Selective Chemical Activation of Piezo1 in Leukemia Cell Membrane: Single Channel Analysis

Piezo1/2 are mechanosensitive calcium-permeable channels that can be activated by various modes of membrane deformation. The identification of the small molecule Yoda1, a synthetic Piezo1 agonist, revealed the possibility of chemical activation of the channel. Stimulating effects of Yoda1 on Piezo1 have been mainly documented using over-expressing cellular systems or channel proteins incorporated in artificial lipid bilayers. However, the activating effect of Yoda1 on native Piezo1 channels in the plasma membrane of living cells remains generally undefined, despite the increasing number of studies in which the agonist is utilized as a functional tool to reveal the contribution of Piezo1 to cellular reactions. In the current study, we used the human myeloid leukemia K562 cell line as a suitable model to examine chemically induced Piezo1 activity with the use of the patch-clamp technique in various specific modes. The functional expression of Piezo1 in leukemia cells was evidenced using a combinative approach, including single channel patch-clamp measurements. Utilizing our established single-current whole-cell assay on K562 cells, we have shown, for the first time, the selective real-time chemical activation of endogenously expressed Piezo1. Extracellular application of 0.5-1 µM Yoda1 effectively stimulated single Piezo1 currents in the cell membrane.