Mucosal repair in the gastrointestinal tract.

OBJECTIVE: The epithelial response to injury in the intestinal mucosa will be described. DESIGN: A comprehensive evaluation of the literature was performed to provide a thorough review of mucosal injury and repair. RESULTS: The intestinal mucosa is a rapidly proliferating sheet of epithelial cells that sustains injury in response to stresses ranging from physiologic daily digestive trauma to severe insults associated with ischemia, chemicals, and infection. Breaks in epithelial continuity impair mucosal barrier function, perturb normal absorptive and secretory transport properties, and render the host susceptible to local infection and distant organ pathology. Minor breaches are rapidly repaired by epithelial restitution, a process independent of cell proliferation. Restitution is regulated by a variety of cytokines and growth factors and is modulated by integrin-dependent interactions with the extracellular matrix. The intracellular mechanisms that control restitution are complex and involve signaling pathways that control dynamic remodeling of the actin cytoskeleton. Emerging understanding of reparative processes suggest several possible therapeutic strategies to enhance gastrointestinal wound healing. CONCLUSION: Minor epithelial injuries are repaired with the complex process of epithelial restitution independent of cell proliferation.