Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research suggests cause of neurodegeneration in Huntington’s disease

31.05.2006


The severe neurodegeneration associated with HuntingtonÕs disease may result from molecular mutations that block the transport of nutrients within cells. Findings from the Emory University School of Medicine indicate that the mutant huntingtin protein limits the efforts of the huntingtin-associated protein-1 (HAP1) to provide nutrients to growing neurons, or neurites. Without those nutrients, neurites fail to develop and mature neurons degenerate.



Huntington’s disease was first identified more than 125 years ago, and often inhibits speech, movement, reasoning and memory. The result of an abnormal Huntington gene, the hereditary disorder is estimated to affect one out of every 10,000 people. Though some current pharmacological treatments do address symptoms, scientists have been unable to stop the disease’s progression.

However, scientists at Emory are making headway in the search for a cure. The findings that appear in the May 31 issue of the Journal of Neuroscience are the latest of more than a decade of Huntington’s disease-related discoveries led by Xiao-Jiang Li, PhD, professor of human genetics at Emory University School of Medicine.


Juan Rong, doctoral student in the neuroscience graduate program at the Emory University School of Medicine, is the lead author of the article. The senior author, Dr. Li, first discovered the protein HAP1 as a postdoctoral fellow in 1995. In previous articles, he has identified the importance of HAP1 to the normal functioning of the hypothalamus, a region of the brain that acts as a central switchboard to regulate feeding and other body functions. Earlier this year, Dr. Li’s group published an article identifying HAP1Õs role connecting insulin to the hypothalamus in the journal Nature Medicine.

"This protein is very important," says Dr. Li. "When an animal does not have HAP1 it dies after birth. Certainly, it’s essential for differentiation and survival of some neurons in the brain."

In this latest paper, Dr. Li, Ms. Rong, and their colleagues used cellular models to show that HAP1 normally links to transport proteins, including the growth factor receptor tyrosine kinase (TrkA), in growing neurites. HAP1 protects TrkA from degrading, ensuring the neurites continue to develop. This trafficking function is regulated by the addition of phosphate and oxygen to the HAP1 protein, a process known as phosphorylation.

However, when mutant huntingtin is present, the Emory researchers have found that this disease protein stops HAP1 from fulfilling its trafficking function. HAP1 cannot prevent the degradation of TrkA. The insufficient amount of TrkA cannot maintain the normal function of nerve terminals.

Although the discovery that HAP1 works as a transporter and plays a crucial role in neuronal function was obtained from cell models, it will assist scientists as they continue to look for a cure for Huntington’s disease. Dr. Li’s current experiments involve selective HAP1 deletions from neurons in animal models, and his results are sure to offer relevant clues to the mechanisms behind HuntingtonÕs disease.

Says Dr. Li, "If we can find the pathogenesis for Huntington’s disease, or if we know how the mutant huntingtin affects the transporting inside cells, maybe then we can find some effective treatment to prevent this kind of defect."

Research into other neurodegenerative disorders may also benefit from a thorough understanding of HAP1. "This work also has implications for understanding the normal physiological processing for neuronal functioning," says Dr. Li.

Holly Korschun | EurekAlert!
Further information:
http://www.emory.edu

More articles from Health and Medicine:

nachricht The end of pneumonia? New vaccine offers hope
23.10.2017 | University at Buffalo

nachricht Scientists track ovarian cancers to site of origin: Fallopian tubes
23.10.2017 | Johns Hopkins Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>