DNA methylation: general information

Methylation is the addition of one carbon and three hydrogen atoms to another molecule. This phenomenon is considered the last word in the health sector. It accompanies the exercise of almost all functions of the body.

Functions

Methyl groups (carbon and hydrogen atoms) participate in:

1. The response of the body to stressful situations.
2. The production and processing of glutathione. It acts as a key antioxidant in the body.
3. Detoxification of hormones, heavy metals and chemical compounds.
4. Control of inflammatory processes.
5. Repair damaged cells.
6. Immune response and its regulation, fight against viruses and infections, control of the production of T-elements.

. Of great importance is the process of DNA methylation . Let's consider it in more detail.

Epigenetic control of development

способствует передаче паттернов следующему поколению клеток при митозе. Methylation of DNA promotes the transfer of patterns to the next generation of cells during mitosis. More recently, it has been established that the process of joining groups of atoms in terminally differentiated structures has a definite relationship with the formation of memory and synaptic plasticity. K. Miller and D. Sweet investigated the methylation of DNA. The study of the phenomenon led them to the conclusion that the activity of deoxyribonucleic acid methylase increases significantly in animals during the memorization of new information. This helps to reduce the expression of genes that suppress memory processes. In addition, the authors point to yet another phenomenon. Researchers report that the formation of the memory of the rhinin gene, which promotes changes in synaptic connections and participates in the pathological course of schizophrenia, affects the formation of memory. The determining factor is demethylase enzymes, which ensure DNA demethylation (release from methyl groups). The established facts make it possible to draw the most important conclusion. , а также обратное ему явление, играют существенную роль при хранении информации и запоминании. DNA methylation as one of the epigenetic mechanisms , as well as the opposite phenomenon, plays an important role in the storage of information and memorization. This idea is confirmed by the results of the study of E. Costa's group. It was found that the demythylation of the genes of glutamate decarboxylase and rylin can be caused in small molecules by mice that interfere with the DNA installation in the nucleus. These studies indicate not only the possibility of changing the current understanding of the formation of memory. является динамическим. They also indicate that DNA methylation , considered to be permanent , is dynamic. Moreover, it can be used in therapy.

Features

имеют определенную связь, нельзя назвать новой. The idea that memory and DNA methylation have a certain connection can not be called new. Earlier, the conditionality of synaptic transmission by histone acetylation was established. They form the skeleton, on which DNA is wound. Acetylation leads to a decrease in the affinity of histones with nucleic acids. As a result, access to DNA and other proteins linked, inter alia, to the activation of genes is made possible. In fact, the histone-acetylotransferase activity of CREBBP (binding protein), acting as a key neuronal transcription factor, was associated with the effect of this protein on memorization. In addition, there was an increase in memory of long-term character during the use of histone-deacetylase inhibitors. It led to an acceleration of the acetylation of histones.

Hypotheses

Sweet and Miller asked the following question about histone-dependent suppression of expression of structures. ? If it can play a role in regulating memory, will DNA methylation lead to a similar effect? This phenomenon was considered primarily as a means of maintaining the activity of structures during mitosis and the formation of systems. However, in the matured brain of mammals, the intensity of methylase was observed, despite the fact that most of its cells are non-fissile. Due to the fact that the phenomenon in question helps to suppress gene expression, scientists could not reject the probability of methylase linkage and regulatory processes in neurons.

Assumptions check

этого явления в формировании памяти, обрабатывали срезы гиппокампа ингибиторами дезоксирибонуклеинокислотных метилтрансфераз. Sweet and his colleagues, investigating DNA methylation, the significance of this phenomenon in memory formation, processed the hippocampal slices with inhibitors of deoxyribonucleic acid methyltransferases. They found that this prevents the onset of a long-term potentiation - the strengthening of synaptic connections as a response to neuronal activity. This process determines the operation of learning and memory mechanisms. Scientists also found that inhibitors reduced the level of methylation in rilin DNA. This indicated its reversibility.

Experiments

Deciding to go further in their studies, Sweet and Miller began to observe changes in the patterns of methylation in mice in a model in which animals learn to associate a specific location with unpleasant stimuli, in particular, a weak shock effect. The behavior of the experimental subjects receiving inhibitors expressed possible learning difficulties. Being in an environment in which they had to fear, they faded much less frequently than control animals.

conclusions

How could methylation affect the memory of mice? The scientists explained this as follows. There are quite a lot of DNA in the DNA, which can be affected by the addition of groups of hydrogen and carbon atoms. In this regard, the researchers decided to address the following phenomenon. They studied, first of all, the methylation of genes, whose role in the formation of memory has already been established. First, a site was examined in which the memory processes of the phosphatase protein are suppressed. Decrease in expression could cause the opposite phenomenon. Indeed, after an hour of contextual conditioning of fear, the level of methylation increased by more than a hundredfold. At the same time, mRNA levels in the region of the hippocampus CA1 underwent a weak but statistically significant decrease. This effect is found in the brain of animals with a combination of a slight shock effect on the extremities and novelty of the context. Separately, these stimuli do not provide any effect on methylation. Accordingly, the joining of groups is carried out exclusively with the present training.

DNA Methylation and Aging

The problems of age and oncological diseases are among the most discussed topics. For many years of research, scientists have offered a variety of theories and models. However, not a single concept currently answers all the questions completely. Meanwhile, the greatest interest in the search for solutions to the problem of aging is the study of changes in gene activity. In particular, Professor Anisimov expressed his opinion on this matter. He points out that the expression (expression) of genes depends, among other things, on methylation, which can affect the rate of aging. Up to 5% of cytosine residues of deoxyribonucleic acid were joined by groups of carbon and hydrogen atoms to form 5mC (5-methylcytosine). This base is considered to be the only constant in the DNA of higher organisms. The joining of groups takes place in both strands symmetrically. The remains of 5mC are always covered with the remains of guanine. In this case, the structures perform different functions. However, it is important to note that methylation is involved in the regulation of gene activity. Changes in the joining of groups are caused by malfunctions in the level of transcription.

Causes

Age demethylation was first described in 1973. At the same time, a difference in the degree of separation of groups in the tissues of rats was revealed. In the brain, demethylation was more active than in the liver. Subsequently, a decrease in 5mC was found with age in the lungs, as well as fibroblast formations of the skin. Researchers have suggested that age-related demethylation causes the predisposition of cells to tumor transformation. This phenomenon can be represented in simple words as follows. The inactive gene combines with the methyl group. Under the influence of chemical reactions, it is disconnected. Accordingly, the gene is activated. A group of atoms acts as a fuse. The smaller their number, the more the cell will be differentiated and, accordingly, the older it is, the younger it is. As a classic example, widely used in the literature, one can cite the development of certain salmon species. The phenomenon of their extremely rapid death immediately after spawning was revealed. Yesterday, even young individuals die in reproductive age for a short time. Biologically, this phenomenon is accelerated aging, which is accompanied by large-scale demethylation of DNA.

How to help the body?

There are various ways in which it is possible to improve the inherent DNA methylation. Among the most popular are:

1. Eating fresh greens. Especially recommended leafy vegetables. They act as sources of folic acid, necessary to ensure proper methylation.
2. The intake of vitamins B12 and B6, riboflavin. Their sources are eggs, fish, almonds, walnuts, asparagus, etc.
3. Receiving a sufficient amount of zinc and magnesium. They ensure the maintenance of methylation.
4. Reception of probiotics. They contribute to the acquisition and assimilation of B-group vitamins and folic acid.

It is also important to minimize stressful situations, to give up harmful habits (drinking, smoking). Care must be taken to ensure that no toxic substances enter the body. These compounds take the methyl groups, load the liver.