Pannexin 1 Channels Play Essential Roles in Urothelial Mechanotransduction and Intercellular Signaling
Figure 5
YoPro-1 uptake by urothelial cells in response to hypoosmotic shock involves Panx1 and P2X7R activation.
(A) TRT-HU1 cells: YoPro-1 uptake induced by cell swelling (hypoosmotic shock, black line) was significantly reduced in the presence of the Panx1 channel blocker mefloquine (MFQ 100 nM; yellow line), the P2X7R blocker A438079 (10 µM; red line) and when both Panx1 and P2X7R were blocked (blue line). Except for hypoosmotic with MFQ vs. A438079 and hypoosmotic with A438079+MFQ vs. isoosmotic, all other comparisons were significantly different at time 2800 sec (P<0.01, N≥6) by two-way repeated measures ANOVA, followed by Tukey’s multiple comparison. (B) Primary mouse urothelial cells: YoPro-1 uptake induced by hypoosmotic shock was significantly lower in P2X7R−/− (red line) compared to wildtype (WT) urothelial cells (black line). Dye uptake by P2X7R−/− cells was abolished in the presence of the Panx1 channel blocker mefloquine (MFQ, 100 nM; green line) and was absent in Panx1−/− urothelial cells (blue line). WT vs P2X7R−/−, P2X7R−/−+MFQ and Panx1−/− (P<0.001, N = 4) by ANOVA followed by Tukey’s multiple comparison.