Figure 1

Neuron-microglia interactions induce elevated expression of secreted APP (sAPP). Relative levels of sAPP were determined in medium from primary cortical neuron cultures treated with IL-1β (0.1–10 ng/mL) and in medium from IL-1β-treated neuron/microglia mixed cultures. Proteins in the medium were concentrated by Centricon, and sAPP was detected by western immunoblot analysis. A) Representative sAPP immunoblot; B) Densitometric quantification of immunoblot results. Values represent the mean ± SEM of three experiments (error bars are smaller than the datapoint symbols). At each IL-1β dose, the sAPP levels in medium of microglial neuronal-mixed cultures were greater than in medium from neurons cultured alone (p < 0.05).