Serum from mice after small bowel resection enhances intestinal epithelial cell growth

Background/Purpose: The adaptive response of the intestine to massive small bowel resection (SBR) is remarkably complex. An in vitro model of adaptation may facilitate the elucidation of signaling pathways involved in this process. In an effort to establish such a model, the effects of serum from resected mice on cultured intestinal epithelial cells were studied. Methods: Serum was collected and pooled from male (CR mice 3 days after either 50% SBR or sham operation. Rat intestinal epithelial cells (RIEC-6) were plated at equal density and grown in the presence of 1% fetal bovine serum (FBS), 10% FBS, 1% FBS plus 9% sham serum, or 1% FBS plus 9% SBR serum. Cell number, proliferation, and caspase-3 activity were determined. Results: RIEC-6 cell growth was reduced significantly in 1% FBS or sham serum. SBR serum markedly accelerated cell growth and proliferation when compared with all other groups and significantly suppressed caspase-3 activity. Conclusions: Massive intestinal resection in mice results in a serum factor that induces intestinal cell growth in vitro. This in vitro model of trophic signaling will permit further detailed investigations into the mechanisms of intestinal adaptation.