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.

[The role of heat shock proteins 27 and 70 in redox-dependent regulation of apoptosis in Jurkat tumor cells].

Heat shock proteins Hsp) act as molecular chaperones, protecting enzymes and other proteins against reactive oxygen species. The objective of the study was to investigate the role of Hsp27 in maintaining the balance of the glutathione system and Hsp70 concentrations as well as in implementing Jurkat tumor cell apoptosis. Addition of the Hsp27 inhibitor KRIBB3 (5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)-isoxazol) to Jurkat cells resulted in glutathione redox imbalance (increased GSSG and increased glutathione reductase activity), a decrease in Hsp70 concentrations, and also increased cell apoptosis as compared with to the intact cell culture.

The Role of Protein Oxidative Modification and the Cellular Redox Status in Realization of Apoptosis of MCF-7 Breast Adenocarcmoma Cells.

The aim of this study was to establish the role of redox modification of proteins and redox status in the realization of apoptosis of MCF-7 breast adenocarcinoma cells du-ing cultivation with the SH-group blocker N-ethylmaleimide (NEM) and the SH-group protector 1,4-dithioerythritol (DTE). The activation of apoptosis in MCF-7 breast adenocarcinoma cells was shown to be due to the irreversible modification of redox sensitive protein molecules. The presence of DTE in the culture medium of cancer.

Comparative Evaluation of β-Catenin and E-Cadherin Expression in Liquid Aspiration Biopsy Specimens of Thyroid Nodules.

We compared the results of gene molecular and immunocytochemical studies of β-catenin and E-cadherin in different variants of nodular thyroid disease (nodular colloid goiter, follicular thyroid adenocarcinoma, papillary thyroid cancer) and revealed changes of the function of the E-cadherin/β-catenin complex leading to switching from adhesion function of β-catenin in nodular colloid goiter to predominantly transcriptional activity in papillary carcinoma. The results confirm the important role of disturbances in E-cadherin-β-catenin interactions in the mechanisms of malignant transformation of follicular epithelium.

[The role of oxidative protein modification and the gluthatione system in modulation of the redox status of breast epithelial cells].

The effects of the SH-group blocker N-ethylmaleimide (NEM) and thiol group protector 1,4-dithioerythritol (DTE) on the redox status of cells HBL-100 cells, oxidative modification of their proteins and the state of glutathione and thioredoxin systems have been investigated. Breast epithelial cells cultivated in the presence of NEM were characterized by decreased redox status, increased glutathione reductase activity, and increased concentrations of products of irreversible oxidative modification of protein and amino acids. Cultivation of HBL-100 cells in the presence of DTE resulted in a shift of the redox status towards reduction processes and increased reversible protein modification by glutathionylation.

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.

[β-Catenin: Structure, Function and Role in Malignant Transformation of Epithelial Cells].

The article presents the data on the structure and mechanisms of β-catenin functioning. The basic aspects of the role of β-catenin in malignant transformation have been studied at various tumors. Primary structure of β-catenin allows it to interact with many factors and ligands, including transcription factors, α-catenin, cadherin, Axin, Rho family GTPases, Bcl9 et al.

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.

Role of heat shock protein 27 in regulation of glutathione system and apoptosis of Jurkat tumor cells and blood lymphocytes.

Reaction of the glutathione system of Jurkat tumor cells and blood lymphocytes was evaluated under conditions of culturing with 5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl) isoxazole (KRIBB3), a selective inhibitor of heat shock protein Hsp27. The results indicated the regulatory role of Hsp27 in the maintenance of the functional activities of glutathione reductase, glutathione peroxidase, and realization of apoptotic death of Jurkat cells and blood lymphocytes. Inhibition of Hsp27 in Jurkat tumor cells led to imbalance of the glutathione system and increase of the share of annexin-positive cells.

The effects of galectin-1 on the gene expression of the transcription factors TBX21, GATA-3, FOXP3 and RORC.

CD4(+) T cells orchestrate the immune response by differentiating into T helper (Th) or regulatory (Treg) cell subsets that secrete distinct sets of cytokines. They also play a critical role in the pathogenesis of autoimmunity, asthma, allergy and, likely, cancer. The mechanisms involved in the regulation of CD4(+) T cell homeostasis by galectin-1 remain poorly characterized.

Modulating effect of matrices with calcium phosphate coating on cytotoxicity of strontium ranelate and ibandronic acid in vitro.

Strontium ranelate (29 μg/ml) and ibandronic acid (50 μM) produced a cytotoxic effect on rat bone marrow myelokaryocytes in vitro. Strontium ranelate increased the number of myelokaryocytes with signs of necrosis, ibandronic acid increased the number of apoptotic and necrotic cells in the 9-day 2D culture of bone marrow cells on the plastic surface of the wells of culture plates. Co-culturing of the bone marrow with 3D matrices with microarc calcium phosphate coating that simulated bone mineral matrix increased intracellular ROS concentration, but abolished the cytotoxic effect of these drugs.

Effect of galectin-1 on apoptosis of CD4(+) lymphocytes differentiated in vitro towards regulatory T cells.

We studied the effect of galectin-1 on apoptosis of CD4(+) lymphocytes intact and in vitro differentiated towards regulatory T cells. An increase in the content of apoptotic CD4(+) lymphocytes was observed after exposure of intact cells with 15 ng/ml galectin-1 and after exposure of regulatory T cells with 10 and 15 ng/ml galectin-1. Apoptosis of regulatory T cells induced by galectin-1 was accompanied by an increase in the content of proapoptotic protein Bad.

Nitric oxide donor NOC-5 increases XIAP and Aven level in Jurkat cells.

Mitochondrial permeabilisation after NO donor application did not activate caspase-9. We have studied the X-linked apoptosis inhibitor (XIAP) and Aven protein content in NO-treated Jurkat cells. The level of both proteins increased in NO-treated cells.

Effects of HSP27 chaperone on THP-1 tumor cell apoptosis.

The role of Hsp27 (heat shock protein 27) chaperone in regulation of THP-1 tumor cell apoptosis was studied. Realization of tumor cell apoptosis under conditions of in vitro culturing with Hsp27 specific inhibitor (KRIBB3) was evaluated by fluorescent microscopy with FITC-labeled annexin V and propidium iodide. Measurements of Bcl-2 family proteins (Bcl-2, Bax, Bad) in tumor cells incubated with Hsp27 inhibitor were carried out by Western blotting.

Role of hydrogen sulfide in the regulation of cell apoptosis.

We studied the effect of a gas transmitter hydrogen sulfide (H(2)S) on the realization of apoptosis in Jurkat cells and mononuclear leukocytes from healthy donors. Treatment with H(2)S donor NaHS was accompanied by a dose-dependent intensification of cell death via apoptosis and necrosis. T-cell leukemia cells were more sensitive to H2S than mononuclear leukocytes from healthy donors.

Structural and functional state of the bone marrow during its in vitro interaction with ferromagnetic nanoparticles.

Hemopoietic islets, associations of stromal (macrophages, fibroblasts) and blood (including stem) cells, are structural and functional units of the bone marrow. We studied cellular and molecular processes developing following short-term (1 h) contact of hemopoietic islets with ferromagnetic nanoparticles in a multicellular system of the bone marrow in vitro. It was established that nanodispersions of magnetite (Fe(3)O(4), mean particle diameter 18 nm) and iron coated with carbon (Fe(C), particle diameter 5-10 nm) in a dose of 3 mg/liter had a minor effect on processes of necrotic and apoptotic cell death.

The role of heat shock protein 90 in the regulation of tumor cell apoptosis.

Programmed death of Jurkat tumor cells was studied under conditions of culturing with 17-AAG selective inhibitor of heat shock protein with a molecular weight of 90 kDa and etoposide. Apoptosis realization was evaluated by fluorescent microscopy with FITC-labeled annexin V and propidium iodide. Activity of caspase-3 was evaluated spectrophotometrically.

Molecular mechanisms of the effect of interleukin-2 on apoptosis of blood lymphocytes.

The effects of recombinant IL-2 on apoptosis of lymphocytes of healthy donors were studied in in vitro experiments. It was shown that the inductive and inhibitory effects of IL-2 on apoptotic process depend on the dose of the cytokine and cell microenvironmental conditions. Culturing of lymphocytes with recombinant IL-2 increases the percent of cells with reduced transmembrane potential, reduces the content of intracellular proteins Bcl-2, Bcl-X(L) and и Bax, and increases the level of Bad.

Role of NF-kB, p53, and p21 in the regulation of TNF-α mediated apoptosis of lymphocytes.

The effect of recombinant TNF-α on programmed death of donor lymphocytes was studied in vitro. The proapoptotic effect of this cytokine is realized through transcription factors and cell cycle inhibitors. Incubation of lymphocytes with recombinant TNF-α revealed increased levels of NF-kB and p21 and reducted content of nonphosphorylated p53.

Effect of blood lipoproteins and apolipoproteins A-I, C, and E on the microviscosity of erythrocyte membranes.

We studied in vitro modifying effect of high-density lipoproteins, low-density lipoproteins, very-low-density lipoproteins, and apolipoproteins A-I, C, and E on membrane structure of rat erythrocytes. Incubation of erythrocyte membranes with lipoproteins was accompanied by significant changes in the behavior of fluorescent probe pyrene in the hydrophobic membrane region. The regulatory effect of lipoproteins was probably realized via exchange of lipid components between these particles and erythrocyte membrane.

Regulatory role of nitric oxide in neutrophil apoptosis.

Apoptosis of blood neutrophils from healthy donors was studied under conditions of cell culturing with different concentrations of H(2)O(2), selective NO synthase inhibitor, and inductor of NO synthesis (L-arginine). In vitro incubation of neutrophilic leukocytes with 5 mM H(2)O(2) led to activation of the apoptotic program in neutrophils, which was seen from increased content of Bax protein in the cells and increased number of apoptotic cells in the culture. Increased content of annexin-positive cells after incubation of neutrophil culture with NO synthase inhibitor suggests involvement of NO in the regulation of neutrophil apoptosis under conditions of oxidative stress, while L-arginine prevented H(2)O(2)-induced programmed cell death.

Role of recombinant mitogen-activated protein kinases JNK and p38 in the regulation of apoptosis in blood mononuclear cells under conditions of oxidative stress in vitro.

Programmed death of peripheral blood mononuclear cells from healthy donors was studied during culturing with various concentrations of H(2)O(2) and selective inhibitors of JNK (SP600125) and p38 MAPK (ML3403). In vitro incubation of mononuclear leukocytes with 1 mM H(2)O(2) stimulated apoptotic cell death. Treatment with inhibitors (SP600125 and ML3403) during in vitro oxidative stress prevented the increase in the number of annexin-positive mononuclear cells.

Modulation of apoptosis of mononuclear cells under conditions of oxidative stress.

We studied mitochondrial and type 1 tumor necrosis factor-a receptor (TNFR1)-mediated pathways triggering the apoptotic program in mononuclear cells under conditions of oxidative stress. Intensification of intracellular production of reactive oxygen forms is accompanied by an increase in the number of annexin-positive TNFRI-presenting cells and mononuclear cells with reduced mitochondrial transmembrane potential in case of induction of oxidative stress with 1 mM H2O2 in vitro and in patients with pneumonia.

Role of genetically determined production of immunoregulatory cytokines in immunopathogenesis of chronic viral hepatitides.

Immunopathogenesis of chronic viral hepatitides was studied by modern immunological, molecular, genetic methods. We revealed an imbalance in the production of immunoregulatory cytokines by mononuclear leukocytes (primarily of the Th2 type). The risk of progression and chronic course of viral hepatitides in Caucasian population was associated with alleles of promoter regions -330G and -592A in the IL-2 and IL-10 genes, respectively, as well as with the T/T genotype of the polymorphic region C590T in the IL-4 gene.

Effect of recombinant interleukin-5, interleukin-3, and eotaxin on apoptosis in eosinophilic granulocytes.

We studied in vitro effects of recombinant interleukin-5, interleukin-3, and eotaxin on programmed death of eosinophils from healthy donors and patients with non-Hodgkin's lymphomas associated with severe blood eosinophilia. Interleukin-5 and eotaxin produced the most potent antiapoptotic effect on eosinophils from healthy donors. In patients with non-Hodgkin's lymphomas, spontaneous apoptosis in eosinophilic leukocytes was low and remained unchanged during incubation with recombinant proteins.