Small extracellular vesicles from rat plasma promote migration and proliferation of vascular smooth muscle cells

Small extracellular vesicles (sEV) contain various molecules and mediate cell-to-cell communication under both physiological and pathological conditions. We have recently reported that sEV isolated from plasma of normotensive Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) regulate systemic blood pressure. The initiation and development of hypertension partly rely on proliferation and migration of vascular smooth muscle cells (SMCs) followed by the structural remodeling of vascular wall. In the present study, we examined the effects of plasma sEV in WKY and SHR on the proliferative and migratory functions of primary rat aortic SMCs. There was no difference in the concentration and size distribution of plasma sEV between WKY and SHR, while the protein expression of CD81 in plasma sEV from SHR was lower than that from WKY. Both plasma sEV from WKY and SHR were internalized into SMCs and stimulated the migration and proliferation with a similar potency. In summary, we, for the first time, demonstrated that plasma sEV in WKY and SHR are physiologically active in terms of proliferative and migratory functions, however, these effects do not seem to be related to the pathogenesis of hypertension development.