Figure 7.

Ficz protects the tight junctions (ZO-1 and occludin) from hypoxia-induced morphological damage and maintains the barrier function in Caco-2 monolayers. (A) The expression and distribution of ZO-1 and occluldin (red) were detected by immunofluorescence staining in four groups (Nx, Nx + Ficz, Hx and Hx + Ficz). Nuclei were counterstained with DAPI (blue) (original magnification, ×1,200; scale bar, 25 µm; n=3). (B) Western blotting was employed to investigate the protein expression of ZO-1, occludin and GAPDH. (C) Relative protein expressions determined by densitometry, GAPDH was used to verify equivalent loading. (D) The TER was detected by the Millipore electric resistance system to evaluate the epithelial permeability of Caco-2 cells in four groups. Data are presented as the mean ± standard deviation. ^*P<0.05, ^**P<0.01, ^***P<0.001 vs. Nx group; ^##P<0.01, ^###P<0.001 vs. Hx group; n=3. ZO-1, tight junction protein 1; Nx, normoxia; Ficz, 6-formylindolo(3,2-b)carbazole; Hx, hypoxia; TER, transepithelium electrical resistance.