Hydrogen peroxide stimulates apoptosis in cultured human retinal pigment epithelial cells

• Published in: Current eye research Vol. 22; no. 3; pp. 165 - 173
• Main Authors: Jin, Gui-Feng, Hurst, John S., Godley, Bernard F.
• Format: Journal Article
• Language: English
• Published: England Informa UK Ltd 2001; Taylor & Francis
• Subjects: Apoptosis - drug effects; Blotting, Western; Caspase 3; Caspases - metabolism; Cells, Cultured; Cyclin-Dependent Kinase Inhibitor p21; Cyclins - metabolism; Humans; Hydrogen Peroxide - pharmacology; Male; Oxidative Stress - drug effects; Pigment Epithelium of Eye - drug effects; Pigment Epithelium of Eye - metabolism; Proto-Oncogene Proteins c-bcl-2 - metabolism; Time Factors; Tumor Suppressor Protein p53 - metabolism
• ISSN: 0271-3683; 1460-2202
• DOI: 10.1076/ceyr.22.3.165.5517

Purpose. To determine whether hydrogen peroxide (H 2 O 2) , a physiological mediator of oxidative stress induces apoptosis in retinal pigment epithelial (RPE) cells. Methods. To demonstrate that oxidatively stressed retinal pigment epithelial cells undergo apoptosis consequential to mitochondrial dysfunction, biochemical parameters of apoptosis were determined in cultured cells after treatment with 50-200 µM H 2 O 2 for different times. Caspase-3 protease activity was determined from hydrolysis of DEVD-?-nitroanilide. Expression of the anti-apoptotic protein, bcl-2 and the pro-apoptotic proteins p53 and p21 were analyzed by western blotting. Results. Caspase-3 activity significantly increased in cells exposed to H 2 O 2. Also, the expression of bcl-2 in cells treated with 200 µM H 2 O 2 was diminished, whereas expression of p53 and p21 waf-1 was increased compared to the controls. Conclusions. Exposure of retinal pigment epithelial cells to concentrations of H 2 O 2 that cause in vitro mitochondrial DNA damage also promotes apoptosis.