title: Epigenetic repression of cardiac progenitor gene expression by Ezh2 is required for postnatal cardiac homeostasis.
abstract: Adult-onset diseases can be associated with in utero events, but mechanisms for this remain unknown(1,2). The Polycomb histone methyltransferase Ezh2 stabilizes transcription by depositing repressive marks during development that persist into adulthood(3-9), but its function in postnatal organ homeostasis is unknown. We show that Ezh2 stabilizes cardiac gene expression and prevents cardiac pathology by repressing the homeodomain transcription factor gene Six1, which functions in cardiac progenitor cells but is stably silenced upon cardiac differentiation. Deletion of Ezh2 in cardiac progenitors caused postnatal myocardial pathology and destabilized cardiac gene expression with activation of Six1-dependent skeletal muscle genes. Six1 induced cardiomyocyte hypertrophy and skeletal muscle gene expression. Furthermore, genetically reducing Six1 levels rescued the pathology of Ezh2-deficient hearts. Thus, Ezh2-mediated repression of Six1 in differentiating cardiac progenitors is essential for stable gene expression and homeostasis in the postnatal heart. Our results suggest that epigenetic dysregulation in embryonic progenitor cells is a predisposing factor for adult disease and dysregulated stress responses.
authors.affiliation: Gladstone Institute of Cardiovascular Disease, San Francisco, California, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Delgado-Olguín
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.forename: Danos
authors.initials: D
authors.lastname: Christodoulou
authors.forename: Christine E
authors.initials: CE
authors.lastname: Seidman
authors.forename: J G
authors.initials: JG
authors.lastname: Seidman
authors.forename: Alexander
authors.initials: A
authors.lastname: Tarakhovsky
authors.forename: Benoit G
authors.initials: BG
authors.lastname: Bruneau
mesh_terms: D000818:Animals; D047369:Chromatin Immunoprecipitation; D018076:DNA, Complementary / Q000235:genetics; D000071221:Enhancer of Zeste Homolog 2 Protein; D044127:Epigenesis, Genetic / Q000502:physiology*; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism*; D006706:Homeostasis / Q000235:genetics* / Q000502:physiology; D051379:Mice; D046228:Microarray Analysis; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism; D063151:Polycomb Repressive Complex 2; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D018398:Homeodomain Proteins; C490947:Six1 protein, mouse; D000071221:Enhancer of Zeste Homolog 2 Protein; C498410:Ezh2 protein, mouse; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2