Project description:Inflammatory bowel diseases encompass gastrointestinal illnesseses typified by chronic inflammation, loss of epithelial integrity and gastrointestinal microbiota dysbiosis. In an effort to counteract these characteristic perturbations, we used stem cells and/or a probiotic preparation in a murine model of Dextran Sodium Sulfate induced colitis to examine both their efficacy in ameliorating disease and impact on niche-specific microbial communities of the lower GI tract. Colitis was induced in C57BL/6 mice by administering 3% DSS in drinking water for 10 days prior to administering one of three treatment plans: daily probiotic (VSL#3) supplementation for 3 days, a single tail vein injection of 1x106 murine mesenchymal stem cells, or both. Controls included DSS-untreated mice and DSS-treated mice that received no therapy. Ileal, cecal and colonic sections were collected for microbiota and histological analyses. Microbiota profiling revealed distinct bacterial community compositions in the ileum, cecum and colon of control untreated animals, all of which were predicted in silico to be enriched for a number of discrete KEGG pathways, indicating compositional and functional niche specificity in healthy animals. DSS- treatment perturbed community composition in all three niches with ileal communities exhibiting the greatest change relative to control animals. Stem cell, VSL#3 and the combination treated animals exhibited treatment-specific microbiota composition in the lower GI tract, though disease scores were only improved in VSL#3 treated animals. This VSL#3-associated shift in the ileal microbiota was characterized by significant Enterobacteriaceae enrichment compared to colitic animals (p<0.05), Mice (n=40) were randomly divided into five experimental groups, four of which received Dextran Sodium Sulfate (DSS; 3% solution in drinking water) for 10 days to induce colitis. Three of the DSS-treated groups received the following treatment modalities: VSL#3 (VSL#3, n=5), mesenchymal stem cells (MSC, n=5), or VSL#3 + mesenchymal stem cells (DUAL, n=5). The fourth DSS-treated group received no intervention (DSS; n=10). The additional fifth group of animals received neither DSS nor any therapeutic intervention and acted as untreated controls (CNTL, n=15). Following colitis induction (Day 10), DSS administration was halted and mice in the VSL#3, MSC and DUAL groups received the following interventions respectively: daily oral supplementation with 5x106 CFUs per supplement of VSL#3 in 100ul PBS (VSL#3); a single tail vein injection of 1x106 murine mesenchymal stem cells in 100_l PBS on Day 10 (MSC) or a combination of both treatments To provide control data for comparison, CNTL mice (n=5 per time point) were euthanized and sampled on days 1, 10, and 14, while DSS mice (n=5 per time point) were euthanized on days 10 and 14. All MSC, VSL#3, and DUAL mice were euthanized on Day 14. Samples collected from each animal included terminal ileum (1cm proximal to the cecum), cecum (divided transversely and stored as two separate samples), and proximal colon. All samples were added to RNAlater, prior to storage at -80C for analysis. Additional colonic samples were obtained, proximal to the initial sample site for microbiome analyses, and were preserved in paraformaldehyde for histological analyses.
Project description:Inflammatory bowel diseases encompass gastrointestinal illnesseses typified by chronic inflammation, loss of epithelial integrity and gastrointestinal microbiota dysbiosis. In an effort to counteract these characteristic perturbations, we used stem cells and/or a probiotic preparation in a murine model of Dextran Sodium Sulfate induced colitis to examine both their efficacy in ameliorating disease and impact on niche-specific microbial communities of the lower GI tract. Colitis was induced in C57BL/6 mice by administering 3% DSS in drinking water for 10 days prior to administering one of three treatment plans: daily probiotic (VSL#3) supplementation for 3 days, a single tail vein injection of 1x106 murine mesenchymal stem cells, or both. Controls included DSS-untreated mice and DSS-treated mice that received no therapy. Ileal, cecal and colonic sections were collected for microbiota and histological analyses. Microbiota profiling revealed distinct bacterial community compositions in the ileum, cecum and colon of control untreated animals, all of which were predicted in silico to be enriched for a number of discrete KEGG pathways, indicating compositional and functional niche specificity in healthy animals. DSS- treatment perturbed community composition in all three niches with ileal communities exhibiting the greatest change relative to control animals. Stem cell, VSL#3 and the combination treated animals exhibited treatment-specific microbiota composition in the lower GI tract, though disease scores were only improved in VSL#3 treated animals. This VSL#3-associated shift in the ileal microbiota was characterized by significant Enterobacteriaceae enrichment compared to colitic animals (p<0.05),
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:L-Arginine (L-Arg) is the substrate for both inducible nitric oxide synthase and arginase, which are upregulated in human IBD and in mouse colitis models. We have found that L-Arg supplementation enhances wound restitution in vitro, and improves the clinical parameters of weight loss, survival, and colon weight/length, in dextran sulfate sodium (DSS) induced murine colitis. Our aim was to further identify the potential mechanisms underlying the clinical benefit of L-Arg supplementation. 12 Total samples were analyzed, 3 samples from each of 4 groups. We generated the following pairwise comparisons: Ctrl vs Ctrl + L-Arg; Ctrl vs DSS; DSS vs DSS + L-Arg; Ctrl + L-Arg vs DSS, Ctrl + L-Arg vs DSS + L-Arg. Genes with a p-value < 0.01 and a fold-change ≥2 were selected. To identify genes that were altered in response to L-Arg, we performed the following multiple sample comparisons using a p-value < 0.01 and a fold-change ≥2: Ctrl vs DSS vs DSS + L-Arg
Project description:Folic acid supplementation (8 mg/kg diet) promotes colon tumor formation in mice with established colitis induced by carcinogen azoxymethane (AOM) and dextran sulfate sodium sulfate (DSS). This induction of colon tumors was associated with hypomethylation of DNA cased by folic acid supplementation.
Project description:Folic acid supplementation (8 mg/kg diet) promotes colon tumor formation in mice with established colitis induced by carcinogen azoxymethane (AOM) and dextran sulfate sodium sulfate (DSS). This induction of colon tumors was associated with hypomethylation of DNA cased by folic acid supplementation.
Project description:H3K27me3 statuses were analyzed in normal mouse colonic epithelial cells and in those exposed to DSS-induced colitis, and aberrant changes of H3K27me3 by DSS-induced colitis were identified.
Project description:Temporal genome profiling of DSS colitis The DSS induced mouse colitis model is often used to emulate Ulcerative Colitis (UC) in order understand pathophysiological mechanism of inflammatory bowel disease (IBD). Given the progressive nature of IBD, colon tissue gene expression changes during the evolution of disease, and knowing the changes in gene expression profiles could indentify potential diagnostic markers or additional therapeutic targets for colitis. Therefore, we performed temporal genome expression profiling analysis using the Affymetrix genome wide microarray system to identify broad scale changes in gene expression associated with the development of colitis. Keywords: Expression time course of mouse colon tissue induced by 3% DSS. C57BL/6J mice were given 3% DSS in the drinking water and tissues from individual cohorts were collected at days 0, 2, 4 and 6. Total RNA were extracted from the colon tissue and detected by Affymerix GeneChip Mouse Genome 430 2.0 Array.
Project description:Study hypothesized that oral supplementation of methylthioadenosine (MTA) would reduce the inflammatory response in mice exposed to an agent that induces colitis (DSS) and that this reduction in inflammatory response would lead to reduced clinical disease burden. Total RNA was collected from isolated colons of mice in the following treatment groups: untreated controls, DSS only, DSS+MTA
Project description:L-Arginine (L-Arg) is the substrate for both inducible nitric oxide synthase and arginase, which are upregulated in human IBD and in mouse colitis models. We have found that L-Arg supplementation enhances wound restitution in vitro, and improves the clinical parameters of weight loss, survival, and colon weight/length, in dextran sulfate sodium (DSS) induced murine colitis. Our aim was to further identify the potential mechanisms underlying the clinical benefit of L-Arg supplementation.