Researchers set out to see if MS is reversible

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Researchers set out to see if MS is reversible

http://www.canoe.ca/Health0112/19_ms-cp.html

December 19, 2001

By HELEN BRANSWELL – Canadian Press

TORONTO (CP) -- Is multiple sclerosis reversible? Can the body be

prompted to regenerate myelin and repair the damage the disease

inflicts on the central nervous system?

Those are some of the questions a team of researchers from Canada and

the United States are attempting to answer in a three-year,

$3.5-million research project being led out of Montreal's McGill

University.

At the core of the project is the idea that there may be ways to

prompt stem cells in the brain to turn into cells that produce

myelin,

which would then encase anew the nerve cells left exposed by the

ravages of multiple sclerosis.

" At one point they were clever enough to make myelin. Why aren't they

clever enough now? " explained Dr. Jack Antel, who is co-ordinating

the

research program that involves top MS scientists at McGill, the

universities of Calgary and Toronto, the Mayo Clinic and the

University of Rochester in New York.

Among the questions the researchers will have to answer is why isn't

the body doing this regeneration itself, if cells with this potential

already exist in the brain.

" Is it that as the body has developed, that the environment is such

that it is holding back that process? And there may be reasons why it

wants to hold back that process. So if the environment is keeping the

system under control, change the environment and boost the process, "

said Antel, a clinical neurologist who is co-ordinator of the MS

program at the Montreal Neurologic Institute, one of McGill's

teaching

hospitals.

Multiple sclerosis is the most common disease of the central nervous

system to strike young adults in Canada, affecting an estimated

50,000

people in this country. Women are slightly more likely to develop the

disease than men.

The degenerative disease causes a wide range of unpredictable

symptoms

that may include vision disturbances, extreme fatigue, balance and

speech problems, even paralysis.

MS is believed to be caused by a malfunction of the body's immune

system, which when working properly protects one from invading germs

and bugs.

In people with MS, the immune system mistakenly attacks one's own

myelin, the substance that coats and protects nerves in the brain and

spinal cord. The result is that messages between nerve cells -- " Pick

up the fork " for instance -- slows down and becomes irregular.

Much research has been done to try to find ways to shut down the

destructive process. But until recently, little effort was aimed at

trying to find ways to help repair the damage the disease causes.

Antel said the thinking was that until science could stop the

destruction of the myelin sheath, there was no point trying to create

new myelin.

But that time has come, he believes. He and his colleagues are

betting

that stem cells provide the answer and they've persuaded the Multiple

Sclerosis Scientific Research Foundation -- an offshoot of the MS

Society of Canada -- to fund their quest.

Also known as progenitor cells, these are primitive cells that have

the potential to develop into any type of cell in the body -- brain

cells, heart cells, or liver cells, for instance.

" You can think of them at the level of cells that haven't decided

what

they want to become, " Antel explained.

Because of their huge potential, stem cells are the subject of a vast

amount of research into a wide range of ailments.

There are two basic approaches to stem cell research. One involves

transplanting stem cells from an external source into a recipient --

a

controversial line of research as the stem cells are taken from

fetuses. The second involves tapping the potential of the body's own

stem cells.

Antel and his colleagues have opted for the latter, side-stepping

both

controversy and the tricky problem of getting the cells to the site

of

the injury.

But they must figure out ways to trigger differentiation -- the

process by which a stem cell chooses to become a distinct type of

adult cell.

Researchers at the University of Toronto and the University of

Rochester are trying to figure out whether there are growth factors

that could be used to encourage the stem cells to become

myelin-producing cells.

Other members of the team are trying to figure out why some stem

cells

begin the process of differentiation into myelin-producing cells but

stop at an immature level. (There is evidence that some remyelination

happens naturally, but the body appears unable to keep pace with the

destruction wreaked by the disease.)

They also want to find out whether the partially differentiated cells

are a more promising target than the totally undifferentiated stem

cells.

Still another, at the Mayo Clinic, is trying to figure out if there

are ways to significantly increase the numbers of these types of

cells, which appear to be in limited supply in the brain.

If the research proves fruitful, it will be a key compliment to

existing therapies aimed at shutting down the disease process. That's

because considerable damage to the central nervous system is already

done by the time doctors realize someone has multiple sclerosis.