Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Circadian clock may impact organ transplant success

04.10.2011
Health care providers assess blood and tissue type as well as organ size and health to enhance transplant success. New research indicates that checklist might also need to include the circadian clock.

While some human studies have shown the time of day transplant surgery is performed can influence the outcome, this study of mice with dysfunctional internal clocks is the first correlating circadian clocks with transplant success, said Dr. Daniel Rudic, vascular biologist at Georgia Health Sciences University and corresponding author of the study published in Proceedings of the National Academy of Sciences.

The GHSU researchers found that arteries of mice with circadian clock dysfunction became thick and diseased within a few weeks of being transplanted to healthy mice. Arteries transplanted from healthy mice to the mutant mice remained healthy.

Blood vessel disease, and resulting blood loss to donated organs, is a key pitfall for transplant patients, potentially leading to organ failure and rejection.

"You take an organ out of a human, you don't think about it having a bad clock," Rudic said. "But the fact is the time at which you do the organ transplant may influence overall success and, if you have a donor who has a sleep disorder or is a night shift worker, it may affect it as well."

Since even healthy clocks produce variability in tissue function across the span of a day, transplantation might be best performed during optimal organ function, he said.

In addition to enabling sleep/wake cycles, circadian clocks are found throughout the body and involved in a lot more than sleep. "The clock is expressed not only in the brain but everywhere in the body and can function autonomously in different areas," Rudic said.

"Our research shows it's the clock within the blood vessel that is key to conferring the disease response in this case," said Dr. Bo Cheng, GHSU postdoctoral fellow and the study's first author.

While the researchers can determine whether clock gene expression is up, down or mutated, there is currently no way to do the tests in humans. Until screening tests are identified, donors could be screened for signs of dysfunction such as a sleep disorder or even aberrant behaviors that can impair healthy clocks, such as shift work, Rudic said. "Ideally this will open up some new research avenues," he said.

Interestingly, when blood vessels from the mutant mouse stay in that mouse, disease progression is much slower. "We believe that bad clock function worsens when it intersects with disease, so if you are eating a high-fat diet or if you undergoing a serious surgery like a transplant, and you have a bad clock, disease may occur and may occur quickly," Rudic said.

In 2009, he reported in the journal Circulation that mice with mutated or missing clock genes were prone to vascular disease similar to smokers and people with high blood pressure and cholesterol. That study showed the blood vessel clocks regulate key signaling that enables blood vessel dilation and remodeling.

Toni Baker | EurekAlert!
Further information:
http://www.georgiahealth.edu

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>