Objective: To explore the effects of oxidative injury induced by hydrogen peroxide on human retinal pigment epithelial (RPE) cells.
Methods: Cultured human RPE cells were treated by 600 micromol/L hydrogen peroxide (H2O2) for 1, 6, 12, 24 and 72 hours. Cell viability was assessed by the MTT assay. Apoptosis was assessed by Annexin V-fluorescein isothiocyanate/Propidium iodium (Annexin V-FITC/PI) staining. The expression of clusterin was assessed by Western blot.
Results: (1) The treatment of RPE cells with 600 micromol/L H2O2 caused a time-dependent decrease of cellular viability. (2) Apoptosis was detected in cultured human RPE cells treated with 600 micromol/L H2O2 for 6 hours. The number of apoptotic cells reached a maximum at 24th hour after being exposed to 600 micromol/L H2O2 (P < 0.05). (3) Western blot showed the expression of clusterin protein was demonstrated in 6 hours exposure to 600 micromol/L H2O2, a significantly increasing of clusterin expression was observed overtime (P < 0.01). Thereafter the expression of clusterin protein decreased at 24th hour after being exposed to 600 micromol/L H2O2. At 72nd hour, the expression of clusterin protein was quite weak.
Conclusion: Hydrogen peroxide can inhibits RPE proliferation and induces apoptosis and aging gene expression;the result suggest that accumulative oxidative injury induced by hydrogen peroxide in RPE in vitro may be similar to the aging changes in vivo.