[Effect of cyclooxygenase-2 on vascular endothelial cell apoptosis induced by cigarette smoke extract].
OBJECTIVE
To explore the effect of cyclooxygenase-2 on vascular endothelial cell apoptosis induced by cigarette smoke extract.


METHODS
Human vascular endothelial cells (ECV-304) were cultured in vitro, and those at the exponential growth phase were studied in experiments. The experiment was completed through 3 steps: (1) ECV-304 cells were cultured with 0.0%, 0.5%, 1.0% and 5.0% CSE for 12 h. (2) ECV-304 cells were exposed to 5.0% CSE for 0, 3, 6, 9, 12 and 24 h. (3) Endothelial cells were treated by 5% CSE, together with different concentrations of selective COX-2 inhibitor celecoxib (0.0, 2.5, 5.0, 10.0, 20.0, 50.0 micromol/L concentrations) for 9 h. The cell apoptosis rate was tested by Hoechst staining and flow cytometry methods, and the expression of COX-2 protein by immunocytochemistry and Western blotting.


RESULTS
CSE induced ECV-304 cell apoptosis and COX-2 expression in a dose-dependent manner. The apoptosis rate of ECV-304 cells with 5.0% CSE was the highest (5.40+/-0.39)%. CSE- induced COX-2 expression reached the highest level with 5.0% CSE (206.1+/-15.5), the differences being significant (F=90.03, 159.94, all P<0.05). Furthermore CSE induced both apoptosis rate and COX-2 expression time-dependently, with the apoptosis rate achieving the peak after 24 h (8.87+/-0.41)%, while COX-2 expression reached the highest level at 9 h. The selective COX-2 inhibitor celecoxib inhibited COX-2 protein expression partially and augmented cell apoptosis induced by CSE.


CONCLUSIONS
CSE induces endothelial cell apoptosis and increases the expression of COX-2 protein in vascular endothelial cells. Celecoxib, the selective COX-2 inhibitor, reduces the expression of COX-2 protein and promotes cell apoptosis induced by CSE in vascular endothelial cells. COX-2 may play an important role in protecting development of CSE-associated apoptosis of endothelial cells.
Pei
Yan-fang
YF
Department of Respiratory Medicine, the Second Xiangya Hospital of Central South University, Changsha 410011, China.
Chen
Ping
P
Li
Jun-li
JL
Wang
Wei
W
Liu
Cai-hong
CH
Liu
Shao-kun
SK
Xiang
Xu-dong
XD
Zhou
Rui
R
D017209:Apoptosis / Q000187:drug effects*; D000068579:Celecoxib; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D006801:Humans; D011720:Pyrazoles / Q000494:pharmacology*; D012906:Smoke / Q000009:adverse effects*; D013449:Sulfonamides / Q000494:pharmacology*; D014026:Nicotiana
D052246:Cyclooxygenase 2 Inhibitors; D011720:Pyrazoles; D012906:Smoke; D013449:Sulfonamides; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D000068579:Celecoxib