Fig. 8

PD-1 inhibitor reverses the advantageous effects of lactate on SCI repair in vivo. A Immunofluorescence staining of BrdU (green) and CX3CR1 (magenta) in sagittal sections of the PBS (control), lactate, and lactate + PD-1 inhibitor groups at 7 dpi in vivo. Scale bar: 20 μm. B Quantification of the density of BrdU⁺CX3CR1⁺ cells in (A). All data are presented as the mean ± SEM, n = 3 mice per group, **p < 0.01; ***p < 0.001. C Immunofluorescence staining of CX3CR1 (red) in sagittal sections of the control, lactate, and lactate + PD-1 inhibitor groups at 28 dpi in vivo. Scale bar: 100 μm. D Quantification of the density of CX3CR1⁺ cells in (C). All data are presented as the mean ± SEM, n = 3 mice per group, ***p < 0.001; ****p < 0.0001. E Images of astrocytes (GFAP, green) stained with neurons (NeuN, magenta) in Z1_Z3 at 28 dpi in control, lactate, and lactate + PD-1 inhibitor groups in vivo. Scale bar: 100 μm. F Quantification of NeuN⁺ neurons in Z1_Z3 in (E). All data are presented as the mean ± SEM, n = 3 mice per group, **p < 0.01; ***p < 0.001; ****p < 0.0001. G Images of GFAP (green) co-stained with axons (5-HT, magenta) at 28 dpi in control, lactate, and lactate + PD-1 inhibitor groups in vivo. Asterisks indicate the lesion site, scale bars: low magnification, 100 μm; high magnification, 20 μm. H Quantification of the percentage of 5-HT⁺ area in the area of the spinal cord segment penetrating into the lesion core at 28 dpi in (G). All data are presented as the mean ± SEM, n = 3 mice per group, ****p < 0.0001. I The locomotor function was evaluated by BMS at the indicated time points. All data are presented as the mean ± SEM, n = 8 mice per group, **p < 0.01; ****p < 0.0001. J Representative images of footprint analysis in mice in control, lactate, and lactate + PD-1 inhibitor groups at 28 dpi. K–M Quantification of the stride length and width and paw rotation at 28 dpi. All data are presented as the mean ± SEM, n = 8 mice per group, **p < 0.01; ***p < 0.001; ****p < 0.0001