Abstract
Enhanced gut permeability due to dysregulated epithelial tight junction is often associated with inflammatory bowel diseases (IBD), which have a greater risk for developing colorectal cancer. STAT6 activation was detected in inflamed colonic epithelium of active IBD patients, suggesting a role of epithelial STAT6 in colitis development. Here, we demonstrated that non-hematopoietic STAT6, but not hematopoietic STAT6, triggered DSS-induced colitis and subsequent tumorigenesis. This could be due to the enhancing-effect of STAT6 on gut permeability and microbiota translocation via interruption of epithelial tight junction integrity. Mechanistically, long-myosin light-chain kinase (MLCK1) was identified as a target of STAT6, leading to epithelial tight junction dysfunction and microbiota-driven colitis. Furthermore, neutralization of IL-13, which was primarily derived from type 2 innate lymphoid cells (ILC2) in a microbiota-dependent way, inhibited epithelial STAT6 activation and improved gut permeability and DSS-induced colitis. Importantly, pharmacological inhibition of STAT6 reduces murine intestinal tumor formation, and tumoral p-STAT6 levels positively correlated to the clinical stage and poor prognosis of human colorectal cancer. Thus, our study reveals a direct role of STAT6 in the disruption of epithelial tight junction integrity and colitis development, and suggests STAT6 as a potential therapeutic and prophylactic target for IBD and colitis-associated cancer.