Transgenic C. elegans as Amyloid Disease Model

描述（由申请人提供）：虽然有令人信服的证据表明，淀粉样肽（A）是中央参与阿尔茨海默氏病的病理，A毒性的机制及其具体目标仍然没有解决。 该项目是我们研究的延续，使用深入研究的线虫秀丽隐杆线虫作为模型，以调查（人类）A？毒性的基础。 我们先前已经表明，转基因蠕虫工程表达人类A1 -42，复制阿尔茨海默病病理的某些方面。 通过分子和遗传方法的结合，我们现在已经确定了一组保守的基因，调节这些转基因蠕虫模型中的A？毒性。 此外，对表达单一氨基酸变体的转基因蠕虫的分析已经导致鉴定出在体内基本上无毒的A？变体。 本提案的目标是综合这些发现以确定：1）有毒A ²物种的身份，2）影响有毒物种形成的细胞途径，以及3）A ²的特定细胞靶点。 本提案的具体目的是：1）通过构建和表征表达变体A？肽的转基因蠕虫，进行A？毒性的体内结构/功能分析。 这些研究将直接测试“毒性A <$寡聚体”模型，2）确定进化上保守的修饰基因改变A <$毒性的分子机制，3）验证我们使用哺乳动物细胞培养物和原代神经元培养物鉴定的A <$毒性和保护基因的拟议机制。 我们提出的研究对阿尔茨海默病的诊断和治疗有直接的相关性。 确定A？的关键毒性形式对于设计防止其形成或毒性活性的药物可能至关重要。 表征影响A？毒性的基因可能对风险评估和开发阿尔茨海默病和其他神经退行性疾病的有效干预措施都很重要。 公共卫生部门：有令人信服的证据表明，一种特定的蛋白质，即淀粉样肽的积累，是阿尔茨海默病中发现的大脑病理学的基础，在美国影响了大约500万人。 这项拟议中的研究旨在确定淀粉样肽毒性的细胞和分子基础。 了解这种蛋白质的毒性机制对于开发阿尔茨海默病的治疗方法至关重要。

DESCRIPTION (provided by applicant): Although there is compelling evidence that the ¿-amyloid peptide (A¿) is centrally involved in Alzheimer's disease pathology, the mechanisms of A¿ toxicity and its specific targets remain unresolved. This project is a continuation of our studies using the intensely studied nematode worm Caenorhabditis elegans as a model to investigate the basis of (human) A¿ toxicity. We have previously shown that transgenic worms engineered to express human A¿ 1-42, replicate some aspects of Alzheimer's disease pathology. By a combination of molecular and genetic approaches, we have now identified a set of conserved genes that modulate A¿ toxicity in these transgenic worm models. In addition, analysis of transgenic worms expressing single amino acid variants has led to the identification of an A¿ variant that is substantially non-toxic in vivo. The goal of this proposal is to synthesize these findings to establish: 1) the identity of the toxic A¿ species, 2) the cellular pathways that influence the formation of the toxic species, and 3) the specific cellular targets of A¿. The Specific Aims of this proposal are to: 1) perform an in vivo structure/function analysis of A¿ toxicity by constructing and characterizing transgenic worms expressing variant A¿ peptides. These studies will directly test the "toxic A¿ oligomer" model, 2) determine the molecular mechanisms by which evolutionarily conserved modifier genes alter A¿ toxicity, and 3) validate the proposed mechanisms for both A¿ toxicity and the protective genes we have identified using mammalian cell culture and primary neuronal cultures. Our proposed studies have direct relevance for the diagnosis and treatment of Alzheimer's disease. The identity of the key toxic form(s) of A¿ may be critical for designing drugs that prevent its formation or toxic activity. Characterization of genes that affect the toxicity of A¿ may be important for both risk assessment and the development of effective interventions for Alzheimer's and other neurodegenerative diseases. PUBLIC HEALTH REVELANCE: There is compelling evidence that accumulation of a specific protein, the ¿- amyloid peptide, underlies the brain pathology found in Alzheimer's disease, which affects ~5,000,000 people in the US. The proposed study seeks to determine the cellular and molecular basis of ¿-amyloid peptide toxicity. Understanding the toxic mechanism of this protein make be critical for developing therapeutics for Alzheimer's disease.