Growth factor regulation of PC4/TIS7, an immediate early gene expressed during gut adaptation after resection

BACKGROUND: To define the molecular mechanisms underlying the intestinal adaptive response after partial small bowel resection, we previously identified a cohort of genes regulated in the remnant adaptive ileum. One is PC4/TIS7, an immediate early gene preferentially up-regulated during the first 48 hours after resection. To further the mechanisms that regulate gut adaptation, we sought to identify upstream regulators of PC4/TIS7 expression. METHODS: PC4/TIS7 expression in adaptive versus transection control mouse gut was examined at 48 hours after 50% intestinal resection, and its cellular localization was determined by immunohistochemistry. The effects of intestinotrophic peptides and growth factors on PC4/TIS7 expression were examined in vitro in the crypt epithelial cell line IEC 18 and in vivo in the mouse. RESULTS: PC4/TIS7 was expressed in the cytoplasm of IEC 18 cells and in adaptive mouse ileal crypt and villus enterocytes. Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) i...