Researchers discover nerve repair mechanism

May 29, 2018, Asociacion RUVID

The research group of the Physiology Department of Elche's Universidad Miguel Hernández (UMH), Hugo Cabedo, has discovered how peripheral nerves induce the repair of the myelin sheath so that communication is properly restored following an injury. This finding could provide clues toward repairing the spinal cord.

Unlike what happens to the spinal cord after an injury, the have significant self-repair capabilities. After an injury, the nerve ending goes through a specialised biological process aimed at creating the required conditions to regenerate. However, it is a slow process that can occasionally go wrong. Understanding how this process works is important to reduce recovery time and take action when it is not happening appropriately.

Spontaneous repair of the peripheral nerves is possible thanks to Schwann cells, which cover the with an insulating layer of . This greasy layer protects nerves and increases the transmission speed of nerve impulses. The research group headed by UMH professor Hugo Cabedo has just discovered how the nerve (axon) induces the production of the myelin layer by the Schwann cell, so that communication is properly restored after damage.

Cabedo says, "Schwann cells play a very important role in the peripheral nervous system by way of a strictly regulated process of differentiation and dedifferentiation, a feature which no other nervous system cell has. This makes them very versatile, and allows them to go from a state in which they produce myelin, to another, less differentiated, in which they contribute towards repairing the damaged nerve."

When damage occurs to a peripheral nerve, such as the one that goes from the spine to the fingers or toes, the Schwann cells temporarily lose the ability to create myelin and go back to a previous developmental state. The objective of this transformation is to help the nerve regenerate and grow again to reach the target tissue. Once the nerve is repaired, the cell recovers its ability to produce myelin once again in order to cover the nerve with the insulating layer and lead to the proper transmission of .

In this process, as Cabedo's research team has discovered, a chemical messenger called cyclic AMP plays a vital role. Hugo Cabedo says, "Cyclic AMP sends a protein called histone deacetylase 4 to the nucleus of Schwann cells, which, once the nerve is repaired, restarts myelination. This is achieved by inactivating the c-Jun gene, which in standard conditions, blocks the production of myelin. Inactivation of the c-Jun gene is necessary and sufficient in order to activate the genes that produce myelin to cover the regenerated nerve."

This process makes it possible to spontaneously repair a nerve or, in some cases, to re-implant a severed finger, for example. "If you sever a peripheral nerve and the surgeon sews it back together properly, it ends up regenerating. Although the deteriorate, the Schwann cells, which are still present, turn into repair cells and help the nerve reach the target tissues once again. Once the nerve reaches its destination, the Schwann cell turns once again into a myelin producer to add the insulation layer. Unfortunately, in larger nerves, and the associated clinical evolution is not complete, which has lifelong consequences," said Cabedo. This finding can facilitate the treatment of peripheral injuries, such as those that take place in road accidents.

This work could contribute to the treatment of some diseases in which myelin is deteriorated, such as Charcot-Marie-Tooth, which has a genetic origin. It can also be relevant in relation to the Guillain-Barré syndrome, a neurological disorder that takes place following an infection, in which the immune system suddenly attacks the Schwann cells.

Explore further: Glial cells assist in the repair of injured nerves

Related Stories

Glial cells assist in the repair of injured nerves

January 28, 2013
When a nerve is damaged, glial cells produce the protein neuregulin1 and thereby promote the regeneration of nerve tissue.

Schwann cells 'dine in' to clear myelin from injured nerves

July 6, 2015
Researchers reveal how cells in the peripheral nervous system (PNS) degrade myelin after nerve injury, a process that fails to occur in the central nervous system (CNS). The study appears in The Journal of Cell Biology.

Scientists find RNA with special role in nerve healing process

August 22, 2017
Scientists may have identified a new opening to intervene in the process of healing peripheral nerve damage with the discovery that an "anti-sense" RNA (AS-RNA) is expressed when nerves are injured. Their experiments in mice ...

It takes a lot of nerve: Scientists make cells to aid peripheral nerve repair

August 6, 2015
Scientists at the University of Newcastle, UK, have used a combination of small molecules to turn cells isolated from human skin into Schwann cells - the specialised cells that support nerves and play a role in nerve repair. ...

Experimental therapy restores nerve insulation damaged by disease

February 12, 2018
When the body attacks its own healthy tissues in an autoimmune disease, peripheral nerve damage handicaps people and causes persistent neuropathic pain when insulation on healing nerves doesn't fully regenerate.

New research may pave the way for peripheral nerve damage repair

January 30, 2017
Research published today, 30th January 2017 online in the Journal of Cell Biology, has for the first time identified how a bodily protein allows nerves of the peripheral nervous system (PNS) to repair following injury.

Recommended for you

Automated detection of focal epileptic seizures in a sentinel area of the human brain

August 17, 2018
Patients with focal epilepsy that does not respond to medications badly need alternative treatments.

People are more honest when using a foreign tongue, research finds

August 17, 2018
New UChicago-led research suggests that someone who speaks in a foreign language is probably more credible than the average native speaker.

CRISPR technology targets mood-boosting receptors in brain

August 17, 2018
An estimated 13 percent of Americans take antidepressant drugs for depression, anxiety, chronic pain or sleep problems. For the 14 million Americans who have clinical depression, roughly one third don't find relief with antidepressants.

Critical role of DHA on foetal brain development revealed

August 17, 2018
Duke-NUS researchers have found evidence that a natural form of Docosahexaenoic Acid (DHA) made by the liver called Lyso-Phosphatidyl-Choline (LPC-DHA), is critical for normal foetal and infant brain development, and that ...

Brain response study upends thinking about why practice speeds up motor reaction times

August 16, 2018
Researchers in the Department of Physical Medicine and Rehabilitation at Johns Hopkins Medicine report that a computerized study of 36 healthy adult volunteers asked to repeat the same movement over and over became significantly ...

Men and women show surprising differences in seeing motion

August 16, 2018
Researchers reporting in the journal Current Biology on August 16 have found an unexpected difference between men and women. On average, their studies show, men pick up on visual motion significantly faster than women do.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.