Effects of increased intracellular calcium and overnutrition on pancreatic beta cell transcriptome
Ontology highlight
ABSTRACT: To determine the individual and combined effects of excitotoxicity and overnutrition on beta-cell gene expression, we analyzed the impact of a high fat diet (HFD) on wild type C57Bl/6J and Abcc8 knockout mice of different sexes. We collected 31 bulk RNA-Seq datasets that originated from FACS-purified pancreatic beta-cells that differed by genotype, diet, and sex.
Project description:To determine the role of Ascl1 in beta cell development, function, and metabolic stress response, we generated beta cell specific Ascl1 knockout mice and assessed their glucose homeostasis, islet morphology, and gene expression after feeding a normal diet, a high fat diet (HFD) for 12 weeks, or on a background of Abcc8 (KATP channel subunit) knockout mice. For the RNA-seq analysis, islets from male Ascl1betaKO and littermate control mice (N = 4 for each genotype and condition) were collected from three different conditions: 1) normal diet fed 2) HFD fed for 12 weeks, 3) on a background of homozygous Abcc8 allele.
Project description:Abcc8 (sulfonylurea receptor 1, SUR1) is an essential part of the ATP-sensitive potassium channel necessary for coupling energy metabolism and membrane potential. In this study we assessed the impact of eliminating Abcc8 on islet morphology, beta-cell identity, and gene expression. Beta cells were isolated by FACS from 60 day old mice based on expression of a MIP-GFP transgene.
Project description:In this study, we generated a novel nuclear-localized red fluorescence knock-in reporter allele (Ins2.Apple) for mouse pancreatic beta-cells. Beta-cells were isolated by FACS from 60-day-old mice, segregated by sex, and RNA-sequencing was performed to assess sex-specific differences in beta-cell gene expression profiles. We also isolated beta-cells (by FACS) from MIP-GFP mice at 60 days of age. RNA-sequencing was performed, and was compared to that of Ins2.Apple beta cells, to assess gene expression changes brought on by the presence of the MIP-GFP transgene.
Project description:Male C57Bl/6J mice were fed 45%kcal fat diet (HF) or regular rodent chow (NC) from 4 weeks to 16 weeks of age. Gene expression was compared between RNA obtained from pancreatic islets of HF fed mice and NC mice. RNA samples from 4 NC group and 4 HF groups were analyzed using GeneChip Mouse Expression Arrays MOE 430v2 (Affymetrix).
Project description:Zfp92, a repressive KRAB domain-containing zinc-finger protein, was identified by Gene Co-expression Network analysis to be an interesting candidate gene involved in endocrine specification and maturation. We examined the role of Zfp92, a KRAB-ZFP that is highly expressed in pancreatic islets of adult mice, by analyzing global Zfp92 knockout (KO) mice. Adult Zfp92 KO animals exhibited only mild changes in glucose homeostasis and no change in islet structure, although, male KO mice exhibited decreased growth, and female KO mice exhibited increased body fat accumulation on a high fat diet. We found that Zfp92 regulates a subset of transposable elements as well as Mafb, a transcription factor involved in islet development.
Project description:Overnutrition during pregnancy inM-oM-,M-^Buences the future health of the offspring, with outcomes differing depending on the childM-bM-^@M-^Ys sex. The placenta is involved in the programming of obesity, type 2 diabetes and cardiovascular disease. Sex-specific adaptation of the placenta may be central to the differences in fetal growth and survival. The impact of diet and fetal sex on placental gene expression and epigenetic marks was investigated in mice fed a high-fat (HFD) or a control diet (CD), during the first 15 days of gestation Microarrays analysis revealed that expression was affected by maternal diet and was sexually dimorphic. We analyzed the placentae of 4 mice litters fed with an high-fat diet (HFD) and 4 with a control diet (CD). For each litter, the placenta transcriptome was analysed according to the foetus sex using the Affymetrix Human Exon 1.0 ST platform. Array data was processed by Affymetrix Exon Array Computational Tool. No technical replicates were performed.
Project description:Pancreatic beta cells use electrical signals to couple changes in blood glucose concentration to insulin release via extracellular calcium (Ca2+) influx. Sorcin (SRI) is a Ca2+-binding protein whose overexpression in cardiomyocytes rescues the abnormal contractile function of the diabetic heart. In order to investigate the role of sorcin in regulating mouse pancreatic beta cell transcriptome, transgenic mice were generated on a C56BL/6 background permitting inducible overexpression of SRI cDNA with the TetOn-system specifically in beta cells. Animals bearing ten copies of the SRI transgene (SRI-tg10), and littermate controls, were fed a high fat diet (60% fat, HFD) and exposed to doxycycline in the drinking water (500mg/L) from 4 weeks onwards. Microarray analysis were performed using total RNA from isolated pancreatic islets of 8-week-old mice.
Project description:We report the application of next-generation sequencing technology for high-throughput profiling of H3K27ac and transcriptome analysis in pancreatic islets derived from C57Bl/6 mice fed a high-fat diet. We find genomic regions showing change in acetylation of histone H3K27 in response to long-term (26 weeks) HFD feeding, which was significantly associated with differential gene expression. Furthermore, increased H3K27ac showed a distinctive genomic distribution surrounding proximal-promoter regions. This study provides a framework for the application of comprehensive chromatin profiling towards characterization of diverse mammalian cells under various environments.
Project description:To gain insights into how pancreatic beta-cells are programmed in vivo, we profiled key histone methylations (H3K4/K27me3) in embryonic stem cells, multipotent progenitors of the nascent embryonic pancreas, purified beta-cells, and 10 other adult tissues (all under normal, untreated conditions). For these cells we also purified RNA to analyze tissue specfic genome wide transcription levels in relation to histone modifications. Corresponding RNA microarrays can be found under accession E-TABM-877.
Project description:Pathways that stimulate β-cell regeneration remain of great clinical interest, yet effective therapeutic avenues that promote survival or reconstitution of β-cell mass remain elusive. Utilizing a mouse model with inducible β-cell apoptosis followed by adiponectin-mediated regeneration, we aimed to identify key molecules boosting β-cell viability. Within the regenerating pancreatic islets, we examined changes within the transcriptome, and observed an extensive upregulation of genes encoding proteins involved in lipid transport and metabolism. The most prominent targets were further confirmed by quantitative PCR and immunofluorescence. Among the upstream regulators predicted by pathway analysis of the transcriptome, we detected enhanced levels of two key transcription factors, HNF4α and PPARα. Enhanced leptin levels in circulation may also contribute to the anti-lipotoxic program in islets. In summary, our data suggest that improving local lipid metabolism as an important anti-lipotoxic phenomenon to boost β-cell regeneration, primarily mediated by adiponectin’s action on the β-cells directly as well as on the adipocyte. RNA profiles of pancreatic islets isolated from PANIC-ATTAT mice crossed with adiponectin wild-type (P-Adn+/+) or the overexpressing transgene (P-AdnTg/+) at 5 weeks after initial dimerizer administration.