干扰素-α对CCl4诱导的大鼠肝纤维化疗效研究

摘要

Objective To explore the curative effect and the underlying mechanism of interferon-α (IFN-α) on rat liver fibrosis induced by CCl4.Methods Forty-five Wistar male rats were randomly divided into 3 groups: a normal control group (n ＝ 15), a liver fibrosis group (n ＝ 15)and a IFN-α treatment group ( n ＝ 15 ).The rats of the control group and the liver fibrosis group received peanut oil (0.2 mL/100 g body weight), twice a week for 8 weeks.The rats of the liver fibrosis group and the IFN-α treatment group were received intraperitoneal injection of 50％ CC14(CCl4: peanut oil ＝1:1,0.2 mL/100 g body weight, ip) or IFN-α (CC14: peanut oil ＝1: 1, 0.2mL/100 g body weight, ip), twice a week for 8 weeks.In the 9th week, the rats of IFN-α treatment group were switch to receive IFN-α at 100 000 units (s.c.) per day for 3 weeks.The rats were all sacrificed in the l lth week.Pathological changes of liver, semi-quantitative scoring of rat liver was observed.Tissue hydroxyproline, the mRNA expression of Collagen Ⅰ, Collagen Ⅲ, transforming growth factor-beta 1 ( TGF-β1 ), connective tissue growth factor (CTGF), a-smooth muscle actin (α-SMA), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1( TIMP-1 ) of rat liver was detected.The protein expression of MMP-9 and TIMP-1 also was detected.Results Semi-quantitative scoring of inflammation, semi-quantitative scoring of liver fibrosis,hydroxyproline and collagen in the IFN-α treatment group were significantly lower than those in the liver fibrosis group ( all P ＜ 0.05 ).The mRNA expression of TGF-β1, CTGF, α-SMA and TIMP-1,and the protein expression of TIMP-1 in the IFN-α treatment group were significantly lower than those in the liver fibrosis group ( all P ＜ 0.05 ).But there was no significant difference in MMP-9between the IFN-α treatment group and the liver fibrosis group.Conclusion IFN-α can decrease the liver fibrogenesis induced by CCl4 in rats and reduce liver inflammation response.The anti-fibrosis effect of IFN-α may be related to decrease in TGF-β1, CTGF and TIMP-1 expression and to inhibiting of the hepatic satellite cells' activation and extracellular matrix synthesis.%目的:观察干扰素-α (interferon α,IFN-α)对四氯化碳(CCl4)诱导的大鼠肝纤维化的治疗效果,并探讨其可能的机制.方法:45只Wistar大鼠随机分为正常组(n=15)、模型组(n=15)、IFN-α治疗组(n=15).正常组大鼠予以橄榄油2 mL/kg腹腔注射,每周注射2次,共8周;模型组及IFN-α治疗组大鼠予以50%CCl4 2 mL/kg腹腔注射造模,每周注射2次,共8周;IFN-α治疗组于第9周予以IFN-α每日 10万U/只,皮下注射,共治疗3周.11周末处死所有大鼠.取肝组织进行炎症活动度半定量评分、纤维化半定量评分,检测羟脯氨酸含量,Ⅰ型和Ⅲ型胶原、转化生长因子-β1(transforming growth factor β1,TGF-β1)、结缔组织生长因子(connective tissue growth factor,CTGF)、α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、基质金属蛋白酶(matrix metalloproteinase,MMPs)及组织金属蛋白酶抑制因子(tissue inhibitor of metalloproteinase,TIMP-1)mRNA表达量,以及MMP-9和TIMP-1蛋白表达量.结果:与模型组比较,IFN-α治疗组肝组织炎症活动度半定量评分、纤维化半定量评分显著降低,差异有统计学意义(P<0.05);羟脯氨酸含量及Ⅰ型、Ⅲ型胶原mRNA表达量显著降低,差异有统计学意义(P<0.05);TGF-β1,CTGF,α-SMA,TIMP-1 mRNA表达量及TIMP-1蛋白表达量显著降低,差异有统计学意义(P<0.05),MMP-9 蛋白及mRNA表达量差异无统计学意义(P>0.05).结论:IFN-α可明显减轻CCl4诱导的大鼠肝纤维化及肝脏炎症反应,其作用机制可能为下调促肝纤维化因子TGF-β1和CTGF的表达,抑制肝星状细胞的活化,减少细胞外基质的合成;抑制肝纤维化降解因子TIMP-1的表达,调节细胞外基质的降解.