Figure 1. DIZE activated ACE2/Ang-(1-7)/MAS1 axis in the brain of SAMP8 mice. (A) The Ang- (1-7) levels in mice brain were detected by ELISA. (B) The activity of ACE2 in mice brain was assessed using a specific detection kit (#AS-72086, AnaSpec, Inc., Fremont, CA, USA) with Mc-Ala/Dnp fluorescence resonance energy transfer peptides as described. The fluorescence of Mc-Ala was monitored at excitation/emission 330 nm/390 nm. The specificity was confirmed using a specific ACE2 inhibitor DX600. (C) The Mas1 mRNA levels in mice brain were evaluated by qRT-PCR, and Gapdh was used as an internal control. (D) The protein levels of MAS1 in mice brain were detected by western blot. β-actin was used as a loading control. (E) Quantitative analysis of MAS1 protein levels. Data from panel B, C and E were expressed as a fold change relative to the vehicle-treated age-matched SAMR1 control mice. All data were analyzed by one-way ANOVA followed by Tukey’s post hoc test. Columns represent mean ± SD (n=8 per group). *P<0.05 versus age-matched vehicle-treated SAMR1 control mice. #P<0.05 versus vehicle-treated SAMP8 mice.