Microvesicles and exosomes for intracardiac communication

The heart is an organ with a complex mixture of well-organized interactions of different cell types that facilitate proper myocardial contractility, sufficient perfusion, balanced myocardial extracellular stiffness, and controlled functioning of the immune system. Several cell types, including cardiomyocytes, endothelial cells, smooth muscle cells, fibroblasts, immune cells, and cardiac-derived stem cells, need a well-controlled communication system to use the complex orchestra of signalling molecules. The intercellular communication includes direct cellcell contact, cellmatrix interaction, long-range signals, and electrical and extracellular chemical molecules. In addition to the extracellular molecules that cells can use to influence their environment, more and more attention is focused on the release of extracellular membrane vesicles by cells. These vesicles were always thought to be cell debris derivatives, but it appeared that these vesicles are used for horizontal transfer of information between cells, containing proteins, peptides, several classes of RNA molecules, and sometimes DNA. The main populations of released vesicles are classified on their (intra)cellular origin and include apoptotic bodies, microvesicles, and exosomes. Here, we provide an overview on the role of vesicles in cardiac communication and their use as potential therapeutics and biomarkers.