Neuroegulin-1 enables spinal cord repair
After a spinal cord injury the central nervous system has some limited capacity to repair itself naturally. Understanding what drives this repair mechanism could aid the development of new treatment strategies. Using ‘tools’ that the spinal cord already possesses these treatments could aim at boosting the self-healing capacity of the injured spinal cord.
For the first time researchers from King’s and Oxford, Professor Elizabeth Bradbury and Professor David Bennett, have identified one of these tools, neuregulin-1. With the help of Wings for Life funding they discovered that it signals from the surface of damaged nerve fibres during a process called ‘spontaneous remyelination.’
Spontaneous remyelination is a period of natural regeneration that happens in the weeks following a spinal cord injury. The process takes place as a result of damage to spinal nerve fibres which have lost their insulating ‘myelin sheath’. However, this natural capacity for repair is not sufficient for full recovery.
In today’s issue of Brain the researchers report that, when the neuregulin-1 gene is absent, spontaneous myelin repair was completely prevented and spinal nerve fibres remained demyelinated (i.e. unable to send nerve signals along the spinal cord). Moreover, the functional outcome (walking, balance, coordinated movements) after spinal cord injury was worse without neuregulin-1.
Not only did neuregulin-1 drive spontaneous remyelination, but it also served as a molecular switch for cells within the spinal cord to transform themselves into cells with remyelinating capacity. This is unusual, according to the researchers, because the ‘Schwann’ cells with new remyelinating capacity normally only myelinate nerve fibres in the peripheral nervous system – not the central nervous system, as observed here.
Dr Katalin Bartus, also from the Institute of Psychiatry, Psychology & Neuroscience at King’s College London, said: ‘We hope this work will provide a platform for future research, in which it will be important to test how enhancing levels of neuregulin-1 will improve functional outcome after spinal cord injury.’