Navigation Links
New Pathways Studied to Repair Nerves
Date:11/6/2008

Two different approaches seek to interfere with mechanisms that inhibit cell regeneration

THURSDAY, Nov. 6 (HealthDay News) -- Nerve cells in the spinal cord and brain can't be repaired now if they are severed or damaged, but two ways to get them to grow again are being proposed by separate groups of researchers.

The basic idea of both approaches is to interfere with the built-in mechanisms that prevent nerve cell regeneration. One approach attacks it from the outside of nerve cells, the other from the inside.

Zhigang He, an associate professor of neurology at Children's Hospital Boston, a teaching affiliate of Harvard University, compared the two approaches to different ways of starting a stalled auto.

"Their idea is that something is blocking the highway," said He, lead author of one of the two papers in the Nov. 7 issue of Science. "Our mechanism deals with possible engine trouble."

Growth controls are built into the genes of nerve cells, He said. His group has identified two of the key genes that inhibit the major growth pathway in nerve cells. When those two genes are knocked out, cells that are damaged or severed can grow new axons, the pathways that carry messages from cell to cell.

A study in which mice whose optic nerves were damaged showed up to 50 percent of those cells engineered to lack the two growth-inhibiting genes survived, compared to 20 percent of the cells carrying those genes. Significant axon growth was seen in up to 10 percent of the mice lacking the genes.

Genetic engineering is not necessary to achieve that kind of nerve growth, He said. "In the future, we could have small-molecule drugs to activate these pathways," He said. "Other people have studied this pathway already, and there are quite a few possible targets."

He's group has started to work with some candidate compounds. "It's too early to say if these compounds would be effective," he said. "We don't know about toxicity, that sort of thing. We have lots of work to do."

A second paper by researchers at the San Francisco-based biotechnology company Genentech looked at the growth-preventing mechanism built into myelin, the protective sheath that surrounds nerve cells. They have identified a previously unknown receptor for the growth-preventing molecules in myelin. Block that receptor, and growth can be restored, said Marc Tessier-Lavigne, executive vice president of research drug discovery at Genentech.

"This is a mechanism we can try to target," Tessier-Lavigne said. The paper describes a molecule that has blocked the receptor in mice. "Now we are working on a human protein."

Both approaches require more work, said Dr. William D. Snider, director of the University of North Carolina Neurosciences Institute, and co-author of an accompanying editorial.

The idea of blocking growth-preventing genes "is a very clever way of restoring normal levels of proteins," Snider said, but he was cautious, because all the work reported in the paper was done in mice.

"Mice are extremely small animals when you compare their nervous systems to humans," Snider said. "Work in primates might be more relevant. Those of us who have been in the field for a while are extremely cautious about extrapolating from mice."

The Genentech myelin approach is not new, Snider noted. "People have known in general that myelin down-regulates nerve cell growth capacity, although they're not certain why that is true," he said. One belief is that the myelin mechanism is designed to prevent errors at times when there is a major change in the central nervous system. Knowledge of a new receptor that governs nerve cell growth could be of practical value, Snider said.

More information

The workings of nerve cells are explained by the U.S. National Institute of Neurological Disorders and Stroke.



SOURCES: Zhigang He, Ph.D., associate professor, neurology, Children's Hospital Boston; Marc Tessier-Lavigne, Ph.D., executive vice president, research drug discovery, Genentech Inc., South San Francisco; William D. Snider, M.D., director, University of North Carolina Neurosciences Institute, Chapel Hill; Nov. 7, 2008, Science


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Embryonic Pathways Induce Stem Cell Traits
2. Breast cancer subtypes originate from different biological pathways
3. Stem Cell Marker Controls Pair of Key Cancer Pathways
4. Georgetown researchers find stem cell marker controls 2 key cancer pathways
5. Different Neural Pathways at Work Going Under, Coming Out of Anesthesia
6. Post-partum suicide attempt risks studied
7. Fish oil and red yeast rice studied for lowering blood cholesterol
8. Effects of healing touch therapy being studied
9. No difference in sleep of OSA patients studied in a hospital vs. a hotel-based sleep center
10. Eltrombopag studied in Idiopathic Thrombocytopenic Purpura
11. New treatment option studied for bladder cancer
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New Pathways Studied to Repair Nerves
(Date:10/13/2017)... , ... October 13, 2017 ... ... of Pharmacy (SOP) alumni Hannah Randall, PharmD ‘17, and Jennifer Huggins, PharmD ... on guideline updates for the primary prevention of cardiovascular diseases during the ...
(Date:10/13/2017)... ... October 13, 2017 , ... Many families have long-term insurance ... care insurance companies have a waiver for care if the client has a cognitive ... the family pays for care, is often waived, so the benefits from their insurance ...
(Date:10/13/2017)... ... , ... Global Healthcare Management’s 4th Annual Kids Fun Run brought out many ... event, sponsored by Global Healthcare Management’s CEO, Jon Letko, is aimed at getting kids ... of all ages; it is a non-competitive, non-timed event, which is all about having ...
(Date:10/13/2017)... ... October 13, 2017 , ... Coveros, a leader ... been awarded a contract by the Center for Medicare and Medicaid Services (CMS). ... the enterprise use of Agile methodologies in a consistent and high value manner ...
(Date:10/12/2017)... ... October 12, 2017 , ... First Healthcare Compliance ... management, will showcase a range of technology and learning solutions at the 68th ... and Expo to be held October 14–18, 2017 at the Mandalay Bay Resort ...
Breaking Medicine News(10 mins):
(Date:9/25/2017)... , Sept. 25, 2017   Montrium , ... File solutions, today—from the IQPC Trial Master Files ... , NL)—announced that EastHORN Clinical Services has selected ... programs and TMF management. EastHORN, a leading European ... platform to increase transparency to enable greater collaboration ...
(Date:9/22/2017)... SAN DIEGO , Sept. 22, 2017 ... ll medical device is now successfully helping those with ... Union. Fibromyalgia diagnosed Amanda in ... getting dressed and washing my hair, experiencing no sleep ... body in painful spasm… I cannot recommend [the AVACEN ...
(Date:9/18/2017)... Sept. 18, 2017 EpiVax, Inc. ... bioinformatics and immune engineering, today announced a ... A (H7N9) vaccine. ... seasonal influenza and presents a challenge for ... exposure to be effective. Using state-of-the-art bioinformatics and ...
Breaking Medicine Technology: