Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Enzyme helps stem cells improve recovery from limb injuries

15.05.2014

While it seems like restoring blood flow to an injured leg would be a good thing, it can actually cause additional damage that hinders recovery, researchers say.

Ischemia reperfusion injury affects nearly two million Americans annually with a wide variety of scenarios that temporarily impede blood flow – from traumatic limb injuries, to heart attacks, to donor organs, said Dr. Babak Baban, immunologist at the Medical College of Georgia and College of Dental Medicine at Georgia Regents University.

Restoring blood flow actually heightens inflammation and cell death rather than recovery for many of these patients.

"Think about trying to hold onto a nuclear power plant after you unplug the electricity and cannot pump water to cool it down," said Dr. Jack Yu, Chief of MCG's Section of Plastic and Reconstructive Surgery. "All kinds of bad things start happening."

... more about:
»IDO »MCG »death »immune »inflammation »injuries »limb »mitochondria »therapy

Baban and Yu are collaborators on a study published in the journal PLOS ONE that shows one way stem cell therapy appears to intervene is with the help of an enzyme also used by a fetus to escape rejection by the mother's immune system.

Earlier studies indicate stem cells may improve recovery both by enabling new blood vessel growth and by turning down the now-severe inflammation, Baban said. The new study shows that indoleomine 2,3 dioxygenase, or IDO, widely known to dampen the immune response and create tolerance, plays an important role in regulating inflammation in that scenario. Stems cells and numerous other cell types are known to express IDO.

In fact, IDO boosted stem cell efficacy by about a third in their studies in animal models comparing the therapy in normal mice versus mice missing IDO. The researchers documented decreased expression of inflammatory markers, swelling and cell death, which correlate with a shorter, improved recovery.

That could be just what the doctor ordered for these patients, said Baban, the study's corresponding author. "We don't want to turn off the immune system, we want to turn it back to normal," he said.

Problems start with even a short period of inadequate blood and nutrients resulting in the rapid accumulation of destructive acidic metabolites, free radicals, and damage to cell structures, Yu said. Cell power plants, called mitochondria, which should be producing the energy source ATP, are among the early casualties, quickly becoming fat, leaky, and dysfunctional.

"The mitochondria are sick; they are very, very sick," Yu said. When blood flow is restored, it can put huge additional stress on sick powerhouses.

"They start to leak things that should not be outside the mitochondria," he said. Without adequate energy and with leaky powerhouses, cells quickly succumb. Inflammation, which is part of the normal healing process, escalates to help clean up the mess, but instead further exacerbates the problem.

While their findings were in limb injuries, the researchers say they should translate to the myriad of scenarios resulting in reperfusion injury. In fact, in just a short two hours in the operating room, Yu has seen free flaps, where tissue is moved from one area of the body to another to cover a burn or rebuild a breast, start dying from ischemia reperfusion injury.

"It cuts across many, many individual disease conditions," Yu said. Transplant centers already are experimenting with pulsing donor organs to avoid reperfusion trauma.

Next steps include seeing if more is better, by giving more stem cells – the researchers only gave one dose in the studies – as well as IDO-enhancing drugs, Baban said. This will include incubating stem cells with IDO, Baban said.

The researchers note that stem cell therapy isn't yet used to help patients' injured limbs recover, but is being studied clinically to aid stroke and heart attack recovery at MCG and other centers. Right now, the most physicians can do is restore blood flow and give broad-spectrum antibiotics.

"Sometimes it works, sometimes it doesn't," Yu said. "That is why this kind of pharmacologic intervention could be very, very important.

Endogenous stems cells enable the body to replace cells that are lost to wear and tear and aging. IDO is one of numerous immune modulators in the body. It remains unclear whether some individuals have higher IDO levels.

Dr. Mohamad Masoumy, a fourth-year general surgery resident at MCG and GR Health System, is first author on the PLOS ONE study.

###

Toni Baker
Communications Director
Medical College of Georgia
Georgia Regents University
706-721-4421 Office
706-825-6473 Cell
tbaker@gru.edu

Toni Baker | Eurek Alert!
Further information:
http://www.gru.edu

Further reports about: IDO MCG death immune inflammation injuries limb mitochondria therapy

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>