双歧杆菌对溃疡性结肠炎大鼠肠黏膜上皮细胞Toll样受体2、4及NF-κB基因表达的影响

Effect of Bifidobacterium on expressions of TLR2,TLR4 and NF-κB genes in the intestinal mucosa of rats with ulcerative colitis

目的观察双歧杆菌(Bf)活制剂对大鼠溃疡性结肠炎(UC)肠黏膜上皮细胞(IECs)TLR2、TLR4、NF-κB基因表达的影响。方法 60只SPF级SD大鼠随机分3组:空白对照组、模型组、Bf组。模型组和Bf组大鼠建立TNBS诱导的UC模型。造模成功后,Bf组予双歧杆菌活菌制剂灌服,空白对照组及模型组不予任何处理。3周后处死全部大鼠,观察一般情况的变化,分离、提取IECs中的总RNA,RT-PCR法检测TLR2、TLR4的表达,免疫组化法检测TLR4、NF-κB表达。结果①Bf组症状、组织损害均较模型组明显减轻。②模型组TLR2、TLR4、NF-κB表达显著高于Bf组与空白对照组(P<0.01)。结论 UC组大鼠结肠上皮细胞TLR2、TLR4及NF-κB基因高表达,Bf组表达明显降低,推测Bf可通过抑制大鼠肠黏膜细胞TLR2、TLR4、NF-κB的表达而缓解肠道的炎症反应。

Objective To investigate the effect of Bifidobacterium（Bf）on expressions of toll-like receptor 2（TLR2）,TLR4 and nuclear factor κB（NF-κB） genes in the intestinal mucosa of rats with ulcerative colitis（UC）.Methods The rats were randomly divided into three groups： the blank control group,the model control group and the Bf group.UC was induced by 2,4,6-trinitrobenzene sulphonic acid（2,4,6-TNBS）and 100% alcohol（1∶ 1,V/V）in the model group and the Bf group.The rats in the Bf group were given Bf by oral gavage after the model was set up.Three weeks later,the rats were killed and total RNA from intestinal epithelial cells（IECs） was extracted for the detection of TLR2,TLR4 and NF-κB.Results ①Both symptoms and lesions of colonic mucosa in the Bf group were slighter than those in the model group.②Expressions of TLR2,TLR4 and NF-κB in the model group were significantly higher than that in the Bf group and blank control group（P〈0.01）.Conclusion High expressions of TLR2,TLR4 and NF-κB genes can be seen in colonic mucosa of rats with UC.Bf can relieve inflammation in the intestinal mucous membrane by inhibiting expressions of TLR2,TLR4 and NF-κB.