Toll样受体4在棕榈酸诱导RAW264.7巨噬细胞炎症反应中的作用及机制

Tianjin Med J,January 2018,Vol.46No.1Toll 样受体4在棕榈酸诱导RAW264.7巨噬细胞炎症反应中的作用及机制

闫美玲1，秦寅鹏1，王文一2，张弋1△

摘要:目的

探讨Toll 样受体4（TLR4）在棕榈酸诱导RAW264.7巨噬细胞炎症反应中的作用及可能机制。方法观察正常对照组（正常饮食）和高脂饲料组（高脂饮食诱导肥胖小鼠模型）C57BL/6J 小鼠血清自由脂肪酸（FFA ）水平及内脏脂肪组织炎症细胞因子肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）和单核细胞趋化蛋白-1（MCP-1）的表达；采用棕榈酸（150μmol/L 组和300μmol/L 组）刺激小鼠RAW264.7巨噬细胞，观察这2组和空白对照（Control ）组、无FFA 牛血清白蛋白（BSA ）组的TNF-α、IL-6和MCP-1的表达和分泌，同时检测TLR4的蛋白表达和核因子-κB （NF-κB ）的激活情况；利用siRNA 干扰实验抑制TLR4，观察在Control 组、BSA 组、棕榈酸（300μmol/L ）组、棕榈酸（300μmol/L ）+Control siRNA 组、棕榈酸（300μmol/L ）+TLR4siRNA 组中棕榈酸诱导巨噬细胞炎症因子的表达和分泌。结果高脂饲料组体质量和Lee ’s 指数高于正常对照组，血清中FFA 水平升高，内脏脂肪组织中TNF-α、IL-6和MCP-1的表达明显增加（P ＜0.05）。与BSA 组比较，棕榈酸150μmol/L 组和棕榈酸300μmol/L 组炎症因子TNF-α、IL-6和MCP-1的表达和分泌均明显增加，TLR4和NF-κB p65磷酸化蛋白水平均增加（P ＜0.05）。与BSA 组比较，棕榈酸300μmol/L 组NF-κB p65的核转运水平和细胞内水平明显升高（P ＜0.05）。TLR4被抑制后，棕榈酸+TLR4siRNA 组的TLR4、TNF-α、IL-6和MCP-1的mRNA 表达和分泌水平明显低于棕榈酸组（P ＜0.05）。结论TLR4可能参与棕榈酸诱导的RAW264.7巨噬细胞炎症反应，诱导炎症因子TNF-α、IL-6和MCP-1的释放，且其介导的炎症反应与NF-κB 的激活有关。

关键词:小鼠，肥胖；棕榈酸；Toll 样受体4；核因子κB ；代谢炎症中图分类号：R589文献标志码：A DOI ：10.11958/20170824

Role of TLR4in RAW264.7macrophage inflammation induced by palmitic acid

YAN Mei-ling 1,QIN Yin-peng 1,WANG Wen-yi 2,ZHANG Yi 1△1Department of Pharmacy,2International Center for Diagnosis and Treatment,

Tianjin First Center Hospital,Tianjin 300192,China

△Corresponding Author E-mail ：wing_zh1821@https://www.360docs.net/doc/0310114636.html,

Abstract:objective To investigate the effect of toll-like receptor 4(TLR4)in RAW264.7macrophage inflammation induced by palmitic acid and its possible mechanisms thereof.Methods C57BL/6J male mice were fed normal (control group)or high-fat diet (high-fat group)for 18weeks.The serum level of free fatty acids (FFA)and mRNA levels of inflammatory cytokines in visceral adipose (TNF-α,IL-6and MCP-1)were detected.Then,palmitic acid (150μmol/L and 300μmol/L)was applied to stimulate RAW264.7macrophage,the mRNA expression and the secretion level of cytokines were detected.Meanwhile,TLR4protein level,the nuclear translocation and intracellular level of NF -κB p65were also detected.After TLR4inhibition by siRNA transfection,the mRNA expression and the secretion level of cytokines were detected.Results The body weight and Lee ’s index were significantly higher in high-fat group than those of control group (P ＜0.05).The serum level of FFA and mRNA levels of inflammatory cytokines (TNF -α,IL-6and MCP-1)in visceral adipose were significantly higher in high-fat group than those of control group (P ＜0.05).Compared with mice without FFA (BSA group),the mRNA expression and the levels of TNF-α,IL-6,and MCP-1were significantly increased (P ＜0.05),and the protein expression of TLR4and NF -κB phosphorylated protein were up-regulated (P ＜0.05)in mice treated with palmitic acid (150μmol/L and 300μmol/L).The nuclear translocation and intracellular level of NF-κB p65were increased 基金项目：天津市卫计委科技基金（2015KY09）

作者单位：1天津市第一中心医院药学部（邮编300192），2国际诊疗中心

作者简介：闫美玲（1984），女，主管药师，主要从事肥胖及代谢综合征的发病机制研究

△通讯作者E-mail ：wing_zh1821@https://www.360docs.net/doc/0310114636.html, 实验研究