Fig 1: MMP-7 increases colonic epithelial permeability by degrading Claudin-7. (A) Representative Western blots showing that active MMP-7 dose-dependently decreased Claudin-7 in FHC cells. (B) Active MMP-7 and forced expression of MMP-7 suppressed Claudin-7 in CCD841 CoN cells. (C) Schematic presentation of pGEX-5x-2-CLDN7 construct used for purification of full-length human Claudin-7 protein. (D) Active MMP-7 cleaved recombinant Claudin-7 protein in enzyme assay followed by WB. (E) Increased Caco-2 monolayer permeability by active MMP-7 was abrogated by Claudin-7 over-expression. n=6. *p<0.01. (F) Representative images of immunohistochemical staining of Claudin-7 in mucosal biopsy samples from control subjects and patients with UC. (G) Quantification of Claudin-7 staining intensity in the human mucosal biopsies, ranging from absent (0) to highest (3). (H) Claudin-7 knock down by Cldn7 siRNA increased Caco-2 permeability. n=5. *p<0.01. NS, not significant.