Figure 3.

sAβ induces interleukin-10 (IL-10) production but no proinflammatory cytokine or nitric oxide (NO) production in monocytic cells. Monocytic cells were stimulated with synthetic 10 μM sAβ or fAβ or 100 ng/ml LPS upto 6 h. Cytokine production was analyzed from cell culture medium with cytometric bead array utilizing flow cytometry. SAβ induced a transient production of IL-10 (A, n = 4–8) but no significant production of IL-12 was detected (B, n = 4–8). Aβ did not cause any production of pro-inflammatory cytokine IL-6 of Tumor necrosis factor α (TNFα) (C,D, n = 4–8). As an annotation, interferon-γ was under detectable level in monocytic cells. While monocyte chemoattractant protein-1 (MCP-1) production in monocytic cells was high (E, n = 4–8), Aβ or LPS did not affect cell migration as determined for 12 h (F, n = 8) when monitoring the cell trajectory length in automated cell culture and analysis system (Cell IQ). When confirming proinflammatory cytokine production with ELISA, TNFα was neither produced if monocytic cells were incubated on top of brain sections from aged APdE9 mice containing native Aβ deposits nor in the presence of synthetic Aβ (G, n = 4). Again, LPS (50 ng/ml) induced high production of TNFα (G, p < 0.001, n = 6). Similarly, synthetic Aβ (n = 8) or native Aβ deposits (n = 4) did not induce NO production like LPS (H, p < 0.001, n = 8). Analyzed with cytometric bead array, 6 h incubation with fAβ induced production of TNFα in primary microglia (I,J, p < 0.001, n = 4). Interferon-γ, as well as IL-10 and IL-12 were under detectable levels in microglia. LPS served as a positive control for cytokine production. *p < 0.05, **p < 0.01, ***p < 0.001.