This is the same news we've seen in two other separate press releases
this past week. This one gives a bit more detail on Dr. Rouault's
research and her quest for MSA patients to study. Please do contact her
if you are interested in participating.
Hugs,
Pam
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http://www.nih.gov/news/pr/jan2001/nichd-30.htm
NATIONAL INSTITUTES OF HEALTH
National Institute of
Child Health and
Human Development
EMBARGOED FOR RELEASE
Tuesday, January 30, 2001
5:00 p.m. EST
Contact:
Robert Bock
(301) 496-5133
Mouse with Iron Disorder Offers Clues to Parkinson's,
Similar Diseases
Mice engineered to lack a gene involved in iron metabolism may
provide important clues for deciphering the nature of a
group of brain disorders similar to Parkinson's Disease
affecting movement, according to a study by researchers at
the National Institute of Child Health and Human Development
(NICHD).
The researchers reported in the February issue of Nature Genetics
that mice lacking the gene for iron regulatory protein
2 (IRP2) develop iron deposits in key areas of the brain. The
progressive deterioration of the mice's nervous system is
like that seen in people with Parkinson's Disease and Multiple
System Atrophy (also known as Parkinson's Plus).
"Researchers have long debated whether the characteristic iron
deposits of these diseases are the cause or the result of
the disease process," said Duane Alexander, M.D., Director of the
NICHD. "This is a strong clue that iron may play a
causative role in Parkinson's and similar disorders."
Diseases in which excess brain iron has been observed include
Parkinson's Disease, Friedreich's Ataxia and
Hallervorden-Spatz disease. However, the brain areas affected
differ from those in the IRP 2 deficient mice, and it is
unlikely that IRP 2 is involved in these human diseases, said the
study's senior investigator, Tracey A. Rouault, M.D., of
NICHD's Cell Biology and Metabolism Branch. Still, the NICHD
finding suggests that other genes involved in iron
metabolism may be good candidates for investigations into the
causes of these disorders.
In addition, the brain areas affected in the IRP 2 deficient mice
correspond closely to those affected in Multiple System
Atrophy (formerly known as Olivopontocerebellar Atrophy). For this
reason, the NICHD researchers are planning a
study to test patients with this disorder for defects of the IRP2
gene.
IRP 2 is a key player in regulating how much iron is in the cell,
Dr. Rouault explained. Although iron is a nutrient, too
much can also be toxic. For this reason, cells have intricate
biochemical machinery to prevent iron from building up to
lethal levels. Like its sister protein, iron regulatory protein 1,
IRP 2 governs the actions of various other proteins involved
in iron metabolism. These include transferrin receptor, which
transports iron into the cell; ferritin, which stores iron safely
away from the cell's internal machinery; and iron exporters, which
ferry iron out of the cell.
Using a method known as "knockout technology," the researchers
developed a strain of mice lacking the IRP 2 gene.
These mice developed normally at first, then progressively had
difficulty walking and moving. Examination of their brains
showed that tiny clumps of iron accumulate in the cerebellum, the
brain structure controlling movement, and in the basal
ganglia, the group of brain cells atop the spinal cord, which
assist in movement. These mice also had high blood levels of
the iron storage protein ferritin.
"In the corresponding human diseases, you see only the end result,"
Dr. Rouault said. "With these mice, we know that
the primary event is removal of the gene."
Currently, Dr. Rouault is seeking patients with Multiple System
Atrophy to take part in a genetic study to learn whether
they have a genetic defect involving IRP 2. Similarly, she is also
seeking patients with Parkinsonian symptoms for the
study, because Multiple System Atrophy often masquerades as
Parkinson's. Dr. Rouault and her colleagues are
especially interested in seeing patients with these diseases who
have relatives with either disorder and have high blood
levels of ferritin. Those wishing to participate may have their
physicians contact Dr. Rouault at Rouault@... or
write her at the Cell Biology and Metabolism Branch, NICHD, Bldg.
18T, Room 101, Bethesda, MD 20892.
The NICHD is part of the National Institutes of Health, the
biomedical research arm of the Federal government. The
Institute sponsors research on development before and after birth;
maternal, child, and family health; reproductive
biology and population issues; and medical rehabilitation. NICHD
publications, as well as information about the Institute,
are available from the NICHD website, http://www.nichd.nih.gov, or
from the NICHD Clearinghouse,
1-800-370-2943; E-mail NICHDClearinghouse@....
The National Institute of Neurological Disorders and Stroke
provides information on the neurological disorders
mentioned in this release on its website.
Parkinson's Disease
http://www.ninds.nih.gov/health_and_medical/disorders/parkinsons_disease.htm
Multiple system Atrophy (Olivopontocerebellar Atrophy)
http://www.ninds.nih.gov/health_and_medical/disorders/opca_doc.htm
Friedreich's Ataxia
http://www.ninds.nih.gov/health_and_medical/pubs/friedreich_ataxia.htm
Hallervorden-Spatz Disease
http://www.ninds.nih.gov/health_and_medical/disorders/hallervorden.htm