Therapeutic Window for Cardiac ROS Suppression (p 348)
Antioxidant therapies may not always be beneficial, say Song et al.
Mitochondria, when damaged, produce reactive oxygen species (ROS) such as hydrogen peroxide, which at high concentrations could induce substantial cell injury. Therefore, damaged and dysfunction mitochondria are removed by a process called mitophagy. Mitophagy is mediated by a protein called mitofusin, and mice lacking mitofusin in their hearts exhibit reduced mitophagy and increased ROS production. These mice also develop cardiomyopathy, but whether the ROS themselves are responsible for this deterioration was unknown. To test the role of hydrogen peroxide, the team gave a low dose of catalase to the mitofusin-lacking mice. As expected, they found that cardiomyopathy was attenuated—there was evidence of reduced hypertrophy and improved left ventricle function. Mitochondrial …