Human stem cells were returned to the most immature state
Researchers at the Cambridge Stem Cell Institute, part of the UK Medical Research Council, have successfully "reset" human pluripotent stem cells to a state corresponding to the level of development of the embryo cells before implantation into the uterine wall (7-9 days). Until now, such "early" stem cells could not be obtained in the laboratory.
Human pluripotent stem cells, capable of giving rise to all types of body cells, can be obtained in the laboratory by isolation from embryos in the early stages of development, or by inducing the transition of adult cells into an undifferentiated state.
However, until now, researchers have not been able to obtain completely undifferentiated cells. All currently existing cell populations show a tendency to differentiate into cells of one type or another, which, apparently, is a reflection of the early stages of differentiation they have passed.
In experiments on human embryonic and induced pluripotent stem cells, the authors demonstrated the possibility of solving this problem by short–term expression of two genes – NANOG and KLF2 - triggering the activation of a gene system that ensures the return of cells to their original undifferentiated state. When cultured in the laboratory, the cells obtained using this approach demonstrated the ability to maintain a population indefinitely and differentiate into all types of cells, including neurons and cardiomyocytes.
Studying the behavior of these cells will allow specialists to understand the mechanisms of development of a normal embryo, as well as its possible disorders leading to spontaneous abortions of pregnancy and birth defects. The primitive state of the "rebooted" stem cells will facilitate their cultivation in the laboratory and manipulation in order to obtain specialized cells and tissues for subsequent use in regenerative medicine.
Above is the expression of characteristic markers (KLF4, TFCP2L1, NANOG) on human blastocyst cells (day 7).
At the bottom there is a similar co-expression of the corresponding markers on the "reloaded" stem cells.
Article by Takashima et al. Resetting transcription factor control circuitry towards ground state pluripotency in human is published in the journal Cell.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the Wellcome Trust-Medical Research Council:
Scientists reset human stem cells to earliest developmental state.
12.09.2014