Fig. 3

CNF1 impairs gut barrier integrity. (A) Changes of Trans-Epithelial Electrical Resistance (TEER) in Caco-2 monolayers cultured for 21 days on 3 μm pore size inserts and exposed for the indicated times to CNF1 or CNF1-C866S (25 pM) or a conditioned medium (CM) from activated THP-1 cells or CM + CNF1. Data are expressed as percent TEER changes compared to the TEER value registered before treatment (day 0). N = 4. (*p < 0.05). (B) Mean fluorescence intensity (MFI) of ZO-1 expression in differentiated Caco-2 monolayers 24 h after the indicated treatments. N = 4. (***p < 0.001). (C) Representative micrographs from CLSM examinations (3D reconstruction images). Cell monolayers were stained with anti ZO-1 (green) and phalloidin (red) to visualize actin proteins. Nuclei are stained with DAPI (blue). Separate channels and merged images are shown. On the right, orthogonal projections of transverse ZX axis of the same image are reported. Scale bars, 20 μm. Images from one representative experiment out of three are shown