Targeting Pannexin 1 as a Novel Mechanism for Arrhythmia and Fibrosis in Duchenne Cardiomyopathy

靶向 Pannexin 1 作为杜氏心肌病心律失常和纤维化的新机制

• 批准号: 10543143
• 负责人: Frank J Raucci
• 金额: $ 14.84万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-07 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10543143
• 关键词: 18 year old; Abbreviations; Ablation; Age; Apoptosis; Apoptotic; Arrhythmia; Biology; Ca(2+)-Transporting ATPase; Calcium; Cardiac; Cardiac Electrophysiologic Techniques; Cardiac Myocytes; Cardiovascular Diseases; Cause of Death; Cell Membrane Permeability; Cell Nucleus; Cells; Cessation of life; Childhood; Coculture Techniques; Complex; Cytoplasm; Data; Dedications; Defect; Development; Diagnosis; Dilated Cardiomyopathy; Disease; Duchenne cardiomyopathy; Duchenne muscular dystrophy; Dystrophin; Fibroblasts; Fibrosis; Foundations; Functional disorder; Funding; Gene Expression; Generations; Genes; Genetic; Goals; Heart Diseases; Heart failure; Histopathology; Home; Human; Hypoxia; Inflammasome; Inflammation; Inflammatory; Investigation; Ions; Isoproterenol; Knock-out; Link; Measures; Mediator; Mentorship; Modality; Modeling; Molecular; Morbidity - disease rate; Muscle Cells; Muscle Weakness; Muscular Dystrophies; Myocardial dysfunction; Pathologic; Pathway interactions; Patients; Persons; Phenotype; Physicians; Play; Population; Primary Myocardial Diseases; Process; Proteins; Proton-Translocating ATPases; Purinoceptor; Regulation; Research; Research Personnel; Risk; Role; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum; Scientist; Signal Pathway; Signal Transduction; Skeletal Muscle; Stimulus; Stretching; Structure; Supportive care; Symptoms; Testing; Time; Training Programs; Transgenic Mice; Transgenic Organisms; Ventricular; Ventricular Arrhythmia; boys; cardioprotection; cardiovascular health; cell motility; cell type; coronary fibrosis; curative treatments; endoplasm; experimental study; extracellular; genetic approach; heart function; heart rhythm; improved; in vivo; induced pluripotent stem cell; inflammatory modulation; marenostrin; migration; mortality; mouse model; new therapeutic target; novel; pharmacologic; preservation; prevent; programs; recruit; skills; small molecule; targeted treatment; translational study; ventilation

PROJECT SUMMARY Cardiovascular disease is the primary cause of death for patients with Duchenne muscular dystrophy (DMD). Arrhythmia and cardiac fibrosis leading to dilated cardiomyopathy are the primary mechanisms of cardiac mortality. Pannexins (Pxs), which are large conductance ion and small molecule channels, have been implicated in other fibroproliferative diseases and are thought to be arrhythmogenic in other model of cardiac disease. Loss of dystrophin, the primary defect in DMD, leads to elevated intracellular calcium (Ca2+) which is also a primary effector of Pxs. The goal of this project is to investigate the mechanisms by which Px1 modulates the development of cardiac fibrosis and arrhythmogenesis in models of DMD cardiomyopathy. Our preliminary data demonstrate a novel role for Px1 in the development of cardiac fibrosis and inducible arrhythmia seen in the D2-mdx model of DMD. Genetic ablation of Px1 in the D2-mdx model (mdxPx1-/-) rescues the cardiac phenotype, including normalization of cardiac fibrosis.as assessed by histopathology and significant reduction in isoproterenol-induced ventricular ectopy. Based on these data, we hypothesize that pathologically elevated intracellular Ca2+, a hallmark of this disease, leads to Px1 activation and results in signaling cascades that activate apoptotic, oxidative, and inflammatory pathways that ultimately lead to fibroblast activation and the development of cardiac fibrosis. We also hypothesize that Px1 channels represent an independent mechanism for ventricular arrhythmia via generation of delayed after-depolarizations (DADs). We with test these hypotheses using the 3 specific aims outlined in this proposal. In Aim 1, we will use transgenic mice with global Px1 deletion in addition to pharmacological Px inhibition to determine if Px1 activation results in triggered arrhythmia. In Aim 2, we will identify the mechanism by which Px1 contributes to cardiac fibrosis in DMD cardiomyopathy using pharmacological and genetic strategies. As Pxs are expressed in both cardiomyocytes and cardiac fibroblasts, Aim 3 will test if fibroblast migration is dependent on Px1 activation in cardiomyocytes and/or fibroblasts using co-culture techniques for human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) and cardiac fibroblasts. The completion of these studies will help to improve our understanding of the mechanisms of cardiovascular disease in DMD and will provide the basis for further investigation of a novel therapeutic target that has the potential to delay or prevent cardiac mortality in DMD patients. Additionally, this proposal will allow a promising young physician scientist to gain important skill in basic and translational studies in cardiac electrophysiology, cell signaling, and inflammation/fibrosis biology under the expert guidance of a highly accomplished and dedicated mentorship committee. These new skills will provide the foundation for a successful transition from junior investigator to an independently-funded academic physician scientist.

项目概要 心血管疾病是杜氏肌营养不良症（DMD）患者死亡的主要原因。 心律失常和心脏纤维化导致扩张型心肌病是心脏疾病的主要机制 死亡。 Pannexins (Pxs) 是一种大电导离子和小分子通道，已被 与其他纤维增生性疾病有关，并被认为在其他心脏模型中会导致心律失常 疾病。肌营养不良蛋白的缺失是 DMD 的主要缺陷，会导致细胞内钙 (Ca2+) 升高， 也是 Pxs 的主要效应器。该项目的目标是研究 Px1 的机制 调节 DMD 心肌病模型中心脏纤维化和心律失常的发生。 我们的初步数据证明了 Px1 在心脏纤维化和诱导性纤维化发展中的新作用 DMD 的 D2-mdx 模型中出现心律失常。 D2-mdx 模型中 Px1 的遗传消融 (mdxPx1-/-) 挽救心脏表型，包括心脏纤维化的正常化。根据组织病理学和 显着减少异丙肾上腺素引起的心室异位。根据这些数据，我们假设 病理性升高的细胞内 Ca2+（该疾病的标志）会导致 Px1 激活并导致 信号级联激活细胞凋亡、氧化和炎症途径，最终导致 成纤维细胞活化和心脏纤维化的发展。我们还假设 Px1 通道代表 通过产生延迟后除极 (DAD) 来治疗室性心律失常的独立机制。 我们使用本提案中概述的 3 个具体目标来测试这些假设。在目标 1 中，我们将使用 除了药理学 Px 抑制外，还具有整体 Px1 缺失的转基因小鼠以确定 Px1 是否 激活会导致触发心律失常。在目标 2 中，我们将确定 Px1 贡献的机制 使用药理学和遗传策略治疗 DMD 心肌病的心脏纤维化。表示为 Pxs 在心肌细胞和心脏成纤维细胞中，目标 3 将测试成纤维细胞迁移是否依赖于 Px1 使用共培养技术激活心肌细胞和/或成纤维细胞以产生人诱导多能干细胞 心肌细胞 (hiPSC-CM) 和心脏成纤维细胞。这些研究的完成将有助于提高 我们对 DMD 心血管疾病机制的了解将为进一步的研究提供基础 研究有可能延迟或预防 DMD 患者心脏死亡的新型治疗靶点 患者。此外，该提案将使一位有前途的年轻医师科学家获得以下方面的重要技能： 心脏电生理学、细胞信号传导和炎症/纤维化生物学的基础和转化研究 在经验丰富且敬业的导师委员会的专家指导下。这些新技能将 为从初级研究员到独立资助的学者的成功过渡奠定基础 医师科学家。