Aging is an essential process in the life cycle In general, aging affects cells, and more specifically, their genetic content.
Of course, this process does not evolve randomly; In fact, not only do we age more or less depending on how we eat and the general lifestyle we lead, but there are also genes that regulate our physical and psychological maturation. In fact, an important discovery in this regard has recently been made: a gene related to the way our brain ages which is interesting for many reasons that we will now see.
At the ends of the double helical chain that forms our DNA (enclosed in all the cells of our body) there are a series of sequences of nucleic acids known as telomeres Every time a cell divides, these ends shorten, and when it reaches a certain limit, it causes cell death. The loss of cells is part of aging, which leads to a decrease in the body’s activities.
One of the organs most sensitive to the passage of time is undoubtedly the brain The loss of neurons takes its toll, and there is a long list of problems that cause this, such as lack of motor coordination or dementia.
In research topics, there has always been a special interest in studying brain aging, such as to reveal its relationship with neurodegenerative diseases such as Parkinson’s or Alzheimer’s. Not long ago, one of these investigations located a gene that is related to this process.
Scientists at Columbia University (United States), Asa Abeliovich and Herve Rhinn, examined nearly 1,900 samples of healthy brains. From their observations they were able to draw the conclusion that a gene, designated TMEM106B plays a fundamental role in how human brains age.
Certain varieties of this gene appear to cause the frontal lobe to age at a faster rate than in other people. This is important because this region is involved in executive functions, such as decision making, managing our focus of attention or planning. Aging of the frontal lobe It causes a decrease in these vital functions and increases the risk of the appearance of diseases known as neurodegenerative.
Genes as risk factors
Finding genes that explain the appearance of biological anomalies is nothing new. An example is the ApoE gene, responsible for the transcription of the Apolipoprotein E protein, which in one of its variants (specifically ApoE4) is associated with an increased risk of Alzheimer’s disease
The novelty of this discovery is having found a gene that controls the rhythm of life of a region of the brain. As the discoverers themselves maintain, aging is the main risk factor for developing neurodegenerative diseases and this research can help predict the appearance of these diseases or even intervene on them through so-called genetic therapies.
How does this brain aging gene work?
For this study, Asa Abeliovich and Herve Rhinn first obtained genetic data from 1,904 autopsy samples of brains that had not suffered from any neurodegenerative disease. Once obtained, they compared them with average data from brains of the same age, looking specifically at 100 genes whose expression increases or decreases with age. The result is that a gene causes differential aging, the one already called TMEM106B.
The concept of differential age is simple; It is nothing more than a difference between the biological age of the organ (in this case the brain), with the chronological age of the organism. The frontal lobe turns out to be older or younger than what corresponds to the person’s age, taking the person’s day of birth as a reference.
According to its discoverers, the TMEM106B gene begins to manifest its effects from the age of 65, and works to reduce the stress caused by aging about the brain. From what has been seen, there are different alleles, that is, variants of the gene. Some protect against this stress (their normal function), while others do not perform this task, which causes the brain aging process to accelerate.
Related to a disease
In their study, these researchers also found that a variant of the progranulin gene It has an effect on aging, but not as prominent as TMEM106B. Although they are two different genes and are found on different chromosomes, both act on the same signaling pathway and are associated with the appearance of a neurodegenerative disease known as frontotemporal dementia
This clinical syndrome stands out for a degeneration of the frontal lobe, which can extend to the temporal lobe. In adults between 45 and 65 years old, it is the second most common form of dementia after early-onset Alzheimer’s, affecting 15 out of every 100,000 people. In people over 65 years of age, it is the fourth most common type of dementia.
Despite everything, the study has been carried out from the perspective of healthy brains, so more studies are needed to confirm certain points with its relationships with diseases. But, as Abeliovich indicated, aging makes one more vulnerable to neurodegenerative diseases and vice versa, diseases cause accelerated aging.
