Fig. 2

LPS-As-CM injection inhibited the regrowth of axons and worsened neurological recovery. A Experiment summary schematic. View of the immunofluorescently stained section in the spinal cord. The time of intrathecal injection and neurological functional assessment. B HE staining was performed to reveal the percentage of injured areas at 4 weeks post-injury (n = 5, data are the mean ± S.D; ∗p < 0.05, ns p > 0.05). C Area occupied by GFAP-positive scar-forming astrocytes and Cnpase-positive oligodendrocytes around the cavity at 4 weeks after SCI. The percentage of Cnpase-positive areas was reduced by the injection of As-CM and LPS-As-CM. The LPS-As-CM-induced alterations were blocked by the addition of Noggin (n = 5, data are the mean ± S.; ∗p < 0.05, ns p > 0.05). D Evaluation of the remyelination of the neurite outgrowths by assessing the double-immunostaining for Cnpase and Tuj1. The bottom panels show that the double-positive areas of Cnpase and Tuj1 (yellow areas) that were selected and used for calculation by ImageJ (n = 5, data are the mean ± S.D; ∗p < 0.05, ns p > 0.05). E The double double-immunostaining for MBP and GFAP revealed that the injection of As-CM and LPS-As-CM markedly reduced the expression of MBP within the GFAP-positive-scar boundary. The addition of Noggin blocked the LPS-As-CM-related effects in the lesion sites (n = 5, data are the mean ± S.; ∗p < 0.05, ns p > 0.05). F The western blot results showed similar data as the immunofluorescence results: 4 weeks after SCI, the expression of Cnpase was reduced by the injection of As-CM and LPS-As-CM, and the LPS-As-CM-associated downregulation of Cnpase expression was countered by the addition of Noggin (n = 3, data are the mean ± S.D; ∗p < 0.05, full length original gels are included in Additional file 2: Figure S2). G, H The BBB scores and incline plane tests in different groups post-SCI. The injection of LPS-As-CM inhibited functional recovery, and the addition of Noggin repressed the LPS-As-CM-induced effect in SCI rats (n = 10, data are the mean ± S. D). Significant differences in BBB scores were noted between the LPS-As-CM group and SCI group, the LPS-As-CM group and As-CM group, and the LPS-As-CM group and LPS-AS-CM + Noggin group at day 28 post-injury. Similarly, differences in the angle of the incline plane tests were found between the LPS-As-CM group and SCI group and the LPS-As-CM group and LPS-AS-CM + Noggin group at 4 weeks post-injury