The Role of Mitochondrial Quality Control in Cardiac Ischemia/Reperfusion Injury

Abstract

A healthy mitochondrial network produces a large amount of ATP and biosynthetic intermediates to provide sufficient energy for myocardium and maintain normal cell metabolism. Mitochondria form a dynamic and interconnected network involved in various cellular metabolic signaling pathways. As mitochondria are damaged, controlling mitochondrial quantity and quality is activated by changing their morphology and tube network structure, mitophagy, and biogenesis to replenish a healthy mitochondrial network to preserve cell function. There is no doubt that mitochondrial dysfunction has become a key factor in many diseases. Ischemia/reperfusion (IR) injury is a pathological manifestation of various heart diseases. Cardiac ischemia causes temporary tissue and organelle damage. Although reperfusion is essential to compensate for nutrient deficiency, blood flow restoration inconsequently further kills the previously ischemic cardiomyocytes. To date, dysfunctional mitochondria and disturbed mitochondrial quality control have been identified as critical IR injury mechanisms. Many researchers have detected abnormal mitochondrial morphology and mitophagy, as well as aberrant levels and activity of mitochondrial biogenesis factors in the IR injury model. Although mitochondrial damage is well-known in myocardial IR injury, the causal relationship between abnormal mitochondrial quality control and IR injury has not been established. This review briefly describes the molecular mechanisms of mitochondrial quality control, summarizes our current understanding of the complex role of mitochondrial quality control in IR injury, and finally speculates on the possibility of targeted control of mitochondria and the methods available to mitigate IR injury.