Fig. 10. The mechanism of SCDEs containing MFG-E8 modify macrophage/microglial polarization through SOCS3/STAT3 pathway after SCI.

Spinal cord injury induced activation of STAT3 phosphorylation in macrophages/microglia, led to M1 polarization and exacerbated inflammatory damage at the site of spinal cord injury. After treatment with SCDEs, they were phagocytosed by macrophages/microglia at the injury site and began to release MFG-E8. This increased the protein levels of SOCS3, which inhibited the phosphorylation of STAT3 to promote the conversion of the macrophage/microglia phenotype to M2 for alleviating inflammatory damage. Moreover, the improved inflammatory microenvironment at the SCI site reduced neuronal apoptosis and promoted nerve regeneration.