The enzyme of youth
A new way to prevent aging in mice has been found, according to a study conducted at Washington University School of Medicine in St. Louis.
It is assumed that the extracellular enzyme nicotinamide phosphoribosyltransferase (extracellular nicotinamide phosphoribosyltransferase, eNAMPT), contained in the blood, plays a vital role in maintaining health. With age, the level of this protein decreases, both in mice and in humans, and the number of health problems only increases: insulin resistance appears, weight increases, cognitive abilities decrease, vision loss, etc. The cellular ability to produce energy is also reduced due to a decrease in the production of nicotinamide adenine dinucleotide molecules (OVER), which are necessary for the normal functioning of the body.
The study showed that increasing the concentration of eNAMPT in the blood seems to be one of the ways to increase the amount of NAD and prevent aging. Scientists have discovered other ways to increase the level of NAD in the body. For example, taking nicotinamide mononucleotide (NMN) orally. NMN is an intermediate in the reaction of the production of NAD.
Unlike other studies devoted to the prolongation of active longevity, instead of transfusion of blood from young mice to old ones, in this case the concentration of only one blood component was increased. This approach has shown its effectiveness, several indicators have improved at once: the ability to produce insulin, sleep quality, photoreceptor functions and cognitive functions when performing memory tests, as well as increased physical capabilities when running on a wheel.
According to the concentration of eNAMPT in the blood, scientists were able to predict the life expectancy of mice. The higher the concentration of eNAMPT, the longer the mouse could live, and vice versa, with a low level of the enzyme, the lifespan was significantly reduced.
When eNAMPT, obtained from young mice, was introduced into the body of old mice, life expectancy increased by about 16%. The mouse receiving the eNAMPT is alive at the time of writing this article. Her life expectancy is already 1029 days (about 2.8 years). While the mice that received saline as a control lived for about 881 days (2.4 years).
Among other things, it turned out that there are sex differences in the concentration of eNAMPT in the blood, and, as a rule, a higher level of the enzyme was found in females.
The study also revealed that the hypothalamus is the main center of aging control throughout the body. It regulates many vital processes, such as body temperature, thirst, sleep, circadian rhythms and hormone levels, and is largely controlled by eNAMPT, which is released into the blood from adipose tissue. NAD in the hypothalamus is also produced by eNAMPT and is carried through the bloodstream by small vesicles called extracellular vesicles. As the level of eNAMPT decreases in the blood, the hypothalamus loses the ability to function normally, shortening life expectancy.
Scientists do not yet know whether there is a similar relationship between the enzyme and life expectancy in humans, and whether it can be used as a potential biomarker of aging. Thus, future studies will be aimed at identifying the association of low enzyme levels with diseases in the elderly and the effectiveness of the introduction of eNAMPT into extracellular vesicles in the fight against aging.
Article by Youshida et al. Extracellular Vesicle-Contained eNAMPT Delays Aging and Extends Lifespan in Mice is published in the journal Cell Metabolism.
Elena Panasyuk, portal "Eternal youth" http://vechnayamolodost.ru / based on the materials of Washington University School of Medicine in St. Louis Aging delayed in older mice given blood component from young mice.