LPS直接诱导对肺微血管内皮细胞核因子κB活化的影响

Effects of direct stimulation by LPS on activation of nuclear factor-kappa B of pulmonary microvascular endothelial cells

目的 探讨内毒素 (lipopolysaccharide ,LPS)的直接诱导作用对肺微血管内皮细胞 (pulmonarymicrovascularen dothelialcells ,PMVECs)核因子κB(NF κB)活化的影响。方法 10 0ng/mlLPS刺激PMVECs 0、0 5、1、2、4、6、8h或 1、10、10 0ng/mlLPS刺激 1h后 ,凝胶电泳迁移率分析 (electrophoreticmobilityshiftassay ,EMSA)检测NF κB的活化 ,免疫细胞化学(ICC)观察其亚基p5 0、p65的核转位。并通过加入NF κB活化阻断剂TPCK观察其对 10 0ng/mlLPS刺激 1h诱导活化的影响。结果 LPS的直接刺激能迅速活化NF κB ,诱导其p5 0、p65亚基核转位 ,1h即达到高峰 ,且呈剂量依赖关系 ,后逐渐下降。TPCK能显著抑制其活化 (P <0 0 1)。结论 LPS的直接刺激能诱导NF κB的活化 ,这可能是LPS诱导炎症反应的一个重要环节。

Objective To investigate the effects of direct stimulation by lipopolysaccharide (LPS) on the activation of nuclear factor kappa B (NF κB) in pulmonary microvascular endothelial cells (PMVECs). Methods Activation of NF κB was measured by electrophoretic mobility shift assay (EMSA), and nuclear translocation of its two subunits, p50 and p65, was observed immunocytochemically when PMVECs were directly stimulated by 100 ng/ml LPS for 0, 0.5, 1, 2, 4, 6, and 8 h or by 1, 10, and 100 ng/ml LPS for 1 h. Effects of TPCK (n tosyl phenylalanine chloromethylketone), an inhibitor of activation, on NF κB induced by 100 ng/ml LPS for 1 h were also observed. Results Direct stimulation by LPS could rapidly induce the activation of NF κB and nuclear translocation of p50 and p65 in a dose dependent manner, reaching the peak at 1 h and decreasing gradually. TPCK could significantly inhibit the activation of NF κB. ( P <0.01). Conclusion Direct stimulation by LPS can induce the activation of NF κB, which may play an important role in inflammatory response induced by LPS.