Fig. 1
Elevated Astrocytic YKL-40 expression in 5xFAD mice. A Representative confocal images (Mag. 10X) of dentate gyrus region from 4-month (m), 7 m, and 9 m 5xFAD mouse brains immuno-stained with DAPI (blue signal), anti-YKL-40 (green signal), and anti-GFAP (red signal) antibodies. Scale bar, 100 μm. Mean intensity (B) and mean surface area (C) of YKL-40 signal in DG region were quantified from 4 m-, 7 m-, and 9 m- WT and 5xFAD mice. 4 m (n = 6), 7 m (n = 6), 9 m (n = 4). Data are mean ± SEM. One-way ANOVA with Tukey’s post hoc comparisons. *p < 0.05, **p < 0.01, ***p < 0.001. D YKL-40 expression level in cerebral spinal fluid (CSF) extracted from WT and 5xFAD mice. E YKL-40 expression level in plasma extracted from WT and 5xFAD mice. YKL-40 protein was measured by ELISA and data was normalized by total protein. Data are mean ± SEM of 6 to 17 animals. One-way ANOVA with Tukey’s post hoc comparisons. *p < 0.05, **p < 0.01, ***p < 0.001 compared to WT-4 m. F Western blotting analysis of YKL-40 expression level from astrocyte lysates and conditioned medium (CM) treated with 0, 50, 200, and 1000 nM Aβ1-42 for 72 h. GAPDH was used as an internal control. The relative YKL-40 expression level in CM was normalized with total protein. G-H Quantification of relative fold change of YKL-40. n = 6. Data are mean ± SEM. One-way ANOVA with Tukey’s post hoc comparisons. *p < 0.05, ***p < 0.001 compared to control. I. Relative Chi3l1 gene expression from primary astrocytes treated with 0, 50, 200, and 1000 nM Aβ1-42 for 72 h. n = 3 to 6 from independent experiments. Data are mean ± SEM. J. Western blotting analysis of PI3-K pathway expression from astrocytes lysates treated with 0, 50 nM, 200 nM, 1000 nM Aβ1-42 for 72 h. GAPDH was used as internal control