Project description:Background and Objectives: Antibiotic (ABx) therapy is associated with an increased risk for Crohn´s Disease but the underlying mechanisms are unknown. We observed high fecal serine protease activity (PA) to be a frequent side effect of ABx therapy in patients. The aim of the present study was to unravel whether this rise in PA may promote colitis development via detrimental effects on the large intestinal barrier. Design: Transwell experiments were used to assess the impact of high PA in ABx-treated patients or vancomycin/metronidazole (V/M)-treated mice on the epithelial barrier. Serine protease profiling was performed using LC-MS/MS analysis. The impact of high PA on the intestinal barrier in WT/IL10-/- mice and on colitis development in IL10-/- mice was investigated using V/M+/-oral serine protease inhibitor (AEBSF) treatment. Results: The ABx-induced high PA was found to be due to significantly increased levels of pancreatic proteases and to impair the epithelial barrier. In WT mice, the rise in PA caused a transient increase in intestinal permeability but did not affect susceptibility towards DSS-induced acute colitis. In IL10-/- mice, the rise in PA caused a lasting impairment of the intestinal barrier, which was associated with inflammatory activation of the large intestinal tissue. In the long term, the lasting increase in PA upon repeated V/M treatment aggravated colitis development in IL10-/-mice. Conclusion: High PA is a frequent adverse effect of ABx therapy which is detrimental to the large intestinal barrier and may contribute to the development of chronic inflammation in genetically susceptible individuals.
Project description:Using Affymetrix data analysis, important signalling pathways and transcription factors relevant to gut inflammation and anti-inflammatory action of probiotics were identified using the clinically validated probiotic VSL#3 and the IL10-knockout mouse, an animal model for inflammatory bowel disease. VSL#3 increased expression of genes in volved in PPAR signalling and metabolism of xenobiotics and decreased expression of genes involved in immune response/inflammatory response. IL10-knockout (IL10-KO) and wildtype (WT) mice housed under specific pathogen free (SPF) conditions were sacrificed at 24 weeks by cervical dislocation. The study is comprised of two independent Microarray experiments. Microarray experiment1 compares gene expression of IL10-KO and WT colon tissue. For microarray analysis RNA was extracted from the colon tissue of each mouse (WT n=7, IL10-KO n=6). Microarray experiment2 compares gene expression of WT and IL10-KO mice fed with either placebo or probiotic VSL#3. IL10-KO and WT mice were fed with placebo or 1.3x109 cfu of lyophilized VSL#3 bacteria post weaning for 21 weeks. For microarray analysis RNA was extracted from the caecum tissue of each mouse (WT Placebo n=6, IL10-KO Placebo n=6, IL10-KO VSL#3 n=6).
Project description:Inflammatory bowel disease (IBD) is a chronic relapsing autoimmune disease of gastrointestinal tract (GI), involving in dysfunction of a variety of genes, such as Interleukin (IL)-10. Intense researches have demonstrated that IL10-deficient (IL10-/-) mice gradually exhibits features of spontaneous enterocolitis at 4-8 weeks of age and IL-10 is a significant immunomodulator in intestinal tract. Therefore, IL10-/- mice have become a classic model of enterocolitis to study the pathogenesis of IBD. The prevailing view is that IL10 deficiency leads to abnormal activation of immune cells and overproduction of a range of inflammation-inducing cytokines, which results in the persistence of intestinal inflammation in the mice. To uncover the role of the underlying molecular mechanisms involved in IL10-/--associated chronic enterocolitis, we construct IL10-deficient mice, sequence transcriptome and proteome of colon tissues from the mice with colitis and perform an integrated analysis of the two omics in this study. Mechanically, we might find out several novel signaling pathways or new therapeutic targets for IBD according to this combined analysis.
Project description:IL10 plays a crucial role in regulating immune responses. Although IL10 deficiency induces spontaneous gut inflammation in a commensal-dependent manner, the importance of IL10 signaling in peripheral tissues other than gut remains poorly understood. To determine how peripheral tissues are transcriptionally responded to the commensal-induced IL10 signaling, we performed bulk RNA-seq on the gut, lungs, mesenteric lymph nodes, and kidneys of human fecal microbiota-transplanted (huFMT) IL10 KO, huFMT WT, untreated germ-free (GF) IL10 KO, and untreated GF WT mice.
Project description:Microbiota dysbiosis has been reported to contribute to the pathogenesis of colitis, to demonstrate whether IL-17D protects against DSS-induced colitis through regulation of microflora, we performed 16S rRNA sequencing in feces from WT and Il17d-deficient mice. Our data indicate that Il17d deficiency results in microbiota dysibiosis in both steady state and DSS-induced colitis.