Neurons from embryonic stem cells: soon?

Stem cells got nervous
Pyotr Smirnov, "Newspaper.Ru»A good prospect for the treatment of severe injuries of the nervous system opens up in the light of the work of a group of Japanese researchers who identified the gene responsible for the transformation of embryonic stem cells into precursors of nervous tissue.

Regardless of the complexity of the organism, all animals develop from a single cell, going through several similar stages. First, this very cell is formed by the fusion of a sperm and an egg, then it divides many times, forming a faceless mass for future tissues and organs, and only then these descendants begin to develop into rudiments and gradually specialize. Acquiring narrow functions – the ability to contract or conduct an electrical impulse, they sacrifice their "potential" and are no longer able to turn into cells of other tissues.

Our life, quite possibly, would be even longer and richer if, in addition to everything else, the cells of the nervous system still retained the ability to divide. Then it would be possible to forget about incurable spinal cord injuries or the consequences of severe strokes. However, it is possible to go an alternative way – to take the same "embryonic precursors", put them on the appropriate path of development and transplant them into the damage zone.

At least one of the problems that arise in this case has been solved – Daisuke Kamiya and his colleagues from the Center for Developmental Biology at the RIKEN Institute have found a gene responsible for the transformation of embryonic stem cells into neurons.

From the very moment when Evans and Kaufman first isolated ESCs in mice in 1981, and in 1998 James Thomson was able to obtain a culture of human ESCs, the medical community became interested in only one question – "when?"

It would seem that the answers to the most difficult questions of developmental biology, the healing of previously incurable diseases, first of all, lesions of the nervous system, whose cells, neurons, as we know from school, do not recover, are already nearby. But time goes by, and there is still no finished product.

There are several reasons for this. Firstly, the issue of an ethical nature is one thing to work with mouse cells, and quite another to work with human cells. After all, it is necessary to take these very ESCs somewhere. Here it should be noted for once the active position of scientists (not without the support of commercial companies), who managed to defend not only the right to work, but even to use embryonic stem cells in clinical practice, at least in California. The fate of this direction in Russia depends on the consideration of the law "On the use of biomedical technologies in medical practice", which is due to take place this year. Moreover, after the appearance of induced pluripotent stem cells, the question of the source of biological material is not so relevant.

The second problem is purely technical. The "take and transplant" approach will lead not only to the restoration of the defect, but also to the growth of very aggressive tumors – after all, ESCs have a really huge potential for growth. So first they need to be guided on the right path. Until recently, this was done exclusively by trial and error, combining a combination of various growth factors and signaling molecules. However, such procedures do not have sufficient effectiveness.

Kamiya and co-authors of the publication in Nature (Intrinsic transition of embryonic stem-cell differentiation into neural progenitors) were able to identify the central link responsible for the formation of the germ of all nerve cells from an undetermined mass. It turned out to be the transcription factor Zfp521, which contains a characteristic zinc finger in its structure. Thanks to this module, it has the ability to bind to DNA and control the transcription of other genes – primarily responsible for the development of nerve cells.

The targeted activation of the Zfp521 is not a problem. After all, genetic engineering already has a lot of tools at its disposal: operons controlled by light or specific drugs. And it's easier to work with one gene in terms of dosing the effect than with a good dozen signaling molecules in modern "differentiation cocktails".

So now we can say with confidence – "soon."

Portal "Eternal youth" http://vechnayamolodost.ru17.02.2011