Oxidative stress in BPAEC at 20% oxygen is ameliorated by overexpression of MnSOD and CuZnSOD or lowering the oxygen level (3%). Panel A: BPAEC were seeded at 5 × 104 cells per well, grown for 24 h or 48 h, and counted. Panel B: BPAEC were seeded at 5 × 104 cells per well, grown for 24 h, and then assayed for metabolic activity using 10% alamarBlue. Values were normalized (arbitrarily set at 100%) to the 3% oxygen condition. Panel C: BPAEC were seeded at 5 × 104 cells per well, grown for 24 h, and then assayed for mitochondrial function using JC-1. *Significant difference at P < 0.05 compared to the 20% oxygen group using ANOVA with Dunnett’s post hoc test. Results are expressed as means ± SE from three to six experiments.