A new role of telomeres in the aging process has been discovered
Researchers at the University of Texas Southwestern Medical Center, working under the leadership of Professor Jerry W. Shay and Professor Woodring Wright, have identified a previously unknown mechanism for the formation of telomerase loops that can shed light on the aging process of cells and the development of age-related diseases.
Telomeres are the terminal protective sections of chromosomes that shorten with each cell division. When the telomeres reach a critical length, the cell enters a phase of physiological aging, which consists in the loss of the ability to divide and change metabolism. Most of the research in this area is devoted to the study of the role of this mechanism in the development of cancer, however, data have been obtained according to which telomere shortening affects the activity profile of cell genes.
In a detailed study of this issue, the authors found that, even before telomeres reach a critical length and subsequent DNA damage, their slow shortening affects the regulation of genes that potentially contribute to aging and the development of associated diseases.
In particular, they demonstrated that the end section of a long telomere can form a loop with a chromosome. As a result, the telomere is attracted to genes that were previously considered too distant from the telomere to be subject to the regulatory influence of its length. The convergence of the telomere with such genes can block their expression.
Conversely, a short telomere cannot form a loop with a chromosome and loses the ability to regulate the expression of target genes.
The authors were able to identify three target genes whose expression is influenced by telomere length, but they believe that this is just the tip of the iceberg.
Based on the data obtained, the researchers formulated a concept according to which telomere shortening can be a kind of synchronization mechanism that responds to physiological changes in the organisms of representatives of long-lived species, such as humans, to optimize the state of the body in accordance with its age.
Article by Jerome D. Robin et al. Telomere position effect: regulation of gene expression with progressive telomere shortening over long distances is published in the journal Genes and Development.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on materials from UT Southwestern Medical Center:
Scientists uncover mechanism that controls the fitness of cells, impacting aging and disease.
19.11.2014