Induced absolutely pluripotent stem cells

Back to the future: Israeli scientists have obtained a new type
human pluripotent stem cells

LifeSciencesToday based on the materials of the Weizmann Institute of Science: New Stem Cells Go Back FurtherOne of the obstacles to the use of human embryonic stem cells in medicine is their main property:

they are born to differentiate quickly into other cell types. Until now, scientists have not been able to effectively preserve human embryonic stem cells in their original "stem" state. The alternative proposed to embryonic stem cells – reprogrammed adult cells called induced pluripotent stem cells (iPS cells) – has the same limitations. Having the ability to differentiate into many cell types, they also tend to differentiate into certain cell lines. A group of scientists from the Weizmann Institute of Science (Weizmann Institute of Science), Israel, has achieved significant success in overcoming this obstacle: researchers have created induced pluripotent stem cells, completely returned to the earliest state, and have learned to suppress the desire of cells to differentiate.

Since its creation in 2006, induced pluripotent stem cells have been presented as an ethical and practical replacement for embryonic stem cells. They are obtained by embedding four genes into the genome of adult cells, for example, skin fibroblasts. This manipulation almost completely – but not completely – reverses the clock of their development and gives cells properties close to those of embryonic stem cells. Dr. Yaqub Hanna from the Department of Molecular Genetics at the Weizmann Institute and scientists from the Israel National Center for Personalized Medicine realized that embedding genes that return cells to their original "stem" state is not enough. It is also necessary to suppress their desire for differentiation.

Scientists knew that this was possible: mouse embryonic stem cells used in many laboratory experiments easily retain their original non-applied state, and working with them does not involve problems that arise when working with human ESCs. Dr. Hanna and his colleagues realized that if they could explain how mouse embryonic stem cells manage to suppress their desire for differentiation in the laboratory, this knowledge could be applied to human cells. Using laboratory experiments and genetic analysis, researchers have developed a "treatment" for human induced pluripotent stem cells that suppresses the in vitro genetic pathway of differentiation.

Human iPS cells treated with their method were injected into mouse blastocysts - embryos at an early stage of development, consisting of only a few cells. If the human iPS cells obtained by scientists were indeed non-simulated, as well as viable, they should have developed together with mouse cells. Adding a fluorescent marker to the iPSCs was supposed to show what was happening to them in the developing embryo, and ten days later the scientists saw that the embryos actually contained both mouse and human tissues.

"These cells correspond to the earliest stages of human embryonic stem cell development that have ever been achieved. We managed to "freeze" what is essentially a very transient stage and obtain a new pluripotent state of stem cells," Dr. Hanna comments on her success.

The results of his research have a wide scope of application in the field of biomedical research, in particular, in gene therapy, as well as in genetic engineering. Scientists plan to continue the study of "humanized" mouse embryos and hope to find ways to direct the development of human tissue into functional organs.

Portal "Eternal youth" http://vechnayamolodost.ru11.11.2013