Expression of cyclin-dependent kinase inhibitors during corneal wound repair

During corneal epithelial wound repair, cells migrating to cover the wound area exhibit a drastic reduction in proliferative activity. In contrast, ce lls distal to the original wound exhibit a greatly enhanced level of prolif erative activity. At least 90% of the basal cells in limbal and peripheral corneal epithelia synchronously progress through the cell cycle. The questi on addressed in this article is whether cyclin-dependent kinase inhibitors play a role in the alterations in proliferative activity seen during cornea l wound repair. These inhibitors specifically block cells in the G1-phase o f the cell cycle. Two families of cyclin-dependent kinase inhibitors have b een identified. The CIP/KIP family includes p21, p27, and p57, while the IN K4 family consists of p16, p15, p18, and p19. Al least five of these inhibi tors are present in the corneal epi thelium. The expression of two of these , p15 and p27, is dramatically altered during wound repair, suggesting that they may be involved in the changes in cell proliferation observed during corneal wound healing. (C) 2000 Elsevier Science Ltd. All rights reserved.