Fig. 5

Oxidative stress and MMP activation are altered in prediabetic and diabetic APP/PS1 mice. A Oxidative stress associated with amyloid plaques (Amplex Red intensity/thioflavin intensity) was significantly increased in APP/PS1-HFD and APP/PS1xdb/db mice [F_(3,117) = 10.009, ‡‡p < 0.001 vs. APP/PS1-RD and APP/PS1, ††p < 0.01 vs. APP/PS1]. MMP activity was also significantly increased in APP/PS1-HFD mice in association with amyloid plaques [F_(3,126) = 7.71, **p < 0.001 vs. rest of the groups] (APP/PS1-RD n = 3 and 15–16 plaques, APP/PS1-HFD n = 4 and 20–22 plaques, APP/PS1 n = 7 and 50–56 plaques, APP/PS1xdb/db n = 6 and 40–41 plaques) (mean ± SEM). B Illustrative example of oxidative stress and MMP activation associated with amyloid plaques in all groups under study. Scale bar = 50 µm. C No differences were observed when oxidative stress or MMP activity were analyzed in association with CAA in prediabetic mice, although oxidative stress was significantly higher in APP/PS1xdb/db mice when compared with APP/PS1 animals [F_(3,387) = 3.32, †p = 0.019 vs. APP/PS1] and a significant increase in MMP activity was also observed in association with CAA in APP/PS1xdb/db mice [F_(3,283) = 3.88, ‡p = 0.01 vs. APP/PS1 and APP/PS1-RD] (APP/PS1-RD n = 3 and 69–72 vessel segments, APP/PS1-HFD n = 4 and 56–62 vessel segments, APP/PS1 n = 7 and 71–73 vessel segments, APP/PS1xdb/db n = 6 and 88–93 vessel segments) (mean ± SEM). D Illustrative example of oxidative stress and MMP activation associated with CAA in all groups under study. Scale bar = 50 µm. E 8-OHdG was increased in AD colony used to study the effect of prediabetes [F_(3,16) = 7.93, ‡‡p < 0.01 vs. APP/PS1-RD and APP/PS1-HFD] F Lipid peroxidation, estimated by MDA content, was significantly increased in APP/PS1xdb/db mice animals [F_(3,18) = 8.92, **p < 0.01 vs. rest of the groups]