Piezo1 activation increases the release of therapeutic extracellular vesicles after mechanical stimulation in bioreactors
Enhancing protocols and methods for producing therapeutic extracellular vesicles (EVs) in bioreactors is crucial to achieve scalable production while ensuring both quality and quantity. Studies have shown that mechanical stress can promote EV release, although the underlying mechanisms remain largely unclear. Here we investigated which mechanisms are responsible for the increase of EV production under shear stress. EVs were produced from adipose tissue-derived stromal cells (ASCs), also described as mesenchymal stromal cells (MSCs) that can support the regeneration of injured tissues via several paracrine factors. The cultures were treated with GsMTx4, an inhibitor which blocks the Piezo1 ion channels, or with YODA1, its agonist, to assess if mechanical or shear forces pathways are involved in enhancing the EV release. EVs were quantified and characterized after high shear (HS) stimulation compared with no shear stress stimulation (3D) and standard cultures methods (2D). These experiments showed that, after mechanical stimulation by shear stress, EV production increased in bioreactors and this effect was blocked by the inhibition of Piezo1 ion channels with GsMTx4 (88%) with no impact on cell viability. Consistently, the agonist YODA1 increased the EV production (149%). The implications of these findings are significant, especially for regenerative medicine and cellular therapies, where the efficient production of high-quality EVs is crucial. By understanding turbulence-induced shear stress and the natural mechanotransductive pathways within cells, it may be possible to optimize the production of therapeutic EVs, paving the way for more effective treatments in the future.