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Reactive oxygen species prolong life

"Search" No. 15-2017

We have already got used to the fact that we need to fight in every possible way with active forms of oxygen, or, as they are also called, free radicals that destroy and age our body. What was the surprise of the scientific world when the respected journal Cell Metabolism published an article authored by scientists from the UK, Spain, Russia and Finland, showing reactive oxygen species on the positive side.

The surprise of the scientific world causes mutual surprise among the enlightened reader. That article by Scialò et al. Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan was published a year ago and has only now reached the press office of ITEB RAS - this is a trifle compared to the fact that there is absolutely nothing to be surprised about. And below in the same press release it is written "Earlier, other scientific groups have already shown that fruit flies and nematode worms live a little longer ...".

It is unlikely that the world scientific community was stirred up by the publication "once again to the question of ...", but you can't praise yourself…

Russia is represented in this study by Nina Gubina, a researcher at the Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences from Pushchina. 

Reactive oxygen species are formed in the cell naturally as a result of the mitochondria. Like any product of metabolism, free radicals must be removed in time, otherwise they will accumulate in the cell and damage it. Free radicals are naturally excreted from the cells of a healthy young organism under normal conditions. And the sick and the old, alas, things are worse with this. 

At the same time, free radicals can be good: they serve as signals to start various processes, including cell preservation. They are necessary, for example, during physical exertion. It turns out that, depending on the circumstances, reactive oxygen species can both kill the cell and treat it. 

In a new, promising breakthrough work, scientists decided to investigate the role of reactive oxygen species on the example of fruit flies Drosophila melanogaster. To do this, they took the protein NDI1, which actually plays a role in the mitochondria of fungi and plants. It carries electrons across the mitochondrial membrane, participating in cellular respiration and synthesis of ATP, the main energy source in the cell. 

Previously, other scientific groups have already shown that fruit flies and nematode worms live a little longer if this protein is injected into their cells. It turned out that it suppresses the level of free radicals, increased due to mutations in cells. Based on this result, the authors of the new study suggested that prolonging life with NDI1 is also associated with the suppression of free radicals. But it turned out that everything is exactly the opposite! There were more free radicals in the brain cells of flies that produced this protein, but were absolutely normal in all other respects. 

To understand the reason for this paradox, scientists have created several genetically modified lines of fruit flies. A gene was introduced into their genome, forcing cells to produce an alien protein NDI1. Then the flies were artificially placed in such conditions that they developed oxidative stress, and they aged faster. 

So, experiments have shown that NDI1, bypassing the main respiratory enzyme, transfers an electron directly to the next participant in the respiratory chain - ubiquinone. Ubiquinone is known as a strong antioxidant, that is, a suppressor of reactive oxygen species. In this case, the mutual work of the NDI1 protein and the ubiquinone enzyme led to an increase in the level of reactive oxygen species, which served as a signal for the treatment of mitochondria damaged by stress. This, in turn, extended the life of the fruit flies.

Now scientists have to find out whether the mechanism they discovered works in mammals. If so, this will open up another way to combat old age and age-related diseases in humans.

Portal "Eternal youth" http://vechnayamolodost.ru  17.04.2017