Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scythe balances life and death during development

14.12.2005


Scythe protein is critical to the normal development of the lungs, kidney and brain, according to St. Jude



A protein called Scythe determines which cells live and which die during the growth and development of the mammalian embryo, according to investigators at St. Jude Children’s Research Hospital.

The St. Jude study is the first to show that Scythe plays a critical role during development of mammals by selectively regulating when and where specific cells either proliferate or undergo apoptosis, the process by which cells self-destruct. Understanding exactly how Scythe balances apoptosis with cell proliferation could provide significant insights into how organs develop in the growing embryo, researchers said.


The St. Jude team showed in laboratory models that in the absence of Scythe the lungs, kidneys and brains develop abnormally and the embryos cannot survive. These defects were caused by the loss of control over both the multiplication of some cells and the process of apoptosis, in which cells self-destruct.

Normally, there is a balance between life and death in the embryo as the various parts of specific organs get "sculpted" out of the growing mass of cells and some cells are eliminated, according to Peter McKinnon, Ph.D., an associate member of the St. Jude Department of Genetics and Tumor Cell Biology. But cells in certain organs of models lacking both copies of the Scythe gene (Scythe-/-) either failed to receive or failed to respond to signals triggering proliferation or apoptosis. The resulting organs were malformed and unable to function properly, he said. McKinnon is the senior author of a report on this work that appears in the December issue of Molecular and Cellular Biology.

"Scythe is critical to the embyro’s ability to survive and develop normally," McKinnon said. "The protein appears to regulate both apoptosis and the multiplication of cells in a way that we don’t yet understand."

Previous work by other researchers suggests that the Scythe protein might work by regulating the folding and activity of the molecules that make up the signaling pathway that controls apoptosis. Scythe was also known to interact with another protein called Reaper to control development of the fruit fly. Therefore, the St. Jude team developed laboratory models lacking both copies of Scythe to study what happens in the gene’s absence. The scientists discovered that major defects in lung development appeared late in the process of embryo development.

Specifically, the lungs were very small and their branching airways were underdeveloped. In addition, there were almost no alveoli--the small air sacs at the end of the smallest airways. Moreover, the kidneys failed to form properly or did not form at all. This showed that Scythe is required for development of both the lung and kidney. The Scythe-/- model also often failed to develop a normal brain. In the absence of Scythe some parts of the brain grew abnormally large and contained excessive amounts of water.

Finally, the St. Jude team showed that cells from the Scythe-/- model responded to ionizing radiation and hydrogen peroxide by undergoing apoptosis like normal cells. However, these cells were more resistant to menadiaone and thapsigarin--two chemicals known to trigger apoptosis. But when the investigators put Scythe genes back into the cells, they became sensitive to these treatments and underwent apoptosis.

"These chemicals affect the movement of calcium inside a special structure where proteins are made," McKinnon said. "This showed that Scythe helps trigger apoptosis in specific circumstances. Further studies are currently underway to elucidate this process."

Part of the Scythe molecule resembles that of molecules known to be involved with protein destruction, according to Fabienne Desmots, the postdoctoral researcher in the Department of Genetics and Tumor Cell Biology who did much of the work on this project. This finding suggests that Scythe might help to regulate the signaling molecules that are involved in either apoptosis or cell proliferation.

"By having a hand in controlling the levels of key proteins involved in these processes, Scythe appears to indirectly balance life and death decisions in the growing embryo," said Desmots, who is the first author of the paper. Desmots is now at the University of Rennes in France.

Carrie Strehlau | EurekAlert!
Further information:
http://www.stjude.org

More articles from Life Sciences:

nachricht Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main

nachricht Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

When corals eat plastics

24.05.2018 | Ecology, The Environment and Conservation

Surgery involving ultrasound energy found to treat high blood pressure

24.05.2018 | Medical Engineering

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>