The fight against aging: the main directions of research
Old age without borders
All this made it possible to significantly increase the average life expectancy of a person. In developed countries, aging is beginning to become the main cause of death. Despite all the achievements of medicine, scientists still cannot stop or even significantly slow down aging, but research in this area is in full swing – although so far mainly on mice.
For a long time, the study of the potential of stem cells has been a popular field of research. They can multiply, and then differentiate – it is with their help that the formation of all organs in embryos takes place. They are used in the treatment of a number of injuries and diseases, and as Harvard scientists have found out, they can "reverse" age-related diseases such as multiple sclerosis.
In their experiment, they connected the circulatory system of an elderly mouse suffering from the destruction of the myelin sheath of nerve cells (the main cause of sclerosis) with the circulatory system of a young healthy mouse. "Fresh" blood reactivated the generation of stem cells of a sick mouse and caused the active restoration of myelin sheaths. Scientists are confident that stimulating the generation of their own stem cells is much more effective than transplanting donor material.
One of the promising areas in the fight against aging is genetic engineering. A number of studies have already shown that by changing certain genes of animals, it is possible to increase their life expectancy, but so far such procedures have been carried out only at the embryonic stage of development, which is not applicable in the case of humans. Scientists from the Spanish Cancer Research Center (CNIO) conducted the world's first successful anti-aging therapy on an adult animal.
As a result of gene therapy, experimental mice that underwent the procedure in adulthood (1 year) lived on average 24% longer than normal mice, aging mice (2 years) showed the worst, but also significant result in a 13% increase in life expectancy. Also, the experimental mice showed better results than their peers in aging tests, such as neuromuscular coordination.
The procedure consisted in injecting mice with a genetically modified virus, the viral genes of which were replaced by the enzyme telomerase, an enzyme responsible for restoring the end sections of chromosomes (telomeres). Telomeres protect chromosomes, but with each cell division, the telomere shrinks, and eventually becomes too short and does not perform its functions. As a result, the cell loses its ability to divide – and, according to many scientists, this is one of the most important factors affecting aging. Telomerase, on the other hand, suspends the shortening of telomeres, and sometimes even restores them, thereby allowing the cell to continue dividing. Adult human cells have no telomerase, except for stem and cancer cells.
Presumably, it is telomerase that is responsible for the "immortality" of cancer cells, so the development of anti-aging technologies based on telomerase is not too active yet due to the danger of developing tumors.
The virus experiment showed no increase in the likelihood of cancer in mice. In addition, CNIO scientists have been particularly careful about choosing a telomerase carrier virus - this is a non–pathogenic strain that has already been used in the treatment of hemophelia and eye diseases. The uniqueness of this method compared to previous attempts to stop aging with telomerase is that a single procedure is enough and it can be carried out even in adulthood – when it is necessary, and when dangerous cancerous micro-tumors can accumulate in the body, and not throughout life, as other methods suggest – this is it will significantly reduce possible side effects.
Of course, the biology of mice is very different from human biology, if only because mice continue to produce telomerase throughout their lives. It is not yet known whether this technology can really find use as a protection against aging, but the authors are confident that it will at least be able to find cures for diseases associated with telomere shortening, such as pulmonary fibrosis.
Scientists of the New York University Department of Medicine are confident that telomerase activity can be controlled "from the inside", at the genetic level. They found that a group of four AUF1 genes is responsible for telomerase activation, and at the same time for controlling inflammatory processes. Thus, one gene is responsible simultaneously for the process of dividing healthy cells – and therefore for aging – as well as for the development or, conversely, the suppression of cancerous tumors. They are currently examining the genomes of various human populations for abnormalities in the AUF1 group of genes, and presumably this will help to identify how the gene can be modified to increase life expectancy.
Another perspective in the fight against aging is hyaluronic acid. Scientists from the University of Rochester in New York are now actively studying the properties of hyaluronate, investigating the biochemistry of metabolic processes of naked diggers, rodents living up to 30 years - ten times longer than ordinary laboratory mice. The innovation of the approach lies in the fact that instead of investigating why the body ages faster or slower when using certain procedures, as happens in ordinary experiments on mice, scientists are trying to find out what is in the body of naked diggers that ordinary mice do not have.
Experiments have shown that, most likely, hyaluronic acid is responsible for resistance to aging and cancer in naked diggers. This viscous acid plays a crucial role in the regeneration of cellular tissue and is an important "building" element of the human body.
Hyaluronic acid is part of the skin and is responsible for its elasticity, and with age, less and less is produced in the body. Cosmetology companies noticed this, but commercially sold hyaluronic acid is produced by bacteria, and has less efficiency than that generated in the body of naked diggers. In humans, the enzyme responsible for the production of hyaluronate in the body is less stable than in a rodent, in which it produces a more stable high-molecular form of acid. Now scientists are looking for a way to isolate the gene responsible for the production of high-molecular hyaluronic acid. If we create a therapy that improves the production of hyaluronan in the human body, it is possible to achieve an increase in life expectancy. In addition, hyaluronan is responsible for the permeability of the walls of blood vessels to cholesterol. Even if it is not possible to achieve "rejuvenation" of cells, hyaluronic acid will at least help fight atherosclerosis.
The scientific community's interest in life extension technologies is steadily growing. Now this is far from a marginal medical topic. However, the very prospect of prolonging life raises a lot of ethical questions – from purely religious ones (is it allowed for a person to change the life path measured to him?) before social (how to dispose of such a resource? what will happen to the planet if people live twice as long?). However, research on stopping aging is very important. In addition to its main goal, as "by-products" of research, discoveries are possible that will help fight serious diseases whose treatment effectiveness is still quite low, such as cancer and atherosclerosis. But, in any case, the actual prolongation of life is still a matter of the distant future – decades may pass from experiments on laboratory mice to use on humans.
Portal "Eternal youth" http://vechnayamolodost.ru08.06.2012