Epigenetics Month
Are epigens to blame for everything?
Yanina Khuzhina, "Scientific Russia"
The year 2021 in Russia was declared the Year of Science and Technology, and September, according to its calendar plan, is dedicated to genetics and quality of life. Today, as part of the Year, we are talking about a fairly young science - one of the branches of biology called epigenetics.
Epigenetics literally means "over-genetics". Epigenetics studies changes in the activity of genes that do not affect the structure of DNA. This is a certain amount of factors affecting the expression (activity) of genes. This may include stress, lifestyle, nutrition, radiation, etc. – that is, what affects us, as well as animals and plants from the outside.
There is a huge variety of life forms on Earth, but all species – from the simplest bacteria to humans – have the same genetic code: from four nucleotides in DNA, which are designated by the letters A, C, G and T (adenine (A), cytosine (C), guanine (G), and thymine (T)). The sequence of these chemical units determines which proteins a cell of a living organism produces. Each human cell contains from two to three meters of DNA.
The science of epigenetics says that the way of life of a person and the environment change our body, its gene activity, while leaving unchanged DNA.
Epigenetics is the science of inherited properties of an organism that are not related to changes in the actual nucleotide sequence of DNA and can be not directly, but indirectly encoded in the genome. Known epigenetic mechanisms (signals) include enzymatic DNA methylation, histone code (various enzymatic modifications of histones – acetylation, methylation, phosphorylation, ubiquitination, etc.) and "silencing" of genes by small RNAs (miRNA, siRNA). Excerpt from the article by L.V. Maksimenko "Epigenetics as an evidence base for the influence of lifestyle on health and disease". Preventive medicine. 2019;22(2):115-120.
Epigenetics began to develop as a separate branch of molecular biology in the 40s of the last century. In 1942, the English scientist Conrad Waddington, who laid the foundations of systems biology, first formulated such a concept as an epigenetic landscape. The biologist used this term as a conceptual model of how genes can interact with their environment during the formation of a phenotype (a set of external and internal signs of an organism acquired as a result of individual development).
Further work in this area was continued, and today epigenetics tells us that we are all born with a genome that does not change during life – but the activity of certain genes changes. And we can strengthen or weaken these epigenetic influences, including by medication. Thanks to epigenetic mechanisms, for example, a person prone to laziness can become more active.
"Active movement, playing sports is a certain dependence. Because a person gets pleasure from it through the release of hormones. Another person may not get any pleasure from it, because there is no release of hormones. This person has a slightly different genetics. We will call them "lazy" and "not lazy". But it will be a kind of label. Because, in general, these two people are the same. And if a lazy person is taught to work from childhood, when he already has a genetic basis, then his epigenetic state is formed, which somehow, within certain limits, can change the work of genes. Then these people will also be able to be more active. As such, laziness does not exist," Sergey Lvovich Kiselyov, Doctor of Biological Sciences, head of the Epigenetics Laboratory at the N.I. Vavilov Institute of General Genetics of the Russian Academy of Sciences, said in an interview with Scientific Russia.
The mechanisms of epigenetics, in particular, are responsible for the fact that our body is able to adapt to changing environmental conditions.
"This is a kind of "interface" between a very stable and identical genome in all cells, genetic information and the environment," says Kiselyov.
The scientist compares epigenetic mechanisms with punctuation: they do not change our genetic text, but punctuate it. Such punctuation marks, for example, may be an additional, methyl group based on cytosine. DNA methylation by cytosines today serves as the main tool for studying epigenetic features.
Engaged in epigenetic research in our country for the first time began Boris Fedorovich Vanyushin – Corresponding Member of the Russian Academy of Sciences, Doctor of Biological Sciences. The scientist discovered that DNA methylation in animals is tissue-specific, which indicates epigenetic modification as a mechanism for controlling gene activity and cellular differentiation. These pioneering works marked the beginning of modern epigenetics of development.
"The task of epigenetics, as well as gerontology, is to regulate gene expression so that a person or any living being can reach its species limit (that is, an increase in life expectancy up to 40%, for a person it is 110-120 years)," says corresponding member of the Russian Academy of Sciences, director of the St. Petersburg Institute of Bioregulation and Gerontology Vladimir Khatskelevich Khavinson.
Even the microclimate in your team influences the work of epigenetic mechanisms, the scientist says. If where you work, everyone constantly swears and finds out the relationship, then this leads to chronic stress, and he, in turn, provokes the suppression of immunity.
"Change your lifestyle – and you will start a chain of biochemical changes that will imperceptibly but steadily help you and, possibly, all your descendants until the end of their lives on Earth," writes a German neuroscientist, popularizer of science and writer Peter Spurk.
Epigenetics is a fairly young science, which, nevertheless, inspires great hopes in terms of prolonging life and improving its quality. The most amazing thing is that we can influence the activity of certain genes during our lifetime. It is believed that epigenetic switches can even neutralize already mutated genes, and this gives a chance to radically change medicine and cope with such formidable diseases as, for example, cancer. But for now, this is a matter of the future. Research continues.
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