Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Researchers Identify Gene Required for Nerve Regeneration

Published: Tuesday, November 06, 2012
Last Updated: Tuesday, November 06, 2012
Bookmark and Share
A gene that is associated with regeneration of injured nerve cells has been identified by scientists at Penn State and Duke University.

The team, led by Melissa Rolls, an assistant professor of biochemistry and molecular biology at Penn State, has found that a mutation in a single gene can entirely shut down the process by which axons -- the parts of the nerve cell that are responsible for sending signals to other cells -- regrow themselves after being cut or damaged. "We are hopeful that this discovery will open the door to new research related to spinal-cord and other neurological disorders in humans," Rolls said. The journal Cell Reports published an early online copy of the paper today (Nov. 1), and also will include the paper in the monthly issue of the journal, which will be published Nov. 29.

Rolls explained that axons, which form long bundles extending out from nerve cells, ideally survive throughout an animal's lifetime. To be able to survive, nerve cells need to be resilient and, in the event of injury or simple wear and tear, some can repair damage by growing new axons. Earlier research from Rolls and others suggested that microtubules -- the intracellular "highways" along which basic building blocks are transported -- might need to be rebuilt as an important step in this type of repair. "In many ways this idea makes sense. In order to grow a new part of a nerve, raw materials will be needed and the microtubule highways will need to be organized to take the new materials to the site of growth," Rolls said. The Rolls team therefore started to investigate the role of microtubule-remodeling proteins in axon regrowth after injury. In particular, the team members focused on a set of proteins that sever microtubules into small pieces. Out of this set, a protein named spastin emerged as a key player in axon regeneration.

"The fact that the spastin protein plays a critical role in regeneration is particularly intriguing because, in humans, it is encoded by a disease gene called SPG4," Rolls explained. "When one copy of this gene is disrupted, affected individuals develop hereditary spastic paraplegia (HSP), which is characterized by progressive lower-limb weakness and spasticity as the long-motor axons in the spinal cord degenerate. Thus, identifying a new neuronal function for spastin may help us to understand this disease."

To study the role of spastin, Rolls and her team chose the fruit fly as their model organism. "On the molecular level, many of the processes associated with nerve-cell growth and regrowth are the same in humans as in fruit flies," Rolls said. "And, like all other animals including humans, fruit flies have two copies of every gene -- one from each parent -- so different combinations of each gene can lead to different observable traits." The team members bred three genetically distinct groups of fruit flies in the laboratory to observe how various spastin gene combinations might affect the behavior of nerve cells after injury. The first group of flies had two normal copies of the gene; the second had one normal copy and one mutant copy; while the third had two mutant copies. Then, in all three groups, the scientists cut the axons of the flies' nerve cells and observed the regeneration process.

"In fruit flies with two normal copies of the gene, we observed that severed axons elegantly reassembled themselves. This process is supposed to take place if the fly is to heal from nerve trauma since life events, as well as wear and tear, tend to cause such damage," Rolls said. "But, interestingly, in the other two groups -- the fruit flies with two or even one abnormal spastin gene -- there was simply no regrowth, indicating that what we have here is a dominant problem." Rolls explained that dominant diseases arise when only one copy of a disease gene is disrupted. For example, Huntington's disease in humans is a dominant disease because people who have inherited a normal gene from one parent and an abnormal gene from the other parent still become ill. Meanwhile, cystic fibrosis is a recessive disease: people with at least one normal gene copy do not manifest the disease at all.

The scientists also found that an impaired spastin gene affected only how the axons regrew after being severed. That is, the gene did not seem to play a role in the developmental stage when axons were being assembled for the first time. In addition, the researchers found that, while the gene affected the flies' axons, their dendrites -- the parts of the neuron that receive information from other cells and from the outside world -- continued to function and repair themselves normally.

"Now that we know that spastin plays an important role in axon regeneration and also that this gene is dominant, we have opened up a possible path toward the study of human diseases involving nerve-cell impairment," Rolls said. "In fact, our next step is to probe the link between hereditary spastic paraplegia (HSP) and axon regeneration." Rolls added that the SPG4 gene that encodes human spastin is only one of the disease genes associated with HSP, so she and her colleagues now are testing whether other disease genes also play a role in nerve-cell regeneration.

In addition to Rolls, other researchers who contributed to this study include Michelle C. Stone, Kavitha Rao, Kyle W. Gheres, Seahee Kim, Juan Tao, Caroline La Rochelle and Christin T. Folker from Penn State; and Nina T. Sherwood from Duke University.

The research was funded by the Spastic Paraplegia Foundation; the National Institutes of Health through its National Institute of Neurological Disorders and Stroke, and its National Institute of General Medical Sciences; and the Pew Scholars in the Biomedical Sciences.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More Than 3,800+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

3-D Model Links Facial Features and DNA
An international team of researchers is beginning to connect genetics with facial features, degrees of femininity and racial admixture.
Friday, March 21, 2014
Professor Leads Project to Breed Beans Resistant to Climate Stresses
With support from a $5 million grant, an international team will establish the Feed the Future Innovation Lab for Climate-Resilient Beans.
Monday, November 11, 2013
Researcher Investigates the Role of Specialized Bone Marrow Cells
NIH Bridge Program scholar aims to slow bone metastasis.
Friday, September 27, 2013
Novel Nanoparticles Developed to Deliver Healing Drugs Directly to Bone Cracks
A novel method for delivering healing drugs to newly formed microcracks in bones may help patients with osteoporosis and other medical conditions.
Monday, September 09, 2013
Comprehensive Parkinson's Biomarker Test Has Prognostic and Diagnostic Value
First biomarker results reported from the Parkinson’s Progression Markers Initiative (PPMI).
Monday, September 02, 2013
Computer Programs Improve Fingerprint Grading
Three computer programs used together can give fingerprint grading unprecedented consistency and objectivity, according to Penn State researchers.
Friday, July 05, 2013
Endangered Lemurs' Complete Genomes are Sequenced and Analyzed for Conservation
For the first time, the complete genomes of three separate populations of aye-ayes have been sequenced and analyzed in an effort to help guide conservation efforts.
Tuesday, March 26, 2013
Search begins for dean of the College of Agricultural Sciences
Penn State initiates U.S. wide search for candidates.
Thursday, January 10, 2013
Students Develop Low-cost Water Filtering System for African Nation
In an effort to bring fresh water to rural Kenyans students of Penn State's Humanitarian Engineering and Social Entrepreneurship (HESE) program develop a ceramic water filtration system.
Thursday, January 10, 2013
Important Gene-Regulation Proteins Pinpointed by New Method
A novel technique has been developed and demonstrated at Penn State to map the proteins that read and regulate chromosomes.
Friday, January 20, 2012
Scientific News
NIH Study Finds Calorie Restriction Lowers Some Risk Factors for Age-Related Diseases
Two-year trial did not produce expected metabolic changes, but influenced other life span markers.
Immunotherapy Agent Benefits Patients with Drug-Resistant Multiple Myeloma in First Human Trial
Daratumumab proved generally safe in patients, even at the highest doses.
Low-level Arsenic Exposure Before Birth Associated with Early Puberty in Female Mice
Study examine whether low-dose arsenic exposure could have similar health outcomes in humans.
Inciting an Immune Attack On Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
‘Mutation-Tracking’ Blood Test for Breast Cancer
Scientists have developed a blood test for breast cancer able to identify which patients will suffer a relapse after treatment, months before tumours are visible on hospital scans.
Cellular Contamination Pathway for Heavy Elements Identified
Berkeley Lab scientists find that an iron-binding protein can transport actinides into cells.
Intensity of Desert Storms May Affect Ocean Phytoplankton
MIT study finds phytoplankton are extremely sensitive to changing levels of desert dust.
Common ‘Heart Attack’ Blood Test May Predict Future Hypertension
Small rises in troponin levels may have value as markers for subclinical heart damage and high blood pressure.
LaVision BioTec Reports on the Neuro Research on the Human Brain After Trauma
Company reports on the work of Dr Ali Ertürk from the Institute for Stroke and Dementia Research at LMU Munich.
NIH Study Shows No Benefit of Omega-3 Supplements for Cognitive Decline
Research was published in the Journal of the American Medical Association.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!