Systematic profiling of lysosomes with age to improve proteostasis in Alzheimer's

项目摘要 尽管最近取得了进展，但仍不清楚衰老是如何导致蛋白稳态受损的， 阿尔茨海默病（AD）和其他神经退行性疾病。一个可能的因素是年龄- 溶酶体功能的相关损伤。溶酶体蛋白酶，也称为组织蛋白酶，需要一个酶的作用。 酸性pH值，以便最佳地发挥作用。这种酸化可能随着年龄的增长而逐渐受损， 导致蛋白质降解受损和潜在的蛋白质聚集增强。尽管如此， 关于溶酶体pH和组织蛋白酶功能随年龄的组织特异性调节知之甚少。的 长期目标是探究神经退行性疾病的基本病理生理学基础， 设计合理的治疗方法。本申请的总体目标是利用系统 生物学方法在C. elegans衰老和神经退化模型，以了解年龄和 应激影响溶酶体酸化、组分和活性。核心假设是年龄和 应激相关的溶酶体功能损伤以组织特异性的方式导致异常的 在AD和相关疾病中观察到的蛋白质稳态。这项工作的基本原理是，通过 系统的探测和操纵溶酶体成分和pH值，可以更好地了解如何 溶酶体随着年龄、压力和疾病而变化。这可能会导致新的战略，以改善 用于治疗或预防神经变性疾病的蛋白质体内平衡。中央 假设将通过三个具体目标进行检验：1）阐明年龄和压力对 组织特异性溶酶体pH值（pHlys）和蛋白酶活性，2）确定年龄相关的基础 通过来自特定组织的溶酶体的分子谱分析的溶酶体功能障碍，3）识别途径 和增强溶酶体酸化的分子。所提出的研究在概念上是创新的 由于其重点是了解溶酶体pH值，成分和 随着年龄的增长和压力的增加而发生的功能。它也是方法创新，通过其使用 一种新的溶酶体pH和组织蛋白酶D生物传感器， 分离于C.和使用蛋白质组学数据来计算模拟溶酶体pH。这 贡献是重要的，因为年龄相关的溶酶体功能是一个研究不足的领域，这些 研究可能会更好地理解进行性溶酶体功能障碍如何有助于 神经退行性疾病的发病机制。

PROJECT SUMMARY Despite recent progress, it remains unclear how aging leads to the impaired proteostasis seen in Alzheimer's Disease (AD) and other neurodegenerative disorders. One possible contributor is age- related impairments in lysosome function. Lysosomal proteases, also known as cathepsins, require an acidic pH in order to function optimally. This acidification may become progressively impaired with age, resulting in impaired protein degradation and potentially enhanced protein aggregation. Despite this, little is known about tissue-specific regulation of lysosomal pH and cathepsin function with age. The long-term goal is to interrogate the basic pathophysiological underpinning of neurodegenerative disease to design rational therapeutics. The overall objective of this application is to utilize systems biology approaches in C. elegans models of aging and neurodegeneration to understand how age and stress affect lysosomal acidification, constituents and activity. The central hypothesis is that age and stress-associated impairments in lysosome function contribute, in a tissue-specific way, to the aberrant protein homeostasis seen in AD and related disorders. The rationale for this work is that through systematic probing and manipulation of lysosomal constituents and pH, one can better understand how the lysosome changes with age, stress and disease. This could lead to new strategies to improve protein homeostasis for treatment or prevention of neurodegenerative diseases. The central hypothesis will be tested through three specific aims: 1) Elucidate the effects of age and stress upon tissue-specific lysosomal pH (pHlys) and protease activity, 2) Determine the basis for age-related lysosome dysfunction via molecular profiling of lysosomes from specific tissues, 3) Identify pathways and molecules that enhance lysosomal acidification. The proposed research is conceptually innovative because of its focus on understanding the tissue-specific changes in lysosomal pH, constituents and function that occur with increasing age and stress. It is also methodologically innovative through its use of a new lysosomal pH and cathepsin D biosensors, development of a new method for lysosome isolation in C. elegans and use of proteomic data to computationally model lysosomal pH. This contribution is significant because age-related lysosome function is an understudied area and these studies could lead to better understanding of how progressive lysosome dysfunction contributes to neurodegenerative disease pathogenesis.