E. A. Stepovaya

Typical Changes of Erythrocytes in Chronic Inflammation

Structural and metabolic status and function of erythrocytes were studied in patients with chronic bronchitis, chronic inflammatory diseases of the upper airways, and chronic colitis. Complex study of the peripheral component of the erythron showed that disorders in erythrocyte morphology and function (decreased erythrocyte dry weight, low concentration of sulfhydryl groups and lipoproteins, decreased content of high molecular weight polypeptides in parallel with increased content of low molecular weight proteins, increased number of transformed cells, and enhanced reversible aggregation) were nonspecific and did not depend on the location of the inflammatory process.

Role of Glutathione System Redox Potential in Apoptosis Dysregulation in MCF-7 Breast Adenocarcinoma

MCF-7 breast cancer cells and HBL-100 breast epithelial cells were cultured with N-ethylmaleimide, a blocker of SH groups. Changes in redox potential of the glutathione system, activities of glutathione reductase, glutathione peroxidase, and intensity of apoptotic cell death were evaluated. The results indicate that incubation with N-ethylmaleimide led to glutathione system imbalance, reduced tumor cell redox potential, and induced their programmed death, which seemed useful for prospective target therapy of tumor diseases.

Structure and Properties of Lipid Bilayer of Erythrocyte Membranes in Patients with Malignant Tumors

The study of erythrocyte membranes in untreated patients with malignant tumors of different location (lung cancer, tumors of the head and neck, stomach and colorectal cancer) revealed changes in the fatty-acid spectrum of phospholipid fraction paralleled by an increase in the viscosity of the lipid bilayer, including the area of protein-lipid contacts. The degree of changes depended on tumor location.

Lipid spectrum of erythrocyte membranes in cancer patients

In patients with untreated tumors (lung cancer, head and neck tumors, stomach and colon cancer), erythrocyte membranes are characterized by a decreased content of total lipids together with increased percentage of cholesterol and lysophosphatidylcholine in comparison with healthy individuals. The observed shifts depend on tumor location.

Typical Changes of Reversible Erythrocyte Aggregation in Various Pathological Processes

Examinations of patients with malignant tumors of different location (lung cancer, stomach, colorectal cancer, and head and neck tumors), patients with paranoid schizophrenia and neurotic disorders revealed enhanced reversible erythrocyte aggregation. It was found that enhancement of erythrocyte aggregation is associated with structural modification of their membrane and appearance of transformed cells (echinocytes, stomatocytes, etc.). The phenomenon of enhanced reversible erythrocyte aggregation in somatic and mental diseases can be regarded as a typical pathological process.

Ultrastructural changes in erythrocytes in patients with mental disorders.

Transmission electron microscopy of peripheral blood erythrocytes from patients with paranoid and residual schizophrenia, mental retardation, and neurotic disturbances revealed nonspecific ultrastructural changes in the membrane and matrix of red blood cells.

Protein spectrum and state of lipid bilayer in erythrocyte membranes in children with insulin-dependent diabetes mellitus: Polyacrylamide gel electrophoresis and fluorescence analysis data

Erythrocyte membranes in children with insulin-dependent diabetes mellitus are characterized by a decreased content of high-molecular-weight proteins and increased content of low-molecular-weight proteins and fractions of aggregated material against the background of increased microviscosity of deep membrane layers and changes in the protein-lipid interactions. These abnormalities were found in phases of clinical metabolic decompensation and subcompensation.

The Role of the Glutathione System in Oxidative Modification of Proteins and Dysregulation of Apoptosis in Jurkat Tumor Cells

We compared changes in the redox status and intensity of oxidative modification of proteins in intact Jurkat tumor cells and cells cultured with buthionine sulfoximine, an inhibitor of the key enzyme of glutathione synthesis γ-glutamylcysteine synthetase. The glutathione system components play a role in modulation of the content of protein-bound glutathione, protein carbonyl derivatives, bityrosine, and oxidized tryptophan, and in dysregulation of apoptosis in Jurkat tumor cells. Inhibition of de novo synthesis of glutathione in Jurkat tumor cells was followed by accumulation of hydroxyl radical, a reduction in the level of protein-bound glutathione and oxidized tryptophan, and a rise in the concentration of protein carbonyl derivatives. These changes were accompanied by activation of programmed cell death.

Effect of insulin, the glutathione system, and superoxide anion radical in modulation of lipolysis in adipocytes of rats with experimental diabetes

Spontaneous lipolysis was found to be increased in adipocytes of rats with alloxan-induced diabetes. In addition, isoproterenol-stimulated hydrolysis of triacylglycerols was inhibited against the background of oxidative stress and decreased redox-status of cells. A decrease in the ability of insulin to inhibit isoproterenol-stimulated lipolysis in adipocytes that were isolated from adipose tissue of rats with experimental diabetes was found, which shows a disorder in regulation of lipolysis in adipocytes by the hormone in alloxan-induced diabetes. Based on these findings, we concluded that there is an influence of reactive oxygen species, superoxide anion radical in particular, and redox potential of the glutathione system on molecular mechanisms of change in lipolysis intensity in rat adipocytes in alloxan-induced oxidative stress. Activation of spontaneous lipolysis under conditions of oxidative stress might be a reason for the high concentration of free fatty acids in blood plasma in experimental diabetes, and this may play a significant role in development of insulin resistance and appearance of complications of diabetes

Role of Thiol-Disulfide System in Mechanisms of Functional Changes in Neutrophils under Conditions of Oxidative Stress

We studied the state of the thiol-disulfide system (contents of reduced and oxidized glutathione, their ratio, and concentrations of protein SH-groups and protein-bound glutathione) and functional properties of neutrophils (production of hydroxyl radicals, IL-8, and TNF-α and myeloperoxidase activity) from healthy donors under conditions of oxidative stress in vitro induced by H2O2 in a final concentration of 200 μM and from patients with community-acquired pneumonia. We evaluated the role of reduced and protein-bound glutathione in the regulation of functional state of blood neutrophils from patients with community-acquired pneumonia and during oxidative stress in vitro under conditions cell incubation with N-ethylmaleimide or 1,4-dithioerythritolsulfhydryl, the blocker and protector of sulfhydryl groups, respectively.