Epidermal growth factor stimulates type-V collagen synthesis in cultured murine palatal shelves

The effects of epidermal growth factor (EGF) on the synthesis of collagen and fibronectin in murine palatal shelves in serum-free organ culture have been examined. Palatal shelves grown in the presence of EGF were substantially larger and showed dramatic increases in immunofluorescent localization of fibronectin, possibly reflecting increased synthesis compared to controls cultured without EGF. EGF also prevented the normal dissolution of the medial palatal epithelium. Net protein synthesis in experimental palatal shelves increased by 18%, whereas net collagen synthesis was approximately 10% of protein synthesis in both conditions. There was, however, an apparent shift in collagen isotypes. Under the influence of EGF, there was a significant increase in synthesis of the alpha 1 (V) and alpha 2 (V) chains of type-V collagen.