The Neuroprotective Effects of Reg-2 Following Spinal Cord Transection Injury

This study was designed to elucidate the potential neuroprotective effects of Reg-2 (regeneration gene protein 2) in a rodent model of spinal cord transection injury at the ninth thoracic level. Reg-2 at 100 and 500 mu g, recombinant rat ciliary neurotrophic factor, or vehicle were delivered intrathecally using Alzet miniosmotic pumps. We found that Reg-2 treatment significantly reduced neuronal death in the spinal cord. There was also an attenuation of inflammation at the injury site and an increase in white matter sparing and retained myelination. Retrograde tracing revealed that Reg-2 protected axons of long descending pathways at 6 weeks post-SCI, and the number of FluoroGold-labeled neurons in spinal and supraspinal regions was also significantly increased. Immunofluorescent staining confirmed that the spared white matter contained neurofilament-positive axons. Moreover, behavioral improvements were revealed by Basso Beattie Bresnahan locomotor rating scores and grid-walk analysis. These results suggest that Reg-2 might promote functional recovery by increasing axonal growth, inhibiting neuronal apoptosis, and attenuating spinal cord secondary injury after SCI. Anat Rec, 294:24-45, 2011. (C) 2010 Wiley-Liss, Inc.