Effects of Reg‐2 on Survival of Spinal Cord Neurons In Vitro

Regeneration gene protein 2 (Reg‐2) is a small secreted protein expressed in motor and sensory neurons of spinal cord during developmental stages and following injury of peripheral nerves. Reg‐2 appears to act as a neurotrophic factor and protects injured neurons from death during regeneration. To illustrate these potential protective effects in vitro, we investigated the blocking effects of Reg‐2 antibodies on the survival of primary cultured spinal cord neurons and astrocytes, as well as on neurite outgrowth. In addition, the effects of Reg‐2 in neuron injury models induced by peroxide and mitochondrial poisoning were assessed. Our results showed that Reg‐2 antibody markedly reduced survival and neurite outgrowth from neurons, whereas astrocyte survival was unaffected. Addition of Reg‐2 into the culture medium had no effect on neuron survival or neurite outgrowth. However, the addition of the Reg‐2 into culture media after peroxide treatment or cellular hypoxia insult induced by mitochondrial poisoning can reduce lactate dehydrogenase release levels and cell death. Thus, the data suggests that Reg‐2 is essential for the survival and neurite outgrowth of developing spinal cord neurons but not the survival of glial cells, and that Reg‐2 plays protective effects on spinal cord neurons against injury in vitro. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.