【作者】 颉宾芳；

【导师】 刘昕；

【作者基本信息】 兰州大学 ， 病理学与病理生理学， 2012， 硕士

【摘要】 目的：复制阿尔茨海默病动物模型,观察其大脑皮层和海马区脑组织中甲状腺素受体THR α1的表达与阿尔茨海默病发生的相关性,并从THRα1表达增加对神经细胞tau蛋白磷酸化影响的角度对其机制进行初步探讨。方法：SD大鼠腹腔注射D-半乳糖50mg·kg-1·d-1,复制阿尔茨海默病动物模型,另设正常对照组,腹腔注射等量生理盐水。连续给药6w后观察观察动物一般情况如精神状态、活动情况、皮毛等；经二次固定法固定后取全脑组织制作病理切片,进行HE染色和改良Bicschowsky染色,用以观察大脑皮层及海马组织中老年斑,神经元纤维缠结及神经元数量、体积、排列状况等形态学变化；分别用实时荧光定量PCR (Real time fluorescence quantitation PCR, FQ-PCR)法和Western blot法检测阿尔茨海默病动物与正常大鼠脑组织中THRα1、CDK-5及p35mRNA的差异性表达和pser404-tau蛋白的表达水平。结果：与正常对照组相比,阿尔茨海默病模型组动物神情呆滞，反应迟钝,撮毛等；镜下见大脑皮层及海马区神经元排列紊乱、层次减少,核呈固缩、深染状,神经元轴突染色较深呈拖尾状,形成神经元纤维缠结,尤以海马区表现更为显著。与对照组相比,模型组皮层区THRα1、CDK-5和p35mRNA表达量增加,分别为1.20±0.30、4.71±0.54、2.11±0.40,差异有统计学意义(P<0.05)；模型组海马区三者的表达量分别为2.53±0.65、18.51±2.77、5.96±0.49,与对照组相比亦有统计学差异(P<0.05)模型组pser404-tau蛋白呈高表达状态,与正常对照组相比P<0.05。结论：阿尔茨海默病动物大脑皮层及海马区神经细胞中THRα1mRNA的表达量显著高于正常对照组大鼠,过高THRα1可提高tau蛋白磷酸化相关激酶CDK-5mRNA及其调节因子p35mRNA的表达水平,进而加剧神经细胞tau蛋白磷酸化,导致动物大脑皮层及海马区出现神经元丢失、神经纤维缠结等典型的AD形态学变化,这可能是THRα1过表达导致阿尔茨海默病发生的主要机制之一。更多还原

【Abstract】 Objective:To study the correlation between Alzheimer’s disease (AD) and the expression of thyroid receptor al (THR al) in brain tissues by establishing a rat model of AD, and therefore to investigate its mechanism primarily from the angle of phosphorylation of protein tau aggravated by the over-expression of THR al.Methods:D-galactose (50mg·kg-1·d-1) was administered by intraperitoneal injection into SD rats from AD group, while equal amount of saline into that from control group. After six weeks’ administration,these rats were observed mental state, activities, etc. Tissues from the whole brain were made into pathological sections by the secondary fixed, whose morphological changes were then observed under optical microscope. The differential expression of mRNA encoding THR al, CDK-5, p35and that of protein pser404-tau were determined using real time fluorescence quantitative PCR and Western-blot respectively.Results:Compared with control group, AD rats were dull appearance and slow reaction., the neurons of cerebral cortex and hippocampus in particular from AD group were disorganized, with their nuclei hyperchromatic、pyknosis, their axons hyperchromatic, trailing, and formed the neurons fiber tangles.The amount of expression of THRα1、CDK-5and p35mRNA increased, were1.20±0.30、4.71±0.54、2.11±0.40with statistical significance(P<0.05); while in the same time, in hippocampal, the amount of expression of them were2.53±0.65、18.51±2.77、5.96±0.49respectively with statistical significance (P<0.05)。And the amount of pser404-tau protein is significantly higher than that of the rats in the control group(P<0.05).Conclusion:The expression of mRNA encoding THR al in neurons of cerebral cortex and hippocampus from AD group is significantly higher than control group. Over-expression of THR al can increase the expression of mRNA encoding protein phosphorylation related kinase, namely CDK-5. And it in turn aggravates the phosphorylation of protein tau in neurons, which may participate or contribute to the pathological process of AD.更多还原