Myofilaments as regulators of heart function in disease

摘要 缺血性心肌病和心力衰竭是#年发病率和死亡率的主要原因。 人类。遗传性和获得性心肌病患者的临床处理具有挑战性 而且受到正在筹备中的新疗法的稀缺的限制。这项提议的当务之急是机械论 对肌节调节和心脏功能的洞察，最终推动小说的长期目标 治疗心脏病的方法。这一努力强调了这项提议对健康的重大意义。 心肌肌节是一个复杂的变构调节系统，它驱动心脏收缩，但 作为心脏疾病的治疗靶点的研究明显不足。几十年来，心脏领域一直 认为在健康和疾病中，细胞内钙处理是调节心脏功能的关键途径。 相比之下，人们较少强调肌节在控制心脏表现中的作用， 代表着巨大的差距和错失的机会。到目前为止，该领域的一个主要限制是 不能直接监测活的心肌细胞中肌节的激活。肌节表演一直是一个 在实时检测活的完整心肌细胞中肌丝激活方面的“黑匣子”。我们在这里利用 一项方法学上的突破，能够实时检测活的心肌细胞中的肌节激活。 这一创新将引领我们对肌节在健康和健康中的功能的机械驱动的研究 疾病，包括阐明肌瘤激活配体的作用。使用这种基于FRET的肌节 激活平台，我们独一无二地准备定义生理意义的调节作用 活细胞中的肌节。利用活细胞阐明心肌肌节调节的基本特性 我们正处于一个独特的位置来测试肌节功能与钙解偶联的假设 遗传性和获得性心肌病模型的处理，指出肌节是 实验性的治疗发现。通过三个相辅相成的目标的整合，我们将确定 肌小球兴奋收缩解偶联的分子机制及其作用研究 疾病引起的肌球蛋白、肌钙蛋白和小分子突变引起的活细胞肌节激活 心肌。这一建议将推进对心脏性能调节的新理解，并开启 肌节调节基因、蛋白质和小分子的潜在突破之门 在健康和疾病中影响心脏表现。

Abstract Ischemic cardiomyopathy and heart failure are the leading causes of combined morbidity and mortality in humans. Clinical management of patients with inherited and acquired forms of cardiomyopathy is challenging and limited by the scarcity of new therapies in the pipeline. This proposal's immediate focus is on mechanistic insights into sarcomere regulation and heart performance with the long-term goal to ultimately advance novel approaches to redress heart disease. This effort underscores the significant health relevance of this proposal. The cardiac sarcomere is a complex allosteric regulatory system that drives heart contraction, but has been significantly under studied as a therapeutic target for cardiac disorders. For decades, the cardiac field has considered intracellular Ca2+ handling as the key pathway regulating heart performance in health and disease. By contrast, less emphasis has been placed on the role of the sarcomere in governing heart performance, representing a significant gap and missed opportunity. Until now, a major limitation in the field has been the inability to directly monitor sarcomere activation in live cardiac myocytes. Sarcomere performance has been a "black box" in terms of detecting, in real time, myofilament activation in live intact myocytes. We leverage here a methodological breakthrough enabling real-time detection of sarcomere activation in live cardiac myocytes. This innovation will lead our mechanistically-driven studies on the function of the sarcomere in health and disease, including elucidating the roles of sarcomeric activating ligands. Using this FRET-based sarcomere activation platform, we are uniquely poised to define the physiological significance of the regulatory role of the sarcomere in live cells. In illuminating fundamental properties of cardiac sarcomere regulation using live cell recordings, we are in a unique position to test the hypothesis that sarcomere function is uncoupled from Ca2+ handling in models of inherited and acquired cardiomyopathy, pointing to the sarcomere as a key target for experimental therapeutic discoveries. By the integration of three complementary Aims, we will determine the molecular mechanism underlying sarcomere-based excitation-contraction uncoupling and investigate the effects on live cell sarcomere activation due to disease causing mutations in myosin, troponin and small molecules in cardiac muscle. This proposal will advance a new understanding of heart performance regulation and open the door to potential breakthroughs in sarcomere modulating genes, proteins and small molecules to positively impact heart performance in health and disease.