Novel Signaling Mechanisms and Molecular Targets in the Stressed Myocardium

应激心肌中的新型信号传导机制和分子靶点

• 批准号: 8009541
• 负责人: Peipei Ping
• 金额: $ 75.24万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8009541
• 关键词: 26S proteasome; Ablation; Address; Area; Attenuated; Biology; Boxing; Cardiac; Cardiovascular system; Cells; Complex; Coronary Occlusions; Data; Defect; Degradation Pathway; Development; Disease; Disease model; Down-Regulation; Ensure; Event; Functional disorder; Genetic; Genetic Models; Goals; Heart; Heart Diseases; Heart Hypertrophy; Heart failure; Homeostasis; Housing; Image; Injury; Investigation; Joints; Knock-in Mouse; Knowledge; Laboratories; LacZ Genes; Lesion; Mediating; Methods; Mitochondria; Mitochondrial Proteins; Modeling; Modification; Molecular; Molecular Target; Mus; Myocardial; Myocardium; Nature; Organism; Oxidative Stress; Pathogenesis; Permeability; Phosphoric Monoester Hydrolases; Post-Translational Protein Processing; Protein phosphatase; Proteins; Proteomics; Quality Control; Reactive Oxygen Species; Reagent; Regulation; Research; Research Infrastructure; Research Personnel; Resolution; Resources; Role; Signal Transduction; Stress; Superoxides; System; Techniques; Technology; Testing; Tetanus Helper Peptide; Therapeutic; clinically relevant; constriction; design; experience; injured; innovation; insight; multicatalytic endopeptidase complex; novel; novel therapeutics; pressure; prevent; protein degradation; public health relevance; research study; tool

DESCRIPTION (provided by applicant): Oxidative stress has been increasingly recognized as a common feature among different forms of heart disease. Elevated reactive oxygen species (ROS) has been shown as a convergent signaling messenger leading to failing heart either of ischemic or non-ischemic origin. Despite significant progress in many areas of ROS related investigations, two fundamental issues remain unresolved and will constitute the center of this proposed investigation. The first question is who are the regulators of ROS in the diseased myocardium? The second question is what are the molecular targets of ROS and how do ROS-induced molecular modifications result in cardiac dysfunction? This application is inspired by our exciting data identifying PP2Cm as a novel regulator of ROS; and by the intriguing preliminary evidence that the cardiac proteasome complexes are a new class of molecular targets for ROS. Accordingly, the proposed investigation will address a novel aspect of ROS signaling: its modulation by PP2Cm, and it will embark on a largely unexplored area of research: the functional consequences of ROS elevation--its impact on the proteasome systems and their substrates. The application will determine the emerging role of PP2Cm in ROS biology; it will establish proteasome subunits as a new set of molecular targets for the elevated ROS; and it will systematically characterize perturbed protein degradation pathways in the normal and stressed myocardium. Furthermore, the application will identify potential therapeutic windows whereby disrupted protein quality control may be rescued. To accomplish our goals, two related models of cardiac stress--pressure overload by transverse-aortic constriction (TAC) and myocardial ischemic injury (I/R)-are employed. Three specific aims are proposed: Aim 1 will elucidate mechanisms underlying PP2Cm mediated protection of the heart; it will determine its role in governing ROS regulation and examine the impact of genetic perturbations of PP2Cm in TAC and I/R using the newly established PP2Cm genetic models in-house (the null/LacZ knock-in KO and the cardiac conditional inducible Tet-Off). Aim 2 will establish roles of the 20S and 26S proteasomes in the two stress models with respect to proteasome complex assembly, function, and degradation capacity; it will decipher molecular events underlying ROS damaged 20S and 26S proteasomes. It will apply a targeted proteomic approach to delineate the molecular modification of proteasome subunits; and it will define the functional significance of such modifications. Aim 3 will define functional consequences of ROS-injured 20S and 26S proteasomes in the two pathological models; it will characterize the substrate repertoire of 20S and 26S proteasomes in the normal and stressed myocardium. Our research plan is supported by "a technology tool box" combining established methods and innovative approaches assembled by the investigator team. It encompasses genetic models, proteasome biology, ROS biology, disease models, quantitative proteomics, and high-resolution imaging. Collectively, the proposed studies will conclusively characterize PP2Cm regulation of ROS in the stress myocardium; it will establish proteasome subunits as novel targets of ROS; and it will provide mechanistic insights into protein homeostasis in the two stress models. PUBLIC HEALTH RELEVANCE: Our proposal addresses a novel hypothesis that oxidative stress in the diseased myocardium is regulated in part by a mitochondria specific protein phosphatase; and one important functional impact of the elevated levels of reactive oxygen species is the damage of cardiac proteasomes. The proposed investigation will gain insights on these diseases and will help to develop new therapeutic strategies to prevent or reverse pathological remodeling in the diseased myocardium. Therefore, our proposal has significant clinical relevance as well as potential key contributions to the fundamental knowledge of mitochondrial biology, ROS biology, proteasome biology, and their functional impact on the cardiovascular systems.

描述（由申请人提供）： 氧化应激越来越被认为是不同形式心脏病的共同特征。活性氧（ROS）升高已被证明是一种会聚的信号信使，导致缺血性或非缺血性心脏衰竭。尽管在ROS相关调查的许多领域取得了重大进展，但两个基本问题仍未得到解决，并将构成本拟议调查的中心。第一个问题是谁是病变心肌中ROS的调节者？第二个问题是ROS的分子靶点是什么，ROS诱导的分子修饰如何导致心功能障碍？ 这个应用程序的灵感来自我们的令人兴奋的数据识别PP 2Cm作为一种新的ROS调节器;和有趣的初步证据表明，心脏蛋白酶体复合物是一种新的分子靶点ROS。因此，拟议的调查将解决一个新的方面的ROS信号：它的调制PP 2Cm，它将开始在很大程度上未探索的研究领域：ROS升高的功能后果-其对蛋白酶体系统及其底物的影响。该应用程序将确定PP 2Cm在ROS生物学中的新兴作用;它将建立蛋白酶体亚基作为一组新的ROS升高的分子靶点;它将系统地表征正常和应激心肌中受干扰的蛋白质降解途径。此外，该应用程序将确定潜在的治疗窗口，从而可以挽救中断的蛋白质质量控制。为了实现我们的目标，两个相关的模型心脏应力-压力超负荷的横向主动脉缩窄（TAC）和心肌缺血性损伤（I/R）-。 提出了三个具体目标：目标1将阐明PP 2Cm介导的心脏保护的潜在机制;它将确定其在控制ROS调节中的作用，并使用新建立的PP 2Cm内部遗传模型（null/LacZ敲入KO和心脏条件诱导Tet-Off）检查PP 2Cm在TAC和I/R中的遗传扰动的影响。目的2将建立20 S和26 S蛋白酶体在两种应激模型中蛋白酶体复合物组装、功能和降解能力方面的作用;它将破译ROS损伤20 S和26 S蛋白酶体的分子事件。它将应用靶向蛋白质组学方法来描述蛋白酶体亚基的分子修饰，并定义这些修饰的功能意义。目的3将定义ROS损伤的20 S和26 S蛋白酶体在两种病理模型中的功能后果;它将表征正常和应激心肌中20 S和26 S蛋白酶体的底物库。我们的研究计划是由“技术工具箱”相结合的既定方法和创新的方法组装的研究团队的支持。它包括遗传模型，蛋白酶体生物学，ROS生物学，疾病模型，定量蛋白质组学和高分辨率成像。总的来说，所提出的研究将最终表征PP 2Cm调节ROS在应激心肌;它将建立蛋白酶体亚基作为ROS的新靶点;它将提供两种应激模型中蛋白质稳态的机制见解。 公共卫生关系： 我们的建议解决了一个新的假设，即氧化应激在病变心肌的线粒体特异性蛋白磷酸酶的一部分进行调节，一个重要的功能性影响的活性氧水平升高是心脏蛋白酶体的损伤。拟议的调查将获得对这些疾病的见解，并将有助于开发新的治疗策略，以防止或逆转病变心肌的病理性重塑。因此，我们的提案具有重要的临床意义，并对线粒体生物学，ROS生物学，蛋白酶体生物学及其对心血管系统的功能影响的基础知识做出了潜在的关键贡献。