Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lost in the labyrinth

04.09.2006
Decoding the instructions that tell cells how to become blood

Blood cells have limited lifespans, which means that they must be continually replaced by calling up reserves, and turning these into the blood cell types needed by the body. Claus Nerlov and his colleagues at the European Molecular Biology Laboratory (EMBL) unit in Monterotondo, Italy, in collaboration with researchers from Sten Eirik Jacobsen’s laboratory at the University of Lund in Sweden, have now uncovered how an intracellular communication pathway contributes to this process. Because defects in such pathways and in the development of stem cells frequently lead to leukemia and other diseases, the work should give researchers a new handle on processes within cells that lead to cancer. The work is published in this week’s online issue of Nature Immunology.

Over the past decades, molecular biologists have identified several pathways – sequences of molecules which manage the flow of information within the cell – responsible for major biological processes. One of these, the “Wingless” pathway, plays a vital role in shaping tissues and organs in developing embryos of nearly all animal species. It also helps organisms manage stem cells, by keeping them on hold and preventing their differentiation until the right time. Such pathways are usually switched on and off by external stimuli that help cells respond properly to the environment. Now Peggy Kirstetter and other members of Nerlov’s lab have shown what happens when Wingless is too active in hematopoietic stem cells in mice.

“We modified one element of the pathway, a protein called beta-catenin, so that it was stuck in ‘transmission mode,’” Kirstetter says. “This created cells in which the pathway was always switched on. We’ve known that Wingless contributes to blood differentiation, but didn’t know how the signals were being transmitted within the hematopoietic stem cell.”

... more about:
»Beta-Catenin »Wingless »blood cell »stem cells

The modified protein had dramatic effects. Usually, most cells undergo numerous transitional stages on their way from stem cells to fully-developed types in the blood. Several types of blood cells vanished entirely; the same thing happened to more basic cell types higher up in the blood lineage hierarchy. Particular kinds of stem cells disappeared from the bone marrow of the mice. Others were too frequent. Bone marrow cells didn’t develop into myeloid and red blood cells. B- and T-cells were also blocked at early stages, but in a different way. This hints that they may be controlled by other protein links in the Wingless pathway as well. Perhaps most strikingly, beta-catenin appears to make cells take decisions about their fate before they leave the stem cell compartment in the bone marrow, something so far not thought to occur.

The study proves that beta-catenin plays a central role in determining whether blood cells form or not. On the other hand, an overactive Wingless pathway doesn’t seem to damage cells that already exist. Thus beta-catenin seems to be a decision-maker, a selector of how information gets routed within the cell, rather than something which maintains the vitality of existing cells.

Nerlov compares the breakdown to people standing at a fork in a labyrinth, hesitating before they go on. “We know there are strong connections to cells’ decisions to divide, to develop or to die. If cells don’t commit themselves to the right developmental path at the right time, they’re very likely to die or to begin an inappropriate type of reproduction. Acute leukemias and other forms of cancer cells derive from defects such as this. Understanding the processes by which they form will require pinpointing the forks in the road where things go wrong.”

Anna-Lynn Wegener | alfa
Further information:
http://www.embl.de

Further reports about: Beta-Catenin Wingless blood cell stem cells

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>