05 September 2017

The size of nucleoli is a biomarker of longevity

German researchers from the Max Planck Institute for the Biology of Aging, working under the guidance of Dr. Adam Antebi, have demonstrated the existence of a relationship between the size of nucleoli – tiny structures inside the cell nucleus – and the life expectancy of the organism. They believe that the size of the nucleolus can be used as a molecular marker of health and aging.


The cells of long-lived fruit flies (on the right) have smaller nucleoli compared to the cells of their short-lived relatives.

Experts in the field of aging have been searching for so-called biomarkers of aging for a long time, which would make it possible to make predictions about the state of health and life expectancy of organisms. Recently, researcher Varnesh Tiku, working under the guidance of Dr. Antebi, in experiments on long-lived roundworm mutants Caenorhabditis elegans, found that such mutants have smaller nucleoli than short-lived worm lines. Moreover, it turned out that this relationship does not depend on the mechanism underlying longevity.

Nucleoli are tiny structures located inside the cell nucleus and assemble ribosomes – organelles that synthesize proteins necessary for the cell.

In subsequent experiments, it was found that the relationship between the size of the nucleolus and longevity extends to other organisms, such as fruit flies of fruit flies and mice.

According to the authors, the revealed correlation may well be relevant for humans. Thus, the analysis of biopsy samples of muscle tissue of people over 60 years old, who for a certain time followed a moderate low-calorie diet in combination with physical exercises, showed that the nucleoles of their muscle cells were smaller in size compared with the results of the analysis conducted before the start of this intervention. Combining a low-calorie diet and physical activity is currently considered the most effective method of improving health and increasing life expectancy.

Researchers believe that the size of the nucleoli is not just a biomarker of longevity. Apparently, their composition includes molecules that have a direct impact on life expectancy. The observations made by the authors are in favor of the correctness of this hypothesis. During the experiments, they found that long-lived roundworm mutants with small nucleoli were characterized by reduced levels of the fibrillarin protein, which is part of the nucleoli and involved in the assembly of ribosomes. Moreover, it turned out that artificially reducing the amount of fibrillarrin in the nucleoli also increases the lifespan of worms.

Does this mean that in the future doctors will be able to estimate the life expectancy of patients by the size of their nucleoli? It is quite possible, however, the authors warn that there is still a lot of work to be done before the introduction of this approach into clinical practice. They also hope that their discovery will allow monitoring the effectiveness of interventions aimed at improving health and increasing life expectancy.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to the Max Planck Institute for Biology of Aging: Nucleolus is a life expectancy predictor.


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