Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UC San Diego biologists discover genes that repair nerves after injury

22.09.2011
Biologists at the University of California, San Diego have identified more than 70 genes that play a role in regenerating nerves after injury, providing biomedical researchers with a valuable set of genetic leads for use in developing therapies to repair spinal cord injuries and other common kinds of nerve damage such as stroke.

In the September 22 issue of the journal Neuron, the scientists detail their discoveries after an exhaustive two-year investigation of 654 genes suspected to be involved in regulating the growth of axons—the thread-like extensions of nerve cells that transmit electrical impulses to other nerve cells. From their large-scale genetic screen, the researchers identified 70 genes that promote axon growth after injury and six more genes that repress the re-growth of axons.

"We don't know much about how axons re-grow after they're damaged," said Andrew Chisholm, a professor of biology at UC San Diego. "When you have an injury to your spinal cord or you have a stroke you cause a lot of damage to your axons. And in your brain or spinal cord, regeneration is very inefficient. That's why spinal cord injuries are basically untreatable."

Chisholm and UC San Diego biology professor and HHMI Investigator Yishi Jin headed the collaborative research team, which also included researchers from the University of Oregon.

While scientists in recent decades have gained a good understanding of how nerve cells, or neurons, develop their connections in the developing embryo, much less is known about how adult animals and humans repair—or fail to repair—those connections when axons are damaged.

"There are many processes not involved in early development that are involved in switching the neurons to this re-growth mode," said Chisholm. "In essence what we found are genes that people had not suspected previously to be part of this process."

Of particular interest to the UC San Diego biologists are the six genes that appear to repress the growth of axons.

"The discovery of these inhibitors is probably the most exciting finding," said Chisholm, because identifying and eliminating the inhibiting factors to the re-growth of axons could be just as essential as the biochemical pathways that promote axon re-growth in repairing spinal cord injuries and other kinds of nerve damage.

The scientists were also surprised to learn that some of the genes they found to be involved in the re-growth of axons were known to have other functions, such as regulating the release of neurotransmitters.

"This was in large part unexpected," said Chisholm. "These genes had not been implicated in the re-growth of axons before."

To find the 76 genes, the researchers conducted painstaking experiments on more than 10,000 tiny laboratory roundworms known as C. elegans. The first step involved developing genetic mutants of these transparent roundworms for each one of 654 genes that were suspected to play a role in the regulation of axon regrowth in worms, fruit flies and mice. They then labeled the roundworm neurons with green fluorescent protein and, with a precise surgical laser, damaged a specific axon.

"The goal was to study this process in its simplest form," said Chisholm. "Because the animals are essentially transparent, we can see the axons expressing this green fluorescent protein."

By examining the re-growth, or lack of growth, of the damaged axon 24 hours later, the scientists were then able to determine which of these 654 genes were actually important to axon re-growth.

Chisholm said that while the 76 genes identified are believed to have similar roles in mammals as well as roundworms, because their functions were "conserved" by the organisms through evolution, he and his research team are now collaborating with other investigators to conduct experiments on mice to verify this connection and determine which of these genes are the most critically important.

"Worms are clearly different from mammals," he added. "But there will be a core of conserved molecules doing the same job."

In addition to Chisholm and Jin, the UC San Diego biologists involved in the study were Lizhen Chen, Zhiping Wang, Anindya Ghosh-Roy, Thomas Hubert, Dong Yan, and Zilu Wu. Sean O'Rourke and Bruce Bowerman from the University of Oregon were also part of the team.

The research project was supported by grants from the National Institutes of Health and the Howard Hughes Medical Institute.

Kim McDonald | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>