Adipose-derived mesenchymal stem cells release microvesicles with procoagulant activity.

Extracellular vesicles are produced by a number of different cell types, among them mesenchymal stromal/stem cells (MSC) of different sources. It has been shown that extracellular vesicles of MSC exert similar therapeutic effects as the cells themselves. Here, we isolated and characterized extracellular vesicles produced by adipose-derived MSC (adMSC) in vitro upon stimulation with the proinflammatory substances lipopolysaccharide (LPS) and tumor necrosis factor (TNF). We found that the number of vesicles produced by adMSC does not change upon stimulation of the cells with LPS and TNF. Furthermore, adMSC-derived extracellular vesicles exert procoagulant activity independent of previous stimulation with LPS or TNF. We found evidence that the vesicles induce coagulation via both the intrinsic and the extrinsic pathway of coagulation.