Proteomic Signature of Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles

Small extracellular vesicles (EVs) are 50-200 nm vesicles secreted by most cells. They are considered as mediators of intercellular communication, and EVs from specific cell types, in particular mesenchymal stem/stromal cells (MSCs), offer powerful therapeutic potential, and can provide a novel therapeutic strategy. They appear promising and safe (as EVs are non-self-replicating), and eventually MSC-derived EVs (MSC-EVs) may be developed to standardized, off-the-shelf allogeneic regenerative and immunomodulatory therapeutics. Promising pre-clinical data have been achieved using MSCs from different sources as EV-producing cells. Similarly, a variety EV isolation and characterization methods have been applied. Interestingly, MSC-EVs obtained from different sources and prepared with different methods show in vitro and in vivo therapeutic effects, indicating that isolated EVs share a common potential. Here, well-characterized and controlled, publicly available proteome profiles of MSC-EVs are compared to identify a common MSC-EV protein signature that might be coupled to the MSC-EVs' common therapeutic potential. This protein signature may be helpful in developing MSC-EV quality control platforms required to confirm the identity and test for the purity of potential therapeutic MSC-EVs.