Fig 1: Effect of lack of saliva on development of DSS-induced colitis. (A) WT (black and green) and Aqp5-/- mice (blue and red) were fed with 3% DSS (green and red) for 15 days. Mice were 22 weeks old, and the numbers in parenthesis indicate the number of mice in each group. The P values are the difference between WT and Aqp5-/- mice fed with DSS. (B) Time course of development of disease activity of the mice in (A). (C and D) WT and AQP5-/- mice age 8 (C) and 13 (D) weeks were treated with 3% DSS added to drinking water. The number of mice in each group is indicated in parenthesis, and the results are mean ± SEM. The P values are relative to WT mice fed with DSS. (E) Intestinal permeability expressed as fold change relative to the permeability measured before DSS treatment started and was taken as 1 for each group of mice. (F) Example images and averages of intestinal length. (G–I) Example images (G) and the level of ZO1 (H) and Occludin (I) measured by immunofluorescence staining. (J–L) Example H&E and PAS images (J) and analysis of cell proliferation (K) and goblet cell density (L). (M and N) Serum (M) and intestinal MPO (N) levels as reporters of neutrophils activity. (O and P) WT and AQP5-/- mice age 18 weeks (5 mice in each group) were treated with 3% DSS and were gavaged with 50 μL PBS (Black, blue, gray and green) or with 50 μL whole saliva collected from 3 WT mice by stimulation with pilocarpine. The mice were gavaged on days 0, 3, and 6. Mice weight (O) was measured in 2-day intervals, and intestinal permeability (P) was measured on days 1, 3, 6, and 12. The results are mean ± SEM.