Objective To explore the expression and significance of p38MAPKin the pathogenesis of nonalcoholic steatohepatitis (NASH).Methods Sixty mice which were 6-weeks-old were randomized by bodyweight into high lipid high fructose group and control group with 30 mice in each and were given the corresponding feed.The nice were sacrificed respectively at the end of weeks 4,8,and 16,and their NASH-related parameters such as liver function,blood lipid etc.were determined,and the liver histopathological changes were evaluated after HE and oil red O staining of liver tissue specimens and NAS scoring was performed; immunohistochemistry and Western Blotting were applied to determine expression of p38MAPK in the model mice at weeks 4,8 and 16,at the same time,RT-PCR was used to determine mRNA expression levels of p38MAPK,TNF-a,MCP-1,IL-1,IL-6 and IL-8.Results As compared with the control mice at the same stage,the oil red O stained area and density increased in the high lipid high fructose group; HE staining showed that foci of different degree occurred with time after the model was established.The NAS score at the end of model establishment was 5-8 points,which reached the diagnostic criterion for NASH.At the end of 4th and 8th weeks,total cholesterol,high density lipoprotein,low density lipoprotein significantly increased as compared to the control group.At the end of the 16th week,the liver function tests and blood lipid of the high lipid high fructose group significantly increased.MCP-1 and IL-1 markedly increased at the early stage,TNF-α and IL-8 increased at the end of the 8th week,while p38MAPK and IL-6 showed a trend of increase,and increased significantly at the end of 16th week.Immunohistochemistry for p-p38MAPK showed nuclear stainingat 8th and 16th weeks; Western Blotting showed significant increase of p38MAPK expression in the model group at 4,8,and 16th weeks in the liver tissue as compared with the control group.Conclusion Mouse model of NASH was successfully established by using modified western food-like feed,and in the model group p38MAPK and inflammatory factors play roles in formation of NASH,and p38MAPK and IL-6 may be used as a basis for assessment of targeted therapy of NASH.%目的 探讨p38MAPK炎症通路在非酒精性脂肪性肝炎(NASH)发病中的作用及意义.方法 6周龄小鼠60只按体重随机分为高脂高果糖组、对照组各30只予以相应喂养,4、8、16周末分批处死小鼠,检测肝功能、血脂等NASH相关指标,通过HE、染色评价肝脏组织病理学改变,进行NAS评分;应用免疫组织化学、Western Blot法检测4、8、16周模型小鼠p38MAPK的表达,同时应用RT-PCR法检测p38MAPK、TNF-a、MCP-1、IL-1、IL-6、IL-8的mRNA表达水平.结果 与同期对照组比较,模型组小鼠HE染色显示随造模时间延长均出现不同程度脂肪变伴炎症灶,造模终点其NAS积分5-8分,达到NASH诊断标准.4周末和8周末,模型组TC、TG、HDL和VLDL较对照组明显增高;16周末,模型组肝功能、血脂均增加明显;MCP-1、IL-1早期增加明显,TNF-a、IL-8均在8周末升高;而p38MAPK和IL-6呈现递增趋势,在16周末升高明显;p-p38MAPK免疫组化在8、16周出现核染;Western Blot显示4、8、16周模型组的肝组织中p38MAPK的表达较对照组明显增加.结论 成功建立了改良西方饮食诱导的NASH小鼠模型,炎症因子在NASH的形成中发挥作用,p38MAPK和IL-6可作为NASH靶向治疗效果的判断依据.
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