Dataset Information

Lack of Effect of Murine Astrovirus Infection on Dextran Sulfate-induced Colitis in NLRP3-deficient Mice.

ABSTRACT: Murine astrovirus (MuAstV) is a recently identified, widespread infection among laboratory mice. MuAstV is found predominantly in the gastrointestinal tract of mice. Human and turkey astroviruses have been shown to disrupt tight junctions in the intestinal epithelium. The potential of MuAstV to alter research results was tested in a well-established dextran sodium sulfate (DSS)-induced colitis model in Nod-like receptor 3 (NLRP3)-deficient mice. This model offers a direct approach to determine whether MuAstV, as a component of the mouse microbiome, contributes to the issue of poor reproducibility in murine inflammatory bowel disease research. In this model, defective inflammasome activation causes loss of epithelial integrity, resulting in leakage of intestinal bacteria and colitis. Our goal was to determine whether MuAstV, which also may affect intestinal permeability, altered the onset or severity of colitis. Male and female mice (age, 8 to 12 wk) homozygous or heterozygous for an NLRP3 mutation were inoculated orally with MuAstV or mock-inoculated with media 3 or 20 d prior to being exposed to 2% DSS in their drinking water for 9 d. MuAstV infection alone did not cause clinical signs or histopathologic changes in NLRP3-/- or NLRP3+/- mice. No significant difference was seen in weight loss, clinical disease, intestinal inflammation, edema, hyperplasia, or mucosal ulceration between MuAstV- infected and mock-infected mice that received 2% DSS for 9 d. Therefore, MuAstV does not appear to be a confounding variable in the DSS colitis model in NLRP3 mice.

SUBMITTER: Compton SR

PROVIDER: S-EPMC5621567 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Lack of Effect of Murine Astrovirus Infection on Dextran Sulfate-induced Colitis in NLRP3-deficient Mice.

Compton Susan R SR Booth Carmen J CJ Macy James D JD

Comparative medicine 20171001 5

Murine astrovirus (MuAstV) is a recently identified, widespread infection among laboratory mice. MuAstV is found predominantly in the gastrointestinal tract of mice. Human and turkey astroviruses have been shown to disrupt tight junctions in the intestinal epithelium. The potential of MuAstV to alter research results was tested in a well-established dextran sodium sulfate (DSS)-induced colitis model in Nod-like receptor 3 (NLRP3)-deficient mice. This model offers a direct approach to determine w ...[more]

PMID: 28935001

Similar Datasets

Project description:Akkermansia muciniphila has been proved to play a crucial role in the progression of colitis, but its underlying mechanism remains inconclusive. In this study, we aim to investigate the effect of A. muciniphila on the development of acute colitis and explore the underlying mechanism. We found that the fecal level of A. muciniphila was decreased in ulcerative colitis (UC) patients compared to the healthy people in the GMrepo database. Oral administration of A. muciniphila strain BAA-835 significantly ameliorated the symptoms in dextran sulfate sodium (DSS)-induced acute colitis, evidenced by decreased body weight loss, colon length shortening, and colon histological inflammatory score. In addition, the number of goblet cells and the mucin family were enhanced after A. muciniphila treatment. Furthermore, proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein 1 (MCP-1) had a downward trend. Mechanistically, the expression of NLRP3, caspase-1 p20, and IL-1β p17 were upregulated in A. muciniphila-treated mice. Additionally, the colon tissues from high-A. muciniphila UC patients had a higher NLRP3 expression than that from low-A. muciniphila UC patients. Moreover, the upregulation of NLRP3 was observed in mouse macrophage Raw264.7 cells and bone marrow-derived macrophage (BMDM) cells after incubation with A. muciniphila. To clarify whether the protective effect of A. muciniphila in colitis depends on NLRP3, we performed the NLRP3-deficient assay in NLRP3-/- mice in vivo. The evidence showed that NLRP3 deficiency eliminated the protective effects of A. muciniphila in acute colitis. In conclusion, A. muciniphila alleviates DSS-induced acute colitis by NLRP3 activation, which enriches the mechanism and provides a new prospect for the probiotic-based treatment of colitis. IMPORTANCE The gut microbiota and host immune response interaction influences the progression of intestinal inflammatory disease. As a well-recognized next-generation probiotic, Akkermansia muciniphila has been proved to play a crucial role in the progression of colitis, but its underlying mechanism remains inconclusive. We found that oral administration of A. muciniphila strain BAA-835 significantly ameliorated the symptoms of acute colitis. Mechanistically, the expression of NLRP3 was upregulated in the A. muciniphila group, and the protective effect of A. muciniphila in colitis depends on NLRP3 activation. This enriches the mechanism and provides a new prospect for the probiotic-based treatment of colitis, which would promote a deeper understanding of the complex characteristics of A. muciniphila and provide guidance for the treatment of human colitis in the future.

Project description:Inflammatory bowel diseases (IBD) are a group of chronic inflammatory disorders of the intestine, with as-yet-unclear etiologies, affecting over a million people in the United States alone. With the emergence of microbiome research, numerous studies have shown a connection between shifts in the gut microbiota composition (dysbiosis) and patterns of IBD development. In a previous study, we showed that interleukin 1? (IL-1?) deficiency in IL-1? knockout (KO) mice results in moderate dextran sodium sulfate (DSS)-induced colitis compared to that of wild-type (WT) mice, characterized by reduced inflammation and complete healing, as shown by parameters of weight loss, disease activity index (DAI) score, histology, and cytokine expression. In this study, we tested whether the protective effects of IL-1? deficiency on DSS-induced colitis correlate with changes in the gut microbiota and whether manipulation of the microbiota by cohousing can alter patterns of colon inflammation. We analyzed the gut microbiota composition in both control (WT) and IL-1? KO mice under steady-state homeostasis, during acute DSS-induced colitis, and after recovery using 16S rRNA next-generation sequencing. Additionally, we performed cohousing of both mouse groups and tested the effects on the microbiota and clinical outcomes. We demonstrate that host-derived IL-1? has a clear influence on gut microbiota composition, as well as on severity of DSS-induced acute colon inflammation. Cohousing both successfully changed the gut microbiota composition and increased the disease severity of IL-1?-deficient mice to levels similar to those of WT mice. This study shows a strong and novel correlation between IL-1? expression, microbiota composition, and clinical outcomes of DSS-induced colitis. IMPORTANCE Here, we show a connection between IL-1? expression, microbiota composition, and clinical outcomes of DSS-induced colitis. Specifically, we show that the mild colitis symptoms seen in IL-1?-deficient mice following administration of DSS are correlated with the unique gut microbiota compositions of the mice. However, when these mice are exposed to WT microbiota by cohousing, their gut microbiota composition returns to resemble that of WT mice, and their disease severity increases significantly. As inflammatory bowel diseases are such common diseases, with limited effective treatments to date, there is a great need to better understand the interactions between microbiota composition, the immune system, and colitis. This study shows correlation between microbiota composition and DSS resistance; it may potentially lead to the development of improved probiotics for IBD treatment.

Project description:BackgroundG protein-coupled receptor 35 (GPR35) is an orphan receptor and is vastly expressed in immune cells and gastrointestinal cells, suggesting the potential physiological importance of GPR35 in these cells. Here, we tested the hypothesis that the lack of GPR35 expression in the colon mucosa exacerbates the severity of dextran sulfate sodium (DSS)-induced experimental colitis in mice.MethodsColitis was induced in GPR35 wild-type (GPR35+/+) and GPR35 knockout (GPR35-/-) mice through the administration of DSS in drinking water for 5 days followed by regular facility water for 1 day. Induction of colitis was evaluated by measuring relative body weight loss, clinical illness scores, and morphological changes in the colon. Abolition of Gpr35 gene expression in the colon mucosa of GPR35-/- mice was confirmed by quantitative real-time PCR (qPCR). Gene expressions of inflammatory and tissue remodeling cytokines were detected by qPCR. Human colorectal epithelial Caco cells were transfected with siRNA against GPR35 before treated with 1% DSS in vitro. Protein expressions were measured using Western blot.ResultsGPR35-/- mice receiving DSS showed a significantly worsened colitis disease with profound loss of body weight and a considerable amount of severe clinical illness compared to GPR35+/+ mice that received DSS. The histology of colon sections from GPR35-/- mice showed extensive pathological changes including submucosal edema, diffuse ulcerations, and evidence of complete loss of crypts compared to wild-type mice. The mean histopathological score was significantly higher in GPR35-/- mice as compared to GPR35+/+ mice. The qPCR data revealed significant expression of pro-inflammatory and tissue remodeling cytokines in GPR35-/- colon mucosa, including IL-1β, CXCL1, CXCL2, CCL2, HMGB1, TGFβ1, TGFβ3, MMP1/9/12. The protein expressions of Zonula occludens-1, E-cadherin, Claudin1 were decreased upon knocking down GPR35 with or without 1% DSS treatment.ConclusionsOur experimental data suggest that lack of GPR35 resulted in worsened disease outcome in DSS-induced experimental colitis, indicating that GPR35 could play a crucial role in protecting from colonic inflammation and serve as a therapeutic target.

Dataset Information

Lack of Effect of Murine Astrovirus Infection on Dextran Sulfate-induced Colitis in NLRP3-deficient Mice.

Publications

Lack of Effect of Murine Astrovirus Infection on Dextran Sulfate-induced Colitis in NLRP3-deficient Mice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets