Davunetide promotes structural and functional recovery of the injured spinal cord by promoting autophagy

After spinal cord injury, programmed cell death is common. In this context, autophagy plays a crucial role in clearing cellular debris, while necroptosis exacerbates neuroinflammation and further damages neural structures. The neuroprotective drug davunetide has shown substantial therapeutic effects on brain diseases, but its role in treating spinal cord injury remains unclear. Therefore, the aim of this study was to investigate the effects of davunetide on cell death after spinal cord injury. To do this, we established a mouse model of spinal cord contusion and administered davunetide intranasally daily at a dose of 0.5 μg/5 μL. Mouse locomotor function was assessed using footprint analysis and Basso Mouse Scale scoring, while the extent of spinal cord injury was evaluated using Masson's trichrome staining. The expression levels of proteins related to locomotor function and spinal cord injury were analyzed by Western blotting and immunofluorescence staining, and protein-protein interactions were evaluated using immunoprecipitation techniques. Our results demonstrated that davunetide not only reduced the size of the injury area but also promoted the recovery of locomotor function after spinal cord injury. Specifically, davunetide exerted its effects by enhancing autophagy and inhibiting necroptosis. Inhibition of autophagy reversed the protective effects of davunetide on necroptosis. Further investigation revealed that davunetide acted through the SIRT1-FOXO1-TFEB signaling pathway, which is key to its therapeutic effects. These findings suggest the potential of davunetide in the treatment of spinal cord injury and provide valuable insights into the underlying mechanisms. This study offers strong scientific evidence to support the development of new therapeutic strategies for spinal cord injury.