Navigation Links
New component of the 'brakes' on nerve regeneration found

Among the principal obstacles to regenerating spinal cord and brain cells after injury is the "braking" machinery in neurons that prevents regeneration. While peripheral nerves have no such machinery and can readily regenerate, central nervous system (CNS) neurons have their brakes firmly in place and locked.

Now, two groups of scientists have independently found a new component of that braking machinery, adding to understanding of the regulation of neuronal regeneration and of possible treatments to switch off the brakes on regrowth of spinal cord or brain tissue.

The two groups--one group led by Jong Bae Park, Glenn Yiu, and colleagues from Children's Hospital Boston and the other led by Sha Mi and colleagues of Biogen Idec, Inc.--discovered that a protein variously called TAJ or TROY acts as an important part of the receptor on neurons that responds to growth-inhibitory molecules in myelin. Specifically, these molecules prevent the growth of the cablelike axons of injured neurons. Myelin is the fatty sheath that encases neurons and acts as an insulator and aid to the transmission of nerve impulses.

Researchers knew that CNS neurons had receptors on their surface that accepted the inhibitory molecules--like a key fitting a lock--and switched-on inhibitory signaling within the neuron. They had also shown that a protein called p75 could function as a component of the complex of proteins that make up this receptor. The puzzle, however, was that p75 is not widely made in the adult neurons in which this inhibitory receptor complex is known to function.

The two research groups turned their attention to TAJ/TROY because it is a member of the same family of receptor proteins--called TNF receptors--as p75. Their experiments revealed that TAJ/TROY is produced throughout the adult brains of mice. Also, they found that TAJ/TROY readily fits into the inhibitory receptor complex and that the resulting receptor complex switches-on the inhibitory ma chinery within neurons. Also, they found that treating neurons with a nonfunctional version of TAJ/TROY abolished neurons' response to the "braking" molecules produced by myelin and encouraged neuron growth.

"Given the limited expression of p75, the discovery of TAJ function is an important step for understanding the regulation of axon regeneration," wrote Mi and colleagues.

Wrote Park and colleagues, "The implication that more than one TNF receptor member may be involved in myelin inhibition adds a new level of complexity to designing therapeutic strategies for treating CNS injury." They cited studies showing that TNF receptors are expressed in many types of cells in the CNS and are intimately involved in inflammatory responses that also play a role--perhaps harmful, perhaps beneficial to regeneration or recovery--in regulating response to injury. "Further characterization of the underlying mechanisms of these findings and their relation to myelin inhibition may provide important insights into designing therapeutic strategies to block myelin inhibition and cell death in the context of CNS injury," they wrote.

###

Jong Bae Park, Glenn Yiu, Shinjiro Kaneko, Jing Wang, Jufang Chang, and Zhigang He: "A TNF Receptor Family Member, TROY, Is a Coreceptor with Nogo Receptor in Mediating the Inhibitory Activity of Myelin Inhibitors"

Zhaohui Shao, Jeffrey L. Browning, Xinhua Lee, Martin L. Scott, Sveltlana Shulga-Morskaya, Norm Allaire, Greg Thill, Melissa Levesque, Dinah Sah, John M. McCoy, Beth Murray, Vincent Jung, R. Blake Pepinsky, and Sha Mi: "TAJ/TROY, an Orphan TNF Receptor Family Member, Binds Nogo-66 Receptor 1 and Regulates Axonal Regeneration"


'"/>

Source:Cell Press


Related biology news :

1. Gap-climbing fruit flies reveal components of goal-driven behaviors
2. Study uncovers dirty little secret: Soil emissions are much-bigger-than-expected component of air pollution
3. Solexa and collaborating scientists illuminate the small RNA component of the transcriptome
4. Uniquely human component of language found in gregarious birds
5. Mice lacking key immune component still control chronic viral infections
6. African parasite makes component of fat differently from all other organisms
7. New study reveals components of cocoa may enhance the appearance of the skin
8. Researchers in Montréal and the US create model of key immune-system component
9. Twin studies reveal genetic components leading to cardiac and kidney disease
10. Wisconsin scientists grow critical nerve cells
11. Clam embryo study shows pollutant mixture adversely affects nerve cell development
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/27/2016)... Research and Markets has announced the addition of the "Biometrics ... The report forecasts the biometrics market ... CAGR of 12.28% during the period 2016-2020. The ... inputs from industry experts. The report covers the market landscape and ... a discussion of the key vendors operating in this market. ...
(Date:6/22/2016)...  The American College of Medical Genetics and Genomics was ... as one of the fastest-growing trade shows during the Fastest ... in Las Vegas . ... in each of the following categories: net square feet of ... attendees. The 2015 ACMG Annual Meeting was ranked 23 out ...
(Date:6/22/2016)... , June 22, 2016   Acuant ... and verification solutions, has partnered with RightCrowd ... solutions for Visitor Management, Self-Service Kiosks and ... products that add functional enhancements to existing ... corporations and venues with an automated ID ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... PHILADELPHIA , June 27, 2016  Alex,s Lemonade ... announced that that it will open a state-of-the-art bioinformatics ... childhood cancer research. This announcement comes as Liz ... attends the National Cancer Moonshot Summit in ... Dr. Biden as a participant and advocate of pediatric ...
(Date:6/27/2016)... -- Global demand for enzymes is forecast to grow ... billion.  This market includes enzymes used in industrial ... animal feed, and other markets) and specialty applications ... beverages will remain the largest market for enzymes, ... containing enzymes in developing regions.  These and other ...
(Date:6/27/2016)... GUELPH, ON , June 27, 2016 /PRNewswire/ - BIOREM ... it has been advised by its major shareholders, Clean ... LP, United States based venture ... common shares of Biorem (on a fully diluted, as ... for the disposition of their entire equity holdings in ...
(Date:6/27/2016)... DIEGO , June 27, 2016  Sequenom, Inc. ... committed to enabling healthier lives through the development of ... Court of the United States ... courts that the claims of Sequenom,s U.S. Patent No. ... patent eligibility criteria established by the Supreme Court,s Mayo ...
Breaking Biology Technology: