Structural Identification and Functional Consequences of Different Amyloid Strains in Alzheimer's Disease

阿尔茨海默病与衰老过程中大脑中淀粉样蛋白的沉积有关。自.以来 淀粉样蛋白的形成与阿尔茨海默病的关系最初被认为是存在的 疾病可能采取的许多亚型和形式。例如，淀粉样蛋白β-蛋白(Aβ)的积累 脑实质是阿尔茨海默病(AD)的标志。尽管如此，还是有一个穷人 了解淀粉样蛋白形成的原因，目前尚不清楚是否存在独特的结构基序 促进导致痴呆症的明显病理后果。这项提议的重点是填补这一点 严重的知识空白。因此，这一提议的总体假设是Aβ肽形成 具有不同亚型的淀粉样蛋白有不同的结构，决定了它们的位置和病理。致信地址 在这一假设中，我们提出了两个具体目标。 首先，我们计划从迟发性阿尔茨海默病和早期阿尔茨海默病死亡后不同亚型的脑组织中分离淀粉样蛋白。 发病为家族性阿尔茨海默病。我们计划比较五种不同的淀粉样斑块亚型：典型AD、非典型AD、棉花 羊毛、早发性AD(EOAD)和极早发型AD(VEOAD)。后两个子类型与 家族性AD突变。可获得有关年龄和性别、发病年龄和病程的临床信息 疾病、病程和症状、用药情况和载脂蛋白E基因。在Eoad和VEOAD中 2例进行APP、PSEN1、PSEN2、tau基因检测。在大多数情况下，脑脊液中的生物标志物 而且神经成像结果也是可用的。分离的淀粉样蛋白将作为种子，使纤维生长成核 体外研究。原纤维的结构和多形性将通过互补结构进行评估 方法包括固体核磁共振光谱、傅里叶变换红外光谱、透射法 电子显微镜和原子力显微镜。 使用从五种不同亚型AD分离的淀粉样蛋白，我们将评估生物功能 使用三种方法对不同菌株的后果进行分析。首先，我们将评估两国之间的差异 用小胶质细胞培养法研究不同纤维形态引起的炎症反应和细胞毒性。第二，我们 将确定淀粉样品系对促进神经炎症的影响。第三，我们将确定 淀粉样蛋白菌株对大鼠脑内组装和繁殖的影响。 总体目标是将不同淀粉样蛋白亚型的病理(生物功能后果)联系起来 细胞培养、大鼠脑和人脑之间的关系，并将这些病理与特定的结构联系起来 与每个亚型中分离的淀粉样蛋白相关的Aβ纤维的特征。

Alzheimer's disease is associated with the deposition of amyloid in the brain during aging. Since the correlation between amyloid formation and AD was originally made, it has been recognized that there are many subtypes and forms that the disease can take. For example, accumulation of the amyloid β-protein (Aβ) in the brain parenchyma is the hallmark of Alzheimer's disease (AD). Nevertheless, there is a poor understanding as to why amyloid forms, and it is not known whether there are unique structural motifs that promote the distinct pathological consequences leading to dementia. The focus of this proposal is to fill this critical void in knowledge. Accordingly, the overall hypothesis of this proposal is that the Aβ peptides forming amyloid with distinct subtypes have distinct structures that determine their location and pathology. To address this hypothesis we propose two specific aims. First, we plan to isolate amyloid from different subtypes of post mortem brain tissue of late-onset AD and early- onset familial AD. We plan to compare five different amyloid plaque subtypes: typical AD, atypical AD, cotton wool, early-onset AD (EOAD) and very early-onset AD (VEOAD). The last two subtypes are associated with familial AD mutations. Clinical information is available concerning age and gender, age of onset and duration of disease, course and symptoms of the disease, medication and ApoE genotype. In the EOAD and VEOAD cases genetic testing was performed for APP, PSEN 1, PSEN2 and tau. For most cases, biomarkers in CSF and neuroimaging results are available. The isolated amyloid will serve as seeds to nucleate fibril growth for in vitro studies. The structure and polymorphism of the fibrils will be assessed by complementary structural approaches including solid-state NMR spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and atomic force microscopy. Using the amyloid isolated from the five different subtypes of AD, we will assess the biofunctional consequences of the different strains using three approaches. First, we will assess the differences in the inflammatory response and cell toxicity due to different fibril forms using microglial cell cultures. Second, we will determine the influence of amyloid strains on promoting neuroinflammation. Third, we will determine the influence of amyloid strains on assembly and propagation in rat brain. The overall objective is to correlate pathologies (biofunctional consequences) of different amyloid subtypes between cell culture, rat brain and human brain, and to relate these pathologies with specific structural characteristics of the Aβ fibrils that are associated with the isolated amyloid from each subtype.