氧化型低密度脂蛋白对NF-κB信号通路的作用

Role of oxidized low-density lipoprotein in NF-κB signal pathway

目的探讨氧化型低密度脂蛋白(ox-LDL)对人脐静脉内皮细胞(HUVEC)P65、P50、肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6)表达的影响。方法设立空白对照组(15、30、60、120)μg/mL ox-LDL分别刺激12、24、48 h的ox-LDL诱导组及NF-κB抑制剂吡咯烷二硫代氢基甲酸盐(PDTC)干预联合ox-LDL诱导组。提取核蛋白,Western blot法检测NF-κB信号通路P65和P50的蛋白表达;ELISA检测细胞上清液中TNF-α、IL-6的浓度变化。结果 Western blot法结果显示ox-LDL诱导HUVEC后P65和P50随ox-LDL诱导时间延长及诱导浓度增加而表达增加,各诱导组之间均存在统计学差异(P<0.05)。而给予PDTC干预后,P65和P50蛋白表达较ox-LDL诱导组明显降低(P<0.05)。ELISA结果显示经ox-LDL诱导24 h后,细胞上清液中的TNF-α和IL-6显著高于正常对照组,而用PDTC干预联合ox-LDL诱导后TNF-α和IL-6浓度明显降低。各组间比较有显著统计学差异(P<0.05)。结论 ox-LDL激活NF-κB信号通路存在时间和浓度效应关系,可增强TNF-α、IL-6表达。

Objective To explore the effects of oxidized low-density lipoprotein （ox-LDL） on P65, P50, tumor necrosisfactor-alpha （TNF-α） and interleukin 6 （IL-6） of human umbilical vein endothelial cells （HUVECs）. Methods HUVECs wererandomly divided into several groups as follows： the control group, the ox-LDL stimulated groups （different concentrations： 15, 30,60,120 μg/mL ox-LDL stimulation for 24 hours, and 30 MQ/mL ox-LDL stimulation for different time periods： 12,24,48 hours）,and the NF-κB inhibitor pyrrolidine dithiocarbamate （PDTC） intervention group （100 pmol/L PDTC pretreatmentfor 1 h before 30 ug/mL ox-LDL stimulation for 24 hours）. Nucleoprotein was extracted to detect P65 and P50 proteinexpression of NF-κB signaling pathway by Western blotting, and the concentrations of TNF-α and IL-6 in cell supernatantswere measured by ELISA. Results Western blotting showed that the expressions of P65 and P50 increased under the induction ofox-LDL in a time- and concentration-dependent manner, and the differences were statistically significant among groups （P〈0.05）, while they were reduced significantly by PDTC intervention （ P 〈 0. 05）. ELISA showed that the concentrations of TNF-α and IL-6 in the supernatants of HUVECs stimulated by ox-LDL for 24 hours were significantly higher than those in thecontrol group, while they were reduced significantly by PDTC intervention. There were significant statistical differencesamong the different treated groups （P〈0.05）. Conclusion Ox-LDL can enhance the activity of NF-κB signaling pathway ina time- and concentration-dependent manner through increasing the expressions of TNF-α and IL-6.