FIGURE 3.

Cofilin activation is transient in phagocytosing control microglia but continuous in phagocytosing SIRPα-KD microglia. Immunoblot analysis of phosphorylated and total cofilin-1 (p- and T-cofilin) in (A) control (Con-Luc) and (B) SIRPα-KD microglia before the onset of phagocytosis (time 0), and after 10 and 30 min of phagocytosis. The antibodies used for immunoblot analysis identify cofilin and cofilin-1 that is phosphorylated at S³. (C) Quantitation of the ratio p/T based on immunoblot analysis. The ratio p/T in non-phagocytosing Con-Luc microglia (i.e., at time 0) was defined 100%. Then, p/T in all other non-phagocytosing and phagocytosing microglia was calculated as percentage of p/T in non-phagocytosing Con-Luc microglia. Average values ±SEM of four to six experiments, each performed in duplicates, 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 post test are *p < 0.05 and ***p < 0.001 for Con-Luc microglia and ^§p < 0.05 for SIRPα-KD microglia. Significance of difference between Con-Luc and SIRPα-KD microglia by two way ANOVA and the Bonferroni post test are ^#p < 0.05 and ^###p < 0.001. Significance of difference between 10 and 30 min in Con-Luc microglia by one way ANOVA and the Tukey’s post test is p < 0.001 (not marked).