EpCAM/claudin-7–dependent barrier maintenance in other epithelial models. (A and E) Immunoblotting of parental MDCK II cells (A) and Caco-2 cells (E) treated with various concentrations of trypsin using rabbit anti-EpCAM mAb and other antibodies. Black, gray, and blue arrowheads indicate full-length, cleaved, and 29-kD bands, respectively. (B and F) Effects of camostat treatment for 16 h on parental MDCK II cells (B) and Caco-2 cells (F). (C and G) Effects of trypsin on the localization of claudin-7 (red) in parental MDCK II cells (C) and Caco-2 cells (G). Cells were co-stained with claudin-2 (green) and ZO-1 (blue; C) or ZO-1 (green) and DAPI (blue; G). Scale bars, 10 µm. (D and H) Effects of camostat on TER and permeability of 10-kD FITC-dextran in parental MDCK II cells (D) and Caco-2 cells (H). ns, P > 0.05; *, P < 0.05; ***, P < 0.001 (two-tailed paired t test). (I and J) Immunostaining of frozen sections of the small intestine (I) and colon (J). Tissue sections were either untreated (upper panels) or treated with NP-40 before fixation (lower panels) and stained for claudin-7 (green), ZO-1 (red), and DAPI (blue). White arrows indicate the tips of the villi. The tip region of villi in the left panels (white rectangle in I) was enlarged and shown in the right panels. l, lumen; v, villus; c, crypt. Scale bars, 50 µm. Source data are available for this figure: SourceData F9.