For the first time: therapeutic cloning of adult cells
Eighteen years ago, Scottish researchers isolated a nucleus from the cell of an adult sheep and injected it into the egg cell of another sheep, from which its own nucleus was previously removed. The resulting cell was implanted into the uterus of the third sheep, resulting in the birth of the first cloned mammal – the famous Dolly.
The appearance of Dolly raised a huge number of ethical questions and at the same time gave hope that such technologies will eventually help in the treatment of a huge number of human diseases.
The method described above became known as somatic cell nuclear transfer (SCNT), or therapeutic cloning. However, it turned out that it was extremely difficult to apply it to human cells. For the first time, this was achieved in 2013 by scientists working under the leadership of Shukhrat Mitalipov at the Oregon Health & Science University, who used a newborn cell as a DNA source.
According to Robert Lanza, head of the scientific department of Advanced Cell Technology, this achievement was an extremely important step, but it is not suitable for use in clinical practice. Many diseases, including diabetes mellitus, Alzheimer's disease or Parkinson's disease, develop mainly in old age. Therefore, to treat these and many other diseases, scientists need to achieve the same success with adult cells.
Recently, an international group of researchers working under the leadership of Lanz managed to accomplish this task. They isolated the nuclei from the skin cells of two men aged 35 and 75 years and injected them into the nucleated eggs of several female donors. The resulting "filled" egg was exposed to a weak electrical discharge, which ensured the fusion of the cytoplasm and its new nucleus. After a few hours, the egg independently formed a blastocyst consisting of pluripotent stem cells genetically identical to the donor's skin cells. Theoretically, these cells can be reprogrammed into cells of any organs and tissues suitable for transplantation (see the diagram from the article in Cell Stem Cell).
Despite the fact that the resulting cells are practically embryonic, the researchers caution that this process cannot be used for human cloning.
They also note that, despite the success of the experiment, a lot of work needs to be done before the implementation of its results in practical medicine. To date, the effectiveness of the approach is very low. Of the 77 eggs used in the work, only 2 gave rise to viable pluripotent stem cell lines – one for each of the male donors.
However, this at least proves that it can be used for therapeutic cloning of cells of people of any age.
Article by Young Gie Chung et al. Human Somatic Cell Nuclear Transfer Using Adult Cells is published in the journal Cell Stem Cell.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru Based on Shots Health News From NPR:
First Embryonic Stem Cells Cloned From A Man's Skin.
22.04.2014