本文研究了Nrf2-ARE通路在姜黄素介导的抑制β-淀粉样蛋白 (Aβ) 诱导SH-SY5Y细胞氧化损伤及细胞凋亡过程中的作用。在没有/含有姜黄素预先保护情况下，10 μM Aβ培养细胞24 h，观察细胞形态的变化，测定细胞存活率、细胞乳酸脱氢酶(LDH)释放水平，评价细胞培养液中H2O2及胞内活性氧水平，SDS-PAGE酶联免疫法测定Nrf2、HO-1蛋白表达水平。结果表明，与对照组相比，Aβ损伤组细胞突起变少、变短，胞体变圆，细胞存活能力降低、释放LDH的水平明显增加、氧化应激水平明显上升。与Aβ损伤组相比，姜黄素保护组细胞胞体突起较多、较长，细胞存活能力明显升高、释放LDH的水平明显降低、氧化应激水平也明显降低。姜黄素增强了Nrf2的表达，降低了Aβ诱导的Nrf2 Ser-40磷酸化及HO-1的相对表达水平。以上结果提示，姜黄素能够削弱Aβ诱导的氧化损伤和细胞凋亡作用，这可能与姜黄素对Nrf2-ARE通路的活性调节相关。

This study investigated the protective effects of curcumin on cellular oxidative damage and cell apoptosis induced by amyloid-β (Aβ) in human neuroblastoma SH-SY5Y cells and discussed the role of the Nrf2-antioxidant response element (ARE) pathway in this protective effect. Cells were treated with 10 μM Aβ1-40 at 37 ℃ for 24 h with or without curcumin pre-treatment. The changes in morphology were observed under the microscope, and the MTT colorimetric assay was used to assess cell viability. Lactate dehydrogenase (LDH) in the culture medium was determined to evaluate cell membrane damage. The relative levels of H2O2 in the culture medium and intracellular reactive oxygen species (ROS) were assessed. In addition, the protein expressions of Nrf2 and HO-1 were detected by western blot analysis. Compared with the vehicle-only control group, cell bodies in the Aβ-damaged group became rounded, with fewer and shorter protuberances. Cell viability decreased, and the level of released LDH increased, while the oxidative stress level was significantly elevated. Compared with the Aβ-damaged group, curcumin treatment promoted cell growth and the protuberances became longer; cell viability increased while released LDH decreased, and the level of oxidative stress also decreased significantly. Notably, curcumin promoted Nrf2 expression and attenuated Aβ-induced up-regulation of phosphorylated Nrf2 at Ser-40 as well as HO-1 expression. Curcumin attenuated cellular oxidative damage and cell apoptosis induced by Aβ, which might be linked to the regulation of the Nrf2-ARE pathway by curcumin.

国家自然科学基金资助项目(31471587);北京市属高等学校高层次人才引进与培养计划项目(CIT&TCD201504034);北京联合大学“启明星”大学生科技创新项目(201511417015)