Fig. 5

Increased axonal regeneration by preemptive hMSC and iMNP transplantation in the SCI lesion. a Confocal images showing synapsin-1 and transplanted cell expression around the lesional site. IF staining of synapsin-1 longitudinal sections. b IF staining of synapsin-1 showing axial sections of the lesional site. Synapsin-1 and transplanted iMNP merged around the lesional site. c WB results of synapsin-1 expression in lesional site segments (\(\sim\) 1 cm). WB showed significantly increased expression of synapsin-1 in the MSC + MNP group compared to the PBS group. d IF staining images of MAP-2 showing a longitudinal section. e IF staining images of MAP-2 showing an axial section from the lesional site. MAP-2 and transplanted iMNP merged around the SCI lesional site. f WB results of MAP2 expression in the lesional site segments. Full-length WB images are presented in Additional file 7: Fig. S7. g Transmission electron microscopy images proximal to the lesional site. 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 only n = 5, iMNP only n = 4, and hMSC + iMNP n = 5, Scale bars = 20 μm. hMSC, human mesenchymal stem cells; iMNP, induced pluripotent stem cell-derived motor neuron progenitor cells; SCI, spinal cord injury; IF, immunofluorescence; BBB, Basso–Beattie–Bresnahan; WB, Western blotting