A synthetic embryo could be the key to solving infertility
(CNN) — Scientists have managed to create mouse embryos in a dish, and this could one day help families hoping to get pregnant, according to a new study.
After 10 years of research, scientists created a synthetic mouse embryo that began to form organs without a sperm or egg, according to the study published Thursday in the academic journal Nature. Only stem cells were needed.
Stem cells are unspecialized cells that can be manipulated to become mature cells with specialized functions.
“Our mouse embryo model not only develops a brain, but also a beating heart, all the components that will make up the body,” said lead study author Magdalena Zernicka-Goetz, professor of mammalian development and cell biology. Mother at the University of Cambridge, UK.
“It’s amazing that we’ve come this far. This has been the dream of our community for years, and one of the main goals of our work for a decade, and we’ve finally achieved it.”
The work is an exciting development and addresses a challenge scientists face when studying mammalian embryos in the womb, said Marianne Bronner, professor of biology at California Institute of Technology in Pasadena, Caltech. Bronner was not involved in the study.
“These develop outside the mother and therefore can be easily visualized through critical developmental stages that were previously difficult to access,” Bronner added.
The researchers hope to move from mouse embryos to creating models of natural human pregnancies, many of which fail in the early stages, Zernicka-Goetz said.
By looking at embryos in a lab rather than in a womb, scientists have a better view of the process to learn why some pregnancies may fail and how to prevent it, he added.
So far, the researchers have only been able to follow about eight days of development in the synthetic mouse embryos, but the process is improving and they are already learning a lot, said study author Gianluca Amadei, a postdoctoral researcher at the University of Cambridge.
“It reveals the fundamental requirements that have to be met to make the correct structure of the embryo with its organs,” said Zernicka-Goetz.
As it stands, the research is not applicable to humans, and “a high degree of improvement is needed for this to be really useful,” said Benoit Bruneau, director of the Gladstone Institute for Cardiovascular Disease and principal investigator of the Gladstone Institutes. Bruneau was not involved in the study.
But the researchers see an important use for it in the future. The process can be used immediately to test new drugs, Zernicka-Goetz said. But in the long term, as scientists move from synthetic mouse embryos to a human embryo model, it could also help build synthetic organs for people in need of transplants, Zernicka-Goetz added.
“I consider this work to be the first example of such work,” said study author David Glover, Research Professor of Biology and Biological Engineering at Caltech.
How they did it?
In the womb, an embryo needs three types of stem cells to form: one becomes body tissue, another in the sac where the embryo develops, and the third in the placenta that connects mothers to the fetus, according to the study. .
In Zernicka-Goetz’s lab, the researchers isolated the three types of stem cells from embryos and grew them on a tilted container to bring the cells together and encourage interaction between them.
Day by day, they could see the cluster of cells forming into an increasingly complex structure, he said.
There are ethical and legal considerations to weigh before moving on to synthetic human embryos, Zernicka-Goetz said. And with the difference in complexity between mouse and human embryos, it could be decades before researchers are able to perform a similar process for human models, Bronner said.
But in the meantime, information gained from the mouse models could help “correct for defective tissues and organs,” Zernicka-Goetz said.
The mystery of human life
The first weeks after fertilization are made up of these three different stem cells that communicate with each other – chemically and mechanically – so that the embryo can grow properly, according to the study.
“Many pregnancies fail at this time, before most women [se den cuenta] that they are pregnant,” said Zernicka-Goetz, who is also a professor of biology and biological engineering at Caltech. “This period is the foundation for everything that follows in pregnancy. If it goes wrong, the pregnancy will fail.”
But at this stage, an embryo created by fertilization in vitro it’s already implanted in the mother, so scientists have limited visibility into the processes it goes through, Zernicka-Goetz said.
They were able to develop the foundations of a brain, a first in these kinds of models and a “holy grail for this field,” Glover said.
“This period of human life is very mysterious, so to be able to see it happen on a plate, to have access to these individual stem cells, to understand why so many pregnancies fail and how we might prevent that from happening, is very special,” he said. Zernicka-Goetz in a press release. “We looked at the dialogue that has to take place between the different types of stem cells at that point: we’ve shown how it happens and how it can go wrong.”