title: Transgenic overexpression of Hdac3 in the heart produces increased postnatal cardiac myocyte proliferation but does not induce hypertrophy.
abstract: Class I and II histone deacetylases (HDACs) play vital roles in regulating cardiac development, morphogenesis, and hypertrophic responses. Although the roles of Hdac1 and Hdac2, class I HDACs, in cardiac hyperplasia, growth, and hypertrophic responsiveness have been reported, the role in the heart of Hdac3, another class I HDAC, has been less well explored. Here we report that myocyte-specific overexpression of Hdac3 in mice results in cardiac abnormalities at birth. Hdac3 overexpression produces thickening of ventricular myocardium, especially the interventricular septum, and reduction of both ventricular cavities in newborn hearts. Our data suggest that increased thickness of myocardium in Hdac3-transgenic (Hdac3-Tg) mice is due to increased cardiomyocyte hyperplasia without hypertrophy. Hdac3 overexpression inhibits several cyclin-dependent kinase inhibitors, including Cdkn1a, Cdkn1b, Cdkn1c, Cdkn2b, and Cdkn2c. Hdac3-Tg mice did not develop cardiac hypertrophy at 3 months of age, unlike previously reported Hdac2-Tg mice. Further, Hdac3 overexpression did not augment isoproterenol-induced cardiac hypertrophy when compared with wild-type littermates. These findings identify Hdac3 as a novel regulator of cardiac myocyte proliferation during cardiac development.
authors.affiliation: Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Chinmay M
authors.initials: CM
authors.lastname: Trivedi
authors.forename: Min Min
authors.initials: MM
authors.lastname: Lu
authors.forename: Qiaohong
authors.initials: Q
authors.lastname: Wang
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Epstein
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D006332:Cardiomegaly / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D002316:Cardiotonic Agents / Q000009:adverse effects / Q000494:pharmacology; D049109:Cell Proliferation; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000096:biosynthesis / Q000235:genetics; D015870:Gene Expression; D006330:Heart Defects, Congenital / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases / Q000096:biosynthesis* / Q000235:genetics; D006965:Hyperplasia / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D007545:Isoproterenol / Q000009:adverse effects / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000201:enzymology* / Q000473:pathology; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics; D000099186:Histone Deacetylase 3
chemical_list: D002316:Cardiotonic Agents; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases; D007545:Isoproterenol; D012097:Repressor Proteins; D000099186:Histone Deacetylase 3; C533424:Hdac2 protein, mouse