耐力训练对帕金森模型小鼠中脑线粒体自噬相关基因表达的影响

Effects of endurance training on the mitophagy related genes expression of Parkinson's disease model mice

目的:探讨耐力训练对帕金森病(PD)模型小鼠中脑线粒体自噬的影响,揭示运动预防帕金森病的分子生物学机制。方法:10周龄雄性C57BL/6小鼠32只,随机分为安静组(C),运动组(E),帕金森模型安静组(P)及帕金森模型运动组(PE),每组8只。E组及PE组小鼠进行为期8周跑台耐力训练,跑台速度15m/min,坡度为0%,每天运动持续50min,每周6次,周日休息。训练结束后,P组和PE组小鼠腹腔注射MPTP(30mg/kg),C组和E组小鼠注射等量生理盐水,持续3d。注射结束1周后,处死各组小鼠,取双侧中脑及纹状体,采用实时PCR及Western blot技术检测线粒体自噬相关基因及TH蛋白表达,HPLC技术检测中脑及纹状体组织内DA含量。结果:与C组比,E组小鼠中脑TH蛋白上调(P<0.05),中脑及纹状体DA含量均增加(P<0.05),P组和PE组小鼠TH蛋白及DA含量均显著下降(P<0.01),而P组较PE组相应指标下降更明显(P<0.05)。与C组比,E组小鼠中脑PINK、PARK2 m RNA及PINK1蛋白表达上调(P<0.05),LC3Ⅱ/Ⅰ比值增加,P组小鼠PINK1m RNA表达下调(P<0.05),PE组小鼠PINK1 m RNA、Parkin蛋白含量及LC3Ⅱ/Ⅰ比值较P组增加。结论:为期3d的MPTP处理可导致小鼠中脑及纹状体TH及DA含量下降,诱导帕金森病发生,耐力训练可缓解这一现象;MPTP诱导的帕金森小鼠模型中脑线粒体自噬水平下降,而耐力训练可作用于线粒体自噬相关基因的表达,抑制MPTP的神经毒性作用。

Objective： To study the effect of endurance pre-training on the mitophagy related genes expression of Parkinson＇s disease（PD） model mice and to unveil the molecular mechanism of the benefits of physical activity on prevention of PD biogenesis.Method： Thirty-two SPF male C57BL/6 mice were randomly divided into control group （C group, n=8）, endur- ance training group （E group, n=8）, 1- methyl- 4- phenyl-1,2,3,6- tetrahydropyricline chloride （MPTP） injection group （P group, n-8） and both endurance training and MPTP injection group （PE group, n=8）. The mice of group E and PE executed 8 weeks＇ treadmill running at 15m/min and for 50min each day, 6d a week. After training, MPTP was injected at 30mg/kg for 3d to the mice of group P and PE, while the normal saline was injected equally to the mice in group C and E for 3d, and the interval was 24h. One week after injection, all the mice were sacrificed and the midbrain and corpus striatum were extracted for further detection. The DA contents of midbrain and striatum were detected by HPLC, and the PINK1 and PARK2 mRNA in midbrain were detected by real-time PCR, and the protein expressions of TH, P1NK1 and Parkin were detected by Western blotting.Result： Compared to group C, the relative protein content of TH increased in the midbrain of mice （P〈0.05）, while the DA relative contents in both midbrain and striatum elevated （P〈0.05）; in both P and PE group, the TH protein and DA content decreased significantly （P〈0.01）, whereas these two indexes in group P reduced more significantly higher than it in group PE P〈0.05）. Compared to group C, the PINK1 mRNA, PARK2 mRNA and PINK1 protein contents were upregulated and the ratio of LC3 1I/I was higher in midbrain of mice in group E; in group P, the PINK1 mRNA relative content was down regulated （P〈0.05）, and the PINK1 mRNA and Parkin protein contents in midbrain of group PE were higher than that in the mice of group E Conclusion： The PD mice model can be induced by MPTP, treatment for 3 days, and in these PD mice the TH and DA contents in midbrain and corpus striatum drop seriously, whereas pre-training can alleviate these phenomena. The mitophagy level in midbrain decreased fiercely in MPTP induced PD mice model, whereas the pre endurance training cart cause the adaptation changes of mitophagy to inhibit the neurotoxicity of MPTP.