Roles of the Epithelial Autophagy in the Intestinal Mucosal Barrier

Abstract

Intestines are a part of the gastrointestinal tract and essential for digestion and absorbtion of food. It is also home to a dense community of resident bacteria and exposed to a very large number of microorganisms associated with food and from the external environment. The epithelial surface of the intestines plays a critical role in host protection by forming the intestinal mucosal layer that functions as a barrier to microorganisms and by producing a diverse repertoire of antimicrobial proteins that directly kill or hinder the growth of microorganisms. Autophagy in the intestinal epithelial cells plays key roles in the mucosal immune defence, whereas its deregulation is one of the major mechanisms that cause intestinal chronic inflammation and subsequent development of intestinal bowel disease such as Crohn’s disease and intestinal ulcerative colitis. Here we review the roles of autophagy in the intestinal epithelial barrier functions and consider the mechanisms by which deregulated autophagy causes intestinal bowel disease.