Figure 1.

PM_2.5 decreases cell viability and induce apoptosis in A549 cells. A. PM_2.5 decreases cell viability in a concentration- and time-dependent manner. Cells were treated with 100 μg/ml PM_2.5 for variable periods (6, 12, 24 and 48 h; left panel), or different concentrations (25, 50, 100, 150 and 200 μg/ml) of PM_2.5 for 24 h (right panel). Cell viability was assessed by trypan blue staining. A representative experiment (left panel) and the mean ± SD from 3 separate experiments (right panel) are shown. Cells from triplicate wells and are representative of 3 independent experiments. B, C. PM_2.5 induces apoptosis in A549 cells. B. Cells were treated with increasing concentrations (50,100 and 150 μg/ml) of PM_2.5 for 24 h. Cell apoptosis was assessed by PI and Annexin V double staining. A representative experiment (left panel) and the mean ± SD from 3 separate experiments (right panel) are shown. C. Cells were treated with 100 μg/ml PM_2.5 for 24 h, and then cell apoptosis was assessed by TUNEL assay. A representative assay (left panel) and the mean ± SD of 3 separate experiments (right panel) are shown, *p < 0.05, **p < 0.01, significant compared to controls.