ADAM17^ex/ex mice are highly susceptible to DSS-induced colitis. (A) Body weight after the onset of treatment with DSS. Numbers of mice per group used are indicated. The experiment was performed three times. (B) Colonoscopy of untreated (top) and treated (bottom) mice. Representative pictures are shown. (C) DSS-treated (4 d) and untreated WT and ADAM17^ex/ex mice were immunostained with anti-ADAM17 (magnification, 100×). Bars, 100 µm. Representative macroscopic pictures of four mice per group are shown. (D) Hematoxylin and eosin (H&E), BrdU, anti–phosho-STAT3, and anti-cyclin D1 staining of colons from mice challenged for 10 d with DSS. Bars: (H&E) 200 µM; (BrdU, p-STAT3, and cyclin D1) 100 µm. Representative microscopic images of three experiments (H&E and BrdU), two experiments (pSTAT3), and one experiment (cyclin D1) of ADAM17^ex/ex, ADAM17^WT/ex, and WT controls (five mice per group) are shown. (E) DSS colitis was induced and plasma FITC-dextran concentrations in ADAM17^WT/WT (n = 7) and ADAM17^ex/ex (n = 7) mice 4 h after FITC-dextran administration by oral gavage (60 mg/100 g of body weight) are shown. Data are shown as mean values ± SD. The experiment was performed twice with similar results.