Photoreactivation of ultraviolet radiation-induced basic fibroblast growthfactor (bFGF) and the role of bFGF in corneal lesion formation in Monodelphis domestica

Chronic ultraviolet radiation (UVR) exposure to the eyes of Monodelphis dom estica causes corneal opacification, neovascularization, and fibrosarcoma i nduction. By immunohistochemistry and Western blotting, we have shown that one to four exposures of the eyes of this opossum to UVR enhances basic fib roblast growth factor (bFGF) expression by the corneal epithelium. Treatmen t with photoreactivating light, which selectively removes UVR-induced pyrim idine dimers, suppresses bFGF induction, indicating that UVR induction of b FGF is ultimately due to DNA damage. Furthermore, UVR-induced corneal tumor s derived from corneal keratocytes express bFGF mRNA and protein, as determ ined by immunohistochemistry and in situ hybridization. Taken together, the se findings suggest that bFGF acts in both an autocrine and a paracrine man ner to stimulate corneal fibroplasia, neovascularization, and tumor develop ment. (C) 2001 Wiley-Liss, Inc.