Fig. 7

C1q expression in different microglia phenotypes. a Representative images of dual labeling of microglia (Iba1, cyan) and C1q (magenta) in all three groups. b-c Box-and-whisker plots with vertical scatter plots of individual cases showing: b the density (% area label) of Iba1 + colocalized with C1q + puncta. (M1: one-way ANOVA, main effect, p = 0.001; Fisher’s LSD post hoc, ctr. vs. veh, p = 0.046; ctr. vs. EV, p = 0.003; veh vs. EV, p = 0.009; PMC: main effect, p = 0.04; post hoc, ctr. vs. EV p = 0.004); c the fraction of C1q + puncta colocalized with microglia (Iba1). Higher fraction of C1q + puncta colocalized with microglia (Iba1) in EV than in veh (main effect, p = 0.06; post hoc, p = 0.05). For b-c, Ctr: n = 3. Veh: n = 4. EV: n = 5 monkeys. d Representative images of dual labeling of microglia (Iba1, cyan) and C1q (magenta), with examples of different microglia morphologies with or without C1q. e–h Box-and-whisker plots with vertical scatter plots of individual cases showing the cell densities of: e microglia by C1q expression. In M1, EV but not veh had greater C1q + microglia density than control (two-way ANOVA group*area, main effect, ‘group’: p = 0.009; post hoc: ctr. vs. veh: p = 0.07; ctr. vs. EV: p = 0.03); and C1q- microglia had greater density in lesion than in controls (main effect, ‘group’: p = 0.006; post hoc: con. vs. veh: p < 0.001; ctr. vs. EV: p = 0.004). In PMC, greater density of C1q + microglia in veh than control group (p = 0.02). f Microglia by morphology (Rami, Hyper and Ame; two-way ANOVA group*area). In M1, hypertrophic microglia had greater density in lesion compared to control group (main effect, ‘group’: p = 0.003; post hoc: con. vs. veh: p = 0.01; con. vs. EV: p = 0.008). g Microglia by both C1q expression and morphology in M1. In M1, the EV group showed higher density of C1q- ramified microglia than control group (p = 0.01). Both groups with lesion had higher density of hypertrophic C1q + microglia than controls (main effect, ‘group’: p < 0.001; post hoc: ctr. vs. veh: p = 0.047; ctr. vs. EV: p < 0.001). However, only veh group had a higher density of hypertrophic C1q- microglia than controls (main effect, ‘group’: p = 0.036; post hoc: p = 0.005). h Microglia by both C1q expression and morphology in PMC revealed no between-group differences. For e–h Ctr: n = 3; Veh: n = 4; EV: n = 5 monkeys. Box-and-whisker plots: bars show interquartile range and median (horizontal line) with error bars = 95% confidence interval; *p < 0.05, **p < 0.01