Featured Research

from universities, journals, and other organizations

RORalpha, the orchestrator of neuron protection

Date:
December 29, 2009
Source:
CNRS (Délégation Paris Michel-Ange)
Summary:
How do the brain cells called astrocytes ensure the protection of neurons? By studying the protagonists in the protection and satisfactory functioning of neurons, scientists have found a mechanism that clarifies the role of astrocytes. Crucial to this mechanism, RORalpha protein is revealed as an essential regulator of inflammatory factors. This discovery constitutes a new path for research on novel drugs in the event of cerebral lesions (e.g. neurodegenerative diseases or trauma).

How do the brain cells called astrocytes ensure the protection of neurons? By studying the protagonists in the protection and satisfactory functioning of neurons, scientists at the Laboratoire Neurobiologie des Processus Adaptatifs (CNRS/UPMC) have found a mechanism that clarifies the role of astrocytes. Crucial to this mechanism, RORalpha protein is revealed as an essential regulator of inflammatory factors. This discovery constitutes a new path for research on novel drugs in the event of cerebral lesions (e.g. neurodegenerative diseases or trauma). These findings were published in the advance edition of PNAS on 1 December 2009.

Astrocytes form part of the glial cells and play a key role in the functioning, well-being and protection of neurons. They react to neuron status and are implicated in the inflammatory response. Inflammation is a complex immune phenomenon that balances the activating and inhibitory actions of a finely-tuned set of molecules. Neuronal inflammation can cause disturbances and hamper the functioning of nerves.

Focusing on glial cells, the scientists hypothesized that there was a contribution of the RORalpha protein in the reaction of these cells to neuronal death. RORalpha is known as a receptor specialized in controlling the expression of genes in the nucleus that exert an anti-inflammatory effect. Until now, it was thought that this protein was exclusively localized in neurons and not in astrocytes.

This discovery thus demonstrates the expression of RORalpha in astrocytes and its role in regulating interleukin-6 (IL-6), an essential mediator of inflammation. In the brain, IL-6 is mainly produced by astrocytes, this production being up-regulated under inflammatory conditions. This molecule has demonstrated neuro-protective properties in several in vivo and in vitro models, but under certain conditions it may also have neurotoxic effects.

The unexpected finding was that RORalpha exerts an ambivalent action on IL-6 production. In astrocytes in an inflammatory situation, RORalpha is up-regulated. It indirectly blocks IL-6 production, preventing any toxicity. However, under normal physiological conditions where the astrocyte is not stimulated, RORalpha activates IL-6 production at concentrations that are beneficial at a basal level. This ambivalence of both RORalpha and IL-6 thus permits astrocytes to react rapidly to attack so as to ensure favorable conditions under all circumstances in the microenvironment of neurons. In vivo, RORalpha is thus the molecular heart of a complex IL-6 regulation mechanism that occurs in the astrocyte to the benefit of neurons.

These results are of particular interest in the context of neuronal death. Indeed, whether this is chronic -- as in neurodegenerative diseases -- or acute -- following a trauma, neuron loss is always associated with a reaction by glial cells. RORalpha is thus a new path that could be followed to search for new drugs for use in these pathological situations.


Story Source:

The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length.


Journal Reference:

  1. Nathalie Journiac, Sarah Jolly, Christopher Jarvis, Vanessa Gautheron, Monique Rogard, Alain Trembleau, Jean-Paul Blondeau, Jean Mariani & Béatrice Vernet-der Garabedian. The nuclear receptor RORalpha exerts a bi-directional regulation of IL-6 in resting and reactive astrocytes. PNAS, 1 December 2009

Cite This Page:

CNRS (Délégation Paris Michel-Ange). "RORalpha, the orchestrator of neuron protection." ScienceDaily. ScienceDaily, 29 December 2009. <www.sciencedaily.com/releases/2009/12/091215164115.htm>.
CNRS (Délégation Paris Michel-Ange). (2009, December 29). RORalpha, the orchestrator of neuron protection. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2009/12/091215164115.htm
CNRS (Délégation Paris Michel-Ange). "RORalpha, the orchestrator of neuron protection." ScienceDaily. www.sciencedaily.com/releases/2009/12/091215164115.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Quintuplets Head Home

Texas Quintuplets Head Home

Reuters - US Online Video (Aug. 1, 2014) — After four months in the hospital, the first quintuplets to be born at Baylor University Medical Center head home. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Ebola Patient Coming to U.S. for Treatment

Ebola Patient Coming to U.S. for Treatment

Reuters - US Online Video (Aug. 1, 2014) — A U.S. aid worker infected with Ebola while working in West Africa will be treated in a high security ward at Emory University in Atlanta. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Ebola Vaccine Might Be Coming, But Where's It Been?

Ebola Vaccine Might Be Coming, But Where's It Been?

Newsy (Aug. 1, 2014) — Health officials are working to fast-track a vaccine — the West-African Ebola outbreak has killed more than 700. But why didn't we already have one? Video provided by Newsy
Powered by NewsLook.com
Study Links Certain Birth Control Pills To Breast Cancer

Study Links Certain Birth Control Pills To Breast Cancer

Newsy (Aug. 1, 2014) — Previous studies have made the link between birth control and breast cancer, but the latest makes the link to high-estrogen oral contraceptives. Video provided by Newsy
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