Sulfatide is the major lipid component of the myelin sheath. Our previous study reported that the gene expression of sulfatide synthase was increased in the spinal cord one day after intraplantar injection of complete Freund‘s adjuvant (CFA), indicating the sulfatide accumulation in the spinal cord during inflammation. Intrathecal injection of sulfatide in naïve mice produced mechanical allodynia and spinal glial cell activation.
Previous reports suggest that sulfatide triggers the inflammatory responses in the immune cells and the glial cells. Moreover, sulfatide binds to the cell adhesion molecule, selectin. Thus, we investigated the contribution of selectin to the sulfatide-induced mechanical allodynia. Intrathecal pretreatment of the selectin inhibitor bimosiamose blocked the sulfatide-induced mechanical allodynia, suggesting that sulfatide caused mechanical allodynia by selectin activation. However, the involvement of the spinal selectin in inflammatory pain is unclear. After CFA treatment, the effects of intrathecal injection of bimosiamose on the mechanical threshold were measured. Bimosiamose reversed mechanical allodynia. Our results lead to the hypothesis that up-regulation of the sulfatide synthesis in the spinal cord contributes to the mechanical allodynia via selectin signaling during inflammatory pain.