Fig. 6
Histological evaluation of regenerated nerves after cell transplantation. a In the immunofluorescence (IF) photographs in the leftmost column, regenerated axons stained with green fluorescence (wrapping or not wrapping around regenerated myelin sheaths labeled with red fluorescence) were found at the midpoint of the implanted segments at week 6 after cell transplantation. The nuclei were stained with blue fluorescence. The photographs in the middle and rightmost columns show Toluidine Blue staining and transmission electron microscopy (TEM) images, respectively, of regenerated nerves located at the distal end of implanted segments at week 12 after cell transplantation. b,c The mean density of myelinated nerve fibers in intermittent dASCs (15,520 ± 694/mm2) was significantly greater (p < 0.01) than those in the hollow (8575 ± 779/mm2), uASCs (7268 ± 637/mm2), and sustaining dASCs 7d groups (13,814 ± 658/mm2) at week 6 after cell transplantation. However, no significant difference was observed compared with the sustaining dASCs 7d (8942 ± 670/mm2 vs. 8461 ± 301/mm2) at week 12 after cell transplantation. d,e The mean diameter of myelinated nerve fibers and mean thickness of myelin sheath showed similar trends, i.e., those in the intermittent dASCs (7.05 ± 0.51 μm in diameter and 1.53 ± 0.16 μm in thickness) were significantly greater (p < 0.05) than those in the hollow (4.43 ± 0.54 μm in diameter and 1.03 ± 0.10 μm in thickness), uASCs (4.44 ± 0.53 μm in diameter and 0.91 ± 0.14 μm in thickness), and sustaining dASCs 7d groups (6.36 ± 0.39 μm in diameter and 1.35 ± 0.13 μm in thickness), but significantly less (p < 0.05) than those in the autograft group (7.70 ± 0.53 μm in diameter and 1.78 ± 0.12 μm in thickness). Data are expressed as means ± SEM. *p < 0.05, **p < 0.01, one-way ANOVA with Tukey’s post-test or Dunnett’s T3 post-test. dASC, differentiated adipose-derived stem cell; n.s., no significant difference; uASC, undifferentiated adipose-derived stem cell