5-脂氧合酶抑制剂AA-861治疗肝纤维化的实验研究

摘要

Objective To investigate the anti-fibrosis effect of a 5-lipoxygenase (5-LO)specific inhibitor AA-861 on liver fibrosis. Methods Liver fibrosis was induced in male Sprague Dawley rats by intraperitoneal injection of carbon tetrachloride(CCI4).AA-861(0.2 mg/100 g/d)was administrated by intraperitoneal injection starting 2 days before the first dosage of CCI4 and rats were killed at weeks 2,4,and 6.Liver specimens were obtained from each animal and fixed with 4%formaldehyde for histological analysis. The Mrna expression of 5-LO,smooth muscle-alpha(α-SMA),Collagen-1,matrix metalloproteinase-2(MMP-2)and tissue inhibitors of metalloproteinase-1(TIMP-1),the protein expression of 5-LO were evaluated by real time PCR and Western blot respectively. Histological analysis was performed by microscopy observation. Fibrosis conditions in rat liver in each group were evaluated according to the semi-quantitative scoring system (SSS), Hyp in rat livers and the hepatic functional biochemistry were also detected. Results Along with the aggravation of liver fibrosis, the gene expression of 5-Lo,α-SMA,Collagen-1,MMP-2 and TIMP-1 increased gradually, and the level of ALT, TBA, Hyp and SSS score also increased gradually. With the administration of AA-861,the Mrna expression of 5-LO,α-SMA,Collagen-1,MMP-2,TIMP-1 and the protein expression of 5-LO decreased remarkably, and the reduction in TIMP-1 Mrna expression was more significant than that in MMP-2.Six weeks after AA-861 treatment, the level of ALT, TBA, Hyp and SSS score were also decreased significantly. Conclusion AA-861 ameliorates CCI4 induced rat liver fibrosis by inhibiting the 5-LO pathway and decreasing the expression of 5-LO,α-SMA,Collagen-1,MMP-2 and TIMP-1.%目的 探讨5-脂氧合酶(5-LO)特异性抑制剂AA-861对四氯化碳(CCI4)诱导的大鼠肝纤维化形成的影响.方法 在CCI4诱导的肝纤维化模型中,在注射CCI4的前2 d开始腹腔内注射AA-861(0.2 mg/100 g,1次/d),分别在注射CCI4的第2、4、6周处死大鼠.应用实时定量PCR检测肝脏中5-LO、平滑肌肌动蛋白-α(α-SMA)、Ⅰ型胶原(collagen-1)、基质金属蛋白酶-2(MMP-2)和金属蛋白酶组织抑制剂-1(TIMP-1)等基因的表达,Western blot榆测肝脏5-LO蛋白的表达;检测肝功能和肝脏组织中羟脯氨酸(Hyp)的含量和组织学变化,并对肝纤维化程度进行半定量计分系统(SSS)分级评分.结果 随着肝纤维化程度的加重,大鼠肝组织中5-LO、α-SMA、Collagen-1、MMP-2和TIMP-1等基因的表达显著增加,同时肝功能ALT、TBA等指标明显升高;而大鼠注射AA-861后各种基因表达明显降低,相对于MMP-2基因,TIMP-1基因mRNA表达的降低更为明显,Hyp、肝功能和肝纤维化程度评分也明显降低. 结论 AA-861可通过抑制5-LO途径,显著降低TIMP-1 Collagen-1和α-SMA等基因的表达,减轻CCI4诱导的大鼠肝纤维化程度.