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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Research Article

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 9

Ad-GATA4 infection induces angiogenesis in quadriceps muscle.

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Ad-GATA4 infection induces angiogenesis in quadriceps muscle. (A) Wester...
(A) Western blot analysis of GATA4 expression in mice 7 days after they were injected with either Ad–β-gal or Ad-GATA4 throughout their right quadriceps muscle (n = 4 Ad–β-gal mice and n = 5 Ad-GATA4 mice). (B) Representative images of CD31 staining (green) in quadriceps muscle of mice 7 days after Ad–β-gal or Ad-GATA4 injection. Counterstaining with WGA was performed (red). (C and D) Quantification of capillaries per field and capillaries per myofiber in mice 7 days after Ad–β-gal or Ad-GATA4 injection. (E) Experimental time line and procedures used to assess the effect of Ad-GATA4 versus Ad–β-gal infection in quadriceps muscle on limb perfusion after femoral artery ligation (ischemia) in the right leg. (F) Representative Doppler images of 1 mouse injected with Ad–β-gal or Ad-GATA4 immediately (day 5), 1 day (day 6), and 3 days (day 8) after femoral artery ligation. Red color indicates greater flow; blue indicates less flow. (G) Quantification of Doppler results from ischemic right leg versus nonischemic left leg in mice injected with Ad–β-gal (red line) or Ad-GATA4 (blue line). *P < 0.05 versus Ad–β-gal–injected mice. (H) Western blot for GATA4 and VEGF-165 in from the ischemic hindlimb muscle 8 days after Ad–β-gal or Ad-GATA4 infection. (I) Capillaries per myofiber in mice 8 days after Ad–β-gal or Ad-GATA4 injection from the ischemic hindlimb musculature analyzed in F–H. Original magnification, ×400.