Fig. 2.

Compensatory mechanism in DJ-1 KO mice. Shown are immunoblot and densitometric analyses of the protein expression of GPx, MnSOD, and catalase in whole brain lysates with β-actin as a loading control (A) and VDAC as a loading control for the mitochondrial fraction (B) in aged mice (18–24 months old). Data are the means ± SEM (n = 3). Significance was determined by Student's t test. (C and D) Mitochondrial activity of antioxidant enzymes of young (2–3 months old) and aged (18–24 months old) WT and KO mice: GPx (C) and MnSOD (D). (E and F) Cytosolic levels of reduced (E) and oxidized (F) forms of glutathione in 2- to 3-month-old and 18- to 24-month-old mice. The enzyme activities are expressed in units per milligram of tissue whereas the reduced and oxidized forms of glutathione are expressed as nanograms per milligram of protein. Data represent the means ± SEM from samples of five different animals measured three times on different days. Significance was determined by ANOVA with the Student–Newman–Keuls test. *, P ≤ 0.05.