Project description:Aim: Transcriptional analysis of E15.5 whole pancreas of Nkx2.2-LacZ/LacZ embryos versus control and Ngn3-Cre; Nkx2.2-flox/flox embryos versus control Methods: Embryonic pancreata were isolated at E15.5 from Nkx2.2 mutant mice and controls. Total RNA was extracted. Libraries were prepared from total RNA (RIN>8) with the TruSeq RNA prep kit (Illumina) and sequenced using the HiSeq2000 (Illumina) instrument. More than 20 million reads were mapped to the mouse genome (UCSC/mm9) using Tophat (version 2.0.4) with 4 mismatches and 10 maximum multiple hits. Significantly differentially expressed genes were calculated using DEseq. Results: There is significant overlap between the differentially expressed genes of whole body Nkx2.2 mutant embryos and endocrine progenitor specific Nkx2.2 mutant embryos; many of the downregulated genes (p-value < 0.05) are genes involved in beta cell function. Conclusion: Nkx2.2 functions within the endocrine progenitor lineage to activate beta cell genes
Project description:The basic helix-loop-helix transcription factor Neurogenin3 (Ngn3/Neurog3) is expressed in endocrine progenitor cells in the embryonic mouse pancreas. Ngn3 controls endocrine cell fate decisions. Ngn3 deficient mice do not develop any pancreatic endocrine cells, including insulin producing beta cells, and die postnatally from diabetes. Therefore, the characterization of gene expression in Ngn3-expressing cells and their progeny is of particular interest for the development of novel strategies for cell replacement therapies in type-1 diabetes. Here we describe two studies. In the first study (8 assays) we used mice where the EYFP (Enhanced Yellow fluorescent Protein) is expressed under the control of Ngn3 regulatory elements (knock add on strategy). EYFP-positive, Ngn3-expressing cells, were FACS sorted from embryonic pancreas at day 15.5 (E15.5), as well as EYFP-negative cells. In the second study (6 assays) we compared wild-type and Ngn3 mutant pancreas at E15.5. All samples were hybridized to Affymetrix GeneChip Mouse Genome 430.2.0 array.
Project description:Pancreatic endocrine cells arise from a NGN3+ population during pancreas organogenesis. To gain a more thorough understanding of this progenitor pool, we used a reporter mouse - NGN3-EGFP - and sorted EGFP+ cells from e15.5 pancreata of control animals. The data generated from this experiment will allow us to visualize gene expression levels in endocrine progenitors during normal development and can be used to compare against mutant animal gene expression.
Project description:The goal of this experiment was to analyze expression changes in the pancreas at embryonic days 12.5 and 13.5 between wild type and Nkx2.2 null mice. We know that Nkx2.2 is essential for pancreatic endocrine differentiation and development. At these early time points which are critical for endocrine cell specification, we would like to identify a transcriptional program that Nkx2.2 regulates. We would also like to identify direct and functional transcriptional targets of Nkx2.2.
Project description:This experiment used RNA-Seq technology to explore gene expression in mouse Ngn3^GFP/+ [het] FACS sorted pancreatic cells at E15.5 (commited endocrine progenitor cells) and in Ngn3^GFP/GFP [null] at E15.5 (defective endocrine progenitor cells). This experiment is designed to understand the gene expression alteration in the endocrine lineage at different embryonic days. The aim is to understand both Ngn3 dependent and independent gene expression profiles so as to reveal the instructive signals that specfy the collective endocrine islet cell fate or specific islet cell type.
Project description:Genes involved in distinct diabetes types suggest shared disease mechanisms. We show that rare ONECUT1 coding variants cause monogenic recessive diabetes (neonatal or very early-onset, syndromic) in two unrelated patients, and monogenic dominant diabetes (early adult-onset) in heterozygous relatives of these and 13 additional unrelated cases. Patients heterozygous for rare ONECUT1 coding variants define a subgroup of T2D with early-onset diabetes and other features. In addition, common regulatory ONECUT1 variants are associated with multifactorial T2D. Directed differentiation of human pluripotent stem cells to the pancreatic lineage revealed that loss of ONECUT1 impairs pancreatic progenitor formation and a subsequent endocrine program. We uncovered that ONECUT1 activates the pro-endocrine genes NKX6.1 and NKX2.2 through binding to their cis-regulatory elements. Globally, ONECUT1-directed gene transcription occurs in association with major islet transcription factors, at clusters of pancreas- and endocrine-specific enhancers within open chromatin. ONECUT1 regulates a transcriptional and epigenetic machinery critical for proper endocrine pancreatic development, involved in a spectrum of diabetes, monogenic recessive and dominant, and multifactorial.
Project description:To investigate the role of RNA methyltransferase-like 3 (Mettl3)-mediated m6A modification in pancreatic endocrine differentiation in early embryonic period. We then performed single cell RNA-seq at E15.5 Mettl3pKO pancreas group and E15.5 WT pancreas group
Project description:To investigate the role of RNA methyltransferase-like 3 (Mettl3)-mediated m6A modification in pancreatic endocrine differentiation in early embryonic period. We then performed m6A MeRIP-seq (GenSeq®️ m6A MeRIP Kit) at E15.5 Mettl3pKO pancreas group and E15.5 WT pancreas group
Project description:The goal of this study was to examine genetic networks that control endocrine cell type specification and differentiation. RNA-Seq technology was used to explore the gene expression profiles of pancreatic endocrine progenitor cells (at E10.5 and E15.5), impaired endocrine progenitor cells (at E10.5 and E15.5), and pre-beta cells (at E15.5) in mouse.
Project description:RNA-seq of FACS Sorted E10.5 Pdx1-GFP+ of genotypes wildtype and Hes1-/-. Summary statement The developmental mechanisms that cause ectopic pancreas are poorly understood. We show that aberrant dorsal pancreas morphogenesis in Hes1 mutants leads to ectopic pancreas depending on the pro-endocrine gene Neurog3. Abstract Mutations in Hes1, a target gene of the Notch signalling pathway, lead to ectopic pancreas by a poorly described mechanism. Here we use genetic inactivation of Hes1 combined with lineage tracing in mouse embryos to reveal an endodermal requirement for Hes1 and that most ectopic pancreas tissue is derived from the E8.5 dorsal pancreas primordium. RNA-seq data from sorted E10.5 Pdx1-GFP+ cells from Hes1+/+ and Hes1−/− suggested that upregulation of endocrine lineage genes in Hes1−/− embryos was the major defect in the endoderm and accordingly early pancreas morphogenesis was normalised and the ectopic pancreas phenotype suppressed in Hes1−/−Neurog3−/− embryos. Analysis of other Notch pathway mutants uncovered a total depletion of progenitors in Mib1 deficient dorsal anlage, which was replaced by an anterior Gcg+ extension. Together, our results demonstrate that aberrant morphogenesis is the cause of ectopic pancreas and that a part of the endocrine differentiation program is mechanistically involved in the dysgenesis. Our results suggest that the ratio of endocrine lineage to progenitor cells is important for morphogenesis and that a strong endocrinogenic phenotype without complete progenitor depletion as seen in Hes1 mutants provokes an extreme dysgenesis that causes ectopic pancreas.