Idebenone Prevents Human Optic Nerve Head Astrocytes From Oxidative Stress, Apoptosis, and Senescence by Stabilizing BAX/Bcl-2 Ratio

Abstract

Oxidative stress plays an important role in the pathogenesis of several neurodegenerative diseases including glaucoma. Astrocytes are supposed to play a role in glaucoma pathogenesis. This study investigates the antiapoptotic and cytoprotective effects of idebenone on optic nerve head astrocytes (ONHA) under oxidative stress. ONHA were treated with 1 to 150 µM idebenone. Cell viability (MTT assay and live-dead assay), induction of intracellular reactive oxygen species, senescence-associated β-galactosidase activity were investigated. In addition, apoptosis (detection of histone-associated DNA fragmentation), and expression of BAX and Bcl-2, and their mRNA were determined after 48 hours and after hydrogen peroxide (H2O2) treatment. Idebenone concentrations from 1 to 50 µM showed no effects on ONHA viability. Pretreatment with 10 µM idebenone led to an increase in viability of ONHA after H2O2 treatment. In addition, idebenone pretreatment significantly attenuated the increase of histone-associated DNA fragmentation, induction of senescence-associated β-galactosidase, and intracellular reactive oxygen species after treatment with H2O2. When ONHA cells were treated with idebenone and H2O2, real-time polymerase chain reaction and Western blot analysis yielded an increased expression of Bcl-2 and a decrease of BAX compared with those cells that were treated with H2O2 only. Idebenone reduced senescence, oxidative stress, and apoptotic cell death in cultured ONHA in vitro. Our results suggest that idebenone may help to protect ONHA in vivo, and therefore might be helpful in preventing the progression of glaucomatous degeneration.