Fig. 6

LPS leads to CLDN4 remodeling in epithelial cells of the airways, which can be attenuated by CVB4-57. a Real-time qRT-PCR for relative mRNA amounts of CLDN1, CLDN3, CLDN4, CLDN7 and ZO-1 in Calu-3 cells cultivated on transwell inserts after treatment for 3 h and 24 h with 1 µg/mL LPS, respectively (n = 3). One-way ANOVA with Dunnet’s multiple comparison test. b Exemplary immunofluorescence staining against ZO-1 (magenta) and CLDN4 (yellow) in Calu-3 cells cultivated on transwell inserts treated with 1 µg/mL LPS ± 5 µM CVB4-57 for 3 h and 24 h. Scale bar = 20 μm. c Tight junction organization rate (TiJOR, intersections/µm) of CLDN4 after application of 1 µg/mL LPS ± 5 µM CVB4-57 for 3 h or 24 h (n = transwell inserts). Kruskal-Wallis test with Dunn’s multiple comparison test (p < 0.01 ** vs. control). d Exemplary immunofluorescence staining against CLDN4 (yellow) in human PCLS cultivated for 24 h with 1 µg/mL LPS or culture medium (control). Upper images: 5 × 3 tile scan, scale bar = 200 μm. Lower images: z-stack of 30 μm with one image every 3 μm, scale bar = 10 μm). A similar result was obtained in PCLS of a second donor. e Exemplary immunofluorescence staining against ZO-1 (magenta) and CLDN4 (yellow) in Calu-3 cells cultivated on transwell inserts 24 h after 3rd application (application every 24 h) of 10 ng/mL LPS ± 5 µM CVB4-57. Scale bar = 20 μm. f TiJOR (intersection/µm) of CLDN4 24 h after the 3rd application of 10 ng/mL LPS ± 5 µM CVB4-57 (n = transwell inserts). One-way ANOVA with Sidak’s multiple comparison test (p < 0.05 * vs. control; p < 0.001 ### vs. LPS)