Th17 cells and Th17-related cytokines (IL-17, IL-21 and IL-22) were increased in the intestinal mucosa in active IBD patients and may play an important role in disease activity and mucosal damage.
Although aberrant microRNA (miRNA) expression has frequently been observed in inflammatory bowel disease (IBD), its biological functions and targets remain largely unknown. Present study found that miR-19b was significantly downregulated in active Crohn’s disease (CD). Using bioinformatics analysis, suppressor of cytokine signalling 3 (SOCS3), a physiological regulator of innate and adaptive immunity that controls several immuno-inflammatory diseases, was predicted to be a potential target of miR-19b. An inverse correlation between miR-19b and SOCS3 protein levels, but not mRNA, was identified in active-CD intestinal tissue samples. By overexpressing or knocking down miR-19b in Caco2 cells and HT29 cells, it was experimentally validated that miR-19b is a direct regulator of SOCS3. Using a luciferase reporter assay, it was confirmed that miR-19b directly recognizes the 3’-untranslated region (3’-UTR) of SOCS3. Furthermore, overexpression of miR-19b decreased SOCS3 expression, leading to increased production of macrophage-inflammatory protein-3α (MIP-3α) in Caco2 cells. In contrast, knockdown of miR-19b increased SOCS3 and decreased MIP-3α. Finally, intracolonically delivered miR-19b decreased the severity of colitis induced with 2,4,6-trinitrobenzene sulphonic acid (TNBS). Taken together, our findings suggest that miR-19b suppresses the inflammatory response by inhibiting SOCS3 to modulate chemokine production in intestinal epithelial cells (IECs) and thereby prevents the pathogenesis of CD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.