Role of the cardiac cytoskeleton in mRNA localization and hypertrophy

心脏细胞骨架在 mRNA 定位和肥大中的作用

• 批准号: 10582513
• 负责人: Emily A Scarborough
• 金额: $ 6.72万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10582513
• 关键词: Actins; Active Biological Transport; Adult; Affect; Biological; Blood; Calcium; Cardiac; Cardiac Myocytes; Cell physiology; Cells; Cessation of life; Chronic; Complex; Coupled; Cytoskeleton; Data; Dependence; Deposition; Diffusion; Disease; Elements; Exercise; Genetic; Goals; Growth; Health; Health Care Costs; Heart; Heart Diseases; Heart Hypertrophy; Heart failure; Human; Hypertrophy; In Vitro; Individual; Kinetics; Knowledge; Location; Maintenance; Mechanics; Messenger RNA; Microscopy; Microtubule-Associated Proteins; Microtubules; Modeling; Molecular; Motor; Muscle Cells; Myosin ATPase; Neonatal; Oxygen; Pathologic; Pharmacology; Physiological; Play; Post-Translational Protein Processing; Pregnancy; Process; Proteins; Pump; Rattus; Reagent; Regulation; Research; Research Proposals; Resolution; Ribosomal Proteins; Ribosomes; Role; Sarcomeres; Site; Stress; Structure; System; Testing; Therapeutic; Transcript; Translating; Translations; United States; Visualization; Work; base; cell growth; cell type; cost; heart function; hemodynamics; improved; in vivo; in vivo Model; mouse model; new growth; protein degradation; protein expression; protein function; response; spatiotemporal; tool; trafficking

PROJECT SUMMARY In the adult heart, remodeling in response to changing hemodynamic demands occurs primarily through hypertrophy, the addition of new sarcomeres to individual cardiomyocytes. Physiological hypertrophy, triggered by pregnancy or exercise, maintains normal organization of cardiac structure and can improve cardiac function. Pathological hypertrophy, however, often precedes heart failure. This can induce drastic changes to the cardiomyocyte cytoskeleton. However, with the exception of cellular mechanics, the role of the cardiomyocyte cytoskeleton in both health and disease has remained understudied. Recent data suggest that both the actinomyosin and microtubule network may play a role in mRNA and ribosomal localization in cardiomyocytes, though the mechanism remains unknown. In non-muscle cell types, actin-based and microtubule-based directed mRNA transport is well characterized. Additionally, myosin and other sarcomeric mRNAs, ribosomes, and protein degradation machinery appear to localize to the sarcomere in the cardiomyocyte, supporting a model of local translation for sarcomere maintenance and/or de novo formation. But how these new sarcomeres are formed remains particularly unclear, and the dependence of hypertrophy on proper mRNA transport and localization is unknown. The goal of my research proposal is to determine the relationship between mRNA localization and cardiac hypertrophy both in health and disease. My preliminary data establishes that the microtubule network is essential for mRNA localization in the rat cardiomyocyte in vivo and in vitro. To determine the specific mechanism of mRNA transport, I will utilize pharmacological reagents to destabilize the actin network and specifically inhibit motor proteins in isolated adult rat cardiomyocytes to test if mRNA localization changes. I will also use the MS2-MCP system to live track single mRNA transcripts to unambiguously define the mode of mRNA transport. I will leverage molecular biological tools to mislocalize specific sarcomeric transcripts and to visualize sites of new sarcomere deposition in growth-responsive neonatal rat cardiomyocytes to test if mRNA sublocalization is required for cardiac hypertrophy. Finally, I will evaluate if hypertrophy disrupts proper mRNA localization, and if so, dissect the relative contribution of pathophysiological microtubule network changes to this mislocalization using both in vitro and in vivo models of hypertrophy. Taken together, the proposed research will definitively establish the mechanism of mRNA transport and localization in the cardiomyocyte and its function in cardiac hypertrophy.

项目摘要 在成人心脏中，重塑对不断变化的血液动力学需求的重塑主要是通过 肥大，在单个心肌细胞中添加新的肉瘤。生理肥大，触发 通过怀孕或运动，可以保持正常的心脏结构组织，并可以改善心脏功能。 然而，病理肥大通常先于心力衰竭。这可以引起急剧变化 心肌细胞细胞骨架。但是，除了细胞力学外，心肌细胞的作用 健康和疾病中的细胞骨架均已研究。 最近的数据表明，放线肌球蛋白和微管网络都可能在mRNA和 尽管该机制仍然未知，但在心肌细胞中的核糖体定位。在非肌肉细胞类型中， 基于肌动蛋白的基于肌动蛋白和基于微管的定向mRNA转运的特征很好。此外，肌球蛋白和 其他肉类的mRNA，核糖体和蛋白质降解机械似乎本地化于肌膜 在心肌细胞中，支持肌节维护和/或从头的局部翻译模型 形成。但是如何形成这些新的肉瘤仍然不清楚，以及 适当的mRNA传输和定位的肥大尚不清楚。我的研究建议的目的是 确定MRNA定位与健康和疾病中心脏肥大之间的关系。我的 初步数据表明，微管网络对于大鼠中的mRNA定位至关重要 体内和体外心肌细胞。为了确定mRNA传输的特定机制，我将使用 药理学试剂可破坏肌动蛋白网络，特别抑制分离的运动蛋白 成年大鼠心肌细胞测试mRNA定位是否改变。我还将使用MS2-MCP系统进行轨道 单个mRNA转录物明确定义了mRNA转运的模式。我将利用分子 生物学工具错误地定位了特定的肉瘤成绩单并可视化新的肌节沉积位置 在生长响应性新生儿大鼠心肌细胞中，以测试MRNA sublocaliation是否需要心脏s型化 肥大。最后，我将评估肥大是否破坏了适当的mRNA定位，如果是，则剖析 病理生理微管网络的相对贡献使用这两者都会改变这种错误的定位 体外和体内肥大模型。综上所述，拟议的研究将确定建立 心肌细胞中mRNA转运和定位的机理及其在心脏肥大中的功能。