Apoptosis of Cultured Rabbit Keratocyte Induced by Mitomycin-C

ABSTRACT

To determine whether mitomycin-C[MMC]treatment induces apoptosis in cultured keratocytes. Cultured rabbit keratocytes were exposed to MMC[up to 0.4 milligram/milliliter]or phosphate-buffered saline[PBS]for 5 minutes. Light and transmission electron microscopic examination, DNA electrophoresis, and flow cytometric analysis with propidium iodide staining were performed 24 hours after MMC or PBS treatment. A characteristic findings consistent with apoptosis were observed under both light and electron microscopic examination and DNA ladder pattern was shown on electrophoresis. The average percentages of apoptosis measured by flow cytometric analysis were as follows;0.16 +/-0.08%in PBS, 0.23 +/-0.13%in 0.1 milligram/milliliter MMC, 0.50 +/-0.13%in 0.2 milligram/milliliter M M C , and 6.50 +/-1.57%in 0.4 milligram/milliliter MMC. Significant differences were shown in the percentage of apoptosis among the groups based on Kruskal-Wallis test[p=0.005]. Clinically relevant doses of MMC induces apoptosis in cultured keratocytes proportionally. This results suggest that MMC may modulate corneal wound healing process by accelerating the resolution phase of wound healing.