纳米银颗粒对人HepG2和A549细胞的氧化损伤效应研究

Silver nanoparticles-induced oxidative damage in human HepG2 and A549 cells

目的探讨纳米银颗粒对人HepG2和A549细胞的氧化损伤效应。方法采用稳定转染了HSPA1A启动子荧光素酶报告基因质粒的HepG2和A549细胞株(HepG2/HSPA1A和A549/HSPA1A细胞)作为细胞株,用不同浓度(6.25、12.5、25、50μg/ml)的纳米银混悬液染毒细胞48h,分别测定细胞存活率、荧光素酶活力、丙二醛(MDA)浓度和细胞内银浓度。结果HepG2/HSPA1A和A549/HSPA1A染毒组的细胞存活率均低于对照组,差异有统计学意义(P<0.05或P<0.01);染毒浓度为50μg/ml时,细胞存活率分别为对照组的25.26%和12.30%。纳米银颗粒可明显诱导HepG2/HSPA1A和A549/HSPA1A细胞内荧光素酶的表达,各染毒组酶活力均高于对照组,差异有统计学意义(P<0.01);HepG2/HSPA1A细胞内荧光素酶活力高于A549/HSPA1A细胞,前者在最高染毒浓度(50μg/ml)时的酶活力为对照组的138.2倍。仅在最高染毒浓度(50μg/ml)时,HepG2/HSPA1A和A549/HSPA1A细胞MDA浓度均高于对照组,差异有统计学意义(P<0.05或P<0.01)。细胞内银浓度随纳米银浓度的增加而升高,有明显的剂量-效应关系,且HepG2/HSPA1A细胞内银浓度略高于A549/HSPA1A细胞。结论纳米银颗粒可直接进入细胞并诱导细胞氧化损伤;HepG2/HSPA1A和A549/HSPA1A细胞荧光素酶活力所反映的HSPA1A启动子转录活力可用于快速评估纳米银颗粒所致细胞氧化损伤水平。

Objective To understand the oxidative damage induced by silver nanoparticles in HepG2 and A549 cells. Methods The stable HepG2 and A549 cells transfected with the HSPA1 A promoter-driven luciferase reporter plasmid（HepG2/HSPA1 A and A549/HSPA1 A cells） were served as cell models. After 48 h-treatment with silver nanoparticles（Ag NPs） at different doses,cell viability, luciferase activity, MDA concentration and cellular Ag concentration were determined. Results After 48 h-exposure to Ag NPs, the cell viabilities were significantly decreased in both reporter cells compared with the control. At 50 μg/ml of Ag NPs, the cell viabilities were 25.26% and 12.30% in HepG2/HSPA1 A and A549/HSPA1 A cells, respectively. Ag NPs could induce dose-dependent luciferase expression in both the reporter cells. Compared with the A549/HSPA1 A cells, the increase in luciferase activity was more obviously in HepG2/HSPA1 A cells,the relative luciferase activity was 138.2 fold of control at the highest concentration tested. However, only at the highest dose（50 μg/ml） of Ag NPs, significant increase in MDA concentration was observed. Cellular Ag levels increased with the concentration of Ag NPs in a dose-related manner, moreover,the cellular Ag level in HepG2/HSPA1 A cells was higher than that in A549/HSPA1 A cells. Conclusion Ag NPs may enter the cells and induce oxidative damage. The transcriptional activation of HSPA1 A indicated by luciferase activity in HepG2/HSPA1 A and A549/HSPA1 A cells can be used for rapid screening of oxidative damage induced by Ag NPs.