The fetus must be big enough to thrive, yet small enough to pass through the birth canal. In a new study, Yale researchers describe the mechanism that keeps these conflicting goals in balance.
Invasive trophoblast (brown colored cells) surround and invade maternal cells. Credit: Harvey Kliman, Yale University
The findings are published in the October 11, 2011 online issue of Reproductive Sciences.
The battle is waged between the mother's uterus and the baby's placenta, which is made up of cells called trophoblasts that are controlled by the father. In the study, led by Harvey J. Kliman, M.D., research scientist in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine, researchers observed how the placenta tricks the mother so she doesn't attack the trophoblasts that are trying to increase the flow of her blood into the placenta. If this placental deception doesn't work the mother may develop preeclampsia, a condition that results in high blood pressure and protein in the mother's urine. The only known cure for preeclampsia is delivery of the baby.
The placenta's job is to get nutrients from the mother during pregnancy. Kliman explained that in a normal pregnancy, specialized invasive trophoblasts leave the placenta and invade the mother's tissues to attack and destroy the walls of her blood vessels. This allows the most blood possible to enter the placenta, resulting in a big baby.
But the mother's own "soldiers," called lymphocytes, are constantly looking to destroy the invasive trophoblast cells. The placenta in turn appears to trick the mother by creating a diversion to occupy her lymphocytes.
The placenta creates this diversion by secreting a protein called placental protein 13 (PP13), also known as galectin 13, into the mother's blood where it travels through her veins into the uterus below the placenta. There the PP13 leaves the veins where it triggers the mother's immune system to react and attack. The entire area around these veins becomes a mass of inflammation and dead cells, called necrosis.
"We realized that these zones of necrosis are likely occupying the mother's soldiers while the invasive trophoblasts sneak into her arteries, leading to more blood flow to the placenta and a bigger baby," said Kliman. "We believe that maintaining this balance could be the key to a healthy pregnancy free from preeclampsia."
Other authors on the study include Marei Sammar, Yael Grimpel, Stephanie Lynch, Kristin Milano, Elah Pick, Jacob Bejar, Ayala Arad, James Lee, Hamutal Meiri and Ron Gonen.
The study was funded by a research grant from the European Union (FP6-grant # 037244, project title Pregenesys), the Finland Israel R&D Fund grant #41256 (Eureka – 3808 RPT), and the Yale University Reproductive and Placental Research Unit.
Citation: Reproductive Sciences doi: 10.1177/1933719111424445 (October 2011)
Karen N. Peart | EurekAlert!
Biophysicists reveal how optogenetic tool works
29.05.2020 | Moscow Institute of Physics and Technology
Mapping immune cells in brain tumors
29.05.2020 | University of Zurich
In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".
Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.
researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...
Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.
When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...
Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.
Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...
Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.
A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
29.05.2020 | Materials Sciences
29.05.2020 | Materials Sciences
29.05.2020 | Power and Electrical Engineering