MicroRNA-602 prevents the development of inflammatory bowel diseases in a microbiota-dependent manner

Inflammatory bowel diseases (IBD) are a group of chronic disorders occurring in the intestinal tract. Previous studies demonstrated that genetics and microbiota play critical roles in the pathogenesis of IBD. Discoveries of genes that may regulate the homeostasis of gut microbiota and pathogenesis of IBD have the potential to provide new therapeutic targets for IBD treatment. The results suggested that the expression level of microRNA (miR)-602 is negatively related to the development of IBD, and that miR-602 overexpression in mice may prevent inflammation and intestinal barrier injuries in dextran sulfate sodium (DSS)-induced IBD mice. It was also found that the microbiota is important for miR-602-mediated prevention of IBD, as the inhibitory effect of miR-602 was lost when the microbiota was depleted using antibiotics. Furthermore, co-housing or adoptive transfer of microbiota from miR-602 could attenuate the pathogenesis of IBD. In addition, it was demonstrated that miR-602 could target tumor necrosis factor receptor-associated factor 6 (TRAF6) in intestinal epithelial cells. Collectively, the present results suggest that miR-602 plays a protective role in DSS-induced IBD by targeting TRAF6 in a microbiota-dependent manner.