http://www.guardian.co.uk/lifeandstyle/2010/may/24/stem-cell-project-brain-disease/print
Team led by Sir Ian Wilmut will hope their research gives an unprecedented insight into motor
neurone disease
One of the longest-living survivors of the motor neurone disease (MND) is Stephen Hawking who
was diagnosed at 21 years old. Photo: Bruno Vincent/Getty Images
British scientists have launched the world's first stem cell project to recreate a devastating
and incurable brain disease in the laboratory. The team, led by Sir Ian Wilmut, the Edinburgh
researcher who cloned Dolly the sheep, will use stem cells to make diseased and healthy brain
cells to study how motor neurone disease progresses into a lethal condition. The research, which
will give scientists unprecedented insight into a disease that is almost impossible to study in
living patients, could be the best long-term hope doctors have for finding treatments for the
condition.
In motor neurone disease (MND), brain and spinal cord nerves that control muscles steadily die
off, leaving patients trapped in a body that becomes increasingly useless. People become
paralysed, unable to talk or eat, and often can only breathe with aid from a mechanical
ventilator.
Around half of all MND patients die within three years of being diagnosed. Five people die
every day from the condition in Britain. One of the longest-living survivors of the condition is
Stephen Hawking, the 68-year-old cosmologist, who was diagnosed at the age of 21.
Wilmut's team at Edinburgh will work with scientists in London and New York to understand how
the disease kills off nerve cells and spreads itself to healthy parts of the brain and central
nervous system.
The project represents a refinement of plans to use controversial "hybrid embryos" to
create stem cells that carry a genetic mutation responsible for motor neurone disease. With
hybrid embryo technology, a skin cell from a disease-carrying patient is fused with an animal
egg to form an early-stage embryo. Stem cells can be collected from these embryos and grown into
adult nerve cells that are prone to developing the disease.
Many scientists have abandoned plans to use hybrid embryos in favour of a simpler and less
controversial technique, in which adult skin cells are chemically reprogrammed into a stem
cell-like state, so called induced pluripotent stem (iPS) cells. Wilmut's team has already taken
skin cells from patients with a rare genetic mutation that causes motor neurone disease and
converted them into iPS cells. They grew these in Petri dishes into two kinds of adult nerve
cells, and did the same with skin cells from healthy people.
The £800,000 project, funded by the Motor Neurone Association, will investigate how the
brain cells grow, and in particular will examine why those carrying the genetic mutation die
off. Understanding what goes wrong will give scientists a clue as to how to slow and even stop
the disease. Drugs that may show promise in slowing or stopping the condition can be tested by
adding them directly to the disease-carrying brain cells in the lab. "Slowing down the
disease is our first aim, stopping the disease is the second, and the home run would be to
repair and restore lost function," said Prof Siddharthan Chandran, a member of the
Edinburgh University team.
The patients in the study carry a mutation in a gene called TDP43. Although the gene is thought
to cause only 1% of cases directly, the mutation is linked to changes seen in 90% of patients
with the disease.
One question the researchers will try to answer is how the disease spreads from one part of the
brain to another. Colin Blakemore, president of the MND Association, said: "There is great
hope that this approach will enable us to unravel the mystery of motor neuron disease: why and
how particular nerve cells die."
May 24, 2010 (The Guardian)