Mechanoresponsive ion channels Piezo1 and TRPV4 stimulate ADAM10 and ADAM17 with differential impact on endothelial migration and proliferation.

backgroundEndothelial cells are constantly exposed to mechanical forces generated by blood flow regulating endothelial homeostasis. Pathological events such as vascular injury or thrombus formation alter these forces, which are sensed by endothelial cells and can trigger repair mechanisms, including inflammation, proliferation and migration. The mechanical changes can be detected by cells through various mechanosensors, particularly ion channels such as Piezo1 and transient receptor potential vanilloid 4 (TRPV4). One possible pathway for the translation of mechanical signals into cellular responses involves the downstream activation of membrane-bound proteases of the a disintegrin and metalloprotease (ADAM) family. These proteases cleave transmembrane proteins such as growth factors, adhesion molecules and cytokines, thereby regulating inflammation, proliferation and migration. This study aimed to investigate the link between the ion channels Piezo1/TRPV4 and the metalloproteases ADAM10/17.

methodsPrimary human umbilical vein endothelial cells (HUVECs) were treated with pharmacological agonists of Piezo1 and TRPV4 or cultured under flow conditions for mechanical stimulation. Pharmacological inhibitors and shRNA-mediated knockdown were used to assess the involvement of specific proteins. ADAM activity was determined indirectly by measuring the release of substrates such as junctional adhesion molecule A (JAM-A) or tumor necrosis factor receptor 1 (TNFR1) into the culture medium or by a reduction in the cell lysates via ELISA, on the cell surface by flow cytometry, and in the immunocytochemical staining of vascular endothelial cadherin (VE-cadherin). The effects on cell proliferation and migration were analyzed via live-cell microscopy or via proliferation marker genes.

resultsMechanical stimulation through flow induced the activation of ADAM10 and ADAM17, which was partially mediated by Piezo1 and TRPV4. This connection was confirmed via the use of specific agonists for both ion channels, which have the potential to independently activate ADAM proteases. Furthermore, specifically Piezo1 activation led to ADAM10/17-dependent increases in proliferation and migration.

conclusionPiezo1 and TRPV4 contribute to the mechanical activation of ADAM10/17 in endothelial cells and thus may play an important role in regulating endothelial functions. As shown for the regulation of endothelial proliferation and migration by the Piezo1-ADAM axis.