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.

项目总结 心血管疾病是杜氏肌营养不良症(DMD)患者的主要死亡原因。 心律失常和心肌纤维化导致扩张型心肌病是心脏疾病的主要机制 死亡率。PAnnexins(PXs)是一种大电导、小分子的离子通道。 与其他纤维增生性疾病有关，并被认为在其他心脏模型中是致心律失常的 疾病。DMD的主要缺陷是Dstrophin的缺失，它会导致细胞内钙(Ca~(2+))升高。 也是PX的主要效应者。该项目的目标是研究PX1 在DMD心肌病模型中调节心脏纤维化和心律失常的发展。 我们的初步数据显示，PX1在心脏纤维化和诱导性心肌纤维化的发展中发挥了新的作用 D2-MDX DMD模型出现心律失常。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。 显著减少异丙肾上腺素诱导的室性异位。根据这些数据，我们假设 病理性细胞内钙离子升高是这种疾病的一个标志，它会导致PX1激活，导致 信号级联激活凋亡、氧化和炎症通路，最终导致 成纤维细胞活化与心肌纤维化的发生发展。我们还假设PX1通道代表 延迟后除极(DAD)是室性心律失常的独立机制。 我们使用这项提案中概述的三个具体目标来检验这些假设。在目标1中，我们将使用 PX1基因整体缺失转基因小鼠在药理学PX抑制的基础上确定PX1是否 激活会导致触发的心律失常。在目标2中，我们将确定PX1对 药物和遗传策略在DMD心肌病中的心脏纤维化。当PX被表达时 在心肌细胞和心脏成纤维细胞中，Aim 3将测试成纤维细胞的迁移是否依赖于PX1 人诱导多能干细胞共培养技术在心肌细胞和/或成纤维细胞中的激活 细胞心肌细胞(hiPSC-CMS)和心脏成纤维细胞。这些研究的完成将有助于改善 我们对DMD心血管疾病发病机制的认识，将为下一步 有可能延缓或预防DMD心脏死亡的新治疗靶点的研究 病人。此外，这项提议将使一位有前途的年轻内科科学家获得重要的技能 心脏电生理学、细胞信号和炎症/纤维化生物学的基础和翻译研究 在一个非常有成就和敬业的指导委员会的专家指导下。这些新技能将 为成功地从初级研究员过渡到独立资助的学术机构奠定基础 内科科学家。