肠三叶因子对小鼠炎症性肠病肠道病变的保护作用

目的 探讨肠三叶因子(ITF)对小鼠炎症性肠病(IBD)肠道病变的影响,分析ITF对小鼠IBD肠道先天性免疫功能的调节作用.方法 48只小鼠随机分为3组,每组16只.三硝基苯磺酸(TNBS)组:用TNBS建立IBD模型后每只小鼠给予9g.L-1盐水0.1 mL腹腔注射；基因重组肠三叶因子(rITF)组:建立IBD模型后每只小鼠给予rITF0.1 mL腹腔注射；乙醇对照组:未造模型小鼠每只小鼠给予9g.L-1盐水0.1 mL腹腔注射.各组均连续5d注射,第14天评估小鼠临床表现,麻醉处死小鼠后取其结肠组织作组织学评分,HE染色行肠组织病理学检查,并采用免疫组织化学法及实时定量PCR法检测其肠道TNF-α及Toll样受体(TLR4)和核因子( NF-κBp65)基因、蛋白表达水平.结果 与TNBS组小鼠比较,r-ITF组小鼠死亡只数、大便性状、血便情况、体质量下降情况等临床表现及肠道局部炎症均明显减轻,肠道病理大体观及组织学评分均明显下降(Pa＜0.05),TNF-α蛋白表达水平明显下降(Pa＜0.05),TLR4、NF-κBp65基因及蛋白表达明显下调(Pa＜0.01).乙醇对照组无死亡,临床症状及肠道局部炎症轻微,TNBS组TNF-α、TLR4、NF-κBp65基因及蛋白表达明显高于乙醇对照组(Pa＜0.01).结论 ITF对IBD小鼠肠道病变具有保护作用,可能与调节肠道先天免疫有关.

Protective Effect of Intestinal Trefoil Factor on Colonic Damage of Mice with Inflammatory Bowel Disease

Objective To explore the influence of intestinal trefoil factor(ITF) on colonic damage in mouse model with inflammatory bowel disease(IBD),and discuss its innate immune regulation on IBD. Methods Forty-eight mice were randomly assigned into 3 groups,group trinitrobenzenesulfonic acid(TNBS) and group recombinant ITF(rITF) as IBD groups,and the ethanol control group.After IBD models were established with TNBS,mice in rITF group were treated with rITF and mice in group TNBS were treated with 9 g·L-1 saline for 5 days,respectively.On the 14th day,signs of colitis,colonic damage score,the levels of toll-like receptor 4(TLR4),nuclear factor κBp65(NF-κBp65) mRNA and protein expression,and TNF-α level in colon were determined,respectively. Results Signs of colitis including weight loss,bloody stools,diarrhea,number of death,both microscopic and macroscopic injuries of the colon in rITF group were improved compared with those in group TNBS.Studies of immunohistochemistry and real time PCR demonstrated that the expressions of TNF-α,TLR4,NF-κBp65 production(P_a<0.05) and TLR4,NF-κBp65 mRNA in rITF group significantly decreased compared with those in group TNBS(P_a<0.01).There was no death mouse and little colonic damage in control group.The level of expression of tissue TNF-α,TLR4,NF-κBp65 production and TLR4,NF-κBp65 mRNA in TNBS group were increased markedly than those in control group(P_a<0.01). Conclusion ITF may ameliorate IBD by protecting the colonic damage,and one of the mechanisms may related to innate immune regulation