帕金森病研究的热点:3-硝基丙酸预处理对多巴胺能神经元的保护作用

背景3-硝基丙酸可以抑制氧化磷酸化过程,损害细胞的能量代谢从而引起细胞的损伤.但是小剂量的3-硝基丙酸却可以通过轻度抑制细胞的氧化磷酸化过程,激发细胞内源性保护因子保护神经元,增加神经元对缺血缺氧的耐受性,但它对多巴胺能神经元是否也有类似的作用尚不十分清楚.目的探讨3-硝基丙酸预处理能否增强多巴胺能神经元对1-甲基-4苯基吡啶离子毒性的耐受.设计以能分泌多巴胺的神经母细胞瘤SH-SY5Y细胞为研究对象,进行随机对照的探索性研究.单位一所大学附属医院的神经科.材料实验于2003-03/11在同济医学院病理生理实验室完成.SH-SY5Y细胞购于北京协和医科大学细胞典藏中心.干预细胞随机分为6组,将1-甲基-4苯基吡啶离子加入到培养的多巴胺能神经元SH-SY5Y细胞中制作帕金森病的细胞模型,在加入1-甲基-4苯基吡啶离子(0.25mmol/L)前,分别单次或多次加入3-硝基丙酸(0.2 mmol/L)形成预处理,应用四氮唑盐检测细胞生存率,[3H]DA摄取率测定多巴胺能细胞突触前功能.主要观察指标主要结局细胞生存率.次要结局[3H]DA摄取率.结果1-甲基-4苯基吡啶离子组细胞生存率(54.3%)较空白对照组明显降低(P＜0.01),3-硝基丙酸预处理后,细胞生存率明显增高,分别为71.8%(单次),85.2%(多次),单次预处理组与多次预处理组相比也有显著性差异(P＜0.05).[3H]DA摄取率结果与细胞生存率结果相似.[3H]DA摄取率分别为65.8%(单次),80.3%(多次),较1-甲基-4苯基吡啶离子组(50.1%)明显提高,且多次预处理较单次预处理效果更好.单加3-硝基丙酸对细胞无影响.结论3-硝基丙酸预处理可明显增强多巴胺能神经元对1-甲基-4苯基吡啶离子毒性作用的耐受性,对多巴胺能神经元有明显的保护作用,多次预处理的保护作用更加显著.

Hotspot in the research of Parkinson disease: the protective effects of 3-nitropropionic acid preconditioning on dopaminergic neurons

BACKGROUND: 3-nitropropionic acid(3-NP) can inhibit the process of oxidative phosphorylation and injure the energy metabolism of the cell and thereby induce cell injury. However, small dose of 3-NP can excite intrinsic cellular protective factor to protect neurons and increase the tolerance of neurons to ischemic hypoxia through mild inhibiting the process of oxidative phosphorylation. It is unclear whether it also has the similar effect on dopaminergic neurons.OBJECTIVE: To investigate whether 3-NP preconditioning could enhance the tolerance of dopaminergic neurons to MPP+(1-methyl-4-phenylpyridine)toxicity.DESIGN: A randomized controlled exploring research based on neuroblastoma SH-SYSY cell that could secrete dopamine.SETTING: Department of neurology of a university hospital.MATERIALS: The study was conducted in the Laboratory of Pathophysiology of Tongji Medical College between March 2003 and November 2003. SH-SYSY cell was obtained from the Cell Center of Peking Union Medical University.INTERVENTIONS: Cells were randomly divided into 6 groups. MPP+ was added into the cultured dopaminergic neuron SH-SY5Y cells for the establishment of the cell model for Parkinson disease. Before the admission of MPP+ (0.25 mmol/L), 3-NP(0. 2 mmol/L) was added once or repetitive times to form preconditioning. Microculture tetrozolium(MTT) was used to detect cell survival rate, and[3H] DA uptake rate was used to test the anterior synaptic function of dopaminergic neurons.MAIN OUTCOME MEASURES: Major consequence: Cell survival rate;Minor consequence: [3H] DA uptake rate.RESULTS: Cell survival rate of MPP+ group was 54.3%, which was significantly lower than that of blank control group( P ＜ 0.01) . After 3-NP preconditioning, cell survival rate significantly elevated, which was 71.8%(single) or 85.2% (repetitive) . There was significant difference between single preconditioning and repetitive preconditioning( P ＜ 0.05 ). The results of[3H] DA uptake rate were similar to that of cell survival rate. [3H] DA uptake rate was 65.8% (single) or 80. 3% (repetitive), which was significantly higher than 50. 1% of MPP+ group. And moreover, repetitive preconditioning had more favorable effect than single preconditioning. Simple admission of 3-NP had no impact on cells.CONCLUSION: 3-NP preconditioning can significantly enhance the tolerance of dopaminergic neuron to MPP+ toxicity, which has significant protective effects on dopaminergic neuron. Repetitive preconditioning have more significant protective effects.