Fig. 2.

Detection of Aβ₄₂ uptake-related receptors and intracellular processing of Aβ₄₂ by monocytes treated with PSK in vitro. A Identification of monocytes by flow cytometry by FSC and SSC after CD14-positive selection by magnetic activated cell sorting. B–E Representative histograms showing the expression levels of TLR2, Trem2, CD36, and MSR1 in monocytes (grey curves indicate negative control staining). F–I Compared with controls, the expression level of TLR2 is increased in monocytes treated with PSK, with no significant difference between the two groups in the levels of TREM2, CD36, and MSR1. J Comparison of Aβ₄₂ uptake by monocytes between groups with different treatments. K–M Confocal stack images of PSK or PBS stimulated monocytes immunolabeled for FITC-Aβ₄₂ (green), endosomal markers (EEA1, Lamp-1, and Lamp-2, red), and nuclei (blue) (scale bar, 10 μm for all panels). N–P Immunoreactive areas of co-localized Aβ₄₂ and endosomal markers (EEA1, Lamp-1, and Lamp-2, red) in human monocytes in the two groups (mean ± SEM of triplicate wells in each treatment group ). *P <0.05, **P <0.01, ***P <0.001, n.s, not significantly different, Student’s t-test or one-way ANOVA. FSC, forward-scatter; SSC, side-scatter; PSK, polysaccharide kestin, Aβ, amyloid β-protein; TLR2, toll-like receptor 2; TREM2, triggering receptor expressed on myeloid cells 2; MSR1, macrophage scavenger receptor 1; EEA1, early endosome antigen 1; LAMP, lysosomal associated membrane protein.