AUTOPHAGY FUNCTION & DYSFUNCTION IN ALZHEIMER'S DISEASE

自噬是细胞降解受损细胞器和细胞质，保护自身免受蛋白酶体无法降解的有毒蛋白聚集体侵害的主要机制。我们将探讨揭示阿尔茨海默病（AD）自噬诱导和损伤的新线索，确定其在β生成中的作用，并显示早老素（PS1）在自噬功能中的要求。我们将在人脑和FAD成纤维细胞、细胞系和AD病理小鼠模型中研究AD自噬受损的假设（目的1和2）。标记自噬途径和其他细胞器的特定区室的新型抗体将用于双免疫荧光和超微结构研究（包括免疫金），以及其他最先进的技术，以确定自噬途径的性质和意义

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.