Translocation of nuclear Factor-κB on corneal epithelial cells induced by ultraviolet B irradiation

Purpose: This study was performed to elucidate the role of nuclear factor-kappa B (NF-kappa B) in the death of corneal epithelial cells after ultraviolet (UV) irradiation. Methods: Simian virus 40-transfected human corneal epithelial cells (T-HCECs) were used in this study. Cell cultures were irradiated with a UVB (312 nm) source located 10 cm from the bottom of the slides for 10, 20, 30, or 40 s. Cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Translocation of NF-kappa B was examined by immunocytochemistry using anti-NF-kappa B p65 antibody and electrophoretic mobility shift assay (EMSA). Sulfasalazine and SN-50, specific NF-kappa B inhibitors, were used to confirm the role of NF-kappa B by pretreating samples for 30 min before UV irradiation, after which cytotoxicity and NF-kappa B translocation were evaluated. Results: When T-HCECs were irradiated with UVB, translocation of NF-kappa B was observed with immunocytochemistry. These translocations peaked 2 h after UV irradiation during EMSA. When pretreated with sulfasalazine or SN-50, the translocation of NF-kappa B was blocked. Cellular death after UV irradiation was also markedly blocked by sulfasalazine. Conclusion: These findings suggest that NF-kappa B plays an important role in cellular death after UV irradiation. Copyright (C) 2005 S. Karger AG, Basel.