Fig. 4

Increased C1q accumulates at synapses in the MRL/lpr hippocampus. a and b Representative images of C1q stained with IBA-1/NeuN in the dentate gyrus (DG) and CA3 (mossy fiber terminals) region of 6-week-old MRL/mpj and MRL/lpr mice. Scale bars as indicated. c and d Representative STED stacks and quantification of C1q (green) stained with synapsin (red) puncta in the CA3 region of MRL/mpj and MRL/lpr mice. Colocalized synapsin and C1q puncta are indicated by circles. Scale bar, 5 μm. d Graph showing the percentages of total synapsin clusters colocalized with C1q. At least 120 synapses per mouse were analyzed. n = 7 mice per group. e and f Representative immunoblots and quantitation of C1q in PSD fractions and total lysates of hippocampus from MRL/mpj and MRL/lpr mice. g and h Coimmunoprecipitation analysis of C1q with synaptophysin or PSD-95 antibodies in MRL/mpj or MRL/lpr hippocampal lysates. The data are the mean ± SEM. ^**P < 0.01 and ^***P < 0.001 according to a two-tailed Student’s t-test in (d) and one-way ANOVA with Tukey’s post hoc test in (f, h). See also Supplementary Fig. 6