Figure 6From: Complement receptor-3 negatively regulates the phagocytosis of degenerated myelin through tyrosine kinase Syk and cofilin Cofilin is continuously activated during prolonged phagocytosis when Syk is either inhibited or its expression reduced, but transiently activated during normal phagocytosis. (A) Quantitation of phospho-cofilin-1 (p-cofilin) and total (T) cofilin after 45 min of phagocytosis by Syk-KD and Syk-inhibited (Syk-in) microglia and their respective controls (Con-Luc and Con SYK-in) based on (B) immunoblot analysis. In (A), p/T ratio in Syk-KD and Syk-inhibited microglia was calculated as percentage of p/T in their respective controls that were defined as 100 % each. Values of individual experiments, averages ± SEM, and significance of difference by double-tailed Mann-Whitney is ***p < 0.001. (C) Quantitation of p/T before (0 min) and after 10 and 30 min (min) of phagocytosis based on (D) immunoblot analysis. In (C), p/T in non-phagocytosing Con-Luc microglia was defined as 100 %. Then p/T in all other non-phagocytosing and phagocytosing microglia was calculated as percentage of p/T in non-phagocytosing control Con-Luc microglia. Average values ± SEM of three to five experiments, each performed in duplicate or triplicate, are given. Significance of differences between initial values at 0 min and those at 10 and 30 min by one-way ANOVA and the Dunnet’s post test are **p < 0.01 and ***p < 0.001 for Con-Luc microglia, and § p < 0.05 and §§§ p < 0.001 for Syk-KD microglia. Significance of difference between Con-Luc and Syk-KD microglia by two-way ANOVA and the Bonferroni post test are # p < 0.05 at 0 min and ### p < 0.001 at 30 min. (E and F) Phagocytosis by Syk-KD and control Con-Luc microglia after (E) 10 min and (F) 30 min of phagocytosis. Values of individual experiments, each performed in triplicate, averages ± SEM, and levels of significance by double-tailed Mann-Whitney are given; ** p < 0.01.Back to article page