Essential roles of the bHLH transcription factor Hrt2 in repression of atrial gene expression and maintenance of postnatal cardiac function

摘要: The basic helix–loop–helix transcriptional repressor Hairy-related transcription factor 2 (Hrt2) is expressed in ventricular, but not atrial, cardiomyocytes, and endothelial vascular smooth muscle cells. Mice homozygous for a null mutation of Hrt2 die perinatally from spectrum cardiac abnormalities, raising questions about the specific functions this regulator individual cell lineages. Using conditional allele, we show that cardiomyocyte-specific deletion mice results ectopic activation atrial genes ventricular myocardium with an associated impairment contractility unique distortion morphology right chamber. Consistent atrialization gene expression mutant mice, forced cardiomyocytes sufficient to repress genes. These findings reveal myocardial cell-autonomous function suppression identity maintenance postnatal function.