SCO-Spondin-Derived Peptide NX210 Promotes Functional Recovery after Spinal Cord Injury in Mice

Abstract

Spinal cord injury (SCI) represents a major public health issue, as the consequences are often irreversible with no treatment currently available. This results in a growing population living with long-lasting motor, sensory, and/or autonomic impairments directly related to their SCI. Here, we have evaluated the therapeutic potential of a thrombospondin repeats peptide analogue, named NX210, in a mouse hemisection model of SCI. Adult female mice were subjected to a thoracic level 8 dorsal hemisection, and treated with intraperitoneal injections of NX210 starting at 4 h post-injury and then twice a week at 4, 8, or 16 mg/kg. Hind limb motor function was assessed once a week for 10 weeks post-injury using the Basso Mouse Scale (BMS) score and sub-score, the rotarod, and the activity chamber tests. Mice were then sacrificed, and the spinal cords were collected for immunohistochemistry. Interestingly, NX210 improved functional recovery (BMS score and sub-score, latency to fall from the rotarod, spontaneous locomotor activity) with rapid rises in function that were maintained throughout the 10-week study. This was accompanied by a reduction of nociceptive reactivity assessed by the tail flick test. NX210 treatment also increased myelin basic protein and reduced neuron/glial antigen 2 at the injury site 10 weeks post-injury while no significant effects were observed on lesion size, inflammation, and neuron survival. Overall, this study highlights a potential new therapeutic strategy to promote repair and decrease long-lasting functional impairments after SCI.

Keywords: SCO-spondin; dorsal hemisection; motor function; neuroprotection; pain; repair; therapeutics.