Fig. 8

Schwann cell remyelination takes place in the absence of CXCR4 or AR signaling. a MPZ/MBP, MPZ/GFAP and MPZ/CXCR4 double-labeling on spinal cord cross sections of wild-type castrated AR^Lox/Lox male mice at 30 dpl. Cell nuclei were counterstained in blue with DAPI. The LPC lesion is delimited by a dotted line. MPZ⁺ Schwann cells, most likely originating from the ventral spinal roots (indicated by arrows) invaded the lesion only in the absence of MBP, GFAP or CXCR4 immunostaining, which means in the absence of T (empty implant) or CXCR4 signaling (AMD3100). Electron microscopy image (b) and its enlargement (c) showing that in the absence of T, axons are remyelinated by Schwann cells (Sc), characterized by a large nucleus close to the myelin sheaths (indicated by a star). Red square indicates an oligodendrocyte in the lesion in contact with two axons, one axon presents a thin myelin sheaths and a second axon seems to be unmyelinated. d–g CXCR4, GFAP, and MPZ immunostaining of spinal cord cross sections of castrated AR^Lox/Lox and AR^NesCre male mice at 30 dpl. Transgenic AR^NesCre mice with CNS-selective ablation of AR and control AR^Lox/Lox mice were used. The LPC lesion is delimited by a dotted line. MPZ⁺ Schwann cells, most likely originating from the ventral spinal roots (indicated by arrows), invaded the lesion only in the absence of CXCR4 and GFAP immunostaining (AR^Lox/Lox mice receiving an empty implant or AR^NesCre mice receiving a T implant). Scale bar: 20 µm in (a, d) and 1 µm in (b, c). e–g Data are presented as means ± S.E.M. (one-way ANOVA with Tukey's multiple comparisons tests). Asterisks mark significant differences. ***P < 0.001, *P < 0.05