Expression and function of recombinant S1179D endothelial nitric oxide synthase in canine cerebral arteries

Stroke. 2002 Apr;33(4):1071-6. doi: 10.1161/hs0402.105553.

Abstract

Background and purpose: Bovine endothelial nitric oxide synthase (eNOS) is phosphorylated directly by the protein kinase Akt at serine 1179. Mutation of this residue to the negatively charged aspartate (S1179DeNOS) increases nitric oxide (NO) production constitutively in the absence of agonist stimulus. The present study was designed to determine the effect of mutant S1179DeNOS gene expression on vasomotor function of canine cerebral arteries.

Methods: Isolated basilar and middle cerebral arteries were exposed ex vivo (30 minutes at 37 degrees C) to an adenoviral vector (10(10) plaque-forming units per milliliter) encoding the S1179DeNOS gene (AdCMVS1179DeNOS), the wild-type eNOS gene (AdCMVeNOS), or the green fluorescent protein (GFP) reporter gene (AdCMVGFP). Twenty-four hours after transduction, arteries were suspended in an organ chamber for isometric force recording, and levels of cGMP were measured by radioimmunoassay.

Results: Transgene protein expression was detected mainly in the vascular adventitia. In AdCMVS1179DeNOS-transduced arteries, basal levels of cGMP were significantly elevated compared with those in control (nontransduced), AdCMVGFP-, or AdCMVeNOS-transduced vessels (n=8; P<0.01). The elevation of cGMP was abolished by a NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), or by incubation in the calcium-free medium in the presence of calcium chelators. In AdCMVS1179DeNOS-transduced arteries, contractions to endothelin-1 (10(-10) to 10(-8) mol/L) were significantly reduced compared with those in control and AdCMVGFP-transduced arteries (n=7; P<0.05). The vasoconstrictor effect of endothelin-1 was restored in the presence of the NOS inhibitor L-NAME.

Conclusions: Our results suggest that in cerebral arteries, expression of recombinant S1179DeNOS increases basal production of NO and inhibits the vasoconstrictor effect of endothelin-1. This effect may have therapeutic application in prevention and treatment of cerebrovascular diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Blotting, Western
  • Bradykinin / pharmacology
  • Cattle
  • Cerebral Arteries / drug effects
  • Cerebral Arteries / enzymology*
  • Cyclic GMP / metabolism
  • Dogs
  • Dose-Response Relationship, Drug
  • Endothelin-1 / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Gene Expression
  • Genes, Reporter
  • In Vitro Techniques
  • Isometric Contraction / drug effects
  • Isometric Contraction / physiology
  • Mutagenesis, Site-Directed
  • Nitric Oxide Donors / pharmacology
  • Nitric Oxide Synthase / administration & dosage
  • Nitric Oxide Synthase / antagonists & inhibitors
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase / metabolism*
  • Nitric Oxide Synthase Type III
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Transduction, Genetic / methods
  • Transgenes / physiology
  • Vasoconstriction / drug effects
  • Vasoconstriction / physiology
  • Vasomotor System / drug effects
  • Vasomotor System / physiology*

Substances

  • Endothelin-1
  • Enzyme Inhibitors
  • Nitric Oxide Donors
  • Recombinant Proteins
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type III
  • Cyclic GMP
  • Bradykinin