Synthetic Day 14 Embryo Models: Pioneering Research Opportunities
Researchers from Israel leveraged their experience in creating synthetic mouse embryo models made entirely of stem cells. Similar to their previous work, they began with pluripotent stem cells, which can differentiate into many but not all cell types. However, they modified these pluripotent stem cells to revert to an even earlier state known as the "naive" state, allowing them to differentiate into various cell types.
The researchers divided the naive pluripotent stem cells into three groups. Those meant to become embryos remained unchanged. Cells in the other two groups were treated with chemical compounds, without genetic modifications, to activate specific genes that would make them differentiate into one of three tissue types required for embryonic development. After mixing, the cells fused together, and about 1% of them self-organized into structures resembling embryos.
These embryo-like structures successfully developed outside the uterus for eight days, reaching a stage of development comparable to the 14th day of human embryo development. At this stage, natural embryos begin to form structures that enable organ development.
The researchers found that their embryo models had structural similarities to natural human embryos described in old textbooks. They also discovered that cells producing human chorionic gonadotropin (hCG), a hormone used in pregnancy tests, were present and active. Applying these cells to a home pregnancy test yielded a positive result.
Artificial human embryos offer numerous prospects for scientific research and medical practice for several key reasons:
Studying Human Development: Artificial embryos enable researchers to meticulously investigate the early stages of human development, previously inaccessible for observation. This enhances our understanding of cell differentiation, organ and system formation, and helps identify potential causes of congenital defects.
Disease Research: Creating and studying artificial embryos can aid in identifying and understanding the mechanisms behind various diseases and genetic pathologies. This may lead to the development of new diagnostic and treatment methods.
Drug and Toxin Testing: Artificial embryos can be used for safety testing of drugs and chemicals during the early stages of human development, helping prevent potential harm to developing embryos.
Infertility Research: Research on artificial embryos can contribute to uncovering the causes of infertility and developing methods for its treatment. This is crucial for couples facing fertility challenges and recurrent miscarriages.
Transplantation and Regenerative Medicine: Artificial embryos can serve as source material for growing tissues and organs for transplantation. This could address organ donor shortages and enhance regenerative medicine capabilities.
Ethical Inquiry: The creation of artificial embryos also fosters deeper discussions on ethical issues related to biological and medical research, including rules and limitations.
In summary, artificial human embryos represent a powerful tool for scientific research and medical practice, poised to make significant contributions to our understanding of human health and quality of life.
A stem cell–derived human embryo model at a developmental stage equivalent to that of a day 14 embryo. The model has all the compartments that define this stage: the yolk sac (yellow) and the part that will become the embryo itself, topped by the amnion (blue) – all enveloped by cells that will become the placenta (pink)
