From stem cells: Creating early stages of human embryos in the laboratory
Researchers may have created early stages of human embryos from stem cells for the first time. However, these do not yet have a beating heart or brain. So far, however, there has been no official scientific publication confirming this.
A research team at the University of Cambridge has succeeded in creating precursors of human embryos with the help of stem cells. They are said to have been cultivated to a stage just beyond the 14-day developmental stage of a natural embryo. This is according to a report in the British "Guardian". The research team led by developmental biologist Magdalena Zernicka-Goetz presented their work during a plenary lecture on 14 June 2023 at the annual meeting of the International Society for Stem Cell Research in Boston.
The embryonic structures apparently have neither a beating heart nor the beginnings of a brain, but contain cells that would normally form the placenta, yolk sac, germ cell precursors and the embryo itself. An important question is whether they theoretically have the potential to initiate organ formation. "Recently, researchers have developed methods to keep IVF embryos alive in a petri dish for 14 days, and these results confirm that the technology is now available to support the first 14 days of embryo development.technology is now available to recreate the first 14 days of development outside the womb," Ildem Akerman, Professor of Functional Genomics and Diabetes at the University of Birmingham, told the Science Media Centre (SMC).
An official scientific publication that could provide more detailed background information on the experiments has not yet been published. "This could be an important scientific step," Alfonso Martinez Arias, a developmental biologist at the Universitat Pompeu Fabra in Barcelona and lecturer at the University of Cambridge, told the SMC. "But we need to see the full study and the data before we can make such statements."
Last year, Zernicka-Goertz's team and a rival group at the Weizmann Institute in Israel had already succeeded in creating synthetic mouse embryos from stem cells. The experiments now apparently discussed at the conference raise serious ethical and legal questions, as the embryos grown in the laboratory are not covered by current legislation in many countries. In many places, it is forbidden to cultivate human embryos in the laboratory beyond 14 days. The guidelines are largely based on a guideline issued by the International Society for Stem Cell Research (ISSCR) in 2016, according to which exceeding the 14-day rule was considered an unauthorised research activity.
In 2021, however, the ISSCR adapted its international guidelines: In future, human embryos created through artificial fertilisation or from human stem cells should be allowed to grow in the laboratory for longer than the previously standard maximum of 14 days. Researchers should be able to cultivate the embryos in the laboratory for as long as it serves the respective research purpose - but only after strict testing. "Until now, an embryo created through in vitro fertilisation and 'embryo models' created from stem cells were two separate things, as the latter did not have the ability to grow or implant," says Ildem Akerman. The authors may have broken this separation. "It is therefore up to the individual ethical committees to decide whether the created entity is an 'embryo' or an 'embryo model' and whether the entity is allowed to grow beyond the 14-day limit," explains Ildem Akerman. According to the current ISSCR guidelines, the transfer of synthetic embryos to a woman in order to carry them to term is prohibited worldwide.
In general, models of human embryos derived from stem cells have great potential, James Briscoe, deputy director of research at the Francis Crick Institute in London, told SMC. "They could provide fundamental insights into critical stages of human development. These are phases that are very difficult to study, and it is a time when many pregnancies fail." According to Briscoe, new findings could lead to a better understanding of the causes of miscarriages.
Spectrum of Science
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