Viral subversion of intercellular coupling during myocarditis

总结 心血管疾病仍然是美国的主要死亡原因，心肌炎也是主要原因之一。 在年轻人的猝死中占42%。人5型腺病毒是病毒性肝炎的主要病原体， 心肌炎，但由于宿主物种特异性限制了模型系统的发展， 心脏感染腺病毒主动感染对心肌细胞功能和心肌细胞增殖的影响 导致免疫反应和心力衰竭的原因尚不清楚。缝隙连接，主要是 在心室闰盘中包含蛋白质连接蛋白43（Cx43）， 在每个心跳期间传播。间隙连接、其他ID之间的密切联系和相互作用 常驻离子通道和机械连接的组成部分现在被广泛接受。ID变更 机械和电耦合导致心律失常，虽然已经证明腺病毒 感染晚期直接靶向粘附，腺病毒性心肌炎与Cx43缺口的关系 连接或其它离子通道的功能和调节仍然未被探索。事实上， 心肌炎在很大程度上是支持性的，没有治疗干预或抗病毒药物显示出显著的临床意义。 功效至今。通过对腺病毒感染心肌的分子水平的研究， 关于感染对心肌细胞影响的潜在机制的知识存在重大差距 细胞间偶联和电生理学，同时鉴定治疗靶点以限制病毒传播和/或 挽救患病心脏的电耦合。我们的长期目标是阐明病理机制 病毒性心肌炎和导致心脏离子通道和连接结构的致炎性破坏。 本R 01提案的目的是确定细胞间电耦合和机械耦合是如何 在急性腺病毒心脏感染期间受影响以沉淀致炎底物。我们的中央 假设腺病毒劫持连接蛋白的表达和功能，导致致瘤性 在大体病理性重塑和明显的宿主免疫应答之前，我们将测试这个 目的1：确定早期腺病毒蛋白在腺病毒感染中的作用。 产生一个致炎细胞景观。这一目标的工作假设是， 腺病毒蛋白激活靶向Cx43和心脏离子通道功能的PI 3 K/β-连环蛋白信号传导轴， 有助于胚胎发育。目的2：确定连接蛋白和间隙连接在细胞间的作用 腺病毒发病机制中的信息交流。这个目标的工作假设是， 稳定细胞连接以促进病毒传播，同时限制细胞间通讯以增强病毒 复制的

SUMMARY Cardiovascular disease remains the principal cause of death in the United States, with myocarditis contributing to 42% of all sudden deaths in young adults. Human adenovirus type 5 is a leading etiological agent of viral myocarditis, yet research is lacking due to host species specificity limiting the development of model systems for cardiac infection. The effect of active adenoviral infection on cardiomyocyte function and arrhythmogenesis that precedes immune responses and progression to heart failure is unknown. Gap junctions, predominantly comprising the protein connexin43 (Cx43) in the ventricular intercalated disc, facilitate action potential propagation during each heartbeat. An intimate association and interplay between gap junctions, other ID resident ion channels, and components of mechanical junctions is now well accepted. Alterations in ID mechanical and electrical coupling cause arrhythmias, and while it has been demonstrated that adenovirus directly targets adhesion late in infection, the relationship between adenoviral myocarditis and Cx43 gap junction, or other ion channel, function and regulation remains unexplored. Indeed, treatment for viral myocarditis is largely supportive, with no therapeutic interventions or antivirals demonstrating significant clinical efficacy to date. Through study of adenoviral infection of cardiac muscle at the molecular level, we will address significant gaps in the knowledge regarding mechanisms underlying the impact of infection on cardiomyocyte intercellular coupling and electrophysiology while identifying therapeutic targets to limit viral spread and/or rescue electrical coupling in diseased hearts. Our long term goal is to elucidate the pathological mechanisms of viral myocarditis and resulting arrhythmogenic subversion of cardiac ion channels and junctional structures. The objective of this R01 proposal is to determine how electrical and mechanical intercellular coupling is affected during acute adenoviral cardiac infection to precipitate an arrhythmogenic substrate. Our central hypothesis is that adenovirus hijacks junction protein expression and function leading to an arrhythmogenic substrate prior to gross pathological remodeling and the appreciable host immune responses. We will test this hypothesis with the following two Specific Aims: Aim 1: Determine the role of early adenoviral proteins in generation of an arrhythmogenic cellular landscape. The working hypothesis for this aim is that early adenoviral proteins activate a PI3K/β-catenin signaling axis targeting Cx43 and cardiac ion channel function, contributing to arrhythmogenesis. Aim 2: Determine the role of connexins and gap junction intercellular communication in adenoviral pathogenesis. The working hypothesis for this aim is that adenovirus stabilizes cellular junctions to facilitate viral spread while limiting intercellular communication to enhance viral replication.