Re: new hope for those with alzheimer's (or down syndrome)

[Guest guest]

Thanks, Kathy

Below are a few more links to the article that you posted.

My links identify the enzyme, I was curious.

Marsha

http://www.alzinfo.org/09/alzheimers/gsap

http://www.nature.com/nature/journal/v467/n7311/abs/nature09325.html

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http://www.gulf-times.com/site/topics/article.asp?cu_no=2 & item_no=383905 & version\

=1 & template_id=46 & parent_id=26

> New hope for Alzheimer's patients

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> *By Dr Cesar Chelala /New York *

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> A finding by a team of Rockefeller University scientists led by Dr

> Greengard, a Nobel laureate, throws light on an important feature of

> Alzheimer's disease. The finding may result in better treatment for both

> this disease and for patients with Down syndrome. Better treatment for both

> diseases could improve the lives of millions of people worldwide.

>

> Patients with both Alzheimer's disease and with Down syndrome have an

> accumulation of a protein called beta-amyloid in their brains. The

> accumulation of this substance is believed to initiate the pathological

> changes (among them the plaque that builds up in the brains of people with

> Alzheimer's) leading to brain dysfunction, cell death and dementia. The

> hallmark lesions (tangles and plaques) of Alzheimer's disease are also

> present in all adults with Down syndrome after the age of 40, suggesting a

> shared genetic susceptibility to both.

>

> Although it wasn't known if beta-amyloid played a role in mental

> retardation, particularly in Down syndrome patients, the Rockefeller

> scientists worked under the hypothesis that it could have an effect. If this

> were true, they reasoned, lowering levels of beta-amyloid could result in an

> improvement of symptoms.

>

> Dr Greengard and his collaborators found an enzyme (enzymes are proteins

> that speed up chemical reactions) that stimulates the production of

> beta-amyloid. In the new study, led by Gen He, a research associate in

> Greengard's lab, the researchers showed that the enzyme stimulates

> production of beta-amyloid in cell lines, and that reducing it brings down

> beta-amyloid. That enzyme could thus be an important target for the

> development of new drugs against Alzheimer's disease.

>

> To test the hypothesis that increased beta-amyloid could be responsible for

> the symptoms of mental retardation, Dr Greengard and his colleagues tested a

> compound which is known to suppress the production of beta-amyloid in a

> mouse model with Down syndrome. Mice treated with this compound not only had

> a rapid reduction of beta-amyloid but also showed a significant improvement

> in their ability to learn to navigate a water maze. They were also able show

> some other signs of improved mental functioning. The control group used did

> not show any of these effects.

>

> In another set of experiments, Dr Greengard and his colleagues developed a

> strain of mice that had a gene for Alzheimer's. When they blocked the gene

> for the enzyme that increases the production of beta-amyloid, the animals

> didn't develop plaque in their brains.

>

> Reality in science is always more complex than anticipated, though. The

> compounds used to lower the levels of beta-amyloid have generally some

> serious toxic side effects. Only one of these compounds, the anti-cancer

> drug Gleevec, used to treat a rare form of leukaemia, was able to lower

> beta-amyloid without toxic side effects. The problem with Gleevec, though,

> is that it doesn't remain in the brain long enough to treat either

> Alzheimer's disease or Down syndrome. The importance of Gleevec, according

> to Dr Greengard, is that it may provide a model for developing new

> anti-beta-amyloid drugs.

>

> The discovery of a new target for these drugs is a new and significant

> development in the treatment of Alzheimer's disease and Down syndrome, both

> of which affect millions of people worldwide. Only in the US, it is

> estimated that approximately 4mn Americans are affected by Alzheimer's

> disease.

>

> In what until recently had been an almost hopeless situation, the

> discoveries of Dr Greengard and his colleagues shed a new light into

> what had been until now a rather dismal situation.

>

>

>

> *** Dr Cesar Chelala, an international public health consultant, conducted

> research in microbial genetics at the Public Health Research Institute of

> the City of New York.

> Send

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