Protection by Induction of Ubiquitin-Proteasome Systems

泛素-蛋白酶体系统的诱导保护

• 批准号: 6938473
• 负责人: THOMAS W KENSLER
• 金额: $ 16.55万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6938473
• 关键词: aging; animal tissue; cell age; cell line; conformation; cytoprotection; dithiol; embryo /fetus; genetic regulation; genetically modified animals; hazardous substances; immunocytochemistry; laboratory mouse; neural degeneration; neurogenetics; neuropharmacology; oxidative stress; proteasome; protein structure function; proteolysis; sulfur aminoacid; transcription factor; ubiquitin

DESCRIPTION (provided by applicant): Damaged proteins and their aggregated products are formed during oxidative stress and aging. 26S proteasomes can recognize and remove these damaged and unfolded proteins; moreover, decreased function of the ubiquitin-proteasome system is associated with the development of age-related degenerative diseases. It is our hypothesis that maintenance or enhancement of ubiquitin-proteasome function is a novel strategy to prevent or attenuate these age-related diseases. Our preliminary results indicate that dithiolethiones, which protect against the toxicities of environmental agents by stimulating expression of the downstream genes of the Nrf2 signaling pathway, increase expression of multiple subunits of 26S proteasomes and ubiquitinating enzymes in mouse liver. This proposal is designed to a) evaluate the physiological benefit of induced proteasome expression in cells following challenge by toxicants, b) determine the impact of inducible proteasome expression and the role of Nrf2 on the accumulation of damaged proteins in young and senescence murine fibroblasts as a model of aging, c) characterize inducible patterns and levels of proteasome expression in murine tissues, especially in the brain, following dithiolethione-treatment. Functional effects of enhanced proteasome induction will be initially investigated in cultured cells using murine embryonic fibroblasts and neuroblastoma cells. Measures of proteasome levels, proteolytic activities, protein turnover rates and accumulation of damaged proteins following chemical challenge will be compared in cell models in which proteasome expression is elevated by pharmacological intervention and through molecular genetic expression of specific proteasome subunits. The role of Nrf2 in these protective effects will be examined using nrf2-disrupted or inhibited cells as well as by comparisons in wild-type and nrf2-deficient mice of different ages. Collectively, these studies will explore the possible protective role of enhanced proteasome expression against exogenous toxic chemicals and degenerative processes that accompany aging. The long-term goal of this project is to rigorously evaluate the concept that increased expression of ubiquitin-proteasomes pathway through activation of the Nrf2 signaling cascade can prevent or retard the progression of human degenerative diseases such as Alzheimer's, Parkinson's disease and amyotrophic lateral sclerosis.

描述(由申请人提供)： 受损的蛋白质及其聚集产物在氧化应激和老化过程中形成。26S蛋白酶体可以识别和去除这些受损和未折叠的蛋白；此外，泛素-蛋白酶体系统功能降低与年龄相关退行性疾病的发生有关。我们的假设是，维持或增强泛素-蛋白酶体功能是预防或减轻这些年龄相关疾病的新策略。我们的初步结果表明，二硫代硫酮通过刺激Nrf2信号通路下游基因的表达来保护小鼠免受环境毒害，增加了小鼠肝脏中26S蛋白酶体的多个亚基和泛素化酶的表达。本建议旨在a)评估毒物攻击后在细胞中诱导蛋白酶体表达的生理学益处，b)确定作为衰老模型的年轻和衰老小鼠成纤维细胞中可诱导的蛋白酶体表达的影响和Nrf2在受损蛋白积累中的作用，c)表征二硫硫硫酮处理后小鼠组织中，尤其是脑组织中蛋白酶体的诱导模式和水平。最初将使用小鼠胚胎成纤维细胞和神经母细胞瘤细胞在培养细胞中研究增强蛋白酶体诱导的功能效应。在细胞模型中，通过药物干预和通过特定蛋白酶体亚基的分子遗传表达来提高蛋白酶体的表达，将比较蛋白酶体水平、蛋白分解活性、蛋白质周转率和化学攻击后受损蛋白质的积累的指标。Nrf2在这些保护作用中的作用将通过Nrf2破坏或抑制的细胞以及不同年龄的野生型和Nrf2缺陷小鼠的比较来检验。总而言之，这些研究将探索增强的蛋白酶体表达对外源性有毒化学物质和伴随衰老的退化过程的可能保护作用。该项目的长期目标是严格评估通过激活Nrf2信号级联增加泛素-蛋白酶体途径的表达可以预防或延缓阿尔茨海默氏症、帕金森氏病和肌萎缩侧索硬化症等人类退行性疾病的进展。