PI3K mediates signaling between MAC1 receptor and PHOX. Microglia-enriched cultures from MAC1+/+ mice were pretreated with wortmannin for 30 min and then challenged with Aβ for 10 min. (A) Extracellular superoxide generation was measured by the SOD-inhibitable reduction of tetrazolium salt, WST-1. (B) Western blot assays for p47phoxlevels in membrane fractions from microglia. (C) Densitometry analysis was performed with values of p47phoxnormalized to loading control and further normalized to control levels. (D) Microglia-enriched cultures from MAC1+/+ mice were treated with vehicle medium (control group) or different concentrations of wortmannin for 12 or 24 hours; cell viability was measured using MTT assay. Data are presented as mean ± SEM for three independent experiments. #: p < 0.05 relative to vehicle-treated control cultures. *: p < 0.05 relative to Aβ-treated cultures.