FIGURE 4.

Paxillin activation is transient in phagocytosing control microglia but continuous in phagocytosing SIRPα-KD microglia. Immunoblot analysis of p- and T-paxillin 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 paxillin and paxillin that is phosphorylated at Y¹¹⁸. (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 eight 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. Significance of difference between Con-Luc and SIRPα-KD microglia by two way ANOVA and the Bonferroni post test is ^###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 < 0.01 (not marked).