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: 10559583
• 负责人: Shannon Elizabeth Paquette
• 金额: $ 3.86万
• 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/10559583
• 关键词: Ablation; Adult; Affect; Arrhythmia; Attention; Autonomic nervous system; Calcium; Calcium Signaling; Cardiac; Cardiac Myocytes; Cardiac conduction system; Cardiac health; Cardiovascular system; Categories; Cells; Complex; Computers and Advanced Instrumentation; Connexin 43; Connexins; Data; Development; Disease; 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; Macrophage; Maintenance; Mediating; Medical; Mentorship; Microscopy; Modeling; Morbidity - disease rate; Morphology; Mus; Myocardial dysfunction; Myocardium; Natural regeneration; Nodal; Optics; Organ; Pattern; Periodicity; Pharmaceutical Preparations; Physiology; Population; Regulation; Reporting; Research; Resolution; Risk; Role; Sentinel; Series; Short QT syndrome; Signal Transduction; Stress; Stretching; System; Taxes; Techniques; Time; Tissues; Transgenic Organisms; Universities; Ventricular; Visualization; 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; mutant; new therapeutic target; novel; novel therapeutic intervention; optogenetics; response; response to injury; sudden cardiac death

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.

项目摘要/摘要 巨噬细胞被很好地表征为哨兵免疫细胞，该细胞对损伤的细胞反应进行了反应 和感染。但是，新兴的证据表明巨噬细胞具有新颖的非典型性 对发育调节，组织稳态和再生至关重要的功能。同样，心脏 巨噬细胞在对冠状动脉脉管系统，瓣膜重塑和中具有重要功能 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 异常心脏病和心律不齐，进一步阐明了心脏巨噬细胞在正常心脏中的作用 开发和功能对于制定新颖的治疗策略至关重要。 在成年哺乳动物心脏中，巨噬细胞在房屋节点上电伴侣到心肌细胞 通过连接蛋白43（一种间隙连接蛋白）。这些巨噬细胞直接调节节点的电活动 心肌细胞，因此心脏传导。但是，尚不清楚是否需要巨噬细胞（1） 胚胎发生以建立适当的传导或（2）如果巨噬细胞衍生的信号调节心脏功能 发育中的心。因此，该建议将解决心脏领域的关键知识差距 发展两个目标。在AIM 1中，我将建立胚胎巨噬细胞的电势来调节 胎儿心脏传导。在AIM 2中，我将确定胚胎巨噬细胞的丧失如何影响传导和 成人心脏健康。在我的方法中，我利用斑马鱼是一种完善的发展模型 特征包括快速的离体发展，光学透明度以及对遗传操作的高舒适性。 该建议将在布朗大学（Brown University）进行，这是一家典范学术研究机构 访问高级仪器。在她的赞助商杰西卡·普拉维奇（Jessica Plavicki）博士的指导和指导下 共同提案国克里斯·摩尔（Chris Moore）博士（申请人）已准备好并配备该奖学金。 我令人兴奋的初步数据揭示了先前未描述的巨噬细胞在胚胎心脏中的作用 传导和心脏病。使用转基因斑马鱼与遗传上巨噬细胞特异性表达 编码的钙指示器，GCAMP6S，我发现种子巨噬细胞具有同步的钙爆发 及时进行心室跳动的活动。在光遗传实验中，我表明可以调节幼虫心率 通过通过巨噬细胞特异性表达光门控离子刺激或沉默巨噬细胞电活动 频道。这提出了一个有趣的问题，即是否可以通过 专门针对巨噬细胞。通过药物诱导的消融或胚胎中的胚胎巨噬细胞丧失 巨噬细胞突变体，胚胎斑马鱼中的心室形成和功能改变了 心肌细胞压实和心脏形态严重。成功完成此研究金将澄清并 扩展我们对发展心脏中非规范巨噬细胞功能的知识，并提供 对调节胚胎心脏功能的细胞类型的宝贵洞察力。