Epithelial regeneration in inflammatory bowel diseases

Inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn’s disease, are characterized not only by the sub-mucosal accumulation of inflammatory cells, but also by the severe damage of the epithelial layer. Recent clinical studies have featured “mucosal healing” as the most significant prognostic factor for long-term remission in IBD patients, suggesting that accomplishment of epithelial regeneration is critically required to improve the treatment for IBD. From series of recent studies, we now know that several key molecular pathways dominantly regulate not only the homeostasis, but also the repair process of the intestinal epithelium. Future studies may allow us to facilitate regeneration of the damaged intestinal epithelia, either by molecular-based manipulation of endogenous regenerative signals, or by a tissue-engineering based strategy utilizing ex-vivo expansion of primary intestinal epithelial cells.