拉米夫定和水飞蓟素对酒精刺激的HBV转基因小鼠肝纤维化相关因子的影响

摘要

目的:观察在肝损伤早期,拉米夫定和水飞蓟素对酒精刺激的乙型肝炎病毒(hepatitis B virus,HBV)转基因小鼠肝组织保护作用,并通过检测肝纤维化相关因子探讨其机制.方法:将40只1.3拷贝HBV转基因BALB/C小鼠随机分为4组.对照组以生理盐水灌胃;模型组以体积分数为50％的白酒5mL/kg灌胃,1次/d;拉米夫定组在模型组处理基础上以拉米夫定溶液(100 mg/kg)灌胃,1次/d;水飞蓟素组在模型组处理基础上以水飞蓟素溶液(200mg/kg)灌胃,1次/d.10周后荧光定量PCR检测各组小鼠血清HBV-DNA载量,全自动生化仪检测血清ALT和AST水平.HE染色,Masson染色镜检观察肝组织病理变化,荧光实时定量PCR检测肝组织TGF-β1,Smad3,Smad7,结缔组织生长因子(connective tissue growth factor,CTGF) mRNA表达水平,免疫组织化学检测肝组织TGF-β1,CTGF,α-平滑肌肌动蛋白(α-SMA)表达水平.结果:与对照组相比,模型组肝组织病理损伤加重,血清HBV病毒载量,ALT和AST水平明显增高,肝组织内TGF-β1,Smad3,Smad7,CTGF mRNA及TGF-β1,CTGF,α-SMA蛋白表达增加(P＜0.05).与模型组相比,拉米夫定组和水飞蓟素组肝组织病理损伤均减轻,肝组织内TGF-β1,Smad3,CTGF mRNA及TGF-β1,CTGF,α-SMA蛋白表达减少(P＜0.05),Smad7 mRNA的表达进一步增加(P＜0.05),水飞蓟素组血清ALT和AST水平降低(P＜0.05).结论:拉米夫定和水飞蓟素可通过调节TGF-β1/Smads信号通路,减少CTGF表达,抑制肝星状细胞活化等机制阻断酒精刺激的HBV转基因小鼠肝组织纤维化的发生和进展.%Objective:To observe the role of lamividine and silymarin preventing and curing liver fibrosisrelevant factors induced by alcohol drinking in hepatitis B virus (HBV) transgenic mice (Tg mice).Methods:Forty HBV-Tg BALB/C mice with 1.3 copy were randomly divided into 4 groups:a control group,a model group,a lamivudine group and a silymarin group.Tg mice in control group were treated with normal saline via intragastric administration;Tg-mice in the model group were treated with 50％ alcohol (5 mL/kg) once a day via intragastric administration;while Tg-mice in lamivudine group and silymarin group were treated with alcohol (5 mL/kg) plus laminvudine (100 mg/kg) and silymarin (200 mg/kg) once a day via intragastric administration respectively.All groups were raised for 10 weeks.The levels of HBV-DNA copy number,ALT,AST in serum,the degree of inflammation,the degree of fibrosis,the mRNA expression levels of TGF-β 1,Smad3,Smad7 and connective tissue growth factor (CTGF),and the protein expression levels of TGF-β1,CTGF and α-SMA in liver tissue were detected.All the images were scanned with electronic computer and the data were analyzed with SPSS13.0 software.Results:Compared with the control group,liver injury were significantly aggravated,while HBVDNA copies,mRNA levels ofTGF-β1,Smad3,Smad7 and CTGF as well as the protein levels of TGF-β1,CTGF and α-SMA were significantly increased (P＜0.05).Compared with the model group,liver injury were significantly attenuated in silymarine group and lamivudine group,while mRNA levels of TGF-β 1,Smad3 and CTGF as well as the protein levels of TGF-β1,CTGF and α-SMA were significantly decreased;mRNA level of Smad7 was further increased (P＜0.05);the levels of ALT and AST in serum were decreased in the silymarine group (P＜0.05).Conclusion:Lamivudine and silymarin relieve the histological damage in the liver of alcohol-fed Tg mice.The mechanisms for the beneficial effects of lamivudine or silymarin might be related to inhibiting the expression of TGF-β 1,Smad3 and CTGF,modulating the expression of Smads and suppressing the activation of HSC.