Abstract The regulation of the activity and selectivity of phospholipase A2 (PLA2), which is capable of cleaving fatty acid in the second position (sn-2) of the phospholipid, is carried out through the membrane-binding and catalytic sites of the enzyme. For hydrolytic activity, PLA2 must first bind to the phospholipid membrane, and the binding efficiency depends on the composition of the membrane.

Abstract— Von Willebrand factor (vWF), the key component of hemostasis, is synthesized in endothelial cells and megakaryocytes and released into the blood as high molecular weight multimeric glycoproteins weighing up to 20 million Daltons. Blood plasma metalloprotease ADAMTS13 cleaves ultra-large vWF multimers to smaller multimeric and oligomeric molecules. The vWF molecules attach to the sites of

Abstract In the plasma membranes of eukaryotic cells, relatively ordered lipid–protein domains can be formed. The characteristics of the interaction of domains can have a significant effect on the processes that require the co-localization of several membrane proteins. The ordered lipid bilayer is thicker than the surrounding disordered membrane. Therefore, it is expected that elastic deformations

Abstract We analyzed the distribution of the ordering parameter of raft-like microdomains in the mitochondrial membranes of halophytes, which differ in the type of salt tolerance: Salicornia perennans, Halocnemum strobilaceum, and Artemisia santonica. The packing density of the membrane lipids (lipid order) was assessed by measuring generalized polarization (GP) of the Laurdan fluorescence. In the

Abstract The lateral distribution of proteins and lipids in plasma membranes of mammalian cells is not uniform. Lipid-protein domains enriched with sphingomyelin and cholesterol are called rafts. The size of cell membrane rafts is extremely small, and this significantly complicates their experimental study. In model membranes, the lipid composition of which is close to the composition of the plasma

Abstract The construction of three-dimensional models of protein macromolecules is a serious challenge due to the possible ambiguity of solving the inverse problem of reconstructing a three-dimensional structure from a one-dimensional small-angle scattering profile. The target function of this task can have several local minima, which leads to the dependence of the solution on the initial values of

Abstract It was found that a decrease in the concentration of extracellular Ca2+ ([Ca2+]out) caused an increase in the surface charge of the erythrocyte membrane, which was accompanied by a change in the conformation of heme and globin, as well as in a redistribution of hemoglobin in the cell (a decrease in the optical path difference (OPD) of the cytoplasm and the content of the membrane-associated

Abstract P-glycoprotein (Pgp) is an ATP-dependent transmembrane protein involved in the efflux of lipophilic substances. The aim of this study was to evaluate the effect of oxidative stress on the transport of a Pgp substrate through the monolayer of Caco-2 cells overexpressing this transport protein. Oxidative stress was modeled by incubating the cells with H2O2. Exposure to H2O2 at concentrations

Abstract— Numerous data obtained in the last 20 years indicate that all parts of the mature central nervous system, from the retina and olfactory bulb to the spinal cord and brain, contain cells connected by gap junctions (GJs). The morphological basis of the GJs is a group of joined membrane hemichannels called connexons, the subunit of each connexon is the protein connexin. In the central nervous

Abstract Dyslipidemia and hyperglycemia portray “cause-and-consequence” of type 2 diabetes mellitus (T2DM). They are linked to malondialdehyde (MDA) and methylglyoxal (MGO) generation that result from membrane lipid peroxidation and oxidative glucose conversions. We compared the effects of exogenous MDA and MGO on human umbilical vein endothelial cells and found that MDA but not MGO impairs insulin

Abstract It has been shown that electrochromic styryl dyes can be used as probes to study proton binding on the membrane surface. These dyes are adsorbed on the membrane as neutral molecules with a significant dipole moment, due to which a dipole potential jump occurs at the boundary of the membrane with the solution. A decrease in pH led to the disappearance of both this potential jump and fluorescence

Abstract— This study examines the effect of glucocorticoid deflazacort on the functioning of rat liver mitochondria. Deflazacort at concentrations up to 100 μM has been shown to have no effect on respiration and oxidative phosphorylation of rat liver mitochondria, energized both in the presence of glutamate/malate (substrates of complex I of the respiratory chain) and succinate (substrate of complex

Abstract The lateral distribution of integral and peripheral proteins, as well as lipids in the plasma membranes of mammalian cells is extremely heterogeneous. It is believed that various lipid-protein domains are formed in membranes. Domains enriched in sphingomyelin and cholesterol are called rafts. It is assumed that the distribution of proteins into rafts is largely related to the presence in their

Abstract Effects of methyltriclosan, a biodegradation product of the antimicrobial agent triclosan, on the functional parameters of rat liver mitochondria were studied. It was found that methyltriclosan inhibits the activity of complexes II and IV of the respiratory chain. This causes a decrease in the rate of oxygen consumption by mitochondria in states 3 and 3UDNP. Methyltriclosan was shown to increase

Abstract The molecular mechanisms of action of dicyclohexyl-containing derivatives of O-iminoisourea, (E)-O-(N,N'-dicyclohexylcarbamimidoyl) oxime of cyclohexanone (1), (E)-O-(N,N'-dicyclohexylcarbodimide) oxime of propane-2-one (2) and (1-(E)-[(E)-(N,N'- dicyclohexylcarbamimidoyl)oxy]imino-1-(pyridine-4-yl)ethane (3), on model lipid membranes, unilamellar vesicles and planar lipid bilayers, were investigated

Abstract Theoretical analysis of the effect of the ionic strength of a solution on the surface (zeta) potential of liposomes formed by an anionic phospholipid (cardiolipin) with adsorbed polycations has been carried out. The experimental data were previously measured by the electrokinetic method in the presence of polylysine molecules of different molecular weights and a supporting electrolyte, KCl

Abstract— Induction changes in chlorophyll fluorescence are associated with photosynthetic electron transfer, generation of the transmembrane proton gradient, and production of carbohydrates in the CO2 fixation cycle. The reactions of photosynthesis are also accompanied by the outflow of photoproducts from illuminated chloroplasts and their long-distance transport. The exchange of metabolites across

Abstract— Compression diagrams were obtained and analyzed for monolayers composed from DOPC, POPC, DMPC, DPPC, DPhPC, and DMPS at the surface of solutions containing KCl, CaCl2, or BeCl2 and in the presence of polylysine (PLL) or chlorpromazine (CPZ). Elastic properties of monolayers are characterized by the area of lipid molecules, presented as an incompressible area with a soft shell, the size of

Abstract This study was focused on the mechanisms of the protective effects of L-arginine and the nitric oxide donor SNAP under the induction of cyclosporine A-dependent mitochondrial permeability transition pore (MPTP) by excess of Ca2+ or D,L-palmitoylcarnitine (PC). The possible involvement of a signaling system that included mitochondrial enzymes NO-synthase (mtNOS), guanylate cyclase (GC), and

Abstract Previously, we found a significant increase in TRAIL (TNFα-related apoptosis-inducing ligand) resistance of acute myeloid leukemia (AML) cells in multicellular aggregates in vitro that simulate the location of leukemia cells in the bone marrow. In this study, we tried to assess whether the increased resistance of the AML cells to the cytotoxic effect of TRAIL in multicellular aggregates in

Abstract The review presents the mechanisms of participation of ions (Na+, K+, and Ca2+) in the processes of synaptic plasticity in the postsynaptic neuron during long-term potentiation and long-term depression. It is assumed that the main participants are AMPA and NMDA receptors, voltage-dependent Na+, K+, Ca2+ channels, Ca2+ and Na+-activated K+ channels, ATP-sensitive K+ channels, and Ca2+ channels

Abstract Photosynthesis is the basis of the plant production process, which makes it extremely relevant to develop methods for evaluating and predicting it under various environmental conditions. The complexity of photosynthetic processes and the presence of numerous feedbacks in it make it important to develop complex approaches to its analysis, including mathematical modeling. This review analyzes

Abstract Platelets are nuclear-free cell fragments responsible for preventing blood loss in case of the vascular wall injury. After a contact with collagen exposed when the vessel is damaged, platelets become activated through the receptor glycoprotein GPVI. This leads to platelet shape change, degranulation, aggregation, and procoagulant responses. The aim of this study was to observe changes in the

Abstract The COVID-19 pandemic has swept the world and required the mobilization of scientists and clinicians around the world to combat this serious disease. Along with SARS-CoV-2 virology research, understanding of the fundamental physiological processes, molecular and cellular mechanisms and intracellular signaling pathways underlying the clinical manifestations of COVID-19 is important for effective

Abstract— Modern pharmaceutics aims at creating new drugs with high bioavailability, biocompatibility and efficiency, as well as minimally toxic effects. One of the ways to reach this goal is to create nanosized particles that carry a small but sufficient dose of a medicinal drug. The diversity of nanoscale delivery systems allows designing therapeutic complexes with necessary characteristics. Liposomes

Abstract Protein–protein interactions (PPIs) are crucial for the successful realization of many metabolic and signaling pathways. Of particular interest are PPIs of membrane proteins, which form stable and/or transient complexes for the signal transduction, ion transport, and electron transfer within electron transfer chains. The Surface Plasmon Resonance (SPR) allows analyzing the thermodynamic and

Abstract— Phospholipases A2 (PLA2) are hydrolytic proteins, which cleave fatty acid off the second position (sn-2) of the phospholipid. An increased activity of PLA2 correlates with the course of many different inflammatory processes in the body. For the purpose of diagnosing and predicting pathological processes, systems for detecting the PLA2 activity are being developed. The key component of all

Abstract— Illuminated giant cells of characean algae exhibit membrane excitability as well as the spatial patterns of photosynthesis and transmembrane H+ fluxes. The excitation of plasmalemma under these conditions results in the transient degradation of external alkaline and acid zones and inhibits photosynthesis in the alkaline zones. The generation of action potential in the patterned internodes

Abstract Amyotrophic lateral sclerosis (ALS) is a progressive incurable neurodegenerative disease, which is characterized by selective death of the motoneurons of the spinal cord and brain. Currently, ALS is considered as a disease with a wide range of etiological causes, which trigger the cellular and molecular mechanisms leading to the development of similar clinical symptoms associated with degeneration

Abstract This study was focused on the problem of regulation of the proinflammatory activity of mast cells through a specific class of protease-activated receptors, PAR1. The study demonstrated for the first time the regulation of the activity of RBL-2H3 cells, mast cell analogues, by a new PAR1 agonist, peptide NPNDKYEPF-amide. It has been shown that the PAR1 agonist peptide, like activated protein

Abstract Biological membranes include various lipids. A heterogeneity of lipid composition can lead to phase separation resulting in the formation of ordered lipid domains, which differ in lipid composition from the other (disordered) part of the membrane. Membrane deformations, which occur at the domain boundary, can affect the lateral distribution of various membrane inclusions. In this paper, in

Abstract Fluctuations in physiological processes are a key property of biosystems; these fluctuations can play both positive and negative roles in living organisms. In particular, fluctuations in the activity of ion channels can increase sensitivity of the receptors and modulate the activity of neural networks. At the same time, a possible influence of fluctuations on the electrical activity in plants

Abstract— Extracellular vesicles (EVs) and, particularly, exosomes are becoming a promising material for “cell-free therapy” of many pathologic conditions. In the recent years therapeutic effects of mesenchymal stromal cells (MSCs) have been attributed to their secretory factors, including EVs. In this study we aim to investigate how EVs produced by MSCs of different tissue origin can influence myogenesis

Abstract Dysfunctions of glomerular podocytes and triggering of apoptotic processes in them are the main molecular causes of diabetic nephropathy and other kidney diseases. Pathogenetic factors causing these dysfunctions of podocytes are hyperglycemia, increased levels of advanced glycation end-products, oxidative stress, increased activity of inflammatory factors, and endoplasmic reticulum stress

Abstract In the present work, the recorded kinetics of chemiluminescence enhanced by coumarin 334 indicated that the complexes of cytochrome c (Cyt) with anionic lipids (Cyt-AL), such as cardiolipin (CL) and phosphatidic acid (PA), when added to mitochondrial and cytoplasmic membranes, are capable of catalysing reactions of lipid free radical formation. The effect of Cyt-CL complex was studied on mitochondria

Abstract Photodynamic therapy (PDT) is regarded as a promising approach to the treatment of malignant tumors, the effect of which is achieved due to the generation of reactive oxygen species upon irradiation of a photosensitizer with light. Reactive oxygen species cause direct destruction of tumor cells, vascular damage, and activate anti-tumor immunity. Hypoxia of tumor tissue significantly reduces

Abstract The effects of tonoplast and rafts isolated from vacuolar membranes on the import of DNA into mitochondria of potato tubers ( Solanum tuberosum ) were studied. It was shown that the addition of rafts isolated from the tonoplast to mitochondria increased 8-fold the activity of the DNA import into mitochondria as compared to the import in the untreated mitochondria.

Abstract Extracellular adenosine is a signaling molecule involved in the regulation of physiological processes in a variety of cells, including mesenchymal stromal cells (MSCs). We have shown using microphotometry and Ca 2+ probes that the population of MSCs isolated from human adipose tissue contained a small (5–10%) subpopulation of adenosinergic cells. In these cells, A1, A2A, and A2B adenosine

Abstract The activity of many membrane proteins, such as receptors, ionic channels, transporters, and enzymes, is cholesterol dependent; however, mechanisms of the cholesterol-dependent regulation of protein functions remain obscure. Recent studies suggest that membrane proteins can directly interact with cholesterol owing to the presence of the cholesterol-recognizing amino-acid consensus (CRAC) motifs

Abstract — Internal ultrastructure of the muscle tissue mitochondria of horsehair worm Gordionus alpestris (Nematomorpha) was studied using morphometry. Surface area of the inner mitochondrial membrane per unit of the mitochondrial volume, or surface density of the inner mitochondrial membrane, was measured as a main morphometric parameter. The surface density of the inner mitochondrial membrane of

Currently, a search for selective antagonists of luteinizing hormone (LH) receptor, which are required to suppress the steroidogenesis in hormone-dependent tumors and to prevent the ovarian hyperstimulation syndrome, is carried out. One approach to tackle this problem is the development of low-molecular-weight antagonists of the allosteric site of this receptor, which is located in its transmembrane

AMPA receptors are the key molecules of excitatory and inhibitory synapses and are involved in synaptic plasticity. Cognitive functions of the brain such as signal perception, processing and analysis of information, memory, storage and exchange of information are reduced when the processes controlling the assembly of AMPA receptors, membrane trafficking and synapse-specific expression are impaired

Endothelial cells (ECs) line the blood vessels and lymphatic vessels, as well as heart chambers, forming the border between the tissues, on the one hand, and blood or lymph, on the other. Such a strategic position of the endothelium determines its most important functional role in the regulation of vascular tone, hemostasis, and inflammatory processes. The damaged endothelium can be both a cause and

Abstract Early sea urchin embryos are sensitive to agonists and antagonists of transmitter receptors, both metabotropic and channel ones. In this work, we studied mechanisms of the cytostatic action of cyproheptadine and haloperidol–antagonists of serotonin 5HT 2 receptors and dopamine D 2 receptors, respectively. For this purpose, we employed the model of the blockade of the first cleavage division

Abstract Gravitational unloading leads to a slow-to-fast shift in the myosin phenotype. The reason for these changes is a decrease in the expression of the genes encoding heavy chains of myosin (MyHC) of the slow type, and an increase in the expression of the genes encoding MyHC of the fast types. Signal cascades such as calcineurin/NFAT and HDAC4/MEF-2D are known to regulate MyHC I gene expression

Abstract The analysis of electron and proton transport in chloroplasts of higher plants has been carried out on the basis of a mathematical model that takes into account the pH-dependent regulation of electron transport and the operation of the ATP synthase. Numerical experiments aimed at simulation of these processes under pseudocyclic electron transport (water–water cycle) have shown good agreement

Abstract The formation of through pores in lipid bilayer membranes occurs in a number of cellular processes and is also applied for biotechnological and biomedical purposes. In the classical theory of pore formation, diffusion of membrane defects in space of radii is considered. When the first pore reaches a critical radius, the membrane irreversibly ruptures. It is usually presumed that the diffusion

Abstract — Having various pathological and molecular subtypes with several causes, breast cancer is the most prevalent malignancy amongst women. Neurotransmitters and neuropeptides are triggers responsible for the growth of cancerous cells and metastasis through their specific receptors. These neurotransmitters and neuropeptides include catecholamines, γ-amino butyric acid, acetylcholine, serotonin

Abstract — Under homeostasis states, proliferation, differentiation and function of immune cells are efficiently regulated to not only support the protection against pathogens, but also to prevent the autoimmune attack against self-tissues. It is now authenticated that immune cell activation is engaged with intense alterations in cellular metabolism. Accumulating body of data indicated that alterations

Abstract Cytokinins, classical plant hormones, are recognized by the cell through receptors—hybrid sensor histidine kinases, multidomain transmembrane proteins. The character of the hormonal effect on the cell and the mode of the hormonal signal transduction to the primary targets depends on the subcellular localization of the receptors. Recently, we cloned and investigated a family of cytokinin receptors

Abstract The combined effect of melatonin and cytarabin at low concentration on the cells of acute promyelocytic leukemia HL-60 was studied. It has been shown that the combined effect of these substances led to a decrease in the number of cells by 70% and the mitotic activity index by 75%. It was found that the combined effect of melatonin and cytarabin also contributed to a decrease in the expression

Abstract Hyaluronic acid (HA) is one of the key polymer components of the extracellular matrix; it can exert different effects on intracellular signaling depending on its molecular weight. We compared the effects of low (LMW) and high molecular weight (HMW) HA polymers on the ability of primary astrocytes, glial brain cells, to release into the extracellular medium omega-3 unsaturated fatty acids,

Abstract Using the previously developed rabbit model of perioperative dry eye syndrome (PDES) and quantitative mass spectrometric technique it is shown that the development of corneal erosion under conditions of general anesthesia is associated with changes in the content of inflammatory metabolites, namely, derivatives of linoleic (LA), alpha-linolenic (ALA), and arachidonic (AA) acids in tear fluid

Abstract — Cisplatin is an effective anticancer drug used to treat various types of cancer. The main disadvantage of the drug is its high toxicity. To reduce the toxic effect of cisplatin, we conjugated it with arabinogalactan, which is capable of forming soluble globules and bind poorly soluble pharmacological compounds by confining them inside spheroid globules. In this study, we compared the biological

Abstract — Extracellular ATP is a potent inflammatory mediator and regulator of neutrophil activity in an inflammatory site. The role of ATP in the regulation of bone marrow granulocyte functions remains unexplored. The aim of this work was to study effects of ATP on the cytoplasmic Ca 2+ concentration ([Ca 2+ ] i ), generation of reactive oxygen species (ROS) and adhesion of bone marrow granulocytes

Abstract The mechanisms underlying changes in spontaneous release of acetylcholine (ACh) induced by exogenous agonists and antagonists of endocannabinoid receptors were investigated by recording miniature endplate potentials (MEPPs) in motor synapses of mouse diaphragm preparations with intracellular microelectrodes. There have not been observed any statistically significant changes either in the membrane

Abstract — In the present study, close spatial relationships between peripheral serotoninergic nerve elements and the musculature of the body in planaria Polycelis tenuis, Schmidtea mediterranea, and Girardia tigrina have been demonstrated using immunocytochemical and histochemical methods and a confocal laser scanning microscopy. Such a localization of serotoninergic neurons and their fibers indicates

Abstract Calcium-permeable kainate (CP-KARs) and AMPA (CP-AMPARs) receptors of the brain neurons are active participants of synaptic plasticity and neurotransmitter release trigger. In this paper, CP-KARs and CP-AMPARs were identified in hippocampal neuroglial culture on 14–17 day of cultivation by a characteristic Ca 2+ response to a selective agonist of CP-KARs and CP-AMPARs, domoic acid (DA), and

Abstract — Thrombin is a multifunctional serine protease that attracts the attention of many researchers in particular in connection with a wide range of its effects in the nervous tissue. It is known that the main thrombin receptor is a protease-activated type 1 receptor, the functional activity of which is associated with adapter protein β-arrestin-2. Here we assessed potential involvement of β-arrestin-2

Abstract — Molecular mechanisms initiating the development of atrophic changes in a mammalian postural muscle remain unclear. We have suggested that AMP-activated protein kinase (AMPK) may play an important role in the regulation of anabolic and catabolic signaling pathways in postural muscle at the initial stage of mechanical unloading, since skeletal muscle inactivation can lead to changes in the