Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms

Abstract

The associations between particulate matter from Asian dust storms (ADS) and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS). THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs), and tumor necrosis factor (TNF)-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control). Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS) and two (one ADS and one non-ADS) collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles.

Keywords: Asian dust storm; THP1; cytokine; particulate matter.

Figure 1

The levels of (a) interleukin (IL)-2; (b) tumor necrosis factor (TNF)-α; (c) IL-10; and (d) IL-12 were measured in a THP1 cell line using a Bio-Plex Human Cytokine Th1/Th2 Assay. Particulate matter was collected in 2013 from 8 to 10 March, on 19 and 20 March, from 8 to 15 April, and from 30 April to 6 May. Particulate matter collected from 8 to 10 March and on March 19 and 20 was defined as Asian dust storm (ADS) particles, whereas matter collected from 8 to 15 April and from 30 April to 6 May represented non-ADS particles. Cells were treated with solvent only (n = 4, negative control) and particulate matter (all n = 4; 200 μg/mL). * p < 0.05 vs. solvent, ** p < 0.0005 vs. solvent, † p < 0.05 vs. solvent, § p < 0.01 vs. particulate matter collected from 8 to 10 March, p < 0.05 vs. particulate matter collected from 30 April to 6 May, ‡ p < 0.03 vs. particulate matter collected from 30 April to 6 May.