TRANSGENIC C. ELEGANS AS AMYLOID DISEASE MODEL

该项目的目标是了解β-淀粉样肽（Abeta）毒性的细胞和分子基础。 这种肽作为不溶性淀粉样蛋白聚集体沉积在阿尔茨海默病（AD）患者脑中发现的老年斑中，并且被认为是这种疾病的病理学的中心。 将采用一种新的AD模型系统，其中深入研究的线虫线虫秀丽隐杆线虫被工程化以表达人Abeta肽。 这些转基因动物表达高水平的Abeta肽，这迅速导致淀粉样蛋白沉积物的形成和相关的毒性作用。 通过构建表达野生型和含有单个或多个氨基酸取代的变体Abeta的转基因动物，该模型系统将用于研究Abeta结构、聚集和毒性之间的关系。 将对这些动物进行淀粉样蛋白形成和Abeta毒性的已知标志物（如蛋白质的氧化损伤）测定。 这些动物的特征还包括完整的A β依赖性基因表达谱的检查，通过mRNA与DNA微阵列杂交来测定，所述DNA微阵列含有绝大多数C β的探针。elegans基因 该模式生物的遗传可及性还将允许通过分离和表征抑制Abeta肽的毒性作用的突变来鉴定直接参与Abeta毒性的基因。

The goal of this project is to understand the cellular and molecular basis of beta-amyloid peptide (Abeta) toxicity. This peptide is deposited as insoluble amyloid aggregates in the senile plaques found in the brains of Alzheimer's Disease (AD) patients, and is believed to be central to the pathology of this disease. A novel AD model system will be employed in which of the intensely studied nematode worm, Caenorhabditis elegans, is engineered to express human Abeta peptide. These transgenic animals express high levels of the Abeta peptide, which rapidly leads to the formation of amyloid deposits and associated toxic effects. This model system will be used to investigate the relationships between Abeta structure, aggregation, and toxicity by the construction of transgenic animals expressing wild-type and variant Abeta containing single or multiple amino acid substitutions. These animals will be assayed for amyloid formation and known markers of Abeta toxicity, such as oxidative damage to proteins. Characterization of these animals will also include examination of the complete Abeta-dependent gene expression profile, assayed by mRNA hybridization to DNA microarrays that contain probes for the vast majority of C. elegans genes. The genetic accessibility of this model organism will also allow the identification of genes directly involved in Abeta toxicity, by the isolation and characterization of mutations that suppress the toxic effects of the Abeta peptide.