雷公藤红素缓解刀豆蛋白A诱导的小鼠急性肝损伤作用及其机制

Effect and Mechanism of Celastrol Alleviated Acute Liver Injury in Mice Induced by Concanavalin A

将36只同一批次体重无明显差异的7周龄C57雄鼠随机分为6组,每组6只,即对照组,模型组,地塞米松(dexamethasone,DXM)组及雷公藤红素(celastrol,Cel)低、中、高剂量组(1.5、3、6mg/kg),连续灌胃7d后尾静脉注射20mg/kg刀豆蛋白A(concanavalin A,ConA),地塞米松(0.5mg/kg)于刀豆蛋白给药前1h腹腔注射.注射8h后处死小鼠,取其血清分别检测白介素-6(IL-6)、白介素-10(IL-10)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和丙氨酸氨基转移酶(ALT)及天冬氨酸转移酶(AST)的含量.取小鼠肝脾称重计算脏器系数,苏木精-伊红(HE)染色观察肝组织病理改变,用实时定量PCR法(RT-qPCR法)检测肝组织中相关基因mRNA的表达水平,流式细胞术检测脾脏中巨噬细胞的极化方向,从而研究雷公藤红素对刀豆蛋白A诱导的小鼠急性肝损伤的保护作用及其机制.结果显示:相较于正常组,模型组小鼠的肝组织明显发生急性肝炎,其小叶结构紊乱,肝细胞结构破坏,汇管区炎症细胞浸润,雷公藤红素处理后肝组织症状明显好转,且存在显著性差异;雷公藤红素处理的小鼠血清中ALT和AST含量以及炎症因子TNF-α和IL-6含量显著下降,具统计学意义(P<0.05),而抑炎因子IL-10的含量却显著升高,具统计学意义(P<0.05);雷公藤红素处理的小鼠肝组织中相关炎症基因的表达较模型组显著下降(P<0.05);流式结果显示,雷公藤红素处理后,小鼠脾脏中M1型巨噬细胞比例明显下降,M2型巨噬细胞比例明显增加,具统计学差异(P<0.05).以上结果表明,雷公藤红素能够通过抑制小鼠脾脏中巨噬细胞M1极化同时促进M2极化来缓解刀豆蛋白A诱导的小鼠急性肝损伤.

The aim of this study was to investigate the protective effect of celastrol(Cel)on acute liver injury induced by concanavalin A(ConA)in mice.36C57male mice with no significant difference in body weight in the same batch were randomly divided into 6groups,with 6in each group,and these group was named control group,model group,dexamethasone(DXM)group and low,medium and high dose group of Cel(1.5,3,6mg/kg).After continuous gavage of Cel for 7days,20mg/kg ConA injected to the caudal vein of mice,then DXM(0.5mg/kg)was intraperitoneally injected one hour early before the disposition of ConA.After 8hof injection,the mice were sacrificed,and the contents of interleukin-6(IL-6),interleukin-10(IL-10),tumor necrosis factor-α(TNF-α),alanine aminotransferase(ALT)and aspartate transferase(AST)were measured in serum.The author weighed livers and spleens of mice to calculate viscera coefficient,using hematoxylin-eosin(HE)staining to observe the liver tissue pathological change,using real time quantitative PCR method(RT-qPCR)to detect the expression of inflammation genes mRNA in liver tissue,using flow cytometry to detect the polarization direction of macrophages of the spleen of mice.The results showed that,compared with the normal group,model group mice acute hepatitis occurred obviously,such as obular structure disorder,liver cell structure destruction and portal area inflammatory cell infiltration.The symptoms of liver injury had significant changeover after treatment with Cel.The levels of ALT and AST,inflammatory cytokines TNF-αand IL-6were significantly reduced in mice treated with Cel(P<0.05);on the other hand,the content of anti-inflammatory factor IL-10was significantly increased,with statistical significance(P<0.05).The expression of inflammatory genes in the liver tissues of mice treated with Cel was significantly decreased compared with the model group(P<0.05).The results of flow cytometry showed that the proportion of M1-type macrophages of the spleen of mice treated with Cel decreased significantly,while the proportion of M2-type macrophages increased significantly in the meanwhile,with statistical difference(P<0.05).These results indicated that Cel could alleviate the acute liver injury induced by ConA in mice by inhibiting the M1polarization of macrophage and promoting the M2polarization of macrophage of the spleen.