K⁺ channel modulation can impede normal K⁺ accumulation across the endocytic network.

(A) A549 cells were treated for 30 min with 10 mM TEA or left untreated. AG4 (10 μM) was then added in the presence or absence of drug for 40 min. Dye was removed and TEA was re-added onto cells. Fluorescence intensities were quantified using IncuCyte ZOOM imaging and analysis software, and data normalised to untreated (unt) controls over three independent cell populations. NS–no significant difference between no-drug and TEA treated controls (p≥0.05). Scale bar = 10 μM. (B) (i) Cells were treated with 10 mM TEA (or left untreated) and AG4 (10 μm) added as in A, with the addition of Magic Red during the 40 min incubation with AG4. Representative images are shown (n≥60 cells). Scale bar = 10 μM. (ii) Total number of AG4 positive puncta were counted per cell ± TEA and the % of colocalised puncta presented. n≥60 cells, (* = p≤0.05). Scale bar = 10 μM. (C) (i) Cells were treated with 10 mM TEA or left untreated, and AG4 (10 μM) added as in A, with the addition of the pH indicator pHrodo red dextran (10 μg/ml) during the 40 min incubation with AG4. Representative images are shown (Scale bar = 10 μM) and the % of co-localised puncta presented in (ii) n≥60 cells (* = p≤0.05). D Fluorescence intensity of Magic Red was quantified using IncuCyte ZOOM imaging and analysis software and data normalised to untreated controls over three independent cell populations. NS–no significant difference between untreated and TEA treated cells (p≥0.05). Representative images are also shown.