核因子-κB及Toll样受体4介导脂多糖诱导内皮细胞单层通透性增高

Effect of nuclear factor-kappa B and toll-like receptor 4 mediate on the increase of monolayer permeability of endothelial cell induced by lipopolysaccharide

目的:探讨核因子-κB(nuclearfactor-kappaB,NF-κB)及Toll样受体4(Toll-likereceptor4,TLR4)在脂多糖(lipopolysaccharide,LPS)诱导的内皮细胞单层通透性增高中的作用。方法:采用免疫荧光法及改良Boydon小室测定LPS对人脐静脉内皮细胞株ECV-304的单层细胞通透性及其F-肌动蛋白分布的影响;以免疫组织化学染色及RT-PCR法检测LPS刺激细胞NF-κB活化后的核转位及TLR4mRNA的表达。结果:LPS作用ECV-3041h后,免疫组织化学染色证实NF-κB活化后发生核转位;LPS以一定的剂量-时间依赖方式上调TLR4mRNA的表达,ECV-304单层通透性也随之增加。结论:NF-κB及TLR4可能在LPS诱导内皮细胞单层损伤导致通透性增高过程中发挥重要作用。

AIM:To explore the effect of nuclear factor kappa B (NF κ B) and toll like receptor 4 (TLR4) on the increase of monolayer permeability of endothelial cell induced by lipopolysaccharide(LPS). METHODS: Monolayer permeability of endothelial cells was evaluated by the improved Boydon chamber and cytoskeleton protein, F actin, was visualized by fluorescence microscopy. Translocation of NF κ B subunits and expression of TLR4 mRNA in endothelial cells stimulated with endotoxin were detected with immunohistochemistry and semi quantitative RT PCR. RESULTS: After the effect of LPS on ECV 304 for 1 h, immunohistochemical staining showed that nuclear translocation was observed after the activation of NF κ B. The expression of TLR4 mRNA level was up regulated in a dose time dependent manner, monolayer permeability of ECV 304 was also increased with it. CONCLUSION: NF κ B and TLR4 may play an important role in endothelial cells activation and injury induced with inflammatory mediators.