Life expectancy does not depend on the length of telomeres
Researchers at the Spanish National Cancer Research Center, working under the leadership of Maria Blasco, demonstrated in experiments on mammals that at the molecular level, longevity is determined not by the length of telomeres at any given time, but by the speed of their shortening.
Chromosomes – repositories of genetic information of living organisms – on both sides end with repeated DNA sequences – telomeres. These sequences act as "fuses" that prevent the loss of genetic material during the doubling of chromosomes that occurs during cell division.
The results of a number of so-called cross-sectional studies, in which telomere length was measured once in large groups of people, demonstrated the existence of a relationship between telomere length and the risk of developing various diseases, including diseases of the cardiovascular system and cancer.
However, until now, no one has evaluated the acceptability of the method of measuring telomeres to estimate the actual life expectancy of mammals. To get an answer to this question, the authors planned a longitudinal study, during which they measured the length of telomeres in the same animals (mice) for a long period of time.
Analysis of the data obtained showed that the longest lived individuals were not those who had the longest telomeres at any age, but mice whose telomeres shortened the slowest.
According to Blasko, while the telomeres of mice are much longer than human ones, it turned out that they degrade 100 times faster. This refutes the old dogma that normal mice do not age because of telomere shortening.
This study indicates the need for further longitudinal studies to study the impact of lifestyle features such as diet, smoking or physical activity on the individual rate of telomere shortening in the long term. The results of such work can help in the development of methods for the prevention of various diseases and new drugs for their treatment.
Article by Elsa Vera et al. The Rate of Increase of Short Telomeres Predicts Longevity in Mammals is published in the journal Cell Reports.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the Centro Nacional de Investigaciones Oncologicas:
CNIO team discovers the first real indicator of longevity in mammals.
10.10.2012