Direct Reprogramming of Adult Human Cardiac Fibroblasts into Induced Cardiomyocytes Using miRcombo

Direct reprogramming of fibroblasts into induced cardiomyocytes (iCMs) through microRNAs (miRNAs) is a new emerging strategy for myocardial regeneration after ischemic heart disease. Previous studies have reported that murine fibroblasts can be directly reprogrammed into iCMs by transient transfection with four miRNAs (miRs-1, 133, 208 and 499 – termed “miRcombo”). While advancement in the knowledge of direct cell reprogramming molecular mechanism is in progress, it is important to investigate if this strategy may be translated to humans. Recently, we demonstrated that miRcombo transfection is able to induce direct reprogramming of adult human cardiac fibroblasts (AHCFs) into iCMs. Although additional studies are needed to achieve iCM maturation, our early findings pave the way toward new therapeutic strategies for cardiac regeneration in humans. This chapter describes methods for inducing direct reprogramming of AHCFs into iCMs through miRcombo transient transfection, showing experiments to perform for assessing iCM generation.