Figure 4

IGF1 protein production by microglia as assessed by ELISA. Microglia in triplicate cultures were stimulated with IFNγ (10, 100, and 1000 ng/ml), IL-4 (10 ng/ml), LPS (100 ng/ml), or medium alone (control) for 24 h and culture supernatants were analyzed for IGF1 protein content by ELISA (A). Microglial cultures were also exposed to different doses of db cAMP (0 to 10 mM) (B) as shown and culture supernatants were analyzed for IGF1 by ELISA. Microglial culture IGF1 levels were low (at the lower detection range of the ELISA) and they were further decreased by proinflammatory stimulants. Mean ± SD, One-way ANOVA with Dunnett’s multiple comparisons * P <0.05, ** P <0.01, *** P <0.001.