Wednesday January 26 2:06 PM ET
By Patricia Reaney
LONDON (Reuters) - Scientists have identified a protein that prevents damaged cells in the brain and spinal cord from regenerating in a discovery that could offer new hope for people paralyzed by stroke or spinal cord injuries.
Unlike tissue in many parts of the body that can repair itself, nerve cells survive injury but the axons or wires that connect them and transmit nerve impulses are severed and do not grow back.
But in three reports in the science journal Nature, scientists in Britain, the United States and Switzerland said an inhibitory protein called Nogo is one of the reasons why.
"It is very likely that Nogo is one reason why but it might be one of several reasons why,'' Stephen Strittmatter, a neurologist at Yale School of Medicine, said in a telephone interview.
Although new experimental therapies for stroke victims and people with spinal cord injuries are still years away, the researchers believe the discovery of the Nogo protein marks a huge advance in the study of neurological disorders.
"It opens up the possibility of allowing axon regeneration to happen in the brain and spinal cord. That is the promise of it. There are many things to be done before that promise is realised,'' he added.
Strittmatter and his Yale colleagues and scientists at Harvard Institutes of Medicine in Boston showed that the Nogo protein generated in the laboratory stops axon growth.
Martin Schwab and scientists at the University of Zurich and the Swiss Federal Institute of Technology and Dr Frank Walsh, who led the team at British drugs giant Smithkline Beecham, reported similar findings about Nogo.
"Now that we have the structure of the Nogo protein we can move on and hopefully identify more specific and more effective ways of neutralizing or inhibiting the effects of Nogo,'' Walsh told Reuters.
The researchers are not sure how the protein works nor how to block its function. That's the next step.
The SmithKline Beecham team have produced Nogo protein in the laboratory to assess its importance. They will also screen Nogo against libraries of genes to try to find receptors to which the protein binds.
In a commentary on the research papers in Nature, J.L. Goldberg and
B.A. Barnes of Stanford University School of Medicine in California described
the Nogo findings as "a landmark step on a long road toward treatments
for patients suffering from neurological conditions, including spinal-cord
injury and stroke.''