Fig. 5.

Conditioned media from Aβ-stimulated monocytes produces TNFα-dependent-neuronal apoptosis. Purified cultures of mouse cortical neurons (E16, 5 d in vitro) were incubated for 72 hr in Neurobasal media from unstimulated THP-1 cells or conditioned Neurobasal media (CM) obtained from THP-1 cells stimulated (48 hr) via surface-immobilized Aβ25–35 or Aβ1–40 fibrils (48 pmol/mm²). The incubations also included, as indicated, anti-human TNFα antibody (5 μg/ml), mouse TNFα (100 ng/ml), and anti-human IL-1β antibody (5 μg/ml). The neurons were fixed and stained for neuron-specific MAP2 protein, and surviving neurons were counted. Neurons from four fields/condition were counted in duplicate wells and averaged ± SEM. The mean values shown (±SEM) are representative of four independent experiments. Unpaired ANOVA was performed with Tukey-Kramer post-comparison to evaluate statistical significance (*p < 0.001).