拮抗Toll样受体4对于溶血磷脂酸诱导的THP-1细胞Toll样受体4/核因子-κB信号通路的影响

Effect of antagonizing TLR4 on TLR4 / NF-κB singaling pathway in human monocytic THP-1 cell lines induced by lysophosphatidic acid

目的：通过拮抗Toll样受体4（TLR4）观察其对于溶血磷脂酸（lysophosphatidic acid，LPA）诱导的人单核细胞株THP-1细胞的核因子-κB（nuclear factor-kappaB，NF-κB）p65表达的影响以及肿瘤坏死因子-α（TNF-α）水平的变化。方法取THP-1细胞，LPA以不同浓度水平（0～10μmol·L－1）刺激4 h，或1μmol·L－1浓度刺激不同时间（0～8 h），酶联免疫吸附法（ELISA）测定细胞因子TNF-α，随后在LPA （1μmol·L－1）条件下分别予不同浓度TLR4单克隆抗体（TLR4 mAb）（5，20，30 mg·L－1）干预THP-1细胞，观察其对LPA诱导的核蛋白NF-κB p65表达及TNF-α分泌水平的影响。结果 LPA以剂量依赖方式促进TNF-α分泌，并可诱导THP-1细胞NF-κB p65活化，予TLR4 mAb阻断TLR4后，可显著抑制NF-κB p65表达及TNF-α分泌。结论 LPA可经由Toll4／NF-κB信号途径激活单核细胞，最终引起TNF-α等炎性因子的分泌，参与动脉粥样硬化进程。

Objective To observe the roles of Toll-like receptor 4 in the expression of nuclear factor-κB（NF-κB）p65 and the changes of cytokine TNF-αmediated by human monocytic THP-1 cell lines induced by lysophosphatidic acid （LPA）via antagonizing TLR4. Methods The human THP-1 cells were stimulated using different levels of LPA （0~10 μmol·L-1 ）for 4h,or treated with LPA 1μmol·L-1 for different hours （0 ~8 h）.The secretion of TNF-αwas detected using a sandwich ELISA,and then under LPA （1μmol·L-1 ）condition,after the THP-1 cells were intervened using different levels of TLR4 mAb（5,20,30 mg·L-1 ）,the effects on the expression levels of LPA-induced nucleoprotein NF-κB p65 and levels of secreted TNF-αwere observed.Results TNF-αsecre-tion in THP-1 cells was up-regulated by LPA in a dose-dependent way,and NF-κB p65 activation was also promoted.After TLR4 was blocked using TLR4 mAb,the expression of NF-κBp65 and secretion of TNF-αwere inhibited significantly.Conclusions The mono-cytic cell may be activated by LPA mediated by TLR4/N F-κB signaling pathway,ultimately up-regulates the secretion of proinflamma-tory cytokines such as TNF-α,thus involving in the pathological process in atherosclerosis.