Dose-effect studies of the antiapoptotic effect of PM
-AW. Apoptosis was quantified simultaneously by four parameters and expressed as percentage of 16HBE cells showing ΔΨm drop (DiOC6(3) low) and ROS production (HE->Eth high) or PS exposure (Annexin V+) and plasma membrane permeabilization (PI high). (A and B) After a 4 h pretreatment with PM2.5-AW (10 μg/cm2), 16HBE cells were exposed to the indicated concentrations of A23187. Significance was calculated with respect to medium conditions (*, p < 0.001, n = 3). (C and D) Particle pretreatment was performed with different doses (1-50 μg/cm2) 4 h prior to induction of apoptosis by 3 μM of A23187. Results are means ± S.D (n = 3). Significance was calculated with respect to non-pretreated cells with particles (#, p < 0.001).