Fig. 3.

Increased production of ROS in progeroid Ercc1^-/Δ mice and old WT mice. Xanthine oxidase (XO) activity was measured in the (a) livers (n = 7–9 per group) and (b) serum of Ercc1^−/Δ and WT mice (n = 3–4 per group) at multiple ages. (c) NADPH oxidase activity was measured in the livers of 4-month-old Ercc1^−/Δ and WT mice as well as 24-month-old aged WT mice (n = 6–13 per group). (d) Measurement of mitochondrial respiration using a Seahorse Bioscience XF Analyzer on mitochondria isolated from liver tissues of 2 month-old Ercc1^−/Δ and WT mice (n = 4 per group). Values represent the mean ± SD, *p < 0.05, **p < 0.01 as determined by one-way ANOVA with Tukey's test or unpaired two-tailed Student’s t-test.