iNOS在EGCG促A549细胞凋亡中的作用

目的观察诱导型一氧化氮合酶（iNOs）在表没食子儿茶素没食子酸酯（EGCG）促A549细胞凋亡中的作用。方法体外培养A549细胞，随机分为对照组、EGCG组，MTT方法检测筛选EGCG最佳作用浓度，流式细胞仪检测EGCG促A549细胞凋亡作用，免疫组化染色法、蛋白质印迹定量分析法与Real time—PCR方法检测各组中iNOS蛋白和mRNA的表达情况。结果200mg／L的EGCG组细胞增殖活性与其他组比较差异有显著意义（F—1000．35，q=3．43～60．00，P〈0．05）。EGCG组晚期A549细胞凋亡率与对照组比较，差异有显著性（x2 =65．23，P〈0．05）。与对照组比较，EGCG同样可以降低A549细胞中iNOS蛋白与mRNA的表达量，差异有显著性（t=9．4、5．7，P〈0．05）。结论EGCG促A549细胞凋亡可能与下调iNOS蛋白与mRNA的表达量有关。

THE ROLE OF iNOS IN EGCG PROMOTING APOPTOSIS OF A549 CELLS

Objective To investigate the effect of inducible NOS （iNOS） on EGCG promoting apoptosis of A549 cells. Methods A549 cells were cultured in vitro and randomized to two groups： control group and model group. Optimal concentration of EGCG was obtained by MTT assay. The apoptosis effect of EGCG on A549 cells was detected by flow cytometry. The expres- sions of iNOS and mRNA were detected by immunocytochemical western blotting and real fime-PCR. Results The results showed that the differences of cell proliferation activity between 200 mg/L EGCG group and other groups were significant （F ： 1 000.35,q = 3.43-60.00, P 〈 0.05）. The differences of the apoptosis rate of advanced stage A549 cells between EGCG group and the control were significant （x2=65.23,P〈0.05）. Compared with the control group, EGCG could also reduce the expressions of iNOS protein and mRNA in A549 cells （t=9.4,5.7;P〈0.05）. Conclusion The apoptosis activity of A549 cells treated with EGCG is likely to be related with downregulation of the expressions of iNOS protein and mRNA.