Researchers at the Francis Crick Institute have developed a new model of stem cells of the ripe human amniotic bag, which reiterates the growth of tissues that support the fetus from two to four weeks after fertilization. This is the first model of amniotic bag development after two weeks.
As described in the survey published today in CellThe new model can be used to study the origin and functioning of human amnium and help identify previously unknown ways in which the amniotic sac can support fetal growth. It also has a promise of medical procedures that use the amniotic membrane.
Amnion is a protective membrane that balloons in a sack containing amniotic fluid, which leaves the body when the mother’s waters break before work. Until recently, its most important role has been considered to surround and protect the baby, it encounters the shock and allowing the nutrients to pass before placenta forms.
The researchers failed to study AMNION in detail, because current models of embryo stem cells do not formally record the later stages of human growth and, for moral reasons, human embryos cannot be studied after fourteen days.
Copy of amniotic sac
The Crick team created a new 3D model called the amniooid meta-pelvis (PGA)-which is very similar to human amnion and other supportive tissues after gastrointestinalization (when fetal cells are organized in layers that will form tissues and organs). They did this by cultivating human embryonic stem cells in a series of steps with just two chemical signals over 48 hours, after which the cells were organized in the inner and outer layers of amnion.
A structure that resembles a bag formed from day 10 to over 90% of PGAs. These were gradually extended in size over 90 days, without being given further signals. The cellular composition in the models has shown a remarkable resemblance to the human amniotic sac and the fluid in PGAS mimics the content of human amniotic fluid.
Order between amnion and fetus
Using genetic manipulation techniques, the researchers found a transcription factor (a gene that converts or turns off other genes) called Gata3 caused an AMNION tissue development if disabled in PGAS.
On the contrary, when they reinforced Gata3 in fetal stem cells, the cells developed a sack -like amniotic structure without being given any other signals. These experiments have shown that Gata3 is essential for the start of Amnion growth.
Finally, the group asked if the amniotic tissues help the fetal cells grow and determine, not just to protect them. PGA cells were mixed with fetal stem cells that had not been treated and saw that unprocessed cells developed a sack -like amniotic structures, showing that the signals from the amnion could actually communicate with embryonic cells.
A new approach for medical procedures
Due to its regenerative, anti-inflammatory and antimicrobial properties, the amniotic bag membrane can be given by people who had selective C-sections to be used for medical procedures such as corneal reconstruction in the eye, repairing the lining of the uterus.
Because the transplanted web is donated, the group believes that PGAs could offer an alternative source of amniotic membranes, which could even be cultivated by patient cells.
The researchers are now working with the Crick Translation Team to explore the possibility of using PGAS in the clinic, as well as further represent the communication between the amniotic sac and the fetal cells.
Shift our point of view of Amnion
Early human development is still a black box due to moral and technical restrictions, but our new model gives us some visibility during this critical period, without having to use human embryos. This project shifts our view of Amnion as just a protective structure: it actively speaks with the fetus and promotes its development. We are also excited about the potential of PGAs as a fast, cheap and escalating way to provide amniotic membranes for medical use. ”
Silvia Santos, leader of the quantitative stem cell team in The Crick and Senior Author
Borzo Gharibi, a key researcher of laboratory researchers in the quantitative germ cell biology in Crick and the first writer, said: “We initially researched how the fetal cells form their identity and then our research took a very interesting research.
This project was made possible through close collaboration with Genomics, Metabolomics and Proteomics in The Crick.
Source:
Magazine report:
Gharibi, B., et al. (2025). Amniooids after the bubble as a model of stem cells of human extracurricular development. Cell. Doi.org/10.1016/j.cell.2025.04.025.
