There has been a long debate about whether humans are able to control the timing of their development. The new study suggests that this “stop button” can be activated in human cells. The findings have important implications for our understanding of early human life and may improve reproductive techniques.
In some mammals, the timing of ongoing embryonic development can be naturally altered to improve the chances of survival for both the fetus and the mother. This mechanism of temporarily slowing development, called embryonic diapause, often occurs at the blastocyst stage, before the embryo implants in the uterus (this early stage of development begins approximately five or six days after fertilization).
The new study reveals that our embryos may possess a capacity for dormancy similar to that observed in many other mammals, opening new possibilities for reproductive medicine and stem cell research.
The team found that by reducing activity in a certain series of biological reactions involved in embryo development, the fertilized embryo could be temporarily stopped from implanting in the uterine wall until conditions became ideal.
By slowing down the production of a protein involved in embryo development, they were able to temporarily stop the growth of the fertilized embryo in its early stages, about a week after conception.
The scientists were able to maintain the embryos in this dormant state for 18 days, after which they reversed the arrest to resume normal development.
The team said this technology could be used to increase the success of artificial insemination by creating a larger time window to evaluate the health of the fetus and improve the chances of implantation in the uterus.
According to the research paper, a team from the Max Planck Institute in Berlin and the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences in Vienna discovered a way to artificially induce a hibernation-like state in human embryonic cells and blastomas grown in the laboratory.
In both embryonic cells and blastomas, scientists changed the activity of a specific series of reactions, also known as molecular cascades.
Molecular sequencing occurs when the movement of one molecule triggers the movement of another molecule, and so on. This begins a cascade of chemical reactions, which act similarly to a row of falling dominoes, with each falling domino causing the next to fall.
The pathway that scientists targeted is called the “mammalian rapamycin” signaling pathway, which is known for short as mTOR. It is an important cellular signaling pathway that plays a crucial role in regulating cell metabolism, growth, reproduction and survival, and also plays an important role in the growth and development of the fetus.
When the researchers inhibited the mTOR signaling pathway, the stem cells and embryonic cells entered a dormant, hibernation-like state.
The results of the study showed that the ability to enter dormancy is active in human cells around the blastocyst stage.
In addition, scientists found that they were able to reverse this after a long period, allowing the embryonic cells to resume normal development.
When they boosted the activity of the mTOR pathway, they found that fetal growth accelerated.
“Although we have lost the ability to enter a dormant state naturally, these experiments suggest that we have retained this internal ability and can “The end is its release.”
Learning how to harness this hidden ability within our cells could have major implications for reproductive health treatments such as IVF.
The detailed study was published in the journal Cell.
Source: Daily Mail
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2024-10-07 13:53:07
