title: Cardiomyocyte GATA4 functions as a stress-responsive regulator of angiogenesis in the murine heart.
abstract: The transcription factor GATA4 is a critical regulator of cardiac gene expression, modulating cardiomyocyte differentiation and adaptive responses of the adult heart. We report what we believe to be a novel function for GATA4 in murine cardiomyocytes as a nodal regulator of cardiac angiogenesis. Conditional overexpression of GATA4 within adult cardiomyocytes increased myocardial capillary and small conducting vessel densities and increased coronary flow reserve and perfusion-dependent cardiac contractility. Coculture of HUVECs with either GATA4-expressing cardiomyocytes or with myocytes expressing a dominant-negative form of GATA4 enhanced or reduced HUVEC tube formation, respectively. Expression of GATA4 in skeletal muscle by adenoviral gene transfer enhanced capillary densities and hindlimb perfusion following femoral artery ablation. Deletion of Gata4 specifically from cardiomyocytes reduced myocardial capillary density and prevented pressure overload-augmented angiogenesis in vivo. GATA4 induced the angiogenic factor VEGF-A, directly binding the Vegf-A promoter and enhancing transcription. GATA4-overexpressing mice showed increased levels of cardiac VEGF-A, while Gata4-deleted mice demonstrated decreased VEGF-A levels. The induction of HUVEC tube formation in GATA4-overexpressing cocultured myocytes was blocked with a VEGF receptor antagonist. Pressure overload-induced dysfunction in Gata4-deleted hearts was partially rescued by adenoviral gene delivery of VEGF and angiopoietin-1. To our knowledge, these results demonstrate [corrected] a previously unrecognized function for GATA4 as a regulator of cardiac angiogenesis through a nonhypoxic, load, and/or disease-responsive mechanism.
authors.affiliation: Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229, USA.
authors.forename: Joerg
authors.initials: J
authors.lastname: Heineke
authors.forename: Mannix
authors.initials: M
authors.lastname: Auger-Messier
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Toru
authors.initials: T
authors.lastname: Oka
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Sargent
authors.forename: Allen
authors.initials: A
authors.lastname: York
authors.forename: Raisa
authors.initials: R
authors.lastname: Klevitsky
authors.forename: Sachin
authors.initials: S
authors.lastname: Vaikunth
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Duncan
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Aronow
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Robbins
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Crombleholme
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Cromblehol
authors.forename: Jeffery D
authors.initials: JD
authors.lastname: Molkentin
mesh_terms: D000818:Animals; D050991:GATA4 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006321:Heart / Q000502:physiology*; D006614:Hindlimb / Q000033:anatomy & histology; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D013312:Stress, Physiological; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D050991:GATA4 Transcription Factor; C484171:Gata4 protein, mouse; D042461:Vascular Endothelial Growth Factor A