纳米氧化锌诱导人肺泡Ⅱ型上皮细胞A549发生炎性凋亡的研究

目的用纳米氧化锌(ZnO-NPs)刺激体外培养的人肺泡Ⅱ型上皮细胞(A549),探讨其是否发生炎性凋亡。方法用10μg/ml和20μg/ml的ZnO-NPs分别刺激A549细胞8和24h,以磷酸盐缓冲液(PBS)为对照,用乳酸脱氢酶(LDH)活力测定试剂盒和白介素-1β(IL-1β)ELISA试剂盒分别检测细胞培养上清液中的LDH酶活力和IL-1β含量,用半胱氨酸天冬氨酸特异性蛋白酶-1(caspase-1)活性测定试剂盒检测细胞caspase-1的活性。结果纳米氧化锌作用于A549细胞8h,染毒组和对照组LDH酶活力差异无显著性,与对照组比较,20μg/ml ZnO-NPs染毒组caspase-1活性和IL-1β含量均升高(P<0.05)。ZnO-NPs作用于A549细胞24h时,染毒组和对照组caspase-1活性差异无显著性。染毒组IL-1β含量和LDH酶活力均显著高于对照组(P<0.05)。结论纳米氧化锌(20μg/ml)刺激A549细胞早期caspase-1活性升高,继之IL-1β含量和LDH酶活力升高,可能发生了炎性凋亡。

Pyroptosis induced by zinc oxide nanoparticles in A549 cells

Objective To explore whether exposure to zinc oxide nanoparticles(ZnO-NPs) induced pyroptosis in human alveolar typeⅡepithelial cells(A549).Methods A549 cells were stimulated with different concentrations of ZnO-NPs(10 and 20μg/ml) for 8 and 24h,respectively.The activity of lactic dehydrogenase(LDH) and the levels of interleukin-1β(IL-1β) in cell culture media were respectively measured by LDH activity kit and human IL-1β ELISA kit.The activity of caspase-1 in A549 cells was detected by caspase-1 colorimetric assay kit.Results At 8h exposure to ZnO-NPs,there was no significant difference in the activity of LDH in the cell culture media among the ZnO-NPs-treated and control groups,but the activity of caspase-1 and the levels of IL-1β in A549 cells were significantly increased in 20μg/ml ZnO-NPs group compared to that in the control group(P<0.05).Levels of IL-1β and activity of LDH in the groups treated with ZnO-NPs(10 or 20μg/ml) were significantly higher than that in the control group after 24 h exposure to ZnO-NPs,but there was no significant difference in the activity of caspase-1 among ZnO-NPs and control group.Conclusion ZnO-NPs(20μg/ml) treatment induces early increase in caspase-1 activity followed by the increase in LDH activity and IL-1 levels,indicative of pyroptosis in A549 cells.