This e-mail was sent to me by Mike Fernandes, who is a wonderful man who
runs the Machado Joseph disease list-serve. MJD is a CAG triplet-repeat
disease with the same mechanism as HD, and we recently held our first MJD
Day clinic at UCD.
People with MJD have slowly progressive ataxia (loss of balance), muscle
spasm, vision problems, speech and swallow problems, and eventually lose
their independence. They don't have chorea. There are very few people
with MJD in the world - far fewer than with HD, but because the molecular
mechanisms are similar, research in one disease can help another.
The article below discusses a breakthrough in RNAi techniques. These
Harvard researchers had the amazing idea of using a small peptide that
would shut down the MJD mutant protein by attaching it to a small strand of
rabies virus that has been modified so that it can't cause the illness
rabies. Rabies virus has a special property: it travels very easily into
the brain, so the RNAi peptide can "hitch a ride" into the brain.
RNAi techniques are being explored to treat infections, cancer and
neurological disorders. This report is about RNAi to block infection, but
it could easily apply to other disorders.
This is a very exciting report!
Vicki
----- Forwarded by Vicki Wheelock/PHY/HS/UCD on 06/20/2007 04:04 PM -----
"Mike Fernandes" To MJDFamily@yahoogroups.com 06/19/2007 09:29 AM  

Subject Blood-brain Barrier Breached By New Therapeutic Strategy - Treatment on the way! mBlood-brain Barrier Breached By New Therapeutic Strategy
Science Daily - A major obstacle in the treatment of infections and
other diseases of the brain is the blood-brain barrier, which prevents
systemically delivered therapeutic drugs from reaching the brain.
Grantees of the National Institute of Allergy and Infectious Diseases,
part of the National Institutes of Health, have now shown that a short
protein (peptide) from the rabies virus can carry a strip of
therapeutic material into the brain via intravenous administration.
Once delivered to the nerve cells of the brain, the strip, called a
small interfering RNA (siRNA), was shown to protect mice from
infection caused by the Japanese encephalitis virus (JEV).
Manjunath N. Swamy, M.D., of the CBR Institute for Biomedical Research
and Harvard Medical School in Boston, and his colleagues used JEV to
infect the brains of mice. They then injected the antiviral siRNA
bound to the rabies peptide through the tail veins in one group of
mice, while other mice served as control groups.
All the mice in the control groups died from JEV infection; in
contrast, 80 percent of the mice that got the antiviral siRNA linked
to the rabies peptide survived. These experiments demonstrate how the
rabies peptide can be used to deliver antiviral siRNA across the
blood-brain barrier and into nerve cells in the brain. Once inside
brain nerve cells, the antiviral siRNA can silence key viral genes to
control the infection. Furthermore, repeated administration of the RNA
interference therapy did not trigger inflammation or antibodies to the
peptide.
Currently, doctors use various methods to deliver therapeutic drugs
directly into the brain. These methods involve invasive procedures
that result in only localized delivery around the site of injection.
The new research provides a safe and non-invasive method for
delivering therapeutic molecules across the blood-brain barrier. It
has the potential to be applied to the treatment of a variety of brain
infections and diseases. The researchers are now trying to improve the
efficacy of this delivery system and to make a stable form of siRNA
that might yield even better results.
Article:"Transvascular delivery of small interfering RNA to the
central nervous system," by N Manjunath et al. Nature DOI:
10.1038/nature05901 (2007)
Note: This story has been adapted from a news release issued by
NIH/National Institute of Allergy and Infectious Diseases.
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