帕金森病模型小鼠黑质纹状体系统氧化应激的增龄性改变

Impact of aging on the nigro-strital oxidative stress in a mice model of Parkinson's disease

目的观察不同月龄小鼠帕金森病(PD)模型黑质纹状体系统氧化应激损伤的增龄性改变并检测老龄PD小鼠氧化应激相关基因的差异性表达。方法选用健康雌性3、6、10月龄快速老化小鼠P8系(SAMP8)42只,各月龄小鼠随机平均分为MPTP组与对照组,分别给予背部皮下急性注射1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)及等量0.9%NaCl处理。给药后72 h,采用开放旷场实验观察其运动功能,高效液相色谱法检测黑质DA含量,分光光度计法检测纹状体超氧化物歧化酶(SOD1)活性和丙二醛(MDA)含量,比较不同月龄小鼠黑质DA系统、纹状体氧化应激相关指标损伤的差异。采用PCR Array检测两组10月龄小鼠纹状体氧化应激相关基因表达的差异。结果与对照组相比,MPTP组各月龄小鼠水平运动距离与站立次数均减少,DA水平、SOD活性明显下降,MDA含量明显增加(P<0.05);与3、6月龄相比,10月龄小鼠上述指标变化更明显;与对照组相比,10月龄MPTP组小鼠环氧化酶-2表达明显上调,而谷胱甘肽过氧化物酶3、6、8,乳酸过氧化物酶、核氧化还原酶、肌红蛋白、神经珠蛋白酶、过氧化物还原酶1和嗜酸粒细胞过氧化物酶9种基因明显下调(倍数改变>2)。结论月龄是影响PD模型黑质纹状体系统损伤的重要因素;与氧化应激相关的基因的上调或下调可能参与了PD的早期发病。

Objective To observe the age-related changes of nigro-strital oxidative stress in a mice model of Parkinsons disease（PD）at different ages and detect the differential expression of oxidative stress related genes in aged PD mice by using PCR Array.Methods Forty-two healthy female senescence-accelerated mouse prone 8 （SAMP8）mice aged 3, 6 and 10-month were averagely and randomly divided into 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine （MPTP） group and control group,which were subcutaneously injected with MPTP or the same volum of 0.9%NaCl,respective-ly.After the first injection for 72 hours,behavioral changes in mice were examined by the open field test.The levels of dopamine （DA）in nigro-striatal system was measured by a high performance liquid chromatography with electochemi-cal detector （HPLC-ECD）.The activities of superoxide dismutase 1 （SOD1 ）and the content of malondialdehyde （MDA）were detected by the spectrophotometer.The injuries of nigraldopamine system and striatal oxidative stress re-lated indexes were compared among mice at different ages.The expression of striatal oxidative stress related gene ex-pression in 10-month mice was detected by PCR Array.Results Compared with control group,the levels of DA and SOD 1 ,the performance in the open field test all decreased in MPTP group at three ages,while the content of MDA in tissue remarkably increased （P〈0.01 ）.Moreover,the above changes in 10-month mice were more obvious than 3-and 6-month mice （P〈0.05 ）.Compared with control group,the PCR Array results of MPTP group showed that COX-2 was up-regulated,while glutathione peroxidase 3,6 and 8,lactoperoxidase,nucleoredoxin,myoglobin,neuro-globin,peroxiredoxin 1 ,eosinophil peroxidase were all down-regulated （fold change〉2 ）.Conclusion Aging plays an important role in nigro-striatal system injury of PD model.Up-or down-regulation of oxidative stress related genes may participate in the early phase of PD.