Abstract
Purpose: :
To determine whether hydrogen peroxide-induced oxidative stress triggers mitochondrial fission and cellular ATP reduction, as well as whether coenzyme Q10 (CoQ10) blocks mitochondrial fission and restores cellular ATP production in primary rat optic nerve head (ONH) astrocytes.
Methods: :
The purified ONH astrocytes from rat were cultured by pre-incubation with 50 μg/ml of CoQ10 for 24 hours and then exposed to hydrogen peroxide (100 μM) for 1 hour. Mitochondrial morphology was assessed by MitoTracker Red staining. The cellular viability was measured by MTT assay and cellular ATP production was assessed by a luciferase-based assay.
Results: :
Hydrogen peroxide treatment triggered mitochondrial fission, characterized by the conversion of tubular fused mitochondria into isolated small organelles, as well as significantly decreased cell viability by 79.5 ± 4.4% and induced a significant reduction of cellular ATP level by 80 ± 9.8% in the ONH astrocytes compared with control cells (P < 0.05). In contrast, CoQ10 treatment blocks mitochondrial fission in hydrogen peroxide-treated ONH astrocytes. In addition, CoQ10 treatment significantly increased cell viability by 115.4 ± 5.2% and restored cellular ATP production by 102.7 ± 4.7% in hydrogen peroxide-treated ONH astrocytes (P < 0.05).
Conclusions: :
These results provide the evidence that CoQ10 may be useful to protect ONH astrocytes against oxidative stress-mediated mitochondrial dysfunction. Based on this observation, we propose that oxidative stress-mediated mitochondrial dysfunction may be an important degenerative pathway in the ONH astrocytes during glaucomatous degeneration.
Keywords: astrocytes: optic nerve head • oxidation/oxidative or free radical damage • antioxidants