Protective effect of MUC2 in mice with colitis and the expression of anti-CBir1 antibody in serum

AIM: To investigate the protective effect of mucin 2 (MUC2) on intestinal mucosa of colitis model mice, and to explore the correlation between the expression of anti-CBir1 flagellin antibody and MUC2. METHODS: The mice were randomly divided into normal control group, 2,4,6-trinitrobenzenesulfonic acid (TNBS) group, lipopolysaccharide (LPS)+ovalalbumin (OVA)+TNBS group and ketotifen+TNBS group. The expression of MUC2 in colon tissue was determined by PAS staining and immunohistochemistry, and the anti-CBir1 antibody level in the serum of mice in each group was measured by ELISA. RESULTS: The scores of disease activity index and histological index in TNBS group were higher than those in normal control group (P<0.05). The scores in LPS+OVA+TNBS group were much higher than those in TNBS group (P<0.05). However, the values in ketotifen+TNBS group were lower than those in TNBS group (P<0.05). PAS staining showed a decrease in goblet cells in TNBS group. Compared with TNBS group, the colonic mucosa integrity in LPS+OVA+TNBS group was destroyed, and the number of goblet cells in ketotifen+TNBS group increased significantly. Immunohistochemical staining showed that the expression of MUC2 in the intestinal tract of each mo-del group was basically consistent with the results of PAS staining. The serum anti-CBir1 antibody level in TNBS group was higher than that in normal control group (P<0.05), and that in LPS+OVA+TNBS group was significantly higher than that in TNBS group (P<0.05), whereas that in ketotifen+TNBS group was decreased slightly (P<0.05). CONCLUSION: MUC2 plays a protective role in the pathogenesis of colitis in mice, and there is a negative correlation between the expression of MUC2 and the bacterial flagellin in the intestinal mucosa of mice with colitis.