Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

2-way cell talk provides clues about neuromuscular disease

19.02.2008
It’s a scientific given that neurons tell other cells what to do, but new evidence suggests that, like with any good relationship, these target cells also have much to contribute, scientists say.

In an animal model, Medical College of Georgia researchers have shown that if a muscle cell fails to produce the protein beta-catenin, its neuron doesn’t develop or function properly.

Their finding provides some of the first proof that in vertebrates such as man, this retrograde communication – from the target cell back to the neuron – is essential, says Dr. Lin Mei, corresponding author on research published online Feb. 17 in Nature Neuroscience.

“Previously, we thought signals flow mainly from neuron to muscle. This shows they can be produced from muscle,” says Dr. Mei, MCG’s chief of developmental neurobiology and Georgia Research Alliance Eminent Scholar in Neuroscience. “This is some of the first clear genetic evidence that when you disturb something in the muscle, you have a nerve problem.”

Dr. Mei’s research team knocked out beta-catenin in the muscle cells of a developing mouse. As a result, nerve terminals, which reach out to target cells, were misaligned. Release of neurotransmitters, which enable cell talk, from the tiny vesicles inside nerve terminals was impaired. Mice died prematurely. “Two-way communication is absolutely essential,” he says. Interestingly when the researchers knocked beta-catenin out of neurons instead, neurons developed and functioned normally.

“Theoretically the finding is very important in that it supports the retrograde hypothesis,” Dr. Mei says. “Practically it is also important because problems with motor neuron survival and differentiation cause many neuromuscular diseases, such as muscular dystrophy and ALS, where motor neurons need to survive,” noting that it’s unknown why neurons die in these diseases.

“We believe there is a retrograde signal downstream of beta-catenin or regulated by beta- catenin,” says Dr. Mei. “If you don’t have beta-catenin in the muscle, that signal may be missing and motor neurons are not happy.”

To find out what that signal is, his lab is comparing genetic expression in the beta-catenin knockout mouse to that of a normal mouse to see which genes are up- or down-regulated. “Those genes may be targeted by beta-catenin and may serve as this retrograde signal. If we can identify that, I can retire,” says Dr. Mei.

Beta-catenin is a protein with many roles, including helping cells stick together, and regulating gene expression in the Wnt pathway, which is essential for development. Dr. Mei’s previous work has shown that at least in a Petri dish, when a signaling component of the Wnt pathway, called disheveled, is disturbed in muscle cells, it causes problems with their co-cultured neurons.

In the early 1900s, German-born Scientist Viktor Hamburger provided some of the first evidence of the importance of retrograde communication in proper development of motor neurons: when he removed the budding limbs of chick embryos, motor neurons decreased in number.

“ … (T)he use of transgenic animals has established the importance of muscle ß-catenin in (neuromuscular junction) formation in vivo,” write Drs. Amy K.Y. Fu, Zelda Cheung and Nancy Y. Ip, of Hong Kong University of Science and Technology in an accompanying News and Views. “These findings also underscore the emerging role of Wnt signaling proteins in the regulation of synapse development. The identification of muscle ß-catenin-dependent signals for motoneurons may also contribute to our understanding of neuromuscular disorders, including muscular dystrophy and amyotrophic lateral sclerosis.”

Toni Baker | EurekAlert!
Further information:
http://www.mcg.edu

Further reports about: Beta-Catenin Disease Neuron neuromuscular retrograde

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>