Mdivi-1对帕金森病大鼠多巴胺能神经元损伤的保护作用研究

Protective effect of Mdivi-1 on dopaminergic neuron damage in rats with Parkinson’s disease

目的 研究线粒体分裂引发帕金森病(Parkinson ’ s disease,PD)大鼠模型中多巴胺能神经元损伤作用及线粒体分裂抑制剂1(mitochondrial division inhibitor 1,Mdivi-1)对神经元损伤的保护作用机制。方法 将大鼠随机分成对照组(生理盐水组)、模型组、美多巴组和Mdivi-1组,采用6-羟基多巴胺(6-hydroxydopamine,6-OHDA)注射大鼠单侧纹状体的方法建立PD动物模型,利用阿朴吗啡(apomorphine,APO)引起的大鼠旋转实验和转棒实验来观察行为学变化。利用免疫组化方法评估酪氨酸羟化酶(tyrosine hydroxylasez,TH)在中脑黑质中阳性细胞比例以及纹状体中TH阳性纤维数量,采用ELISA法检测大鼠黑质和纹状体中超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、还原型谷胱甘肽(glutathione,GSH)、过氧化氢酶(catalase,CAT)、丙二醛(malondialdehyde,MDA)、一氧化氮(nitric oxide,NO)及一氧化氮合酶(nitric oxide synthase,NOS)的含量。结果 与对照组相比,PD模型组大鼠在APO诱发第3周和6周后旋转圈数均显著增加,同时转棒上停留时间均显著缩短;大脑黑质TH阳性细胞数和纹状体中TH阳性纤维数目显著减少;组织内SOD、GSH-Px、CAT的活性显著降低,而NOS 活性显著升高,MDA和NO含量升高,而GSH含量则降低。美多巴及Mdivi-1处理3周和6周后均可显著改善PD大鼠的相关行为学症状,并增加黑质TH阳性细胞数和纹状体中TH阳性纤维数目,同时增加组织内SOD,GSH-Px,CAT,GSH含量,降低NOS 活性,减少MDA和NO含量。结论 Mdivi-1对6-OHDA诱导PD大鼠的多巴胺能神经元损伤具有保护作用,其机制可能与其抗氧化能力有关。

Objective To study the effect of mitochondrial division on the dopaminergic neuron injury in a rat model of Parkinson’s disease( PD) and the protective effect of mitochondrial division inhibitor 1( Mdivi-1). Methods The rats were randomly divided into control group,model group,Madopar group and Mdivi-1 group. Then the animal model of PD was established by injecting6-hydroxydopamine( 6-OHDA) into rat unilateral striatum. The expression of mitochondrial dynamicsrelated regulatory molecules was detected by real-time quantitative PCR,and differentially expressed genes were explored. Apomorphine( APO)-induced rat rotation test and rotating rod experiment to observe behavioral changes. Immunohistochemical method was used to evaluate the proportion of tyrosine hydroxylase( TH) positive cells in the substantia nigra and the number of TH positive fibers in the striatum. The activity of superoxide dismutase( SOD),glutathione peroxidase( GSH-Px) and reduced glutathione( GSH) and the contents of catalase( CAT),malondialdehyde( MDA),nitric oxide( NO),and nitric oxide synthase( NOS) in the substantia nigra and striatum of rats were measured by ELISA. Results Compared with control group,the number of rotations of the rats in model group increased significantly after APO induction,and the residence time on the rotating rod was significantly decreased in three and six weeks. At the same time,the number of TH-positive cells in the substantia nigra and the number of TH-positive fibers in the striatum were significantly reduced. Further studies found that the activity of SOD,GSH-Px,and CAT in tissues was significantly decreased,while the activity of NOS was significantly increased. The corresponding MDA and NO levels increased,while the GSH content decreased.The behavioral symptoms of PD rats were significantly improved by Mardopa treatment and Mdivi-1 treatment in three and six weeks. Meanwhile,the number of TH cells in the substantia nigra and the number of TH-positive fibers in the striatum were significantly increased in the Mardopa group and the Mdivi-1 group. At the same time,the activity of SOD,GSH-Px,CAT and GSH in tissues was increased,while the activity of NOS was decreased in Mardopa group and Mdivi-1 group. The content of MDA and NO was decreased in Mardopa group and Mdivi-1 group. Conclusion Mdivi-1 has a protective effect on 6-OHDA-induced dopaminergic neurons in PD rats and its mechanism may be related to its antioxidant capacity.