Electrical Silencing of the Pulmonary Veins

肺静脉电沉默

• 批准号: 7787967
• 负责人: David J Milan
• 金额: $ 26.33万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-02-03 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7787967
• 关键词: Ablation; Academic Medical Centers; Address; Animal Model; Animals; Anterior; Anticoagulation; Arrhythmia; Atrial Fibrillation; Biological; Cardiac Myocytes; Cardiac Tamponade; Cell Survival; Cells; Complication; Coupled; Data; Dose; Epitopes; Esophageal Fistula; Evaluation; Experimental Animal Model; Family; Family member; Gene Delivery; Gene Transfer; Genes; Goals; Heart Atrium; Heterogeneity; Holter Electrocardiography; Hour; In Vitro; Maps; Membrane Potentials; Methods; Molecular; Muscle Cells; Nature; Nerve Paralysis; Neurons; Pacemakers; Play; Potassium; Potassium Channel; Prevalence; Procedures; Proteins; Pulmonary veins; Radiofrequency Interstitial Ablation; Rest; Right atrial structure; Risk; Role; Sheep; Stenosis; Stroke; Structure; Structure of phrenic nerve; Technology; Time; Tissues; Toxic effect; Transfection; Transient Ischemic Attack; Work; atrioventricular node; cytotoxicity; gene discovery; gene therapy; implantation; in vivo; novel strategies; overexpression; programs; public health relevance; radiofrequency; response; success

DESCRIPTION (provided by applicant): The recent discovery of genes responsible for the potassium leak currents, the KCNK family of potassium channels, has created the opportunity to directly target arrhythmogenic triggers of atrial fibrillation, rather than merely trying to contain them through pulmonary vein isolation. Expression of the KCNK0 gene in neurons can render these cells electrically silent by effectively shorting out any depolarizing currents. We have extended this work to demonstrate that expression of KCNK0 in cardiomyocytes renders them inexcitable. We thus propose to evaluate the KCNK0 gene for its ability to silence cardiomyocytes as a treatment for atrial fibrillation in the following specific aims: Specific Aim1: In vitro evaluation of KCNK0 for the electrical silencing of cardiomyocytes. This will involve assessment of biological effects in cardiomyocytes - establishing transfection efficiency targets, assessing cell viability, studying the electrophysiologic effects of heterogeneity from mosaic KCNK0 expression, and assessing possible cytotoxicity. Specific Aim 2: In vivo adenoviral delivery of KCNK0 to the anterior right atrium to create a line of block. This will involve linear delivery of the Ad.KCNK0 followed 5 days later by multielectrode recordings of electrical activity. Comparison of two gene delivery methods and dose response will be evaluated with assessment of gene transfer efficiency, toxicity, and protein levels. Specific Aim 3: In vivo adenoviral delivery of KCNK0 to silence pulmonary vein myocytes in a large animal model. This will involve baseline electroanatomic mapping, followed by KCNK0 gene delivery to the pulmonary veins, and then remapping of the pulmonary veins to document electrical silencing. Animals will also undergo atrial programmed stimulation and Holter monitoring to assess for proarrhythmia. Comparison will be made to Ad.GFP treated animals as well as animals treated with traditional radiofrequency pulmonary vein isolation. PUBLIC HEALTH RELEVANCE: Our primary objective is to demonstrate the feasibility of electrically silencing the pulmonary veins using gene transfer as a potential treatment for atrial fibrillation in an experimental animal model. In this project, sheep be will be used to determine whether expression of a modified potassium leak current, KCNKO, by adenoviral gene therapy approach leads to loss of electrical excitability (electrical silencing) of the cardiomyocytes investing the pulmonary vein ostia.

描述（由申请人提供）：最近发现的负责钾泄漏电流的基因（钾通道 KCNK 家族）创造了直接针对心房颤动的心律失常触发因素的机会，而不仅仅是试图通过肺静脉隔离来遏制它们。 KCNK0 基因在神经元中的表达可以通过有效地短路任何去极化电流来使这些细胞处于电沉默状态。我们扩展了这项工作，以证明心肌细胞中 KCNK0 的表达使它们变得不兴奋。因此，我们建议评估 KCNK0 基因沉默心肌细胞作为心房颤动治疗的能力，具体目标如下： 具体目标 1：体外评估 KCNK0 对心肌细胞电沉默的作用。这将涉及评估心肌细胞的生物效应 - 建立转染效率目标、评估细胞活力、研究嵌合 KCNK0 表达异质性的电生理效应，以及评估可能的细胞毒性。具体目标 2：体内腺病毒将 KCNK0 递送至右前心房以形成阻滞线。这将涉及 Ad.KCNK0 的线性传递，然后 5 天后进行电活动的多电极记录。将通过评估基因转移效率、毒性和蛋白质水平来评估两种基因递送方法和剂量反应的比较。具体目标 3：体内腺病毒递送 KCNK0 以沉默大型动物模型中的肺静脉肌细胞。这将涉及基线电解剖映射，然后将 KCNK0 基因传递到肺静脉，然后重新映射肺静脉以记录电沉默。动物还将接受心房程序刺激和动态心电图监测以评估致心律失常。将与 Ad.GFP 治疗的动物以及用传统射频肺静脉隔离治疗的动物进行比较。 公共健康相关性：我们的主要目标是证明使用基因转移电沉默肺静脉作为实验动物模型中心房颤动的潜在治疗方法的可行性。在该项目中，将使用绵羊来确定通过腺病毒基因治疗方法表达修饰的钾泄漏电流KCNKO是否会导致位于肺静脉口的心肌细胞电兴奋性丧失（电沉默）。