p38促进尼古丁诱导的大鼠血管平滑肌细胞的细胞外基质表达

p38 promotes the expression of extracellular matrix induced by nicotine in vascular smooth muscle cells of rats

目的探讨尼古丁对大鼠胸主动脉血管平滑肌细胞(VSMCs)的细胞外基质(ECM)表达的影响及可能的机制。方法用终浓度为100μmol/L的尼古丁作用于体外培养的大鼠VSMCs 24 h,以不加尼古丁的细胞为对照组,采用反转录-聚合酶链式反应(RT-PCR)、免疫印迹(Western blotting)方法检测ECM包括Ⅰ型胶原、纤维黏连蛋白和膜受体整合素表达的差异,以及可能参与信号转导的蛋白激酶p38的活性变化。结果与对照组相比,尼古丁刺激组细胞的两种细胞外基质包括I型胶原和纤维黏连蛋白及膜受体整合素β1的表达均升高,分别为对照组的1.8倍、1.7倍和1.6倍,差异显著(P<0.05);尼古丁刺激组的蛋白激酶p38的活性比对照组高1.95倍,差异极其显著(P<0.01);p38的活性被特异抑制剂SB202190抑制后,尼古丁诱导的I型胶原的表达也随之下降。结论 p38参与尼古丁诱导的细胞外基质的高表达。

Objective To investigate the effect of nicotine on expression of extracelllular matrix （ ECM ） and integrin β1 （ β1 ） in vascular smooth muscle cells （VSMCs） of rats in order to explore the possible mechanism of the smoking-induced atherosclerosis. Methods VSMCs isolated from rats were subjected to 100μmol/L nicotine for 24 hours, and the cells without nicotine treatment were used as control. The expression of collagen I , fibronectio and integrin 131 was detected by reverse transcription-polymerase chain reaction （RT-PCR）, and the p38 activity was detected by Western blotting. Results Compared with the control group, the expression of ECM including collagen I , fibronectin, and integrin 131 , and the cell membrane receptor significantly increased in nicotine group, and were respectively 1.8 times, 1.7 times, and I. 6 times higher than the control group （P 〈 0. 05）. The p38 activity, increased 1.95 fiAds （ P 〈 0. 01 ）. After incubation with SB202190, specific inhibitor of p38, the higher expression of collagen l induced by tricotine was depressed. Conclusion P38 promotes the high secretion of extracellular matrix induced by nicotine in vitro, suggesting that the higher expression of extracellular matrix and its receptor, integrin β1 , in VSMCs induced by smoking in vivo may contribute to the atherosclerosis.