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 Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>