MUC2在结肠炎小鼠中的保护作用和血清抗CBir1抗体的表达

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

目的:探究黏蛋白2(MUC2)对结肠炎模型小鼠肠黏膜的保护作用,并探究抗CBir1鞭毛蛋白抗体与MUC2表达的相关性。方法:将小鼠随机分为正常对照组、2,4,6-三硝基苯磺酸(TNBS)组、脂多糖(LPS)+卵清蛋白(OVA)+TNBS组和酮替芬+TNBS组,采用PAS染色法和免疫组织化学法测定各组小鼠结肠组织MUC2的表达情况,ELISA法对各组小鼠血清抗CBir1抗体的水平进行测定。结果:各模型组小鼠的疾病活动度指数评分和组织学指数评分中,TNBS组小鼠的分值较正常对照组增高(P<0.05),LPS+OVA+TNBS组小鼠的分值较TNBS组更加增高(P<0.05),而酮替芬+TNBS组小鼠的分值与TNBS组相比有所降低(P<0.05)。PAS染色结果显示,与正常对照组比较,TNBS组杯状细胞减少,LPS+OVA+TNBS组与TNBS组相比结肠黏膜完整性出现破坏,而酮替芬+TNBS组与TNBS组相比杯状细胞数量明显增多。免疫组化染色结果表明,各模型组小鼠肠道内MUC2的表达量与PAS染色结果基本保持一致。TNBS组小鼠血清抗CBir1抗体的含量较正常对照组有所增高(P<0.05),LPS+OVA+TNBS组小鼠与TNBS组相比明显增高(P<0.05),而酮替芬+TNBS组小鼠与TNBS组相比有所降低(P<0.05)。结论:MUC2在结肠炎小鼠的发病过程中具有肠黏膜保护作用。结肠炎小鼠MUC2的表达量与肠道内细菌鞭毛蛋白存在一定的负相关。

AIM:To investigate the protective effect of mucin2(MUC2)on intestinal mucosa of colitis model mice,and to explore the correlation between the expression of anti-CBir1flagellin 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 MUC2in colon tissue was determined by PAS staining and immunohistochemistry,and the anti-CBir1antibody 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 MUC2in the intestinal tract of each mo-del group was basically consistent with the results of PAS staining.The serum anti-CBir1antibody 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:MUC2plays a protective role in the pathogenesis of colitis in mice,and there is a negative correlation between the expression of MUC2and the bacterial flagellin in the intestinal mucosa of mice with colitis.