Cardiomyocyte GATA4 functions as a stress-responsive regulator of angiogenesis in the murine heart
Joerg Heineke, … , Timothy M. Crombleholm, Jeffery D. Molkentin
Joerg Heineke, … , Timothy M. Crombleholm, Jeffery D. Molkentin
Published November 1, 2007
Citation Information: J Clin Invest. 2007;117(11):3198-3210. https://doi.org/10.1172/JCI32573.
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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 what is to our knowledge a previously unrecognized function for GATA4 as a regulator of cardiac angiogenesis through a nonhypoxic, load, and/or disease-responsive mechanism.

Authors

Joerg Heineke, Mannix Auger-Messier, Jian Xu, Toru Oka, Michelle A. Sargent, Allen York, Raisa Klevitsky, Sachin Vaikunth, Stephen A. Duncan, Bruce J. Aronow, Jeffrey Robbins, Timothy M. Crombleholm, Jeffery D. Molkentin

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Figure 2

Induction of coronary angiogenesis by GATA4.

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Induction of coronary angiogenesis by GATA4. (A) Representative staining...
(A) Representative staining of histological sections in WT and DTG mice by H&E staining, Masson’s Trichrome staining (Tri), CD31 (green), and CD31 + WGA (red). Original magnification, ×100 (H&E and Tri); ×400 (CD31 and CD31 + WGA). (B–E) Quantification of absolute number of capillaries per microscopic field or capillaries per cardiomyocyte in control mice (Con; WT and tTA), DTG, and CnA Tg mice. *P < 0.01 versus WT and tTA. (F) Conductance vessels quantified by size: small (20–50 μm), medium (50–100 μm), and large (>100 μm). *P < 0.01 versus control (WT and tTA). (G) Coronary flow (ml/min) was measured in a working heart preparation in control (WT and tTA) and DTG mice with (2 μg/min) and without nitroprusside. *P < 0.01 versus control vehicle; #P < 0.01 versus control nitroprusside. (H) Cardiac contractile function measured as +dP/dt (mmHg/s) in the presence (2 μg/min) or absence of nitroprusside in control and DTG mice. *P < 0.01 versus control with nitroprusside and control and DTG without nitroprusside. Numbers inside the bars indicate the number of animals analyzed. Hearts were sectioned and multiple sections per heart were quantified.