Abstract
Abstract: :
Purpose: Recent publications have presented evidence for the involvement of neutrophils in normal corneal wound healing. In the present study, the role of a family of molecules (CD18 intergrins) known to be important to neutrophil mobility was evaluated in corneal wound healing in mice. Methods: The central corneal epithelium (3 mm in diameter) was demarcated with a trephine and subsequently removed using a blade under a stereomicroscope on CD18-/- and wild-type mouse corneas. The injured corneas were stained with fluorescein and photographed with a stereomicroscope every 6 h, beginning immediately after wounding, to evaluate the reepithelialization with imagine analysis. In addition, extracts of injured corneas were assayed by ELISA for the presence and dynamic changes of seven different cytokines (IL-1, MCP-1, VEGF and TNF) at different time points after wounds. Results: A significant difference in wound size and rate of healing were evident when CD18-/- and wild-type wounds were compared between hours 6 and 30 after wounding. None of the animals exhibited evidence of overt infection. The rate of CD18-/- healing at hours 6, 12, 18, 24, 30 is 101, 73, 42, 29, 3%, of original wound area, but wild-type is 90, 42, 23, 0, 0%. There is a 6-hour delay in the time required by the CD18-/- mice for complete healing (p<0.01). Similarly, the peak times of production of IL-1, MCP-1, VEGF and TNF were delayed by at least 6 hours, and peak levels of these cytokines were higher in CD18 -/- corneas. Conclusions: Collectively, our results indicate that CD18 intergrins contribute to epithelial wound healing possibly through their role in supporting important neutrophil function.
Keywords: cornea: epithelium • cornea: basic science