Fig. 4

Pro- and anti-inflammatory gene-expression profiles of isolated microglia by qPCR. Early after the bleeding (day 4), individual changes in pro (a)- and anti-inflammatory (b) gene expression levels were seen. a Only TNFα levels after PLX3397-treatment were significantly elevated (3-fold compared to Sham, p < 0.01 and 2-fold compared to LPS treatment p < 0.05) early after the bleeding. Fourteen days after the bleeding, a significant rise of pro-inflammatory cytokine-levels was documented in SAH-animals (IL1β: 4.7-fold compared to Sham, IL6: 2,3-fold compared to sham). Inflammatory preconditioning as well as PLX3397-treatment led to significant amelioration of the gene expression near sham values (IL1β/IL6: LPS pretreatment vs. SAH p < 0.01, PLX3397 treatment vs. SAH p < 0.001). b For anti-inflammatory cytokines, no significant changes were seen early after the bleeding (day 4). On day 14 after the bleeding, PLX3397-treatment led to a significant loss of gene-expression of TGFβ when compared to SAH and of IL10 when compared to LPS preconditioning (both p < 0.05). At both time points, 4-fold elevation of IL4 after LPS preconditioning did not reach significance levels due to high standard deviation. c In line with the pro-inflammatory cytokines, levels of the pro-inflammatory enzyme COX2 showed only slight changes on day 4 (n.s.). On day 14, a significant reduction was seen in PLX3397-treated animals only when compared to SAH (p < 0.01), n = 3–5 per group, ANOVA: *p < 0.05; **p < 0.01; ***p < 0.001, normalized to Sham-group (RQ = relative quantity, statistical comparison to sham group not given due to normalization for delta-delta CT model)