Decipher Mechano-Chemo-Transduction Pathway and Function in Cardiomyocytes

破译心肌细胞中的机械化学传导途径和功能

基本信息

批准号：
10317392
负责人：
Ye Chen-Izu
金额：
$ 76.31万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2025-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10317392
关键词：
3-Dimensional Action Potentials Affect Behavior Biochemical Biomedical Engineering Blood Circulation Cardiac Myocytes Cardiac Output Cardiomyopathies Cell surface Cells Complex Contracts Coupling Data Disease Dystroglycan Dystrophin Electrophysiology (science)Environment Extracellular Matrix Feedback Functional disorder Gel Glycoproteins Goals Grant Health Heart Heart Diseases Homeostasis Hydrogels Image Impairment In Situ Knock-out Knowledge Lead Link Maps Mechanical Stress Mechanics Modeling Molecular Muscle Muscle Cells Muscular Dystrophies Muscular dystrophy cardiomyopathy Mutation Myocardium Nitric Oxide Synthase Type I Outcome Pathologic Pathway interactions Peripheral Resistance Pharmacology Reporter Reporting Signal Transduction Skeletal Muscle Stress Sturnus vulgaris System Technology Testing Time Tissues Transgenic Organisms Utrophin alpha Dystroglycan base blood pump calmodulin-dependent protein kinase II dynamic system glycosylation heart function inhibitor/antagonist innovation innovative technologies mathematical model mechanical load mechanotransduction multidisciplinary new technology predictive modeling pressure response viscoelasticity

项目摘要

The heart pumps blood into circulation against systemic vascular resistance; the heart can also sense mechanical load changes and regulate contractility to maintain cardiac output. The heart’s load adaptivity had been described by Frank-Starling and Anrep over 108 years ago. The current understanding is that the Anrep effect upregulates Ca2+ transient to enhance contractility when the cardiomyocyte is contracting under afterload, which is predominant in pathological pressure overload. However, the mechano-chemo-transduction (MCT) mechanism that transduces mechanical load to biochemical signals to regulate excitation-Ca2+ signaling-contraction (E-C) coupling in cardiomyocytes remains unresolved. Emerging evidence show that the load adaptivity resides within single cardiomyocytes. We recently found that the cardiomyocytes contracting in viscoelastic hydrogels can regulate the Ca2+ transient and contractility in compensatory response to afterload changes, showing autoregulation of contraction. But the underlying MCT mechanisms are yet to be resolved. An important clue comes from our mathematical model prediction that the observed autoregulatory behavior can arise from cell-surface mechanosensors that sense the 3D mechanical stress on cardiomyocytes during contraction in a 3D viscoelastic environment as in situ. The goals of this grant are 2-fold: first we will decipher the cell-surface mechanosensor, dystrophin-glycoprotein complex (DGC) and the downstream MCT pathway; next, we will determine the functional impact of MCT on regulating E-C coupling in the cardiomyocyte under mechanical load. Our multi-disciplinary team will combine bioengineering, electrophysiology, Ca2+ imaging, and muscle mechanics to develop innovative technology and achieve three specific aims. INNOVATION: We will develop new Cell-in-Gel with molecular-tether and stress-reporter (Cell-in-Gel-TS) technology, which is used to control mechanical load on myocytes during beat-to-beat contraction, report the stress level, and tether/untether cell surface mechanosensors to probe MCT pathways. Aim-1: Decipher the MCT pathway from DGC mechanosensor to chemotransducer to E-C coupling molecules. Aim-2: Determine how mechanical load regulates the excitation-Ca2+ signaling-contraction coupling systems. Aim-3: Test hypothesis that DGC mutations disrupt the MCT pathway to cause dysregulation of E-C coupling. Successful outcomes will (A) shift the E-C coupling paradigm from the current feed-forward model to a new MCT feedback autoregulatory model, (B) open a unifying conceptual framework for understanding the heart’s intrinsic adaptive response to mechanical load changes in health and diseases, and (C) develop the new Cell- in-Gel-TS platform to control afterload at single-cell and molecular levels, which can be widely used to study myocytes under afterload (replacing load-free setting) to mimic pathophysiological loading in 3D myocardium. 1

心脏将血液泵入循环以抵抗全身血管阻力；心脏也可以感知。机械负荷变化并调节收缩力以维持心输出量。 Frank-Starling 和 Anrep 在 108 年前就已经描述过，目前的理解是 Anrep。当心肌细胞在以下条件下收缩时，效果上调 Ca2+ 瞬变以增强收缩力然而，后负荷在病理性压力超负荷中占主导地位。 (MCT) 将机械负荷转换为生化信号以调节兴奋 Ca2+ 的机制心肌细胞中的信号传导-收缩（E-C）耦合仍未得到解决。负荷适应性存在于单个心肌细胞内。我们最近发现心肌细胞收缩。粘弹性水凝胶可以调节 Ca2+ 瞬态和收缩性对后负荷的代偿反应变化，显示收缩的自动调节，但潜在的 MCT 机制尚未解决。一个重要的线索来自我们的数学模型预测，即观察到的自动调节行为可以由细胞表面机械传感器产生，该传感器在运动过程中感知心肌细胞上的 3D 机械应力 3D 粘弹性环境中的原位收缩这项资助的目标有两个：首先我们将破译。细胞表面机械传感器、肌营养不良蛋白-糖蛋白复合物 (DGC) 和下游 MCT 通路；接下来，我们将确定 MCT 对调节心肌细胞 E-C 耦合的功能影响我们的多学科团队将结合生物工程、电生理学、Ca2+ 成像和肌肉力学开发创新技术并实现三个具体目标。创新：我们将开发带有分子系链和应力报告器的新型 Cell-in-Gel (Cell-in-Gel-TS) 该技术用于控制逐次收缩期间心肌细胞的机械负荷，报告称压力水平，以及束缚/松开细胞表面机械传感器来探测 MCT 途径。 Aim-1：破译从 DGC 机械传感器到化学转导器再到 E-C 耦合分子的 MCT 途径。目标 2：确定机械负荷如何调节兴奋-Ca2+ 信号-收缩耦合系统。 Aim-3：检验 DGC 突变破坏 MCT 通路导致 E-C 耦合失调的假设。成功的结果将 (A) 将 E-C 耦合范式从当前的前馈模型转变为新的 MCT 反馈自动调节模型，(B) 开启一个统一的概念框架来理解心脏的对健康和疾病中机械负荷变化的内在适应性反应，以及 (C) 开发新的 Cell- in-Gel-TS 平台可在单细胞和分子水平上控制后载，可广泛用于研究后负荷下的心肌细胞（代替无负荷设置）以模拟 3D 心肌中的病理生理负荷。 1