Human NgR-Fc decoy protein via lumbar intrathecal bolus administration enhances recovery from rat spinal cord contusion

J Neurotrauma. 2014 Dec 15;31(24):1955-66. doi: 10.1089/neu.2014.3355. Epub 2014 Oct 16.


Axonal growth and neurological recovery after traumatic spinal cord injury (SCI) is limited by the presence of inhibitory proteins in myelin, several of which act via the NgR1 protein in neurons. A truncated soluble ligand-binding fragment of NgR1 serves as a decoy and promotes recovery in acute and chronic rodent SCI models. To develop the translational potential of these observations, we created a human sequence-derived NgR1(310)-Fc protein. This protein is active in vitro. When the human NgR1 decoy is administered by continuous intracerebroventricular infusion to rats with a spinal contusion injury at doses of 0.09-0.53 mg/kg/d, neurological recovery is improved. Effective doses double the percentage of rats able to bear weight on their hindlimbs. Next, we considered the half-life and distribution of NgR1(310)-Fc after bolus delivery to the lumbar intrathecal space. The protein is found throughout the neuraxis and has a tissue half-life of approximately 2 days in the rat, and 5 days in the nonhuman primate. At an intermittent, once every 4 day, lumbar bolus dosing schedule of 0.14 mg/kg/d, NgR1(310)-Fc promoted locomotor rat recovery from spinal cord contusion at least as effectively as continuous infusion in open field and grid walking tasks. Moreover, the intermittent lumbar NgR1(310)-Fc treatment increased the growth of raphespinal axons into the lumbar spinal cord after injury. Thus, human NgR1(310)-Fc provides effective treatment for recovery from traumatic SCI in this preclinical model with a simplified administration regimen that facilitates clinical testing.

Keywords: Nogo; Nogo receptor; contusion; myelin; pharmacokinetics; translational science; traumatic spinal cord injury.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Female
  • GPI-Linked Proteins / administration & dosage
  • Humans
  • Injections, Spinal
  • Myelin Proteins / administration & dosage*
  • Neuroprotective Agents / administration & dosage*
  • Nogo Receptor 1
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cell Surface / administration & dosage*
  • Receptors, Fc / administration & dosage*
  • Recombinant Proteins / administration & dosage
  • Recovery of Function / drug effects*
  • Spinal Cord Injuries / drug therapy*


  • GPI-Linked Proteins
  • Myelin Proteins
  • Neuroprotective Agents
  • Nogo Receptor 1
  • RTN4R protein, human
  • Receptors, Cell Surface
  • Receptors, Fc
  • Recombinant Proteins