Saturday October 31, 1998
New Way Found In U.S. To Grow Human Brain Cells
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Scientists said Friday they had developed a new
way to grow human brain cells for use in transplants,
and said cells grown this way had fixed brain defects in mice.
They hope their new technology can lead to better ways to treat a range
of brain damage, from Parkinson's disease to paralysis
caused by stroke.
Evan Snyder of Harvard Medical School in Boston and colleagues got human
fetal brain cells to grow in a laboratory dish,
transplanted them into the brains of newborn mice -- where they grew and
seemed to work. The mice seemed normal.
There are two achievements here -- the development of the perpetual line
of human brain cells, and getting them to spread around,
grow and operate correctly in the brains of mice.
``This kind of thing can put fetal tissue out of business,'' Snyder, who
reported his findings in the journal Nature Biotechnology, said
in a telephone interview.
Researchers have made headlines by injecting brain cells from aborted
fetuses into the brains of Parkinson's patients, and finding
these cells seem to help the patients.
But the use of fetal tissue is controversial, and getting a good supply
of clean cells at the right time is hard.
Snyder's team used brain cells from a single aborted or miscarried fetus
-- he does not know which -- and got them to grow in the
laboratory. The cells grow and die perpetually.
``We got this tissue and we've never had to go back to a fetus again,''
Snyder said. ``It's a pure culture, abundant, and the cells can
be manipulated. We can do genetic manipulation on them. Perhaps we can
engineer them to be the right cells (for a specific
treatment).''
And the cells are useful, Snyder's team found.
``We wanted to show that they do engraft, they behave normally, the mice
are normal,'' he said. ``These cells should be useful for
human therapies.''
Tests in humans are a long way off, but Snyder ran a battery of trials
in mice to see what the cells can do.
They used mice that had a genetic mutation that leads to the equivalent
of Tay-Sachs disease, an untreatable genetic disease that
causes the brain to deteriorate. Victims die by age 3 or 4.
Human brains cells put into a dish with brain cells from such
genetically engineered mice -- but separated by a membrane --
produced enzymes that corrected the defects in the mouse brain cells.
They them injected their human cells into the brains of mutant mice
known as ``meander tail'' mice. They have a genetic defect
that causes many of their brain cells to be missing.
The human cells grew into their brains and replaced the missing cells.
Although they worked with newborn mice, whose brains are still
developing, Snyder thinks the technique will work in adults or
children with damaged or diseased brains.
``We believe that in adults, certain injuries actually do recapitulate
certain developmental processes,'' Snyder said.
``It's sort of like re-seeding the lawn. It's using the initial cells
the brain was started with to fill in the gaps.''
In a second study in the same journal, Ronald McKay of the National
Institute of Neurological Disorders and Stroke in Bethesda,
Maryland, and colleagues in Germany and France did a similar experiment
with cells from aborted fetuses.
They placed them into the rat brains. The human neural cells spread
throughout the rats' brains and differentiated into different
kinds of cells.
Snyder said the experiments show that everything scientists have been
doing with rats and mice for years should work in humans,
too. ``It brings us closer to clonical (human) trials,'' he said.
--
Judith Richards, London, Ontario, Canada
<[log in to unmask]>
^^^
\ /
\ | / Today’s Research
\\ | // ...Tomorrow’s Cure
\ | /
\|/
```````
