Featured Research

from universities, journals, and other organizations

Discovery Of A Mechanism Controlling The Fate Of Hematopoietic Stem Cells

Date:
August 13, 2009
Source:
CNRS
Summary:
Hematopoietic stem cells are capable of manufacturing all types of blood cells. But which factors influence the production of a specific type of cell? Until now, it was thought that this was a random process. Scientists have now discovered the factors that determine the type of cells produced. The mechanism they have demonstrated in the mouse involves one factor intrinsic to the cell and one extrinsic factor.

Microscopy image of a hematopoietic stem cell (in yellow) surrounded by other cells, in a spleen section.
Credit: Copyright Frιdιric Mourcin

Hematopoietic stem cells are capable of manufacturing all types of blood cells. But which factors influence the production of a specific type of cell? Until now, it was thought that this was a random process. At the Centre d'Immunologie de Marseille-Luminy (1), a team of CNRS and Inserm researchers led by Michael Sieweke has discovered the factors that determine the type of cells produced. The mechanism they have demonstrated in the mouse involves one factor intrinsic to the cell and one extrinsic factor.

These results were published in the journal Cell on July 24, 2009.

Stem cells are a source of much hope, thanks to their extraordinary ability to produce all types of cell in the body or an organ, depending on their origin.  Scientists are now trying to understand the mechanisms that commit stem cells to a particular specialization.

At the Centre d'Immunologie de Marseille-Luminy, CNRS and INSERM researchers have been working on mouse hematopoietic stem cells.  They studied the development of myeloid cells, a lineage of white blood cells that combats microorganisms by "eating" them, by releasing toxins or by alerting other specialized immune cells.  Until now, it was thought that the production of different specialized cells from a hematopoietic stem cell was a random process.  Sieweke's team has discovered that in the case of myeloid cells, it is the combined action of two proteins which is relevant; one protein that is situated inside the cell (transcription factor) and the other outside (a cytokine).

Transcription factors are capable of switching genes on or off.  The identity of a cell is the combination of active genes it possesses.  Because of this, scientists already suspected that transcription factors played an important role in the orientation of differentiation.  They also knew that blood cells can only prosper in an environment containing a particular cytokine, a type of hormone specific to each cell type.  But until now, they thought that cytokines assisted the survival and renewal of cells without affecting their "fate".  The team in Marseille has now shown that a specific cytokine (M-CSF) places stem cells on a "myeloid pathway", but that these stem cells can only follow this path if levels of a certain transcription factor (MafB) within the cells is low. 

These findings help to solve a mystery that has fascinated specialists during the past fifty years.  In the longer term, these results may throw new light on the mechanisms of leukemia, where abnormal stem cells remain "undecided" and are still able to escape therapy.

Until now, studies on hematopoietic stem cells had opened the way to research on stem cells in other tissues.  In this context, the results achieved and published by Michael Sieweke and his colleagues may provide more general information on how stem cells function (in the brain, muscle or intestine).


Story Source:

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


Journal Reference:

  1. Sandrine Sarrazin, Noushine Mossadegh-Keller, Taro Fukao, Athar Aziz, Frederic Mourcin, Laurent Vanhille, Louise M. Kelly-Modis, Philippe Kastner, Susan Chan, Estelle Duprez, Claas Otto and Michael H. Sieweke. MAFB Restricts M-CSF Dependent Myeloid Commitment Divisions of Hematopoietic Stem Cells. Cell, 24 July 2009

Cite This Page:

CNRS. "Discovery Of A Mechanism Controlling The Fate Of Hematopoietic Stem Cells." ScienceDaily. ScienceDaily, 13 August 2009. <www.sciencedaily.com/releases/2009/07/090730233126.htm>.
CNRS. (2009, August 13). Discovery Of A Mechanism Controlling The Fate Of Hematopoietic Stem Cells. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2009/07/090730233126.htm
CNRS. "Discovery Of A Mechanism Controlling The Fate Of Hematopoietic Stem Cells." ScienceDaily. www.sciencedaily.com/releases/2009/07/090730233126.htm (accessed September 22, 2014).

Share This



More Health & Medicine News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) — Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) — Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) — A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) — The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. 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