Fig. 2.
POS phagocytosis attenuates oxidative stress-induced apoptosis. Cells were plated and maintained in culture for 72 h followed by 8 h of serum starvation before the addition of POS or polystyrene microspheres. (A) Hoechst staining shows an increase in cell death after 16 h of H2O2/TNF-α (oxidative stress) exposure, which is ameliorated by POS phagocytosis but not by polystyrene microspheres. (B) Quantitative analysis of Hoechst-stained ARPE-19 cells indicates that POS phagocytosis significantly decreases the amount of apoptosis observed during oxidative stress. Phagocytosis of polystyrene microspheres during oxidative stress does not alter the amount of apoptosis observed during oxidative stress alone. Results represent averages ± SEM of repeats of two independent experiments.