Protein oxidation increases with age in transgenic mice expressing mutant hSOD1. (A-B) Representative Western blot images of the aging biomarkers (P53, P16, SIRT1, and SIRT6) in the brain (A) and liver (B) tissues. (C-D) Quantitative analysis of P53, P16, SIRT1, and SIRT6 protein levels (n = 3, mean ± SEM, *p < 0.05, **p < 0.01). (E) MalPEG modification and Western blotting analysis of hSOD1 in the brain tissues from hSOD1G93A mice at 50, 100, 120, and 150 days. (F) Quantitative analysis data of oxidized hSOD1(n = 3, mean ± SEM, *p < 0.05). (G) The proportion of the thiol group in total hSOD1 was quantified in brain tissues from 135-day hSOD1WT and hSOD1G93A transgenic mice (n = 6, mean ± SEM, *p < 0.05). (H–I) Representative analysis of carboxyl and MDA levels in brain tissues from 135-day hSOD1WT and hSOD1G93A mice (n = 3, mean ± SEM, **p < 0.01).