Figure 4. Overexpression of Lf in astrocytes enhances PP2A activity and reduces tau phosphorylation in APP/PS1 mouse brains. (A-B) The expressions of p-GSK3α/β (21/9) and p-p38 were increased, and the p-CDK5 was decreased, and the expressions of GSK3α/β, CDK5, p38, p-Erk1/2, Erk1/2 and PP2Ac were unchanged in APP/PS1/Lf mice compared to that in APP/PS1 mice. n = 6; Two-way ANOVA followed by the Bonferroni’s post hoc test. (C) Overexpression of Lf in astrocytes elevated the activity of PP2A in APP/PS1 mice. (D) The phosphorylations of tau at Thr181 and Ser404 were upregulated in Astro-Lf mice compared to WT mice, whereas overexpression of Lf in astrocytes reversed the upregulated phosphorylation of tau at Thr18, Ser396 and Ser404 in APP/PS1 mice. n = 6; Two-way ANOVA followed by the Bonferroni’s post hoc test. (E) Immunochemistry staining showing the decreased p-tau (Ser396) intensity in APP/PS1/Lf mouse cortex. n = 5. *P < 0.05, **P < 0.01.