Effects of Intestine-specifc SREBP2 overactivation on gene expression in mouse jejnum
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ABSTRACT: The active form of the SREBP2 transcription factor was specifically overexpressed in the intesitne. This was achieved by generating transgenic mouse model (designated as ISR2) in which the transgene represents the N-terminal active SREBP2 transcription factor driven by the villin promoter. In this project, we investigated the effects of overactivation of SREBP2 on gene expression in mouse jejunum Gene expression profile in the jejunum of ISR2 was compared to gene expression profile in the jejunum of their wild type littermates.
Project description:The active form of the SREBP2 transcription factor was specifically overexpressed in the intesitne. This was achieved by generating transgenic mouse model (designated as ISR2) in which the transgene represents the N-terminal active SREBP2 transcription factor driven by the villin promoter. In this project, we investigated the effects of overactivation of SREBP2 on gene expression in mouse jejunum
Project description:GATA6 is a transcription factor involved in the differentiation of intestinal epithelial cells into differentiated absorptive epithelial cells. GATA6 is expressed in all segments of the small intestine. We examined the impact of deleting GATA6 from intestinal epithelial cells of the adult ileum 6-8 week old Villin-CreERT2 mice or Villin-CreERT2 mice crossed to GATA6 flox/flox mice were treated with a single injection of tamoxifen. (100 mg/ml) for 5 consecutive days. 28 days later the ileum was dissected and RNA prepared from the whole ileal segment using the RNAeasy method with DNAse treatment. Three individual mice were examined in each of the control and GATA6 KO groups.
Project description:Background and Aims: Although the zinc finger transcription factor GATA4 has been implicated in regulating jejunal gene expression, the contribution of GATA4 in controlling jejunal physiology has not been addressed. Methods: We generated mice in which the Gata4 gene was specifically deleted in the small intestinal epithelium. Measurements of plasma cholesterol and phospholipids, intestinal absorption of dietary fat and cholesterol, and gene expression were performed on these animals. Results: Mice lacking GATA4 in the intestine displayed a dramatic block in their ability to absorb cholesterol and dietary fat. Comparison of the global gene expression profiles of control jejunum, control ileum, and GATA4 null jejunum by gene array analysis demonstrated that GATA4 null jejunum lost expression of 53% of the jejunal-specific gene set and gained expression of 47% of the set of genes unique to the ileum. These alterations in gene expression included a decrease in mRNAs encoding lipid and cholesterol transporters as well as an increase in mRNAs encoding proteins involved in bile acid absorption. Conclusion: Our data demonstrate that GATA4 is essential for jejunal function including fat and cholesterol absorption and confirm that GATA4 plays a pivotal role in determining jejunal versus ileal identity. Experiment Overall Design: Total RNA was harvested from the following sources and used to Affymetrix array analysis following manufacturer defined protocols: Experiment Overall Design: control jejunum (Gata4loxP/+VilCre), 3 male mice, adult (6-8 wk) Experiment Overall Design: mutant jejunum (Gata4loxP/-VilCre), 3 male mice, adult (6-8 wk) Experiment Overall Design: control ileum (Gata4loxP/+VilCre), 3 male mice, adult (6-8 wk). Experiment Overall Design: A total of nine Mouse Genome 430_2.0 arrays were hybridized for this study. Experiment Overall Design: Jejunum was defined as 10 cm from the pyloric sphincter, and ileum was defined as 1 cm from the cecum. The animals used to harvest control jejunum and ileum were independent of each other.
Project description:Background and Aims: Although the zinc finger transcription factor GATA4 has been implicated in regulating jejunal gene expression, the contribution of GATA4 in controlling jejunal physiology has not been addressed. Methods: We generated mice in which the Gata4 gene was specifically deleted in the small intestinal epithelium. Measurements of plasma cholesterol and phospholipids, intestinal absorption of dietary fat and cholesterol, and gene expression were performed on these animals. Results: Mice lacking GATA4 in the intestine displayed a dramatic block in their ability to absorb cholesterol and dietary fat. Comparison of the global gene expression profiles of control jejunum, control ileum, and GATA4 null jejunum by gene array analysis demonstrated that GATA4 null jejunum lost expression of 53% of the jejunal-specific gene set and gained expression of 47% of the set of genes unique to the ileum. These alterations in gene expression included a decrease in mRNAs encoding lipid and cholesterol transporters as well as an increase in mRNAs encoding proteins involved in bile acid absorption. Conclusion: Our data demonstrate that GATA4 is essential for jejunal function including fat and cholesterol absorption and confirm that GATA4 plays a pivotal role in determining jejunal versus ileal identity. Keywords: genetic modification
Project description:The aim of the project is to generate a peptidomics map of gut hormone peptides along the gastrointestinal tract, starting with the stomach and including the duodenum, jejunum, ileum, ascending colon, sigmoid colon and rectum. The tissues would be collected after surgery and the peptide fraction extracted and anlysed by nano LC-MS to identify what peptide hormones are present. These data will then be used to compare against the human transcriptome, and also for comparison against equivent peptides from murine intestinal extracts.
Project description:The aim of the project is to generate a peptidomics map of gut hormone peptides along the gastrointestinal tract, starting with the stomach and including the duodenum, jejunum, ileum, colon and rectum. The tissues would be collected after surgery and the peptide fraction extracted and anlysed by nano LC-MS to identify what peptide hormones are present. These data will then be used to compare against the murine transcriptome, and also for comparison against equivent peptides from human intestinal extracts.
Project description:The entire small intestine was obseved by balloon endoscopy. Biopsy specimens were taken from jejunum, ileum and colon, respectively.
Project description:To determine whether Ex-4 and Fgf7 acitvate a subset of overlapping gene expression profiles in mouse jejunum. Total RNA islolated from mucosal scrapings taken from the jejunum of C57BL/6 male mice treated with a single dose of Ex-4 (10 nmol/kg, ip), human recombinant KGF/Fgf7 (1 mg/kg, ip), or vehicle/control (PBS) for 1 h (n=3 for each group), 5h (n=4 for each group), or 20 h (n=3 for each group).
Project description:XBP1 is the transcriptino factor that is activated by the ER stress. XBP1 is known to induce the ER dexpansion and increase the expression of the ER chaperone genes to prtect the cell from the ER stress. We generated a mouse strain that lacked XBP1 specifically in the mouse intestine by breeding the XBP1flox mice with Villin-cre mice. Here we examined genes that are differentially expressed between WT and XBP1 KO mouse intestine to identify genes that are downstream of XBP1. Experiment Overall Design: Total RNAs were pooled from three mice of indicated genotypes. Microarray experiments were performed by using Affymetrix GeneChip® Mouse Genome 430 2.0 Array in Biopolymers Facility at Harvard Medical School.