Editorial: Cell Communication in Vascular Biology

Abstract

Editorial on the Research Topic Cell Communication in Vascular Biology This Research Topic comprises 5 review articles and 10 original contributions in the field of cell communication in Vascular Biology. Contributors used a variety of experimental approaches and models, or exercised keen analysis of published reports, to assess intercellular signaling between different pairs of cell types, such as the endothelium with vascular smooth muscle (VSM), platelets, leukocytes, tumor cells, and trophoblasts; but also, VSM and macrophages or among complex systems like intact vessels, the neurovascular unit and placenta. Communication includes direct cell-cell contact by adhesion molecules or gap junctions; classic receptor-mediated paracrine signaling and intercellular genetic modification by non-coding RNAs (NcRNA) or microvesicles transfer; all of this in the context of physiological regulation and different pathologies. Control of blood flow supply by the vascular system is essential to keep the homeostasis of each cell of the organism, and then, blood flow distribution must be dynamically regulated to match the changing metabolic demand of surrounding tissue. Although the amount of blood flow depends on the total cross-sectional area of arteries (i.e., total number and caliber) irrigating a particular territory, blood vessels are not inert conduits aimed to passively transport blood into the tissues, but they actually are complex, multicellular structures that must work as a unit to rapidly adjust the distribution of blood flow according to the minute-to minute cellular requirements (Segal et al., 2000; Segal, 2005). The vessel wall is mainly constituted by smooth muscle cells and endothelial cells; thus, cell-to-cell communication is fundamental for the fine synchronization of function between these two cell types along the length of the vessels (Segal, 2015). It should be noted that synchronization and coordination are accomplished by an intricate system of complementary signaling pathways, which involves the interaction of direct cell-to-cell communication via gap junctions and the release of autocrine/paracrine signals (Figueroa and Duling, 2009; Moncada and Higgs, 2018). The relevance of this interaction is highlighted by the fine coordination of endothelial and smooth muscle cell function observed in the control of vasomotor tone through gap junctions located at the myoendothelial junctions (i.e., myoendothelial gap junctions) and endotheliumderived relaxing signals, such as nitric oxide (NO), prostaglandins and an unidentified signal known as endothelium-derived hyperpolarizing factor (EDHF) (Busse et al., 2002). The regulation of these signaling pathways is elegantly depicted in this Research Topic by Schmidt and de Wit. Gap junctions are made up by the association of two hemichannels provided by each adjacent cell and, in turn, hemichannels are formed by connexin proteins (Sáez et al., 2003; Molica et al., 2018). However, individual hemichannels can be functional and work as a complementary signaling pathway...