双歧杆菌对实验性大鼠结肠炎中热休克蛋白70的影响

Effects of Bifidobacterium on HSP70 of trinitrobenzene sulfonic acid induced colitis in rats

目的观察实验性结肠炎热休克蛋白(HSP70)、白介素-10(IL-10)、肿瘤坏死因子-α(TNF-α)表达变化并研究双歧杆菌对其表达的影响。方法 40只SD大鼠随机均分为正常组、模型组、5-ASA组及双歧杆菌组。2,4,6-三硝基苯磺酸(TNBS)/乙醇制备大鼠结肠炎模型。5-ASA组给予奥沙拉秦钠胶囊100 mg/(kg·d),双歧杆菌组给予双歧杆菌0.1 ml/d(108cfu/ml),正常组与模型组给予生理盐水2ml/d;连续灌胃14 d。每天观察各组大鼠结肠炎疾病活动指数(DAI),评价结肠大体形态损伤指数(CMDI)和组织学损伤指数(TDI),免疫组化法检测结肠组织HSP70的表达,ELISA法检测血清HSP70、IL-10和TNF-α含量。结果与正常组相比,模型组DAI、CMDI、TDI、血清TNF-α显著升高(P<0.01),IL-10水平下降,血清及结肠组织HSP70表达减少(P<0.01)。5-ASA组和双歧杆菌组DAI、CMDI和TDI、血清TNF-α明显低于模型组(P<0.01);血清IL-10、HSP70及结肠组织HSP70明显高于模型组(P<0.01)。5-ASA组和双歧杆菌组之间差异无统计学意义。结论 HSP70表达减少参与了实验性结肠炎的发病;双歧杆菌可能通过提高保护性蛋白水平,调节促炎因子与抗炎因子之间平衡对实验性结肠炎发挥治疗作用。

Objective To study the expression of heat shock protein 70（HSP70）,and the changes of interleukin 10（IL-10）,tumor necrosis factor-α（TNF-α）in 2,4,6-trinitrobenzene sulfonic acid（TNBS）/ethanol induced colitis,and to investigate the effect of Bifidobacterium supplementation on the experimental colitis,and its possible mechanism.Methods Forty SD rats were randomly divided into four groups（n=10）：normal control group,model group,5-ASA treatment group,and Bifidobacterium treatment group.The colitis model of rats was established with TNBS/ethanol.Treatment groups was respectively given Olsalazine 100 mg/（kg·d）,Bifidobacterium 0.1ml/d（108 cfu/ml）,normal group and model group was given 2 ml normal saline.After continuous administration for 14 d,the colonic inflammation including disease activity index（DAI）,colonic macroscopic damage index（CMDI）and tissue damage index（TDI）were observed,and the expressions of HSP70 in the colon tissues of rats were detected by immunohistochemical method,and the levels of HSP70,IL-10,and TNF-α in serum were detected by ELISA.Results The DAI,CMDI and TDI,and the serum levels of TNF-α were significantly higher（P〈0.01）,and the serum levels of HSP70 and IL-10,and the expressions of HSP70 in colon tissues were significantly lower in model group than that in normal group respectively.5-ASA and Bifidobacterium reduced the DAI,CMDI,TDI and the serum levels of TNF-α significantly,and increased the serum levels of HSP70 and IL-10,and the expressions of HSP70 in the colon tissues（P〈0.01）.But two treatment groups had no significant difference.Conclusion HSP70 may play an important role in pathogenesis of experimental colitis throught its expression decreaseing.Bifidobacterium possiblely produces treatment effect in experimental colitis rats by increasing protective proteins and regulating the dynamic balance between proinflammatory and inflammation cytokines.