IPSC according to the "gold standard"

Induced stem cells are similar to embryonic ones

"The Attic" Pluripotent stem cells can divide indefinitely

and turn into all other kinds of cells.
Drawing provided by the MIPT press service

Russian scientists have proved that stem cells obtained from ordinary cells of the body by reprogramming almost do not differ from the reference ones. The work of researchers can bring us closer to the creation of artificial organs in a test tube.

Pluripotent stem cells can divide indefinitely and turn into other types of cells. They are responsible for the restoration of body tissues, and theoretically almost any organ can be obtained from them. But there are no pluripotent stem cells in the adult body – this condition is characteristic only for cells of the first days of embryonic development. Therefore, stem cells for medicine are proposed to be taken from early human embryos obtained in incubators by in vitro fertilization. However, many people consider this approach unethical, and therefore scientists are looking for an alternative to embryonic stem cells.

So, in 2007, Japanese researchers showed that ordinary cells of the body can be turned back into stem cells with the help of several operations that turn off the genes responsible for cellular specialization, and, conversely, turn on the genes active in the stem cell. However, until now it was unclear how such induced, or reprogrammed, stem cells differ from embryonic stem cells.

New research

Russian scientists from the Institute of General Genetics, the Federal Research Center of Physico-Chemical Medicine (FNCC FHM), MIPT and Kazan Federal University compared embryonic stem cells, three types of ordinary cells obtained from them (these were neurons, fibroblasts – connective tissue cells and retinal epithelial cells), as well as three types of induced stem cells, reprogrammed back from normal cells. All cells contained the same set of genes, and the differences between them were explained only by different gene activities.

They determined the transcriptome of cells, that is, they listed all the products actively synthesized by cell DNA, and also determined which parts of cellular DNA are methylated, that is, chemically modified with methyl groups – methylation reduces the activity of genes. As a result, scientists have shown that induced stem cells from neurons, fibroblasts and epithelium almost do not differ from the original embryonic ones, and all subtle differences in the mechanism of regulation of the activity of their genes can be explained by random factors.

"In the course of the study, we also formulated the concept of the best line of induced pluripotent cells," says Dmitry Ishchenko, a graduate student at MIPT and a researcher at FNCC FHM. "If you first take an embryonic stem cell, then let it turn into five different specialized cells, and then reprogram them into stem cells, then there is a 95% probability that at least one of these five lines will be the same as the original embryonic ones."

The results of the scientists' work are published in the journal Cell Cycle (Shutova et al., An integrative analysis of reprogramming in human isogenic system identified a clone selection criterion).

Portal "Eternal youth" http://vechnayamolodost.ru  10.06.2016