Alterations of IL-1beta and TNF-alpha expression in RAW264.7 cell damage induced by two samples of PM_2.5 with...

Fine particulate matter 2.5 (PM_2.5) has been demonstrated by previous studies to be associated with cell damage. To explore the impact of the composition of PM_2.5 on PM_2.5-mediated inflammation, this study investigated the composition of PM_2.5 collected during the wintertime indoor heating season and observed its inflammatory effect. Samples were collected during the heating season from December 5, 2017, to January 8, 2018, in Xi'an. Compositions of organic carbon (OC), elemental carbon (EC), and water-soluble ions were analysed. Two representative samples (sample 1 and 2) were selected with significant differences in compositions. They were configured into four concentrations (0.1 μg/mL, 1 μg/mL, 10 μg/mL, 20 μg/mL) and used as interventions on RAW264.7 cells for 4 h and 24 h separately. Cell viability was detected by CCK-8. Tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) gene and protein expression levels were detected by real-time quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. The results showed that the cell viability of sample 1 intervened cells at 4 h and 24 h was lower than that of sample 2. IL-1β gene in most PM_2.5 intervention groups was lower than in the control group. Protein expression was higher at 4 h than at 24 h. In conclusion, PM_2.5 components influence cell viability and expression of IL-1β and TNF-α, while high concentrations of NO₃^-, Cl^-, Na⁺, K⁺, Mg²⁺, Ca^2+, and others in the PM_2.5 composition have a significant harmful effect.