LOCALIZATION OF HEPARIN-BINDING EPIDERMAL GROWTH FACTOR-LIKE GROWTH-FACTOR IN HUMAN GASTRIC-MUCOSA

Background & Aims: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) has been recently identified as a member of the EGF f amily. EGF receptors to which HB-EGF can bind have been detected in so me types of gastric epithelial cells. The aim of this study was to inv estigate whether HB-EGF is produced in gastric epithelial cells to mai ntain normal gastric mucosa. Methods: Gene expression and production o f HB-EGF protein were investigated using Northern hybridization and im munohistochemistry, and the types of cells producing this protein were determined in human gastric mucosa. Results: HB-EGF messenger RNA was detected in the body and antrum. Immunohistochemical staining showed that HB-EGF was localized mainly in parietal cells of fundic glands an d in gastrin cells of pyloric glands. Also, the immunoreactivity of EG F receptors was observed in parietal cells and gastrin cells and faint ly in surface epithelial cells and mucous neck cells of the proliferat ive zone. Conclusions: The results suggest that HB-EGF is synthesized mainly in parietal cells and gastrin cells and may act in an autocrine and/or paracrine manner in the regulation of proliferation and differ entiation of the gastric mucosal cells through their surface EGF recep tors.