Alzheimer Mouse Model for Intraneuronal Amyloid-Beta Oligomer Biology

项目摘要 最近，许多注意力转向了对所谓的“寡聚”形式的聚合物的研究。 淀粉样蛋白β肽（A？））可能是阿尔茨海默病痴呆的关键介质。我们 我选择利用荷兰A的倾向，形成低聚物是为了创造一个 转基因小鼠模型的生化病理学，神经病理学，和行为 Thy 1上荷兰APP过度表达导致神经源性A？寡聚体的病理学 启动子（Thyl-Dutch APPE 693 Q转基因小鼠系）。在初步表征这些 Thy 1-Dutch APPE 693 Q小鼠，我们观察到年龄依赖性认知下降， 可量化的神经病理学变化然而，在我们手中，Thy 1-APPE 693 Q小鼠从未 在其寿命期间发展任何种类的实质淀粉样蛋白沉积物;然而， 免疫可检测的A？寡聚体积累，这些寡聚体似乎定位于 神经元内体-溶酶体系统。为了生成A？组织病理学，我们必须 将Thy 1- Dutch APPE 693 Q小鼠与缺乏外显子的家族性阿尔茨海默病突变型早老素杂交 9（PS1 <$9）. PS1的这种致病性突变形式提高了A42的水平，从而导致 在双基因小鼠中形成噬斑（这些小鼠被命名为Thy 1-Dutch APPE 693 Q x PS1 <$9 bigenics）。然而，虽然突变PS1导致斑块形成，但淀粉样蛋白的出现 斑块对认知衰退的时间进程或初始严重程度没有明显影响。 总之，我们观察到：（1）神经元内APP/A <$衍生物在单个细胞中的积累， 荷兰APP转基因和双基因PS/APP小鼠;和（2）荷兰CAA的积累。为此 MERIT应用程序，我们建议对单个荷兰APP进行定量表征 转基因和双基因PS/APP小鼠，根据性别和在不同年龄， 寿命，使用（a）在Morris水迷宫中评估行为表现， （B）空间学习和记忆的抑制性回避模型; APP、<$CTFs和<$CTFs、A <$40、A <$42、A <$寡聚体和突触素;（c）亚细胞定位 APP-A？样免疫反应性，包括荷兰CAA;（d）定量形态测定， 确定海马神经元群体的完整性，并估计神经元内A？ 负担 低聚物损伤且从未发生淀粉样蛋白的小鼠品系的可用性 噬菌斑将极大地促进在寻找抗- 用于治疗阿尔茨海默病的寡聚体药物。

Project summary Recently, much attention has turned to the study of so-called "oligomeric" forms of the amyloid beta peptide (A¿)) as possible key mediators of dementia in Alzheimer's disease. We have chosen to exploit the propensity of Dutch A¿ to form oligomers is order to create a transgenic mouse model of the biochemical pathology, neuropathology, and behavioral pathology of neuronally-derived A¿ oligomers by overexpressing Dutch APP on the Thy1 promoter (Thy1-Dutch APPE693Q transgenic mouse line). In preliminary characterization of these Thy1-Dutch APPE693Q mice, we have observed aging-dependent cognitive decline and a number of quantifiable neuropathological changes. However, in our hands, Thy1-APPE693Q mice never develop parenchymal amyloid deposits of any sort during their lifespan; however, immunodetectable A¿ oligomers accumulate, and these oligomers appear to be localized to the neuronal endosomal-lysosomal system. In order to generate A¿ histopathology, we have crossed the Thy1- Dutch APPE693Q mice with familial Alzheimer's mutant presenilin lacking exon 9 (PS1¿9). This pathogenic mutant form of PS1 elevates levels of A¿42, thereby causing plaques to form in bigenic mice (these mice are designated Thy1-Dutch APPE693Q x PS1¿9 bigenics). However, while the mutant PS1 causes plaques to form, the appearance of amyloid plaques has no obvious effect on the time course or initial severity of cognitive decline. In summary, we observe: (1) accumulation of intraneuronal APP/A¿ derivatives in single Dutch APP transgenic and bigenic PS/APP mice; and (2) accumulation of Dutch CAA. For this MERIT application, we propose to perform quantitative characterization of single Dutch APP transgenic and bigenic PS/APP mice, according to gender and at various ages over their lifespans, using (a) Assessment of behavioral performance in the Morris water maze and inhibitory avoidance models of spatial learning and memory; (b) Quantification of brain levels of APP, ¿ and ¿ CTFs, A¿40, A¿42, A¿ oligomers, and synaptophysin; (c) Subcellular localization of APP-A¿-like immunoreactivity, including Dutch CAA; (d) Quantitative morphometry to determine integrity of hippocampal neuronal populations and to estimate intraneuronal A¿ burden. The availability of lines of mice that are impaired by oligomers and never develop amyloid plaques would greatly facilitate the construction of in vivo efficacy screens in the search for anti- oligomer drugs for the treatment of Alzheimer's disease.