Fig. 2

Monocyte-specific overexpression of human cystatin F exacerbated cognitive impairment in APP/PS1 transgenic mice. A Construction of monocyte-specific overexpression of human cystatin F under the control of the human CD68 promoter. B Schematic for generating APP/PS1/Hmo-cys F⁺ mice, behavioural tests, and pathological analysis. C Identification of transgenic mice by PCR analysis of the genomic DNA. D Transcript levels of human cystatin F in the monocytes of 6-month-old WT (n = 6), Hmo-cys F⁺ (n = 6), APP/PS1 (n = 6), and APP/PS1/Hmo-cys F⁺ mice (n = 6). E Immunofluorescence and statistical analysis of Aβ plaques in brain sections from transgenic mice. Scale bar: 1000 μm F, G ELISA analysis for soluble F Aβ40 and G Aβ42 levels in brains extracted with RIPA buffer. H, I ELISA analysis for insoluble H Aβ40 and I Aβ42 levels in brains extracted with SDS buffer. J, K MWM analysis showing the latency (s), L number of target crosses, and M mean speed (cm/s) in the invisible platform test. N Representative images of the track plots in the MWM test. O, P ELISA analysis of O Aβ40 and P Aβ42 levels in the plasma of mice. All the mice in the behavioural test and Aβ analysis were 12 months old and included WT (n = 6), Hmo-cys F⁺ (n = 7), APP/PS1 (n = 7), and APP/PS1/Hmo-cys F⁺ mice (n = 8). The data are presented as the means ± SD and were analysed using Student’s t test and one-way ANOVA. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001, ^****p < 0.0001