Mechanisms of tissue protection and repair in inflammatory bowel disease.

Investigators have increasingly appreciated the importance of the breakdown of the epithelial barrier in the pathogenesis of inflammatory bowel disease. Epithelial cells secrete trefoil factors, heat shock proteins, and secretory leukocyte proteinase inhibitors that protect the integrity of the epithelial barrier. Other agents, including growth factors, regulate the repair of the epithelium after injury has occurred. Drugs that would either enhance protection of barrier function from injury or accelerate repair after injury would have therapeutic potential in inflammatory bowel disease.