Who to be?
Scientists have found out how stem cells "understand" which cell they need to turn into
Vladimir Kuznetsov, Hi-News
We have all known for a long time that stem cells are very unique living mechanisms capable of turning into any other cells (and subsequently forming organs). But how exactly do these very stem cells "decide who to be"? After all, they all contain the same genetic material and do not differ from each other. And, apparently, researchers from the University of Copenhagen have received new data on exactly how the "transformation" takes place.
Article by Hamilton et al. Dynamic lineage priming is driven via direct enhancer regulation by ERK published in the journal Nature – VM.
A popular retelling can be read in the press release of Researchers discover how cells know their future and forget their past.
What is the uniqueness of stem cells?
All stem cells have a common potential for development into any specific cell of our body. Therefore, many researchers are trying to answer fundamental questions about what determines the "fate" of cell development, as well as when and why cells lose this potential. Researchers from the Novo Nordisk Foundation Center for Stem Cell Biology at the University of Copenhagen found that proteins called transcription factors, which, according to some ideas, were the cause of cell modification, play a completely different role.
For 30 years, scientists have thought that transcription factors are what triggers genes to work, turning them on and off. Which leads to a change in cells. However, new research results show something completely different.
We previously thought that transcription factors control the process that determines whether a gene is expressed and subsequently translated into the corresponding protein. The results indicate that these proteins may be something like cell memory. As long as the transcription factors are linked to the gene, the gene can be read (turned on). Once the transcription factors disappear, the cells can no longer return to their "starting point," explains Josh Brickman, professor at the University of Copenhagen and lead author of the project.
Researchers have developed a stem cell model that simulates the cell's response to incoming signals from outside and used it to accurately determine the sequence of events associated with the switching on and off of genes in response to an incoming signal.
Transcription factors are still a key element, but they do not control the process as previously thought. After the signal arrives and the differentiation process begins, the factors cause the genes to change and remain in place for some time after the gene is read. And when they "understand" that the cell modification has begun, the factors disappear. You can compare this process with the traces that an airplane leaves in the sky. They are in the air for a while, but slowly dissipate.
This discovery primarily changes fundamental assumptions about molecular biology. The new findings are particularly important for researchers working on stem cells. They give an understanding of how cells develop, how the pathways of change are determined and when it becomes impossible to reverse these changes. This is also important because the same pathways are involved in the formation of cancer cells. This means that it will be possible to develop new methods to combat this terrible condition.
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