Project description:Genes specific to Sox9+ pancreatic progenitors were identified by comparing the gene expression in embryonic and adult Sox9+ cells. We used microarray analysis to detail the global changes in gene expression as Sox9 positive embryonic pancreatic progenitors differentiatiate into adult ductal cells or the endocrine lineage. GFP positive cells from Sox9-EGFP mouse pancreas were isolated by FACS at different stages of development (e10.5, e15.5, and p23) for RNA extraction and hybridization to Affymetrix microarrays. To obtain populations highly enriched in Sox9 expression, we collected only GFP Hi populations for analysis. To identify gene expression changes specific to the differentiation of progenitors to ductal cells or endocrine cells, we also isolated and analyzed the gene expression profile of GFP negative cells isolated at p23, as well as GFP positive cells isolated from Ngn3-EGFP mouse pancreas at e15.5. These two populations allow the identification of genes whose expression is associated with the newly differentiated endocrine progeny in the embryo (Ngn3-GFP positive) and adult acinar and endocrine cells at p23.
Project description:This experiment was designed to analyze the expression of genes in dorsal pancreatic cells at two temporally separated stages of pancreas development. This was accomplished by comparing expression profiles of embryonic dorsal pancreas tissue from Ngn3 null mice with wild-type littermates at days 13 and 15 of embryonic development. The comparison of gene expression in mutant and wild-type pancreas was used primarily to show genes that are lower expressed/missing in the mutant, as Ngn3 null mice have no endocrine pancreas tissue. From each developmental stage, five wild-type and five mutant samples were chosen, representing embryos from at least three different litters. Wild-type and mutant samples from the common stage of development were paired randomly and analysed in flipped colour. Probes were spotted in duplicate on each slide in a randomised (fixed) layout, effectively distributing the duplicate spots randomly over the slide.
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:NGN3 is a transcription factor whose transient expression during pancreatic development is vital for the generation of endocrine pancreatic cells, including beta cells. NGN3 stabilisation has been shown to induce exocrine-to-endocrine cell plasticity in the murine pancreas, making it a viable target for therapies aiming to replenish beta cells after immune-mediated destruction in type 1 diabetes patients. Here, we set out to identify new interactors of NGN3 that could play a role in its post-translational regulation. We transfected HEK293A cells with HA-tagged NGN3 and carried out immunoprecipitation of the HA-tag, followed by analysis of co-immunoprecipitated interactors via LC-MS/MS.
Project description:Pancreas study with 5 sub-studies: (i) 14 assays (7 done on Affymetrix MGU74Av2 and 7 on MOE430 2.0) looking at 7 different time points in pancreas development, (ii) 2 assays (done on Affymetrix MGU74Av2) looking at tumorgenic cell lines alphaTC and betaTC, (iii) 8 assays (6 done on Affymetrix MGU74Av2 and 2 done on MOE430 2.0) looking at Ngn3 mutant and wildtype pancreas at 3 different embryonic time points in pancreas development, (iv) 3 assays (done on Affymetrix MGU74Av2) looking at embryonic e12.5, newborn pancreas and adult islets, (v) 3 assays (done on Affymetrix MGU74Av2) looking at e11.5 separated pancreatic epithelium and mesenchyme or the intact e11.5 pancreas.
Project description:Neurogenin3 (Ngn3) is a basic helix-loop-helix transcription factor which is expressed in scattered cells in the embryonic pancreas. Mice deficient for Ngn3 fail to produce any pancreatic endocrine cells and die shortly after birth. Expression of transcription factors critical to pancreatic development (Isl1, NeuroD, Pax4, and Pax6) is missing and endocrine precursors are absent in mutant pancreatic epithelium. This study utilizes mice which were engineered to contain EGFP (Enhanced Green Fluorescent Protein) under the control of the Ngn3 promoter. In this way, cells which express Ngn3 can be FACS sorted and studied throughout embryonic development (E13.5, E14.5, E15.5, E16.5, and E17.5). EGFP positive cells from the embryonic time-points in addition to adult islets (no cells expressing Ngn3) were hybridized to the BCBC PancChip 6.0 expression microarray, thus generating a profile of gene expression during this critical stage of development of the endocrine pancreas.
Project description:Ngn3 is a master regulator of pancreatic endocrine development. It is necessary for the creation of all endocrine cells in mice. Little is known about the genes that act downstream of the transcription factor Ngn3 in pancreas endocrine development to specify each of the endocrine lineages. As a consequence, little is known about the genes involved in early development and the specification of the beta cell. We used microarrays to identify Ngn3 downstream genes that are involved in early and ectopic beta cell development in Xenopus laevis. We overexpressed Ngn3 in the Xenopus early endoderm and analyzed the genes that are upregulated four hours after.