Figure 7. Inhibition of TGF-β1/Smad3 signaling reverses the therapeutic effect of ADSCs on SCI. (A) H&E staining images depicting pathological changes in the rat spinal cord following experimental SCI. Scale bar: 200 μm. Nissl staining analysis of residual neurons in transverse spinal cord sections 3-5 mm away from the injury site. Scale bar: 20 μm. Immunofluorescence analysis of MAP2 expression in injured spinal cord tissue showing reduced neuronal injury after ADSC transplantation. Scale bar: 50 μm. All the samples were obtained 3 days after ADSC transplantation. (B) MAP2 immunofluorescence in injured spinal cord tissue. The increase in MAP2 expression induced by ADSCs transplantation was attenuated by SB431542 treatment. (C) Assessment of locomotor behavior (BBB scale) after spinal cord injury (n=6/group). Results are mean ± SD; differences were evaluated with one-way ANOVA and t-test. *P<0.05 vs 3 days, #P<0.05, ADSC vs ADSC+SB. (D) ELISA analysis of rat serum TGF-β1 levels 3 days after ADSC transplantation/SB administration. *P<0.05, compared to sham and ADSC groups; #P<0.05, compared to ADSC and SB groups; &P<0.05, compared to PBS and ADSC+SB groups.