Connexin-based Signaling in the Heart: Cellular and Exosomal

心脏中基于连接蛋白的信号传导：细胞和外泌体

基本信息

批准号：
10553255
负责人：
ROBERT G GOURDIE
金额：
$ 84.53万
依托单位：
VIRGINIA POLYTECHNIC INST AND ST UNIV
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-01-20 至 2028-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10553255
关键词：
Actins Action Potentials Acute Animal Model Anti-Arrhythmia Agents Area Arrhythmia Biomedical Engineering Brain Cardiac Cardiology Clinical Collaborations Complex Connexin 43 Connexins Coupling Data Drug Design Drug Targeting Gap Junctions Goals Heart Hour Human Knockout Mice Mammals Medicine Mutation Myocardial Myocardial Infarction Myocardium Phase Phase III Clinical Trials Production Protein Isoforms Proteins Reporting Role Severities Signal Transduction Skin Sodium Channel Sudden Death Testing Therapeutic Tissues Translating Ventricular Virus exosome heart preservation human female in silico induced pluripotent stem cell invention ischemic injury novel novel therapeutic intervention peptidomimetics pharmacologic porcine model response superresolution imaging voltage

Actins Action Potentials Acute Animal Model Anti-Arrhythmia Agents Area Arrhythmia Biomedical Engineering Brain Cardiac Cardiology Clinical Collaborations Complex Connexin 43 Connexins Coupling Data Drug Design Drug Targeting Gap Junctions Goals Heart Hour Human Knockout Mice Mammals Medicine Mutation Myocardial Myocardial Infarction Myocardium Phase Phase III Clinical Trials Production Protein Isoforms Proteins Reporting Role Severities Signal Transduction Skin Sodium Channel Sudden Death Testing Therapeutic Tissues Translating Ventricular Virus exosome heart preservation human female in silico induced pluripotent stem cell invention ischemic injury novel novel therapeutic intervention peptidomimetics pharmacologic porcine model response superresolution imaging voltage

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项目摘要

PROJECT ABSTRACT/SUMMARY The gap junction (GJ) protein Connexin 43 (Cx43) has long been held to be obligate for conduction of action potential (AP) in the ventricular myocardium. However, accumulating evidence during the last two decades from non-mammals, Cx43 knockout mice and human Cx43 mutations suggests that Cx43 GJs do not provide a sufficient explanation for how AP propagates in the heart – and indeed, that Cx43 GJs may be dispensable for cardiac conduction. Based on its short half (~1.5 hours), we recently estimated that on average the human female heart produces more than 80 grams of Cx43 per year – a rate more than 30-times that of actin, the most abundant myocardial protein in steady state. My lab is focused on two questions that are raised by these data. First, what is the mechanism of AP propagation in the ventricle, if Cx43 GJ-based coupling alone cannot account for this phenomenon? Second, if not absolutely required for cardiac conduction, for what purpose does the heart produce Cx43 at such high rates? In recently reported studies, we have determined that: A) Trans- interacting complexes of voltage-gated sodium channels (trans-VGSCs) located at the GJ edge (the perinexus) contribute to cardiac conduction; and B) That the Cx43 carboxyl terminus (CT) has key roles in modulating the heart's response to ischemic injury. Building on these findings, the goals of this project are to: 1) Determine the contribution of trans-VGSCs to cardiac AP propagation and the extent to which this mechanism operates independent of Cx43 GJ-based coupling; 2) Develop a pharmacologic approach to targeting trans-VGSCs as a novel anti-arrhythmic strategy; 3) Determine the extent to which the high levels of Cx43 production by the heart may be accounted for by recent findings that Cx43 is exported in exosomes; 4) Determine whether circulating exosomal Cx43, including Cx43 CT isoforms, are part of a natural signaling mechanism that modulates ischemic injury severity; and 5) Develop a novel therapeutic approach to treat myocardial infarction based on exosomes carrying Cx43 CT mimetic peptides, including translational testing in a large animal model – the pig. The project will involve cross-disciplinary collaboration between biologists, medicinal chemists, biomedical engineers and clinicians – both human and veterinary. The PI has genuine translational bona-fides, with a drug targeting the Cx43 CT invented in his lab currently in multiple Phase III clinical trials. State-of-the-art approaches will be used including super resolution imaging, in silico drug design, genetically modified viruses, iPSCs and testing of exosome-based therapeutics on large animal models. We posit that the primary assignment of myocardial Cx43 may not be in AP propagation. Rather, it is our hypothesis that the high energetic commitment to Cx43 production made by the heart, and other tissues (e.g., skin, vasculature and brain), relates mainly to functions of Cx43 in an exosome-based signaling mechanism that modulates response to ischemic injury in humans and other mammals. This R35 project seeks to challenge prevailing views on the role of the GJ protein Cx43 and translate the new perspectives gained for clinical benefit in treatment of arrhythmia and myocardial infarction.

项目摘要/摘要长期以来，GAP连接（GJ）蛋白连接蛋白连接蛋白43（CX43）长期以来一直保持着行动的义务室心肌的潜力（AP）。但是，在过去的二十年中积累了证据非哺乳动物，CX43敲除小鼠和人CX43突变表明CX43 GJ不提供充分说明AP如何在心脏中传播 - 实际上，CX43 GJ可能是可分配的心脏传导。基于其短的一半（〜1.5小时），我们最近估计，人类女性平均心脏每年产生80克CX43，这是肌动蛋白的30倍以上，最丰富的速度心肌蛋白处于稳定状态。我的实验室专注于这些数据提出的两个问题。第一的，如果仅基于CX43 GJ的耦合，通风中AP传播的机制是什么这个现象？第二，即使不是绝对必需的心脏传导，心脏是什么目的以如此高的速度生产CX43？在最近报道的研究中，我们确定：a）跨性别位于GJ边缘（Perinexus）的电压门控钠通道（Trans-VGSC）的相互作用复合物有助于心脏传导； b）CX43羧基末端（CT）在调制调制中具有关键作用心脏对缺血性损伤的反应。在这些发现的基础上，该项目的目标是：1）确定 Trans-VGSC对心脏AP传播的贡献以及该机制运作的程度独立于基于CX43 GJ的耦合； 2）开发一种靶向反vGSC作为一个的药物方法新颖的反心律失常策略； 3）确定心脏高水平的CX43产生程度最近的发现，CX43在外泌体中出口。 4）确定是否循环外泌体CX43，包括CX43 CT同工型，是调节缺血性的自然信号传导机制的一部分受伤严重程度； 5）开发一种新型的治疗方法来基于外泌体治疗心肌梗死携带CX43 CT模拟肽，包括大型动物模型中的翻译测试 - 猪。项目将涉及生物学家，药物学家，生物医学工程师和临床医生 - 人类和兽医。 PI具有真正的翻译善意，其药物针对 CX43 CT目前在他的实验室中发明了III期临床试验。将使用最先进的方法包括超级分辨率成像，在硅药物设计中，转基因病毒，IPSC和测试大型动物模型的基于外泌体的治疗。我们指出，心肌CX43的主要分配可能不在AP传播中。相反，我们的假设是对CX43的高能量承诺由心脏和其他组织（例如皮肤，脉管系统和大脑）产生的生产，主要与 CX43在基于外泌体的信号传导机制中，该机制调节了对人类和其他人类缺血性损伤的反应哺乳动物。这个R35项目旨在挑战有关GJ蛋白CX43角色的主要观点并翻译为了治疗心律不齐和心肌梗塞的临床益处而获得了新的观点。