烧伤血清对单核细胞抑制性κB降解和核因子-κB活化的影响

目的:了解烧伤血清对单核细胞抑制性κB(IκBα)降解、核因子-κB(NF-κB)活化的影响,进一步探讨烧伤血清诱导单核细胞活化分泌细胞因子的机理。方法:采用体外培养的人外周血单核细胞(PBMC),分别用正常人血清(对照组)、烧伤患者血清、烧伤患者血清+吡咯烷二硫代氨基甲酸盐(PDTC)刺激单核细胞,采用Western印迹法检测血清刺激30、60、90、120min后单核细胞IκBα蛋白降解情况,电泳迁移率分析检测血清刺激30、60、120、240min后NF-κB活性的变化。结果:烧伤血清刺激单核细胞后30min,IκBα发生明显降解,刺激60min达高峰,2h后表达逐渐升高。而烧伤血清刺激单核细胞后30min,NF-κB活性迅速升高,30-60min达高峰,2h后接近基础状态。PDTC能有效抑制烧伤血清作用条件下单核细胞IκBα降解、NF-κB活化。结论:烧伤血清可诱导单核细胞IκBα降解,活化NF-κB,从而在机体烧伤后单核细胞分泌细胞因子过程中起重要作用。

Effects of burn sera on IκBα degradation and NF-κBactivation in monocytes in vitro

AIM: To investigate the effects of burn sera on IκBα degradation, NF-κB activation in peripheral blood monocytes (PBMCs) in order to explore the role of burn sera on activation of monocytes. METHODS: PBMCs isolated from healthy volunteers were stimulated by sera from healthy volunteers and burn patients and by burn sera together with PDTC (pyrrolidine dithioncarbamate). Activation of monocytic NF-κB was tested by electrophoretic mobility shift assay (EMSA) and the degradation of monocytic IκBα was determined by Western blotting. RESULTS: When compared to that in control group, cytosolic IκBα degradation occurred within 30 min after PBMCs stimulated by burn sera, and peaked at 60 min. But IκBα gradually recovered in the cytoplasm after 2 h of stimulation. Meanwhile, activity of monocytic NF-κB was markedly increased, reached the peak at 30 min to 60 min after stimulation, and gradually decreased after 2 h of stimulation. PDTC (an antioxidants) effectively inhibited the monocytic IκBα degradation and activation of NF-κB induced by burn sera. CONCLUSION: Burn sera might induce the degradation of IκBα, then activate NF-κB, which ultimately lead to the secretion of cytokines from the monocytes.