Extracellular vesicle (Exosome) (EV)

Extracellular vesicles (EVs), including exosomes, are nano-sized, membrane-bound particles (30–150 nm) secreted by almost all cell types into the extracellular environment (Kalluri & LeBleu, 2020, Science). They serve as critical mediators of intercellular communication by transporting a diverse cargo of proteins, lipids, and various RNA species, such as microRNA and messenger RNA, to recipient cells (Pegtel & Gould, 2019, Annu Rev Biochem). In the context of disease, exosomes play a dual role; they can facilitate the progression of cancer by remodeling the tumor microenvironment and promoting metastasis, or they can contribute to neurodegenerative processes by spreading misfolded proteins like tau or alpha-synuclein (Théry et al., 2018, J Extracell Vesicles). From a therapeutic perspective, the targets involved in exosome-mediated signaling are often heterogeneous, involving the vesicle's surface ligands and the internal cargo that interacts with intracellular pathways upon uptake. Current pharmacological strategies involve either inhibiting the biogenesis and release of pathogenic exosomes using small molecules like GW4869 or engineering synthetic and cell-derived exosomes to deliver specific therapeutic payloads to target tissues (Kalluri & LeBleu, 2020, Science). Because exosomes can cross biological barriers, including the blood-brain barrier, they represent a sophisticated mechanism for targeted drug delivery, although the complexity of their heterogeneous targets presents significant challenges for standardization and safety (Pegtel & Gould, 2019, Annu Rev Biochem).

Other names

ExosomesMicrovesiclesEctosomesSecretory vesiclesNanovesiclesExtracellular vesicle-mediated signaling

Facilitation of horizontal transfer of bioactive molecules (proteins, lipids, and nucleic acids) to recipient cells via endocytosis, direct fusion, or receptor-ligand interactions (Kalluri & LeBleu, 2020, Science; Pegtel & Gould, 2019, Annu Rev Biochem).