RNA-seq analysis of diploid and tetraploid neonatal rat cardiomyocytes

In response to pathological stress such as congenital heart disease and heart valvular disease, cardiomyocytes (CMs) generally increased the content of DNA and the number of nuclear. This process named CM polyploidization and multi-nucleation, result in the presence of multi-nucleated polyploid CM. However, the significance of multi-nucleated polyploid CM (M*Pc CM) for heart disease remains enigmatic. We speculated that the process of CM polyploidization and multinucleation may be an adaptative response, which may help CM function recovery and survive the stress condition. We sought to determine the mechanism of enhanced mitophagy in M*Pc CMs during hypoxia adaptation. Overall design: After hypoxia (1% oxygen) for 48h, neonatal rat cardiomyocytes (NRCMs) were stained with Hoechst 33342 and sorted into two subpopulation including diploid (2n) and tetraploid (4n). Four biological replicates of each condition (hypoxia) and flow cytometry sorting were used from independent experiments.