miRNAs in Myocardial Infarction

The aim of this chapter is to provide an overview on the role of miRNAs in myocardial ischemia, ischemia/reperfusion injury and ischemic preconditioning. Myocardial ischemia due to occlusion of coronary arteries constitutes the major cause of mortality and morbidity of humans worldwide by causing an array of injuries. Timely myocardial reperfusion remains the most effective treatment strategy for reducing myocardial infarct size, preventing left ventricular remodelling, preserving left ventricular systolic function and improving clinical outcomes. However, the full benefits of myocardial reperfusion are not realized, given that the actual process of reperfusing ischemic myocardium can independently induce myocardial injury. On the other hand, heart has endogenous cardioprotective capability against myocardial/reperfusion injury, called ischemic preconditioning. Recent studies indicate that miRNAs are implicated in all these different aspects of myocardial ischemia. This chapter describes the role of miR-1 and mR-133 in myocardial ischemia, miR-21, miR-29 and miR-320 in ischemia/reperfusion injury, and miR-21 and miR-199a in preconditioning.