Heart-platelet crosstalk: JNK, AF, and thrombogenesis

心脏-血小板串扰：JNK、AF 和血栓形成

• 批准号: 10525312
• 负责人: Xun Ai
• 金额: $ 56.28万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-13 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10525312
• 关键词: Abnormal Platelet; Age; Aging; Agonist; Alcohol abuse; Alcohols; Animal Model; Animals; Antibodies; Arrhythmia; Atrial Fibrillation; Biochemical; Blood; Blood Platelets; Blood coagulation; Cardiac; Cardiac Electrophysiologic Techniques; Cardiovascular Diseases; Clinical; Clinical Data; Coupling; Data; Development; Electrophysiology (science); Endocytosis; Event; Experimental Designs; Foundations; Gene Transfer; Gene Transfer Techniques; Genetic; Goals; Heart; Heart Atrium; Heart failure; Hemorrhage; Homeostasis; Human; ITPR1 gene; Image; Intervention; Knock-out; Knowledge; Lead; Link; MAPK8 gene; MAPK9 gene; Maintenance; Measurement; Mechanics; Mediating; Messenger RNA; Modeling; Molecular; Molecular Biology; Morbidity - disease rate; Mus; Myocardial Infarction; N-terminal; Optics; Organ Donor; Oryctolagus cuniculus; Outcome; Pathogenicity; Patients; Phospholipase C; Phosphotransferases; Physiology; Platelet Activation; Platelet aggregation; Predisposition; Prevalence; Process; Proteins; Reporting; Rest; Risk; Risk Factors; Role; Signal Pathway; Signal Transduction; Sinus; Specific qualifier value; Stress; Stress Response Signaling; Stroke; Techniques; Testing; Therapeutic; Therapeutic Intervention; Thromboembolism; Thrombophilia; Thrombosis; Thrombus; Time; Translating; aged; alcohol exposure; base; biological adaptation to stress; calmodulin-dependent protein kinase II; clinically significant; design; heart cell; high risk; human tissue; in vivo; in vivo imaging; inhibitor; mortality; mouse model; novel; novel therapeutics; platelet function; prevent; stroke risk; targeted treatment; thrombogenesis; voltage

Atrial fibrillation is the most common arrhythmia with a high risk of stroke and stroke-associated mortality and morbidity. The prevalence of AF and stroke, increases markedly with age and alcohol abuse. The classic pathophysiological concept is atrial mechanical stasis during AF promotes thromboembolism formation. Thus, antithrombotic therapy has been a key component of AF management. However, due to the stroke-bleeding dilemma, and the varying risk of thromboemobolic events, only about half of all AF patients receive antithrombotic therapies. Emerging clinical findings are challenging our long-standing AF-stroke dogma, leaveing the causal link between AF and thrombogenesis even more baffling. The goal of this proposal is to fill this knowledge gap, establish a previously unrecognized crosstalk between heart and platelets through circulating microparticles containing heart-origin activated stress molecule JNK2 and reveal the underlying mechanism of the dual functional role of cardiac JNK2 in both thrombogenesis and AF development. Our intriguing preliminary findings suggest that age- and alcohol-driven JNK activation in the heart is mechanistically linked to the platelet activation and thus increased thrombogenesis. This is potentially a paradigm-shifting concept. Next, we found heart cells shed JNK-microparticles (JNK-MPs) and these MPs could then interact with platelets through an action of JNK2-specific endocytosis. Consequently, increased platelet JNK2 could lead to abnormal platelet Ca homeostasis and increase resting platelet reactivity. All these intriguing preliminary results and our previous findings point to a previously unrecognized JNK2-signaling crosstalk between the heart and platelets. In this proposal, we will use complementary electrophysiological approaches (dual voltage/Ca optical mapping, intravital confocal platelet Ca imaging, in vivo atrial painting gene transfer, ex vivo platelet aggregation, in vivo thrombus formation, and single IP3R channel recording) and biochemical techniques in intact atria, platelets, and even in single channels to gain a comprehensive picture of the relationship between cardiac JNK2, thrombogenesis and AF risk. The JNK2 actions on AF propensity, platelet Ca handling, and resting platelet reactivity will be dissected using several novel cardiac specific inducible Tg mouse models with manipulated JNK2 (JNK1) activity (activated or inactivated) and aged animals with and without atrial-specific JNK2 inhibition using a unique in vivo atrial painting gene transfer technique. To potentially translate the results from animal models to humans, we will perform selective studies in viable human platelets and hearts from organ donors. Our specific aims are: 1) Define the link between cardiac JNK2 (cJNK2) activation, platelet function, thrombogenesis and AF and 2) Delineate how the heart talks to platelets through circulating JNK2-MPs, governing platelet Ca handling and hyper-reactivity. This proposal integrates important functional measurements and fundamental mechanistic studies along with appropriate alternative approaches. Cardiac specific interventions (in vivo atrial gene transfer & genetic JNK inhibition) that limit cardiac JNK2 activity will be tested as proof-in-principle studies and explored as potential therapeutic options to prevent and/or treat thrombogenesis and AF.

心房颤动是最常见的心律失常，具有很高的中风风险和中风相关的死亡率和发病率。 房颤和中风的患病率随着年龄和酗酒而显着增加。经典的病理生理学 概念是房颤期间心房机械停滞促进血栓栓塞形成。因此，抗血栓治疗 一直是 AF 管理的关键组成部分。然而，由于中风出血的困境以及不同的风险 在血栓栓塞事件中，只有大约一半的 AF 患者接受抗血栓治疗。新兴临床 研究结果挑战了我们长期以来关于房颤中风的教条，留下了房颤与中风之间的因果关系。 血栓形成更令人费解。该提案的目标是填补这一知识空白，建立以前的 通过含有心脏来源的循环微粒，心脏和血小板之间未被识别的串扰 激活应激分子JNK2并揭示心脏JNK2双重功能作用的潜在机制 血栓形成和房颤发展。我们有趣的初步发现表明，年龄和酒精驱动的 心脏中的 JNK 激活在机制上与血小板激活相关，从而增加血栓形成。这 可能是一个范式转变的概念。接下来，我们发现心脏细胞脱落 JNK 微粒 (JNK-MP)，这些 然后 MP 可以通过 JNK2 特异性内吞作用与血小板相互作用。因此，增加了 血小板JNK2可能导致血小板Ca稳态异常并增加静息血小板反应性。所有这些 有趣的初步结果和我们之前的发现指出了以前未被识别的 JNK2 信号串扰 心脏和血小板之间。在本提案中，我们将使用互补的电生理学方法（双 电压/Ca 光学测绘、活体共聚焦血小板 Ca 成像、体内心房染色基因转移、离体血小板 聚集、体内血栓形成和单 IP3R 通道记录）和生化技术完好无损 心房、血小板，甚至单个通道，以全面了解心脏之间的关系 JNK2、血栓形成和房颤风险。 JNK2 对 AF 倾向、血小板 Ca 处理和静息血小板的作用 将使用几种新型心脏特异性诱导 Tg 小鼠模型与操纵 JNK2 来剖析反应性 (JNK1) 活性（激活或灭活）以及使用或不使用心房特异性 JNK2 抑制的老年动物 独特的体内心房绘画基因转移技术。可能将动物模型的结果转化为 人类，我们将对来自器官捐赠者的活的人类血小板和心脏进行选择性研究。我们的具体目标 是：1) 定义心脏 JNK2 (cJNK2) 激活、血小板功能、血栓形成和 AF 之间的联系；2) 描述心脏如何通过循环 JNK2-MP 与血小板对话，控制血小板 Ca 处理和 过度反应。该提案整合了重要的功能测量和基本机制研究 以及适当的替代方法。心脏特异性干预措施（体内心房基因转移和遗传 限制心脏 JNK2 活性的 JNK 抑制）将作为原理验证研究进行测试，并探索其潜力 预防和/或治疗血栓形成和房颤的治疗选择。