Oxidative damage to human lens epithelial cells in culture: estrogen protection of mitochondrial potential, ATP, and cell viability

摘要: Purpose Epidemiologic studies demonstrate a higher incidence of cataracts in estrogen-deprived postmenopausal women, but the mechanism for increased risk is unclear. An elevated level H(2)O(2) aqueous humor and whole lenses has been associated with cataractogenesis. In present study, first time, protective effect estrogens against oxidative stress were tested cultured human lens epithelial cells (HLECs). Methods To investigate involvement 17beta-estradiol (17beta-E(2)) protection stress, HLECs exposed to insult at physiological (100 microM) over time course several hours, without pretreatment 17beta-E(2). Cell viability was measured by calcein AM assay, 2',7'-dichlorofluorescein diacetate (DCFH-DA) used determine intracellular reactive oxygen species (ROS). Intracellular adenosine triphosphate (ATP) quantified luciferin- luciferase-based assay mitochondrial potential (deltapsi(m)) monitored fluorescence resonance energy-transfer technique. Results caused dose-dependent decrease membrane potential, ATP levels, cell viability. Dose-dependent increases observed 17beta-E(2) 2 hours before insult. At 1 nM, from 39% +/- 4% 75% 3%, 100 nM or higher, it survival greater than 95%. The approached normal higher. Pretreatment did not diminish ROS accumulation after exposure H(2)O(2). Moreover, two nonfeminizing estrogens, 17alpha-E(2) ent-E(2), both which do bind either estrogen receptor alpha beta, as effective recovery antagonist, ICI 182,780, block Both 17beta- moderated collapse deltapsi(m) response excessive Ca(2+) loading. Conclusions study indicates that 17alpha- can preserve function, viability, levels during stress. Although precise responsible estradiols remains be determined, ability receptors, protect toxicity this conservation likely mediated through classic receptors.