Cardiac Sonogenetics: Noninvasive Stimulation of the Heart With Low-Intensity Focused Ultrasound

心脏声遗传学：用低强度聚焦超声对心脏进行无创刺激

• 批准号: 10599091
• 负责人: Christian W Zemlin
• 金额: $ 19.69万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10599091
• 关键词: Ablation; Achievement; Action Potentials; Address; Animals; Anti-Arrhythmia Agents; Arrhythmia; Atrial Fibrillation; Behavior; Brain; Cardiac; Cardiac ablation; Cardiovascular system; Cell model; Communities; Control Animal; Development; Devices; Eating; Electric Countershock; Electrocardiogram; Electrophysiology (science); Focused Ultrasound; Focused Ultrasound Therapy; Foundations; Frequencies; Future; Genetic; Goals; Heart; Heart Rate; Human; Image; Imaging Device; Implant; Implantable Defibrillators; Ion Channel; Light; Lung; Maps; Mechanical Stimulation; Mechanics; Membrane Potentials; Monitor; Morbidity - disease rate; Mus; Muscle Contraction; Mutation; Myocardial tissue; Myocardium; Operative Surgical Procedures; Optics; Outcome; Pain; Painless; Patients; Pattern; Penetration; Pharmacological Treatment; Physiology; Preparation; Rattus; Regulation; Reporting; Research; Safety; Source; Survival Rate; Technology; Testing; Therapeutic; Time; Tissues; Ultrasonography; United States Food and Drug Administration; Validation; Viral; Viral Vector; cardiac pacing; cell type; clinical application; clinical translation; design; electronic pacemaker; experience; falls; frontier; heart electrical activity; heart function; high risk; in vitro Model; in vivo; in vivo Model; mortality; optogenetics; rib bone structure; safety and feasibility; safety assessment; success; tool; ultrasound

Our goal is to develop for the first time sonogenetics in the heart for cardiac stimulation, by expressing exogenous ultrasound-sensitive ion channels in rat hearts and stimulating cardiac function using ultrasound. Arrhythmias are a major source of mortality and morbidity. Pharmacological treatment does not achieve acceptable outcomes in a large fraction of patients. Catheter ablation and surgical ablation can be effective, but they require invasive surgery. Optogenetics has been investigated in the past decade as an alternative to electronic pacemakers, offering non-electrical, low-energy pacing that can be cell-type specific and painless. However, the limited light penetration through the rib cage and into the myocardium curtails the clinical translation of optogenetics in cardiac applications. To address the unmet need in arrhythmia management, we propose to develop a new strategy, namely cardiac sonogenetics, to introduce mechanically sensitive ion channels into the heart and activate these channels using low-intensity focused ultrasound (LIFU) for antiarrhythmic therapy. Aim 1: Select and optimize the ion channels suitable for cardiac sonogenetics. Mechanosensitive ion channels need to meet the following criteria to be suitable for cardiac sonogenetics: 1) they can be activated by LIFU and respond sufficiently quickly for pacing rat hearts; 2) they can be virally expressed in the heart and can depolarize the membrane potential when activated by ultrasound to excite the heart; and 3) they are minimally activated by mechanical stimulation that mimics the muscle contraction during the normal heart beat such that they do not severely alter normal cardiac function. Based on these criteria, we will evaluate two candidate channels, MscL-G22S (a MscL channel with the mutation G22S) and TRPV4. We may make mutations of these channels to enhance ultrasound sensitivity. In this aim, we will use in vitro model cells and electrophysiology and Ca2+ imaging in parallel with the ex vivo model in Aim 2 for the validation. Aim 2. Demonstrate the feasibility and safety of sonogenetics in rat hearts. We will express MscL-G22S and TRPV4 channels in rat hearts and test the ability of LIFU to pace the heart rate with various energy, duration, frequency, and waveforms ex vivo using a Langendorff preparation. We will also evaluate the influence of the exogenous mechanosensitive ion channels on heart physiology. To assess the safety of sonogenetic stimulation, we will monitor survival rate, body mass, food intake, and ECG of the animals with expression of the exogenous ion channels, compare them with control animals with expression of viral vectors, and animals with no exogenous expression. We will also compare action potential waveform, conduction velocity, and activation patterns for sonogenetically modified and control animals using optical mapping. Successful completion of these aims will provide the cardiovascular community with a transformative tool, capable of noninvasively stimulating the hearts of large animals and humans in vivo. This tool has the potential to become the next frontier in antiarrhythmic research and future of therapeutic applications in humans.

我们的目标是通过表达外源性信号，首次在心脏中开发用于心脏刺激的声遗传学 大鼠心脏中的超声敏感离子通道并使用超声刺激心脏功能。心律失常 是死亡率和发病率的主要来源。药物治疗未达到可接受的结果 在很大一部分患者中。导管消融和手术消融可能有效，但需要侵入性 外科手术。光遗传学在过去十年中作为电子起搏器的替代品进行了研究， 提供非电力、低能量的起搏，可以针对细胞类型特定且无痛。但光线有限 穿过胸腔并进入心肌限制了光遗传学的临床转化 心脏应用。为了解决心律失常管理中未满足的需求，我们建议开发一种新的 策略，即心脏声遗传学，将机械敏感的离子通道引入心脏并 使用低强度聚焦超声 (LIFU) 激活这些通道进行抗心律失常治疗。 目标 1：选择并优化适合心脏声遗传学的离子通道。 机械敏感离子通道需要满足以下标准才能适用于心脏声遗传学：1) 它们可以被 LIFU 激活，并对大鼠心脏起搏做出足够快的反应； 2）它们可以像病毒一样传播 在心脏中表达，当被超声波激活以激发心脏时可以使膜电位去极化 心; 3）它们通过模仿肌肉收缩的机械刺激而被最小程度地激活 正常的心跳，因此不会严重改变正常的心脏功能。基于这些标准，我们 将评估两个候选通道：MscL-G22S（具有突变 G22S 的 MscL 通道）和 TRPV4。我们 可能会使这些通道发生突变以增强超声敏感性。为了这个目标，我们将使用体外模型 细胞和电生理学以及 Ca2+ 成像与 Aim 2 中的离体模型并行进行验证。 目标 2. 证明声遗传学在大鼠心脏中的可行性和安全性。 我们将在大鼠心脏中表达MscL-G22S和TRPV4通道并测试LIFU调节心率的能力 使用 Langendorff 制剂进行体外各种能量、持续时间、频率和波形。我们还将 评估外源性机械敏感离子通道对心脏生理的影响。评估 声遗传学刺激的安全性，我们将监测动物的存活率、体重、食物摄入量和心电图 与外源离子通道的表达，将它们与表达病毒的对照动物进行比较 载体和没有外源表达的动物。我们还将比较动作电位波形、传导 使用光学映射对声遗传学修饰和控制动物进行速度和激活模式。 成功完成这些目标将为心血管界提供变革性工具， 能够无创地刺激大型动物和人类的体内心脏。这个工具有潜力 成为抗心律失常研究的下一个前沿和人类治疗应用的未来。