17 September 2012

Induced pluripotent stem cells: new data

New details have been discovered in the somatic cell reprogramming mechanism

Andrey Vasilkov, ComputerraA research team led by Professor Rudolf Jaenisch has identified new epigenetic mechanisms that allow for the effective reprogramming of mature somatic cells into induced pluripotent stem cells (iPSCs, iPS) in a period of 32 to 94 days.

In recent years, many promising studies and hopes for the development of methods for the treatment of severe diseases have been associated with these cells.

Professor Janish is one of the honorary members of the Whitehead Institute in Cambridge and a professor of biology at the Massachusetts Institute of Technology. His priority area of scientific interests is genetics and cell biology. The study conducted by his group is the first in which individual cells were subjected to the study of transformation into an "embryonic" pluripotent state.

(Article by Buganim et al. Single-Cell Expression Analyses during Cellular Reprogramming Reveal an Early Stochastic and a Late Hierarchical Phase published in the latest issue of the journal Cell; for a brief retelling, see on the Whitehead Institute for Biomedical Research website: Whitehead scientists bring new efficiency to stem cell reprogramming – VM.)

Due to this, it was found that the main role in the formation of iPSCs belongs to four genes: (Esrrb, Utf1, Lin28 and Dppa2). These genes were activated at an early stage and showed high activity in all cells undergoing full transformation.


Fibroblasts of the mouse embryo. Each colored dot corresponds to an mRNA involved in the expression of certain genes
(photo: Dina Faddah/Whitehead Institute)

In addition, during the study, it was possible to weed out many previously assumed candidates for the role of leading genes and regulators, since it was found that they lead to an incomplete transformation of cells into polypotent ones.

Similar experiments have been conducted since 2007, but they were mainly aimed at the expression of four other genes (Oct4, Sox2, c-Myc and Klf4), and in large cell populations at once. At the same time, less than 1% of somatic cells underwent a full-fledged transformation, which complicated the task of identifying other genes and regulatory mechanisms that really lead to a complete transformation.

iPSCs are interesting because they can differentiate into cells of almost any other tissue, thereby restoring structure and function in the lesion. For example, in experiments on rats with spinal cord injuries, damaged nerve tissue was restored with the help of IPSC, paralysis was eliminated, and lost sensitivity returned.

It is clear that most people have a poor understanding of medical genetics. The desire to actively defend their right to ignorance is surprising. Ignorance breeds unreasonable fear, and under public pressure, such studies are sought to be banned. Now they are already severely restricted, and soon they may be completely banned at the level of federal laws.

Portal "Eternal youth" http://vechnayamolodost.ru17.09.2012

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