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 Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>