SOD2在姜黄素减轻氧糖剥夺所致神经元损伤中的作用

目的:探讨二型超氧化物歧化酶(Mn-SOD,SOD2)是否介导了姜黄素(Curcumin,Cur)对氧糖剥夺模型(Oxygen-Glucose Deprivation,OGD)损伤神经元的保护作用。方法:本研究采用HT22神经元细胞暴露于OGD环境中3 h模拟神经元缺血缺氧损伤,SOD2-si RNA抑制神经元SOD2蛋白表达后,通过噻唑蓝法(Methylthiazolyldiphenyl-tetrazolium bromide,MTT)检测细胞活力,比色法测量培养基乳酸脱氢酶(Lactic Dehydrogenase LDH)水平,流式细胞仪计算细胞凋亡率,Western blot测定凋亡蛋白Cleaved Caspase-3表达,并观察细胞形态和线粒体功能。结果:与正常培养的Control组相比,OGD组细胞活力显著降低,LDH释放明显增加,细胞凋亡率和Cleaved Caspase-3表达显著上升,细胞形态破坏并降低线粒体膜电位(MMP)和线粒体复合物1(Mitochondrial Complex 1 Activity)的活力(P0.05),100 ng/ml的Cur可显著减轻OGD诱导的神经元细胞的上述损伤性改变(P0.05)。而SOD2-si RNA显著逆转Cur对OGD诱导的神经元细胞损伤的保护作用(P0.05),SC-si RNA则未对Cur产生的神经保护作用造成显著干扰(P0.05)。结论:Cur可能通过上调SOD2的表达,减轻OGD对神经元细胞的损伤。

SOD2 Mediates Curcumin-induced Protection in Neurons Exposed to Oxygen-glucose Deprivation

ABSTRACT Objective: To explore whether Mn-SOD (SOD2) mediates curcumin-induced neuroprotection against oxygen-glucose deprivation (OGD) in neurons. Methods: HT22 neurons were exposed to OGD for 3 h to mimic neuronal ischemic injury, after down-reg- ulating SOD2 expression in neurons by using SOD2-siRNA, methylthiazolyldiphenyl-tetrazolium bromide (MTT) was used to assess cell viability, reagent kit was taken to evaluate lactic dehydrogenase (LDH) in the medium, flow cytometry was taken to calculate cell apoptosis rate, western blot was used to measure cleaved caspase-3 expression, neuronal morphology and mitochondrial function were also ob- served. Results: Compared with the cells in the control group, OGD reduced cell viability, increased LDH release, cell apoptosis rate and cleaved caspase-3 expression, damaged cell morphology, and inhibited mitochondrial membrane potential (MMP) and complex 1 activity (P<0.05), 100 ng/mL Cur obviously reduced the OGD-induced damage mentioned above, SOD2-siRNA significantly reversed the Cur-in- duced neuroprotective effects (P<0.05), but the scrambled siRNA (SC-siRNA) showed little influence on the Cur-induced neuroprotec- tive effects (P>0.05). Conclusion: Cur can reduce OGD-induced injury in neurons by up-regulating SOD2 protein.