Reactive oxygen species are involved in smoking-induced dysfunction of nitric oxide biosynthesis and upregulation of endothelial nitric oxide synthase: an in vitro demonstration in human coronary artery endothelial cells.
BACKGROUND
Our group has previously shown that human umbilical vein endothelial cells exposed to smokers' serum decreased nitric oxide (NO) production and endothelial nitric oxide synthase (eNOS) activity in the presence of increased eNOS expression. In the present study, we examined whether these observations extended to human coronary artery endothelial cells (HCAECs). In addition, the role of reactive oxygen species in the observed alterations was examined.


RESULTS
HCAECs were incubated with serum from 10 nonsmokers and 15 smokers for 12 hours with or without the addition of either polyethylene glycol-superoxide dismutase (PEG-SOD, 300 U/mL), PEG-SOD+PEG-catalase (1000 U/mL), chelerythrine (3 micromol/L), or tetrahydrobiopterin (20 micromol/L). At the end of incubation, NO, eNOS protein, and eNOS activity were measured from the same culture. HCAECs incubated with smokers' serum alone showed significantly lower NO production (P<0.05) and eNOS activity (P<0.005) but higher eNOS expression (P<0.005) compared with nonsmokers. In smokers, addition of PEG-SOD, PEG-SOD+PEG-catalase, or tetrahydrobiopterin significantly (P<0.05) improved NO levels and eNOS activity. Interestingly, in the same smokers, a significant decrease in eNOS expression was only seen with the addition of PEG-SOD+PEG-catalase (P<0.05) and treatment with PEG-SOD alone insignificantly increased eNOS expression.


CONCLUSIONS
The present study indicates that in vitro, HCAECs show similar changes in NO biosynthesis as human umbilical vein endothelial cells when exposed to smokers' serum and also confirms that oxidative stress plays a central role in smoking-mediated dysfunction of NO biosynthesis in endothelial cells. Furthermore, these data support other studies suggesting a role for hydrogen peroxide in the upregulation of eNOS.
Barua
Rajat S
RS
Saint Vincent Catholic Medical Centers of New York, New York 10011, USA.
Ambrose
John A
JA
Srivastava
Sudhesh
S
DeVoe
Mary C
MC
Eales-Reynolds
Lesley-Jane
LJ
D000328:Adult; D000470:Alkaloids; D053119:Benzophenanthridines; D001708:Biopterins / Q000031:analogs & derivatives* / Q000494:pharmacology; D001769:Blood; D002374:Catalase / Q000494:pharmacology; D002460:Cell Line; D003331:Coronary Vessels / Q000166:cytology; D004730:Endothelium, Vascular / Q000201:enzymology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D010617:Phenanthridines / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012907:Smoking; D013482:Superoxide Dismutase / Q000494:pharmacology; D015854:Up-Regulation
D000470:Alkaloids; D053119:Benzophenanthridines; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D010617:Phenanthridines; D017382:Reactive Oxygen Species; C070295:catalase-polyethylene glycol; D001708:Biopterins; D009569:Nitric Oxide; D011092:Polyethylene Glycols; C016299:chelerythrine; D002374:Catalase; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; D013482:Superoxide Dismutase; C063471:polyethylene glycol-superoxide dismutase; D011493:Protein Kinase C; C003402:sapropterin