Figure 6.

Application of FGF9-induced NLCs promoted myelin sheath formation and regenerated injured nerve. (A) NLCs or FGF9-induced NLCs (NLC-FGF9) were applied into the nerve conduit (CC) to bridge the transected nerves. Images of gross morphology (1^st row) show the regenerated sciatic nerve after 6 weeks of injury. P: proximal nerve; D: distal nerve. Myelin structure across different treatments was revealed by semi-thin sections (2^nd row) in the middle section of nerve tissue (white box region of 1^st row). The immunofluorescent staining of S100β visualized the co-localization of transplanted Dil-labeled FGF9-NLCs on the circular myelin sheath structure (arrows). Zoom-in image of the yellow box for NLC (area 1) and FGF9-NLCs (area2) treatments. (B) Quantitative analysis showed improvements in nerve fiber diameter and G-ratio of myelin sheath following FGF9-NLCs treatment. (C) Immunofluorescent staining of GAP43 revealed immature SCs on myelination in NLC treatment, whereas the application of FGF9-NLCs led to positive staining with the mature SC marker MBP. (D) The recovery of the sciatic nerve was illustrated by the obvious prevention of muscle atrophy in the gastrocnemius muscle. Quantitative results of RGMW and gastrocnemius muscle fiber cross section area. Scale bar: 40 μm. N=3. Data are represented as the mean ± SD of three independent biological repeats. *p < 0.05 compared to PBS. #p < 0.05 compared to NLC.