Fig. 5

Actin disruption reduces Aβ uptake by astrocytes. a, b Confocal fluorescence micrographs of WT astrocytes were sham washed or exposed to 100 nM CytD for 1 h, then incubated with 1 μM FITC-Aβ_1–42 (A) or FITC-Aβ_1–40 (B) (green dots, arrowheads) for 15 min at 37 °C. The plasma membrane was stained with Alexa Fluor 594-WGA (red). Uptake of both FITC-Aβ_1–42 and FITC-Aβ₁₋40 was noticeably reduced in CytD-treated cells compared with WT control cells. The lower panel represents the corresponding 3D images. Scale bar, 20 μm. c, d Bars depict the percentage of FITC⁺ cells. The values were normalized to the percentage of FITC-Aβ_1–42 ⁺ (C) or FITC-Aβ_1–40 ⁺ (D) cells in WT controls, defined as 100 % (***P < 0.001 vs. WT CTL; n = 4 cultures). e Western blots for Aβ monomers and oligomers. Astrocytes from WT mice, which were sham washed or treated with 100 nM CytD for 1 h, were incubated with 1 μM Aβ monomers. After 24 h, the cells were lysed and immunoblotted with an anti-6E10 antibody. f, g Bars indicate changes in the density ratio of Aβ oligomers (F) and Aβ monomers (G) relative to tubulin. All ratio values were normalized to the ratio in WT controls, defined as 1 (**P < 0.01 vs. WT CTL, *P < 0.05 vs. WT Aβ groups; n = 4 experiments)