Molecular Determinants of Regional Differences in Human Ventricular Repolarization and Remodeling

人类心室复极和重塑区域差异的分子决定因素

• 批准号: 9904737
• 负责人: JEANNE M. NERBONNE
• 金额: $ 39.34万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9904737
• 关键词: Action Potentials; Adult; Affect; Animal Experimentation; Animal Model; Animals; Arrhythmia; Attention; Attenuated; Automobile Driving; Biochemical Genetics; Biophysics; Cardiac; Cardiac Electrophysiologic Techniques; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular system; Closure by clamp; Critical Pathways; Data; Diagnosis; Electrophysiology (science); Experimental Animal Model; Family; Goals; Health Care Costs; Heart; Heart failure; Human; In Vitro; Individual; Infrastructure; Knowledge; Left; Life; Link; Maintenance; Membrane; Messenger RNA; Methods; MicroRNAs; Modeling; Molecular; Molecular Genetics; Muscle Cells; Myocardial; Patients; Pharmacology; Phase; Physiological; Physiology; Play; Procedures; Property; Public Health; Quality of life; RNA; Regulation; Research; Resources; Risk; Role; Shapes; Sudden Death; Testing; Tissues; Translating; United States; Universities; Untranslated RNA; Ventricular; Ventricular Arrhythmia; Washington; adenoviral-mediated; base; biobank; cell type; clinically relevant; differential expression; experimental study; extracellular; genetic approach; heart rhythm; indium arsenide; insight; mortality risk; novel; patient stratification; prevent; programs; regional difference; repository; sudden cardiac death; transcriptome; voltage

ABSTRACT Heart failure, which afflicts more than five million adults in the United States alone, is associated with markedly increased risk of ventricular arrhythmias and sudden death. The molecular, cellular and systemic mechanisms linking heart failure to increased sudden death risk, however, are poorly understood and, despite considerable attention and effort, risk stratifying patients remains an enormous challenge. Although numerous experimental (animal/cellular) heart failure models have been developed and extensively studied, only limited insights into human arrhythmia mechanisms have been provided. Motivated to change this and advance the field, we have undertaken a comprehensive research effort aimed at defining the mechanisms involved in the physiological regulation of membrane excitability in the human heart and the pathophysiological electrical remodeling associated with human heart failure. Utilizing the infrastructure developed in the Translational Cardiovascular Biobank and Repository at Washington University for the acquisition of non-failing and failing human hearts, we have established robust, reliable methods for the isolation and in vitro maintenance of human ventricular myocytes. Here, we utilize these unique resources to test directly the hypothesis that there are regional differences in the regulation and remodeling of three voltage-dependent conductance pathways critical for the coordinated propagation of activity through the ventricles and the maintenance of normal cardiac rhythms: the Kv4.3-encoded, fast transient, outward K+ current, Ito,f; the recently identified, novel, non-inactivating Kv current component, Iss; and, the Nav1.5-encoded voltage-gated Na+ current, INa. In aim #1, we will define the functional impact of heterogeneous Ito,f remodeling on LV action potential waveforms, and identify the molecular determinants of native Ito,f channels in non-failing human LV and of Ito,f remodeling in failing human LV. In aim #2, we will test the hypothesis that there are also transmural differences in the expression and the remodeling of Iss, and define the functional consequences of cell type-specific differences in Iss expression and remodeling on LV action potential waveforms. Experiments in aim #3 will test the hypothesis that there are transmural differences in the expression, properties and remodeling of Nav1.5-encoded INa channels, particularly the late component of INa, INa,L, in non-failing and failing human LV myocytes and define the functional impact on LV action potential waveforms of heterogeneous INa,L expression and remodeling. These studies will provide new, clinically relevant, insights into the cellular/molecular mechanisms contributing to the physiological regulation and pathophysiological remodeling of native human ventricular Ito,f, Iss and INa channels. These insights will transform the refinement of human cardiac myocyte and whole heart models and translate to novel, mechanism-based strategies to target specific cell types to reduce the risk of life-threatening ventricular arrhythmias in patients suffering human heart failure.

抽象的 仅在美国就有超过 500 万成年人患有心力衰竭，它与显着的 室性心律失常和猝死的风险增加。分子、细胞和系统机制 然而，人们对心力衰竭与猝死风险增加之间的联系知之甚少，并且尽管有相当多的研究 尽管需要关注和努力，但对患者进行风险分层仍然是一个巨大的挑战。尽管进行了大量的实验 （动物/细胞）心力衰竭模型已被开发并进行了广泛研究，但对这些模型的了解有限 已经提供了人类心律失常的机制。为了改变这一现状并推进该领域的发展，我们有 进行了全面的研究工作，旨在确定生理学中涉及的机制 人心脏膜兴奋性的调节和病理生理电重塑 与人类心力衰竭有关。利用转化心血管领域开发的基础设施 华盛顿大学的生物银行和存储库用于获取非衰竭和衰竭的人类心脏，我们 已经建立了稳健、可靠的方法来分离和体外维持人类心室 肌细胞。在这里，我们利用这些独特的资源来直接检验存在区域性的假设 三个电压依赖性电导通路的调节和重塑的差异对于 通过心室协调活动的传播和维持正常的心律： Kv4.3编码，快速瞬态，向外K+电流，Ito,f；最近发现的、新颖的、非失活的 Kv 电流 组件，Iss；以及 Nav1.5 编码的电压门控 Na+ 电流 INa。在目标#1中，我们将定义函数 异质 Ito,f 重塑对 LV 动作电位波形的影响，并确定分子 非衰竭人类 LV 中天然 Ito,f 通道和衰竭人类 LV 中 Ito,f 重塑的决定因素。瞄准目标 #2，我们将检验表达和重塑也存在跨壁差异的假设 Iss，并定义 Iss 表达和重塑中细胞类型特异性差异的功能后果 左室动作电位波形。目标#3 中的实验将检验存在跨壁物质的假设 Nav1.5 编码的 INa 通道的表达、特性和重塑方面的差异，特别是晚期 正常和衰竭人类左室肌细胞中 INa、INa,L 的组成部分，并定义对左室功能的影响 异质 INa,L 表达和重塑的动作电位波形。 这些研究将为细胞/分子机制提供新的、临床相关的见解。 对天然人心室 Ito、f、Iss 和 INa 的生理调节和病理生理重塑 渠道。这些见解将改变人类心肌细胞和整个心脏模型的完善， 转化为新颖的、基于机制的策略，针对特定细胞类型，以降低危及生命的风险 人类心力衰竭患者的室性心律失常。