Fig. 4

Enhancement of MN differentiation and maturation by preemptive cell transplantation of hMSC and iMNP in contusive SCI model. a Schematic image of preemptive transplantation of hMSC and iMNP in a contusive SCI model. Multiple intravenous injections of hMSC were administered at 24 h and one week post injury. Six weeks post injury, iMNPs were transplanted to the lesional site using intralesional injection. b BBB scale scores in the hMSC + iMNP group was significantly higher than that in the PBS group. c Transplanted hMSC and iMNP show white and gray matter at the epicenter of the lesion. d SMI-32 differentiation of transplanted iMNP cells is predominant. e Orthogonal view of confocal images showing SMI-32 and transplanted cell expression around the lesional site. f WB results of SMI-32 expression in the hMSC + iMNP group were significantly higher than those in the PBS group. Full-length WB images are presented in Additional file 7: Fig. S7. Data are presented as mean ± SEM. Statistical significance was estimated using Kruskal–Wallis test with post hoc analysis and Mann–Whitney (†) test with least significant difference post hoc analysis (*); *, † P < 0.05. (WB analysis: PBS n = 6, hMSC n = 5, iMNP n = 4 and hMSC + iMNP n = 5, BBB locomotor scales: PBS n = 10, hMSC n = 10, iMNP n = 8 and hMSC + iMNP n = 10) Scale bars = 20 and 10 μm. hMSC, human mesenchymal stem cells; iMNP, induced pluripotent stem cell-derived motor neuron progenitor cells; SCI, spinal cord injury; BBB, Basso–Beattie–Bresnahan; WB, Western blotting