Regulation of intestinal regeneration: New insights

Intestinal regeneration is the process by which intestinal injury penetrati ng deep to the lamina propria heals. The regenerative process involves epit helial cell migration and proliferation, changes in cellular function, adap tation of subepithelial tissues, and contraction of the injured area. This requires interaction of multiple cell types. While many observations have b een made about the process of regeneration, its regulation is not well unde rstood. Previous studies, performed primarily in a serosal patch model, hav e identified many potential regulatory factors. These include location and size of the injury, other associated injury, e.g., resection, and a variety of agents that influence one or more of the primary processes involved. Ep idermal growth factor (EGF), in particular, appears to play a role in many aspects of regeneration. Recent advances in the understanding of intestinal growth regulation have provided new insights into the regulation of intest inal regeneration. Developmental studies in genetically manipulated mice su ggest a role for gene products not previously implicated in regeneration. T he importance of apoptosis in growth regulation has recently been emphasize d. Mesenchymal-epithelial interactions have gained greater appreciation. Fi nally, it has become clear that immune cells and cytokines are important fa ctors in this process. Transforming growth factor-beta (TGF beta) has been implicated as another important regulator of several of the processes invol ved in intestinal regulation. Improved understanding of the regulation of i ntestinal regeneration will lead to new therapeutic approaches to stimulate intestinal healing in the clinical setting. (C) 2000 Wiley-Liss, Inc.