Project description:MafA and MafB transcription factors have been shown to be key regulators of insulin and glucagon transcription. MafB is essential for alpha and beta cell differentiation, as MafB deficient mice produced fewer insulin+ and glucagon+ cells during development, with MafA expressed in remaining insulin+ cells. In contrast, beta cell development was reported to be normal in a total MafA knock out, although the animals developed beta cell dysfunction and diabetes as adults. However, we have found that MafB expression is elevated during development and retained in adult insulin+ cells after conditional removal of MafA in the pancreas. These studies will evaluate the broader significance of these insulin and glucagon regulators in alpha and beta cell development and function. Our efforts will focus on determining if the concerted actions of MafA and MafB factors are significant to beta cell formation, and we specifically plan to: Determine how alpha and beta cell differentiation is affected in MafA/MafB compound mutant mice during pancreas development. cDNA microarray studies (pancchip 6.0) with wild type, MafAKO, MafB-/-, and MafAKOMafB-/- mutant E18.5 pancreata will be performed to comprehensively identify genes controlled by MafA and MafB in developing alpha and beta cells.
Project description:Recent studies have identified dysregulation of RNA-binding proteins (RBPs) and aberrant mRNA splicing in the onset of diseases including diabetes. Here we investigated the role of RBFOX2 in the pancreatic β cell through the conditional mutation of Rbfox2 in the mouse pancreas (Pdx1:Cre; Rbfox2fl/lf) and RNAi experiments in the mouse insulinoma cell line, MIN6. We then identified the direct targets of RBFOX2 in the mouse β cell transcriptome my eCLIP-Seq in MIN6 cells.
Project description:Recent studies have identified dysregulation of RNA-binding proteins (RBPs) and aberrant mRNA splicing in the onset of diseases including diabetes. Here we investigated the role of RBFOX2 in the pancreatic β cell through the conditional mutation of Rbfox2 in the mouse pancreas (Pdx1:Cre; Rbfox2fl/lf) and RNAi experiments in the mouse insulinoma cell line, MIN6. We then identified the direct targets of RBFOX2 in the mouse β cell transcriptome my eCLIP-Seq in MIN6 cells.
Project description:Analysis of the transcriptional differences between mouse ES cells from the D3 cell line and transformed beta-cells (MIN6 cell line) as determined by a direct comparative analysis of their transcriptome. The results show that 40% of transcripts were differentially expressed between D3 and MIN6 cells. There is thus a marked difference in the pattern of transcription between the ES cell and beta-cell genomes.
Project description:Analysis of the transcriptional differences between mouse ES cells from the D3 cell line and transformed beta-cells (MIN6 cell line) as determined by a direct comparative analysis of their transcriptome. The results show that 40% of transcripts were differentially expressed between D3 and MIN6 cells. There is thus a marked difference in the pattern of transcription between the ES cell and beta-cell genomes. Total RNA was extracted from three independent replicates of passage 21 D3 cells and passage 23 MIN6 cells. A whole mouse genome comparison between D3 and MIN6 cells was performed using the Mouse WG-6 v2.0 Expression Beadchip from Illumina.
Project description:Analysis of MIN6 murine beta cell line transfected with ARH3 RNAi and treated with pro-inflammatory cytokines TNF-alpha, IL-1beta and IFN-gamma.
Project description:Analysis of MIN6 murine beta cell line transfected with Pla2g6 RNAi and treated with pro-inflammatory cytokines TNF-alpha, IL-1beta and IFN-gamma.
Project description:Pax6os1 was knocked using by a pool of 3 siRNAs in the mouse insulinoma (beta cell) line MIN6. A parallel experiment using 3 control siRNAs was performed and RNA extracted 72 hours after transfection and subjected to RNA-Seq.
Project description:Type 2 diabetes (T2D) is associated with compromised identity of insulin-producing pancreatic islet beta (β) cells, characterized by inappropriate production of other islet cell-enriched hormones. Here we examined how hormone misexpression was influenced by the MAFA and MAFB transcription factors, closely related proteins that maintain islet cell function. Mice specifically lacking MafA in β cells demonstrated broad, population-wide changes in hormone gene expression with an overall gene signature closely resembling islet gastrin (Gast)-positive cells generated under conditions of chronic hyperglycemia and obesity. A human b cell line deficient in MAFB, but not one lacking MAFA, also produced a gastrin (GAST)-positive gene expression pattern. In addition, GAST was detected in human T2D β cells with low levels of MAFB. Moreover, evidence is provided that human MAFB can directly repress GAST gene transcription. These results support a novel, species-specific role for MafA and MAFB in maintaining adult mouse and human β cell identity, respectively, by repressing expression of Gast/GAST and other non-b cell hormones.
