Vol 3, No 4 (2011)


Letter from the Editors

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Acta Naturae. 2011;3(4):1-1
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A Statistical Analysis of Competitive Research Contracting in the Field of Life Sciences

Poverennaya E.V., Lisitsa A.V., Petrov A.N., Makarov A.A., Luzgina N.G.
Acta Naturae. 2011;3(4):6-11
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Escort Aptamers: New Tools for the TargetedDelivery of Therapeutics into Cells

Davydova A.S., Vorobjeva M.A., Venyaminova A.G.


Escort aptamers are DNA or RNA sequences with high affinity to certain cell-surface proteins, which can be used for targeted delivery of various agents into cells of a definite type. The peculiarities of the selection of escort aptamers are discussed in this review. The methods used in selection of escort aptamers via the SELEX technique are considered, including selection against isolated cell-surface proteins, cell fragments, living eukaryotic cells, and bacteria. Particular attention is given to the design and chemical modification of escort aptamers. The different fields of application of escort aptamers are described, including the targeted delivery of siRNAs, nanoparticles, toxins, and photoagents, as well as the identification of specific cell markers and the detection or isolation of cells of a definite type. The potential for the application of escort aptamers in the development of new therapeutic agents and diagnostic systems is also discussed.
Acta Naturae. 2011;3(4):12-29
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Mesenchymal Stem Cells in Tissue Growth and Repair

Kalinina N.I., Sysoeva V.Y., Rubina K.A., Parfenova Y.V., Tkachuk V.A.


It has been established in the recent several decades that stem cells play a crucial role in tissue renewal and regeneration. Mesenchymal stem cells (MSCs) are part of the most important population of adult stem cells.bentley replica kits These cells have hereby been identified for the very first time and subsequently isolated from bone marrow stroma. Bone marrow-derived MSCs have been believed to play the role of a source of cells for the renewal and repair of connective tissues, including bone, cartilage and adipose tissues. Cells similar to bone marrow-derived MSCs have now been identified in all postnatal tissues. Data on rolex replica watch the distribution and function of MSCs in vivo collected using novel approaches pertaining to the identification of MSCs in situ, to their isolation from tissues, and finally to the determination of their biological properties have enabled successful revision of the role of MSCs in various organs and tissues. This review summarizes our own, as well as others’, data concerning the role of MSCs in the regulation processes of tissue repair and regeneration. In our opinion, MSCs provide the connection between the blood-vascular, immune, endocrine, repair rolex replica and nervous systems and tissue-specific stem cells in the body.
Acta Naturae. 2011;3(4):30-37
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NAD+-dependent Formate Dehydrogenase from Plants

Alekseeva A.A., Savin S.S., Tishkov V.I.


NAD +-dependent formate dehydrogenase (FDH, EC widely occurs in nature. FDH consists of two identical subunits and contains neither prosthetic groups nor metal ions. This type of FDH was found in different microorganisms (including pathogenic ones), such as bacteria, yeasts, fungi, and plants. As opposed to microbiological FDHs functioning in cytoplasm, plant FDHs localize in mitochondria. Formate dehydrogenase activity was first discovered as early as in 1921 in plant; however, until the past decade FDHs from plants had been considerably less studied than the enzymes from microorganisms. This review summarizes the recent results on studying the physiological role, properties, structure, and protein engineering of plant formate dehydrogenases.
Acta Naturae. 2011;3(4):38-54
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Screening of Potential HIV-1 Inhibitors/ Replication Blockers Using Secure Lentiviral in Vitro System

Prokofjeva M.M., Spirin P.V., Yanvarev D.V., Ivanov A.V., Novikov M.S., Stepanov O.A., Gottikh M.B., Kochetkov S.N., Fehse B., Stocking C., Prassolov V.S.


The development and usage of safe cell systems for testing agents which possess anti-HIV activity is a very important factor in the design of new drugs. We have described in detail a system we designed that is based on lentiviral vectors (Prokofjeva et. al., Antiviral Therapy, in print) for swift and completely safe screening of potential HIV-1 replication inhibitors. The system enables one to test the efficiency of the inhibitory activity of compounds whose action is directed towards either wild-type HIV-1 reverse transcriptase or integrase, or mutant enzymes corresponding to the drug-resistant virus form. Testing results of a number of already known drugs, which correlate well with published data as well as data on newly synthesized compounds, were obtained. Application of this system substantially broadens the possibilities of preclinical anti-HIV drugs testing
Acta Naturae. 2011;3(4):55-65
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Behavior of Transplanted Multipotent Cells after in Vitro Transplantation into the Damaged Retina

Sergeev S.A., Khramova Y.V., Semenova M.L., Saburina I.N., Kosheleva N.V.


The use of stem cell technologies in retinal defect reparation therapy has produced beneficial results. Nowadays, numerous protocols exist which provide a neural differentiation of the stem cells transplanted into the retina. However, questions concerning the functional replacement of the missing retinal neurons by transplanted cells thus far remain unanswered. The organotypic culture protocol was used in this study in order to prove the possibility of transdifferentiation of bone marrow stromal cells (MMSCs) and neural stem/progenitor cells (NSPCs) from EGFP-positive mice and the functional integration of these cells. This technique enables a detailed characterization of cell behavior post-transplantation. Using atomic force microscopy, we reliably demonstrated the difference (p < 0.01) between the thickness of the outgrowths formed by glial and endothelial retina cells and the thickness of neurites and neuro-like transplanted MMSC outgrowths. MMSCs are also shown to form synapses up to 2.5 ± 0.06 μm in diameter on day 4 after the transplantation. Following electrical stimulation (20V, 0.5Hz, 200ms), clear depolarization of retinal neurons and their outgrowths is detected. It is shown that some of these GFP+ MMSCs, which changed their morphology after the transplantation in retinal explants to neuro-like MMSCs, are capable of depolarizing after exogenous stimulation.
Acta Naturae. 2011;3(4):66-72
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New Viral Vector for Superproduction of Epitopes of Vaccine Proteins in Plants

Tyulkina L.G., Skurat E.V., Frolova O.Y., Komarova T.V., Karger E.M., Atabekov I.G.


The novel viral vectors PVX-CP AltMV and PVXdt-CP AltMV are superexpressors of the capsid protein (CP). These viral vectors were constructed on the basis of the potato virus X (PVX) genome and Alternanthera mosaic virus (AltMV) CP gene. The expression, based on the hybrid viral vectors, is genetically safe, since the systemic transport and formation of infective viral particles are blocked. CP AltMV can self-assemble into virus-like particles (VLPs) in the absence of genomic RNA. The vectors can be used for the presentation of foreign peptides (including epitopes of human pathogens) on the surface of the VLP. The N-terminal extracellular domain (M2e) of the influenza virus A M2 protein and its truncated variant (ΔM2e) were used as model heterologous peptides for the construction of the chimeric CP AltMV. Chimeric CP AltMV retains its ability to self-assemble into VLP. The epitopes of the M2 influenza virus protein were not eliminated during the process of accumulation, polymerization and purification of chimeric VLP AltMV, providing evidence of the stability of chimeric VLP with C-terminal heterologous epitopes. It appears that VLP produced by the vectors PVX-CP AltMV and PVXdt-CP AltMV can be used in the field of biotechnology for the presentation of the epitopes of vaccine proteins on their surfaces. The chimeric VLP AltMV with the presented foreign epitopes can be used as candidate vaccines.
Acta Naturae. 2011;3(4):73-82
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Triggering of Toll-like Receptor-2 in Mouse Myelomonocytic Leukaemia Cells WEHI-3B Leads to the Suppression of Apoptosis and Promotes Tumor Progression in Vivo

Shcheblyakov D.V., Logunov D.Y., Rakovskaya I.V., Shmarov M.M., Naroditsky B.S., Ginzburg A.L.


Toll-like receptors are the essential components of innate immunity. It is shown that TLRs play an essential role in the immune resistance of an organism to bacterial and viral infections. The binding of TLR to its own ligands results in the activation of several adapter molecules and kinases, inducing the activation of the main pro-inflammatory transcriptional factors, which in turn induce the activation of the main pro-inflammatory transcriptional factors. This activation results in the development of both the innate immune response triggered by the enhanced expression of a number of pro-inflammatory cytokines and antimicrobial peptides and that of the adaptive immune response, via the activation of dendritic cells and enhancement of antigen presentation, etc. The ability of TLR agonists to bolster the immune reaction makes them promising for use in the therapy of infectious diseases and in the chemotherapy of malignant neoformations. However, different TLR ligands may have either antitumor activity (lipopolysaccharide, imiquimod, CpG) or, conversely, could beef up the resistance of tumor cells to apoptosis, stimulating their proliferation under certain conditions (lipopolysaccharide, lipopeptide). It has been shown that the TLR2-dependent signalling pathway in the myelomonocytic mouse leukaemia cell line WEHI-3B leads to the constitutive activation of the transcriptional factor NF-kB, suppression of apoptosis in tumor cells, and progression of myelomonocytic mouse leukaemia in vivo, upon the addition of TLR2 agonist (synthetic lipopeptide Pam2CSK4) or following the infection of tumor cells with Mycoplasma arginini.
Acta Naturae. 2011;3(4):83-93
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Inhibition of DNA Gyrase by Levofloxacin and Related Fluorine-Containing Heterocyclic Compounds

Tunitskaya V.L., Khomutov A.R., Kochetkov S.N., Kotovskaya S.K., Charushin V.N.


Fluoroquinolones are an important class of modern and efficient antibacterial drugs with a broad spectrum of activity. Levofloxacin (the optically active form of ofloxacin) is one of the most promising fluoroquinolone drugs, and its antibacterial activity is substantially higher than the activity of other drugs of the fluoroquinolone family. Earlier, in the Postovsky Institute of Organic Synthesis, UB RAS, an original method of levofloxacin synthesis was developed, and now the pilot batch of the drug is being prepared. Bacterial DNA gyrase is a specific target of fluoroquinolones; hence, the study of the enzyme-drug interaction is of theoretical and practical importance. Moreover, the parameters of DNA gyrase inhibition may serve as a criterion for drug quality. Here, we present the results of studying the interaction of DNA gyrase with a number of fluoroquinolones and their analogs: intermediates and semi-products of the levofloxacin synthesis, and also samples from the pilot batches of this drug. The importance of two structural elements of the levofloxacin molecule for the efficiency of the inhibition is revealed. The data obtained may be useful for the design of new drugs derived from levofloxacin.
Acta Naturae. 2011;3(4):94-99
pages 94-99 views

The Fate of the Nucleolus during Mitosis: Comparative Analysis of Localization of Some Forms of Pre-rRNA by Fluorescent in Situ Hybridization in NIH/3T3 Mouse Fibroblasts

Shishova K.V., Zharskaya О.О., Zatsepina О.


Nucleolus is the major structural domain of the cell nucleus, which in addition to proteins contains ribosomal RNA (rRNA) at different stages of maturation (or pre-rRNA). In mammals, the onset of mitosis is accompanied by the inhibition of rRNA synthesis, nucleolus disassembly, and the migration of pre-rRNA to the cytoplasm. However, the precise role of cytoplasmic pre-rRNA in mitosis remains unclear, and no comparative analysis of its different forms at consequent mitotic stages has thus far been performed. The focus of this research was the study of the localization of pre-rRNA in mitotic NIH/3T3 mouse fibroblasts by fluorescent in situ hybridization (FISH) with probes to several regions of mouse primary 47S pre-rRNA transcripts and by confocal laser microscopy. The results reveal that all types of pre-rRNA appear in the cytoplasm at the beginning of mitosis, following the breakdown of the nucleolus and nuclear envelope. However, not all pre-rRNA are transported by chromosomes from maternal cells into daughter cells. At the end of mitosis, all types of pre-rRNA and 28S rRNA can be visualized in nucleolus-derived foci (NDF), structures containing many proteins of mature nucleoli the appearance of which indicates the commencement of nucleologenesis. However, early NDF are enriched in less processed pre-RNA, whereas late NDF contain predominantly 28S rRNA. Altogether, the results of this study strengthen the hypotheses that postulate that different forms of pre-rRNA may play various roles in mitosis, and that NDF can be involved in the maturation of pre-rRNA, remaining preserved in the cytoplasm of dividing cells.
Acta Naturae. 2011;3(4):100-106
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Effect of Sodium Chloride on Aggregation of Merocyanine 540 and Photosensitized Inactivation of Staphylococcus aureus and Pseudomonas aeruginosa

Shmigol T.A., Bekhalo V.A., Sysolyatina Е., Nagurskaya E.V., Ermolaeva S.A., Potapenko A.Y.


Merocyanine 540 (MC540) is used as a photosensitizer for the inactivation of microorganisms. The following is already known about MC540: firstly, MC540 exists in distilled water in both monomeric and dimeric forms, and the addition of salts into a MC540 solution leads to the formation of large aggregates that can be detected by the resonance light scattering technique. Secondly, singlet oxygen can only be photogenerated by MC540 monomers. In the present work, we studied the effect of MC540 in the aggregated state on the rate of photosensitized inactivation of Staphylococcus aureus and Pseudomonas aeruginosa. To this end, bacteria either in MC540-containing distilled water or in a 0.25 M sodium chloride aqueous solution also containing MC540 are irradiated (546 nm). The results show that, in the presence of salt, the aggregation of MC540 greatly increases the efficiency of the MC540-photosensitized inactivation of P. aeruginosa and S. aureus. In the presence of salt, the rates of P. aeruginosa and S. aureus inactivation increase by factors of 10 and 30, respectively, in comparison with the rate of inactivation observed in the case of distilled water. Our results suggest that a salt-induced photosensitization mechanism can switch from the singlet oxygen to the free-radical pathway.
Acta Naturae. 2011;3(4):107-113
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Deficient Response to Experimentally Induced Alkalosis in Mice with the Inactivated insrr Gene

Deyev I.E., Rzhevsky D.I., Berchatova A.A., Serova O.V., Popova N.V., Murashev A.N., Petrenko A.G.


Currently, the molecular mechanisms of the acid-base equilibrium maintenance in the body remain poorly understood. The development of alkalosis under various pathological conditions poses an immediate threat to human life. Understanding the physiological mechanisms of alkalosis compensation may stimulate the development of new therapeutic approaches and new drugs for treatment. It was previously shown that the orphan insulin receptor-related receptor (IRR) is activated by mildly alkaline media. In this study, we analyzed mutant mice with targeted inactivation of the insrr gene encoding IRR, and revealed their phenotype related to disorders of the acid-base equilibrium. Higher concentrations of bicarbonate and CO 2 were found in the blood of insrr knockout mice in response to metabolic alkalosis.
Acta Naturae. 2011;3(4):114-117
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Guidelines for Authors

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Acta Naturae. 2011;3(4):118-119
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