Figure 4

Phagocytosis of C3bi-opsonized and unopsonized myelin is augmented in Syk knocked-down (Syk-KD) microglia. (A) Immunoblot of Syk and actin in wild-type BalbC (BC), control (Con-Luc), and Syk-KD microglia. (B) Quantitation of Syk levels based on (A). Syk/actin ratio in BalbC and Syk-KD microglia was calculated as percentage of Syk/actin in control Con-Luc microglia, which was defined as 100 %. Values of individual experiments, averages ± SEM, and significance of differences by double-tailed Mann-Whitney is *** p < 0.001. (C) Phagocytosis of C3bi-opsonized (C3bi-op) and unopsonized (unop) myelin by Syk-KD and control Con-Luc microglia. Levels of phagocytosis that were determined after 30 and 45 min of exposure to myelin were similar and thus combined. Phagocytosis by Syk-KD microglia was calculated as percentage of phagocytosis by control Con-Luc microglia, which was defined as 100 %. Values of individual experiments, each performed in triplicates, averages ± SEM, and significance of differences by double-tailed Mann-Whitney is *** p < 0.001.