纳米SiO2对人神经母细胞瘤SH-SY5Y细胞的凋亡诱导作用及其机制

目的:探讨纳米二氧化硅(SiO₂)对人神经母细胞瘤SH-SY5Y细胞凋亡和周期的影响,阐明其作用机制。方法:选取不同浓度粒径为90 nm的SiO₂颗粒作用于SH-SY5Y细胞,分别为0、3.125、6.250、12.500、25.000、50.000 mg·L^-1 SiO₂组,其中0 mg·L^-1组为对照组。MTT法检测各组SH-SY5Y细胞存活率;采用AO/EB染色和 Annexin Ⅴ-FITC/PI法检测各组细胞凋亡率;流式细胞术(FCM)检测细胞周期百分比和细胞中活性氧(ROS)水平。结果:MTT检测,6.250、12.500、25.000和50.000 mg·L^-1 SiO₂组细胞存活率低于对照组 (P<0.05),12.500、25.000和50.000 mg·L^-1 SiO₂组细胞存活率低于3.125 mg·L^-1 SiO₂组 (P<0.05)。AO/EB染色和 Annexin V-FITC/PI法检测,6.250、12.500、25.000和50.000 mg·L^-1 SiO₂组细胞凋亡率高于对照组(P<0.05),12.500、25.000和50.000 mg·L^-1 SiO₂组细胞凋亡率高于3.125 mg·L^-1 SiO₂组(P<0.05)。FCM检测,3.125、6.250、12.500、25.000和50.000 mg·L^-1 SiO₂组细胞中ROS水平高于对照组 (P<0.05)。25.000和50.000 mg·L^-1 SiO₂组G₀/G₁期细胞百分比低于3.125 mg·L^-1SiO₂组和对照组(P<0.05),50.000 mg·L^-1 SiO₂组G₂/M期细胞百分比高于对照组 (P<0.05)。结论:纳米SiO₂ 可降低SH-SY5Y细胞的活力,诱导细胞凋亡,增加细胞中ROS水平,可干扰细胞周期进程,对SH-SY5Y细胞的增殖具有抑制作用。

Induction effect of nano-SiO2 on apoptosis of neuroblastoma SH-SY5Y cells and its mechanism

Objective To observe the effects of nano-SiO₂ on apoptosis and cell cycle of human neuroblastoma SH-SY5Y cells,and to explore the mechanism.Methods The SH-SY5Y cells were treated with different concentrations of 90 nm SiO₂ and divided into 0,3.125,6.250,12.500,25.000, and 50.000 mg·L^-1 SiO₂ groups. The survival rates of the cells in various groups were assessed by MTT method;the apoptotic rates of SH-SY5Y cells were determined by AO/EB staining and Annexin Ⅴ-FITC/P method; the percentage of cell cycle and the level of intracellular reactive oxygen species(ROS) were tested by flow cytometry(FCM) method.Results The MTT results showed the survival rates of the cells in 6.250,12.500,25.000 and 50.000 mg·L^-1 SiO₂ groups were significantly lower than that in control group (P<0.05);the survival rates of the cells in 12.500,25.000, and 50.000 mg·L^-1 SiO₂ groups were significantly lower than that in 3.125 mg·L^-1 SiO₂ group (P<0.05); the AO/EB staining and Annexin Ⅴ-FITC/PI results showed the apoptotic rates of the cells in 6.250,12.500,25.000,and 50.000 mg·L^-1 SiO₂ groups were higher than that in control group(P<0.05);the apoptotic rates of the cells in 12.500,25.000,and 50.000 mg·L^-1 SiO₂ groups were higher than that in 3.125 mg·L^-1 group(P<0.05).The FCM results showed the levels of ROS of the cells in 3.125,6.250,12.500,25.000, and 50.000 mg·L^-1 SiO₂ groups were significantly higher than that in control group (P<0.05); compared with control group,the percentages of the cells at G₀/G₁ phase in 25.000 and 50.000 mg·L^-1 SiO₂ groups were increased (P<0.05);the percentage of the cells at G₂/M phase in 50.000 mg·L^-1 SiO₂ group was increasd (P<0.05).Conclusion Nano-SiO₂ can decrease the activity of SH-SY5Y cells and increase the apoptosis and the level of ROS,and nano-SiO₂ can interfere the cell cycle and inhibit the proliferation of SH-SY5Y cells.