The relationship between aging and sleep quality is revealed
Researchers at the University of Pennsylvania, working under the guidance of Dr. Nirinjini Naidoo, have discovered the intersection between the signaling cascades of the aging process and the body's response to cellular stress, which, among other things, causes senile sleep disorders. They believe that exposure to the appropriate mechanisms can help the elderly suffering from insomnia. At least, this was achieved in experiments on fruit flies.
It is known that aging is often accompanied by various sleep disorders. Many elderly people complain of both a decrease in the duration and a deterioration in the quality of night sleep. At the same time, they often fall asleep in the daytime.
Earlier, the authors studying the molecular mechanisms of this phenomenon found that aging is associated with an increase in the content of unfolded protein molecules in cells. This so-called "uncoiled protein reaction" is a sign of cellular stress.
Abnormal folding of protein molecules is typical for a number of age-related diseases, including Parkinson's and Alzheimer's diseases, and, as it turned out, sleep disorders. The researchers decided to find out whether the restoration of the folding mechanisms of protein molecules can at least partially normalize the sleep of an aging organism.
Using a video monitoring system, they compared the sleep characteristics of "young" (9-12 days) and "old" (8 weeks) fruit flies. It turned out that, like elderly people, elderly flies in general slept less and more sensitively, and also recovered longer after a forced lack of sleep than their young relatives. However, stimulating the normal folding of protein globules, a compound known as sodium 4-phenylbutyrate eliminated most of these manifestations and returned aging fruit flies to almost youthful sleep.
Molecular analysis of drosophila cells showed that sodium 4-phenylbutyrate exerts its effect by correcting the reaction of non-folded proteins. Currently, this drug is used to treat diseases associated with abnormal folding of protein molecules, such as Parkinson's disease and cystic fibrosis.
The authors also decided to find out whether abnormal protein folding can affect the sleep of young individuals. To do this, they used another drug – tunicamycin, which disrupts the formation of protein globules and causes cellular stress. Its addition to the feed of young fruit flies led to the development of typically senile sleep disorders in them: a decrease in the total duration of sleep, an increase in its sensitivity and a deterioration in the ability to recover from lack of sleep.
Based on the results obtained, the authors formulated three main conclusions. Firstly, lack of sleep leads to disruption of protein molecules folding and cellular stress, and with age, the body's ability to recover from stress worsens. Secondly, these phenomena seem to be components of a positive feedback loop, in which lack or intermittent sleep causes cellular stress, which, in turn, leads to impaired functioning of neurons and further worsens the quality of sleep.
And finally, most importantly, if the results obtained can be reproduced in mice and in clinical studies, drugs such as sodium 4-phenylbutyrate can be used to restore sleep quality.
Article by Marishka K. Brown et al. Aging induced endoplasmic reticulum stress alters sleep and sleep homeostasis is published in the journal Neurobiology of Aging.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of Pennsylvania:
Penn Study in Fruitflies Strengthens Connection Among Protein Misfolding, Sleep Loss, and Age.
27.02.2014