Research areas:
group led by N Agalakova
- Investigation of molecular mechanisms underlying the toxic effects of fluoride ions on brain cells. Investigation of morphological and molecular changes in the cells of hippocampus and cerebral cortex of rats after long-term consumption of excessive doses of fluoride (NaF) with water.
- Investigation of intracellular mechanisms of adaptation to the state of natural prespawning starvation in one of the representative of cyclostomes – river lamprey Lampetra fluviatilis.
- A comparative analysis of the expression of protein kinases, protein phosphatases and structural cytoskeletal proteins in erythrocytes and liver cells of lampreys in different periods of prespawning starvation.
- Investigation of some mechanisms underlying the development of a depressive-like state in the model experiments on rats. The relationship between the development of a depressive-like state induced by chronic unpredictable stress, the age of animal, and the activity of ionotropic glutamate receptors, expression levels of transcriptional factors, and inflammatory processes in hippocampus and cerebral cortex of rats.
Research methods:
The work uses a wide range of contemporary methods that make it possible to carry out molecular biological research comparable with the world level:
- Methods of working with animals: modeling of fluorosis (long-term consumption of excessive doses of fluorine in drinking water by rats), modeling of a depressive-like state (chronic unpredictable stress).
- Behavioral tests for assessing cognitive abilities, level of anxiety or degree of depression-like state in rats: Morris water maze, novel object recognition test, T-maze, open field test, Porsolt forced swimming test, sucrose preference test.
- Molecular biological and biochemical methods:
- real-time polymerase chain reaction method for assessing gene expression.
- immunoblotting for semi-quantitative determination of expression levels of native and phosphorylated forms of proteins.
- flow cytometry method for counting the number of apoptotic cells, cells with elevated level of free Ca2+ and reactive oxygen species.
- spectrophotometric methods for determining the content of hemoglobin in erythrocytes, total protein and RNA in tissues, etc.
Main results and achievements:
- The mechanisms underlying the toxic effect of fluorine ions on brain cells are characterized using doses that are comparable to F consumption by humans in the regions of endemic fluorosis or that causing chronic poisoning at industrial sites. It was established that long-term consumption of excessive fluoride doses with water by rats leads to numerous morphological, functional and molecular alterations in hippocampal cells. The ability of animals to spatial learning and the formation of long-term memory decreased. Morphological damage and death of neurons in the hippocampal zones CA1 and CA3 were accompanied by activation of mitochondrial and TGFβ-dependent apoptotic pathways. F excess caused hyperstimulation of signaling cascade of the early phase of long-term potentiation (calpain-1 and its effectors) but did not affect the activity of molecules of the late phase of long-term potentiation (calpain-2 and its mediators), which indicates a disturbance between memory induction and consolidation. F consumption led to the changes in phosphorylation level and the ratio of the number of AMPA receptors containing Ca2+-permeable GluA1 and Ca2+-impermeable GluA2 subunits, as well as increased the ratio of GluN2A/GluN2B subunits of NMDA receptors. This indicates an increased Ca2+ entry in the cells and disruption of the functional activity of ionotropic glutamate receptors.
- For the first time, a comparative analysis of the expression of a number of protein kinases and structural proteins of the cytoskeleton in erythrocytes and liver of lamprey Lampetra fluviatilis during prespawning starvation was carried out. It was shown that in the cells of both tissues, the expression of mitogen-activated protein kinases ERK1/2 and JNK, AMP-activated kinase (AMPK), PI3K, Akt, and PKC kinases is remarkable stable throughout the entire pre-spawning period; however, before spawning, the content of JNK, PI3K and Akt sharply decreases, while the level of ERK1/2, AMPK and PKC remains at a high level, especially in membrane fractions. The content of actin in the membranes of erythrocyte cells did not change as the spawning approached, however, another important component of the membranes, spectrin, was subjected to gradual proteolytic degradation, besides, the structure of the 4.1R protein changed and the content of the G-protein RhoA increased, which stabilizes the interaction between actin and spectrin. Obviously, membrane-bound forms of proteins play a more important role in adaptive processes to natural starvation, which allows animals to survive, while before spawning and death of animals they become critically necessary to maintain the viability of cells, constancy of their internal milieu, shape and mechanical properties.
group led by E Belyaeva
The field of scientific interests of Belyaeva E.A. includes research of molecular mechanisms of functioning, regulation and bioenergetics of ion transport via membranes and cellular layers of different types, role of ion-transporting systems in normal and pathological conditions, as well an influence of various environmental factors on these processes. At present Belyaeva E.A. investigates role(s) and peculiarities of functioning of respiratory chain and ion channels of inner mitochondrial membrane (Ca2+-dependent nonselective pore, ATP-sensitive potassium channel, and Ca2+-activated large-conductance potassium channel) in the process of induction of cell death and pathological conditions of different types. Emphasis is placed on clarifying the role of mitochondria in the mechanism(s) of cytotoxic action of heavy metal ions, such as Cd2+, Hg2+, and Cu2+, and comparing their effects with the action of other metals/metalloids (Ca2+, Zn2+, Na2SeO3). The work is carried out on various types of rat cells, namely AS-30D, PC12 and some others, as well as on isolated rat liver mitochondria. In recent years, the main efforts have been directed at studying the role of mitochondria in the mechanism of the cytotoxic action of heavy metals, such as Cd2+, Hg2+, Cu2+, Zn2+ etc. A comparative biochemical investigation of their action was conducted and the molecular mechanisms of mitochondrial dysfunction induced by the studied heavy metals were established. Currently, experiments are being carried out to elucidate the role of the mitochondrial respiratory chain and the Ca2+-dependent non-selective pore in the toxic effect of heavy metals and to identify the molecular mechanisms of the modulating action of the regulators of the activity of the ATP-dependent potassium channel and the Ca2+-activated big- conductance potassium channel on toxicity and cell death induced by these metals.
Group led by S Sobol
Heavy metals confidently occupy the second place in terms of danger, yielding to pesticides. It is known that the level of the factor of technogenic enrichment with heavy metals has increased significantly in recent years, which has a particularly negative effect on people with cardiovascular and nervous pathologies. Acute or chronic poisoning can occur through contact with heavy metals through contaminated air, water, soil, and consumer products.
The laboratory studies the influence of the destructive activity of heavy and rare earth metals on living organisms. Particular attention is paid to the effect of heavy metals on the cardiovascular system and mitochondrial energy. Studies are carried out on isolated mitochondria, on a contractile model of the heart and blood vessels, as well as on isolated cardiomyocytes. Various models of ischemia/hypoxia in heavy metal poisoning are being investigated. On the model of chemical hypoxia under conditions of inhibition of mitochondrial functions with the help of sodium azide, the effect of heavy ions on the cardiovascular system is studied.
Techniques:
1) Computer system for intracellular image analysis and photometry (Intracellular Imaging & Photometry System, USA)
2) Devices for recording contractions of the heart and blood vessels.
3) a technique for isolating mitochondria, analyzing respiration, swelling, and changing the potential on the inner membrane of mitochondria.
Group led by V Nesterov
The results of many years of in vitro studies of the contractile characteristics of muscle tissues of various animals stimulated interest in the study of in vivo muscle structures in humans. An analysis of the literature data showed the prospect of developing a technology for differential sphygmography based on modern piezoelectric sensors, which would provide a higher accuracy of diagnosis compared to common methods of volumetric sphygmography. Based on this, we have developed new methods (Patents of the Russian Federation for inventions, 2006-2020) for non-invasive piezopulsometric study of the functional characteristics of the components of the cardiovascular system (CVS) and the mechanisms of their regulation in humans. At the same time, it was taken into account that the pumping function of the CVS, which provides blood supply to organs and tissues in humans, is determined by the contractile activity of muscle effectors, mainly cardiomyocytes and smooth muscle cells of the arterial walls, controlled by the system of autonomous (neuroendocrine) regulation. At the same time, it was taken into account that the contractile activity of muscle effectors itself is quantitatively reflected in the values of the parameters of pulse arterial blood pressure waves and, therefore, can also be determined non-invasively using hemodynamic parameters. It was also significant that the results obtained using piezopulsometry do not depend on uncontrolled fluctuations in the volume of tissues under the sensor. These ideas formed the basis of our choice of differential sphygmography as a promising analytical method that could be used to evaluate the functional properties of the left ventricular myocardium, as well as the activity of peripheral mechanisms of autonomic regulation of CVS in humans by the variability of the parameters of blood pressure pulse waves. Such studies opened up the possibility of a non-invasive study of the physiological mechanisms involved in ensuring an optimal and stable dynamic balance of the body’s blood supply in the examined individuals.
