Deficiency of microRNA-10b promotes DSS-induced inflammatory response via impairing intestinal barrier function

Inflammatory bowel disease (IBD) is a non-specific inflammatory disease of the intestine with the pathogenesis to be largely unknown. We found that microRNA (miR)-10b knock-out mice displayed mild IBD symptoms, suggesting that miR-10b may be involved in the onset and development of IBD. This study focuses on elucidating the role of miR-10b in IBD. The colitis model was induced by feeding the mice with 2.5% dextran sodium sulfate (DSS), and the expression levels of miR-10b in colon tissue and blood samples were examined. The severity of colitis was assessed by disease activity index, colon length, histopathological damage, intestinal permeability and ELISA. Then, after transfection of Caco-2 cells with miR-10b mimic and inhibitor, qRT-PCR was used to detect the expression levels of intestinal barrier related genes in colon tissues and cells. miR-10b levels were significantly reduced in mice with DSS-induced acute colitis. Compared with wild-type (WT) mice, miR-10b knockout mice were more sensitive to DSS-induced colitis characterized by increased inflammatory cell infiltration and more severe disruption of colonic barrier function. In addition, by inhibiting miR-10b and thus increasing intestinal barrier gene expression in Caco-2 cells, we found that miR-10b suppressed inflammatory responses and enhanced intestinal barrier function both in vivo and in vitro. miR-10b inhibits the inflammatory response in DSS-induced acute colitis mice in vivo and enhances intestinal barrier function in vitro, suggesting that miR-10b plays a key role in the developmental process of IBD. Thus, miR-10b may be expected to be a new target for the treatment of IBD.