ABSTRACT: Transcription profiling by array of Mus musculus colonic mucosa after treatment with dextran sodium sulphate (DSS) for 2 or 7 days which induces experimental colitis
Project description:The lack of suitable animal models reflecting chronically relapsing inflammation and tissue remodeling have hindered fibrosis research in inflammatory bowel diseases (IBD). This study investigated changes in connective tissue in a chronic murine model using different cycles of dextran sodium sulphate (DSS) to mimic the relapsing nature of the disease. We used whole gene expression arrays to study differences in colonic gene expression levels between acute and more chronic DSS colitis,
Project description:Protracted inflammatory responses are signatures common to many gastrointestinal disorders. Severe and chronic disorders often bring about extensive tissue damage, in turn leading to hypercytokinemia. Here, we show that stimuli like dextran sulphate sodium salt (DSS) and stearic acid (SA) cause acute colonic inflammation, and ANGPTL4 is an important regulator in mediating the extent of colonic inflammation. Using comparative microarray gene expression analysis, we seek to identify genes whose expression are altered during inflammation between ANGPTL4+/+ and ANGPTL4-/- mice.
Project description:The lack of suitable animal models reflecting chronically relapsing inflammation and tissue remodeling have hindered fibrosis research in inflammatory bowel diseases (IBD). This study investigated changes in connective tissue in a chronic murine model using different cycles of dextran sodium sulphate (DSS) to mimic the relapsing nature of the disease. We used whole gene expression arrays to study differences in colonic gene expression levels between acute and more chronic DSS colitis, Acute and chronic relapsing colonic inflammation was induced in C57BL6 female mice using several cycles of exposure to DSS in drinking water, followed by recovery phases. Total RNA, extracted from snap frozen colon from five mice per condition was used to analyze mRNA expression via Affymetrix Mouse Gene 1.0 ST arrays.
Project description:This study uses whole-transcriptome sequencing to characterize the transcriptomes of the AOM/DSS mouse model. In this model, mice are treated with dextran sodium sulfate (DSS) to induce colitis. When this treatment is preceded by injections of the weak carcinogen azoxymethane (AOM) the mice develop intestinal tumors. Our results identify sets of differentially expressed genes which are correlated with methylation changes of the corresponding genes. Whole transcriptome analysis of Mus musculus. Three conditions were sequenced and analyzed, the first is an untreated control, the second corresponds to inflammation induced by applying DSS, the third to cancer induced by inflammation and application of AOM. The control condition as well as the AOM-induced cancer condition were analyzed using three replicates, the second condition using 4 replicates.
Project description:Colorectal cancer (CRC) was induced in Foxp3/eGFP reporter mice by the azoxymethane/dextran sulphate sodium salt (AOM/DSS) protocol. Mice were injected i.p. with the procarcinogen AOM (12.5 mg/kg of body weight). After 1 week, mice received drinking water supplemented with 2.5% DSS for 5 to 7 days, followed by 2 weeks of regular water. The DSS administration was repeated twice with 2% DSS. Mice were sacrificed at week 11 and lamina propia lymphocytes (LPLs) from the colon were isolated. CD4+FOXP3+ (eGFP+) ST2+ or ST2- Tregs were separated from colonic LPLs of CRC induced mice using a FACSAria II cell sorter. Microarray analysis was performed to analyze if ST2+ FOXP3+ Tregs from the colon of CRC mice present a distinct transcription pattern compared to ST2- FOXP3+ Tregs. By this, the role of ST2 for Treg function during intestinal tumorigenesis should be characterized.
Project description:BACKGROUND: Peroxisome proliferator-activated receptor g (PPAR g) is a nuclear receptor whose activation has been shown to modulate macrophage and epithelial cell-mediated inflammation. The objective of this study was to use a systems approach for investigating the mechanism by which the deletion of PPAR g in epithelial cells modulates the severity of dextran-sodium sulfate (DSS)-induced colitis, immune cell distribution and global gene expression. RESULTS: The deficiency of PPAR g in epithelial cells does not significantly affect disease activity or body weight but worsens colon histopathlogy. WT mice have greater CD4+IL10+ T cells and fewer MHC II+ macrophages in mesenteric lymph nodes. Global gene expression analysis reveals greater changes after 7 days of DSS challenge (compared to 2 days). Colonic mucosa from VC- (WT) and VC+ (PPARg knock-out in epithelial cells) mice were sampled at 0 (no DSS), 2, and 7 days of DSS-induced experimental colitis
Project description:Background & Aims: Dextran sulphate sodium (DSS) induced colitis in rats is one of the most widely used models of inflammatory bowel disease. Animal models can provide new insights into the pathogenesis of intestinal inflammation, which is still unknown. We have performed a genomic analysis of the DSS rat colitis including an acute and a recovery phase. Methods: Expression profile of 6 control rats were compared with colitic rats at day 1 every other day until day 23 after DSS treatment using the GeneChip Rat Genome 230 2.0 Array (Affymetrix). Functional and pathways analysis were made with the differentially expressed genes. Experiment Overall Design: Experimental design: DSS was administered to animals in drinking water as follows:5%DSS from day 1 to 7, 3%DSS from day 8 to 15, 0% DSS from day 16 to 23. Samples were recovered at days 1, 3, 5, 7 (5%DSS), 9, 11, 13, 15 (2%DSS), 17, 19, 21 and 23 (0%DSS). According to inflammatory markers (Myeloperoxidase activity activity, body weight loss, colonic weigth/length ratio), three replicates at each time point were selected for genomic analysis and 6 control healthy rats (42 arrays). Experiment Overall Design: RNA was extracted from homogenized full-thickness colonic tissues in Trizol® reagent (Invitrogen) and purified with RNeasy affinity columns (Qiagen), according to manufacturer´s protocol. The microarray analysis was performed by Progenika Biopharma (Bilbao, Spain) on GeneChip® Rat Genome 230 2.0 Array (Affymetrix). All sample labeling (biotin), hybridization, staining and scanning procedures were carried out using Affimetrix, standard protocols (www.affymetrix.com). Normalization was carried out using Bioconductor sofware (affyPLM package).
Project description:Increased levels of tissue inhibitor of metalloproteinase-1 (TIMP-1) have been detected in fibrotic strictures in Crohnâs disease. In a murine model of chronic inflammation, fibrosis was associated with an increase in TIMP-1 and inhibition of matrix metalloproteinase (MMP)-mediated degradation. We investigated the effect of TIMP-1 deficiency on the colonic gene expression in acute and chronic murine models of colitis, using whole genome gene expression arrays. Colitis was induced via oral administration of dextran sodium sulphate (DSS) to B6.129S4-Timp1tm1Pds/J knock-out (KO) and C57BL/6J wild-type (WT) mice. Total RNA extracted from snap frozen colon was used to analyze mRNA expression via Affymetrix Mouse Gene 1.0 ST Arrays
Project description:BACKGROUND: Peroxisome proliferator-activated receptor g (PPAR g) is a nuclear receptor whose activation has been shown to modulate macrophage and epithelial cell-mediated inflammation. The objective of this study was to use a systems approach for investigating the mechanism by which the deletion of PPAR g in T cells modulates the severity of dextran-sodium sulfate (DSS)-induced colitis, immune cell distribution and global gene expression. METHODS: Wild-type (WT) or PPAR g flfl; CD4 Cre+ (CD4cre) mice in a C57BL/6 background were challenged with 2.5% DSS in their drinking water for 0, 2, or 7 days. Mice were scored on disease severity both clinically and histopathologically. Flow cytometry was used to assess lymphocyte and macrophage populations in the blood, spleen, and mesenteric lymph nodes (MLN). Global gene expression in colonic mucosa was profiled using Affymetrix microarrays. RESULTS: Both disease severity and inflammation-related body weight loss were accelerated by the deficiency of PPAR g in T cells. Examination of colon histopathology revealed significantly greater epithelial erosion, leukocyte infiltration, and mucosal thickening in the CD4cre mice on day 7. CD4cre mice had more CD8+ T cells than wt mice and fewer CD4+FoxP3+ regulatory T cells (Treg) and IL10+CD4+ T cells in blood and MLN, respectively. Transcriptomic profiling revealed around 3000 genes being transcriptionally altered as a result of DSS challenge in CD4cre mice. These included up-regulated adhesion molecules on day 7 and proinflammatory cytokines interleukin-6 (IL-6) and IL-1b, and suppressor of cytokine signaling 3 (SOCS-3) mRNA expression. CONCLUSIONS: These findings suggest that T cell PPAR g down-regulates inflammation during DSS colitis by inhibiting colonic expression of inflammatory mediators and increasing MLN Treg. Colonic mucosa from wt and CD4cre mice were sampled at 0 (no DSS), 2, and 7 days of DSS-induced experimental colitis