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 New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego

nachricht Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>