Scientists have discovered an unusual gene in human DNA, a mutation that can accelerate the aging of the brain in the elderly for dozens of years and or slow it down with a similar force, according to an article published in the journal Cell Systems.
“If you look at the elderly, some of them will look unusually old and others look unusually young, and the same happens in the frontal cortex, the brain region responsible for the work of the mind.” We found that many of these differences are related to variations in Gene TMEM106B.In people who have two “bad” copies of this gene, the frontal cortex looks 12 years older than in the elderly with two normal versions of TMEM106B, “explains Asa Abeliovich from Columbia University in New York, New York (USA).
In recent years, a debate has revived among scientists about what constitutes the process of aging and death of humans and animals. Some biologists and evolutionists believe that it is controlled by a kind of “death program” – a certain set of genes that makes the body grow old and die, giving way to a new generation of their kind.
Abelevich and his colleagues discovered one of the potential aging genes by comparing DNA samples from almost two thousand pieces of the brain sacrificed for the sake of science by people who died for natural reasons and did not suffer from Aitzheimer’s disease, multiple sclerosis or other neurodegenerative disorders.
Studying these genomes, scientists compared not only the structure of the genes themselves, but also how actively they were read by brain cells. This allowed us to reveal not only how the differences in the structure of genes influenced the work of the cortex and other layers of the brain, but also to understand how the nature of their work changed with the aging of the organism.
Comparing how the “pattern” of gene activity in different elderly people differed, and how their cortex looked, Abelevich and his colleagues identified several DNA sections that affected the aging rate of the brain.
Most strongly, as calculations of biologists have shown, this gene was influenced by the gene TMEM106B – a DNA site responsible for the formation of connections between nerve cells and their purification from protein “garbage”. Even small mutations in its structure affected the appearance of the cortex in old age, speeding up or slowing its aging for several years, scientists found.
Interestingly, this gene was “included” only in the elderly, beginning to affect the work of the brain at about 65 years. Why this happens, the scientists do not yet know, but they assume that this is due to the inclusion of some stress mechanisms in the event of old.
In addition, Abelevich’s team managed to find a link between the aging of the cortex and another genome, GRN, which performs similar functions, but which affects the decrepitude of the brain to a much lesser extent. According to scientists, a few dozen such genes, controlling the aging of different organs, can be present in human DNA. Their study will help to understand whether it is possible to slow down the aging process and how to do it.
Original: Ученые открыли ген, управляющий старением мозга