Department of Cell and Chemical Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
Biomolecules. 2020 Mar 5;10(3):404. doi: 10.3390/biom10030404.
The epicardium, the outer layer of the heart, has been of interest in cardiac research due to its vital role in the developing and diseased heart. During development, epicardial cells are active and supply cells and paracrine cues to the myocardium. In the injured adult heart, the epicardium is re-activated and recapitulates embryonic behavior that is essential for a proper repair response. Two indispensable processes for epicardial contribution to heart tissue formation are epithelial to mesenchymal transition (EMT), and tissue invasion. One of the key groups of cytokines regulating both EMT and invasion is the transforming growth factor β (TGFβ) family, including TGFβ and Bone Morphogenetic Protein (BMP). Abundant research has been performed to understand the role of TGFβ family signaling in the developing epicardium. However, less is known about signaling in the adult epicardium. This review provides an overview of the current knowledge on the role of TGFβ in epicardial behavior both in the development and in the repair of the heart. We aim to describe the presence of involved ligands and receptors to establish if and when signaling can occur. Finally, we discuss potential targets to improve the epicardial contribution to cardiac repair as a starting point for future investigation.
心外膜是心脏的外层，由于其在心脏发育和疾病中的重要作用，在心 脏研究中备受关注。在发育过程中，心外膜细胞活跃，并向心肌提供细胞 和旁分泌线索。在受伤的成年心脏中，心外膜被重新激活，并再现了胚胎 行为，这对于适当的修复反应至关重要。心外膜对心脏组织形成的两个不 可或缺的贡献过程是上皮间质转化 (EMT) 和组织浸润。调节 EMT 和侵 润的关键细胞因子之一是转化生长因子 β (TGFβ) 家族，包括 TGFβ 和 骨形态发生蛋白 (BMP)。已经进行了大量研究来了解 TGFβ 家族信号在发 育中心外膜中的作用。然而，对于成年心外膜中的信号知之甚少。本评 述概述了 TGFβ 在心脏发育和修复中心外膜行为中的作用的现有知识。 我们旨在描述涉及的配体和受体的存在，以确定信号是否以及何时发生。 最后，我们讨论了潜在的靶点，以提高心外膜对心脏修复的贡献，作为未 来研究的起点。
