Interesting story: Scientists Find Protein Key to Alzheimer's
By Maggie Fox
Reuters Health and Science Correspondent
Thursday, October 21, 1999; 10:09 a.m. EDT
WASHINGTON ? Researchers have found a protein essential to the
development of Alzheimer's disease, and say that drugs similar to those that
have helped subdue the AIDS virus might be used to treat the brain-destroying
Alzheimer's.
Although such drugs will not be on the market for years, the researchers, at
California-based Amgen Inc. and the Harvard Medical School in Boston, say
their discovery gives them a target to aim for.
Writing Friday's edition of the journal Science, the researchers say the protein,
which they have called BACE, allows other brain proteins to turn into the
harmful form that marks Alzheimer's disease.
"The problem with Alzheimer's disease is that there is no effective treatment,"
said Martin Citron of Amgen, who led the research, in a telephone interview.
Alzheimer's, which affects about four million people in the United States,
including former President Ronald Reagan, starts with memory loss and
progresses to profound dementia and death. There is no cure, although a few
drugs can slow its progression.
The ailment is marked by brain clots known as amyloid plaques, and tangles of
nerve cells.
A peptide, or protein fragment, known as amyloid beta peptide is believed to
be key to the development of these plaques.
"OVERWHELMING EVIDENCE" FOR ROLE
"There has been overwhelming evidence over the last six years or so that the
beta peptide that forms amyloid plaques plays an early and critical role in the
disease," Citron said.
This peptide is cut, or cleaved, off a larger protein known as amyloid
precursor protein. It was known that two special slicing proteins, known as
proteases, did this. But no one could find them.
Citron's team said they have now identified one of these two proteases. Their
protease, BACE, cuts, or cleaves, the amyloid precursor protein. The next
step, Citron said, is to come up with a compound that stops it from doing this.
Such a compound might even be a protease inhibitor similar to the drugs that,
when added to cocktails of other drugs, have helped keep HIV infection at
manageable levels in thousands of patients.
"We think the same kind of inhibitor development strategy might be useful. We
are interested in that," Citron said.
But unlike the HIV protease inhibitors, one designed to work against
Alzheimer's might work on its own.
"HIV is an infectious agent and it mutates at a very rapid pace whereas this
one is not an infectious agent," Citron said. "There is a possibility that a
protease inhibitor alone could do it. But only clinical trials could show that."
Such trials would be years away. Citron declined to comment if Amgen had
started trials of such compounds in animals, or whether the company had
patented its discovery. |
