THE ROLE OF INTERACTIONS BETWEEN TROPHOBLASTDERIVED EXTRACELLULAR MICROVESICLES, IMMUNE CELLS AND ENDOTHELIUM IN PATHOGENESIS OF PRE-ECLAMPSIA

Pre-eclampsia is a multisystemic disease that occurs in the second half of pregnancy, being characterized by the development of hypertension and proteinuria. Pre-eclampsia is still one of the main causes of maternal and neonatal morbidity and mortality. Pre-eclampsia is believed to be a result of complex interactions between maternal and placental factors. However, the exact pathophysiology of this syndrome remains unclear. Intercellular interactions are the basis of fetoplacental development in physiological pregnancy. A special mechanism of intercellular interactions is associated with the release of membranebound extracellular microvesicles by cells. Concentration and molecular composition of extracellular vesicles in biological fluids depend on the producer cell types, as well as the stimuli that trigger their formation. The studies of extracellular vesicles in pre-eclampsia focus on the particles produced by the cells of maternal cardiovascular system (endothelium, smooth muscle cells of blood vessels), and blood (erythrocytes, leukocytes, and platelets), like as by the cells of syncytiotrophoblast. Changed concentrations and molecular composition of these extracellular vesicles can contribute to the pathophysiology of pre-eclampsia, due to increased proinflammatory and procoagulant state occurring during pregnancy. This review focuses, firstly, on characteristics of the extracellular vesicles produced by syncytiotrophoblast, and possible role of their interaction with maternal immune cells, endothelial cells and platelets in the course of developing pre-eclampsia. Understanding the role of extracellular vesicles of syncytiotrophoblast in pathogenesis of pre-eclampsia could suggest an opportunity of providing these results for early and non-invasive diagnostics of placental disorders, as well as for predicting development of this disease

Phenotypic and functional characteristics of endothelial cells: the <i>in vitro</i> effects of protein fractions from the lysate of natural killer-derived microvesicles

Microvesicles are membrane-derived formations ranging in size from 100 to 1000 nm, being produced by a variety of resting and activated cells. They can transfer their cargo to target cells, regulate physiological processes, and participate in the development of clinical disorders. Among the microvesicles of different origin, natural killers are of special interest. They represent a subpopulation of lymphocytes that eliminate aberrant cells, including virally infected and malignant cells, and participate in regulation of angiogenesis. By producing various stimuli and inhibitors of the latter process, natural killers are able to change functional activity of endothelial cells by means of microvesicle-mediated contacts. There are only scarce literature data on ability of the extracellular vesicles to influence endothelial functions, depending on the intrinsic balance of pro- and anti-angiogenic factors. Therefore, the aim of our study was to evaluate the effect of protein fractions derived from microvesicle lysate of the NK-92 natural killer cell line upon phenotype and functional characteristics of EA.hy926 endothelial cell line under in vitro experimental conditions. Using chromatographic micro-preparatory separation, twelve protein fractions (inducers) were obtained from the lysate. It was found that proliferation and migration of EA.hy926 cells after their cultivation with 10 of 12 protein fractions, were changed in different directions. These effects were dose-dependent, or remained unchanged, at distinct concentrations of active components in the fractions. The inducing factors from these fractions exerted predominantly stimulating effects on proliferation of the target cells, thus suggesting presence of proteins which are able of regulating endothelial functions. However, the size of residual area free of migrating endothelial cells treated by the inducers did not always correlate with the migration intensity and did not inversely correlate with the number of migrating cells. Moreover, it was found that the obtained protein fractions had no effect upon expression of CD54 (ICAM-1), CD34, CD31 (PECAM-1) and CD119 (IFNγR1) receptors by EA.hy926 cells. The data obtained confirm an involvement of microvesicles in communications between natural killer cells and endothelial cells, and presume different participation modes of microvesicle-derived effector proteins in the angiogenesis machinery

Importance of c-Type cytochromes for U(VI) reduction by Geobacter sulfurreducens

BACKGROUND: In order to study the mechanism of U(VI) reduction, the effect of deleting c-type cytochrome genes on the capacity of Geobacter sulfurreducens to reduce U(VI) with acetate serving as the electron donor was investigated. RESULTS: The ability of several c-type cytochrome deficient mutants to reduce U(VI) was lower than that of the wild type strain. Elimination of two confirmed outer membrane cytochromes and two putative outer membrane cytochromes significantly decreased (ca. 50–60%) the ability of G. sulfurreducens to reduce U(VI). Involvement in U(VI) reduction did not appear to be a general property of outer membrane cytochromes, as elimination of two other confirmed outer membrane cytochromes, OmcB and OmcC, had very little impact on U(VI) reduction. Among the periplasmic cytochromes, only MacA, proposed to transfer electrons from the inner membrane to the periplasm, appeared to play a significant role in U(VI) reduction. A subpopulation of both wild type and U(VI) reduction-impaired cells, 24–30%, accumulated amorphous uranium in the periplasm. Comparison of uranium-accumulating cells demonstrated a similar amount of periplasmic uranium accumulation in U(VI) reduction-impaired and wild type G. sulfurreducens. Assessment of the ability of the various suspensions to reduce Fe(III) revealed no correlation between the impact of cytochrome deletion on U(VI) reduction and reduction of Fe(III) hydroxide and chelated Fe(III). CONCLUSION: This study indicates that c-type cytochromes are involved in U(VI) reduction by Geobacter sulfurreducens. The data provide new evidence for extracellular uranium reduction by G. sulfurreducens but do not rule out the possibility of periplasmic uranium reduction. Occurrence of U(VI) reduction at the cell surface is supported by the significant impact of elimination of outer membrane cytochromes on U(VI) reduction and the lack of correlation between periplasmic uranium accumulation and the capacity for uranium reduction. Periplasmic uranium accumulation may reflect the ability of uranium to penetrate the outer membrane rather than the occurrence of enzymatic U(VI) reduction. Elimination of cytochromes rarely had a similar impact on both Fe(III) and U(VI) reduction, suggesting that there are differences in the routes of electron transfer to U(VI) and Fe(III). Further studies are required to clarify the pathways leading to U(VI) reduction in G. sulfurreducens

Анализ методов электронной компенсации опорного сигнала в целевом канале полуактивного когерентного бистатического DVB-T2 радара

This paper provides an overview of different electronic compensation methods of a reference signal. An algorithm for electronic compensation of the DVB-T2 direct signal in a semi-active coherent radar has been proposed. A filter that provides direct signal suppression of at least 50 dB has been developed. The results of experimental studies on the detection of low-speed target with low effective scattering surface in the presence of a powerful reference signal have been presented.В статье проанализированы различные методы электронной компенсации опорного сигнала в целевом канале. Предложен алгоритм электронной компенсации прямого сигнала DVB-T2 в полуактивном когерентном радаре. Разработан фильтр, обеспечивающий подавление прямого сигнала не менее 50 дБ. Представлены результаты экспериментальных исследований по обнаружению низкоскоростной цели с малой эффективной поверхностью рассеяния при наличии мощного опорного сигнала

MALDI-TOF mass spectrometric protein profiling of microvesicles produced by the NK-92 natural killer cell line

Extracellular vesicles that are shed from the plasma membrane contain a wide range of molecules, among  which  are proteins, lipids, nucleic  acids,  and sugars. The cytotoxic proteins of natural killer cells play a key role in the implementation of their cytolytic  functions. One of the important steps in understanding the distant  communication of cells is the determination of the proteome of microvesicles. This study was aimed at the protein profiling of the microvesicles produced by the NK-92 natural killer cell line. 986 proteins with a variety of functions were identified in the lysate of microvesicles using the MALDI-TOF mass spectrometric analysis.  With automated methods of functional analysis  applied, it has been  shown  that  the  largest  protein groups  are  hypothetical proteins, proteins with  unknown functions, and  domains. The  most  representative groups  are  also  comprised by  transcription  regulators; intracellular  signaling  proteins; RNA  translation, transcription, processing, and utilization regulators; receptors; protein processing  and proteolysis regulators; amino acid metabolism enzymes, as well as transport proteins and transport regulators. Minor functional groups are represented by vitamins and mineral metabolism enzymes, membrane and microdomain-forming proteins, hormones, hemostatic regulators, regulators of sensory  systems,  specific  mitochondrial and  Golgi  apparatus proteins, and extracellular signaling proteins. An intermediate position is occupied by various functional groups, including cytoskeleton and motor proteins; proteins of centrioles; ion channels and their regulators; proteins of the ubiquitin-proteasome pathway  of protein degradation; lipid,  steroid, and fatty acid metabolism enzymes; nucleic  acid  base and  carbohydrate metabolism enzymes, as well as energy  metabolism enzymes  and  other proteins involved  in intermediate metabolism; proteins of the immune response  and  inflammation; antigens and histocompatibility proteins; cytokines and growth factors; regulators of apoptosis, autophagy, endocytosis, and  exocytosis;  regulators of the  cell cycle and  division;  regulators of proliferation, cell differentiation, and morphogenesis; regulators of cell adhesion and  matrix  metabolism; nuclear transport proteins; transposition proteins; DNA  replication and  repair  proteins, as well as inactive  proteins. The  data  obtained expand  the existing knowledge of the distant  communication of cells and indicate new mechanisms of interaction between natural killer and target cells

ИЗМЕРИТЕЛЬНЫЙ КОМПЛЕКС ТРЕХМИЛЛИМЕТРОВОГО ДИАПАЗОНА ДЛИН ВОЛН

The problems of development as well as methods of construction of measuring devices of 3-mm wavelength range are examined, which allow to provide high degree of accuracy of frequency and power of an input signal measurement. The opportunity and expediency of using the frequency synthesizers, sub-harmonic mixers in heterodyne channel, and logarithmic amplifiers in modulation receiver are shown. The experimental parameters are shown as well as characteristics and parameters of major units of measuring device.Рассмотрены проблемы создания и методы построения измерительных комплексов трехмиллиметрового диапазона длин волн, позволяющих обеспечить высокую точность измерения частоты и мощности входного сигнала. Показана возможность и целесообразность использования синтезаторов частот в гетеродинном тракте субгармонических смесителей и логарифмических усилителей в модуляционном приемнике. Приведены экспериментальные параметры и характеристики основных узлов измерительного комплекса и его параметры

СИНТЕЗАТОР ШИРОКОПОЛОСНЫХ СИГНАЛОВ, СФОРМИРОВАННЫХ МЕТОДОМ ПРЯМОГО ЦИФРОВОГО СИНТЕЗА

Development and experimental studies of the generator of wideband signals were conducted by the method of direct digital synthesis. Generator allows for the correction of phasefrequency characteristics of the formed broadband signal. The level of spurious radiation was investigated at the output of the frequency mixer in the transfer of the signal spectrum in the band of UHF.Проведены разработка и экспериментальные исследования формирователя широкополосных сигналов методом прямого цифрового синтеза. Формирователь позволяет обеспечивать коррекцию фазо-частотных характеристик формируемого широкополосного сигнала. Исследован уровень побочных излучений на выходе смесителя сдвига при переносе спектра сигнала в диапазон СВЧ

MALDI-TOF mass spectrometric protein profiling of THP-1 cells and their microvesicles

Extracellular vesicles that are shed from the plasma membranes take an active part in intercellular communication, transporting a wide range of molecules, including proteins, lipids, nucleic acids and carbohydrates, being of great functional importance. One of the steps to better understanding of distant communications of cells and their regulatory mechanisms is a proteomic study of various extracellular vesicles, including microvesicles and exosomes. Pro-inflammatory cytokines produced by monocytes and individual complement system components play a key role in their specific functioning. The aim of this work was to study proteomic composition of THP-1 monocyte-like cells and their microvesicles. The MALDI-mass spectrometric analysis of electrophoretic protein fractions of cell lysates and microvesicles allowed for identifying 107 proteins that perform various functions. Among 19 determined functional groups, the largest ones comprise transcription regulators and proteins with unknown functions. The smallest functional groups include regulators of cell differentiation and development, proteins participating in immune response and inflammation, cellular receptors and their regulators, transporter and transport regulatory proteins, as well as cell proteins mediating adhesion and matrix structures, processing regulators, proteins of ubiquitin-proteasome system, intracellular signaling, autophagy and exocytosis regulators, chromatin structural proteins, hemostatic regulators, and peptide hormones. An intermediate position is occupied by cytokines and growth factors, enzymes, cytoskeleton and motor proteins, as well as RNA processing and translation regulators. The subsequent DAVID Functional Annotation Clustering analysis allowed for identifying the most common groups distributed by their molecular function, biological processes, and cellular component. Separately, in the microvesicles derived from THP-1 monocyte-like cells, proteins of the immune response and inflammation, cytokines and growth factors, intracellular signaling proteins, cell differentiation regulators and developmental proteins, as well as cell adhesion and matrix proteins were identified among other protein molecules. The data obtained on the partial proteome of THP-1 monocyte-like cells and their microvesicles extend the existing knowledge on distant communications between the cells and suggest new mechanisms of interaction between monocytes/macrophages and their microenvironment

ПРИБОР ДЛЯ ИЗМЕРЕНИЯ ПАРАМЕРОВ ВРЕМЕННОГО РАССЕИВАНИЯ РАДИОВОЛН МИЛЛИМЕТРОВОГО ДИАПАЗОНА ПРИ МНОГОЛУЧЕВОМ РАСПРОСТРАНЕНИИ

Possibility of temporal characteristics of scattered radiosignals under multipath propagation was analyzed. A scheme of millimeter-length radiowaves transceiver was presented. The feasibility of “window” function using for processing of received signal was shown based on the modelling of the measuring system operation.Рассмотрена возможность измерения временного рассеивания при многолучевом распространении сигналов. Приведена схема построения приемо-передающего устройства миллиметрового диапазона длин волн. Моделирование работы измерительного комплекса показало целесообразность использования оконных функций при обработке принятого сигнала

СИНТЕЗАТОР СВЧ С ПРЯМЫМ ЦИФРОВЫМ СИНТЕЗОМ

A synthesizer of frequencies with direct digital synthesis and a frequency multiplier on PLL are developed. Phase noises of an output signal of the synthesizer, noise of a loop of PLL, level of collateral radiations on outputs of the digital synthesizer (frequency of 100 MHz) and the frequency multiplier output on a loop of PLL (frequency of 8 GHz) are probed.Разработан синтезатор частот с прямым цифровым синтезом и умножителем частоты на петле фазовой автоподстройки частоты (ФАПЧ). Исследованы фазовые шумы выходного сигнала синтезатора, шумы петли ФАПЧ, уровень побочных излучений на выходах цифрового синтезатора (частота 100 МГц) и выходе умножителя частоты на петле ФАПЧ (частота 8 ГГц)