NALP3炎性体在小鼠非酒精性脂肪性肝炎发病中的作用

Potential effect of NALP3 inflammasome in mice model of nonalcoholic steatohepatitis

目的探讨NALP3炎性体在非酒精性脂肪性肝炎(NASH)小鼠发病中的作用。方法予C57BL小鼠高脂饮食(高脂组)及脂多糖建立非酒精性脂肪肝模型(NASH组),同时设立正常饮食组作为对照。观察各组小鼠血清ALT、AST值与计算肝指数,评定脂肪性肝炎程度,ELISA法测定肝脏TNF-α水平,蛋白质印迹法测定NF-κB、NALP3、caspase-1、ASC的表达;实时荧光定量反转录-PCR检测NALP3、caspase-1、ASC mRNA的表达水平。数据处理采用单因素方差分析及LSD法。结果 NASH组小鼠ALT、AST及肝指数明显高于高脂组,差异有统计学意义(P<0.05),高脂组和NASH组的NALP3 mRNA表达高于正常对照组(P<0.05)。NASH组caspase-1和ASC mRNA表达水平明显高于正常对照组及高脂组(P<0.01),高脂组caspase-1和ASC mRNA表达高于正常对照组(P<0.05)。NASH组NALP3、caspase-1和ASC表达水平明显高于正常对照组(P<0.01),NASH组NALP3、caspase-1和ASC表达水平明显高于高脂组(P<0.05),高脂组NALP3、caspase-1和ASC表达水平与正常对照组无明显差异(P>0.05)。结论 NALP3炎性体参与胰岛素抵抗的形成,可能是影响NASH发生和发展的重要因素。

Objective To explore the potential effects of NALP3 inflammasome on nonalcoholic steatohepatitis in mice and its possible mechanism. Methods High-fat fed mice were intraperitoneal injected lipopolysaccharide （LPS 10 mg/kg） to build NASH model and other mice randomized with normal diet as control group. The serum levels of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, Liver index were investigated. The severity of NASH was evaluated in liver sections using Haematoxylin ~ Eosin （HE） Staining, The level of TNF-a in liver was measured by ELISA. The expressions of NF-kB, NALP3, caspase-1 and ASC were detected by Western blot. The expressions of NALP3, caspase-i and ASC mRNA were detected by real-time fluorescent quantitative reverse transcription- polymerase chain reaction （RT-PCR）. Results Mouse model of NASH was successfully established. In the model group of NASH, the levels of ALT, AST and Liver Index significantly increased those of the high-fat（HF） group （P〈0.05）. The level of NALP3 mRNA in the HF group and the model group of NASH was higher than in normal control group （P〈0. 05） ; the expression level of caspase-1 and ASC mRNA in the model group of NASH was significantly higher than those in the HF group and normal control group （P〈0.0l）; the expression levels of NALP3, caspase-i and ASC in the model group of NASH was significantly higher than those in in the HF group and normal control group （P〈0.01 and P〈0.05） ; there was no significant difference in the expression levels of NALP3, caspase-1 and ASC between the HF group and normal control group（P〉0.05）. Conclusion A preliminary conclusion was drawn that NALP3 inflammasome can contribute to the generation of insulin resistance which may be important in the occurrence and development of NASH.