北京城区大气细颗粒物对肺腺癌细胞炎性作用及NF-кB表达的影响

Role of Nuclear Factor-kappa B Activation in Inflammatory Effect Induced by PM2.5 from Beijing Urban Area in A549 Cells

目的探讨北京城区大气细颗粒物(PM2.5)对肺腺癌细胞(A549)的损伤作用及NF-κB表达的影响。方法以终浓度为25、50、100、200μg/ml的PM2.5染毒A549细胞24h,采用MTT法测定细胞毒性,以ELISA法检测核因子-κB(NF-κB)的活性,以Western blot方法检测核内NF-κB p65亚基的表达,以硝酸还原酶法检测NO的含量。结果PM2.5对A549细胞产生了低剂量促进细胞增殖、高剂量抑制细胞增殖的双向作用。随着染毒浓度的增加,PM2.5诱导NF-κB的活性在细胞核中表达升高,而在细胞质中逐渐降低,且呈明显的剂量-反应关系(P<0.01)。100μg/ml的PM2.5可引起细胞核内NF-κB p65亚基的显著高表达。各剂量PM2.5染毒细胞24h可引起NO表达量明显增加(P<0.01)。结论PM2.5可引起A549细胞的炎性损伤,诱导细胞质中有活性的NF-κB向核内转移行使其调控炎性反应的功能。

Objective To study the adverse effects of PM2.5 from Beijing urban areas on human lung adenocarcinoma cells （A549）and the expression of NF-KB in the cells. Methods A549 cells were treated with PM2.5 at 25, 50, 100 and 200 μg/ml for 24 h. Cytotoxicity of PM2.5 was measured by MTT assay. The activity of NF-κB was measured by ELISA assay. Western blot method was used to detect the expression of NF-κB and NO levels was determined by using the nitrate reductase method. Results PM2.5 could induce A549 cell proliferation at low doses, but inhibit cell proliferation at high doses. The activity of NF-κB increased in the cell nucleus, but decreased in the cytoplasm after exposure to PM2.5 with a significant dose-dependent manner （P〈0.01）. 100 μg/ml of PM2.5 could cause the high expression of NF-κB in A549 nucleus, the levels of NO increased after exposure to PM2.5 for 24 h （P〈0.01）. Conclusion PM2.5 can induce inflammatory damage in A549 cells and maybe the activated NF-κB getting into the cell nucleus from cytoplasm plays an important role in the inflammatory damage induced by PM2.5.