Table 1.
Characteristics of main extracellular vesicles
| Feature | Exosome | Apoptotic body | MV |
|---|---|---|---|
| Size | Homologous 30–100 nm |
Heterogeneous 1–5 μm |
Heterogeneous 100–1000 nm |
| Markers | Membrane impermeable (PI negative) CD63, TSG101, Alix, flottilin |
Membrane permeable (PI positive) Annexin V, DNA, histones |
Membrane impermeable (PI negative) integrin, selectin, flotillin-2 |
| Density | 1.13–1.19 g/mL | 1.16–1.28 g/mL | 1.25–1.30 g/mL |
| Contents | Protein, lipid, different RNA species, and DNA | Cytosolic content (protein, RNAs, fragmented DNA) and cellular organelles | Protein, lipid, different RNA species, and DNA |
| Determinant of controlled contents | The cellular origin and physiological state of the cell | The cellular origin and stimuli | No direct correlation |
| Lipids | A major sorting of lipidic molecules from the parental cells (include BMP) | Characterized by phosphatidylserine externalization | The lipid contents are primarily derived from plasma membrane, and resemble the parental cells (without BMP) |
| Origin | Multivesicular bodies fusion with plasmatic membrane | Cellular debris, plasma membrane blebbing during cell apoptosis | Direct outward budding or blebbing from the plasma membrane |
| Mechanism of release | Constitutive or inducible, depending on the cell type of origin | Rho-associated kinase I and myosin ATPase activity | Relocation of phospholipids to the outer membrane, cytoskeleton rearrangements, generation of membrane curvature, and vesicle release |
| Detection methods | Electron microscopy, Western blot for exosome enriched markers | Flow cytometry, electron microscopy, | Flow cytometry, electron microscopy |
| Isolation methods | Ultracentrifugation (100,000–200,000×g) filtration, density gradient Immunoprecipitation, Immune affinity capture and ExoQuick precipitation methods | Ultracentrifugation (10,000–20,000×g) | No standardized methods |
| Size determination and quantification | Dynamic light scattering Nanoparticle tracking analysis Surface plasmon resonance |
||
| References | [19, 20, 48, 50, 122–124] | [29, 75, 125, 126] | [28, 48, 123, 124, 127, 128] |
MV Microvesicle, BMP bone morphogenetic protein, PI propidium iodide