Angiogenesis induced by hVEGF165 gene controlled by hypoxic response elements in rabbit ischemia myocardium

Exp Biol Med (Maywood). 2009 Dec;234(12):1417-24. doi: 10.3181/0904-RM-130.

Abstract

Hypoxic response element (HRE) offers satisfactory control over expression of hVEGF(165) in cell levels. However, the characteristics of regenerated blood vessels induced by long-term expression of transferred hVEGF(165) under control of HRE in vivo remain unknown. This study aims to investigate the effect of HRE on control of long-term expression of rAAV-delivered hVEGF(165) gene to ischemic myocardium and evaluate characteristics of angiogenesis induced by hVEGF(165) in vivo. Rabbit ischemic heart models were established surgically, rAAV-9HRE-hVEGF(165) was transfected to ischemia hearts subjected to 12 week ischemia. Molecular biological and immunohistochemistry were employed to determine expressions of HIF-1alpha and hVEGF(165). Microvessel densities of CD31(+) and alpha-SMA(+) regenerated vessels were also evaluated. Expressions of both hVEGF(165) mRNA and protein were upregulated following over-expression of endogenous HIF-1alpha early after ischemia, peaked at 4-6 weeks post-MI, declined, and approached pre-ischemia level at the end of 12 weeks of ischemia (P < 0.01). The significantly upregulated CD31 in hVEGF(165)-treated hearts presented from 8 to 12 weeks of ischemia compared with the control (P < 0.01). However, alpha-SMA expression was rapidly downregulated after ischemia and remained lower than the control level by the end of 12 weeks post-MI (P < 0.01). Overexpression of hVEGF(165) controlled by HIF-1alpha-HRE system shows a stably regional angiogenic efficacy in vivo. But, VEGF, as an early angiogenic cytokine, is inadequate for mediating histologically mature vessels in ischemia myocardium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / biosynthesis
  • Actins / genetics
  • Animals
  • Dependovirus
  • Gene Expression Regulation*
  • Genetic Therapy*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / biosynthesis
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Myocardial Ischemia / genetics
  • Myocardial Ischemia / pathology
  • Myocardial Ischemia / therapy*
  • Neovascularization, Physiologic*
  • Platelet Endothelial Cell Adhesion Molecule-1 / biosynthesis
  • Platelet Endothelial Cell Adhesion Molecule-1 / genetics
  • Rabbits
  • Response Elements*
  • Transduction, Genetic
  • Vascular Endothelial Growth Factor A / biosynthesis*
  • Vascular Endothelial Growth Factor A / genetics

Substances

  • Actins
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Platelet Endothelial Cell Adhesion Molecule-1
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A