The roles of microRNA-22 in myocardial infarction.

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. The regeneration capacity of the adult mammalian heart is very limited, so that the lost cells are replaced by fibrotic scar. This is followed by remodeling of the surrounding myocardium, which includes cardiac hypertrophy and fibrosis, and makes the ventricular wall thicken and stiffen.

Upregulation of microRNA-22 contributes to myocardial ischemia-reperfusion injury by interfering with the mitochondrial function.

Mitochondrial oxidative damage is critically involved in cardiac ischemia reperfusion (I/R) injury. MicroRNA-22 (miR-22) has been predicted to potentially target sirtuin-1 (Sirt1) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α), both of which are known to provide protection against mitochondrial oxidative injury. The present study aims to investigate whether miR-22 is involved in the regulation of cardiac I/R injury by regulation of mitochondrial function.