PM2.5对THP1巨噬细胞TLR4表达及氧化应激水平的影响

目的探讨大气细颗粒物（particulate matters，PM）2.5对THP1巨噬细胞TLR4表达及氧化应激水平的影响。方法THP1巨噬细胞分别给予来自中国北京、美国巴尔的摩地区的PM2.5刺激24 h，检测巨噬细胞TLR4、Nrf2表达水平，以及细胞内活性氧（ROS）产生水平。结果与对照组比较，低浓度（50 μg/mL）北京地区和巴尔的摩地区PM2.5刺激24 h后，细胞TLR4、Nrf2表达水平与细胞内ROS产生水平均升高（P < 0.05）。与对照组比较，高浓度（200 μg/mL）北京地区和巴尔的摩地区PM2.5刺激24 h后，细胞TLR4表达水平、Nrf2表达水平均降低（P < 0.05），北京地区组细胞内ROS产生水平降低（P < 0.05），巴尔的摩地区组细胞内ROS升高（P < 0.05）。结论低浓度PM2.5可促进巨噬细胞TLR4表达，升高氧化应激水平，高浓度PM2.5可降低巨噬细胞TLR4表达，降低氧化应激水平。

Effect of PM2.5 on the TLR4 expression and oxidative stress levels in THP1 macrophages

ObjectiveTo investigate the effects of atmospheric fine particulate matters(PM)2.5 on TLR4 expression and oxidative stress levels in THP1 macrophages.MethodsThe THP1 macrophages from Beijing China and Baltimore United States were stimulated by PM2.5 for 24 h.The expression levels of TLR4 and Nrf2 in macrophages and degree of intracellular reactive oxygen species(ROS) production were detected.ResultsThe expression levels of TLR4 and Nrf2 and degree of intracellular ROS production significantly increased after low concentration(50 μg/mL) PM2.5 from Beijing and Baltimore stimulating for 24h compared with the control group(P < 0.05).Compared with the control group, after the cells were stimulated using high concentration(200μg/mL) PM2.5 from Beijing and Baltimore for 24 h, the expression levels of TLR4 and Nrf2 decreased, the intracellular ROS production in Beijing area decreased(P < 0.05), and the intracellular ROS production in Baltimore increased(P < 0.05).ConclusionsThe low concentration of PM2.5 can promote the expression of TLR4 in macrophages, and increase the level of oxidative stress.The high concentration of PM2.5 can reduce the expression of TLR4 and level of oxidative stress in macrophages.