TUDCA缓解小鼠肠炎对内质网应激与双氧化酶2表达的研究

Effect of mouse colitis alleviated by Tauroursodeoxycholate on expressions of endoplasmic reticulum stress and dual oxidase2

目的探讨特异性内质网应激抑制剂牛磺熊去氧胆酸(Tauroursodeoxycholate,TUDCA)缓解DSS诱导的小鼠肠炎对内质网应激(endoplasmic reticulum stress,ERS)蛋白与肠黏膜过氧化氢产生酶双氧化酶2(dual oxidase2,Duox2)表达的研究。方法 7周C57BL/6J雄性小鼠适应喂养1周后随机分为对照组、炎症组、干预组。炎症组和干预组饮用2.5%葡聚糖硫酸钠(dextran sulphate sodium,DSS)溶液诱导小鼠肠炎,干预组再以500 mg/kg的TUDCA灌胃。8 d后处死小鼠,收集结肠作HE和免疫组化染色,Western blotting检测Duox2及ERS相关蛋白Grp78、Atf6、P-Ire1α/Ire1α、Ire1β、P-Perk/Perk的表达。结果 TUDCA明显减轻DSS诱导的小鼠肠炎。Western blotting结果显示炎症组Grp78、P-Perk/Perk蛋白及Duox2表达均升高,干预组这三种蛋白表达恢复到对照组水平,其余ERS相关蛋白表达无变化。免疫组化结果显示Grp78和Duox2三组表达水平与Western blotting结果相一致。结论 TUDCA缓解小鼠肠炎可能与抑制内质网Grp78-Perk通路有关,该通路与Duox2表达相互影响。

Objective To investigate the effect of Tauroursodeoxycholate（TUDCA）,a specific inhibitor of endoplasmic reticulum stress（ERS）,which alleviate mouse colitis induced by dextran sulfate sodium（DSS） on the expressions of chaperone proteins of ERS and the dual oxidase2（Duox2）. Methods Seven-week-old C57 BL/6J male mice were divided randomly into control group,DSS group,TUDCA treatment group. Mice in the treatment group and inflammation group were used 2. 5% DSS to induce colitis. Mice in the treatment group were received 500 mg/kg TUDCA by gavage. On 8th day,all mice were sacrificed,the colon tissues were collected,HE staining was used to evaluate pathology of colon,Western blotting and immunohistochemistry（IHC） were used to examine the expressions of proteins including Duox2 and Grp78,Atf6,P-Ire1α/Ire1α,Ire1β,P-Perk/Perk. Results Mice colitis induced by DSS was alleviated by TUDCA. The expressions of Grp78,Duox2,P-Perk/Perk in DSS group were increased,and the expressions of these proteins were down to the level of control in treatment mice. Other proteins were not affected by inflammation or TUDCA. The IHC results were consistent with the results of Grp78 and Duox2 by Western blotting. Conclusion Mouse colitis alleviated by TUDCA could be associated with the inhibition of Grp78-Perk signal pathway,they may be interaction between Duox2 expression and Grp78-Perk signal pathway.