BACKGROUND The elaborate patterning of coronary arteries critically supports the high metabolic activity of the beating heart. How coronary endothelial cells coordinate hierarchical vascular remodeling and achieve arteriovenous specification remains largely unknown. Understanding the molecular and cellular cues that pattern coronary arteries is crucial to develop innovative therapeutic strategies that restore functional perfusion within the ischemic heart. METHODS Single-cell transcriptomics and histological validation were used to delineate heterogeneous transcriptional states of the developing and mature coronary endothelium with a focus on sprouting endothelium and arterial cell specification. Genetic lineage tracing and high-resolution 3-dimensional imaging were used to characterize the origin and mechanisms of coronary angiogenic sprouting, as well as to fate-map selective endothelial lineages. Integration of single-cell transcriptomic data from ischemic adult mouse hearts and human embryonic data served to assess the conservation of transcriptional states across development, disease, and species. RESULTS We discover that coronary arteries originate from cells that have previously transitioned through a specific tip cell phenotype. We identify nonoverlapping intramyocardial and subepicardial tip cell populations with differential gene expression profiles and regulatory pathways. Esm1-lineage tracing confirmed that intramyocardial tip cells selectively contribute to coronary arteries and endocardial tunnels, but not veins. Notably, prearterial cells are detected from development stages to adulthood, increasingly in response to ischemic injury, and in human embryos, suggesting that tip cell-to-artery specification is a conserved mechanism. CONCLUSIONS A tip cell-to-artery specification mechanism drives arterialization of the intramyocardial plexus and endocardial tunnels throughout life and is reactivated upon ischemic injury. Differential sprouting programs govern the formation and specification of the venous and arterial coronary plexus.

中文翻译：

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心肌内芽尖细胞指定冠状动脉化。


背景技术冠状动脉的复杂模式至关重要地支持跳动心脏的高代谢活动。冠状动脉内皮细胞如何协调分层血管重塑并实现动静脉规范仍然很大程度上未知。了解冠状动脉模式的分子和细胞线索对于开发恢复缺血心脏功能性灌注的创新治疗策略至关重要。方法 使用单细胞转录组学和组织学验证来描述发育和成熟冠状动脉内皮的异质转录状态，重点关注萌芽内皮和动脉细胞规范。遗传谱系追踪和高分辨率 3 维成像用于表征冠状血管生成萌芽的起源和机制，以及绘制选择性内皮谱系的命运图谱。来自缺血成年小鼠心脏的单细胞转录组数据和人类胚胎数据的整合可用于评估发育、疾病和物种中转录状态的保守性。结果我们发现冠状动脉起源于先前通过特定尖端细胞表型转变的细胞。我们鉴定了具有差异基因表达谱和调控途径的非重叠心肌内和心外膜下尖端细胞群。 Esm1谱系追踪证实，心肌内尖端细胞选择性地参与冠状动脉和心内膜隧道，但不参与静脉。值得注意的是，从发育阶段到成年期，动脉前细胞都被检测到，并且越来越多地响应缺血性损伤，并且在人类胚胎中，这表明尖端细胞到动脉的特异化是一种保守的机制。 结论 尖端细胞到动脉的规范机制在整个生命过程中驱动心肌内丛和心内膜隧道的动脉化，并在缺血性损伤时重新激活。差异萌芽程序控制静脉和动脉冠状丛的形成和规格。