关于MPTP诱导的小鼠帕金森病模型认知障碍及Tau蛋白磷酸化的研究

发布时间：2018-02-26 05:02

本文关键词： 帕金森病 MPTP 认知障碍帕金森病 MPTP tau蛋白磷酸化　出处：《华中科技大学》2014年博士论文　论文类型：学位论文

【摘要】：第一部分MPTP亚急性及慢性损伤PD小鼠模型认知障碍的研究目的：探讨MPTP亚急性损伤及慢性损伤PD小鼠模型的认知改变。方法：本研究分别用多次腹腔注射的MPTP亚急性损伤(25mg/kg*5天)和慢性损伤(25mg/kg*10次,3.5d/次)C57BL/6小鼠作为PD的动物模型,等量生理盐水腹腔注射作为对照,通过对多种神经行为学指标的动态观察,和认知功能指标的动态观察,探讨各模型的运动障碍和认知障碍,采用免疫组织化学方法了解MPTP导致的黑质致密部酪氨酸轻化酶(TH)阳性染色神经元的变化。结果：与对照组相比,亚急性损伤模型实验组小鼠爬杆试验和网格试验均异常,但是症状逐渐恢复,3w、7w时和对照组相比无明显意义；线索提示Morris水迷宫2w时潜伏期明显延长,避暗实验4w时潜伏期有明显延长,并持续存在；免疫组化显示,小鼠中脑黑质TH阳性细胞数下降,随时间延长逐渐恢复,2w时损伤小于50%。与对照组相比,慢性损伤模型实验组小鼠爬杆试验和网格试验均异常,持续至7w时；线索提示Morris水迷宫2w时潜伏期明显延长,避暗实验4w时潜伏期明显延长,并持续存在；免疫组化显示,小鼠中脑黑质TH阳性细胞数下降,随时间延长逐渐恢复,8w时损伤依然大于50%。结论：1、MPTP亚急性及慢性损伤PD小鼠模型,均出现运动障碍,亚急性模型运动障碍随时间延长恢复,慢性模型持续时间更长,和TH阳性细胞数变化一致。 2、MPTP亚急性及慢性损伤PD小鼠模型,均出现认知障碍。第二部分MPTP诱导的小鼠帕金森病认知障碍模型中Tau蛋白磷酸化的变化目的：观察MPTP诱导的亚急性和慢性小鼠帕金森病认知障碍模型中不同部位、不同时间Tau蛋白磷酸化的变化。方法：采用western blot方法测定两种模型中不同分组脑组织(纹状体、黑质、海马、前额叶皮质)总tau蛋白和磷酸化tau蛋白的变化。结果：在MPTP诱导的小鼠亚急性模型和慢性模型中,总tau蛋白水平没有明显变化,磷酸化tau (Ser262, Ser214, Ser396/404)蛋白的水平增加,Thr205位点tau蛋白磷酸化不明显；造模后1W两种模型中均是纹状体磷酸化水平最高；亚急性模型实验组小鼠前额叶皮质、海马、纹状体、黑质磷酸化水平在1W或2W磷酸化水平达到最高,随时间增加很快下降；慢性模型实验组黑质在造模后第1W磷酸化水平增长较少；纹状体区第1W增长较快,但是低于亚急性模型实验组；慢性模型实验组纹状体、黑质磷酸化水平在第1W或第2W达到最高水平；前额叶皮质、海马磷酸化水平缓慢增长,达到高峰时间晚于黑质和纹状体；总体磷酸化水平低于亚急性模型实验组,但是下降缓慢。结论：MPTP诱导的亚急性和慢性小鼠帕金森病认知障碍可能和磷酸化的tau蛋白有关。
[Abstract]:Part one: cognitive impairment in PD mice with subacute and chronic injury of MPTP. Objective: to investigate the cognitive changes of PD mice model with subacute and chronic injury of MPTP. Methods: in this study, MPTP subacute injury (25 mg / kg / kg for 5 days) and chronic injury (25 mg / kg / kg) were used as PD animal model, and normal saline was injected intraperitoneally as control. Based on the dynamic observation of various neurobehavioral indexes and cognitive function indexes, the motor and cognitive disorders of each model were discussed. Immunohistochemical method was used to investigate the changes of tyrosine light enzyme (THH) -positive neurons in the substantia nigra densification caused by MPTP. Results: compared with the control group, the Rod climbing test and grid test were abnormal in the subacute injury group, but there was no significant difference between the control group and the control group when the symptoms recovered gradually for 3 weeks, indicating that the latency of Morris water labyrinth was significantly prolonged at 2 weeks. The incubation period was significantly prolonged and continued to exist at 4 weeks after the dark avoidance test, and immunohistochemical staining showed that the number of th positive cells in the substantia nigra decreased, and the damage was less than 50 at 2 weeks after the gradual recovery of the cells in the substantia nigra of mice. Compared with the control group, the mice in the model group of chronic injury were abnormal in pole climbing test and grid test until 7 weeks, indicating that the latency of Morris water labyrinth was significantly prolonged at 2 weeks, and that of avoidance test was prolonged at 4 weeks. Immunohistochemical staining showed that the number of th positive cells in the substantia nigra decreased, and the damage was still greater than 50 at 8 weeks after recovery. Conclusion the subacute and chronic injuried PD mice models of MPTP have motor disorders. The motor disorders of subacute models recover with time, and the duration of chronic models is longer, which is consistent with the changes of th positive cells. 2 PD mice model with subacute and chronic injury of MPTP showed cognitive impairment. Part two changes of Tau protein phosphorylation in cognitive impairment model of Parkinson's disease in mice induced by MPTP. Aim: to observe the changes of Tau protein phosphorylation in subacute and chronic Parkinson's disease cognitive impairment models induced by MPTP. Methods: the changes of total tau protein and phosphorylated tau protein in different groups of brain tissues (striatum, substantia nigra, hippocampus, prefrontal cortex) were measured by western blot method. Results: in MPTP induced subacute model and chronic model, the level of total tau protein did not change significantly, but the level of phosphorylated tau ser262,214, Ser396 / 404) protein increased the phosphorylation of tau protein at Thr205 site. The phosphorylation level of prefrontal cortex, hippocampus, striatum and substantia nigra reached the highest at 1W or 2W in the subacute model group, and decreased rapidly with the increase of time. The level of phosphorylation in the substantia nigra of the chronic model group increased less at the 1st week after modeling, the first week in the striatum area increased more rapidly, but it was lower than that in the subacute model group, and the striatum of the chronic model experimental group increased more rapidly than the subacute model group. The level of phosphorylation in the substantia nigra reached its highest level at the first or second week, the phosphorylation level in the hippocampus of the prefrontal cortex increased slowly, reaching the peak time later than that of the substantia nigra and striatum, and the total phosphorylation level was lower than that in the subacute model group. But the decline is slow. Conclusion the cognitive impairment of subacute and chronic Parkinson's disease induced by 1: MPTP may be related to phosphorylated tau protein.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R742.5

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