Fig. 5.

Microglia are necessary for myelin homeostasis during adulthood. a Scheme of experimental setup. 6–10-week-old Cx3cr1^GFP/Wt mice were treated with BLZ945 for 7 consecutive days by oral gavage. Analysis was performed 1 day after the last application. b, c Quantification of CX₃CR1⁺ microglia, PDGFRα⁺ OPCs, CC-1⁺ oligodendrocytes, Sox9⁺ astrocytes (b, d) in the corpus callosum (b) and cerebellum (c) using immunohistochemically stained brain sections at day 8. n = 4–7; samples from two independent experiments. Significant differences were examined by an unpaired t test and marked with asterisks (*P < 0.05, **P < 0.01, ***P < 0.001; n.s not significant.) Each symbol represents one mouse. Mean ± SEM are depicted. d Quantitative RT-PCR of the genes proteolipid protein (Plp), myelin basic protein (Mbp), myelin oligodendrocyte glycoprotein (Mog), chondroitin sulfate proteoglycan 4 (Cspg4), platelet derived growth factor receptor alpha (Pdgfrα), colony stimulating 1 receptor (Csf1r), and allograft inflammatory factor 1 (Aif1) in tissue isolated from the corpus callosum and cerebellum at day 8 (n = 4–7; samples from two independent experiments). Data were normalized to Gapdh and β-actin and are presented as fold change normed to vehicle. Significant differences were examined by an unpaired t test and marked with asterisks (*P < 0.05, **P < 0.01, ***P < 0.001). Bars represent mean ± SEM. e Western blot analysis for proteolipid protein (PLP) and myelin basic protein (MBP) in the corpus callosum at P8, 1 day after the last BLZ945 application. GAPDH was used as a loading control. Quantification (right) was performed by normalization of the myelin proteins to GAPDH. Bars indicate mean ± SEM. Significant differences were examined by an unpaired t test (n.s not significant). f Scheme of experimental setup. 8–10-week-old Sox10-iCreER^T2 × CAG-eGFP mice were treated with BLZ945 for 5 consecutive days by oral gavage. Analysis was performed 1 day after the last application. g, i Quantification of Iba-1⁺ microglia, Sox10-GFP⁺/NG2⁺ OPCs (g), Sox10-GFP⁺/NG2⁻ oligodendrocytes and GFAP⁺/S100β⁺ astrocytes (i) in the corpus callosum using immunohistochemically stained brain sections at day 6. n = 5–6, samples from two independent experiments. Significant differences were examined by an unpaired t test and marked with asterisks (**P < 0.01, ***P < 0.001; n.s not significant.) Each symbol represents one mouse. Mean ± SEM are depicted. h Representative confocal images of a NG2-immunofluorescence in the corpus callosum of a mouse treated with vehicle (left) or BLZ945 for 5 consecutive days. Scale bar 50 μm