科研之友
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摘要
Objective Neurotensin (NT) mediates colonic inflammation through its receptor neurotensin receptor 1 (NTR1). NT stimulates miR-133 alpha expression in colonic epithelial cells. We investigated the role of miR-133 alpha in NT-associated colonic inflammation in vitro and in vivo. Design miR-133 alpha and aftiphilin (AFTPH) levels were measured by quantitative PCR. Antisense (as)-miR-133 alpha was administrated intracolonicaly prior to induction of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced colitis and dextran sodium sulfate (DSS)-induced colitis. The effect of AFTPH was examined by gene silencing in vitro. Results NT increased miR-133 alpha levels in NCM-460 overexpressing NTR1 (NCM460-NTR1) and HCT-116 cells. NT-induced p38, ERK1/2, c-Jun, and NF-kappa B activation, as well as IL-6, IL-8 and IL-1 beta messenger RNA (mRNA) expression in NCM-460-NTR1 cells were reduced in miR-133 alpha-silenced cells, while overexpression of miR-133 alpha reversed these effects. MiR-133 alpha levels were increased in TNBS (2 day) and DSS (5 day) colitis, while NTR1 deficient DSS-exposed mice had reduced miR-133 alpha levels, compared to wild-type colitic mice. Intracolonic as-miR-133 alpha attenuated several parameters of colitis as well expression of proinflammatory mediators in the colonic mucosa. In silico search coupled with qPCR identified AFTPH as a downstream target of miR-133 alpha, while NT decreased AFTPH expression in NCM-460-NTR1 colonocytes. Gene silencing of AFTPH enhanced NT-induced proinflammatory responses and AFTPH levels were downregulated in experimental colitis. Levels of miR-133 alpha were significantly upregulated, while AFTPH levels were downregulated in colonic biopsies of patients with ulcerative colitis compared to controls. Conclusions NT-associated colitis and inflammatory signalling are regulated by miR-133 alpha-AFTPH interactions. Targeting of miR-133 alpha or AFTPH may represent a novel therapeutic approach in inflammatory bowel disease.
- 出版日期2015-7
