Effect of PM2.5expose time and concentration on gene expression of inflammatory factors. (A) Heat map of gene expression of main inflammatory factors in FA-, PM2.5-3L- and PM2.5-3H-exposed lungs. To verify the RNA-seq results, mRNA levels of Hspa1a (B), Hspa1b (C), Fis1 (D), CD14 (E), Cd5l(F) and Tnfrsf4 (G) were measured by real-time qPCR. N = 3, data are shown as mean ± SEM. *p < 0.05; **p < 0.01; NS, not significant.