Fig. 3

Inhibition of gut inflammation by TRAIL is through TRAIL receptor (TRAIL-R). Wild-type C57BL/6 (WT) mice and TRAIL-R knockout (TRAIL-R KO) mice were fed 2.5% DSS in sterilized drinking water for 5 days (days 0–5), followed by 2 days of normal water (days 6 and 7) and treated with either the vehicle (200 μl/mouse/day, i.p.) or TRAIL (50 μg/mouse/day, i.p.) from day 0. Control (WT) mice were given normal drinking water only. a Body weight changes (% original body weight) in each group were recorded and are presented as the mean ± SD (n = 15 in each group). *p < 0.05 by Mann–Whitney U test, compared to WT mice treated with the vehicle. b Quantitative colon length and c the ratio of the colon weight to length of each group are shown at the end of treatment (day 7). Data are presented as the mean ± SD. *p < 0.05, **p < 0.01 by Student’s t test. d Representative H&E staining of colon tissues (distal part of colon, day 7) from each group is shown (left panel) and quantified by a histological injury score (right panel). **p < 0.01 by Student’s t test