Cardiac macrophages maintain homeostasis and orchestrate response to disease. Utilization of genetic fate-mapping and single-cell RNA sequencing shifted the paradigm of macrophage heterogeneity from the canonical M1/M2 classification in favour of a nuanced approach that reconciles divergent origins, lifecycles, and transcriptional states. Here, we provide a conceptual framework to assess cardiac macrophage complexity that integrates transcriptional and functional heterogeneity that tracks with subset-specific markers (TIMD4 and CCR2). Our goal is to provide a starting point for researchers to dissect the functions of known resident cardiac macrophage subpopulations. We discuss recent advances and limitations in our understanding of cardiac macrophage diversity in ischemic injury, hypertension and myocarditis.

心脏巨噬细胞维持体内平衡并协调对疾病的反应。利用遗传命运图谱和单细胞 RNA 测序将巨噬细胞异质性的范式从规范的 M1/M2 分类转变为一种微妙的方法，可以调和不同的起源、生命周期和转录状态。在这里，我们提供了一个概念框架来评估心脏巨噬细胞的复杂性，该框架整合了跟踪子集特异性标记（TIMD4 和 CCR2）的转录和功能异质性。我们的目标是为研究人员剖析已知常驻心脏巨噬细胞亚群的功能提供一个起点。我们讨论了我们对缺血性损伤、高血压和心肌炎中心脏巨噬细胞多样性的理解的最新进展和局限性。