Transcriptome profiling of neonatal rat ventricular cardiomyocytes overexpressing NFYa or NFE2L1

The adult mammalian heart is incapable of regeneration following injury. In contrast, the neonatal mouse heart has a transient ability to regenerate, however the molecular mechanism that mediates this regenerative response is not fully understood. Here, by single-nucleus RNA sequencing we map the transcriptome landscape of cardiomyocytes in neonatal mouse hearts at healthy, regenerative, and remodeling conditions. We show that an immature cardiomyocyte population enters cell-cycle in response to injury. Absence of this cardiomyocyte population overtime is associated with the loss of the ability of the heart to regenerate. We show a defined injury response in these cardiomyocytes, including activation of transcription factors NFYa and NFE2L1, which play proliferative and protective roles, respectively. We further show that overexpression of these two factors in vivo promotes heart regeneration. Thus, these findings refined our understanding of cellular basis of neonatal heart regeneration and reveal dynamic transcriptome landscape of cardiomyocytes in response to injury. NFYa or NFE2L1 was overexpressed in cultured neonatal rat ventricular cardiomyocytes (NRVMs) by adenoviral delivery. GFP was overexpressed as a negative control. RNA was isolated from NRVMs overexpressing GFP, NFYa, or NFE2L1 in triplicate for mRNA-Seq.