Tafazzin, a mitochondrial
acyltransferase, plays an important role in
cardiolipin side chain remodeling. Previous studies have shown that dysfunction of tafazzin reduces
cardiolipin content, impairs mitochondrial function, and causes
dilated cardiomyopathy in
Barth syndrome.
Reactive oxygen species (ROS) have been implicated in the development of
cardiomyopathy and are also the obligated byproducts of mitochondria. We hypothesized that tafazzin knockdown increases ROS production from mitochondria, and a mitochondria-targeted
antioxidant prevents tafazzin knockdown induced mitochondrial and cardiac dysfunction. We employed cardiac myocytes transduced with an adenovirus containing tafazzin
shRNA as a model to investigate the effects of the mitochondrial
antioxidant, mito-
Tempo. Knocking down tafazzin decreased steady state levels of
cardiolipin and increased mitochondrial ROS. Treatment of cardiac myocytes with mito-
Tempo normalized tafazzin knockdown enhanced mitochondrial ROS production and cellular
ATP decline. Mito-
Tempo also significantly abrogated tafazzin knockdown induced
cardiac hypertrophy, contractile dysfunction, and cell death. We conclude that mitochondria-targeted
antioxidant prevents cardiac dysfunction induced by tafazzin gene knockdown in cardiac myocytes and suggest mito-
Tempo as a potential therapeutic for
Barth syndrome and other
dilated cardiomyopathies resulting from mitochondrial oxidative stress.