For scientists at the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, what seemed like a disappointing result turned out to be an important discovery.
Their findings, published online this week in the journal Proceedings of the National Academy of Sciences (PNAS), provide conclusive proof that, when a muscle is injured, white blood cells called macrophages play a crucial role in its regeneration. The scientists also uncovered the genetic switch that controls this process, a finding that opens the door for new therapeutic approaches not only to sports injuries but also to diseases such as Duchenne muscular dystrophy.
Normally, macrophages – the white blood cells known for engulfing and eliminating bacteria and other infectious agents – are drawn to areas of injury. Once there, they act as garbage men, eliminating the dead cells and releasing pro-inflammatory factors, fending off infection. After clearing up the debris, macrophages stop releasing those pro-inflammatory factors, and start making anti-inflammatory factors that promote repair in the damaged area. This shift from clearing debris to promoting building is known as macrophage polarization, and Claus Nerlov, Nadia Rosenthal and colleagues proved that it is essential for muscles to regenerate properly.
“There seems to be this point of no return”, says Rosenthal: “if macrophages don’t make this switch, then the muscle won’t repair itself – you just end up with scar, instead of new tissue”.
Nerlov and his research group at EMBL were studying a protein called C/EBPâ, whose production increases in response to inflammation. They had genetically engineered mice in which this boost in C/EBPâ production was blocked, to see what effect this had on the development of the different cells involved in the immune system. To their dismay, the answer appeared to be ‘almost none’. The modified mice developed normally, and had normal blood cells – except their macrophages didn’t polarize. Although this result fell short of the scientists’ expectations of understanding how blood cells develop, it raised an interesting possibility in the context of Rosenthal’s research into muscle regeneration. If these mice could not repair muscle injuries properly, it would prove that macrophage polarization is indispensable for muscle regeneration. The two groups teamed up to investigate how the ability to respond to muscle injury was affected in mice whose C/EBPâ production boost had been blocked. Their findings proved that macrophages still migrated to the injured site and cleared the debris, but because they failed to make that all-important switch, the muscle didn’t repair properly, becoming scarred instead.
At a stroke, the EMBL scientists confirmed the importance of macrophages in repairing muscle tissue and discovered its genetic basis. Normally, inflammatory factors trigger an increase in C/EBPâ production, which in turn activates genes that cause the macrophage to polarize.
“From a medical point of view, it would seem that the trick to improve muscle repair is finding a way to increase C/EBPâ production and keep it high”, Nerlov concludes, adding “if we can now figure out exactly which key genes C/EBPâ controls, that will give us even more potential targets.”
As well as investigating the other steps on this molecular pathway, the scientists are currently studying a possible role for macrophage polarization in repairing heart muscle, with a view to better understanding and treating heart disease.Source Article
Lena Raditsch | EMBL
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses