By studying nerve regeneration in roundworms, researchers in Japan have discovered another signaling pathway that induces nerves to regenerate.
Certain types of nerve injury, such as those from automobile accidents and falls, can damage or sever the axons that connect neurons and allow them to communicate with each other. Although axons elsewhere in the body can regenerate to some extent after such damage, those in nerves are far less capable, resulting in long-lasting or permanent impairment.
Treating such injuries requires clarification of how certain nerves are induced to regenerate and which molecular pathways are involved. By studying nerve regeneration in roundworms, Nagoya University researchers have discovered another signaling pathway that induces nerves to regenerate. The team also showed that this pathway is the same as the one that leads to identification and subsequent clearance of dying cells.
Neurons communicate with each other via electrical signals conveyed through dendrites and axons. This connectivity within the nerve is a source of the multiple functions of this organ, but damage to these connections due to trauma can cause functional impairment. Nerve regeneration after nerve injury is therefore an issue of special interest, but is difficult to study in humans. A non-parasitic, free-living roundworm nematode is a useful model for studying this issue as it avoids the ethical problems associated with human experimentation and its short generation time and simple development facilitate genetic engineering experiments.
To shed light on how damaged nerves are induced to regenerate, the researchers investigated various strains of this worm in which different genes were mutated or inactivated. They subjected the worms to a range of experiments, including labeling nerves with a fluorescent marker, cutting the nerves with a laser, and then monitoring their regrowth under a microscope.
They also examined the worms’ resistance with different genetic backgrounds to heavy metal stress, based on earlier findings that similar genes may be involved in both resistance to heavy metal exposure and nerve regeneration. When certain proteins encoded by these genes were absent or dysfunctional in the worms, their nerves were less able to regenerate, particularly during adulthood. They were also less able to endure exposure to a toxic level of copper.
By comparing these results among the strains in which single or multiple genes had been inactivated, the researchers established a complex molecular pathway that allows nerves to regenerate. They also found that the key molecular machinery involved in this is the same as that by which dying cells are recognized, engulfed by immune system cells, and disposed of.
“Many of the molecules and mechanisms we identified in worms have equivalents in humans,” corresponding author Naoki Hisamoto says. “Our findings should therefore lead us to targets in humans that we can use to improve recovery after nerve injury by promoting regrowth of damaged axons.”
The article “The Core Molecular Machinery Used for Engulfment of Apoptotic Cells Regulates the JNK Pathway Mediating Axon Regeneration in Caenorhabditis elegans” was published in The Journal of Neuroscience at doi: 10.1523/JNEUROSCI.0453-16.2016
This work was supported by the Ministry of Education, Culture and Science of Japan; MEXT (Grant-in-Aid for Scientific Research on Innovative Areas "Homeostatic regulation by various types of cell death," 15H01375); the Mitsubishi Foundation; the Naito Foundation; the Daiko Foundation; and the Astellas Foundation.
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses