Modulation of Amyloid-Beta Aggregation in the Endosomal/Lysosomal Pathway

内体/溶酶体途径中淀粉样蛋白-β 聚集的调节

• 批准号: 8453848
• 负责人: Scott L Crick
• 金额: $ 4.71万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8453848
• 关键词: Alzheimer' s Disease; American; Amyloid; Appearance; Atomic Force Microscopy; Biochemical; Biological; Biological Assay; Brain; Cathepsins B; Cells; Cellular biology; Cerebrospinal Fluid; Characteristics; Chemicals; Data; Deposition; Development; Disease; Endocytosis; Endosomes; Energy Transfer; Environment; Environmental Risk Factor; Equilibrium; Extracellular Space; Family; Fluorescence; Fluorescence Spectroscopy; Fractionation; Genetic; Goals; In Vitro; Intercellular Fluid; Lead; Location; Lysosomes; Maintenance; Measurement; Measures; Methods; Microscopic; Microscopy; Mutation; Nerve Degeneration; Neurons; Pathogenesis; Pathway interactions; Peptide Hydrolases; Peptides; Phase; Play; Presenile Alzheimer Dementia; Proteins; Quality Control; Role; Route; Senile Plaques; Solutions; Specificity; Staging; Testing; Time; Toxic effect; Vesicle; Work; abeta accumulation; amyloid formation; amyloid pathology; brain tissue; extracellular; in vivo; insight; late endosome; mutant; novel; prion-like; protein aggregate; public health relevance; research study; tool; trafficking; uptake; Alzheimer' s Disease; American; Amyloid; Appearance; Atomic Force Microscopy; Biochemical; Biological; Biological Assay; Brain; Cathepsins B; Cells; Cellular biology; Cerebrospinal Fluid; Characteristics; Chemicals; Data; Deposition; Development; Disease; Endocytosis; Endosomes; Energy Transfer; Environment; Environmental Risk Factor; Equilibrium; Extracellular Space; Family; Fluorescence; Fluorescence Spectroscopy; Fractionation; Genetic; Goals; In Vitro; Intercellular Fluid; Lead; Location; Lysosomes; Maintenance; Measurement; Measures; Methods; Microscopic; Microscopy; Mutation; Nerve Degeneration; Neurons; Pathogenesis; Pathway interactions; Peptide Hydrolases; Peptides; Phase; Play; Presenile Alzheimer Dementia; Proteins; Quality Control; Role; Route; Senile Plaques; Solutions; Specificity; Staging; Testing; Time; Toxic effect; Vesicle; Work; abeta accumulation; amyloid formation; amyloid pathology; brain tissue; extracellular; in vivo; insight; late endosome; mutant; novel; prion-like; protein aggregate; public health relevance; research study; tool; trafficking; uptake

DESCRIPTION (provided by applicant): The goal of this project is to investigate a potential mechanism by which amyloid-¿ peptides (A¿) form aggregates in the brain. This is directly relevant to the pathogenesis of Alzheimer's disease (AD). In vitro studies have shown that A¿ forms aggregates only at concentrations that are more than one thousand times higher than those measured in cerebrospinal fluid and in brain tissue. Even so, A¿ plaque formation is characteristic for AD and genetic evidence demonstrates that mutations that increase A¿ aggregation propensity lead to early onset AD. This apparent contradiction suggests that there must either be: 1) high local concentrations of A¿ somewhere in the brain, or 2) cellular and/or biochemical mechanisms which lower the concentration required for A¿ to aggregate. Growing evidence suggests that A¿ can accumulate in intraneuronal vesicles well before the first appearance of amyloid plaques. Our preliminary data suggest that A¿ can be endocytosed and trafficked through the endo/lysosomal pathway. Moreover, we have found that A¿ is concentrated in late endo/lysosomes to levels that would support A¿ aggregation. This occurs even when low, physiologically relevant concentrations of A¿ are added to the outside of the cell. Also, we know that certain features of the endo/lysosomal environment, such as low pH, favor A¿ aggregation. This makes the endo/lysosomal pathway particularly attractive for nascent A¿ aggregate formation in vivo. The hypothesis to be tested in this work is that the earliest stages of A¿ aggregation in vivo occur within neural cells during endo/lysosome maturation. In this proposal, we will investigate A¿ uptake from the extracellular space and the effect of trafficking along the endo/lysosomal pathway on its aggregation state. We will use modern fluorescence spectroscopic and microscopic methods to develop a detailed time course of the uptake, trafficking, and aggregation of A¿ along the endo/lysosomal pathway. These experiments will be combined with modern cell biology tools to interrogate how specific environmental factors of the endo/lysosomal pathway contribute to the aggregation of A¿. We speculate that endocytosis and trafficking of A¿ along the endo/lysosomal pathway represents a normal pathway for quality control and maintenance of extracellular A¿ levels. However, characteristics of the endo/lysosomal environment, such as low pH and locally high protein concentrations, favor A¿ aggregation. It is quite possible that the balance between A¿ aggregation and degradation along the endo/lysosomal pathway is a critical determinant in AD pathogenesis.

描述（由应用程序提供）：该项目的目的是研究一种潜在的机制，淀粉样蛋白肽（a¿）形成大脑中的聚集体。这与阿尔茨海默氏病（AD）的发病机理直接相关。体外研究表明，A形式仅在浓度的浓度比脑脊髓液和脑组织中测得的浓度高一千倍以上。即便如此，A斑块的形成也是AD的特征，遗传证据表明，增加A聚集的突变会导致AD早期发作。这种明显的矛盾表明必须存在：1）大脑中某个地方的高局部浓度，或2）细胞和/或生化机制，这些机制降低了A聚集所需的浓度。越来越多的证据表明，在首次出现淀粉样蛋白斑块之前，a可以在神经元囊泡中积聚。我们的初步数据表明，可以通过内部/溶酶体途径进行内吞和运输。此外，我们发现a已集中在晚期/溶酶体上，以支持A聚集的水平。即使在细胞的外部添加了a检验的低，物理相关的浓度，也会发生这种情况。另外，我们知道内托/溶酶体环境的某些特征，例如低pH值，有利于A聚集。这使得内鼠/溶酶体途径对体内的新生骨形成特别有吸引力。在这项工作中要检验的假设是，体内A聚集的最早阶段发生在内部/溶酶体成熟期间神经细胞内。在此提案中，我们将研究细胞外空间的吸收以及沿着内托/溶酶体途径对其聚集状态的贩运的影响。我们将使用现代的荧光光谱和微观方法来开发沿着沿着内部/溶酶体途径的A级吸收，运输和聚集的详细时间过程。这些实验将与现代细胞生物学工具相结合，以询问内部/溶酶体途径的特定环境因素如何有助于A？的聚集。我们推测，沿着溶酶体途径的A域内吞和运输是质量控制和维持细胞外A水平的正常途径。然而，内部/溶酶体环境（例如低pH值和局部较高蛋白质浓度）的特征有利于聚集。沿着溶酶体途径的聚集和降解之间的平衡很有可能是AD发病机理中的关键决定因素。