Fig. 2

Smoking and PM_2.5 triggered lung injury and increased inflammation. (A) Timeline of COPD model and PM_2.5 treatment. (B) Representative H&E stained lung tissue from mice in control, smoking, PM_2.5, and smoking with PM_2.5 groups (100X original magnification, scale bar = 500 μm). The upper images show peribronchial inflammatory cell infiltration. The lower images show alveolar destruction. The MLI of lung tissue samples from each group (n = 4 control mice, n = 4 SM mice, n = 5 PM mice, and n = 8 SMPM mice). (C) Total number of cells in the BALF infiltrating the airways. Differential cell numbers of BALF in each group (n = 4 control mice, n = 4 SM mice, n = 6 PM mice, and n = 4 SMPM mice). (D) Levels of cytokines IL-6 and IFN-γ in BALF determined by ELISA (n = 4 control mice, n = 4 SM mice, n = 4 PM mice, and n = 5 SMPM mice). (E) The relative mRNA levels of TNF-α, IL-1α, IL-1β, IL-6, IL-18, IL-33, and IFN-γ in lung tissues (n = 4 control mice, n = 4 SM mice, n = 6 PM mice, and n = 5 SMPM mice). (F) Representative TUNEL images of lung tissue of mice and TUNEL score (%) of each group (n = 4 control mice, n = 4 SM mice, n = 5 PM mice, and n = 6 SMPM mice, 400X original magnification, scale bar = 100 μm). (G) NLRP3 expression levels in lung tissue of mice (n = 3 control mice, n = 3 SM mice, n = 4 PM mice, and n = 4 SMPM mice. The data are represented as mean ± SD. The significance is determined using one-way ANOVA, followed by post hoc Tukey’s test. * P < 0.05, ** P < 0.01, *** P < 0.001. H&E, Hematoxylin and eosin; MLI, Mean linear intercept; SD, standard deviation; CTL, control; SM, smoking; PM, PM_2.5; SMPM, smoking and PM_2.5