Is antioxidant potential of the mitochondrial targeted ubiquinone derivative MitoQ conserved in cells lacking mtDNA?

MitoQ has been developed as a mitochondrial targeted antioxidant for diseases associated with oxidative stress. Here we show that MitoQ blocks the generation of reactive oxygen species ( ROS) and mitochondrial protein thiol oxidation, and preserves mitochondrial function and ultrastructure after glutathione ( GSH) depletion. Furthermore, the antioxidant effect of MitoQ is conserved in cells lacking mitochondrial DNA, indicating that its antioxidant properties do not depend on a functional electron transport chain ( ETC). Our results elucidate the antioxidant mechanism of MitoQ and suggest that it may be a useful therapeutic for disorders associated with a dysfunctional ETC and increased ROS production.