Fibroblast growth factor-2 gene transfer can stimulate hepatocyte growth factor expression irrespective of hypoxia-mediated downregulation in ischemic limbs

Circ Res. 2002 Nov 15;91(10):923-30. doi: 10.1161/01.res.0000043281.66969.32.

Abstract

Hepatocyte growth factor (HGF) is a potent angiogenic polypeptide that stimulates angiogenesis. Transcriptional regulation of HGF, however, has not been fully defined, with the exception of the hypoxia-mediated downregulation in cultured cells. In the present study, we report that angiogenic growth factors, including HGF, were upregulated in a murine model of critical limb ischemia in vivo, a finding that was in conflict with previous in vitro data. Mice deficient in basic fibroblast growth factor-2 (FGF-2) showed reduced induction of HGF protein in ischemic muscles, and overexpression of FGF-2 via gene transfer stimulated endogenous HGF, irrespective of the presence of ischemia. In culture, FGF-2 rapidly stimulated HGF mRNA, and a sustained expression was evident in the time course in vascular smooth muscle cells and fibroblasts. FGF-2-mediated induction of HGF was fully dependent on the mitogen-activated protein kinase pathway yet was not affected by either hypoxia or a protein kinase A inhibitor. In the early expression, FGF-2 directly stimulated HGF mRNA without the requirement of new protein synthesis, whereas sustained induction of HGF in the later phase was partly mediated by platelet-derived growth factor-AA. Furthermore, in vivo overexpression of FGF-2 significantly improved the blood perfusion, and the effect was abolished by systemic blockade of HGF in ischemic limbs. This is the first demonstration of a regulational mechanism of HGF expression via FGF-2 that was independent of the presence of hypoxia. The harmonized therapeutic effects of FGF-2, accompanied with the activity of endogenous HGF, may provide a beneficial effect for the treatment of limb ischemia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Flow Velocity / drug effects
  • Cell Line
  • Disease Models, Animal
  • Fibroblast Growth Factor 2 / biosynthesis
  • Fibroblast Growth Factor 2 / genetics*
  • Fibroblast Growth Factor 2 / pharmacology
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Gene Expression Regulation / drug effects
  • Gene Transfer Techniques
  • Growth Substances / metabolism
  • Hepatocyte Growth Factor / genetics
  • Hepatocyte Growth Factor / metabolism*
  • Hindlimb / blood supply
  • Hindlimb / physiopathology
  • Humans
  • Ischemia / pathology
  • Ischemia / physiopathology*
  • Laser-Doppler Flowmetry
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microcirculation / drug effects
  • Microcirculation / physiopathology
  • Muscle, Skeletal / blood supply
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology
  • Muscle, Smooth, Vascular / cytology
  • Muscle, Smooth, Vascular / metabolism
  • Platelet-Derived Growth Factor / metabolism
  • RNA, Messenger / metabolism
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / physiology
  • Up-Regulation / drug effects
  • Up-Regulation / physiology

Substances

  • Growth Substances
  • Platelet-Derived Growth Factor
  • RNA, Messenger
  • platelet-derived growth factor A
  • Fibroblast Growth Factor 2
  • Hepatocyte Growth Factor