Healthy capillaries – a happy old age
In the process of aging, the endurance and stability of the body decreases. One of the reasons for this is age-related changes in blood vessels: the full supply of oxygen and nutrients to tissues and organs is disrupted.
A group of researchers from the Massachusetts Institute of Technology in their article boldly declares that they are able to reverse the aging process and return activity to old mice with the help of a substance that stimulates the growth of new blood vessels.
The researchers targeted sirtuins, a group of proteins that promote the growth of blood vessels and muscles. It is proved that an increased level of sirtuins leads to an improvement in the general condition of the elderly body, its stability and endurance. In the study on mice, the complex indicator improved by 80%. If we achieve a similar effect in humans, we can talk about solving many problems associated with aging, including the victory over osteoporosis. The muscles are directly adjacent to the bone and constantly interact with each other. Age-related decrease in muscle mass can lead to loss of bone strength, osteoporosis and associated frequent fractures.
Leonard Guarente and his colleagues decided to pay close attention to the effect of sirtuins on the endothelium, the layer of cells lining blood vessels from the inside. To do this, they suppressed the SIRT1 gene encoding the synthesis of sirtuin in the endothelial cells of mice. It was found that at a young age (6 months), their capillary density decreased, and the mice could perform only half of the physical activity compared to peers from the control group.
The researchers then increased sirtuin production in healthy mice as they aged. To do this, they were injected with nicotinamide mononucleotide (nicotinamide mononucleotide, NMN), which is a precursor of nicotinamide dinucleotide (NAD), a coenzyme that activates the SIRT1 gene. Normally, the level of NAD gradually decreases with age due to a decrease in production and increased decay.
Middle-aged mice (18 months) were injected with NMN for two months. At the end of the course, the density of capillaries in them increased and compared with that in young mice. Their complex endurance index increased from 56 to 80%. Similar results were observed in mice under the age of 32 months, which by the standards of human age corresponds to 80 years.
The results of the experiment can be useful in the treatment of diseases accompanied by impaired microcirculation of organs such as the brain or heart.
The researchers also found that stimulation of the gene encoding the synthesis of sirtuins in endothelial cells contributes to increased physical activity in young mice. Training promotes the growth of the vascular network and muscles, but when the SIRT1 gene was suppressed in 10-month-old mice, a 4-month course of exercises in the form of running on a special track gave a much more modest result compared to mice of the same age after the same course of training, but with normal levels of sirtuin.
If the results of the study can be duplicated in humans, the NMN-based drug will help prolong active and healthy longevity.
Article A. Das et al. Impairment of an Endothelial NAD -H 2 S Signaling Network Is a Reversible Cause of Vascular Aging published in the journal Cell.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on materials from Harvard Medical School: Rewinding the Clock.