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.

[Regulation of the genes expression of CD4+ T-lymphocytes differentiation transcription factors by galectin-3 in vitro].

Now a number of CD4+ T-lymphocytes, known as Th1, Th2, Treg and Th17, is currently identified and well- studied. The methods basing on the targeted regulation of differentiation process of the Th-lymphocytes that carry out the immune response polarization attract an attention of scientists dealing with a correction of immune-mediated. In the present study, endogenous beta-galactoside-binding protein of the lectin family, galectin-3, was investigated as a regulator of T-cell homeostasis. A galectin-3 is known to be actively produced by tumor cells in malignant transformation and able to influence the processes of signal transduction, cell-cell cooperation and the implementation of programmed death. As cell differentiation processes are directly connected with the regulation of gene expression, we investigated the effect of recombinant galectin-3 on expression of mRNA of transcription.factors, which guide the differentiation of CD4+ lymphocytes. The study was performed on peripheral blood mononuclear cells of healthy individuals. The gene expression levels were evaluated by a real-time PCR. In the experiments in vitro, it has been first found the recombinant galectin-3 (0.5 mg/mL) up-regulating the expression of transcription factors Gata-3 and Rorc mRNAs and down-regulating the mRNA expression of transcription factors T-bet and FoxP3. Up to a concentration of 1 mg/mL recombinant galectin-3 stimulates Th-cells by dose-dependent manner, whereas at higher concentrations stimulating effect weakens, and inhibiting action starts prevailing. Thus, one can suppose that galectin-3 through regulation of lymphocytes differentiation promote development of allergic, autoimmune and neoplastic diseases that allows us to consider the galectin-3 as a.potential target for therapy of these diseases.

[Intracellular targets of proapoptotic influence of gaseous transmitters].

Main molecular targets of nitric oxide, hydrogen sulfide and carbon monoxide proapoptotic action in Jurkat cells were determined in this study. Decrease of mitochondrial transmembrane potential was shown during all three gases action. Reason of this event is the Bcl-2 family members disbalance. Proapoptotic proteins release after mitochondrion membranes permeabilisation could be abolished by protein xIAP inhibition of caspase -9 and -3 activity during NO and CO application.

[Intracellular gaseous messengers, nitric oxide, carbon monoxide and hydrogen sulfide participate in apoptosis regulation].

In this paper, participation of gases, nitric oxide, carbon monoxide and hydrogen sulfide, in cell apoptosis regulation has been analyzed according to the literature data and our own findings. Different mechanisms of nitric oxide influence on apoptotic reaction including modulation of transcription factors activity and increase in mitochondrion membrane permeabilisation are described. Brief description of the generation and signal transduction pathways of carbon monoxide is presented. Pro- and antiapoptotic mechanisms of hydrogen sulfide influence on cell fate are analyzed.

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. H(2)S-induced cell apoptosis was accompanied by activation of caspase-3 and caspase-9.

[The role of p53 and NF-kappaB transcription factors in redox-dependent dysregulation of mononuclear leukocyte apoptosis].

The aim of this work was to study programmed death of blood mononuclear leukocytes taken from healthy donors and patients with acute inflammatory diseases (acute appendicitis, community-acquired pneumonia). Cellular p53 and NF-kappaB transcription factors were detected by western blotting. Active form of NF-kappaB was shown to appear in mononuclear leukocytes undergoing oxidative stress in experiment and during acute inflammation, p53 was found only under oxidative stress conditions in vitro. Despite enhanced expression of target gene mRNA of these transcription factors in oxidative stress (proapoptotic protein Bax and antiapoptotic protein Bcl-XL), the resulting vector of p53 and NF-kappaB activation is stimulation of cell's apoptotic reaction.

[Mitogenactivated protein kinases JNK and p38 as redox-dependent molecular targets correction of programmed cell death disturbances in oxidative stress condition].

The article summarizes information from recent literature and results of the author's own investigations concerning role of mitogenactivated protein kinases JNK and p38 in disturbances of programmed cell death regulation in oxidative stress condition.

[The role of redox-dependent signal systems in the regulation of apoptosis under oxidative stress condition].

Programmed death of peripheral blood mononuclear cells from donors with acute inflammatory diseases (an acute appendicitis, a community-acquired pneumonia) was investigated under condition of oxidative stress in vitro and under effect of selective inhibitors of MAP-kinases JNK and p38. Levels of active and inactive forms of MAP-kinases, and factors of transcription were determined by immunoblotting (western blot analysis). The increase in the activity of apoptosis under condition of oxidative stress in vivo and during the acute inflammatory diseases is associated with the increase in the level of reactive oxygen species (ROS) in the cells. The action of inhibitors of MAP-kinases JNK (SP600125) and p38 (ML3403) in vitro under condition of oxidative stress prevents increase in the quantity of annexin-positive mononuclear leucocytes that testifies to involving JNK and p38 MAP-kinases in apoptosis deregulation oxidative mechanisms. The appearance of NF-kappaB in the mononuclear leucocytes under condition of oxidative stress during the acute inflammatory diseases and at the experiment was shown; p53 was registered only under condition of oxidative stress in vitro. The effect of p53 and NF-kappaB results in the increase in the quantity of apoptosis annexin-positive mononuclear leucocytes that testify to inoperativeness of antiapoptotic regulation NF-kappaB.

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.

[Redox-dependent regulation of apoptosis as a function of intracellular reactive oxygen species in oxidative stress].

Programmed cell death of mononuclear cells in conditions of oxidative stress in vitro and selective inhibitors of MAP-kinases JNK, p38 were investigated. Levels of active and inactive forms of MAP-kinases, factors of transcription P53, NF-kB and proteins-regulators of apoptosis Bcl-X(L), Bad, Bcl-2 were determined by immunoblotting (Western blotting). The increasing of number of annexin-plus mononuclears/lymphocytes in the culture associated with enhance of the level of intracellular reactive oxygen species was shown. The treatment of selective inhibitors JNK SP600125 and p38 ML3403 in vitro prevents peroxide-induced appearance of P53 and NF-kB in blood mononuclear cells, associated with increasing of their apoptotic activity. The disturbance of the balance of pro- and antiapoptotic proteins of Bcl-2, family (the increase of the Bax level without changes of Bcl-X(L) and Bcl-2) leads to the growth of apoptosis process of mononuclear leucocytes activity in oxidative stress conditions.

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. Our results indicate that MAP kinases JNK and p38 are involved in the mechanisms of oxidative dysregulation of apoptosis.