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Orlov YL, Chen M, Kolchanov NA, Hofestädt R. BGRS: bioinformatics of genome regulation and data integration. J Integr Bioinform 2023; 20:jib-2023-0032. [PMID: 37972410 PMCID: PMC10757072 DOI: 10.1515/jib-2023-0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023] Open
Affiliation(s)
- Yuriy L. Orlov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090Novosibirsk, Russia
- Life Sciences Department, Novosibirsk State University, 630090Novosibirsk, Russia
- The Digital Health Institute, I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), 119991Moscow, Russia
- Agrarian and Technological Institute, Peoples’ Friendship University of Russia, 117198Moscow, Russia
| | - Ming Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou310058, China
| | - Nikolay A. Kolchanov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090Novosibirsk, Russia
- Life Sciences Department, Novosibirsk State University, 630090Novosibirsk, Russia
| | - Ralf Hofestädt
- Faculty of Technology, Bielefeld University, Bielefeld, Germany
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Khlebodarova TM. The molecular view of mechanical stress of brain cells, local translation, and neurodegenerative diseases. Vavilovskii Zhurnal Genet Selektsii 2021; 25:92-100. [PMID: 34901706 PMCID: PMC8629365 DOI: 10.18699/vj21.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/03/2022] Open
Abstract
The assumption that chronic mechanical stress in brain cells stemming from intracranial hypertension,
arterial hypertension, or mechanical injury is a risk factor for neurodegenerative diseases was put forward in the
1990s and has since been supported. However, the molecular mechanisms that underlie the way from cell exposure to mechanical stress to disturbances in synaptic plasticity followed by changes in behavior, cognition, and
memory are still poorly understood. Here we review (1) the current knowledge of molecular mechanisms regulating local translation and the actin cytoskeleton state at an activated synapse, where they play a key role in the
formation of various sorts of synaptic plasticity and long-term memory, and (2) possible pathways of mechanical
stress intervention. The roles of the mTOR (mammalian target of rapamycin) signaling pathway; the RNA-binding
FMRP protein; the CYFIP1 protein, interacting with FMRP; the family of small GTPases; and the WAVE regulatory
complex in the regulation of translation initiation and actin cytoskeleton rearrangements in dendritic spines of the
activated synapse are discussed. Evidence is provided that chronic mechanical stress may result in aberrant activation of mTOR signaling and the WAVE regulatory complex via the YAP/TAZ system, the key sensor of mechanical
signals, and influence the associated pathways regulating the formation of F actin filaments and the dendritic spine
structure. These consequences may be a risk factor for various neurological conditions, including autistic spectrum
disorders and epileptic encephalopathy. In further consideration of the role of the local translation system in the
development of neuropsychic and neurodegenerative diseases, an original hypothesis was put forward that one
of the possible causes of synaptopathies is impaired proteome stability associated with mTOR hyperactivity and
formation of complex dynamic modes of de novo protein synthesis in response to synapse-stimulating factors,
including chronic mechanical stress.
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Affiliation(s)
- T M Khlebodarova
- Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia Kurchatov Genomic Center of the Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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Khlebodarova TM, Kogai VV, Likhoshvai VA. On the dynamical aspects of local translation at the activated synapse. BMC Bioinformatics 2020; 21:258. [PMID: 32921299 PMCID: PMC7488754 DOI: 10.1186/s12859-020-03597-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 02/01/2023] Open
Abstract
Background The key role in the dynamic regulation of synaptic protein turnover belongs to the Fragile X Mental Retardation Protein, which regulates the efficiency of dendritic mRNA translation in response to stimulation of metabotropic glutamate receptors at excitatory synapses of the hippocampal pyramidal cells. Its activity is regulated via positive and negative regulatory loops that function in different time ranges, which is an absolute factor for the formation of chaotic regimes that lead to disrupted proteome stability. The indicated condition may cause a number of neuropsychiatric diseases, including autism and epilepsy. The present study is devoted to a theoretical analysis of the local translation system dynamic properties and identification of parameters affecting the chaotic potential of the system. Results A mathematical model that describes the maintenance of a specific pool of active receptors on the postsynaptic membrane via two mechanisms – de novo synthesis of receptor proteins and restoration of protein function during the recycling process – has been developed. Analysis of the model revealed that an increase in the values of the parameters describing the impact of protein recycling on the maintenance of a pool of active receptors in the membrane, duration of the signal transduction via the mammalian target of rapamycin pathway, influence of receptors on the translation activation, as well as reduction of the rate of synthesis and integration of de novo synthesized proteins into the postsynaptic membrane – contribute to the reduced complexity of the local translation system dynamic state. Formation of these patterns significantly depends on the complexity and non-linearity of the mechanisms of exposure of de novo synthesized receptors to the postsynaptic membrane, the correct evaluation of which is currently problematic. Conclusions The model predicts that an increase of “receptor recycling” and reduction of the rate of synthesis and integration of de novo synthesized proteins into the postsynaptic membrane contribute to the reduced complexity of the local translation system dynamic state. Herewith, stable stationary states occur much less frequently than cyclic states. It is possible that cyclical nature of functioning of the local translation system is its “normal” dynamic state.
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Affiliation(s)
- Tamara M Khlebodarova
- Department of Systems Biology, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia. .,Novosibirsk State University, Novosibirsk, 630090, Russia.
| | | | - Vitaly A Likhoshvai
- Department of Systems Biology, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
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Likhoshvai VA, Golubyatnikov VP, Khlebodarova TM. Limit cycles in models of circular gene networks regulated by negative feedback loops. BMC Bioinformatics 2020; 21:255. [PMID: 32921311 PMCID: PMC7488683 DOI: 10.1186/s12859-020-03598-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The regulatory feedback loops that present in structural and functional organization of molecular-genetic systems and the phenomenon of the regulatory signal delay, a time period between the moment of signal reception and its implementation, provide natural conditions for complicated dynamic regimes in these systems. The delay phenomenon at the intracellular level is a consequence of the matrix principle of data transmission, implemented through the rather complex processes of transcription and translation.However, the rules of the influence of system structure on system dynamics are not clearly understood. Knowledge of these rules is particularly important for construction of synthetic gene networks with predetermined properties. RESULTS We study dynamical properties of models of simplest circular gene networks regulated by negative feedback mechanisms. We have shown existence and stability of oscillating trajectories (cycles) in these models. Two algorithms of construction and localization of these cycles have been proposed. For one of these models, we have solved an inverse problem of parameters identification. CONCLUSIONS The modeling results demonstrate that non-stationary dynamics in the models of circular gene networks with negative feedback loops is achieved by a high degree of non-linearity of the mechanism of the autorepressor influence on its own expression, by the presence of regulatory signal delay, the value of which must exceed a certain critical value, and transcription/translation should be initiated from a sufficiently strong promoter/Shine-Dalgarno site. We believe that the identified patterns are key elements of the oscillating construction design.
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Affiliation(s)
- Vitaly A Likhoshvai
- Department of Systems Biology, Institute of Cytology and Genetics, Siberian Branch RAS, Novosibirsk, Russia
| | - Vladimir P Golubyatnikov
- Laboratory of Inverse Problems of Mathematical Physics, Sobolev Institute of Mathematics Siberian Branch RAS, Novosibirsk, Russia.
- Novosibirsk State University, Novosibirsk, Russia.
| | - Tamara M Khlebodarova
- Department of Systems Biology, Institute of Cytology and Genetics, Siberian Branch RAS, Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk, Russia
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Affiliation(s)
- Yuriy L. Orlov
- The Digital Health Institute, I.M.Sechenov First Moscow State Medical University (Sechenov University), 119991 Moscow, Russia
- Novosibirsk State University, 630090 Novosibirsk, Russia
- Agrarian and Technological Institute, Peoples’ Friendship University of Russia (RUDN), 117198 Moscow, Russia
| | - Elvira R. Galieva
- Novosibirsk State University, 630090 Novosibirsk, Russia
- Agrarian and Technological Institute, Peoples’ Friendship University of Russia (RUDN), 117198 Moscow, Russia
| | - Tatiana V. Tatarinova
- La Verne University, La Verne, CA 91750 USA
- Department of Fundamental Biology and Biotechnology, Siberian Federal University, 660074 Krasnoyarsk, Russia
- Vavilov Instutute of General Genetics RAS, 119991 Moscow, Russia
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Garte S, Albert A. Genotype Components as Predictors of Phenotype in Model Gene Regulatory Networks. Acta Biotheor 2019; 67:299-320. [PMID: 31286303 DOI: 10.1007/s10441-019-09350-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 07/04/2019] [Indexed: 10/26/2022]
Abstract
Models of gene regulatory networks (GRN) have proven useful for understanding many aspects of the highly complex behavior of biological control networks. Randomly generated non-Boolean networks were used in experimental simulations to generate data on dynamic phenotypes as a function of several genotypic parameters. We found that predictive relationships between some phenotypes and quantitative genotypic parameters such as number of network genes, interaction density, and initial condition could be derived depending on the strength of the topological (positional) genotype on specific phenotypes. We quantitated the strength of the topological genotype effect (TGE) on a number of phenotypes in multi-gene networks. For phenotypes with a low influence of topological genotype, derived and empirical relationships using quantitative genotype parameters were accurate in phenotypic outcomes. We found a number of dynamic network properties, including oscillation behaviors, that were largely dependent on genotype topology, and for which no such general quantitative relationships were determinable. It remains to be determined if these results are applicable to biological gene regulatory networks.
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Basios V, Antonopoulos CG. Hyperchaos & labyrinth chaos: Revisiting Thomas–Rössler systems. J Theor Biol 2019; 460:153-159. [DOI: 10.1016/j.jtbi.2018.10.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/27/2018] [Accepted: 10/09/2018] [Indexed: 11/16/2022]
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Dynamic landscape of the local translation at activated synapses. Mol Psychiatry 2018; 23:107-114. [PMID: 29203851 PMCID: PMC5754473 DOI: 10.1038/mp.2017.245] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 10/09/2017] [Indexed: 01/17/2023]
Abstract
The mammalian target of rapamycin (mTOR) signaling pathway is the central regulator of cap-dependent translation at the synapse. Disturbances in mTOR pathway have been associated with several neurological diseases, such as autism and epilepsy. RNA-binding protein FMRP, a negative regulator of translation initiation, is one of the key components of the local translation system. Activation and inactivation of FMRP occurs via phosphorylation by S6 kinase and dephosphorylation by PP2A phosphatase, respectively. S6 kinase and PP2A phosphatase are activated in response to mGluR receptor stimulation through different signaling pathways and at different rates. The dynamic aspects of this system are poorly understood. We developed a mathematical model of FMRP-dependent regulation of postsynaptic density (PSD) protein synthesis in response to mGluR receptor stimulation and conducted in silico experiments to study the regulatory circuit functioning. The modeling results revealed the possibility of generating oscillatory (cyclic and quasi-cyclic), chaotic and even hyperchaotic dynamics of postsynaptic protein synthesis as well as the presence of multiple attractors in a wide range of parameters of the local translation system. The results suggest that autistic disorders associated with mTOR pathway hyperactivation may be due to impaired proteome stability associated with the formation of complex dynamic regimes of PSD protein synthesis in response to stimulation of mGluR receptors on the postsynaptic membrane of excitatory synapses on pyramidal hippocampal cells.
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Orlov YL, Kolchanov NA, Hofestädt R, Wong L. Editorial - Bioinformatics development at the BGRS\SB conference series: 10th anniversary. J Bioinform Comput Biol 2017; 15:1702001. [PMID: 28317416 DOI: 10.1142/s0219720017020012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Yuriy L Orlov
- 1 Institute of Cytology and Genetics SB RAS, Russia.,2 Novosibirsk State University, Russia
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Chaos and Hyperchaos in a Model of Ribosome Autocatalytic Synthesis. Sci Rep 2016; 6:38870. [PMID: 27941909 PMCID: PMC5151018 DOI: 10.1038/srep38870] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/14/2016] [Indexed: 02/07/2023] Open
Abstract
Any vital activities of the cell are based on the ribosomes, which not only provide the basic machinery for the synthesis of all proteins necessary for cell functioning during growth and division, but for biogenesis itself. From this point of view, ribosomes are self-replicating and autocatalytic structures. In current work we present an elementary model in which the autocatalytic synthesis of ribosomal RNA and proteins, as well as enzymes ensuring their degradation are described with two monotonically increasing functions. For certain parameter values, the model, consisting of one differential equation with delayed argument, demonstrates both stationary and oscillatory dynamics of the ribosomal protein synthesis, which can be chaotic and hyperchaotic dependent on the value of the delayed argument. The biological interpretation of the modeling results and parameter estimation suggest the feasibility of chaotic dynamics in molecular genetic systems of eukaryotes, which depends only on the internal characteristics of functioning of the translation system.
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Khlebodarova TM, Kogai VV, Fadeev SI, Likhoshvai VA. Chaos and hyperchaos in simple gene network with negative feedback and time delays. J Bioinform Comput Biol 2016; 15:1650042. [PMID: 28052708 DOI: 10.1142/s0219720016500426] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Today there are examples that prove the existence of chaotic dynamics at all levels of organization of living systems, except intracellular, although such a possibility has been theoretically predicted. The lack of experimental evidence of chaos generation at the intracellular level in vivo may indicate that during evolution the cell got rid of chaos. This work allows the hypothesis that one of the possible mechanisms for avoiding chaos in gene networks can be a negative evolutionary selection, which prevents fixation or realization of regulatory circuits, creating too mild, from the biological point of view, conditions for the emergence of chaos. It has been shown that one of such circuits may be a combination of negative autoregulation of expression of transcription factors at the level of their synthesis and degradation. The presence of such a circuit results in formation of multiple branches of chaotic solutions as well as formation of hyperchaos with equal and sufficiently low values of the delayed argument that can be implemented not only in eukaryotic, but in prokaryotic cells.
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Affiliation(s)
- Tamara M Khlebodarova
- * Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, pr., Lavrentieva 10, Novosibirsk, 630090, Russia
| | - Vladislav V Kogai
- † Sobolev Institute of Mathematics, Siberian Branch, Russian Academy of Sciences, Prospect Koptyuga 4, Novosibirsk, 630090, Russia
| | - Stanislav I Fadeev
- † Sobolev Institute of Mathematics, Siberian Branch, Russian Academy of Sciences, Prospect Koptyuga 4, Novosibirsk, 630090, Russia
| | - Vitaly A Likhoshvai
- * Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, pr., Lavrentieva 10, Novosibirsk, 630090, Russia.,‡ Novosibirsk State University, av. Pirogova 2, Novosibirsk, 630090, Russia
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Suzuki Y, Lu M, Ben-Jacob E, Onuchic JN. Periodic, Quasi-periodic and Chaotic Dynamics in Simple Gene Elements with Time Delays. Sci Rep 2016; 6:21037. [PMID: 26876008 PMCID: PMC4753448 DOI: 10.1038/srep21037] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 01/15/2016] [Indexed: 01/24/2023] Open
Abstract
Regulatory gene circuit motifs play crucial roles in performing and maintaining vital cellular functions. Frequently, theoretical studies of gene circuits focus on steady-state behaviors and do not include time delays. In this study, the inclusion of time delays is shown to entirely change the time-dependent dynamics for even the simplest possible circuits with one and two gene elements with self and cross regulations. These elements can give rise to rich behaviors including periodic, quasi-periodic, weak chaotic, strong chaotic and intermittent dynamics. We introduce a special power-spectrum-based method to characterize and discriminate these dynamical modes quantitatively. Our simulation results suggest that, while a single negative feedback loop of either one- or two-gene element can only have periodic dynamics, the elements with two positive/negative feedback loops are the minimalist elements to have chaotic dynamics. These elements typically have one negative feedback loop that generates oscillations, and another unit that allows frequent switches among multiple steady states or between oscillatory and non-oscillatory dynamics. Possible dynamical features of several simple one- and two-gene elements are presented in details. Discussion is presented for possible roles of the chaotic behavior in the robustness of cellular functions and diseases, for example, in the context of cancer.
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Affiliation(s)
- Yoko Suzuki
- Department of Physics, School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo 191-8506, Japan.,Center for Theoretical Biological Physics, Rice University, Houston, TX 77005-1827, USA
| | - Mingyang Lu
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005-1827, USA
| | - Eshel Ben-Jacob
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005-1827, USA.,School of Physics and Astronomy and The Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - José N Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005-1827, USA.,Department of Physics and Astronomy, Rice University, Houston, TX 77005-1827, USA.,Department of Chemistry, Rice University, Houston, TX 77005-1827, USA.,Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005-1827, USA
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Likhoshvai VA, Kogai VV, Fadeev SI, Khlebodarova TM. Alternative splicing can lead to chaos. J Bioinform Comput Biol 2015; 13:1540003. [PMID: 25556917 DOI: 10.1142/s021972001540003x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Alternative splicing is a widespread phenomenon in higher eukaryotes, where it serves as a mechanism to increase the functional diversity of proteins. This phenomenon has been described for different classes of proteins, including transcription regulatory proteins. We demonstrated that in the simplest genetic system model the formation of the alternatively spliced isoforms with opposite functions (activators and repressors) could be a cause of transition to chaotic dynamics. Under the simplest genetic system we understand a system consisting of a single gene encoding the structure of a transcription regulatory protein whose expression is regulated by a feedback mechanism. As demonstrated by numerical analysis of the models, if the synthesized isoforms regulate the expression of their own gene acting through different sites and independently of each other, for the generation of chaotic dynamics it is sufficient that the regulatory proteins have a dimeric structure. If regulatory proteins act through one site, the chaotic dynamics is generated in the system only when the repressor protein is either a tetrameric or a higher-dimensional multimer. In this case the activator can be a dimer. It was also demonstrated that if the transcription factor isoforms exhibit either activating or inhibiting activity and are lower-dimensional multimers (< 4), independently of the regulation type the model demonstrates either cyclic or stationary trajectories.
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Affiliation(s)
- Vitaly A Likhoshvai
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, pr. Lavrentieva 10, Novosibirsk 630090, Russia , Novosibirsk State University, av. Pirogova 2, Novosibirsk 630090, Russia
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Likhoshvai VA, Khlebodarova TM, Bazhan SI, Gainova IA, Chereshnev VA, Bocharov GA. Mathematical model of the Tat-Rev regulation of HIV-1 replication in an activated cell predicts the existence of oscillatory dynamics in the synthesis of viral components. BMC Genomics 2014; 15 Suppl 12:S1. [PMID: 25564443 PMCID: PMC4303933 DOI: 10.1186/1471-2164-15-s12-s1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background The life cycle of human immunodeficiency virus type-1 (HIV-1) makes possible the realization of regulatory strategies that can lead to complex dynamical behavior of the system. We analyze the strategy which is based on two feedback mechanisms, one mediating a positive regulation of the virus replication by Tat protein via the antitermination of the genomic RNAs transcription on TAR (transactivation responsive) element of the proviral DNA and the second mechanism providing a negative regulation of the splicing of the full-length (9 kb) RNAs and incompletely spliced (4 kb) RNAs via their transport from the nucleus to the cytoplasm. Although the existence of these two regulatory feedback loops has been considered in other mathematical models, none of them examined the conditions for the emergence of complex oscillatory patterns in the intracellular dynamics of viral components. Results We developed a mechanistic mathematical model for the Tat-Rev mediated regulation of HIV-1 replication, which considers the activation of proviral DNA transcription, the Tat-specific antitermination of transcription on TAR-element, resulting in the synthesis of the full-length 9 kb RNA, the splicing of the 9 kb RNA down to the 4 kb RNA and the 4 kb RNA to 2 kb RNA, the transport of 2 kb mRNAs from the nucleus to the cytoplasm by the intracellular mechanisms, the multiple binding of the Rev protein to RRE (Rev Response Element) sites on 9 kb and 4 kb RNA resulting in their export to the cytoplasm and the synthesis of Tat and Rev proteins in the cytoplasm followed by their transport into the nucleus. The degradation of all viral proteins and RNAs both in the cytoplasm and the nucleus is described. The model parameters values were derived from the published literature data. The model was used to examine the dynamics of the synthesis of the viral proteins Tat and Rev, the mRNAs under the intracellular conditions specific for activated HIV-1 infected macrophages. In addition, we analyzed alternative hypotheses for the re-cycling of the Rev proteins both in the cytoplasm and the nuclear pore complex. Conclusions The quantitative mathematical model of the Tat-Rev regulation of HIV-1 replication predicts the existence of oscillatory dynamics which depends on the efficacy of the Tat and TAR interaction as well as on the Rev-mediated transport processes. The biological relevance of the oscillatory regimes for the HIV-1 life cycle is discussed.
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Marzotto M, Olioso D, Brizzi M, Tononi P, Cristofoletti M, Bellavite P. Extreme sensitivity of gene expression in human SH-SY5Y neurocytes to ultra-low doses of Gelsemium sempervirens. Altern Ther Health Med 2014; 14:104. [PMID: 24642002 PMCID: PMC3999908 DOI: 10.1186/1472-6882-14-104] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 03/13/2014] [Indexed: 12/28/2022]
Abstract
Background Gelsemium sempervirens L. (Gelsemium s.) is a traditional medicinal plant, employed as an anxiolytic at ultra-low doses and animal models recently confirmed this activity. However the mechanisms by which it might operate on the nervous system are largely unknown. This work investigates the gene expression of a human neurocyte cell line treated with increasing dilutions of Gelsemium s. extract. Methods Starting from the crude extract, six 100 × (centesimal, c) dilutions of Gelsemium s. (2c, 3c, 4c, 5c, 9c and 30c) were prepared according to the French homeopathic pharmacopoeia. Human SH-SY5Y neuroblastoma cells were exposed for 24 h to test dilutions, and their transcriptome compared by microarray to that of cells treated with control vehicle solutions. Results Exposure to the Gelsemium s. 2c dilution (the highest dose employed, corresponding to a gelsemine concentration of 6.5 × 10-9 M) significantly changed the expression of 56 genes, of which 49 were down-regulated and 7 were overexpressed. Several of the down-regulated genes belonged to G-protein coupled receptor signaling pathways, calcium homeostasis, inflammatory response and neuropeptide receptors. Fisher exact test, applied to the group of 49 genes down-regulated by Gelsemium s. 2c, showed that the direction of effects was significantly maintained across the treatment with high homeopathic dilutions, even though the size of the differences was distributed in a small range. Conclusions The study shows that Gelsemium s., a medicinal plant used in traditional remedies and homeopathy, modulates a series of genes involved in neuronal function. A small, but statistically significant, response was detected even to very low doses/high dilutions (up to 30c), indicating that the human neurocyte genome is extremely sensitive to this regulation.
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Kolchanov NA, Orlov YL. INTRODUCTORY NOTE FOR BGRS-2012 SPECIAL ISSUE. J Bioinform Comput Biol 2013; 11:1302001. [PMID: 28847203 DOI: 10.1142/s0219720013020010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Nikolay A Kolchanov
- Organizing Committee of BGRS\SB-2012 conference, Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia
| | - Yuriy L Orlov
- Organizing Committee of BGRS\SB-2012 conference, Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia
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