To prevent the heart from aging, turn off your PI3K

Scientists have learned to turn off the aging gene in miceAlexey Tymoshenko, GZT.RU
Molecular biologists have identified a gene whose deactivation in the mouse body led to the fact that the rodent's heart stopped aging.

According to Japanese scientists who published the results of their research in the journal Circulation: Journal of the American Heart Association, the discovery will help to understand why and how the heart ages not only in mice, but also in humans.

Previously, experiments with the PI3K gene of roundworms and fruit flies led to an increase in the life expectancy of animals. A study conducted by Japanese scientists from the Kyoto Graduate School of Medicine made it possible to take another step, if not to gene therapy of cardiovascular diseases, then at least to understanding the causes of age-related deterioration of the heart in mammals. After all, there is less difference between a mouse and a human than between a human and a roundworm.

Another aging gene

There are many genes that are somehow involved in the aging process. A significant part of them were discovered in experiments with short-lived and rapidly proliferating organisms like fruit flies or C.elegans roundworms, and some genes in response to prolonging life cause side effects in the form of a decrease in body size or even infertility.

To find genes that can help in the treatment of diseases or prolong a person's life, it is impossible to go through the method of brute force, turning off one gene after another, of course, it is impossible. Moreover, all such studies are based on information about a particular gene, which is already available to biologists. However, even the name itself can tell a lot. And the PI3K chosen by the Japanese team is no exception.

What do these letters mean?

Most genes have little expressive names in the form of abbreviations. PI3K is another example of this. The reason for the brevity lies in the fact that biochemists and molecular biologists give names that reflect what this protein does.

In the work of Japanese scientists, we are talking about a protein capable of attaching several other atoms to the molecules of the cell membrane, the so-called phosphate group. Thus, the protein activates the membrane molecules, and they, in turn, begin to participate in the transmission of various signals inside the cell, reacting with other substances and affecting vital activity.

The molecules that activate the PI3K protein are the substance phosphatidylinositol. Proteins are switches of other molecules – kinases. So, the full name of the protein is phosphatidinositol-3-kinase, or more simply, PI3K.

Why him?

Proteins that switch the activity of other molecules are especially interesting because they can affect a variety of processes. Aging, the appearance of tumors, cell damage in diseases – all this in the vast majority of cases is associated with the disruption of finely tuned control systems of the cell. Scientists who decided to suppress the activity of this gene in the mouse turned off not just one protein, but several different processes at once – in the hope that the chain of changes caused by their intervention would reach the vital functions of the body.

Results of the experience

After the birth of the first transgenic mice with the PI3K gene disabled, we had to wait for the rodents to grow old. After some time (and the mouse lives up to three years), scientists compared genetically modified rodents with ordinary ones. That's what happened in the end.

• The heart muscle of mice that had the PI3K gene turned off was in better condition compared to normal mice.
• The modified rodents showed fewer signs of fibrosis – the growth of connective tissue around the heart muscle.
• The genes, whose activity changes with age, worked in modified mice in the same way as in a young animal.

Scientists speak cautiously about why disabling one gene caused such changes. There may be mechanisms that have not yet been studied – in particular, biologists talk about the connection of the PI3K gene with the action of insulin on cells. In any case, thanks to the conducted research, the direction for further work has been determined.

Portal "Eternal youth" http://vechnayamolodost.ru13.10.2009