中文摘要：

目的探讨纳米二氧化硅（nano-SiO_2）暴露对人支气管上皮细胞（16 HBE）的损伤作用及维生素E对其的保护作用。方法根据CCK-8细胞毒性结果,选取对照,微米级SiO_2（micro-SiO_2,20μg/ml）、纳米nano-SiO_2（5、10和20μg/ml）和维生素E（20μg/ml nano-SiO_2＋50μmol/L维生素E）处理16 HBE细胞24 h,采用倒置显微镜观察细胞形态改变,Hochest 33342和膜联蛋白V-碘化丙啶（PI）双染法检测细胞凋亡,RNA酶A消化和PI染色来检测细胞周期分布。结果当nano-SiO_2浓度达10μg/ml时,细胞活力明显降低（P〈0.05）,随着nano-SiO_2浓度进一步增高,细胞活力呈剂量依赖性降低;细胞体积缩小,核固缩,细胞的折光性减弱。随着nano-SiO_2浓度的增加,凋亡率呈剂量依赖性升高;而维生素E组较20μg/ml nano-SiO_2组,细胞凋亡率有所降低;细胞周期出现轻微的G1期阻滞,维生素E可以改善这种阻滞现象。结论维生素E干预对由于nano-SiO_2引起的16 HBE的凋亡及细胞周期改变具有一定的保护作用。

英文摘要：

[Objective]To study the protective effects of vitamin E（VE） on human bronchial epithelia（16 HBE） cell damage induced by nano-silicon dioxide（nano-SiO_2）exposure.[Methods]According to cytotoxicity results of CCK-8,16 HBE cells were treated with micro-SiO_2（20 μg/ml）,nano-SiO_2（5,10 and 20 μg/ml）,and nano-SiO_2（20 μg/ml）＋VE（50 μmol/L）for 24 hours.The morphology changes of cells were observed under inverted microscope.Cell apoptosis was detected by Hochest 33342 and Annexin V-Propidium Iodide（PI） double-staining method.RNase A and PI were used to determine the cell cycle distribution.[Results]The cell activity decreased significantly when the concentration of nano-SiO_2 reached 10 μg/ml.There was a dose dependent reduction of cell activity with further increased nano-SiO_2 concentration.The cell shrinkage,karyopyknosis,and cell refraction weaken were observed under inverted fluorescence microscope.Meanwhile,there was a dose dependent increase of cell apoptosis rate with increased concentration of nano-SiO_2.The cell apoptosis rate in VE group was lower than that in 20 μg/ml nano-SiO_2 group.There was mild GI phase arrest induced by nano-SiO_2,and it had been improved by VE.[Conclusion]VE has significant protective effects on the cell apoptosis and cell cycle change induced by nano-SiO_2 exposure in 16 HBE cells.