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Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico
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Осолодкин Дмитрий Иванович
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Phytochemistry |
|
|
Biological effects of hormones in both plants and animals are based on high-affinity interaction with cognate receptors resulting in their activation. The signal of cytokinins, classical plant hormones, is perceived in Arabidopsis by three homologous membrane receptors: AHK2, AHK3, and CRE1/AHK4. To study the cytokinin-receptor interaction, we used 25 derivatives of potent cytokinin N6-benzyladenine (BA) with substituents in the purine heterocycle and/or in the side chain. The study was focused primarily on individual cytokinin receptors from Arabidopsis. The main in planta assay system was based on Arabidopsis double mutants retaining only one isoform of cytokinin receptors and harboring cytokinin-sensitive reporter gene. Classical cytokinin biotest with Amaranthus seedlings was used as an additional biotest. In parallel, the binding of ligands to individual cytokinin receptors was assessed in the in vitro test system. Quantitative comparison of results of different assays confirmed the partial similarity of ligand-binding properties of receptor isoforms. Substituents at positions 8 and 9 of adenine moiety, elongated linker up to 4 methylene units, and replacement of N6 by sulfur or oxygen have resulted in the suppression of cytokinin activity of the derivative toward all receptors. Introduction of a halogen into position 2 of adenine moiety, on the contrary, often increased the ligand activity, especially toward AHK3. Features both common and distinctive of cytokinin receptors in Arabidopsis and Amaranthus were revealed, highlighting species specificity of the cytokinin perception apparatus. Correlations between the extent to which a compound binds to a receptor in vitro and its ability to activate the same receptor in planta were evaluated for each AHK protein. Interaction patterns between individual receptors and ligands were rationalized by structure analysis and molecular docking in sensory modules of AHK receptors. The best correlation between docking scores and specific binding was observed for AHK3. In addition, receptor-specific ligands have been discovered with unique properties to predominantly activate or block distinct cytokinin receptors. These ligands are promising for practical application and as molecular tools in the study of the cytokinin perception by plant cells.
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тезис
Публикация |
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Experts’ opinion about the primary headache diagnostic criteria of the ICHD-3rd edition beta in children and adolescents
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Сергеев Алексей Владимирович
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Journal of Headache and Pain |
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BACKGROUND:
The 2013 International Classification of Headache Disorders-3 (ICHD-3) was published in a beta version to allow the clinicians to confirm the validity of the criteria or to suggest improvements based on field studies. The aim of this work was to review the Primary Headache Disorders Section of ICHD-3 beta data on children and adolescents (age 0-18 years), and to suggest changes, additions, and amendments.
METHODS:
Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the literature available on pediatric headache, they made observations and proposed suggestions for the primary headache disorders section of ICHD-3 beta data on children and adolescents.
RESULTS:
Some headache disorders in children have specific features which are different from those seen in adults and which should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psycho-social basis in children and adolescents making primary headache disorders in children distinct from those in adults.
CONCLUSIONS:
Several recommendations are presented in order to make ICHD-3 more appropriate for use with children.
Читать
тезис
Публикация |
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Molecular and clinical aspects of embryotoxicity induced by acetylcholinesterase inhibitors
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Бурыкина Татьяна Ивановна
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Toxicology |
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Acetylcholinesterase inhibitors are widely used for a variety of medical, agricultural and public health purposes. Consequently, exposure is highly possible during lifetime. However, their systematic use raises concerns for the potential impact on the fetus and newborn since these substances may affect angiogenesis, the neonatal and maternal intensive care, neuroimmune function and response, mammary growth/lactation via cholinergic/non-cholinergic central and peripheral neuroendocrine pathways. New methodologies, neuroscientific technologies and research studies are needed to harness existing knowledge along with the proper management, availability for new acetylcholinesterase inhibitors, with stable pharmacodynamics and clinical outcomes.
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тезис
Публикация |
|
A novel lipopeptaibol emericellipsin a with antimicrobial and antitumor activity produced by the extremophilic fungus emericellopsis alkalina
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Андреев Ярослав Алексеевич
Люндуп Алексей Валерьевич
Крашенинников Михаил Евгеньевич
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Molecules |
|
|
Soil fungi are known to contain a rich variety of defense metabolites that allow them to compete with other organisms (fungi, bacteria, nematodes, and insects) and help them occupy more preferential areas at the expense of effective antagonism. These compounds possess antibiotic activity towards a wide range of other microbes, particularly fungi that belong to different taxonomical units. These compounds include peptaibols, which are non-ribosomal synthesized polypeptides containing non-standard amino acid residues (alpha-aminoisobutyric acid mandatory) and some posttranslational modifications. We isolated a novel antibiotic peptide from the culture medium of Emericellopsis alkalina, an alkalophilic strain. This peptide, called emericellipsin A, exhibited a strong antifungal effect against the yeast Candida albicans, the mold fungus Aspergillus niger, and human pathogen clinical isolates. It also exhibited antimicrobial activity against some Gram-positive and Gram-negative bacteria. Additionally, emericellipsin A showed a significant cytotoxic effect and was highly active against Hep G2 and HeLa tumor cell lines. We used NMR spectroscopy to reveal that this peptaibol is nine amino acid residues long and contains non-standard amino acids. The mode of molecular action of emericellipsin A is most likely associated with its effects on the membranes of cells. Emericellipsin A is rather short peptaibol and could be useful for the development of antifungal, antibacterial, or anti-tumor remedies. View Full-Text
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тезис
Публикация |
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How regularities of mortality statistics explain why we age despite having potentially ageless somatic stem cells
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Крутько Вячеслав Николаевич
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Biogerontology |
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Researchers working in the area of ageing have found numerous manifestations of this process at the molecular biological level, including DNA and protein damage, accumulation of metabolic by-products, lipids peroxidation, macromolecular cross-linking, non-enzymatic glycosylation, anti-oxidant/pro-oxidant misbalance, rising of pro-inflammatory cytokines, etc. This results in an increase in the proportion of cells in growth arrest, reduction of the rate of information processing, metabolic rate decrease, and decrease in rates of other processes characterizing dynamic aspects of the organism’s interaction with its environment. Such staggering multilevel diversity in manifestation of senescence precludes (without methodology of systems biology) development of a correct understanding of its primary causes and does not allow for developing approaches capable of postponing ageing or reducing organisms’ ageing rate to attain health preservation. Moreover, it turns out that damage production and damage elimination processes, the misbalance of which results in the ageing process, can to a large extent be regulated by external signals. The purpose of this report is to provide evidence supporting this view and its compatibility with the regularities of mortality statistics, because the main idea is very simple. Even potentially a non-senescent but certainly not immortal body must start to age under inadequate conditions (like a non-melting piece of ice taken out from the deepfreeze inevitably start to melt at the temperatures above zero Celsius). This conclusion is totally consistent with existing patterns of mortality and with agelessness potential of somatic stem cells. Therefore, there is no need to build up and explore too complicated, computational and sophisticated systems models of intrinsic ageing to understand the origin of this mainly extrinsic root cause of natural ageing, which is controlled by environmental signals. In our case, a simple phenomenological black-box approach with Input–Output analysis is ample. Here Input refers to the environmentally dependent initial force of mortality, whereas Output is a rate of age-related increase of mortality force.
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тезис
Публикация |
|
Peroxidase Activity of Human Hemoproteins: Keeping the Fire under Control
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Власова Ирина Ивановна
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Molecules |
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The heme in the active center of peroxidases reacts with hydrogen peroxide to form highly reactive intermediates, which then oxidize simple substances called peroxidase substrates. Human peroxidases can be divided into two groups: (1) True peroxidases are enzymes whose main function is to generate free radicals in the peroxidase cycle and (pseudo)hypohalous acids in the halogenation cycle. The major true peroxidases are myeloperoxidase, eosinophil peroxidase and lactoperoxidase. (2) Pseudo-peroxidases perform various important functions in the body, but under the influence of external conditions they can display peroxidase-like activity. As oxidative intermediates, these peroxidases produce not only active heme compounds, but also protein-based tyrosyl radicals. Hemoglobin, myoglobin, cytochrome c/cardiolipin complexes and cytoglobin are considered as pseudo-peroxidases. Рeroxidases play an important role in innate immunity and in a number of physiologically important processes like apoptosis and cell signaling. Unfavorable excessive peroxidase activity is implicated in oxidative damage of cells and tissues, thereby initiating the variety of human diseases. Hence, regulation of peroxidase activity is of considerable importance. Since peroxidases differ in structure, properties and location, the mechanisms controlling peroxidase activity and the biological effects of peroxidase products are specific for each hemoprotein. This review summarizes the knowledge about the properties, activities, regulations and biological effects of true and pseudo-peroxidases in order to better understand the mechanisms underlying beneficial and adverse effects of this class of enzymes. View Full-Text
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тезис
Публикация |
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Oncobox bioinformatical platform for selecting potentially effective combinations of target cancer drugs using high-throughput gene expression data
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|
Буздин Антон Александрович
Сорокин Максим Игоревич
Поддубская Елена Владимировна
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Cancers |
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Sequential courses of anticancer target therapy lead to selection of drug-resistant cells, which results in continuous decrease of clinical response. Here we present a new approach for predicting effective combinations of target drugs, which act in a synergistic manner. Synergistic combinations of drugs may prevent or postpone acquired resistance, thus increasing treatment efficiency. We cultured human ovarian carcinoma SKOV-3 and neuroblastoma NGP-127 cancer cell lines in the presence of Tyrosine Kinase Inhibitors (Pazopanib, Sorafenib, and Sunitinib) and Rapalogues (Temsirolimus and Everolimus) for four months and obtained cell lines demonstrating increased drug resistance. We investigated gene expression profiles of intact and resistant cells by microarrays and analyzed alterations in 378 cancer-related signaling pathways using the bioinformatical platform Oncobox. This revealed numerous pathways linked with development of drug resistant phenotypes. Our approach is based on targeting proteins involved in as many as possible signaling pathways upregulated in resistant cells. We tested 13 combinations of drugs and/or selective inhibitors predicted by Oncobox and 10 random combinations. Synergy scores for Oncobox predictions were significantly higher than for randomly selected drug combinations. Thus, the proposed approach significantly outperforms random selection of drugs and can be adopted to enhance discovery of new synergistic combinations of anticancer target drugs. View Full-Text Читать
тезис
Публикация |
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Experts’ opinion about the primary headache diagnostic criteria of the ICHD-3rd edition beta in children and adolescents
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|
Сергеев Алексей Владимирович (Ассистент)
Николенко В. Н. (Директор)
Несвижский Юрий Владимирович (Профессор)
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Journal of Headache and Pain |
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|
BACKGROUND:
The 2013 International Classification of Headache Disorders-3 (ICHD-3) was published in a beta version to allow the clinicians to confirm the validity of the criteria or to suggest improvements based on field studies. The aim of this work was to review the Primary Headache Disorders Section of ICHD-3 beta data on children and adolescents (age 0-18 years), and to suggest changes, additions, and amendments.
METHODS:
Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the literature available on pediatric headache, they made observations and proposed suggestions for the primary headache disorders section of ICHD-3 beta data on children and adolescents.
RESULTS:
Some headache disorders in children have specific features which are different from those seen in adults and which should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psycho-social basis in children and adolescents making primary headache disorders in children distinct from those in adults.
CONCLUSIONS:
Several recommendations are presented in order to make ICHD-3 more appropriate for use with children.
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тезис
PUBMED DOI |
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ROLE OF ORGANISM REACTIVITY AND MUCOSAL IMMUNITY IN MODULATING OF PATHOGENICITY AND VIRULENCE OF OPPORTUNISTIC MICROFLORA IN DYNAMICS OF INFECTIOUS PROCESS AND ALSO IN MACROAND MICROORGANISMS GENE POOLS MAINTENANCE (Роль реактивности организма и мукозальн
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Караулов Александр Викторович (Заведующий кафедрой)
Афанасьев Максим Станиславович (Профессор)
Несвижский Юрий Владимирович (Профессор)
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Инфекционные болезни |
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The review is summarizing for the first time the results of original research and literature data revealing the conditions of opportunistic microflora (OM) pathogenicity and virulence formation in the dynamics of the infectious process, as well as maintenance and formation of gene pools in host cells and microorganisms. It is established, that formation or loss of pathogenic and virulent properties of microorganisms in the body happens under the influence of its external environment, its overall physiological and immunological reactivity, mucosal immunity, as well as with the direct participation of horizontal gene transfer. Newly created microbial pathogens cause infectious-inflammatory diseases. However, acquired pathogenicity factors are lost after recovery. Plasticity of gene pools of the macroorganism and microorganisms allows owners of gene pools to respond adequately to changes in the external and internal body environment, improve and enhance overall and immunological reactivity of the macroorganism in ontogenesis, generate optimal for specific situations symbiotic or antagonistic relationships between them taking into account newly acquired or lost pathogenicity and virulence factors and form new phenotypic or genetic properties of microorganisms. Horizontal genetic transfer is the process of moving the genetic information which is possible between prokaryotic and eukaryotic cells both ways, as well as within a single cell.
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Публикация |
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Indispensable Role of Proteases in Plant Innate Immunity
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Замятнин Андрей Александрович (директор)
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International Journal of Molecular Sciences |
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Plant defense is achieved mainly through the induction of microbe-associated molecular patterns (MAMP)-triggered immunity (MTI), effector-triggered immunity (ETI), systemic acquired resistance (SAR), induced systemic resistance (ISR), and RNA silencing. Plant immunity is a highly complex phenomenon with its own unique features that have emerged as a result of the arms race between plants and pathogens. However, the regulation of these processes is the same for all living organisms, including plants, and is controlled by proteases. Different families of plant proteases are involved in every type of immunity: some of the proteases that are covered in this review participate in MTI, affecting stomatal closure and callose deposition. A large number of proteases act in the apoplast, contributing to ETI by managing extracellular defense. A vast majority of the endogenous proteases discussed in this review are associated with the programmed cell death (PCD) of the infected cells and exhibit caspase-like activities. The synthesis of signal molecules, such as salicylic acid, jasmonic acid, and ethylene, and their signaling pathways, are regulated by endogenous proteases that affect the induction of pathogenesis-related genes and SAR or ISR establishment. A number of proteases are associated with herbivore defense. In this review, we summarize the data concerning identified plant endogenous proteases, their effect on plant-pathogen interactions, their subcellular localization, and their functional properties, if available, and we attribute a role in the different types and stages of innate immunity for each of the proteases covered. View Full-Text
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Публикация |
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Pro-neurogenic, Memory-Enhancing and Anti-stress Effects of DF302, a Novel Fluorine Gamma-Carboline Derivative with Multi-target Mechanism of Action
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Петер Леш (руководитель лаборатории Психиатрической Нейробиологии)
Стрекалова Т.В. ( зам руководителя лаборатории Психиатрической Нейробиологии)
Умрюхин А.T. (старший научный сотрудник)
Баженова Н.С. (младший научный сотрудник)
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Molecular Neurobiology |
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A comparative study performed in mice investigating the action of DF302, a novel fluoride-containing gamma-carboline derivative, in comparison to the structurally similar neuroprotective drug dimebon. Drug effects on learning and memory, emotionality, hippocampal neurogenesis and mitochondrial functions, as well as AMPA-mediated currents and the 5-HT6 receptor are reported. In the step-down avoidance and fear-conditioning paradigms, bolus administration of drugs at doses of 10 or 40 mg/kg showed that only the higher dose of DF302 improved long-term memory while dimebon was ineffective at either dosage. Short-term memory and fear extinction remained unaltered across treatment groups. During the 5-day predation stress paradigm, oral drug treatment over a period of 2 weeks at the higher dosage regimen decreased anxiety-like behaviour. Both compounds supressed inter-male aggression in CD1 mice, the most eminent being the effects of DF302 in its highest dose. DF302 at the higher dose decreased floating behaviour in a 2-day swim test and after 21-day ultrasound stress. The density of Ki67-positive cells, a marker of adult neurogenesis, was reduced in the dentate gyrus of stressed dimebon-treated and non-treated mice, but not in DF302-treated mice. Non-stressed mice that received DF302 had a higher density of Ki67-positive cells than controls unlike dimebon-treated mice. Similar to dimebon, DF302 effectively potentiated AMPA receptor-mediated currents, bound to the 5-HT6 receptor, inhibited mitochondrial permeability transition and displayed cytoprotective properties in cellular models of neurodegeneration. Thus, DF302 exerts multi-target effects on the key mechanisms of neurodegenerative pathologies and can be considered as an optimized novel analogue of the neuroprotective agent dimebon.
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тезис
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Dependence of Nanoparticle Toxicity on Their Physical and Chemical Properties
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Караулов А.В. (Зав. кафедрой)
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NANOSCALE RESEARCH LETTERS |
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Studies on the methods of nanoparticle (NP) synthesis, analysis of their characteristics, and exploration of new fields of their applications are at the forefront of modern nanotechnology. The possibility of engineering water-soluble NPs has paved the way to their use in various basic and applied biomedical researches. At present, NPs are used in diagnosis for imaging of numerous molecular markers of genetic and autoimmune diseases, malignant tumors, and many other disorders. NPs are also used for targeted delivery of drugs to tissues and organs, with controllable parameters of drug release and accumulation. In addition, there are examples of the use of NPs as active components, e.g., photosensitizers in photodynamic therapy and in hyperthermic tumor destruction through NP incorporation and heating. However, a high toxicity of NPs for living organisms is a strong limiting factor that hinders their use in vivo. Current studies on toxic effects of NPs aimed at identifying the targets and mechanisms of their harmful effects are carried out in cell culture models; studies on the patterns of NP transport, accumulation, degradation, and elimination, in animal models. This review systematizes and summarizes available data on how the mechanisms of NP toxicity for living systems are related to their physical and chemical properties.
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Публикация |
|
Cytokinin activity of N6-benzyladenine derivatives assayed by interaction with the receptors in planta, in vitro, and in silico
|
|
Осолодкин Дмитрий Иванович (Доцент)
|
Phytochemistry |
|
|
Biological effects of hormones in both plants and animals are based on high-affinity interaction with cognate receptors resulting in their activation. The signal of cytokinins, classical plant hormones, is perceived in Arabidopsis by three homologous membrane receptors: AHK2, AHK3, and CRE1/AHK4. To study the cytokinin-receptor interaction, we used 25 derivatives of potent cytokinin N6-benzyladenine (BA) with substituents in the purine heterocycle and/or in the side chain. The study was focused primarily on individual cytokinin receptors from Arabidopsis. The main in planta assay system was based on Arabidopsis double mutants retaining only one isoform of cytokinin receptors and harboring cytokinin-sensitive reporter gene. Classical cytokinin biotest with Amaranthus seedlings was used as an additional biotest. In parallel, the binding of ligands to individual cytokinin receptors was assessed in the in vitro test system. Quantitative comparison of results of different assays confirmed the partial similarity of ligand-binding properties of receptor isoforms. Substituents at positions 8 and 9 of adenine moiety, elongated linker up to 4 methylene units, and replacement of N6 by sulfur or oxygen have resulted in the suppression of cytokinin activity of the derivative toward all receptors. Introduction of a halogen into position 2 of adenine moiety, on the contrary, often increased the ligand activity, especially toward AHK3. Features both common and distinctive of cytokinin receptors in Arabidopsis and Amaranthus were revealed, highlighting species specificity of the cytokinin perception apparatus. Correlations between the extent to which a compound binds to a receptor in vitro and its ability to activate the same receptor in planta were evaluated for each AHK protein. Interaction patterns between individual receptors and ligands were rationalized by structure analysis and molecular docking in sensory modules of AHK receptors. The best correlation between docking scores and specific binding was observed for AHK3. In addition, receptor-specific ligands have been discovered with unique properties to predominantly activate or block distinct cytokinin receptors. These ligands are promising for practical application and as molecular tools in the study of the cytokinin perception by plant cells.
Читать
тезис
Публикация |
|
Experts’ opinion about the primary headache diagnostic criteria of the ICHD-3rd edition beta in children and adolescents
|
|
Сергеев Алексей Владимирович (ассистент)
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Journal of Headache and Pain |
|
|
BACKGROUND:
The 2013 International Classification of Headache Disorders-3 (ICHD-3) was published in a beta version to allow the clinicians to confirm the validity of the criteria or to suggest improvements based on field studies. The aim of this work was to review the Primary Headache Disorders Section of ICHD-3 beta data on children and adolescents (age 0-18 years), and to suggest changes, additions, and amendments.
METHODS:
Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the literature available on pediatric headache, they made observations and proposed suggestions for the primary headache disorders section of ICHD-3 beta data on children and adolescents.
RESULTS:
Some headache disorders in children have specific features which are different from those seen in adults and which should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psycho-social basis in children and adolescents making primary headache disorders in children distinct from those in adults.
CONCLUSIONS:
Several recommendations are presented in order to make ICHD-3 more appropriate for use with children.
Читать
тезис
Публикация |
|
Molecular and clinical aspects of embryotoxicity induced by acetylcholinesterase inhibitors
|
|
Бурыкина Татьяна Ивановна (Доцент)
|
Toxicology |
|
|
Acetylcholinesterase inhibitors are widely used for a variety of medical, agricultural and public health purposes. Consequently, exposure is highly possible during lifetime. However, their systematic use raises concerns for the potential impact on the fetus and newborn since these substances may affect angiogenesis, the neonatal and maternal intensive care, neuroimmune function and response, mammary growth/lactation via cholinergic/non-cholinergic central and peripheral neuroendocrine pathways. New methodologies, neuroscientific technologies and research studies are needed to harness existing knowledge along with the proper management, availability for new acetylcholinesterase inhibitors, with stable pharmacodynamics and clinical outcomes.
Читать
тезис
Публикация |
|
A novel lipopeptaibol emericellipsin a with antimicrobial and antitumor activity produced by the extremophilic fungus emericellopsis alkalina
|
|
Андреев Ярослав Алексеевич (Заведующий лаборатории)
Люндуп Алексей Валерьевич (Заведующий отделом)
Крашенинников Михаил Евгеньевич (Ведущий научный сотрудник)
|
Molecules |
|
|
Soil fungi are known to contain a rich variety of defense metabolites that allow them to compete with other organisms (fungi, bacteria, nematodes, and insects) and help them occupy more preferential areas at the expense of effective antagonism. These compounds possess antibiotic activity towards a wide range of other microbes, particularly fungi that belong to different taxonomical units. These compounds include peptaibols, which are non-ribosomal synthesized polypeptides containing non-standard amino acid residues (alpha-aminoisobutyric acid mandatory) and some posttranslational modifications. We isolated a novel antibiotic peptide from the culture medium of Emericellopsis alkalina, an alkalophilic strain. This peptide, called emericellipsin A, exhibited a strong antifungal effect against the yeast Candida albicans, the mold fungus Aspergillus niger, and human pathogen clinical isolates. It also exhibited antimicrobial activity against some Gram-positive and Gram-negative bacteria. Additionally, emericellipsin A showed a significant cytotoxic effect and was highly active against Hep G2 and HeLa tumor cell lines. We used NMR spectroscopy to reveal that this peptaibol is nine amino acid residues long and contains non-standard amino acids. The mode of molecular action of emericellipsin A is most likely associated with its effects on the membranes of cells. Emericellipsin A is rather short peptaibol and could be useful for the development of antifungal, antibacterial, or anti-tumor remedies. View Full-Text
Читать
тезис
Публикация |
|
How regularities of mortality statistics explain why we age despite having potentially ageless somatic stem cells
|
|
Крутько Вячеслав Николаевич (Профессор )
|
Biogerontology |
|
|
Researchers working in the area of ageing have found numerous manifestations of this process at the molecular biological level, including DNA and protein damage, accumulation of metabolic by-products, lipids peroxidation, macromolecular cross-linking, non-enzymatic glycosylation, anti-oxidant/pro-oxidant misbalance, rising of pro-inflammatory cytokines, etc. This results in an increase in the proportion of cells in growth arrest, reduction of the rate of information processing, metabolic rate decrease, and decrease in rates of other processes characterizing dynamic aspects of the organism’s interaction with its environment. Such staggering multilevel diversity in manifestation of senescence precludes (without methodology of systems biology) development of a correct understanding of its primary causes and does not allow for developing approaches capable of postponing ageing or reducing organisms’ ageing rate to attain health preservation. Moreover, it turns out that damage production and damage elimination processes, the misbalance of which results in the ageing process, can to a large extent be regulated by external signals. The purpose of this report is to provide evidence supporting this view and its compatibility with the regularities of mortality statistics, because the main idea is very simple. Even potentially a non-senescent but certainly not immortal body must start to age under inadequate conditions (like a non-melting piece of ice taken out from the deepfreeze inevitably start to melt at the temperatures above zero Celsius). This conclusion is totally consistent with existing patterns of mortality and with agelessness potential of somatic stem cells. Therefore, there is no need to build up and explore too complicated, computational and sophisticated systems models of intrinsic ageing to understand the origin of this mainly extrinsic root cause of natural ageing, which is controlled by environmental signals. In our case, a simple phenomenological black-box approach with Input–Output analysis is ample. Here Input refers to the environmentally dependent initial force of mortality, whereas Output is a rate of age-related increase of mortality force.
Читать
тезис
Публикация |
|
Peroxidase Activity of Human Hemoproteins: Keeping the Fire under Control
|
|
Власова Ирина Ивановна (старший научный сотрудник)
|
Molecules |
|
|
The heme in the active center of peroxidases reacts with hydrogen peroxide to form highly reactive intermediates, which then oxidize simple substances called peroxidase substrates. Human peroxidases can be divided into two groups: (1) True peroxidases are enzymes whose main function is to generate free radicals in the peroxidase cycle and (pseudo)hypohalous acids in the halogenation cycle. The major true peroxidases are myeloperoxidase, eosinophil peroxidase and lactoperoxidase. (2) Pseudo-peroxidases perform various important functions in the body, but under the influence of external conditions they can display peroxidase-like activity. As oxidative intermediates, these peroxidases produce not only active heme compounds, but also protein-based tyrosyl radicals. Hemoglobin, myoglobin, cytochrome c/cardiolipin complexes and cytoglobin are considered as pseudo-peroxidases. Рeroxidases play an important role in innate immunity and in a number of physiologically important processes like apoptosis and cell signaling. Unfavorable excessive peroxidase activity is implicated in oxidative damage of cells and tissues, thereby initiating the variety of human diseases. Hence, regulation of peroxidase activity is of considerable importance. Since peroxidases differ in structure, properties and location, the mechanisms controlling peroxidase activity and the biological effects of peroxidase products are specific for each hemoprotein. This review summarizes the knowledge about the properties, activities, regulations and biological effects of true and pseudo-peroxidases in order to better understand the mechanisms underlying beneficial and adverse effects of this class of enzymes. View Full-Text
Читать
тезис
Публикация |
|
Oncobox bioinformatical platform for selecting potentially effective combinations of target cancer drugs using high-throughput gene expression data
|
|
Буздин Антон Александрович (Заведующий лабораторией)
Сорокин Максим Игоревич (Научный сотрудник)
Поддубская Елена Владимировна (Старший научный сотрудник)
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Cancers |
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|
Sequential courses of anticancer target therapy lead to selection of drug-resistant cells, which results in continuous decrease of clinical response. Here we present a new approach for predicting effective combinations of target drugs, which act in a synergistic manner. Synergistic combinations of drugs may prevent or postpone acquired resistance, thus increasing treatment efficiency. We cultured human ovarian carcinoma SKOV-3 and neuroblastoma NGP-127 cancer cell lines in the presence of Tyrosine Kinase Inhibitors (Pazopanib, Sorafenib, and Sunitinib) and Rapalogues (Temsirolimus and Everolimus) for four months and obtained cell lines demonstrating increased drug resistance. We investigated gene expression profiles of intact and resistant cells by microarrays and analyzed alterations in 378 cancer-related signaling pathways using the bioinformatical platform Oncobox. This revealed numerous pathways linked with development of drug resistant phenotypes. Our approach is based on targeting proteins involved in as many as possible signaling pathways upregulated in resistant cells. We tested 13 combinations of drugs and/or selective inhibitors predicted by Oncobox and 10 random combinations. Synergy scores for Oncobox predictions were significantly higher than for randomly selected drug combinations. Thus, the proposed approach significantly outperforms random selection of drugs and can be adopted to enhance discovery of new synergistic combinations of anticancer target drugs. View Full-Text Читать
тезис
Публикация |
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Analysis of the expression levels of genes that encode cytoskeletal proteins in Drosophila melanogaster larvae during micro- and hypergravity effect simulations of different durations
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Огнева И. В. (Профессор)
Свистунов А.А (Первый проректор)
Несвижский Юрий Владимирович (Профессор)
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Biophysics (Russian Federation) |
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The goal of this study was to find genes that encode cytoskeletal proteins that are potential candidates for the role of triggers in cell mechanosensitivity in the fruit fly. Centrifugation was used to simulate the hypergravity effects (2g group); the constantly changing orientation of the larvae in the gravity field was performed in order to simulate the effects of microgravity (0g group) for 1.5, 6, 12 and 24 h. mRNA levels of different genes that encode the components of both tubulin and actin cytoskeleton were assessed by qRT-PCR. In the 0g group the mRNA levels of beta-tubulin and Msps were reduced after 1.5 h of the exposure and remained unchanged until 12 h, while they exceeded the control level after 24 h. The mRNA level of chaperonin containing T-complex 1 polypeptide subunits recovered earlier: after 6 and 12 h of the microgravity exposure. At the same time, the hypergravity effect led to more significant changes in the mRNA level of TCP1 complex components compared with those of tubulin and Msps. The mRNA level of beta-actin isoforms under micro- and hypergravity was decreased up to 12 h of the exposure, however, it remained reduced under microgravity conditions, while it recovered (Act87E) and even exceeded (Act57B) the reference level under hypergravity conditions. The mRNA level of supervillin was almost unchanged. Under microgravity conditions the mRNA level of fimbrin was decreased (it recovered by the 24 h time point), while the mRNA level of alpha-actinin was significantly increased by the 12 h time point of the exposure and after 24 h it was reduced to the control level. In contrast, under hypergravity conditions the mRNA level of fimbrin initially increased, and after 24 h it dropped below the control, while the mRNA level of alpha-actinin was significantly reduced, and after 24 h it was higher than the reference level. Similar results were obtained earlier in the experiments in rodents, but similar dynamics were observed for alpha-actinin isoforms 1 and 4, although no changes were observed for fimbrin. Since Drosophila melanogaster has no alpha-actinin isoform 4, it is hypothesized that its role in the cell is played by fimbrin.
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