Kinetic of apoptosis and necrosis in HMECs. HMEC monolayers were treated for 6, 12, 24, and 48 h with 200 μg/mL MRP8/MRP14, 1 μg/mL ActD, 200 nM STS, or were left untreated (control). The percentages of late apoptotic cells with hypodiploid cell nuclei (A) and necrotic PI-positive cells (B) were determined by flow cytometry. The results show the mean ± SEM of 6 independent experiments. *Significant differences between treated and untreated cells (P < .05).