摘要
目的探讨肿瘤坏死因子-α诱导蛋白8样分子-2(TIPE2)对脂多糖或白细胞介素4(IL-4)诱导的脂肪组织巨噬细胞(ATM)表型转化的作用和分子机制。方法应用免疫组化、Western印迹法和实时定量PCR(RT-qPCR)检测肥胖小鼠和TIPE2敲除小鼠(KO)及其各自对照小鼠内脏脂肪组织中TIPE2、诱导型一氧化氮合酶(iNOS)、单核细胞趋化蛋白1(MCP-1)、CD206和精氨酸酶1(Arg-1)的表达水平。分离培养TIPE2敲除小鼠(KO)和野生型小鼠(WT)的腹腔巨噬细胞及RAW 264.7小鼠巨噬细胞系,给予脂多糖(100 ng/mL)或IL-4(20 ng/mL)刺激6 h,Western印迹法和RT-qPCR检测TIPE2、iNOS、MCP-1、CD206和Arg-1的表达水平。结果在肥胖小鼠中,TIPE2表达下调,促炎因子iNOS和MCP-1表达升高,抑炎因子CD206和Arg-1表达降低。脂多糖降低RAW 264.7细胞和小鼠腹腔巨噬细胞TIPE2的表达,诱导经典活化的巨噬细胞(M1表型)标志物iNOS和MCP-1表达升高,降低替代活化的巨噬细胞(M2表型)标志物CD206和Arg-1的表达。IL-4增加RAW 264.7细胞和小鼠腹腔巨噬细胞中TIPE2的表达,降低iNOS和MCP-1表达的同时增加CD206和Arg-1的表达。在巨噬细胞向M1型转化时,脂多糖增加巨噬细胞中Toll样受体(TLR4)的表达和核转录抑制因子α(IκBα)、NF-κB的磷酸化,敲除TIPE2进一步增加TLR4/IκBα/NF-κB信号通路和M1型巨噬细胞标记物的升高,进一步降低M2型巨噬细胞标记物的表达。结论TIPE2通过抑制TLR4/IκBα/NF-κB信号通路调节ATM表型转化,改善肥胖状态下脂肪组织炎症状态。
Objective To investigate the effect and molecular mechanism of tumor necrosis factor-α-inducible protein 8-like 2(TIPE2)on lipopolysaccharide(LPS)or interleukin-4(IL-4)-induced phenotypic switch of adipose tissue macrophages(ATM).Methods The expression levels of TIPE2,inducible nitric oxide synthase(iNOS),monocyte chemoattractant protein 1(MCP-1),CD206,and arginase 1(Arg-1)in the visceral adipose tissue of obese mice,TIPE2-knockout(KO)mice,and control mice were detected by immunohistochemistry,Western blotting,and real-time PCR(RT-qPCR).Peritoneal macrophages isolated from KO and wild-type mice and RAW 264.7 mouse macrophage cell line were cultured,and then stimulated with LPS(100 ng/mL)or IL-4(20 ng/mL)for 6 hours.The expression levels of TIPE2,iNOS,MCP-1,CD206,and Arg-1 were detected by Western blotting and RT-qPCR.Results Obese mice showed down-regulated TIPE2 expression,up-regulated pro-inflammatory markers iNOS and MCP-1 expressions,and down-regulated anti-inflammatory markers CD206 and Arg-1 expressions.LPS decreased the expression of TIPE2 in RAW 264.7 cells and peritoneal macrophages from mice,increased the expression of the classically activated macrophages(M1 phenotype)markers iNOS and MCP-1,and decreased the expression of the substituting activated macrophages(M2 phenotype)markers CD206 and Arg-1.IL-4 increased the expression of TIPE2 in RAW 264.7 cells and peritoneal macrophages,decreased the expression of iNOS and MCP-1,and increased the expression of CD206 and Arg-1.During the M1 polarization of macrophages,LPS increased toll-like receptor(TLR4)expression as well as nuclear transcription factorκBαsuppressor protein(IκBα)and NF-κB phosphorylations in macrophages.Knockout of TIPE2 further increased the expression of the TLR4/IκBα/NF-κB signaling pathway and M1 macrophage markers,and further reduced the expression of the M2 macrophage markers.Conclusion TIPE2 regulates ATM phenotypic transformation through inhibition of the TLR4/IκBα/NF-κB signaling pathway,which ameliorates adipose tissue
作者
陈亚琳
于翠云
程怡
郭雪莹
黄春晓
郑文祥
李兰兰
周健
相新新
Chen Yalin;Yu Cuiyun;Cheng Yi;Guo Xueying;Huang Chunxiao;Zheng Wenxiang;Li Lanlan;Zhou Jian;Xiang Xinxin(Center of Translational Medicine,Zibo Central Hospital,Zibo 255036,China)
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2023年第10期882-889,共8页
Chinese Journal of Endocrinology and Metabolism
基金
国家自然科学基金(81600695)
山东省重点研发计划(2019GSF108269)。
