Sports epigenetics
How physical education affects DNA
Kirill Stasevich, "Science and Life"
We are so used to saying that sports strengthen muscles, protect against cardiovascular diseases and diabetes, and generally prolong life, that we do not even think about what is happening here from the point of view of physiology, biochemistry, cell biology, etc. Of course, we can assume that an increase in muscle mass with constant exercise is a consequence of changed activity some genes – but what kind of genes are there and, most importantly, how exactly is their activity regulated? Meanwhile, until very recently, no one could give a more or less concrete answer to this question.
Part of the problem is solved by the latest work of Carl Johan Sundberg and his colleagues from the Swedish Karolinska Institute (see the post Long-term endurance training impacts muscle epigenetics). They decided to check whether epigenetic markers on human DNA do not change under the influence of physical stress. Epigenetic mechanisms of regulation of genetic activity are among the most universal and effective (and one of the most studied), so it would be strange to pass them by.
It is known that sports turn off some genes and turn on others; on the other hand, it has also been known for a long time that the epigenetics of human cells depends on lifestyle and environmental conditions. For example, some pollutants stimulate the redistribution of methyl groups attached to DNA by special enzymes; in turn, the activity of genes depends on whether there are methyl groups on them or not. There is also evidence that the methyl pattern on DNA is influenced by diet. (The DNA sequence itself does not change, the order of the nitrogenous bases – genetic letters – in the gene remains the same, which is why such mechanisms are called epigenetic, that is, working not inside the genes, but on top of them.)
At the same time, almost nothing is known about how physical activity affects DNA methylation. Some works say that a short-term heavy load immediately leads to epigenetic consequences. And if, without exposing yourself to outright stress, you just train regularly – will such training affect the methyl regulation of gene activity?
The Swedish researchers' experiment involved a little more than two dozen young men and women who had to work out on an exercise bike for three months. However, they had to pedal with only one foot. The fact is that epigenetic mechanisms are very sensitive to everything that happens to us, and it would be quite difficult to say whether the observed changes were really due to training, or due to some previous life circumstances of a particular person. And you can't compare him with anyone else. But one leg can be compared with the other, their past epigenetic modifications will be the same.
Before and after the three-month classes, the volunteers performed various tests, before and after they took a biopsy of the leg muscles. Of course, by the end of the experiment, one leg was clearly stronger than the other. But at the same time, the methyl pattern changed at about 5,000 points on the DNA of the trained leg; somewhere methylation increased, somewhere weakened. Accordingly, the activity of a number of genes changed, most of which regulated the energy of the cell, inflammatory processes and cellular response to insulin. In untrained legs, nothing like this could be found. The results of the work are published in the journal Epigenetics (Lindholm et al., An integrative analysis reveals coordinated reprogramming of the epigenome and the transcriptome in human skeletal muscle after training).
So, it is no exaggeration to say that sports affect DNA, and as a result, certain changes occur in our physiology and in our well-being. Although, of course, the question immediately arises: and if you stop doing sports, how long will the altered picture of genetic activity persist, how long will the methyl groups remain in their places on DNA? However, the physiology of the cell depends not only on epigenetic mechanisms, and the "physical culture" state can be maintained at the expense of other molecular cellular processes triggered by physical exercise.
Portal "Eternal youth" http://vechnayamolodost.ru24.12.2014