鸟苷酸二钠对Con A致小鼠免疫性肝损伤保护作用的NF-κB信号通路机制

Protective effects of disodium guanylate on mice with immunological liver injury induced by Concanavalin A and its mechanism in inhibiting the NF-κB signaling pathway

目的探讨鸟苷酸二钠对刀豆蛋白A(Con A)致小鼠免疫性肝损伤保护作用及NF-κB信号通路机制。方法将60只小鼠随机分为正常对照组、模型组(Con A)、阳性对照药组(联苯双酯200 mg/kg)及鸟苷酸二钠高、中、低(250、125、62.5 mg/kg)剂量组,每组10只,每天灌胃给药1次,连续给药7 d。于末次给药后2 h,除正常对照组尾静脉注射生理盐水外,其余各组小鼠均尾静脉注射Con A(25 mg/kg)建立免疫性肝损伤模型。造模24 h后,取小鼠血清检测ALT及AST活性,取肝左叶组织用于HE染色病理检测,取肝右叶部分组织检测SOD、MDA、GSH-pX及T-AOC水平;取肝右叶部分组织采用RT-PCR及Western Blot法分析IKKβ、IκBα、NF-κB和TNF-αmRNA和蛋白表达水平。结果与模型组比较,鸟苷酸二钠250、125 mg/kg组小鼠血清ALT、AST活性降低,肝组织SOD、GSH-Px及T-AOC水平显著升高,MDA含量下降;鸟苷酸二钠250 mg/kg组小鼠肝组织病理性损伤明显减轻,肝组织IKKβ、NF-κB和TNF-αm RNA和蛋白表达水平下调,IκBαm RNA和蛋白表达水平上调。结论鸟苷酸二钠对Con A致小鼠肝损伤具有防治作用,其机制与抗氧化应激和抑制NF-κB信号通路有关。

Objective To explore the protective effect of disodium guanylate(Disodium guanylate,GMP-Na2)on mice with immunological liver injury induced by condanavailin A(Con A)and its′ mechanism about NF-κB signaling pathway. Methods 16 mice were randomly divided into a normal control group,a model group(Con A),positive control group(Bifendate 200 mg/kg)and a GMP-Na2 high,medium and low dose(250,125 and 62.5 mg/kg)group,10 mice in each group. Mice were intragastrically administrated once a day for 7 day. Two hours after last medication,except for normal control group,mice in other groups were injected Con A(25 mg/kg)via tail?vein to establish the animal model of immunological liver injury. After 24 hours of modeling,the activities of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)in serum were detected by colorimetric method;the pathological changes of liver tissue were observed by HE staining;the levels of SOD(hydroxylamine method),MDA(TBA method),GSH-Px(colorimetric method)and T-AOC(colorimetric method)in liver tissue were detected;the expression levels of IKKβ,IκBα,NF-κB and TNF-α mRNA and protein were analyzed by reverse transcription-polymerase chain reaction(RT-PCR)and Western bolt method. Results Compared with the model group,the activities of ALT and AST in serum and the levels of SOD,GSH-Px and T-AOC in liver tissue of mice in the GMP-Na2 250 and 125 mg/kg groups were increased significantly,while the contents of MDA in livers tissue of mice was decreased;in the GMP-Na2 250 mg/kg group,the pathological injury in liver tissue were alleviated,the expression levels of IKKβ,NF-κB and TNF-α mRNA and protein in liver tissue were down-regulated,and the expression levels of IκBα mRNA and protein in liver tissue were up-regulated. Conclusion GMP-Na2 has the protective effect on mice with liver injury induced by Con A,and the mechanism may be associated with its antioxidant stress and inhibited the NF-κB signaling pathway.