Figure 5

Microglial co-localization on surface-bound Aβ alone and in combination with soluble Aβ.

(a) Microglial cells were cultured in wells uniformly coated with bAβ₄₂ fibrils and tracked individually. (b) The bAβ₄₂ fibrils induce the simultaneous decrease of the mobility and the viability of microglia, proportional to increased concentrations of the bAβ fibrils. (c) The level of secreted MCP-1 is elevated by about two-fold on surfaces coated with bAβ₄₂ oligomers and bAβ₄₂ fibrils of 9 ng.mm⁻² compared to an uncoated surface. (d) Fluorescent image visualized co-localized microglia in red on a spot of bAβ₄₂ fibrils at 90 ng.mm⁻² in green. Co-localization of microglia on the patterned bAβ₄₂, becomes more effective as the concentration increases with 1.5-fold enrichment on bAβ₄₂ oligomers (e) and 2-fold on bAβ fibrils (f) at 90 ng.mm⁻² on a ‘day 6’, respectively. (g) Fluorescent image visualized co-localized microglia on bAβ₄₂ fibrils at 90 ng.mm⁻² combined with sAβ₄₂ oligomers at 23 ng.mL⁻¹ in a microfluidic platform. Co-localization is 1.6-fold on bAβ₄₂ fibrils alone (h) compared to 2.5-fold on bAβ₄₂ fibrils at 90 ng.mm⁻² in combination with a gradient of sAβ₄₂ oligomers at 23 ng.mL⁻¹ (i). Scale bars, 1 mm. (Student's t-test. * P < 0.1, ** P < 0.05 with respect to no bAβ₄₂). n_well = 2 in ‘(a)’, ‘(b)’, ‘(e)’, ‘(f)’ and n_platform = 2, n_cell ≈ 2,000 in ‘(h)’, ‘(i)’ for each condition. Data represent mean ± s.e.m.