C. elegans Model for Neurodegenerative Diseases of Aging

描述（由申请人提供）：蛋白质组的稳定性对所有生物合成过程的保真度至关重要，并对细胞的长期健康和生物体的寿命有显著贡献。虽然错误折叠蛋白质的表达是蛋白质生物合成所固有的，但受损蛋白质的积累已越来越被认为是衰老和年龄相关疾病的主要贡献者。我们已经表明，在应激和衰老过程中受损蛋白质的慢性表达对蛋白质稳态（蛋白质稳态）具有破坏性的后果，导致了一系列令人困惑的表型，影响了几乎所有的生物过程。这项资助的目的是了解衰老过程中蛋白质稳态失调的基础，以及这些事件如何增加疾病的风险。为了解决这个问题，我们将研究如何表达疾病相关的，亚稳态的，聚集倾向的蛋白质在C。elegans导致蛋白质稳定机制的崩溃，以及有效的细胞保护途径恢复其平衡的作用。这将在三个目标：1。衰老和疾病中蛋白质稳态的遗传学。我们将采取系统的方法来确定调控疾病相关的聚集倾向蛋白质的折叠稳定性的基因网络。这将通过在C. elegans中鉴定polyQ-扩增蛋白（雄激素受体、共济失调蛋白-3、亨廷顿蛋白、突变体SOD 1、A2和相关淀粉样蛋白ADan和ABri，以及酵母朊病毒（Sup 35））的蛋白质稳定网络。这些屏幕的比较分析将提供一个遗传基础，以确定共同的和不同的特点，每个聚集倾向的蛋白质，以及如何组成的蛋白质稳定网络反映折叠稳定性的每种蛋白质，2。衰老和疾病中蛋白质稳态的蛋白质组学。易聚集蛋白的老化和慢性表达干扰蛋白质稳态，这反过来又导致蛋白质损伤的进一步放大，因为其他亚稳态蛋白质错误折叠。我们提出了一个细胞生物学和蛋白质组学的方法相结合，以确定不稳定的蛋白质组是在面对老化和蛋白质毒性应激的风险，和3。蛋白质稳态崩溃的细胞机制。我们的研究结果表明，受损的非天然蛋白隔离分子伴侣，随着时间的推移，导致伴侣依赖的细胞过程失调。由于分子伴侣在细胞浓度和细胞和组织类型之间变化，我们提出分子伴侣隔离是细胞功能障碍和组织病理学的一个促成因素，并提出了一种恢复年轻蛋白质稳定状态的方法。 公共卫生相关性：蛋白质组的稳定性对细胞的健康和生物体的寿命至关重要。蛋白质损伤及其对蛋白质生物合成的影响越来越被认为是衰老和年龄相关疾病的重要因素。这里提出的研究是确定保护细胞免受错误折叠蛋白质压力的蛋白质稳态网络，确定蛋白质损伤如何干扰健康的蛋白质稳态和细胞功能，并激活应激反应途径以恢复蛋白质组。认识到与年龄相关的蛋白质稳态失衡是疾病的一个突出贡献者，为疾病管理提供了一种新的方法，该方法优先考虑所有错误折叠和受损蛋白质共同的早期分子事件，而不管受影响的组织如何。

DESCRIPTION (provided by applicant): The stability of the proteome is of central importance to the fidelity of all biosynthetic processes, and contributes significantly to the long-term health of the cell and the lifespan of the organism. While the expression of misfolded proteins is intrinsic to protein biogenesis, the accumulation of damaged proteins has become increasingly recognized as a prominent contributor to aging and age-associated disease. We have shown that chronic expression of damaged proteins in response to stress and aging has devastating consequences on protein homeostasis (proteostasis), resulting in a bewildering collection of phenotypes affecting nearly all biological processes. The aims of this grant are to understand the basis of proteostasis dysregulation during aging, and how these events enhance the risk of disease. To address this, we will examine how the expression of disease associated, metastable, aggregation-prone proteins in C. elegans leads to the collapse of the proteostasis machinery, and the role of potent cytoprotective pathways to restore its balance. This will be presented in three aims: 1. The genetics of proteostasis in aging and disease. We will take a systems approach to identify the gene networks that regulate the folding stability of disease associated aggregation-prone proteins. This will be accomplished by genome-wide RNAi screens in C. elegans to identify the proteostasis network for polyQ-expansion proteins (Androgen Receptor, Ataxin-3, Huntingtin, mutant SOD1, A2 and related amyloidogenic proteins ADan and ABri, and yeast prions (Sup35). Comparative analysis of these screens will provide a genetic basis to identify common and distinct features of each aggregation-prone protein and how the composition of the proteostasis network reflects the folding stability of each protein, 2. The proteomics of proteostasis in aging and disease. Aging and chronic expression of aggregation-prone proteins interfere with proteostasis, which in turn leads to a further amplification of protein damage as other metastable proteins misfold. We propose a combination of cell biological and proteomic approaches to identify the unstable proteome that is at risk in the face of aging and proteotoxic stress, and 3. Cellular mechanisms of proteostasis collapse. Our results suggest that damaged non-native proteins sequester molecular chaperones, which over time, results in the dysregulation of chaperone-dependent cellular processes. As chaperones vary in cellular concentration and among cell and tissue types, we propose that chaperone sequestration is a contributing factor to cellular dysfunction and tissue pathology and suggest an approach to restore the youthful proteostatic state. PUBLIC HEALTH RELEVANCE: The stability of the proteome is central to the health of the cell, and lifespan of the organism. Protein damage and its consequence to protein biogenesis are increasingly recognized as a prominent contributor to aging and age-associated disease. The research proposed here is to identify the proteostasis network that protects the cell against the stress of misfolded proteins, establish how protein damage interferes with healthy proteostasis and cellular function, and to activate stress responsive pathways to restore the proteome. The recognition that age-associated imbalance in proteostasis is a prominent contributor to disease offers a new approach for disease management that places a priority on early molecular events common to all misfolded and damaged proteins regardless of the affected tissue.