Navigation Links
To regenerate muscle, cellular garbage men must become builders
Date:9/22/2009

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
lena.raditsch@embl.de
European Molecular Biology Laboratory
Source:Eurekalert  

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:
*Name:
*Comment:
*Email:
Related Image:
To regenerate muscle, cellular garbage men must become builders
(Date:12/7/2016)... ... ... They are musicians and librarians, fashion designers and fitness instructors, actors, athletes ... and around the nation. What do they have in common? All have been affected ... compelling new photographic exhibit debuting Friday, December 9 at Logan International Airport in Boston. ...
(Date:12/7/2016)... ... December 07, 2016 , ... ODU, ... promoting to the US market its advanced highly customizable contact technology solutions. , ... TURNTAC®. These advanced technologies are ideal for a wide range of applications that ...
(Date:12/7/2016)... ... December 07, 2016 , ... Baciocco Brothers ... to residents in the Sacramento/Folsom region, is initiating a charity event to raise ... Another Choice Another Chance treatment center in Sacramento works to provide area teens ...
(Date:12/7/2016)... , ... December 07, 2016 , ... One of two ... of the securement tape is painful for her. "This is why the co-inventor and ... heads," she said. , They then created a prototype of the patent-pending AV-AIR, a ...
(Date:12/7/2016)... ... December 07, 2016 , ... A. Kevin Spann Insurance, a ... throughout the Five Boroughs, is launching a charity drive to raise funds that will ... traditions and spirit of marines and Navy FMF Corpsmen. Working closely with the MCL, ...
Breaking Medicine News(10 mins):
(Date:12/7/2016)... KEY FINDINGS Patient warming ... reducing loss of blood during surgeries, lowering the ... recovery after surgeries, and decreasing risks of SSIs. ... convective warming system, surface warming systems, and intravascular ... stay at hospitals thus, lowering the healthcare costs ...
(Date:12/7/2016)... 7, 2016 Global Hospital Linen Supply and ... global hospital linen supply and management services market presents ... a global and regional level. The study provides historic ... between 2015 and 2024 based on revenue (US$ Bn). ... market along with their impact on demand during the ...
(Date:12/7/2016)... N.J. , Dec. 7, 2016  Palatin ... it has closed on a previously disclosed underwritten ... $16,500,000.  Canaccord Genuity acted as sole book-running manager, ... Chardan Capital Markets acted as co-manager for the ... approximately $15.4 million in net proceeds, allowing us ...
Breaking Medicine Technology: