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）：最近发现的钾漏电流基因，即钾通道KCNK家族，为直接靶向房颤的致炎性触发因素创造了机会，而不仅仅是试图通过肺静脉隔离来控制它们。KCNK 0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保持电沉默。我们已经扩展了这项工作，以证明KCNK 0在心肌细胞中的表达使它们变得不可兴奋。因此，我们建议评估KCNK 0基因沉默心肌细胞的能力，作为治疗房颤的以下具体目标：具体目标1：在体外评估KCNK 0的电沉默心肌细胞。这将涉及评估心肌细胞中的生物学效应-建立转染效率目标，评估细胞活力，研究来自镶嵌KCNK 0表达的异质性的电生理学效应，以及评估可能的细胞毒性。具体目标2：在体内腺病毒递送KCNK 0至右心房前以产生阻断线。这将涉及线性递送Ad.KCNK0，5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价两种基因递送方法的比较和剂量反应。具体目标3：在大型动物模型中体内腺病毒递送KCNK 0以沉默肺静脉肌细胞。这将涉及基线电解剖标测，然后将KCNK 0基因递送到肺静脉，然后重新标测肺静脉以记录电沉默。动物还将接受心房程控刺激和霍尔特监测，以评估促心律失常。将对Ad.GFP处理的动物以及用传统射频肺静脉隔离处理的动物进行比较。 公共卫生关系：我们的主要目的是证明在实验动物模型中使用基因转移电沉默肺静脉作为心房颤动的潜在治疗的可行性。在这个项目中，绵羊将被用来确定是否修饰的钾漏电流，KCNKO，腺病毒基因治疗方法的表达导致投资肺静脉口的心肌细胞的电兴奋性（电沉默）的损失。