R. Heller et al., Nitric oxide inhibits proliferation of human endothelial cells via a mechanism independent of cGMP, ATHEROSCLER, 144(1), 1999, pp. 49-57
Citations number
42
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Endothelial cell-derived nitric oxide (NO) has been suggested to inhibit sm
ooth muscle cell proliferation, resulting in the reduction of intimal hyper
plasia during atherogenesis. The present study investigates the role of NO
from exogenous and endogenous sources on the proliferation of human umbilic
al vein endothelial cells (HUVEC) and human coronary artery endothelial cel
ls (CAEC). Three different NO-generating compounds [sodium nitroprusside (S
NP), S-nitroso-glutathione (GSNO) and S-nitroso-acetylpenicillamine (SNAP)]
were found to inhibit endothelial cell proliferation measured with three i
ndependent methods (cell counting, [H-3]thymidine incorporation, DNA histog
rams) with significant inhibition occurring at concentrations greater than
or equal to 100 mu M. Growth-inhibiting effects were observed after long-te
rm treatment (18-96 h) as well as after short stimulation with NO donors (1
0 min with a subsequent NO donor-free culture period of 18 h) and were comp
arable in culture medium (20% serum, growth factor supplementation) and ser
um-deficient medium (1% serum). The NO donor effects were mediated by the r
elease of NO as they were prevented by NO scavenging. Superoxide dismutase
(SOD) was found not to interfere with these effects suggesting that peroxyn
itrite formation was unlikely to be involved. 1H-[1,2,4]Oxadiazolo[4,3,-alp
ha]quinoxalin-1-one (ODQ), a specific inhibitor of the soluble guanylate cy
clase, was observed not to alter the antiproliferative effects of NO donors
although it completely prevented NO-mediated increase of cyclic guanosine
3',5'-monophosphate (cGMP), suggesting that the NO-induced growth inhibitio
n was not mediated by cGMP. Furthermore, inhibition of endogenous NO produc
tion by N-nitro-L-arginine methylester (L-NAME) did not affect endothelial
cell growth regardless of using serum plus growth factor supplement, growth
factor supplement alone, or thrombin to stimulate proliferation. We sugges
t that constitutively synthesized NO may not regulate endothelial cell prol
iferation whereas the growth-inhibiting NO effects may occur when an induci
ble NO synthase associated with a persistently high NO production is expres
sed in the atherosclerotic vessel wall. (C) 1999 Elsevier Science Ireland L
td. All rights reserved.