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:Lgr5-EGFP-IRES-Cre-ERT2 mice were exposed to azoxymethane/dextrane sodium sulfate (AOM/DSS) which induces inflammation-driven colon tumors. Tumors were then flow-sorted into fractions of epithelial cells that expressed high or low levels of Lgr5. To exclude that transcriptional differences between Lgr5 high and low mouse colon tumor cells were imposed by distinct patterns of chromosomal aberrations in the two cell fractions, we also performed array comparative genomic hybridization (aCGH) from these tumors. All eight analyzed tumors were chromosomally stable, and thus, no difference between Lgr5 high and low cells could be detected. AOM/DSS-induced mouse colon tumors were flow-sorted into Lgr5 high and low cells before aCGH was performed. Biological replicates: 8. Two CGH array platforms.
Project description:Comparative gene expression profiling between DSS-treated crypts and normal colon crypts Comparative gene expression profiling between normal colon crypts and tumor crypts
Project description:Dextran sodium sulfate (DSS) causes inflammation in the gut similar to ulcerative colitis in humans. Patients with ulcerative colitis have increased risk of developing colon cancer. We sought to determine whether genes altered in the normal colonic epithelium or tumor differed between sporadic and inflammation-associated tumor development. 97 day old (ACIxF344)F1-Pirc male rats either untreated or given 4% DSS in the drinking water from 40-47 and 54-61 days of age, housed in 12 hour light:12 dark, ad lib feeding and drinking conditions. Normal colonic tissue and tumors were harvested from the distal colon at 97 days of age. A two color, reference design experiment hybridized according to Agilent protocols against a reference pool of RNA made up from colon tissue taken from pooled wild type rats which was labeled with Cy5.
Project description:IL17B protected mice from dextran sodium sulfate (DSS)-induced colitis since IL17B deficiency resulted in severe DSS-induced colitis with exaggerated weight loss, shorter colon length, and elevated proinflammatory cytokine production in colon. For mechanism study, we use single cell transcriptional analyses of CD45+ immune cells in colonic lamina propria to detect the effect of IL-17B on colon LP immune cells in colitis. We found increased inflammatory macrophages infiltration in colon lamina propria after colitis induction expressing inflammatory cytokines such as S100a9, S100a8, Tnf, which was confirmed by real-time PCR and flow cytometry. Reconstitute of Il17b-/- mice with recombinant IL17B alleviated the severity of DSS-induced colitis. IL17B treatment also inhibited LPS-induced inflammation in bone marrow derived macrophage and in mice. These data indicate that IL17B exerting its inhibitory role in inflammation by regulating inflammatory macrophage response. In view of the protective effect of IL17B on DSS-induced colitis and LPS-induced inflammation, IL17B might represent a novel potential therapeutic approach to treat the inflammation.
Project description:IL17B protected mice from dextran sodium sulfate (DSS)-induced colitis since IL17B deficiency resulted in severe DSS-induced colitis with exaggerated weight loss, shorter colon length, and elevated proinflammatory cytokine production in colon. For mechanism study, we use single cell transcriptional analyses of CD45+ immune cells in colonic lamina propria to detect the effect of IL-17B on colon LP immune cells in colitis. We found increased inflammatory macrophages infiltration in colon lamina propria after colitis induction expressing inflammatory cytokines such as S100a9, S100a8, Tnf, which was confirmed by real-time PCR and flow cytometry. Reconstitute of Il17b-/- mice with recombinant IL17B alleviated the severity of DSS-induced colitis. IL17B treatment also inhibited LPS-induced inflammation in bone marrow derived macrophage and in mice. These data indicate that IL17B exerting its inhibitory role in inflammation by regulating inflammatory macrophage response. In view of the protective effect of IL17B on DSS-induced colitis and LPS-induced inflammation, IL17B might represent a novel potential therapeutic approach to treat the inflammation.
Project description:Inflammatory conditions can contribute to tumor formation. However, any clear marker predicting progression to cancer are still lacking. The aim of our study was to analyze microRNA modulations accompanying inflammation-induced tumor development to determine whether these microRNA may jointly affect the expression of genes involved in cancer. For this purpose, we used the well-established azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced mouse model of colitis-associated cancer. We performed a microRNA microarray to establish microRNA expression profiles in mouse whole colon at early and late time points during inflammation and/or tumor growth. Chronic inflammation and carcinogenesis were associated with distinct changes in microRNA expression. Nevertheless, prediction algorithms of microRNA-mRNA interactions and computational analyses based on ranked microRNA lists consistently identified putative target genes that play essential roles in tumor growth or belong to key carcinogenesis-related networks or signaling pathways. Hence, inflammation, through microRNA, may affect unexpected genes or signaling pathways, thereby contributing to carcinogenesis. The present method can lead to the identification of novel genes or signaling pathways involved in cancer development. miRNA microarray profiling in whole mouse colon at 4 time points during AOM/DSS treatment. Controls : PBS, DSS alone or AOM alone, at two time points; 10 experimental conditions, 5 replicates per experimental conditions, one replicate per array hybridized in dual color with a commercial reference (Universal Reference, Miltenyi Biotec GmbH)
Project description:In the DSS-induced colitis model, the epithelial damage and resulting inflammation is restricted to the colon, with a potential influence on the microbial composition in the adjacent cecum. Several studies have reported changes of the gut microbiota in the DSS-induced colitis model and other mouse models of IBD. Furthermore, metaproteomics analysis of the gut microbiome in a mouse model of Crohn’s disease demonstrated that disease severity and location are microbiota-dependent, with clear evidence for the causal role of bacterial dysbiosis in the development of chronic ileal inflammation. We have developed a refined model of chronic DSS-induced colitis that reflects typical symptoms of human IBD without a risky body weight loss usually observed in DSS models [Hoffmann et al., submitted]. In this study, we used metaproteomics to characterize the disease-related changes in bacterial protein abundance and function in the refined model of DSS-induced colitis. To assess the structural and functional changes, we applied 16S rRNA gene sequencing and metaproteomics analysis of the intestinal microbiota in three different entities of the intestinal environment, i.e. colon mucus, colon content and cecum content.
Project description:This study identifies a novel mechanism linking IL-17A with colon tissue repair and tumor development. Abrogation of IL-17A signaling mice attenuated tissue repair of DSS-induced damage in colon epithelium and markedly reduced tumor development in AOM/DSS model of colitis-associated cancer. The goal of these studies is to identify genes associated with IL-17RC deficiency during AOM-DSS induced tumorigenesis