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.