The cytoskeleton is formed by a network of protein filaments, including microtubules, actin filaments and intermediate filaments. Filaments permeate the entire cytoplasm; they are involved in maintaining the cell shape, they organize and anchor the organelles, they control the transport of various molecules, cell division and provide signal transduction. To implement these diverse and complex functions, the components of the cytoskeleton must be very dynamic and mobile, be able to rebuilt quickly and interact with each other. This is due to the presence of a large number of actin-binding proteins – nucleators, activators, inactivators of polymerization and depolymerization of actin filaments. This review describes the regulation of actin dynamics by the Arp2/3 complex. In the cell, this complex is in an inactive state. Its activation occurs after the interaction with activators. Activators change the conformation and spatial arrangement of the domains of the Arp2/3 complex, providing its interaction with monomeric and polymeric actin.
Activators of the Arp2/3-complex have been known for a long time and include such proteins as WASp and WAVE. All activators possess a specific VCA domain, which is responsible for their binding to the Arp2/3 complex. The structure of the complex with bound activators has been studied using various physico-chemical methods. The inactivators of the complex only recently attracted specific attention of the investigators. At present, at least five different proteins are known to inactivate the Arp2/3 complex by binding to its various subunits. Examples of inactivators are coronin, Gmf and arpin. The structure of the Arp2/3 complex with inactivators was recently published and showed that despite their binding to different subunits of the complex, all inactivators transform the Arp2/3 complex into an “open” state, moving the actin-like Arp subunits
apart from each other. Studies of the spatial organization of actin-binding proteins are necessary for understanding the patterns of interaction between them while providing the vital activity of the cell. These data can later be used in the search for new ligands to prevent metastasis of tumor cells.

Exogenous ribonuclease of bacilli can selectively induce apoptosis of malignant cells. The analysis of the ability of Bacillus pumilus ribonuclease – binase – to induce processes, which lead to a dynamic disruption of the integrity of A549 human adenocarcinoma cell membranes, was performed. The influence of different enzyme concentrations on the state of the cytoplasmic membrane of cells and mitochondrial membranes was characterized. Using the methods of flow cytometry and fluorescence microscopy, it has been established that binase leads to normal functioning disruption of both types of membranes, with mitochondrial membranes affected first.
The study allowed to identify and visualize the effects of binase on the membrane structures of target cells and to confirm that bacterial RNase induces apoptosis of target cells mainly through the “internal” (mitochondrial) pathway.

Multipotent mesenchymal stromal cells (MSCs) are stromal precursors with capacity to differentiate in osteo-, adipo-, and chondrodirections, participate in repair, regeneration and immune response. Those abilities, especially immunosuppression, make MSCs a perspective tool for cell therapy and regenerative medicine. Short-term hypoxic stress can occur in damaged tissues and negatively affect MSC capacities to modulate functions of activated peripheral blood mononuclear cells (PBMCs). In present paper, the impact of short-term hypoxic stress (<1% of oxygen) on immunosuppressive potential of tissue oxygen (5%) adapted MSCs was evaluated. At tissue oxygen level, we detected an increase of the ratio of innate immune cells (natural killers, NK) and a decrease of the ratio of adaptive immune cells (HLA-DR+ Т-cells) within floating PBMCs in the presence of MSCs. Additionally, inhibition of T-cell proliferation was observed.
Within adhered PBMCs the ratio of monocytes was higher and the ratio of NK-T-cells was lower.
Short-term hypoxic stress did not affect MSC immunosuppression toward lymphocytes in suspension.
Nevertheless, a decrease of percent of monocytes and NK-T-cells within adhered PBMCs was detected. Thus, hypoxic stress did not influence immunosuppressive activity of MSCs toward floating PBMCs. Attenuation of monocyte adhesion to MSCs upon cell-to-cell interaction may negatively impact on development of MSC-educated macrophages phenotype with anti-inflammatory activity. In vivo it may provoke slowdown of “response to injury” during inflammation.

Non-transcribed spacers (NTS) of 5S rDNA are often polymorphic in closely related species and even in the same genome. The polymorphism of 5S rDNA NTS was shown between genomes St, J and V of Triticeae species Thinopyrum bessarabicum, Pseudoroegneria spicata, and Dasypyrum villosum, respectively. A molecular genetic marker was designed based on the 5S rDNA NTS polymorphism that allows identification of the St, J and V genomes. We designed a pair of primers that correspond to the conserved regions of 5S rDNA NTS between the genomes studied. The PCR amplicon length is 158 bp for V, 171 bp for St and 172 bp for J genome. The fragment of St genome is characterized by SmiM I restriction site that enables its differentiation from J genome fragment that lacks this site. The developed marker showed its efficiency for verification of germplasm accessions and the study of allopolyploids.

Photocurable hydrogels were fabricated from methacrylated gelatin and silk proteins, including recombinant analogue of spidroin from Nephila clavipes spider web and fibroin from the cocoons of the silkworm Bombyx mori. These polymers have high applicability in tissue engineering due to their biocompatibility and biodegradability. Hydrogels were fabricated using two different methods that allowed us to obtain either large-sized products or microstructures of certain shape.
For the production of extensive hydrogels, samples were photopolymerized in the UV light within ten minutes. As a result samples of hydrogels were obtained as disks with a diameter of 13 mm.
Scanning electron microscopy confirmed their porous structure. Microstructures were formed on coverslips using confocal microscope Eclipse Ti-E with 405 nm laser. This approach gives us an opportunity to control the topographic features of the obtained substrates and is applicable for creating micropatterns for studying the interaction of cells with a substrate.

The study of the cell wall structure was performed for 10 species of Euastrum – E. ansatum (Ehrenb.) Ralfs, E. bidentatum Näg., E. binale (Turp.) Ehrenb. ex Ralfs, E. dubium Näg., E. elegans (Bréb.) Kütz. ex Ralfs, E. germanicum (Schmidle) W. Krieger, E. oblongum (Grev.) Ralfs ex Ralfs, E. pectinatum Bréb. ex Bréb. in Ralfs, E. validum West et G.S.West, E. verrucosum (Ehrenb.) ex Ralfs. The investigation of the cell wall ultrastructure has established, for the first time, that the pore canal in 6 of 10 species always has to some degree coiled form. Three species (E. germanicum, E. pectinatum и E. verrucosum) have both coiled and straight canals, and E. ansatum – only straight ones. Also new type of pores (P7), typical only for representatives of the genus Euastrum, was noted. Besides, simple and effective method of preparing desmidium algal cells for investigation with transmission electron microscope has been developed.

In Moscow Oblast Thorea hispida (Thore) Desv. was first time recorded at the beginning of the 20th century. Subsequently T. hispida was found in the Moskva River within the territory of Moscow City in 2004 where it still occurs. This species is included in the Red List of Russia, the Red List of Moscow Oblast and in the Red Lists of some European countries. In this paper authors present new data on the distribution of T. hispida in the Moskva River and discuss some problems concerning the morphology and conservation status of this species.

The purpose of this work was to investigate the sorbents on the basis of polyethylenimine (PEI) intended for collecting biomass of microalgae (MA). For this purpose, a series of porous and insoluble polymeric materials were synthesized by cross-linking of PEI with epichlorohydrine.
The analysis of kinetics and efficiency of immobilization assessed for the model culture Chlorella vulgaris, revealed that already within 3 h of incubation, 39–75% of MA cells attached to the surface of tested sorbents. It was shown that on the initial stage of immobilization the sorption activity of polymeric materials depended on the “PEI:crosslinker” ratio. One of the tested sorbents was additionally quartenized by alkylation with dimethyl sulphate resulting in sharp increase of its sorption activity. The estimation of the MA desorption from polymeric surface showed that most Ch. vulgaris cells were practically irreversibly immobilized on all tested sorbents based on the PEI cross-linked with epichlorohydrine.

Proteolytic activity of extracellular enzymes of 11 strains of different Aspergillus species was studied. Comparison of the enzymatic indices of strains grown on agar medium with casein and fibrin allowed us to select the strain A. terreus 2 as a promising producer of fibrinolytic proteases.
It was found that A. terreus 2 proteases show maximum activity at pH 8.0. The highest values of fibrinolytic and total proteolytic activities expressed in UTyr (amount of micromoles of tyrosine released from fibrin or casein for 1 min) were 34.0 and 358.3, respectively. Maximums of activity were detected with when growing the producer on a medium containing only amine nitrogen sources (fish flour hydrolysate and peptone), however, the amount of extracellular protein and the specific fibrinolytic and total proteolytic activity were greater in the medium containing both mineral and amine nitrogen sources (fish flour hydrolysate and sodium nitrate), rather than on a medium containing fish flour hydrolysate and peptone as nitrogen sources.

Diadenosine tetraphosphate (Ap4A) belongs to a wide group of naturally-derived endogenous purine compounds that have been recently considered as new neurotransmitters in autonomic nervous system. It has been shown that Ap4A induces inhibitory effects and modulate adrenergic control in the heart of adult mammals. Nevertheless, the physiological significance of Ap4A in early postnatal development, when sympathetic innervation remains yet immature, has
not been investigated. The aim of the present study was to elucidate the effects Ap4A on heart bioelectrical activity in early postnatal ontogenesis. Action potentials (AP) were recorded with use of standard microelectrode technique in multicellular isolated right atrial (RA), left atrial (LA) and ventricle (RV) preparations from male Wistar rats at postnatal day 1, 14, 21 and, also, from 60-day animals which were considered as adult. The application of Ap4A caused significant reduction of AP duration in atrial (RA and LA) preparations from rats of all ages. Also, Ap4A caused significant AP shortening in RV preparations from rats of various ages, however, the effect was more pronounced in 21-day and adult rats. Ap4A failed to alter automaticity of RA preparations from rats at postnatal day 1, 14, 21 and weakly decreased spontaneous rhythm in RA preparations from the adult rats. The effect of Ap4A was partially abolished by P2-receptor blocker PPADS in LA preparations from both 21 day and adult rats, while failed to suppress Ap4Acaused AP shortening in preparations from 1- and 14-day animals. Thus, extracellular Ap4A causes shortening of AP both in the atrial and ventricular myocardium in early postnatal ontogenesis and adult rats. The effect of Ap4A depends on age only in ventricular myocardium where it may be attributed with growing contribution of diadenosine polyphosphates to the control of myocardium inotropy.