Anti-LPA mAb (B3) reduces glial scar after SCI. Immunostaining at the injury site of mouse spinal cords 1 week after SCI shows a dense network of astrocytes expressing high levels of GFAP (A and B), which is reduced after B3 treatment (D and E). C: Immunostaining for chondroitin sulfate proteoglycans 2 weeks after lesioning revealed that the scar was diminished in B3-treated mice (F). G: Quantitation of GFAP density around the lesion site showed a significant decrease with B3 treatment. Results are the mean ± SEM percentage of GFAP staining density in the field (n = 7 in each group). *P < 0.001 by two-tailed t-test, 95% confidence). Most proliferating cells at the lesion site are GFAP positive. H: Quantitation of Ki-67–positive cells at the lesion site showed a significant decrease with B3 treatment. Results are the mean ± SEM number of Ki-67–positive cells in the field (n = 7 in each group). *P < 0.001 by two-tailed t-test, 95% confidence). I: p-MAPK levels were reduced on astrocytes at the lesion site in B3-treated mice. Western blot analysis of spinal cord tissue 1 week after injury showed a significant reduction in p-MAPK signaling (n = 7) (J) and Rho-GTP levels (n = 4) (K) in B3-treated mice. Data are expressed as the mean ± SEM from at least three independent animals. *P < 0.05, **P < 0.01 by one-way analysis of variance followed by the Tukey test, α = 0.001. Scale bars: 200 μm (A, C, D, and F); 50 μm (B, E, H, and I).