Piezo1-dependent inhibition of background potassium current in the rat bladder smooth muscle cells

Abstract

The smooth muscle layer of the urinal bladder (detrusor), along with the urothelium, has autonomous mechanosensitivity and serves as a main sensitive receptor in the organ. Piezo1, together with TREK-1 channel, could play a role of local mechanoreceptors in bladder detrusor smooth muscle (DSM) cells. Piezo1 is a so-called “true” mechanosensitive calcium-permeable ion channel, sensitive to pressure, shear stress, and is activated by pharmacological agonist Yoda1. Using patch-clamp and microfluorescence calcimetry, an unexpected effect from Yoda1 was shown, that is inhibition of rest K+ currents at depolarizing command voltage up to +80 mV. The functional presence of Piezo1 is confirmed by Yoda1-induced rise of intracellular Ca2+ concentration in DSM cells, this was visualized using a Ca2+ sensitive dye Fluo-4 AM, and polymerase cyclic reaction with reverse transcription. In conclusion, Piezo1 channels present in DSM cells and are selectively activated with Yoda1, that causes the inhibition of resting potassium currents.