Topical administration of peroxiredoxin-6 on the cornea suppresses inflammation and neovascularization induced by ultraviolet radiation.

PURPOSE: To investigate the effect of topical administration of peroxiredoxin-6 (PRDX6) on ultraviolet-induced corneal injury. METHODS: Corneal transparency and neovascularization were observed with a slit-lamp microscope and hematoxylin and eosin staining. The oxidative damage was determined with a commercial malondialdehyde (MDA) kit. The expressions of PRDX6, polymorphonuclear neutrophil (PMN), vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor (PEDF) were determined by immunohistochemistry and Western blot. The expressions of genes related with antioxidant defense systems and cell apoptosis were detected by RT-PCR. RESULTS: The irradiated corneas appeared opaque and had high levels of MDA. Peripheral neovascularization and neutrophils appeared in the control and buffer-treated groups (with no treatment or PRDX6 diluent, respectively), whereas they were significantly suppressed in the PRDX6-treated group. The MDA content of the corneas in the PRDX6-treated group was significantly lower than that of the control and buffer-treated groups (P < 0.05). In the PRDX6-treated group the immunoreactivity of VEGF was lower, and that of PEDF was higher, than that in the control and buffer-treated groups. In addition, there were expression correlations between PRDX6 and PMN, VEGF, PEDF. The expressions of genes related with antioxidant defense systems and cell apoptosis were significant different between buffer- and PRDX6-treated groups (P < 0.05). CONCLUSIONS: The topically administered PRDX6 maintained the homeostasis of corneal cells, reduced inflammation, and suppressed neovascularization and apoptosis under ultraviolet irradiation.