β-Amyloid peptide induces tumor necrosis factor-α and nitric oxide production in murine macrophage cultures

We investigated the effect of β-amyloid peptide (βA) on the activation of the murine-derived monocyte/macrophage J774 cell-line. βA induced tumor necrotic factor-α (TNFα) in these cells in a dose-dependent manner. Incubation of cells with βA slightly increased nitric oxide (NO) production, an effect that was significantly enhanced by the addition of interferon-γ (IFNγ). Substitution of βA4 with TFNα and incubation of the cultures with IFNγ resulted in significant NO production, although this was lower than that obtained in the presence of the peptide. Incubation of cultures with a monoclonal antibody (mAb) against TNFα abrogated NO production. Our results suggest that βA4-induced TNFα production is a crucial event in the activation of peripheral macrophages.