Figure 6.

Piezo1 is functionallyexpressedon both apical and basolateral membranes of the collecting duct cells.A, representative continuous current trace from a cell-attached patch clamp experiment on the apical membrane of a cell within a split-opened collecting duct, as shown on the left. Examples of polygonal shape principal (PCs) and round-shape intercalated (ICs) cells are highlighted with red and yellow, respectively. The pipette was backfilled with Piezo1 agonist Yoda-1 (20 μM), which diffused toward the tip, as shown by a scheme on the top. Inward currents are downward. “c” and “o” denote closed and open states, respectively. The applied pipette voltage was -V_p = −60 mV. Black bars above the trace denote areas shown below with an expanded timescale. B, the unitary current (i) – voltage (V) relation of the Yoda-1 activated nonselective cation channel similar to that shown in (A). The channel conductance (18.6 ± 0.7 pS) was assessed as a slope of linear fit. The numbers of individual recordings are shown for each applied voltage. C, representative continuous current trace from a cell-attached patch clamp experiment on the basolateral membrane of a collecting duct cell, as shown on the left. Examples of polygonal shape principal (PCs) and round-shape intercalated (ICs) cells are highlighted with red and yellow, respectively. The pipette was backfilled with Piezo1 agonist Yoda-1 (20 μM), which diffused toward the tip, as shown by a scheme on the top. Inward currents are downward. “c” and “o_i” denote closed and open states, respectively. The applied pipette voltage was -V_p = −60 mV. D, summary graphs comparing changes in Piezo-1 activity (NP_o) at the start (1) and at the end (2) of Yoda-1 application in cell-attached experiments on the apical and basolateral sides. Experiments on PCs and ICs are highlighted with black and gray colors, respectively. ICs, intercalated cells; PCs, principal cells.