Inactivity of nitric oxide synthase gene in the atherosclerotic human carotid artery.
OBJECTIVE
Nitric oxide (NO) inhibits thrombus formation, vascular contraction, and smooth muscle cell proliferation. We investigated whether NO release is enhanced after endothelial NO synthase (eNOS) gene transfer in atherosclerotic human carotid artery ex vivo.


RESULTS
Western blotting and immunohistochemistry revealed that transduction enhanced eNOS expression; however, neither nitrite production nor NO release measured by porphyrinic microsensor was altered. In contrast, transduction enhanced NO production in non-atherosclerotic rat aorta and human internal mammary artery. In transduced carotid artery, calcium-dependent eNOS activity was minimal and did not differ from control conditions. Vascular tetrahydrobiopterin concentrations did not differ between the experimental groups. Treatment of transduced carotid artery with FAD, FMN, NADPH, L-arginine, and either sepiapterin or tetrahydrobiopterin did not alter NO release. Superoxide formation was similar in transduced carotid artery and control. Treatment of transduced carotid artery with superoxide dismutase (SOD), PEG-SOD, PEG-catalase did not affect NO release.


CONCLUSIONS
eNOS transduction in atherosclerotic human carotid artery results in high expression without any measurable activity of the recombinant protein. The defect in the atherosclerotic vessels is neither caused by cofactor deficiency nor enhanced NO breakdown. Since angioplasty is performed in atherosclerotic arteries,eNOS gene therapy is unlikely to provide clinical benefit.
Tanner
Felix C
FC
Cardiovascular Research, Physiology Institute University of Zürich, Zürich, Switzerland.
van der Loo
Bernd
B
Shaw
Sidney
S
Greutert
Helen
H
Bachschmid
Markus M
MM
Berrozpe
Maria
M
Rozenberg
Izabela
I
Blau
Nenad
N
Siebenmann
Robert
R
Schmidli
Jürg
J
Meyer
Peter
P
Lüscher
Thomas F
TF
D000256:Adenoviridae / Q000235:genetics; D000368:Aged; D000818:Animals; D001011:Aorta / Q000201:enzymology / Q000378:metabolism; D050197:Atherosclerosis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D002339:Carotid Arteries / Q000201:enzymology / Q000378:metabolism*; D002460:Cell Line; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000201:enzymology / Q000378:metabolism; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D046509:Tissue Culture Techniques; D014161:Transduction, Genetic
D013481:Superoxides; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III