Bmi1-mediated epigenetic signature acts as a critical barrier for direct reprogramming to mature cardiomyocytes

Direct lineage reprogramming of specialized cell types has eliminated some of the traditional problems regarding the epigenetic instability of induced pluripotent stem cells (iPSCs) (1). The adult heart has limited regenerative potential and the predominant response after cardiac injury is dysfunctional fibroblast proliferation. Direct reprogramming of induced cardiomyocytes (iCM) is an increasingly promising option for further development of novel treatments for heart pathologies. The technology is still inefficient and the main mechanisms involved in reprogramming are largely unknown; nonetheless, RNAi screens, single-cell analysis and simpler genetic methods are beginning to focus on epigenetic status as a key barrier (2).