Telomere shortening rate and age-related diseases
Within the framework of the ENGAGE international consortium, a group of scientists from 8 countries and 14 research centers, working under the leadership of Professor Nilesh Samani from the University of Leicester, received new evidence that rapid "biological aging" is associated with the risk of developing a number of age-related diseases, including heart disease, multiple sclerosis and various types of cancer.
The aim of the project was to study the end sections of chromosomes – telomeres. These DNA sequences that do not contain genetic information are shortened with each cell division until their length reaches a critical value, after which the cell loses its ability to divide and eventually dies. As the body ages, telomeres gradually shorten. However, different individuals are born with telomeres of different lengths, moreover, the rate of their shortening also varies from organism to organism. The rate at which telomeres shorten is a measure of "biological aging".
According to Professor Samani, the incidence of heart disease and cancer increases with age, but they do not occur in everyone, while in some people these diseases appear at a relatively early age. It has been suggested that the risk of developing age-related diseases may be due to the fact that the biological aging of some people proceeds faster than the biological aging of other people.
The researchers measured the telomere length of more than 48,000 people, then analyzed their DNA and identified variants of single-nucleotide polymorphisms (snips) in seven genes, two of which were previously known to be associated with telomere length, and in five more, whose relationship with telomere length was revealed for the first time. At the next stage of their work, they tried to get an answer to the question: do the identified alleles (gene variants) affect the risk of developing various diseases? Given that the sequence of nucleotides in DNA does not change under the influence of lifestyle or environmental factors, the existence of a relationship between genetic variants that determine the length of telomeres and age-related diseases would indicate the existence of a causal relationship between telomere length and the risk of developing these diseases.
The results showed that the identified genetic variants are indeed associated with the risk of developing several types of cancer, including rectal cancer, as well as diseases such as multiple sclerosis and gluten enteropathy. The most interesting was the fact that the presence of all seven identified "unsuccessful" alleles is associated with an increased (on average by 21%) risk of coronary heart disease, which can lead to myocardial infarction.
According to the authors, the observations made indicate that theoretically manipulations over the length of telomeres can have a therapeutic effect. It is obvious that clinical use is still very far away, however, there is evidence that in a number of experimental models, an increase in telomere length provided a slowdown, and in some cases, a restoration of age-related changes in some organs.
Article by Veryan Codd et al. Identification of seven loci affecting mean telomere length and their association with disease is published in the journal Nature Genetics.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to the University of Leicester: Scientists identify link between faster 'biological' aging and risk of developing age-related diseases such as heart disease and cancer.
08.04.2013