The elixir of immortality may be in our own brain.

People have long been trying to find a means to extend their life, ideally - something like the elixir of immortality. They did it in the Middle Ages, they do it now. But, of course, the methods used by modern scientists are incomparable with those used by alchemists. Modern specialists are trying to either find or create something that will stop aging or even reverse this process. So far, the most interesting results have been demonstrated by the project team, led by successful people from the IT sector - billionaire Peter Thiel from Silicon Valley and ex-Google employee Bill Marris.



They, together with a group of other scientists, conducted a large-scale study on the relationship between the workings of the human brain and aging. The results of this study are published in the journal Nature. As it turned out, mammals and humans have this relationship, and it can be traced quite well.



Scientists conducted research not on humans, but on mice. Cells found in their brain regulate the rate of aging of the body. At the beginning of their work, the project representatives took as a basis the developments of other scientists who showed that the human nervous system plays an important role in regulating the aging process, namely, the part of the brain called the hypothalamus. It is he who connects the nervous and endocrine regulation of a variety of biochemical processes occurring in humans and animals.



As it turned out, nerve stem cells (NSC), which are responsible for the growth of brain tissue in adult mice, are involved in the process of regulating aging. NSCs were identified in the so-called mediobasal region of the hypothalamus of young mice. We managed to identify them with the help of special markers - transcription factors Sox2 and nuclear protein Bmi1. The maximum concentration of such cells was found in young animals. In older mice, the number of these cells decreases, and in older mice (which have reached 22 or more years old) their number has decreased to zero.



But, perhaps, a decrease in the number of such cells is a consequence of some kind of process, but not the cause of aging? To find out, scientists used a specific virus to kill more than 70% of the NSC in the hypothalamus in middle-aged mice. After that, the animals began to age much faster than before the operation, and they died much earlier than usual for mice.



This was followed by a new stage of the experiment, during which the NSC of only born animals was introduced into the mediobasal region of the hypothalamus of middle-aged mice. These cells were modified in a special way so that they did not die during transplantation. After one and a half months, scientists found that the mice that went through this procedure had an increased level of activity, improved muscular endurance, coordination, and some other functions. After some time, signs of rejuvenation became more pronounced. The control group of mice was injected with other cells — astrocytes and mesenchymal stem cells. But an effect similar to working with the NSC was not noticed.





After completing this phase of the experiment, scientists decided to find out exactly which NSC cells are responsible for regulating the aging process. To do this, an analysis of biological active molecules that produce hypothalamic NSC would be carried out. As it turned out, these cells secrete exosomes with various miRNAs into the so-called cerebrospinal fluid. About them it is known that they do not participate in protein synthesis, but are actively involved in the regulation of gene expression.



In order to find out how microRNA exosomes affect the aging process, specialists took this material from donors and injected into the spinal fluid of recipient mice. In both groups of mice, the age group was approximately equal. In addition, the hypothalamic NSC partially removed. As it turned out, those mice that received exosomes with miRNA slowed down the aging process significantly. Thus, the influence of cells and their derivatives can be considered proven.



In general, the study is far from complete. Scientists have yet to figure out the structure and specific functions of miRNA in hypothalamic NSCs. It is also planned to study other cell derivatives, perhaps they also in some way affect the aging process. Surely, specialists will be able to find out a lot of interesting things in the course of the new research.



Whatever it was, and gerontology is now one of the most rapidly developing areas in medicine, because more and more wealthy people with significant resources (not only financial) pay attention to the problem of aging. Very few people want to be old and sick, nobody has invented anything better than health and youth.

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