罗格列酮对大鼠非酒精性脂肪性肝炎逆转机制的研究  

An experimental study on the reverse mechanism of PPAR- γ agonist rosiglitazone in rats with nonalcoholic steatohepatitis

作　　者：赵彩彦[1] 王亚东[1] 周俊英[1] 贾蓓[1] 崔俊峰[1] 

机构地区：[1]河北医科大学第三医院感染科,石家庄050051

出　　处：《中华肝脏病杂志》2007年第6期450-455,共6页Chinese Journal of Hepatology

基　　金：河北省自然科学基金（C200500780）

摘　　要：目的 探讨过氧化物酶体增殖物激活受体γ（PPAR-γ）激动剂罗格列酮对库普弗细胞中LPS诱导的IκB激酶-β（IKK-β）表达以及对NASH大鼠肝组织核因子-κB（NF-κB）活性和环氧合酶-2（COX-2）表达水平的影响及意义。方法 采用Ⅳ型胶原酶消化和密度梯度离心的方法分离纯化正常Wistar大鼠库普弗细胞,并应用LPS（1μg／ml）及不同浓度的罗格列酮（10 nmol／L和50 nmol／L）干预培养,收集细胞及培养上清液。体内实验：健康雄性Wistar大鼠随机分为正常组和模型组,后者以高脂饲料（2％胆固醇＋10%猪油＋5％玉米油）喂养复制NASH大鼠动物模型,造模成功后,分别以1 mg·kg^-1·d^-1、4mg·kg^-1·d^-1剂量的罗格列酮和等容积等渗盐水灌胃,实验结束后采集大鼠血清和肝组织标本。RT-PCR检测库普弗中细胞IKK-β、肝组织中COX-2 mRNA的表达,Western blot和电泳迁移率改变分析（EMSA）分别检测库普弗细胞中IKK-β蛋白表达和肝组织NF-κB活性变化,ELISA检测细胞培养上清液及血清中TNFα水平。结果 LPS可显著增高体外培养库普弗细胞中IKK-βmRNA、蛋白的表达及上清液中TNFα水平。模型组大鼠肝组织COX-2 mRNA和蛋白的表达均较正常对照组增强,NF-κB活性与COX-2的表达和血清TNFα水平呈正相关。罗格列酮体外可抑制LPS诱导库普弗细胞中IKK-βmRNA和蛋白的表达,体内通过抑制肝组织NF-κB活化,减少COX-2表达,均表明罗格列酮可通过抑制炎症细胞活化,下调炎症介质基因表达,从而减少了NFα等炎症介质合成、释放,抑制肝脏炎症反应。结论 PPAR-γ特异性激动剂罗格列酮通过干预IKK-β／IκB／NF-κβB／TNFα信号通路而发挥抗炎作用,从细胞分子水平逆转NASH大鼠肝组织的炎症反应,这为临床上有效治疗NASH提供了新思路。Objectives To investigate the influence and significance of peroxisome proliforatoractivated receptor- γ （PPAR- γ） agonist rosiglitazone on the expression of Ⅰκ B kinase- β （IKK- β） mRNA and protein induced by LPS in Kupffer cells （KCs） cultured in vitro and to investigate the activity of nuclear factor- κ B （NF- κ B） together with the expression of cyclooxygenase-2 （COX-2） in livers of rats with nonalcoholic steatohepatitis （NASH）. Methods （1） KCs from healthy Wistar rats were isolated and purified with IV collagenase digestion and gradient centrifugalization, and then were incubated in the presence or absence of LPS （1 μ g/ml） together with two different concentrations of rosiglitazone （10 nmol/L and 50 nmol/L）. （2） Thirty-eight healthy Wistar rats were randomly divided into a normal blank control group （10 rats） fed with a normal diet and a NASH model group （28 rats） fed with a fat-rich diet （10% lard ＋ 2% cholesterol ＋ 5% corn oil）. After the NASH model was established successfully and confirmed by pathologi- cal examination of the livers of 4 rats, 24 rats that continued with the high fat-rich diet, were divided into three groups （8 rats in each group）： a control group fed normal saline （NS）, a lower dose rosiglitazone group （1 mg· kg^-1·d^1） and a higher dose rosiglitazone group （4 mg·kg^-1·d^-1） for 12 weeks. The mRNA expression of IKK- β in KCs and COX-2 in livers were measured using reverse transcription-polymerase chain reaction （RT-PCR）. The IKK- β protein in KCs and the NF- κB activity of hepatic tissues were determined respectively by Western blot and electrophoretic mobility shift assay （EMSA）. The concentration of tumor necrosis factor α （TNF α ） in the supernatant of KCs cultures and serum of the rats was quantified by enzyme linked immunosorbent assay （ELISA）. Results LPS significantly increased the expression of IKK- β mRNA and protein in the KCs and the concentration of TNF α in the su

关 键 词：过氧化物酶体类 脂肪肝 非酒精性 

分 类 号：R686[医药卫生—骨科学]