Fig. 5

Tocilizumab facilitates axon regeneration after SCI. A, B, G and H Representative images of sham, PBS, and Tocilizumab groups mice spinal cord are stained for NF (red, A and B), 5-HT (red, G and H), and GFAP (green, A, B, G and H ) at 14 (A, G) and 28 dpi (B, H), which exhibit fewer NF⁺ axons in the injured core and 5-HT⁺ axons 0.5 mm distal to the injured core in the PBS group compared to sham group, while there are more NF⁺ axons in the injured core and 5-HT⁺ axons 0.5 mm distal to the injured core in the Tocilizumab group than in the PBS group. C, D, I and J Quantitative analysis of the number of NF⁺ axons (C, D) and 5-HT⁺ axons (I, J) at 14 (C, I) and 28 dpi (D, J). E, K Representative images of the spinal cords of the sham, PBS, and Tocilizumab groups are stained for GAP-43 (red, E), NeuN (red, K), and GFAP (green, E and K) at 28 dpi, which exhibit fewer GAP-43⁺ axons in the injured core and NeuN ⁺ neurons 1.5 mm distal to the injured core in the PBS group compared to sham group, while there are more GAP-43⁺ axons in the injured core and NeuN ⁺ neurons 1.5 mm distal to the injured core in the Tocilizumab group compared to PBS group. F, L Quantitative analysis of the number of GAP-43⁺ axons (F) and NeuN⁺ neurons (L) in the GFAP⁻ region at 28 dpi. The ROI shows a higher magnification of the left boxed region (A, B and E). Asterisks indicate the injured core. Scale bars: 100 μm (low magnification, A, B and E), 20 μm (higher magnification, A, B and E), 50 μm (G, H), and 200 μm (K). R, and C represent the rostral and caudal sides of the injury, respectively. Data are presented as the mean ± SEM (n = 5 in each group). *p < 0.05, **p < 0.01, and ***p < 0.001 (Tocilizumab vs. PBS). ^#p < 0.05, ^###p < 0.001 and ^####p < 0.0001 (Tocilizumab vs. sham). ^&&&&p < 0.0001 (PBS vs. sham)