Senescence associated β galactosidase activity in human retinal pigment epithelial cells exposed to mild hyperoxia in vitro
- 1Department of Ophthalmology, University of California, Davis, CA, USA
- 2Departments of Ophthalmology and Molecular and Cellular Biology University of California, Davis, CA, USA
- Correspondence to: James T Handa, MD, 3-109 Jefferson Building, Johns Hopkins Hospital, 600 N Wolfe Street, Baltimore, MD 21287, USA; jthanda{at}jhmi.edu
- Accepted 25 September 2001
Abstract
Aims: To determine if mild hyperoxia induces senescence in retinal pigment epithelium (RPE) cells in vitro.
Methods: RPE340 cells and WI38 cells were grown in 20% oxygen and 40% oxygen until proliferative exhaustion. A combined senescence associated β galactosidase (SABG) and 5-bromo-2`-deoxyuridine (BrdU) double labelling technique was performed at different times and labelled cells were counted.
Results: 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.
Conclusion: Mild hyperoxia induces premature senescence in a specific RPE cell line.
- BrdU, 5-bromo-2`-deoxyuridine
- PDL, population doubling level
- RPE, retinal pigment epithelium
- SABG, senescent associated β galactosidase
