Endothelium-targeted overexpression of constitutively active FGF receptor induces cardioprotection in mice myocardial infarction

J Mol Cell Cardiol. 2009 May;46(5):663-73. doi: 10.1016/j.yjmcc.2009.01.015.

Abstract

Fibroblast growth factor receptor (FGFR) is expressed in a variety of cells and is involved in their proliferation/migration/survival. To elucidate FGFR-mediated specific action of vascular endothelial cells (ECs) on myocardial ischemia, we generated endothelium-targeted transgenic mice overexpressing constitutively active FGFR2 using Tie2 promoter (FGFR2-Tg). Infarct size, vessel formation and blood perfusion were significantly improved 28 days after myocardial infarction (MI) in FGFR2-Tg, compared with wild-type mice. Aortic ECs isolated from FGFR-Tg showed a marked increase in migratory capacity and tube formation. These in vitro angiogenic activities were blocked by PI3-kinase inhibitor. Whereas, parameters obtained from echocardiography were already improved at three days after MI. Cardiomyocyte apoptosis at the ischemic border zone was decreased in FGFR2-Tg (32.1%, p < 0.05) and cardiac mRNA expression of FGF2 (basic FGF) was also up-regulated (142%, p < 0.05) at 3 days after MI. 1% oxygen-mediated apoptosis was significantly inhibited in FGFR2-Tg-ECs and this inhibition was abolished by PI3-kinase inhibitor. FGFR2-Tg-ECs exposed to 1% oxygen exhibited enhanced phosphorylation of 416-Tyr-Src, 473-Ser-Akt, and HIF1alpha accumulation. The production of FGF2 was enhanced 2.1-fold in FGFR-Tg-ECs under 1% oxygen via the Src/Akt/HIF1alpha pathway, which induced the peri-vessel migration of vascular smooth muscle cells (VSMCs) and anti-apoptotic effects on VSMCs and cardiomyocytes. FGF receptor signaling in ECs promoted migration, survival and autocrine production of FGF2, leading to reduced infarct size, which is associated with anti-apoptotic action in the early stage and with enhanced angiogenesis in the late stage after MI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Autocrine Communication
  • Cell Movement
  • Endothelial Cells / enzymology
  • Endothelial Cells / pathology
  • Endothelium, Vascular / enzymology*
  • Endothelium, Vascular / pathology
  • Enzyme Activation
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Mice
  • Mice, Transgenic
  • Muscle, Smooth, Vascular / cytology
  • Myocardial Infarction / enzymology*
  • Myocardial Infarction / pathology
  • Myocardial Infarction / prevention & control*
  • Myocytes, Cardiac / pathology
  • Myocytes, Smooth Muscle / pathology
  • Neovascularization, Physiologic
  • Organ Specificity
  • Phosphatidylinositol 3-Kinases / metabolism
  • Promoter Regions, Genetic / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptor, Fibroblast Growth Factor, Type 2 / metabolism*
  • Receptor, TIE-2 / genetics
  • src-Family Kinases / metabolism

Substances

  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Phosphatidylinositol 3-Kinases
  • Receptor, Fibroblast Growth Factor, Type 2
  • Receptor, TIE-2
  • src-Family Kinases
  • Proto-Oncogene Proteins c-akt