Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Enabling nerve regeneration means evicting the cleanup crew

01.03.2007
Macrophages are the immune cells that engulf and destroy the debris of damaged tissue to enable the healing process to begin. Their presence at the scene of damage is critical, but once their task is complete, it is just as critical that macrophages exit rapidly, ending the inflammatory process and making way for regrowth. In fact, the continued presence of macrophages could damage tissue, compromising repair.

While researchers know a great deal about the molecular machinery that launches this cellular cleanup crew into action, little has been known about the just-as-critical exit process.

Now, researchers have identified a key process by which macrophages are cleared from sites of peripheral nerve injury. The scientists say their findings could also have implications for understanding the same fundamental mechanism in spinal cord injury, stroke and multiple sclerosis.

Samuel David and colleagues published their findings in the March 1, 2007 issue of the journal Neuron, published by Cell Press.

... more about:
»Myelin »NgR1 »macrophages »receptor

The researchers concentrated on a family of cell receptors known as Nogo receptors, already known to be present on nerve cells and to play a role in nerve growth. Specifically, David and colleagues explored the role of one such Nogo receptor, NgR1. Receptors such as NgR1 are protein switches that nestle in the membranes of cells, and which induce a cellular response when triggered by a specific chemical signal, or ligand.

In the researchers' experiments, they induced damage in the sciatic nerve in the thigh of rats and mice and analyzed the role of NgR1 in the repair process.

They found that macrophages showed the presence of NgR1 on their surface once they arrive at the injury site and began their cleanup. Further experiments revealed that as the healing nerve began to form the protein myelin—the insulating sheath around nerves—this receptor not only caused a reduction in the macrophages' binding to myelin, but also an outright repulsion from the forming myelin. In fact, when the researchers created nerve injury such that new myelin would not be formed, the macrophages continued to lurk around the injury site. The researchers' experiments also identified specific molecules on myelin that triggered such repulsion.

The findings could also apply to nerves other than peripheral nerves, because macrophages activated during stroke, multiple sclerosis injury, and spinal cord injury also express NgR1 on their surface, pointed out the researchers.

"Our discovery of this novel (to our knowledge) role for NgRs in mediating the efflux of macrophages from inflamed neural tissue via interactions with myelin could therefore have broader implications for the regulation of inflammatory responses not only in other peripheral nerve pathologies, but also in [central nervous system] inflammation such as in spinal cord injuries, stroke, and multiple sclerosis," they concluded.

Erin Doonan | EurekAlert!
Further information:
http://www.neuron.org
http://www.cell.com

Further reports about: Myelin NgR1 macrophages receptor

More articles from Life Sciences:

nachricht Show me your leaves - Health check for urban trees
12.12.2017 | Gesellschaft für Ökologie e.V.

nachricht Liver Cancer: Lipid Synthesis Promotes Tumor Formation
12.12.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>