Figure 1

Schematic representation of extracellular vesicles (EVs) and the transfer of genetic material by exosomes. These EVs include different types of membrane vesicles (apoptotic bodies [ABs], microparticles/microvesicles, and exosomes), which can be found in body fluids including plasma and urine. The signals of extracellular vesicles can be activated through different steps based on environmental stimuli such as stress or hypoxia. Extracellular signals activate the fusion of multivesicular bodies (MVBs) into the plasma membrane and foster the release of their intraluminal vesicles (ILVs) as exosomes from the donor cells as illustrated in Panel (A). Once the exosomes are released and reach their targets they will start to fuse with the recipient cells (Panel B). Some proteins are directed by the ESCRT (endosomal sorting complex required for transport) machinery to the MVB route. Extracellular vesicles, which are secreted into the extracellular environment, contain functional molecules that can be taken up by recipient cells through mechanisms that include fusion with the plasma membrane, phagocytosis and endocytosis. Panel (C) represents the content of exosomes which contains a large array of proteins some of which are involved in membrane transport and fusion (such as RAB proteins and annexins), cytoskeletal proteins, adhesion molecules and tetraspanins, lipid rafts, as well as RNA (mainly miRNA and RNA), and DNA. Exosome membranes are enriched in lipid-based rafts such as cholesterol, ceramide and sphingolipids.