Cloned beta cells of a diabetic patient

Insulin cells were obtained by cloning

Kirill Stasevich, CompulentaJust the other day we reported that it was possible to clone human cells taken from people 35 and 75 years old.

And one of the most sensational news on the topic of human cloning took place last year, when specialists under the leadership of Shukhrat Mitalipov announced the receipt of human embryonic stem cells. Although this work caused a lot of skeptical comments, she still managed to revive interest in the topic of cloning, which has almost disappeared since the days of Dolly the sheep.

The essence of the method used in these works is as follows: a nucleus from another cell is transplanted into an egg (its own nucleus is removed from the egg at the same time); a program of embryonic development wakes up in the transplanted nucleus, and as a result we get embryonic stem cells that can be directed along any path of development. Cloning by replacing the nucleus is an alternative to the method of induced stem cells; over time, it turned out that induced stem cells are still not quite similar to natural ones, so scientists again remembered cloning: the cells obtained with its help behave more naturally.

However, Mr. Mitalipov and his colleagues took either human germ cells or cells of 8-month-old children for nuclear transplantation. But if we mean the replacement with the help of stem cells of a certain diseased organ, then the nuclei will have to be taken from the cells of an adult who, say, by the age of 40-50-75, something inside has deteriorated. How will the "elderly" genome behave once it gets into the egg? One of the mentioned works seems to convince us that the nuclei from old cells are quite capable of "remembering youth" and launching a program of embryonic development, once in someone else's egg.

But that's only half of it. And can embryonic stem cells obtained from "old" nuclei turn into what is needed? Researchers from the New York Stem Cell Foundation Research Institute (USA) tried to verify this.

Dieter Egli and his colleagues set out to obtain beta cells of the pancreas. These cells secrete insulin, and their death leads to type I diabetes; if these cells could be grown in the laboratory and then transplanted to patients, it would solve the problem of diabetes, at least one of its varieties. (Let's not forget that such beta cells would grow on nuclear genetic material taken from the patient himself, that is, they would be quite compatible with his body.)

In an article published in Nature (Yamada et al., Human oocytes reprogram adult somatic nuclei of a type 1 diabetic to diploid pluripotent stem cells), the authors of the work write that they managed to obtain embryonic stem cell lines by transplanting the nucleus of a human skin cell with type I diabetes into an egg. Moreover, these cells behaved in the same way as those obtained from "baby" nuclei (that is, taken from the cells of a newborn child).

A colony of human embryonic stem cells obtained from a patient with type I diabetes
(photo by Bjarki Johannesson / NYSCF)

Later, the embryonic cells were transformed into neurons, cartilage tissue and pancreatic cells, including beta cells.

However, as for type I diabetes, it is believed to occur due to the fact that the immune system attacks the pancreas. Therefore, to grow new beta cells to replace those eaten by the immune system is half the battle, we still need to figure out how to calm the immune system so that it does not eat these new cells that we will transplant to the patient. But in general, the results inspire great enthusiasm in scientists, since it was possible to show that genetic material can be taken from an adult for cloning and that differentiated cells can be "produced" from embryonic cells obtained by this method for regenerative replacement. As for the competition of this technology with induced stem cells, most likely, no one will displace anyone, and both methods will be used to achieve various biomedical goals (for example, induced stem cells could be used to clarify some fundamental questions of developmental biology and to analyze the effects of new drugs). Well, embryonic cells can be thrown into purely regenerative procedures.

However, there is another problem here – of an ethical and legal nature. This study itself turned out to be quite long, and not only because of the methodological complexity itself, but also because of the restrictions imposed in different US states on the use of, for example, human eggs. In addition, the complex of cells that is formed in our country shortly after the launch of the embryo development program is considered an object subject to legal laws. That is, roughly speaking, these cells are considered a full-fledged organism.

In general, such studies can be used to study not only the biology of development, but also the features of various legal systems, and as long as this state of affairs persists, it is hardly possible to talk about cloned organs and other things.

Prepared based on the materials of the New York Stem Cell Foundation: First Disease-Specific Stem Cell Line by SCNT.

Portal "Eternal youth" http://vechnayamolodost.ru30.04.2014