Erythrocyte Membrane Components Research Articles

Erythrocyte Phospholipid Fatty Acid Profile in High-Level Endurance Runners

Fatty acids (FAs) are the major structural component of erythrocyte membranes. Diet and physical exercise directly influence their incorporation and function. Endurance runners engage in high volumes of weekly aerobic training, alternating between low-intensity and high-intensity sessions. The aim of the study was to assess and compare the erythrocyte FA profile in a group of high-level male endurance runners (EG) with a control group of non-athlete subjects (CG). This observational study was conducted on 85 subjects, 63 high-level male endurance runners (23 ± 3 years; height: 1.76 ± 0.05) and 22 subjects who did not engage in regular physical exercise (21 ± 0.5 years; height: 1.68 ± 0.39). Runners had at least five years of training experience, and all of them were participants in national and international tournaments. FAs determination was performed using gas chromatography. Higher percentages of Palmitic Acid (PA), Stearic Acid (SA), Oleic Acid (OA), Calendic Acid (CA), Eicosapentaenoic Acid (EPA) and Docosapentaenoic Acid (DPA), and lower percentages of Docosahexaenoic Acid (DHA) were found in the EG compared to the CG. High-level endurance runners exhibit altered erythrocyte FA profiles with low percentages of omega-3 index (ω-3 index) and DHA, which may affect erythrocyte membrane function as well as their performance.

THE MORFOFUNCTIONAL STATE OF PERIPHERAL ERYTHROCYTES AT CHRONIC HEART FAILURE AND VITAMIN D DEFICIENCY IN

The aim of the work To study the effect of vitamin D deciency in blood plasma on the morphofunctional state of peripheral blood erythrocytes after exercise in patients with chronic heart failure. Methods: scanning electron microscopy of peripheral blood erythrocytes, enzyme immunoassay to determine the level of vitamin D. Results. A morphological study revealed heterogeneity of erythrocyte subpopulations in 90% of patients with CHF and vitamin D deciency. In peripheral blood, in addition to normocytes with sufcient hemoglobinization, subpopulations of macro- and microcytes were recorded. In most patients with vitamin D deciency, several types of morphological changes in the shape of erythrocytes were revealed, manifested in the form of echino-, acantho- and stomatocytosis, which indicates destabilization of the erythrocyte's membrane. After a 6-minute walk test in CHF patients with vitamin D deciency, the number of discocytes decreases, the ability to deform decreases, lytic cells were recorded with a reduced number of normocytes. The Conclusion: identied morphobiochemical changes indicate the destructurization of the erythrocyte membrane components and have negative consequences, taking into account the likely impact on the somatic health of patients who, in addition to changes characteristic of CHF, receive signicant stress during physical exertion against the background of hypovitaminosis. D.

Peculiarities of phospholipiid changes in erythrocyte membranes in parturient women with COVID-19-associated community-acquired pneumonia

Aim. To evaluate the phospholipid composition of erythrocyte membranes in parturient women who had COVID-19-associated community-acquired pneumonia (CAP) in the third trimester.Materials and methods. The material for the study was erythrocytes of peripheral blood of 65 parturient women diagnosed with COVID-19, moderate/severe course, CAP of viral etiology (main group). Patients of the main group, depending on the severity of CAP, were divided into two subgroups: subgroup 1 – moderate course of pneumonia (n=33), subgroup 2 – severe course of pneumonia (n=32). The control group consisted of 35 healthy parturient women. The quantitative composition of phospholipids was studied by two-dimensional thin-layer chromatography according to Kirchner.Results. In subgroup 1, the concentration of phosphatidylethanolamine and phosphatidylcholine in erythrocyte membranes was below the standard values by 38% and 29%, respectively (p<0.001), in subgroup 2, these indicators decreased by 32% and 48%, respectively (p<0.001). At the same time, a significant increase in the concentration of lysophosphatidylcholine was found in patients of subgroup 1 by 92% (p<0.001) and in patients of subgroup 2 by 110% (p<0.001), compared with the group of healthy individuals. In addition, structural changes in the lipid bilayer of erythrocyte membranes under conditions of COVID-19associated CAP were characterized by a pronounced increase in the concentration of minor fractions of phospholipids: phosphatidylserine and phosphatidylinositol in subgroup 1 by 63% and 53%, respectively (p<0.001), in subgroup 2 by 79% and 68%, respectively (p<0.001), compared with similar indicators in the control group.Conclusion. With COVID19-associated CAP in maternity women, structural disorganization of the phospholipid components of erythrocyte membranes is determined, manifested by a decrease in the concentration of phosphatidylethanolamine and phosphatidylcholine with a simultaneous increase in the level of lysophosphatidylcholine, phosphatidylserine and phosphatidylinositol. These disorders increase with increasing severity of pulmonary inflammation. The revealed changes in the lipid spectrum of peripheral blood and the composition of erythrocyte membrane phospholipids in COVID-19-associated CAP indicate the need to develop methods for their correction.

U2AF1 and EZH2 mutations are associated with nonimmune hemolytic anemia in myelodysplastic syndromes

AbstractHemolysis is a well-recognized but poorly characterized phenomenon in a subset of patients with myelodysplastic syndromes (MDS). Its pathobiological basis seems to underpin a nonimmune etiology whose clinical significance has not been adequately characterized. Hemolysis in MDS is often attributed to either ineffective intramedullary erythropoiesis or acquired hemoglobinopathies and red blood cell (RBC) membrane defects. These heterogeneous processes have not been associated with specific genetic subsets of the disease. We aimed to describe the prevalence of hemolysis among patients with MDS, their baseline characteristics, molecular features, and resulting impact on outcomes. We considered baseline serum haptoglobin <10 mg/dL a surrogate marker for intravascular hemolysis. Among 519 patients, 10% had hemolysis. The baseline characteristics were similar among both groups. Only 13% of patients with hemolysis were Coombs-positive, suggesting that hemolysis in MDS is largely not immune-mediated. Inferior survival trends were observed among lower-risk patients with MDS undergoing hemolysis. Decreased response rates to erythropoiesis-stimulating agents (ESA) and higher responses to hypomethylating agents (HMA) were also observed in the hemolysis group. U2AF1 and EZH2 hotspot mutations were more prevalent among those undergoing hemolysis (P < .05). U2AF1 mutations were observed in 30% of patients with hemolysis and occurred almost exclusively at the S34 hotspot. Somatic mutations encoding splicing factors may affect erythrocyte membrane components, biochemical properties, and RBC metabolic function, which underpin the development of atypical clones from erythroid precursors in MDS presenting with hemolysis. Future studies will explore the contribution of altered splicing to the development of acquired hemoglobinopathies.

Pathophysiology of Severe Malaria Infection

Background: Malaria infection is a multisystem pathology with various clinical complications in both adults and children. The clinical manifestation originates in humans following the invasion of erythrocytes by merozoites. Methods: The relevant information and data was collated from scientific databases such as Google Scholar, Science Direct, PubMed, Mendeley, Springer Link, and Medline using keywords such as ‘severe malaria infection’, ‘pathophysiology of severe malaria’, ‘complications of severe malaria’ and ‘erythrocyte impairment in severe malaria’. Results: Generally speaking, the pathophysiology of severe malaria infection encompasses a succession of stages involving the metabolic products of the malaria parasites inclusive of hemoglobin digestion, damaged erythrocyte membrane components, the actions of the pro- and anti-inflammatory cytokines, and the cytoadherence of the malaria parasites to the vascular endothelium as well as sequestration and rosetting. The major complications connected with severe malaria infection include acute respiratory distress syndrome, neurological disorders resulting from cerebral malaria, liver and kidney dysfunction, anaemia and thrombocytopenia, and fatal placental malaria. Conclusion: The effective management of severe malaria infection involves a proper diagnosis followed by the subjection of the patient to suitable antimalarial treatment with the necessary medications depending on the various clinical manifestations of the infection.

The role of short- and medium-chain fatty acids in homeostatic regulation reactions

The article analyzes the role of fatty acids in the life support processes of the organism. For some short- and medium-chain fatty acids, the ability to inactivate a number of microorganisms, in particular Helicobacter pylory, has been shown. Information on the role of ω-6 polyunsaturated acids of the arachidonic and docosahexaenoic family in the structural and functional development of the nervous system has been presented. The materials presented in the article expand the understanding of the role of lipids in metabolic processes and dictate the need to continue the study of lipids as the main energy substrates, sources of plastic material, structural components of erythrocyte membranes, nervous tissue, and skeletal muscles.

Effects of Interaction of Protein Components of erythrocyte Membrane in Healthy Individuals and Patients with Ulcerative Colitis

Background. It is known that in ulcerative colitis there is a violation of the barrier function of the colon mucosa, which can lead to pathological changes inside cells, including in the membranes of red blood cells. The stability of the erythrocyte membrane and its ability to deform largely depends on the composition and interaction of protein structures inside it. A significant decrease in the content of the main protein components of the erythrocyte membrane in ulcerative colitis was found in comparison with healthy people. Aim of the research . Taking into account the available data, we conducted an additional study to analyze the effects of the relationship between the protein components of the cytoplasmic membrane of erythrocytes in patients with ulcerative colitis and clinically healthy people. Materials and methods . The study involved men and women with ulcerative colitis in the period of exacerbation (n = 51) and clinically healthy individuals matched by sex and age (n = 30). The analysis of the interaction effects of ten main protein components of the erythrocyte membrane was carried out. For each protein under study, its average value was determined, and within the studied groups all proteins were divided into two categories – above and below their average level. Analysis of variance was used to quantify the contribution of each identified factor. Results. It was found that the effect of the relationship is not inherent in all categories of protein components. In ulcerative colitis, the effects of interaction with such important structural proteins as spectrins and ankyrin disappear. In the effect of band 4.1 protein, in contrast to clinically healthy individuals, a new independent factor appears – glyceraldehyde-3-phosphate dehydrogenase, and in the effect on actin – an anion-transport protein. Conclusion . In ulcerative colitis, significant changes occur in the membrane of red blood cells, leading to a violation of the relationships between proteins, a decrease in the total content of the studied proteins and the loss of some of the effects of independent factors on the level of certain protein structures. Based on the findings, adjustments can be made to the treatment of ulcerative colitis in order to strengthen the erythrocyte membrane.

РОЛЬ ЖИРНЫХ КИСЛОТ В ЭМБРИОНАЛЬНОМ РАЗВИТИИ (ОБЗОР ЛИТЕРАТУРЫ)

The review provides information on the physiological role of medium-chain saturated and unsaturated (myristic, pentadecanoic) and long-chain (palmitic, stearic, oleic) fatty acids in embryonic development. The value of fatty acids in the formation of the lung surfactant of the developing fetus is shown. There is presented the information about the role of polyunsaturated acids of arachidonic and docosahexaenoic ω-6 family in the structural and functional development of the nervous system and the visual analyzer of the fetus and the newborn. The interdependent stimulating effect of unsaturated oleic and linoleic fatty acids on the differentiation of muscle cells is shown; the role of oleic and acids with 20 carbohydrate atoms in the mineralization of bone tissue is demonstrated; the value of oleic acid in the regulation of placental transport of amino acids through tol-like receptors 4 and cellular signaling is presented. The above mentioned factors allow drawing the conclusion about the need for further study of lipids as the main energy substrates, sources of plastic material, structural components of erythrocyte membranes, nerve tissue, visual analyzer, pulmonary surfactant and skeletal muscles. The accumulated data broadens the understanding of the role of lipids in metabolic processes, which will allow us to move from a fundamental research to practical aspects of the use of these substances in obstetrics and perinatology. In the long term, these results can be used to interpret and predict changes in metabolic disorders of lipids in various pathological conditions during pregnancy.

Comparative analysis of BPA and HQ toxic impacts on human erythrocytes, protective effect mechanism of tannins (Rhus typhina)

Several studies reported that bisphenol A (BPA) and its metabolite hydroquinone (HQ) have adverse effects on human and animal health. In this work, a comparative study of influence of the BPA and HQ, environment pollutants, on human erythrocytes was carried out. It was shown that BPA and HQ to varying extents caused oxidative damage in human erythrocytes: hemolysis, decreased GSH level, and methemoglobin formation. It was demonstrated that hydrolysable tannins 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-β-d-glucose (C55H40O34) and 1,2,3,4,6-penta-O-galloyl-β-d-glucose (C41H32O26) (PGG) isolated from the Rhus typhina L. leaves in the range of 1–50 μM concentrations inhibited hemolysis and methemoglobin formation and also increased intracellular reduced glutathione in erythrocytes treated with BPA or HQ. It was revealed by electron paramagnetic resonance (EPR) using 5-doxyl-stearic acid (5-DS) that C55H40O34 and C41H32O26 increased the rigidity of erythrocyte membranes at the depth of 5th carbon atom of the fatty acid hydrocarbon chain. Taken together, these results allow to conclude that tannins from the Rhus typhina L. leaves protect erythrocytes from oxidative stress caused by BPA or HQ both due to their antioxidant activity as well as their interaction with the erythrocyte membrane components.

The role of interspecies differences in the ratio of choline-containing phospholipid fractions of rodent erythrocytes in response of these cells to the effect of membranotropic compounds

In in vitro experiments, interspecies differences were revealed in the erythrocyte responses in varied rodent species—laboratory mice (Mus musculus L.), tundra voles (Microtus oeconomus Pall.) and bank voles (Myodes glareolus Pall.)—to the effect of chemical agents able to interact with membrane lipids and disrupt the membrane structure (detergent Triton X-100, oxidative stress inductor AAPH, antioxidant ionol or BHT, uranyl ion). It was hypothesized that these differences are due to physicochemical peculiarities of the erythrocyte membrane structure, specifically, the ratio of choline-containing fractions of phospholipids (phosphatidylcholine and sphingomyelin). The use of blood erythrocytes as an in vitro experimental model to study the mechanisms of toxicity as well as antioxidant and membrane-protective properties of compounds of different nature was shown to imply the choice of an adequate source of erythrocytes in view of considerable speciesdependent structural specificity of the lipid component of mammalian erythrocyte membranes.

Antimicrobial Peptide Impacts the Lateral Diffusion and Bending Rigidity of Phospholipid Membrane

Antimicrobial peptides (AMPs) are the first line of defense system against foreign microorganisms. They are well known for their strong interaction with the cell membrane of pathogens. Quasielastic neutron scattering (QENS) and Neutron spin echo (NSE) measurements have been carried out on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membrane to understand the effect of melittin, an important AMP on the dynamical and mechanical behavior of membrane. Even at low concentration (0.2 mol%), the addition of melittin is found to influence the membrane dynamics significantly in a different way, depending on the phase of the lipid bilayers. In the gel phase, it acts as a plasticizer, enhancing the lateral motion of DMPC. However, in the fluid phase, it acts as a stiffening agent, hindering the lateral motion of the lipid molecules. Various interesting results on the impact of melittin on the phase behavior and lateral diffusion of the membrane will be discussed here. Their importance originate from the fact that many cellular functions, including cell signaling, membrane trafficking, and cell recognition are controlled to a great extent by the lateral diffusion of lipids in the membrane. NSE measurements indicate that incorporation of melittin modify the bending rigidity of the membrane, which is found to decrease with the concentration of melittin. Cholesterol is a vital component of erythrocyte membranes, which is a natural target for melittin. To understand the role of cholesterol, both QENS and NSE experiments have also been carried out on cholesterol-supplemented DMPC membrane in the absence and presence of melittin. Our measurements show that the destabilizing effect of melittin on the membranes can be mitigated by the presence of cholesterol. This study might provide new insights into the mechanism of action of antimicrobial peptides and their selective toxicity towards foreign microorganisms.

Кількісні зміни основних компонентів

Кількісні зміни основних компонентів

Haemolytic activity and characterization of nematocyst venom from Pelagia noctiluca (Cnidaria: Scyphozoa)

We investigated the haemolytic capacity of the crude venom extracted from isolated nematocysts of Pelagia noctiluca (Cnidaria: Scyphozoa), and evidenced the proteic fractions responsible for this activity. The nematocyst venom was used at various concentrations to evaluate the haemolytic activity and the lysosomal membrane stability of red blood cells of two teleostean species treated with the extract. The nematocyst extract was assayed against erythrocytes of the two teleostean species living in different environments, Carassius auratus as a common freshwater species, and Liza aurata as a representative of seawater species. Experiments on the haemolytic activity of P. noctiluca in the presence of lipid components of erythrocyte membranes showed that sphyngomyelin strongly inhibited this activity. The crude venom was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis SDS-PAGE and high performance liquid chromatography (HPLC) to detect the proteic composition, and it was found that the active haemolytic components of this venom are distributed in at least four protein fractions. The results of our experiments indicated that Pelagia noctiluca venom induces haemolysis and lysosomal membrane destabilisation in both species and that Carassius auratus was more susceptible to jellyfish venom than was Liza aurata. No significant differences in glutathione (GSH) levels were observed between control and treatments; consequently the toxins do not cause the oxidative stress but likely recognize specific targets (i.e. sphyngomyelin) in the plasmatic membrane of red blood cells.

Experimental assessment of the efficiency of erythrocyte membrane repair by an extract of the tunic of the ascidian purple sea squirt in carbon tetrachloride poisoning

We present here data from studies of the physiological characteristics and lipid components of erythrocyte membranes in tetrachloride (CCl 4 ) poisoning and correction of changes with a water-ethanol extract of the tunic (sheath) of the ascidian purple sea squirt (Halocynthia aurantium). CCl 4 poisoning was accompanied by increases in the mean volume and diameter of erythrocytes, along with alterations to the phoshoplipid:neutral lipids ratio and the membrane fatty acid composition. During the deprivation period, most of the study parameters remained at the levels recorded after CCl 4 poisoning. Administration of the ascidian tunic extract widened the thresholds of erythrocyte hemolysis resistance and promoted preservation of the lipid components ratio in erythrocyte membranes and their physiological characteristics. The combination of the high biological activity and the low toxicity of the extract suggests potential for creating new, effective formulations based on marine hydrobionts for use in poisoning.

Cesium's Affects on Morphological Changes of Human Erythrocytes

AbstractCesium could play a toxic role in several pathological processes. Atomic force microscopy (AFM) was used to study morphological changes of human erythrocytes after incubating with different concentrations of CsCl, and the Raman spectra were used to study the effects of CsCl on the chemistry components of erythrocyte membrane. The AFM images showed that the "domain structures" that appeared after incubation with higher concentration of CsCl (150 mmol·L−1), are featured by the particles aggregated to form ranges and the separations among them enlarged to gorges, and this change may increase the permeability of cell membranes. The Raman results showed that the polar part of membrane phospholipid become more order and with the increasing of the concentration of CsCl, the longitudinal order of nonpolar parts first decreased and then increased. It is concluded that the aggregation of membrane proteins and the order changes of the phospholipid cause a change in the distribution and conformation of the phospholipid membrane. And the effects of CsCl on the erythrocyte membrane are mainly dependent on its concentration.

Interaction Mechanism of Anabolic Steroid Hormones with Structural Components of Erythrocyte Membranes

The interaction of testosterone, androsterone, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEAS) with erythrocyte membranes was studied. It was shown that testosterone and androsterone have a high constant of binding to the membranes (K(b) ≈ 10(6) M(-1)), whereas K(b)'s for DHEA and DHEAS are 2 orders of magnitude lower. Hydrogen bonds and hydrophobic interactions play an important role in binding of anabolic steroids. Hydrogen bonds form with CO and NH groups both of membrane proteins and phospholipids. This results in the formation of complex domains rising above the surface of membranes. Strengthening of hydrophobic interactions in the domains promotes the displacement of water dipoles to adjacent regions, thus loosening the phospholipid bilayer. Overall, microviscosity of erythrocyte membranes strongly increases, which decreases the plasticity of erythrocytes and hampers their motion in blood capillaries. This mechanism may underlie the development of diffusion myocardial hypoxia and hypoxic cardiac arrest.

Antioxidant and membrane-protective properties of an extract from the brown alga Laminaria japonica

This paper presents comparative data on the antioxidant and membrane-protective activities of an extract from the brown seaweed Laminaria japonica and the commercial drug Legalon. It was shown that intoxication with carbon tetrachloride was accompanied by the exhaustion of the antioxidant defense system of erythrocytes, an increase in their dimensional characteristics, and a change in the phospholipids to neutral lipids ratio. The Laminaria extract appeared to be more efficient than Legalon in the restoration of the lipid component of erythrocyte membranes and the removal of toxic stress.

On the association of lipid rafts to the spectrin skeleton in human erythrocytes

Lipid rafts are local inhomogeneities in the composition of the plasma membrane of living cells, that are enriched in sphingolipids and cholesterol in a liquid-ordered state, and proteins involved in receptor-mediated signalling. Interactions between lipid rafts and the cytoskeleton have been observed in various cell types. They are isolated as a fraction of the plasma membrane that resists solubilization by nonionic detergents at 4°C (detergent-resistant membranes, DRMs). We have previously described that DRMs are anchored to the spectrin-based membrane skeleton in human erythrocytes and can be released by increasing the pH and ionic strength of the solubilization medium with sodium carbonate. It was unexplained why this carbonate treatment was necessary and why this requirement was not reported by other workers in this area. We show here that when contaminating leukocytes are present in erythrocyte preparations that are subjected to detergent treatment, the isolation of DRMs can occur without the requirement for carbonate treatment. This is due to the uncontrolled breakdown of erythrocyte membrane components by hydrolases that are released from contaminating neutrophils that lead to proteolytic disruption of the supramolecular assembly of the membrane skeleton. Results presented here corroborate the concept that DRMs are anchored to the membrane skeleton through electrostatic interactions that most likely involve the spectrin molecule.

Interaction Mechanism of Cortisol and Catecholamines with Structural Components of Erythrocyte Membranes

Nonspecific mechanisms of the stress hormones interaction with erythrocyte membranes were studied by means of atomic force microscopy, fluorescence analysis, and IR spectroscopy. It was shown that stress hormones (cortisol, adrenaline, noradrenaline) can bind to erythrocyte membranes with high affinity (K(b) approximately 10(6) M(-1)). The binding mechanism involves hydrogen bonds and hydrophobic and electrostatic interactions. Active groups of the hormones (NH(2), NHCH(3), keto, and hydroxy groups) interact simultaneously with CO and NH groups both of proteins and phospholipids. This leads to the formation of complex protein-lipid domains that distort the surface of the erythrocyte membrane. Water dipoles are displaced from the domains to adjacent regions and facilitate membrane loosening. The interaction of hormones with the membrane is accompanied by structural transitions of disorder --> order (tangle --> alpha-helix, tangle --> beta-structure) in membrane proteins and structural transitions of order --> order in phospholipids. Formation of large domains (clusters) of the lipid-protein and lipid nature leads to distortion of membranes and deteriorates their elasticity and rheological properties.

Phospholipid composition of blood erythrocytes of tundra voles (Microtus oeconomus Pall.) inhabiting under different radioecological conditions

Phospholipid composition has been studied in blood erythrocytes of tundra voles Microtus oeconomus inhabiting territories with normal and increased levels of natural radioactivity at different phases of the populational cycle. It has been shown that rearrangement in the lipid component of blood erythrocyte membranes in tundra voles from radioactively polluted areas are associated with intensification of the lipid peroxidation (LPO) processes and are similar to those observed at the organism natural aging. It has been noted that the capability for peroxide oxidation in erythrocyte lipids is one of the most sensitive stages of the LPO processes to action of the low-intensity radiation in the natural habitat of animals. The change of the populational cycle phases, which is accompanied by hormonal rearrangement in the animal organism, produces an essential effect on the degree of expression of the radiation-induced changes of the studied parameters.