一次性大剂量二甲基亚硝胺致大鼠肝纤维化模型中肝星状细胞的病理变化  

Pathological changes of hepatic stellate cells in rat liver fibrosis induced by one high-dose injection of dimethylnitrosamine

作　　者：郭丽梅[1] 林梅[1] 陆珊[1] 杜娟[1] 宫恩聪[1] 

机构地区：[1]北京大学医学部病理学系,北京市100191

出　　处：《实用肝脏病杂志》2009年第4期244-247,264,共5页Journal of Practical Hepatology

基　　金：国家自然科学基金主任专项基金(编号:30440012)部分资助

摘　　要：目的观察一次性大剂量二甲基亚硝胺(DMN)致大鼠肝纤维化模型中肝星状细胞的病理学变化。方法将大鼠分为对照组和模型组。造模组以DMN50mg·kg-1大鼠体重的剂量一次性腹腔注射。分别于注射后6、12、24和36小时,2、3、5、7、10和14天,1、3、6和12个月取肝组织进行病理形态学观察及α-平滑肌肌动蛋白(α-SMA)、单核/巨噬细胞表面特异性标志抗原(Ectodermal dysplasia-1,ED-1)和转化生长因子β1(TGF-β1)免疫组织化学染色,并采用逆转录-聚合酶链式反应(RT-PCR)法检测肝组织内I型胶原和TGF-β1 mRNA的表达。结果模型组大鼠在损伤后出现6小时～5天、5～14天和14天～12月三个不同的反应阶段。6小时后中央静脉周围肝实质细胞开始出现点状坏死,于36小时达到急性亚大片出血性坏死的高峰,坏死区内无残存的肝星状细胞;3天时残存肝实质内出现α-SMA阳性的活化肝星状细胞。坏死区内大量ED-1阳性的巨噬细胞聚集,并表达TGF-β1蛋白;第5天时,坏死区内组织碎片和红细胞被巨噬细胞清除。肝星状细胞不断活化、增生、并向坏死区周围及坏死区内移动。部分肝星状细胞开始表达TGF-β1蛋白;第7天时,大量活化的肝星状细胞沿肝窦和中央静脉间纤细的纤维间隔内分布,并与巨噬细胞一起表达TGF-β1蛋白;第14天时,坏死灶完全被再生的肝细胞及纤维组织取代,中央静脉之间桥接纤维化完全形成。纤维间隔内存在大量活化的肝星状细胞和巨噬细胞;此后至12个月,肝纤维化形态始终保持,无其他进展性或可逆性变化发生。结论采用一次性大剂量DMN注射,可获得大鼠肝脏亚大片坏死后性纤维化的稳定模型。研究形成过程中的肝星状细胞、巨噬细胞和肝细胞等实质细胞的形态和功能变化以及它们之间的相互作用对进一步阐明肝纤维化及其相关肝脏疾病的发生机制有重要的意义。Objective To explore the pathological changes of hepatic stellate cells （HSCs） in rat liver fibrosis induced by one high-dose injection of dimethylnitrosamine（DMN）. Methods The rats were divided into control and model groups. Rats were injected intraperitoneally with DMN at one high-dose of 50mg＇kg-1 body weight to establish the model.The rats were sacrificed at each of the following post-injection time：hour 6,12,24,36; day 2,3,5,7,10,14;month 1,3,6 and 12. Liver tissues were used for HE staining and immunohistochemical staining of α-smooth muscle actin,ectodermal dysplasia-1（ED-1） and transforming growth faetor-β1. Reverse transcription-polymerase chain reaction was used to detect mRNA expression of collagen Ⅰ and TGF-（31 in liver tissues. Results The pathological characteristics included three stages：early injury-response（6 hours to 5 days）,regeneration-fibrosis（5 to 14 days）and perpetuation of fibrosis （14 days to 12 months）. At 6h,focal necrosis of liver parenchyma appeared and got the peak of acute submassive hemorrhagic necrosis at 36h; At 3d, HSCs were activated in the residual parenchyma and plenty of macrophages expressing TGF-β1 were infiltrated in the necrotic area;At day 5,HSCs were activated,proliferated and migrated into the necrosis. Some HSCs began to express TGF-β1;At day 7,diffuse activated HSCs were distributed along the sinusoid and in the thin fi- brotic septa. At 14d,central-central bridging fibrosis was completely formed. Plenty of activated HSCs were paralleled in the fibrotic septa with macrophages. From then on to 12 mons,the morphology of liver fibrosis was kept without obvious changes. Conclusion The model of rat liver post- necrotic fibrosis by one high-dose injection of DMN was practical. The pathological changes of HSCs,macrophages and hepatocytes,and the interaction among these cells were basis for further studies of liver fibrosis and related liver diseases.

关 键 词：肝纤维化 二甲基亚硝胺 肝星状细胞 转化生长因子-Β1 大鼠 

分 类 号：R575.2[医药卫生—消化系统]