Fig. 3

Mbp drives myelin-induced NPC dendrite regeneration via cleaving extracellular L1cam to produce L1-70. a Wild-type (WT) and Mbp-null (Mbp^−/−) spinal cord-derived E12 mouse neural progenitor cells (E12 mNPCs) were stained with L1cam antibody-557 followed by pan-MBP antibody staining, fixation, Cy2-and Cy3-labeled secondary antibody staining, and DAPI (blue). Scale bars: 10 μm. b Immunoblotting of whole-cell lysates from WT and Mbp^−/− E12 mNPCs with either L1cam antibody-557 or antibody-172-R. Gapdh used as a loading control. c Whole-cell lysates from WT E12 mNPCs transfected with Mbp and treated with aprotinin were subjected to L1cam antibody-557 immunoblotting. Gapdh used as a loading control. d–o Analysis of neuritogenesis in d–g WT or Mbp^−/− E12 mNPCs, h–k WT or Mbp^−/− spinal cord-derived E14 rat neural progenitor cells (E14 rNPCs), and l–o D1 WT or Mbp^−/− NPCs derived from human iPSCs (D1 hNPCs) transduced with pcDNA3-Ctrl or pcDNA3-L1-70 after 48 h of Poly-d-lysine control (PDL Ctrl) or myelin (Mye) substrate culture. WT PDL Ctrl was used to normalize values for mNPCs and rNPCs. WT Lam Ctrl was used to normalize values for hNPCs. All panels report means ± standard deviations (SDs). n = 3 embryos/genotype × 3 wells/embryo. *P < 0.05, **P < 0.01 [two-way ANOVA, post-hoc Tukey’s test]