Background: Substantial evidences support the hypothesis that the epicardium has a role in cardiac repair and regeneration in part providing, by epithelial to mesenchymal transition (EMT), progenitor cells that differentiate into cardiac cell types and in part releasing paracrine factors that contribute to cardiac repair. Besides cell contribution, a significant paracrine communication occurs between the epicardium and the myocardium that improves the whole regenerative response. Signaling pathways underlying this communication are multiple as well as soluble factors involved in cardiac repair and secreted both by myocardial and epicardial cells. Most recently, extracellular vesicles, i.e. exosomes, that accumulate in the pericardial fluid (PF) and are able to transport bioactive molecules (cytosolic proteins, mRNAs, miRNAs and other non-coding RNAs), have been also identified as potential mediators of epicardial-mediated repair following myocardial injury.

Conclusion: This mini-review provides an overview of the epicardial-myocardial signaling in regulating cardiac repair in ischemic heart diseases. Indeed, a detailed understanding of the crosstalk between myocardial and epicardial cells and how paracrine mechanisms are involved in the context of ischemic heart diseases would be of tremendous help in developing novel therapeutic approaches to promote cardiomyocytes survival and heart regeneration following myocardial infarction (MI).

背景：大量证据支持以下假设：心外膜在心脏修复和再生中发挥作用，部分通过上皮间质转化 (EMT) 提供分化为心脏细胞类型的祖细胞，部分释放有助于心脏修复的旁分泌因子. 除了细胞贡献外，心外膜和心肌之间发生显着的旁分泌通讯，可改善整个再生反应。这种通讯背后的信号通路是多种可溶性因子，参与心脏修复并由心肌和心外膜细胞分泌。最近，细胞外囊泡，即外泌体，在心包液 (PF) 中积累并能够运输生物活性分子（胞质蛋白、mRNA、

结论：这篇小型综述概述了在缺血性心脏病中调节心脏修复的心外膜-心肌信号传导。事实上，详细了解心肌和心外膜细胞之间的串扰以及旁分泌机制如何参与缺血性心脏病的背景将极大地帮助开发新的治疗方法，以促进心肌梗死 (MI) 后心肌细胞的存活和心脏再生。