title: Histone Deacetylase 3 Coordinates Deacetylase-independent Epigenetic Silencing of Transforming Growth Factor-β1 (TGF-β1) to Orchestrate Second Heart Field Development.
abstract: About two-thirds of human congenital heart disease involves second heart field-derived structures. Histone-modifying enzymes, histone deacetylases (HDACs), regulate the epigenome; however, their functions within the second heart field remain elusive. Here we demonstrate that histone deacetylase 3 (HDAC3) orchestrates epigenetic silencing of Tgf-β1, a causative factor in congenital heart disease pathogenesis, in a deacetylase-independent manner to regulate development of second heart field-derived structures. In murine embryos lacking HDAC3 in the second heart field, increased TGF-β1 bioavailability is associated with ascending aortic dilatation, outflow tract malrotation, overriding aorta, double outlet right ventricle, aberrant semilunar valve development, bicuspid aortic valve, ventricular septal defects, and embryonic lethality. Activation of TGF-β signaling causes aberrant endothelial-to-mesenchymal transition and altered extracellular matrix homeostasis in HDAC3-null outflow tracts and semilunar valves, and pharmacological inhibition of TGF-β rescues these defects. HDAC3 recruits components of the PRC2 complex, methyltransferase EZH2, EED, and SUZ12, to the NCOR complex to enrich trimethylation of Lys-27 on histone H3 at the Tgf-β1 regulatory region and thereby maintains epigenetic silencing of Tgf-β1 specifically within the second heart field-derived mesenchyme. Wild-type HDAC3 or catalytically inactive HDAC3 expression rescues aberrant endothelial-to-mesenchymal transition and epigenetic silencing of Tgf-β1 in HDAC3-null outflow tracts and semilunar valves. These findings reveal that epigenetic dysregulation within the second heart field is a predisposing factor for congenital heart disease.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Lewandowski
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605.
authors.forename: Harish P
authors.initials: HP
authors.lastname: Janardhan
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605. Electronic address: chinmay.trivedi@umassmed.edu.
authors.forename: Chinmay M
authors.initials: CM
authors.lastname: Trivedi
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D044127:Epigenesis, Genetic; D005260:Female; D005318:Fetal Heart / Q000002:abnormalities / Q000196:embryology* / Q000378:metabolism*; D006330:Heart Defects, Congenital / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D006351:Heart Valves / Q000002:abnormalities / Q000196:embryology / Q000378:metabolism; D006655:Histone Deacetylases / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011247:Pregnancy; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000235:genetics* / Q000378:metabolism*; D000099186:Histone Deacetylase 3
chemical_list: D006655:Histone Deacetylases; D053773:Transforming Growth Factor beta1; D000099186:Histone Deacetylase 3; C508961:Tgfb1 protein, mouse
keywords: cardiac development; chromatin regulation; development; epigenetics; gene regulation; molecular bases of disease