Featured Research

from universities, journals, and other organizations

Why Neural Stem Cells Divide And Differentiate

Date:
July 17, 2009
Source:
Goethe University Frankfurt
Summary:
Neural stem cells represent the cellular backup of our brain. These cells are capable of self-renewal to form new stem cells or differentiate into neurons, astrocytes or oligodendrocytes. The receptors of the Notch family play a significant role in this process. So far, only stimulating extracellular ligands of Notch receptors had been described. Biochemists now describe a long time assumed but not yet identified soluble Notch inhibitor.

Neural stem cells represent the cellular backup of our brain. These cells are capable of self-renewal to form new stem cells or differentiate into neurons, astrocytes or oligodendrocytes. Astrocytes have supportive functions in the environment of neurons, while oligodendrocytes form the myelin layer around axons in order to accelerate neuronal signal transmission.

But how does a neural stem cell "know" which way it is supposed to develop? On the molecular level receptors of the Notch family play a significant role in this process. So far, only stimulating extracellular ligands of Notch receptors had been described. Biochemists of Goethe University Medical School now describe a long time assumed but not yet identified soluble Notch inhibitor.

Franfurt scientists led by Mirko Schmidt and Ivan Dikic reported in the renowned journal Nature Cell Biology that the secreted protein EGFL7 (Epidermal Growth Factor-like domain 7) is such an inhibitory factor. EGFL7 had already been known from its involvement in the development of blood vessels. "It was a surprise when we discovered that EGFL7 bound the extracellular domains of Notch receptors and competed with known Notch ligands" explains Ivan Dikic from the Institute of Biochemistry and CEF Institute in Frankfurt.

Researchers analyzed the antagonistic effects of EGFL7 in adult neural stem cells. The self-renewal potential of these cells depends on an intact interaction of the ligand Jagged1 and its receptor Notch1. Addition of EGFL7 blocked the essential interaction and reduced the division of neural stem cells. At the same time, EGFL7 stimulated the differentiation of neural stem cells into neurons.

"It has been well defined that Notch signaling drives the formation of astrocytes from neural stem cells while it suppresses the formation of neurons and the maturation of oligodendrocytes," explains Mirko Schmidt at the Institute of Neurology. Inhibition of Notch signaling reverses the situation and more neural stem cells differentiate into neurons. This is exactly what happened upon the addition of EGFL7. In order to verify their findings in vivo, the researchers analyzed mouse brains and identified mature neurons as a source of EGFL7 in the adult brain. The distribution of these cells in the brain was biologically significant, as EGFL7 was absent from regions with high amounts of neural stem cells, e.g. the subventricular zone. "This way EGFL7 may promote the formation of new neurons" suggests Schmidt.

The findings of Schmidt and Dikic offer a plethora of medical applications. Maturation of adult stem or precursor cells is significant for the development of multiple tissues, e.g. in the central nerve system or in the heart. Moreover, cancer stem cells have been described, which are important for the formation of tumors, especially in the human brain. EGFL7 might also be applied as a neuronal differentiation factor in ischemic insults or neurodegenerative diseases such as Alzheimer or Parkinson predict both researchers. Future work will unravel in which diseases EGFL7 can unfold its therapeutic potential.


Story Source:

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


Journal Reference:

  1. Schmidt et al. Epidermal growth factor-like domain 7 (EGFL7) modulates Notch signalling and affects neural stem cell renewal. Nature Cell Biology, 2009; DOI: 10.1038/ncb1896

Cite This Page:

Goethe University Frankfurt. "Why Neural Stem Cells Divide And Differentiate." ScienceDaily. ScienceDaily, 17 July 2009. <www.sciencedaily.com/releases/2009/06/090630091033.htm>.
Goethe University Frankfurt. (2009, July 17). Why Neural Stem Cells Divide And Differentiate. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/06/090630091033.htm
Goethe University Frankfurt. "Why Neural Stem Cells Divide And Differentiate." ScienceDaily. www.sciencedaily.com/releases/2009/06/090630091033.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
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:
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