Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Enzyme helps stem cells improve recovery from limb injuries


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

Toni Baker | Eurek Alert!
Further information:

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

More articles from Life Sciences:

nachricht When fat cells change their colour
28.10.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Aquaculture: Clear Water Thanks to Cork
28.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>