Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study identifies molecule essential for proper localization of blood stem cells

16.01.2006


Result supports interaction between bone formation and production of blood, immune cells



Scientists at the Massachusetts General Hospital (MGH) Center for Regenerative Medicine and the Harvard Stem Cell Institute (HCSI) have defined a molecule that dictates how blood stem cells travel to the bone marrow and establish blood and immune cell production. The discovery may help improve bone marrow stem cell transplantation and the treatment of several blood disorders.

"This is another remarkable example of how bone and bone marrow interact. A receptor known to participate in the body’s regulation of calcium and bone also is critical for stem cells to engraft in the bone marrow and regenerate blood and immune cells," says David Scadden, MD, director of the MGH Center for Regenerative Medicine and co-director of the HSCI. "It reminds us how tissues interact and how looking closely at where stem cells reside may tell us a lot about how to manipulate them." Scadden is senior author of the report, which will be published in the journal Nature and has received early online release.


Hematopoietic or blood stem cells are critical to the daily production of over 10 billion blood cells and are the basis for bone marrow transplant therapy for cancer. Rare and difficult to identify, these cells are extremely powerful at regenerating blood and immune cells but only if they travel to the proper location when introduced into the body. Typically the cells are infused into a vein, and they find their way to the bone marrow through a process that depends on largely unknown molecules.

Within the bone marrow cavity, stem cells are usually found in the outer layer close to the inner surface of the bone. Since the process of remodeling bone takes place in the adjacent bone tissue and because studies by Scadden’s group and others have shown that bone-forming osteoblast cells are essential to the regulation of the stem cell environment, it seemed probable that fundamental interactions exist between the processes of bone formation and stem cell development. As increased extracellular calcium is required for bone formation, the researchers theorized that a molecule called the calcium-sensing receptor (CaR), present on many cells, might be key to the localization of blood stem cells.

To test their theory, the researchers first verified the presence of CaR on primitive marrow cells taken from normal mice. They then ran several experiments using transgenic mice that do not produce the CaR protein and found that, while many types of marrow and adjacent bone cells were present in normal proportions, levels of blood stem cells were very low in the marrow cavities of the transgenic mice. Other experiments showed that the absence of other cell-surface molecules did not affect the numbers of stem cells in the marrow.

Examination of the spleens and the blood of the transgenic mice showed that the numbers of primitive blood stem cells were significantly elevated in those areas, indicating that the absence of CaR did not affect the production of stem cells by the fetal liver. In a group of normal mice that received radiation at doses that would destroy the bone marrow, transplantation of fetal liver cells from mice with and without CaR allowed the animals to survive, but those who received cells from CaR-negative mice had dramatically fewer stem cells in their bone marrow. Additional experiments showed that the CaR-negative cells were unable to adhere to collagen I, an essential bone protein produced by the osteoblasts.

"Since there are already drugs available that target this receptor, we may be able to quickly adapt these findings in animals to the treatment of human patients," says Scadden, who is a professor of Medicine at Harvard Medical School.

Sue McGreevey | EurekAlert!
Further information:
http://www.mgh.harvard.edu/

More articles from Life Sciences:

nachricht Progress in Super-Resolution Microscopy
17.12.2018 | Julius-Maximilians-Universität Würzburg

nachricht Communication between neural networks
17.12.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

When a fish becomes fluid

17.12.2018 | Studies and Analyses

Progress in Super-Resolution Microscopy

17.12.2018 | Life Sciences

How electric heating could save CO2 emissions

17.12.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>