Figure 4. Reactive oxidative species (ROS) could be the trigger for release of high-mobility group box protein 1 (HMGB1) in retinal ganglion cell (RGC)-5 cells. A: Flow cytometric histogram shows an increase in ROS at 3 h in RGC-5 cells treated with advanced glycation end products–BSA (AGE-BSA; red) or BSA alone (black). B: Histogram shows that DCF fluorescence changes with time (n=3). C: Pretreatment of RGC-5 cells with the antioxidant N-acetyl-L-cysteine (NAC) reduces the AGE-BSA-induced HMGB1 protein levels in the supernatant at 3 h in a dose-dependent manner. Abbreviations: A, AGEs; B, BSA; N1, N5, and N10: RGC-5 cells pretreated with NAC at concentrations of 1, 5, and 10 mM respectively (n=4).