Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists find a key culprit in stroke brain cell damage

31.03.2008
Researchers have identified a key player in the killing of brain cells after a stroke or a seizure. The protein asparagine endopeptidase (AEP) unleashes enzymes that break down brain cells' DNA, scientists at Emory University School of Medicine have found.

The results are published in the March 28 issue of the journal Molecular Cell.

Finding drugs that block AEP may help doctors limit permanent brain damage following strokes or seizures, says senior author Keqiang Ye, PhD, associate professor of pathology and laboratory medicine at Emory.

When a stroke obstructs blood flow to part of the brain, the lack of oxygen causes a buildup of lactic acid, the same chemical that appears in the muscles during intense exercise. In addition, a flood of chemicals that brain cells usually use to communicate with each other over-excites the cells. Epileptic seizures can have similar effects.

... more about:
»AEP »DNA »Programmed »damage »seizure »stroke

While some brain cells die directly because of lack of oxygen, others undergo programmed cell death, a normal developmental process where cells actively destroy their own DNA.

"The mystery was: how do the acidic conditions trigger DNA damage?" Ye says. "This was a very surprising result because previously we had no idea that AEP was involved in this process."

AEP is a protease, a class of enzymes that cuts other proteins. AEP is also called legumain because of its relatives in plants, and is found at its highest levels in the kidney, says Ye.

He and his co-workers had suspected that another class of proteases called caspases, involved in programmed cell death, controlled DNA damage after a stroke.

At first, he and postdoctoral fellow Zhixue Liu, PhD, thought the results of a critical experiment that led them to AEP were an aberration because the experiment was performed under overly acidic conditions.

"But if you can repeat the mistake, it's not a mistake," Dr. Ye says, adding that follow-up work allowed them to set aside caspases as suspects and focus on AEP.

The researchers began by looking for proteins that stick to another protein called PIKE-L, which they previously had studied because of its ability to interfere with programmed cell death in brain cells.

They discovered that PIKE-L sticks to SET, a protein that other scientists had found regulates DNA-eating enzymes involved in programmed cell death. In addition, PIKE-L appears to protect SET from attack by AEP.

Liu and Ye found that a drug scientists use to mimic the acidic overload induced by stroke activates AEP, driving it to break down DNA in brain cells. In mice genetically engineered to lack AEP, both the drug and an artificial stroke resulted in reduced DNA damage and less brain cell death than in regular mice.

This outcome suggests "that AEP might be the major proteinase mediating this devastating process," the authors wrote.

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

Further reports about: AEP DNA Programmed damage seizure stroke

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>