Validation of Premature Ventricular Contraction-induced Cardiomyopathy on a Swine Model

在猪模型上验证室性早搏诱发的心肌病

• 批准号: 10664914
• 负责人: Jose Francisco Huizar
• 金额: --
• 依托单位: VA VETERANS ADMINISTRATION HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10664914
• 关键词: Acute; Admission activity; Animal Model; Animals; Biopsy; Canis familiaris; Cardiac; Cardiomyopathies; Caring; Chemosensitization; Chronic; Clinical; Coupled; Coupling; Development; Down-Regulation; Echocardiography; Etiology; Evaluation; Experimental Models; Exposure to; Family suidae; Financial Hardship; Frequencies; Functional disorder; Future; Genes; Healthcare; Heart; Heart failure; Impairment; Implant; Interleukins; Mediator; Mesenchyme; Methods; Mitral Valve Insufficiency; Modeling; Molecular; Muscle Contraction; Neurons; Pacemakers; Pathway interactions; Patients; Phase; Prevention; Procedures; Proteins; Randomized; Recovery; Risk; Role; Scaffolding Protein; Secondary to; Signal Transduction; Structure; TNF gene; Techniques; Testing; Time; Transfection; Validation; Ventricular; Ventricular Premature Complexes; Veterans; Viral; canine model; design; hemodynamics; high risk; improved; mortality; placebo group; porcine model; premature; prevent; resilience; response; restoration; transcriptomic profiling; transcriptomics

Background. Frequent premature ventricular contractions (PVCs) can cause LV dysfunction or cardiomyopathy (CM), referred to as PVC-cardiomyopathy (PVC-CM). The mechanism responsible this CM is unclear. A PVC—CM canine model was key not only to prove that PVC-CM can be induced in a normal structural heart, but also to identify preliminary cellular and molecular features that may explain the development of LV dysfunction. Until recently an alternative PVC-Cardiomyopathy model has been described in the swine species. This model appears to have similar echocardiographic features to the canine model, although molecular features remain unknown. The main objective of this study is to validate a PVC-CM in a swine model. Hypotheses. Our main hypotheses is that similar to the PVC-CM canine model, the swine model will demonstrate: 1) mild to moderate LV dysfunction, mild mitral regurgitation and diastolic dysfunction in early- coupled PVC, while early PVCs will demonstrate less degree of LV dyssynchrony when compared to late-coupled PVCs (Aim 1); 2) an increase in interleukin and TNF-alpha signaling, while a decrease in mesenchyme development, neuron projection extension and muscle contraction genes (Aim 2); 3) similar changes in the dyad, characterized by decrease in ICaL and down-regulation of Cav1.2, JPH-2, L-type Ca2+ channel misplacement out of the dyad and decrease in BIN1 with impaired Ca2+-induced Ca2+-release (Aim 3); 3); and 4) a minimum chronic exposure of 25% PVC burden is required to develop PVC-CM (Aim 4). Aim 1. Validate the cardiac structural changes in a PVC-CM swine model and impact of post-extrasystolic potentiation and PVC coupling interval in the development of PVC-CM. Aim 2. Confirm Transcriptomic profiling associated with PVC-CM in the swine model. Aim 3. Corroborate the structural and molecular changes including their role on the pathophysiology of PVC- CM and recovery upon PVC cessation in the swine model. Aim 4. Validate PVC burden, baseline echocardiographic, hemodynamic and molecular features that can predict the development of, or resilience to PVC-CM in the swine model despite identical ventricular ectopy. Methods. 56animals will undergo pacemaker implant to reproduce frequent ventricular ectopy (PVCs). They will be randomized to one of 5 groups: 1) late-coupled 50% PVCs (n=13), 2) early-coupled 50% PVCs (n=13), 3) early-coupled PVCs 33% PVCs (n=10), early-coupled 25% PVCs (n=10), or 4) sham (n=10). At the end of a 12- week PVC period, a recovery phase (disabling PVCs) will be allowed in 5 animals of each group exposed to 50% burden and sham group (Fig. 6). Serial cardiac evaluation and biopsies will allow us to assess LV function, transcriptomic profile, dyad structure, Ca2+ transients (EC coupling), changes in JPH-2 and Cav1.2 expression, function and distribution and their mediators at baseline and different time points of PVC-CM in all groups. Significance. This proposal is designed to validate most echocardiographic, hemodynamic, molecular and cellular changes demonstrated in a new PVC-CM Swine model. A new swine PVC-CM model will provide: 1) corroboration of this clinical entity in mammalians, 2) expand our understanding of the mechanism t of PVC- CM as swine has some favorable techniques and procedures, such as viral transfection with AAV-9 to modify cellular and molecular expression, but most importantly 3) minimize the use of a unique and special large species such as the dog. Understanding the mechanism of PVC-CM will help us to identify high-risk patients to develop PVC-CM, but most importantly find future targets to prevent and treat subjects with PVC-CM.

背景。频繁的室性早搏 (PVC) 可导致左心室功能障碍或 心肌病（CM），简称PVC-心肌病（PVC-CM）。负责该 CM 的机制是 不清楚。 PVC-CM 犬模型不仅是证明 PVC-CM 可以在正常结构中诱导的关键 心脏，还可以确定可以解释 LV 发展的初步细胞和分子特征 功能障碍。直到最近，另一种 PVC 心肌病模型已在猪中被描述。 该模型似乎具有与犬模型相似的超声心动图特征，尽管分子特征 仍然未知。本研究的主要目的是在猪模型中验证 PVC-CM。 假设。我们的主要假设是，与 PVC-CM 犬模型类似，猪模型将 证明：1）早期轻度至中度左心室功能障碍、轻度二尖瓣反流和舒张功能障碍 耦合 PVC，而与晚期耦合相比，早期 PVC 将表现出较小程度的 LV 不同步 PVC（目标 1）； 2）白细胞介素和TNF-α信号传导增加，而间充质减少 发育、神经元投射延伸和肌肉收缩基因（目标 2）； 3）二元组中的类似变化， 以 ICaL 减少和 Cav1.2、JPH-2、L 型 Ca2+ 通道错位输出下调为特征 Ca2+ 诱导的 Ca2+ 释放受损，导致二元组的减少和 BIN1 的减少（目标 3）； 3）； 4) 最低慢性病 开发 PVC-CM 需要暴露 25% PVC 负荷（目标 4）。 目标 1. 验证 PVC-CM 猪模型中的心脏结构变化以及期外收缩的影响 PVC-CM 开发中的增强作用和 PVC 偶联间隔。 目标 2. 确认猪模型中与 PVC-CM 相关的转录组学分析。 目标 3. 证实结构和分子变化，包括它们对 PVC-病理生理学的作用 猪模型中停止 PVC 后的 CM 和恢复。 目标 4. 验证 PVC 负荷、基线超声心动图、血流动力学和分子特征， 尽管存在相同的心室异位，但仍可预测猪模型中 PVC-CM 的发展或恢复能力。 方法。 56 只动物将接受起搏器植入以重现频繁的心室异位 (PVC)。他们 将被随机分配到 5 组之一：1) 晚耦合 50% PVC (n=13)，2) 早耦合 50% PVC (n=13)，3) 早期偶联 PVC 33% PVC (n=10)、早期偶联 25% PVC (n=10) 或 4) 假 (n=10)。在 12 结束时 周 PVC 期，每组 5 只动物将允许暴露于 50% 的恢复阶段（禁用 PVC） 负荷组和假手术组（图6）。连续心脏评估和活检将使我们能够评估左心室功能， 转录组谱、二联体结构、Ca2+ 瞬变（EC 偶联）、JPH-2 和 Cav1.2 表达的变化， 各组 PVC-CM 基线和不同时间点的功能和分布及其调节因子。 意义。该提案旨在验证大多数超声心动图、血流动力学、分子和 新型 PVC-CM 猪模型展示了细胞变化。新型猪 PVC-CM 模型将提供：1) 在哺乳动物中证实了这一临床实体，2）扩大了我们对PVC-机制的理解 CM作为猪有一些有利的技术和程序，例如用AAV-9病毒转染来修饰 细胞和分子表达，但最重要的是3）尽量减少使用独特和特殊的大 诸如狗之类的物种。了解PVC-CM的机制将有助于我们识别高危患者 开发 PVC-CM，但最重要的是找到预防和治疗 PVC-CM 受试者的未来目标。