摘要
目的 研究 3 硝基丙酸 (3 NPA)多次预处理对多巴胺能神经元的保护及即早基因N myc在其中的作用。方法 选择C5 7BL小鼠 ,应用 1 甲基 4 苯基 1,2 ,3,6 四氢吡啶 (1 methy 4 phenyl 1,2 ,3,6 tetrahydropyridine,MPTP)制造帕金森病小鼠模型 ,应用免疫组织化学方法观察 3 NPA单次与多次预处理后小鼠中脑黑质酪氨酸羟化酶 (TH)阳性细胞数量的改变 ;应用免疫组织化学及蛋白印迹 (WesternBlot)方法观察即早基因N myc在中脑黑质中的表达及蛋白水平的变化。 结果 3 NPA单次预处理后 ,中脑黑质酪氨酸羟化酶 (TH)阳性细胞数量由MPTP组的 2 7.3± 5 .6上升到 5 9.3± 11.2 (P <0 .0 5 ) ,而 3 NPA多次预处理后 ,阳性细胞数量上升至 88.6± 14 .8(P <0 .0 1) ,单次预处理与多次预处理也有显著性差异 (P <0 .0 5 ) ;在空白对照组 ,中脑黑质几乎看不见N myc阳性细胞 (4 .1± 0 .5 ) ,经MPTP处理后 ,N myc阳性细胞数量明显增加 (89.3± 12 .7,P <0 .0 1) ,蛋白水平增加 ;3 NPA单次预处理后 ,中脑黑质N myc阳性细胞数量与MPTP组比较无明显变化 (81.8± 13.6 ,P >0 .0 5 ) ;3 NPA多次预处理后 ,N myc阳性细胞数量明显减少 4 7.9± 11.8(P <0 .0 5 ) ,N myc蛋白水平也有相同的变化。 结论 3
Objective To investigate the neuroprotective effect of repetitive preconditioning with 3-nitropropionic acid (3-NPA) on dopaminergic neurons and the role of N-myc in it. Methods MPTP was administered to C57BL mouse to produce Parkinson disease model.The positive neuron of tyrosine hydroxylase (TH) in the midbrain substantia nigra was deteced by immunohistochemistry ;The immunohistochemistry and Western Blot were used to assay the expression and the level of protein of early gene N-myc. Results After single preconditioning with 3-NPA,the number of TH positive neurons increased from 27.3±5.6 (MPTP group) to 59.3±11.2 (P<0.05), while it was 88.6±14.8(P<0.01) after repetitive preconditioning with 3-NPA. The difference was significant between the single and repetitive preconditioning groups (P<0.05).The number of N-myc positive neurons of MPTP group was 89.3±12.7 (P<0.01), while it was (4.1)±0.5 of control group.There was no obvious change after single preconditioning with 3-NPA(81.8±13.6). However,the number of N-myc positive neurons of repetitive preconditioning group was 47.9±11.8((P<0.05).) Similar changes were found in the level of protein of N-myc. Conclusion 3-NPA preconditioning had the neuroprotective effect on the dopaminergic neurons, which was more of repetitive preconditioning than single preconditioning.The mechanism was probablely involved in depressing the expression of N-myc and decreasing the protein of N-myc.
基金
国家自然科学基金资助项目[30170334]
