c-Jun氨基末端激酶抑制剂对大鼠非酒精性脂肪性肝炎的防治及机制

Protective effect of SP600125,a JNK inhibitor, against nonalcoholic steatohepatitis

目的:探讨选择性c-Jun氨基末端激酶(Jun N-terminal kinase,JNK)抑制剂SP600125对大鼠非酒精性脂肪性肝炎(nonalcoholic steatohepatitis,NASH)的保护作用及机制.方法:48只♂SD大鼠随机分为正常对照组(NC,18只)、模型组(HF组,15只)和SP600125干预组(SP干预组,15只).HF组及SP干预组大鼠高脂饮食12 wk,建立高脂诱导的NASH模型,12 wk时分别处死NC组大鼠6只,HF组及SP干预组各3只,用于NASH模型病理学鉴定.最终NC组、HF组及SP干预组大鼠数目均为12只.HF组及SP干预组大鼠建立经皮肠系膜上静脉给药途径,HF组给予二甲基亚砜,SP干预组给予SP600125(50 mg/kg),1次/d,连续4 wk.第16周处死全部大鼠,采用ELISA法测定匀浆液的肿瘤坏死因子α、白介素-6含量;HE染色观察肝组织普通病理变化.Masson染色观察肝组织纤维化程度.苏丹Ⅳ染色观察肝组织脂肪变的程度.采用RT-PCR方法检测JNK mRNA.采用免疫印迹(Western blot)法检测c-Jun蛋白和磷酸化蛋白水平.结果:高脂饮食16 wk后,SD大鼠肝组织呈弥漫性脂肪变性,炎性细胞浸润及小叶内坏死灶增多,可见明显的窦周纤维化及中央静脉周围纤维化.SP干预组大鼠肝组织炎性反应、脂肪变性及纤维化程度均较模型对照组改善,差异具有统计学意义;RT-PCR结果显示:正常大鼠肝脏组织内JNK mRNA表达量少,HF组表达量增加,差异具有统计学意义.而SP干预组较模型JNK mRNA表达量减少,差异具有统计学意义.Wstern blot结果显示:HF组较NC组大鼠肝组织中c-Jun蛋白及p-c-Jun升高,差异具有统计学意义.而SP干预组c-Jun蛋白及p-c-Jun较HF组明显减少,差异具有统计学显著性意义.结论:SP600125可能通过抑制JNK通路阻止NASH发生,有望成为治疗NASH的新型药物.

AIM： To investigate the potentially protective effect of SP600125, a selective c-Jun N-terminal kinase inhibitor, in a rat model of nonalcoholic steatohepatitis（NASH） induced with a high fat diet. METHODS： Forty-eight Sprague-Dawley rats were randomly divided into three groups： a normal control group（NC group）, a high-fat model group（HF group） and an SP600125 treatment group（SP group）. All rats were sub-jected to a percutaneous superior mesenteric vein retention catheter operation and fed a standard diet for 4 wk. The HF group was then fed an HF diet and treated with dimethyl sulf-oxide, while the SP group was fed an HF diet and treated with SP600125（50 mg/kg） once per day.RESULTS： Feeding an HF diet successfully induced NASH in rats, with varying degrees of hepatic steatosis and hepatic inflammation. SP600125 treatment substantially decreased the level of inflammation and the expression of c-Jun and p-cJun proteins. CONCLUSION： SP600125 has the potential to remarkably attenuate steatosis and inflammation and may be a novel therapeutic drug against NASH.