This is the first study to detail the mechanism by which the steroid hormone estrogen spurs cell differentiation and blood-vessel growth in the uterus during pregnancy, the researchers report.
The findings, from researchers at the University of Illinois, Emory University, Baylor College of Medicine and New York University, appear in the journal Development.
Connexin 43 (Cx43) belongs to a family of proteins that form junctions between cells that regulate the flow of ions and small signaling molecules from cell to cell. At the time of embryo implantation, this gap junction protein is essential to the rapid growth of new blood vessels needed to support the development of the embryo and allow it to implant in the uterine wall, the researchers discovered.
The researchers chose to study Cx43 after analyzing genes that are activated in the presence of estrogen in uterine cells. They found that Cx43 was prominent among the genes whose expression was increased in cells after exposure to estrogen.
University of Illinois veterinary biosciences doctoral student Mary Laws studied the role of Cx43 in pregnant mice and in human endometrial cells. By deleting the Cx43 gene in the uterus immediately after pregnancy in mice, a technique developed by researchers at Baylor, Laws was able to reliably prevent implantation of the embryo in the uterus.
In human endometrial cells (provided by co-author Robert Taylor of Emory University), Cx43 enhanced the differentiation of cells that make up the stromal tissue of the uterus. These cells produce factors that promote the growth of new blood vessels.
One of the factors secreted by the endometrial cells, vascular endothelial growth factor (VEGF), is essential to angiogenesis. In the absence of Cx43, Laws found, the cells failed to differentiate or to produce enough VEGF to spur blood vessel growth.
“The formation of these new blood vessels is extremely critical for embryonic growth at this stage of pregnancy, when the embryo has begun to invade into the uterine tissue, but has yet to make a connection to the placenta where it ultimately gets its nutrients,” said Illinois veterinary biosciences professor Indrani Bagchi, corresponding author on the study. “I think this is the first animal model that shows that disruption of one particular molecule or gene leads to a defect in uterine angiogenesis.”
The findings have important implications for early pregnancy loss and female infertility, she said.
“A fundamental aspect of female reproductive biology is how these hormones signal in uterine tissue in order to support the pregnancy,” said molecular and integrative physiology professor Milan Bagchi, an author on the study. “One of our major goals is to identify the genes that are regulated by estrogen and progesterone precisely at the time when the embryo implants in the uterine wall.”
“Connexin 43 has been shown to be in the uterus in many animal systems – cows and pigs and rodents and humans,” Laws said. “But this is the first time that it’s been shown to be critical for pregnancy.”
This research was sponsored by the recently established Center for Research in Reproduction and Infertility, which is funded by the National Institute of Child Health and Human Development.
Based at the U. of I., the center also draws expertise from Emory University Medical School and Baylor College of Medicine.Editor’s note: To reach Indrani Bagchi, call 217-333-7986; e-mail: firstname.lastname@example.org.
Diana Yates | University of Illinois
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine