Exosomes derived from stimulated monocytes promote endothelial dysfunction and inflammation in vitro

During the last few years, the scientific community interest on the role of extracellular vesicles (EVs) in physiology and pathophysiology of several human diseases has increased exponentially (1). These vesicles present the capability of transferring different kind of molecules (lipids, RNAs, DNA, protein…) between cells and may exert some effects on the cell phenotype. The content of these vesicles can vary depending on the cell type of origin (2). Although nowadays there is no consensus regarding the appropriate nomenclature, three well-known types of vesicles can be categorized on the basis of size and biogenesis: apoptotic bodies (>1 µm), microvesicles (150 nm–1 µm, budding from plasma membrane) and exosomes (30–150 nm, formed within the endosomal network and released upon fusion of multi-vesicular bodies with the plasma membrane) (1,2). Exosome is the most commonly used term to designate any type of EV; it has become a “catchword” for EV-related science. Despite the fact that the isolated fractions generally studied consist of a mixture of EVs. Unfortunately, the EVs scientific community is not able to propose a list of EV-specific markers to classify subsets of EVs (3).