丹参酮IIA对过氧化氢诱导的人晶状体上皮细胞凋亡和氧化应激的影响

目的　探讨丹参酮IIA（Tan IIA）对过氧化氢（H₂O₂）诱导的人晶状体上皮细胞凋亡和氧化应激的调控作用及可能的机制。方法　以人晶状体上皮细胞SRA01/04为研究对象，分为空白组、H₂O₂组（H₂O₂处理细胞建立氧化损伤模型）、Tan IIA组（Tan IIA溶液预处理24 h后，H₂O₂作用24 h）、Tan IIA+siNC组（转染阴性对照，其他处理方式同Tan IIA组）和Tan IIA+siNrf2组［转染核因子E2相关因子2（Nrf2） siRNA(siNrf2)，其他处理方式同Tan IIA组］。CCK-8法检测细胞活力，流式细胞术分别检测细胞凋亡率和活性氧簇（ROS）水平，酶联免疫吸附试验测定细胞中过氧化氢酶（CAT）活性、超氧化物歧化酶（SOD）含量、谷胱甘肽过氧化物酶（GSH-Px）含量，Western blot检测细胞总蛋白中Nrf2、血红素氧合酶-1（HO-1）表达及核蛋白中Nrf2表达情况。结果　通过CCK-8法确定H₂O₂和Tan IIA最佳实验浓度为300 μmol·L^-1和20 μmol·L^-1。与空白组相比，H₂O₂组SRA01/04细胞活力及细胞中CAT活性、SOD含量、GSH-Px含量均降低，凋亡率和ROS水平均增加，同时总蛋白中Nrf2和HO-1蛋白相对表达量及核蛋白中Nrf2蛋白相对表达量均下调（均为P<0.05）。与H₂O₂组相比，Tan IIA组SRA01/04细胞活力及细胞中CAT活性、SOD含量、GSH-Px含量均增加，凋亡率和ROS水平均降低，总蛋白中Nrf2和HO-1蛋白相对表达量及核蛋白中Nrf2蛋白相对表达量均上调（均为P<0.05）。而沉默Nrf2基因后，Tan IIA对SRA01/04细胞的保护作用被逆转。结论　Tan IIA能够抑制H₂O₂诱导的人晶状体上皮细胞氧化应激性损伤和凋亡，其机制与Nrf2/HO-1通路的激活有关。

Influence of tanshinone IIA on H2O2-induced apoptosis and oxidative stress in human lens epithelial cells via activating the Nrf2/HO-1 pathway

Objective　To study the effect of tanshinone IIA (Tan IIA) on H₂O₂-induced apoptosis and oxidative stress in human lens epithelial cells, and the possible mechanism.Methods　The human lens epithelial cell line SRA01/04 was divided into blank group, H₂O₂ group (treated with H₂O₂), Tan IIA group (pre-treated with 300 μmol·L^-1 Tan IIA solution for 24 h before H₂O₂ exposure for 24 h), Tan IIA+siNC group (pre-treated with 300 μmol·L^-1 Tan IIA solution for 24 h before H₂O₂ exposure for 24 h in cells transfected with siNC) and Tan IIA + siNrf2 group (pre-treated with 300 μmol·L^-1 Tan IIA solution for 24 h before H₂O₂ exposure for 24 h in cells transfected with siNrf2). The cell viability was measured by CCK-8 assay. The apoptosis rate and the reactive oxygen species (ROS) level were measured by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to detect the activity of catalase (CAT) and the contents of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Western blot was used to detect protein levels of Nrf2 and heme oxygenase-1 (HO-1).Results　The optimal concentrations of H₂O₂ and Tan IIA solution were determined by CCK-8 assay at 300 μmol·L^-1 and 20 μmol·L^-1, respectively. Compared with the blank group, the cell viability, CAT activity, and SOD and GSH-Px contents decreased, while the apoptosis rate and ROS level increased in SRA01/04 cells of H₂O₂ group. Moreover, expression levels of total Nrf2 and HO-1, and nuclear protein level of Nrf2 were down-regulated (all P<0.05). Compared with H₂O₂ group, the viability, CAT activity, and SOD and GSH-Px contents increased, while the apoptosis rate and ROS level decreased in SRA01/04 cells of Tan IIA group. Meanwhile, protein levels of total Nrf2 and HO-1, and nuclear protein level of Nrf2 were up-regulated (all P<0.05). The protective effect of Tan IIA on SRA01/04 cells was reversed by silencing Nrf2.Conclusion　Tanshinone IIA can inhibit H₂O₂-induced apoptosis and oxidative stress in human lens epithelial cells via activating the Nrf2/HO-1 pathway.