SYK-inhibitor augments CR3-mediated phagocytosis of C3bi-opsonized and unopsonized myelin in microglia and macrophages. SYK inhibitor augmented phagocytosis of C3bi-opsonized (C3bi-op) and unopsonized (unop) myelin in (A) wild-type BalbC (BC) and SRA−/− microglia, (B) wild-type C57BL (C57) but not CR3−/− microglia, and (C) wild-types BalbC and C57BL macrophages. (D) Piceatannol inhibited phagocytosis of C3bi-opsonized myelin by wild-type BalbC and C57BL microglia. Levels of phagocytosis that were determined after 30 and 60 min of exposure to myelin were similar and thus combined. Phagocytosis of C3bi-opsonized and unopsonized myelin in control/vehicle (Con) was each defined as 100 %. Phagocytosis at indicated concentrations of either SYK inhibitor or piceatannol was calculated as percentage of respective control. Averages ± SEM of six to ten experiments, each performed in triplicates, and levels of significance by one-way ANOVA and the Dunnett post test are: * p < 0.05, ** p < 0.01, *** p < 0.001. In (A) and (C), p < 0.001 for all values at 5 μM and 10 μM. In (D), p < 0.05 for all values at 25 μM and p < 0.01 for all values at 50 μM and 75 μM.