MicroRNA boosts heart regeneration

The mammalian heart has a poor capacity to regenerate, with the ability of cardiomyocytes to proliferate disappearing soon after birth. In this study, Mauro Giacca and colleagues screened a synthetic microRNA (miRNA) library of human origin for the ability to induce cardiomyocyte proliferation, with aim of identifying potential human therapeutics. Forty miRNAs strongly increased both DNA synthesis and cytokinesis in rodent cardiomyocytes. The two most potent, hsa-miR-590 and hsa-miR-199a, were tested further and shown to induce cardiac regeneration after myocardial infarction in mice. In vivo treatment with these miRNAs led to almost complete and stable recovery of cardiac function.