Figure 5.

Activation of β₂AR on microglia cells increases the protein level of IDE and enhances Aβ degradation. A, N9 cells were treated with 10 μm ISO for 12 and 24 h and cell lysates were subjected to immunoblot analysis with antibodies against IDE, neprilysin (NEP), or β-actin. B, Primary microglia were treated with 10 μm ISO or 1 μm NE for 12 and 24 h and then examined for IDE expression by immunoblot analysis. Data are the mean ± SD (n = 3); *p < 0.05, **p < 0.01, compared with cells cultured in medium alone. C–F, N9 cells (C, D) or primary microglia (E, F) pretreated with control medium, 10 μm ISO, or 10 μm ISO combined with 100 μg/ml insulin for 24 h were incubated with 2 μm Aβ₄₂ for an additional 12 h and then examined for Aβ in cell lysate and supernatant with Western blot. Data are the mean ± SD (n = 3); **p < 0.01, compared with Aβ in cells treated with Aβ₄₂ alone; ^##p < 0.01, compared with Aβ in cells treated with ISO followed by Aβ₄₂.