Role of titin in age-associated diastolic dysfunction

肌联蛋白在年龄相关舒张功能障碍中的作用

• 批准号: 7128162
• 负责人: CHEE CHEW LIM
• 金额: $ 4.79万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-30 至 2006-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7128162
• 关键词: aging; antioxidants; biomechanics; cardiovascular disorder chemotherapy; cardiovascular pharmacology; free radical oxygen; heart contraction; heart disorder; laboratory mouse; mass spectrometry; muscle cells; muscle proteins; nonhuman therapy evaluation; oxidation; posttranslational modifications; protein structure function; proteolysis; two dimensional gel electrophoresis

DESCRIPTION (provided by applicant): The applicant's long-term career objective is to develop into an independent investigator studying the role of oxidative stress in the aging myocardium. In the current research plan, the applicant has proposed to learn new techniques in single myocyte mechanics and mass spectrometry at Boston University School of Medicine. For his early career development, the applicant has assembled a team of leading experts in the field of oxidative stress, proteomics research, myocyte mechanics, and biogerontology. At the end of the award period, the applicant will have acquired invaluable training which will allow him to develop and critically test new hypotheses central to biogerontology research. One of the hallmarks of aging is an increase in the ventricular passive stiffness leading to diastolic heart failure. With advancing age, the cellular redox state is shifted towards increased formation of reactive oxygen species (ROS). The giant elastic protein titin is the major determinant of passive mechanical properties of the cardiomyocyte. With progressive aging, post-translational oxidative modification of the elastic domain of titin could decrease cardiomyocyte compliance, and thus contribute to the diastolic dysfunction seen in aging myocardium. The overall goal of this research proposal is to test the hypothesis that age-associated accumulation of posttranslationally oxidized titin contributes to diastolic dysfunction with age. The first aim will test if myocyte diastolic properties are redox sensitive. Freshly isolated myocytes from adult and aging mouse hearts will be treated with or without ROS generators, skinned, and titin mechanics will be assessed. The second aim will test if aging induces post-translational oxidation of the elastic domain of titin. Titin will be isolated from adult and aging mouse hearts and processed for mass spectrometry. The third aim will test if pharmacological antioxidant treatment in aging mice reverses oxidative modification of titin and improves diastolic function. The fourth aim will test if mechanisms involved in proteolytic processing of titin are impaired with aging.

描述（由申请人提供）：申请人的长期职业目标是发展成为一名独立研究者，研究氧化应激在衰老心肌中的作用。在目前的研究计划中，申请人提出在波士顿大学医学院学习单肌细胞力学和质谱新技术。为了早期的职业发展，申请人组建了一支由氧化应激、蛋白质组学研究、肌细胞力学和生物老年学领域的顶尖专家组成的团队。在奖励期结束时，申请人将获得宝贵的培训，这将使他能够发展和批判性地测试生物老年学研究的核心新假设。衰老的标志之一是心室被动僵硬度增加，导致舒张性心力衰竭。随着年龄的增长，细胞氧化还原状态转向增加活性氧（ROS）的形成。巨大的弹性蛋白肌联是心肌细胞被动机械特性的主要决定因素。随着衰老的进行，肌联蛋白弹性域的翻译后氧化修饰可能会降低心肌细胞的顺应性，从而导致衰老心肌中出现的舒张功能障碍。本研究提案的总体目标是检验以下假设：与年龄相关的翻译后氧化肌联蛋白的积累会导致随年龄增长的舒张功能障碍。第一个目标是测试心肌细胞舒张特性是否对氧化还原敏感。从成年和衰老小鼠心脏中新鲜分离的肌细胞将使用或不使用 ROS 发生器进行处理，剥皮，并评估肌联蛋白力学。第二个目标是测试衰老是否会引起肌联蛋白弹性域的翻译后氧化。将从成年和衰老小鼠心脏中分离出肌联蛋白，并进行质谱分析。第三个目标是测试衰老小鼠的药物抗氧化治疗是否可以逆转肌联蛋白的氧化修饰并改善舒张功能。 第四个目标是测试肌联蛋白水解过程中涉及的机制是否会随着衰老而受损。