About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Clue to Regrowing Nerve Cells Identified

by Bidita Debnath on November 10, 2013 at 10:33 PM
Font : A-A+

 Clue to Regrowing Nerve Cells Identified

At Washington University School of Medicine in St. Louis, researchers have identified a chain reaction that triggers the regrowth of some damaged nerve cell branches.

A discovery that one day may help improve treatments for nerve injuries that can cause loss of sensation or paralysis.

Advertisement

The scientists also showed that nerve cells in the brain and spinal cord are missing a link in this chain reaction. The link, a protein called HDAC5, may help explain why these cells are unlikely to regrow lost branches on their own. The new research suggests that activating HDAC5 in the central nervous system may turn on regeneration of nerve cell branches in this region, where injuries often cause lasting paralysis.

"We knew several genes that contribute to the regrowth of these nerve cell branches, which are called axons, but until now we didn't know what activated the expression of these genes and, hence, the repair process," said senior author Valeria Cavalli, PhD, assistant professor of neurobiology. "This puts us a step closer to one day being able to develop treatments that enhance axon regrowth."
Advertisement

The research appears Nov. 7 in the journal Cell.

Axons are the branches of nerve cells that send messages. They typically are much longer and more vulnerable to injury than dendrites, the branches that receive messages.

In the peripheral nervous system - the network of nerve cells outside the brain and spinal column - cells sometimes naturally regenerate damaged axons. But in the central nervous system, comprised of the brain and spinal cord, injured nerve cells typically do not replace lost axons.

Working with peripheral nervous system cells grown in the laboratory, Yongcheol Cho, PhD, a postdoctoral research associate in Cavalli's laboratory, severed the cells' axons. He and his colleagues learned that this causes a surge of calcium to travel backward along the axon to the body of the cell. The surge is the first step in a series of reactions that activate axon repair mechanisms.

In peripheral nerve cells, one of the most important steps in this chain reaction is the release of a protein, HDAC5, from the cell nucleus, the central compartment where DNA is kept. The researchers learned that after leaving the nucleus, HDAC5 turns on a number of genes involved in the regrowth process. HDAC5 also travels to the site of the injury to assist in the creation of microtubules, rigid tubes that act as support structures for the cell and help establish the structure of the replacement axon.

When the researchers genetically modified the HDAC5 gene to keep its protein trapped in the nuclei of peripheral nerve cells, axons did not regenerate in cell cultures. The scientists also showed they could encourage axon regrowth in cell cultures and in animals by dosing the cells with drugs that made it easier for HDAC5 to leave the nucleus.

When the scientists looked for the same chain reaction in central nervous system cells, they found that HDAC5 never left the nuclei of the cells and did not travel to the site of the injury. They believe that failure to get this essential player out of the nucleus may be one of the most important reasons why central nervous system cells do not regenerate axons.

"This gives us the hope that if we can find ways to manipulate this system in brain and spinal cord neurons, we can help the cells of the central nervous system regrow lost branches," Cavalli said. "We're working on that now."

Cavalli also is collaborating with Susan Mackinnon, MD, the Sydney M. Shoenberg Jr. and Robert H. Shoenberg Professor of Surgery, chief of the Division of Plastic and Reconstructive Surgery and a pioneer in peripheral nerve transplants. The two are investigating whether HDAC5 or other components of the chain reaction can be used to help restore sensory functions in nerve grafts.

Funding from the National Institutes of Health (DE022000 and NS082446), the McDonnell Center for Cellular and Molecular Neurobiology, the Hope Center for Neurological Disorders and the National Research Foundation of Korea supported this research.

Cho Y, Sloutsky R, Naegle KM, Cavalli V. Injury-induced HDAC5 nuclear export is essential for axon regeneration. Cell, online Nov. 7, 2013.

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked sixth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

Source: Newswise
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
Sensory Processing Disorder (SPD)
First Dose of COVID-19 Vaccines May Improve Mental Health
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Parkinsons Disease Surgical Treatment Brachial Plexus Injury 

Recommended Reading
Blocking Nerve Cells Could Help Curb Eczema
A new link between the immune and nervous system which lead to itching an inflammation during ......
Botox Helps NIH Identify New Role of Molecules Used by Nerve Cells in Brain
Botox has proven to be a valuable agent for researchers at National Institutes of Health who have .....
What Makes Nerve Cells So Strong? Read On To Know The Answer
How do nerve cells keep from rupturing or falling apart when they can be up to three feet long in .....
Brachial Plexus Injury
Brachial plexus is a network of nerves that transmits signals from the spine to shoulder, arm and .....

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use