Molecular mechanisms of activation of endothelial nitric oxide synthase mediated by transient receptor potential vanilloid type 1

Cardiovasc Res. 2011 Aug 1;91(3):492-501. doi: 10.1093/cvr/cvr104. Epub 2011 Apr 14.

Abstract

Aims: We investigated the molecular mechanism underlying the role of transient receptor potential vanilloid type 1 (TRPV1), a Ca(2+)-permeable non-selective cation channel, in the activation of endothelial nitric oxide (NO) synthase (eNOS) in endothelial cells (ECs) and mice.

Methods and results: In ECs, TRPV1 ligands (evodiamine or capsaicin) promoted NO production, eNOS phosphorylation, and the formation of a TRPV1-eNOS complex, which were all abrogated by the TRPV1 antagonist capsazepine. TRPV1 ligands promoted the phosphorylation of Akt, calmodulin-dependent protein kinase II (CaMKII) and TRPV1, and increased the formation of a TRPV1-Akt-CaMKII complex. Removal of extracellular Ca(2+) abolished the ligand-induced increase in the phosphorylation of Akt and CaMKII, formation of a TRPV1-eNOS complex, and eNOS activation. Inhibition of PI3K and CaMKII suppressed the ligand-induced increase in TRPV1 phosphorylation, formation of a TRPV1-eNOS complex, and eNOS activation. TRPV1 activation increased the phosphorylation of Akt, CaMKII, and eNOS in the aortas of wild-type mice but failed to activate eNOS in TRPV1-deficient aortas. Additionally, TRPV1 ligand-induced angiogenesis was diminished in eNOS- or TRPV1-deficient mice. When compared with apolipoprotein E (ApoE)-deficient mice, ApoE/TRPV1-double-knockout mice displayed reduced phosphorylation of eNOS, Akt, and CaMKII in aortas but worsened atherosclerotic lesions.

Conclusion: TRPV1 activation in ECs may trigger Ca(2+)-dependent PI3K/Akt/CaMKII signalling, which leads to enhanced phosphorylation of TRPV1, increased TRPV1-eNOS complex formation, eNOS activation and, ultimately, NO production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apolipoproteins E / genetics
  • Apolipoproteins E / metabolism
  • Atherosclerosis / enzymology
  • Atherosclerosis / genetics
  • Atherosclerosis / pathology
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism
  • Capsaicin / analogs & derivatives
  • Capsaicin / pharmacology
  • Cattle
  • Cells, Cultured
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Endothelial Cells / drug effects
  • Endothelial Cells / enzymology*
  • Enzyme Activation
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase Type III / deficiency
  • Nitric Oxide Synthase Type III / genetics
  • Nitric Oxide Synthase Type III / metabolism*
  • Phosphatidylinositol 3-Kinase / metabolism
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism
  • Quinazolines / pharmacology
  • RNA Interference
  • Signal Transduction
  • TRPV Cation Channels / deficiency
  • TRPV Cation Channels / drug effects
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism*
  • Time Factors
  • Transfection

Substances

  • Apolipoproteins E
  • Quinazolines
  • TRPV Cation Channels
  • TRPV1 protein, human
  • TRPV1 protein, mouse
  • Nitric Oxide
  • evodiamine
  • NOS3 protein, human
  • Nitric Oxide Synthase Type III
  • Nos3 protein, mouse
  • Phosphatidylinositol 3-Kinase
  • Proto-Oncogene Proteins c-akt
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • capsazepine
  • Capsaicin