姜黄素对纳米二氧化硅致A549细胞氧化损伤影响

Effect of curcumin on nano-silicon dioxide induced oxidative damage in A549 cells

目的研究姜黄素对纳米二氧化硅(SiO_2)刺激A549细胞所致氧化应激的影响,探讨相关作用机制。方法取A549细胞随机分6组。纳米SiO_2组细胞予终质量浓度为20 mg/L的纳米SiO_2溶液刺激;姜黄素低、中、高剂量组细胞分别予含终浓度为5、10、20μmol/L姜黄素和终质量浓度为20 mg/L纳米SiO_2溶液处理,溶剂对照组细胞予体积分数为0.10%的二甲基亚砜处理,空白对照组细胞不予上述任何处理。6组细胞经12 h孵育后,以分光光度计检测细胞内丙二醛(MDA)水平和总超氧化物歧化酶(T-SOD)活力,分别以实时荧光定量聚合酶链式反应和免疫印迹法检测细胞核因子E2相关因子2(NRF2)、硫氧还蛋白(TRX)1、硫氧还蛋白互作蛋白(TXNIP)的mRNA和蛋白相对表达水平。结果与空白对照组和溶剂对照组比较,纳米SiO_2组A549细胞内MDA水平升高(P<0.05),T-SOD活力下降(P<0.05),NRF2、TRX1的mRNA和蛋白相对表达水平均上调(P<0.05),TXNIP的mRNA和蛋白相对表达水平均下调(P<0.05)。予姜黄素干预后,随姜黄素浓度的增加,A549细胞内MDA水平下降,T-SOD活力升高,NRF2 mRNA相对表达水平和TRX1的mRNA、蛋白相对表达水平均上调,TXNIP的mRNA和蛋白相对表达水平均下调,均呈剂量-依赖性关系(P<0.01)。结论姜黄素对纳米SiO_2所致A549细胞氧化应激具有保护作用;其可能通过调控NRF2/抗氧化反应元件通路,激活TRX系统,发挥抗氧化作用,保护细胞免受过度的氧化损伤。

Objective To study the effect of curcumin on the oxidative stress induced by nano-silicon dioxide（ SiO2） in A549 cells and to explore its potential mechanism. Methods A549 cells were randomly divided into 6 groups. Nano-SiO2 group cells were stimulated with nano-SiO2 solution with a final concentration of 20 mg/L; curcumin low-,medium-,and high-dose group cells were treated with curcumin at final concentrations of 5,10,and 20 μmol/L respectively and 20 mg/L nano-SiO2 solution; the solvent control group was treated with dimethyl sulfoxide with a volume fraction of 0. 10%. The cells in the blank control group were not given any treatment. The cells in these 6 groups were incubated for 12 hours,and the level of malondialdehyde（ MDA） and the activity of total superoxide dismutase（ T-SOD） in the cells were measured by spectrophotometer. The relative expression of mRNA and protein of nuclear factor E2-associated factor 2（ NRF2）,thioredoxin-1（ TRX1）,and thioredoxin interaction protein（ TXNIP） were analyzed by real-time fluorescent quantitative polymerase chain reaction and Western blot respectively. Results The MDA level in A549 cells of nano-SiO2 group increased（ P 0. 05）,the T-SOD activity decreased（ P 0. 05）,and the mRNA and protein relative expression of NRF2 and TRX1 were up-regulated（ P 0. 05）,TXNIP relative expression of mRNA and protein were down-regulated（ P 0. 05）,when compared with the blank control group and the solvent control group. After intervention with curcumin,with the increased of curcumin concentration,the MDA level in A549 cells decreased,the T-SOD activity increased,the relative expression of NRF2 mRNA and TRX1 mRNA and protein was up-regulated,the mRNA and protein relative expression of TXNIP was down-regulated,and showed a dose-dependent manner（ P 0. 01）. Conclusion Curcumin can protect nano-SiO2-induced oxidative stress in A549 cells. It may activate TRX system by regulating NRF2/antioxidant response elements pathway,exerting an anti-oxidation effect and protecting cells from excessive oxidative damage.