AUTOPHAGY FUNCTION & DYSFUNCTION IN ALZHEIMER'S DISEASE

自噬功能

• 批准号: 6920487
• 负责人: RALPH A. NIXON
• 金额: $ 34.01万
• 依托单位: NATHAN S. KLINE INSTITUTE FOR PSYCH RES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6920487
• 关键词: Alzheimer' s disease; Downs syndrome; RNA interference; amyloid proteins; aspartic endopeptidases; autophagy; cell line; cellular pathology; endocytosis; enzyme activity; fibroblasts; gene deletion mutation; gene mutation; genetically modified animals; green fluorescent proteins; immunoelectron microscopy; immunofluorescence technique; laboratory mouse; lysosomes; molecular pathology; neurons; neuropathology; neuroprotectants; presenilin; protein degradation

Autophagy is the cell's primary mechanism to degrade damaged organelles and cytoplasm and to protect itself from toxic protein aggregates not degradable by the proteasome. We will address new leads revealing induction and impairment of autophagy in Alzheimer's Disease (AD), identifying its role in Abeta generation, and showing for a requirement for presenilin (PS1) in autophagy function. The hypothesis that autophagy is impaired in AD will be investigated in human brain and FAD fibroblasts, cell lines, and mouse models of AD pathology (Aims 1 and 2). Novel antibodies marking specific compartments of the autophagic pathway and other organelles will be used in double-immunofluorescence and ultrastructural studies (including immunogold), along with other state-of-the-art techniques, to define the nature and significance of autophagy dysfunction in AD. The roles of PS1, PS2, and g-secretase activity in modulating autophagy will be determined and the basis for the observed selective impairment in autophagy-mediated protein degradation caused by FAD-related PS1 mutations will be investigated (Aim 2). We will also investigate the basis for distinctive autophagy abnormalities in Trisomy 21 (Down syndrome) and test the hypothesis that FAD-related APP mutations (Aim 3) also impair autophagy. Autophagy as a neuroprotective mechanism will be studied in primary neurons from normal mice, AD mouse models, and a novel transgenic mouse expressing GFP-tagged LC3, a protein associated with autophagy induction, which will enable real-time visualization of autophagy and will facilitate in vivo studies of autophagy modulation (Aim 4). As a prelude to modulating autophagy as a therapeutic intervention in neurodegenerative disease, we will investigate strategies to manipulate autophagy in the brain in vivo (Aim 4). These ongoing studies, the first to investigate autophagy systematically in AD, will provide a comprehensive assessment of the impact of autophagy and autophagy dysfunction and identify novel approaches to treat proteinopathies, including AD.

自噬是细胞降解受损细胞器和细胞质并保护自身免受蛋白酶体不可降解的有毒蛋白质聚集体的主要机制。我们将探讨揭示阿尔茨海默病 (AD) 中自噬的诱导和损伤的新线索，确定其在 Abeta 生成中的作用，并表明自噬功能需要早老素 (PS1)。 AD 中自噬受损的假设将在人脑和 FAD 成纤维细胞、细胞系和 AD 病理学小鼠模型中进行研究（目标 1 和 2）。标记自噬途径和其他细胞器特定区室的新型抗体将与其他最先进的技术一起用于双免疫荧光和超微结构研究（包括免疫金），以定义自噬途径的性质和意义 AD 中的自噬功能障碍。将确定 PS1、PS2 和 g 分泌酶活性在调节自噬中的作用，并研究观察到的由 FAD 相关 PS1 突变引起的自噬介导的蛋白质降解选择性损伤的基础（目标 2）。我们还将研究 21 三体（唐氏综合症）中独特的自噬异常的基础，并检验 FAD 相关 APP 突变（目标 3）也会损害自噬的假设。自噬作为一种神经保护机制将在正常小鼠、AD小鼠模型和表达 GFP 标记的 LC3 的新型转基因小鼠中进行研究，LC3 是一种与自噬诱导相关的蛋白质，这将能够实现实时 自噬可视化并将促进自噬调节的体内研究（目标 4）。作为调节自噬作为神经退行性疾病治疗干预的前奏，我们将研究在体内操纵大脑自噬的策略（目标 4）。这些正在进行的研究首次系统地研究了 AD 中的自噬，将对自噬和自噬功能障碍的影响进行全面评估，并确定治疗包括 AD 在内的蛋白质病的新方法。