Fig. 4

Involvement of intracellular Ca²⁺ in the LPS- and TNF-α-induced enhanced dye uptake rate. a Ca²⁺ imaging using Fura-2-loaded Calu-3 cells to estimate baseline [Ca²⁺]_i levels (mean F_{360 nm}/F_{380 nm} of 5 min measurement) in cells treated with 1 ng/mL LPS for 24 h or 10 ng/mL TNF-α for 1 h (n = single cells). One-way ANOVA with Sidak’s multiple comparison test (p < 0.05 * vs. vehicle). b EtdBr dye uptake rates in absence of [Ca²⁺]_ex relative to the rates obtained in presence of [Ca²⁺]_ex in Calu-3 cells treated for 24 h with vehicle, 1 ng/mL LPS ± preincubation (0.5 h) with 10 µM BAPTA, with BAPTA alone or for 1 h with 10 ng/mL TNF-α ± preincubation (0.5 h) with 10 µM BAPTA (n = cell patches). Kruskal-Wallis test with Dunn’s multiple comparison test (p < 0.001 *** vs. vehicle; p < 0.001 ### vs. LPS; p < 0.001 +++ vs. TNF-α)