Transcriptional Landscape of Cardiomyocyte Maturation

Decades of progress in developmental cardiology has advanced our understanding of the early aspects of heart development, including cardiomyocyte (CM) differentiation. However, control of CM maturation which is subsequently required to generate adult myocytes, remains elusive. Here, we analyzed over 200 microarray datasets from early embryonic to adult hearts and identified a large number of genes whose expression shifts gradually and continuously during maturation. We generated an atlas of integrated gene expression, biological pathways, transcriptional regulators, and gene regulatory networks (GRNs), which show discrete sets of key transcriptional regulators and pathways activated or suppressed during CM maturation. We developed a GRN-based program named MatStatCM that indexes CM maturation status. MatStatCM reveals that pluripotent stem cell-derived CMs mature early in culture, but are arrested at the late embryonic stage with aberrant regulation of key transcription factors. Our study provides a foundation for understanding CM maturation. We have analyzed >200 microarray dataset from GEO for heart development and maturation. To assess maturation status of pluripotent stem cell derived cardiomyocytes (PSC-CMs) in vitro, we differentiate PSC-CMs, cultured up to 30 days and performed microarray analysis.