Sirtuins: take under the supervision of a psychiatrist!
Over the past 10 years, MIT scientists working under the leadership of Leonard Guarente and other research groups have demonstrated that a low-calorie diet triggers a complex physiological reaction mediated by proteins of the sirtuin family. The result of this is a significant increase in the lifespan of the organism.
In their latest work, Guarente and his colleagues have shown that, among other things, sirtuins play a key role in the development of a psychological response to nutrient deficiency. It turned out that an increase in the concentration of sirtuins in brain tissues, accompanying a decrease in caloric intake, makes mice more restless.
The experiment consisted in placing two groups of mice (with elevated levels and without SIRT1 protein in brain tissues) on a raised circular platform divided into four sectors, two of which were protected by walls. Animal observation showed that individuals with abnormally high levels of sirtuin in the brain spent most of their time in close proximity to the walls, whereas mice without this protein were characterized by much more risky behavior.
The study of the molecular mechanisms underlying this phenomenon showed that sirtuins activate the enzyme monoamine oxidase (MAO), which destroyed the neurotransmitter serotonin, low levels of which are associated with symptoms of anxiety and depression.
Moreover, an analysis of the results of two large-scale genetic studies conducted jointly with specialists from the University of Lausanne and Virginia Commonwealth University showed that mutations that enhance the production of sirtuins are associated with a greater likelihood of developing anxiety and panic disorders in humans.
Researchers believe that anxiety may be a manifestation of evolutionary adaptation that stimulates mammals, including humans, to more actively search for food. They also suggest that excessive anxiety can be suppressed with the help of drugs that inhibit the activity of sirtuins.
On the other hand, the data obtained raise concerns about the unsafe treatment of patients with drugs that increase the activity of sirtuins. Several such drugs are currently being tested in clinical trials as agents for the treatment of metabolic diseases, such as diabetes mellitus. These drugs cannot penetrate the brain, but experts are considering the use of sirtuin inhibitors for the treatment of neurological diseases such as Alzheimer's and Parkinson's diseases. In the event of the appearance of such drugs capable of penetrating the blood-brain barrier, doctors will have to consider the possibility of developing such a side effect as a state of increased anxiety, which can be suppressed with secondary therapy with selective serotonin reuptake inhibitors, such as prozac.
Article by Sergiy Libert et al. SIRT1 Activates MAO-A in the Brain to Mediate Anxiety and Exploratory Drive published in the journal Cell.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on MIT materials:
Proteins linked to longevity may be involved in mood control.
13.12.2011