- Lynda J-S Yang: Department of Neurosurgery, University of Michigan Health System, Ann Arbor, MI 48109-5338, USA. ljsyang@med.umich.edu
OBJECTIVE: To increase awareness of the advancements in nerve regeneration.
METHODS: Review of the literature regarding inhibitors of nerve outgrowth and presentation of potential agents that reverse the inhibition, thereby promoting nerve regeneration.
RESULTS: The injured adult central nervous system (CNS) inhibits axon outgrowth, thereby limiting recovery from traumatic injury. Axon regeneration inhibitors (ARIs) that contribute to inhibition of recovery include myelin-associated glycoprotein, Nogo, oligodendrocyte-myelin glycoprotein and chondroitin sulfate proteoglycans. The ARIs bind to specific receptors on the axon growth cone to halt outgrowth; consequently, reversing or blocking the actions of ARIs may promote recovery after CNS injury. Sialidase, an enzyme that cleaves one class of axonal receptors for myelin-associated glycoprotein, enhances spinal axon outgrowth into implanted peripheral nerve grafts in a rat model of brachial plexus avulsion, a traumatic injury in which nerve roots are torn from the spinal cord.
CONCLUSION: Repair using peripheral nerve grafts is a promising restorative surgical treatment in humans, although functional improvement remains limited. Molecular therapies targeting ARIs may aid functional recovery after brachial plexus avulsion or other nervous system injuries and diseases.