Corneal endothelial wound closure in vitro. Effects of EGF and/or indomethacin

In response to stress, the corneal endothelium must maintain or region its barrier function. To study cellular responses of the corneal endothelium, our laboratory has developed an in vitro model of rabbit corneal endothelial wound closure. When cells are free to divide, a 3 mm diameter wound closes within 4 days. 5-fluorouracil added to these cultures does not affect the cellular morphology or ultrastructure, but does inhibit cell division. In the presence of 5-fluorouracil, wounds close in approximately 7 days. These conditions mimic the amitotic state and general behavior of adult human corneal endothelium in vivo. Using this model, we studied the effects of epidermal growth factor (EGF) and/or indomethacin treatment on corneal endothelial wound closure in mitotically competent and inhibited cultures. EGF appeared to stimulate migration, whereas indomethacin appeared to enhance cell spreading in response to wounding, particularly in mitotically inhibited cultures. Treatment with the above agents at the time of wounding had little effect on wound closure rates, but did affect closure patterns. In contrast, pretreatment of cultures, particularly with indomethacin, significantly accelerated closure in mitotically inhibited cultures. In the presence of indomethacin, wounds closed in 3-4 days compared to 7-8 days for controls. These results indicate that the response of corneal endothelial cells to wounding can be pharmacologically manipulated, and perhaps accelerated, and suggest that the treatment of the endothelium with nonsteroidal anti-inflammatory drugs or EGF-like growth factors may be clinically useful.