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

项目总结 年龄增长是阿尔茨海默病(AD)的唯一最重要的危险因素。尽管重新- 随着进展，尚不清楚衰老是如何导致AD和其他疾病的蛋白平衡受损的 神经退行性疾病。一个可能的因素是与年龄相关的溶酶体功能障碍。 溶酶体蛋白水解酶，也被称为组织蛋白酶，需要酸性的pH才能发挥最佳功能。 这种酸化可能会随着年龄的增长而逐渐受损，导致蛋白质降解受损。 基因和潜在的增强蛋白质聚集。尽管如此，人们对组织特异性却知之甚少。 溶酶体pH和组织蛋白酶功能的增龄调节。长期目标是审问 神经退行性疾病的基本病理生理基础，以设计合理的治疗方法。 本应用程序的总体目标是在线虫模型中利用系统生物学方法。 衰老和神经退化，以了解年龄和压力如何影响溶酶体酸化， 成分和活性。中心假设是年龄和压力相关的损害在 溶酶体功能以一种组织特异性的方式促进了阿尔茨海默病患者异常的蛋白质稳态 以及相关的疾病。这项工作的基本原理是通过系统地探测和操纵 溶酶体的组成和pH值，可以更好地理解溶酶体如何随着年龄、压力的变化而变化 和疾病。这可能会导致新的策略来改善治疗或治疗的蛋白质稳态 预防神经退行性疾病。核心假设将通过三个具体的 目的：1)阐明年龄和应激对组织特异性溶酶体pH(PHlys)和蛋白酶的影响 活性，2)通过分子图谱确定年龄相关溶酶体功能障碍的基础 来自特定组织的溶酶体，3)识别增强溶酶体的途径和分子 酸化。拟议的研究在概念上是创新的，因为它侧重于理解 溶酶体pH、成分和功能随增龄而发生的组织特异性变化 和压力。通过使用新的溶酶体pH和组织蛋白酶，它在方法上也是创新的 D生物传感器、线虫溶酶体分离新方法的开发和蛋白质组学的应用 用来计算模拟溶酶体pH的数据。这一贡献是显著的，因为与年龄有关 溶酶体功能是一个研究较少的领域，这些研究可能有助于更好地理解 进行性溶酶体功能障碍与神经退行性疾病的发病机制有关。

PROJECT SUMMARY Increased age is the single most important risk factor for Alzheimer’s Disease (AD). Despite re- cent progress, it remains unclear how aging leads to the impaired proteostasis seen in 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 degrada- tion 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.