulin+ cells also displayed hypersensitivity to lipotoxicity. A high-content chemical screen identified a candidate drug that rescued CDKAL1-/--specific defects by inhibiting the AP1 (FOS/JUN) pathway. These studies establish a platform using isogenic hESCs to evaluate the function of GWAS-identified loci, and identify a drug candidate that rescues gene-specific defects, paving the way to precision therapy of metabolic diseases.
Project description:Cytokine-induced beta-cell apoptosis is a key event for the death of pancreatic beta cells in the development of type-1 diabetes. We identified BRD0476 as a novel suppressor of cytokine-induced beta-cell apoptosis. We used microarrays to look for gene set(s) that are regulated by BRD0476.
Project description:Cytokine-induced beta-cell apoptosis is a key event for the death of pancreatic beta cells in the development of type-1 diabetes. We identified BRD0476 as a novel suppressor of cytokine-induced beta-cell apoptosis. We used microarrays to look for gene set(s) that are regulated by BRD0476. Rat INS-1E cells were treated with cytokine cocktails (IL-1b, IFN-g and TNF-a) and/or BRD0476 for 6 or 12 hours. Total RNAs were isolated using the RNEasy kit from Qiagen.
Project description:Pancreatic beta-cell dysfunction and death are central in the pathogenesis of type 2 diabetes. Saturated fatty acids cause beta-cell failure and contribute to diabetes development in genetically predisposed individuals. Here we used RNA-sequencing to map transcripts expressed in five palmitate-treated human islet preparations, observing 1,325 modified genes. Palmitate induced fatty acid metabolism and endoplasmic reticulum (ER) stress. Functional studies identified novel mediators of adaptive ER stress signaling. Palmitate modified genes regulating ubiquitin and proteasome function, autophagy and apoptosis. Inhibition of autophagic flux and lysosome function contributed to lipotoxicity. Palmitate inhibited transcription factors controlling beta-cell phenotype including PAX4 and GATA6. 59 type 2 diabetes candidate genes were expressed in human islets, and 11 were modified by palmitate. Palmitate modified expression of 17 splicing factors and shifted alternative splicing of 3,525 transcripts. Ingenuity Pathway Analysis of modified transcripts and genes confirmed that top changed functions related to cell death. DAVID analysis of transcription binding sites in palmitate-modified transcripts revealed a role for PAX4, GATA and the ER stress response regulators XBP1 and ATF6. This human islet transcriptome study identified novel mechanisms of palmitate-induced beta-cell dysfunction and death. The data point to crosstalk between metabolic stress and candidate genes at the beta-cell level. 5 human islet of Langerhans preparations examined under 2 conditions (control and palmitate treatment)
Project description:Genetic variation at ~160 gene loci is associated with type 2 diabetes (T2D). Using an F2 mouse intercross segregating for T2D, we searched for a driver of GWAS gene expression and found that ~40% of the GWAS genes are regulated in trans by a locus on chromosome 2 in islets. We identified Nfatc2 as a candidate driver of GWAS gene expression. Overexpression of Nfatc2 induced β-cell proliferation in mouse and human islets. We show that many T2D GWAS genes are responsive to NFAT and thus may act coordinately as intermediate traits to promote diabetes.