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

Abstract

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, 293:464-476, 2010. V V C 2010 Wiley-Liss, Inc.

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

“…Our data suggest that Reg-2 is essential for survival and neurite outgrowth of developing spinal cord neurons, and it plays a protective effect on spinal cord neurons against following in vitro injury (Fang et al, 2010).…”

“…The addition of the Reg-2 into the culture media after peroxide treatment or cellular hypoxia insult induced by mitochondrial poisoning reduced lactate dehydrogenase levels and cell death. Our data suggest that Reg-2 is essential for survival and neurite outgrowth of developing spinal cord neurons, and it plays a protective effect on spinal cord neurons against following in vitro injury (Fang et al, 2010).…”

“…The addition of the Reg-2 into the culture media after peroxide treatment or cellular hypoxia insult induced by mitochondrial poisoning reduced lactate dehydrogenase levels and cell death. Our data suggest that Reg-2 is essential for survival and neurite outgrowth of developing spinal cord neurons, and it plays a protective effect on spinal cord neurons against following in vitro injury (Fang et al, 2010).As a continuation of our investigations, the present studies were aimed at determining whether Reg-2 has a neuroprotective effects in vivo using an adult rat spinal cord transection model, because the increase expression of Reg-2 has been detected in both motor and sensory neurons following transection injury of the spinal cord (Fang et al, 2010). The agents were delivered intrathecally into the site of injury over a period of 7 days, and the in vivo effects of Reg-2 at two doses (based on in vitro tested concentrations; Ye et al, 2004;Fang et al, 2010) were compared with CNTF and saline vehicle.…”

“…Reg-2 normally is not expressed in the adult rat central (CNS) or peripheral nervous system (PNS), but it is expressed in a cytokine-dependent manner in both sensory and motor neurons during development (Livesey et al, 1997). Interestingly, Reg-2 is strongly upregulated in the PNS after nerve axotomy or crushing in adult rats, and it is also reexpressed in the CNS during Alzheimer's disease, spinal cord injury (SCI), or inflammation of peripheral motor and sensory nerves (De la Monte et al, 1990;Nishimune et al, 2000;Averill et al, 2002Averill et al, , 2008Fang et al, 2010). The expression of Reg-2 is driven by cytokines including the interleukin-6 family, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor, and cardiotrophin (CT-1; Livesey et al, 1997).…”

“…As a continuation of our investigations, the present studies were aimed at determining whether Reg-2 has a neuroprotective effects in vivo using an adult rat spinal cord transection model, because the increase expression of Reg-2 has been detected in both motor and sensory neurons following transection injury of the spinal cord (Fang et al, 2010). The agents were delivered intrathecally into the site of injury over a period of 7 days, and the in vivo effects of Reg-2 at two doses (based on in vitro tested concentrations; Ye et al, 2004;Fang et al, 2010) were compared with CNTF and saline vehicle.…”