脂多糖通过TLR4参与小鼠脂肪性肝损伤模型炎症反应观察  

Lipopolysaccharide participates in inflammatory response of a mouse model of fatty liver injury through TLR4

作　　者：纪晓方 李伟阳[1] 杨琳[1] 李丽英[1] JI Xiaofang;LI Weiyang;YANG Lin;LI Liying(Department of Cell Biology,Capital Medical University,Municipal Laboratory for Liver Protection and Regulation of Regeneration,Beijing 100069)

机构地区：[1]首都医科大学细胞生物学系肝脏保护与再生调节北京市重点实验室,北京100069

出　　处：《郑州大学学报（医学版）》2019年第3期390-394,共5页Journal of Zhengzhou University(Medical Sciences)

基　　金：国家自然科学基金资助项目(81430013)

摘　　要：目的:研究在小鼠脂肪性肝损伤中脂多糖(LPS)参与肝脏炎症反应的机制。方法:动物实验采用30只雄性ICR小鼠,随机分为对照组、造模第3天组、造模第7天组、造模第14天组、造模第28天组,每组6只。对照组饲喂正常饲料,4个造模组饲喂蛋氨酸胆碱缺乏联合高脂饲料建立小鼠脂肪性肝损伤模型。造模后取肝脏采用ELISA法检测LPS含量; qRT-PCR法检测Toll样受体4 (TLR4) mRNA的表达;免疫荧光染色观察TLR4蛋白的分布。细胞实验采用从小鼠骨髓分离培养的单核/巨噬细胞,分为对照组和LPS组,分别用PBS或LPS刺激6 h后采用qRT-PCR法检测单核细胞趋化蛋白-1(MCP-1)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、诱导型一氧化氮合酶(i NOS)、巨噬细胞炎症蛋白-1β(MIP-1β)、白细胞介素-6(IL-6) mRNA的表达; ELISA法检测细胞培养上清中MCP-1蛋白的含量。结果:5组小鼠肝组织中LPS含量比较,差异无统计学意义(P=0. 313);与对照组比较,造模第14、28天组肝组织中TLR4 mRNA表达增加(P <0. 05); TLR4蛋白在造模第14天小鼠肝脏的非实质细胞中表达。与对照组比较,LPS组MCP-1、TNF-α、IL-1β、iNOS、MIP-1β、IL-6 mRNA和MCP-1蛋白表达增加(P <0. 05)。结论:LPS在小鼠脂肪性肝损伤中通过上调单核/巨噬细胞炎症因子的表达发挥促炎作用。Aim:To investigate the mechanism of LPS involved in hepatic inflammatory response in fatty liver injury in mice.Methods:In the animal experiment,30 male ICR mice were randomly allocated into 5 groups:control group,model 3 days group,model 7 days group,model 14 days group,and model 28 days group.The control group was fed normal diet,and the 4 model groups were fed with methionine choline deficient combined with high fat diet to establish a model of fatty liver injury.The LPS content in liver tissue was detected by ELISA after liver model establishment.The expression of Toll-like receptor 4(TLR4)mRNA in liver tissue was detected by qRT-PCR.The distribution of TLR4 protein in liver was observed by immunofluorescence.The cell experiments were performed using mononuclear/macrophages isolated from mouse bone marrow and allocated into control group and LPS group.After stimulation with PBS or LPS for 6 hours,qRT-PCR was used to detect monocyte chemotactic protein-1(MCP-1),tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),inducible nitric oxide synthase(iNOS),macrophage inflammatory protein-1β(MIP-1β),interleukin-6(IL-6)mRNA expression.The content of MCP-1 protein in the cell culture supernatant was determined by ELISA.Results:There was no significant change in LPS content among the 5 groups of mice(P=0.313).Compared with control group,the TLR4 mRNA expression of the model 14 and 28 days groups was significantly increased(P<0.05),and the TLR4 protein expressed in non-parenchymal cells of the liver tissue of the mice in the model 14 days group.Compared with control group,the expression of MCP-1,TNF-α,IL-1β,iNOS,MIP-1β,IL-6 mRNA and MCP-1 protein in monocytes/macrophages up-regulated in LPS group(P<0.05).Conclusion:In mouse fatty liver injury,LPS might exert pro-inflammatory effects by up-regulating the expressions of inflammatory factors in monocytes/macrophages.

关 键 词：小鼠 脂肪性肝损伤 脂多糖 TOLL样受体4 炎症 

分 类 号：R575.1[医药卫生—消化系统]