Scientists have read the genomes of the oldest people on the planet

Longevity remains a mystery

Nadezhda Markina, "Newspaper.Ru»

Having deciphered the genomes of 17 people over 110 years old, geneticists have not found any gene variations that distinguish centenarians from the rest of humanity. A possible explanation for this is that these differences lie not in the structure of genes, but in their activity.

The problem of slowing down aging and increasing life expectancy occupies the minds of reputable scientists around the world. But where else to look for the secret of eternal youth, if not among centenarians? Today there are 74 people living on the planet who have crossed the threshold of their 110th anniversary. In the hope of reading the hereditary code of longevity, scientists turned to their genome.

If they managed to live so long, it means they have happily avoided those age-related diseases that affect others: some at 80, some at 70, and some even earlier.

The influence of genes is confirmed by the fact that longevity is of a family nature. If a person is over 100, then most often, at least one of his parents has lived a long time, and his children can count on it. Interestingly, according to the nature of the lifestyle, including alcohol consumption, smoking, nutrition and physical activity, there is no significant difference between centenarians and the rest of the population.

Scientists are turning to the genes of centenarians, of course, not for the first time. Previously, it was possible to find genetic variations (polymorphisms) that favor long life in a population of 95-year-olds and older. About the fact that it was possible to find areas in the genome associated with longevity, "The newspaper.En" was also told by Claudio Francesco, professor at the University of Bologna in Italy.

Now, researchers from Stanford University and their colleagues from other universities in the USA and Australia have decided to turn to the oldest people on the planet.

They sequenced the genomes of 17 super-long-livers, people aged 110 years and older. Among them were 16 women (the oldest was 116 years old) and one man.

For the purity of the experiment, the genomes of 13 women of European origin were included in the main genetic analysis, excluding two Latin American women, one African American woman and one man.

(Article by Gierman et al. Whole-Genome Sequencing of the World's Oldest People is published in open access in the journal PLOS ONE – VM.)

Of the entire set of age–related diseases, only one woman was diagnosed with Alzheimer's disease, and a man with cancer. No one suffered from heart and vascular diseases or diabetes. Most of them were in good physical shape and able to work: one woman worked as a doctor until she was 103, the other drove a car until she was 107.

Scientists initially assumed that there may be rare genetic variants in the genome of super-long-livers, which are almost not found in the main population. And during the analysis, they tried to find these rare options.

But, contrary to expectations, biologists have not found rare genetic variants that would distinguish centenarians among other people.

The only gene that scientists expect to somehow cling to was the TSHZ3 gene (involved in the development of the nervous system), but due to the small amount of data, they cannot draw unambiguous conclusions about its variants that contribute to longevity.

Then geneticists began to find out whether there are any pathological variants of genes in the genome of super-long-livers. To do this, we used an extensive database of mutations associated with human diseases. In one long-lived woman, they found a mutation that was supposed to lead to a deadly pathology of the right ventricle of the heart.

Nevertheless, its owner at the age of 110 did not complain about her heart. So, during all this time, this mutation has not shown its harmful nature and has not led to cardiopathy.

The results of the research "Newspaper.Ru" commented Doctor of Biological Sciences Alexey Moskalev, Head of the Laboratory of Molecular Radiobiology and Gerontology of the Institute of Biology Komi UroRAN, Head of the Laboratory of life expectancy and Aging MIPT.

"According to the hypothesis of demographic selection, in that part of the population that is characterized by longevity, gene variants (alleles) that determine premature mortality from age-related diseases may be lost, or, on the contrary, genetic variants associated with slowing aging and increased stress resistance may be accumulated. However, recent studies carried out by Thomas Perls and colleagues in Boston, Nir Barzilai and Yuxin Su in the Bronx, and now Stuart Kim and colleagues in Los Angeles, have not revealed any noticeable genetic differences in people living more than 110 years.

Some of them even had genetic variants that were associated with a very high risk of cardiovascular pathologies or a high probability of tumors.

Many researchers, including me, are increasingly inclined to the point of view that longevity in humans is determined not by any rare alleles (mutant state of the gene), but by epialleles, which are due to the special location of the sites of methylation of genomic DNA.

However, the epigenome of the "super–long-livers" still remains unexplored, and new exciting discoveries are still waiting for us here," the Russian scientist summed up.

Portal "Eternal youth" http://vechnayamolodost.ru 13.11.2014