AP-1 activation mediates postnatal cardiomyocyte maturation

Mammalian cardiomyocytes rapidly mature after birth, with hallmarks such as cell-cycle exit, binucleation, and metabolic switch to oxidative phosphorylation of lipids. The causes and transcriptional programs regulating cardiomyocyte maturation are not fully understood yet. Thus, we performed single cell RNA-seq of neonatal and postnatal day 7 rat hearts to identify the key factors for this process and found AP-1 as a key factor to regulate cardiomyocyte maturation. To find the mechanism of AP-1 during cardiomyocyte maturation, we performed RNA-seq analysis of neonatal rat ventricular cardiomyocytes and found Ap-1 promote cardiomyocyte maturation by regulating cardiomyocyte metabolism. Single cell RNA-seq analysis of NRVCs postnatal day 1 and day 7; RNA-Seq analysis of knocking down Atf3 or Jun versus control (2 replicates per group).