Featured Research

from universities, journals, and other organizations

Long-distance distress signal from periphery of injured nerve cells begins with locally made protein

Date:
July 30, 2012
Source:
Drexel University
Summary:
New research is one of the strongest indicators yet of molecular signaling from end to end in peripheral nerve cells. The new discoveries may help scientists better understand nerve cells' distress signals and nerve cell repair, so they can eventually control and enhance the process to speed up recovery from nerve injuries.

Diagram shows the role of the protein importin beta1 in signaling after nerve damage at the axon, from the axon to the cell body.
Credit: Image courtesy of Drexel University

When the longest cells in the body are injured at their farthest reaches, coordinating the cells' repair is no easy task. This is in part because these peripheral nerve cells can be extremely long -- up to one meter in adult humans -- which is a lot of distance for a molecular distress signal to cover in order to reach the "command center" of the cell's nucleus.

Scientists have believed this process to be even more challenging because their textbook understanding for many years has been that the axons -- the long extensions of nerve cells away from the main cell body containing the nucleus -- do not manufacture the proteins involved in the molecular signal themselves. Yet, in recent years, some scientists have begun to challenge that textbook understanding, with preliminary evidence that one key protein involved in setting off a distress signal for cellular repair, known as importin beta1, was locally produced in the axons. They just weren't sure how.

"Now these textbooks need to be rewritten," said Dr. Jeffery Twiss, a professor and head of the department of biology in Drexel University's College of Arts and Sciences. Twiss co-authored new research recently published in Neuron, led by collaborators from the Weizmann Institute of Science. "Our new research is one of the strongest indicators yet of molecular signaling from end to end in peripheral nerve cells."

These researchers have provided strong new evidence that the protein importin beta1 is indeed produced locally in the axons of peripheral nerve cells. They also found that the version of the protein, when found in the axon, is made using a different molecular recipe than the version found in the nucleus, where it performs different essential cell functions. These discoveries may help scientists better understand how subsequent steps operate in the distress signal and in nerve cell repair, so they can eventually control and enhance the process to speed up recovery from nerve injuries.

Finding this evidence was far from simple: Importins are so crucial in the cell's nucleus that even the smallest embryo could not survive without them. But Rotem Ben-Tov Perry, a research student at the Weizmann Institute who was lead author of the new study, found a way to distinguish the importin beta1 in the cell body from that in the axon: The axonal protein was apparently made from a longer version of messenger RNA, the cell's working recipe for building a protein. To see if they could selectively affect just the axonal version of the protein, the Weizmann researchers worked with Drexel's Twiss to take advantage of high precision knock-out technology. Rather than knocking a whole gene out of the system, they managed to remove one little piece of the messenger RNA's recipe for manufacturing importins- just the longer bit that sends the RNA to the axon.

Now they observed plenty of importin beta1 in the cell body, but none in the axons. With the axonal segment of RNA knocked out of the recipe for importin beta1, a mouse embryo still had the importin it needed near the nucleus of its cells to grow and develop into a living animal -- but it took much longer to recover from peripheral nerve injury. Genes that are normally active in response to nerve damage were activated to a lesser degree. All of this suggests that the importin beta1 that normally helps inform the extended nerve cell about injury is, indeed, produced locally in the axon -- and that this protein found in the axon is a key part of the nerve repair signaling process.

"The data shows conclusively that importin beta1 protein is produced in axons, Rotem's work has validated the importins' crucial role in nerve repair," said Dr. Michael Fainzilber, senior author and professor at the Weizmann Institute.

Twiss said that next steps will be to better describe how the signaling process involving importin beta1 delivers a signal to begin nerve cell repair and, ultimately, develop strategies to better control these molecular steps of the repair mechanisms to improve nerve cell regeneration after injury.


Story Source:

The above story is based on materials provided by Drexel University. Note: Materials may be edited for content and length.


Journal Reference:

  1. RotemBen-Tov Perry, Ella Doron-Mandel, Elena Iavnilovitch, Ida Rishal, ShacharY. Dagan, Michael Tsoory, Giovanni Coppola, MargueriteK. McDonald, Cynthia Gomes, DanielH. Geschwind, JefferyL. Twiss, Avraham Yaron, Mike Fainzilber. Subcellular Knockout of Importin β1 Perturbs Axonal Retrograde Signaling. Neuron, 2012; 75 (2): 294 DOI: 10.1016/j.neuron.2012.05.033

Cite This Page:

Drexel University. "Long-distance distress signal from periphery of injured nerve cells begins with locally made protein." ScienceDaily. ScienceDaily, 30 July 2012. <www.sciencedaily.com/releases/2012/07/120730112105.htm>.
Drexel University. (2012, July 30). Long-distance distress signal from periphery of injured nerve cells begins with locally made protein. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2012/07/120730112105.htm
Drexel University. "Long-distance distress signal from periphery of injured nerve cells begins with locally made protein." ScienceDaily. www.sciencedaily.com/releases/2012/07/120730112105.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

More Coverage


Crucial Protein for Peripheral Nerve Repair Manufactured Within Axon Near Injury Site

July 25, 2012 Contrary to scientific belief, a crucial protein for peripheral nerve repair is manufactured within the axon near the injury ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins