Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cell death following blood 'reflow' injury tracked to natural toxin

01.12.2006
Researchers at Johns Hopkins have discovered what they believe is the "smoking gun" responsible for most tissue and organ damage after a period of blood oxygen loss followed by a sudden restoration of blood oxygen flow.

Working with mice, the Hopkins team found that the sudden oxygen bath triggered by restored blood flow causes cells to make a chemical so toxic it kills the cells. The work was published in two papers in the Proceedings of the National Academy of Sciences last week.

Although not sure why it happens, the Hopkins scientists believe the toxic chemical, PAR-polymer, acts like a molecular sledgehammer, or a death switch. "We've found evidence of it in cells following all types of injury," says Ted Dawson, M.D., Ph.D., the Leonard and Madlyn Abramson Professor of Neurodegenerative Diseases, professor of neurology and co-director of Hopkins' Neuroregeneration and Repair Program in the Institute of Cell Engineering (ICE).

The research team has named the cell death process caused by PAR-polymer "parthanatos," after Thanatos, the personification of death from Greek mythology.

To establish that PAR-polymer is indeed the culprit in the kind of reperfusion injuries long linked to heart attacks, strokes and a variety of blood vessel injuries, the researchers pumped mouse nerve cells full of PAR-polymer. The cells died, but to be sure PAR-polymer (and not something else) killed them, they examined the brains of mice engineered to lack an enzyme that chews up and gets rid of PAR. These mouse brains contained twice as much PAR-polymer as those of normal mice.

After the researchers induced a blood clot injury like a stroke, the same mice showed a 62 percent increase in the area of brain damage compared to normal littermates. Mice that contain more of the PAR-chewing enzyme suffered less brain damage than their normal littermates.

To figure out what triggers the death switch, the researchers tracked PAR-polymer's journey after cells made it. After 15 minutes, PAR-polymer hadn't gone anywhere. But after 30 to 60 minutes, the researchers discovered that much of it traveled right to areas where the switch normally resides.

The fate of the cell is irreversible once PAR-polymer sets off the trigger, says Valina Dawson, Ph.D., professor of neurology, co-director of the Neuroregeneration and Repair Program and author of the papers. "If we could figure out how to block PAR-polymer, we could design drugs that protect the switch and prevent cells from dying after heart attacks, stroke or other injuries," she says.

Audrey Huang | EurekAlert!
Further information:
http://www.jhmi.edu
http://www.neuroice.org/

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

Single nanoparticle mapping paves the way for better nanotechnology

24.10.2017 | Physics and Astronomy

A quantum spin liquid

24.10.2017 | Physics and Astronomy

Antibiotic resistance: a strain of multidrug-resistant Escherichia coli is on the rise

24.10.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>