RNA-Seq analysis of E18.5 mouse Zfp800 knockout vs wild-type
Ontology highlight
ABSTRACT: Zfp800 was identified by Gene Co-expression Network analysis to be an interesting candidate gene involved in endocrine specification and β-cell maturation. We found that Zfp800 null mice exhibited early post-natal lethality, and at E18.5 their pancreata exhibited a reduced number of pancreatic endocrine cells, alterations in exocrine cell morphology, and marked changes in genes involved in protein translation, hormone secretion, and developmental pathways in the pancreas.
Project description:This experiment used RNA-Seq technology to explore gene expression in mouse Insm1GFP.Cre/+ controls and Insm1 (Insm1GFP.Cre/GFP.Cre), Neurod1 (Insm1GFP.Cre/+; Neurod1LacZ/LacZ), or Pax6 (Insm1GFP.Cre/+; Pax6fl/fl) knockout FACS sorted pancreatic endocrine cells at E15.5. Comparison of Insm1GFP.Cre+/- and knockout animals revealed sets of differentially expressed genes that are required for endocrine cell specification and development.
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: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:Development of the pancreas from the endoderm is initiated at embryonic day 9 of mouse development and over the following days several different cell types develop from pancreas progenitor cells. A distinct phase of pancreas development, known as the secondary transition, is initiated at day 13 of development and one of the key features of this transition is a massive increase in the number of mature endocrine cells. To study gene expression in pancreas during the secondary transition we performed high-density oligonucleotide microarray experiments on dorsal pancreas tissue isolated from NMRI embryos on consecutive days from e12.5 to e16.5. Experiment Overall Design: Dorsal pancreata were isolated from embryos at embryonic day 12.5, 13.5, 14.5, 15.5, and 16.5 and pooled litter-wise prior to total RNA extraction. From each pool, two independent labelling reactions were made, and each sample was hybridized to the entire Murine Genome U74 version 2 chip set (A, B, and C).
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:SET-domain containing proteins play a vital role in regulating gene expression during development through modifications in chromatin structure. To study molecular function of SET domain containing 5 (Setd5), we assessed global changes in the mouse embryonic stem cell transcriptome when Setd5 gene is knocked out.
Project description:Mouse Ikbkap gene encodes IKAP/Elp1- one of the core subunits of Elongator- and has been implicated in translational regulation. However, a role for IKAP in genome maintenance remains unclear. In this study, we analyze proteins from control and Ikbkap depletion mouse embryonic fibroblasts (MEF) using MS. Using MS-based proteomics, we show that several proteins involved in cancer and DNA damage response were found to be differentially expressed upon Ikbkap depletion.
Project description:Factor induced reprogramming is a slow and inefficient process with only rare cells progressing towards induced pluripotent stem cells (iPSCs). Owing to these restraints, mechanistic studies have been limited to analyses of heterogeneous bulk populations undergoing reprogramming and partially reprogrammed cell lines. Here, by combining surface markers (Thy1, SSEA1) and an Oct4-GFP fluorescent reporter allele, we analyzed defined intermediate cell populations poised to becoming iPSCs at the transcriptional and epigenetic levels using genome-wide and single cell technologies. We found that factor-induced reprogramming elicits two discernible transcriptional waves that are characterized by the initial extinction of the somatic gene expression program and the concomitant acquisition of an ESC-like proliferative and metabolic state, followed by the activation of an embryonic pluripotent state primed for differentiation. The first wave is mostly driven by gene activation through c-Myc and gene repression by Klf4, whereas the second wave is a result of gradually activated Oct4/Sox2 targets in cooperation with Klf4 targets and other downstream regulators. While microRNA expression and enrichment for individual histone modifications (H3K4me3 or H3K27me3 enriched promoters) mirrored the observed biphasic transcriptional pattern, the establishment of bivalent domains (H3K4me3/H3K27me3 enriched promoters) occurred more gradually. In contrast, changes in DNA methylation took place predominantly at the end of reprogramming when cells assumed a stable pluripotent state. Cells that became refractory to reprogramming activated the first but failed to initiate the second transcriptional wave. However, introduction of additional copies of the reprogramming transgenes into these cells rescued their ability to form iPSCs, indicating that suboptimal transcription factor levels are a limiting factor for efficient iPSC formation. This integrative analysis allowed us to identify novel genes and microRNAs that enhance reprogramming and surface markers that further subdivide intermediate cell populations. Collectively, our data offer new mechanistic insights into the nature and sequence of molecular events inherent to cellular reprogramming and provide a valuable resource of molecules that may act as roadblocks during iPSC formation. Time series design with samples sorted into subpopulations according to surface markers. 18 Samples total
Project description:Direct lineage conversion of adult cells is a promising approach for regenerative medicine. A major challenge of lineage conversion is to generate specific subtypes of cells, closely related cells with distinct properties. The pancreatic islets contain three major hormone-secreting endocrine subtypes: insulin+ β-cells, glucagon+ α-cells, and somatostatin+ δ-cells. We previously reported that a combination of three transcription factors, Ngn3, Mafa, and Pdx1, directly reprogram pancreatic acinar cells to β-cells. We now show that acinar cells can be converted to δ-like and α-like cells by Ngn3 and Ngn3+Mafa respectively. Thus, three major islet endocrine subtypes can be derived by acinar reprogramming. Ngn3 promotes establishment of a generic endocrine state in acinar cells at the onset of reprogramming in addition to promoting δ-specification. Mafa and Pdx1 suppress δ-specification in α- and β-cell formation. These studies identify a set of defined factors whose combinatorial actions reprogram acinar cells to distinct islet endocrine subtypes in vivo. induced beta cells samples at day 10 collected for the microarray
Project description:Extracellular matrix (ECM) is an important component of the pancreatic microenvironment which regulates β cell proliferation, differentiation and insulin secretion. Protocols have recently been developed for the decellularization of the human pancreas to generate functional scaffolds and hydrogels. In this work, we characterized human pancreatic ECM composition before and after decellularization using isobaric dimethylated leucine (DiLeu) labeling for relative quantification of ECM proteins. A novel correction factor was employed in the study to eliminate the bias introduced during sample preparation. In comparison to the commonly employed proteomic approaches (urea and FASP), a recently developed surfactant and chaotropic agent assisted sequential extraction/on pellet digestion (SCAD) protocol was proven to be a superior strategy for ECM protein extraction of human pancreatic ECM matrix. The quantitative proteomic results revealed the preservation of matrisome proteins while most of the cellular proteins were removed. This method was compared with a well-established label-free quantification (LFQ) approach which rendered similar expressions of different categories of proteins (collagens, ECM glycoproteins, proteoglycans, etc.). The distinct expression of ECM proteins was quantified comparing adult and fetal pancreas ECM, shedding light on the correlation between matrix composition and post-natal β cell maturation. Despite the distinct profiles of different subcategories in the native pancreas, the distribution of matrisome protein exhibited similar trends after the decellularization process. Our method generates the largest dataset of matrisome proteins from a single tissue type. These results provide valuable insight into the possibilities of constructing a bioengineered pancreas. It also facilitates an understanding of the significant roles that matrisome proteins play in post-natal cell maturation.