Scientists have made a breakthrough by growing "mini-placentas" in a lab, offering valuable insights into how the placenta develops and interacts with the uterus lining. This discovery holds promise for a better understanding of conditions like pre-eclampsia and potential future treatments.
Published in Cell Stem Cell, the study demonstrates the possibility of actively experimenting on developing human placentas, rather than merely observing specimens, to study pregnancy disorders more effectively.
A successful pregnancy relies on the placenta's proper development in the initial weeks of gestation. During this crucial period, the placenta embeds itself into the endometrium, the mucosal lining of the mother's uterus.
Critical interactions between endometrial and placental cells determine the success of a pregnancy. These interactions play a vital role in enhancing maternal blood supply to the placenta, crucial for fetal growth and development.
Complications arise when these interactions go awry, leading to conditions like pre-eclampsia, characterized by high blood pressure during pregnancy. Pre-eclampsia affects approximately six in 100 first pregnancies, posing risks to both the mother and the baby.
Professor Ashley Moffett from the University of Cambridge's Department of Pathology emphasizes, "Most major disorders of pregnancy depend on failings in the way the placenta develops in the first few weeks. This is a process that is incredibly difficult to study."
To address this challenge, Professor Moffett and colleagues have utilized "mini-placentas," known as trophoblast organoids, a cellular model closely resembling early placental stages. These organoids offer a unique window into early pregnancy and aid in understanding reproductive disorders.
In a groundbreaking approach, the researchers applied proteins secreted by uterine natural killer cells, crucial immune cells found in the uterus, to mimic conditions where the placenta implants itself. Identifying specific proteins crucial for organoid development, they enhance successful implantation, allowing the placenta to invade the uterus and transform maternal arteries.
Professor Moffett highlights the significance, stating, "This is the only time that we know of where a normal cell invades and transforms an artery, and these cells are coming from another individual, the baby."
Failure in proper invasion can result in insufficient blood flow, leading to nutrient and oxygen deprivation for the baby. This is a key factor in later pregnancy complications.
The study also identified genes regulating blood flow, providing valuable insights for future research on pre-eclampsia and related disorders.
Dr. Margherita Turco from the Friedrich Miescher Institute underscores the importance of understanding pre-eclampsia in the early weeks of pregnancy. "Using 'mini-placentas,' we can do just that, providing clues as to how and why pre-eclampsia occurs," she said.
Supported by Wellcome, the Royal Society, European Research Council, and Medical Research Council, this research showcases the power of basic science in advancing our understanding of fundamental biology, with the potential to significantly impact the health of mothers and their babies in the future.