α7烟碱型乙酰胆碱受体抑制脂多糖诱导人脐静脉内皮表达细胞间黏附分子-1

α7 nicotine acetylcholine receptor inhibits lipopolysaccharide -inducedintercellular adhesion molecule -1 expression in endothelial cells

目的探讨α7烟碱型乙酰胆碱受体（α7nAchR）对脂多糖（LPS）诱导人脐静脉内皮细胞中细胞间黏附分子-1（ICAM-1）表达调控及其机制。方法体外培养人脐静脉内皮细胞EVC-304细胞株。（1）1μg／ml LPS刺激，检测α7nAChR和ICAM-1表达；（2）LPS、LPS＋GTS-21、LPS＋α-银环蛇毒素（α-BTX）刺激，检测ICAM-1表达及丝裂原活化蛋白激酶（p38MAPK）信号通路激活；（3）通过SB203580阻断p38MAPK后，1μg／mlLPS刺激，检测ICAM-1表达。结果LPS刺激后，α7nAchRmRNA及蛋白相对表达量均显著高于对照组（14．70±2．08比3．93±1．01，P=0．002；0．40±0．08比0．17±0．04，P=0．008），ICAM-1mRNA及蛋白表达也显著高于对照组（6．65±0．21比2．00±0．29，P=0．029；0．78±0．04比0．58±0．11，P=0．032），同时p38MAPK磷酸化（p-p38）激活也显著增高（0．73±0．08比0．29±0．06，P=0．008）；与LPS组比较，通过GTS-21预处理后，LPS诱导的P-p38显著下降（0．49±0．09比0．73±0．08，P=0．008），ICAM-1表达显著下降（0．42±0．07比0．76±0．13，P=0．002）；而通过d-BTX预处理后，与LPS组比较，LPS诱导的p-p38表达无显著下降（0．80±0．10比0．73±0．08，P=0．310），ICAM-1表达也无显著下降（0．82±0．09比0．76±0．13，P=0．305）；与LPS组比较，通过SB203580阻断p38MAPK信号通路后，LPS诱导的ICAM-1表达出现显著下降（0．554±0．10比0．82±0．08，P=0．001）。结论LPS可以诱导血管内皮细胞表达α7nAchR和ICAM-1，激动α7nAchR可以抑制这种LPS诱导的ICAM-1表达，其可能通过抑制丝裂原活化蛋白激酶信号通路的激活，从而抑制其下游细胞间黏附分子ICAM-1表达。

Objective To investigate the effects of α7 nicotine acetylcholine receptor （aTnAChR） on lipopolysaccharide （LPS） - induced expressions of intercellular adhesion molecule - 1 （ ICAM - 1 ） in human umbilical vein endothelial cells. Methods Human umbilical vein endothelial cell line EVC -304 were cultured and treated with LPS, and the expressions of ICAM -1 and oL7nAChR were detected by reverse transcriptase- polymerase chain reaction （RT- PCR） and Western blotting. Then cells were treated with LPS, LPS ＋ GTS -21 and LPS ＋ α - bungarotoxin （ct-BTX） separately. Expressions of ICAM - 1 and phosphorylated p38 Mitogen - activated protein kinase （ p - p38 ） were determined by Western blotting. Finally, cells were pretreated with p38MAPK inhibitor SB203580, and the expressions of ICAM - 1 were determined. Results LPS could significantly increase the expressions of ct7nAChR in endothelial cells （ 14. 70±2.08 vs. 3.93 ± 1.01, P = 0. 002 ; 0. 40 ± 0. 08 vs. 0. 17 ± 0.04, P -0. 008）. LPS stimulation could promote expressions of ICAM - 1 （6. 65 ±. 21 vs. 2.00 ±0. 29, P = 0. 029 ; 0. 78 ±0. 04 vs. 0. 58 ±0. 11, P = 0. 032 ） and p38 phosphorylation （ 0. 73 ±0. 08 vs. 0. 29 ± 0. 06, P = 0. 008 ） which could be could be attenuated by activation of α7nAChR （ p - p38 ： 0. 49 ± 0. 09 vs. 0.73 ±.08, P=0.008, ICAM -1：0.42 ±0.07 vs. 0. 17 ±.06, P=0.002） , and this inhibitory effect could be relieved by ct7nAChR antagonist （ p - p38 ： 0. 80 ± 0. 10 vs. 0. 73 ± 0. 08, P = 0. 310, ICAM-I： 0.42 ±.07 vs. 0.76 ±. 13, P=0.002）. The expressions of ICAM- 1 also could be re-straint by the treatment of p38MAPK inhibitor （0. 55 ＋0. 10 vs. 0. 82 ＋0.08, P =0. 001 ）. Conclusion LPS could marked increase the expressions of ct7nAChR and ICAM - 1. Activation of ot7nAChR could reduce expressions of ICAM - 1 by suppression the activation of p38MAPK pathway.