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

项目摘要 年龄增长是阿尔茨海默病（AD）的最重要的风险因素。尽管重新- 尽管进展缓慢，但仍不清楚衰老是如何导致AD和其他疾病中蛋白质稳态受损的。 神经退行性疾病一个可能的贡献者是年龄相关的溶酶体功能障碍。 溶酶体蛋白酶，也称为组织蛋白酶，需要酸性pH值才能发挥最佳功能。 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。 并可能增强蛋白质聚集。尽管如此，对组织特异性 溶酶体pH和组织蛋白酶功能随年龄的调节。长期目标是审问 神经退行性疾病的基本病理生理学基础，以设计合理的治疗方法。 这个应用程序的总体目标是利用系统生物学方法在C。elegans模型 衰老和神经退行性变，以了解年龄和压力如何影响溶酶体酸化， 成分和活动。中心假设是，年龄和压力相关的损伤， 溶酶体功能以组织特异性方式促进AD中所见的异常蛋白质稳态 和相关疾病。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，可以更好地了解溶酶体如何随着年龄，压力 和疾病这可能会导致新的策略，以改善蛋白质稳态的治疗或 预防神经退行性疾病。中心假设将通过三个具体的测试 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）通过以下的分子谱确定年龄相关的溶酶体功能障碍的基础： 3）识别增强溶酶体活性的途径和分子， 酸化所提出的研究在概念上是创新的，因为它的重点是理解 随着年龄的增长，溶酶体pH、成分和功能发生组织特异性变化 和压力它还通过使用新的溶酶体pH和组织蛋白酶在方法上进行了创新 D生物传感器，建立了一种新的C.蛋白质组学的应用 这一贡献是重要的，因为年龄相关的 溶酶体功能是一个未充分研究的领域，这些研究可能会导致更好地了解如何 进行性溶酶体功能障碍有助于神经变性疾病的发病机制。

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.