Determining the role of macrophages in the developing cardiac conduction system

确定巨噬细胞在心脏传导系统发育中的作用

• 批准号: 10395422
• 负责人: Shannon Elizabeth Paquette
• 金额: $ 4.68万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10395422
• 关键词: Ablation; Address; Adult; Affect; Arrhythmia; Attention; Autonomic nervous system; Calcium; Calcium Signaling; Cardiac; Cardiac Myocytes; Cardiac conduction system; Cardiac development; Cardiac health; Cardiovascular system; Cells; Complex; Computers and Advanced Instrumentation; Connexin 43; Connexins; Data; Development; Echocardiography; Economic Burden; Electric Stimulation; Electrocardiogram; Embryo; Embryo Loss; Embryonic Development; Embryonic Heart; Fellowship; Fetal Heart; Goals; Health; Heart; Heart Abnormalities; Heart Atrium; Heart Diseases; Heart Rate; Homeostasis; Image; Immune; Infection; Inherited; Institution; Ion Channel Gating; Ions; Knowledge; Larva; Longevity; Lung; Maintenance; Mediating; Medical; Mentorship; Microscopy; Modeling; Morbidity - disease rate; Morphology; Mus; Myocardial dysfunction; Myocardium; Natural regeneration; Nodal; Optics; Organ; Pattern; Periodicity; Pharmaceutical Preparations; Physiology; Regulation; Reporting; Research; Resolution; Risk; Role; Sentinel; Series; Short QT syndrome; Signal Transduction; Stress; Stretching; System; Taxes; Techniques; Time; Tissues; Transgenic Organisms; Universities; Ventricular; Work; Zebrafish; atrioventricular node; calcium indicator; cardiogenesis; cell type; cellular targeting; constriction; coronary vasculature; electrical potential; experience; experimental study; fetal; genetic manipulation; heart function; immunoregulation; in vivo; insight; light gated; macrophage; mutant; new therapeutic target; novel; novel therapeutic intervention; optogenetics; response; response to injury

PROJECT SUMMARY/ABSTRACT Macrophages are well-characterized as sentinel immune cells that coordinate cellular responses to injury and infection. However, emerging evidence demonstrates that macrophages have novel, non-canonical functions critical for developmental regulation, tissue homeostasis, and regeneration. Likewise, cardiac macrophages have essential functions in patterning the coronary vasculature, valvular remodeling, and in modulating adult heart conduction. Considering the substantial morbidity and economic burden associated with abnormal cardiogenesis and arrhythmias, further elucidating the roles of cardiac macrophages in normal heart development and function is critical for devising novel therapeutic strategies. In adult mammalian hearts, macrophages electrically couple to cardiomyocytes at the atrioventricular node via Connexin 43, a gap junction protein. These macrophages directly modulate electrical activity of nodal cardiomyocytes, and thus cardiac conduction. However, it is not known if macrophages (1) are required during embryogenesis to establish proper conduction or (2) if macrophage-derived signals modulate heart function in the developing heart. Therefore, this proposal will address a critical knowledge gap in the field of cardiac development in two aims. In Aim 1, I will establish the electrical potential of embryonic macrophages to modulate fetal cardiac conduction. In Aim 2, I will determine how loss of embryonic macrophage affects conduction and adult heart health. In my approach, I utilize zebrafish, a well-established developmental model whose salient features include rapid ex vivo development, optical transparency, and high amenability to genetic manipulation. This proposal will be carried out at Brown University, an exemplar academic research institution with extensive access to advanced instrumentation. With the guidance and mentorship of her sponsor, Dr. Jessica Plavicki, and co-sponsor, Dr. Chris Moore, the applicant is prepared and equipped to carryout this fellowship. My exciting preliminary data reveal previously undescribed roles of macrophages in embryonic cardiac conduction and cardiogenesis. Using transgenic zebrafish with macrophage-specific expression of a genetically encoded calcium indicator, GCaMP6s, I found that seeded macrophages have synchronous bursts of calcium activity in time with ventricular beating. In optogenetic experiments, I show that larval heart rate can be modulated by stimulating or silencing macrophage electrical activity via macrophage-specific expression of light-gated ion channels. This poses an intriguing question of whether developmental arrythmias could be corrected by specifically targeting macrophages. Loss of embryonic macrophages, via drug-inducible ablation or in embryonic macrophage mutants, altered ventricular chamber formation and function in embryonic zebrafish, as well as adult cardiomyocyte compaction and gross heart morphology. Successful completion of this fellowship will clarify and expand our knowledge of non-canonical macrophage functions in the developing heart, as well as provide valuable insight into the cell types modulating embryonic heart function.

项目总结/摘要 巨噬细胞作为哨兵免疫细胞，协调细胞对损伤的反应 和感染然而，新的证据表明，巨噬细胞具有新的，非典型的， 对发育调节、组织稳态和再生至关重要的功能。同样，心脏 巨噬细胞在冠状动脉血管系统的形成、瓣膜重塑和 调节成人心脏传导。考虑到与之相关的大量发病率和经济负担， 异常心脏发生和心律失常，进一步阐明心脏巨噬细胞在正常心脏中的作用 发育和功能对于设计新的治疗策略至关重要。 在成年哺乳动物心脏中，巨噬细胞在房室结处与心肌细胞电偶联 连接蛋白43，一种间隙连接蛋白。这些巨噬细胞直接调节结 心肌细胞，从而心脏传导。然而，目前尚不清楚巨噬细胞（1）是否需要在 胚胎发育以建立适当的传导或（2）如果巨噬细胞来源的信号调节心脏功能， 发展的心脏。因此，该提案将解决心脏领域的关键知识缺口， 发展有两个目标。在目的1中，我将建立胚胎巨噬细胞的电位，以调节 胎儿心传导在目标2中，我将确定胚胎巨噬细胞的损失如何影响传导， 成人心脏健康在我的方法中，我利用斑马鱼，一种成熟的发育模型，其突出的特点是 特征包括快速离体发育、光学透明性和对遗传操作的高度适应性。 这项建议将在布朗大学进行，布朗大学是一个典型的学术研究机构， 先进的仪器设备在她的赞助商杰西卡·普拉维奇博士的指导和指导下， 共同赞助人，克里斯摩尔博士，申请人准备和装备，以执行这项奖学金。 我令人兴奋的初步数据揭示了巨噬细胞在胚胎心脏中以前未描述的作用。 传导和心脏发生。使用具有巨噬细胞特异性表达的转基因斑马鱼， 编码的钙指示剂，GCaMP 6s，我发现接种的巨噬细胞有同步的钙爆发， 与心室搏动同步。在光遗传学实验中，我证明了幼虫的心率可以被调节， 通过经由光门控离子的巨噬细胞特异性表达刺激或沉默巨噬细胞电活性 渠道这提出了一个有趣的问题，即发育性心律失常是否可以通过 专门针对巨噬细胞。胚胎巨噬细胞的损失，通过药物诱导的消融或在胚胎 巨噬细胞突变体，改变了胚胎斑马鱼的心室腔形成和功能，以及成年 心肌细胞致密化和总体心脏形态。成功完成本奖学金将澄清和 扩大我们对发育中心脏中非典型巨噬细胞功能的了解，并提供 对调节胚胎心脏功能的细胞类型的有价值的见解。