Navigation Links
Discovery Sheds Light on Huntington's Disease

Researchers identify protein that could lead to treatment or prevention

THURSDAY, June 4 (HealthDay News) -- Scientists have pinpointed a protein that plays a key role in cell death in Huntingdon's disease, a degenerative disorder that leads to uncontrolled movements and loss of intellectual functioning.

The discovery raises hope that drugs could be developed to slow or halt the disease, according to a study in the June 5 issue of Science.

In Huntington's disease, cells in the corpus striatum, the area of the brain that controls movement, gradually die off.

Previous research has shown that people with Huntington's have a genetic defect that produces a mutant version of the protein "huntingtin," which accumulates in cells throughout the body.

But for reasons scientists didn't understand, the protein only kills cells in the corpus striatum. The protein causes little damage to tissues elsewhere.

In the new study, researchers discovered that a tiny protein called "rhes" -- found only in the corpus striatum -- interacts with the mutant huntingtin proteins, causing cell death.

The findings explain the pattern of brain damage in Huntington's disease and suggest strategies for developing new drug therapies, researchers at Johns Hopkins University said.

"It's always been a mystery why, if the protein made by the HD (Huntington's disease) gene is seen in all cells of the body, only the brain, and only a particular part of the brain, the corpus striatum, deteriorates," said Dr. Solomon H. Snyder, a professor of neuroscience at Johns Hopkins. "By finding the basic culprit, the potential is there to develop drugs that target it and either prevent symptoms or slow them down."

Huntington's is a familial disease, passed from parent to child through a gene mutation. A child of someone with Huntington's has a 50-50 chance of inheriting the gene, according to the National Institute of Neurological Disorders and Stroke.

Because the damage from the faulty gene is limited to the corpus striatum, researchers went searching for proteins that interacted specifically and exclusively with the huntingtin protein in that part of the brain.

Rhes is found almost exclusively in the corpus striatum, according to the study.

Using human and mouse cells, researchers found that rhes interacted with both healthy and mutant versions of huntingtin protein, but that it bound much more strongly to mutant huntingtin, also known as mHtt.

"Touching or binding is one matter, but death is altogether another," Snyder said.

Further tests using human embryonic cells and brain cells taken from mice showed that when both mHtt and rhes were present in the same cells, half the cells died within 48 hours. Rhes or mHtt alone did not cause cell death.

"Here's the rhes protein, we've known about it for years, nobody ever really knew what it did in the brain or anywhere else," Snyder said. "And it turns out it looks like the key to Huntington's disease."

Researchers also did a set of tests to learn more about the role of rhes. Previous research has shown that the abnormal huntingtin proteins form clumps in cells throughout the body and brain, but that there are fewer of the clumps in the corpus striatum.

"This has led to much controversy: Are the clumps toxic, or is it the lack of clumps that's toxic to these brain cells?" said Srinivasa Subramaniam, a postdoctoral fellow at Johns Hopkins.

Experiments showed that adding rhes to cells with abnormal huntingtin led to fewer clumps, but the cells died.

Researchers said that the unclumping of mutant huntingtin proteins by rhes might cause the cell death.

"Since rhes is highly found in the corpus striatum, clumping somehow protects cells in other tissues of the body from dying," Subramaniam said.

The team is currently testing to see if removing rhes from mice with Huntington's disease can slow or stop brain cells from dying.

"Now that we've uncovered the role of rhes, it's possible that drugs can be designed that specifically target rhes to treat or even prevent the disease," Snyder said.

More information

The National Institute of Neurological Disorders and Stroke.

-- Jennifer Thomas

SOURCE: Johns Hopkins University, news release, June 4, 2009

Copyright©2009 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Discovery of sugar sensor in intestine could benefit diabetes
2. Discovery suggests location of genes for breast density, a strong risk factor for breast cancer
3. Stem cell research produces a key discovery for Fragile X Syndrome
4. Welch Foundation gives $1.6 million for drug discovery research
5. New discovery leaves blood-doping athletes scratching their heads
6. Chemical Diversity Initiates International Prostrate Cancer Discovery Partnership
7. New discovery leaves blood-doping athletes scratching their heads
8. Discovery of widespread tumor growth gene holds promise for effective anti-cancer treatment
9. Discovery supports theory of Alzheimers disease as form of diabetes
10. Discovery Health CME Explores the Benefits and Risks of Aspirin in Aspirin Therapy: Maximizing the Benefits
11. New discovery may improve treatment of one of the worlds leading causes of blindness
Post Your Comments:
Related Image:
Discovery Sheds Light on Huntington's Disease 
(Date:10/12/2017)... Francisco, CA (PRWEB) , ... October 12, 2017 ... ... Dr. Cheng, are now treating sleep apnea using cutting-edge Oventus O2Vent ... apnea, a serious sleep disorder characterized by frequent cessation in breathing. Oral appliances ...
(Date:10/12/2017)... ... October 12, 2017 , ... The company ... of today’s consumer and regulatory authorities worldwide. From Children’s to Adults 50+, every ... meet the highest standard. , These products are also: Gluten Free, Non-GMO, ...
(Date:10/12/2017)... ... 2017 , ... The American College of Medical Informatics (ACMI) will present the ... Opening Session of AMIA’s Annual Symposium in Washington, D.C. AMIA’s Annual Symposium ... a pioneer in the field of medical informatics, this prestigious award is presented to ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... that we intend to develop to enable prevention of a major side effect ... hearing loss, especially in pediatric patients. For cisplatin, hearing loss is FDA listed ...
(Date:10/12/2017)... ... 2017 , ... HMP , a leader in healthcare events and education, today ... Digital Award for ‘Best B-to-B Healthcare Website.’ Winners were announced during the Eddie & ... award competition recognizes editorial and design excellence across a range of sectors. This year’s ...
Breaking Medicine News(10 mins):
(Date:9/19/2017)... a venture-backed medical device company developing a non-invasive, robotically assisted, platform therapy that uses pulsed ...   ... Jim Bertolina, ... Tom Tefft ... medical device executive Josh Stopek , PhD, who has led R&D and business development ...
(Date:9/18/2017)... , Sept. 18, 2017 ... fields of bioinformatics and immune engineering, today ... protective avian influenza A (H7N9) vaccine. ... related to seasonal influenza and presents a ... on prior exposure to be effective. Using ...
(Date:9/12/2017)... -- Consumer reviews on the independent review site Consumer Affairs ... for hearing aids, ranking it higher than Miracle Ear ™, ... ... Hearing Aids ... store that provides high performance, state-of-the-art, German-engineered hearing aids directly to ...
Breaking Medicine Technology: