酒精性肝纤维化大鼠模型的建立及Smad7/TGF-β表达变化  

Establishment of a rat model of alcoholic liver fibrosis and detection of hepatic expression of Smad7/TGF-β

作　　者：何培元[1] 侯志平[2] 高淑梅[3] 王明娟[2] 马立新[1] 李炳庆[1] 

机构地区：[1]承德医学院附属医院消化内科,河北省承德市067000 [2]承德医学院病理教研室,河北省承德市067000 [3]承德医学院附属医院心电室,河北省承德市067000

出　　处：《世界华人消化杂志》2014年第19期2692-2702,共11页World Chinese Journal of Digestology

基　　金：河北省卫生厅基金资助项目;No.20110179~~

摘　　要：目的:为酒精性肝病发病机制及治疗研究提供简便、经济、成模率高的动物模型并探究酒精性肝病的发病机制.方法:以单笼喂养,自由摄取食水的方式饲养大鼠.对照组不予饮酒,自由摄取食水;实验组予饮酒,分为正常饲料组、高脂饲料组及高脂限食组.将市售白酒稀释成(6%、9%、12%、20%)等不同浓度的水溶液,以其作为大鼠的唯一水源.先给予6%的白酒水溶液,待大鼠适应白酒气味之后,逐渐提高白酒浓度,第4周时将白酒浓度提高至20%,一直到实验结束.实验结束后取肝组织观察病理学变化,用生化检测仪检测大鼠血浆丙氨酸氨基转移酶(alanine aminotransferase,ALT)和天门冬氨酸氨基转移酶(aspartate aminotransferase,AST)变化.用Real-time RCR检测肝组织转化生长因子β1(transforming growth factor beta1,TGF-β1)和Smad7 mRNA水平变化,并用Western blot检测蛋白水平变化.结果:对照组肝脏组织形态正常,实验组中正常饲料组肝组织出现脂肪肝表现,高脂饲料组脂肪变性程度加重并出现了肝炎及胶原纤维增生.限食高脂组肝组织出现了大量成束的胶原纤维并伴有肝炎及脂肪肝表现.血清ALT、AST结果显示:至实验结束时,对照组比实验组转氨酶活性明显升高(P<0.05),不同实验组间比较高脂饮食组和限食高脂组转氨酶活性无差别,但均较正常饲料组高(P<0.05).TGF-β1和Smad7这两个基因的蛋白丰度与他们各自的mRNA表达水平呈正相关,与对照组比较3个实验组TGF-β1表达水平升高,并与肝脏病理损伤程度呈正相关,实验组Smad7表达水平降低,但与肝脏病理变化无相关性.结论:饮用白酒水溶液结合限食及高脂饮食的方法可以成功建立酒精性肝纤维化的大鼠模型,Smad7不能有效抑制TGF-β1促进了肝纤维化的形成.AIM： To develop a suitable rat model of alcohol-ic liver fibrosis, which is easily available and lowin cost with a high success rate, and to detect thealteration of expression of genes involved in thepathogenesis of alcoholic liver disease.METHODS： Rats were raised individually inrespective cages and were fed ad libitum. Rats were divided into two groups： a normal control group and an experimental group. The normal control group was given a normal diet with alcohol-free water. The experimental group was further divided into three subgroups, namely, a normal diet subgroup, a high fat diet subgroup and a limited high fat diet subgroup. Commer-cially available Chinese spirit was diluted into different concentrations（6%, 9%, 12%, 20%） using distilled water and used as the source of alcohol consumption for rats in the experimental group. Rats in the experimental group were fed distilled water containing 6%（v/v） alcohol at the beginning of the experiment, and the con-centration of alcohol was gradually increased to 20% within 4 wk. Ultimately, water containing 20% alcohol was maintained towards the end of the study. At the end of the experiment, livers of rats were dissected for histological studies whereas serum samples were taken to detect the levels of alanine aminotransferase（ALT） and as-partate aminotransferase（AST）. The mRNA and protein expression of transforming growth fac-tor β1（TGF-β1） and Smad7 in liver tissues was detected by real-time PCR and Western blot, respectively.RESULTS： No pathological changes were ob-served in the liver of rats in the normal control group. However, rats in the experimental group demonstrated histopathological changes such as fatty change, inflammation as well as fibro-sis. The histopathological changes were most severe in the subgroup fed a limited high fat diet, followed by those fed a high fat diet. Fatty changes were observed in the liver of rats in the experimental subgroup fed a normal diet. A small amount of collagen fibrils, inflammation and a m

关 键 词：酒精性肝纤维化 大鼠模型 转化生长因子Β1 SMAD7 高脂饲料 

分 类 号：R575.2[医药卫生—消化系统]