AMP-activated protein kinase signaling stimulates VEGF expression and angiogenesis in skeletal muscle

Circ Res. 2005 Apr 29;96(8):838-46. doi: 10.1161/01.RES.0000163633.10240.3b. Epub 2005 Mar 24.

Abstract

AMP-activated protein kinase (AMPK) is regulated by various cellular stresses. Vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, is also upregulated by several stress-inducible factors such as hypoxia and stimulation by cytokines and growth factors. Here, we investigated whether AMPK signaling in muscle has a role in regulating VEGF-mediated angiogenic processes. AICAR stimulated VEGF mRNA and protein levels in C2C12 myotube cultures. Transduction with dominant-negative AMPK abolished AICAR-induced VEGF expression at both steady state mRNA and protein levels. AICAR increased VEGF mRNA stability without affecting VEGF promoter activity. AICAR also stimulated p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation. Activation of p38 MAPK was suppressed by transduction with dominant-negative AMPK, suggesting that AMPK is upstream of p38 MAPK. The p38 MAPK inhibitor SB203580 blocked AICAR-induced increase in VEGF mRNA and protein levels, indicating that AICAR-mediated VEGF induction is dependent on p38 MAPK signaling. AICAR treatment increased VEGF expression and accelerated angiogenic repair of ischemic hindlimbs in mice in an AMPK-dependent manner. These data indicate that AMPK-p38 MAPK signaling cascade can increase VEGF production in muscle and promote angiogenesis in response to ischemic injury.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AMP-Activated Protein Kinases
  • Aminoimidazole Carboxamide / analogs & derivatives
  • Aminoimidazole Carboxamide / pharmacology
  • Animals
  • Cells, Cultured
  • Imidazoles / pharmacology
  • MAP Kinase Signaling System
  • Mice
  • Multienzyme Complexes / physiology*
  • Muscle, Skeletal / blood supply*
  • Neovascularization, Physiologic*
  • Protein Serine-Threonine Kinases / physiology*
  • Pyridines / pharmacology
  • RNA, Messenger / metabolism
  • Ribonucleotides / pharmacology
  • Signal Transduction / physiology*
  • Vascular Endothelial Growth Factor A / genetics*
  • p38 Mitogen-Activated Protein Kinases / physiology

Substances

  • Imidazoles
  • Multienzyme Complexes
  • Pyridines
  • RNA, Messenger
  • Ribonucleotides
  • Vascular Endothelial Growth Factor A
  • Aminoimidazole Carboxamide
  • Protein Serine-Threonine Kinases
  • p38 Mitogen-Activated Protein Kinases
  • AMP-Activated Protein Kinases
  • AICA ribonucleotide
  • SB 203580