Increased expression of epidermal growth factor receptor and betacellulin during the early stage of gastric ulcer healing.

Epidermal growth factor receptor (EGFR) is important for the proliferation and differentiation of gastric mucosal cells. Betacellulin (BTC) is a novel ligand for EGFR Since their role is unclear in the ulcer healing process, we investigated their expression. Gastric ulcers in 30 Sprague-Dawley rats were induced by acetic acid. RT-PCR and Western blotting were performed to detect EGFR and BTC. Immunohistochemical studies were performed to detect EGFR, BTC and proliferating cell nuclear antigen (PCNA). The expression of EGFR and the BTC gene was significantly increased at 12 h, 24 h and 3 days after ulcer induction (P<0.05). The expression of EGFR and BTC protein was significantly increased at 24 h and 3 days and at 12 h, 24 h and 3 days after ulcer induction, respectively (P<0.05). The phosphorylation of EGFR also increased significantly and reached a maximum 24 h after ulcer induction (P<0.05). Immunostaining for EGFR and BTC was observed in numerous epithelial cells from the ulcer margin and ulcer bed, and corresponded to the localization of PCNA. To conclude, there was an increase in EGFR and BTC expression in the early stages of ulcer healing, localized in the epithelial cells of the ulcer margins and regenerating glands with proliferating activity. BTC/EGFR may play an important role in the early stages of ulcer healing.