Methylprednisolone promotes recovery of neurological function after spinal cord injury:association with Wnt/β-catenin signaling pathway activation

Some studies have indicated that the Wnt/β-catenin signaling pathway is activated following spinal cord injury,and expression levels of specific proteins,including low-density lipoprotein receptor related protein-6 phosphorylation,β-catenin,and glycogen synthase kinase-3β,are significantly altered.We hypothesized that methylprednisolone treatment contributes to functional recovery after spinal cord injury by inhibiting apoptosis and activating the Wnt/β-catenin signaling pathway.In the current study,30 mg/kg methylprednisolone was injected into rats with spinal cord injury immediately post-injury and at 1 and 2 days post-injury.Basso,Beattie,and Bresnahan scores showed that methylprednisolone treatment significantly promoted locomotor functional recovery between 2 and 6 weeks post-injury.The number of surviving motor neurons increased,whereas the lesion size significantly decreased following methylprednisolone treatment at 7 days post-injury.Additionally,caspase-3,caspase-9,and Bax protein expression levels and the number of apoptotic cells were reduced at 3 and 7days post-injury,while Bcl-2 levels at 7 days post-injury were higher in methylprednisolone-treated rats compared with saline-treated rats.At 3 and 7 days post-injury,methylprednisolone up-regulated expression and activation of the Wnt/β-catenin signaling pathway,including low-density lipoprotein receptor related protein-6 phosphorylation,β-catenin,and glycogen synthase kinase-3β phosphorylation.These results indicate that methylprednisolone-induced neuroprotection may correlate with activation of the Wnt/β-catenin signaling pathway.