The Pdx1 Cistrome of Pancreatic Islets
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REPOSITORIES: ENA
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Project description:We performed global location analysis of Pdx1 occupancy in mouse and human islets.
2012-05-23 | E-MTAB-1143 | biostudies-arrayexpress
Project description:Nkx6.1 target genes were identified in mature pancreatic islets by comparing gene expression in conditional Nkx6.1-ablated islets versus control islets using microarray analysis. Nkx6.1 was conditionally ablated in mature pancreatic islets by recombination of a Nkx6.1-flox allele using the tamoxifen-inducible Pdx1-CreERTM allele (Gu et al 2002). Mice were injected with 2 mg/25 g tamoxifen in corn oil four times between 4 and 6 weeks of age. Islets were isolated after the final tamoxifen injection. Total RNA was isolated and pooled from pancreata of 6 week old Nkx6.1fl/-;Pdx1-CreERTM (mutant) versus Nkx6.1fl/+;Pdx1-CreERTM (control) littermates for 3 biological replicates.
2013-09-12 | E-GEOD-40470 | biostudies-arrayexpress
Project description:To gain insights into how pancreatic cells are programmed in vivo, we profiled RNA expression in pancreatic islets of pancreatic Ring1b conditional KO mice (conditional using a pancreas specfic Cre; Pdx1-Cre) and their littermate controls
2013-02-10 | E-MTAB-1404 | biostudies-arrayexpress
Project description:Vitamin K-dependent carboxylation is necessary to the acquisition of an adequate beta-cell mass and for insulin secretion in mice. To better understand how this pathway affect pancreatic beta-cell function, we analysed the expression profile of pancreatic islets from Ggcxff; Pdx1-Cre and Ggcxff mice by RNA-sequencing.
2023-05-08 | GSE199319 | GEO
Project description:The aim of this experiment was to use global gene expression profiling to identify genes that are differentially expressed in the islets from Pdx1+/- mice compared to islets isolated from Pdx1 +/+ littermates. The Pdx1 null mutation consists of a nuclear targeted _-galactosidase cassette fused in-frame with the N terminus of PDX-1.
2009-12-02 | E-MTAB-127 | biostudies-arrayexpress
Project description:ABSTRACT: The human growth hormone (hGH) minigene is frequently used in the derivation of transgenic mouse lines to enhance transgene expression. Although this minigene is present in the transgenes as a secondcistron, and thus not thought to be expressed, we found that three commonly used lines, Pdx1-CreLate, RIP-Cre, and MIP-GFP, each expressed significant amounts of hGH in pancreatic islets. Locally secreted hGH binds to prolactin receptors on β cells, activates STAT5 signaling, and induces pregnancy-like changes in gene expression, thereby augmenting pancreatic β cell mass and insulin content. In addition, islets of Pdx1-CreLate mice have lower GLUT2 expression and reduced glucose-induced insulin release and are protected against the β cell toxin streptozotocin. These findings may be important when interpreting results obtained when these and other hGH minigene-containing transgenic mice are used. Data obtained for the Pdx1-creLate and control samples were compaired to investigate the effect of hGH on the mRNA profile of islets. The data obtained from the islets of pregnant mice was added to the analysis to confirm the pregnacy-like phenotype in the Pdx1-creLate islets. The data of the different days of pregnancy was already described in Schraenen et al. 2010 (PMID: 20886204 and PMID: 20938637).
2014-02-14 | GSE50851 | GEO
Project description:ABSTRACT: The human growth hormone (hGH) minigene is frequently used in transgenic mouse lines to ensure proper transgene expression. Here, we show that hGH is expressed in islets isolated from the commonly used Pdx1-CreLate mouse model. Locally secreted hGH activates prolactin receptors on M-NM-2 cells causing phosphorylation of STAT5, and induces a pregnancy-like change in gene expression, augmented pancreatic M-NM-2 cell mass and insulin content. In addition, islets of Pdx1-CreLate mice had lower GLUT2 expression, reduced glucose-induced insulin release and were protected against the M-NM-2 cell toxin streptozotocin. As the hGH minigene is commonly used in a great number of Cre-driver and other transgenic mouse models in diabetes research, the currently reported profound phenotypic changes may necessitate the re-evaluation of a large amount of previously published work. Data obtained for the Pdx1-creLate and control samples were compaired to investigate the effect of hGH on the mRNA profile of islets. The data obtained from the islets of pregnant mice was added to the analysis to confirm the pregnacy-like phenotype in the Pdx1-creLate islets. The data of the different days of pregnancy was already described in Schraenen et al. 2010 (PMID: 20886204 and PMID: 20938637). Islets were isolated from Pdx1-creLate, control and pregnant mice for RNA extraction and hybridization on Affymetrix microarrays. For every condition, at least 3 biological replicates were used.
2014-02-14 | E-GEOD-50851 | biostudies-arrayexpress
Project description:Progressive decline of pancreatic beta cell function is central to the pathogenesis of type 2 diabetes. Protein phosphorylation regulates glucose-stimulated insulin secretion from beta cells, but how signaling networks are remodeled in diabetic islets in vivo remains unknown. Using high-sensitivity mass spectrometry-based proteomics we quantified 6,500 proteins and 13,000 phosphopeptides in islets of obese diabetic mice and matched controls, revealing drastic remodeling of key kinase hubs and signaling pathways. Integration with a literature-derived signaling network implicated GSK3 kinase in the control of the beta cell-specific transcription factor PDX1. Deep phosphoproteomic analysis of human islets chronically treated with high glucose demonstrated a conserved glucotoxicity-dependent role of GSK3 kinase in regulating insulin secretion. Remarkably, the ability of beta cells to secrete insulin in response to glucose was rescued almost completely by pharmacological inhibition of GSK3. Thus, our resource enables investigation of mechanisms and drug targets in type 2 diabetes.
2019-03-15 | PXD012671 | Pride
Project description:Pancreas specific deletion of the Haster promoter region results in a variegated phenotype in pancreatic islets with overexpression or silencing of the Hnf1a gene. To determine the transcriptional consequence of the overexpression or silencing of Hnf1a is islet cells from the Haster pKO mice (Haster loxP/loxP;Pdx1-Cre), we performed scRNA-seq of pancreatic islets from control and adult female Haster pKO mice.
2022-05-01 | E-MTAB-11477 | biostudies-arrayexpress
Project description:Objective: Homozygous loss-of-function mutations in the gene coding for the homeobox transcription factor (TF) PDX1 leads to pancreatic agenesis, whereas heterozygous mutations can cause Maturity-Onset Diabetes of the Young 4 (MODY4). Although the function of Pdx1 is well studied in pre-clinical models during insulin-producing β-cell development and homeostasis, it remains elusive how this TF controls human pancreas development by regulating a downstream transcriptional program. Furthermore, many studies reported the association between single nucleotide polymorphisms (SNPs) and T2DM and it has been shown that islet enhancers are enriched in T2DM-associated SNPs. Whether regions, harboring T2DM-associated SNPs are PDX1 bound and active at the pancreatic progenitor stage has not been reported so far. Methods: In this study, we have generated a novel induced pluripotent stem cell (iPSC) line that efficiently differentiates into human pancreatic progenitors (PPs). Furthermore, PDX1 and H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify PDX1 transcriptional targets and active enhancer and promoter regions. To address potential differences in the function of PDX1 during development and adulthood, we compared PDX1 binding profiles from PPs and adult islets. Moreover, combining ChIP-seq and GWAS meta-analysis data we identified T2DM-associated SNPs in PDX1 binding sites and active chromatin regions. Results: ChIP-seq for PDX1 revealed a total of 8088 PDX1-bound regions that map to 5664 genes in iPSC-derived PPs. The PDX1 target regions included important pancreatic TFs, such as PDX1 itself, RFX6, HNF1B and MEIS1, which were activated during the differentiation process as revealed by the active mono-acetylated chromatin mark H3K27ac and mRNA expression profiling, suggesting that auto-regulatory feedback regulation maintains PDX1 expression and initiates a pancreatic TF program. Remarkably, we identified several PDX1 target genes that have not been reported in human so far, including RFX3, required for ciliogenesis and endocrine differentiation in mouse, and the ligand for the Notch receptor, DLL1, which is important for endocrine induction and tip-trunk patterning. The comparison of PDX1 profiles from PPs and adult human islets identified sets of stage-specific target genes, associated with early pancreas development and adult β-cell function. Furthermore, we found an enrichment of T2DM-associated SNPs in active chromatin regions from iPSC-derived PPs. Two of these SNPs fall into PDX1 occupied sites that are located in the intronic regions of TCF7L2 and HNF1B. Both of these genes are key transcriptional regulators of endocrine induction and mutations in cis-regulatory regions predispose to diabetes. Conclusions: Our data provides stage-specific target genes of PDX1 during in vitro differentiation of stem cells into pancreatic progenitors that could be useful to identify pathways and molecular targets that predispose for diabetes. In addition, we show that T2DM-associated SNPs are enriched in active chromatin regions at the pancreatic progenitor stage, suggesting that the susceptibility to T2DM might originate from imperfect execution of a β-cell developmental program.
2018-02-27 | GSE106813 | GEO