Skin Microhemodynamics and Mechanisms of Its Regulation in Type 2 Diabetes Mellitus.

The review presents modern ideas about peripheral microhemodynamics, approaches to the ana-lysis of skin blood flow oscillations and their diagnostic significance. Disorders of skin microhemodynamics in type 2 diabetes mellitus (DM) and the possibility of their interpretation from the standpoint of external and internal interactions between systems of skin blood flow regulation, based on a comparison of couplings in normal and pathological conditions, including models of pathologies on animals, are considered. The factors and mechanisms of vasomotor regulation, among them receptors and signaling events in endothelial and smooth muscle cells considered as models of microvessels are discussed. Attention was drawn to the disturbance of Ca2+-dependent regulation of coupling between vascular cells and NO-dependent regulation of vasodilation in diabetes mellitus. The main mechanisms of insulin resistance in type 2 DM are considered to be a defect in the number of insulin receptors and impaired signal transduction from the receptor to phosphatidylinositol-3-kinase and downstream targets. Reactive oxygen species plays an important role in vascular dysfunction in hyperglycemia. It is assumed that the considered molecular and cellular mechanisms of microhemodynamics regulation are involved in the formation of skin blood flow oscillations. Parameters of skin blood microcirculation can be used as diagnostic and prognostic markers for assessing the state of the body.

Mechanisms of ERK phosphorylation triggered via mouse formyl peptide receptor 2.

Formyl peptide receptors (FPRs) are expressed in the cells of the innate immune system and provide binding with pathogen and damage-associated molecular patterns with subsequent activation of the phagocytes for defense reactions such as chemotaxis, secretory degranulation and ROS generation. Probably, FPR2 is one of the unique receptors in the organism; it is able to recognize numerous ligands of different chemical structure, and moreover, these ligands can trigger opposite phagocyte responses promoting either pro- or anti-inflammatory reactions. Therefore, FPR2 and its signaling pathways are of intense research interest. We found only slight activation of ERK1/2 in the response to peptide ligand WKYMVM in the accelerating phase of ROS generation and more intense ERK1/2 phosphorylation in the declining phase of it in mouse bone marrow granulocytes. Lipid agonist BML-111 did not induce significant ERK phosphorylation when applied for 10-1800 s. To some extent co-localization of ERK1/2 and NADPH oxidase subunits was observed even in the intact cells and didn't change under FPR2 stimulation by WKYMVM, while direct PKC activation by PMA resulted to more efficient interaction between ERK1/2 and p47phox/p67phox and their translocation to plasma membrane. We have shown that phosphorylation and activation of ERK1/2 in bone marrow granulocytes depended on FPR2-triggered activity of PI3K and PKC, phosphatase DUSP6, and, the most but not the least, on ROS generation. Since blocking of ROS generation led to a slowdown of ERK activation indicating a significant contribution of ROS to the secondary regulation of ERK activity.

Role of additive stochastic modulation of the heart activity in the formation of 0.1-Hz blood flow oscillations in the human cardiovascular system.

In the framework of our previous hypothesis about the participation of structural and hydrodynamic properties of the vascular bed in the formation of the 0.1-Hz component of blood flow oscillations in the human cardiovascular system and on the basis of the reduced hydrodynamic model, the role of additive stochastic perturbations of the operation of the single-chamber pump that simulates the heart was investigated. It was shown that aperiodic noise modulation of the rigidity of the walls of the pump or its valves generates low-frequency oscillations of pressure and blood flow velocity of arterial vascular bed with the maximum amplitude at a frequency close to 0.1 Hz.

Production of active oxygen species by blood phagocytes of pregnant women and their newborns with intrauterine infection.

We studied the relationship between changes in the maternal and newborn granulocyte functions under conditions of infection risk and realization. Women with normal gestation and their healthy newborns, pregnant women with a high risk of infection and their newborns, healthy or with intrauterine infection, were examined. Changes in the active oxygen species-dependent phagocytosis system were found in the blood of risk group patients. An inverse relationship between the parameters venous and umbilical cord blood was detected indicating a relationship between changes in functional activities of maternal and newborn granulocytes. The percentage of CD11b(+)cells in venous and umbilical cord blood strictly correlated with the percent of cells that phagocytosed FITC-labeled E. coli. Deviations in the generation of active oxygen species in phagocytosis seemed to be related to the expression of surface receptors in the risk groups.

Common regularities in changes of the neutrophil functional activity during in vivo growth of tumors of different immunogenic activity.

Studies on BALB/c mice with tumors of different immunogenic activity (nonimmunogenic J774, WEHI 164 and immunogenic NS0) have showed that the development of a tumor is associated with changes in the neutrophil morphology and functions: the counts and size of the cells migrating to the focus increase and their capacity to produce active oxygen species is changed.

[Ambiguity role of neutrophils in oncogenesis].

The review is focused on the participation of polymorphonuclear granulocytes (neutrophils) in development and spreading of a tumor. We consider both the well known functions of neutrophils (degranulation, production of reactive oxygen species (ROS)) and the recently shown one (presentation of an antigene). The special attention is focused on the ambiguity of the neutrophil role in oncogenesis. The dominant view is that neutrophils display exclusively antitumor properties. The update information testifies about protumoral activity of neutrophils: they migrate to a tumor and promote angiogenesis and metastasis at late stages of the tumor. It is interesting that certain components of neutrophil cytotoxic arsenal (ROS, cytokines, specific enzymes) participate both in antitumoral defenses of an organism and protumoral activity.

Evaluation of the Role of FMLF chemotaxic peptide receptors in umbilical cord blood granulocytes from newborns at risk of infectious inflammatory diseases.

We studied the role of receptors with high and low affinity for fMLF chemotaxic peptide in the generation of active oxygen species by umbilical cord blood granulocytes from newborns with normal neonatal period, born after normal or complicated gestation, in children with manifestations of bacterial infection born after complicated pregnancy, and in granulocytes of non-pregnant women with normal reproductive function. Granulocytes of children born after complicated pregnancy exhibited high reactivity in induction of respiratory burst in a wide range of fMLF concentrations. The presentation of receptors with high and low affinity on granulocytes during initiation of the respiratory burst differs in children born after complicated pregnancy and in healthy babies born after normal gestation. Presumably, the detected differences result from high expression of receptors with low affinity for fMLF and disorders or immaturity of mechanisms responsible for receptor inactivation.

[Effect of negative air ions on respiratory organs and blood].

The effect of negatively charged ions on respiratory organs and blood of rats has been studied. It was shown that the inhaling of negative air ions (NAI) for 60 min with a concentration of NAI at the place of location of animals 320-350 000 ions/cm2 activated the secretion of goblet cells without damaging the mucosa of the trachea and changed the spectrum of proteins of bronchopulmonary lavage. It was also found that the spontaneous production of reactive oxygen species (ROS) by cells of nonfractionated blood after the exposure to NAI increased in both males and females; the intensity of ROS generation induced by opsonized zymosan increased only in females. Different sensitivity of the antioxidant enzymes superoxide dismutase and glutathione reductase of blood to NAI in females and males was revealed. These results enable one to consider the effect of NAI as priming and a weak activation of the respiratory organs through the direct action on the mucosa of the primary target organs of the respiratory tract and then on the blood.

[Possible mechanisms of antioxidant activity of glycyrrhizic acid].

Possible mechanisms of antioxidant activity of glycyrrhizinic acid (GA) were studied. GA did not exhibit antiradical properties at the range of concentrations 1-100 mM as was shown in the experiments with stable radical 1,1-Diphenyl-2-picrylhydrazyl. These data were conformed by the study of GA influence on chemiluminescence of luminol in cell-free system with hydrogen peroxide. However, GA decreased generation of reactive oxygen species by PMA-FMLF-activated neutrophils. Addition of GA did not ifluence free radical level in neurons, however, cell preincubation with GA resulted in the decrease of free radicals production and the increase of intracellular glutathione level.

[Dynamic analysis of modification of peripheral neutrophils functional activity and its regulation during tumor growth in vivo].

Polymorphonuclear granulocytes (neutrophils) release the reactive oxygen species (ROS) for destruction of pathogens, providing quicker of an organism from infections and own defective of transformed cells. Reactive oxygen species are also potential carcinogens because they facilitate mutagenesis, tumor promotion and progression. Balance between these opposite influences is supported by coordinated interrelations in intracellular signaling systems. Tumor growth influence on the NADPH oxidase in peripheral innate immune cells is unclear. A solid cancer model was developed after an intramuscular injection of Ehrlich carcinoma cells into hind leg of NMRI strain mice. Intensity of the respiratory burst was estimated by luminol-dependent chemiluminescence technique. Transformation of inflammatory reaction was revealed during tumor growth: greater amounts of neutrophils were recruited into peritoneal cavity; sizes of the cells, their nuclei and granules were enlarged; the ratio of different cell types in peritoneal exudation was changed. The study revealed that tumor progression was accompanied by significant changes in functional activity of neutrophils. Dynamic increase in spontaneous level of ROS production and concentration-dependent change of intensity of the respiratory burst induced with chemotactic peptide N-formyl-Met-Leu-Phe (fMLF) was revealed in peripheral neutrophils under tumor growth conditions. It was found that effects of inhibitors of tyrosine protein kinases, protein kinase C, mitogen-activated protein kinase p38MAPK (p38MAPK) and phosphatidylinositol 3-kinase (PI3K) were altered in neutrophils from tumor-bearing mice in comparison with the cells of control mice. This indicates a change in the role of the enzymes in regulation of the neutrophil respiratory burst. Data obtained show that p38MAPK and PI3K entangle up- and down-regulation of NADPH oxidase in peripheral neutrophils during tumor growth.

Generation of reactive oxygen species by umbilical blood cells and immune status of newborns at risk of infectious inflammatory diseases.

We carried out a comparative clinical and immunological examination of newborns whose mothers were at risk of infectious inflammatory diseases. Umbilical blood cell phenotype was evaluated by flow cytofluorometry. ROS level was evaluated by chemiluminescence intensity. Spontaneous production of ROS and phagocytic activity of cells in the whole umbilical blood was reduced in newborns born after complicated pregnancy. Low immunoregulatory index indicating changed CD4+/CD8+ ratio and low percentage of natural killer cells were observed in children with manifestations of bacterial infection. ROS production by isolated granulocytes and the effects of PI3K and p38 MAPK (kinases involved in the regulation of activity of NADPH oxidase responsible for the production of ROS) in the risk group infants differed from the corresponding parameters in the control group. The results indicate shifts in the phagocytosis system, immune status, and the receptor-conjugated regulatory systems of ROS generation by granulocytes in newborns at risk of infectious inflammatory diseases.

Regulation of reactive oxygen species production by peripheral blood neutrophils from women with postpartum endometritis.

Production of reactive oxygen species in unfractionated peripheral blood increased in parturient women without postpartum infectious complications and patients with postpartum endometritis. The control group included nonpregnant women with normal reproductive function. Intergroup differences were revealed in the degree of respiratory burst activation with opsonized zymosan and response of isolated granulocytes to chemotactic peptide N-formyl-Met-Leu-Phen (1 muM). Production of reactive oxygen species tended to normal after therapy. We studied the effects of a specific mitogen-activated protein kinase p38MAPK inhibitor and inhibitors of tyrosine protein phosphatases and phosphatidylinositol-3-kinase. The role of p38MAPK in reactive oxygen species generation by cells changes significantly in parturient women.

Changes in regulation of oxidase activity of peripheral blood granulocytes in women with habitual abortions.

Generation of active oxygen forms by blood granulocytes was studied in women with a history of habitual abortions (2-3 spontaneous abortions in the first trimester, undeveloped pregnancies). The level of spontaneous luminol-dependent chemiluminescence of nonfractionated peripheral blood was increased in this patient population (study group) in comparison with women with normal reproductive function (reference group). The two groups differed by the level of activation of respiratory burst induced by opsonized zymosan and by activity of isolated granulocytes in response to chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (1-50 microM). Differences in the effects of inhibitor of tyrosine protein kinases and protein phosphatases and inhibitor of mitogen-activated proteinkinase p38 MAPK were detected. The results attest to predisposition to oxidative stress and poor cytotoxic functions of granulocytes in women with habitual abortions, which can be due to specific features of regulation of oxidase activity by tyrosine protein kinases and protein phosphatases and by p38 MAPK.

[Effect of perfluorocarbon emulsions on function of enzyme systems responsible for generating active forms of oxygen in neutrophils]. / Vliianie émul'sii perftoruglerodov na funktsionirovanie fermentnykh sistem, otvetstvennykh za generatsiiu aktivnykh form kisloroda v neitrofilakh.

The ability of the emulsion of perfluoroorganic compounds stabilized with proxanol 268 to affect the functions of peritoneal neutrophils was evaluated. The functional activity of neutrophils was estimated from the intensity of generation of reactive oxygen species using the method of chemiluminescent analysis. The emulsion was shown to suppress the neutrophil responses to phorbol-12-myristate-13-acetate in a dose-dependent manner. No inhibition of the activity of neutrophils in the presence of the emulsion was observed in N-formylmethionylleucylphenylalanine stimulated cells. The data obtained indirectly confirm the suggestion that the perfluoride emulsion inhibits neutrophil NADPH oxidase activity. In the presence of the perfluoride emulsion, myeloperoxidase plays a more important role in the generation of luminescent responses in both N-formylmethionylleucylphenylalanine- and phorbol-12-myristate-13-acetate-stimulated neutrophils. The effect of perfluoride emulsion results in the preferential myeloperoxidase-produced generation of reactive oxygen species in the neutrophil respiratory burst.

[Reactive oxygen forms and luminescence of intact microspore cells]. / Aktivnye formy kisloroda i liuminestsentsiia intaktnykh kletok mikrospor.

The participation of reactive oxygen species (ROS) in luminescence (chemiluminescence and autofluorescence induced by ultraviolet light of 360-380 nm) was analyzed. Microspores, the pollen (male gametophyte) of Hippeastrum hybridum, Philadelphus grandiflorus, and Betula verrucosa and vegetative microspores of the spore-breeding plant Equisetum arvense served as models. It was found that the addition of the chemiluminescent probe lucigenin, which luminesces in the presence of superoxide anionradicals, leads to intensive chemiluminescence of microspores. No emission was observed in the absence of lucigenin and in the presence of the dye luminol as a chemiluminescent probe. The emission decreased significantly if superoxide dismutase, an enzyme of the superoxide anionradical dismutation during which this radical disappeared, was added before the dye addition. The autofluorescence intensity of microspores decreased in the presence of both superoxide dismutase and peroxidase, an enzyme destroying hydrogen peroxide and organic peroxides. The most significant effect was noted after the addition of peroxidase, which indicates a greater contribution of peroxides to this type of emission. The fumigation with ozone, which increases the amount of ROS on the cell surface, enhanced the intensity of the chemiluminescence of microspores with lucigenin, but decreased the intensity of the autofluorescence of microspores. Exogenous peroxides (hydrogen peroxide and tert-butylhydroperoxide) stimulated the autofluorescence of pollen and vegetative spores in a concentration-dependent manner. It was shown that the formation of ROS contributes to the luminescence of plant microspores, which reflects their functional state.

Modern concept on the role of phagocytes in the pathogenesis of complications during pregnancy.

Here we review modern concept of the role of phagocytes, the key cell component of natural immunity, in the course of pregnancy and in the pathogenesis of its complications. Phagocytes contribute to the development, maintenance, and favorable outcome of pregnancy. These cells play a role in the pathogenesis of various pregnancy complications, including fetal growth retardation, late gestosis, and intrauterine infections. The understanding of the pathophysiological mechanisms that occur in the mother-placenta-fetus system would allow us to improve diagnostic procedures, perform pathogenetically substantiated therapy, and decrease the incidence of obstetrical complications.

Variations of the effect of insulin on neutrophil respiratory burst. The role of tyrosine kinases and phosphatases.

The priming effect of insulin on the fMLP-induced respiratory burst of mouse neutrophils as well as the involvement of tyrosine protein kinases and phosphatases in this process have been studied. Peritoneal evoked neutrophils of NMRI strain mice were incubated with 0.01-100 nM insulin for 1-60 min at 22, 30, or 37 degrees C and activated by 0.1-50 microM N-formyl-methionyl-leucyl-phenylalanine (fMLP). The production of reactive oxygen species (ROS) by neutrophils was monitored by luminol-dependent chemiluminescence. We found that 125I-labeled insulin binding by mouse neutrophils occurred with saturation and high affinity. Insulin itself did not change the basal level of the ROS production but could modulate fMLP-induced respiratory burst. The effect of insulin depended on temperature and duration of pretreatment of the neutrophils with insulin and the concentration combination of the insulin and fMLP. The tyrosine kinase inhibitor tyrphostin 51 decreased the fMLP-induced respiratory burst significantly. Insulin did not change the fMLP response of neutrophils pretreated with tyrphostin. However, the effect of tyrphostin on the response to 50 microM fMLP was considerably decreased in neutrophils treated with insulin. There was no such effect during activation by 5 microM fMLP, for which the priming effect of insulin was not observed. Insulin did not increase the fMLP-induced respiratory burst in neutrophils treated with the protein phosphatase inhibitors orthovanadate and pyrophosphate. If the inhibitors were added after insulin, the combined effect was nearly additive. It is possible that priming by insulin of the fMLP-induced respiratory burst is triggered by tyrosine phosphorylation, realized with its participation, and involves the signaling pathways initiated by tyrosine phosphorylation but subsequently is not dependent on the latter. The role of protein phosphatases in priming by insulin is of little importance. The data indirectly confirm the idea that priming of the neutrophil respiratory burst is a result of crosstalk of signaling pathways of the insulin and fMLP receptors with the participation of tyrosine phosphorylation.

[Role of phospholipase A2 and epoxygenase in inhibition of respiration burst in neutrophils by low intensity radiation of extremely high frequency]. / Rol' fosfolipazy A2 i époksigenazy v ingibirovanii respiratornogo vzryva neitrofilov nizkointensivnym élektromagnitnym izlucheniem kraine vysokoi chastoty.

The role of some components of the phospholipid metabolism in the activation of neutrophil respiratory burst and its inhibition by electromagnetic radiation (EMR) of extremely high frequencies (EHF) was studied. It was shown that EHF EMR has effect on cells with a high sensitivity to the inhibitor of phospholipase A2 4-bromophenacyl bromide. However, againsts the background of the inhibitor, the effect of EHF EMR was not observed on cells with either high or low sensitivity to the inhibitor. EHF EMR was also inefficient with cells pretreated with proadifen, an inhibitor of epoxygenase (cytochrome P-450). The results obtained suggest that the effect of EHF EMR manifests itself in cells with a high activity of phospholipase A2 and is realized with the participation of epoxygenase metabolites of arachidonic acid.

[Viscumin modulates neutrophil respiratory burst, caused by a chemotactic peptide]. / Viskumin moduliruet respiratornyi vzryv v neitrofilakh, vyzvannyi khemotaksicheskim peptidom.

The ability of viscum at different concentrations to modulate the respiratory burst in neutrophils, induced by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine was studied. This does not exclude the possibility that viscum can interact with the receptor of this peptide. The analysis of the primary structure of viscum revealed elements structurally analogous to the chemotactic peptide. It is assumed that viscum can exhibit the properties an antagonist of the receptor of N-formyl-methionyl-leucyl-phenylalanine, and the mechanism of action of viscum depends on its concentration.