Fig. 5

Effects of generalized immunosuppression on soluble and epigenetic markers of neurodegeneration. a Representative western blot illustrating total tau, phosphorylated tau, and β-actin protein levels in TBS homogenates extracted from the cortex of 6-month-old mice. b Densitometric analysis of western blots revealed that 6-month-old 3xTg-AD females had elevated levels of TBS-soluble total tau (normalized to β-actin) in comparison to WT controls, but this genotype-related difference was not noted in males (Genotype × Sex: F_{1, 81} = 18.77, p < .001) and was not altered by CY immunosuppression. c 3xTg-AD females also exhibited an increase in phospho-tau (Thr181) in comparison to all other groups (Genotype × Sex: F_{1, 81} = 16.354, p < .001), but CY had no appreciable effect on the phosphorylation status of tau. d Soluble human Aβ₄₂ was greater in 3xTg-AD males than females (Genotype × Sex: F_{1, 68} = 8.921, p = .004, η2p = .116). No significant third order interaction was detected, but between-group comparisons with t tests revealed that CY-treated 3xTg-AD males had lower Aβ₄₂ load than Veh-treated controls (p < .01). e BDNF mRNA levels were downregulated in 3xTg-AD mice of both sexes compared to controls. CY did not affect BDNF mRNA levels (normalized to β-actin) in 3xTg-AD mice. f 3xTg-AD mice treated with vehicle only had significantly higher H2afy mRNA expression compared to controls (p < .0001). CY treatment reversed the upregulated H2afy expression observed in vehicle-treated 3xTg-AD mice compared to WT mice (p = .046). No significant third order interaction was detected, but between-group comparisons with t tests revealed H2afy downregulation in CY-treated 3xTg-AD females. WT Veh males (n = 11), WT CY males (n = 11), 3xTg-AD Veh males (n = 9), 3xTg-AD CY males (n = 9), WT Veh females (n = 13), WT CY females (n = 14), 3xTg-AD Veh females (n = 10), 3xTg-AD CY females (n = 11). Overall group comparisons were carried out using three-way ANOVA (Genotype × Treatment × Sex), followed by post hoc t tests. Error bars = SEM, *p ≤ .05, **p < .01, ***p < .001. Abbreviations: Aβ, amyloid-beta; BDNF, brain-derived neurotrophic factor; mRNA, messenger RNA; pTau, phosphorylated tau; tTau, total tau; TBS, tris-buffered saline