Senescence associated beta galactosidase activity in human retinal pigment epithelial cells exposed to mild hyperoxia in vitro.

Abstract

To determine if mild hyperoxia induces senescence in retinal pigment epithelium (RPE) cells in vitro. RPE340 cells and WI38 cells were grown in 20% oxygen and 40% oxygen until proliferative exhaustion. A combined senescence associated beta galactosidase (SABG) and 5-bromo-2'-deoxyuridine (BrdU) double labelling technique was performed at different times and labelled cells were counted. Cells grown in 40% oxygen stopped proliferating at an earlier population doubling level than when grown in 20% oxygen. An increase in SABG positive cells and decrease of BrdU positive cells in 40% oxygen developed at an earlier time than when grown in 20% oxygen. Mild hyperoxia induces premature senescence in a specific RPE cell line.