Extracellular Vesicles: Unique Intercellular Delivery Vehicles

Proteins, RNA, DNA, lipids, and metabolites can be transferred to recipient cells and exert functional effects on target molecules either immediately (external cargoes) or after extracellular vesicle (EV) fusion and/or endosomal uptake (internal cargoes). Functional events for internal cargoes include EV miRNA inhibition of target mRNA translation and EV mRNA-to-protein translation. EVs can serve autocrine and paracrine functions, controlling multiple cell processes in development, proliferation, migration, and pathology. The lipid membrane of EVs may serve to protect and stabilize EV cargoes in the extracellular space. EV cargoes may be dysregulated and/or have abnormal content in disease states and serve as ‘snapshots’ of diseased cells. EVs are formed by multiple biogenesis mechanisms, which is likely to affect their cargo content. Extracellular vesicles (EVs) are a heterogeneous collection of membrane-bound carriers with complex cargoes including proteins, lipids, and nucleic acids. While the release of EVs was previously thought to be only a mechanism to discard nonfunctional cellular components, increasing evidence implicates EVs as key players in intercellular and even interorganismal communication. EVs confer stability and can direct their cargoes to specific cell types. EV cargoes also appear to act in a combinatorial manner to communicate directives to other cells. This review focuses on recent findings and knowledge gaps in the area of EV biogenesis, release, and uptake. In addition, we highlight examples whereby EV cargoes control basic cellular functions, including motility and polarization, immune responses, and development, and contribute to diseases such as cancer and neurodegeneration. Extracellular vesicles (EVs) are a heterogeneous collection of membrane-bound carriers with complex cargoes including proteins, lipids, and nucleic acids. While the release of EVs was previously thought to be only a mechanism to discard nonfunctional cellular components, increasing evidence implicates EVs as key players in intercellular and even interorganismal communication. EVs confer stability and can direct their cargoes to specific cell types. EV cargoes also appear to act in a combinatorial manner to communicate directives to other cells. This review focuses on recent findings and knowledge gaps in the area of EV biogenesis, release, and uptake. In addition, we highlight examples whereby EV cargoes control basic cellular functions, including motility and polarization, immune responses, and development, and contribute to diseases such as cancer and neurodegeneration.