Project description:Lactobacillus brevis alleviates DSS-induced colitis by reprograming intestinal microbiota and influencing serum metabolome in murine model
| PRJNA564033 | ENA
Project description:Lactobacillus brevis alleviates DSS-induced colitis by reprograming intestinal microbiota and influencing serum metabolome in murine model
Project description:Lactobacillus pentosus alleviates DSS-induced colitis by increasing Akkermansia and affecting the serum metabolome in the murine model
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:Primary cilia (PC) are important signaling hubs in cells and we explored their role in colorectal cancer (CRC) and colitis. In the colon we found PC to be mostly present on different subtypes of fibroblasts and exposure of mice to either chemically induced colitis-associated colon carcinogenesis (CAC) or dextran sodium sulfate (DSS)-induced acute colitis decreased PC numbers. We employed conditional knock-out strains for the PC essential genes, Kif3A and Ift88, to generate mice with reduced numbers of PC on colonic fibroblasts. These mice showed an increased susceptibility in the CAC model as well as in DSS-induced colitis. Secretome and immunohistochemical analyses of DSS-treated mice displayed an elevated production of the pro-inflammatory cytokine IL-6 in PC-deficient colons. An inflammatory environment diminished PC presence in primary fibroblast cultures. This was triggered by IL-6 as identified by RNAseq analysis together with blocking experiments, suggesting an activation loop between IL-6 production and PC loss. Notably, an analysis of PC presence on biopsies of patients with ulcerative colitis as well as CRC patients revealed decreased numbers of PC on colonic fibroblasts in pathological versus surrounding normal tissue. Taken together, we provide evidence that a decrease in colonic PC numbers promotes colitis and CRC.
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: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:To identify potential unique miRs that contribute to shaping the intestinal stemness in colitis, we analyzed the miRNome of colonic crypt stem cells from DSS-induced colitis mice.
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
Project description:Dextran Sulfate Sodium (DSS) is widely used to model colitis due to its ability to disrupt the colonic epithelial barrier and trigger inflammation. While DSS is a valuable tool for studying colitis-related diseases, its impact on mitochondrial bioenergetics and the proteomic landscape of colonic tissue remains poorly understood. To address this gap, we administered 3% DSS in drinking water to C57BL/6J mice and analyzed resected colonic tissue from treated and control mice. Longitudinally opened colon segments were cleaned and subjected to high-resolution respirometry and mass spectrometry-based proteomic profiling. DSS treatment led to a global lowering of mitochondrial respiration, with the most pronounced impairments observed in complex I-supported respiration. Proteomic analysis revealed that these functional deficits occurred largely independently of changes in the mitochondrial proteome, except for an upregulation of NIPSNAP1, a mitophagy-related protein. However, lentiviral knockdown of NIPSNAP1 in HCT116 cells did not rescue the observed bioenergetic defects, suggesting it is not the primary driver. Collectively, our findings show that DSS impairs mitochondrial respiration in the colon—most notably at complex I—without major alterations to the mitochondrial proteome. Given the role of mitochondrial dysfunction in various diseases, these effects should be carefully considered when using DSS-based models to study colitis pathophysiology.