Navigation Links
To regenerate muscle, cellular garbage men must become builders

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/EBPβ, whose production increases in response to inflammation. They had genetically engineered mice in which this boost in C/EBPβ 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/EBPβ 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/EBPβ 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/EBPβ production and keep it high", Nerlov concludes, adding "if we can now figure out exactly which key genes C/EBPβ 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.


Contact: Lena Raditsch
European Molecular Biology Laboratory

Related medicine news :

1. USC researcher identifies stem cells in tendons that regenerate tissue in animal model
2. Brain cells help neighboring nerves regenerate
3. Weizmann Institute scientists discover how an injured embryo can regenerate itself
4. Baby's Blindness Resolved, Nerves in Knee Regenerated and Other Unusual Complimentary Therapies from BiomagScience
5. Stem cells with potential to regenerate injured liver tissue identified by Penn researchers
6. Heart regenerates after infarction -- first trials with mice
7. Study uses bone marrow stem cells to regenerate skin
8. Embryonic Human Stem Cells May Help Repair Heart Muscle, Lab Study Shows
9. Story ideas from molecular & cellular proteomics
10. A Chinese medicine compound has satisfactory anti-cancer effects on hepatocellular carcinoma
11. ReCellular Named Exclusive Cell Phone Recycling Partner for Consumer Cellular
Post Your Comments:
Related Image:
To regenerate muscle, cellular garbage men must become builders
(Date:11/27/2015)... PA (PRWEB) , ... November 27, 2015 , ... ... be a safe and convenient way to dispense prescription medications at home, so ... and effective way to monitor and dispense prescription medications. In doing so, it ...
(Date:11/27/2015)... ... ... ProSidebar: Fashion is a set of 30 kinetic edge graphics ... editors can easily add an informative sidebar to any FCPX production. Create lists, ... self-animating drop zones, lines, bars, and text with the ease of FCPX's drag and ...
(Date:11/27/2015)... ... ... A simply groundbreaking television series, "Voices in America", which is hosted by ... of issues that are presently affecting Americans. Dedicated to providing the world with a ... the subjects consumers focus on, one episode at a time. , In the ...
(Date:11/27/2015)... ... November 27, 2015 , ... The men and ... nonprofit healthcare organizations in the country. They have overseen financial turnarounds, shown commitment ... advance the healthcare industry as a whole through their advocacy and professional efforts. ...
(Date:11/26/2015)... ... November 26, 2015 , ... ... located in central Michigan, have come together on Thanksgiving Day to share the ... available for viewing on the Serenity Point YouTube channel, patients displayed what they ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... november 2015 AAIPharma Services Corp./Cambridge ... investering aan van ten minste $15,8 miljoen ... het mondiale hoofdkantoor in Wilmington, ... in extra kantoorruimte en extra capaciteit voor ... behoeften van de farmaceutische en biotechnologische markten. ...
(Date:11/26/2015)... -- --> --> Juntendo ... optimal contrast weighting of MRI for patients with Multiple ... research agreement with SyntheticMR in order to use SyMRI in ... possible to generate multiple contrast images from a single scan ... thus making it possible to both fine tune images and ...
(Date:11/26/2015)... , Nov. 26, 2015 Research ... addition of the "2016 Future Horizons and ... (TDM) Market: Supplier Shares, Country Segment Forecasts, Competitive ... --> --> ... analysis of the Japanese therapeutic drug monitoring market, ...
Breaking Medicine Technology: