In an article published in the scientific journal Cell, we can read that scientists have carried out a ape-man chimera. In other words, they inserted human stem cells into a monkey embryo. Another study, this time French, also managed to create these same types of embryos a few months ago. What for ?
First of all, the goal is not to make an ape-man, far from it. The chimera was obtained at the embryonic stage, then the experiment stopped after 20 days. The idea was to work on pluripotent stem cells (which has already been the case for several years). The latter are present in any animal type embryo at the very beginning of its formation, they are those which activate the production of organs. They are the engines of development.
Chimeras, for what purpose?
The idea is to take human stem cells, rework them back to a primary state (when they were pluripotent, at the very beginning of the process) and inject them into an embryo to see if they can have an impact on its development.
Several experiments of this type have already been carried out, human-pig, human-mouse, human-rabbit chimeras… Without conclusive results. You can’t do it on a human embryo, for ethical reasons. This time the trial was done on macaques, scientists thought the similarities between the two species might help make the trial work. It didn’t really happen.
Improving cell therapies and in vitro fertilization
The longer-term objective is to advance in vitro medicine. This experiment has a therapeutic aim, it could help procreation (improve in vitro fertilization) and help to advance cell therapies that help fight against cell degeneration, which is responsible for Alzheimer’s or Parkinson’s for example.
The wildest hope for scientists would be to be one day capable of creating human organs in vitro for transplants in patients. Studying the integration and functioning of these stem cells is essential to advance research in these fields.
This work, carried out on these chimeric embryos, is not without raising ethical questions.. The issue is being debated in the context of the bioethics review, with the Senate fiercely opposed to authorizing the implantation of human cells into an animal embryo. The text should return to the Assembly in June for a final reading.
“This research is not intended to do everything and anything. We are very aware of their biomedical and ethical issues”, assures Pierre Savatier of the National Institute of Health and Medical Research (Inserm) in Lyon, who coordinated the French study, in an interview with the newspaper Le Monde. In contrast, “we all agree to ban the opposite paradigm, which would consist of injecting animal cells into a human embryo”, says the researcher.
Sources:
- Chimeric contribution of human extended pluripotent stem cells to monkey embryos ex vivo, Cell, March 20, 2021.
- Stem Cell Reports, January 12, 2021.
Read also:
- Stem cells: 10 years of promising research
- Reprogram cells to perform transplants without rejection?
