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 , ... The International Association of Eating ... excellence for the field of eating disorders, announces the opening of early registration ... Orlando, Florida at the Omni Resort at ChampionsGate. , The annual ...
(Date:10/13/2017)... LUIS OBISPO, Calif. (PRWEB) , ... October 13, 2017 , ... ... Alzheimer’s or dementia. However, many long-term care insurance companies have a waiver for care ... is the 90-day elimination period, when the family pays for care, is often waived, ...
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... ... will be giving viewers the lowdown on sciatica in a new episode of ... that focuses on current events and innovation and investigates each subject in-depth with ...
(Date:10/12/2017)... ... 12, 2017 , ... CitiDent and San Francisco dentists, Dr. ... Oventus O2Vent technology. As many as 18 million Americans are estimated to suffer ... Oral appliances can offer significant relief to about 75 percent of people with ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... AccentCare, a leader in post-acute health care, have expanded their existing home health ... Home Health. , AccentCare has been operating a joint venture home health company ...
Breaking Medicine News(10 mins):
(Date:10/12/2017)... , Oct. 12, 2017 AVACEN Medical ... the company with their  2017 New Product Innovation Award ... on extensive primary and secondary medical device market research by ... through its first-to-market OTC, drug-free pain relief product, the AVACEN ... approach to treating fibromyalgia widespread pain. ...
(Date:10/11/2017)... Oct. 11, 2017  True Health, a leader ... its effort during National Breast Cancer Awareness month ... risks. Research ... calculated that more than 10 million American women ... in BRCA1 or BRCA2 and have not had testing. ...
(Date:10/5/2017)... Oct. 5, 2017  In response to the ... and Maxillofacial Surgeons (AAOMS) released prescribing recommendations that ... be used as a first-line therapy to manage ... Recognizing the value and ... Paper "Opioid Prescribing: Acute and Postoperative Pain Management" ...
Breaking Medicine Technology: