Fig. 5
Redistribution of Nav1.4 during POS phagocytosis. The redistribution of Nav1.4 during phagocytosis and the effect of Nav blockers to the process was studied in mouse and hESC-derived RPE. Filamentous actin was stained with phalloidin (red) to highlight epithelial cell-cell junctions. Laser scanning confocal microscopy Z-maximum intensity projections of a Nav1.4 localization in mouse RPE at light onset and 2 h after it showed strong reduction of the beads-on-a-string type labeling from cell–cell junctions. Different assays were used to investigate Nav1.4 distribution during phagocytosis and the effect of selective blockers for Nav1.4 (600 nM μ-Conotoxin GIIB) and Nav1.8 (1 μM A-803467) in combination with 10 μM TTX, or only of the selective blocker for Nav1.4. b The redistribution of Nav1.4 was studied ex vivo by incubating opened mouse eyecups in control solution or with the selective blockers. In both of the blocker samples, the redistribution was inhibited and the beads-on-a-string type labeling remained visible (white arrows) in the cell-cell junctions. c The hESC-derived RPE phagocytosis assay in vitro showed a highly similar redistribution of Nav1.4 and the blockers had the same effect as in the ex vivo mouse eyecup assay. Scale bars 10 μm