Figure 3

Combinations of pro-inflammatory cytokines elevate endogenous secreted Aβ40 levels in conditioned media from mouse primary astrocyte cultures. Conditioned media (CM) of cytokine-stimulated mouse primary astrocytes analyzed in Fig. 1A-C and Fig. 2A, B were harvested after 24, 48, or 96 h of proinflammatory agent (individual and combinations) stimulation and analyzed for endogenous mouse Aβ40 levels by sandwich ELISA. The amount of Aβ40 in CM was expressed as pg/mg total protein in the cell lysate (A) or as percent of vehicle control (B). Note that TNF-α+IFN-γ stimulation was overall more potent at increasing astrocytic secreted Aβ40 levels, while IL-1β reduced Aβ40 levels at all time points. Statistical analysis was the same as described in Fig. 1. Significance indicates comparison to individual vehicle control within each time point (n = 3; *p < 0.05, **p < 0.01). Error bars, SEM.