Fig 2: Nrf2 signaling blockade in the HG condition had significant effect on inhibiting aFGF-medicated SC proliferation and migration.a, b Representative images and quantitative analysis of immunostaining for Ki67 (green) in different treatment groups. Scale bar = 50 μm. c, d Representative wound-healing images and quantification data of SCs at 0 h and 12 h after treatment. Scale bar = 100 μm. Data are the mean ± SEM from three independent experiments. n.s indicated not significant difference between the control and control+si-Nrf2 groups, and between the HG and HG + si-Nrf2 groups; **P < 0.01 vs. the control group; ##P < 0.001 vs. the HG + aFGF group; &P < 0.05 vs. the HG + aFGF+si-Nrf2 group; n.s indicated not significant difference between compared two groups.

Fig 3: The antioxidant capacity of aFGF is associated with activating the Keap1/ Nrf2 signal.a Western blotting analysis showing the protein level of Keap1 and Nrf2 separated from the cytoplasm and nucleus in the sciatic nerves of T2DM model treating with/without aFGF. b, d Densitometric analyses of these proteins from (a). e Representative Western blotting of Keap1, cytoplasmic Nrf2, and nuclear Nrf2 in the control, HG and HG + aFGF groups. f–h Quantification of these proteins from (e). All data were normalized to GAPDH or Histone H3 and showed as relative levels to that of the control. Moreover, all data are the mean ± SEM (n = 3). *P < 0.05, **P < 0.01 vs. the control group; ##P < 0.01, ###P < 0.001 vs. the T2DM group or HG group.

Fig 4: aFGF inhibits SCs apoptosis.a–c Representative western blotting bands plus the corresponding statistical results of Bax, Bcl-2 and cleaved caspase-3 in control, T2DM and T2DM + aFGF groups. Data were repeated three times. d Co-staining of cleaved caspase-3 (green) and S100 (red) in each group. Nucleus were labeled with DAPI (blue). Scale bar equals 10 μm. e Quantification of positive cleaved caspase-3 area from (d). n = 7 animals per group. f Representative SC apoptosis images at 12 h after HG. Scale bar = 50 μm. g Quantification of the percentage of TUNEL-positive SCs from (f). This test was independently repeated 5 times. h Protein level of Bax, Bcl-2 and cleaved caspase-3 among the Control, HG, HG + aFGF groups. i, j Densitometric analyses of Western blotting from (h). This experiment was repeated in triplicate. Data are the mean ± SEM, **P < 0.01, ***P < 0.001 vs. the control group; #P < 0.05, ##P < 0.01, ###P < 0.001 vs. the T2DM group or HG group.

Fig 5: aFGF enhances SCs proliferation and migration.a Co-immunofluorescence images showed the distribution of Ki67+ (green) labeling nucleus were colocalized with S100 (red) in the control, T2DM and T2DM + aFGF groups. Scale bar equals 100 μm. b Quantification of Ki67 positive cells/100 mm2 in each group. n = 7 animals per group. c-e Western blotting analyzed the level of PCNA and Ki67 in each group (n = 3). GAPDH was used as an internal loading control and all protein expression was shown as relative levels to that of the control. f–h The expression of PCNA and Ki67 proteins was quantified in SCs of control, HG and HG + aFGF groups (n = 3). i–j Immunofluorescence staining and quantification data of Ki67 (green) and S100 (red) signals in the cell level. Nucleus was stained with DAPI. Scale bar = 25 μm. k, l SC migration analysis was detected through a wound-healing assay at 0 and 12 h after scratch. n = 3, scale bar = 100 μm. Data are the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 vs. the control group; #P < 0.05, ##P < 0.01, ###P < 0.001 vs. the T2DM group or HG group.