Fig 2: FGF5 overexpression reduces inflammation and oxidative stress in SCI mice. (A) Mice were overexpressed with FGF5 using lentiviral vectors, and then were exposed to SCI or sham surgery 2 weeks post‐injection. IL‐6 and TNF‐α levels in the spinal cord were detected. (B) MPO activity in the spinal cord. (C) Western blot images and quantification of p65 phosphorylation. (D) Relative NF‐κB transcription activity. (E, F) Relative levels of NRF2 protein and transcription activity. (G) ROS level detected by DCFH‐DA probe. (H) Quantification of hydrogen peroxide and superoxide anion in spinal cord. (I) The levels of MDA, 3‐NT and 8‐OHdG. n = 6 for each groups. Data are expressed as the mean ± standard deviation and p < 0.05 was considered statistically significant. *p < 0.05.

Fig 3: FGF5 overexpression reduces inflammation, oxidative stress and SCI through activating AMPK. (A) Mice were overexpressed with FGF5 using lentiviral vectors, and then were exposed to SCI or sham surgery 2 weeks post‐injection. Western blot images and quantification of AMPK phosphorylation in the spinal cord were detected. (B) To inhibit AMPK, mice with or without FGF5 overexpression were intraperitoneally injected with CC every 2 days 1 week pre‐SCI. IL‐6 and TNF‐α levels in the spinal cord were detected. (C) ROS level detected by DCFH‐DA probe. (D) The levels of MDA, 3‐NT and 8‐OHdG. (E) BMS score, from 0 (no ankle movement) to 9 (normal gait), was determined at indicating times. (F, G) Sensitivities to mechanical and thermal stimulation were determined 28 days after SCI. (H) Extravasation of Evans blue dye was determined 28 days after SCI. n = 6 for each groups. Data are expressed as the mean ± standard deviation and p < 0.05 was considered statistically significant. *p < 0.05.

Fig 4: Serum FGF5 level positively correlates with the sensory and motor function in SCI patients. (A) Serum levels of FGF5 in Ctrl and SCI patients. (B, C) SCI patients were divided into four groups according to serum FGF5 levels, and ASIA sensation and motor scores were measured at indicating groups. n = 56 for Ctrl group and n = 92 for SCI group. Data are expressed as the mean ± standard deviation and p < 0.05 was considered statistically significant. *p < 0.05.

Fig 5: FGF5 knockdown exacerbates SCI in mice. (A, B) Mice were intraspinally injected with 2 μL lentivirus carrying shFGF5 to knockdown FGF5 in the spinal cord, and FGF5 mRNA and protein levels were detected 2 weeks post‐injection. (C) Mice were injected with shFGF5, and then were exposed to SCI or sham surgery 2 weeks post‐injection. BMS score, from 0 (no ankle movement) to 9 (normal gait), was determined at indicating times. (D, E) Sensitivities to mechanical and thermal stimulation were determined 28 days after SCI. (F) Extravasation of Evans blue dye was determined 28 days after SCI. n = 6 for each groups. Data are expressed as the mean ± standard deviation and p < 0.05 was considered statistically significant. *p < 0.05.