Role of the different components of PM
in the antiapoptotic effect. (A) 16HBE cells were treated 4 h with different batches of PM2.5 10 μg/cm2 (AW, AS, VW and VS), the equivalent concentration of organic extracts (Oex, 4.27 mg/ml), aqueous extracts (Aex), washed particles (wash, 10 μg/cm2) of PM2.5-AW and carbon black (CB, 10 μg/cm2) before a 20 h exposure to A23187 (3 μM). Apoptosis was assessed by flow cytometry and expressed as induction of apoptosis. Results are mean ± SD (n = 3). * p < 0.001 compared with A23187 alone. (B and C) Effect of heavy PAH on A23187-induced apoptosis. Treatments with PM2.5-AW (10 μg/cm2), the vehicle (Cylohexane, 1%), Benzo[a]pyrene (B(a)P, 270 nM), Dibenzo[a,h]anthracene (D,B(a,h)A, 35 nM), Benzo[g,h,i]perylene (B(g,h,i)P, 443 nM), Indeno[1,2,3-cd]pyrene (iP, 217 nM) and Benzo[b]fluoranthrene (B(b)F, 333 nM), were performed 4 h prior to induction of apoptosis by A23187 (3 μM). Results are mean ± SD (n = 4). * vs. control, p < 0.001; # vs. A23187, p < 0.05.