Effects of Ripasudil Hydrochloride on Epithelial Repair in a Mouse Cornea.

Purpose: Effect of topical administration of a Rho kinase inhibitor, ripasudil, on epithelial wound healing in a mouse cornea was investigated. Effects of treatment of cultured human corneal epithelial cell (HCEC) line and organ-cultured corneal epithelium with ripasudil on expression of p-ERK was also examined.

Methods: Epithelial defects with a diameter of 2.0 mm were prepared in the central corneas of C57BL/6 mice with or without 1-week travoprost pre-treatment, to which ripasudil or PBS as a control was instilled every 6 h immediately after preparation. The mice eyes were cultured with or without travoprost for 24-hrs. The expression levels of p-ERK in epithelium of mice eyes were compared by immunostaining after further 24-hrs culture with or without ripasudil for 24-hrs. HCEC were cultured with or without ripasudil and processed for examination for proliferation activity and protein expression of p-ERK by either immunostaining or Western blotting. The cells were also treated with or without travoprost for 24-hrs, and were further cultured with or without ripasudil. Expression levels of p-ERK were examined by Western blotting.

Results: Ripasudil treatment suppressed post-debridement epithelial healing in association with reduced proliferation activity in peripheral (limbal) epithelium in cornea with or without pre-treatment with travoprost. Ripasudil treatment accelerated p-ERK expression. Ripasudil supplementation upregulated proliferation with increased p-ERK in HCEC.

Conclusion: Ripasudil treatment promotes wound healing of the mouse corneal epithelium by enhancing cell proliferation on peripheral (limbal) epithelium.