Fig. 7.

Evaluation of dextran sodium sulfate (DSS)-induced colitis in WT and NHE3 KO maintained in the conventional environment, barrier facility, or reconventionalized. A: mortality of WT and NHE3^−/− mice housed in conventional environment, barrier facilities, or reconventionalized in response to 4% DSS. Table depicts body weight loss in WT and NHE3^−/− mice treated with 4% DSS. B: histological analysis (H&E staining) of colonic morphology after treatment with 4% DSS in WT and NHE3^−/− mice housed in barrier facility (magnification ×200). Sections were graded by scoring based on the degree of lamina propria mononuclear cell infiltration, crypt hyperplasia, and architectural distortion by an unbiased pathologist. C: cumulative (proximal + distal colon) histology score in barrier-housed WT and NHE3^−/− mice treated with 4% DSS for 7 days. Statistical analysis was performed with ANOVA followed by Fisher's PLSD post hoc test with P ≤ 0.05 considered significant (conventionalized WT n = 9, NHE3^−/− n = 9; barrier WT n = 19, NHE3^−/− n = 15; reconventionalized WT n = 5, NHE3^−/− n = 8) (n.s., not significant).