Redox signaling regulates commensal mediated mucosal homeostasis and restitution and requires formyl peptide receptor 1 (FPR1)

The mammalian gut microbiota is essential for normal intestinal development, renewal and repair. Injury to the intestinal mucosa can occur with infection, surgical trauma, and in idiopathic inflammatory bowel disease. Repair of mucosal injury, termed restitution, as well as restoration of intestinal homeostasis involves induced and coordinated proliferation and migration of intestinal epithelial cells. N-formyl peptide receptors (FPRs) are widely expressed pattern recognition receptors that can specifically bind and induce responses to host derived and bacterial peptides and small molecules. Here we report that specific members of the gut microbiota stimulate FPR1 on intestinal epithelial cells to generate reactive oxygen species via enterocyte NADPH oxidase NOX1, causing rapid phosphorylation of Focal Adhesion Kinase (FAK) and ERK MAPK. These events stimulate migration and proliferation of enterocytes adjacent to colonic wounds. Together, these findings identify a novel role of FPR1 as pattern recognition receptors for perceiving the enteric microbiota that promotes repair of mucosal wounds via generation of ROS from the enterocyte NOX1.