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LV功能障碍或 心肌病（CM），称为PVC-心肌病（PVC-CM）。负责此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，但也确定初步的细胞和分子特征，可以解释LV的发展 功能障碍直到最近，在猪种属中描述了一种替代的PVC-心肌病模型。 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犬模型相似，猪模型将 证明：1）早期轻度至中度LV功能障碍，轻度二尖瓣返流和舒张功能障碍， 与晚期偶联PVC相比，早期PVC的LV不同步程度较低 PVC（目标1）; 2）白细胞介素和TNF-α信号传导增加，而间质细胞减少 发育，神经元投射延伸和肌肉收缩基因（Aim 2）; 3）二分体中类似的变化， 特征是ICaL降低，Cav1.2、JPH-2下调，L型Ca 2+通道错位出局 二分体和BIN 1减少与受损的Ca 2+诱导的Ca 2+释放（目的3）; 3）;和4）最小的慢性 需要暴露25%的PVC负荷以开发PVC-CM（目标4）。 目标1.在PVC-CM猪模型中观察心脏结构变化和期外收缩后的影响 增强和PVC偶联间隔在PVC-CM的发展。 目标2.确认猪模型中与PVC-CM相关的转录组学分析。 目标3.证实了结构和分子变化，包括其在PVC病理生理学中的作用， 猪模型中PVC停止后的CM和恢复。 目标4。PVC负荷，基线超声心动图，血流动力学和分子特征， 预测猪模型中PVC-CM的发展或恢复，尽管心室异位相同。 方法. 56只动物将接受起搏器植入术以复制频繁的心室异位（PVC）。他们 将被随机分配至5组之一：1）晚期偶联50% PVC（n=13），2）早期偶联50% PVC（n=13），3） 早期偶联PVC 33%PVC（n=10），早期偶联PVC 25%PVC（n=10），或4）假手术（n=10）。在一个12- 在为期5周的PVC期，将允许每组5只动物进入恢复期（PVC失能），暴露于50% 负荷组和假手术组（图6）。连续的心脏评估和活组织检查可以让我们评估左心室功能， 转录组谱、二分体结构、Ca 2+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介质。 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 在新的PVC-CM猪模型中证实的细胞变化。新的猪PVC-CM模型将提供：1） 证实了这一临床实体在意大利，2）扩大我们的理解机制的PVC- CM作为猪有一些有利的技术和程序，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）最大限度地减少使用独特的和特殊的大 像狗这样的物种。了解PVC-CM的发病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。