Resveratrol prevention of oxidative stress damage to lens epithelial cell cultures is mediated by forkhead box o activity.
Invest Ophthalmol Vis Sci. 2011 Feb 23. Epub 2011 Feb 23. PMID: 21345980
Department of Ophthalmology, Duke Eye Center, Duke University Medical Center, Durham, NC.
Purpose: To evaluate the potential role that FoxO transcription factors play in modulating resveratrol's protective effects against oxidative stress in lens epithelial cells. Methods: Primary human or porcine lens epithelial cells (LEC) were treated with resveratrol (RES) 25μM and incubated under either physiologic (5%) or chronic hyperoxic (40%) oxygen conditions. Acute oxidative stress was applied using 600 μM H(2)O(2). Changes in expression of FoxO1A, FoxO3A, and FoxO4 were analyzed. The production of intracellular reactive oxygen species (iROS), SA-beta-galactosidase (SA-β-gal) activity, and autofluorescence (AF) was assessed by flow cytometry. SiRNAs of FoxO1A, 3A and 4 were used to study the roles that these transcription factors play in resveratrol's protective effects against cell death induced by oxidative stress. Results: RES incubation under 40% oxygen increased the expression of FoxO1A, 3A, and 4. RES also increases mitochondrial membrane potential under 5% and/or 40% O2 conditions and significantly decreased iROS, SA-β-gal, and AF normally induced by hyperoxic conditions. While RES had a mild pro-apoptotic effect in non-stressed cells, it significantly prevented apoptosis induced by H(2)O(2) stress. SiRNA inhibition of FoxO1A, 3A, and FoxO4 not only led to loss of the anti-apoptotic effects of RES in stressed cells but actually exhibited a mild pro-apoptotic effect. Conclusion: RES exerts a protective effect against oxidative damage in LEC cultures. The levels of expression of FoxO1A, 3A, and 4 appear to play a central role in determining the pro- or anti-apoptotic effects of RES. This has implications for future studies on oxidative stress related lenticular disorders such as cataract formation.