【摘要】 目的探讨不同质量浓度的大气颗粒物PM_2.5对人支气管上皮细胞（HBE）毒性和氧化应激的作用。方法用不同质量浓度（0、2.5、5、10、25、50、100、250、500mg/L）的PM_2.5处理HBE细胞,分别用八肽胆囊收缩素（CCK-8）检测细胞存活情况,用2’,7’-二氯荧光素二乙酸酯（DCFH-DA）探针检测细胞内活性氧（ROS）的水平;用活性氧抑制剂N-乙酰半胱氨酸（NAC）预处理HBE细胞后,观察PM_2.5所致HBE细胞相关指标的变化。结果以不同质量浓度的PM_2.5处理HBE细胞24h,25、50mg/L剂量组细胞存活率均高于对照组（P值均<0.05）,500mg/L剂量组细胞存活率低于对照组（P<0.01）。与对照组相比,以不同质量浓度PM_2.5处理HBE细胞6h,细胞内ROS生成水平随着暴露浓度的增加而升高,呈明显的剂量效应关系（r2=0.792,P<0.01）。HBE细胞经3mmol/L NAC预处理和25mg/L PM_2.5处理后,细胞内ROS水平、细胞存活率均降低,差异均有统计学意义（P值均<0.05）。结论不同质量浓度的PM_2.5对HBE细胞增殖有双向刺激作用;PM_2.5可诱导HBE细胞内ROS增加,而适度的氧化应激可以促进HBE细胞增殖加快。更多还原

【Abstract】 Objective To investigate the effect of different concentrations of PM_2.5 on cytotoxicity and intercellular reactive oxygen（ROS）in human bronchial epithelial（HBE）cells.Methods HBE cells were treated with various concentrations of PM_2.5（0,2.5,5,10,25,50,100,250,500 mg/L）.The cell viability and the ROS level were examined by Cell Counting Kit（CCK-8）assay and 2’,7’-dichlorofluorescin（DCFH-DA）assay,respectively.HBE cells were pre-treated with N-acetyl-L-cysteine（NAC）and the change of related indexes induced by PM_2.5 in HBE cells were detected.Results After the cells were exposed to various concentrations of PM_2.5 for 24 h.The cells viabilities of 25 or 50 mg/L PM_2.5 dose groups were significantly higher than that in control group（all P<0.05）.The cell viability induced by 500 mg/L PM_2.5 was significantly lower than that of control group（P<0.01）.After 6 hexposure,the ROS level induced by PM_2.5 significantly increased with exposure level,positive correlation was found between the ROS level and the exposure dose of PM_2.5（r2=0.792,P<0.01）.After HBE cells were treated with 3 mmol/L NAC and were exposed to 25 mg/L PM_2.5,the ROS level and the cell viability were both decreased（all P<0.05）.Conclusion Different concentrations of PM_2.5 have dual effects on HBE cells.PM_2.5 can induce the generation of ROS in HBE cells,while moderate oxidative stress can accelerate the proliferation of HBE cells.更多还原