Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Absence of critical protein linked to infertility

18.01.2006


The absence of a key protein may lead to infertility.



Researchers at the University of Illinois at Urbana-Champaign report that experiments involving mice -- to be detailed in the Proceedings of the National Academy of Sciences -- indicate that the transcription factor protein C/EBPb must be present in the uterus for pregnancy to occur. The study appears online this week at the PNAS Web site.

Without it, they say, an embryo cannot survive in uterine tissue or attach to a mother’s blood supply. Other genes also play roles, but C/EBPb is critical for implantation of an embryo, said Milan K. Bagchi, a professor of molecular and integrative physiology.


C/EBPb is scientifically known as CCAAT/Enhancer Binding Protein beta. It is regulated by the hormones estrogen and progesterone. In normal conditions, the protein, driven mostly by progesterone, is expressed rapidly and in large quantities during the critical four-day implantation period in mice, Bagchi said.

During this period, an embryo attaches to the wall of the uterus, advances into it and eventually attaches to the blood supply and forms the placenta. For a successful pregnancy to occur, stromal cells of the uterus must be transformed into decidual cells, which secrete nutrients that allow the embryo to survive until it plugs into the blood supply. C/EBPb is necessary for decidualization, the researchers discovered.

"This protein in the mouse is also in humans," Bagchi said. "We believe it plays a critical role in human pregnancy. It is expressed in the human endometrium at a time that coincides with the time of implantation. We have demonstrated very clearly in the mouse that in the absence of C/EBPb there is no decidualization. We transferred viable mouse embryos from healthy mice into mice lacking the gene, and pregnancy failed."

The project began more than four years ago. First, researchers used DNA microarrays to identify gene expression under normal and abnormal conditions during implantation. After messenger RNA profiling zeroed in on C/EBPb’s activity, the researchers collaborated with Peter F. Johnson of the National Cancer Institute’s Laboratory of Protein Dynamics and Signaling, who created mice that lacked the protein.

The experimental mice were then used to observe the relationships of the hormones and their receptors with the protein under varying conditions during the critical implantation period. In doing so, researchers determined that C/EBPb is a critical mediator of steroid hormone responsiveness in the uterus.

"This gene is expressed when the uterus is ready for embryo attachment," said co-author Indrani C. Bagchi, a professor of veterinary biosciences in the College of Veterinary Medicine at Illinois. "Its presence indicates a window for success."

If the findings are replicated in human tissue, as expected, she said, the protein’s presence could become a vital gene marker for predicting uterine readiness for pregnancy.

"The success rate for the practice of in vitro fertilization currently is, on average, about 25 percent," she said. "The major problem is that the conditions occurring when the embryo is transferred often are not the best in the uterus. It’s not known if the uterus is ready to accept an embryo, so often multiple embryos are transferred in hopes that one will attach. In future studies, confirmation of C/EBPb as a marker that correctly indicates uterine readiness for implantation in the human is likely to alleviate these shortcomings."

Other co-authors of the paper were doctoral student Srinivasa Raju Mantena, postdoctoral researchers Athilakshmi Kannan and Yong-Pil Cheon, and research scientist Quanxi Li, all in Indrani Bagchi’s veterinary biosciences laboratory.

Jim Barlow | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>