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Sample records for transduction pathways leading

  1. Examination of the signal transduction pathways leading to upregulation of tissue type plasminogen activator by Porphyromonas endodontalis in human pulp cells.

    Science.gov (United States)

    Huang, F-M; Chen, Y-J; Chou, M-Y; Chang, Y-C

    2005-12-01

    To investigate the tissue type plasminogen activator (t-PA) activity in human pulp cells stimulated with Porphyromonas endodontalis (P. endodontalis) in the absence or presence of p38 inhibitor SB203580, mitogen-activated protein kinase kinase (MEK) inhibitor U0126 and phosphatidylinositaol 3-kinase (PI3K) inhibitor LY294002. The supernatants of P. endodontalis were used to evaluate t-PA activity in human pulp cells using casein zymography and enzyme-linked immunosorbent assay (ELISA). Furthermore, to search for possible signal transduction pathways, SB203580, U0126 and LY294002 were added to test how they modulated the t-PA activity. The main casein secreted by human pulp cells migrated at 70 kDa and represented t-PA. Secretion of t-PA was found to be stimulated with P. endodontalis during 2-day cultured period (P endodontalis stimulated t-PA production respectively (P endodontalis stimulated t-PA production (P > 0.05). Porphyromonas endodontalis enhances t-PA production in human pulp cells, and the signal transduction pathways p38 and MEK are involved in the inhibition of t-PA.

  2. Microenvironment Dependent Photobiomodulation on Function-Specific Signal Transduction Pathways

    Directory of Open Access Journals (Sweden)

    Timon Cheng-Yi Liu

    2014-01-01

    Full Text Available Cellular photobiomodulation on a cellular function has been shown to be homeostatic. Its function-specific pathway mechanism would be further discussed in this paper. The signal transduction pathways maintaining a normal function in its function-specific homeostasis (FSH, resisting the activation of many other irrelative signal transduction pathways, are so sparse that it can be supposed that there may be normal function-specific signal transduction pathways (NSPs. A low level laser irradiation or monochromatic light may promote the activation of partially activated NSP and/or its redundant NSP so that it may induce the second-order phase transition of a function from its dysfunctional one far from its FSH to its normal one in a function-specific microenvironment and may also induce the first-order functional phase transition of the normal function from low level to high level.

  3. Signal transduction in mitogenesis: Further evidence for multiple pathways

    International Nuclear Information System (INIS)

    Rozengurt, E.; Erusalimsky, J.; Mehmet, H.; Morris, C.; Nanberg, E.; Sinnett-Smith, J.

    1988-01-01

    Growth factors are implicated in a wide variety of physiological and pathological processes, including embryogenesis, hematopoiesis, would healing, immune responses, atherosclerosis, and neoplasia. An important link between growth factors and their receptors and oncogene products has also been established. Thus, the elucidation of the mechanism of action of growth factors has emerged as one of the fundamental problems in biology and may prove crucial for understanding the unrestrained proliferation of cancer cells. A new and intriguing development is the discovery that neuropeptides localized in neural and neuroendocrine cells of mammalian tissue can also act as growth factors for cells in culture. Furthermore, indirect evidence is accumulating that the mitogenic effects of neuropeptides may be relevant for a variety of long-term biological processes, including development and oncogenesis. In this context, the peptides of the bombesin family are of particular significance. These peptides are potent mitogens for Swiss 3T3 cells and may act as autocrine growth factors for small cell lung cancer. Here, the authors summarize their recent studies using bombesin-like peptides for elucidating the signal transduction pathways leading to mitogenesis and compare these pathways with those elicited by other growth factors

  4. Signal transduction pathways involved in mechanotransduction in bone cells

    International Nuclear Information System (INIS)

    Liedert, Astrid; Kaspar, Daniela; Blakytny, Robert; Claes, Lutz; Ignatius, Anita

    2006-01-01

    Several in vivo and in vitro studies with different loading regimens showed that mechanical stimuli have an influence on proliferation and differentiation of bone cells. Prerequisite for this influence is the transduction of mechanical signals into the cell, a phenomenon that is termed mechanotransduction, which is essential for the maintenance of skeletal homeostasis in adults. Mechanoreceptors, such as the integrins, cadherins, and stretch-activated Ca 2+ channels, together with various signal transduction pathways, are involved in the mechanotransduction process that ultimately regulates gene expression in the nucleus. Mechanotransduction itself is considered to be regulated by hormones, the extracellular matrix of the osteoblastic cells and the mode of the mechanical stimulus

  5. Olfactory transduction pathways in the Senegalese sole Solea senegalensis.

    Science.gov (United States)

    Velez, Z; Hubbard, P C; Barata, E N; Canário, A V M

    2013-09-01

    This study tested whether differences in sensitivity between the upper and lower olfactory epithelia of Solea senegalensis are associated with different odorant receptors and transduction pathways, using the electro-olfactogram. Receptor mechanisms were assessed by cross-adaptation with amino acids (L-cysteine, L-phenylalanine and 1-methyl-L-tryptophan) and bile acids (taurocholic acid and cholic acid). This suggested that relatively specific receptors exist for 1-methyl-L-tryptophan and L-phenylalanine (food-related odorants) in the lower epithelium, and for taurocholic acid (conspecific-derived odorant) in the upper. Inhibition by U73122 [a phospholipase C (PLC) inhibitor] suggested that olfactory responses to amino acids were mediated mostly, but not entirely, by PLC-mediated transduction (IC50 ; 15-55 nM), whereas bile acid responses were mediated by both PLC and adenylate cyclase-cyclic adenosine monophosphate (AC-cAMP) (using SQ-22536; an AC inhibitor). Simultaneous application of both drugs rarely inhibited responses completely, suggesting possible involvement of non-PLC and non-AC mediated mechanisms. For aromatic amino acids and bile acids, there were differences in the contribution of each transduction pathway (PLC, AC and non-PLC and non-AC) between the two epithelia. These results suggest that differences in sensitivity of the two epithelia are associated with differences in odorant receptors and transduction mechanisms. © 2013 The Fisheries Society of the British Isles.

  6. Influenza A induced cellular signal transduction pathways

    Science.gov (United States)

    Michael, Paul; Brabant, Danielle; Bleiblo, Farag; Ramana, Chilakamarti V.; Rutherford, Michael; Khurana, Sandhya; Tai, T.C.; Kumar, Anand

    2013-01-01

    Influenza A is a negative sense single stranded RNA virus that belongs to the Orthomyxoviridae Family. This enveloped virus contains 8 segments of viral RNA which encodes 11 viral proteins. Influenza A infects humans and is the causative agent of the flu. Annually it infects approximately 5% to 15% of the population world wide and results in an estimated 250,000 to 500,000 deaths a year. The nature of influenza A replication results in a high mutation rate which results in the need for seasonal vaccinations. In addition the zoonotic nature of the influenza virus allows for recombination of viral segments from different strains creating new variants that have not been encountered before. This type of mutation is the method by which pandemic strains of the flu arises. Infection with influenza results in a respiratory illness that for most individuals is self limiting. However in susceptible populations which include individuals with pre-existing pulmonary or cardiac conditions, the very young and the elderly fatal complications may arise. The most serious of these is the development of viral pneumonia which may be accompanied by secondary bacterial infections. Progression of pneumonia leads to the development of acute respiratory distress syndrome (ARDS), acute lung injury (ALI) and potentially respiratory failure. This progression is a combined effect of the host immune system response to influenza infection and the viral infection itself. This review will focus on molecular aspects of viral replication in alveolar cells and their response to infection. The response of select innate immune cells and their contribution to viral clearance and lung epithelial damage will also be discussed. Molecular aspects of antiviral response in the cells in particular the protein kinase RNA dependent response, and the oligoadenylate synthetase RNAse L system in relation to influenza infection. PMID:23977434

  7. Signal Transduction Pathways of TNAP: Molecular Network Analyses.

    Science.gov (United States)

    Négyessy, László; Györffy, Balázs; Hanics, János; Bányai, Mihály; Fonta, Caroline; Bazsó, Fülöp

    2015-01-01

    Despite the growing body of evidence pointing on the involvement of tissue non-specific alkaline phosphatase (TNAP) in brain function and diseases like epilepsy and Alzheimer's disease, our understanding about the role of TNAP in the regulation of neurotransmission is severely limited. The aim of our study was to integrate the fragmented knowledge into a comprehensive view regarding neuronal functions of TNAP using objective tools. As a model we used the signal transduction molecular network of a pyramidal neuron after complementing with TNAP related data and performed the analysis using graph theoretic tools. The analyses show that TNAP is in the crossroad of numerous pathways and therefore is one of the key players of the neuronal signal transduction network. Through many of its connections, most notably with molecules of the purinergic system, TNAP serves as a controller by funnelling signal flow towards a subset of molecules. TNAP also appears as the source of signal to be spread via interactions with molecules involved among others in neurodegeneration. Cluster analyses identified TNAP as part of the second messenger signalling cascade. However, TNAP also forms connections with other functional groups involved in neuronal signal transduction. The results indicate the distinct ways of involvement of TNAP in multiple neuronal functions and diseases.

  8. Signaling transduction pathways involved in basophil adhesion and histamine release

    DEFF Research Database (Denmark)

    Sha, Quan; Poulsen, Lars K.; Gerwien, Jens

    2006-01-01

    Little is known about basophil with respect to the different signaling transduction pathways involved in spontaneous, cytokine or anti-IgE induced adhesion and how this compares to IgE-dependent and IgE-independent mediator secretion. The purpose of the present study was to investigate the roles...... of beta1 and beta2 integrins in basophil adhesion as well as hosphatidylinositol 3-kinase (PI3K), src-kinases and extracellular signal regulated kinase (ERK) 1/2 in basophil adhesion and histamine release (HR)....

  9. Influence of arsenate and arsenite on signal transduction pathways: an update

    Energy Technology Data Exchange (ETDEWEB)

    Druwe, Ingrid L.; Vaillancourt, Richard R. [The University of Arizona College of Pharmacy, Department of Pharmacology and Toxicology, Tucson, AZ (United States)

    2010-08-15

    Arsenic has been a recognized contaminant and toxicant, as well as a medicinal compound throughout human history. Populations throughout the world are exposed to arsenic and these exposures have been associated with a number of human cancers. Not much is known about the role of arsenic as a human carcinogen and more recently its role in non-cancerous diseases, such as cardiovascular disease, hypertension and diabetes mellitus have been uncovered. The health effects associated with arsenic are numerous and the association between arsenic exposure and human disease has intensified the search for molecular mechanisms that describe the biological activity of arsenic in humans and leads to the aforementioned disease states. Arsenic poses a human health risk due in part to the regulation of cellular signal transduction pathways and over the last few decades, some cellular mechanisms that account for arsenic toxicity, as well as, signal transduction pathways have been discovered. However, given the ubiquitous nature of arsenic in the environment, making sense of all the data remains a challenge. This review will focus on our knowledge of signal transduction pathways that are regulated by arsenic. (orig.)

  10. Radiation-induced adaptive response and intracellular signal transduction pathways

    International Nuclear Information System (INIS)

    Tachibana, Akira

    2009-01-01

    As an essential biological function, cells can sense the radiation even at low dose and respond to it, and which is one of bases of the radiation-induced adaptive response (AR) where effects caused by high dose radiation are reduced by prior exposure to low dose radiation (LDR). Here described are studies of AR in well established m5S cells on the intracellular signal transduction that involves sensing of LDR and transmitting of its signal within the cell network. The first signal for AR yielded by LDR on the cell membrane is exactly unknown though hydrogen peroxide and phorbol ester (PMA) can reportedly cause AR. As PMA activates protein kinase C (PKC) and its inhibitors suppress AR, participation of PKC in AR has been suggested and supported by studies showing PKCα activation by LDR. In addition, p38 mitogen-activated protein kinase (MAPK) is shown to participate in AR by those facts that the enzyme is activated by LDR, a p38 MAPK inhibitor suppresses AR, and PKC inhibitors suppress the enzyme activation, which also suggesting that the signaling from PKC to p38 MAPK can become operative by LDR. However, the possible reverse signaling is also suggested, and thus the activation of positive feedback mechanism is postulated in PKC/p38 MAPK/phospholipase δ1/ PKC pathway. Cells introduced with siRNA against Prkca gene (coding PKCs) produce reduced amount of the enzyme, particularly, of PKCα. In those cells, AR by 5 Gy X-ray is not observed and thereby PKCα is involved in AR. The signaling in AR is only partly elucidated at present as above, and more detailed studies including identification of more PKC subtypes and signaling to DNA repair system are considered necessary. (K.T.)

  11. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pathways media

  12. Multiple signal transduction pathways in okadaic acid induced apoptosis in HeLa cells

    International Nuclear Information System (INIS)

    Jayaraj, R.; Gupta, Nimesh; Rao, P.V. Lakshmana

    2009-01-01

    Okadaic acid (OA) is the major component of diarrhetic shell fish poisoning toxins and a potent inhibitor of protein phosphatase 1 and 2A. We investigated the signal transduction pathways involved in OA induced cell death in HeLa cells. OA induced cytotoxicity and apoptosis at IC50 of 100 nM. OA treatment resulted in time dependent increase in reactive oxygen species and depleted intracellular glutathione levels. Loss of mitochondrial membrane permeability led to translocation of bax, cytochrome-c and AIF from mitochondria to cytosol. The cells under fluorescence microscope showed typical apoptotic morphology with condensed chromatin, and nuclear fragmentation. We investigated the mitochondrial-mediated caspase cascade. The time dependent activation and cleavage of of bax, caspases-8, 10, 9, 3 and 7 was observed in Western blot analysis. In addition to caspase-dependent pathway AIF mediated caspase-independent pathway was involved in OA mediated cell death. OA also caused time dependent inhibition of protein phosphatase 2A activity and phosphorylation of p38 and p42/44 MAP kinases. Inhibitor studies with Ac-DEVO-CHO and Z-VAD-FMK could not prevent the phosphorylation of p38 and p42/44 MAP kinases. Our experiments with caspase inhibitors Ac-DEVD-CHO, Z-IETD-FMK and Z-VAD-FMK inhibited capsase-3, 8 cleavages but did not prevent OA-induced apoptosis and DNA fragmentation. Similarly, pretreatment with cyclosporin-A and N-acetylcysteine could not prevent the DNA fragmentation. In summary, the results of our study show that OA induces multiple signal transduction pathways acting either independently or simultaneously leading to apoptosis

  13. Erythrocyte signal transduction pathways, their oxygenation dependence and functional significance.

    Science.gov (United States)

    Barvitenko, Nadezhda N; Adragna, Norma C; Weber, Roy E

    2005-01-01

    Erythrocytes play a key role in human and vertebrate metabolism. Tissue O2 supply is regulated by both hemoglobin (Hb)-O2 affinity and erythrocyte rheology, a key determinant of tissue perfusion. Oxygenation-deoxygenation transitions of Hb may lead to re-organization of the cytoskeleton and signalling pathways activation/deactivation in an O2-dependent manner. Deoxygenated Hb binds to the cytoplasmic domain of the anion exchanger band 3, which is anchored to the cytoskeleton, and is considered a major mechanism underlying the oxygenation-dependence of several erythrocyte functions. This work discusses the multiple modes of Hb-cytoskeleton interactions. In addition, it reviews the effects of Mg2+, 2,3-diphosphoglycerate, NO, shear stress and Ca2+, all factors accompanying the oxygenation-deoxygenation cycle in circulating red cells. Due to the extensive literature on the subject, the data discussed here, pertain mainly to human erythrocytes whose O2 affinity is modulated by 2,3-diphosphoglycerate, ectothermic vertebrate erythrocytes that use ATP, and to bird erythrocytes that use inositol pentaphosphate. Copyright 2005 S. Karger AG, Basel.

  14. DMPD: When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18631453 When signaling pathways collide: positive and negative regulation of toll-...uction. PubmedID 18631453 Title When signaling pathways collide: positive and neg...l) Show When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transd...likereceptor signal transduction. O'Neill LA. Immunity. 2008 Jul 18;29(1):12-20. (.png) (.svg) (.html) (.csm

  15. Network features and pathway analyses of a signal transduction cascade

    Directory of Open Access Journals (Sweden)

    Ryoji Yanashima

    2009-05-01

    Full Text Available The scale-free and small-world network models reflect the functional units of networks. However, when we investigated the network properties of a signaling pathway using these models, no significant differences were found between the original undirected graphs and the graphs in which inactive proteins were eliminated from the gene expression data. We analyzed signaling networks by focusing on those pathways that best reflected cellular function. Therefore, our analysis of pathways started from the ligands and progressed to transcription factors and cytoskeletal proteins. We employed the Python module to assess the target network. This involved comparing the original and restricted signaling cascades as a directed graph using microarray gene expression profiles of late onset Alzheimer's disease. The most commonly used method of shortest-path analysis neglects to consider the influences of alternative pathways that can affect the activation of transcription factors or cytoskeletal proteins. We therefore introduced included k-shortest paths and k-cycles in our network analysis using the Python modules, which allowed us to attain a reasonable computational time and identify k-shortest paths. This technique reflected results found in vivo and identified pathways not found when shortest path or degree analysis was applied. Our module enabled us to comprehensively analyse the characteristics of biomolecular networks and also enabled analysis of the effects of diseases considering the feedback loop and feedforward loop control structures as an alternative path.

  16. Signal Transduction Pathways that Regulate CAB Gene Expression

    Energy Technology Data Exchange (ETDEWEB)

    Chory, Joanne

    2004-12-31

    The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

  17. Signal Transduction Pathways that Regulate CAB Gene Expression

    Energy Technology Data Exchange (ETDEWEB)

    Chory, Joanne

    2006-01-16

    The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

  18. Beacon Editor: Capturing Signal Transduction Pathways Using the Systems Biology Graphical Notation Activity Flow Language.

    Science.gov (United States)

    Elmarakeby, Haitham; Arefiyan, Mostafa; Myers, Elijah; Li, Song; Grene, Ruth; Heath, Lenwood S

    2017-12-01

    The Beacon Editor is a cross-platform desktop application for the creation and modification of signal transduction pathways using the Systems Biology Graphical Notation Activity Flow (SBGN-AF) language. Prompted by biologists' requests for enhancements, the Beacon Editor includes numerous powerful features for the benefit of creation and presentation.

  19. Effects of matrine on JAK-STAT signaling transduction pathways in ...

    African Journals Online (AJOL)

    The current study aims to investigate the effects of matrine on the JAK-STAT signaling transduction pathways in bleomycin (BLM)-induced pulmonary fibrosis (PF) and to explore its action mechanism. A total of 72 male C57BL/6 mice were randomized into the control, model, and treatment groups. PF models were ...

  20. The Drosophila rolled locus encodes a MAP kinase required in the sevenless signal transduction pathway.

    OpenAIRE

    Biggs, W H; Zavitz, K H; Dickson, B; van der Straten, A; Brunner, D; Hafen, E; Zipursky, S L

    1994-01-01

    Mitogen-activated protein (MAP) kinases have been proposed to play a critical role in receptor tyrosine kinase (RTK)-mediated signal transduction pathways. Although genetic and biochemical studies of RTK pathways in Caenorhabditis elegans, Drosophila melanogaster and mammals have revealed remarkable similarities, a genetic requirement for MAP kinases in RTK signaling has not been established. During retinal development in Drosophila, the sevenless (Sev) RTK is required for development of the ...

  1. Sensors and signal transduction pathways in vertebrate cell volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Pedersen, Stine F

    2006-01-01

    The ability to control cell volume is fundamental for proper cell function. This review highlights recent advances in the understanding of the complex sequences of events by which acute cell volume perturbation alters the activity of osmolyte transport proteins in cells from vertebrate organisms...... will be discussed. In contrast to the simple pathway of osmosensing in yeast, cells from vertebrate organisms appear to exhibit multiple volume sensing systems, the specific mechanism(s) activated being cell type- and stimulus-dependent. Candidate sensors include integrins and growth factor receptors, while other...

  2. Presynaptic signal transduction pathways that modulate synaptic transmission

    NARCIS (Netherlands)

    de Jong, A.P.H.; Verhage, M.

    2009-01-01

    Presynaptic modulation is a crucial factor in the adaptive capacity of the nervous system. The coupling between incoming action potentials and neurotransmitter secretion is modulated by firstly, recent activity of the presynaptic axon that leads to the accumulation of residual calcium in the

  3. Downstream reporter gene imaging for signal transduction pathway of dopamine type 2 receptor

    International Nuclear Information System (INIS)

    Le, Uyenchi N.; Min, Jung Joon; Moon, Sung Min; Bom, Hee Seung

    2004-01-01

    The Dopamine 2 receptor (D2R) signal pathway regulates gene expression by phosphorylation of proteins including cAMP reponse element-binding protein (CREB), a transcription factor. In this study, we developed a reporter strategy using the GAL4 fusion CREB to assess the phosphorylation of CREB, one of the targets of the D2R signal transduction pathway. We used three plasmids: GAL4 fusion transactivator (pCMV-CREB), firefly luciferase reporter with GAL4 binding sites (pG5-FLUC), and D2R plasmid (pCMV-D2R). Group 1 293T cells were transiently transfected with pCMV-CREB and pG5-FLUC, and group 2 cells were transfected with all three plasmids. Transfected cells were stimulated with different concentrations of dopamine (0-200 M). For animal studies, group 1 and 2 cells (1x10 6 ) were subcutaneously injected on the left and right thigh of six nude mice, respectively. Dopamine stimiulation was performed with intraperitoneal injection of L-DOPA incombination with carbidopa, a peripheral DOPA decarboxylase inhibitor. Bioluminescence optical imaging studies were performed before and after L-DOPA injection. In cell culture studies, group 1 cells showed strong luciferase activity which implies direct activation of the signaling pathway due to growth factors contained in culture medium. Group 2 cells showed strong luciferase activity and a further increase after administration of dopamine. In animal studies, group 1 and 2 cells showed bioluminescence signal before L-DOPA injection, but signal from group 2 cells significantly increased 12 h after L-DOPA injection. The signal from group 1 cells disappeared thereafter, but group 2 cells continued to show signal until 36 h of L-DOPA injection. This study demonstrates imaging of the D2R signal transduction pathway and should be useful for noninvasive imaging of downstream effects of G-coupled protein pathways

  4. Creating and analyzing pathway and protein interaction compendia for modelling signal transduction networks

    Directory of Open Access Journals (Sweden)

    Kirouac Daniel C

    2012-05-01

    Full Text Available Abstract Background Understanding the information-processing capabilities of signal transduction networks, how those networks are disrupted in disease, and rationally designing therapies to manipulate diseased states require systematic and accurate reconstruction of network topology. Data on networks central to human physiology, such as the inflammatory signalling networks analyzed here, are found in a multiplicity of on-line resources of pathway and interactome databases (Cancer CellMap, GeneGo, KEGG, NCI-Pathway Interactome Database (NCI-PID, PANTHER, Reactome, I2D, and STRING. We sought to determine whether these databases contain overlapping information and whether they can be used to construct high reliability prior knowledge networks for subsequent modeling of experimental data. Results We have assembled an ensemble network from multiple on-line sources representing a significant portion of all machine-readable and reconcilable human knowledge on proteins and protein interactions involved in inflammation. This ensemble network has many features expected of complex signalling networks assembled from high-throughput data: a power law distribution of both node degree and edge annotations, and topological features of a “bow tie” architecture in which diverse pathways converge on a highly conserved set of enzymatic cascades focused around PI3K/AKT, MAPK/ERK, JAK/STAT, NFκB, and apoptotic signaling. Individual pathways exhibit “fuzzy” modularity that is statistically significant but still involving a majority of “cross-talk” interactions. However, we find that the most widely used pathway databases are highly inconsistent with respect to the actual constituents and interactions in this network. Using a set of growth factor signalling networks as examples (epidermal growth factor, transforming growth factor-beta, tumor necrosis factor, and wingless, we find a multiplicity of network topologies in which receptors couple to downstream

  5. Non Linear Programming (NLP) formulation for quantitative modeling of protein signal transduction pathways.

    Science.gov (United States)

    Mitsos, Alexander; Melas, Ioannis N; Morris, Melody K; Saez-Rodriguez, Julio; Lauffenburger, Douglas A; Alexopoulos, Leonidas G

    2012-01-01

    Modeling of signal transduction pathways plays a major role in understanding cells' function and predicting cellular response. Mathematical formalisms based on a logic formalism are relatively simple but can describe how signals propagate from one protein to the next and have led to the construction of models that simulate the cells response to environmental or other perturbations. Constrained fuzzy logic was recently introduced to train models to cell specific data to result in quantitative pathway models of the specific cellular behavior. There are two major issues in this pathway optimization: i) excessive CPU time requirements and ii) loosely constrained optimization problem due to lack of data with respect to large signaling pathways. Herein, we address both issues: the former by reformulating the pathway optimization as a regular nonlinear optimization problem; and the latter by enhanced algorithms to pre/post-process the signaling network to remove parts that cannot be identified given the experimental conditions. As a case study, we tackle the construction of cell type specific pathways in normal and transformed hepatocytes using medium and large-scale functional phosphoproteomic datasets. The proposed Non Linear Programming (NLP) formulation allows for fast optimization of signaling topologies by combining the versatile nature of logic modeling with state of the art optimization algorithms.

  6. Non Linear Programming (NLP formulation for quantitative modeling of protein signal transduction pathways.

    Directory of Open Access Journals (Sweden)

    Alexander Mitsos

    Full Text Available Modeling of signal transduction pathways plays a major role in understanding cells' function and predicting cellular response. Mathematical formalisms based on a logic formalism are relatively simple but can describe how signals propagate from one protein to the next and have led to the construction of models that simulate the cells response to environmental or other perturbations. Constrained fuzzy logic was recently introduced to train models to cell specific data to result in quantitative pathway models of the specific cellular behavior. There are two major issues in this pathway optimization: i excessive CPU time requirements and ii loosely constrained optimization problem due to lack of data with respect to large signaling pathways. Herein, we address both issues: the former by reformulating the pathway optimization as a regular nonlinear optimization problem; and the latter by enhanced algorithms to pre/post-process the signaling network to remove parts that cannot be identified given the experimental conditions. As a case study, we tackle the construction of cell type specific pathways in normal and transformed hepatocytes using medium and large-scale functional phosphoproteomic datasets. The proposed Non Linear Programming (NLP formulation allows for fast optimization of signaling topologies by combining the versatile nature of logic modeling with state of the art optimization algorithms.

  7. Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway.

    Science.gov (United States)

    Sato, Yukuto; Hashiguchi, Yasuyuki; Nishida, Mutsumi

    2009-02-20

    Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization) and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization). Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 3.1.4.17) 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8-9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT) pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our analyses imply that an increase in gene product sometimes

  8. Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway

    Directory of Open Access Journals (Sweden)

    Nishida Mutsumi

    2009-02-01

    Full Text Available Abstract Background Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization. Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. Results We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 3.1.4.17 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8–9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. Conclusion The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our

  9. Rice PLASTOCHRON genes regulate leaf maturation downstream of the gibberellin signal transduction pathway.

    Science.gov (United States)

    Mimura, Manaki; Nagato, Yasuo; Itoh, Jun-Ichi

    2012-05-01

    Rice PLASTOCHRON 1 (PLA1) and PLA2 genes regulate leaf maturation and plastochron, and their loss-of-function mutants exhibit small organs and rapid leaf emergence. They encode a cytochrome P450 protein CYP78A11 and an RNA-binding protein, respectively. Their homologs in Arabidopsis and maize are also associated with plant development/organ size. Despite the importance of PLA genes in plant development, their molecular functions remain unknown. Here, we investigated how PLA1 and PLA2 genes are related to phytohormones. We found that gibberellin (GA) is the major phytohormone that promotes PLA1 and PLA2 expression. GA induced PLA1 and PLA2 expression, and conversely the GA-inhibitor uniconazole suppressed PLA1 and PLA2 expression. In pla1-4 and pla2-1 seedlings, expression levels of GA biosynthesis genes and the signal transduction gene were similar to those in wild-type seedlings. GA treatment slightly down-regulated the GA biosynthesis gene GA20ox2 and up-regulated the GA-catabolizing gene GA2ox4, whereas the GA biosynthesis inhibitor uniconazole up-regulated GA20ox2 and down-regulated GA2ox4 both in wild-type and pla mutants, suggesting that the GA feedback mechanism is not impaired in pla1 and pla2. To reveal how GA signal transduction affects the expression of PLA1 and PLA2, PLA expression in GA-signaling mutants was examined. In GA-insensitive mutant, gid1 and less-sensitive mutant, Slr1-d1, PLA1 and PLA2 expression was down-regulated. On the other hand, the expression levels of PLA1 and PLA2 were highly enhanced in a GA-constitutive-active mutant, slr1-1, causing ectopic overexpression. These results indicate that both PLA1 and PLA2 act downstream of the GA signal transduction pathway to regulate leaf development.

  10. Elucidation of the Signal Transduction Pathways Activated by the Plant Natriuretic Peptide AtPNP-A

    KAUST Repository

    Turek, Ilona

    2014-11-01

    Plant natriuretic peptides (PNPs) comprise a novel class of hormones that share some sequence similarity in the active site with their animal analogues that function as regulators of salt and water balance. A PNP present in Arabidopsis thaliana (AtPNP-A) has been assigned a role in abiotic and biotic stress responses, and the recombinant protein has been demonstrated to elicit cyclic guanosine monophosphate (cGMP)-dependent stomatal guard cell opening, regulate ion movements, and induce osmoticum-dependent water uptake. Although the importance of the hormone in maintaining ion and fluid homeostasis has been established, key components of the AtPNP-A-dependent signal transduction pathway remain unknown. Since identification of the binding partners of AtPNP-A, including its receptor(s), is fundamental to understanding the mode of its action at the molecular level, comprehensive protein-protein interaction studies, involving yeast two-hybrid screening, affinity-based assays, protein cross-linking and co-immunoprecipitation followed by mass spectrometric (MS) analyses have been performed. Several candidate binding partners of AtPNP-A identified with at least two independent methods were subsequently expressed as recombinant proteins, purified, and the specificity of their interactions with the recombinant AtPNP-A was verified using surface plasmon resonance. Several specific binary interactants of AtPNP-A were subjected to functional assays aimed at unraveling the consequences of the interactions in planta. These experiments have revealed that reactive oxygen species (ROS) are novel secondary messengers involved in the transduction of AtPNP-A signal in suspension-cultured cells of A. thaliana (Col-0). Further insight into the AtPNP-A dependent signalling events occurring in suspension-cultured cells in ROS-dependent or ROS-independent manner have been obtained from the large-scale proteomics study employing tandem mass tag (TMT) labelling followed by MS analysis to

  11. Signal transduction of p53-independent apoptotic pathway induced by hexavalent chromium in U937 cells

    International Nuclear Information System (INIS)

    Hayashi, Yoko; Kondo, Takashi; Zhao Qingli; Ogawa Ryohei; Cui Zhengguo; Feril, Loreto B.; Teranishi, Hidetoyo; Kasuya, Minoru

    2004-01-01

    It has been reported that the hexavalent chromium compound (Cr(VI)) can induce both p53-dependent and p53-independent apoptosis. While a considerable amount of information is available on the p53-dependent pathway, only little is known about the p53-independent pathway. To elucidate the p53-independent mechanism, the roles of the Ca 2+ -calpain- and mitochondria-caspase-dependent pathways in apoptosis induced by Cr(VI) were investigated. When human lymphoma U937 cells, p53 mutated cells, were treated with 20 μM Cr(VI) for 24 h, nuclear morphological changes and DNA fragmentation were observed. Production of hydroxyl radicals revealed by electron paramagnetic resonance (EPR)-spin trapping, and increase of intracellular calcium ion concentration monitored by digital imaging were also observed in Cr(VI)-treated cells. An intracellular Ca 2+ chelator, BAPTA-AM, and calpain inhibitors suppressed the Cr(VI)-induced DNA fragmentation. The number of cells showing low mitochondrial membrane potential (MMP), high level of superoxide anion radicals (O 2 - ), and high activity of caspase-3, which are indicators of mitochondria-caspase-dependent pathway, increased significantly in Cr(VI)-treated cells. An antioxidant, N-acetyl-L-cysteine (NAC), decreased DNA fragmentation and inhibited the changes in MMP, O 2 - formation, and activation of caspase-3 induced by Cr(VI). No increase of the expressions of Fas and phosphorylated JNK was observed after Cr(VI) treatment. Cell cycle analysis revealed that the fraction of G2/M phase tended to increase after 24 h of treatment, suggesting that Cr(VI)-induced apoptosis is related to the G2 block. These results indicate that Ca 2+ -calpain- and mitochondria-caspase-dependent pathways play significant roles in the Cr(VI)-induced apoptosis via the G2 block, which are independent of JNK and Fas activation. The inhibition of apoptosis and all its signal transductions by NAC suggests that intracellular reactive oxygen species (ROS) are

  12. The p75NTR mediates a bifurcated signal transduction cascade through the NFκB and JNK pathways to inhibit cell survival

    International Nuclear Information System (INIS)

    Allen, Jeffrey; Khwaja, Fatima; Byers, Stephen; Djakiew, Daniel

    2005-01-01

    p75 NTR is most abundantly expressed in the nervous system, but is also widely expressed in many other organs and tissues where it primarily functions as a negative regulator of cell survival. In the prostate, p75 NTR functions as an inhibitory protein capable of slowing proliferation and inducing apoptosis. It has been shown that p75 NTR is expressed in the normal prostate, progressively lost from malignant tumor cells in vivo, and largely absent from prostate cancer cell lines derived from metastases. Although the role of p75 NTR in prostate cancer has been well established, the signal transduction pathway that mediates its inhibitory activity has only been partially elucidated. This study demonstrates that exogenous expression of p75 NTR down-regulates, in a dose-dependent manner, a bifurcated signaling cascade that results in reduced expression of potent transcription effectors. This two-arm signal transduction cascade was directly linked to the upstream receptor by using dominant-negative deletion constructs of p75 NTR that rescued tumor cells from p75 NTR -induced loss of survival and promotion of apoptosis. Furthermore, the dominant negatives rescued alterations in the levels of signal transduction intermediates. Conversely, the use of kinase-inactive intermediates that are downstream of the receptor further reduced expression of involved transcription effectors and reduced survival of the cells. These results provide a definitive link between the proximate p75 NTR and signal transduction intermediates leading to the transcription effectors NFκB and JNK, with associated growth suppression and induction of apoptosis

  13. Immunophilin ligands demonstrate common features of signal transduction leading to exocytosis or transcription.

    Science.gov (United States)

    Hultsch, T; Albers, M W; Schreiber, S L; Hohman, R J

    1991-01-01

    Investigations of the actions and interactions of the immunophilin ligands FK506, cyclosporin A (CsA), rapamycin, and 506BD suggest that complexes of FK506 with an FK506-binding protein or of CsA with a cyclophilin (CsA-binding protein) inhibit the T-cell receptor-mediated signal transduction that results in the transcription of interleukin 2. Now we report an identical spectrum of activities of FK506, CsA, rapamycin, and 506BD on IgE receptor-mediated signal transduction that results in exocytosis of secretory granules from the rat basophilic leukemia cell line RBL-2H3, a mast cell model. Both FK506 and CsA inhibit receptor-mediated exocytosis (CsA IC50 = 200 nM; FK506 IC50 = 2 nM) without affecting early receptor-associated events (hydrolysis of phosphatidylinositol, synthesis and release of eicosanoids, uptake of Ca2+). In contrast, rapamycin and 506BD, which share common structural elements with FK506, by themselves have no effect on IgE receptor-mediated exocytosis. Both compounds, however, prevent inhibition by FK506 but not by CsA. Affinity chromatography with FK506, CsA, and rapamycin matrices indicates that the same set of immunophilins present in RBL-2H3 cells have been found in Jurkat T cells and calf thymus; however, the relative amounts of these proteins differ in the two cell types. These results suggest the existence of a common step in cytoplasmic signaling in T cells and mast cells that may be part of a general signaling mechanism. Images PMID:1712484

  14. Relationship between nitric oxide- and calcium-dependent signal transduction pathways in growth hormone release from dispersed goldfish pituitary cells.

    Science.gov (United States)

    Chang, John P; Sawisky, Grant R; Davis, Philip J; Pemberton, Joshua G; Rieger, Aja M; Barreda, Daniel R

    2014-09-15

    Nitric oxide (NO) and Ca(2+) are two of the many intracellular signal transduction pathways mediating the control of growth hormone (GH) secretion from somatotropes by neuroendocrine factors. We have previously shown that the NO donor sodium nitroprusside (SNP) elicits Ca(2+) signals in identified goldfish somatotropes. In this study, we examined the relationships between NO- and Ca(2+)-dependent signal transduction mechanisms in GH secretion from primary cultures of dispersed goldfish pituitary cells. Morphologically identified goldfish somatotropes stained positively for an NO-sensitive dye indicating they may be a source of NO production. In 2h static incubation experiments, GH release responses to the NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) were attenuated by CoCl2, nifedipine, verapamil, TMB-8, BHQ, and KN62. In column perifusion experiments, the ability of SNP to induce GH release was impaired in the presence of TMB-8, BHQ, caffeine, and thapsigargin, but not ryanodine. Caffeine-elicited GH secretion was not affected by the NO scavenger PTIO. These results suggest that NO-stimulated GH release is dependent on extracellular Ca(2+) availability and voltage-sensitive Ca(2+) channels, as well as intracellular Ca(2+) store(s) that possess BHQ- and/or thapsigargin-inhibited sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases, as well as TMB-8- and/or caffeine-sensitive, but not ryanodine-sensitive, Ca(2+)-release channels. Calmodulin kinase-II also likely participates in NO-elicited GH secretion but caffeine-induced GH release is not upstream of NO production. These findings provide insights into how NO actions many integrate with Ca(2+)-dependent signalling mechanisms in goldfish somatotropes and how such interactions may participate in the GH-releasing actions of regulators that utilize both NO- and Ca(2+)-dependent transduction pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Proatherogenic pathways leading to vascular calcification

    International Nuclear Information System (INIS)

    Mazzini, Michael J.; Schulze, P. Christian

    2006-01-01

    Cardiovascular disease is the leading cause of morbidity and mortality in the western world and atherosclerosis is the major common underlying disease. The pathogenesis of atherosclerosis involves local vascular injury, inflammation and oxidative stress as well as vascular calcification. Vascular calcification has long been regarded as a degenerative process leading to mineral deposition in the vascular wall characteristic for late stages of atherosclerosis. However, recent studies identified vascular calcification in early stages of atherosclerosis and its occurrence has been linked to clinical events in patients with cardiovascular disease. Its degree correlates with local vascular inflammation and with the overall impact and the progression of atherosclerosis. Over the last decade, diverse and highly regulated molecular signaling cascades controlling vascular calcification have been described. Local and circulating molecules such as osteopontin, osteoprogerin, leptin and matrix Gla protein were identified as critical regulators of vascular calcification. We here review the current knowledge on molecular pathways of vascular calcification and their relevance for the progression of cardiovascular disease

  16. The human keratinocyte two-dimensional gel protein database (update 1995): mapping components of signal transduction pathways

    DEFF Research Database (Denmark)

    Celis, J E; Rasmussen, H H; Gromov, P

    1995-01-01

    identified (protein name, organelle components, etc.) using a procedure or a combination of procedures that include (i) comigration with known human proteins, (ii) 2-D gel immunoblotting using specific antibodies, (iii) microsequencing of Coomassie Brilliant Blue stained proteins, (iv) mass spectrometry, (v......)vaccinia virus expression of full length cDNAs, and (vi) in vitro transcription/translation of full-length cDNAs. This year, special emphasis has been given to the identification of signal transduction components by using 2-D gel immunoblotting of crude keratinocyte lysates in combination with enhanced......--through a systematic study of ekeratinocytes--qualitative and quantitative information on proteins and their genes that may allow us to identify abnormal patterns of gene expression and to pinpoint signaling pathways and components affected in various skin diseases, cancer included. Udgivelsesdato: 1995-Dec...

  17. Plasma Gelsolin Induced Glomerular Fibrosis via the TGF-β1/Smads Signal Transduction Pathway in IgA Nephropathy

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2017-02-01

    Full Text Available Glomerular fibrosis has been shown to be closely related to the progression and prognosis of IgA nephropathy (IgAN. However, mechanism underlying IgAN glomerular fibrosis remains unclear. Recently, our study showed that plasma gelsolin (pGSN was decreased in the serum of an IgAN mouse model and that pGSN deposition was found in the glomeruli. Another cytokine, TGF-β1, which is closely related to glomerular fibrosis, was also found to be highly expressed in the glomeruli. In the present study, we report that pGSN induces glomerular fibrosis through the TGF-β1/Smads signal transduction pathway. This is supported by the following findings: human mesangial cells (HMCs show remarkable morphological changes and proliferation in response to co-stimulation with pGSN and polymeric IgA1 (pIgA1 from IgAN patients compared to other controls. Moreover, ELISA assays showed that more TGF-β1 secretion was found in HMCs supernatants in the co-stimulation group. Further experiments showed increased TGF-β1, Smad3, p-Smad2/3, Smad4, and collagen 1 and decreased Smad7 expression in the co-stimulation group. Our present study implied that the synergistic effect of pGSN and pIgA induced glomerular fibrosis via the TGF-β1/Smads signal transduction pathway. This might be a potential mechanism for the glomerular fibrosis observed in IgAN patients.

  18. Plasma Gelsolin Induced Glomerular Fibrosis via the TGF-β1/Smads Signal Transduction Pathway in IgA Nephropathy

    Science.gov (United States)

    Zhang, Lei; Han, Changsong; Ye, Fei; He, Yan; Jin, Yinji; Wang, Tianzhen; Wu, Yiqi; Jiang, Yang; Zhang, Fengmin; Jin, Xiaoming

    2017-01-01

    Glomerular fibrosis has been shown to be closely related to the progression and prognosis of IgA nephropathy (IgAN). However, mechanism underlying IgAN glomerular fibrosis remains unclear. Recently, our study showed that plasma gelsolin (pGSN) was decreased in the serum of an IgAN mouse model and that pGSN deposition was found in the glomeruli. Another cytokine, TGF-β1, which is closely related to glomerular fibrosis, was also found to be highly expressed in the glomeruli. In the present study, we report that pGSN induces glomerular fibrosis through the TGF-β1/Smads signal transduction pathway. This is supported by the following findings: human mesangial cells (HMCs) show remarkable morphological changes and proliferation in response to co-stimulation with pGSN and polymeric IgA1 (pIgA1) from IgAN patients compared to other controls. Moreover, ELISA assays showed that more TGF-β1 secretion was found in HMCs supernatants in the co-stimulation group. Further experiments showed increased TGF-β1, Smad3, p-Smad2/3, Smad4, and collagen 1 and decreased Smad7 expression in the co-stimulation group. Our present study implied that the synergistic effect of pGSN and pIgA induced glomerular fibrosis via the TGF-β1/Smads signal transduction pathway. This might be a potential mechanism for the glomerular fibrosis observed in IgAN patients. PMID:28208683

  19. The ARG1-LIKE2 gene of Arabidopsis functions in a gravity signal transduction pathway that is genetically distinct from the PGM pathway

    Science.gov (United States)

    Guan, Changhui; Rosen, Elizabeth S.; Boonsirichai, Kanokporn; Poff, Kenneth L.; Masson, Patrick H.

    2003-01-01

    The arl2 mutants of Arabidopsis display altered root and hypocotyl gravitropism, whereas their inflorescence stems are fully gravitropic. Interestingly, mutant roots respond like the wild type to phytohormones and an inhibitor of polar auxin transport. Also, their cap columella cells accumulate starch similarly to wild-type cells, and mutant hypocotyls display strong phototropic responses to lateral light stimulation. The ARL2 gene encodes a DnaJ-like protein similar to ARG1, another protein previously implicated in gravity signal transduction in Arabidopsis seedlings. ARL2 is expressed at low levels in all organs of seedlings and plants. arl2-1 arg1-2 double mutant roots display kinetics of gravitropism similar to those of single mutants. However, double mutants carrying both arl2-1 and pgm-1 (a mutation in the starch-biosynthetic gene PHOSPHOGLUCOMUTASE) at the homozygous state display a more pronounced root gravitropic defect than the single mutants. On the other hand, seedlings with a null mutation in ARL1, a paralog of ARG1 and ARL2, behave similarly to the wild type in gravitropism and other related assays. Taken together, the results suggest that ARG1 and ARL2 function in the same gravity signal transduction pathway in the hypocotyl and root of Arabidopsis seedlings, distinct from the pathway involving PGM.

  20. Characterization of Heregulin-Stimulated Signal Transduction Pathways to the Nucleus

    National Research Council Canada - National Science Library

    Wilson, Kristin

    2000-01-01

    ... 40% of breast cancers and correlates with a poor prognosis for women with breast cancer. Mapping the molecular determinants of the heregulin/ErbB2 signaling pathway will be important in determining viable cellular targets for therapeutic intervention...

  1. Signaling in Parasitic Nematodes: Physicochemical Communication Between Host and Parasite and Endogenous Molecular Transduction Pathways Governing Worm Development and Survival.

    Science.gov (United States)

    Lok, James B

    2016-12-01

    Signaling or communication between host and parasite may occur over relatively long ranges to enable host finding and acquisition by infective parasitic nematode larvae. Innate behaviors in infective larvae transmitted from the soil that enhance the likelihood of host contact, such as negative geotaxis and hypermotility, are likely mediated by mechanoreception and neuromuscular signaling. Host cues such as vibration of the substratum, elevated temperature, exhaled CO 2 , and other volatile odorants are perceived by mechanosensory and chemosensory neurons of the amphidial complex. Beyond this, the molecular systems that transduce these external cues within the worm are unknown at this time. Overall, the signal transduction mechanisms that regulate switching between dauer and continuous reproductive development in Caenorhabditis elegans , and doubtless other free-living nematodes, have provided a useful framework for testing hypotheses about how the morphogenesis and development of infective parasitic nematode larvae and the lifespan of adult parasites are regulated. In C. elegans , four major signal transduction pathways, G protein-coupled receptor signaling, insulin/insulin-like growth factor signaling, TGFβ-like signaling and steroid-nuclear hormone receptor signaling govern the switch between dauer and continuous development and regulate adult lifespan. Parasitic nematodes appear to have conserved the functions of G-protein-coupled signaling, insulin-like signaling and steroid-nuclear hormone receptor signaling to regulate larval development before and during the infective process. By contrast, TGFβ-like signaling appears to have been adapted for some other function, perhaps modulation of the host immune response. Of the three signal transduction pathways that appear to regulate development in parasitic nematodes, steroid-nuclear hormone signaling is the most straightforward to manipulate with administered small molecules and may form the basis of new

  2. Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

    Science.gov (United States)

    Saher, G; Hildt, E

    1999-09-24

    Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

  3. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  4. Diet-induced obesity mediated by the JNK/DIO2 signal transduction pathway

    Science.gov (United States)

    Vernia, Santiago; Cavanagh-Kyros, Julie; Barrett, Tamera; Jung, Dae Young; Kim, Jason K.; Davis, Roger J.

    2013-01-01

    The cJun N-terminal kinase (JNK) signaling pathway is a key mediator of metabolic stress responses caused by consuming a high-fat diet, including the development of obesity. To test the role of JNK, we examined diet-induced obesity in mice with targeted ablation of Jnk genes in the anterior pituitary gland. These mice exhibited an increase in the pituitary expression of thyroid-stimulating hormone (TSH), an increase in the blood concentration of thyroid hormone (T4), increased energy expenditure, and markedly reduced obesity compared with control mice. The increased amount of pituitary TSH was caused by reduced expression of type 2 iodothyronine deiodinase (Dio2), a gene that is required for T4-mediated negative feedback regulation of TSH expression. These data establish a molecular mechanism that accounts for the regulation of energy expenditure and the development of obesity by the JNK signaling pathway. PMID:24186979

  5. MAPK Signal Transduction Pathway Regulation: A Novel Mechanism of Rat HSC-T6 Cell Apoptosis Induced by FUZHENGHUAYU Tablet

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2013-01-01

    Full Text Available FUZHENGHUAYU Tablets have been widely used in the treatment of liver fibrosis in China. Here, we investigate the apoptotic effect of FUZHENGHUAYU Tablet in rat liver stellate cell line HSC-T6. HSC-T6 cells were incubated with control serum or drug serum from rats fed with 0.9% NaCl or FUZHENGHUAYU Tablet, respectively. Cells exposed to drug serum showed higher proportions of early and late apoptotic cells than controls. The mRNA levels of collagens I and III, TGF-β1 and α-SMA were reduced by drug serum compared to control serum. Differentially expressed mRNAs and miRNAs were analyzed by microarray and sequencing, respectively. We identified 334 differentially expressed mRNAs and also 60 GOs and two pathways related to the mRNAs. Seventy-five differentially expressed miRNAs were down-regulated by drug serum and 1963 target genes were predicted. 134 GOs up-regulated in drug serum group were linked to miRNA targets, and drug serum also regulated 43 miRNA signal transduction pathways. Protein levels were evaluated by Western blot. Drug serum down-regulated (phospho-SAPK/JNK/(SAPK/JNK and up-regulated phospho-p38/p38 ratios. The study showed that FUZHENGHUAYU Tablet induced apoptosis in rat HSC-T6 cells possibly in part by activating p38 and inhibiting SAPK/JNK.

  6. An alternative mode of CD43 signal transduction activates pro-survival pathways of T lymphocytes.

    Science.gov (United States)

    Bravo-Adame, Maria Elena; Vera-Estrella, Rosario; Barkla, Bronwyn J; Martínez-Campos, Cecilia; Flores-Alcantar, Angel; Ocelotl-Oviedo, Jose Pablo; Pedraza-Alva, Gustavo; Rosenstein, Yvonne

    2017-01-01

    CD43 is one of the most abundant co-stimulatory molecules on a T-cell surface; it transduces activation signals through its cytoplasmic domain, contributing to modulation of the outcome of T-cell responses. The aim of this study was to uncover new signalling pathways regulated by this sialomucin. Analysis of changes in protein abundance allowed us to identify pyruvate kinase isozyme M2 (PKM2), an enzyme of the glycolytic pathway, as an element potentially participating in the signalling cascade resulting from the engagement of CD43 and the T-cell receptor (TCR). We found that the glycolytic activity of this enzyme was not significantly increased in response to TCR+CD43 co-stimulation, but that PKM2 was tyrosine phosphorylated, suggesting that it was performing moonlight functions. We report that phosphorylation of both Y 105 of PKM2 and of Y 705 of signal transducer and activator of transcription 3 was induced in response to TCR+CD43 co-stimulation, resulting in activation of the mitogen-activated protein kinase kinase 5/extracellular signal-regulated kinase 5 (MEK5/ERK5) pathway. ERK5 and the cAMP response element binding protein (CREB) were activated, and c-Myc and nuclear factor-κB (p65) nuclear localization, as well as Bad phosphorylation, were augmented. Consistent with this, expression of human CD43 in a murine T-cell hybridoma favoured cell survival. Altogether, our data highlight novel signalling pathways for the CD43 molecule in T lymphocytes, and underscore a role for CD43 in promoting cell survival through non-glycolytic functions of metabolic enzymes. © 2016 John Wiley & Sons Ltd.

  7. Trichoderma Biocontrol: Signal Transduction Pathways Involved in Host Sensing and Mycoparasitism

    Directory of Open Access Journals (Sweden)

    Susanne Zeilinger

    2007-01-01

    Full Text Available Fungi of the genus Trichoderma are used as biocontrol agents against several plant pathogenic fungi like Rhizoctonia spp., Pythium spp., Botrytis cinerea and Fusarium spp. which cause both soil-borne and leaf- or flower-borne diseases of agricultural plants. Plant disease control by Trichoderma is based on complex interactions between Trichoderma, the plant pathogen and the plant. Until now, two main components of biocontrol have been identified: direct activity of Trichoderma against the plant pathogen by mycoparasitism and induced systemic resistance in plants. As the mycoparasitic interaction is host-specific and not merely a contact response, it is likely that signals from the host fungus are recognised by Trichoderma and provoke transcription of mycoparasitism-related genes.In the last few years examination of signalling pathways underlying Trichoderma biocontrol started and it was shown that heterotrimeric G-proteins and mitogen-activated protein (MAP kinases affected biocontrol-relevant processes such as the production of hydrolytic enzymes and antifungal metabolites and the formation of infection structures. MAPK signalling was also found to be involved in induction of plant systemic resistance in Trichoderma virens and in the hyperosmotic stress response in Trichoderma harzianum. Analyses of the function of components of the cAMP pathway during Trichoderma biocontrol revealed that mycoparasitism-associated coiling and chitinase production as well as secondary metabolism are affected by the internal cAMP level; in addition, a cross talk between regulation of light responses and the cAMP signalling pathway was found in Trichoderma atroviride.

  8. Failure of signal transduction pathway of DNA damage in hereditary microcephaly

    International Nuclear Information System (INIS)

    Miyamoto, Tatsuo; Matsuura, Shinya

    2009-01-01

    Mechanisms underlying the brain size determination are considered from an aspect of DNA-damage signaling recently revealed by studies on hereditary microcephaly (M), in relation to the radiation-induced M. International Commission of Radiological Protection (ICRP) assesses the risk of M by in utero exposure as 40%/Sv, the threshold dose is about 0.2 Gy (deterministic effect), A-bomb M is conceived to be due to the exposure at 8-5 weeks of gestation, and M is induced by radiation at 10 days after fertilization in the mouse. Recent studies on causing genes of M have revealed its particular connection with signaling pathways: in ataxia-telangiectasia (AT), genes of ATM; in Seckel syndrome, of ATR (AT and Rad3-related) and pericentrin (PCNT); Nijmegen syndrome (NBS), of NBS1; NBS-like disease, of Rad50 and Mre11; AT-like disease, of Mre11; Lig4 syndrome, of Lig4; immunodeficiency combined with M, of XLF; primary M, of MCPH1, ASPM, CdkRap2, CENP-J and STIL. Single and double strand breaks of DNA respectively activate the signaling pathway of ATR where PCNT and MCPH1 participate, and pathway of ATM where NBS1, Mre11 and Rad50 do. PCNT is a major protein, pericentrin, composing the centrosome, of which defect results in the Seckel disease with spindle dysfunction. At present, M can be thus said to be of the cellular common features of failure of ATM/ATR signaling and of dysfunction of centrosome. As well, ASPM gene expression is recently reported to be suppressed by radiation. Thus future studies on M will spread to wider biological field of cell and development as well as radiation and inheritance. (K.T.)

  9. Supernatant from bifidobacterium differentially modulates transduction signaling pathways for biological functions of human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Cyrille Hoarau

    Full Text Available BACKGROUND: Probiotic bacteria have been shown to modulate immune responses and could have therapeutic effects in allergic and inflammatory disorders. However, the signaling pathways engaged by probiotics are poorly understood. We have previously reported that a fermentation product from Bifidobacterium breve C50 (BbC50sn could induce maturation, high IL-10 production and prolonged survival of DCs via a TLR2 pathway. We therefore studied the roles of mitogen-activated protein kinases (MAPK, glycogen synthase kinase-3 (GSK3 and phosphatidylinositol 3-kinase (PI3K pathways on biological functions of human monocyte-derived DCs treated with BbC50sn. METHODOLOGY/PRINCIPAL FINDINGS: DCs were differentiated from human monocytes with IL-4 and GM-CSF for 5 days and cultured with BbC50sn, lipopolysaccharide (LPS or Zymosan, with or without specific inhibitors of p38MAPK (SB203580, ERK (PD98059, PI3K (LY294002 and GSK3 (SB216763. We found that 1 the PI3K pathway was positively involved in the prolonged DC survival induced by BbC50sn, LPS and Zymosan in contrast to p38MAPK and GSK3 which negatively regulated DC survival; 2 p38MAPK and PI3K were positively involved in DC maturation, in contrast to ERK and GSK3 which negatively regulated DC maturation; 3 ERK and PI3K were positively involved in DC-IL-10 production, in contrast to GSK3 that was positively involved in DC-IL-12 production whereas p38MAPK was positively involved in both; 4 BbC50sn induced a PI3K/Akt phosphorylation similar to Zymosan and a p38MAPK phosphorylation similar to LPS. CONCLUSION/SIGNIFICANCE: We report for the first time that a fermentation product of a bifidobacteria can differentially activate MAPK, GSK3 and PI3K in order to modulate DC biological functions. These results give new insights on the fine-tuned balance between the maintenance of normal mucosal homeostasis to commensal and probiotic bacteria and the specific inflammatory immune responses to pathogen bacteria.

  10. Signal Transduction Pathways Involved in Brain Death-Induced Renal Injury

    NARCIS (Netherlands)

    Bouma, H. R.; Ploeg, R. J.; Schuurs, T. A.

    Kidneys derived from brain death organ donors show an inferior survival when compared to kidneys derived from living donors. Brain death is known to induce organ injury by evoking an inflammatory response in the donor. Neuronal injury triggers an inflammatory response in the brain, leading to

  11. Integrin-mediated signal transduction linked to Ras pathway by GRB2 binding to focal adhesion kinase.

    Science.gov (United States)

    Schlaepfer, D D; Hanks, S K; Hunter, T; van der Geer, P

    The cytoplasmic focal adhesion protein-tyrosine kinase (FAK) localizes with surface integrin receptors at sites where cells attach to the extracellular matrix. Increased FAK tyrosine phosphorylation occurs upon integrin engagement with fibronectin. Here we show that adhesion of murine NIH3T3 fibroblasts to fibronectin promotes SH2-domain-mediated association of the GRB2 adaptor protein and the c-Src protein-tyrosine kinase (PTK) with FAK in vivo, and also results in activation of mitogen-activated protein kinase (MAPK). In v-Src-transformed NIH3T3, the association of v-Src, GRB2 and Sos with FAK is independent of cell adhesion to fibronectin. The GRB2 SH2 domain binds directly to tyrosine-phosphorylated FAK. Mutation of tyrosine residue 925 of FAK (YENV motif) to phenylalanine blocks GRB2 SH2-domain binding to FAK in vitro. Our results show that fibronectin binding to integrins on NIH3T3 fibroblasts promotes c-Src and FAK association and formation of an integrin-activated signalling complex. Phosphorylation of FAK at Tyr 925 upon fibronectin stimulation creates an SH2-binding site for GRB2 which may link integrin engagement to the activation of the Ras/MAPK signal transduction pathway.

  12. Opposing effects of bile acids deoxycholic acid and ursodeoxycholic acid on signal transduction pathways in oesophageal cancer cells.

    Science.gov (United States)

    Abdel-Latif, Mohamed M; Inoue, Hiroyasu; Reynolds, John V

    2016-09-01

    Ursodeoxycholic acid (UDCA) was reported to reduce bile acid toxicity, but the mechanisms underlying its cytoprotective effects are not fully understood. The aim of the present study was to examine the effects of UDCA on the modulation of deoxycholic acid (DCA)-induced signal transduction in oesophageal cancer cells. Nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) activity was assessed using a gel shift assay. NF-κB activation and translocation was performed using an ELISA-based assay and immunofluorescence analysis. COX-2 expression was analysed by western blotting and COX-2 promoter activity was assessed by luciferase assay. DCA induced NF-κB and AP-1 DNA-binding activities in SKGT-4 and OE33 cells. UDCA pretreatment inhibited DCA-induced NF-κB and AP-1 activation and NF-κB translocation. This inhibitory effect was coupled with a blockade of IκB-α degradation and inhibition of phosphorylation of IKK-α/β and ERK1/2. Moreover, UDCA pretreatment inhibited COX-2 upregulation. Using transient transfection of the COX-2 promoter, UDCA pretreatment abrogated DCA-induced COX-2 promoter activation. In addition, UDCA protected oesophageal cells from the apoptotic effects of deoxycholate. Our findings indicate that UDCA inhibits DCA-induced signalling pathways in oesophageal cancer cells. These data indicate a possible mechanistic role for the chemopreventive actions of UDCA in oesophageal carcinogenesis.

  13. Comprehensive logic based analyses of Toll-like receptor 4 signal transduction pathway.

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar Padwal

    Full Text Available Among the 13 TLRs in the vertebrate systems, only TLR4 utilizes both Myeloid differentiation factor 88 (MyD88 and Toll/Interleukin-1 receptor (TIR-domain-containing adapter interferon-β-inducing Factor (TRIF adaptors to transduce signals triggering host-protective immune responses. Earlier studies on the pathway combined various experimental data in the form of one comprehensive map of TLR signaling. But in the absence of adequate kinetic parameters quantitative mathematical models that reveal emerging systems level properties and dynamic inter-regulation among the kinases/phosphatases of the TLR4 network are not yet available. So, here we used reaction stoichiometry-based and parameter independent logical modeling formalism to build the TLR4 signaling network model that captured the feedback regulations, interdependencies between signaling kinases and phosphatases and the outcome of simulated infections. The analyses of the TLR4 signaling network revealed 360 feedback loops, 157 negative and 203 positive; of which, 334 loops had the phosphatase PP1 as an essential component. The network elements' interdependency (positive or negative dependencies in perturbation conditions such as the phosphatase knockout conditions revealed interdependencies between the dual-specific phosphatases MKP-1 and MKP-3 and the kinases in MAPK modules and the role of PP2A in the auto-regulation of Calmodulin kinase-II. Our simulations under the specific kinase or phosphatase gene-deficiency or inhibition conditions corroborated with several previously reported experimental data. The simulations to mimic Yersinia pestis and E. coli infections identified the key perturbation in the network and potential drug targets. Thus, our analyses of TLR4 signaling highlights the role of phosphatases as key regulatory factors in determining the global interdependencies among the network elements; uncovers novel signaling connections; identifies potential drug targets for

  14. Neurospora crassa female development requires the PACC and other signal transduction pathways, transcription factors, chromatin remodeling, cell-to-cell fusion, and autophagy.

    Directory of Open Access Journals (Sweden)

    Jennifer L Chinnici

    Full Text Available Using a screening protocol we have identified 68 genes that are required for female development in the filamentous fungus Neurospora crassa. We find that we can divide these genes into five general groups: 1 Genes encoding components of the PACC signal transduction pathway, 2 Other signal transduction pathway genes, including genes from the three N. crassa MAP kinase pathways, 3 Transcriptional factor genes, 4 Autophagy genes, and 5 Other miscellaneous genes. Complementation and RIP studies verified that these genes are needed for the formation of the female mating structure, the protoperithecium, and for the maturation of a fertilized protoperithecium into a perithecium. Perithecia grafting experiments demonstrate that the autophagy genes and the cell-to-cell fusion genes (the MAK-1 and MAK-2 pathway genes are needed for the mobilization and movement of nutrients from an established vegetative hyphal network into the developing protoperithecium. Deletion mutants for the PACC pathway genes palA, palB, palC, palF, palH, and pacC were found to be defective in two aspects of female development. First, they were unable to initiate female development on synthetic crossing medium. However, they could form protoperithecia when grown on cellophane, on corn meal agar, or in response to the presence of nearby perithecia. Second, fertilized perithecia from PACC pathway mutants were unable to produce asci and complete female development. Protein localization experiments with a GFP-tagged PALA construct showed that PALA was localized in a peripheral punctate pattern, consistent with a signaling center associated with the ESCRT complex. The N. crassa PACC signal transduction pathway appears to be similar to the PacC/Rim101 pathway previously characterized in Aspergillus nidulans and Saccharomyces cerevisiae. In N. crassa the pathway plays a key role in regulating female development.

  15. Neurospora crassa female development requires the PACC and other signal transduction pathways, transcription factors, chromatin remodeling, cell-to-cell fusion, and autophagy.

    Science.gov (United States)

    Chinnici, Jennifer L; Fu, Ci; Caccamise, Lauren M; Arnold, Jason W; Free, Stephen J

    2014-01-01

    Using a screening protocol we have identified 68 genes that are required for female development in the filamentous fungus Neurospora crassa. We find that we can divide these genes into five general groups: 1) Genes encoding components of the PACC signal transduction pathway, 2) Other signal transduction pathway genes, including genes from the three N. crassa MAP kinase pathways, 3) Transcriptional factor genes, 4) Autophagy genes, and 5) Other miscellaneous genes. Complementation and RIP studies verified that these genes are needed for the formation of the female mating structure, the protoperithecium, and for the maturation of a fertilized protoperithecium into a perithecium. Perithecia grafting experiments demonstrate that the autophagy genes and the cell-to-cell fusion genes (the MAK-1 and MAK-2 pathway genes) are needed for the mobilization and movement of nutrients from an established vegetative hyphal network into the developing protoperithecium. Deletion mutants for the PACC pathway genes palA, palB, palC, palF, palH, and pacC were found to be defective in two aspects of female development. First, they were unable to initiate female development on synthetic crossing medium. However, they could form protoperithecia when grown on cellophane, on corn meal agar, or in response to the presence of nearby perithecia. Second, fertilized perithecia from PACC pathway mutants were unable to produce asci and complete female development. Protein localization experiments with a GFP-tagged PALA construct showed that PALA was localized in a peripheral punctate pattern, consistent with a signaling center associated with the ESCRT complex. The N. crassa PACC signal transduction pathway appears to be similar to the PacC/Rim101 pathway previously characterized in Aspergillus nidulans and Saccharomyces cerevisiae. In N. crassa the pathway plays a key role in regulating female development.

  16. Distinct UV-B and UV-A/blue light signal transduction pathways induce chalcone synthase gene expression in Arabidopsis cells

    International Nuclear Information System (INIS)

    Christie, J.M.; Jenkins, G.I.

    1996-01-01

    UV and blue light control the expression of flavonoid biosynthesis genes in a range of higher plants. To investigate the signal transduction processes involved in the induction of chalcone synthase (CHS) gene expression by UV-B and UV-A/blue light, we examined the, effects of specific agonists and inhibitors of known signaling components in mammalian systems in a photomixotrophic Arabidopsis cell suspension culture. CHS expression is induced specifically by these wavelengths in the cell culture, in a manner similar to that in mature Arabidopsis leaf tissue. Both the UV-B and UV-A/blue phototransduction processes involve calcium, although the elevation of cytosolic calcium is insufficient on its own to stimulate CHS expression. The UV-A/blue light induction of CHS expression does not appear to involve calmodulin, whereas the UV-B response does; this difference indicates that the signal transduction pathways are, at least in part, distinct. We provide evidence that both pathways involve reversible protein phosphorylation and require protein synthesis. The UV-B and UV-A/blue light signaling pathways are therefore different from the phytochrome signal transduction pathway regulating CHS expression in other species

  17. [Effect of total glucosides of paeony on Wnt/β-catenin signal transduction pathway expression in kidney of diabetic rats].

    Science.gov (United States)

    Chang, Bao-Chao; Chen, Wei-Dong; Zhang, Yan; Yang, Ping; Liu, Lei; Wang, Jing

    2014-10-01

    The study is to explore the effect of total glucosides of paeony (TGP)on Wnt/β-catenin signal transduction pathway expression in kidney of diabetic rats, and discuss the protection of TGP in diabetic nephropathy and possible mechanism. Ninety male SD rats of 8 weeks age were randomly divided into normal control group (n = 10) and model group (n = 80). Rats of the normal control group were fed with regular diet, while rats of the model group were fed with high-fat high-sugar diet and 4 weeks later were given an intraperitoneal injection of 35 mg x kg(-1) streptozotocin (STZ). The successfully induced type 2 diabetic rat models were then randomly divided into DM group, three TGP (50, 100, 200 mg x kg(-1) x d(-1)) treatment group and tripterygium wilfordii glycosides (8 mg x kg(-1) x d(-1)) control group. Rats of DM group and each treatment group were given high-fat high-sugar diet. At week 14, the levels of blood sugar, 24 hour urine protein, serum creatinine and blood urea nitrogen were tested. The rats were then sacrificed. Renal pathological changes were examined. Renal tissue Wnt-1 and β-catenin expressions were detected by immunohistochemical assay. Wnt-1 mRNA and β-catenin mRNA expression was semi-quantified by RT-PCR. Wnt-1 protein and β-catenin protein expression was semi-quantified by Western blot. The Result show that Wnt-1 and β-catenin expression increased in kidney of high-fat high-sugar induced type 2 diabetic rats. Compared with diabetic group, the level of serum creatinine, blood urea nitrogen, 24 h urine protein, mean glomerular area and mean glomerular volume were decreased, renal histopathology were improved, expression of Wnt-1 and β-catenin mRNA and protein was reduced in TGP group. Tripterygium wilfordii glycosides had the similar effect. In conclusion, these results showed that Wnt/β-catenin abnormal activation in kidney of type 2 diabetic rats, TGP can improve kidney damage in diabetic rats and delay the development of diabetic

  18. Kinetics in Signal Transduction Pathways Involving Promiscuous Oligomerizing Receptors Can Be Determined by Receptor Specificity : Apoptosis Induction by TRAIL

    NARCIS (Netherlands)

    Szegezdi, Eva; van der Sloot, Almer M.; Mahalingam, Devalingam; O'Leary, Lynda; Cool, Robbert H.; Munoz, Ines G.; Montoya, Guillermo; Quax, Wim J.; de Jong, Steven; Samali, Afshin; Serrano, Luis

    Here we show by computer modeling that kinetics and outcome of signal transduction in case of hetero-oligomerizing receptors of a promiscuous ligand largely depend on the relative amounts of its receptors. Promiscuous ligands can trigger the formation of nonproductive receptor complexes, which slows

  19. DMPD: Gram-negative endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 1916089 Gram-negative endotoxin: an extraordinary lipid with profound effects oneuk...ep;5(12):2652-60. (.png) (.svg) (.html) (.csml) Show Gram-negative endotoxin: an extraordinary lipid with profound effects...tive endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. Authors Raetz

  20. Selection of personalized patient therapy through the use of knowledge-based computational models that identify tumor-driving signal transduction pathways.

    Science.gov (United States)

    Verhaegh, Wim; van Ooijen, Henk; Inda, Márcia A; Hatzis, Pantelis; Versteeg, Rogier; Smid, Marcel; Martens, John; Foekens, John; van de Wiel, Paul; Clevers, Hans; van de Stolpe, Anja

    2014-06-01

    Increasing knowledge about signal transduction pathways as drivers of cancer growth has elicited the development of "targeted drugs," which inhibit aberrant signaling pathways. They require a companion diagnostic test that identifies the tumor-driving pathway; however, currently available tests like estrogen receptor (ER) protein expression for hormonal treatment of breast cancer do not reliably predict therapy response, at least in part because they do not adequately assess functional pathway activity. We describe a novel approach to predict signaling pathway activity based on knowledge-based Bayesian computational models, which interpret quantitative transcriptome data as the functional output of an active signaling pathway, by using expression levels of transcriptional target genes. Following calibration on only a small number of cell lines or cohorts of patient data, they provide a reliable assessment of signaling pathway activity in tumors of different tissue origin. As proof of principle, models for the canonical Wnt and ER pathways are presented, including initial clinical validation on independent datasets from various cancer types. ©2014 American Association for Cancer Research.

  1. [Effects of Betel shisanwei ingredients pill on AC-cAMP-PKA signal transduction pathways in hippocampus and prefrontal cortex of depressive rats].

    Science.gov (United States)

    Tong, Hai-Ying; Wu, Jisiguleng; Bai, Liang-Feng; Bao, Wu-Ye; Hu, Rilebagen; Li, Jing; Zhang, Yue

    2014-05-01

    To observe the effects of Mongolian pharmaceutical Betel shisanwei ingredients pill on AC-cAMP-PKA signal transduction pathways in hippocampus and prefrontal cortex of depressive rats. Sixty male Wistar rats were randomly divided into six groups according to the sugar consumption test (10 rats in each group), normal control group,model group,fluoxetine group (3.3 mg x kg(-1)) and low dose, medium dose and high dose group (0.25, 0.5, 1 g x kg(-1)) of Betel shisanwei ingredients pill. Except the normal control,the other groups were treated with the chronic unpredictable mild stress stimulation combined with lonely raising for 28 days. 10 mL x kg(-1) of drugs were given to each rat once daily,continuously for 28 days. The AC activity of the hippocampus and prefrontal cortex were determined by radiation immunity analysis (RIA), while cAMP and PKA quantity were determinated by Enzyme-linked immunosorbent (ELISA). The AC activity, cAMP and PKA quantity of hippocampus and prefrontal of mouse model of Chronic stress depression decreased significantly than those of control group (P Betel shisanwei ingredients pill group indecreased significantly than those of model group (P Betel shisanwei ingredients pill. The AC-cAMP-PKA signal transduction pathways in hippocampus and prefrontal cortex of depression model of rats is down-regulated, whereas Mongolian pharmaceutical Betel shisanwei ingredients pill could up-regulated it to resist depression.

  2. Mutations in the thyrotropin receptor signal transduction pathway in the hyperfunctioning thyroid nodules from multinodular goiters: a study in the Turkish population.

    Science.gov (United States)

    Gozu, Hulya; Avsar, Melike; Bircan, Rifat; Sahin, Serap; Deyneli, Oguzhan; Cirakoglu, Beyazit; Akalin, Sema

    2005-10-01

    Many studies have been carried out to determine G(s) alpha and TSHR mutations in autonomously functioning thyroid nodules. Variable prevalences for somatic constitutively activating TSHR mutations in hot nodules have been reported. Moreover, the increased prevalence of toxic multinodular goiters in iodine-deficient regions is well known. In Turkey, a country with high incidence rates of goiter due to iodine deficiency, the frequency of mutations in the thyrotropin receptor signal transduction pathway has not been evaluated up to now. In the present study, a part of the genes of the TSHR, G(s)alpha and the catalytic subunit of the PKA were checked for activating mutations. Thirty-five patients who underwent thyroidectomy for multinodular goiters were examined. Genomic DNAs were extracted from 58 hyperactive nodular specimens and surrounding normal thyroid tissues. Mutation screening was done by single-strand conformational polymorphism (SSCP) analysis. In those cases where a mutation was detected, the localization of the mutation was determined by automatic DNA sequencing. No G(s)alpha or PKA mutations were detected, whereas ten mutations (17%) were identified in the TSHR gene. All mutations were somatic and heterozygotic. In conclusion, the frequency of mutations in the cAMP signal transduction pathway was found to be lower than expected in the Turkish population most likely because of the use of SSCP as a screening method and sequencing only a part of TSHR exon 10.

  3. Insulin regulates multiple signaling pathways leading to monocyte/macrophage chemotaxis into the wound tissue

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2018-01-01

    Full Text Available Wound healing is a complex process that involves sequential phases that overlap in time and space and affect each other dynamically at the gene and protein levels. We previously showed that insulin accelerates wound healing by stimulating faster and regenerative healing. One of the processes that insulin stimulates is an increase in monocyte/macrophage chemotaxis. In this study, we performed experiments in vivo and in vitro to elucidate the signaling transduction pathways that are involved in insulin-induced monocyte/macrophage chemotaxis. We found that insulin stimulates THP-1 cell chemotaxis in a dose-dependent and insulin receptor-dependent manner. We also show that the kinases PI3K-Akt, SPAK/JNK, and p38 MAPK are key molecules in the insulin-induced signaling pathways that lead to chemoattraction of the THP-1 cell. Furthermore, both PI3K-Akt and SPAK/JNK signaling involve Rac1 activation, an important molecule in regulating cell motility. Indeed, topical application of Rac1 inhibitor at an early stage during the healing process caused delayed and impaired healing even in the presence of insulin. These results delineate cell and molecular mechanisms involved in insulin-induced chemotaxis of monocyte/macrophage, cells that are critical for proper healing.

  4. Next generation of adeno-associated virus 2 vectors: Point mutations in tyrosines lead to high-efficiency transduction at lower doses

    Science.gov (United States)

    Zhong, Li; Li, Baozheng; Mah, Cathryn S.; Govindasamy, Lakshmanan; Agbandje-McKenna, Mavis; Cooper, Mario; Herzog, Roland W.; Zolotukhin, Irene; Warrington, Kenneth H.; Weigel-Van Aken, Kirsten A.; Hobbs, Jacqueline A.; Zolotukhin, Sergei; Muzyczka, Nicholas; Srivastava, Arun

    2008-01-01

    Recombinant adeno-associated virus 2 (AAV2) vectors are in use in several Phase I/II clinical trials, but relatively large vector doses are needed to achieve therapeutic benefits. Large vector doses also trigger an immune response as a significant fraction of the vectors fails to traffic efficiently to the nucleus and is targeted for degradation by the host cell proteasome machinery. We have reported that epidermal growth factor receptor protein tyrosine kinase (EGFR-PTK) signaling negatively affects transduction by AAV2 vectors by impairing nuclear transport of the vectors. We have also observed that EGFR-PTK can phosphorylate AAV2 capsids at tyrosine residues. Tyrosine-phosphorylated AAV2 vectors enter cells efficiently but fail to transduce effectively, in part because of ubiquitination of AAV capsids followed by proteasome-mediated degradation. We reasoned that mutations of the surface-exposed tyrosine residues might allow the vectors to evade phosphorylation and subsequent ubiquitination and, thus, prevent proteasome-mediated degradation. Here, we document that site-directed mutagenesis of surface-exposed tyrosine residues leads to production of vectors that transduce HeLa cells ≈10-fold more efficiently in vitro and murine hepatocytes nearly 30-fold more efficiently in vivo at a log lower vector dose. Therapeutic levels of human Factor IX (F.IX) are also produced at an ≈10-fold reduced vector dose. The increased transduction efficiency of tyrosine-mutant vectors is due to lack of capsid ubiquitination and improved intracellular trafficking to the nucleus. These studies have led to the development of AAV vectors that are capable of high-efficiency transduction at lower doses, which has important implications in their use in human gene therapy. PMID:18511559

  5. [Study of signal transduction pathway in the expression of inflammatory factors stimulated by lipopolysaccharides from Porphyromonas endodontalis in osteoblasts].

    Science.gov (United States)

    Yang, Di; Qiu, Li-hong; Li, Ren; Li, Zi-mu; Li, Chen

    2010-04-01

    To quantify the interleukin (IL)-1beta mRNA and IL-6 mRNA expression induced by lipopolysaccharides ([PS) extracted from Porphyromonoas endodontalis (P. endodontalis) in osteoblasts, and to relate P. endodontalis LPS to the bone resorptive pathogenesis in the lesions of chronic apical periodontitis. MG63 cells was pretreated with PD98059 or SB203580 for 1 h and then treated with P. endodontolis LPS for 6 h. The expression of IL-1beta mRNA and IL-6 mRNA were detected by reverse transcription polymerase chain reaction (RT-PCR) technique. The production of IL-1beta mRNA induced by P. endodontalis LPS decreased in osteoblasts pretreated with PD98059. Both of the production of IL-1beta mRNA and JL-6 mRNA induced by P. endodontalis LPS decreased in osteoblasts pretreated with SB203580. The synthesis of IL-1beta mRNA stimulated by Pendodontalis LPS in MG63 probably occur via extracellular signal-regulated kinase (ERK) 1/2 and p38 mitogen activated protein kinase (MAPK) signal transduction system. The synthesis of IL-6 mRNA stimulated by P.endodontalis LPS in MG63 probahly occur via p38MAPK signal transduction system.

  6. DMPD: Multiple signaling pathways leading to the activation of interferon regulatoryfactor 3. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12213596 Multiple signaling pathways leading to the activation of interferon regula...(.html) (.csml) Show Multiple signaling pathways leading to the activation of interferon regulatoryfactor 3.... PubmedID 12213596 Title Multiple signaling pathways leading to the activation of

  7. Presence of Tube isoforms in Litopenaeus vannamei suggests various regulatory patterns of signal transduction in invertebrate NF-κB pathway.

    Science.gov (United States)

    Li, Chaozheng; Chen, Yixiao; Weng, Shaoping; Li, Sedong; Zuo, Hongliang; Yu, Xiaoqiang; Li, Haoyang; He, Jianguo; Xu, Xiaopeng

    2014-02-01

    The toll-like receptor (TLR)/NF-κB signaling pathways play critical roles in the innate immune system. The intracellular signal transduction of most TLR pathways in invertebrate cells is triggered by formation of a heterotrimeric complex composed of MyD88, Tube and Pelle. In this study, we identified a Litopenaeus vannamei Pelle (LvPelle) and an isoform of L. vannamei Tube (LvTube) designated as LvTube-1. The interactions among LvPelle, LvTube/LvTube-1 and LvMyD88/LvMyD88-1 were elucidated and their functions during pathogen infections were investigated. Knockdowns of LvPelle and LvTube/LvTube-1 using RNAi strategy led to higher mortalities of shrimps during Vibrio parahemolyticus infection, and could reduce the genome copy number of white spot syndrome virus (WSSV) in the infected muscle tissue but did not affect the mortality caused by WSSV infection. The effects of LvPelle and LvTube/LvTube-1 on promoters containing NF-κB binding motifs were analyzed by dual-luciferase reporter assays and the results demonstrated that LvTube-1 could activate the NF-κB activity to significantly higher level than LvTube did. Moreover, tissue distributions of LvTube and LvTube-1 mRNAs and their expression profiles during pathogen and immune stimulant challenges were different, indicating that they could play different roles in immune responses. This is the first report of Tube isoforms in invertebrates. Together with our previous study on LvMyD88 isoforms, our results suggest that various isoforms of adaptor components may be involved in various regulatory patterns of signal transduction in invertebrate TLR/NF-κB pathway and this could be a strategy adopted by invertebrates to modulate immune responses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Apurinic/apyrimidinic endonuclease1/redox factor-1 (Ape1/Ref-1) is essential for IL-21-induced signal transduction through ERK1/2 pathway

    International Nuclear Information System (INIS)

    Juliana, Farha M.; Nara, Hidetoshi; Onoda, Tadashi; Rahman, Mizanur; Araki, Akemi; Jin, Lianjin; Fujii, Hodaka; Tanaka, Nobuyuki; Hoshino, Tomoaki; Asao, Hironobu

    2012-01-01

    Highlights: ► IL-21 induces nuclear accumulation of Ape1/Ref-1 protein. ► Ape1/Ref-1 is indispensable in IL-21-induced cell proliferation and survival signal. ► Ape1/Ref-1 is required for IL-21-induced ERK1/2 activation. -- Abstract: IL-21 is a pleiotropic cytokine that regulates T-cell and B-cell differentiation, NK-cell activation, and dendritic cell functions. IL-21 activates the JAK-STAT, ERK, and PI3K pathways. We report here that Ape1/Ref-1 has an essential role in IL-21-induced cell growth signal transduction. Overexpression of Ape1/Ref-1 enhances IL-21-induced cell proliferation, but it is suppressed by overexpressing an N-terminal deletion mutant of Ape1/Ref-1 that lacks the redox domain. Furthermore, knockdown of the Ape1/Ref-1 mRNA dramatically compromises IL-21-induced ERK1/2 activation and cell proliferation with increasing cell death. These impaired activities are recovered by the re-expression of Ape1/Ref-1 in the knockdown cells. Our findings are the first demonstration that Ape1/Ref-1 is an indispensable molecule for the IL-21-mediated signal transduction through ERK1/2 activation.

  9. Effect of Lipoglycans from Mycobacterium Chelonae on the expression of inflammatory factors IL-8 and IL-6 in human corneal epithelial cells and its possible signal transduction pathway

    Directory of Open Access Journals (Sweden)

    Chun-Zhou Tang

    2015-06-01

    Full Text Available AIM: To study the influence of Lipoglycans from Mycobacterium Chelonae(Cheon the expression of IL-6 and IL-8 in human corneal epithelia cells and its possible signal transduction pathway.METHODS: Lipoglycans was extracted by the Triton X-114 phase partitioning. Lipoglycans from Che were purified, by successive detergent and phenol extractions. Lipoglycans were separated by gel filtration on a Sephacryl 200 column and Sephacryl 100 column in series, followed by extensive dialisis. Purified Lipoglycans(50μg/mLwere added into culture medium to stimulate primary human corneal epithelial(HCEcells. Cells and supernatant were collected at 0, 6, 12, 24h after the stimulation. The IL-6 and IL-8 expression at mRNA level was assayed by using real time RT-PCR and the secreted IL-6 and IL-8 in the supernatants was measured by ELISA. Immunochemistry was used to detect the expression and location of NF-κB in HCE cells.RESULTS: After the treatment of Lipoglycans, the expression of IL-8 and IL-6 at mRNA level obviouly increased within 12h, and reached peak level at 6h(IL-8 was 36.8 times that of the blank control, and IL-6 was 32.7 times. Compared with the blank control group, the expression of IL-8 at protein level in the supernatant increased 2.8 folds at 6h(P>0.05, 13.4 folds at 12h(PPPPPCONCLUSION: Lipoglycans from Che can induce HCE cells to produce inflammatory factors(IL-6 and IL-8, and its signal transduction pathway probably is mediated by NF-κB.

  10. Portulaca oleracea extract can inhibit nodule formation of colon cancer stem cells by regulating gene expression of the Notch signal transduction pathway.

    Science.gov (United States)

    Jin, Heiying; Chen, Li; Wang, Shuiming; Chao, Deng

    2017-07-01

    To investigate whether Portulaca oleracea extract affects tumor formation in colon cancer stem cells and its chemotherapy sensitivity. In addition, to analyze associated genetic changes within the Notch signal transduction pathway. Serum-free cultures of colon cancer cells (HT-29) and HT-29 cancer stem cells were treated with the chemotherapeutic drug 5-fluorouracil to assess sensitivity. Injections of the stem cells were also given to BALB/c mice to confirm tumor growth and note its characteristics. In addition, the effect of different concentrations of P. oleracea extract was tested on the growth of HT-29 colon cancer cells and HT-29 cancer stem cells, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The effects of P. oleracea extract on the expression of β-catenin, Notch1, and Notch2 in the HT-29 cells were studied using reverse transcription polymerase chain reaction and Western blotting. The tumor volume of the HT29 cells was two times larger than that of HT29 cancer stem cells. Treatment with P. oleracea extract inhibited the proliferation of both HT-29 cancer cells and HT-29 cancer stem cells at doses from 0.07 to 2.25 µg/mL. Apoptosis of HT-29 cancer cells and HT-29 cancer stem cells was assessed by flow cytometry; it was enhanced by the addition of P. oleracea extract. Finally, treatment with P. oleracea extract significantly downregulated the expression of the Notch1 and β-catenin genes in both cell types. The results of this study show that P. oleracea extract inhibits the growth of colon cancer stem cells in a dose-dependent manner. Furthermore, it inhibits the expression of the Notch1 and β-catenin genes. Taken together, this suggests that it may elicit its effects through regulatory and target genes that mediate the Notch signal transduction pathway.

  11. Sugar-induced cephalic-phase insulin release is mediated by a T1r2+T1r3-independent taste transduction pathway in mice.

    Science.gov (United States)

    Glendinning, John I; Stano, Sarah; Holter, Marlena; Azenkot, Tali; Goldman, Olivia; Margolskee, Robert F; Vasselli, Joseph R; Sclafani, Anthony

    2015-09-01

    Sensory stimulation from foods elicits cephalic phase responses, which facilitate digestion and nutrient assimilation. One such response, cephalic-phase insulin release (CPIR), enhances glucose tolerance. Little is known about the chemosensory mechanisms that activate CPIR. We studied the contribution of the sweet taste receptor (T1r2+T1r3) to sugar-induced CPIR in C57BL/6 (B6) and T1r3 knockout (KO) mice. First, we measured insulin release and glucose tolerance following oral (i.e., normal ingestion) or intragastric (IG) administration of 2.8 M glucose. Both groups of mice exhibited a CPIR following oral but not IG administration, and this CPIR improved glucose tolerance. Second, we examined the specificity of CPIR. Both mouse groups exhibited a CPIR following oral administration of 1 M glucose and 1 M sucrose but not 1 M fructose or water alone. Third, we studied behavioral attraction to the same three sugar solutions in short-term acceptability tests. B6 mice licked more avidly for the sugar solutions than for water, whereas T1r3 KO mice licked no more for the sugar solutions than for water. Finally, we examined chorda tympani (CT) nerve responses to each of the sugars. Both mouse groups exhibited CT nerve responses to the sugars, although those of B6 mice were stronger. We propose that mice possess two taste transduction pathways for sugars. One mediates behavioral attraction to sugars and requires an intact T1r2+T1r3. The other mediates CPIR but does not require an intact T1r2+T1r3. If the latter taste transduction pathway exists in humans, it should provide opportunities for the development of new treatments for controlling blood sugar. Copyright © 2015 the American Physiological Society.

  12. [6]-Gingerol Prevents Disassembly of Cell Junctions and Activities of MMPs in Invasive Human Pancreas Cancer Cells through ERK/NF-κB/Snail Signal Transduction Pathway

    Directory of Open Access Journals (Sweden)

    Sung Ok Kim

    2013-01-01

    Full Text Available To study the effects of [6]-gingerol, a ginger phytochemical, on tight junction (TJ molecules, we investigated TJ tightening and signal transduction pathways in human pancreatic duct cell-derived cancer cell line PANC-1. The following methods were utilized: MTT assay to determine cytotoxicity; zymography to examine matrix metalloproteinase (MMP activities; transepithelial electrical resistance (TER and paracellular flux for TJ measurement; RT-PCR and immunoblotting for proteins related to TJ and invasion; and EMSA for NF-κB activity in PANC-1 cells. Results revealed that TER significantly increased and claudin 4 and MMP-9 decreased compared to those of the control. TJ protein levels, including zonula occludens (ZO- 1, occludin, and E-cadherin, increased in [6]-gingerol-treated cells, which correlated with a decrease in paracellular flux and MMP activity. Furthermore, NF-κB/Snail nuclear translocation was suppressed via downregulation of the extracellular signal-regulated kinase (ERK pathway in response to [6]-gingerol treatment. Moreover, treatment with U0126, an ERK inhibitor, completely blocked NF-κB activity. In conclusion, these findings demonstrate that [6]-gingerol regulates TJ-related proteins and suppresses invasion and metastasis through NF-κB/Snail inhibition via inhibition of the ERK pathway. Therefore, [6]-gingerol may suppress the invasive activity of PANC-1 cells.

  13. Characterization of Cell Surface and EPS Remodeling of Azospirillum brasilense Chemotaxis-like 1 Signal Transduction Pathway mutants by Atomic Force Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Billings, Amanda N [ORNL; Siuti, Piro [ORNL; Bible, Amber [University of Tennessee, Knoxville (UTK); Alexandre, Gladys [University of Tennessee, Knoxville (UTK); Retterer, Scott T [ORNL; Doktycz, Mitchel John [ORNL; Morrell-Falvey, Jennifer L [ORNL

    2011-01-01

    To compete in complex microbial communities, bacteria must quickly sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the modulation of multiple cellular responses, including motility, EPS production, and cell-to-cell interactions. Recently, the Che1 chemotaxis-like pathway from Azospirillum brasilense was shown to modulate flocculation. In A. brasilense, cell surface properties, including EPS production, are thought to play a direct role in promoting flocculation. Using atomic force microscopy (AFM), we have detected distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains that are absent in the wild type strain. Whereas the wild type strain produces a smooth mucosal extracellular matrix, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition and lectin-binding assays suggest that the composition of EPS components in the extracellular matrix differs between the cheA1 and cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that mutations in the Che1 pathway that result in increased flocculation are correlated with distinctive changes in the extracellular matrix structure produced by the mutants, including likely changes in the EPS structure and/or composition.

  14. Characterization of cell surface and extracellular matrix remodeling of Azospirillum brasilense chemotaxis-like 1 signal transduction pathway mutants by atomic force microscopy.

    Science.gov (United States)

    Edwards, Amanda Nicole; Siuti, Piro; Bible, Amber N; Alexandre, Gladys; Retterer, Scott T; Doktycz, Mitchel J; Morrell-Falvey, Jennifer L

    2011-01-01

    To compete in complex microbial communities, bacteria must sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the regulation of multiple behaviors in response to changes in the environment, including motility patterns, exopolysaccharide production, and cell-to-cell interactions. In Azospirillum brasilense, cell surface properties, including exopolysaccharide production, are thought to play a direct role in promoting flocculation. Recently, the Che1 chemotaxis-like pathway from A. brasilense was shown to modulate flocculation, suggesting an associated modulation of cell surface properties. Using atomic force microscopy, distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains were detected. Whereas the wild-type strain produces a smooth mucosal extracellular matrix after 24 h, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition, lectin-binding assays, and comparison of lipopolysaccharides profiles suggest that the extracellular matrix differs between the cheA1 and the cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that disruption of the Che1 pathway is correlated with distinctive changes in the extracellular matrix, which likely result from changes in surface polysaccharides structure and/or composition. FEMS Microbiology Letters © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. No claim to original US government works.

  15. Characterization of cell surface and extracellular matrix remodeling of Azospirillum brasilense chemotaxis-like 1 signal transduction pathway mutants by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Doktycz, Mitchel John [ORNL; Morrell-Falvey, Jennifer L [ORNL

    2011-01-01

    To compete in complex microbial communities, bacteria must sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the regulation of multiple behaviors in response to changes in the environment, including motility patterns, exopolysaccharide production, and cell-to-cell interactions. In Azospirillum brasilense, cell surface properties, including exopolysaccharide production, are thought to play a direct role in promoting flocculation. Recently, the Che1 chemotaxis-like pathway from A. brasilense was shown to modulate flocculation, suggesting an associated modulation of cell surface properties. Using atomic force microscopy, distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains were detected. Whereas the wild-type strain produces a smooth mucosal extracellular matrix after 24 h, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition, lectin-binding assays, and comparison of lipopolysaccharides profiles suggest that the extracellular matrix differs between the cheA1 and the cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that disruption of the Che1 pathway is correlated with distinctive changes in the extracellular matrix, which likely result from changes in surface polysaccharides structure and/or composition.

  16. Physiological and Pathogenic Roles of Prolyl Isomerase Pin1 in Metabolic Regulations via Multiple Signal Transduction Pathway Modulations

    Directory of Open Access Journals (Sweden)

    Yusuke Nakatsu

    2016-09-01

    Full Text Available Prolyl isomerases are divided into three groups, the FKBP family, Cyclophilin and the Parvulin family (Pin1 and Par14. Among these isomerases, Pin1 is a unique prolyl isomerase binding to the motif including pSer/pThr-Pro that is phosphorylated by kinases. Once bound, Pin1 modulates the enzymatic activity, protein stability or subcellular localization of target proteins by changing the cis- and trans-formations of proline. Several studies have examined the roles of Pin1 in the pathogenesis of cancers and Alzheimer’s disease. On the other hand, recent studies have newly demonstrated Pin1 to be involved in regulating glucose and lipid metabolism. Interestingly, while Pin1 expression is markedly increased by high-fat diet feeding, Pin1 KO mice are resistant to diet-induced obesity, non-alcoholic steatohepatitis and diabetic vascular dysfunction. These phenomena result from the binding of Pin1 to several key factors regulating metabolic functions, which include insulin receptor substrate-1, AMPK, Crtc2 and NF-κB p65. In this review, we focus on recent advances in elucidating the physiological roles of Pin1 as well as the pathogenesis of disorders involving this isomerase, from the viewpoint of the relationships between signal transductions and metabolic functions.

  17. DMPD: Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available -4. Palsson-McDermott EM, O'Neill LA. Immunology. 2004 Oct;113(2):153-62. (.png) (.svg) (.html) (.csml) Show...Palsson-McDermott EM, O'Neill LA. Publication Immunology. 2004 Oct;113(2):153-62. Pathway - PNG File (.png)

  18. Microglial Janus kinase/signal transduction and activator of transcription 3 pathway activity directly impacts astrocyte and spinal neuron characteristics

    Czech Academy of Sciences Publication Activity Database

    Molet, J.; Mauborgne, A.; Diallo, Michael; Armand, V.; Geny, D.; Villanueva, L.; Boucher, Y.; Pohl, M.

    2016-01-01

    Roč. 136, č. 1 (2016), s. 133-147 ISSN 0022-3042 R&D Projects: GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : astrocytes * cell plasticity * JAK/STAT3 pathway * microglia conditioned media * spinal cord neurons Subject RIV: FH - Neurology Impact factor: 4.083, year: 2016

  19. Second messenger/signal transduction pathways in major mood disorders: moving from membrane to mechanism of action, part I: major depressive disorder.

    Science.gov (United States)

    Niciu, Mark J; Ionescu, Dawn F; Mathews, Daniel C; Richards, Erica M; Zarate, Carlos A

    2013-10-01

    The etiopathogenesis and treatment of major mood disorders have historically focused on modulation of monoaminergic (serotonin, norepinephrine, dopamine) and amino acid [γ-aminobutyric acid (GABA), glutamate] receptors at the plasma membrane. Although the activation and inhibition of these receptors acutely alter local neurotransmitter levels, their neuropsychiatric effects are not immediately observed. This time lag implicates intracellular neuroplasticity as primary in the mechanism of action of antidepressants and mood stabilizers. The modulation of intracellular second messenger/signal transduction cascades affects neurotrophic pathways that are both necessary and sufficient for monoaminergic and amino acid-based treatments. In this review, we will discuss the evidence in support of intracellular mediators in the pathophysiology and treatment of preclinical models of despair and major depressive disorder (MDD). More specifically, we will focus on the following pathways: cAMP/PKA/CREB, neurotrophin-mediated (MAPK and others), p11, Wnt/Fz/Dvl/GSK3β, and NFκB/ΔFosB. We will also discuss recent discoveries with rapidly acting antidepressants, which activate the mammalian target of rapamycin (mTOR) and release of inhibition on local translation via elongation factor stimulation. Throughout this discourse, we will highlight potential intracellular targets for therapeutic intervention. Finally, future clinical implications are discussed.

  20. Modeling evolution of crosstalk in noisy signal transduction networks

    Science.gov (United States)

    Tareen, Ammar; Wingreen, Ned S.; Mukhopadhyay, Ranjan

    2018-02-01

    Signal transduction networks can form highly interconnected systems within cells due to crosstalk between constituent pathways. To better understand the evolutionary design principles underlying such networks, we study the evolution of crosstalk for two parallel signaling pathways that arise via gene duplication. We use a sequence-based evolutionary algorithm and evolve the network based on two physically motivated fitness functions related to information transmission. We find that one fitness function leads to a high degree of crosstalk while the other leads to pathway specificity. Our results offer insights on the relationship between network architecture and information transmission for noisy biomolecular networks.

  1. Is autoinducer-2 a universal signal for interspecies communication: a comparative genomic and phylogenetic analysis of the synthesis and signal transduction pathways

    Directory of Open Access Journals (Sweden)

    Wagner-Döbler Irene

    2004-09-01

    Full Text Available Abstract Background Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. Recently, it has been proposed that autoinducer-2 (AI-2, a furanosyl borate diester derived from the recycling of S-adenosyl-homocysteine (SAH to homocysteine, serves as a universal signal for interspecies communication. Results In this study, 138 completed genomes were examined for the genes involved in the synthesis and detection of AI-2. Except for some symbionts and parasites, all organisms have a pathway to recycle SAH, either using a two-step enzymatic conversion by the Pfs and LuxS enzymes or a one-step conversion using SAH-hydrolase (SahH. 51 organisms including most Gamma-, Beta-, and Epsilonproteobacteria, and Firmicutes possess the Pfs-LuxS pathway, while Archaea, Eukarya, Alphaproteobacteria, Actinobacteria and Cyanobacteria prefer the SahH pathway. In all 138 organisms, only the three Vibrio strains had strong, bidirectional matches to the periplasmic AI-2 binding protein LuxP and the central signal relay protein LuxU. The initial two-component sensor kinase protein LuxQ, and the terminal response regulator luxO are found in most Proteobacteria, as well as in some Firmicutes, often in several copies. Conclusions The genomic analysis indicates that the LuxS enzyme required for AI-2 synthesis is widespread in bacteria, while the periplasmic binding protein LuxP is only present in Vibrio strains. Thus, other organisms may either use components different from the AI-2 signal transduction system of Vibrio strains to sense the signal of AI-2, or they do not have such a quorum sensing system at all.

  2. A new highly conserved antibiotic sensing/resistance pathway in firmicutes involves an ABC transporter interplaying with a signal transduction system.

    Directory of Open Access Journals (Sweden)

    Stéphanie Coumes-Florens

    2011-01-01

    Full Text Available Signal transduction systems and ABC transporters often contribute jointly to adaptive bacterial responses to environmental changes. In Bacillus subtilis, three such pairs are involved in responses to antibiotics: BceRSAB, YvcPQRS and YxdJKLM. They are characterized by a histidine kinase belonging to the intramembrane sensing kinase family and by a translocator possessing an unusually large extracytoplasmic loop. It was established here using a phylogenomic approach that systems of this kind are specific but widespread in Firmicutes, where they originated. The present phylogenetic analyses brought to light a highly dynamic evolutionary history involving numerous horizontal gene transfers, duplications and lost events, leading to a great variety of Bce-like repertories in members of this bacterial phylum. Based on these phylogenetic analyses, it was proposed to subdivide the Bce-like modules into six well-defined subfamilies. Functional studies were performed on members of subfamily IV comprising BceRSAB from B. subtilis, the expression of which was found to require the signal transduction system as well as the ABC transporter itself. The present results suggest, for the members of this subfamily, the occurrence of interactions between one component of each partner, the kinase and the corresponding translocator. At functional and/or structural levels, bacitracin dependent expression of bceAB and bacitracin resistance processes require the presence of the BceB translocator loop. Some other members of subfamily IV were also found to participate in bacitracin resistance processes. Taken together our study suggests that this regulatory mechanism might constitute an important common antibiotic resistance mechanism in Firmicutes. [Supplemental material is available online at http://www.genome.org.].

  3. Tamarind Seed Xyloglucans Promote Proliferation and Migration of Human Skin Cells through Internalization via Stimulation of Proproliferative Signal Transduction Pathways

    Directory of Open Access Journals (Sweden)

    W. Nie

    2013-01-01

    Full Text Available Xyloglucans (XGs of Tamarindus indica L. Fabaceae are used as drug vehicles or as ingredients of cosmetics. Two xyloglucans were extracted from T. indica seed with cold water (TSw and copper complex precipitation (TSc. Both were analyzed in regard to composition and influence on cell viability, proliferation, cell cycle progression, migration, MAPK phosphorylation, and gene expression of human skin keratinocytes (NHEK and HaCaT and fibroblasts (NHDF in vitro. TSw and TSc differed in molecular weight, rhamnose content, and ratios of xylose, arabinose, galactose, and glucose. Both XGs improved keratinocytes and fibroblast proliferation, promoted the cell cycle, and stimulated migration and intracellular enzyme activity of NHDF after endosomal uptake. Only TSw significantly enhanced HaCaT migration and extracellular enzyme activity of NHDF and HaCaT. TSw and TSc predominantly enhanced the phosphorylation of molecules that referred to Erk signaling in NHEK. In NHDF parts of the integrin signaling and SAPK/JNK pathway were affected. Independent of cell type TSw marginally regulated the expression of genes, which referred to membrane proteins, cytoskeleton, cytokine signaling, and ECM as well as to processes of metabolism and transcription. Results show that T. indica xyloglucans promote skin regeneration by a direct influence on cell proliferation and migration.

  4. The c-Myc target glycoprotein1balpha links cytokinesis failure to oncogenic signal transduction pathways in cultured human cells.

    Directory of Open Access Journals (Sweden)

    Qian Wu

    2010-05-01

    Full Text Available An increase in chromosome number, or polyploidization, is associated with a variety of biological changes including breeding of cereal crops and flowers, terminal differentiation of specialized cells such as megakaryocytes, cellular stress and oncogenic transformation. Yet it remains unclear how cells tolerate the major changes in gene expression, chromatin organization and chromosome segregation that invariably accompany polyploidization. We show here that cancer cells can initiate increases in chromosome number by inhibiting cell division through activation of glycoprotein1b alpha (GpIbalpha, a component of the c-Myc signaling pathway. We are able to recapitulate cytokinesis failure in primary cells by overexpression of GpIbalpha in a p53-deficient background. GpIbalpha was found to localize to the cleavage furrow by microscopy analysis and, when overexpressed, to interfere with assembly of the cellular cortical contraction apparatus and normal division. These results indicate that cytokinesis failure and tetraploidy in cancer cells are directly linked to cellular hyperproliferation via c-Myc induced overexpression of GpIbalpha.

  5. Molecular characterization of the cold- and heat-induced Arabidopsis PXL1 gene and its potential role in transduction pathways under temperature fluctuations.

    Science.gov (United States)

    Jung, Chang Gyo; Hwang, Sun-Goo; Park, Yong Chan; Park, Hyeon Mi; Kim, Dong Sub; Park, Duck Hwan; Jang, Cheol Seong

    2015-03-15

    LRR-RLK (Leucine-Rich Repeat Receptor-Like Kinase) proteins are believed to play essential roles in cell-to-cell communication during various cellular processes including development, hormone perception, and abiotic stress responses. We isolated an LRR-RLK gene previously named Arabidopsis PHLOEM INTERCALATED WITH XYLEM-LIKE 1 (AtPXL1) and examined its expression patterns. AtPXL1 was highly induced by cold and heat stress, but not by drought. The fluorescence signal of 35S::AtPXL1-EGFP was closely localized to the plasma membrane. A yeast two-hybrid and bimolecular fluorescence complementation assay exhibited that AtPXL1 interacts with both proteins, A. thaliana histidine-rich dehydrin1 (AtHIRD1) and A. thaliana light-harvesting protein complex I (AtLHCA1). We found that AtPXL1 possesses autophosphorylation activity and phosphorylates AtHIRD1 and AtLHCA1 in an in vitro assay. Subsequently, we found that the knockout line (atpxl1) showed hypersensitive phenotypes when subjected to cold and heat during the germination stage, while the AtPXL1 overexpressing line as well as wild type plants showed high germination rates compared to the knockout plants. These results provide an insight into the molecular function of AtPXL1 in the regulation of signal transduction pathways under temperature fluctuations. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on signal transduction pathway-related protein expression in liver and cerebrum of rhesus monkey

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, Mari; Akema, Satoshi; Tsuzuki, Masami; Kubota, Shunichiro [Tokyo Univ. (Japan); Korenaga, Tatsumi; Fukusato, Toshio [Teikyo Univ. of School of Medicine, Tokyo (Japan); Asaoka, Kazuo [Kyoto Univ. (Japan); Murata, Nobuo [Teikyo Univ. of School of Medicine, Kawasaki (Japan); Nomizu, Motoyoshi [Hokkaido Univ., Sapporo (Japan); Arima, Akihiro [Shin Nippon Biomedical Laboratories, Ltd., Kagoshima (Japan)

    2004-09-15

    2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to produce a wide range of toxic and biochemical effects in experimental animals, including immunological dysfunctions, chloracne, tetragenecity and carcinogenesis. Recently, the potential impact of dioxins on neurological disorders with particular focus on attention deficit hyperactivity disorder (ADHD) are concerned. Although a lot of information is available from studies in rodents, not much is known of the low dose effects of TCDD in non-human primates. In higher animals, dioxins are metabolized slowly, as evidenced by the estimated TCDD half-life of 5.8 to 14.1 years. Therefore, it is necessary to investigate the long-term effects of TCDD on human health. Considering the pronounced species differences observed in some studies of TCDD, the studies using primates are needed for assessment of TCDD exposure on human health. We have been studying the metabolism and the effects of single administration of TCDD on pregnant monkey (F0) and F1 rhesus monkey. The focus of the present study is to study the effects of TCDD on signal transduction pathway-related protein levels in various organs, especially in liver and brain of F0 monkeys.

  7. Genistein, a tyrosine kinase inhibitor, enhanced radiosensitivity in human esophageal cancer cell lines in vitro: Possible involvement of inhibition of survival signal transduction pathways

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Nonaka, Tetsuo; Ishikawa, Hitoshi; Sakurai, Hideyuki; Saitoh, Jun-ichi; Takahashi, Takeo; Mitsuhashi, Norio

    2001-01-01

    Purpose: The effect of genistein, a tyrosine kinase inhibitor, on radiosensitivity was examined, especially focusing on 'survival signal transduction pathways'. Methods and Materials: Two human esophageal squamous cell cancer cell lines, TE-1 (p53, mutant) and TE-2 (p53, wild), were used. Radiosensitivity was determined by clonogenic assay, and activation of survival signals was examined by Western blot. Results: Genistein (30 μM) greatly enhanced radiosensitivity in these cell lines by suppressing radiation-induced activation of survival signals, p42/p44 extracellular signal-regulated kinase and AKT/PKB. Significant increase in the percentage of apoptotic cells and increased poly[ADP-ribose] polymerase cleavage were observed in TE-2, but not in TE-1 even after combination of genistein with irradiation. In terms of changes in expression of p53-related proteins, increase in expression of Bax and decrease in that of Bcl-2 were observed in TE-2 but not in TE-1, suggesting that the main mode of cell death induced by genistein in a cell line with wild type p53 differed from that with mutant p53. Conclusions: This study suggested that survival signals, including p42/p44 ERK and AKT/PKB, may be involved in determining radiosensitivity, and genistein would be a potent therapeutic agent that has an enhancing effect on radiation

  8. Which downstream signal transduction pathway(s) of H-ras are necessary for the cellular response(s) to ionizing radiation? (Results of an astro research fellowship year)

    International Nuclear Information System (INIS)

    Rudoltz, Marc S.; Muschel, Ruth J.; McKenna, W. Gillies

    1996-01-01

    Purpose/Background: The H-ras oncogene encodes a protein which is an essential component of multiple downstream effector pathways required for induction of proliferation and differentiation. Ras plays a role in the control some of these signal transduction pathways, such as the MAP kinase pathway which controls gene expression and the Rac-Rho pathway which controls cell morphology. Previous work from our laboratory has associated H-ras expression with radiation resistance, a prolonged delay in G2 following exposure to ionizing radiation, and suppression of radiation-induced apoptosis. In addition, H-ras cooperates with myc in transformation. Recent work by White et al. (Cell 80:533-541, 1995) and Joneson et al. (Science 271: 810-812, 1996) describes three mutations in H-ras which were engineered to eliminate different downstream signal transduction pathways of H-ras. T35S contains a serine in place of threonine at amino acid 35 and is defective for ras-induced cytoskeletal changes and initiation of DNA synthesis. E37G contains a glutamic acid in place of glycine at amino acid 37 which eliminates interaction of H-ras with a GDP/GTP exchange factor. C40 contains a substitution of cysteine for tyrosine at amino acid 40 and is defective for H-ras induction of the MAP kinase pathway. We propose that by expressing these mutant H-ras proteins in immortalized cells the downstream pathways of H-ras which regulate the cellular response(s) to ionizing radiation may be determined. Materials and Methods: pHP-5 plasmids encoding these H-ras mutant genes (see White et al.) were transfected by calcium phosphate precipitation into MR4 cells, rat embryo fibroblasts immortalized by expression of v-myc. In this vector, the cDNA for H-ras is placed under the control of a CMV constitutive promoter, and selection is provided by hygromycin. The transfections performed were as follows: V12Ras (no mutation), T35S, E37G, C40, T35S + E37G, and T35S + C40. Twenty four hours after transfection

  9. Role of estrogen in lung cancer based on the estrogen receptor-epithelial mesenchymal transduction signaling pathways

    Directory of Open Access Journals (Sweden)

    Zhao XZ

    2015-10-01

    Full Text Available Xiao-zhen Zhao,1,* Yu Liu,1,* Li-juan Zhou,1,* Zhong-qi Wang,1 Zhong-hua Wu,2 Xiao-yuan Yang31Department of Tumor, Longhua Hospital, 2Center of Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 3Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA*These authors contributed equally to this workBackground/aim: Estrogen is reported to promote the occurrence and development of several human cancers. Increasing evidence shows that most human lung tumors exert estrogen receptor expression. In the present study, we investigated the underlying mechanism of estrogen effect in lung cancer through estrogen receptor-epithelial–mesechymal-transition signaling pathways for the first time.Materials and methods: A total of 36 inbred C57BL/6 mice (18 male and 18 female were injected subcutaneously with human lung adenocarcinoma cell line, Lewis. After the lung tumor model was established, mice with lung adenocarcinoma were randomly divided into three groups for each sex (n=6, such as vehicle group, estrogen group, and estrogen plus tamoxifen group. The six groups of mice were sacrificed after 21 days of drug treatment. Tumor tissue was stripped and weighed, and tumor inhibition rate was calculated based on average tumor weight. Protein and messenger RNA (mRNA expressions of estrogen receptor α (ERα, estrogen receptor β (ERβ, phosphatidylinositol 3'-kinase (PI3K, AKT, E-cadherin, and vimentin were detected in both tumor tissue and lung tissue by using immunohistochemistry and real-time reverse transcription-polymerase chain reaction.Results: 1 For male mice: in the estrogen group, estrogen treatment significantly increased ERα protein and mRNA expressions in tumor tissue and protein expression of PI3K, AKT, and vimentin in both tumor tissue and lung tissue compared with the vehicle-treated group. Besides, m

  10. Molecular pathway profiling of T lymphocyte signal transduction pathways; Th1 and Th2 genomic fingerprints are defined by TCR and CD28-mediated signaling

    NARCIS (Netherlands)

    Smeets, Ruben L.; Fleuren, Wilco W. M.; He, Xuehui; Vink, Paul M.; Wijnands, Frank; Gorecka, Monika; Klop, Henri; Bauerschmidt, Sussane; Garritsen, Anja; Koenen, Hans J. P. M.; Joosten, Irma; Boots, Annemieke M. H.; Alkema, Wynand

    2012-01-01

    Background: T lymphocytes are orchestrators of adaptive immunity. Naive T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we

  11. Molecular pathway profiling of T lymphocyte signal transduction pathways; Th1 and Th2 genomic fingerprints are defined by TCR and CD28-mediated signaling.

    NARCIS (Netherlands)

    Smeets, R.L.; Fleuren, W.W.M.; He, X.; Vink, P.M.; Wijnands, F.; Gorecka, M.; Klop, H.; Bauerschmidt, S.; Garritsen, A.; Koenen, H.J.P.M.; Joosten, I.; Boots, A.M.H.; Alkema, W.

    2012-01-01

    BACKGROUND: T lymphocytes are orchestrators of adaptive immunity. Naive T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we

  12. Overexpression of extracellular superoxide dismutase reduces severity of radiation-induced lung toxicity through downregulation of the TGF-β signal transduction pathway

    International Nuclear Information System (INIS)

    Rabbani, Z.N.; Anscher, M.S.; Archer, E.; Chen, L.; Samulski, T.V.; Folz, R.J.; Dewhirst, M.W.; Vujaskovic, Z.

    2003-01-01

    The objective of this study is to determine whether overexpression of ECSOD, ameliorates acute radiation induced lung injury by inhibiting activation of TGF-β and down regulating phosphorylation of (p)Smad 3 signal transduction protein. Transgenic (TG) B6C3 mice that overexpress human EC-SOD (hEC-SOD) and wild-type (WT) littermates received single dose of 15 Gy to the whole thorax and sacrificed at 1day, 1wk, 2wk, 3wk, 6wk, 10 and 14 weeks. Different endpoints were assessed to look for lung damage. Starting at 3rd week after radiation, there was significant increase in breathing rates, right lung wet weights and lung tissue damage score of XRT-WT vs. XRT-TG (p<0.05). In BALF, total cell counts per ml were significantly increased in XRT-WT whereas XRT-TG animals did not show any significant increase except at 14 weeks after irradiation (p<0.05). Macrophages and lymphocytes were the predominant inflammatory cells in BALF of XRT-WT compared to XRT-TG (p<0.05). XRT-WT group had a significantly higher percentage of activated TGF-β1 than the XRT-TG (p=0.04) at 14 weeks. There was a mild immunoreactivity of pSmad3 in bronchial epithelium and type II pneumocytes of control animals. In XRT-WT pSmad3 immunostaining was moderate at 1 week and moderate to strong at 3, 6 and 10 weeks whereas in XRT-TG mice immmunostaining was mild to moderate. This study shows that, the overexpression of ECSOD in transgenic animals is radioprotective in acute phase of radiation induced lung injury. Fewer inflammatory cells in XRT-TG group confirms the deprivation of important source for free radicals and TGF-β cytokine. Significant reduction in TGF-β activation in ECSOD overexpressing animals, followed by downregulation of pSmad3 indicates important role of reactive oxygen species in activation of TGF-β signal transduction pathway

  13. Identification of Novel Signal Transduction, Immune Function, and Oxidative Stress Genes and Pathways by Topiramate for Treatment of Methamphetamine Dependence Based on Secondary Outcomes

    Directory of Open Access Journals (Sweden)

    Tianhua Niu

    2017-12-01

    Full Text Available BackgroundTopiramate (TPM is suggested to be a promising medication for treatment of methamphetamine (METH dependence, but the molecular basis remains to be elucidated.MethodsAmong 140 METH-dependent participants randomly assigned to receive either TPM (N = 69 or placebo (N = 71 in a previously conducted randomized controlled trial, 50 TPM- and 49 placebo-treated participants had a total 212 RNA samples available at baseline, week 8, and week 12 time points. Following our primary analysis of gene expression data, we reanalyzed the microarray expression data based on a latent class analysis of binary secondary outcomes during weeks 1–12 that provided a classification of 21 responders and 31 non-responders with consistent responses at both time points.ResultsBased on secondary outcomes, 1,381, 576, 905, and 711 differentially expressed genes at nominal P values < 0.05 were identified in responders versus non-responders for week 8 TPM, week 8 placebo, week 12 TPM, and week 12 placebo groups, respectively. Among 1,381 genes identified in week 8 TPM responders, 359 genes were identified in both week 8 and week 12 TPM groups, of which 300 genes were exclusively detected in TPM responders. Of them, 32 genes had nominal P values < 5 × 10−3 at either week 8 or week 12 and false discovery rates < 0.15 at both time points with consistent directions of gene expression changes, which include GABARAPL1, GPR155, and IL15RA in GABA receptor signaling that represent direct targets for TPM. Analyses of these 300 genes revealed 7 enriched pathways belonging to neuronal function/synaptic plasticity, signal transduction, inflammation/immune function, and oxidative stress response categories. No pathways were enriched for 72 genes exclusively detected in both week 8 and week 12 placebo groups.ConclusionThis secondary analysis study of gene expression data from a TPM clinical trial not only yielded consistent results with those of primary

  14. Molecular pathway profiling of T lymphocyte signal transduction pathways; Th1 and Th2 genomic fingerprints are defined by TCR and CD28-mediated signaling

    Directory of Open Access Journals (Sweden)

    Smeets Ruben L

    2012-03-01

    Full Text Available Abstract Background T lymphocytes are orchestrators of adaptive immunity. Naïve T cells may differentiate into Th1, Th2, Th17 or iTreg phenotypes, depending on environmental co-stimulatory signals. To identify genes and pathways involved in differentiation of Jurkat T cells towards Th1 and Th2 subtypes we performed comprehensive transcriptome analyses of Jurkat T cells stimulated with various stimuli and pathway inhibitors. Results from these experiments were validated in a human experimental setting using whole blood and purified CD4+ Tcells. Results Calcium-dependent activation of T cells using CD3/CD28 and PMA/CD3 stimulation induced a Th1 expression profile reflected by increased expression of T-bet, RUNX3, IL-2, and IFNγ, whereas calcium-independent activation via PMA/CD28 induced a Th2 expression profile which included GATA3, RXRA, CCL1 and Itk. Knock down with siRNA and gene expression profiling in the presence of selective kinase inhibitors showed that proximal kinases Lck and PKCθ are crucial signaling hubs during T helper cell activation, revealing a clear role for Lck in Th1 development and for PKCθ in both Th1 and Th2 development. Medial signaling via MAPkinases appeared to be less important in these pathways, since specific inhibitors of these kinases displayed a minor effect on gene expression. Translation towards a primary, whole blood setting and purified human CD4+ T cells revealed that PMA/CD3 stimulation induced a more pronounced Th1 specific, Lck and PKCθ dependent IFNγ production, whereas PMA/CD28 induced Th2 specific IL-5 and IL-13 production, independent of Lck activation. PMA/CD3-mediated skewing towards a Th1 phenotype was also reflected in mRNA expression of the master transcription factor Tbet, whereas PMA/CD28-mediated stimulation enhanced GATA3 mRNA expression in primary human CD4+ Tcells. Conclusions This study identifies stimulatory pathways and gene expression profiles for in vitro skewing of T helper cell

  15. Physalis peruviana extract induces apoptosis in human Hep G2 cells through CD95/CD95L system and the mitochondrial signaling transduction pathway.

    Science.gov (United States)

    Wu, Shu-Jing; Ng, Lean-Teik; Lin, Doung-Liang; Huang, Shan-Ney; Wang, Shyh-Shyan; Lin, Chun-Ching

    2004-11-25

    Physalis species is a popular folk medicine used for treating cancer, leukemia, hepatitis and other diseases. Studies have shown that the ethanol extract of Physalis peruviana (EEPP) inhibits growth and induces apoptotic death of human Hep G2 cells in culture, whereas proliferation of the mouse BALB/C normal liver cells was not affected. In this study, we performed detailed studies to define the molecular mechanism of EEPP-induced apoptosis in Hep G2 cells. The results further confirmed that EEPP inhibited cell proliferation in a dose- and time-dependent manner. At 50 microg/ml, EEPP significantly increased the accumulation of the sub-G1 peak (hypoploid) and the portion of apoptotic annexin V positive cells. EEPP was found to trigger apoptosis through the release of cytochrome c, Smac/DIABLO and Omi/HtrA2 from mitochondria to cytosol and consequently resulted in caspase-3 activation. Pre-treatment with a general caspase inhibitor (z-VAD-fmk) prevented cytochrome c release. After 48 h of EEPP treatment, the apoptosis of Hep G2 cells was found to associate with an elevated p53, and CD95 and CD95L proteins expression. Furthermore, a marked down-regulation of the expression of the Bcl-2, Bcl-XL and XIAP, and up-regulation of the Bax and Bad proteins were noted. Taken together, the present results suggest that EEPP-induced Hep G2 cell apoptosis was possibly mediated through the CD95/CD95L system and the mitochondrial signaling transduction pathway.

  16. Cellular and Molecular Pathways Leading to External Root Resorption

    Science.gov (United States)

    Iglesias-Linares, A.; Hartsfield, J.K.

    2016-01-01

    External apical root resorption during orthodontic treatment implicates specific molecular pathways that orchestrate nonphysiologic cellular activation. To date, a substantial number of in vitro and in vivo molecular, genomic, and proteomic studies have supplied data that provide new insights into root resorption. Recent mechanisms and developments reviewed here include the role of the cellular component—specifically, the balance of CD68+, iNOS+ M1- and CD68+, CD163+ M2-like macrophages associated with root resorption and root surface repair processes linked to the expression of the M1-associated proinflammatory cytokine tumor necrosis factor, inducible nitric oxide synthase, the M1 activator interferon γ, the M2 activator interleukin 4, and M2-associated anti-inflammatory interleukin 10 and arginase I. Insights into the role of mesenchymal dental pulp cells in attenuating dentin resorption in homeostasis are also reviewed. Data on recently deciphered molecular pathways are reviewed at the level of (1) clastic cell adhesion in the external apical root resorption process and the specific role of α/β integrins, osteopontin, and related extracellular matrix proteins; (2) clastic cell fusion and activation by the RANKL/RANK/OPG and ATP-P2RX7-IL1 pathways; and (3) regulatory mechanisms of root resorption repair by cementum at the proteomic and transcriptomic levels. PMID:27811065

  17. Pyrrolizidine Alkaloids: Metabolic Activation Pathways Leading to Liver Tumor Initiation.

    Science.gov (United States)

    Fu, Peter P

    2017-01-17

    Pyrrolizidine alkaloids (PAs) and PA N-oxides are a class of phytochemical carcinogens contained in over 6000 plant species spread around the world. It has been estimated that approximately half of the 660 PAs and PA N-oxides that have been characterized are cytotoxic, genotoxic, and tumorigenic. It was recently determined that a genotoxic mechanism of liver tumor initiation mediated by PA-derived DNA adducts is a common metabolic activation pathway of a number of PAs. We proposed this set of PA-derived DNA adducts could be a common biological biomarker of PA exposure and a potential biomarker of PA-induced liver tumor formation. We have also found that several reactive secondary pyrrolic metabolites can dissociate and interconvert to other secondary pyrrolic metabolites, resulting in the formation of the same exogenous DNA adducts. This present perspective reports the current progress on these new findings and proposes future research needed for obtaining a greater understanding of the role of this activation pathway and validating the use of this set of PA-derived DNA adducts as a biological biomarker of PA-induced liver tumor initiation.

  18. [Various pathways leading to the progression of chronic liver diseases].

    Science.gov (United States)

    Egresi, Anna; Lengyel, Gabriella; Somogyi, Anikó; Blázovics, Anna; Hagymási, Krisztina

    2016-02-21

    As the result of various effects (viruses, metabolic diseases, nutritional factors, toxic agents, autoimmune processes) abnormal liver function, liver steatosis and connective tissue remodeling may develop. Progression of this process is complex including various pathways and a number of factors. The authors summarize the factors involved in the progression of chronic liver disease. They describe the role of cells and the produced inflammatory mediators and cytokines, as well as the relationship between the disease and the intestinal flora. They emphasize the role of oxidative stress, mitochondrial dysfunction and cell death in disease progression. Insulin resistance and micro-elements (iron, copper) in relation to liver damage are also discussed, and genetic and epigenetic aspects underlying disease progression are summarized. Discovery of novel treatment options, assessment of the effectiveness of treatment, as well as the success and proper timing of liver transplantation may depend on a better understanding of the process of disease progression.

  19. Characterization of sur-2, a Novel Ras-Mediated Signal Transduction Component in C. elegans

    National Research Council Canada - National Science Library

    DesJardins, Edward

    1998-01-01

    ... (oncogenes). A subset of proto-oncogenes comprise the RAS signal transduction pathway. Vulval development in the nematode worm Caenorhabditis elegans is controlled by a RAS signal transduction pathway...

  20. Characterization of sur-2, a Novel Ras-Mediated Signal Transduction Component in C. elegans

    National Research Council Canada - National Science Library

    DesJardins, Edward

    1999-01-01

    ... (oncogenes). A subset of proto-oncogenes comprise the RAS signal transduction pathway. Vulval development in the nematode worm Caenorhabditis elegans is controlled by a RAS signal transduction pathway. C...

  1. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Simões, Maylla Ronacher, E-mail: yllars@hotmail.com [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Aguado, Andrea [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Zhenyukh, Olha; Briones, Ana María [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Alonso, María Jesús [Dept. of Biochemistry, Physiology and Molecular Genetics, Universidad Rey Juan Carlos, Alcorcón (Spain); Vassallo, Dalton Valentim [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Health Science Center of Vitória-EMESCAM, Vitória, ES CEP 29045-402 (Brazil); Salaices, Mercedes, E-mail: mercedes.salaices@uam.es [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain)

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  2. Abscisic acid-activated SNRK2 protein kinases function in the gene-regulation pathway of ABA signal transduction by phosphorylating ABA response element-binding factors.

    Science.gov (United States)

    Kobayashi, Yuhko; Murata, Michiharu; Minami, Hideyuki; Yamamoto, Shuhei; Kagaya, Yasuaki; Hobo, Tokunori; Yamamoto, Akiko; Hattori, Tsukaho

    2005-12-01

    The plant hormone abscisic acid (ABA) induces gene expression via the ABA-response element (ABRE) present in the promoters of ABA-regulated genes. A group of bZIP proteins have been identified as ABRE-binding factors (ABFs) that activate transcription through this cis element. A rice ABF, TRAB1, has been shown to be activated via ABA-dependent phosphorylation. While a large number of signalling factors have been identified that are involved in stomatal regulation by ABA, relatively less is known about the ABA-signalling pathway that leads to gene expression. We have shown recently that three members of the rice SnRK2 protein kinase family, SAPK8, SAPK9 and SAPK10, are activated by ABA signal as well as by hyperosmotic stress. Here we show that transient overexpression in cultured cell protoplasts of these ABA-activated SnRK2 protein kinases leads to the activation of an ABRE-regulated promoter, suggesting that these kinases are involved in the gene-regulation pathway of ABA signalling. We further show several lines of evidence that these ABA-activated SnRK2 protein kinases directly phosphorylate TRAB1 in response to ABA. Kinetic analysis of SAPK10 activation and TRAB1 phosphorylation indicated that the latter immediately followed the former. TRAB1 was found to be phosphorylated not only in response to ABA, but also in response to hyperosmotic stress, which was interpreted as the consequence of phosphorylation of TRAB1 by hyperosmotically activated SAPKs. Physical interaction between TRAB1 and SAPK10 in vivo was demonstrated by a co-immunoprecipitation experiment. Finally, TRAB1 was phosphorylated in vitro by the ABA-activated SnRK2 protein kinases at Ser102, which is phosphorylated in vivo in response to ABA and is critical for the activation function.

  3. On the nanotoxicity of PAMAM dendrimers: Superfect® stimulates the EGFR-ERK1/2 signal transduction pathway via an oxidative stress-dependent mechanism in HEK 293 cells.

    Science.gov (United States)

    Akhtar, Saghir; Chandrasekhar, Bindu; Attur, Sreeja; Yousif, Mariam H M; Benter, Ibrahim F

    2013-05-01

    Polyamidoamine (PAMAM) dendrimers are cationic branch-like macromolecules that may serve as drug delivery systems for gene-based therapies such as RNA interference. For their safe use in the clinic, they should ideally only enhance drug delivery to target tissues and exhibit no adverse effects. However, little is known about their toxicological profiles in terms of their interactions with cellular signal transduction pathways such as the epidermal growth factor receptor (EGFR). The EGFR is an important signaling cascade that regulates cell growth, differentiation, migration, survival and apoptosis. Here, we investigated the impact of naked, unmodified Superfect (SF), a commercially available generation 6 PAMAM dendrimer, on the epidermal growth factor receptor (EGFR) tyrosine kinase-extracellular-regulated kinase 1/2 (ERK1/2) signaling pathway in human embryonic kidney (HEK 293) cells. At concentrations routinely used for transfection, SF exhibited time and dose-dependent stimulation of EGFR and ERK1/2 phosphorylation whereas AG1478, a selective EGFR tyrosine kinase antagonist, inhibited EGFR-ERK1/2 signaling. SF-induced phosphorylation of EGFR for 1h was partly reversible upon removal of the dendrimer and examination of cells 24 later. Co-treatment of SF with epidermal growth factor (EGF) ligand resulted in greater EGFR stimulation than either agent alone implying that the stimulatory effects of SF and the ligand are synergistic. Dendrimer-induced stimulation of EGFR-ERK1/2 signaling could be attenuated by the antioxidants apocynin, catalase and tempol implying that an oxidative stress dependent mechanism was involved. These results show for the first time that PAMAM dendrimers, aside from their ability to improve drug delivery, can modulate the important EGFR-ERK1/2 cellular signal transduction pathway - a novel finding that may have a bearing on their safe application as drug delivery systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Blocking Modification of Eukaryotic Initiation 5A2 Antagonizes Cervical Carcinoma via Inhibition of RhoA/ROCK Signal Transduction Pathway.

    Science.gov (United States)

    Liu, Xiaojun; Chen, Dong; Liu, Jiamei; Chu, Zhangtao; Liu, Dongli

    2017-10-01

    Cervical carcinoma is one of the leading causes of cancer-related death for female worldwide. Eukaryotic initiation factor 5A2 belongs to the eukaryotic initiation factor 5A family and is proposed to be a key factor involved in the development of diverse cancers. In the current study, a series of in vivo and in vitro investigations were performed to characterize the role of eukaryotic initiation factor 5A2 in oncogenesis and metastasis of cervical carcinoma. The expression status of eukaryotic initiation factor 5A2 in 15 cervical carcinoma patients was quantified. Then, the effect of eukaryotic initiation factor 5A2 knockdown on in vivo tumorigenicity ability, cell proliferation, cell cycle distribution, and cell mobility of HeLa cells was measured. To uncover the mechanism driving the function of eukaryotic initiation factor 5A2 in cervical carcinoma, expression of members within RhoA/ROCK pathway was detected, and the results were further verified with an RhoA overexpression modification. The level of eukaryotic initiation factor 5A2 in cervical carcinoma samples was significantly higher than that in paired paratumor tissues ( P cycle arrest ( P ROCK I, and ROCK II were downregulated. The above-mentioned changes in eukaryotic initiation factor 5A2 knockdown cells were alleviated by the overexpression of RhoA. The major findings outlined in the current study confirmed the potential of eukaryotic initiation factor 5A2 as a promising prognosis predictor and therapeutic target for cervical carcinoma treatment. Also, our data inferred that eukaryotic initiation factor 5A2 might function in carcinogenesis of cervical carcinoma through an RhoA/ROCK-dependent manner.

  5. Relative importance of dissolved and food pathways for lead contamination in shrimp

    International Nuclear Information System (INIS)

    Boisson, F.; Cotret, O.; Teyssie, J.-L.; El-Baradeie, M.; Fowler, S.W.

    2003-01-01

    The relative importance of dissolved and food pathways and the influence of food type in the bioaccumulation and retention of lead in the shrimp Palaemonetes varians were examined using a radiotracer method. Shrimp were exposed to 210 Pb-labelled seawater or fed two types of 210 Pb-labelled food, viz. mussels or worms. The amount of radiotracer accumulated by shrimp was examined over a 7-day period, followed by a 1-month and a 7-day depuration period for the dissolved and food source, respectively. Steady state in the uptake was reached after 2 days exposure to dissolved lead, with a resultant estimated concentration factor of 98 ± 3. Transfer factors following ingestion of contaminated mussels and worms were lower than unity for both food types, with lead transfer from worms being significantly higher than that from mussels. Accumulation of dissolved Pb by shrimp was found to occur mainly through adsorption on the exoskeleton with a minor accumulation in the internal tissues probably resulting from the intake of seawater for osmoregulation. In contrast, lead taken up from contaminated food was readily absorbed and bound in the internal tissues of P. varians. Although the transfer of lead to P. varians through the ingestion of contaminated food was low (TF < 1%), it still represented 4 to 8% of the lead content in the prey which is a significant additional contribution of lead to the shrimp body burden. Independent of food type, following ingestion of contaminated food, approximately 23-27% of total lead accumulated in shrimp was located in the edible parts (e.g. muscle). Therefore, the food pathway is suggested to be a significant contributor to the lead transfer to humans through ingestion of contaminated shrimp. After exposure to contaminated food, lead loss kinetics were described by a two-component model, whereas Pb loss following direct uptake from seawater was best described by a three-component model. The additional compartment representing 64% of total Pb

  6. Relative importance of dissolved and food pathways for lead contamination in shrimp

    Energy Technology Data Exchange (ETDEWEB)

    Boisson, F.; Cotret, O.; Teyssie, J.-L.; El-Baradeie, M.; Fowler, S.W

    2003-12-01

    The relative importance of dissolved and food pathways and the influence of food type in the bioaccumulation and retention of lead in the shrimp Palaemonetes varians were examined using a radiotracer method. Shrimp were exposed to {sup 210}Pb-labelled seawater or fed two types of {sup 210}Pb-labelled food, viz. mussels or worms. The amount of radiotracer accumulated by shrimp was examined over a 7-day period, followed by a 1-month and a 7-day depuration period for the dissolved and food source, respectively. Steady state in the uptake was reached after 2 days exposure to dissolved lead, with a resultant estimated concentration factor of 98 {+-} 3. Transfer factors following ingestion of contaminated mussels and worms were lower than unity for both food types, with lead transfer from worms being significantly higher than that from mussels. Accumulation of dissolved Pb by shrimp was found to occur mainly through adsorption on the exoskeleton with a minor accumulation in the internal tissues probably resulting from the intake of seawater for osmoregulation. In contrast, lead taken up from contaminated food was readily absorbed and bound in the internal tissues of P. varians. Although the transfer of lead to P. varians through the ingestion of contaminated food was low (TF < 1%), it still represented 4 to 8% of the lead content in the prey which is a significant additional contribution of lead to the shrimp body burden. Independent of food type, following ingestion of contaminated food, approximately 23-27% of total lead accumulated in shrimp was located in the edible parts (e.g. muscle). Therefore, the food pathway is suggested to be a significant contributor to the lead transfer to humans through ingestion of contaminated shrimp. After exposure to contaminated food, lead loss kinetics were described by a two-component model, whereas Pb loss following direct uptake from seawater was best described by a three-component model. The additional compartment representing 64

  7. The role of the PI3K-Akt signal transduction pathway in Autographa californica multiple nucleopolyhedrovirus infection of Spodoptera frugiperda cells

    International Nuclear Information System (INIS)

    Xiao Wei; Yang Yi; Weng Qingbei; Lin Tiehao; Yuan Meijin; Yang Kai; Pang Yi

    2009-01-01

    Many viruses activate the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway, thereby modulating diverse downstream signaling pathways associated with antiapoptosis, proliferation, cell cycling, protein synthesis and glucose metabolism, in order to augment their replication. To date, the role of the PI3K-Akt pathway in Baculovirus replication has not been defined. In the present study, we demonstrate that infection of Sf9 cells with Autographa californica multiple nucleopolyhedrovirus (AcMNPV) elevated cellular Akt phosphorylation at 1 h post-infection. The maximum Akt phosphorylation occurred at 6 h post-infection and remained unchanged until 18 h post-infection. The PI3K-specific inhibitor, LY294002, suppressed Akt phosphorylation in a dose-dependent manner, suggesting that AcMNPV-induced Akt phosphorylation is PI3K-dependent. The inhibition of PI3K-Akt activation by LY294002 significantly reduced the viral yield, including a reduction in budded viruses and occlusion bodies. The virus production was reduced only when the inhibitor was added within 24 h of infection, implying that activation of PI3K occurred early in infection. Correspondingly, both viral DNA replication and late (VP39) and very late (POLH) viral protein expression were impaired by LY294002 treatment; LY294002 had no effect on immediate-early (IE1) and early-late (GP64) protein expression. These results demonstrate that the PI3K-Akt pathway is required for efficient Baculovirus replication.

  8. Saccharomyces boulardii Preserves the Barrier Function and Modulates the Signal Transduction Pathway Induced in Enteropathogenic Escherichia coli-Infected T84 Cells

    Science.gov (United States)

    Czerucka, Dorota; Dahan, Stephanie; Mograbi, Baharia; Rossi, Bernard; Rampal, Patrick

    2000-01-01

    Use of the nonpathogenic yeast Saccharomyces boulardii in the treatment of infectious diarrhea has attracted growing interest. The present study designed to investigate the effect of this yeast on enteropathogenic Escherichia coli (EPEC)-associated disease demonstrates that S. boulardii abrogated the alterations induced by an EPEC strain on transepithelial resistance, [3H]inulin flux, and ZO-1 distribution in T84 cells. Moreover, EPEC-mediated apoptosis of epithelial cells was delayed in the presence of S. boulardii. The yeast did not modify the number of adherent bacteria but lowered by 50% the number of intracellular bacteria. Infection by EPEC induced tyrosine phosphorylation of several proteins in T84 cells, including p46 and p52 SHC isoforms, that was attenuated in the presence of S. boulardii. Similarly, EPEC-induced activation of the ERK1/2 mitogen-activated protein (MAP) kinase pathway was diminished in the presence of the yeast. Interestingly, inhibition of the ERK1/2 pathway with the specific inhibitor PD 98059 decreased EPEC internalization, suggesting that modulation of the ERK1/2 MAP pathway might account for the lowering of the number of intracellular bacteria observed in the presence of S. boulardii. Altogether, this study demonstrated that S. boulardii exerts a protective effect on epithelial cells after EPEC adhesion by modulating the signaling pathway induced by bacterial infection. PMID:10992512

  9. Chemical form of selenium differentially influences DNA repair pathways following exposure to lead nitrate.

    Science.gov (United States)

    McKelvey, Shauna M; Horgan, Karina A; Murphy, Richard A

    2015-01-01

    Lead, an environmental toxin is known to induce a broad range of physiological and biochemical dysfunctions in humans through a number of mechanisms including the deactivation of antioxidants thus leading to generation of reactive oxygen species (ROS) and subsequent DNA damage. Selenium on the other hand has been proven to play an important role in the protection of cells from free radical damage and oxidative stress, though its effects are thought to be form and dose dependent. As the liver is the primary organ required for metabolite detoxification, HepG2 cells were chosen to assess the protective effects of various selenium compounds following exposure to the genotoxic agent lead nitrate. Initially DNA damage was quantified using a comet assay, gene expression patterns associated with DNA damage and signalling were also examined using PCR arrays and the biological pathways which were most significantly affected by selenium were identified. Interestingly, the organic type selenium compounds (selenium yeast and selenomethionine) conferred protection against lead induced DNA damage in HepG2 cells; this is evident by reduction in the quantity of DNA present in the comet tail of cells cultured in their presence with lead. This trend also followed through the gene expression changes noted in DNA damage pathways analysed. These results were in contrast with those of inorganic sodium selenite which promoted lead induced DNA damage evident in both the comet assay results and the gene expression analysis. Over all this study provided valuable insights into the effects which various selenium compounds had on the DNA damage and signalling pathway indicating the potential for using organic forms of selenium such as selenium enriched yeast to protect against DNA damaging agents. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Academic provenance: Investigation of pathways that lead students into the geosciences

    Science.gov (United States)

    Houlton, Heather R.

    Pathways that lead students into the geosciences as a college major have not been fully explored in the current literature, despite the recent studies on the "geoscience pipeline model." Anecdotal evidence suggests low quality geoscience curriculum in K-12 education, lack of visibility of the discipline and lack of knowledge about geoscience careers contribute to low geoscience enrollments at universities. This study investigated the reasons why college students decided to major in the geosciences. Students' interests, experiences, motivations and desired future careers were examined to develop a pathway model. In addition, self-efficacy was used to inform pathway analyses, as it is an influential factor in academic major and career choice. These results and interpretations have strong implications for recruitment and retention in academia and industry. A semi-structured interview protocol was developed, which was informed by John Flanagan's critical incident theory. The responses to this interview were used to identify common experiences that diverse students shared for reasons they became geoscience majors. Researchers used self-efficacy theory by Alfred Bandura to assess students' pathways. Seventeen undergraduate geoscience majors from two U.S. Midwest research universities were sampled for cross-comparison and analysis. Qualitative analyses led to the development of six categorical steps for the geoscience pathway. The six pathway steps are: innate attributes/interest sources, pre-college critical incidents, college critical incidents, current/near future goals, expected career attributes and desired future careers. Although, how students traversed through each step was unique for individuals, similar patterns were identified between different populations in our participants: Natives, Immigrants and Refugees. In addition, critical incidents were found to act on behavior in two different ways: to support and confirm decision-making behavior (supportive critical

  11. cAMP and EPAC are key players in the regulation of the signal transduction pathway involved in the α-hemolysin autophagic response.

    Directory of Open Access Journals (Sweden)

    María Belén Mestre

    Full Text Available Staphylococcus aureus is a microorganism that causes serious diseases in the human being. This microorganism is able to escape the phagolysosomal pathway, increasing intracellular bacterial survival and killing the eukaryotic host cell to spread the infection. One of the key features of S. aureus infection is the production of a series of virulence factors, including secreted enzymes and toxins. We have shown that the pore-forming toxin α-hemolysin (Hla is the S. aureus-secreted factor responsible for the activation of the autophagic pathway and that this response occurs through a PI3K/Beclin1-independent form. In the present report we demonstrate that cAMP has a key role in the regulation of this autophagic response. Our results indicate that cAMP is able to inhibit the autophagy induced by Hla and that PKA, the classical cAMP effector, does not participate in this regulation. We present evidence that EPAC and Rap2b, through calpain activation, are the proteins involved in the regulation of Hla-induced autophagy. Similar results were obtained in cells infected with different S. aureus strains. Interestingly, in this report we show, for the first time to our knowledge, that both EPAC and Rap2b are recruited to the S. aureus-containing phagosome. We believe that our findings have important implications in understanding innate immune processes involved in intracellular pathogen invasion of the host cell.

  12. Gene expression of insulin signal-transduction pathway intermediates is lower in rats fed a beef tallow diet than in rats fed a safflower oil diet.

    Science.gov (United States)

    Kim, Y B; Nakajima, R; Matsuo, T; Inoue, T; Sekine, T; Komuro, M; Tamura, T; Tokuyama, K; Suzuki, M

    1996-09-01

    To elucidate the effects of dietary fatty acid composition on the insulin signaling pathway, we measured the gene expression of the earliest steps in the insulin action pathway in skeletal muscle of rats fed a safflower oil diet or a beef tallow diet. Rats were meal-fed an isoenergetic diet based on either safflower oil or beef tallow for 8 weeks. Both diets provided 45%, 35%, and 20% of energy as fat, carbohydrate, and protein, respectively. Insulin resistance, assessed from the diurnal rhythm of plasma glucose and insulin and the oral glucose tolerance test (OGTT), developed in rats fed a beef tallow diet. Body fat content was greater in rats fed a beef tallow diet versus a safflower oil diet. The level of insulin receptor mRNA, relative expression of the insulin receptor mRNA isoforms, and receptor protein were not affected by the composition of dietary fatty acids. The abundance of insulin receptor substrate-1 (IRS-1) and phosphatidylinositol (PI) 3-kinase mRNA and protein was significantly lower in rats fed a beef tallow diet versus a safflower oil diet. We conclude that long-term feeding of a high-fat diet with saturated fatty acids induces decrease in IRS-1 and PI 3-kinase mRNA and protein levels, causing insulin resistance in skeletal muscle.

  13. Functional significance of the signal transduction pathways Akt and Erk in ovarian follicles: in vitro and in vivo studies in cattle and sheep

    Directory of Open Access Journals (Sweden)

    Ryan Kate E

    2008-10-01

    Full Text Available Abstract Background The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell function in vitro, and on follicle development in vivo. Methods Bovine granulosa and theca cells were cultured for six days and stimulated with FSH and/or IGF, or LH in combination with PD98059 (Erk inhibitor and/or LY294002 (Akt inhibitor and their effect on cell number and hormone secretion (estradiol, activin-A, inhibin-A, follistatin, progesterone and androstenedione determined. In addition, ovarian follicles were treated in vivo with PD98059 and/or LY294002 in ewes on Day 3 of the cycle and follicles were recovered 48 hours later. Results We have shown that gonadotropin- and IGF-stimulated hormone production by granulosa and theca cells is reduced by treatment with PD98059 and LY294002 in vitro. Furthermore, treatment with PD98059 and LY294002 reduced follicle growth and oestradiol production in vivo. Conclusion These results demonstrate an important functional role for the Akt and Erk signalling pathways in follicle function, growth and development.

  14. Influence of Unweighting on Insulin Signal Transduction in Muscle

    Science.gov (United States)

    Tischler, Marc E.

    2002-01-01

    Unweighting of the juvenile soleus muscle is characterized by an increased binding capacity for insulin relative to muscle mass due to sparing of the receptors during atrophy. Although carbohydrate metabolism and protein degradation in the unweighted muscle develop increased sensitivity to insulin in vivo, protein synthesis in vivo and system A amino acid transport in vitro do not appear to develop such an enhanced response. The long-term goal is to identify the precise nature of this apparent resistance in the insulin signal transduction pathway and to consider how reduced weight-bearing may elicit this effect, by evaluating specific components of the insulin signalling pathway. Because the insulin-signalling pathway has components in common with the signal transduction pathway for insulin-like growth factor (IGF-1) and potentially other growth factors, the study could have important implications in the role of weight-bearing function on muscle growth and development. Since the insulin signalling pathway diverges following activation of insulin receptor tyrosine kinase, the immediate specific aims will be to study the receptor tyrosine kinase (IRTK) and those branches, which lead to phosphorylation of insulin receptor substrate-1 (IRS-1) and of Shc protein. To achieve these broader objectives, we will test in situ, by intramuscular injection, the responses of glucose transport, system A amino acid transport and protein synthesis to insulin analogues for which the receptor has either a weaker or much stronger binding affinity compared to insulin. Studies will include: (1) estimation of the ED(sub 50) for each analogue for these three processes; (2) the effect of duration (one to four days) of unweighting on the response of each process to all analogues tested; (3) the effect of unweighting and the analogues on IRTK activity; and (4) the comparative effects of unweighting and analogue binding on the tyrosine phosphorylation of IRTK, IRS-1, and Shc protein.

  15. Effects of liver depression and psychological stress on human uterine leiomyoma cells by an AR-cAMP-PKA signal transduction pathway.

    Science.gov (United States)

    Xia, Tian; Li, Shuang; Ma, Ruihong; Guan, Sufen; Li, Jiacui; Li, Hongqin; Zhang, Hexin; Lin, Qiu; Zhao, Zhimei; Wang, Baojuan

    2017-06-01

    Based on the emotional theory of Traditional Chinese Medicine, and combined with the modern medicine theory of psychological stress, a research model of human uterine leiomyoma cells (ULM) was cultured in vitro to determine the effectiveness of adrenergic receptor (AR) agonists in human ULM cell growth. In addition, we studied the functional influence of "liver depression and psychological stress theory" on fibroid formation by intervening in the AR-cAMP-PKA signaling pathway. The intention was to establish a new method to prevent and cure fibroids through "liver depression and psychological stress theory" and provide an experimental basis for the Traditional Chinese Medicine emotional theory. Primary human ULM cells were enriched by collagenase digestion. Immunohistochemistry and hematoxylin and eosin (HE) staining were used for cytological identification. Using this model, we studied intervention using specific AR agonists on ULM cells to observe the influence of "liver depression and psychological stress theory" on estrogen receptor (ER), progesterone receptor (PR), vascular endothelial growth factor (VEGF) and fibroblast growth factors (FGF). Norepinephrine (NE) and epinephrine (E) are adrenergic receptor agonists. They promoted ULM cell proliferation and increased the levels of ER, PR, VEGF and FGF. In contrast, isoproterenol (ISO) inhibited ULM cell proliferation and decreased the levels of ER, PR, VEGF and FGF. The protein expression of cAMP and PKA in ULM cells was reduced and the levels of ER, PR, VEGF and FGF were increased when co-treatment with the α-AR blocker (phentolamine). The β-AR blocker (metoprolol) displayed an opposite effect. AR agonists modulated ER, PR, VEGF and FGF levels in ULM cells in an AR-cAMP-PKA-dependent signaling pathways to influence fibroid occurrence and development. Copyright © 2017. Published by Elsevier B.V.

  16. Signal Transduction Pathways (MAPKs, NF-κB, and C/EBP) Regulating COX-2 Expression in Nasal Fibroblasts from Asthma Patients with Aspirin Intolerance

    Science.gov (United States)

    Garcia-Garcia, Francesc Josep; Mullol, Joaquim; Perez-Gonzalez, Maria; Pujols, Laura; Alobid, Isam

    2012-01-01

    Background Recent studies have revealed that cyclooxygenase-2 (COX-2) expression is down-regulated in aspirin-induced asthma (AIA). Various signal pathways (MAPKs, NF-κB and C/EBP) are involved in COX-2 regulation. Objective To investigate the regulation of COX-2 expression through MAP-kinase pathway activation and nuclear factor translocation in aspirin-induced asthma (AIA). Methods Fibroblasts were isolated from specimens of nasal mucosa (NM, N = 5) and nasal polyps (NP, N = 5). After IL-1β (1 ng/ml) incubation, COX-2 and phosphorylated forms of ERK, JNK and p38 MAPK were measured by Western blot. MAPK’s role in IL-1β-induced COX-2 expression was assessed by treating cells with ERK (PD98059), JNK (SP600125) and p38 MAPK (SB203580) inhibitors (0.1–10 µM) prior to IL-1β exposure. NF-κB and C/EBP nuclear translocation was measured by Western blot and TransAM® after IL-1β (10 ng/ml) exposure. Results No differences were observed in the MAPK phosphorylation time-course between NM and NP-AIA fibroblasts. The p38 MAPK inhibitor at 10 µM significantly reduced IL-1β-induced COX-2 expression in NM fibroblasts (85%). In NP-AIA fibroblasts the COX-2 inhibition (65%) at 1 and 10 µM was not statistically significant compared to non-treated cells. ERK and JNK inhibitors had no significant effect in either the NM or NP-AIA cultures. The effect of IL-1β on NF-κB and C/EBP subunits’ nuclear translocation was similar between NM and NP-AIA fibroblasts. Conclusions These results suggest that p38 MAPK is the only MAPK involved in IL-1β-induced COX-2 expression. NM and NP-AIA fibroblasts have similar MAPK phosphorylation dynamics and nuclear factor translocation (NF-κB and C/EBP). COX-2 downregulation observed in AIA patients appears not to be caused by differences in MAPK dynamics or transcription factor translocation. PMID:23240010

  17. Arsenic interferes with the signaling transduction pathway of T cell receptor activation by increasing basal and induced phosphorylation of Lck and Fyn in spleen cells

    International Nuclear Information System (INIS)

    Soto-Pena, Gerson A.; Vega, Libia

    2008-01-01

    Arsenic is known to produce inhibition as well as induction of immune cells proliferative responses depending on the doses as one of its mechanisms of immunotoxicity. Here we evaluate the effect of arsenic exposure on the activation of splenic mononuclear cells (SMC) in male CD57BL6N mice. Intra-gastric exposure to arsenic (as sodium arsenite) for 30 days (1, 0.1, or 0.01 mg/kg/day), reduced the proportion of CD4+ cells and the CD4+/CD8+ ratio in the spleen, increasing the proportion of CD11b+ cells. Arsenic exposure did not modify the proportion of B cells. SMC showed an increased level of phosphorylation of lck and fyn kinases (first kinases associated to TCR complex when activated). Although normal levels of apoptosis were observed on freshly isolated SMC, an increase in apoptotic cells related with the increase in phosphorylation of lck and fyn was observed when SMC were activated with Concanavalin-A (Con-A). Arsenic exposure reduced the proliferative response of SMC to Con-A, and also reduced secretion of IL-2, IL-6, IL-12 and IFNγ. No effect was observed on IL-4, and IL-10 secretion. The same effects were observed when SMC of exposed animals were activated with anti-CD3/CD28 antibodies for 24 h, but these effects were transitory since a recovery, up to control levels or even higher, were observed after 72 h of stimulation. This study demonstrates that repeated and prolonged exposure to arsenic alters cell populations and produces functional changes depending on the specific activation pathway, and could be related with the phosphorylation status of lck and fyn kinases

  18. Lead (Pb) induced ATM-dependent mitophagy via PINK1/Parkin pathway.

    Science.gov (United States)

    Gu, Xueyan; Qi, Yongmei; Feng, Zengxiu; Ma, Lin; Gao, Ke; Zhang, Yingmei

    2018-07-01

    Lead (Pb), a widely distributed environmental pollutant, is known to induce mitochondrial damage as well as autophagy in vitro and in vivo. In this study, we found that Pb could trigger mitophagy in both HEK293 cells and the kidney cortex of male Kunming mice. However, whether ataxia telangiectasis mutated (ATM) which is reported to be linked with PTEN-induced putative kinase 1 (PINK1)/Parkin pathway (a well-characterized mitophagic pathway) participates in the regulation of Pb-induced mitophagy and its exact role remains enigmatic. Our results indicated that Pb activated ATM in vitro and in vivo, and further in vitro studies showed that ATM could co-localize with PINK1 and Parkin in cytosol and interact with PINK1. Knockdown of ATM by siRNA blocked Pb-induced mitophagy even under the circumstance of enhanced accumulation of PINK1 and mitochondrial Parkin. Intriguingly, elevation instead of reduction in phosphorylation level of PINK1 and Parkin was observed in response to ATM knockdown and Pb did not contribute to the further increase of their phosphorylation level, implying that ATM indirectly regulated PINK1/Parkin pathway. These findings reveal a novel mechanism for Pb toxicity and suggest the regulatory importance of ATM in PINK1/Parkin-mediated mitophagy. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. [Effect of ginseng polysaccharide-induced wnt/beta-catenin signal transduction pathway on apoptosis of human nasopharyngeal cancer cells CNE-2].

    Science.gov (United States)

    Fan, Jia-Ming; Liu, Ze-Hong; Li, Jing; Wang, Ya-Ping; Yang, Lv-Yuan; Huang, Jiang-Ju

    2013-10-01

    proliferation of CNE-2 cells and promote thier apoptosis. The obstruction of Wnt/beta-catenin signaling pathway may be an important mechanism for GPS to induce the apoptosis of human nasopharyngeal cancer cells CNE-2.

  20. Genetic analysis of gravity signal transduction in roots

    Science.gov (United States)

    Masson, Patrick; Strohm, Allison; Baldwin, Katherine

    To grow downward into the soil, roots use gravity as a guide. Specialized cells, named stato-cytes, enable this directional growth response by perceiving gravity. Located in the columella region of the cap, these cells sense a reorientation of the root within the gravity field through the sedimentation of, and/or tension/pressure exerted by, dense amyloplasts. This process trig-gers a gravity signal transduction pathway that leads to a fast alkalinization of the cytoplasm and a change in the distribution of the plasma membrane-associated auxin-efflux carrier PIN3. The latter protein is uniformly distributed within the plasma membrane on all sides of the cell in vertically oriented roots. However, it quickly accumulates at the bottom side upon gravis-timulation. This process correlates with a preferential transport of auxin to the bottom side of the root cap, resulting in a lateral gradient across the tip. This gradient is then transported to the elongation zone where it promotes differential cellular elongation, resulting in downward curvature. We isolated mutations that affect gravity signal transduction at a step that pre-cedes cytoplasmic alkalinization and/or PIN3 relocalization and lateral auxin transport across the cap. arg1 and arl2 mutations identify a common genetic pathway that is needed for all three gravity-induced processes in the cap statocytes, indicating these genes function early in the pathway. On the other hand, adk1 affects gravity-induced PIN3 relocalization and lateral auxin transport, but it does not interfere with cytoplasmic alkalinization. ARG1 and ARL2 encode J-domain proteins that are associated with membranes of the vesicular trafficking path-way whereas ADK1 encodes adenosine kinase, an enzyme that converts adenosine derived from nucleic acid metabolism and the AdoMet cycle into AMP, thereby alleviating feedback inhibi-tion of this important methyl-donor cycle. Because mutations in ARG1 (and ARL2) do not completely eliminate

  1. The freeze-thaw stress response of the yeast Saccharomyces cerevisiae is growth phase specific and is controlled by nutritional state via the RAS-cyclic AMP signal transduction pathway.

    Science.gov (United States)

    Park, J I; Grant, C M; Attfield, P V; Dawes, I W

    1997-10-01

    The ability of cells to survive freezing and thawing is expected to depend on the physiological conditions experienced prior to freezing. We examined factors affecting yeast cell survival during freeze-thaw stress, including those associated with growth phase, requirement for mitochondrial functions, and prior stress treatment(s), and the role played by relevant signal transduction pathways. The yeast Saccharomyces cerevisiae was frozen at -20 degrees C for 2 h (cooling rate, less than 4 degrees C min-1) and thawed on ice for 40 min. Supercooling occurred without reducing cell survival and was followed by freezing. Loss of viability was proportional to the freezing duration, indicating that freezing is the main determinant of freeze-thaw damage. Regardless of the carbon source used, the wild-type strain and an isogenic petite mutant ([rho 0]) showed the same pattern of freeze-thaw tolerance throughout growth, i.e., high resistance during lag phase and low resistance during log phase, indicating that the response to freeze-thaw stress is growth phase specific and not controlled by glucose repression. In addition, respiratory ability and functional mitochondria are necessary to confer full resistance to freeze-thaw stress. Both nitrogen and carbon source starvation led to freeze-thaw tolerance. The use of strains affected in the RAS-cyclic AMP (RAS-cAMP) pathway or supplementation of an rca1 mutant (defective in the cAMP phosphodiesterase gene) with cAMP showed that the freeze-thaw response of yeast is under the control of the RAS-cAMP pathway. Yeast did not adapt to freeze-thaw stress following repeated freeze-thaw treatment with or without a recovery period between freeze-thaw cycles, nor could it adapt following pretreatment by cold shock. However, freeze-thaw tolerance of yeast cells was induced during fermentative and respiratory growth by pretreatment with H2O2, cycloheximide, mild heat shock, or NaCl, indicating that cross protection between freeze-thaw stress

  2. Pathways leading to self-perceived general health and overall quality of life in burned adults.

    Science.gov (United States)

    Moi, Asgjerd L; Nilsen, Roy M

    2012-12-01

    The aim of the study was to explore pathways leading to self-perceived general health and overall quality of life in burn patients. Data on burn-specific health, generic health, overall quality of life, injury characteristics and socio-demographics were obtained from 95 adult burn patients 47.0 (23.8) [mean (SD)] months after injury. A theoretical path model was established based on the concepts of Wilson and Cleary's model on health-related quality of life [1], and the proposed model was examined by structural equation modelling. Two main paths were identified, one leading to general health perception and the other leading to overall quality of life. Together, direct and indirect paths explained 63% of the variance of perceived general health and 43% of the variance in overall quality of life. The total effects of the SF-36 domain Vitality on perceived general health and overall quality of life were 0.62 and 0.66, respectively. No statistically significant path could be revealed between general health perception and overall quality of life. The results indicate that self-perceived general health and overall quality of life are related but distinct constructs. Moreover, vitality seems to be an important factor for the perception of both general health and overall quality of life in burned adults. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  3. Genetic Analysis of Gravity Signal Transduction in Arabidopsis Roots

    Science.gov (United States)

    Masson, Patrick; Strohm, Allison; Barker, Richard; Su, Shih-Heng

    Like most other plant organs, roots use gravity as a directional guide for growth. Specialized cells within the columella region of the root cap (the statocytes) sense the direction of gravity through the sedimentation of starch-filled plastids (amyloplasts). Amyloplast movement and/or pressure on sensitive membranes triggers a gravity signal transduction pathway within these cells, which leads to a fast transcytotic relocalization of plasma-membrane associated auxin-efflux carrier proteins of the PIN family (PIN3 and PIN7) toward the bottom membrane. This leads to a polar transport of auxin toward the bottom flank of the cap. The resulting lateral auxin gradient is then transmitted toward the elongation zones where it triggers a curvature that ultimately leads to a restoration of vertical downward growth. Our laboratory is using strategies derived from genetics and systems biology to elucidate the molecular mechanisms that modulate gravity sensing and signal transduction in the columella cells of the root cap. Our previous research uncovered two J-domain-containing proteins, ARG1 and ARL2, as contributing to this process. Mutations in the corresponding paralogous genes led to alterations of root and hypocotyl gravitropism accompanied by an inability for the statocytes to develop a cytoplasmic alkalinization, relocalize PIN3, and transport auxin laterally, in response to gravistimulation. Both proteins are associated peripherally to membranes belonging to various compartments of the vesicular trafficking pathway, potentially modulating the trafficking of defined proteins between plasma membrane and endosomes. MAR1 and MAR2, on the other end, are distinct proteins of the plastidic outer envelope protein import TOC complex (the transmembrane channel TOC75 and the receptor TOC132, respectively). Mutations in the corresponding genes enhance the gravitropic defects of arg1. Using transformation-rescue experiments with truncated versions of TOC132 (MAR2), we have shown

  4. Radioinduced intestinal fibrosis: from molecular mechanisms to therapy applications. Contribution of the TGF--{beta}1, of the CTGF and of the transduction pathway of the Rho/ROCK signal; La fibrose intestinale radio-induite: des mecanismes moleculaires aux applications therapeutiques. Roles du TGF-{beta}1, du CTGF et de la voie de transduction du signal Rho/ROCK

    Energy Technology Data Exchange (ETDEWEB)

    Haydont, V

    2006-12-15

    Delayed radiation enteritis is an intestinal fibrosis induced by accidental or therapeutic radiation for pelvic and abdominal cancer treatments. Studies of molecular mechanisms involved in the development and maintenance of fibrosis have showed the respective contribution of CTGF, low TGF-{beta}1 concentrations and Rho/ROCK pathway. Thus, based on the relationship between CTGF, TGF-{beta}1 and Rho pathway, 2 therapeutics strategies have been develop. First, a pravastatin curative gift leads to a fibro-lysis involving an inhibition of Rho and in cascade a reduction of CTGF expression and extracellular matrix deposition. The data suggest that reversal of established radiation fibrosis in the gut is possible. Second, a pravastatin prophylactic gift prevents the installation of a chronic fibrosis but does not protect the tumor. On the base of these results, the radiation therapy department of the Institut Gustave Roussy will soon initiate 2 clinical trials. (author)

  5. THE ADVERSE OUTCOME PATHWAY (AOP) FRAMEWORK: A FRAMEWORK FOR ORGANIZING BIOLOGICAL KNOWLEDGE LEADING TO HEALTH RISKS.

    Science.gov (United States)

    An Adverse Outcome Pathway (AOP) represents the organization of current and newly acquired knowledge of biological pathways. These pathways contain a series of nodes (Key Events, KEs) that when sufficiently altered influence the next node on the pathway, beginning from an Molecul...

  6. Mechanistic Insights in Ethylene Perception and Signal Transduction1

    Science.gov (United States)

    Ju, Chuanli; Chang, Caren

    2015-01-01

    The gaseous hormone ethylene profoundly affects plant growth, development, and stress responses. Ethylene perception occurs at the endoplasmic reticulum membrane, and signal transduction leads to a transcriptional cascade that initiates diverse responses, often in conjunction with other signals. Recent findings provide a more complete picture of the components and mechanisms in ethylene signaling, now rendering a more dynamic view of this conserved pathway. This includes newly identified protein-protein interactions at the endoplasmic reticulum membrane, as well as the major discoveries that the central regulator ETHYLENE INSENSITIVE2 (EIN2) is the long-sought phosphorylation substrate for the CONSTITUTIVE RESPONSE1 protein kinase, and that cleavage of EIN2 transmits the signal to the nucleus. In the nucleus, hundreds of potential gene targets of the EIN3 master transcription factor have been identified and found to be induced in transcriptional waves, and transcriptional coregulation has been shown to be a mechanism of ethylene cross talk. PMID:26246449

  7. MAPKs are essential upstream signaling pathways in proteolytic cartilage degradation--divergence in pathways leading to aggrecanase and MMP-mediated articular cartilage degradation

    DEFF Research Database (Denmark)

    Sondergaard, B-C; Schultz, N; Madsen, S H

    2010-01-01

    Matrix metalloproteinases (MMPs) and aggrecanases are essential players in cartilage degradation. However, the signaling pathways that results in MMP and/or aggrecanase synthesis and activation are not well understood. We investigated the molecular events leading to MMP- and aggrecanase-mediated ......Matrix metalloproteinases (MMPs) and aggrecanases are essential players in cartilage degradation. However, the signaling pathways that results in MMP and/or aggrecanase synthesis and activation are not well understood. We investigated the molecular events leading to MMP- and aggrecanase......-mediated cartilage degradation....

  8. Integrated GWAS and Pathway profiling for feed efficiency traits in pigs leads to novel genes and their molecular pathways

    DEFF Research Database (Denmark)

    Do, Duy Ngoc; Ostersen, Tage; Strathe, Anders Bjerring

    2013-01-01

    Genome wide association studies (GWAS) are being extensively used in revealing genetic architecture of complex traits. However, GWAS offer limited understanding of the biological role of significant single nucleotide polymorphisms (SNPs) affecting complex traits. Pathway analysis using GWAS results...... is an important step where we firstly detect genes located near GWAS-detected SNPs and subsequently we detect enrichment of these genes in various biological processes and pathways. The objective of this study was to apply these steps to identify relevant pathways involved in residual feed intake (RFI) in pigs....... Residual feed intake is a feed efficiency measure and is highly economically important in animal production. In our study, a total of 596 Yorkshire boars had phenotypic and genotypic records. After quality control, 37,915 SNPs were available for GWAS which was implemented in the DMU software package...

  9. Mechanical transduction via a single soft polymer

    Science.gov (United States)

    Hou, Ruizheng; Wang, Nan; Bao, Weizhu; Wang, Zhisong

    2018-04-01

    Molecular machines from biology and nanotechnology often depend on soft structures to perform mechanical functions, but the underlying mechanisms and advantages or disadvantages over rigid structures are not fully understood. We report here a rigorous study of mechanical transduction along a single soft polymer based on exact solutions to the realistic three-dimensional wormlike-chain model and augmented with analytical relations derived from simpler polymer models. The results reveal surprisingly that a soft polymer with vanishingly small persistence length below a single chemical bond still transduces biased displacement and mechanical work up to practically significant amounts. This "soft" approach possesses unique advantages over the conventional wisdom of rigidity-based transduction, and potentially leads to a unified mechanism for effective allosterylike transduction and relay of mechanical actions, information, control, and molecules from one position to another in molecular devices and motors. This study also identifies an entropy limit unique to the soft transduction, and thereby suggests a possibility of detecting higher efficiency for kinesin motor and mutants in future experiments.

  10. The Protective Effect of Gangliosides on Lead (Pb)-Induced Neurotoxicity Is Mediated by Autophagic Pathways.

    Science.gov (United States)

    Meng, Hongtao; Wang, Lan; He, Junhong; Wang, Zhufeng

    2016-03-25

    Lead (Pb) is a ubiquitous environmental and industrial pollutant and can affect intelligence development and the learning ability and memory of children. Therefore, necessary measures should be taken to protect the central nervous system (CNS) from Pb toxicity. Gangliosides are sialic acid-containing glycosphingolipids that are constituents of mammalian cell membranes and are more abundantly expressed in the CNS. Studies have shown that gangliosides constitute a useful tool in the attempt to promote functional recovery of CNS and can reverse Pb-induced impairments of synaptic plasticity in rats. However, the detailed mechanisms have yet to be fully understood. In our present study, we tried to investigate the role of gangliosides in Pb-induced injury in hippocampus neurons and to further confirm the detailed mechanism. Our results show that Pb-induced injuries in the spatial reference memory were associated with a reduction of cell viability and cell apoptosis, and treatment with gangliosides markedly ameliorated the Pb-induced injury by inhibition of apoptosis action. Gangliosides further attenuated Pb-induced the abnormal autophagic process by regulation of mTOR pathways. In summary, our study establishes the efficacy of gangliosides as neuroprotective agents and provides a strong rationale for further studies on the underlying mechanisms of their neuroprotective functions.

  11. The Protective Effect of Gangliosides on Lead (Pb-Induced Neurotoxicity Is Mediated by Autophagic Pathways

    Directory of Open Access Journals (Sweden)

    Hongtao Meng

    2016-03-01

    Full Text Available Lead (Pb is a ubiquitous environmental and industrial pollutant and can affect intelligence development and the learning ability and memory of children. Therefore, necessary measures should be taken to protect the central nervous system (CNS from Pb toxicity. Gangliosides are sialic acid-containing glycosphingolipids that are constituents of mammalian cell membranes and are more abundantly expressed in the CNS. Studies have shown that gangliosides constitute a useful tool in the attempt to promote functional recovery of CNS and can reverse Pb-induced impairments of synaptic plasticity in rats. However, the detailed mechanisms have yet to be fully understood. In our present study, we tried to investigate the role of gangliosides in Pb-induced injury in hippocampus neurons and to further confirm the detailed mechanism. Our results show that Pb-induced injuries in the spatial reference memory were associated with a reduction of cell viability and cell apoptosis, and treatment with gangliosides markedly ameliorated the Pb-induced injury by inhibition of apoptosis action. Gangliosides further attenuated Pb-induced the abnormal autophagic process by regulation of mTOR pathways. In summary, our study establishes the efficacy of gangliosides as neuroprotective agents and provides a strong rationale for further studies on the underlying mechanisms of their neuroprotective functions.

  12. Radioinduced intestinal fibrosis: from molecular mechanisms to therapy applications. Contribution of the TGF--β1, of the CTGF and of the transduction pathway of the Rho/ROCK signal

    International Nuclear Information System (INIS)

    Haydont, V.

    2006-12-01

    Delayed radiation enteritis is an intestinal fibrosis induced by accidental or therapeutic radiation for pelvic and abdominal cancer treatments. Studies of molecular mechanisms involved in the development and maintenance of fibrosis have showed the respective contribution of CTGF, low TGF-β1 concentrations and Rho/ROCK pathway. Thus, based on the relationship between CTGF, TGF-β1 and Rho pathway, 2 therapeutics strategies have been develop. First, a pravastatin curative gift leads to a fibro-lysis involving an inhibition of Rho and in cascade a reduction of CTGF expression and extracellular matrix deposition. The data suggest that reversal of established radiation fibrosis in the gut is possible. Second, a pravastatin prophylactic gift prevents the installation of a chronic fibrosis but does not protect the tumor. On the base of these results, the radiation therapy department of the Institut Gustave Roussy will soon initiate 2 clinical trials. (author)

  13. Food contamination as a pathway for lead exposure in children during the 2010-2013 lead poisoning epidemic in Zamfara, Nigeria.

    Science.gov (United States)

    Tirima, Simba; Bartrem, Casey; von Lindern, Ian; von Braun, Margrit; Lind, Douglas; Anka, Shehu Mohamed; Abdullahi, Aishat

    2018-05-01

    In 2010, an estimated 400 to 500 children died of acute lead poisoning associated with artisanal gold mining in Zamfara, Nigeria. Processing of gold ores containing up to 10% lead within residential compounds put residents, especially children, at the highest risk. Principal routes of exposure were incidental ingestion and inhalation of contaminated soil and dusts. Several Nigerian and international health organizations collaborated to reduce lead exposures through environmental remediation and medical treatment. The contribution of contaminated food to total lead exposure was assessed during the environmental health response. Objectives of this investigation were to assess the influence of cultural/dietary habits on lead exposure pathways and estimate the contribution of contaminated food to children's blood lead levels (BLLs). A survey of village dietary practices and staple food lead content was conducted to determine dietary composition, caloric intakes, and lead intake. Potential blood lead increments were estimated using bio-kinetic modeling techniques. Most dietary lead exposure was associated with contamination of staple cereal grains and legumes during post-harvest processing and preparation in contaminated homes. Average post-harvest and processed cereal grain lead levels were 0.32mg/kg and 0.85mg/kg dry weight, respectively. Age-specific food lead intake ranged from 7 to 78μg/day. Lead ingestion and absorption were likely aggravated by the dusty environment, fasting between meals, and nutritional deficiencies. Contamination of staple cereal grains by highly bioavailable pulverized ores could account for as much as 11%-34% of children's BLLs during the epidemic, and were a continuing source after residential soil remediation until stored grain inventories were exhausted. Copyright © 2017. Published by Elsevier B.V.

  14. Immunocytochemical evidence for co-expression of Type III IP3 receptor with signaling components of bitter taste transduction

    Directory of Open Access Journals (Sweden)

    Kinnamon Sue C

    2001-04-01

    Full Text Available Abstract Background Taste receptor cells are responsible for transducing chemical stimuli into electrical signals that lead to the sense of taste. An important second messenger in taste transduction is IP3, which is involved in both bitter and sweet transduction pathways. Several components of the bitter transduction pathway have been identified, including the T2R/TRB taste receptors, phospholipase C β2, and the G protein subunits α-gustducin, β3, and γ13. However, the identity of the IP3 receptor subtype in this pathway is not known. In the present study we used immunocytochemistry on rodent taste tissue to identify the IP3 receptors expressed in taste cells and to examine taste bud expression patterns for IP3R3. Results Antibodies against Type I, II, and III IP3 receptors were tested on sections of rat and mouse circumvallate papillae. Robust cytoplasmic labeling for the Type III IP3 receptor (IP3R3 was found in a large subset of taste cells in both species. In contrast, little or no immunoreactivity was seen with antibodies against the Type I or Type II IP3 receptors. To investigate the potential role of IP3R3 in bitter taste transduction, we used double-label immunocytochemistry to determine whether IP3R3 is expressed in the same subset of cells expressing other bitter signaling components. IP3R3 immunoreactive taste cells were also immunoreactive for PLCβ2 and γ13. Alpha-gustducin immunoreactivity was present in a subset of IP3R3, PLCβ2, and γ13 positive cells. Conclusions IP3R3 is the dominant form of the IP3 receptor expressed in taste cells and our data suggest it plays an important role in bitter taste transduction.

  15. Physician scientist research pathway leading to certification by the American Board of Pathology.

    Science.gov (United States)

    Weiss, Sharon W; Johnson, Rebecca L

    2016-06-01

    In 2014, the American Board of Pathology, in response to the pathology community, approved a physician scientist research pathway (PSRP). This brief report summarizes the history of and objectives for creating the physician scientist research pathway and the requirements of the American Board of Pathology for the certification of physician scientist research pathway trainees. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Evidence for some signal transduction elements involved in UV-light-dependent responses in parsley protoplasts

    International Nuclear Information System (INIS)

    Frohnmeyer, H.; Bowler, C.; Schäfer, E.

    1997-01-01

    The signalling pathways used by UV-light are largely unknown. Using protoplasts from a heterotrophic parsley (Petroselinum crispum L.) cell culture that exclusively respond to UV-B light between 300 and 350 nm with a fast induction of genes encoding flavonoid biosynthetic enzymes, information was obtained about the UV-light signal transduction pathway for chalcone synthase (CHS) and phenylalanine ammonia-lyase (PAL) gene expression. Pharmacological effectors which influence intracellular calcium levels, calmodulin and the activity of serine/threonine kinases also changed the UV-light-dependent expression of these genes. This evaluation indicated the participation of these components on the UV-B-mediated signal transduction cascade to CHS. In contrast, neither membrane-permeable cyclic GMP nor the tyrosine kinase inhibitor genistein affected CHS or PAL expression. Similar results were obtained in protoplasts, which have been transiently transformed with CHS-promoter/GUS (β-glucuronidase) reporter fusion constructs. The involvement of calcium and calmodulin was further indicated in a cell-free light-responsive in vitro transcription system from evacuolated parsley protoplasts. In conclusion, there is evidence now that components of the UV-light-dependent pathway leading to the CHS-promoter are different from the previously characterized cGMP-dependent pathway to CHS utilized by phytochrome in soybean (Glycine max) and tomato seedlings (Lycopersicon esculentum). (author)

  17. Ecdysone receptor agonism leading to lethal molting disruption in arthropods: Review and adverse outcome pathway development

    Science.gov (United States)

    Molting is a key biological process in growth, development, reproduction and survival in arthropods. Complex neuroendocrine pathways are involved in the regulation of molting and may potentially become targets of environmental endocrine disrupting compounds (EDCs). For example, s...

  18. DMPD: Interferon gene regulation: not all roads lead to Tolls. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16095970 Interferon gene regulation: not all roads lead to Tolls. Jefferies CA, Fit...zgerald KA. Trends Mol Med. 2005 Sep;11(9):403-11. (.png) (.svg) (.html) (.csml) Show Interferon gene regulation: not all roads... lead to Tolls. PubmedID 16095970 Title Interferon gene regulation: not all roads lead to

  19. Nutrient starvation leading to triglyceride accumulation activates the Entner Doudoroff pathway in Rhodococcus jostii RHA1.

    Science.gov (United States)

    Juarez, Antonio; Villa, Juan A; Lanza, Val F; Lázaro, Beatriz; de la Cruz, Fernando; Alvarez, Héctor M; Moncalián, Gabriel

    2017-02-27

    Rhodococcus jostii RHA1 and other actinobacteria accumulate triglycerides (TAG) under nutrient starvation. This property has an important biotechnological potential in the production of sustainable oils. To gain insight into the metabolic pathways involved in TAG accumulation, we analysed the transcriptome of R jostii RHA1 under nutrient-limiting conditions. We correlate these physiological conditions with significant changes in cell physiology. The main consequence was a global switch from catabolic to anabolic pathways. Interestingly, the Entner-Doudoroff (ED) pathway was upregulated in detriment of the glycolysis or pentose phosphate pathways. ED induction was independent of the carbon source (either gluconate or glucose). Some of the diacylglycerol acyltransferase genes involved in the last step of the Kennedy pathway were also upregulated. A common feature of the promoter region of most upregulated genes was the presence of a consensus binding sequence for the cAMP-dependent CRP regulator. This is the first experimental observation of an ED shift under nutrient starvation conditions. Knowledge of this switch could help in the design of metabolomic approaches to optimize carbon derivation for single cell oil production.

  20. Synergy and interactions among biological pathways leading to preterm premature rupture of membranes.

    Science.gov (United States)

    Lannon, Sophia M R; Vanderhoeven, Jeroen P; Eschenbach, David A; Gravett, Michael G; Adams Waldorf, Kristina M

    2014-10-01

    Preterm premature rupture of membranes (PPROM) occurs in 1% to 2% of births. Impact of PPROM is greatest in low- and middle-income countries where prematurity-related deaths are most common. Recent investigations identify cytokine and matrix metalloproteinase activation, oxidative stress, and apoptosis as primary pathways to PPROM. These biological processes are initiated by heterogeneous etiologies including infection/inflammation, placental bleeding, uterine overdistention, and genetic polymorphisms. We hypothesize that pathways to PPROM overlap and act synergistically to weaken membranes. We focus our discussion on membrane composition and strength, pathways linking risk factors to membrane weakening, and future research directions to reduce the global burden of PPROM. © The Author(s) 2014.

  1. Long-term human exposure to lead from different media and intake pathways.

    Science.gov (United States)

    Pizzol, Massimo; Thomsen, Marianne; Andersen, Mikael Skou

    2010-10-15

    Lead (Pb) is well known as an environmental pollutant: it can accumulate in various media, so actual lead exposure reflects both historical and present contaminations. Two main challenges then emerge: obtaining updated information to gain an overall picture of the sources of exposure, and predicting the resulting internal body exposure levels and effects that occur under long-term exposure conditions. In this paper, a modeling approach is used to meet these challenges with reference to Danish exposure conditions. Levels of lead content in various media have been coupled with data for lead intake and absorption in the human body, for both children and adults. An age-dependent biokinetic model allows then for determination of the blood lead levels resulting from chronic exposure. The study shows that the actual intake of lead is up to 27% of the Provisional Tolerable Daily Intake (PTDI) for children and around 8% for adults. It is confirmed that the critical route of exposure is via ingestion, accounting for 99% of total lead intake, while inhalation contributes only to 1% of total lead intake. The resulting lead levels in the blood after 2 years of exposure to actual contamination conditions have been estimated as up to 2.2μg/dl in children and almost 1μg/dl in adults. Impacts from lead can occur even at such levels. The role of historical and present sources to lead in the environment is discussed, and, for specific child and adult exposure scenarios, external-internal concentration relationships for the direct linkage between lead in environmental media and resulting concentrations of lead in blood are then presented. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. PUTATIVE ADVERSE OUTCOME PATHWAY FOR INHIBITON OF BRAIN AROMATASE IN FISH LEADING TO REPRODUCTIVE IMPAIRMENT

    Science.gov (United States)

    The adverse outcome pathway (AOP) provides a framework for organizing knowledge to define links between a molecular initiating event (MIE) and an adverse outcome (AO) occurring at a higher level of biological organization, such as the individual or population. The AOP framework p...

  3. Long-term human exposure to lead from different media and intake pathways

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Thomsen, Marianne; Andersen, Mikael Skou

    2010-01-01

    , and predicting the resulting internal body exposure levels and effects that occur under long-term exposure conditions. In this paper, a modeling approach is used to meet these challenges with reference to Danish exposure conditions. Levels of lead content in various media have been coupled with data for lead......Lead (Pb) is well known as an environmental pollutant: it can accumulate in various media, so actual lead exposure reflects both historical and present contaminations. Two main challenges then emerge: obtaining updated information to gain an overall picture of the sources of exposure......–internalconcentration relationships for the direct linkage between lead in environmental media and resultingconcentrations of lead in blood are then presented....

  4. IGF-1 signaling mediated cell-specific skeletal mechano-transduction.

    Science.gov (United States)

    Tian, Faming; Wang, Yongmei; Bikle, Daniel D

    2018-02-01

    Mechanical loading preserves bone mass and stimulates bone formation, whereas skeletal unloading leads to bone loss. In addition to osteocytes, which are considered the primary sensor of mechanical load, osteoblasts, and bone specific mesenchymal stem cells also are involved. The skeletal response to mechanical signals is a complex process regulated by multiple signaling pathways including that of insulin-like growth factor-1 (IGF-1). Conditional osteocyte deletion of IGF-1 ablates the osteogenic response to mechanical loading. Similarly, osteocyte IGF-1 receptor (IGF-1R) expression is necessary for reloading-induced periosteal bone formation. Transgenic overexpression of IGF-1 in osteoblasts results in enhanced responsiveness to in vivo mechanical loading in mice, a response which is eliminated by osteoblastic conditional disruption of IGF-1 in vivo. Bone marrow derived stem cells (BMSC) from unloaded bone fail to respond to IGF-1 in vitro. IGF-1R is required for the transduction of a mechanical stimulus to downstream effectors, transduction which is lost when the IGF-1R is deleted. Although the molecular mechanisms are not yet fully elucidated, the IGF signaling pathway and its interactions with potentially interlinked signaling cascades involving integrins, the estrogen receptor, and wnt/β-catenin play an important role in regulating adaptive response of cancer bone cells to mechanical stimuli. In this review, we discuss recent advances investigating how IGF-1 and other interlinked molecules and signaling pathways regulate skeletal mechano-transduction involving different bone cells, providing an overview of the IGF-1 signaling mediated cell-specific response to mechanical stimuli. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:576-583, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Probabilistic Modeling of Childhood Multimedia Lead Exposures: Examining the Soil Ingestion Pathway

    Science.gov (United States)

    BACKGROUND: Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)’s National Drinking Water Advis...

  6. A mechanistic study on the reaction pathways leading to benzene and naphthalene in cellulose vapor phase cracking

    International Nuclear Information System (INIS)

    Norinaga, Koyo; Yang, Huamei; Tanaka, Ryota; Appari, Srinivas; Iwanaga, Keita; Takashima, Yuka; Kudo, Shinji; Shoji, Tetsuya; Hayashi, Jun-ichiro

    2014-01-01

    The reaction pathways leading to aromatic hydrocarbons such as benzene and naphthalene in gas-phase reactions of multi-component mixtures derived from cellulose fast pyrolysis were studied both experimentally and numerically. A two-stage tubular reactor was used for evaluating the reaction kinetics of secondary vapor phase cracking of the nascent pyrolysates at temperature ranging from 400 to 900 °C, residence time from 0.2 to 4.3 s, and at 241 kPa. The products of alkyne and diene were identified from the primary pyrolysis of cellulose even at low temperature range 500–600 °C. These products include acetylene, propyne, propadiene, vinylacetylene, and cyclopentadiene. Experiments were also numerically validated by a detailed chemical kinetic model consisting of more than 8000 elementary step-like reactions with over 500 chemical species. Acceptable capabilities of the kinetic model in predicting concentration profiles of the products enabled us to assess reaction pathways leading to benzene and naphthalene via the alkyne and diene from primary pyrolysates of cellulose. C 3 alkyne and diene are primary precursors of benzene at 650 °C, while combination of ethylene and vinylacetylene produces benzene dominantly at 850 °C. Cyclopentadiene is a prominent precursor of naphthalene. Combination of acetylene with propyne or allyl radical leads to the formation of cyclopentadiene. Furan and acrolein are likely important alkyne precursors in cellulose pyrolysis at low temperature, whereas dehydrogenations of olefins are major route to alkyne at high temperatures. - Highlights: • Analytical pyrolysis experiments provided data for kinetic modeling. • Detailed chemical kinetic model was used and evaluated. • Alkyne and diene were important intermediates for aromatic hydrocarbon formation. • Reaction pathways leading to aromatic hydrocarbons were proposed

  7. Drug metabolism by cytochrome p450 enzymes: what distinguishes the pathways leading to substrate hydroxylation over desaturation?

    Science.gov (United States)

    Ji, Li; Faponle, Abayomi S; Quesne, Matthew G; Sainna, Mala A; Zhang, Jing; Franke, Alicja; Kumar, Devesh; van Eldik, Rudi; Liu, Weiping; de Visser, Sam P

    2015-06-15

    Cytochrome P450 enzymes are highly versatile biological catalysts in our body that react with a broad range of substrates. Key functions in the liver include the metabolism of drugs and xenobiotics. One particular metabolic pathway that is poorly understood relates to the P450 activation of aliphatic groups leading to either hydroxylation or desaturation pathways. A DFT and QM/MM study has been carried out on the factors that determine the regioselectivity of aliphatic hydroxylation over desaturation of compounds by P450 isozymes. The calculations establish multistate reactivity patterns, whereby the product distributions differ on each of the spin-state surfaces; hence spin-selective product formation was found. The electronic and thermochemical factors that determine the bifurcation pathways were analysed and a model that predicts the regioselectivity of aliphatic hydroxylation over desaturation pathways was established from valence bond and molecular orbital theories. Thus, the difference in energy of the OH versus the OC bond formed and the π-conjugation energy determines the degree of desaturation products. In addition, environmental effects of the substrate binding pocket that affect the regioselectivities were identified. These studies imply that bioengineering P450 isozymes for desaturation reactions will have to include modifications in the substrate binding pocket to restrict the hydroxylation rebound reaction. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Proanthocyanidins Attenuation of Chronic Lead-Induced Liver Oxidative Damage in Kunming Mice via the Nrf2/ARE Pathway

    Directory of Open Access Journals (Sweden)

    Miao Long

    2016-10-01

    Full Text Available Lead is harmful for human health and animals. Proanthocyanidins (PCs, a natural antioxidant, possess a broad spectrum of pharmacological and medicinal properties. However, its protective effects against lead-induced liver damage have not been clarified. This study was aimed to evaluate the protective effect of PCs on the hepatotoxicity of male Kunming mice induced by chronic lead exposure. A total of 70 healthy male Kunming mice were averagely divided into four groups: control group, i.e., the group exposed to lead, the group treated with PCs, and the group co-treated with lead and PCs. The mice exposed to lead were given water containing 0.2% lead acetate. Mice treated in the PCs and PCs lead co-treated groups were given PC (100 mg/kg in 0.9% saline by oral gavage. Lead exposure caused a significant elevation in the liver function parameters, lead level, lipid peroxidation, and inhibition of antioxidant enzyme activities. The induction of oxidative stress and histological alterations in the liver were minimized by co-treatment with PCs. Meanwhile, the number of Transferase-Mediated Deoxyuridine Triphosphate-Biotin Nick End Labeling (TUNEL-positive cells was significantly reduced in the PCs/lead co-treated group compared to the lead group. In addition, the lead group showed an increase in the expression level of Bax, while the expression of Bcl-2 was decreased. Furthermore, the lead group showed an increase in the expression level of endoplasmic reticulum (ER stress-related genes and protein (GRP78 and CHOP. Co-treated with PCs significantly reversed these expressions in the liver. PCs were, therefore, demonstrated to have protective, antioxidant, and anti-ER stress and anti-apoptotic activities in liver damage caused by chronic lead exposure in the Kunming mouse. This may be due to the ability of PCs to enhance the ability of liver tissue to protect against oxidative stress via the Nrf2/ARE signaling pathway, resulting in decreasing ER stress

  9. Early transcriptional response to aminoglycoside antibiotic suggests alternate pathways leading to apoptosis of sensory hair cells in the mouse inner ear

    Directory of Open Access Journals (Sweden)

    Neil eSegil

    2015-05-01

    Full Text Available Aminoglycoside antibiotics are the drug of choice for treating many bacterial infections, but their administration results in hearing loss in nearly one fourth of the patients who receive them. Several biochemical pathways have been implicated in aminoglycoside antibiotic ototoxicity; however, little is known about how hair cells respond to aminoglycoside antibiotics at the transcriptome level. Here we have investigated the genome-wide response to the aminoglycoside antibiotic gentamicin. Using organotypic cultures of the perinatal organ of Corti, we performed RNA sequencing using cDNA libraries obtained from FACS-purified hair cells. Within 3 hours of gentamicin treatment, the messenger RNA level of more than three thousand genes in hair cells changed significantly. Bioinformatic analysis of these changes highlighted several known signal transduction pathways, including the JNK pathway and the NF-κB pathway, in addition to genes involved in the stress response, apoptosis, cell cycle control, and DNA damage repair. In contrast, only 698 genes, mainly involved in cell cycle and metabolite biosynthetic processes, were significantly affected in the non-hair cell population. The gene expression profiles of hair cells in response to gentamicin share a considerable similarity with those previously observed in gentamicin-induced nephrotoxicity. Our findings suggest that previously observed early responses to gentamicin in hair cells in specific signaling pathways are reflected in changes in gene expression. Additionally, the observed changes in gene expression of cell cycle regulatory genes indicate a disruption of the postmitotic state, which may suggest an alternative pathway regulating gentamicin-induced hair cell death. This work provides a more comprehensive view of aminoglycoside antibiotic ototoxicity, and thus contribute to identifying potential pathways or therapeutic targets to alleviate this important side effect of aminoglycoside

  10. Multiple Pathways of Genome Plasticity Leading to Development of Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Didier Mazel

    2013-05-01

    Full Text Available The emergence of multi-resistant bacterial strains is a major source of concern and has been correlated with the widespread use of antibiotics. The origins of resistance are intensively studied and many mechanisms involved in resistance have been identified, such as exogenous gene acquisition by horizontal gene transfer (HGT, mutations in the targeted functions, and more recently, antibiotic tolerance through persistence. In this review, we focus on factors leading to integron rearrangements and gene capture facilitating antibiotic resistance acquisition, maintenance and spread. The role of stress responses, such as the SOS response, is discussed.

  11. The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

    Science.gov (United States)

    Keegan, A D; Pierce, J H

    1994-02-01

    Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

  12. Bioactive lysophospholipids generated by hepatic lipase degradation of lipoproteins lead to complement activation via the classical pathway.

    Science.gov (United States)

    Ma, Wanchao; Paik, David C; Barile, Gaetano R

    2014-09-09

    We determined bioactivity of lysophospholipids generated by degradation of the low-density (LDL), very low-density (VLDL), and high-density (HDL) lipoproteins with hepatic lipase (HL), cholesterol esterase (CE), and lipoprotein-associated phospholipase A2 (Lp-PLA2). The LDL, VLDL, and HDL were treated with HL, CE, and Lp-PLA2 after immobilization on plates, and complement activation studies were performed with diluted human serum. Complement component 3 (C3) fixation, a marker for complement activation, was determined with a monoclonal anti-human C3d antibody. Enzymatic properties of HL and CE were assayed with triglyceride and phosphatidylcholine substrates for triglyceride hydrolase and phospholipase A activities. The ARPE-19 cells were used for viability studies. The HL degradation of human lipoproteins LDL, VLDL, or HDL results in the formation of modified lipoproteins that can activate the complement pathway. Complement activation is dose- and time-dependent upon HL and occurs via the classical pathway. Enzymatic studies suggest that the phospholipase A1 activity of HL generates complement-activating lysophospholipids. C-reactive protein (CRP), known to simultaneously interact with complement C1 and complement factor H (CFH), further enhances HL-induced complement activation. The lysophospholipids, 1-Palmitoyl-sn-glycero-3-phosphocholine and 1-Oleoyl-sn-glycero-3-phosphocholine, can be directly cytotoxic to ARPE-19 cells. The HL degradation of lipoproteins, known to accumulate in the outer retina and in drusen, can lead to the formation of bioactive lysophospholipids that can trigger complement activation and induce RPE cellular dysfunction. Given the known risk associations for age-related macular degeneration (AMD) with HL, CRP, and CFH, this study elucidates a possible damage pathway for age-related macular degeneration (AMD) in genetically predisposed individuals, that HL activity may lead to accumulation of lysophospholipids to initiate complement

  13. Dynamic Testing of Signal Transduction Deregulation During Breast Cancer Initiation

    Science.gov (United States)

    2012-07-01

    Std. Z39.18 Victoria Seewaldt, M.D. Dynamic Testing of Signal Transduction Deregulation During Breast Cancer Initiation Duke University Durham...attomole- zeptomole range. Internal dilution curves insure a high-dynamic calibration range. DU -26 8L DU -26 6L DU -29 5R DU -22 9.2 L DU...3: Nanobiosensor technology is translated to test for pathway deregulation in RPFNA cytology obtained from 10 high-risk women with cytological

  14. Persistent ER stress induces the spliced leader RNA silencing pathway (SLS, leading to programmed cell death in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Hanoch Goldshmidt

    2010-01-01

    Full Text Available Trypanosomes are parasites that cycle between the insect host (procyclic form and mammalian host (bloodstream form. These parasites lack conventional transcription regulation, including factors that induce the unfolded protein response (UPR. However, they possess a stress response mechanism, the spliced leader RNA silencing (SLS pathway. SLS elicits shut-off of spliced leader RNA (SL RNA transcription by perturbing the binding of the transcription factor tSNAP42 to its cognate promoter, thus eliminating trans-splicing of all mRNAs. Induction of endoplasmic reticulum (ER stress in procyclic trypanosomes elicits changes in the transcriptome similar to those induced by conventional UPR found in other eukaryotes. The mechanism of up-regulation under ER stress is dependent on differential stabilization of mRNAs. The transcriptome changes are accompanied by ER dilation and elevation in the ER chaperone, BiP. Prolonged ER stress induces SLS pathway. RNAi silencing of SEC63, a factor that participates in protein translocation across the ER membrane, or SEC61, the translocation channel, also induces SLS. Silencing of these genes or prolonged ER stress led to programmed cell death (PCD, evident by exposure of phosphatidyl serine, DNA laddering, increase in reactive oxygen species (ROS production, increase in cytoplasmic Ca(2+, and decrease in mitochondrial membrane potential, as well as typical morphological changes observed by transmission electron microscopy (TEM. ER stress response is also induced in the bloodstream form and if the stress persists it leads to SLS. We propose that prolonged ER stress induces SLS, which serves as a unique death pathway, replacing the conventional caspase-mediated PCD observed in higher eukaryotes.

  15. Metabolic pathways leading to detoxification of triptolide, a major active component of the herbal medicine Tripterygium wilfordii.

    Science.gov (United States)

    Du, Fuying; Liu, Zhaohua; Li, Xinxiu; Xing, Jie

    2014-08-01

    Triptolide (TP) shows promising anti-inflammatory and antitumor activity but with severe toxicity. TP is a natural reactive electrophile containing three epoxide groups, which are usually linked to hepatotoxicity via their ability to covalently bind to cellular macromolecules. In this study, metabolic pathways leading to detoxification of TP were evaluated in glutathione (GSH)-depleted (treated with L-buthionine-S,R-sulfoxinine, BSO) and aminobenzotriazole (ABT; a non-specific inhibitor for P450s)-treated mice. The toxicity of TP in mice was evaluated in terms of mortality and levels of serum alanine transaminase (ALT). In incubates with NADPH- and GSH-supplemented liver microsomes, seven GSH conjugates derived from TP were detected. In mice, these hydrolytically unstable GSH conjugates underwent γ-glutamyltranspeptidase/dipeptidases-mediated hydrolysis leading to two major cysteinylglycine conjugates, which underwent further hydrolysis by dipeptidases to form two cysteine conjugates of TP. In ABT-treated mice, the hydroxylated metabolites of TP were found at a lower level than normal mice, and their subsequent conjugated metabolites were not found. The level of cysteinylglycine and cysteine conjugates derived from NADPH-independent metabolism increased in mice treated with both TP and BSO (or ABT), which could be the stress response to toxicity of TP. Compared with normal mice, mortality and ALT levels were significantly higher in TP-treated mice, indicating the toxicity of TP. Pretreatment of ABT increased the toxicity caused by TP, whereas the mortality decreased in GSH-depleted mice. Metabolism by cytochrome P450 enzymes to less reactive metabolites implied a high potential for detoxification of TP. The GSH conjugation pathway also contributed to TP's detoxification in mice. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Regulation of autophagy by amino acids and MTOR-dependent signal transduction

    NARCIS (Netherlands)

    Meijer, Alfred J.; Lorin, Séverine; Blommaart, Edward F.; Codogno, Patrice

    2015-01-01

    Amino acids not only participate in intermediary metabolism but also stimulate insulin-mechanistic target of rapamycin (MTOR)-mediated signal transduction which controls the major metabolic pathways. Among these is the pathway of autophagy which takes care of the degradation of long-lived proteins

  17. Targeting Wnt Pathways in Disease

    Science.gov (United States)

    Zimmerman, Zachary F.; Moon, Randall T.

    2012-01-01

    Wnt-mediated signal transduction pathways have long been recognized for their roles in regulating embryonic development, and have more recently been linked to cancer, neurologic diseases, inflammatory diseases, and disorders of endocrine function and bone metabolism in adults. Although therapies targeting Wnt signaling are attractive in theory, in practice it has been difficult to obtain specific therapeutics because many components of Wnt signaling pathways are also involved in other cellular processes, thereby reducing the specificity of candidate therapeutics. New technologies, and advances in understanding the mechanisms of Wnt signaling, have improved our understanding of the nuances of Wnt signaling and are leading to promising new strategies to target Wnt signaling pathways. PMID:23001988

  18. Quantum Transduction with Adaptive Control

    Science.gov (United States)

    Zhang, Mengzhen; Zou, Chang-Ling; Jiang, Liang

    2018-01-01

    Quantum transducers play a crucial role in hybrid quantum networks. A good quantum transducer can faithfully convert quantum signals from one mode to another with minimum decoherence. Most investigations of quantum transduction are based on the protocol of direct mode conversion. However, the direct protocol requires the matching condition, which in practice is not always feasible. Here we propose an adaptive protocol for quantum transducers, which can convert quantum signals without requiring the matching condition. The adaptive protocol only consists of Gaussian operations, feasible in various physical platforms. Moreover, we show that the adaptive protocol can be robust against imperfections associated with finite squeezing, thermal noise, and homodyne detection, and it can be implemented to realize quantum state transfer between microwave and optical modes.

  19. Cellular semiotics and signal transduction

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio

    2007-01-01

    Semiosis, the processes of production, communication and interpretation of signs - coding and de-coding - takes place within and between organisms. The term "endosemiosis" refers to the processes of interpretation and sign transmission inside an organism (as opposed to "exosemiosis", which refers...... to the processes of sign interpretation and transmission between organisms of the same or different species). In Biosemiotics it is customary to recognise the cell as the most elementary integration unit for semiosis. Therefore intra and intercellular communication constitute the departure point for the study...... considering semiotic logic in order to construct our understanding of living phenomena. Given the central integrating role of signal transduction in physiological and ecological studies, this chapter outlines its semiotic implications. The multi-modality and modularity of signal molecules and relative...

  20. Quantum Transduction with Adaptive Control.

    Science.gov (United States)

    Zhang, Mengzhen; Zou, Chang-Ling; Jiang, Liang

    2018-01-12

    Quantum transducers play a crucial role in hybrid quantum networks. A good quantum transducer can faithfully convert quantum signals from one mode to another with minimum decoherence. Most investigations of quantum transduction are based on the protocol of direct mode conversion. However, the direct protocol requires the matching condition, which in practice is not always feasible. Here we propose an adaptive protocol for quantum transducers, which can convert quantum signals without requiring the matching condition. The adaptive protocol only consists of Gaussian operations, feasible in various physical platforms. Moreover, we show that the adaptive protocol can be robust against imperfections associated with finite squeezing, thermal noise, and homodyne detection, and it can be implemented to realize quantum state transfer between microwave and optical modes.

  1. Strain-specific variation in a soilborne phytopathogenic fungus for the expression of genes involved in pH signal transduction pathway, pathogenesis and saprophytic survival in response to environmental pH changes.

    Science.gov (United States)

    Daval, Stéphanie; Lebreton, Lionel; Gracianne, Cécile; Guillerm-Erckelboudt, Anne-Yvonne; Boutin, Morgane; Marchi, Muriel; Gazengel, Kévin; Sarniguet, Alain

    2013-12-01

    The soilborne fungus Gaeumannomyces graminis var. tritici (Ggt) causes take-all, a wheat root disease. In an original strain-specific way, a previous study indicates that inside the Ggt species, some strains grow preferentially at acidic pH and other strains at neutral/alkaline pH. The most important mechanism for a fungal response to the environmental pH is the Pal pathway which integrates the products of the six pal genes and the transcription factor PacC. To evaluate whether the Ggt strain-specific growth in function of the ambient pH is mediated via the Pal pathway, a transcriptional study of the genes encoding this pathway was carried out. This study provided the first evidence that the pH signalling pathway similar to those described in other fungi operated in Ggt. The pacC gene was induced at neutral pH whatever the strain. In an original way, the expression of Ggt genes coding for the different Pal proteins depended on the strain and on the ambient pH. In the strain growing better at acidic pH, few pal genes were pH-regulated, and some were overexpressed at neutral pH when regulated. In the strain growing better at neutral pH, underexpression of most of the pal genes at neutral pH occurred. The strains displayed higher gene expression in the ambient pH that unfavoured their growth as if it was a compensation system. All pH taken together, a globally weaker Pal transcript level occurred in the strains that were less sensitive to acidic pH, and on the contrary, the strain growing better on neutral pH showed higher Pal mRNA levels. The expression of genes involved in pathogenesis and saprophytic growth was also regulated by the ambient pH and the strain: each gene displayed a specific pH-regulation that was similar between strains. But all pH taken together, the global transcript levels of four out of six genes were higher in the strain growing better on neutral pH. Altogether, for the first time, the results show that inside a species, conditions affecting

  2. Specific intracellular signal transduction pathways downstream of CSF-1 receptors: their relationship to breast cancer local recurrence and distant relapse in vivo. Potential targets for the development of new, specific anti-breast cancer therapies to improve local control and block metastatic spread?

    International Nuclear Information System (INIS)

    Kacinski, Barry M.; Sapi, Eva; Flick, Maryann B.; Turner, Bruce; Perrotta, Peter; Maher, M. Grey; Carter, Darryl; Haffy, Bruce

    1997-01-01

    Purpose/Objective: Several earlier studies have implicated CSF-1 and its receptor (CSF-1R) in the biology of mammary neoplasms and those of the female reproductive tract. CSF-1Rs are expressed by the majority (<80%) of invasive breast carcinomas and their activation as evidenced by co-expression of CSF-1 has been correlated with adverse prognosis both in breast and ovarian carcinomas. In the studies, summarized below, we attempt to further correlate expression of CSF-1R with prognosis in breast cancer. We have also attempted to better define the intracellular signal transduction pathways controlled by CSF-1R which are responsible for such clinically relevant phenotypes as protease production, invasiveness, and tumorigenicity and have designed immunological reagents capable of discriminating the activated tyrosine phosphorylated form of CSF-1R from its inactive, unphosphorylated precursor in fixed tissue. Materials and Methods and Results: To study the role of specific tyrosine phosphorylations on downstream signal transduction pathways, we transfected the murine mammary epithelial cell line HC11 with a wild-type murine CSF-1R and two mutant CSF-1Rs in which two of the earliest and most prominent sites of tyrosine autophosphorylation TYR-721 (which couples the receptor to PI-3' kinase and indirectly to pp70-S6kinase and PKC) and TYR-809 (which couples the receptor to RAS-GAP) were mutated to PHE. Transfection of HC11 cells with an unmutated, wild-type CSF-1R increased cellular synthesis of active urokinase and increased their ability to invade basement membrane analogues. It also rendered them competent for anchorage- independent growth in soft agar and able to form pulmonary metastases in isogenic C57 mice after intravenous injection. A TYR-721→PHE mutation completely abolished anchorage- independent growth in vitro and pulmonary metastatic tumorigenicity in vivo without any effects on urokinase production or on cellular ability to invade basement membrane

  3. Endothelial cell oxidative stress and signal transduction

    Directory of Open Access Journals (Sweden)

    ROCIO FONCEA

    2000-01-01

    Full Text Available Endothelial dysfunction (ED is an early event in atherosclerotic disease, preceding clinical manifestations and complications. Increased reactive oxygen species (ROS have been implicated as important mechanisms that contribute to ED, and ROS’s may function as intracellular messengers that modulate signaling pathways. Several intracellular signal events stimulated by ROS have been defined, including the identification of two members of the mitogen activated protein kinase family (ERK1/2 and big MAP kinase, BMK1, tyrosine kinases (Src and Syk and different isoenzymes of PKC as redox-sensitive kinases. ROS regulation of signal transduction components include the modification in the activity of transcriptional factors such as NFkB and others that result in changes in gene expression and modifications in cellular responses. In order to understand the intracellular mechanisms induced by ROS in endothelial cells (EC, we are studying the response of human umbilical cord vein endothelial cells to increased ROS generation by different pro-atherogenic stimuli. Our results show that Homocysteine (Hcy and oxidized LDL (oxLDL enhance the activity and expression of oxidative stress markers, such as NFkB and heme oxygenase 1. These results suggest that these pro-atherogenic stimuli increase oxidative stress in EC, and thus explain the loss of endothelial function associated with the atherogenic process

  4. Architectures and representations for string transduction

    NARCIS (Netherlands)

    Chrupala, Grzegorz

    2015-01-01

    String transduction problems are ubiquitous in natural language processing: they include transliteration, grapheme-to-phoneme conversion, text normalization and translation. String transduction can be reduced to the simpler problems of sequence labeling by expressing the target string as a sequence

  5. Human hematopoietic cell culture, transduction, and analyses

    DEFF Research Database (Denmark)

    Bonde, Jesper; Wirthlin, Louisa; Kohn, Donald B

    2008-01-01

    This unit provides methods for introducing genes into human hematopoietic progenitor cells. The Basic Protocol describes isolation of CD34(+) cells, transduction of these cells with a retroviral vector on fibronectin-coated plates, assaying the efficiency of transduction, and establishing long-te...

  6. Disruption of Microtubules Post-Virus Entry Enhances Adeno-Associated Virus Vector Transduction

    Science.gov (United States)

    Xiao, Ping-Jie; Mitchell, Angela M.; Huang, Lu; Li, Chengwen; Samulski, R. Jude

    2016-01-01

    Perinuclear retention of viral particles is a poorly understood phenomenon observed during many virus infections. In this study, we investigated whether perinuclear accumulation acts as a barrier to limit recombinant adeno-associated virus (rAAV) transduction. After nocodazole treatment to disrupt microtubules at microtubule-organization center (MT-MTOC) after virus entry, we observed higher rAAV transduction. To elucidate the role of MT-MTOC in rAAV infection and study its underlying mechanisms, we demonstrated that rAAV's perinuclear localization was retained by MT-MTOC with fluorescent analysis, and enhanced rAAV transduction from MT-MTOC disruption was dependent on the rAAV capsid's nuclear import signals. Interestingly, after knocking down RhoA or inhibiting its downstream effectors (ROCK and Actin), MT-MTOC disruption failed to increase rAAV transduction or nuclear entry. These data suggest that enhancement of rAAV transduction is the result of increased trafficking to the nucleus via the RhoA-ROCK-Actin pathway. Ten-fold higher rAAV transduction was also observed by disrupting MT-MTOC in brain, liver, and tumor in vivo. In summary, this study indicates that virus perinuclear accumulation at MT-MTOC is a barrier-limiting parameter for effective rAAV transduction and defines a novel defense mechanism by which host cells restrain viral invasion. PMID:26942476

  7. Reciprocal subsidies and food web pathways leading to chum salmon fry in a temperate marine-terrestrial ecotone.

    Science.gov (United States)

    Romanuk, Tamara N; Levings, Colin D

    2010-04-08

    Stable isotope analysis was used to determine the relative proportions of terrestrial and marine subsidies of carbon to invertebrates along a tidal gradient (low-intertidal, mid-intertidal, high-intertidal, supralittoral) and to determine the relative importance of terrestrial carbon in food web pathways leading to chum salmon fry Oncorhynchus keta (Walbaum) in Howe Sound, British Columbia. We found a clear gradient in the proportion of terrestrially derived carbon along the tidal gradient ranging from 68% across all invertebrate taxa in the supralittoral to 25% in the high-intertidal, 20% in the mid-intertidal, and 12% in the low-intertidal. Stable isotope values of chum salmon fry indicated carbon contributions from both terrestrial and marine sources, with terrestrially derived carbon ranging from 12.8 to 61.5% in the muscle tissue of chum salmon fry (mean 30%). Our results provide evidence for reciprocal subsidies of marine and terrestrially derived carbon on beaches in the estuary and suggest that the vegetated supralittoral is an important trophic link in supplying terrestrial carbon to nearshore food webs.

  8. [Transduction peptides, the useful face of a new signaling mechanism].

    Science.gov (United States)

    Joliot, Alain; Prochiantz, Alain

    2005-03-01

    Transduction peptides that cross the plasma membrane of live cells are commonly used for the in vitro and in vivo targeting of hydrophilic drugs into the cell interior. Although this family of peptides has recently increased and will probably continue to do so, the two mainly used peptides are derived from transcription factors. Indeed, TAT is a 12 amino acid long arginine-rich peptide present in the HIV transcription factor, and penetratin - or its variants - corresponds to 16 amino acids that define the highly conserved third helix of the DNA-binding domain (homeodomain) of homeoprotein transcription factors. In this review, we shall recall the different steps that have led to the discovery of transduction peptides and present the most likely hypotheses concerning the mechanisms involved in their internalization. At the risk of being incomplete or, even, biased, we shall concentrate on penetratins and TAT. The reason is that these peptides have been studied for over ten years leading to the edification of robust knowledge regarding their properties. This attitude will not preclude comparisons with other peptides, if necessary. Our goal is to describe the mode of action of these transduction peptides, their range of activity in term of cell types that accept them and cargoes that they can transport, and, also, some of the limitations that one can encounter in their use. Finally, based on the idea that peptide transduction is the technological face of a physiological property of some transcription factors, we shall discuss the putative physiological function of homeoprotein transduction, and, as a consequence, the possibility to use these factors as therapeutic proteins.

  9. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    International Nuclear Information System (INIS)

    Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol; Kwon, Jungkee; Hwang, Jae-Won; Bae, Cheol-Hyeon; Seo, Young-Kwon; Lee, Jeong-Chae

    2014-01-01

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways

  10. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Kook, Sung-Ho [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Lim, Shin-Saeng [School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Kwon, Jungkee [College of Veterinary Medicine, Chonbuk National University, Jeonju (Korea, Republic of); Hwang, Jae-Won; Bae, Cheol-Hyeon [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of); Seo, Young-Kwon [Research Institute of Biotechnology, Dongguk University, Seoul (Korea, Republic of); Lee, Jeong-Chae, E-mail: leejc88@jbnu.ac.kr [Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences and School of Dentistry, Chonbuk National University, Jeonju (Korea, Republic of)

    2014-12-12

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

  11. The age- and sex-specific decline of the 20s proteasome and the Nrf2/CncC signal transduction pathway in adaption and resistance to oxidative stress in Drosophila melanogaster.

    Science.gov (United States)

    Pomatto, Laura C D; Wong, Sarah; Carney, Caroline; Shen, Brenda; Tower, John; Davies, Kelvin J A

    2017-04-01

    Hallmarks of aging include loss of protein homeostasis and dysregulation of stress-adaptive pathways. Loss of adaptive homeostasis, increases accumulation of DNA, protein, and lipid damage. During acute stress, the Cnc-C ( Drosophila Nrf2 orthologue) transcriptionally-regulated 20S proteasome degrades damaged proteins in an ATP-independent manner. Exposure to very low, non-toxic, signaling concentrations of the redox-signaling agent hydrogen peroxide (H 2 O 2 ) cause adaptive increases in the de novo expression and proteolytic activity/capacity of the 20S proteasome in female D. melanogaster (fruit-flies). Female 20S proteasome induction was accompanied by increased tolerance to a subsequent normally toxic but sub-lethal amount of H 2 O 2 , and blocking adaptive increases in proteasome expression also prevented full adaptation. We find, however, that this adaptive response is both sex- and age-dependent. Both increased proteasome expression and activity, and increased oxidative-stress resistance, in female flies, were lost with age. In contrast, male flies exhibited no H 2 O 2 adaptation, irrespective of age. Furthermore, aging caused a generalized increase in basal 20S proteasome expression, but proteolytic activity and adaptation were both compromised. Finally, continual knockdown of Keep1 (the cytosolic inhibitor of Cnc-C) in adults resulted in older flies with greater stress resistance than their age-matched controls, but who still exhibited an age-associated loss of adaptive homeostasis.

  12. Propiconazole-enhanced hepatic cell proliferation is associated with dysregulation of the cholesterol biosynthesis pathway leading to activation of Erk1/2 through Ras farnesylation

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Lynea A.; Moore, Tanya; Nesnow, Stephen, E-mail: nesnow.stephen@epa.gov

    2012-04-15

    Propiconazole is a mouse hepatotumorigenic fungicide designed to inhibit CYP51, a key enzyme in the biosynthesis of ergosterol in fungi and is widely used in agriculture to prevent fungal growth. Metabolomic studies in mice revealed that propiconazole increased levels of hepatic cholesterol metabolites and bile acids, and transcriptomic studies revealed that genes within the cholesterol biosynthesis, cholesterol metabolism and bile acid biosyntheses pathways were up-regulated. Hepatic cell proliferation was also increased by propiconazole. AML12 immortalized hepatocytes were used to study propiconazole's effects on cell proliferation focusing on the dysregulation of cholesterol biosynthesis and resulting effects on Ras farnesylation and Erk1/2 activation as a primary pathway. Mevalonate, a key intermediate in the cholesterol biosynthesis pathway, increases cell proliferation in several cancer cell lines and tumors in vivo and serves as the precursor for isoprenoids (e.g. farnesyl pyrophosphate) which are crucial in the farnesylation of the Ras protein by farnesyl transferase. Farnesylation targets Ras to the cell membrane where it is involved in signal transduction, including the mitogen-activated protein kinase (MAPK) pathway. In our studies, mevalonic acid lactone (MVAL), a source of mevalonic acid, increased cell proliferation in AML12 cells which was reduced by farnesyl transferase inhibitors (L-744,832 or manumycin) or simvastatin, an HMG-CoA reductase inhibitor, indicating that this cell system responded to alterations in the cholesterol biosynthesis pathway. Cell proliferation in AML12 cells was increased by propiconazole which was reversed by co-incubation with L-744,832 or simvastatin. Increasing concentrations of exogenous cholesterol muted the proliferative effects of propiconazole and the inhibitory effects of L-733,832, results ascribed to reduced stimulation of the endogenous cholesterol biosynthesis pathway. Western blot analysis of subcellular

  13. Leading High School Transformation for College and Career Success: A Guide for Developing a System of Linked Learning Pathways

    Science.gov (United States)

    Stearns, Roman

    2014-01-01

    This ConnectEd Guide for Developing a System of Linked Learning Pathways will introduce school district leaders and their community partners to Linked Learning and a system of quality pathways that can transform high schools, instructional practice, and the student experience. Not intended to be prescriptive, this document can and should be…

  14. Protein Transduction Based Therapies for Breast Cancer

    National Research Council Canada - National Science Library

    Robbins, Paul D

    2004-01-01

    We have demonstrated that certain transduction peptides such as 12 lysines and 12 arginines can facilitate internalization into breast tumor lines with higher efficiency than smaller polymers of cationic amino acids...

  15. Protein Transduction Based Therapies for Breast Cancer

    National Research Council Canada - National Science Library

    Robbins, Paul D

    2005-01-01

    We have demonstrated that certain transduction peptides such as 12 lysines and 12 arginines can facilitate internalization into breast tumor lines with higher efficiency than smaller polymers of cationic amino acids...

  16. Prenatal inhibition of the kynurenine pathway leads to structural changes in the hippocampus of adult rat offspring

    OpenAIRE

    Khalil, Omari S; Pisar, Mazura; Forrest, Caroline M; Vincenten, Maria C J; Darlington, L Gail; Stone, Trevor W

    2014-01-01

    Glutamate receptors for N-methyl-d-aspartate (NMDA) are involved in early brain development. The kynurenine pathway of tryptophan metabolism includes the NMDA receptor agonist quinolinic acid and the antagonist kynurenic acid. We now report that prenatal inhibition of the pathway in rats with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl]benzenesulphonamide (Ro61-8048) produces marked changes in hippocampal neuron morphology, spine density and the immunocytochemical localisation of developme...

  17. Leading coordinate analysis of reaction pathways in proton chain transfer: Application to a two-proton transfer model for the green fluorescent protein

    International Nuclear Information System (INIS)

    Wang Sufan; Smith, Sean C.

    2006-01-01

    The 'leading coordinate' approach to computing an approximate reaction pathway, with subsequent determination of the true minimum energy profile, is applied to a two-proton chain transfer model based on the chromophore and its surrounding moieties within the green fluorescent protein (GFP). Using an ab initio quantum chemical method, a number of different relaxed energy profiles are found for several plausible guesses at leading coordinates. The results obtained for different trial leading coordinates are rationalized through the calculation of a two-dimensional relaxed potential energy surface (PES) for the system. Analysis of the 2-D relaxed PES reveals that two of the trial pathways are entirely spurious, while two others contain useful information and can be used to furnish starting points for successful saddle-point searches. Implications for selection of trial leading coordinates in this class of proton chain transfer reactions are discussed, and a simple diagnostic function is proposed for revealing whether or not a relaxed pathway based on a trial leading coordinate is likely to furnish useful information

  18. Systems Perturbation Analysis of a Large-Scale Signal Transduction Model Reveals Potentially Influential Candidates for Cancer Therapeutics

    Science.gov (United States)

    Puniya, Bhanwar Lal; Allen, Laura; Hochfelder, Colleen; Majumder, Mahbubul; Helikar, Tomáš

    2016-01-01

    Dysregulation in signal transduction pathways can lead to a variety of complex disorders, including cancer. Computational approaches such as network analysis are important tools to understand system dynamics as well as to identify critical components that could be further explored as therapeutic targets. Here, we performed perturbation analysis of a large-scale signal transduction model in extracellular environments that stimulate cell death, growth, motility, and quiescence. Each of the model’s components was perturbed under both loss-of-function and gain-of-function mutations. Using 1,300 simulations under both types of perturbations across various extracellular conditions, we identified the most and least influential components based on the magnitude of their influence on the rest of the system. Based on the premise that the most influential components might serve as better drug targets, we characterized them for biological functions, housekeeping genes, essential genes, and druggable proteins. The most influential components under all environmental conditions were enriched with several biological processes. The inositol pathway was found as most influential under inactivating perturbations, whereas the kinase and small lung cancer pathways were identified as the most influential under activating perturbations. The most influential components were enriched with essential genes and druggable proteins. Moreover, known cancer drug targets were also classified in influential components based on the affected components in the network. Additionally, the systemic perturbation analysis of the model revealed a network motif of most influential components which affect each other. Furthermore, our analysis predicted novel combinations of cancer drug targets with various effects on other most influential components. We found that the combinatorial perturbation consisting of PI3K inactivation and overactivation of IP3R1 can lead to increased activity levels of apoptosis

  19. Evidence that membrane transduction of oligoarginine does not require vesicle formation

    International Nuclear Information System (INIS)

    Zaro, Jennica L.; Shen Weichiang

    2005-01-01

    The involvement of vesicular formation processes in the membrane transduction and nuclear transport of oligoarginine is currently a subject of controversy. In this report, a novel quantitative method which allows for the selective measurement of membrane transduction excluding concurrent endocytosis was used to determine the effects of temperature, endosomal acidification, endosomolysis, and several known inhibitors of endocytic pathways on the internalization of oligoarginine. The results show that, unlike endocytosis, transduction of oligoarginine was not affected by incubation at 16 deg. C as compared to the 37 deg. C control, and was only partially inhibited at 4 deg. C incubation. Additionally, membrane transduction was not inhibited to the same extent as endocytosis following treatment with ammonium chloride, hypertonic medium, amiloride, or filipin. The endosomolytic activity of oligoarginine was investigated by examining the leakage of FITC-dextran into the cytosolic compartment, which was not higher in the presence of oligoarginine. Furthermore, ammonium chloride showed no effect on the nuclear transport of oligoarginine. The data presented in this report indicate that membrane transduction is likely to occur at the plasma membrane without the formation of membrane vesicles, and the nuclear localization involves membrane transduction, rather than endocytosis of oligoarginine

  20. Novel bioassay for the discovery of inhibitors of the 2-C-methyl-D-erythritol 4-phosphate (MEP and terpenoid pathways leading to carotenoid biosynthesis.

    Directory of Open Access Journals (Sweden)

    Natália Corniani

    Full Text Available The 2-C-methyl-D-erythritol 4-phosphate (MEP pathway leads to the synthesis of isopentenyl diphosphate in plastids. It is a major branch point providing precursors for the synthesis of carotenoids, tocopherols, plastoquinone and the phytyl chain of chlorophylls, as well as the hormones abscisic acid and gibberellins. Consequently, disruption of this pathway is harmful to plants. We developed an in vivo bioassay that can measure the carbon flow through the carotenoid pathway. Leaf cuttings are incubated in the presence of a phytoene desaturase inhibitor to induce phytoene accumulation. Any compound reducing the level of phytoene accumulation is likely to interfere with either one of the steps in the MEP pathway or the synthesis of geranylgeranyl diphosphate. This concept was tested with known inhibitors of steps of the MEP pathway. The specificity of this in vivo bioassay was also verified by testing representative herbicides known to target processes outside of the MEP and carotenoid pathways. This assay enables the rapid screen of new inhibitors of enzymes preceding the synthesis of phytoene, though there are some limitations related to the non-specific effect of some inhibitors on this assay.

  1. The sugarcane signal transduction (SUCAST catalogue: prospecting signal transduction in sugarcane

    Directory of Open Access Journals (Sweden)

    Glaucia Mendes Souza

    2001-12-01

    Full Text Available EST sequencing has enabled the discovery of many new genes in a vast array of organisms, and the utility of this approach to the scientific community is greatly increased by the establishment of fully annotated databases. The present study aimed to identify sugarcane ESTs sequenced in the sugarcane expressed sequence tag (SUCEST project (http://sucest.lad.ic.unicamp.br that corresponded to signal transduction components. We also produced a sugarcane signal transduction (SUCAST catalogue (http://sucest.lad.ic.unicamp.br/private/mining-reports/QG/QG-mining.htm that covered the main categories and pathways. Expressed sequence tags (ESTs encoding enzymes for hormone (gibberellins, ethylene, auxins, abscisic acid and jasmonic acid biosynthetic pathways were found and tissue specificity was inferred from their relative frequency of occurrence in the different libraries. Whenever possible, transducers of hormones and plant peptide signaling were catalogued to the respective pathway. Over 100 receptors were found in sugarcane, which contains a large family of Ser/Thr kinase receptors and also photoreceptors, histidine kinase receptors and their response regulators. G-protein and small GTPases were analyzed and compared to known members of these families found in mammalian and plant systems. Major kinase and phosphatase pathways were mapped, with special attention being given to the MAP kinase and the inositol pathway, both of which are well known in plants.O sequenciamento de ESTs (etiquetas de sequencias transcritas tem possibilitado a descoberta de muitos novos genes em uma ampla variedade de organismos. Um aumento do aproveitamento desta informação pela comunidade científica tem sido possível graças ao desenvolvimento de base de dados contendo seqüências completamente anotadas. O trabalho aqui relatado teve como objetivo a identificação de ESTs de cana de açúcar seqüenciadas através do projeto SUCEST (http://sucest.lad.ic. unicamp.br que

  2. Signal transduction pathways involved in intestinal salt and water secretion

    NARCIS (Netherlands)

    W. van den Berghe (Nina)

    1992-01-01

    textabstractThis thesis describes some novel aspects of the regulation of salt and water secretion in the intestinal epithelium. This process is not unique for the intestine, but a common and necessary function of many other organs, including the stomach (gastric juice), kidney (urine), sweatglands

  3. Dissection of pathways leading to antigen receptor-induced and Fas/CD95-induced apoptosis in human B cells

    NARCIS (Netherlands)

    Lens, S. M.; den Drijver, B. F.; Pötgens, A. J.; Tesselaar, K.; van Oers, M. H.; van Lier, R. A.

    1998-01-01

    To dissect intracellular pathways involved in B cell Ag receptor (BCR)-mediated and Fas-induced human B cell death, we isolated clones of the Burkitt lymphoma cell line Ramos with different apoptosis sensitivities. Selection for sensitivity to Fas-induced apoptosis also selected for clones with

  4. Towards the systematic discovery of signal transduction networks using phosphorylation dynamics data

    Directory of Open Access Journals (Sweden)

    Yachie Nozomu

    2010-05-01

    Full Text Available Abstract Background Phosphorylation is a ubiquitous and fundamental regulatory mechanism that controls signal transduction in living cells. The number of identified phosphoproteins and their phosphosites is rapidly increasing as a result of recent mass spectrometry-based approaches. Results We analyzed time-course phosphoproteome data obtained previously by liquid chromatography mass spectrometry with the stable isotope labeling using amino acids in cell culture (SILAC method. This provides the relative phosphorylation activities of digested peptides at each of five time points after stimulating HeLa cells with epidermal growth factor (EGF. We initially calculated the correlations between the phosphorylation dynamics patterns of every pair of peptides and connected the strongly correlated pairs to construct a network. We found that peptides extracted from the same intracellular fraction (nucleus vs. cytoplasm tended to be close together within this phosphorylation dynamics-based network. The network was then analyzed using graph theory and compared with five known signal-transduction pathways. The dynamics-based network was correlated with known signaling pathways in the NetPath and Phospho.ELM databases, and especially with the EGF receptor (EGFR signaling pathway. Although the phosphorylation patterns of many proteins were drastically changed by the EGF stimulation, our results suggest that only EGFR signaling transduction was both strongly activated and precisely controlled. Conclusions The construction of a phosphorylation dynamics-based network provides a useful overview of condition-specific intracellular signal transduction using quantitative time-course phosphoproteome data under specific experimental conditions. Detailed prediction of signal transduction based on phosphoproteome dynamics remains challenging. However, since the phosphorylation profiles of kinase-substrate pairs on the specific pathway were localized in the dynamics

  5. Proteomic Analysis Reveals Coordinated Regulation of Anthocyanin Biosynthesis through Signal Transduction and Sugar Metabolism in Black Rice Leaf.

    Science.gov (United States)

    Chen, Linghua; Huang, Yining; Xu, Ming; Cheng, Zuxin; Zheng, Jingui

    2017-12-15

    Black rice ( Oryza sativa L.) is considered to be a healthy food due to its high content of anthocyanins in the pericarp. The synthetic pathway of anthocyanins in black rice grains has been identified, however, the proteomic profile of leaves during grain development is still unclear. Here, isobaric Tags Relative and Absolute Quantification (iTRAQ) MS/MS was carried out to identify statistically significant changes of leaf proteome in the black rice during grain development. Throughout three sequential developmental stages, a total of 3562 proteins were detected and 24 functional proteins were differentially expressed 3-10 days after flowering (DAF). The detected proteins are known to be involved in various biological processes and most of these proteins were related to gene expression regulatory (33.3%), signal transduction (16.7%) and developmental regulation and hormone-like proteins (12.5%). The coordinated changes were consistent with changes in regulatory proteins playing a leading role in leaves during black rice grain development. This indicated that signal transduction between leaves and grains may have an important role in anthocyanin biosynthesis and accumulation during grain development of black rice. In addition, four identified up-regulated proteins associated with starch metabolism suggested that the remobilization of nutrients for starch synthesis plays a potential role in anthocyanin biosynthesis of grain. The mRNA transcription for eight selected proteins was validated with quantitative real-time PCR. Our results explored the proteomics of the coordination between leaf and grain in anthocyanins biosynthesis of grain, which might be regulated by signal transduction and sugar metabolism in black rice leaf.

  6. Proteomic Analysis Reveals Coordinated Regulation of Anthocyanin Biosynthesis through Signal Transduction and Sugar Metabolism in Black Rice Leaf

    Directory of Open Access Journals (Sweden)

    Linghua Chen

    2017-12-01

    Full Text Available Black rice (Oryza sativa L. is considered to be a healthy food due to its high content of anthocyanins in the pericarp. The synthetic pathway of anthocyanins in black rice grains has been identified, however, the proteomic profile of leaves during grain development is still unclear. Here, isobaric Tags Relative and Absolute Quantification (iTRAQ MS/MS was carried out to identify statistically significant changes of leaf proteome in the black rice during grain development. Throughout three sequential developmental stages, a total of 3562 proteins were detected and 24 functional proteins were differentially expressed 3–10 days after flowering (DAF. The detected proteins are known to be involved in various biological processes and most of these proteins were related to gene expression regulatory (33.3%, signal transduction (16.7% and developmental regulation and hormone-like proteins (12.5%. The coordinated changes were consistent with changes in regulatory proteins playing a leading role in leaves during black rice grain development. This indicated that signal transduction between leaves and grains may have an important role in anthocyanin biosynthesis and accumulation during grain development of black rice. In addition, four identified up-regulated proteins associated with starch metabolism suggested that the remobilization of nutrients for starch synthesis plays a potential role in anthocyanin biosynthesis of grain. The mRNA transcription for eight selected proteins was validated with quantitative real-time PCR. Our results explored the proteomics of the coordination between leaf and grain in anthocyanins biosynthesis of grain, which might be regulated by signal transduction and sugar metabolism in black rice leaf.

  7. The application of multiple biophysical cues to engineer functional neocartilage for treatment of osteoarthritis. Part II: signal transduction.

    Science.gov (United States)

    Brady, Mariea A; Waldman, Stephen D; Ethier, C Ross

    2015-02-01

    The unique mechanoelectrochemical environment of cartilage has motivated researchers to investigate the effect of multiple biophysical cues, including mechanical, magnetic, and electrical stimulation, on chondrocyte biology. It is well established that biophysical stimuli promote chondrocyte proliferation, differentiation, and maturation within "biological windows" of defined dose parameters, including mode, frequency, magnitude, and duration of stimuli (see companion review Part I: Cellular Response). However, the underlying molecular mechanisms and signal transduction pathways activated in response to multiple biophysical stimuli remain to be elucidated. Understanding the mechanisms of biophysical signal transduction will deepen knowledge of tissue organogenesis, remodeling, and regeneration and aiding in the treatment of pathologies such as osteoarthritis. Further, this knowledge will provide the tissue engineer with a potent toolset to manipulate and control cell fate and subsequently develop functional replacement cartilage. The aim of this article is to review chondrocyte signal transduction pathways in response to mechanical, magnetic, and electrical cues. Signal transduction does not occur along a single pathway; rather a number of parallel pathways appear to be activated, with calcium signaling apparently common to all three types of stimuli, though there are different modes of activation. Current tissue engineering strategies, such as the development of "smart" functionalized biomaterials that enable the delivery of growth factors or integration of conjugated nanoparticles, may further benefit from targeting known signal transduction pathways in combination with external biophysical cues.

  8. Signal transduction by the major histocompatibility complex class I molecule

    DEFF Research Database (Denmark)

    Pedersen, A E; Skov, Svend; Bregenholt, S

    1999-01-01

    Ligation of cell surface major histocompatibility class I (MHC-I) proteins by antibodies, or by their native counter receptor, the CD8 molecule, mediates transduction of signals into the cells. MHC-I-mediated signaling can lead to both increased and decreased activity of the MHC-I-expressing cell...... and functioning, MHC-I molecules might be of importance for the maintenance of cellular homeostasis not only within the immune system, but also in the interplay between the immune system and other organ systems....

  9. On a Generalized Entropy Measure Leading to the Pathway Model with a Preliminary Application to Solar Neutrino Data

    Directory of Open Access Journals (Sweden)

    Hans J. Haubold

    2013-09-01

    Full Text Available An entropy for the scalar variable case, parallel to Havrda-Charvat entropy, was introduced by the first author, and the properties and its connection to Tsallis non-extensive statistical mechanics and the Mathai pathway model were examined by the authors in previous papers. In the current paper, we extend the entropy to cover the scalar case, multivariable case, and matrix variate case. Then, this measure is optimized under different types of restrictions, and a number of models in the multivariable case and matrix variable case are obtained. Connections of these models to problems in statistical and physical sciences are pointed out. An application of the simplest case of the pathway model to the interpretation of solar neutrino data by applying standard deviation analysis and diffusion entropy analysis is provided.

  10. Targeting multiple cannabinoid anti-tumour pathways with a resorcinol derivative leads to inhibition of advanced stages of breast cancer.

    Science.gov (United States)

    Murase, Ryuichi; Kawamura, Rumi; Singer, Eric; Pakdel, Arash; Sarma, Pranamee; Judkins, Jonathon; Elwakeel, Eiman; Dayal, Sonali; Martinez-Martinez, Esther; Amere, Mukkanti; Gujjar, Ramesh; Mahadevan, Anu; Desprez, Pierre-Yves; McAllister, Sean D

    2014-10-01

    The psychoactive cannabinoid Δ(9) -tetrahydrocannabinol (THC) and the non-psychoactive cannabinoid cannabidiol (CBD) can both reduce cancer progression, each through distinct anti-tumour pathways. Our goal was to discover a compound that could efficiently target both cannabinoid anti-tumour pathways. To measure breast cancer cell proliferation/viability and invasion, MTT and Boyden chamber assays were used. Modulation of reactive oxygen species (ROS) and apoptosis was measured using dichlorodihydrofluorescein and annexin/propidium iodide, respectively, in combination with cell flow cytometry. Changes in protein levels were evaluated using Western analysis. Orthotopic and i.v. mouse models of breast cancer metastasis were used to test the activity of cannabinoids in vivo. CBD reduced breast cancer metastasis in advanced stages of the disease as the direct result of down-regulating the transcriptional regulator Id1. However, this was associated with moderate increases in survival. We therefore screened for analogues that could co-target cannabinoid anti-tumour pathways (CBD- and THC-associated) and discovered the compound O-1663. This analogue inhibited Id1, produced a marked stimulation of ROS, up-regulated autophagy and induced apoptosis. Of all the compounds tested, it was the most potent at inhibiting breast cancer cell proliferation and invasion in culture and metastasis in vivo. O-1663 prolonged survival in advanced stages of breast cancer metastasis. Developing compounds that can simultaneously target multiple cannabinoid anti-tumour pathways efficiently may provide a novel approach for the treatment of patients with metastatic breast cancer. © 2014 The British Pharmacological Society.

  11. Missed cleavage opportunities by FEN1 lead to Okazaki fragment maturation via the long-flap pathway

    KAUST Repository

    Zaher, Manal S.

    2018-01-27

    RNA-DNA hybrid primers synthesized by low fidelity DNA polymerase α to initiate eukaryotic lagging strand synthesis must be removed efficiently during Okazaki fragment (OF) maturation to complete DNA replication. In this process, each OF primer is displaced and the resulting 5\\'-single-stranded flap is cleaved by structure-specific 5\\'-nucleases, mainly Flap Endonuclease 1 (FEN1), to generate a ligatable nick. At least two models have been proposed to describe primer removal, namely short- and long-flap pathways that involve FEN1 or FEN1 along with Replication Protein A (RPA) and Dna2 helicase/nuclease, respectively. We addressed the question of pathway choice by studying the kinetic mechanism of FEN1 action on short- and long-flap DNA substrates. Using single molecule FRET and rapid quench-flow bulk cleavage assays, we showed that unlike short-flap substrates, which are bound, bent and cleaved within the first encounter between FEN1 and DNA, long-flap substrates can escape cleavage even after DNA binding and bending. Notably, FEN1 can access both substrates in the presence of RPA, but bending and cleavage of long-flap DNA is specifically inhibited. We propose that FEN1 attempts to process both short and long flaps, but occasional missed cleavage of the latter allows RPA binding and triggers the long-flap OF maturation pathway.

  12. Missed cleavage opportunities by FEN1 lead to Okazaki fragment maturation via the long-flap pathway

    KAUST Repository

    Zaher, Manal S.; Rashid, Fahad; Song, Bo; Joudeh, Luay I; Sobhy, Mohamed Abdelmaboud; Tehseen, Muhammad; Hingorani, Manju M; Hamdan, Samir

    2018-01-01

    RNA-DNA hybrid primers synthesized by low fidelity DNA polymerase α to initiate eukaryotic lagging strand synthesis must be removed efficiently during Okazaki fragment (OF) maturation to complete DNA replication. In this process, each OF primer is displaced and the resulting 5'-single-stranded flap is cleaved by structure-specific 5'-nucleases, mainly Flap Endonuclease 1 (FEN1), to generate a ligatable nick. At least two models have been proposed to describe primer removal, namely short- and long-flap pathways that involve FEN1 or FEN1 along with Replication Protein A (RPA) and Dna2 helicase/nuclease, respectively. We addressed the question of pathway choice by studying the kinetic mechanism of FEN1 action on short- and long-flap DNA substrates. Using single molecule FRET and rapid quench-flow bulk cleavage assays, we showed that unlike short-flap substrates, which are bound, bent and cleaved within the first encounter between FEN1 and DNA, long-flap substrates can escape cleavage even after DNA binding and bending. Notably, FEN1 can access both substrates in the presence of RPA, but bending and cleavage of long-flap DNA is specifically inhibited. We propose that FEN1 attempts to process both short and long flaps, but occasional missed cleavage of the latter allows RPA binding and triggers the long-flap OF maturation pathway.

  13. Purinergic mechanosensory transduction and visceral pain

    Directory of Open Access Journals (Sweden)

    Burnstock Geoffrey

    2009-11-01

    Full Text Available Abstract In this review, evidence is presented to support the hypothesis that mechanosensory transduction occurs in tubes and sacs and can initiate visceral pain. Experimental evidence for this mechanism in urinary bladder, ureter, gut, lung, uterus, tooth-pulp and tongue is reviewed. Potential therapeutic strategies are considered for the treatment of visceral pain in such conditions as renal colic, interstitial cystitis and inflammatory bowel disease by agents that interfere with mechanosensory transduction in the organs considered, including P2X3 and P2X2/3 receptor antagonists that are orally bioavailable and stable in vivo and agents that inhibit or enhance ATP release and breakdown.

  14. The root hair assay facilitates the use of genetic and pharmacological tools in order to dissect multiple signalling pathways that lead to programmed cell death.

    Directory of Open Access Journals (Sweden)

    Joanna Kacprzyk

    Full Text Available The activation of programmed cell death (PCD is often a result of complex signalling pathways whose relationship and intersection are not well understood. We recently described a PCD root hair assay and proposed that it could be used to rapidly screen genetic or pharmacological modulators of PCD. To further assess the applicability of the root hair assay for studying multiple signalling pathways leading to PCD activation we have investigated the crosstalk between salicylic acid, autophagy and apoptosis-like PCD (AL-PCD in Arabidopsis thaliana. The root hair assay was used to determine rates of AL-PCD induced by a panel of cell death inducing treatments in wild type plants treated with chemical modulators of salicylic acid synthesis or autophagy, and in genetic lines defective in autophagy or salicylic acid signalling. The assay demonstrated that PCD induced by exogenous salicylic acid or fumonisin B1 displayed a requirement for salicylic acid signalling and was partially dependent on the salicylic acid signal transducer NPR1. Autophagy deficiency resulted in an increase in the rates of AL-PCD induced by salicylic acid and fumonisin B1, but not by gibberellic acid or abiotic stress. The phenylalanine ammonia lyase-dependent salicylic acid synthesis pathway contributed only to death induced by salicylic acid and fumonisin B1. 3-Methyladenine, which is commonly used as an inhibitor of autophagy, appeared to influence PCD induction in all treatments suggesting a possible secondary, non-autophagic, effect on a core component of the plant PCD pathway. The results suggest that salicylic acid signalling is negatively regulated by autophagy during salicylic acid and mycotoxin-induced AL-PCD. However, this crosstalk does not appear to be directly involved in PCD induced by gibberellic acid or abiotic stress. This study demonstrates that the root hair assay is an effective tool for relatively rapid investigation of complex signalling pathways leading to

  15. High-precision Pb isotopic measurements of teeth and environmental samples from Sofia (Bulgaria): insights for regional lead sources and possible pathways to the human body

    Science.gov (United States)

    Kamenov, George D.

    2008-08-01

    High-precision Pb isotopic measurements on teeth and possible sources in a given area can provide important insights for the lead (Pb) sources and pathways in the human body. Pb isotopic analyses on soils from the area of Sofia, Bulgaria show that Pb is contributed by three end-members represented by two natural sources and leaded gasoline. Sequential leaching experiments reveal that the alumosilicate fraction of the soils is mainly controlled by natural Pb derived from two mountain massifs bordering the city. Around 1/3 to a half of the Pb in the soil leachates, however, can be explained by contamination from leaded gasoline. Contemporary teeth from Sofia residents show very similar Pb isotopic compositions to the soil leachates, also indicating that around 1/3 to a half of the Pb can be explained by derivation from leaded gasoline. The remarkable isotopic similarities between the teeth and the most labile fractions of the local soils suggest that the lead can be derived from the latter. Pb incorporation in the human body via soil-plant-human or soil-plant-animal-human chains is unlikely due to the fact that no significant farming occurs in the city area. The isotopic compositions of the local soil labile fractions can be used as approximation of the bioaccessible lead for humans. Considering all possible scenarios it appears that soil and/or soil-born dust inhalation and/or ingestion is the most probable pathway for incorporation of local soil lead in the local population. The high-precision Pb isotope data presented in this work indicate that apparently the local soil is what plays major role in the human Pb exposure.

  16. Information Thermodynamics of the Cell Signal Transduction as a Szilard Engine

    Directory of Open Access Journals (Sweden)

    Tatsuaki Tsuruyama

    2018-03-01

    Full Text Available A cell signaling system is in a non-equilibrium state, and it includes multistep biochemical signaling cascades (BSCs, which involve phosphorylation of signaling molecules, such as mitogen-activated protein kinase (MAPK pathways. In this study, the author considered signal transduction description using information thermodynamic theory. The ideal BSCs can be considered one type of the Szilard engine, and the presumed feedback controller, Maxwell’s demon, can extract the work during signal transduction. In this model, the mutual entropy and chemical potential of the signal molecules can be redefined by the extracted chemical work in a mechanicochemical model, Szilard engine, of BSC. In conclusion, signal transduction is computable using the information thermodynamic method.

  17. Systematic Prediction of Scaffold Proteins Reveals New Design Principles in Scaffold-Mediated Signal Transduction

    Science.gov (United States)

    Hu, Jianfei; Neiswinger, Johnathan; Zhang, Jin; Zhu, Heng; Qian, Jiang

    2015-01-01

    Scaffold proteins play a crucial role in facilitating signal transduction in eukaryotes by bringing together multiple signaling components. In this study, we performed a systematic analysis of scaffold proteins in signal transduction by integrating protein-protein interaction and kinase-substrate relationship networks. We predicted 212 scaffold proteins that are involved in 605 distinct signaling pathways. The computational prediction was validated using a protein microarray-based approach. The predicted scaffold proteins showed several interesting characteristics, as we expected from the functionality of scaffold proteins. We found that the scaffold proteins are likely to interact with each other, which is consistent with previous finding that scaffold proteins tend to form homodimers and heterodimers. Interestingly, a single scaffold protein can be involved in multiple signaling pathways by interacting with other scaffold protein partners. Furthermore, we propose two possible regulatory mechanisms by which the activity of scaffold proteins is coordinated with their associated pathways through phosphorylation process. PMID:26393507

  18. Signal perception, transduction, and gene expression involved in anthocyanin biosynthesis

    International Nuclear Information System (INIS)

    Mol, J.; Jenkins, G.; Schäfer, E.; Weiss, D.

    1996-01-01

    Anthocyanin pigments provide fruits and flowers with their bright red and blue colors and are induced in vegetative tissues by various signals. The biosynthetic pathway probably represents one of the best‐studied examples of higher plant secondary metabolism. It has attracted much attention of plant geneticists because of the dispensable nature of the compounds it produces. Not unexpectedly, several excellent reviews on anthocyanin biosynthesis have been published over the last 5 years (Dooner et al., 1991; Martin and Gerats, 1993a, 1993b; Koes et al., 1994; Holton and Cornish, 1995). These reviews emphasize the late steps of pigment biosynthesis rather than the early and intermediate events of signal perception and transduction. This review is broader and not only covers the identification of components of the anthocyanin signal perception/transduction networks but also provides a description of our current understanding of how they evoke the responses that they do. Progress has derived from a combination of biochemical, molecular and genetic studies. We discuss a range of relevant research to highlight the different experimental approaches being used and the diverse biological systems under investigation. (author)

  19. Health risk assessment of various metal(loid)s via multiple exposure pathways on children living near a typical lead-acid battery plant, China

    International Nuclear Information System (INIS)

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2015-01-01

    Manufacture of lead-acid batteries is of widespread interest because of its emissions of heavy metals and metalloids into environment, harming environmental quality and consequently causing detrimental effects on human health. In this study, exposure pathways and health risks of children to heavy metal(loid)s (Pb, Cd, As, etc) were investigated based on field sampling and questionnaire. Pb was one of the most abundant elements in children's blood, with an elevated blood lead level of 12.45 μg dL −1 . Soil/dust and food were heavily polluted by targeted metal(loid)s. Food ingestion accounted for more than 80% of the total exposure for most metal(loid)s. The non-cancer risks to children were 3–10 times higher than the acceptable level of 1, while the cancer risks were 5–200 times higher than the maximum acceptable level of 1.0 × 10 −4 . The study emphasized the significance of effective environmental management, particularly to ensure food security near battery facilities. - Highlights: • The health risks of children living around a typical lead-acid battery was analyzed. • The exposure pathways of children to 12 heavy metal(loid)s were assessed. • Courtyard soil and indoor dust and duplicate food were contaminated by metal(loid)s. • Food ingestion was the major pathway for children's exposure to most metal(loid)s. • Higher potentially non-cancer and cancer risks happened to the local children. - The children living around a typical lead-acid battery plant suffered from serious health risks, which mainly attributed to food ingestion and air inhalation exposure

  20. A Tox21 Approach to Altered Epigenetic Landscapes: Assessing Epigenetic Toxicity Pathways Leading to Altered Gene Expression and Oncogenic Transformation In Vitro

    Directory of Open Access Journals (Sweden)

    Craig L. Parfett

    2017-06-01

    Full Text Available An emerging vision for toxicity testing in the 21st century foresees in vitro assays assuming the leading role in testing for chemical hazards, including testing for carcinogenicity. Toxicity will be determined by monitoring key steps in functionally validated molecular pathways, using tests designed to reveal chemically-induced perturbations that lead to adverse phenotypic endpoints in cultured human cells. Risk assessments would subsequently be derived from the causal in vitro endpoints and concentration vs. effect data extrapolated to human in vivo concentrations. Much direct experimental evidence now shows that disruption of epigenetic processes by chemicals is a carcinogenic mode of action that leads to altered gene functions playing causal roles in cancer initiation and progression. In assessing chemical safety, it would therefore be advantageous to consider an emerging class of carcinogens, the epigenotoxicants, with the ability to change chromatin and/or DNA marks by direct or indirect effects on the activities of enzymes (writers, erasers/editors, remodelers and readers that convey the epigenetic information. Evidence is reviewed supporting a strategy for in vitro hazard identification of carcinogens that induce toxicity through disturbance of functional epigenetic pathways in human somatic cells, leading to inactivated tumour suppressor genes and carcinogenesis. In the context of human cell transformation models, these in vitro pathway measurements ensure high biological relevance to the apical endpoint of cancer. Four causal mechanisms participating in pathways to persistent epigenetic gene silencing were considered: covalent histone modification, nucleosome remodeling, non-coding RNA interaction and DNA methylation. Within these four interacting mechanisms, 25 epigenetic toxicity pathway components (SET1, MLL1, KDM5, G9A, SUV39H1, SETDB1, EZH2, JMJD3, CBX7, CBX8, BMI, SUZ12, HP1, MPP8, DNMT1, DNMT3A, DNMT3B, TET1, MeCP2, SETDB2, BAZ2

  1. Mutations in the HECT domain of NEDD4L lead to AKT-mTOR pathway deregulation and cause periventricular nodular heterotopia.

    Science.gov (United States)

    Broix, Loïc; Jagline, Hélène; Ivanova, Ekaterina; Schmucker, Stéphane; Drouot, Nathalie; Clayton-Smith, Jill; Pagnamenta, Alistair T; Metcalfe, Kay A; Isidor, Bertrand; Louvier, Ulrike Walther; Poduri, Annapurna; Taylor, Jenny C; Tilly, Peggy; Poirier, Karine; Saillour, Yoann; Lebrun, Nicolas; Stemmelen, Tristan; Rudolf, Gabrielle; Muraca, Giuseppe; Saintpierre, Benjamin; Elmorjani, Adrienne; Moïse, Martin; Weirauch, Nathalie Bednarek; Guerrini, Renzo; Boland, Anne; Olaso, Robert; Masson, Cecile; Tripathy, Ratna; Keays, David; Beldjord, Cherif; Nguyen, Laurent; Godin, Juliette; Kini, Usha; Nischké, Patrick; Deleuze, Jean-François; Bahi-Buisson, Nadia; Sumara, Izabela; Hinckelmann, Maria-Victoria; Chelly, Jamel

    2016-11-01

    Neurodevelopmental disorders with periventricular nodular heterotopia (PNH) are etiologically heterogeneous, and their genetic causes remain in many cases unknown. Here we show that missense mutations in NEDD4L mapping to the HECT domain of the encoded E3 ubiquitin ligase lead to PNH associated with toe syndactyly, cleft palate and neurodevelopmental delay. Cellular and expression data showed sensitivity of PNH-associated mutants to proteasome degradation. Moreover, an in utero electroporation approach showed that PNH-related mutants and excess wild-type NEDD4L affect neurogenesis, neuronal positioning and terminal translocation. Further investigations, including rapamycin-based experiments, found differential deregulation of pathways involved. Excess wild-type NEDD4L leads to disruption of Dab1 and mTORC1 pathways, while PNH-related mutations are associated with deregulation of mTORC1 and AKT activities. Altogether, these data provide insights into the critical role of NEDD4L in the regulation of mTOR pathways and their contributions in cortical development.

  2. MRP-1/CD9 gene transduction regulates the actin cytoskeleton through the downregulation of WAVE2.

    Science.gov (United States)

    Huang, C-L; Ueno, M; Liu, D; Masuya, D; Nakano, J; Yokomise, H; Nakagawa, T; Miyake, M

    2006-10-19

    Motility-related protein-1 (MRP-1/CD9) is involved in cell motility. We studied the change in the actin cytoskeleton, and the expression of actin-related protein (Arp) 2 and Arp3 and the Wiskott-Aldrich syndrome protein (WASP) family according to MRP-1/CD9 gene transduction into HT1080 cells. The frequency of cells with lamellipodia was significantly lower in MRP-1/CD9-transfected HT1080 cells than in control HT1080 cells (PMRP-1/CD9 gene transduction affected the subcellular localization of Arp2 and Arp3 proteins. Furthermore, MRP-1/CD9 gene transduction induced a downregulation of WAVE2 expression (PMRP-1/CD9 monoclonal antibody inhibited downregulation of WAVE2 in MRP-1/CD9-transfected HT1080 cells (PMRP-1/CD9 gene transduction. Furthermore, downregulation of WAVE2 by transfection of WAVE2-specific small interfering RNA (siRNA) mimicked the morphological effects of MRP-1/CD9 gene transduction and suppressed cell motility. However, transfection of each siRNA for Wnt1, Wnt2b1 or Wnt5a did not affect WAVE2 expression. Transfection of WAVE2-specific siRNA also did not affect expressions of these Wnts. These results indicate that MRP-1/CD9 regulates the actin cytoskeleton by downregulating of the WAVE2, through the Wnt-independent signal pathway.

  3. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis

    Directory of Open Access Journals (Sweden)

    Gareth W. Fearnley

    2016-05-01

    Full Text Available Vascular endothelial growth factor A (VEGF-A binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A–VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor–ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145 promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes.

  4. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis.

    Science.gov (United States)

    Fearnley, Gareth W; Smith, Gina A; Abdul-Zani, Izma; Yuldasheva, Nadira; Mughal, Nadeem A; Homer-Vanniasinkam, Shervanthi; Kearney, Mark T; Zachary, Ian C; Tomlinson, Darren C; Harrison, Michael A; Wheatcroft, Stephen B; Ponnambalam, Sreenivasan

    2016-05-15

    Vascular endothelial growth factor A (VEGF-A) binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A-VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor-ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145) promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes. © 2016. Published by The Company of Biologists Ltd.

  5. Osseointegration of Plateau Root Form Implants: Unique Healing Pathway Leading to Haversian-Like Long-Term Morphology.

    Science.gov (United States)

    Coelho, Paulo G; Suzuki, Marcelo; Marin, Charles; Granato, Rodrigo; Gil, Luis F; Tovar, Nick; Jimbo, Ryo; Neiva, Rodrigo; Bonfante, Estevam A

    2015-01-01

    Endosteal dental implants have been utilized as anchors for dental and orthopedic rehabilitations for decades with one of the highest treatment success rates in medicine. Such success is due to the phenomenon of osseointegration where after the implant surgical placement, bone healing results into an intimate contact between bone and implant surface. While osseointegration is an established phenomenon, the route which osseointegration occurs around endosteal implants is related to various implant design factors including surgical instrumentation and implant macro, micro, and nanometer scale geometry. In an implant system where void spaces (healing chambers) are present between the implant and bone immediately after placement, its inherent bone healing pathway results in unique opportunities to accelerate the osseointegration phenomenon at the short-term and its maintenance on the long-term through a haversian-like bone morphology and mechanical properties.

  6. Prenatal inhibition of the kynurenine pathway leads to structural changes in the hippocampus of adult rat offspring.

    Science.gov (United States)

    Khalil, Omari S; Pisar, Mazura; Forrest, Caroline M; Vincenten, Maria C J; Darlington, L Gail; Stone, Trevor W

    2014-05-01

    Glutamate receptors for N-methyl-d-aspartate (NMDA) are involved in early brain development. The kynurenine pathway of tryptophan metabolism includes the NMDA receptor agonist quinolinic acid and the antagonist kynurenic acid. We now report that prenatal inhibition of the pathway in rats with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl]benzenesulphonamide (Ro61-8048) produces marked changes in hippocampal neuron morphology, spine density and the immunocytochemical localisation of developmental proteins in the offspring at postnatal day 60. Golgi-Cox silver staining revealed decreased overall numbers and lengths of CA1 basal dendrites and secondary basal dendrites, together with fewer basal dendritic spines and less overall dendritic complexity in the basal arbour. Fewer dendrites and less complexity were also noted in the dentate gyrus granule cells. More neurons containing the nuclear marker NeuN and the developmental protein sonic hedgehog were detected in the CA1 region and dentate gyrus. Staining for doublecortin revealed fewer newly generated granule cells bearing extended dendritic processes. The number of neuron terminals staining for vesicular glutamate transporter (VGLUT)-1 and VGLUT-2 was increased by Ro61-8048, with no change in expression of vesicular GABA transporter or its co-localisation with vesicle-associated membrane protein-1. These data support the view that constitutive kynurenine metabolism normally plays a role in early embryonic brain development, and that interfering with it has profound consequences for neuronal structure and morphology, lasting into adulthood. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  7. Does lead use the intestinal absorptive pathways of iron? Impact of iron status on murine 210Pb and 59Fe absorption in duodenum and ileum in vivo

    International Nuclear Information System (INIS)

    Elsenhans, Bernd; Janser, Heinz; Windisch, Wilhelm; Schuemann, Klaus

    2011-01-01

    Highlights: → Absorption of 210 Pb increases much less than that of 59 Fe in murine duodena. → 210 Pb-absorption is almost equally high in murine duodenal and ileal segments. → 59 Fe absorption is much lower in ileal than in duodenal segments. → There must be an additional DMT1-independet pathway for intestinal Pb absorption. -- Abstract: Background: Human isotope studies and epidemiological trials are controversial as to whether lead absorption shares the absorptive pathways of iron and whether body lead content can be reduced by iron supplementation. Aim: To compare the impact of iron-deficiency on 59 Fe- and 210 Pb-absorption rates in duodenal and ileal segments. Methods: 59 Fe- and 210 Pb-absorption was determined in ligated duodenal and ileal segments from juvenile and adult iron-deficient and iron-adequate C57Bl6 wild-type mice (n = 6) in vivo at luminal concentrations corresponding to human exposure (Fe: 1 and 100 μmol/L; Pb: 1 μmol/L). Results and discussion: 59 Fe-absorption increased 10-15-fold in iron-deficient duodena from adult and adolescent mice. Ileal 59 Fe-absorption was 4-6 times lower than in iron-adequate duodena showing no adaptation to iron-deficiency. This in accordance to expectation as the divalent metal transport 1 (DMT1) shows low ileal expression levels. Juvenile 59 Fe-absorption was about twice as high as in adult mice. In contrast, duodenal 210 Pb-absorption was increased only 1.5-1.8-fold in iron-deficiency in juvenile and adult mice and, again in contrast to 59 Fe, ileal 210 Pb-absorption was as high as in iron-adequate duodena. Conclusions: The findings suggest a DMT1-independent pathway to mediate lead absorption along the entire small intestine in addition to DMT1-mediated duodenal uptake. Ileal lead absorption appears substantial, due the much longer residence of ingesta in the distal small intestine. Differences in lead-solubility and -binding to luminal ligands can, thus, explain the conflicting findings regarding the

  8. Identification of a novel Gnao-mediated alternate olfactory signaling pathway in murine OSNs

    Directory of Open Access Journals (Sweden)

    Paul eScholz

    2016-03-01

    Full Text Available It is generally agreed that in olfactory sensory neurons (OSNs, the binding of odorant molecules to their specific olfactory receptor (OR triggers a cAMP-dependent signaling cascade, activating cyclic-nucleotide gated (CNG channels. However, considerable controversy dating back more than 20 years has surrounded the question of whether alternate signaling plays a role in mammalian olfactory transduction. In this study, we demonstrate a specific alternate signaling pathway in Olfr73-expressing OSNs. Methylisoeugenol (MIEG and at least one other known weak Olfr73 agonist (Raspberry Ketone trigger a signaling cascade independent from the canonical pathway, leading to the depolarization of the cell. Interestingly, this pathway is mediated by Gnao activation, leading to Cl- efflux; however, the activation of adenylyl cyclase III (ACIII, the recruitment of Ca2+ from extra-or intracellular stores, and phosphatidylinositol 3-kinase-dependent signaling (PI signaling are not involved. Furthermore, we demonstrated that our newly identified pathway coexists with the canonical olfactory cAMP pathway in the same OSN and can be triggered by the same OR in a ligand-selective manner. We suggest that this pathway might reflect a mechanism for odor recognition predominantly used in early developmental stages before olfactory cAMP signaling is fully developed. Taken together, our findings support the existence of at least one odor-induced alternate signal transduction pathway in native OSNs mediated by Olfr73 in a ligand-selective manner.

  9. Disrupted Signaling through the Fanconi Anemia Pathway Leads to Dysfunctional Hematopoietic Stem Cell Biology: Underlying Mechanisms and Potential Therapeutic Strategies

    Science.gov (United States)

    Geiselhart, Anja; Lier, Amelie; Walter, Dagmar; Milsom, Michael D.

    2012-01-01

    Fanconi anemia (FA) is the most common inherited bone marrow failure syndrome. FA patients suffer to varying degrees from a heterogeneous range of developmental defects and, in addition, have an increased likelihood of developing cancer. Almost all FA patients develop a severe, progressive bone marrow failure syndrome, which impacts upon the production of all hematopoietic lineages and, hence, is thought to be driven by a defect at the level of the hematopoietic stem cell (HSC). This hypothesis would also correlate with the very high incidence of MDS and AML that is observed in FA patients. In this paper, we discuss the evidence that supports the role of dysfunctional HSC biology in driving the etiology of the disease. Furthermore, we consider the different model systems currently available to study the biology of cells defective in the FA signaling pathway and how they are informative in terms of identifying the physiologic mediators of HSC depletion and dissecting their putative mechanism of action. Finally, we ask whether the insights gained using such disease models can be translated into potential novel therapeutic strategies for the treatment of the hematologic disorders in FA patients. PMID:22675615

  10. Maternal Chromium Restriction Leads to Glucose Metabolism Imbalance in Mice Offspring through Insulin Signaling and Wnt Signaling Pathways

    Science.gov (United States)

    Zhang, Qian; Sun, Xiaofang; Xiao, Xinhua; Zheng, Jia; Li, Ming; Yu, Miao; Ping, Fan; Wang, Zhixin; Qi, Cuijuan; Wang, Tong; Wang, Xiaojing

    2016-01-01

    An adverse intrauterine environment, induced by a chromium-restricted diet, is a potential cause of metabolic disease in adult life. Up to now, the relative mechanism has not been clear. C57BL female mice were time-mated and fed either a control diet (CD), or a chromium-restricted diet (CR) throughout pregnancy and the lactation period. After weaning, some offspring continued the diet diagram (CD-CD or CR-CR), while other offspring were transferred to another diet diagram (CD-CR or CR-CD). At 32 weeks of age, glucose metabolism parameters were measured, and the liver from CR-CD group and CD-CD group was analyzed using a gene array. Quantitative real-time polymerase chain reaction (qPCR) and Western blot were used to verify the result of the gene array. A maternal chromium-restricted diet resulted in obesity, hyperglycemia, hyperinsulinemia, increased area under the curve (AUC) of glucose in oral glucose tolerance testing and homeostasis model assessment of insulin resistance (HOMA-IR). There were 463 genes that differed significantly (>1.5-fold change, p chromium deficiency influences glucose metabolism in pups through the regulation of insulin signaling and Wnt signaling pathways. PMID:27782077

  11. Improvement of hairy root cultures and plants by changing biosynthetic pathways leading to pharmaceutical metabolites: strategies and applications.

    Science.gov (United States)

    Ludwig-Müller, Jutta; Jahn, Linda; Lippert, Annemarie; Püschel, Joachim; Walter, Antje

    2014-11-01

    A plethora of bioactive plant metabolites has been explored for pharmaceutical, food chemistry and agricultural applications. The chemical synthesis of these structures is often difficult, so plants are favorably used as producers. While whole plants can serve as a source for secondary metabolites and can be also improved by metabolic engineering, more often cell or organ cultures of relevant plant species are of interest. It should be noted that only in few cases the production for commercial application in such cultures has been achieved. Their genetic manipulation is sometimes faster and the production of a specific metabolite is more reliable, because of less environmental influences. In addition, upscaling in bioreactors is nowadays possible for many of these cultures, so some are already used in industry. There are approaches to alter the profile of metabolites not only by using plant genes, but also by using bacterial genes encoding modifying enzymes. Also, strategies to cope with unwanted or even toxic compounds are available. The need for metabolic engineering of plant secondary metabolite pathways is increasing with the rising demand for (novel) compounds with new bioactive properties. Here, we give some examples of recent developments for the metabolic engineering of plants and organ cultures, which can be used in the production of metabolites with interesting properties. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Guanine nucleotide exchange factor αPIX leads to activation of the Rac 1 GTPase/glycogen phosphorylase pathway in interleukin (IL)-2-stimulated T cells

    DEFF Research Database (Denmark)

    Llavero, Francisco; Urzelai, Bakarne; Osinalde, Nerea

    2015-01-01

    Recently, we have reported that the active form of Rac 1 GTPase binds to the glycogen phosphorylase muscle isoform (PYGM) and modulates its enzymatic activity leading to T cell proliferation. In the lymphoid system, Rac 1 and in general other small GTPases of the Rho family participate...... in the signaling cascades that are activated after engagement of the T cell antigen receptor. However, little is known about the IL-2-dependent Rac 1 activator molecules. For the first time, a signaling pathway leading to the activation of Rac 1/PYGM in response to IL-2-stimulated T cell proliferation is described....... More specifically, αPIX, a known guanine nucleotide exchange factor for the small GTPases of the Rho family, preferentially Rac 1, mediates PYGM activation in Kit 225 T cells stimulated with IL-2. Using directed mutagenesis, phosphorylation of αPIX Rho-GEF serines 225 and 488 is required for activation...

  13. Inhibition of Inflammation Mediated Through the Tumor Necrosis Factor α Biochemical Pathway Can Lead to Favorable Outcomes in Alzheimer Disease.

    Science.gov (United States)

    Shamim, Daniah; Laskowski, Michael

    2017-01-01

    Tumor necrosis factor α (TNF-α) inhibitors have long been used as disease-modifying agents in immune disorders. Recently, research has shown a role of chronic neuroinflammation in the pathophysiology of neurodegenerative diseases such as Alzheimer disease, and interest has been generated in the use of anti-TNF agents and TNF-modulating agents for prevention and treatment. This article extensively reviewed literature on animal studies testing these agents. The results showed a role for direct and indirect TNF-α inhibition through agents such as thalidomide, 3,6-dithiothalidomide, etanercept, infliximab, exendin-4, sodium hydrosulfide, minocycline, imipramine, and atorvastatin. Studies were performed on mice, rats, and monkeys, with induction of neurodegenerative physiology either through the use of chemical agents or through the use of transgenic animals. Most of these agents showed an improvement in cognitive function as tested with the Morris water maze, and immunohistochemical and histopathological staining studies consistently showed better outcomes with these agents. Brains of treated animals showed significant reduction in pro-inflammatory TNF-α and reduced the burden of neurofibrillary tangles, amyloid precursor protein, and β-amyloid plaques. Also, recruitment of microglial cells in the central nervous system was significantly reduced through these drugs. These studies provide a clearer mechanistic understanding of the role of TNF-α modulation in Alzheimer disease. All studies in this review explored the use of these drugs as prophylactic agents to prevent Alzheimer disease through immune modulation of the TNF inflammatory pathway, and their success highlights the need for further research of these drugs as therapeutic agents.

  14. Signal transduction and chemotaxis in mast cells

    Czech Academy of Sciences Publication Activity Database

    Dráber, Petr; Hálová, Ivana; Polakovičová, Iva; Kawakami, T.

    2016-01-01

    Roč. 778, jaro (2016), s. 11-23 ISSN 0014-2999 R&D Projects: GA ČR(CZ) GA14-09807S; GA ČR(CZ) GBP302/12/G101; GA ČR(CZ) GA14-00703S Institutional support: RVO:68378050 Keywords : Mast cell * IgE receptor * KIT receptor * Signal transduction * Chemotaxis * Plasma membrane Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.896, year: 2016

  15. Macro-Fiber Composite Based Transduction

    Science.gov (United States)

    2016-03-01

    substrate Material properties of single crystal macro fiber composite actuators for active twist rotor blades Park, Jae-Sang (Seoul National...Passive Smart Structures and Integrated Systems 2007 Material properties of single crystal macro fiber composite actuators for active twist rotor ...19b. TELEPHONE NUMBER (Include area code) 10-03-20 16 Final Report 01 Jan 2013 - 31 Dec 2015 Macro-Fiber Composite Based Transduction N000-14-13-1-0212

  16. Computer-assisted study on the reaction between pyruvate and ylide in the pathway leading to lactyl-ThDP.

    Science.gov (United States)

    Alvarado, Omar; Jaña, Gonzalo; Delgado, Eduardo J

    2012-08-01

    In this study the formation of the lactyl-thiamin diphosphate intermediate (L-ThDP) is addressed using density functional theory calculations at X3LYP/6-31++G(d,p) level of theory. The study includes potential energy surface scans, transition state search, and intrinsic reaction coordinate calculations. Reactivity is analyzed in terms of Fukui functions. The results allow to conclude that the reaction leading to the formation of L-ThDP occurs via a concerted mechanism, and during the nucleophilic attack on the pyruvate molecule, the ylide is in its AP form. The calculated activation barrier for the reaction is 19.2 kcal/mol, in agreement with the experimental reported value.

  17. Disruption of the Cx43/miR21 pathway leads to osteocyte apoptosis and increased osteoclastogenesis with aging.

    Science.gov (United States)

    Davis, Hannah M; Pacheco-Costa, Rafael; Atkinson, Emily G; Brun, Lucas R; Gortazar, Arancha R; Harris, Julia; Hiasa, Masahiro; Bolarinwa, Surajudeen A; Yoneda, Toshiyuki; Ivan, Mircea; Bruzzaniti, Angela; Bellido, Teresita; Plotkin, Lilian I

    2017-06-01

    Skeletal aging results in apoptosis of osteocytes, cells embedded in bone that control the generation/function of bone forming and resorbing cells. Aging also decreases connexin43 (Cx43) expression in bone; and osteocytic Cx43 deletion partially mimics the skeletal phenotype of old mice. Particularly, aging and Cx43 deletion increase osteocyte apoptosis, and osteoclast number and bone resorption on endocortical bone surfaces. We examined herein the molecular signaling events responsible for osteocyte apoptosis and osteoclast recruitment triggered by aging and Cx43 deficiency. Cx43-silenced MLO-Y4 osteocytic (Cx43 def ) cells undergo spontaneous cell death in culture through caspase-3 activation and exhibit increased levels of apoptosis-related genes, and only transfection of Cx43 constructs able to form gap junction channels reverses Cx43 def cell death. Cx43 def cells and bones from old mice exhibit reduced levels of the pro-survival microRNA miR21 and, consistently, increased levels of the miR21 target phosphatase and tensin homolog (PTEN) and reduced phosphorylated Akt, whereas PTEN inhibition reduces Cx43 def cell apoptosis. miR21 reduction is sufficient to induce apoptosis of Cx43-expressing cells and miR21 deletion in miR21 fl/fl bones increases apoptosis-related gene expression, whereas a miR21 mimic prevents Cx43 def cell apoptosis, demonstrating that miR21 lies downstream of Cx43. Cx43 def cells release more osteoclastogenic cytokines [receptor activator of NFκB ligand (RANKL)/high-mobility group box-1 (HMGB1)], and caspase-3 inhibition prevents RANKL/HMGB1 release and the increased osteoclastogenesis induced by conditioned media from Cx43 def cells, which is blocked by antagonizing HMGB1-RAGE interaction. These findings identify a novel Cx43/miR21/HMGB1/RANKL pathway involved in preventing osteocyte apoptosis that also controls osteoclast formation/recruitment and is impaired with aging. © 2017 The Authors. Aging Cell published by the Anatomical Society

  18. Fetus Sound Stimulation: Cilia Memristor Effect of Signal Transduction

    Directory of Open Access Journals (Sweden)

    Svetlana Jankovic-Raznatovic

    2014-01-01

    Full Text Available Background. This experimental study evaluates fetal middle cerebral artery (MCA circulation after the defined prenatal acoustical stimulation (PAS and the role of cilia in hearing and memory and could explain signal transduction and memory according to cilia optical-acoustical properties. Methods. PAS was performed twice on 119 no-risk term pregnancies. We analyzed fetal MCA circulation before, after first and second PAS. Results. Analysis of the Pulsatility index basic (PIB and before PAS and Pulsatility index reactive after the first PAS (PIR 1 shows high statistical difference, representing high influence on the brain circulation. Analysis of PIB and Pulsatility index reactive after the second PAS (PIR 2 shows no statistical difference. Cilia as nanoscale structure possess magnetic flux linkage that depends on the amount of charge that has passed between two-terminal variable resistors of cilia. Microtubule resistance, as a function of the current through and voltage across the structure, leads to appearance of cilia memory with the “memristor” property. Conclusion. Acoustical and optical cilia properties play crucial role in hearing and memory processes. We suggest that fetuses are getting used to sound, developing a kind of memory patterns, considering acoustical and electromagnetically waves and involving cilia and microtubules and try to explain signal transduction.

  19. Molecular mechanisms of root gravity sensing and signal transduction.

    Science.gov (United States)

    Strohm, Allison K; Baldwin, Katherine L; Masson, Patrick H

    2012-01-01

    Plants use gravity as a guide to direct their roots down into the soil to anchor themselves and to find resources needed for growth and development. In higher plants, the columella cells of the root tip form the primary site of gravity sensing, and in these cells the sedimentation of dense, starch-filled plastids (amyloplasts) triggers gravity signal transduction. This generates an auxin gradient across the root cap that is transmitted to the elongation zone where it promotes differential cell elongation, allowing the root to direct itself downward. It is still not well understood how amyloplast sedimentation leads to auxin redistribution. Models have been proposed to explain how mechanosensitive ion channels or ligand-receptor interactions could connect these events. Although their roles are still unclear, possible second messengers in this process include protons, Ca(2+), and inositol 1,4,5-triphosphate. Upon gravistimulation, the auxin efflux facilitators PIN3 and PIN7 relocalize to the lower side of the columella cells and mediate auxin redistribution. However, evidence for an auxin-independent secondary mechanism of gravity sensing and signal transduction suggests that this physiological process is quite complex. Furthermore, plants must integrate a variety of environmental cues, resulting in multifaceted relationships between gravitropism and other directional growth responses such as hydro-, photo-, and thigmotropism. Copyright © 2011 Wiley Periodicals, Inc.

  20. Murine gammaherpesvirus M2 protein induction of IRF4 via the NFAT pathway leads to IL-10 expression in B cells.

    Directory of Open Access Journals (Sweden)

    Udaya S Rangaswamy

    2014-01-01

    Full Text Available Reactivation of the gammaherpesviruses Epstein-Barr virus (EBV, Kaposi's sarcoma-associated herpesvirus (KSHV and murine gammaherpesvirus 68 (MHV68 from latently infected B cells has been linked to plasma cell differentiation. We have previously shown that the MHV68 M2 protein is important for virus reactivation from B cells and, when expressed alone in primary murine B cells, can drive B cell differentiation towards a pre-plasma cell phenotype. In addition, expression of M2 in primary murine B cells leads to secretion of high levels of IL-10 along with enhanced proliferation and survival. Furthermore, the absence of M2 in vivo leads to a defect in the appearance of MHV68 infected plasma cells in the spleen at the peak of MHV68 latency. Here, employing an inducible B cell expression system, we have determined that M2 activates the NFAT pathway in a Src kinase-dependent manner--leading to induction of the plasma cell-associated transcription factor, Interferon Regulatory Factor-4 (IRF4. Furthermore, we show that expression of IRF4 alone in a B cell line up-regulates IL-10 expression in culture supernatants, revealing a novel role for IRF4 in B cell induced IL-10. Consistent with the latter observation, we show that IRF4 can regulate the IL-10 promoter in B cells. In primary murine B cells, addition of cyclosporine (CsA resulted in a significant decrease in M2-induced IL-10 levels as well as IRF4 expression, emphasizing the importance of the NFAT pathway in M2- -mediated induction of IL-10. Together, these studies argue in favor of a model wherein M2 activation of the NFAT pathway initiates events leading to increased levels of IRF4--a key player in plasma cell differentiation--which in turn triggers IL-10 expression. In the context of previous findings, the data presented here provides insights into how M2 facilitates plasma cell differentiation and subsequent virus reactivation.

  1. Development of the adverse outcome pathway "alkylation of DNA in male premeiotic germ cells leading to heritable mutations" using the OECD's users' handbook supplement.

    Science.gov (United States)

    Yauk, Carole L; Lambert, Iain B; Meek, M E Bette; Douglas, George R; Marchetti, Francesco

    2015-12-01

    The Organisation for Economic Cooperation and Development's (OECD) Adverse Outcome Pathway (AOP) programme aims to develop a knowledgebase of all known pathways of toxicity that lead to adverse effects in humans and ecosystems. A Users' Handbook was recently released to provide supplementary guidance on AOP development. This article describes one AOP-alkylation of DNA in male premeiotic germ cells leading to heritable mutations. This outcome is an important regulatory endpoint. The AOP describes the biological plausibility and empirical evidence supporting that compounds capable of alkylating DNA cause germ cell mutations and subsequent mutations in the offspring of exposed males. Alkyl adducts are subject to DNA repair; however, at high doses the repair machinery becomes saturated. Lack of repair leads to replication of alkylated DNA and ensuing mutations in male premeiotic germ cells. Mutations that do not impair spermatogenesis persist and eventually are present in mature sperm. Thus, the mutations are transmitted to the offspring. Although there are some gaps in empirical support and evidence for essentiality of the key events for certain aspects of this AOP, the overall AOP is generally accepted as dogma and applies broadly to any species that produces sperm. The AOP was developed and used in an iterative process to test and refine the Users' Handbook, and is one of the first publicly available AOPs. It is our hope that this AOP will be leveraged to develop other AOPs in this field to advance method development, computational models to predict germ cell effects, and integrated testing strategies. © 2015 Her Majesty the Queen in Right of Canada.

  2. Mechanism of active transport: free energy dissipation and free energy transduction.

    OpenAIRE

    Tanford, C

    1982-01-01

    The thermodynamic pathway for "chemiosmotic" free energy transduction in active transport is discussed with an ATP-driven Ca2+ pump as an illustrative example. Two innovations are made in the analysis. (i) Free energy dissipated as heat is rigorously excluded from overall free energy bookkeeping by focusing on the dynamic equilibrium state of the chemiosmotic process. (ii) Separate chemical potential terms for free energy donor and transported ions are used to keep track of the thermodynamic ...

  3. Signal transduction by normal isoforms and W mutant variants of the Kit receptor tyrosine kinase.

    OpenAIRE

    Reith, A D; Ellis, C; Lyman, S D; Anderson, D M; Williams, D E; Bernstein, A; Pawson, T

    1991-01-01

    Germline mutations at the Dominant White Spotting (W) and Steel (Sl) loci have provided conclusive genetic evidence that c-kit mediated signal transduction pathways are essential for normal mouse development. We have analysed the interactions of normal and mutant W/c-kit gene products with cytoplasmic signalling proteins, using transient c-kit expression assays in COS cells. In addition to the previously identified c-kit gene product (Kit+), a second normal Kit isoform (KitA+) containing an i...

  4. WAFs lead molting retardation of naupliar stages with down-regulated expression profiles of chitin metabolic pathway and related genes in the copepod Tigriopus japonicus.

    Science.gov (United States)

    Hwang, Dae-Sik; Lee, Min-Chul; Kyung, Do-Hyun; Kim, Hui-Su; Han, Jeonghoon; Kim, Il-Chan; Puthumana, Jayesh; Lee, Jae-Seong

    2017-03-01

    Oil pollution is considered being disastrous to marine organisms and ecosystems. As molting is critical in the developmental process of arthropods in general and copepods, in particular, the impact will be adverse if the target of spilled oil is on molting. Thus, we investigated the harmful effects of water accommodated fractions (WAFs) of crude oil with an emphasis on inhibition of chitin metabolic pathways related genes and developmental retardation in the copepod Tigriopus japonicus. Also, we analysed the ontology and domain of chitin metabolic pathway genes and mRNA expression patterns of developmental stage-specific genes. Further, the developmental retardation followed by transcriptional modulations in nuclear receptor genes (NR) and chitin metabolic pathway-related genes were observed in the WAFs-exposed T. japonicus. As a result, the developmental time was found significantly (P<0.05) delayed in response to 40% WAFs in comparison with that of control. Moreover, the NR gene, HR3 and chitinases (CHT9 and CHT10) were up-regulated in N4-5 stages, while chitin synthase genes (CHS-1, CHS-2-1, and CHS-2-2) down-regulated in response to WAFs. In brief, a high concentration of WAFs repressed nuclear receptor genes but elicited activation of some of the transcription factors at low concentration of WAFs, resulting in suppression of chitin synthesis. Thus, we suggest that WAF can lead molting retardation of naupliar stages in T. japonicus through down-regulations of chitin metabolism. These findings will provide a better understanding of the mode of action of chitin biosynthesis associated with molting mechanism in WAF-exposed T. japonicus. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. ARG1 and ARL2 contribute to gravity signal transduction in the statocytes of Arabidopsis thaliana roots and hypocotyls

    Science.gov (United States)

    Masson, Patrick; Harrison, Benjamin; Stanga, John; Otegui, Marisa; Sedbrook, John

    Gravity is an important cue that plant organs use to guide their growth. Each organ is characterized by a defined gravity set point angle that dictates its optimal orientation within the gravity field. Specialized cells, named statocytes, enable this directional growth response by perceiving gravity via the sedimentation of, and/or tension/pressure exerted by, starch-filled plastids within their cytoplasm. Located in the columella region of the cap in roots and in the endodermis of hypocotyls and stems, these cells modulate the lateral transport of auxin across the corresponding organ in a gravistimulus-dependent manner. Upon plant reorientation within the gravity field, a gravity signal transduction pathway is activated within those cells, which in roots leads to a relocalization of the PIN3 auxin efflux carrier toward the lower membrane and an alkalinization of the cytoplasm. In turn, these events appear to promote a lateral transport of auxin toward the bottom side of the stimulated organ, which promotes a curvature. We previously uncovered ARG1 and ARL2 as essential contributors to these cellular processes. Mutations in these genes result in altered root and hypocotyl gravitropism. In roots, this abnormal growth behavior is associated with a lack of PIN3 relocalization within the statocytes and an absence of preferential downward auxin transport upon gravistimulation. These two genes encode paralogous J-domain proteins that are associated with the plasma membrane and other membranes of the vesicular trafficking pathway, and appear to modulate protein trafficking within the statocytes. An analysis of the root gravitropic phenotypes associated with different double mutant configurations affecting ARG1, ARL2 and PIN3 suggest that all three proteins function in a common gravity-signaling pathway. Surprisingly, when a mutation that affects starch biosynthesis (pgm) is introgressed into an arg1-2 mutant, the gravitropic defects are dramatically enhanced relative to

  6. Inquiry into Chemotherapy-Induced P53 Activation in Cancer Cells as a Model for Teaching Signal Transduction

    Science.gov (United States)

    Srougi, Melissa C.; Carson, Susan

    2013-01-01

    Intracellular and extracellular communication is conducted through an intricate and interwoven network of signal transduction pathways. The mechanisms for how cells speak with one another are of significant biological importance to both basic and industrial scientists from a number of different disciplines. We have therefore developed and…

  7. A B Cell-Driven Autoimmune Pathway Leading to Pathological Hallmarks of Progressive Multiple Sclerosis in the Marmoset Experimental Autoimmune Encephalomyelitis Model

    Directory of Open Access Journals (Sweden)

    Bert A. ’t Hart

    2017-07-01

    Full Text Available The absence of pathological hallmarks of progressive multiple sclerosis (MS in commonly used rodent models of experimental autoimmune encephalomyelitis (EAE hinders the development of adequate treatments for progressive disease. Work reviewed here shows that such hallmarks are present in the EAE model in marmoset monkeys (Callithrix jacchus. The minimal requirement for induction of progressive MS pathology is immunization with a synthetic peptide representing residues 34–56 from human myelin oligodendrocyte glycoprotein (MOG formulated with a mineral oil [incomplete Freund’s adjuvant (IFA]. Pathological aspects include demyelination of cortical gray matter with microglia activation, oxidative stress, and redistribution of iron. When the peptide is formulated in complete Freund’s adjuvant, which contains mycobacteria that relay strong activation signals to myeloid cells, oxidative damage pathways are strongly boosted leading to more intensive pathology. The proven absence of immune potentiating danger signals in the MOG34–56/IFA formulation implies that a narrow population of antigen-experienced T cells present in the monkey’s immune repertoire is activated. This novel pathway involves the interplay of lymphocryptovirus-infected B cells with MHC class Ib/Caja-E restricted CD8+ CD56+ cytotoxic T lymphocytes.

  8. How could differences in 'control over destiny' lead to socio-economic inequalities in health? A synthesis of theories and pathways in the living environment.

    Science.gov (United States)

    Whitehead, Margaret; Pennington, Andy; Orton, Lois; Nayak, Shilpa; Petticrew, Mark; Sowden, Amanda; White, Martin

    2016-05-01

    We conducted the first synthesis of theories on causal associations and pathways connecting degree of control in the living environment to socio-economic inequalities in health-related outcomes. We identified the main theories about how differences in 'control over destiny' could lead to socio-economic inequalities in health, and conceptualised these at three distinct explanatory levels: micro/personal; meso/community; and macro/societal. These levels are interrelated but have rarely been considered together in the disparate literatures in which they are located. This synthesis of theories provides new conceptual frameworks to contribute to the design and conduct of theory-led evaluations of actions to tackle inequalities in health. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Protein kinase A (PKA) phosphorylation of Na+/K+-ATPase opens intracellular C-terminal water pathway leading to third Na+-binding site in molecular dynamics simulations

    DEFF Research Database (Denmark)

    Poulsen, Hanne; Nissen, Poul; Mouritsen, Ole G.

    2012-01-01

    -atom Molecular Dynamics (MD) simulations to investigate the structural consequences of phosphorylating the Na+/K+- ATPase (NKA) residue S936, which is the best characterized phosphorylation site in NKA, targeted in vivo by Protein Kinase A (PKA) (1-3). The MD simulations suggest that S936 phosphorylation opens......Phosphorylation is one of the major mechanisms for posttranscriptional modification of proteins. The addition of a compact, negatively charged moiety to a protein can significantly change its function and localization by affecting its structure and interaction network. We have used all...... a C-terminal hydrated pathway leading to D926, a transmembrane residue proposed to form part of the third sodium ion-binding site (4). Simulations of a S936E mutant form, for which only subtle effects are observed when expressed in Xenopus oocytes and studied with electrophysiology, does not mimic...

  10. Metabolic pathways leading to hyperhomocysteinemia

    Czech Academy of Sciences Publication Activity Database

    Šenholdová, Z.; Navrátil, Tomáš; Přistoupilová, K.; Přistoupil, T. I.; Heyrovský, Michael; Kohlíková, E.; Petr, M.

    2005-01-01

    Roč. 9, 3-4 (2005), s. 93-96 ISSN 1335-2253 R&D Projects: GA MPO 1H-PK/42; GA MZd NR8107 Grant - others:Univerzita Karlova(CZ) 534 Institutional research plan: CEZ:AV0Z40400503 Keywords : urine * voltammetry * thiodiglycolic acid * TDGA Subject RIV: CF - Physical ; Theoretical Chemistry

  11. Genetic Analysis of Gravity Signal Transduction in Arabidopsis thaliana Seedlings

    Science.gov (United States)

    Boonsirichai, K.; Harrison, B.; Stanga, J.; Young, L.-S.; Neal, C.; Sabat, G.; Murthy, N.; Harms, A.; Sedbrook, J.; Masson, P.

    The primary roots of Arabidopsis thaliana seedlings respond to gravity stimulation by developing a tip curvature that results from differential cellular elongation on opposite flanks of the elongation zone. This curvature appears modulated by a lateral gradient of auxin that originates in the gravity-perceiving cells (statocytes) of the root cap through an apparent lateral repositioning of a component the auxin efflux carrier complex within these cells (Friml et al, 2002, Nature 415: 806-809). Unfortunately, little is known about the molecular mechanisms that govern early phases of gravity perception and signal transduction within the root-cap statocytes. We have used a molecular genetic approach to uncover some of these mechanisms. Mutations in the Arabidopsis ARG1 and ARL2 genes, which encode J-domain proteins, resulted in specific alterations in root and hypocotyl gravitropism, without pleiotropic phenotypes. Interestingly, ARG1 and ARL2 appear to function in the same genetic pathway. A combination of molecular genetic, biochemical and cell-biological approaches were used to demonstrate that ARG1 functions in early phases of gravity signal transduction within the root and hypocotyl statocytes, and is needed for efficient lateral auxin transport within the cap. The ARG1 protein is associated with components of the secretory and/or endosomal pathways, suggesting its role in the recycling of components of the auxin efflux carrier complex between plasma membrane and endosome (Boonsirichai et al, 2003, Plant Cell 15:2612-2625). Genetic modifiers of arg1-2 were isolated and shown to enhance the gravitropic defect of arg1-2, while resulting in little or no gravitropic defects in a wild type ARG1 background. A slight tendency for arg1-2;mar1-1 and arg1-2;mar2-1 double-mutant organs to display an opposite gravitropic response compared to wild type suggests that all three genes contribute to the interpretation of the gravity-vector information by seedling organs. The

  12. Prenatal Alcohol Exposure Damages Brain Signal Transduction Systems

    National Research Council Canada - National Science Library

    Caldwell, Kevin

    2001-01-01

    .... One and twenty-four hours following fear conditioning this learning deficit is associated with altered brain signal transduction mechanisms that are dependent on an enzyme termed phosphatidylinositol...

  13. Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation); Verfluechtigungspfade des Poloniums aus einem Pb-Bi-Spallationstarget (Thermochemische Kalkulation)

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, B.; Neuhausen, J

    2004-06-01

    An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead

  14. The cellular response to vascular endothelial growth factors requires co-ordinated signal transduction, trafficking and proteolysis.

    Science.gov (United States)

    Smith, Gina A; Fearnley, Gareth W; Tomlinson, Darren C; Harrison, Michael A; Ponnambalam, Sreenivasan

    2015-08-18

    VEGFs (vascular endothelial growth factors) are a family of conserved disulfide-linked soluble secretory glycoproteins found in higher eukaryotes. VEGFs mediate a wide range of responses in different tissues including metabolic homoeostasis, cell proliferation, migration and tubulogenesis. Such responses are initiated by VEGF binding to soluble and membrane-bound VEGFRs (VEGF receptor tyrosine kinases) and co-receptors. VEGF and receptor splice isoform diversity further enhances complexity of membrane protein assembly and function in signal transduction pathways that control multiple cellular responses. Different signal transduction pathways are simultaneously activated by VEGFR-VEGF complexes with membrane trafficking along the endosome-lysosome network further modulating signal output from multiple enzymatic events associated with such pathways. Balancing VEGFR-VEGF signal transduction with trafficking and proteolysis is essential in controlling the intensity and duration of different intracellular signalling events. Dysfunction in VEGF-regulated signal transduction is important in chronic disease states including cancer, atherosclerosis and blindness. This family of growth factors and receptors is an important model system for understanding human disease pathology and developing new therapeutics for treating such ailments. © 2015 Authors.

  15. Emergence, development and diversification of the TGF-beta signalling pathway within the animal kingdom.

    Science.gov (United States)

    Huminiecki, Lukasz; Goldovsky, Leon; Freilich, Shiri; Moustakas, Aristidis; Ouzounis, Christos; Heldin, Carl-Henrik

    2009-02-03

    The question of how genomic processes, such as gene duplication, give rise to co-ordinated organismal properties, such as emergence of new body plans, organs and lifestyles, is of importance in developmental and evolutionary biology. Herein, we focus on the diversification of the transforming growth factor-beta (TGF-beta) pathway -- one of the fundamental and versatile metazoan signal transduction engines. After an investigation of 33 genomes, we show that the emergence of the TGF-beta pathway coincided with appearance of the first known animal species. The primordial pathway repertoire consisted of four Smads and four receptors, similar to those observed in the extant genome of the early diverging tablet animal (Trichoplax adhaerens). We subsequently retrace duplications in ancestral genomes on the lineage leading to humans, as well as lineage-specific duplications, such as those which gave rise to novel Smads and receptors in teleost fishes. We conclude that the diversification of the TGF-beta pathway can be parsimoniously explained according to the 2R model, with additional rounds of duplications in teleost fishes. Finally, we investigate duplications followed by accelerated evolution which gave rise to an atypical TGF-beta pathway in free-living bacterial feeding nematodes of the genus Rhabditis. Our results challenge the view of well-conserved developmental pathways. The TGF-beta signal transduction engine has expanded through gene duplication, continually adopting new functions, as animals grew in anatomical complexity, colonized new environments, and developed an active immune system.

  16. Integration of adeno-associated virus vectors in CD34+ human hematopoietic progenitor cells after transduction.

    Science.gov (United States)

    Fisher-Adams, G; Wong, K K; Podsakoff, G; Forman, S J; Chatterjee, S

    1996-07-15

    Gene transfer vectors based on adeno-associated virus (AAV) appear promising because of their high transduction frequencies regardless of cell cycle status and ability to integrate into chromosomal DNA. We tested AAV-mediated gene transfer into a panel of human bone marrow or umbilical cord-derived CD34+ hematopoietic progenitor cells, using vectors encoding several transgenes under the control of viral and cellular promoters. Gene transfer was evaluated by (1) chromosomal integration of vector sequences and (2) analysis of transgene expression. Southern hybridization and fluorescence in situ hybridization analysis of transduced CD34 genomic DNA showed the presence of integrated vector sequences in chromosomal DNA in a portion of transduced cells and showed that integrated vector sequences were replicated along with cellular DNA during mitosis. Transgene expression in transduced CD34 cells in suspension cultures and in myeloid colonies differentiating in vitro from transduced CD34 cells approximated that predicted by the multiplicity of transduction. This was true in CD34 cells from different donors, regardless of the transgene or selective pressure. Comparisons of CD34 cell transduction either before or after cytokine stimulation showed similar gene transfer frequencies. Our findings suggest that AAV transduction of CD34+ hematopoietic progenitor cells is efficient, can lead to stable integration in a population of transduced cells, and may therefore provide the basis for safe and efficient ex vivo gene therapy of the hematopoietic system.

  17. Cytoplasmic transduction peptide (CTP): New approach for the delivery of biomolecules into cytoplasm in vitro and in vivo

    International Nuclear Information System (INIS)

    Kim, Daeyou; Jeon, Choonju; Kim, Jeong-Hwan; Kim, Mi-Seon; Yoon, Cheol-Hee; Choi, In-Soo; Kim, Sung-Hoon; Bae, Yong-Soo

    2006-01-01

    The protein transduction domain (PTD) of HIV-1 TAT has been extensively documented with regard to its membrane transduction potential, as well as its efficient delivery of biomolecules in vivo. However, the majority of PTD and PTD-conjugated molecules translocate to the nucleus rather than to the cytoplasm after transduction, due to the functional nuclear localization sequence (NLS). Here, we report a cytoplasmic transduction peptide (CTP), which was deliberately designed to ensure the efficient cytoplasmic delivery of the CTP-fused biomolecules. In comparison with PTD, CTP and its fusion partners exhibited a clear preference for cytoplasmic localization, and also markedly enhanced membrane transduction potential. Unlike the mechanism underlying PTD-mediated transduction, CTP-mediated transduction occurs independently of the lipid raft-dependent macropinocytosis pathway. The CTP-conjugated Smac/DIABLO peptide (Smac-CTP) was also shown to be much more efficient than Smac-PTD in the blockage of the antiapoptotic properties of XIAP, suggesting that cytoplasmic functional molecules can be more efficiently targeted by CTP-mediated delivery. In in vivo trafficking studies, CTP-fused β-gal exhibited unique organ tropisms to the liver and lymph nodes when systemically injected into mice, whereas PTD-β-gal exhibited no such tropisms. Taken together, our findings implicate CTP as a novel delivery peptide appropriate for (i) molecular targeting to cytoplasmic compartments in vitro, (ii) the development of class I-associated CTL vaccines, and (iii) special drug delivery in vivo, without causing any untoward effects on nuclear genetic material

  18. Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function

    Directory of Open Access Journals (Sweden)

    Gina A. Smith

    2017-10-01

    Full Text Available Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A and vascular endothelial growth factor receptor 2 (VEGFR2 regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response.

  19. Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function.

    Science.gov (United States)

    Smith, Gina A; Fearnley, Gareth W; Abdul-Zani, Izma; Wheatcroft, Stephen B; Tomlinson, Darren C; Harrison, Michael A; Ponnambalam, Sreenivasan

    2017-10-15

    Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response. © 2017. Published by The Company of Biologists Ltd.

  20. Mannotriose regulates learning and memory signal transduction in the hippocampus

    Institute of Scientific and Technical Information of China (English)

    Lina Zhang; Weiwei Dai; Xueli Zhang; Zhangbin Gong; Guoqin Jin

    2013-01-01

    Rehmannia is a commonly used Chinese herb, which improves learning and memory. However, the crucial components of the signal transduction pathway associated with this effect remain elusive. Pri-mary hippocampal neurons were cultured in vitro, insulted with high-concentration (1 × 10-4 mol/L) cor-ticosterone, and treated with 1 × 10-4 mol/L mannotriose. Thiazolyl blue tetrazolium bromide assay and western blot analysis showed that hippocampal neuron survival rates and protein levels of glucocorti-coid receptor, serum and glucocorticoid-regulated protein kinase, and brain-derived neurotrophic factor were al dramatical y decreased after high-concentration corticosterone-induced injury. This effect was reversed by mannotriose, to a similar level as RU38486 and donepezil. Our findings indicate that mannotriose could protect hippocampal neurons from high-concentration corticosterone-induced injury. The mechanism by which this occurred was associated with levels of glucocorticoid receptor protein, serum and glucocorticoid-regulated protein kinase, and brain-derived neurotrophic factor.

  1. Modulation of signal transduction by tea catechins and related phytochemicals

    International Nuclear Information System (INIS)

    Shimizu, Masahito; Weinstein, I. Bernard

    2005-01-01

    Epidemiologic studies in human populations and experimental studies in rodents provide evidence that green tea and its constituents can inhibit both the development and growth of tumors at a variety of tissue sites. In addition, EGCG, a major biologically active component of green tea, inhibits growth and induces apoptosis in a variety of cancer cell lines. The purpose of this paper is to review evidence that these effects are mediated, at least in part, through inhibition of the activity of specific receptor tyrosine kinases (RTKs) and related downstream pathways of signal transduction. We also review evidence indicating that the antitumor effects of the related polyphenolic phytochemicals resveratrol, genistein, curcumin, and capsaicin are exerted via similar mechanisms. Some of these agents (EGCG, genistein, and curcumin) appear to directly target specific RTKs, and all of these compounds cause inhibition of the activity of the transcription factors AP-1 and NF-κB, thus inhibiting cell proliferation and enhancing apoptosis. Critical areas of future investigation include: (1) identification of the direct molecular target(s) of EGCG and related polyphenolic compounds in cells; (2) the in vivo metabolism and bioavailability of these compounds; (3) the ancillary effects of these compounds on tumor-stromal interactions; (4) the development of synergistic combinations with other antitumor agents to enhance efficacy in cancer prevention and therapy, and also minimize potential toxicities

  2. Structural basis for energy transduction by respiratory alternative complex III.

    Science.gov (United States)

    Sousa, Joana S; Calisto, Filipa; Langer, Julian D; Mills, Deryck J; Refojo, Patrícia N; Teixeira, Miguel; Kühlbrandt, Werner; Vonck, Janet; Pereira, Manuela M

    2018-04-30

    Electron transfer in respiratory chains generates the electrochemical potential that serves as energy source for the cell. Prokaryotes can use a wide range of electron donors and acceptors and may have alternative complexes performing the same catalytic reactions as the mitochondrial complexes. This is the case for the alternative complex III (ACIII), a quinol:cytochrome c/HiPIP oxidoreductase. In order to understand the catalytic mechanism of this respiratory enzyme, we determined the structure of ACIII from Rhodothermus marinus at 3.9 Å resolution by single-particle cryo-electron microscopy. ACIII presents a so-far unique structure, for which we establish the arrangement of the cofactors (four iron-sulfur clusters and six c-type hemes) and propose the location of the quinol-binding site and the presence of two putative proton pathways in the membrane. Altogether, this structure provides insights into a mechanism for energy transduction and introduces ACIII as a redox-driven proton pump.

  3. Phosphoproteomics-based systems analysis of signal transduction networks

    Directory of Open Access Journals (Sweden)

    Hiroko eKozuka-Hata

    2012-01-01

    Full Text Available Signal transduction systems coordinate complex cellular information to regulate biological events such as cell proliferation and differentiation. Although the accumulating evidence on widespread association of signaling molecules has revealed essential contribution of phosphorylation-dependent interaction networks to cellular regulation, their dynamic behavior is mostly yet to be analyzed. Recent technological advances regarding mass spectrometry-based quantitative proteomics have enabled us to describe the comprehensive status of phosphorylated molecules in a time-resolved manner. Computational analyses based on the phosphoproteome dynamics accelerate generation of novel methodologies for mathematical analysis of cellular signaling. Phosphoproteomics-based numerical modeling can be used to evaluate regulatory network elements from a statistical point of view. Integration with transcriptome dynamics also uncovers regulatory hubs at the transcriptional level. These omics-based computational methodologies, which have firstly been applied to representative signaling systems such as the epidermal growth factor receptor pathway, have now opened up a gate for systems analysis of signaling networks involved in immune response and cancer.

  4. Defect in radiation signal transduction in ataxia-telangiectasia

    International Nuclear Information System (INIS)

    Lavin, M.F.

    1994-01-01

    Exposure of mammalian cells to ionizing radiation causes a delay in progression through the cycle at several checkpoints. Cells from patients with ataxia-telangiectasia (A-T) ignore these checkpoint controls postirradiation. The tumour suppressor gene product p53 plays a key role at the G 1 /S checkpoint preventing the progression of cells into S phase. The induction of p53 by radiation is reduced and/or delayed in A-T cells, which appears to account for the failure of delay at the G 1 /S checkpoint. We have investigated further this defect in radiation signal transduction in A-T. While the p53 response was defective after radiation, agents that interfered with cell cycle progression such as mimosine, aphidicolin and deprivation of serum led to a normal p53 response in A-T cells. None of these agents caused breaks in DNA, as determined by pulse-field gel electrophoresis, in order to elicit the response. Since this pathway is mediated by protein kinases, we investigated the activity of several of these enzymes in control and A-T cells. Ca +2 -dependent and -independent protein kinase C activities were increased by radiation to the same extent in the two cell types, a variety of serine/threonine protein kinase activities were approximately the same and anti-tyrosine antibodies failed to reveal any differences in protein phosphorylation between A-T and control cells. (author)

  5. A-Site Cation Substitutions in Strained Y-Doped BaZrO3 Multilayer Films Leading to Fast Proton Transport Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Aruta, Carmela [Univ. of Roma Tor Vergata, Rome (Italy); Han, Chu [Georgia Inst. of Technology, Atlanta, GA (United States); Zhou, Si [Dalian Univ. of Technology, Dalian (China); Cantoni, Claudia [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yang, Nan [Univ. of Roma Tor Vergata, Rome (Italy); Tebano, Antonello [Univ. of Roma Tor Vergata, Rome (Italy); Lee, Tien -Lin [Diamond Light Source Ltd., Didcot (United Kingdom); Schlueter, Christoph [Diamond Light Source Ltd., Didcot (United Kingdom); Bongiorno, Angelo [College of Staten Island, Staten Island, NY (United States); The Graduate Center of the City Univ. of New York, New York, NY (United States)

    2016-03-31

    Proton-conducting perovskite oxides form a class of solid electrolytes for novel electrochemical devices operating at moderate temperatures. Here, we use hard X-ray photoelectron spectroscopy, scanning transmission electron microscopy, and density functional theory calculations to investigate the structure and elucidate the origin of the fast proton transport properties of strained ultrathin films of Y-doped BaZrO3 grown by pulsed lased deposition on NdGaO3. Our study shows that our BaZr0.8Y0.2O3 films incorporate a significant amount of Y dopants, and to a lesser extent also Zr ions, substituting for Ba2+, and that these substitutional defects agglomerate forming columnar regions crossing vertically from the surface to the interface the entire film. In conclusion, our calculations also show that, in regions rich in Y substitutions for both Zr and Ba, the proton transfer process involves nearly zero-energy barriers, indicating that A-site cation substitutions by Y lead to fast transport pathways and hence are responsible for the previously observed enhanced values of the proton conductivity of these perovskite oxide films.

  6. Enhanced transduction of photonic crystal dye lasers for gas sensing via swelling polymer film

    DEFF Research Database (Denmark)

    Smith, Cameron; Lind, Johan Ulrik; Christiansen, Mads Brøkner

    2011-01-01

    We present the enhanced transduction of a photonic crystal dye laser for gas sensing via deposition of an additional swelling polymer film. Device operation involves swelling of the polymer film during exposure to specific gases, leading to a change in total effective refractive index. Experimental...... in its application to other intracavity-based detection schemes to enable gas sensing. © 2011 Optical Society of America....

  7. An overview of bioinformatics methods for modeling biological pathways in yeast.

    Science.gov (United States)

    Hou, Jie; Acharya, Lipi; Zhu, Dongxiao; Cheng, Jianlin

    2016-03-01

    The advent of high-throughput genomics techniques, along with the completion of genome sequencing projects, identification of protein-protein interactions and reconstruction of genome-scale pathways, has accelerated the development of systems biology research in the yeast organism Saccharomyces cerevisiae In particular, discovery of biological pathways in yeast has become an important forefront in systems biology, which aims to understand the interactions among molecules within a cell leading to certain cellular processes in response to a specific environment. While the existing theoretical and experimental approaches enable the investigation of well-known pathways involved in metabolism, gene regulation and signal transduction, bioinformatics methods offer new insights into computational modeling of biological pathways. A wide range of computational approaches has been proposed in the past for reconstructing biological pathways from high-throughput datasets. Here we review selected bioinformatics approaches for modeling biological pathways inS. cerevisiae, including metabolic pathways, gene-regulatory pathways and signaling pathways. We start with reviewing the research on biological pathways followed by discussing key biological databases. In addition, several representative computational approaches for modeling biological pathways in yeast are discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. pathways in myogenesis

    Directory of Open Access Journals (Sweden)

    Marta Milewska

    2014-05-01

    Full Text Available The commitment of myogenic cells in skeletal muscle differentiation requires earlier irreversible interruption of the cell cycle. At the molecular level, several key regulators of the cell cycle have been identified: cyclin-dependent kinases and their cyclins stimulate the cell cycle progress and its arrest is determined by the activity of cdk inhibitors (Cip/Kip and INK protein families and pocket protein family: Rb, p107 and p130. The biological activity of cyclin/cdk complexes allows the successive phases of the cell cycle to occur. Myoblast specialization, differentiation and fusion require the activity of myogenic regulatory factors, which include MyoD, myogenin, Myf5 and MRF4. MyoD and Myf5 play a role in muscle cell specialization, myogenin controls the differentiation process, whereas MRF4 is involved in myotube maturation. The deregulation of the cell cycle leads to uncontrolled proliferation, which antagonizes the functions of myogenic factors and it explains the lack of differentiation-specific gene expression in dividing cells. Conversely, the myogenic factor MyoD seems to cooperate with cell cycle inhibitors leading to inhibition of cell cycle progress and commitment to the differentiation process. The hypophosphorylated form of Rb and cdk inhibitors play an important role in permanent arrest of the cell cycle in differentiated myotubes. Furthermore, cyclin/cdk complexes not only regulate cell division by phosphorylation of several substrates, but may also control other cellular processes such as signal transduction, differentiation and apoptosis. Beyond regulating the cell cycle, Cip/Kip proteins play an important role in cell death, transcription regulation, cell fate determination, cell migration and cytoskeletal dynamics. The article summarizes current knowledge concerning the interactions of intracellular signaling pathways controlling crucial stages of fetal and regenerative myogenesis.

  9. A novel miR-371a-5p-mediated pathway, leading to BAG3 upregulation in cardiomyocytes in response to epinephrine, is lost in Takotsubo cardiomyopathy.

    Science.gov (United States)

    d'Avenia, M; Citro, R; De Marco, M; Veronese, A; Rosati, A; Visone, R; Leptidis, S; Philippen, L; Vitale, G; Cavallo, A; Silverio, A; Prota, C; Gravina, P; De Cola, A; Carletti, E; Coppola, G; Gallo, S; Provenza, G; Bossone, E; Piscione, F; Hahne, M; De Windt, L J; Turco, M C; De Laurenzi, V

    2015-10-29

    Molecular mechanisms protecting cardiomyocytes from stress-induced death, including tension stress, are essential for cardiac physiology and defects in these protective mechanisms can result in pathological alterations. Bcl2-associated athanogene 3 (BAG3) is expressed in cardiomyocytes and is a component of the chaperone-assisted autophagy pathway, essential for homeostasis of mechanically altered cells. BAG3 ablation in mice results in a lethal cardiomyopathy soon after birth and mutations of this gene have been associated with different cardiomyopathies including stress-induced Takotsubo cardiomyopathy (TTC). The pathogenic mechanism leading to TTC has not been defined, but it has been suggested that the heart can be damaged by excessive epinephrine (epi) spillover in the absence of a protective mechanism. The aim of this study was to provide more evidence for a role of BAG3 in the pathogenesis of TTC. Therefore, we sequenced BAG3 gene in 70 TTC patients and in 81 healthy donors with the absence of evaluable cardiovascular disease. Mutations and polymorphisms detected in the BAG3 gene included a frequent nucleotide change g2252c in the BAG3 3'-untranslated region (3'-UTR) of Takotsubo patients (PBAG3 upregulation on exposure to epi through an ERK-dependent upregulation of miR-371a-5p. In conclusion, the presence of a g2252c polymorphism in the BAG3 3'-UTR determines loss of miR-371a-5p binding and results in an altered response to epi, potentially representing a new molecular mechanism that contributes to TTC pathogenesis.

  10. Expression of the synaptic exocytosis-regulating molecule complexin 2 in taste buds and its participation in peripheral taste transduction.

    Science.gov (United States)

    Kurokawa, Azusa; Narukawa, Masataka; Ohmoto, Makoto; Yoshimoto, Joto; Abe, Keiko; Misaka, Takumi

    2015-06-01

    Taste information from type III taste cells to gustatory neurons is thought to be transmitted via synapses. However, the molecular mechanisms underlying taste transduction through this pathway have not been fully elucidated. In this study, to identify molecules that participate in synaptic taste transduction, we investigated whether complexins (Cplxs), which play roles in regulating membrane fusion in synaptic vesicle exocytosis, were expressed in taste bud cells. Among four Cplx isoforms, strong expression of Cplx2 mRNA was detected in type III taste cells. To investigate the function of CPLX2 in taste transduction, we observed taste responses in CPLX2-knockout mice. When assessed with electrophysiological and behavioral assays, taste responses to some sour stimuli in CPLX2-knockout mice were significantly lower than those in wild-type mice. These results suggested that CPLX2 participated in synaptic taste transduction from type III taste cells to gustatory neurons. A part of taste information is thought to be transmitted via synapses. However, the molecular mechanisms have not been fully elucidated. To identify molecules that participate in synaptic taste transduction, we investigated complexins (Cplxs) expression in taste bud cells. Strong expression of Cplx2 mRNA was detected in taste bud cells. Furthermore, taste responses to some sour stimuli in CPLX2- knockout mice were significantly lower than those in wild-type mice. These suggested that CPLX2 participated in synaptic taste transduction. © 2015 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of The International Society for Neurochemistry.

  11. Signal transduction in the footsteps of goethe and schiller.

    Science.gov (United States)

    Friedrich, Karlheinz; Lindquist, Jonathan A; Entschladen, Frank; Serfling, Edgar; Thiel, Gerald; Kieser, Arnd; Giehl, Klaudia; Ehrhardt, Christina; Feller, Stephan M; Ullrich, Oliver; Schaper, Fred; Janssen, Ottmar; Hass, Ralf

    2009-02-04

    The historical town of Weimar in Thuringia, the "green heart of Germany" was the sphere of Goethe and Schiller, the two most famous representatives of German literature's classic era. Not yet entirely as influential as those two cultural icons, the Signal Transduction Society (STS) has nevertheless in the last decade established within the walls of Weimar an annual interdisciplinary Meeting on "Signal Transduction - Receptors, Mediators and Genes", which is well recognized as a most attractive opportunity to exchange results and ideas in the field.The 12th STS Meeting was held from October 28 to 31 and provided a state-of-the-art overview of various areas of signal transduction research in which progress is fast and discussion lively. This report is intended to share with the readers of CCS some highlights of the Meeting Workshops devoted to specific aspects of signal transduction.

  12. Falsification of the ionic channel theory of hair cell transduction.

    Science.gov (United States)

    Rossetto, Michelangelo

    2013-11-01

    The hair cell provides the transduction of mechanical vibrations in the balance and acoustic sense of all vertebrates that swim, walk, or fly. The current theory places hair cell transduction in a mechanically controlled ion channel. Although the theory of a mechanical input modulating the flow of ions through an ion pore has been a useful tool, it is falsified by experimental data in the literature and can be definitively falsified by a proposed experiment.

  13. Signal transduction through the IL-4 and insulin receptor families.

    Science.gov (United States)

    Wang, L M; Keegan, A; Frankel, M; Paul, W E; Pierce, J H

    1995-07-01

    Activation of tyrosine kinase-containing receptors and intracellular tyrosine kinases by ligand stimulation is known to be crucial for mediating initial and subsequent events involved in mitogenic signal transduction. Receptors for insulin and insulin-like growth factor 1 (IGF-1) contain cytoplasmic tyrosine kinase domains that undergo autophosphorylation upon ligand stimulation. Activation of these receptors also leads to pronounced and rapid tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1) in cells of connective tissue origin. A related substrate, designated 4PS, is similarly phosphorylated by insulin and IGF-1 stimulation in many hematopoietic cell types. IRS-1 and 4PS possess a number of tyrosine phosphorylation sites that are within motifs that bind specific SH2-containing molecules known to be involved in mitogenic signaling such as PI-3 kinase, SHPTP-2 (Syp) and Grb-2. Thus, they appear to act as docking substrates for a variety of signaling molecules. The majority of hematopoietic cytokines bind to receptors that do not possess intrinsic kinase activity, and these receptors have been collectively termed as members of the hematopoietin receptor superfamily. Despite their lack of tyrosine kinase domains, stimulation of these receptors has been demonstrated to activate intracellular kinases leading to tyrosine phosphorylation of multiple substrates. Recent evidence has demonstrated that activation of different members of the Janus family of tyrosine kinases is involved in mediating tyrosine phosphorylation events by specific cytokines. Stimulation of the interleukin 4 (IL-4) receptor, a member of the hematopoietin receptor superfamily, is thought to result in activation of Jak1, Jak3, and/or Fes tyrosine kinases.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Plant Genes Involved in Symbiotic Sinal Perception/Signal Transduction

    DEFF Research Database (Denmark)

    Binder, A; Soyano, T; Hayashi, H

    2014-01-01

    to nodule primordia formation, and the infection thread initiation in the root hairs guiding bacteria towards dividing cortical cells. This chapter focuses on the plant genes involved in the recognition of the symbiotic signal produced by rhizobia, and the downstream genes, which are part of a complex...... symbiotic signalling pathway that leads to the generation of calcium spiking in the nuclear regions and activation of transcription factors controlling symbiotic genes induction...

  15. Obesity-driven gut microbiota inflammatory pathways to metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Agra eCavalcante-Silva

    2015-11-01

    Full Text Available The intimate interplay between immune system, metabolism and gut microbiota plays an important role in controlling metabolic homeostasis and possible obesity development. Obesity involves impairment of immune response affecting both innate and adaptive immunity. The main factors involved in the relationship of obesity with inflammation have not been completely elucidated. On the other hand, gut microbiota, via innate immune receptors, has emerged as one of the key factors regulating events triggering acute inflammation associated with obesity and metabolic syndrome. Inflammatory disorders lead to several signalling transduction pathways activation, inflammatory cytokine, chemokine production and cell migration, which in turn cause metabolic dysfunction. Inflamed adipose tissue, with increased macrophages infiltration, is associated with impaired preadipocyte development and differentiation to mature adipose cells, leading to ectopic lipid accumulation and insulin resistance. This review focuses on the relationship between obesity and inflammation, which is essential to understand the pathological mechanisms governing metabolic syndrome.

  16. Presence of Ca2+-dependent K+ channels in chemosensory cilia support a role in odor transduction.

    Science.gov (United States)

    Delgado, Ricardo; Saavedra, M Veronica; Schmachtenberg, Oliver; Sierralta, Jimena; Bacigalupo, Juan

    2003-09-01

    Olfactory receptor neurons (ORNs) respond to odorants with changes in the action potential firing rate. Excitatory responses, consisting of firing increases, are mediated by a cyclic AMP cascade that leads to the activation of cationic nonselective cyclic nucleotide-gated (CNG) channels and Ca2+-dependent Cl- (ClCa) channels. This process takes place in the olfactory cilia, where all protein components of this cascade are confined. ORNs from various vertebrate species have also been shown to generate inhibitory odor responses, expressed as decreases in action potential discharges. Odor inhibition appears to rely on Ca2+-dependent K+ (KCa) channels, but the underlying transduction mechanism remains unknown. If these channels are involved in odor transduction, they are expected to be present in the olfactory cilia. We found that a specific antibody against a large conductance KCa recognized a protein of approximately 116 kDa in Western blots of purified rat olfactory ciliary membranes. Moreover, the antibody labeled ORN cilia in isolated ORNs from rat and toad (Caudiverbera caudiverbera). In addition, single-channel recordings from inside-out membrane patches excised from toad chemosensory cilia showed the presence of 4 different types of KCa channels, with unitary conductances of 210, 60, 12, and 29 and 60 pS, high K+-selectivity, and Ca2+ sensitivities in the low micromolar range. Our work demonstrates the presence of K+ channels in the ORN cilia and supports their participation in odor transduction.

  17. A Biosensor for Urea from Succinimide-Modified Acrylic Microspheres Based on Reflectance Transduction

    Directory of Open Access Journals (Sweden)

    Musa Ahmad

    2011-08-01

    Full Text Available New acrylic microspheres were synthesised by photopolymerisation where the succinimide functional group was incorporated during the microsphere preparation. An optical biosensor for urea based on reflectance transduction with a large linear response range to urea was successfully developed using this material. The biosensor utilized succinimide-modified acrylic microspheres immobilized with a Nile blue chromoionophore (ETH 5294 for optical detection and urease enzyme was immobilized on the surface of the microspheres via the succinimide groups. No leaching of the enzyme or chromoionophore was observed. Hydrolysis of the urea by urease changes the pH and leads to a color change of the immobilized chromoionophore. When the color change was monitored by reflectance spectrophotometry, the linear response range of the biosensor to urea was from 0.01 to 1,000 mM (R2 = 0.97 with a limit of detection of 9.97 mM. The biosensor response showed good reproducibility (relative standard deviation = 1.43%, n = 5 with no interference by major cations such as Na+, K+, NH4+ and Mg2+. The use of reflectance as a transduction method led to a large linear response range that is better than that of many urea biosensors based on other optical transduction methods.

  18. Regulation of autophagy by amino acids and MTOR-dependent signal transduction.

    Science.gov (United States)

    Meijer, Alfred J; Lorin, Séverine; Blommaart, Edward F; Codogno, Patrice

    2015-10-01

    Amino acids not only participate in intermediary metabolism but also stimulate insulin-mechanistic target of rapamycin (MTOR)-mediated signal transduction which controls the major metabolic pathways. Among these is the pathway of autophagy which takes care of the degradation of long-lived proteins and of the elimination of damaged or functionally redundant organelles. Proper functioning of this process is essential for cell survival. Dysregulation of autophagy has been implicated in the etiology of several pathologies. The history of the studies on the interrelationship between amino acids, MTOR signaling and autophagy is the subject of this review. The mechanisms responsible for the stimulation of MTOR-mediated signaling, and the inhibition of autophagy, by amino acids have been studied intensively in the past but are still not completely clarified. Recent developments in this field are discussed.

  19. Reciprocity and gyrotropism in magnetic resonance transduction

    International Nuclear Information System (INIS)

    Tropp, James

    2006-01-01

    We give formulas for transduction in magnetic resonance - i.e., the appearance of an emf due to Larmor precession of spins - based upon the modified Lorentz reciprocity principle for gyrotropic (also called 'nonreciprocal') media, i.e., in which a susceptibility tensor is carried to its transpose by reversal of an external static field [cf., R. F. Harrington and A. T. Villeneuve IRE Trans. Microwave Theory and Technique MTT6, 308 (1958)]. Prior applications of reciprocity to magnetic resonance, despite much success, have ignored the gyrotropism which necessarily arises due to nuclear and/or unpaired electronic spins. For detection with linearly polarized fields, oscillating at the Larmor frequency, the emf is written in terms of a volume integral containing a product of two factors which we define as the antenna patterns, i.e. (H 1x ±iH 1y ), where, e.g., for a single transceive antenna, the H's are just the spatially dependent oscillatory magnetic field strengths, per the application of some reference current at the antenna terminals, with the negative sign obtaining for transmission, and the positive for reception. Similar expressions hold for separate transmit and receive antennas; expressions are also given for circular polarization of the fields. We then exhibit a receive-only array antenna of two elements for magnetic resonance imaging of protons, which, due an intensity artifact arising from stray reactive coupling of the elements, produces, despite its own bilateral symmetry, asymmetric proton NMR images of a symmetric cylindrical phantom containing aqueous saline solution [J. Tropp and T. Schirmer, J. Magn. Reson. 151, 146 (2001)]. Modification of this two-port antenna, to function in transmit-receive mode, allows us to demonstrate highly nonreciprocal behavior: that is, to record images (of cylindrical test phantoms containing aqueous saline solution) whose appearance dramatically changes, when the roles of transmission and reception are swapped between

  20. Theory and modeling of cylindrical thermo-acoustic transduction

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Lihong, E-mail: lhtong@ecjtu.edu.cn [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China); Lim, C.W. [Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Zhao, Xiushao; Geng, Daxing [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China)

    2016-06-03

    Models both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed and the corresponding acoustic pressure solutions are obtained. The acoustic pressure for an individual carbon nanotube (CNT) as a function of input power is investigated analytically and it is verified by comparing with the published experimental data. Further numerical analysis on the acoustic pressure response and characteristics for varying input frequency and distance are also examined both for solid and thinfilm-solid cylindrical thermo-acoustic transductions. Through detailed theoretical and numerical studies on the acoustic pressure solution for thinfilm-solid cylindrical transduction, it is concluded that a solid with smaller thermal conductivity favors to improve the acoustic performance. In general, the proposed models are applicable to a variety of cylindrical thermo-acoustic devices performing in different gaseous media. - Highlights: • Theory and modeling both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed. • The modeling is verified by comparing with the published experimental data. • Acoustic response characteristics of cylindrical thermo-acoustic transductions are predicted by the proposed model.

  1. Integrated Electromechanical Transduction Schemes for Polymer MEMS Sensors

    Directory of Open Access Journals (Sweden)

    Damien Thuau

    2018-04-01

    Full Text Available Polymer Micro ElectroMechanical Systems (MEMS have the potential to constitute a powerful alternative to silicon-based MEMS devices for sensing applications. Although the use of commercial photoresists as structural material in polymer MEMS has been widely reported, the integration of functional polymer materials as electromechanical transducers has not yet received the same amount of interest. In this context, we report on the design and fabrication of different electromechanical schemes based on polymeric materials ensuring different transduction functions. Piezoresistive transduction made of carbon nanotube-based nanocomposites with a gauge factor of 200 was embedded within U-shaped polymeric cantilevers operating either in static or dynamic modes. Flexible resonators with integrated piezoelectric transduction were also realized and used as efficient viscosity sensors. Finally, piezoelectric-based organic field effect transistor (OFET electromechanical transduction exhibiting a record sensitivity of over 600 was integrated into polymer cantilevers and used as highly sensitive strain and humidity sensors. Such advances in integrated electromechanical transduction schemes should favor the development of novel all-polymer MEMS devices for flexible and wearable applications in the future.

  2. The effect of aquaporin 5 overexpression on the Ras signaling pathway

    International Nuclear Information System (INIS)

    Woo, Janghee; Lee, Juna; Kim, Myoung Sook; Jang, Se Jin; Sidransky, David; Moon, Chulso

    2008-01-01

    Human aquaporin 5 (AQP5) has been shown to be overexpressed in multiple cancers, such as pancreatic cancer and colon cancer. Furthermore, it has been reported that ectopic expression of AQP5 leads to many phenotypic changes characteristic of transformation. However, the biochemical mechanism leading to transformation in AQP5-overexpressing cells has not been clearly elucidated. In this report, the overexpression of AQP5 in NIH3T3 cells demonstrated a significant effect on Ras activity and, thus, cell proliferation. Furthermore, this influence was shown to be mediated by phosphorylation of the PKA consensus site of AQP5. This is the first evidence demonstrating an association between AQP5 and a signaling pathway, namely the Ras signal transduction pathway, which may be the basis of the oncogenic properties seen in AQP-overexpressing cells

  3. Logical network of genotoxic stress-induced NF-kappaB signal transduction predicts putative target structures for therapeutic intervention strategies

    Directory of Open Access Journals (Sweden)

    Rainer Poltz

    2009-12-01

    Full Text Available Rainer Poltz1, Raimo Franke1,#, Katrin Schweitzer1, Steffen Klamt2, Ernst-Dieter Gilles2, Michael Naumann11Institute of Experimental Internal Medicine, Otto von Guericke University, Magdeburg, Germany; 2Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany; #Present address: Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, GermanyAbstract: Genotoxic stress is induced by a broad range of DNA-damaging agents and could lead to a variety of human diseases including cancer. DNA damage is also therapeutically induced for cancer treatment with the aim to eliminate tumor cells. However, the effectiveness of radio- and chemotherapy is strongly hampered by tumor cell resistance. A major reason for radio- and chemotherapeutic resistances is the simultaneous activation of cell survival pathways resulting in the activation of the transcription factor nuclear factor-kappa B (NF-κB. Here, we present a Boolean network model of the NF-κB signal transduction induced by genotoxic stress in epithelial cells. For the representation and analysis of the model, we used the formalism of logical interaction hypergraphs. Model reconstruction was based on a careful meta-analysis of published data. By calculating minimal intervention sets, we identified p53-induced protein with a death domain (PIDD, receptor-interacting protein 1 (RIP1, and protein inhibitor of activated STAT y (PIASy as putative therapeutic targets to abrogate NF-κB activation resulting in apoptosis. Targeting these structures therapeutically may potentiate the effectiveness of radio- and chemotherapy. Thus, the presented model allows a better understanding of the signal transduction in tumor cells and provides candidates as new therapeutic target structures.Keywords: apoptosis, Boolean network, cancer therapy, DNA-damage response, NF-κB

  4. Physical aspects of sensory transduction on seeing, hearing and smelling.

    Science.gov (United States)

    Yoshioka, Tohru; Sakakibara, Manabu

    2013-01-01

    What is the general principle of sensory transduction? Sensory transduction is defined as energy transformation from the external world to the internal world. The energy of the external world, such as thermal energy (heat), electro-magnetic energy (light), mechanical energy (sound) and the energy from molecules (chemicals), is converted into electrochemical events in the animal nervous system. The following five classes of special sense receptors are utilized for energy conversion: vision (photo); audition (sound); taste and smell (chemo); and tactile (mechano). There are also other special sense receptors, including thermo and noxious receptors. The focus of this study is on photoreceptors, sound-receptors and odorant-receptors because the transduction mechanisms of these receptors are explained biochemically and understood by a common physical principle; these biochemical models are well known in neuroscience. The following notable problems are inherent in these biochemical models: the cGMP ionophore model of the vertebrate photoreceptor cannot explain the fast photo-response (∼msec); the tip links connection model of stereocilia in the basilar membrane for opening the K(+) channel on the tip of a hair has difficulty explaining the high frequency vibration of hair cells without a damping of the oscillation, and the odorant shape-specific receptor model for olfactory transduction has difficulty in discriminating the minute differences among similar fragrant smells of essential oils with different molecular shapes. These difficulties might arise from a lack of the physical sense when the transduction models were proposed. This article will reconsider these problems and propose rational models for visual, olfactory and auditory transduction.

  5. Transfer functions for protein signal transduction: application to a model of striatal neural plasticity.

    Directory of Open Access Journals (Sweden)

    Gabriele Scheler

    Full Text Available We present a novel formulation for biochemical reaction networks in the context of protein signal transduction. The model consists of input-output transfer functions, which are derived from differential equations, using stable equilibria. We select a set of "source" species, which are interpreted as input signals. Signals are transmitted to all other species in the system (the "target" species with a specific delay and with a specific transmission strength. The delay is computed as the maximal reaction time until a stable equilibrium for the target species is reached, in the context of all other reactions in the system. The transmission strength is the concentration change of the target species. The computed input-output transfer functions can be stored in a matrix, fitted with parameters, and even recalled to build dynamical models on the basis of state changes. By separating the temporal and the magnitudinal domain we can greatly simplify the computational model, circumventing typical problems of complex dynamical systems. The transfer function transformation of biochemical reaction systems can be applied to mass-action kinetic models of signal transduction. The paper shows that this approach yields significant novel insights while remaining a fully testable and executable dynamical model for signal transduction. In particular we can deconstruct the complex system into local transfer functions between individual species. As an example, we examine modularity and signal integration using a published model of striatal neural plasticity. The modularizations that emerge correspond to a known biological distinction between calcium-dependent and cAMP-dependent pathways. Remarkably, we found that overall interconnectedness depends on the magnitude of inputs, with higher connectivity at low input concentrations and significant modularization at moderate to high input concentrations. This general result, which directly follows from the properties of

  6. TRP channel proteins and signal transduction.

    Science.gov (United States)

    Minke, Baruch; Cook, Boaz

    2002-04-01

    TRP channel proteins constitute a large and diverse family of proteins that are expressed in many tissues and cell types. This family was designated TRP because of a spontaneously occurring Drosophila mutant lacking TRP that responded to a continuous light with a transient receptor potential (hence TRP). In addition to responses to light, TRPs mediate responses to nerve growth factor, pheromones, olfaction, mechanical, chemical, temperature, pH, osmolarity, vasorelaxation of blood vessels, and metabolic stress. Furthermore, mutations in several members of TRP-related channel proteins are responsible for several diseases, such as several tumors and neurodegenerative disorders. TRP-related channel proteins are found in a variety of organisms, tissues, and cell types, including nonexcitable, smooth muscle, and neuronal cells. The large functional diversity of TRPs is also reflected in their diverse permeability to ions, although, in general, they are classified as nonselective cationic channels. The molecular domains that are conserved in all members of the TRP family constitute parts of the transmembrane domains and in most members also the ankyrin-like repeats at the NH2 terminal of the protein and a "TRP domain" at the COOH terminal, which is a highly conserved 25-amino acid stretch with still unknown function. All of the above features suggest that members of the TRP family are "special assignment" channels, which are recruited to diverse signaling pathways. The channels' roles and characteristics such as gating mechanism, regulation, and permeability are determined by evolution according to the specific functional requirements.

  7. Disrupting BCR-ABL in combination with secondary leukemia-specific pathways in CML cells leads to enhanced apoptosis and decreased proliferation.

    Science.gov (United States)

    Woessner, David W; Lim, Carol S

    2013-01-07

    Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by expression of the fusion gene BCR-ABL following a chromosomal translocation in the hematopoietic stem cell. Therapeutic management of CML uses tyrosine kinase inhibitors (TKIs), which block ABL-signaling and effectively kill peripheral cells with BCR-ABL. However, TKIs are not curative, and chronic use is required in order to treat CML. The primary failure for TKIs is through the development of a resistant population due to mutations in the TKI binding regions. This led us to develop the mutant coiled-coil, CC(mut2), an alternative method for BCR-ABL signaling inhibition by targeting the N-terminal oligomerization domain of BCR, necessary for ABL activation. In this article, we explore additional pathways that are important for leukemic stem cell survival in K562 cells. Using a candidate-based approach, we test the combination of CC(mut2) and inhibitors of unique secondary pathways in leukemic cells. Transformative potential was reduced following silencing of the leukemic stem cell factor Alox5 by RNA interference. Furthermore, blockade of the oncogenic protein MUC-1 by the novel peptide GO-201 yielded reductions in proliferation and increased cell death. Finally, we found that inhibiting macroautophagy using chloroquine in addition to blocking BCR-ABL signaling with the CC(mut2) was most effective in limiting cell survival and proliferation. This study has elucidated possible combination therapies for CML using novel blockade of BCR-ABL and secondary leukemia-specific pathways.

  8. Salicylic acid-independent plant defence pathways

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are

  9. Absence of both Sos-1 and Sos-2 in peripheral CD4+ T cells leads to PI3K pathway activation and defects in migration

    Science.gov (United States)

    Guittard, Geoffrey; Kortum, Robert L; Balagopalan, Lakshmi; Çuburu, Nicolas; Nguyen, Phan; Sommers, Connie L; Samelson, Lawrence E

    2015-01-01

    Sos-1 and Sos-2 are ubiquitously expressed Ras-Guanine Exchange Factors involved in Erk-MAP kinase pathway activation. Using mice lacking genes encoding Sos-1 and Sos-2, we evaluated the role of these proteins in peripheral T-cell signaling and function. Our results confirmed that TCR-mediated Erk activation in peripheral CD4+ T cells does not depend on Sos-1 and Sos-2, although IL-2-mediated Erk activation does. Unexpectedly, however, we show an increase in AKT phosphorylation in Sos-1/2dKO CD4+ T cells upon TCR and IL-2 stimulation. Activation of AKT was likely a consequence of increased recruitment of PI3K to Grb2 upon TCR and/or IL-2 stimulation in Sos-1/2dKO CD4+ T cells. The increased activity of the PI3K/AKT pathway led to downregulation of the surface receptor CD62L in Sos-1/2dKO T cells and a subsequent impairment in T-cell migration. PMID:25973715

  10. Absence of both Sos-1 and Sos-2 in peripheral CD4(+) T cells leads to PI3K pathway activation and defects in migration.

    Science.gov (United States)

    Guittard, Geoffrey; Kortum, Robert L; Balagopalan, Lakshmi; Çuburu, Nicolas; Nguyen, Phan; Sommers, Connie L; Samelson, Lawrence E

    2015-08-01

    Sos-1 and Sos-2 are ubiquitously expressed Ras-guanine exchange factors involved in Erk-MAP kinase pathway activation. Using mice lacking genes encoding Sos-1 and Sos-2, we evaluated the role of these proteins in peripheral T-cell signaling and function. Our results confirmed that TCR-mediated Erk activation in peripheral CD4(+) T cells does not depend on Sos-1 and Sos-2, although IL-2-mediated Erk activation does. Unexpectedly, however, we show an increase in AKT phosphorylation in Sos-1/2dKO CD4(+) T cells upon TCR and IL-2 stimulation. Activation of AKT was likely a consequence of increased recruitment of PI3K to Grb2 upon TCR and/or IL-2 stimulation in Sos-1/2dKO CD4(+) T cells. The increased activity of the PI3K/AKT pathway led to downregulation of the surface receptor CD62L in Sos-1/2dKO T cells and a subsequent impairment in T-cell migration. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  11. Insulin resistance and improvements in signal transduction.

    Science.gov (United States)

    Musi, Nicolas; Goodyear, Laurie J

    2006-02-01

    Type 2 diabetes and obesity are common metabolic disorders characterized by resistance to the actions of insulin to stimulate skeletal muscle glucose disposal. Insulin-resistant muscle has defects at several steps of the insulin-signaling pathway, including decreases in insulin-stimulated insulin receptor and insulin receptor substrate-1 tyrosine phosphorylation, and phosphatidylinositol 3-kinase (PI 3-kinase) activation. One approach to increase muscle glucose disposal is to reverse/improve these insulin-signaling defects. Weight loss and thiazolidinediones (TZDs) improve glucose disposal, in part, by increasing insulin-stimulated insulin receptor and IRS-1 tyrosine phosphorylation and PI 3-kinase activity. In contrast, physical training and metformin improve whole-body glucose disposal but have minimal effects on proximal insulin-signaling steps. A novel approach to reverse insulin resistance involves inhibition of the stress-activated protein kinase Jun N-terminal kinase (JNK) and the protein tyrosine phosphatases (PTPs). A different strategy to increase muscle glucose disposal is by stimulating insulin-independent glucose transport. AMP-activated protein kinase (AMPK) is an enzyme that works as a fuel gauge and becomes activated in situations of energy consumption, such as muscle contraction. Several studies have shown that pharmacologic activation of AMPK increases glucose transport in muscle, independent of the actions of insulin. AMPK activation is also involved in the mechanism of action of metformin and adiponectin. Moreover, in the hypothalamus, AMPK regulates appetite and body weight. The effect of AMPK to stimulate muscle glucose disposal and to control appetite makes it an important pharmacologic target for the treatment of type 2 diabetes and obesity.

  12. Effect of saw palmetto extract on PI3K cell signaling transduction in human glioma.

    Science.gov (United States)

    Yang, Yang; Hui, Lv; Yuqin, Che; Jie, Li; Shuai, Hou; Tiezhu, Zhou; Wei, Wang

    2014-08-01

    Saw palmetto extract can induce the apoptosis of prostate cancer cells. The aim of the present study was to investigate the effect of saw palmetto extract on the phosphatidylinositol 3-kinase (PI3K)/Akt signaling transduction pathway in human glioma U87 and U251 cell lines. Suspensions of U87 and U251 cells in a logarithmic growth phase were seeded into six-well plates at a density of 10 4 cells/well. In the experimental group, 1 μl/ml saw palmetto extract was added, while the control group was cultured without a drug for 24 h. The expression levels of PI3K, B-cell lymphoma-extra large (Bcl-xL) and p53 were evaluated through western blot analysis. In the experimental group, the U87 and U251 cells exhibited a lower expression level of PI3K protein as compared with the control group (t=6.849; Psaw palmetto extract induces glioma cell growth arrest and apoptosis via decreasing PI3K/Akt signal transduction.

  13. Mitogen-activated protein kinase and abscisic acid signal transduction

    NARCIS (Netherlands)

    Heimovaara-Dijkstra, S.; Testerink, C.; Wang, M.

    1998-01-01

    The phytohormone abscisic acid (ABA) is a classical plant hormone, responsible for regulation of abscission, diverse aspects of plant and seed development, stress responses and germination. It was found that ABA signal transduction in plants can involve the activity of type 2C-phosphatases (PP2C),

  14. Molecular methods for the study of signal transduction in plants

    KAUST Repository

    Irving, Helen R.; Gehring, Christoph A

    2013-01-01

    as well as at the systems level where transcriptomics and particularly phosphoproteomics afford a window into complex biological responses. Here we review the role of the cyclic nucleotides cAMP and cGMP in plant signal transduction as well

  15. Cell biology symposium: Membrane trafficking and signal transduction

    Science.gov (United States)

    In general, membrane trafficking is a broad group of processes where proteins and other large molecules are distributed throughout the cell as well as adjacent extracellular spaces. Whereas signal transduction is a process where signals are transmitted through a series of chemical or molecular event...

  16. Protein phosphorylation and its role in archaeal signal transduction

    Science.gov (United States)

    Esser, Dominik; Hoffmann, Lena; Pham, Trong Khoa; Bräsen, Christopher; Qiu, Wen; Wright, Phillip C.; Albers, Sonja-Verena; Siebers, Bettina

    2016-01-01

    Reversible protein phosphorylation is the main mechanism of signal transduction that enables cells to rapidly respond to environmental changes by controlling the functional properties of proteins in response to external stimuli. However, whereas signal transduction is well studied in Eukaryotes and Bacteria, the knowledge in Archaea is still rather scarce. Archaea are special with regard to protein phosphorylation, due to the fact that the two best studied phyla, the Euryarchaeota and Crenarchaeaota, seem to exhibit fundamental differences in regulatory systems. Euryarchaeota (e.g. halophiles, methanogens, thermophiles), like Bacteria and Eukaryotes, rely on bacterial-type two-component signal transduction systems (phosphorylation on His and Asp), as well as on the protein phosphorylation on Ser, Thr and Tyr by Hanks-type protein kinases. Instead, Crenarchaeota (e.g. acidophiles and (hyper)thermophiles) only depend on Hanks-type protein phosphorylation. In this review, the current knowledge of reversible protein phosphorylation in Archaea is presented. It combines results from identified phosphoproteins, biochemical characterization of protein kinases and protein phosphatases as well as target enzymes and first insights into archaeal signal transduction by biochemical, genetic and polyomic studies. PMID:27476079

  17. Expression of SMAD signal transduction molecules in the pancreas

    DEFF Research Database (Denmark)

    Brorson, Michael; Hougaard, D.; Nielsen, Jens Høiriis

    2001-01-01

    Members of the TGF-beta superfamily of cytokines have been implicated in pancreatic cancer, pancreatitis and in regulation and differentiation of pancreatic endocrine and exocrine cells. Different TGF-beta members signal through phosphorylation of different signal transduction proteins, which eve...

  18. Program Design Analysis using BEopt Building Energy Optimization Software: Defining a Technology Pathway Leading to New Homes with Zero Peak Cooling Demand; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.; Christensen, C.; Horowitz, S.

    2006-08-01

    An optimization method based on the evaluation of a broad range of different combinations of specific energy efficiency and renewable-energy options is used to determine the least-cost pathway to the development of new homes with zero peak cooling demand. The optimization approach conducts a sequential search of a large number of possible option combinations and uses the most cost-effective alternatives to generate a least-cost curve to achieve home-performance levels ranging from a Title 24-compliant home to a home that uses zero net source energy on an annual basis. By evaluating peak cooling load reductions on the least-cost curve, it is then possible to determine the most cost-effective combination of energy efficiency and renewable-energy options that both maximize annual energy savings and minimize peak-cooling demand.

  19. Overexpression of the PP2A regulatory subunit Tap46 leads to enhanced plant growth through stimulation of the TOR signalling pathway

    Science.gov (United States)

    Ahn, Chang Sook; Ahn, Hee-Kyung; Pai, Hyun-Sook

    2015-01-01

    Tap46, a regulatory subunit of protein phosphatase 2A (PP2A), plays an essential role in plant growth and development through a functional link with the Target of Rapamycin (TOR) signalling pathway. Here, we have characterized the molecular mechanisms behind a gain-of-function phenotype of Tap46 and its relationship with TOR to gain further insights into Tap46 function in plants. Constitutive overexpression of Tap46 in Arabidopsis resulted in overall growth stimulation with enlarged organs, such as leaves and siliques. Kinematic analysis of leaf growth revealed that increased cell size was mainly responsible for the leaf enlargement. Tap46 overexpression also enhanced seed size and viability under accelerated ageing conditions. Enhanced plant growth was also observed in dexamethasone (DEX)-inducible Tap46 overexpression Arabidopsis lines, accompanied by increased cellular activities of nitrate-assimilating enzymes. DEX-induced Tap46 overexpression and Tap46 RNAi resulted in increased and decreased phosphorylation of S6 kinase (S6K), respectively, which is a sensitive indicator of endogenous TOR activity, and Tap46 interacted with S6K in planta based on bimolecular fluorescence complementation and co-immunoprecipitation. Furthermore, inactivation of TOR by estradiol-inducible RNAi or rapamycin treatment decreased Tap46 protein levels, but increased PP2A catalytic subunit levels. Real-time quantitative PCR analysis revealed that Tap46 overexpression induced transcriptional modulation of genes involved in nitrogen metabolism, ribosome biogenesis, and lignin biosynthesis. These findings suggest that Tap46 modulates plant growth as a positive effector of the TOR signalling pathway and Tap46/PP2Ac protein abundance is regulated by TOR activity. PMID:25399018

  20. Overexpression of the PP2A regulatory subunit Tap46 leads to enhanced plant growth through stimulation of the TOR signalling pathway.

    Science.gov (United States)

    Ahn, Chang Sook; Ahn, Hee-Kyung; Pai, Hyun-Sook

    2015-02-01

    Tap46, a regulatory subunit of protein phosphatase 2A (PP2A), plays an essential role in plant growth and development through a functional link with the Target of Rapamycin (TOR) signalling pathway. Here, we have characterized the molecular mechanisms behind a gain-of-function phenotype of Tap46 and its relationship with TOR to gain further insights into Tap46 function in plants. Constitutive overexpression of Tap46 in Arabidopsis resulted in overall growth stimulation with enlarged organs, such as leaves and siliques. Kinematic analysis of leaf growth revealed that increased cell size was mainly responsible for the leaf enlargement. Tap46 overexpression also enhanced seed size and viability under accelerated ageing conditions. Enhanced plant growth was also observed in dexamethasone (DEX)-inducible Tap46 overexpression Arabidopsis lines, accompanied by increased cellular activities of nitrate-assimilating enzymes. DEX-induced Tap46 overexpression and Tap46 RNAi resulted in increased and decreased phosphorylation of S6 kinase (S6K), respectively, which is a sensitive indicator of endogenous TOR activity, and Tap46 interacted with S6K in planta based on bimolecular fluorescence complementation and co-immunoprecipitation. Furthermore, inactivation of TOR by estradiol-inducible RNAi or rapamycin treatment decreased Tap46 protein levels, but increased PP2A catalytic subunit levels. Real-time quantitative PCR analysis revealed that Tap46 overexpression induced transcriptional modulation of genes involved in nitrogen metabolism, ribosome biogenesis, and lignin biosynthesis. These findings suggest that Tap46 modulates plant growth as a positive effector of the TOR signalling pathway and Tap46/PP2Ac protein abundance is regulated by TOR activity. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  1. Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

    Institute of Scientific and Technical Information of China (English)

    Vicente Felipo

    2006-01-01

    Patients with liver disease may present hepatic encephalopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations,including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death.The mechanisms leading to HE which are not well known are being studied using animal models. The neurological alterations in HE are a consequence of impaired cerebral function mainly due to alterations in neurotransmission. We review here some studies indicating that alterations in neurotransmission associated to different types of glutamate receptors are responsible for some of the cognitive and motor alterations present in HE.These studies show that the function of the signal transduction pathway glutamate-nitric oxide-cGMP associated to the NMDA type of glutamate receptors is impaired in brain in vivo in HE animal models as well as in brain of patients died of HE. Activation of NMDA receptors in brain activates this pathway and increases cGMP. In animal models of HE this increase in cGMP induced by activation of NMDA receptors is reduced,which is responsible for the impairment in learning ability in these animal models. Increasing cGMP by pharmacological means restores learning ability in rats with HE and may be a new therapeutic approach to improve cognitive function in patients with HE.However, it is necessary to previously assess the possible secondary effects.Patients with HE may present psychomotor slowing,hypokinesia and bradykinesia. Animal models of HE also show hypolocomotion. It has been shown in rats with HE that hypolocomotion is due to excessive activation of metabotropic glutamate receptors (mGluRs) in substantia nigra pars reticulata. Blocking mGluR1 in this brain area normalizes motor activity in the rats, suggesting that a similar treatment for patients with HE could be useful to treat psychomotor slowing and

  2. Salicylic acid-independent plant defence pathways

    OpenAIRE

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independent of salicylic acid. Evidence is emerging that jasmonic acid and ethylene play key roles in these salicylic acid-independent pathways. Cross-talk between the salicylic acid-dependent and the salicy...

  3. Alterations in energy metabolism, neuroprotection and visual signal transduction in the retina of Parkinsonian, MPTP-treated monkeys.

    Directory of Open Access Journals (Sweden)

    Laura Campello

    Full Text Available Parkinson disease is mainly characterized by the degeneration of dopaminergic neurons in the central nervous system, including the retina. Different interrelated molecular mechanisms underlying Parkinson disease-associated neuronal death have been put forward in the brain, including oxidative stress and mitochondrial dysfunction. Systemic injection of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP to monkeys elicits the appearance of a parkinsonian syndrome, including morphological and functional impairments in the retina. However, the intracellular events leading to derangement of dopaminergic and other retinal neurons in MPTP-treated animal models have not been so far investigated. Here we have used a comparative proteomics approach to identify proteins differentially expressed in the retina of MPTP-treated monkeys. Proteins were solubilized from the neural retinas of control and MPTP-treated animals, labelled separately with two different cyanine fluorophores and run pairwise on 2D DIGE gels. Out of >700 protein spots resolved and quantified, 36 were found to exhibit statistically significant differences in their expression levels, of at least ± 1.4-fold, in the parkinsonian monkey retina compared with controls. Most of these spots were excised from preparative 2D gels, trypsinized and subjected to MALDI-TOF MS and LC-MS/MS analyses. Data obtained were used for protein sequence database interrogation, and 15 different proteins were successfully identified, of which 13 were underexpressed and 2 overexpressed. These proteins were involved in key cellular functional pathways such as glycolysis and mitochondrial electron transport, neuronal protection against stress and survival, and phototransduction processes. These functional categories underscore that alterations in energy metabolism, neuroprotective mechanisms and signal transduction are involved in MPTP-induced neuronal degeneration in the retina, in similarity to

  4. Emergence, development and diversification of the TGF-β signalling pathway within the animal kingdom

    Directory of Open Access Journals (Sweden)

    Moustakas Aristidis

    2009-02-01

    Full Text Available Abstract Background The question of how genomic processes, such as gene duplication, give rise to co-ordinated organismal properties, such as emergence of new body plans, organs and lifestyles, is of importance in developmental and evolutionary biology. Herein, we focus on the diversification of the transforming growth factor-β (TGF-β pathway – one of the fundamental and versatile metazoan signal transduction engines. Results After an investigation of 33 genomes, we show that the emergence of the TGF-β pathway coincided with appearance of the first known animal species. The primordial pathway repertoire consisted of four Smads and four receptors, similar to those observed in the extant genome of the early diverging tablet animal (Trichoplax adhaerens. We subsequently retrace duplications in ancestral genomes on the lineage leading to humans, as well as lineage-specific duplications, such as those which gave rise to novel Smads and receptors in teleost fishes. We conclude that the diversification of the TGF-β pathway can be parsimoniously explained according to the 2R model, with additional rounds of duplications in teleost fishes. Finally, we investigate duplications followed by accelerated evolution which gave rise to an atypical TGF-β pathway in free-living bacterial feeding nematodes of the genus Rhabditis. Conclusion Our results challenge the view of well-conserved developmental pathways. The TGF-β signal transduction engine has expanded through gene duplication, continually adopting new functions, as animals grew in anatomical complexity, colonized new environments, and developed an active immune system.

  5. The dynamic basis of energy transduction in enzymes.

    Science.gov (United States)

    Somogyi, B; Welch, G R; Damjanovich, S

    1984-09-06

    The most important idea underlying our treatment herein is the unity of the enzyme molecule and the medium. Appreciation of this relationship is vital, if enzymology is to graduate from its present reductionistic status to a more holistic posture. Enzymes are biological entities firstly, and isolated objects of physicochemical analysis secondly. Perhaps the most crucial 'biological lesson', particularly apropos of enzymes in intermediary metabolism, concerns the 'cytosociology' of enzyme action in vivo [94,128]. The natural habitat of many enzymes in the living cell is far different from that in bulk aqueous solution in vitro. In order to obtain a real grasp of the nature of enzyme function, one must ultimately couch enzymology in concepts emerging from contemporary cell biology [95]. Notwithstanding, analysis precedes synthesis; and one must needs begin with the individual enzyme molecule. The trenchant efforts of the physical chemist and the organic chemist have produced a wealth of information on the nature of the binding and catalytic events at the enzyme active site. While it is not yet possible to explain precisely the complete sequence of events in the catalytic process, nevertheless, the basic mechanisms by which enzymes effect catalysis (i.e., reduce activation energy) now seem apparent [81,129]. The new frontier is to be found, in exploring the dynamic role of the protein matrix [17]. Not only does the protein provide the 3-D scaffolding for active-site processes, but, more importantly, it serves as the local solvent for the bound chemical subsystem. Thus, the dynamical aspects of enzyme catalysis (for thermally based systems) must arise from the fluctuational properties of the protein molecule. This notion is the common denominator in all of the models in subsection IIC. It is the anisotropic nature of this fluctuational behavior, which would characterize the energy-transduction phenomenon leading to localized catalytic events at the active-site. In

  6. Quercetin, ascorbic acid, caffeine and ellagic acid are more efficient than rosiglitazone, metformin and glimepiride in interfering with pathways leading to the development of neurological complications associated with diabetes: A comparative in-vitro study

    Directory of Open Access Journals (Sweden)

    Vineet Mehta

    2017-06-01

    Full Text Available Neuropathy is the least understood and most devastating complication associated with diabetes. Diabetic neuropathy develops in patients despite of regular therapy, indicating that marketed drugs has minimal effect on pathways leading to the development and progression of these complications. Present study was aimed to evaluate natural compounds for their ability to interfere with pathways leading to the development of diabetes mediated neurological complications and compare their efficacy with marketed anti-diabetic drugs. Anti-diabetic potential of ascorbic acid, gallic acid, quercetin, ellagic acid, cinnamic acid, caffeine and piperine was predicted by evaluating in-silico interaction energy (kcal/mol of these compounds with insulin receptor, peroxisome proliferator-activated receptor gamma-γ and dipeptidyl peptidase-4 proteins. Ascorbic acid, gallic acid, quercetin and ellagic acid showed excellent in-vitro antioxidant activity in DPPH radical scavenging and inhibition of lipid peroxidation assay, which was 1.5–3 folds better than the marketed drugs. Quercetin, gallic acid, cinnamic acid, piperine and caffeine efficiently prevented H2O2 induced genotoxicity, which commercial drugs failed to prevent. Further, quercetin, ellagic acid, caffeine and ascorbic acid were 3–4.7 folds better than marketed drugs in inhibiting α-amylase activity. Herbal molecules and rosiglitazone showed comparable results for glucose uptake, which may be attributed to enhanced GLUT4 translocation into primary neuronal culture under hyperglycemic conditions. In conclusion, currently available marketed anti-diabetic drugs have minimal effect on the pathways leading to diabetic neuropathy and supplementing diabetic therapeutics with quercetin, ascorbic acid, caffeine and ellagic acid may be better suited to counter diabetic neuropathy through inhibiting oxidative stress, genotoxicity and improving neuronal glucose utilization.

  7. Perinatal Western Diet Consumption Leads to Profound Plasticity and GABAergic Phenotype Changes within Hypothalamus and Reward Pathway from Birth to Sexual Maturity in Rat

    Directory of Open Access Journals (Sweden)

    Julie Paradis

    2017-08-01

    Full Text Available Perinatal maternal consumption of energy dense food increases the risk of obesity in children. This is associated with an overconsumption of palatable food that is consumed for its hedonic property. The underlying mechanism that links perinatal maternal diet and offspring preference for fat is still poorly understood. In this study, we aim at studying the influence of maternal high-fat/high-sugar diet feeding [western diet (WD] during gestation and lactation on the reward pathways controlling feeding in the rat offspring from birth to sexual maturity. We performed a longitudinal follow-up of WD and Control offspring at three critical time periods (childhood, adolescence, and adulthood and focus on investigating the influence of perinatal exposure to palatable diet on (i fat preference, (ii gene expression profile, and (iii neuroanatomical/architectural changes of the mesolimbic dopaminergic networks. We showed that WD feeding restricted to the perinatal period has a clear long-lasting influence on the organization of homeostatic and hedonic brain circuits but not on fat preference. We demonstrated a period specific evolution of the preference for fat that we correlated with specific brain molecular signatures. In offspring from WD fed dams, we observed during childhood the existence of fat preference associated with a higher expression of key gene involved in the dopamine (DA systems; at adolescence, a high-fat preference for both groups, progressively reduced during the 3 days test for the WD group and associated with a reduced expression of key gene involved in the DA systems for the WD group that could suggest a compensatory mechanism to protect them from further high-fat exposure; and finally at adulthood, a preference for fat that was identical to control rats but associated with profound modification in key genes involved in the γ-aminobutyric acid network, serotonin receptors, and polysialic acid–NCAM-dependent remodeling of the

  8. Two Sets of Piwi Proteins Are Involved in Distinct sRNA Pathways Leading to Elimination of Germline-Specific DNA

    Directory of Open Access Journals (Sweden)

    Dominique I. Furrer

    2017-07-01

    Full Text Available Piwi proteins and piRNAs protect eukaryotic germlines against the spread of transposons. During development in the ciliate Paramecium, two Piwi-dependent sRNA classes are involved in the elimination of transposons and transposon-derived DNA: scan RNAs (scnRNAs, associated with Ptiwi01 and Ptiwi09, and iesRNAs, whose binding partners we now identify as Ptiwi10 and Ptiwi11. scnRNAs derive from the maternal genome and initiate DNA elimination during development, whereas iesRNAs continue DNA targeting until the removal process is complete. Here, we show that scnRNAs and iesRNAs are processed by distinct Dicer-like proteins and bind Piwi proteins in a mutually exclusive manner, suggesting separate biogenesis pathways. We also demonstrate that the PTIWI10 gene is transcribed from the developing nucleus and that its transcription depends on prior DNA excision, suggesting a mechanism of gene expression control triggered by the removal of short DNA segments interrupting the gene.

  9. Protective Effects of Green Tea Polyphenol Against Renal Injury Through ROS-Mediated JNK-MAPK Pathway in Lead Exposed Rats.

    Science.gov (United States)

    Wang, Haidong; Li, Deyuan; Hu, Zhongze; Zhao, Siming; Zheng, Zhejun; Li, Wei

    2016-06-30

    To investigate the potential therapeutic effects of polyphenols in treating Pb induced renal dysfunction and intoxication and to explore the detailed underlying mechanisms. Wistar rats were divided into four groups: control groups (CT), Pb exposure groups (Pb), Pb plus Polyphenols groups (Pb+PP) and Polyphenols groups (PP). Animals were kept for 60 days and sacrificed for tests of urea, serum blood urea nitrogen (BUN) and creatinine. Histological evaluations were then performed. In vitro studies were performed using primary kidney mesangial cells to reveal detailed mechanisms. Cell counting kit-8 (CCK-8) was used to evaluate cell viability. Pb induced cell apoptosis was measured by flow cytometry. Reactive oxygen species (ROS) generation and scavenging were tested by DCFH-DA. Expression level of tumor necrosis factor-α (TNF-α), interleukin-1-β (IL-1-β) and IL-6 were assayed by ELISA. Western blot and qPCR were used to measure the expression of ERK1/2, JNK1/2 and p38. Polyphenols have obvious protective effects on Pb induced renal dysfunction and intoxication both in vivo and in vitro. Polyphenols reduced Pb concentration and accumulation in kidney. Polyphenols also protected kidney mesangial cells from Pb induced apoptosis. Polyphenols scavenged Pb induced ROS generation and suppressed ROS-mediated ERK/JNK/p38 pathway. Downstream pro-inflammatory cytokines were inhibited in consistency. Polyphenol is protective in Pb induced renal intoxication and inflammatory responses. The underlying mechanisms lie on the antioxidant activity and ROS scavenging activity of polyphenols.

  10. Specific cellular signal-transduction responses to in vivo combination therapy with ATRA, valproic acid and theophylline in acute myeloid leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Skavland, J; Jørgensen, K M [Hematology Section, Institute of Medicine, University of Bergen, Bergen (Norway); Hadziavdic, K [Department of Informatics, University of Bergen, Bergen (Norway); Hovland, R [Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen (Norway); Jonassen, I [Department of Informatics, University of Bergen, Bergen (Norway); Computational Biology Unit, Bergen Centre for Computational Science, University of Bergen, Bergen (Norway); Bruserud, Ø; Gjertsen, B T, E-mail: bjorn.gjertsen@med.uib.no [Hematology Section, Institute of Medicine, University of Bergen, Bergen (Norway); Hematology Section, Department of Medicine, Haukeland University Hospital, Bergen (Norway)

    2011-02-01

    Acute myeloid leukemia (AML) frequently comprises mutations in genes that cause perturbation in intracellular signaling pathways, thereby altering normal responses to growth factors and cytokines. Such oncogenic cellular signal transduction may be therapeutic if targeted directly or through epigenetic regulation. We treated 24 selected elderly AML patients with all-trans retinoic acid for 2 days before adding theophylline and the histone deacetylase inhibitor valproic acid (ClinicalTrials.gov NCT00175812; EudraCT no. 2004-001663-22), and sampled 11 patients for peripheral blood at day 0, 2 and 7 for single-cell analysis of basal level and signal-transduction responses to relevant myeloid growth factors (granulocyte-colony-stimulating factor, granulocyte/macrophage-colony-stimulating factor, interleukin-3, Flt3L, stem cell factor, erythropoietin, CXCL-12) on 10 signaling molecules (CREB, STAT1/3/5, p38, Erk1/2, Akt, c-Cbl, ZAP70/Syk and rpS6). Pretreatment analysis by unsupervised clustering and principal component analysis divided the patients into three distinguishable signaling clusters (non-potentiated, potentiated basal and potentiated signaling). Signal-transduction pathways were modulated during therapy and patients moved between the clusters. Patients with multiple leukemic clones demonstrated distinct stimulation responses and therapy-induced modulation. Individual signaling profiles together with clinical and hematological information may be used to early identify AML patients in whom epigenetic and signal-transduction targeted therapy is beneficial.

  11. Fisetin Ameliorated Photodamage by Suppressing the Mitogen-Activated Protein Kinase/Matrix Metalloproteinase Pathway and Nuclear Factor-κB Pathways.

    Science.gov (United States)

    Chiang, Hsiu-Mei; Chan, Shih-Yun; Chu, Yin; Wen, Kuo-Ching

    2015-05-13

    Ultraviolet (UV) irradiation is one of the most important extrinsic factors contributing to skin photodamage. After UV irradiation, a series of signal transductions in the skin will be activated, leading to inflammatory response and photoaged skin. In this study, fisetin, a flavonol that exists in fruits and vegetables, was investigated for its photoprotective effects. The results revealed that 5-25 μM fisetin inhibits cyclooxygenase-2 (COX-2) and matrix metalloproteinase (MMP)-1, MMP-3, MMP-9 expression induced by ultraviolet B (UVB) irradiation in human skin fibroblasts. In addition, fisetin suppressed UVB-induced collagen degradation. With regard to its effect on upper-stream signal transduction, we found that fisetin reduced the expression of ultraviolet (UV)-induced ERK, JNK, and p38 phosphorylation in the mitogen-activated protein kinase (MAP kinase) pathway. Furthermore, fisetin reduced inhibitor κB (IκB) degradation and increased the amount of p65, which is a major subunit of nuclear factor-κB (NF-κB), in cytoplasm. It also suppressed NF-κB translocated to the nucleus and inhibited cAMP response element-binding protein (CREB) Ser-133 phosphorylation level in the phosphoinositide 3-kinase/protein kinase B/CREB (PI3K/AKT/CREB) pathway. Finally, fisetin inhibited UV-induced intracellular reactive oxygen species (ROS), prostaglandin E2 (PGE2), and nitric oxide (NO) generation. The mentioned effects and mechanisms suggest that fisetin can be used in the development of photoprotective agents.

  12. Elevated CO2 leads to carbon sequestration by modulating C4 photosynthesis pathway enzyme (PPDK) in Suaeda monoica and S. fruticosa.

    Science.gov (United States)

    Yadav, Sonam; Mishra, Avinash; Jha, Bhavanath

    2018-01-01

    The C 4 halophytic species Suaeda monoica and S. fruticosa, possess the C 4 photosynthesis pathway without Kranz anatomy were grown at ambient (470ppm CO 2 ) and elevated (850ppm CO 2 ) atmospheric CO 2 under control containment facility to study the plant response under CO 2 stress condition. The relative growth of both Suaeda species was enhanced with atmospheric CO 2 enrichment compared to control (ambient) condition. The photosynthesis rate was found 2.5μmolCO 2 m -2 s -1 in both species under stress condition compared to about 1.9μmolCO 2 m -2 s -1 under control conditions. About 0.3molH 2 Om -2 s -1 conductance was detected under an unstressed condition which decreased significantly to ~0.07molH 2 Om -2 s -1 on the 6th day of stress treatment. Similarly, transpiration rate was also decreased significantly from 4.4-5.2mmolH 2 Om -2 s -1 to 1.7-1.9 under stress condition. In contrast, VpdL increased significantly from 1.9kPa to 2.5kPa under stress condition. A higher total chlorophyll content observed in S. monoica (56.36mgg -1 tissue) compared to S. fruticosa (33.12mgg -1 tissue) under unstressed (control) condition. A significant increase was found in the total chlorophyll content of S. fruticosa (45.47mgg -1 tissue) with stress treatment compared to control (33.12mgg -1 tissue). In contrast, the total chlorophyll decreased in S. monoica (51.58mgg -1 tissue) under similar stress condition compared to control plants (56.36mgg -1 tissue). About 6-6.8mg total sugar per gram tissue found under control condition which enhanced further (7.5 to 11mgg -1 tissue) under stress condition. Similarly, total reducing sugar (~2mgg -1 tissue) and total starch content (6.5-11mgg -1 tissue) increased under stress condition. About 6.5- and 3- fold higher expression of PPDK gene was observed for S. monoica and S. fruticosa, respectively under CO 2 stress condition. PPDK (1.2- and 1.5- fold) and antioxidant enzymes; APX (12.7- and two-fold), CAT (2.2- and 6.4- fold) and SOD (4

  13. Differential Expression of Adhesion-Related Proteins and MAPK Pathways Lead to Suitable Osteoblast Differentiation of Human Mesenchymal Stem Cells Subpopulations.

    Science.gov (United States)

    Leyva-Leyva, Margarita; López-Díaz, Annia; Barrera, Lourdes; Camacho-Morales, Alberto; Hernandez-Aguilar, Felipe; Carrillo-Casas, Erika M; Arriaga-Pizano, Lourdes; Calderón-Pérez, Jaime; García-Álvarez, Jorge; Orozco-Hoyuela, Gabriel; Piña-Barba, Cristina; Rojas-Martínez, Augusto; Romero-Díaz, Víktor; Lara-Arias, Jorge; Rivera-Bolaños, Nancy; López-Camarillo, César; Moncada-Saucedo, Nidia; Galván-De los Santos, Alejandra; Meza-Urzúa, Fátima; Villarreal-Gómez, Luis; Fuentes-Mera, Lizeth

    2015-11-01

    Cellular adhesion enables communication between cells and their environment. Adhesion can be achieved throughout focal adhesions and its components influence osteoblast differentiation of human mesenchymal stem cells (hMSCs). Because cell adhesion and osteoblast differentiation are closely related, this article aimed to analyze the expression profiles of adhesion-related proteins during osteoblastic differentiation of two hMSCs subpopulations (CD105(+) and CD105(-)) and propose a strategy for assembling bone grafts based on its adhesion ability. In vitro experiments of osteogenic differentiation in CD105(-) cells showed superior adhesion efficiency and 2-fold increase of α-actinin expression compared with CD105(+) cells at the maturation stage. Interestingly, levels of activated β1-integrin increased in CD105(-) cells during the process. Additionally, the CD105(-) subpopulation showed 3-fold increase of phosphorylated FAK(Y397) compared to CD105(+) cells. Results also indicate that ERK1/2 was activated during CD105(-) bone differentiation and participation of mitogen-activated protein kinase (MAPK)-p38 in CD105(+) differentiation through a focal adhesion kinase (FAK)-independent pathway. In vivo trial demonstrated that grafts containing CD105(-) showed osteocytes embedded in a mineralized matrix, promoted adequate graft integration, increased host vascular infiltration, and efficient intramembranous repairing. In contrast, grafts containing CD105(+) showed deficient endochondral ossification and fibrocartilaginous tissue. Based on the expression of α-actinin, FAKy,(397) and ERK1/2 activation, we define maturation stage as critical for bone graft assembling. By in vitro assays, CD105(-) subpopulation showed superior adhesion efficiency compared to CD105(+) cells. Considering in vitro and in vivo assays, this study suggests that integration of a scaffold with CD105(-) subpopulation at the maturation stage represents an attractive strategy for clinical use in

  14. Molecular methods for the study of signal transduction in plants

    KAUST Repository

    Irving, Helen R.

    2013-09-03

    Novel and improved analytical methods have led to a rapid increase in our understanding of the molecular mechanism underlying plant signal transduction. Progress has been made both at the level of single-component analysis and in vivo imaging as well as at the systems level where transcriptomics and particularly phosphoproteomics afford a window into complex biological responses. Here we review the role of the cyclic nucleotides cAMP and cGMP in plant signal transduction as well as the discovery and biochemical and biological characterization of an increasing number of complex multi-domain nucleotide cyclases that catalyze the synthesis of cAMP and cGMP from ATP and GTP, respectively. © Springer Science+Business Media New York 2013.

  15. Six-year longitudinal study of pathways leading to explosive anger involving the traumas of recurrent conflict and the cumulative sense of injustice in Timor-Leste.

    Science.gov (United States)

    Silove, Derrick; Mohsin, Mohammed; Tay, Alvin Kuowei; Steel, Zachary; Tam, Natalino; Savio, Elisa; Da Costa, Zelia Maria; Rees, Susan

    2017-10-01

    Cumulative evidence suggests that explosive anger may be a common reaction among survivors of mass conflict. However, little is known about the course of explosive anger in the years following mass conflict, or the psychosocial factors that influence the trajectory of that reaction pattern. We examined these issues in a 6-year longitudinal study (2004-2010) conducted among adult residents of a rural and an urban village in Timor-Leste (n = 1022). We derived a brief, context-specific index of explosive anger using qualitative methods. Widely used measures of post-traumatic stress disorder (PTSD) and severe psychological distress were calibrated to the Timor context. We developed an index of the cumulative sense of injustice related to consecutive historical periods associated with conflict in Timor-Leste. We applied partial structural equation modeling (SEM) to examine pathways from baseline explosive anger, socio-demographic factors, recurrent trauma, mental health indices (PTSD, severe psychological distress) and the sense of injustice, to explosive anger. Half of the sample with explosive anger at baseline continued to report that reaction pattern after 6 years; and a third of those who did not report explosive anger at baseline developed the response by follow-up. A symmetrical pattern of younger age, female gender and the trauma count for the preceding historical period predicted explosive anger at each assessment point. The sense of injustice was related to explosive anger at follow-up. Explosive anger was associated with impairment in functioning and conflict with the intimate partner and wider family. Sampling constraints caution against generalizing our findings to other populations. Nevertheless, our data suggest that explosive anger may persist for a prolonged period of time following mass conflict and that the response pattern is initiated and maintained by recurrent trauma exposure associated with a sense of injustice. Averting recurrence of mass

  16. Tuning piezoresistive transduction in nanomechanical resonators by geometrical asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Llobet, J.; Sansa, M.; Lorenzoni, M.; Pérez-Murano, F., E-mail: francesc.perez@csic.es [Institut de Microelectrònica de Barcelona (IMB-CNM CSIC), Campus UAB, 08193 Bellaterra (Spain); Borrisé, X. [Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, 08193 Bellaterra Spain (Spain); San Paulo, A. [Instituto de Microelectrónica de Madrid (IMM-CSIC), 28760 Tres Cantos, Madrid (Spain)

    2015-08-17

    The effect of geometrical asymmetries on the piezoresistive transduction in suspended double clamped beam nanomechanical resonators is investigated. Tapered silicon nano-beams, fabricated using a fast and flexible prototyping method, are employed to determine how the asymmetry affects the transduced piezoresistive signal for different mechanical resonant modes. This effect is attributed to the modulation of the strain in pre-strained double clamped beams, and it is confirmed by means of finite element simulations.

  17. Efficiency of Energy Transduction in a Molecular Chemical Engine

    OpenAIRE

    Sasaki, Kazuo; Kanada, Ryo; Amari, Satoshi

    2006-01-01

    A simple model of the two-state ratchet type is proposed for molecular chemical engines that convert chemical free energy into mechanical work and vice versa. The engine works by catalyzing a chemical reaction and turning a rotor. Analytical expressions are obtained for the dependences of rotation and reaction rates on the concentrations of reactant and product molecules, from which the performance of the engine is analyzed. In particular, the efficiency of energy transduction is discussed in...

  18. Tumor necrosis factor-alpha activates signal transduction in hypothalamus and modulates the expression of pro-inflammatory proteins and orexigenic/anorexigenic neurotransmitters.

    Science.gov (United States)

    Amaral, Maria E; Barbuio, Raquel; Milanski, Marciane; Romanatto, Talita; Barbosa, Helena C; Nadruz, Wilson; Bertolo, Manoel B; Boschero, Antonio C; Saad, Mario J A; Franchini, Kleber G; Velloso, Licio A

    2006-07-01

    Tumor necrosis factor-alpha (TNF-alpha) is known to participate in the wastage syndrome that accompanies cancer and severe infectious diseases. More recently, a role for TNF-alpha in the pathogenesis of type 2 diabetes mellitus and obesity has been shown. Much of the regulatory action exerted by TNF-alpha upon the control of energy stores depends on its action on the hypothalamus. In this study, we show that TNF-alpha activates canonical pro-inflammatory signal transduction pathways in the hypothalamus of rats. These signaling events lead to the transcriptional activation of an early responsive gene and to the induction of expression of cytokines and a cytokine responsive protein such as interleukin-1beta, interleukin-6, interleukin-10 and suppressor of cytokine signalling-3, respectively. In addition, TNF-alpha induces the expression of neurotransmitters involved in the control of feeding and thermogenesis. Thus, TNF-alpha may act directly in the hypothalamus inducing a pro-inflammatory response and the modulation of expression of neurotransmitters involved in energy homeostasis.

  19. State–time spectrum of signal transduction logic models

    International Nuclear Information System (INIS)

    MacNamara, Aidan; Terfve, Camille; Henriques, David; Bernabé, Beatriz Peñalver; Saez-Rodriguez, Julio

    2012-01-01

    Despite the current wealth of high-throughput data, our understanding of signal transduction is still incomplete. Mathematical modeling can be a tool to gain an insight into such processes. Detailed biochemical modeling provides deep understanding, but does not scale well above relatively a few proteins. In contrast, logic modeling can be used where the biochemical knowledge of the system is sparse and, because it is parameter free (or, at most, uses relatively a few parameters), it scales well to large networks that can be derived by manual curation or retrieved from public databases. Here, we present an overview of logic modeling formalisms in the context of training logic models to data, and specifically the different approaches to modeling qualitative to quantitative data (state) and dynamics (time) of signal transduction. We use a toy model of signal transduction to illustrate how different logic formalisms (Boolean, fuzzy logic and differential equations) treat state and time. Different formalisms allow for different features of the data to be captured, at the cost of extra requirements in terms of computational power and data quality and quantity. Through this demonstration, the assumptions behind each formalism are discussed, as well as their advantages and disadvantages and possible future developments. (paper)

  20. The role of aryl hydrocarbon receptor signaling pathway in cardiotoxicity of acute lead intoxication in vivo and in vitro rat model.

    Science.gov (United States)

    Ansari, Mushtaq A; Maayah, Zaid H; Bakheet, Saleh A; El-Kadi, Ayman O; Korashy, Hesham M

    2013-04-05

    Lead (Pb(2+)) is a naturally occurring systemic toxicant heavy metal that affects several organs in the body including the kidneys, liver, and central nervous system. However, Pb(2+)-induced cardiotoxicity has never been investigated yet and the exact mechanism of Pb(2+) associated cardiotoxicity has not been studied. The current study was designed to investigate the potential effect of Pb(2+) to induce cardiotoxicity in vivo and in vitro rat model and to explore the molecular mechanisms and the role of aryl hydrocarbon receptor (AhR) and regulated gene, cytochrome P4501A1 (CYP1A1), in Pb(2+)-mediated cardiotoxicity. For these purposes, Wistar albino rats were treated with Pb(2+) (25, 50 and 100mg/kg, i.p.) for three days and the effects on physiological and histopathological parameters of cardiotoxicity were determined. At the in vitro level, rat cardiomyocyte H9c2 cell lines were incubated with increasing concentration of Pb(2+) (25, 50, and 100 μM) and the expression of hypertrophic genes, α- and β-myosin heavy chain (α-MHC and β-MHC), brain Natriuretic Peptide (BNP), and CYP1A1 were determined at the mRNA and protein levels using real-time PCR and Western blot analysis, respectively. The results showed that Pb(2+) significantly induced cardiotoxicity and heart failure as evidenced by increase cardiac enzymes, lactate dehydrogenase and creatine kinase and changes in histopathology in vivo. In addition, Pb(2+) treatment induced β-MHC and BNP whereas inhibited α-MHC mRNA and protein levels in vivo in a dose-dependent manner. In contrast, at the in vitro level, Pb(2+) treatment induced both β-MHC and α-MHC mRNA levels in time- and dose-dependent manner. Importantly, these changes were accompanied with a proportional increase in the expression of CYP1A1 mRNA and protein expression levels, suggesting a role for the CYP1A1 in cardiotoxicity. The direct evidence for the involvement of CYP1A1 in the induction of cardiotoxicity by Pb(2+) was evidenced by the

  1. LEADING WITH LEADING INDICATORS

    International Nuclear Information System (INIS)

    PREVETTE, S.S.

    2005-01-01

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites

  2. Rab11-FIP3 Regulation of Lck Endosomal Traffic Controls TCR Signal Transduction.

    Science.gov (United States)

    Bouchet, Jérôme; Del Río-Iñiguez, Iratxe; Vázquez-Chávez, Elena; Lasserre, Rémi; Agüera-González, Sonia; Cuche, Céline; McCaffrey, Mary W; Di Bartolo, Vincenzo; Alcover, Andrés

    2017-04-01

    The role of endosomes in receptor signal transduction is a long-standing question, which remains largely unanswered. The T cell Ag receptor and various components of its proximal signaling machinery are associated with distinct endosomal compartments, but how endosomal traffic affects T cell signaling remains ill-defined. In this article, we demonstrate in human T cells that the subcellular localization and function of the protein tyrosine kinase Lck depends on the Rab11 effector FIP3 (Rab11 family interacting protein-3). FIP3 overexpression or silencing and its ability to interact with Rab11 modify Lck subcellular localization and its delivery to the immunological synapse. Importantly, FIP3-dependent Lck localization controls early TCR signaling events, such as tyrosine phosphorylation of TCRζ, ZAP70, and LAT and intracellular calcium concentration, as well as IL-2 gene expression. Interestingly, FIP3 controls both steady-state and poststimulation phosphotyrosine and calcium levels. Finally, our findings indicate that FIP3 modulates TCR-CD3 cell surface expression via the regulation of steady-state Lck-mediated TCRζ phosphorylation, which in turn controls TCRζ protein levels. This may influence long-term T cell activation in response to TCR-CD3 stimulation. Therefore, our data underscore the importance of finely regulated endosomal traffic in TCR signal transduction and T cell activation leading to IL-2 production. Copyright © 2017 by The American Association of Immunologists, Inc.

  3. Targeted genome editing by lentiviral protein transduction of zinc-finger and TAL-effector nucleases.

    Science.gov (United States)

    Cai, Yujia; Bak, Rasmus O; Mikkelsen, Jacob Giehm

    2014-04-24

    Future therapeutic use of engineered site-directed nucleases, like zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), relies on safe and effective means of delivering nucleases to cells. In this study, we adapt lentiviral vectors as carriers of designer nuclease proteins, providing efficient targeted gene disruption in vector-treated cell lines and primary cells. By co-packaging pairs of ZFN proteins with donor RNA in 'all-in-one' lentiviral particles, we co-deliver ZFN proteins and the donor template for homology-directed repair leading to targeted DNA insertion and gene correction. Comparative studies of ZFN activity in a predetermined target locus and a known nearby off-target locus demonstrate reduced off-target activity after ZFN protein transduction relative to conventional delivery approaches. Additionally, TALEN proteins are added to the repertoire of custom-designed nucleases that can be delivered by protein transduction. Altogether, our findings generate a new platform for genome engineering based on efficient and potentially safer delivery of programmable nucleases.DOI: http://dx.doi.org/10.7554/eLife.01911.001. Copyright © 2014, Cai et al.

  4. Exploring Transduction Mechanisms of Protein Transduction Domains (PTDs in Living Cells Utilizing Single-Quantum Dot Tracking (SQT Technology

    Directory of Open Access Journals (Sweden)

    Yasuhiro Suzuki

    2012-01-01

    Full Text Available Specific protein domains known as protein transduction domains (PTDs can permeate cell membranes and deliver proteins or bioactive materials into living cells. Various approaches have been applied for improving their transduction efficacy. It is, therefore, crucial to clarify the entry mechanisms and to identify the rate-limiting steps. Because of technical limitations for imaging PTD behavior on cells with conventional fluorescent-dyes, how PTDs enter the cells has been a topic of much debate. Utilizing quantum dots (QDs, we recently tracked the behavior of PTD that was derived from HIV-1 Tat (TatP in living cells at the single-molecule level with 7-nm special precision. In this review article, we initially summarize the controversy on TatP entry mechanisms; thereafter, we will focus on our recent findings on single-TatP-QD tracking (SQT, to identify the major sequential steps of intracellular delivery in living cells and to discuss how SQT can easily provide direct information on TatP entry mechanisms. As a primer for SQT study, we also discuss the latest findings on single particle tracking of various molecules on the plasma membrane. Finally, we discuss the problems of QDs and the challenges for the future in utilizing currently available QD probes for SQT. In conclusion, direct identification of the rate-limiting steps of PTD entry with SQT should dramatically improve the methods for enhancing transduction efficiency.

  5. Cryptochromes and Hormone Signal Transduction under Near-Zero Magnetic Fields: New Clues to Magnetic Field Effects in a Rice Planthopper.

    Directory of Open Access Journals (Sweden)

    Gui-Jun Wan

    Full Text Available Although there are considerable reports of magnetic field effects (MFE on organisms, very little is known so far about the MFE-related signal transduction pathways. Here we establish a manipulative near-zero magnetic field (NZMF to investigate the potential signal transduction pathways involved in MFE. We show that exposure of migratory white-backed planthopper, Sogatella furcifera, to the NZMF results in delayed egg and nymphal development, increased frequency of brachypterous females, and reduced longevity of macropterous female adults. To understand the changes in gene expression underlying these phenotypes, we examined the temporal patterns of gene expression of (i CRY1 and CRY2 as putative magnetosensors, (ii JHAMT, FAMeT and JHEH in the juvenile hormone pathway, (iii CYP307A1 in the ecdysone pathway, and (iv reproduction-related Vitellogenin (Vg. The significantly altered gene expression of CRY1 and CRY2 under the NZMF suggest their developmental stage-specific patterns and potential upstream location in magnetic response. Gene expression patterns of JHAMT, JHEH and CYP307A1 were consistent with the NZMF-triggered delay in nymphal development, higher proportion of brachypterous female adults, and the shortened longevity of macropterous female adults, which show feasible links between hormone signal transduction and phenotypic MFE. By conducting manipulative NZMF experiments, our study suggests an important role of the geomagnetic field (GMF in modulating development and physiology of insects, provides new insights into the complexity of MFE-magnetosensitivity interactions, and represents an initial but crucial step forward in understanding the molecular basis of cryptochromes and hormone signal transduction involved in MFE.

  6. Quantitative evaluation of the biosynthetic pathways leading to δ-aminolevulinic acid from the Shemin precursor glycine via the C5 pathway in Arthrobacter hyalinus by analysis of 13C-labeled coproporphyrinogen III biosynthesized from [2-13C]glycine, [1-13C]acetate, and [2-13C]acetate using 13C NMR spectroscopy

    International Nuclear Information System (INIS)

    Katsumi Iida

    2013-01-01

    The biosynthetic pathways leading to δ-aminolevulinic acid (ALA) from the Shemin precursor glycine via the C5 pathway in Arthrobacter hyalinus were quantitatively evaluated by means of feeding experiments with [2- 13 C]glycine, sodium [1- 13 C]acetate, and sodium [2- 13 C]acetate, followed by analysis of the labeling patterns of coproporphyrinogen III (Copro'gen III) (biosynthesized from ALA) using 13 C NMR spectroscopy. Two biosynthetic pathways leading to ALA from glycine via the C5 pathway were identified: i.e., transformation of glycine to l-serine catalyzed by glycine hydroxymethyltransferase, and glycine synthase-catalyzed catabolism of glycine to N 5 , N 10 -methylene-tetrahydrofolic acid (THF), which reacts with another molecule of glycine to afford l-serine. l-Serine is transformed to acetyl-CoA via pyruvic acid. Acetyl-CoA enters the tricarboxylic acid cycle, affording 2-oxoglutaric acid, which in turn is transformed to l-glutamic acid. The l-glutamic acid enters the C5 pathway, affording ALA in A. hyalinus. A 13 C NMR spectroscopic comparison of the labeling patterns of Copro'gen III obtained after feeding of [2- 13 C]glycine, sodium [1- 13 C]acetate, and sodium [2- 13 C]acetate showed that [2- 13 C]glycine transformation and [2- 13 C]glycine catabolism in A. hyalinus proceed in the ratio of 52 and 48 %. The reaction of [2- 13 C]glycine and N 5 , N 10 -methylene-THF, that of glycine and N 5 , N 10 -[methylene- 13 C]methylene-THF generated from the [2- 13 C]glycine catabolism, and that of [2- 13 C]glycine and N 5 , N 10 -[methylene- 13 C]methylene-THF transformed the fed [2- 13 C]glycine to [1- 13 C]acetyl-CoA, [2- 13 C]acetyl-CoA, and [1,2- 13 C 2 ]acetyl-CoA in the ratios of 42, 37, and 21 %, respectively. These labeled acetyl-CoAs were then incorporated into ALA. Our results provide a quantitative picture of the pathways of biosynthetic transformation to ALA from glycine in A. hyalinus. (author)

  7. Cannabinoid inhibition of adenylate cyclase-mediated signal transduction and interleukin 2 (IL-2) expression in the murine T-cell line, EL4.IL-2.

    Science.gov (United States)

    Condie, R; Herring, A; Koh, W S; Lee, M; Kaminski, N E

    1996-05-31

    Cannabinoid receptors negatively regulate adenylate cyclase through a pertussis toxin-sensitive GTP-binding protein. In the present studies, signaling via the adenylate cyclase/cAMP pathway was investigated in the murine thymoma-derived T-cell line, EL4.IL-2. Northern analysis of EL4.IL-2 cells identified the presence of 4-kilobase CB2 but not CB1 receptor-subtype mRNA transcripts. Southern analysis of genomic DNA digests for the CB2 receptor demonstrated identical banding patterns for EL4.IL-2 cells and mouse-derived DNA, both of which were dissimilar to DNA isolated from rat. Treatment of EL4.IL-2 cells with either cannabinol or Delta9-THC disrupted the adenylate cyclase signaling cascade by inhibiting forskolin-stimulated cAMP accumulation which consequently led to a decrease in protein kinase A activity and the binding of transcription factors to a CRE consensus sequence. Likewise, an inhibition of phorbol 12-myristate 13-acetate (PMA)/ionomycin-induced interleukin 2 (IL-2) protein secretion, which correlated to decreased IL-2 gene transcription, was induced by both cannabinol and Delta9-THC. Further, cannabinoid treatment also decreased PMA/ionomycin-induced nuclear factor binding to the AP-1 proximal site of the IL-2 promoter. Conversely, forskolin enhanced PMA/ionomycin-induced AP-1 binding. These findings suggest that inhibition of signal transduction via the adenylate cyclase/cAMP pathway induces T-cell dysfunction which leads to a diminution in IL-2 gene transcription.

  8. Avian Reovirus Protein p17 Functions as a Nucleoporin Tpr Suppressor Leading to Activation of p53, p21 and PTEN and Inactivation of PI3K/AKT/mTOR and ERK Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Wei-Ru Huang

    Full Text Available Avian reovirus (ARV protein p17 has been shown to regulate cell cycle and autophagy by activation of p53/PTEN pathway; nevertheless, it is still unclear how p53 and PTEN are activated by p17. Here, we report for the first time that p17 functions as a nucleoporin Tpr suppressor that leads to p53 nuclear accumulation and consequently activates p53, p21, and PTEN. The nuclear localization signal (119IAAKRGRQLD128 of p17 has been identified for Tpr binding. This study has shown that Tpr suppression occurs by p17 interacting with Tpr and by reducing the transcription level of Tpr, which together inhibit Tpr function. In addition to upregulation of PTEN by activation of p53 pathway, this study also suggests that ARV protein p17 acts as a positive regulator of PTEN. ARV p17 stabilizes PTEN by stimulating phosphorylation of cytoplasmic PTEN and by elevating Rak-PTEN association to prevent it from E3 ligase NEDD4-1 targeting. To activate PTEN, p17 is able to promote β-arrestin-mediated PTEN translocation from the cytoplasm to the plasma membrane via a Rock-1-dependent manner. The accumulation of p53 in the nucleus induces the PTEN- and p21-mediated downregulation of cyclin D1 and CDK4. Furthermore, Tpr and CDK4 knockdown increased virus production in contrast to depletion of p53, PTEN, and LC3 reducing virus yield. Taken together, our data suggest that p17-mediated Tpr suppression positively regulates p53, PTEN, and p21 and negatively regulates PI3K/AKT/mTOR and ERK signaling pathways, both of which are beneficial for virus replication.

  9. Regulation of Early Steps of GPVI Signal Transduction by Phosphatases: A Systems Biology Approach.

    Directory of Open Access Journals (Sweden)

    Joanne L Dunster

    2015-11-01

    Full Text Available We present a data-driven mathematical model of a key initiating step in platelet activation, a central process in the prevention of bleeding following Injury. In vascular disease, this process is activated inappropriately and causes thrombosis, heart attacks and stroke. The collagen receptor GPVI is the primary trigger for platelet activation at sites of injury. Understanding the complex molecular mechanisms initiated by this receptor is important for development of more effective antithrombotic medicines. In this work we developed a series of nonlinear ordinary differential equation models that are direct representations of biological hypotheses surrounding the initial steps in GPVI-stimulated signal transduction. At each stage model simulations were compared to our own quantitative, high-temporal experimental data that guides further experimental design, data collection and model refinement. Much is known about the linear forward reactions within platelet signalling pathways but knowledge of the roles of putative reverse reactions are poorly understood. An initial model, that includes a simple constitutively active phosphatase, was unable to explain experimental data. Model revisions, incorporating a complex pathway of interactions (and specifically the phosphatase TULA-2, provided a good description of the experimental data both based on observations of phosphorylation in samples from one donor and in those of a wider population. Our model was used to investigate the levels of proteins involved in regulating the pathway and the effect of low GPVI levels that have been associated with disease. Results indicate a clear separation in healthy and GPVI deficient states in respect of the signalling cascade dynamics associated with Syk tyrosine phosphorylation and activation. Our approach reveals the central importance of this negative feedback pathway that results in the temporal regulation of a specific class of protein tyrosine phosphatases in

  10. U12, a UDCA derivative, acts as an anti-hepatoma drug lead and inhibits the mTOR/S6K1 and cyclin/CDK complex pathways.

    Directory of Open Access Journals (Sweden)

    Yang Xu

    Full Text Available U12, one of 20 derivatives synthesized from ursodeoxycholic acid (UDCA, has been found to have anticancer effects in liver cancer cell lines (SMMC-7721 and HepG2 and to protect normal liver cells from deoxycholic acid (DCA damage (QSG-7701. Its anticancer mechanism was investigated using computer-aided network pharmacology and comparative proteomics. Results showed that its anti-malignancy activities were activated by mTOR/S6K1, cyclinD1/CDK2/4 and caspase-dependent apoptotic signaling pathways in hepatocellular carcinoma cells (HCC. The action of U12 may be similar to that of rapamycin. Animal testing confirmed that U12 exerted better anti-tumor activity than UDCA and had less severe side effects than fluorouracil (5-Fu. These observations indicate that U12 differs from UDCA and other derivatives and may be a suitable lead for the development of compounds useful in the treatment of HCC.

  11. FY1995 transduction method and CAD database systems for integrated design; 1995 nendo transduction ho to CAD database togo sekkei shien system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Transduction method developed by the research coordinator and Prof. Muroga is one of the most popular methods to design large-scale integrated circuits, and thus used by major design tool companies in USA and Japan. The major objectives of the research is to improve capability and utilize its reusable property by combining with CAD databases. Major results of the project is as follows, (1) Improvement of Transduction method : Efficiency, capability and the maximum circuit size are improved. Error compensation method is also improved. (2) Applications to new logic elements : Transduction method is modified to cope with wired logic and FPGAs. (3) CAD databases : One of the major advantages of Transduction methods is 'reusability' of already designed circuits. It is suitable to combine with CAD databases. We design CAD databases suitable for cooperative design using Transduction method. (4) Program development : Programs for Windows95 and developed for distribution. (NEDO)

  12. FY1995 transduction method and CAD database systems for integrated design; 1995 nendo transduction ho to CAD database togo sekkei shien system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Transduction method developed by the research coordinator and Prof. Muroga is one of the most popular methods to design large-scale integrated circuits, and thus used by major design tool companies in USA and Japan. The major objectives of the research is to improve capability and utilize its reusable property by combining with CAD databases. Major results of the project is as follows, (1) Improvement of Transduction method : Efficiency, capability and the maximum circuit size are improved. Error compensation method is also improved. (2) Applications to new logic elements : Transduction method is modified to cope with wired logic and FPGAs. (3) CAD databases : One of the major advantages of Transduction methods is 'reusability' of already designed circuits. It is suitable to combine with CAD databases. We design CAD databases suitable for cooperative design using Transduction method. (4) Program development : Programs for Windows95 and developed for distribution. (NEDO)

  13. Salinity stress induces the production of 2-(2-phenylethyl)chromones and regulates novel classes of responsive genes involved in signal transduction in Aquilaria sinensis calli.

    Science.gov (United States)

    Wang, Xiaohui; Gao, Bowen; Liu, Xiao; Dong, Xianjuan; Zhang, Zhongxiu; Fan, Huiyan; Zhang, Le; Wang, Juan; Shi, Shepo; Tu, Pengfei

    2016-05-26

    Agarwood, is a resinous portion derived from Aquilaria sinensis, has been widely used in traditional medicine and incense. 2-(2-phenylethyl)chromones are principal components responsible for the quality of agarwood. However, the molecular basis of 2-(2-phenylethyl)chromones biosynthesis and regulation remains almost unknown. Our research indicated that salt stress induced production of several of 2-(2-phenylethyl)chromones in A. sinensis calli. Transcriptome analysis of A. sinensis calli treated with NaCl is required to further facilitate the multiple signal pathways in response to salt stress and to understand the mechanism of 2-(2-phenylethyl)chromones biosynthesis. Forty one 2-(2-phenylethyl)chromones were identified from NaCl-treated A. sinensis calli. 93 041 unigenes with an average length of 1562 nt were generated from the control and salt-treated calli by Illmunina sequencing after assembly, and the unigenes were annotated by comparing with the public databases including NR, Swiss-Prot, KEGG, COG, and GO database. In total, 18 069 differentially expressed transcripts were identified by the transcriptome comparisons on the control calli and calli induced by 24 h or 120 h salinity stress. Numerous genes involved in signal transduction pathways including the genes responsible for hormone signal transduction, receptor-like kinases, MAPK cascades, Ca(2+) signal transduction, and transcription factors showed clear differences between the control calli and NaCl-treated calli. Furthermore, our data suggested that the genes annotated as chalcone synthases and O-methyltransferases may contribute to the biosynthesis of 2-(2-phenylethyl)chromones. Salinity stress could induce the production of 41 2-(2-phenylethyl)chromones in A. sinensis calli. We conducted the first deep-sequencing transcriptome profiling of A. sinensis under salt stress and observed a large number of differentially expressed genes in response to salinity stress. Moreover, salt stress induced

  14. Signal transduction by VEGF receptors in regulation of angiogenesis and lymphangiogenesis

    International Nuclear Information System (INIS)

    Shibuya, Masabumi; Claesson-Welsh, Lena

    2006-01-01

    The VEGF/VPF (vascular endothelial growth factor/vascular permeability factor) ligands and receptors are crucial regulators of vasculogenesis, angiogenesis, lymphangiogenesis and vascular permeability in vertebrates. VEGF-A, the prototype VEGF ligand, binds and activates two tyrosine kinase receptors: VEGFR1 (Flt-1) and VEGFR2 (KDR/Flk-1). VEGFR1, which occurs in transmembrane and soluble forms, negatively regulates vasculogenesis and angiogenesis during early embryogenesis, but it also acts as a positive regulator of angiogenesis and inflammatory responses, playing a role in several human diseases such as rheumatoid arthritis and cancer. The soluble VEGFR1 is overexpressed in placenta in preeclampsia patients. VEGFR2 has critical functions in physiological and pathological angiogenesis through distinct signal transduction pathways regulating proliferation and migration of endothelial cells. VEGFR3, a receptor for the lymphatic growth factors VEGF-C and VEGF-D, but not for VEGF-A, regulates vascular and lymphatic endothelial cell function during embryogenesis. Loss-of-function variants of VEGFR3 have been identified in lymphedema. Formation of tumor lymphatics may be stimulated by tumor-produced VEGF-C, allowing increased spread of tumor metastases through the lymphatics. Mapping the signaling system of these important receptors may provide the knowledge necessary to suppress specific signaling pathways in major human diseases

  15. Reduced modeling of signal transduction – a modular approach

    Directory of Open Access Journals (Sweden)

    Ederer Michael

    2007-09-01

    Full Text Available Abstract Background Combinatorial complexity is a challenging problem in detailed and mechanistic mathematical modeling of signal transduction. This subject has been discussed intensively and a lot of progress has been made within the last few years. A software tool (BioNetGen was developed which allows an automatic rule-based set-up of mechanistic model equations. In many cases these models can be reduced by an exact domain-oriented lumping technique. However, the resulting models can still consist of a very large number of differential equations. Results We introduce a new reduction technique, which allows building modularized and highly reduced models. Compared to existing approaches further reduction of signal transduction networks is possible. The method also provides a new modularization criterion, which allows to dissect the model into smaller modules that are called layers and can be modeled independently. Hallmarks of the approach are conservation relations within each layer and connection of layers by signal flows instead of mass flows. The reduced model can be formulated directly without previous generation of detailed model equations. It can be understood and interpreted intuitively, as model variables are macroscopic quantities that are converted by rates following simple kinetics. The proposed technique is applicable without using complex mathematical tools and even without detailed knowledge of the mathematical background. However, we provide a detailed mathematical analysis to show performance and limitations of the method. For physiologically relevant parameter domains the transient as well as the stationary errors caused by the reduction are negligible. Conclusion The new layer based reduced modeling method allows building modularized and strongly reduced models of signal transduction networks. Reduced model equations can be directly formulated and are intuitively interpretable. Additionally, the method provides very good

  16. Polybrene inhibits human mesenchymal stem cell proliferation during lentiviral transduction.

    Directory of Open Access Journals (Sweden)

    Paul Lin

    Full Text Available Human mesenchymal stem cells (hMSCs can be engineered to express specific genes, either for their use in cell-based therapies or to track them in vivo over long periods of time. To obtain long-term expression of these genes, a lentivirus- or retrovirus-mediated cell transduction is often used. However, given that the efficiency with these viruses is typically low in primary cells, additives such as polybrene are always used for efficient viral transduction. Unfortunately, as presented here, exposure to polybrene alone at commonly used concentratons (1-8 µg/mL negatively impacts hMSC proliferation in a dose-dependent manner as measured by CyQUANT, EdU incorporation, and cell cycle analysis. This inhibition of proliferation was observable in culture even 3 weeks after exposure. Culturing the cells in the presence of FGF-2, a potent mitogen, did not abrogate this negative effect of polybrene. In fact, the normally sharp increase in hMSC proliferation that occurs during the first days of exposure to FGF-2 was absent at 4 µg/mL or higher concentrations of polybrene. Similarly, the effect of stimulating cell proliferation under simulated hypoxic conditions was also decreased when cells were exposed to polybrene, though overall proliferation rates were higher. The negative influence of polybrene was, however, reduced when the cells were exposed to polybrene for a shorter period of time (6 hr vs 24 hr. Thus, careful evaluation should be done when using polybrene to aid in lentiviral transduction of human MSCs or other primary cells, especially when cell number is critical.

  17. Electro-Optomechanical Transduction & Quantum Hard-Sphere Model for Dissipative Rydberg-EIT Media

    DEFF Research Database (Denmark)

    Zeuthen, Emil

    by two key parameters, the signal transfer efficiency and added noise temperature. In terms of these, we may evaluate its performance in various tasks ranging from classical signal detection to quantum state conversion between, e.g., superconducting circuitry and traveling optical signals. Having...... transduction functionality into the well-established framework of electrical engineering, thereby facilitating its implementation in potential applications such as nuclear magnetic resonance imaging and radio astronomy. We consider such optomechanical sensing of weak electrical signals and discuss how...... in a cold, optically dense cloud with light fields propagating under the condition of electromagnetically induced transparency (EIT). This can lead to strong and non-linear dissipative dynamics at the quantum level that prevent slow-light polaritons from coexisting within a blockade radius of one another...

  18. Practical considerations of image analysis and quantification of signal transduction IHC staining.

    Science.gov (United States)

    Grunkin, Michael; Raundahl, Jakob; Foged, Niels T

    2011-01-01

    The dramatic increase in computer processing power in combination with the availability of high-quality digital cameras during the last 10 years has fertilized the grounds for quantitative microscopy based on digital image analysis. With the present introduction of robust scanners for whole slide imaging in both research and routine, the benefits of automation and objectivity in the analysis of tissue sections will be even more obvious. For in situ studies of signal transduction, the combination of tissue microarrays, immunohistochemistry, digital imaging, and quantitative image analysis will be central operations. However, immunohistochemistry is a multistep procedure including a lot of technical pitfalls leading to intra- and interlaboratory variability of its outcome. The resulting variations in staining intensity and disruption of original morphology are an extra challenge for the image analysis software, which therefore preferably should be dedicated to the detection and quantification of histomorphometrical end points.

  19. Sensory Transduction in Microorganisms 2008 Gordon Research Conference (January 2008)

    Energy Technology Data Exchange (ETDEWEB)

    Ann M. Stock

    2009-04-08

    Research into the mechanisms involved in the sensing and responses of microorganisms to changes in their environments is currently very active in a large number of laboratories worldwide. An increasingly wide range of prokaryotic and eukaryotic species are being studied with regard to their sensing of diverse chemical and physical stimuli, including nutrients, toxins, intercellular signaling molecules, redox indicators, light, pressure, magnetic fields, and surface contact, leading to adaptive responses affecting motile behavior, gene expression and/or development. The ease of manipulation of microorganisms has facilitated application of a broad range of techniques that have provided comprehensive descriptions of cellular behavior and its underlying molecular mechanisms. Systems and their molecular components have been probed at levels ranging from the whole organism down to atomic resolution using behavioral analyses; electrophysiology; genetics; molecular biology; biochemical and biophysical characterization; structural biology; single molecule, fluorescence and cryo-electron microscopy; computational modeling; bioinformatics and genomic analyses. Several model systems such as bacterial chemotaxis and motility, fruiting body formation in Myxococcus xanthus, and motility and development in Dictyostelium discoideum have traditionally been a focus of this meeting. By providing a basis for assessment of similarities and differences in mechanisms, understanding of these pathways has advanced the study of many other microbial sensing systems. This conference aims to bring together researchers investigating different prokaryotic and eukaryotic microbial systems using diverse approaches to compare data, share methodologies and ideas, and seek to understand the fundamental principles underlying sensory responses. Topic areas include: (1) Receptor Sensing and Signaling; (2) Intracellular Signaling (two-component, c-di-GMP, c-AMP, etc.); (3) Intracellular Localization and

  20. Benefits of gene transduction of granulocyte macrophage colony-stimulating factor in cancer vaccine using genetically modified dendritic cells.

    Science.gov (United States)

    Ojima, Toshiyasu; Iwahashi, Makoto; Nakamura, Masaki; Matsuda, Kenji; Nakamori, Mikihito; Ueda, Kentaro; Naka, Teiji; Katsuda, Masahiro; Miyazawa, Motoki; Yamaue, Hiroki

    2007-10-01

    Granulocyte macrophage colony-stimulating factor (GM-CSF) is a key cytokine for the generation and stimulation of dendritic cells (DCs), and it may also play a pivotal role in promoting the survival of DCs. In this study, the feasibility of creating a cancer vaccine using DCs adenovirally transduced with the carcinoembryonic antigen (CEA) gene and the GM-CSF gene was examined. In addition, the effect of the co-transduction of GM-CSF gene on the lifespan of these genetically modified DCs was determined. A cytotoxic assay using peripheral blood mononuclear cell (PBMC)-derived cytotoxic T lymphocytes (CTLs) was performed in a 4-h 51Cr release assay. The apoptosis of DCs was examined by TdT-mediated dUTP-FITC nick end labeling (TUNEL) assay. CEA-specific CTLs were generated from PBMCs stimulated with genetically modified DCs expressing CEA. The cytotoxicity of these CTLs was augmented by co-transduction of DCs with the GM-CSF gene. Co-transduction of the GM-CSF gene into DCs inhibited apoptosis of these DCs themselves via up-regulation of Bcl-x(L) expression, leading to the extension of the lifespan of these DCs. Furthermore, the transduction of the GM-CSF gene into DCs also suppressed the incidence of apoptosis of DCs induced by transforming growth factor-beta1 (TGFbeta-1). Immunotherapy using these genetically modified DCs may therefore be useful with several advantages as follows: i) adenoviral toxicity to DCs can be reduced; ii) the lifespan of vaccinated DCs can be prolonged; and iii) GM-CSF may protect DCs from apoptosis induced by tumor-derived TGFbeta-1 in the regional lymph nodes.

  1. Aberrant Signaling Pathways in Glioma

    International Nuclear Information System (INIS)

    Nakada, Mitsutoshi; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka; Teng, Lei; Pyko, Ilya V.; Hamada, Jun-Ichiro

    2011-01-01

    Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies

  2. DNA Cleavage/Repair and Signal Transduction Pathways in Irradiated Breast Tumor Cells

    National Research Council Canada - National Science Library

    Gewirtz, David

    2001-01-01

    ... (both immediate and delayed) to normal host tissue Consequently, the identification of approaches to enhance the effectiveness of low doses of radiation without concomitant increases in host tissue toxicity (i.e...

  3. [Effect of P38MAPK signal transduction pathway on apoptosis of THP-1 induced by allicin].

    Science.gov (United States)

    Liao, Yang; Chen, Jianbin; Tang, Weixue; Ge, Qunfang; Lu, Qianwei; Yang, Zesong

    2009-06-01

    The objective of this paper was to study the change of P38MAPK and Fas in the apoptosis of THP-1 cells induced by allicin. The proliferation inhibition rates of THP-1 cells after various treatments were examined by MTT assay. Apoptosis rate was determined with Annexin V- FITC/PI double staining by flow cytometry. The expression and distribution change of the phosphorylation p38MAPK (P-p38MAPK) were detected by immunohistochemical staining. The changes of P-p38 MAPK and Fas proteins were detected by Western blot. The proliferations of leukemia cell line THP-1 are inhibited by allicin. MTT assay showed that allicin can inhibit the proliferation of the THP-1 cell, and the inhibition was dependent on both dose and time. The IC50 of 72 hours was 12.8 mg x L(-1). Apoptosis rate detected by Annexin V-FITC/PI was proportional to the concentration of the allicin. After the immunohistochemical staining test, the P-p38MAPK was located in the cell nucleus and plasma, showing deep brown, when adding allicin to THP-1 cell. Western blot test showed that the P-p38MAPK proteins expression was proportional to the concentration of Allicin and was also dose dependent. The levels of P-p38MAPK in negative control group, 1/2 IC50 of 72 hours group and IC50 of 72 hours group were 0.259 8 +/- 0.013 2, 0.61 2 +/- 0.008 3 and 0.505 6 +/- 0.005 5 respectively, and the levels of Fas proteins were 0.287 4 +/- 0.008 9, 0.426 8 +/- 0.007 9 and 0.597 1 +/- 0.010 9 respectively. The difference was statistically significant when compared with the negative control group (P THP-1 cells apoptosis, and its mechanism may be related to the activation of P38MAPK/Fas.

  4. DMPD: Endotoxin signal transduction in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available File (.html) CSML File (.csml) Open .csml file with CIOPlayer Open .csml file with CIOPlayer - ※CIO Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ...

  5. Expansion of Signal Transduction Pathways in Fungi by Extensive Genome Duplication

    NARCIS (Netherlands)

    Corrochano, Luis M; Kuo, Alan; Marcet-Houben, Marina; Polaino, Silvia; Salamov, Asaf; Villalobos-Escobedo, José M; Grimwood, Jane; Álvarez, M Isabel; Avalos, Javier; Bauer, Diane; Benito, Ernesto P; Benoit, Isabelle|info:eu-repo/dai/nl/314410023; Burger, Gertraud; Camino, Lola P; Cánovas, David; Cerdá-Olmedo, Enrique; Cheng, Jan-Fang; Domínguez, Angel; Eliáš, Marek; Eslava, Arturo P; Glaser, Fabian; Gutiérrez, Gabriel; Heitman, Joseph; Henrissat, Bernard; Iturriaga, Enrique A; Lang, B Franz; Lavín, José L; Lee, Soo Chan; Li, Wenjun; Lindquist, Erika; López-García, Sergio; Luque, Eva M; Marcos, Ana T; Martin, Joel; McCluskey, Kevin; Medina, Humberto R; Miralles-Durán, Alejandro; Miyazaki, Atsushi; Muñoz-Torres, Elisa; Oguiza, José A; Ohm, Robin A|info:eu-repo/dai/nl/304837628; Olmedo, María; Orejas, Margarita; Ortiz-Castellanos, Lucila; Pisabarro, Antonio G; Rodríguez-Romero, Julio; Ruiz-Herrera, José; Ruiz-Vázquez, Rosa; Sanz, Catalina; Schackwitz, Wendy; Shahriari, Mahdi; Shelest, Ekaterina; Silva-Franco, Fátima; Soanes, Darren; Syed, Khajamohiddin; Tagua, Víctor G; Talbot, Nicholas J; Thon, Michael R; Tice, Hope; de Vries, Ronald P|info:eu-repo/dai/nl/186324960; Wiebenga, Ad|info:eu-repo/dai/nl/314110763; Yadav, Jagjit S; Braun, Edward L; Baker, Scott E; Garre, Victoriano; Schmutz, Jeremy; Horwitz, Benjamin A; Torres-Martínez, Santiago; Idnurm, Alexander; Herrera-Estrella, Alfredo; Gabaldón, Toni; Grigoriev, Igor V

    2016-01-01

    Plants and fungi use light and other signals to regulate development, growth, and metabolism. The fruiting bodies of the fungus Phycomyces blakesleeanus are single cells that react to environmental cues, including light, but the mechanisms are largely unknown [1]. The related fungus Mucor

  6. Developmental evolutionary biology of the vertebrate ear: conserving mechanoelectric transduction and developmental pathways in diverging morphologies

    Science.gov (United States)

    Fritzsch, B.; Beisel, K. W.; Bermingham, N. A.

    2000-01-01

    This brief overview shows that a start has been made to molecularly dissect vertebrate ear development and its evolutionary conservation to the development of the insect hearing organ. However, neither the patterning process of the ear nor the patterning process of insect sensory organs is sufficiently known at the moment to provide more than a first glimpse. Moreover, hardly anything is known about otocyst development of the cephalopod molluscs, another triploblast lineage that evolved complex 'ears'. We hope that the apparent conserved functional and cellular components present in the ciliated sensory neurons/hair cells will also be found in the genes required for vertebrate ear and insect sensory organ morphogenesis (Fig. 3). Likewise, we expect that homologous pre-patterning genes will soon be identified for the non-sensory cell development, which is more than a blocking of neuronal development through the Delta/Notch signaling system. Generation of the apparently unique ear could thus represent a multiplication of non-sensory cells by asymmetric and symmetric divisions as well as modification of existing patterning process by implementing novel developmental modules. In the final analysis, the vertebrate ear may come about by increasing the level of gene interactions in an already existing and highly conserved interactive cascade of bHLH genes. Since this was apparently achieved in all three lineages of triploblasts independently (Fig. 3), we now need to understand how much of the morphogenetic cascades are equally conserved across phyla to generate complex ears. The existing mutations in humans and mice may be able to point the direction of future research to understand the development of specific cell types and morphologies in the formation of complex arthropod, cephalopod, and vertebrate 'ears'.

  7. Elucidation of the Signal Transduction Pathways Activated by the Plant Natriuretic Peptide AtPNP-A

    KAUST Repository

    Turek, Ilona

    2014-01-01

    Plant natriuretic peptides (PNPs) comprise a novel class of hormones that share some sequence similarity in the active site with their animal analogues that function as regulators of salt and water balance. A PNP present in Arabidopsis thaliana (At

  8. Signal transduction pathways participating in homeostasis and malignant transformation of the intestinal tissue

    Czech Academy of Sciences Publication Activity Database

    Krausová, Michaela; Kořínek, Vladimír

    2012-01-01

    Roč. 59, č. 6 (2012), s. 708-718 ISSN 0028-2685 R&D Projects: GA ČR GAP305/11/1780; GA ČR GAP305/12/2347; GA ČR GAP304/11/1252; GA ČR GD204/09/H058 Keywords : colorectal cancer * epithelium * gut * intestine * mouse models * stem cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.574, year: 2012

  9. Signal transduction pathways in hepatocyte cell death : new targets for therapy

    NARCIS (Netherlands)

    Karimian, Golnar

    2012-01-01

    Cholestatische en steatotische leverziekten hebben een significant aandeel in het totaal van leverziekten. Zowel cholestatische als steatotische leverziekten zijn geassocieerd met hoge morbiditeit en sterftecijfers. Bestaande therapieën zijn of niet erg effectief of zijn geassocieerd met hun eigen

  10. Discovery and characterization of a potent Wnt and hedgehog signaling pathways dual inhibitor.

    Science.gov (United States)

    Ma, Haikuo; Chen, Qin; Zhu, Fang; Zheng, Jiyue; Li, Jiajun; Zhang, Hongjian; Chen, Shuaishuai; Xing, Haimei; Luo, Lusong; Zheng, Long Tai; He, Sudan; Zhang, Xiaohu

    2018-04-10

    Embryonic stem cell pathways such as hedgehog and Wnt pathways are central to the tumorigenic properties of cancer stem cells (CSC). Since CSCs are characterized by their ability to self-renew, form differentiated progeny, and develop resistance to anticancer therapies, targeting the Wnt and hedgehog signaling pathways has been an important strategy for cancer treatment. Although molecules targeting either Wnt or hedgehog are common, to the best of our knowledge, those targeting both pathways have not been documented. Here we report a small molecule (compound 1) that inhibits both Wnt (IC 50  = 0.5 nM) and hedgehog (IC 50  = 71 nM) pathways based on reporter gene assays. We further identified that the molecular target of 1 for Wnt pathway inhibition was porcupine (a member of the membrane-bound O-acyltransferase family of proteins), a post-translational modification node in Wnt signaling; while the target of 1 mitigating hedgehog pathway was Smoothened, a key G protein coupled receptor (GPCR) mediating hedgehog signal transduction. Preliminary analysis of structure-activity-relationship identified key functional elements for hedgehog/Wnt inhibition. In in vivo studies, compound 1 demonstrated good oral exposure and bioavailability while eliciting no overt toxicity in mice. An important consideration in cancer treatment is the potential therapeutic escape through compensatory activation of an interconnected pathway when only one signaling pathway is inhibited. Toward this end, compound 1 may not only lead to the development of new therapeutics for Wnt and hedgehog related cancers, but may also help to develop potential cancer treatment which needs to target Wnt and hedgehog signaling simultaneously. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  11. Stochasticity in the yeast mating pathway

    International Nuclear Information System (INIS)

    Hong-Li, Wang; Zheng-Ping, Fu; Xin-Hang, Xu; Qi, Ouyang

    2009-01-01

    We report stochastic simulations of the yeast mating signal transduction pathway. The effects of intrinsic and external noise, the influence of cell-to-cell difference in the pathway capacity, and noise propagation in the pathway have been examined. The stochastic temporal behaviour of the pathway is found to be robust to the influence of inherent fluctuations, and intrinsic noise propagates in the pathway in a uniform pattern when the yeasts are treated with pheromones of different stimulus strengths and of varied fluctuations. In agreement with recent experimental findings, extrinsic noise is found to play a more prominent role than intrinsic noise in the variability of proteins. The occurrence frequency for the reactions in the pathway are also examined and a more compact network is obtained by dropping most of the reactions of least occurrence

  12. Analysis and logical modeling of biological signaling transduction networks

    Science.gov (United States)

    Sun, Zhongyao

    The study of network theory and its application span across a multitude of seemingly disparate fields of science and technology: computer science, biology, social science, linguistics, etc. It is the intrinsic similarities embedded in the entities and the way they interact with one another in these systems that link them together. In this dissertation, I present from both the aspect of theoretical analysis and the aspect of application three projects, which primarily focus on signal transduction networks in biology. In these projects, I assembled a network model through extensively perusing literature, performed model-based simulations and validation, analyzed network topology, and proposed a novel network measure. The application of network modeling to the system of stomatal opening in plants revealed a fundamental question about the process that has been left unanswered in decades. The novel measure of the redundancy of signal transduction networks with Boolean dynamics by calculating its maximum node-independent elementary signaling mode set accurately predicts the effect of single node knockout in such signaling processes. The three projects as an organic whole advance the understanding of a real system as well as the behavior of such network models, giving me an opportunity to take a glimpse at the dazzling facets of the immense world of network science.

  13. Discriminative clustering on manifold for adaptive transductive classification.

    Science.gov (United States)

    Zhang, Zhao; Jia, Lei; Zhang, Min; Li, Bing; Zhang, Li; Li, Fanzhang

    2017-10-01

    In this paper, we mainly propose a novel adaptive transductive label propagation approach by joint discriminative clustering on manifolds for representing and classifying high-dimensional data. Our framework seamlessly combines the unsupervised manifold learning, discriminative clustering and adaptive classification into a unified model. Also, our method incorporates the adaptive graph weight construction with label propagation. Specifically, our method is capable of propagating label information using adaptive weights over low-dimensional manifold features, which is different from most existing studies that usually predict the labels and construct the weights in the original Euclidean space. For transductive classification by our formulation, we first perform the joint discriminative K-means clustering and manifold learning to capture the low-dimensional nonlinear manifolds. Then, we construct the adaptive weights over the learnt manifold features, where the adaptive weights are calculated through performing the joint minimization of the reconstruction errors over features and soft labels so that the graph weights can be joint-optimal for data representation and classification. Using the adaptive weights, we can easily estimate the unknown labels of samples. After that, our method returns the updated weights for further updating the manifold features. Extensive simulations on image classification and segmentation show that our proposed algorithm can deliver the state-of-the-art performance on several public datasets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Signal transduction of vitamin K3 for pancreas cancer therapy

    Directory of Open Access Journals (Sweden)

    Toshiyuki Tanahashi

    2011-10-01

    Full Text Available We characterized molecular mechanisms of vitamin K3 (VK3-induced inhibition of proliferation to evaluate VK3 effectiveness in treating advanced pancreatic cancer. A novel endoscopic drug delivery system, ultrasound injection technique, was used to study local effects of VK3. VK3 inhibited pancreas cancer cell growth by rapid phosphorylation of growth factor receptor and cellular signal factors such as extracellular signal-regulated kinase. VK3 also activated apoptosis, and apoptosis inhibitor antagonized the apoptosis pathway without inhibiting cell growth. Thiol antioxidant treatment completely abrogated VK3-induced ERK but not JNK phosphorylation or inhibition of proliferation. Non-thiol antioxidant did not affect ERK phosphorylation or growth inhibitory actions. Arylation was considered the main mechanism of VK3-induced growth inhibition through ERK activation. VK3 may lead to favorable outcomes in the treatment of pancreatic tumors. Detection of ERK phosphorylation in tissue is important to predict VK3 effect. Endoscopic ultrasound-guided fine-needle injection may be beneficial for treating pancreatic cancer with VK3.

  15. Arm-in-Arm Response Regulator Dimers Promote Intermolecular Signal Transduction

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Anna W.; Satyshur, Kenneth A.; Morales, Neydis Moreno; Forest, Katrina T. (UW)

    2016-02-01

    ABSTRACT

    Bacteriophytochrome photoreceptors (BphPs) and their cognate response regulators make up two-component signal transduction systems which direct bacteria to mount phenotypic responses to changes in environmental light quality. Most of these systems utilize single-domain response regulators to transduce signals through unknown pathways and mechanisms. Here we describe the photocycle and autophosphorylation kinetics of RtBphP1, a red light-regulated histidine kinase from the desert bacteriumRamlibacter tataouinensis. RtBphP1 undergoes red to far-red photoconversion with rapid thermal reversion to the dark state. RtBphP1 is autophosphorylated in the dark; this activity is inhibited under red light. The RtBphP1 cognate response regulator, theR. tataouinensisbacteriophytochrome response regulator (RtBRR), and a homolog, AtBRR fromAgrobacterium tumefaciens, crystallize unexpectedly as arm-in-arm dimers, reliant on a conserved hydrophobic motif, hFWAhL (where h is a hydrophobic M, V, L, or I residue). RtBRR and AtBRR dimerize distinctly from four structurally characterized phytochrome response regulators found in photosynthetic organisms and from all other receiver domain homodimers in the Protein Data Bank. A unique cacodylate-zinc-histidine tag metal organic framework yielded single-wavelength anomalous diffraction phases and may be of general interest. Examination of the effect of the BRR stoichiometry on signal transduction showed that phosphorylated RtBRR is accumulated more efficiently than the engineered monomeric RtBRR (RtBRRmon) in phosphotransfer reactions. Thus, we conclude that arm-in-arm dimers are a relevant signaling intermediate in this class of two-component regulatory systems.

  16. Staurosporine Increases Lentiviral Vector Transduction Efficiency of Human Hematopoietic Stem and Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Gretchen Lewis

    2018-06-01

    Full Text Available Lentiviral vector (LVV-mediated transduction of human CD34+ hematopoietic stem and progenitor cells (HSPCs holds tremendous promise for the treatment of monogenic hematological diseases. This approach requires the generation of a sufficient proportion of gene-modified cells. We identified staurosporine, a serine/threonine kinase inhibitor, as a small molecule that could be added to the transduction process to increase the proportion of genetically modified HSPCs by overcoming a LVV entry barrier. Staurosporine increased vector copy number (VCN approximately 2-fold when added to mobilized peripheral blood (mPB CD34+ cells prior to transduction. Limited staurosporine treatment did not affect viability of cells post-transduction, and there was no difference in in vitro colony formation compared to vehicle-treated cells. Xenotransplantation studies identified a statistically significant increase in VCN in engrafted human cells in mouse bone marrow at 4 months post-transplantation compared to vehicle-treated cells. Prostaglandin E2 (PGE2 is known to increase transduction efficiency of HSPCs through a different mechanism. Combining staurosporine and PGE2 resulted in further enhancement of transduction efficiency, particularly in short-term HSPCs. The combinatorial use of small molecules, such as staurosporine and PGE2, to enhance LVV transduction of human CD34+ cells is a promising method to improve transduction efficiency and subsequent potential therapeutic benefit of gene therapy drug products. Keywords: lentiviral, HSPC, transduction

  17. Polymerase chain reaction-based detection of myc transduction in feline leukemia virus-infected cats.

    Science.gov (United States)

    Sumi, Ryosuke; Miyake, Ariko; Endo, Taiji; Ohsato, Yoshiharu; Ngo, Minh Ha; Nishigaki, Kazuo

    2018-04-01

    Feline lymphomas are associated with the transduction and activation of cellular proto-oncogenes, such as c-myc, by feline leukemia virus (FeLV). We describe a polymerase chain reaction assay for detection of myc transduction usable in clinical diagnosis. The assay targets c-myc exons 2 and 3, which together result in a FeLV-specific fusion gene following c-myc transduction. When this assay was conducted on FeLV-infected feline tissues submitted for clinical diagnosis of tumors, myc transduction was detected in 14% of T-cell lymphoma/leukemias. This newly established system could become a useful diagnostic tool in veterinary medicine.

  18. Coagulation factor VIIa-mediated protease-activated receptor 2 activation leads to β-catenin accumulation via the AKT/GSK3β pathway and contributes to breast cancer progression.

    Science.gov (United States)

    Roy, Abhishek; Ansari, Shabbir A; Das, Kaushik; Prasad, Ramesh; Bhattacharya, Anindita; Mallik, Suman; Mukherjee, Ashis; Sen, Prosenjit

    2017-08-18

    Cell migration and invasion are very characteristic features of cancer cells that promote metastasis, which is one of the most common causes of mortality among cancer patients. Emerging evidence has shown that coagulation factors can directly mediate cancer-associated complications either by enhancing thrombus formation or by initiating various signaling events leading to metastatic cancer progression. It is well established that, apart from its distinct role in blood coagulation, coagulation factor FVIIa enhances aggressive behaviors of breast cancer cells, but the underlying signaling mechanisms still remain elusive. To this end, we investigated FVIIa's role in the migration and invasiveness of the breast cancer cell line MDA-MB-231. Consistent with previous observations, we observed that FVIIa increased the migratory and invasive potential of these cells. We also provide molecular evidence that protease-activated receptor 2 activation followed by PI3K-AKT activation and GSK3β inactivation is involved in these processes and that β-catenin, a well known tumor-regulatory protein, contributes to this signaling pathway. The pivotal role of β-catenin was further indicated by the up-regulation of its downstream targets cyclin D1, c-Myc, COX-2, MMP-7, MMP-14, and Claudin-1. β-Catenin knockdown almost completely attenuated the FVIIa-induced enhancement of breast cancer migration and invasion. These findings provide a new perspective to counteract the invasive behavior of breast cancer, indicating that blocking PI3K-AKT pathway-dependent β-catenin accumulation may represent a potential therapeutic approach to control breast cancer. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Characterization of the human oncogene SCL/TAL1 interrupting locus (Stil) mediated Sonic hedgehog (Shh) signaling transduction in proliferating mammalian dopaminergic neurons

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Lei [Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Physiology, Nankai University School of Medicine, Tianjin 300071 (China); Carr, Aprell L. [Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Center for Zebrafish Research, University of Notre Dame, Notre Dame, IN 46556 (United States); Li, Ping; Lee, Jessica; McGregor, Mary [Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Li, Lei, E-mail: Li.78@nd.edu [Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Center for Zebrafish Research, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2014-07-11

    Highlights: • Stil is a human oncogene that is conserved in vertebrate species. • Stil functions in the Shh pathway in mammalian cells. • The expression of Stil is required for mammalian dopaminergic cell proliferation. - Abstract: The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in all vertebrate species. In humans, the expression of Stil is involved in cancer cell survival, apoptosis and proliferation. In this research, we investigated the roles of Stil expression in cell proliferation of mammalian dopaminergic (DA) PC12 cells. Stil functions through the Sonic hedgehog (Shh) signal transduction pathway. Co-immunoprecipitation tests revealed that STIL interacts with Shh downstream components, which include SUFU and GLI1. By examining the expression of Stil, Gli1, CyclinD2 (cell-cycle marker) and PCNA (proliferating cell nuclear antigen), we found that up-regulation of Stil expression (transfection with overexpression plasmids) increased Shh signaling transduction and PC12 cell proliferation, whereas down-regulation of Stil expression (by shRNA) inhibited Shh signaling transduction, and thereby decreased PC12 cell proliferation. Transient transfection of PC12 cells with Stil knockdown or overexpression plasmids did not affect PC12 cell neural differentiation, further indicating the specific roles of Stil in cell proliferation. The results from this research suggest that Stil may serve as a bio-marker for neurological diseases involved in DA neurons, such as Parkinson’s disease.

  20. Lead poisoning

    Science.gov (United States)

    ... drinking water in homes containing pipes that were connected with lead solder . Although new building codes require ... lead in their bodies when they put lead objects in their mouths, especially if they swallow those ...

  1. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  2. Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction System

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor)

    2014-01-01

    A novel full piezoelectric multilayer stacked hybrid actuation/transduction system. The system demonstrates significantly-enhanced electromechanical performance by utilizing the cooperative contributions of the electromechanical responses of multilayer stacked negative and positive strain components. Both experimental and theoretical studies indicate that for this system, the displacement is over three times that of a same-sized conventional flextensional actuator/transducer. The system consists of at least 2 layers which include electromechanically active components. The layers are arranged such that when electric power is applied, one layer contracts in a transverse direction while the second layer expands in a transverse direction which is perpendicular to the transverse direction of the first layer. An alternate embodiment includes a third layer. In this embodiment, the outer two layers contract in parallel transverse directions while the middle layer expands in a transverse direction which is perpendicular to the transverse direction of the outer layers.

  3. Construction and Deciphering of Human Phosphorylation-Mediated Signaling Transduction Networks.

    Science.gov (United States)

    Zhang, Menghuan; Li, Hong; He, Ying; Sun, Han; Xia, Li; Wang, Lishun; Sun, Bo; Ma, Liangxiao; Zhang, Guoqing; Li, Jing; Li, Yixue; Xie, Lu

    2015-07-02

    Protein phosphorylation is the most abundant reversible covalent modification. Human protein kinases participate in almost all biological pathways, and approximately half of the kinases are associated with disease. PhoSigNet was designed to store and display human phosphorylation-mediated signal transduction networks, with additional information related to cancer. It contains 11 976 experimentally validated directed edges and 216 871 phosphorylation sites. Moreover, 3491 differentially expressed proteins in human cancer from dbDEPC, 18 907 human cancer variation sites from CanProVar, and 388 hyperphosphorylation sites from PhosphoSitePlus were collected as annotation information. Compared with other phosphorylation-related databases, PhoSigNet not only takes the kinase-substrate regulatory relationship pairs into account, but also extends regulatory relationships up- and downstream (e.g., from ligand to receptor, from G protein to kinase, and from transcription factor to targets). Furthermore, PhoSigNet allows the user to investigate the impact of phosphorylation modifications on cancer. By using one set of in-house time series phosphoproteomics data, the reconstruction of a conditional and dynamic phosphorylation-mediated signaling network was exemplified. We expect PhoSigNet to be a useful database and analysis platform benefiting both proteomics and cancer studies.

  4. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B

    1999-01-01

    of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

  5. Identifying pathways affected by cancer mutations.

    Science.gov (United States)

    Iengar, Prathima

    2017-12-16

    Mutations in 15 cancers, sourced from the COSMIC Whole Genomes database, and 297 human pathways, arranged into pathway groups based on the processes they orchestrate, and sourced from the KEGG pathway database, have together been used to identify pathways affected by cancer mutations. Genes studied in ≥15, and mutated in ≥10 samples of a cancer have been considered recurrently mutated, and pathways with recurrently mutated genes have been considered affected in the cancer. Novel doughnut plots have been presented which enable visualization of the extent to which pathways and genes, in each pathway group, are targeted, in each cancer. The 'organismal systems' pathway group (including organism-level pathways; e.g., nervous system) is the most targeted, more than even the well-recognized signal transduction, cell-cycle and apoptosis, and DNA repair pathway groups. The important, yet poorly-recognized, role played by the group merits attention. Pathways affected in ≥7 cancers yielded insights into processes affected. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Downstream divergence of the ethylene signaling pathway for harpin-stimulated Arabidopsis growth and insect defense.

    Science.gov (United States)

    Dong, Hong-Ping; Peng, Jianling; Bao, Zhilong; Meng, Xiangdong; Bonasera, Jean M; Chen, Guangyong; Beer, Steven V; Dong, Hansong

    2004-11-01

    Ethylene (ET) signal transduction may regulate plant growth and defense, depending on which components are recruited into the pathway in response to different stimuli. We report here that the ET pathway controls both insect resistance (IR) and plant growth enhancement (PGE) in Arabidopsis (Arabidopsis thaliana) plants responding to harpin, a protein produced by a plant pathogenic bacterium. PGE may result from spraying plant tops with harpin or by soaking seeds in harpin solution; the latter especially enhances root growth. Plants treated similarly develop resistance to the green peach aphid (Myzus persicae). The salicylic acid pathway, although activated by harpin, does not lead to PGE and IR. By contrast, PGE and IR are induced in both wild-type plants and genotypes that have defects in salicylic acid signaling. In response to harpin, levels of jasmonic acid (JA) decrease, and the COI1 gene, which is indispensable for JA signal transduction, is not expressed in wild-type plants. However, PGE and IR are stimulated in the JA-resistant mutant jar1-1. In the wild type, PGE and IR develop coincidently with increases in ET levels and the expression of several genes essential for ET signaling. The ET receptor gene ETR1 is required because both phenotypes are arrested in the etr1-1 mutant. Consistently, inhibition of ET perception nullifies the induction of both PGE and IR. The signal transducer EIN2 is required for IR, and EIN5 is required for PGE because IR and PGE are impaired correspondingly in the ein2-1 and ein5-1 mutants. Therefore, harpin activates ET signaling while conscribing EIN2 and EIN5 to confer IR and PGE, respectively.

  7. The Role of Cgrp-Receptor Component Protein (Rcp in Cgrp-Mediated Signal Transduction

    Directory of Open Access Journals (Sweden)

    M. A. Prado

    2001-01-01

    Full Text Available The calcitonin gene-related peptide (CGRP-receptor component protein (RCP is a 17-kDa intracellular peripheral membrane protein required for signal transduction at CGRP receptors. To determine the role of RCP in CGRP-mediated signal transduction, RCP was depleted from NIH3T3 cells using antisense strategy. Loss of RCP protein correlated with loss of cAMP production by CGRP in the antisense cells. In contrast, loss of RCP had no effect on CGRP-mediated binding; therefore RCP is not acting as a chaperone for the CGRP receptor. Instead, RCP is a novel signal transduction molecule that couples the CGRP receptor to the cellular signal transduction machinery. RCP thus represents a prototype for a new class of signal transduction proteins that are required for regulation of G protein-coupled receptors.

  8. Signal transduction by normal isoforms and W mutant variants of the Kit receptor tyrosine kinase.

    Science.gov (United States)

    Reith, A D; Ellis, C; Lyman, S D; Anderson, D M; Williams, D E; Bernstein, A; Pawson, T

    1991-09-01

    Germline mutations at the Dominant White Spotting (W) and Steel (Sl) loci have provided conclusive genetic evidence that c-kit mediated signal transduction pathways are essential for normal mouse development. We have analysed the interactions of normal and mutant W/c-kit gene products with cytoplasmic signalling proteins, using transient c-kit expression assays in COS cells. In addition to the previously identified c-kit gene product (Kit+), a second normal Kit isoform (KitA+) containing an in-frame insertion, Gly-Asn-Asn-Lys, within the extracellular domain, was detected in murine mast cell cultures and mid-gestation placenta. Both Kit+ and KitA+ isoforms showed increased autophosphorylation and enhanced association with phosphatidylinositol (PI) 3' kinase and PLC gamma 1, when stimulated with recombinant soluble Steel factor. No association or increase in phosphorylation of GAP and two GAP-associated proteins, p62 and p190, was observed. The two isoforms had distinct activities in the absence of exogenous soluble Steel factor; Kit+, but not KitA+, showed constitutive tyrosine phosphorylation that was accompanied by a low constitutive level of association with PI-3' kinase and PLC gamma 1. Introduction of the point substitutions associated with W37 (Glu582----Lys) or W41 (Val831----Met) mutant alleles into c-kit expression constructs abolished (W37) or reduced (W41) the Steel factor-induced association of the Kit receptor with signalling proteins in a manner proportional to the overall severity of the corresponding W mutant phenotype. These data suggest a diversity of normal Kit signalling pathways and indicate that W mutant phenotypes result from primary defects in the Kit receptor that affect its interaction with cytoplasmic signalling proteins.

  9. Protein tyrosine kinase and mitogen-activated protein kinase signalling pathways contribute to differences in heterophil-mediated innate immune responsiveness between two lines of broilers

    Science.gov (United States)

    Protein tyrosine phosphorylation mediates signal transduction of cellular processes, with protein tyrosine kinases (PTKs) regulating virtually all signaling events. The mitogen-activated protein kinase (MAPK) super-family consists of three conserved pathways that convert receptor activation into ce...

  10. Lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Beijers, J A

    1952-01-01

    Three cases of acute lead poisoning of cattle herds via ingestion are reported, and reference is made to several other incidents of lead in both humans and animals. The quantity of lead which was found in the livers of the dead cows varied from 6.5 to 19 mg/kg, while 1160 mg/kg of lead in the liver was found for a young cow which was poisoned experimentally with 5 gms of lead acetate per day; hence, there appears to be great variability in the amounts deposited that can lead to intoxication and death. No evidence was found for a lead seam around the teeth, prophyrinuria, or basophil granules in the erythrocytes during acute or chronic lead poisoning of cattle or horses examined. Reference is made to attempts of finding the boundary line between increased lead absorption and lead intoxication in humans, and an examination of 60 laborers in an offset-printing office containing a great deal of inhalable lead (0.16 to 1.9 mg/cu m air) is reviewed. Physical deviation, basophylic granulation of erythrocytes, increased lead content of the urine, and porphyrinuria only indicate an increased absorption of lead; the use of the term intoxication is justified if, in addition, there are complaints of lack of appetite, constipation, fatigue, abdominal pain, and emaciation.

  11. Lead Toxicity

    Science.gov (United States)

    ... o Do not use glazed ceramics, home remedies, cosmetics, or leaded-crystal glassware unless you know that they are lead safe. o If you live near an industry, mine, or waste site that may have contaminated ...

  12. Relational Leading

    DEFF Research Database (Denmark)

    Larsen, Mette Vinther; Rasmussen, Jørgen Gulddahl

    2015-01-01

    This first chapter presents the exploratory and curious approach to leading as relational processes – an approach that pervades the entire book. We explore leading from a perspective that emphasises the unpredictable challenges and triviality of everyday life, which we consider an interesting......, relevant and realistic way to examine leading. The chapter brings up a number of concepts and contexts as formulated by researchers within the field, and in this way seeks to construct a first understanding of relational leading....

  13. Lead Test

    Science.gov (United States)

    ... to do renovation and repair projects using lead-safe work practices to avoid creating more lead dust or ... in a dangerous area? Yes. If you are working in a potentially harmful environment with exposure to lead dust or fumes: Wash ...

  14. The carboxyl terminal tyrosine 417 residue of NOK has an autoinhibitory effect on NOK-mediated signaling transductions

    International Nuclear Information System (INIS)

    Li Yinghua; Zhong Shan; Rong Zhili; Ren Yongming; Li Zhiyong; Zhang Shuping; Chang Zhijie; Liu Li

    2007-01-01

    Receptor protein tyrosine kinases (RPTKs) are essential mediators of cell growth, differentiation, migration, and metabolism. Recently, a novel RPTK named NOK has been cloned and characterized. In current study, we investigated the role of the carboxyl terminal tyrosine 417 residue of NOK in the activations of different signaling pathways. A single tyrosine to phenylalanine point mutation at Y417 site (Y417 F) not only dramatically enhanced the NOK-induced activation of extracellular signal-regulated kinase (ERK), but also markedly promoted the NOK-mediated activation of both signal transducer and activator of transcription 1 and 3 (STAT1 and 3). Moreover, the proliferation potential of NIH3T3-NOK (Y417F) stable cells were significantly elevated as compared with that of NIH3T3-NOK. Overall, our results demonstrate that the tyrosine Y417 residue at the carboxyl tail of NOK exhibits an autoinhibitory role in NOK-mediated signaling transductions

  15. Insulin signal transduction in skeletal muscle from glucose-intolerant relatives of type 2 diabetic patients [corrected

    DEFF Research Database (Denmark)

    Storgaard, H; Song, X M; Jensen, C B

    2001-01-01

    before and during a euglycemic-hyperinsulinemic clamp. IGT relatives were insulin-resistant in oxidative and nonoxidative pathways for glucose metabolism. In vivo insulin infusion increased skeletal muscle insulin receptor substrate-1 (IRS-1) tyrosine phosphorylation (P = 0.01) and phosphatidylinositide......To determine whether defects in the insulin signal transduction cascade are present in skeletal muscle from prediabetic individuals, we excised biopsies from eight glucose-intolerant male first-degree relatives of patients with type 2 diabetes (IGT relatives) and nine matched control subjects...... 3-kinase (PI 3-kinase) activity (phosphotyrosine and IRS-1 associated) in control subjects (P increase in insulin action on IRS-1 tyrosine phosphorylation was lower in IGT relatives versus control subjects (P

  16. Impairment of the Ubiquitin-Proteasome Pathway by Methyl N-(6-Phenylsulfanyl-1H-benzimidazol-2-yl)carbamate Leads to a Potent Cytotoxic Effect in Tumor Cells

    Science.gov (United States)

    Dogra, Nilambra; Mukhopadhyay, Tapas

    2012-01-01

    In recent years, there has been a great deal of interest in proteasome inhibitors as a novel class of anticancer drugs. We report that fenbendazole (FZ) (methyl N-(6-phenylsulfanyl-1H-benzimidazol-2-yl)carbamate) exhibits a potent growth-inhibitory activity against cancer cell lines but not normal cells. We show here, using fluorogenic substrates, that FZ treatment leads to the inhibition of proteasomal activity in the cells. Succinyl-Leu-Leu-Val-Tyr-methylcoumarinamide (MCA), benzyloxycarbonyl-Leu-Leu-Glu-7-amido-4-MCA, and t-butoxycarbonyl-Gln-Ala-Arg-7-amido-4-MCA fluorescent derivatives were used to assess chymotrypsin-like, post-glutamyl peptidyl-hydrolyzing, and trypsin-like protease activities, respectively. Non-small cell lung cancer cells transiently transfected with an expression plasmid encoding pd1EGFP and treated with FZ showed an accumulation of the green fluorescent protein in the cells due to an increase in its half-life. A number of apoptosis regulatory proteins that are normally degraded by the ubiquitin-proteasome pathway like cyclins, p53, and IκBα were found to be accumulated in FZ-treated cells. In addition, FZ induced distinct ER stress-associated genes like GRP78, GADD153, ATF3, IRE1α, and NOXA in these cells. Thus, treatment of human NSCLC cells with fenbendazole induced endoplasmic reticulum stress, reactive oxygen species production, decreased mitochondrial membrane potential, and cytochrome c release that eventually led to cancer cell death. This is the first report to demonstrate the inhibition of proteasome function and induction of endoplasmic reticulum stress/reactive oxygen species-dependent apoptosis in human lung cancer cell lines by fenbendazole, which may represent a new class of anticancer agents showing selective toxicity against cancer cells. PMID:22745125

  17. Fenspiride and membrane transduction signals in rat alveolar macrophages.

    Science.gov (United States)

    Féray, J C; Mohammadi, K; Taouil, K; Brunet, J; Garay, R P; Hannaert, P

    1997-07-15

    Fenspiride inhibits the calcium signal evoked by the inflammatory peptide formyl-Met-Leu-Phe (fMLP) in peritoneal macrophages, but at concentrations (approximately 1 mM) far above the therapeutic range (approximately 1 microM). Here, in rat alveolar macrophages, high fenspiride concentrations (1 mM) were required to inhibit the calcium signals evoked by the calcium agonist Bay K8644 or by ionomycin. Moreover, fenspiride (1 mM) was a poor inhibitor of the cell membrane depolarization induced by gramicidine D. By contrast, fenspiride blocked Na+-H+ antiport activation by (i) fMLP with an IC50 = 3.1 +/- 1.9 nM and (ii) PMA (phorbol 12-myristate 13-acetate) with an IC50 = 9.2 +/- 3.1 nM. Finally, protein kinase C (PKC) activity of macrophage homogenate was not significantly modified by 10 or 100 microM fenspiride (at 100 microM: 2.57 +/- 1.60 vs. 2.80 +/- 1.71 pmol/10(6) cells/min). In conclusion, fenspiride inhibits fMLP- and PMA-induced pH signals in rat alveolar macrophages, probably by acting distally on the PKC transduction signal. This pH antagonistic action may be relevant for the antiinflammatory mechanism of fenspiride and requires further investigation.

  18. Signal transduction in cells of the immune system in microgravity

    Directory of Open Access Journals (Sweden)

    Huber Kathrin

    2008-10-01

    Full Text Available Abstract Life on Earth developed in the presence and under the constant influence of gravity. Gravity has been present during the entire evolution, from the first organic molecule to mammals and humans. Modern research revealed clearly that gravity is important, probably indispensable for the function of living systems, from unicellular organisms to men. Thus, gravity research is no more or less a fundamental question about the conditions of life on Earth. Since the first space missions and supported thereafter by a multitude of space and ground-based experiments, it is well known that immune cell function is severely suppressed in microgravity, which renders the cells of the immune system an ideal model organism to investigate the influence of gravity on the cellular and molecular level. Here we review the current knowledge about the question, if and how cellular signal transduction depends on the existence of gravity, with special focus on cells of the immune system. Since immune cell function is fundamental to keep the organism under imnological surveillance during the defence against pathogens, to investigate the effects and possible molecular mechanisms of altered gravity is indispensable for long-term space flights to Earth Moon or Mars. Thus, understanding the impact of gravity on cellular functions on Earth will provide not only important informations about the development of life on Earth, but also for therapeutic and preventive strategies to cope successfully with medical problems during space exploration.

  19. Signal transduction by the platelet-derived growth factor receptor

    International Nuclear Information System (INIS)

    Williams, L.T.; Escobedo, J.A.; Keating, M.T.; Coughlin, S.R.

    1988-01-01

    The mitogenic effects of platelet-derived growth factor (PDGF) are mediated by the PDGF receptor. The mouse PDGF receptor was recently purified on the basis of its ability to become tyrosine phosphorylated in response to the A-B human platelet form of PDGF, and the receptor amino acid sequence was determined from a full-length cDNA clone. Both the human and mouse receptor cDNA sequences have been expressed in Chinese hamster ovary fibroblast (CHO) cells that normally lack PDGF receptors. This paper summarizes recent results using this system to study signal transduction by the PDGF receptor. Some of the findings show that the KI domain of the PDGF receptor plays an important role in the stimulation of DNA synthesis by PDGF. Surprisingly, the kinase insert region is not essential for PDGF stimulation of PtdIns turnover, pH change, increase in cellular calcium, and receptor autophosphorylation. In addition, PDGF stimulates a conformational change in the receptor

  20. Metformin selectively targets redox control of complex I energy transduction

    Directory of Open Access Journals (Sweden)

    Amy R. Cameron

    2018-04-01

    Full Text Available Many guanide-containing drugs are antihyperglycaemic but most exhibit toxicity, to the extent that only the biguanide metformin has enjoyed sustained clinical use. Here, we have isolated unique mitochondrial redox control properties of metformin that are likely to account for this difference. In primary hepatocytes and H4IIE hepatoma cells we found that antihyperglycaemic diguanides DG5-DG10 and the biguanide phenformin were up to 1000-fold more potent than metformin on cell signalling responses, gluconeogenic promoter expression and hepatocyte glucose production. Each drug inhibited cellular oxygen consumption similarly but there were marked differences in other respects. All diguanides and phenformin but not metformin inhibited NADH oxidation in submitochondrial particles, indicative of complex I inhibition, which also corresponded closely with dehydrogenase activity in living cells measured by WST-1. Consistent with these findings, in isolated mitochondria, DG8 but not metformin caused the NADH/NAD+ couple to become more reduced over time and mitochondrial deterioration ensued, suggesting direct inhibition of complex I and mitochondrial toxicity of DG8. In contrast, metformin exerted a selective oxidation of the mitochondrial NADH/NAD+ couple, without triggering mitochondrial deterioration. Together, our results suggest that metformin suppresses energy transduction by selectively inducing a state in complex I where redox and proton transfer domains are no longer efficiently coupled. Keywords: Diabetes, Metformin, Mitochondria, NADH, NAD+

  1. Signal transduction around thymic stromal lymphopoietin (TSLP in atopic asthma

    Directory of Open Access Journals (Sweden)

    Kuepper Michael

    2008-08-01

    Full Text Available Abstract Thymic stromal lymphopoietin (TSLP, a novel interleukin-7-like cytokine, triggers dendritic cell-mediated inflammatory responses ultimately executed by T helper cells of the Th2 subtype. TSLP emerged as a central player in the development of allergic symptoms, especially in the airways, and is a prime regulatory cytokine at the interface of virus- or antigen-exposed epithelial cells and dendritic cells (DCs. DCs activated by epithelium-derived TSLP can promote naïve CD4+ T cells to adopt a Th2 phenotype, which in turn recruite eosinophilic and basophilic granulocytes as well as mast cells into the airway mucosa. These different cells secrete inflammatory cytokines and chemokines operative in inducing an allergic inflammation and atopic asthma. TSLP is, thus, involved in the control of both an innate and an adaptive immune response. Since TSLP links contact of allergen with the airway epithelium to the onset and maintainance of the asthmatic syndrome, defining the signal transduction underlying TSLP expression and function is of profound interest for a better understandimg of the disease and for the development of new therapeutics.

  2. Load-induced modulation of signal transduction networks.

    Science.gov (United States)

    Jiang, Peng; Ventura, Alejandra C; Sontag, Eduardo D; Merajver, Sofia D; Ninfa, Alexander J; Del Vecchio, Domitilla

    2011-10-11

    Biological signal transduction networks are commonly viewed as circuits that pass along information--in the process amplifying signals, enhancing sensitivity, or performing other signal-processing tasks--to transcriptional and other components. Here, we report on a "reverse-causality" phenomenon, which we call load-induced modulation. Through a combination of analytical and experimental tools, we discovered that signaling was modulated, in a surprising way, by downstream targets that receive the signal and, in doing so, apply what in physics is called a load. Specifically, we found that non-intuitive changes in response dynamics occurred for a covalent modification cycle when load was present. Loading altered the response time of a system, depending on whether the activity of one of the enzymes was maximal and the other was operating at its minimal rate or whether both enzymes were operating at submaximal rates. These two conditions, which we call "limit regime" and "intermediate regime," were associated with increased or decreased response times, respectively. The bandwidth, the range of frequency in which the system can process information, decreased in the presence of load, suggesting that downstream targets participate in establishing a balance between noise-filtering capabilities and a circuit's ability to process high-frequency stimulation. Nodes in a signaling network are not independent relay devices, but rather are modulated by their downstream targets.

  3. Microfluidic Transduction Harnesses Mass Transport Principles to Enhance Gene Transfer Efficiency.

    Science.gov (United States)

    Tran, Reginald; Myers, David R; Denning, Gabriela; Shields, Jordan E; Lytle, Allison M; Alrowais, Hommood; Qiu, Yongzhi; Sakurai, Yumiko; Li, William C; Brand, Oliver; Le Doux, Joseph M; Spencer, H Trent; Doering, Christopher B; Lam, Wilbur A

    2017-10-04

    Ex vivo gene therapy using lentiviral vectors (LVs) is a proven approach to treat and potentially cure many hematologic disorders and malignancies but remains stymied by cumbersome, cost-prohibitive, and scale-limited production processes that cannot meet the demands of current clinical protocols for widespread clinical utilization. However, limitations in LV manufacture coupled with inefficient transduction protocols requiring significant excess amounts of vector currently limit widespread implementation. Herein, we describe a microfluidic, mass transport-based approach that overcomes the diffusion limitations of current transduction platforms to enhance LV gene transfer kinetics and efficiency. This novel ex vivo LV transduction platform is flexible in design, easy to use, scalable, and compatible with standard cell transduction reagents and LV preparations. Using hematopoietic cell lines, primary human T cells, primary hematopoietic stem and progenitor cells (HSPCs) of both murine (Sca-1 + ) and human (CD34 + ) origin, microfluidic transduction using clinically processed LVs occurs up to 5-fold faster and requires as little as one-twentieth of LV. As an in vivo validation of the microfluidic-based transduction technology, HSPC gene therapy was performed in hemophilia A mice using limiting amounts of LV. Compared to the standard static well-based transduction protocols, only animals transplanted with microfluidic-transduced cells displayed clotting levels restored to normal. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Iron-induced nitric oxide leads to an increase in the expression of ferritin during the senescence of Lotus japonicus nodules.

    Science.gov (United States)

    Chungopast, Sirinapa; Duangkhet, Mallika; Tajima, Shigeyuki; Ma, Jian Feng; Nomura, Mika

    2017-01-01

    Iron is an essential nutrient for legume-rhizobium symbiosis and accumulates abundantly in the nodules. However, the concentration of free iron in the cells is strictly controlled to avoid toxicity. It is known that ferritin accumulates in the cells as an iron storage protein. During nodule senescence, the expression of the ferritin gene, Ljfer1, was induced in Lotus japonicus. We investigated a signal transduction pathway leading to the increase of Ljfer1 in the nodule. The Ljfer1 promoter of L. japonicus contains a conserved Iron-Dependent Regulatory Sequence (IDRS). The expression of Ljfer1 was induced by the application of iron or sodium nitroprusside, which is a nitric oxide (NO) donor. The application of iron to the nodule increased the level of NO. These data strongly suggest that iron-induced NO leads to increased expression of Ljfer1 during the senescence of L. japonicus nodules. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Participation of intracellular signal transduction in the radio-adaptive response induced by low-dose X-irradiation in human embryonic cells

    International Nuclear Information System (INIS)

    Ishii, Keiichiro; Hoshi, Yuko; Iwasaki, Toshiyasu; Watanabe, Masami.

    1996-01-01

    To elucidate the induction mechanism of radio-adaptive response in normal cells, we searched the literatures of the intracellular signal transduction. Furthermore, we examined the induction of radio-adaptive response with or without inhibitors of several kinds of protein kinase. The major results obtained were as follows; (1) According to the literature survey it is revealed that there are 4 intracellular signal transduction pathways which are possibly involved in the induction of radio-adaptive response: pathways depending on cAMP, calcium, cGMP, or protein-tyrosine kinase. (2) Addition of either inhibitor of protein-tyrosine kinase or protein kinase C to the cell culture medium during the low-dose X-irradiation inhibited the induction of radio-adaptive response. However, the addition of inhibitor of cAMP-dependent protein kinase, cGMP-dependent protein kinase, or Ca 2+ -calmodulin kinase II failed to inhibit the induction of radio-adaptive response. (3) These results suggest that the signal induced in cells by low-dose X-irradiation was transduced from protein-tyrosine kinase to protein kinase C via either pathway of phosphatidylinositol 3-kinase or splitting of profilin binding phosphatidylinositol 4,5-bisphosphate. (author)

  6. Crystallization Pathways in Biomineralization

    Science.gov (United States)

    Weiner, Steve; Addadi, Lia

    2011-08-01

    A crystallization pathway describes the movement of ions from their source to the final product. Cells are intimately involved in biological crystallization pathways. In many pathways the cells utilize a unique strategy: They temporarily concentrate ions in intracellular membrane-bound vesicles in the form of a highly disordered solid phase. This phase is then transported to the final mineralization site, where it is destabilized and crystallizes. We present four case studies, each of which demonstrates specific aspects of biological crystallization pathways: seawater uptake by foraminifera, calcite spicule formation by sea urchin larvae, goethite formation in the teeth of limpets, and guanine crystal formation in fish skin and spider cuticles. Three representative crystallization pathways are described, and aspects of the different stages of crystallization are discussed. An in-depth understanding of these complex processes can lead to new ideas for synthetic crystallization processes of interest to materials science.

  7. Graph Regularized Meta-path Based Transductive Regression in Heterogeneous Information Network.

    Science.gov (United States)

    Wan, Mengting; Ouyang, Yunbo; Kaplan, Lance; Han, Jiawei

    2015-01-01

    A number of real-world networks are heterogeneous information networks, which are composed of different types of nodes and links. Numerical prediction in heterogeneous information networks is a challenging but significant area because network based information for unlabeled objects is usually limited to make precise estimations. In this paper, we consider a graph regularized meta-path based transductive regression model ( Grempt ), which combines the principal philosophies of typical graph-based transductive classification methods and transductive regression models designed for homogeneous networks. The computation of our method is time and space efficient and the precision of our model can be verified by numerical experiments.

  8. Radioresistance-related signaling pathways in nasopharyngeal carcinoma cells

    International Nuclear Information System (INIS)

    Guo Ya; Zhu Xiaodong; Qu Song; Su Fang; Wang Qi; Zhang Wei

    2011-01-01

    Objective: To study the difference of gene expression profile between the radioresistant human nasopharyngeal carcinoma cell line CNE-2R and CNE-2, and to screen the signaling pathway associated with radioresistance of nasopharyngeal carcinoma. Methods: The radioresistant nasopharyngeal carcinoma cell line CNE-2R was constructed from the original cell line CNE-2. CNE-2R and CNE-2 cells were cultured and administered with 60 Co γ-ray irradiation at the dose of 400 cGy for 15 times. Human-6v 3.0 whole genome expression profile was used to screen the differentially expressed genes. Bioinformatic analysis was used to identify the pathways related to radioresistance. Results: The number of the differentially expressed genes that were found in these 2 experiments was 374. The Kegg pathway and Biocarta pathway analysis of the differentially expressed genes showed the biological importance of Toll-like receptor signaling pathway and IL-1 R-mediated signal transduction pathway to the radioresistance of the CNE-2R cells and the significant differences of 13 genes in these 2 pathways,including JUN, MYD88, CCL5, CXCL10, STAT1, LY96, FOS, CCL3, IL-6, IL-8, IL-1α, IL-1β, and IRAK2 (t=13.47-66.57, P<0.05). Conclusions: Toll-like receptor signaling pathway and IL-1R-mediated signal transduction pathway might be related to the occurrence of radioresistance. (authors)

  9. Impact of constitutional copy number variants on biological pathway evolution.

    Science.gov (United States)

    Poptsova, Maria; Banerjee, Samprit; Gokcumen, Omer; Rubin, Mark A; Demichelis, Francesca

    2013-01-23

    Inherited Copy Number Variants (CNVs) can modulate the expression levels of individual genes. However, little is known about how CNVs alter biological pathways and how this varies across different populations. To trace potential evolutionary changes of well-described biological pathways, we jointly queried the genomes and the transcriptomes of a collection of individuals with Caucasian, Asian or Yoruban descent combining high-resolution array and sequencing data. We implemented an enrichment analysis of pathways accounting for CNVs and genes sizes and detected significant enrichment not only in signal transduction and extracellular biological processes, but also in metabolism pathways. Upon the estimation of CNV population differentiation (CNVs with different polymorphism frequencies across populations), we evaluated that 22% of the pathways contain at least one gene that is proximal to a CNV (CNV-gene pair) that shows significant population differentiation. The majority of these CNV-gene pairs belong to signal transduction pathways and 6% of the CNV-gene pairs show statistical association between the copy number states and the transcript levels. The analysis suggested possible examples of positive selection within individual populations including NF-kB, MAPK signaling pathways, and Alu/L1 retrotransposition factors. Altogether, our results suggest that constitutional CNVs may modulate subtle pathway changes through specific pathway enzymes, which may become fixed in some populations.

  10. Effects of obesity and exercise on testicular leptin signal transduction and testosterone biosynthesis in male mice.

    Science.gov (United States)

    Yi, Xuejie; Gao, Haining; Chen, Dequan; Tang, Donghui; Huang, Wanting; Li, Tao; Ma, Tie; Chang, Bo

    2017-04-01

    To explore the role of the testicular leptin and JAK-STAT[leptin (LEP)-JAK-STAT] pathway in testosterone biosynthesis during juvenile stages and exercise for weight loss, male C57BL/6J mice were randomly divided into normal-diet and high-fat diet groups. After 10 wk, mice in the high-fat diet-fed group were further divided randomly into obese control, obese moderate-volume exercise, and obese high-volume exercise groups. Mice in the obese moderate-volume exercise group were provided with 2 h/day, 6 days/wk swimming exercise for 8 wk, and mice in the obese high-volume exercise group underwent twice the amount of daily exercise intervention as the obese moderate-volume exercise group. The results showed that a high-fat diet causes obesity, leptin resistance, inhibition of the testicular LEP-JAK-STAT pathway, decreased mRNA and protein expression of steroidogenic factor-1, steroidogenic acute regulatory protein, and the P -450 side-chain cleavage enzyme, a decrease in the serum testosterone-to-estradiol ratio, and declines in sperm quality parameters. Both moderate and high-volume exercise were able to reduce body fat and increase the mRNA and protein expression of LEP-JAK-STAT, but only moderate exercise significantly increased the mRNA and protein expression of steroidogenic factor-1, steroidogenic acute regulatory protein, and P -450 side-chain cleavage enzyme and significantly reversed the serum testosterone-to-estradiol ratio and sperm quality parameters. These findings suggest that by impairing the testicular LEP-JAK-STAT pathway, early-stage obesity inhibits the biosynthesis of testosterone and sexual development and reduces male reproductive potential. Long-term moderate and high-volume exercise can effectively reduce body fat and improve obesity-induced abnormalities in testicular leptin signal transduction, whereas only moderate-volume exercise can reverse the negative impacts of obesity on male reproductive function. Copyright © 2017 the American

  11. Leading Democratically

    Science.gov (United States)

    Brookfield, Stephen

    2010-01-01

    Democracy is the most venerated of American ideas, the one for which wars are fought and people die. So most people would probably agree that leaders should be able to lead well in a democratic society. Yet, genuinely democratic leadership is a relative rarity. Leading democratically means viewing leadership as a function or process, rather than…

  12. Signal perception, transduction, and response in gravity resistance. Another graviresponse in plants

    Science.gov (United States)

    Hoson, T.; Saito, Y.; Soga, K.; Wakabayashi, K.

    Resistance to the gravitational force is a serious problem that plants have had to solve to survive on land. Mechanical resistance to the pull of gravity is thus a principal graviresponse in plants, comparable to gravitropism. Nevertheless, only limited information has been obtained for this gravity response. We have examined the mechanism of gravity-induced mechanical resistance using hypergravity conditions produced by centrifugation. As a result, we have clarified the outline of the sequence of events leading to the development of mechanical resistance. The gravity signal may be perceived by mechanoreceptors (mechanosensitive ion channels) on the plasma membrane and it appears that amyloplast sedimentation in statocytes is not involved. Transformation and transduction of the perceived signal may be mediated by the structural or physiological continuum of microtubule-cell membrane-cell wall. As the final step in the development of mechanical resistance, plants construct a tough body by increasing cell wall rigidity. The increase in cell wall rigidity is brought about by modification of the metabolism of certain wall constituents and modification of the cell wall environment, especially pH. We need to clarify the details of each step by future space and ground-based experiments.

  13. Computational study of noise in a large signal transduction network

    Directory of Open Access Journals (Sweden)

    Ruohonen Keijo

    2011-06-01

    Full Text Available Abstract Background Biochemical systems are inherently noisy due to the discrete reaction events that occur in a random manner. Although noise is often perceived as a disturbing factor, the system might actually benefit from it. In order to understand the role of noise better, its quality must be studied in a quantitative manner. Computational analysis and modeling play an essential role in this demanding endeavor. Results We implemented a large nonlinear signal transduction network combining protein kinase C, mitogen-activated protein kinase, phospholipase A2, and β isoform of phospholipase C networks. We simulated the network in 300 different cellular volumes using the exact Gillespie stochastic simulation algorithm and analyzed the results in both the time and frequency domain. In order to perform simulations in a reasonable time, we used modern parallel computing techniques. The analysis revealed that time and frequency domain characteristics depend on the system volume. The simulation results also indicated that there are several kinds of noise processes in the network, all of them representing different kinds of low-frequency fluctuations. In the simulations, the power of noise decreased on all frequencies when the system volume was increased. Conclusions We concluded that basic frequency domain techniques can be applied to the analysis of simulation results produced by the Gillespie stochastic simulation algorithm. This approach is suited not only to the study of fluctuations but also to the study of pure noise processes. Noise seems to have an important role in biochemical systems and its properties can be numerically studied by simulating the reacting system in different cellular volumes. Parallel computing techniques make it possible to run massive simulations in hundreds of volumes and, as a result, accurate statistics can be obtained from computational studies.

  14. Transduction-like gene transfer in the methanogen Methanococcus voltae

    Science.gov (United States)

    Bertani, G.

    1999-01-01

    Strain PS of Methanococcus voltae (a methanogenic, anaerobic archaebacterium) was shown to generate spontaneously 4.4-kbp chromosomal DNA fragments that are fully protected from DNase and that, upon contact with a cell, transform it genetically. This activity, here called VTA (voltae transfer agent), affects all markers tested: three different auxotrophies (histidine, purine, and cobalamin) and resistance to BES (2-bromoethanesulfonate, an inhibitor of methanogenesis). VTA was most effectively prepared by culture filtration. This process disrupted a fraction of the M. voltae cells (which have only an S-layer covering their cytoplasmic membrane). VTA was rapidly inactivated upon storage. VTA particles were present in cultures at concentrations of approximately two per cell. Gene transfer activity varied from a minimum of 2 x 10(-5) (BES resistance) to a maximum of 10(-3) (histidine independence) per donor cell. Very little VTA was found free in culture supernatants. The phenomenon is functionally similar to generalized transduction, but there is no evidence, for the time being, of intrinsically viral (i.e., containing a complete viral genome) particles. Consideration of VTA DNA size makes the existence of such viral particles unlikely. If they exist, they must be relatively few in number;perhaps they differ from VTA particles in size and other properties and thus escaped detection. Digestion of VTA DNA with the AluI restriction enzyme suggests that it is a random sample of the bacterial DNA, except for a 0.9-kbp sequence which is amplified relative to the rest of the bacterial chromosome. A VTA-sized DNA fraction was demonstrated in a few other isolates of M. voltae.

  15. Transduction on Directed Graphs via Absorbing Random Walks.

    Science.gov (United States)

    De, Jaydeep; Zhang, Xiaowei; Lin, Feng; Cheng, Li

    2017-08-11

    In this paper we consider the problem of graph-based transductive classification, and we are particularly interested in the directed graph scenario which is a natural form for many real world applications.Different from existing research efforts that either only deal with undirected graphs or circumvent directionality by means of symmetrization, we propose a novel random walk approach on directed graphs using absorbing Markov chains, which can be regarded as maximizing the accumulated expected number of visits from the unlabeled transient states. Our algorithm is simple, easy to implement, and works with large-scale graphs on binary, multiclass, and multi-label prediction problems. Moreover, it is capable of preserving the graph structure even when the input graph is sparse and changes over time, as well as retaining weak signals presented in the directed edges. We present its intimate connections to a number of existing methods, including graph kernels, graph Laplacian based methods, and interestingly, spanning forest of graphs. Its computational complexity and the generalization error are also studied. Empirically our algorithm is systematically evaluated on a wide range of applications, where it has shown to perform competitively comparing to a suite of state-of-the-art methods. In particular, our algorithm is shown to work exceptionally well with large sparse directed graphs with e.g. millions of nodes and tens of millions of edges, where it significantly outperforms other state-of-the-art methods. In the dynamic graph setting involving insertion or deletion of nodes and edge-weight changes over time, it also allows efficient online updates that produce the same results as of the batch update counterparts.

  16. Second-chance signal transduction explains cooperative flagellar switching.

    Science.gov (United States)

    Zot, Henry G; Hasbun, Javier E; Minh, Nguyen Van

    2012-01-01

    The reversal of flagellar motion (switching) results from the interaction between a switch complex of the flagellar rotor and a torque-generating stationary unit, or stator (motor unit). To explain the steeply cooperative ligand-induced switching, present models propose allosteric interactions between subunits of the rotor, but do not address the possibility of a reaction that stimulates a bidirectional motor unit to reverse direction of torque. During flagellar motion, the binding of a ligand-bound switch complex at the dwell site could excite a motor unit. The probability that another switch complex of the rotor, moving according to steady-state rotation, will reach the same dwell site before that motor unit returns to ground state will be determined by the independent decay rate of the excited-state motor unit. Here, we derive an analytical expression for the energy coupling between a switch complex and a motor unit of the stator complex of a flagellum, and demonstrate that this model accounts for the cooperative switching response without the need for allosteric interactions. The analytical result can be reproduced by simulation when (1) the motion of the rotor delivers a subsequent ligand-bound switch to the excited motor unit, thereby providing the excited motor unit with a second chance to remain excited, and (2) the outputs from multiple independent motor units are constrained to a single all-or-none event. In this proposed model, a motor unit and switch complex represent the components of a mathematically defined signal transduction mechanism in which energy coupling is driven by steady-state and is regulated by stochastic ligand binding. Mathematical derivation of the model shows the analytical function to be a general form of the Hill equation (Hill AV (1910) The possible effects of the aggregation of the molecules of haemoglobin on its dissociation curves. J Physiol 40: iv-vii).

  17. Pathway Model of the Kinetics of the TGFbeta Antagonist Smad7 and Cross-Talk with the ATM and WNT Pathways

    Science.gov (United States)

    Carra, Claudio; Wang, Minli; Huff, Janice L.; Hada, Megumi; ONeill, Peter; Cucinotta, Francis A.

    2010-01-01

    Signal transduction controls cellular and tissue responses to radiation. Transforming growth factor beta (TGFbeta) is an important regulator of cell growth and differentiation and tissue homeostasis, and is often dis-regulated in tumor formation. Mathematical models of signal transduction pathways can be used to elucidate how signal transduction varies with radiation quality, and dose and dose-rate. Furthermore, modeling of tissue specific responses can be considered through mechanistic based modeling. We developed a mathematical model of the negative feedback regulation by Smad7 in TGFbeta-Smad signaling and are exploring possible connections to the WNT/beta -catenin, and ATM/ATF2 signaling pathways. A pathway model of TGFbeta-Smad signaling that includes Smad7 kinetics based on data in the scientific literature is described. Kinetic terms included are TGFbeta/Smad transcriptional regulation of Smad7 through the Smad3-Smad4 complex, Smad7-Smurf1 translocation from nucleus to cytoplasm, and Smad7 negative feedback regulation of the TGFO receptor through direct binding to the TGFO receptor complex. The negative feedback controls operating in this pathway suggests non-linear responses in signal transduction, which are described mathematically. We then explored possibilities for cross-talk mediated by Smad7 between DNA damage responses mediated by ATM, and with the WNT pathway and consider the design of experiments to test model driven hypothesis. Numerical comparisons of the mathematical model to experiments and representative predictions are described.

  18. Signal Sensing and Transduction by Histidine Kinases as Unveiled through Studies on a Temperature Sensor.

    Science.gov (United States)

    Abriata, Luciano A; Albanesi, Daniela; Dal Peraro, Matteo; de Mendoza, Diego

    2017-06-20

    experiments and molecular simulations further showed that reversible formation of a two-helix coiled coil in the fifth TM segment and the N-terminus of the cytoplasmic domain is essential for the sensing and signal transduction mechanisms. Together with other structural and functional works, the emerging picture suggests that diverse HKs possess distinct sensing and transduction mechanisms but share as rather general features (i) a symmetric phosphatase state and an asymmetric kinase state and (ii) similar functional outputs on the conserved DHp and ABD domains, achieved through different mechanisms that depend on the nature of the initial signal. We here advance (iii) an important role for TM prolines in transducing the initial signals to the cytoplasmic coiled coils, based on simulations of DesK's TM helices and our previous work on a related HK, PhoQ. Lastly, evidence for DesK, PhoQ, BvgS, and DctB HKs shows that (iv) overall catalytic output is tuned by a delicate balance between hydration potentials, coiled coil stability, and exposure of hydrophobic surface patches at their cytoplasmic coiled coils and at the N-terminal and C-terminal sides of their TM helices. This balance is so delicate that small perturbations, either physiological signals or induced by mutations, lead to large remodeling of the underlying conformational landscape achieving clear-cut changes in catalytic output, mirroring the required response speed of these systems for proper biological function.

  19. Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Theilade, M D; Gram, G J; Jensen, P B

    1999-01-01

    Multidrug resistance (MDR) remains a major problem in the successful treatment of small cell lung cancer (SCLC). New treatment strategies are needed, such as gene therapy specifically targeting the MDR cells in the tumor. Retroviral LacZ gene-containing vectors that were either pseudotyped...... for the gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage...... of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

  20. Efficient, Broadband and Wide-Angle Hot-Electron Transduction using Metal-Semiconductor Hyperbolic Metamaterials

    KAUST Repository

    Sakhdari, Maryam; Hajizadegan, Mehdi; Farhat, Mohamed; Chen, Pai-Yen

    2016-01-01

    Hot-electron devices are emerging as promising candidates for the transduction of optical radiation into electrical current, as they enable photodetection and solar/infrared energy harvesting at sub-bandgap wavelengths. Nevertheless, poor

  1. [Cellular adhesion signal transduction network of tumor necrosis factor-alpha induced hepatocellular carcinoma cells].

    Science.gov (United States)

    Zheng, Yongchang; Du, Shunda; Xu, Haifeng; Xu, Yiyao; Zhao, Haitao; Chi, Tianyi; Lu, Xin; Sang, Xinting; Mao, Yilei

    2014-11-18

    To systemically explore the cellular adhesion signal transduction network of tumor necrosis factor-alpha (TNF-α)-induced hepatocellular carcinoma cells with bioinformatics tools. Published microarray dataset of TNF-α-induced HepG2, human transcription factor database HTRI and human protein-protein interaction database HPRD were used to construct and analyze the signal transduction network. In the signal transduction network, MYC and SP1 were the key nodes of signaling transduction. Several genes from the network were closely related with cellular adhesion.Epidermal growth factor receptor (EGFR) is a possible key gene of effectively regulating cellular adhesion during the induction of TNF-α. EGFR is a possible key gene for TNF-α-induced metastasis of hepatocellular carcinoma.

  2. Spatial modeling of the membrane-cytosolic interface in protein kinase signal transduction.

    Directory of Open Access Journals (Sweden)

    Wolfgang Giese

    2018-04-01

    Full Text Available The spatial architecture of signaling pathways and the interaction with cell size and morphology are complex, but little understood. With the advances of single cell imaging and single cell biology, it becomes crucial to understand intracellular processes in time and space. Activation of cell surface receptors often triggers a signaling cascade including the activation of membrane-attached and cytosolic signaling components, which eventually transmit the signal to the cell nucleus. Signaling proteins can form steep gradients in the cytosol, which cause strong cell size dependence. We show that the kinetics at the membrane-cytosolic interface and the ratio of cell membrane area to the enclosed cytosolic volume change the behavior of signaling cascades significantly. We suggest an estimate of average concentration for arbitrary cell shapes depending on the cell volume and cell surface area. The normalized variance, known from image analysis, is suggested as an alternative measure to quantify the deviation from the average concentration. A mathematical analysis of signal transduction in time and space is presented, providing analytical solutions for different spatial arrangements of linear signaling cascades. Quantification of signaling time scales reveals that signal propagation is faster at the membrane than at the nucleus, while this time difference decreases with the number of signaling components in the cytosol. Our investigations are complemented by numerical simulations of non-linear cascades with feedback and asymmetric cell shapes. We conclude that intracellular signal propagation is highly dependent on cell geometry and, thereby, conveys information on cell size and shape to the nucleus.

  3. Leading change.

    Science.gov (United States)

    2017-02-27

    In response to feedback from nursing, midwifery and other care staff who wanted to understand better how the Leading Change, Adding Value framework applies to them, NHS England has updated its webpage to include practice examples.

  4. Investigation of the charge effect on the electrochemical transduction in a quinone-based DNA sensor

    DEFF Research Database (Denmark)

    Reisberg, S.; Piro, B.; Noel, V.

    2008-01-01

    To elucidate the mechanism involved in the electrochemical transduction process of a conducting polymer-based DNA sensor, peptide nucleic acids (PNA) were used. PNA are DNA analogues having similar hybridization properties but are neutral. This allows to discriminate the electrostatic effect of D...... strands from the steric hindrance generated on the bioelectrode upon hybridization. It can be concluded that DNA conformational changes are determinant in the transduction process and that the electrostatic effect is negligible....

  5. Cavity opto-electromechanical system combining strong electrical actuation with ultrasensitive transduction

    OpenAIRE

    McRae, Terry G.; Lee, Kwan H.; Harris, Glen I.; Knittel, Joachim; Bowen, Warwick P.

    2010-01-01

    A cavity opto-electromechanical system is reported which combines the ultrasensitive transduction of cavity optomechanical systems with the electrical actuation of nanoelectromechanical systems. Ultrasensitive mechanical transduction is achieved via opto-mechanical coupling. Electrical gradient forces as large as 0.40 $\\mu$N are realized, facilitating strong actuation with ultralow dissipation. A scanning probe microscope is implemented, capable of characterizing the mechanical modes. The int...

  6. Polyploidization without mitosis improves in vivo liver transduction with lentiviral vectors.

    Science.gov (United States)

    Pichard, Virginie; Couton, Dominique; Desdouets, Chantal; Ferry, Nicolas

    2013-02-01

    Lentiviral vectors are efficient gene delivery vehicles for therapeutic and research applications. In contrast to oncoretroviral vectors, they are able to infect most nonproliferating cells. In the liver, induction of cell proliferation dramatically improved hepatocyte transduction using all types of retroviral vectors. However, the precise relationship between hepatocyte division and transduction efficiency has not been determined yet. Here we compared gene transfer efficiency in the liver after in vivo injection of recombinant lentiviral or Moloney murine leukemia viral (MoMuLV) vectors in hepatectomized rats treated or not with retrorsine, an alkaloid that blocks hepatocyte division and induces megalocytosis. Partial hepatectomy alone resulted in a similar increase in hepatocyte transduction using either vector. In retrorsine-treated and partially hepatectomized rats, transduction with MoMuLV vectors dropped dramatically. In contrast, we observed that retrorsine treatment combined with partial hepatectomy increased lentiviral transduction to higher levels than hepatectomy alone. Analysis of nuclear ploidy in single cells showed that a high level of transduction was associated with polyploidization. In conclusion, endoreplication could be exploited to improve the efficiency of liver-directed lentiviral gene therapy.

  7. Wnt-11 signaling leads to down-regulation of the Wnt/β-catenin, JNK/AP-1 and NF-κB pathways and promotes viability in the CHO-K1 cells

    International Nuclear Information System (INIS)

    Railo, Antti; Nagy, Irina I.; Kilpelaeinen, Pekka; Vainio, Seppo

    2008-01-01

    The Wnt family of glycoprotein growth factors controls a number of central cellular processes such as proliferation, differentiation and ageing. All the Wnt proteins analyzed so far either activate or inhibit the canonical β-catenin signaling pathway that regulates transcription of the target genes. In addition, some of them activate noncanonical signaling pathways that involve components such as the JNK, heterotrimeric G proteins, protein kinase C, and calmodulin-dependent protein kinase II, although the precise signaling mechanisms are only just beginning to be revealed. We demonstrate here that Wnt-11 signaling is sufficient to inhibit not only the canonical β-catenin mediated Wnt signaling but also JNK/AP-1 and NF-κB signaling in the CHO cells, thus serving as a noncanonical Wnt ligand in this system. Inhibition of the JNK/AP-1 pathway is mediated in part by the MAPK kinase MKK4 and Akt. Moreover, protein kinase C is involved in the regulation of JNK/AP-1 by Wnt-11, but not of the NF-κB pathway. Consistent with the central role of Akt, JNK and NF-κB in cell survival and stress responses, Wnt-11 signaling promotes cell viability. Hence Wnt-11 is involved in coordination of key signaling pathways

  8. Full Piezoelectric Multilayer-Stacked Hybrid Actuation/Transduction Systems

    Science.gov (United States)

    Su, Ji; Jiang, Xiaoning; Zu, Tian-Bing

    2011-01-01

    The Stacked HYBATS (Hybrid Actuation/Transduction system) demonstrates significantly enhanced electromechanical performance by using the cooperative contributions of the electromechanical responses of multilayer, stacked negative strain components and positive strain components. Both experimental and theoretical studies indicate that, for Stacked HYBATS, the displacement is over three times that of a same-sized conventional flextensional actuator/transducer. The coupled resonance mode between positive strain and negative strain components of Stacked HYBATS is much stronger than the resonance of a single element actuation only when the effective lengths of the two kinds of elements match each other. Compared with the previously invented hybrid actuation system (HYBAS), the multilayer Stacked HYBATS can be designed to provide high mechanical load capability, low voltage driving, and a highly effective piezoelectric constant. The negative strain component will contract, and the positive strain component will expand in the length directions when an electric field is applied on the device. The interaction between the two elements makes an enhanced motion along the Z direction for Stacked-HYBATS. In order to dominate the dynamic length of Stacked-HYBATS by the negative strain component, the area of the cross-section for the negative strain component will be much larger than the total cross-section areas of the two positive strain components. The transverse strain is negative and longitudinal strain positive in inorganic materials, such as ceramics/single crystals. Different piezoelectric multilayer stack configurations can make a piezoelectric ceramic/single-crystal multilayer stack exhibit negative strain or positive strain at a certain direction without increasing the applied voltage. The difference of this innovation from the HYBAS is that all the elements can be made from one-of-a-kind materials. Stacked HYBATS can provide an extremely effective piezoelectric

  9. Signal transduction, receptors, mediators and genes: younger than ever - the 13th meeting of the Signal Transduction Society focused on aging and immunology

    Directory of Open Access Journals (Sweden)

    Klotz Lars-Oliver

    2010-02-01

    Full Text Available Abstract The 13th meeting of the Signal Transduction Society was held in Weimar, from October 28 to 30, 2009. Special focus of the 2009 conference was "Aging and Senescence", which was co-organized by the SFB 728 "Environmentally-Induced Aging Processes" of the University of Düsseldorf and the study group 'Signal Transduction' of the German Society for Cell Biology (DGZ. In addition, several other areas of signal transduction research were covered and supported by different consortia associated with the Signal Transduction Society including the long-term associated study groups of the German Society for Immunology and the Society for Biochemistry and Molecular Biology, and for instance the SFB/Transregio 52 "Transcriptional Programming of Individual T Cell Subsets" located in Würzburg, Mainz and Berlin. The different research areas that were introduced by outstanding keynote speakers attracted more than 250 scientists, showing the timeliness and relevance of the interdisciplinary concept and exchange of knowledge during the three days of the scientific program. This report gives an overview of the presentations of the conference.

  10. CHARACTERISTICS OF SIGNALING PATHWAYS MEDIATING A CYTOTOXIC EFFECT OF DENDRITIC CELLS UPON ACTIVATED Т LYMPHOCYTES AND NK CELLS

    Directory of Open Access Journals (Sweden)

    T. V. Tyrinova

    2012-01-01

    Full Text Available Abstract. Cytotoxic/pro-apoptogenic effects of IFNα-induced dendritic cells (IFN-DCs directed against Т-lymphocytes and NK cells were investigated in healthy donors. Using an allogenic MLC system, it was revealed that IFN-DCs induce apoptosis of both activated CD4+ and CD8+ T-lymphocytes, and NK cells. Apoptosis of CD4+ and CD8+ T-lymphocytes induced by their interaction with IFN-DCs was mediated by various signaling pathways. In particular, activated CD4+Т-lymphocytes were most sensitive to TRAIL- и Fas/ FasL-transduction pathways, whereas activated CD8+ T-lymphocytes were induced to apoptosis via TNFα-mediated pathway. PD-1/B7-H1-signaling pathway also played a distinct role in cytotoxic activity of IFNDCs towards both types of T lymphocytes and activated NK cells. The pro-apoptogenic/cytotoxic activity of IFN-DC against activated lymphocytes may be regarded as a mechanism of a feedback regulation aimed at restriction of immune response and maintenance of immune homeostasis. Moreover, upregulation of proapoptogenic molecules on DCs under pathological conditions may lead to suppression of antigen-specific response, thus contributing to the disease progression.

  11. Ecotoxicology: Lead

    Science.gov (United States)

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  12. Antitumor activity of novel chimeric peptides derived from cyclinD/CDK4 and the protein transduction domain 4.

    Science.gov (United States)

    Wang, Haili; Chen, Xi; Chen, Yanping; Sun, Lei; Li, Guodong; Zhai, Mingxia; Zhai, Wenjie; Kang, Qiaozhen; Gao, Yanfeng; Qi, Yuanming

    2013-02-01

    CyclinD1/CDK4 and cyclinD3/CDK4 complexes are key regulators of the cell progression and therefore constitute promising targets for the design of anticancer agents. In the present study, the key peptide motifs were selected from these two complexes. Chimeric peptides with these peptides conjugated to the protein transduction domain 4 (PTD4) were designed and synthesized. The chimeric peptides, PTD4-D1, PTD4-D3, PTD4-K4 exhibited significant anti-proliferation effects on cancer cell lines. These peptides could compete with the cyclinD/CDK4 complex and induce the G1/S phase arrest and apoptosis of cancer cells. In the tumor challenge experiment, these peptides showed potent antitumor effects with no significant side effects. Our results suggested that these peptides could be served as novel leading compounds with potent antitumor activity.

  13. Leading men

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2016-01-01

    Through a systematic comparison of c. 50 careers leading to the koinarchate or high priesthood of Asia, Bithynia, Galatia, Lycia, Macedonia and coastal Pontus, as described in funeral or honorary inscriptions of individual koinarchs, it is possible to identify common denominators but also disting...

  14. Scoring systems used for the interpretation and reporting of multiparametric MRI for prostate cancer detection, localization, and characterization: Could standardization lead to improved utilization of imaging within the diagnostic pathway?

    NARCIS (Netherlands)

    Dickinson, L.; Ahmed, H.U.; Allen, C.; Barentsz, J.O.; Carey, B.; Futterer, J.J.; Heijmink, S.W.T.P.J.; Hoskin, P.; Kirkham, A.P.; Padhani, A.R.; Persad, R.; Puech, P.; Punwani, S.; Sohaib, A.; Tombal, B.; Villers, A.; Emberton, M.

    2013-01-01

    Multiparametric magnetic resonance imaging (mpMRI) is increasingly being used earlier in the prostate cancer diagnostic pathway in order to detect and localize disease. Its results can be used to help decide on the indication, type, and localization of a prostate biopsy for cancer diagnosis. In

  15. Single Amino Acid Modification of Adeno-Associated Virus Capsid Changes Transduction and Humoral Immune Profiles

    Science.gov (United States)

    Diprimio, Nina; Bowles, Dawn E.; Hirsch, Matthew L.; Monahan, Paul E.; Asokan, Aravind; Rabinowitz, Joseph; Agbandje-McKenna, Mavis

    2012-01-01

    Adeno-associated virus (AAV) vectors have the potential to promote long-term gene expression. Unfortunately, humoral immunity restricts patient treatment and in addition provides an obstacle to the potential option of vector readministration. In this study, we describe a comprehensive characterization of the neutralizing antibody (NAb) response to AAV type 1 (AAV1) through AAV5 both in vitro and in vivo. These results demonstrated that NAbs generated from one AAV type are unable to neutralize the transduction of other types. We extended this observation by demonstrating that a rationally engineered, muscle-tropic AAV2 mutant containing 5 amino acid substitutions from AAV1 displayed a NAb profile different from those of parental AAV2 and AAV1. Here we found that a single insertion of Thr from AAV1 into AAV2 capsid at residue 265 preserved high muscle transduction, while also changing the immune profile. To better understand the role of Thr insertion at position 265, we replaced all 20 amino acids and evaluated both muscle transduction and the NAb response. Of these variants, 8 mutants induced higher muscle transduction than AAV2. Additionally, three classes of capsid NAb immune profile were defined based on the ability to inhibit transduction from AAV2 or mutants. While no relationship was found between transduction, amino acid properties, and NAb titer or its cross-reactivity, these studies map a critical capsid motif involved in all steps of AAV infectivity. Our results suggest that AAV types can be utilized not only as templates to generate mutants with enhanced transduction efficiency but also as substrates for repeat administration. PMID:22593151

  16. Intravenous administration of the adeno-associated virus-PHP.B capsid fails to upregulate transduction efficiency in the marmoset brain.

    Science.gov (United States)

    Matsuzaki, Yasunori; Konno, Ayumu; Mochizuki, Ryuta; Shinohara, Yoichiro; Nitta, Keisuke; Okada, Yukihiro; Hirai, Hirokazu

    2018-02-05

    Intravenous administration of adeno-associated virus (AAV)-PHP.B, a capsid variant of AAV9 containing seven amino acid insertions, results in a greater permeability of the blood brain barrier (BBB) than standard AAV9 in mice, leading to highly efficient and global transduction of the central nervous system (CNS). The present study aimed to examine whether the enhanced BBB penetrance of AAV-PHP.B observed in mice also occurs in non-human primates. Thus, a young adult (age, 1.6 years) and an old adult (age, 7.2 years) marmoset received an intravenous injection of AAV-PHP.B expressing enhanced green fluorescent protein (EGFP) under the control of the constitutive CBh promoter (a hybrid of cytomegalovirus early enhancer and chicken β-actin promoter). Age-matched control marmosets were treated with standard AAV9-capsid vectors. The animals were sacrificed 6 weeks after the viral injection. Based on the results, only limited transduction of neurons (0-2%) and astrocytes (0.1-2.5%) was observed in both AAV-PHP.B- and AAV9-treated marmosets. One noticeable difference between AAV-PHP.B and AAV9 was the marked transduction of the peripheral dorsal root ganglia neurons. Indeed, the soma and axons in the projection from the spinal cord to the nucleus cuneatus in the medulla oblongata were strongly labeled with EGFP by AAV-PHP.B. Thus, except for the peripheral dorsal root ganglia neurons, the AAV-PHP.B transduction efficiency in the CNS of marmosets was comparable to that of AAV9 vectors. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Benzo[a]pyrene affects Jurkat T cells in the activated state via the antioxidant response element dependent Nrf2 pathway leading to decreased IL-2 secretion and redirecting glutamine metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Murugaiyan, Jayaseelan; Rockstroh, Maxie; Wagner, Juliane [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Baumann, Sven [Department of Metabolomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Schorsch, Katrin [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Trump, Saskia; Lehmann, Irina [Department of Environmental Immunology, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Bergen, Martin von [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Department of Environmental Immunology, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany); Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg (Denmark); Tomm, Janina M., E-mail: Janina.tomm@ufz.de [Department of Proteomics, Helmholtz-Centre for Environmental Research — UFZ, Permoserstr. 15, 04318 Leipzig (Germany)

    2013-06-15

    There is a clear evidence that environmental pollutants, such as benzo[a]pyrene (B[a]P), can have detrimental effects on the immune system, whereas the underlying mechanisms still remain elusive. Jurkat T cells share many properties with native T lymphocytes and therefore are an appropriate model to analyze the effects of environmental pollutants on T cells and their activation. Since environmental compounds frequently occur at low, not acute toxic concentrations, we analyzed the effects of two subtoxic concentrations, 50 nM and 5 μM, on non- and activated cells. B[a]P interferes directly with the stimulation process as proven by an altered IL-2 secretion. Furthermore, B[a]P exposure results in significant proteomic changes as shown by DIGE analysis. Pathway analysis revealed an involvement of the AhR independent Nrf2 pathway in the altered processes observed in unstimulated and stimulated cells. A participation of the Nrf2 pathway in the change of IL-2 secretion was confirmed by exposing cells to the Nrf2 activator tBHQ. tBHQ and 5 μM B[a]P caused similar alterations of IL-2 secretion and glutamine/glutamate metabolism. Moreover, the proteome changes in unstimulated cells point towards a modified regulation of the cytoskeleton and cellular stress response, which was proven by western blotting. Additionally, there is a strong evidence for alterations in metabolic pathways caused by B[a]P exposure in stimulated cells. Especially the glutamine/glutamate metabolism was indicated by proteome pathway analysis and validated by metabolite measurements. The detrimental effects were slightly enhanced in stimulated cells, suggesting that stimulated cells are more vulnerable to the environmental pollutant model compound B[a]P. - Highlights: • B[a]P affects the proteome of Jurkat T cells also at low concentrations. • Exposure to B[a]P (50 nM, 5 μM) did not change Jurkat T cell viability. • Both B[a]P concentrations altered the IL-2 secretion of stimulated cells.

  18. Iodine-131 treatment of thyroid cancer cells leads to suppression of cell proliferation followed by induction of cell apoptosis and cell cycle arrest by regulation of B-cell translocation gene 2-mediated JNK/NF-κB pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.M.; Pang, A.X., E-mail: zhaoliming515@126.com [Department of Nuclear Medicine, Linyi People' s Hospital, Linyi (China); Department of Urology, Linyi People' s Hospital, Linyi (China)

    2017-10-01

    Iodine-131 ({sup 131}I) is widely used for the treatment of thyroid-related diseases. This study aimed to investigate the expression of p53 and BTG2 genes following {sup 131}I therapy in thyroid cancer cell line SW579 and the possible underlying mechanism. SW579 human thyroid squamous carcinoma cells were cultured and treated with {sup 131}I. They were then assessed for {sup 131}I uptake, cell viability, apoptosis, cell cycle arrest, p53 expression, and BTG2 gene expression. SW579 cells were transfected with BTG2 siRNA, p53 siRNA and siNC and were then examined for the same aforementioned parameters. When treated with a JNK inhibitor of SP600125 and {sup 131}I or with a NF-kB inhibitor of BMS-345541 and {sup 131}I, non-transfected SW579 cells were assessed in JNK/NFkB pathways. It was observed that {sup 131}I significantly inhibited cell proliferation, promoted cell apoptosis and cell cycle arrest. Both BTG2 and p53 expression were enhanced in a dose-dependent manner. An increase in cell viability by up-regulation in Bcl2 gene, a decrease in apoptosis by enhanced CDK2 gene expression and a decrease in cell cycle arrest at G{sub 0}/G{sub 1} phase were also observed in SW579 cell lines transfected with silenced BTG2 gene. When treated with SP600125 and {sup 131}I, the non transfected SW579 cell lines significantly inhibited JNK pathway, NF-kB pathway and the expression of BTG2. However, when treated with BMS-345541 and {sup 131}I, only the NF-kB pathway was suppressed. {sup 131}I suppressed cell proliferation, induced cell apoptosis, and promoted cell cycle arrest of thyroid cancer cells by up-regulating B-cell translocation gene 2-mediated activation of JNK/NF--κB pathways. (author)

  19. Who Leads China's Leading Universities?

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  20. Understanding the role of nonlinearities in the transduction of vibratory energy harvesters

    Science.gov (United States)

    Masana, Ravindra Shiva Charan

    The last two decades have witnessed several advances in micro-fabrication technologies and electronics, leading to the development of small, low-power devices for wireless sensing, data transmission, actuation, and medical implants. Unfortunately, the actual implementation of such devices in their respective environment has been hindered by the lack of scalable energy sources that are necessary to power and maintain them. Batteries, which remain the most commonly used power source, have not kept pace with the demands of these devices, especially in terms of energy density. In light of this challenge, the concept of vibratory energy harvesting has flourished in recent years as a possible alternative to power and maintain low-power electronics. While linear vibratory energy harvesters have received the majority of the literature's attention, a significant body of the current research activity is focused on the concept of purposeful inclusion of nonlinearities for broadband transduction. When compared to their linear resonant counterparts, nonlinear energy harvesters have a wider steady-state frequency bandwidth, leading to the common belief that they can be utilized to improve performance especially in random and non-stationary vibratory environments. This dissertation aims to critically investigate this belief by drawing a clearer picture of the role of nonlinearities in the transduction of energy harvesters and by defining the conditions under which nonlinearities can be used to enhance performance. To achieve this goal, the Thesis is divided into three parts. The first part investigates the performance of mono- and bi-stable energy harvesters under harmonic excitations and carries a detailed analysis of their relative performance. The second part investigates their response to broadband and narrowband random excitations and again analyzes their relative behavior. The third part exploits the super-harmonic resonance bands of bi-stable energy harvesters for the

  1. Computational identification of signalling pathways in Plasmodium falciparum.

    Science.gov (United States)

    Oyelade, Jelili; Ewejobi, Itunu; Brors, Benedikt; Eils, Roland; Adebiyi, Ezekiel

    2011-06-01

    Malaria is one of the world's most common and serious diseases causing death of about 3 million people each year. Its most severe occurrence is caused by the protozoan Plasmodium falciparum. Reports have shown that the resistance of the parasite to existing drugs is increasing. Therefore, there is a huge and urgent need to discover and validate new drug or vaccine targets to enable the development of new treatments for malaria. The ability to discover these drug or vaccine targets can only be enhanced from our deep understanding of the detailed biology of the parasite, for example how cells function and how proteins organize into modules such as metabolic, regulatory and signal transduction pathways. It has been noted that the knowledge of signalling transduction pathways in Plasmodium is fundamental to aid the design of new strategies against malaria. This work uses a linear-time algorithm for finding paths in a network under modified biologically motivated constraints. We predicted several important signalling transduction pathways in Plasmodium falciparum. We have predicted a viable signalling pathway characterized in terms of the genes responsible that may be the PfPKB pathway recently elucidated in Plasmodium falciparum. We obtained from the FIKK family, a signal transduction pathway that ends up on a chloroquine resistance marker protein, which indicates that interference with FIKK proteins might reverse Plasmodium falciparum from resistant to sensitive phenotype. We also proposed a hypothesis that showed the FIKK proteins in this pathway as enabling the resistance parasite to have a mechanism for releasing chloroquine (via an efflux process). Furthermore, we also predicted a signalling pathway that may have been responsible for signalling the start of the invasion process of Red Blood Cell (RBC) by the merozoites. It has been noted that the understanding of this pathway will give insight into the parasite virulence and will facilitate rational vaccine design

  2. Effects of the TAT peptide orientation and relative location on the protein transduction efficiency.

    Science.gov (United States)

    Guo, Qingguo; Zhao, Guojie; Hao, Fengjin; Guan, Yifu

    2012-05-01

    To understand the protein transduction domain (PTD)-mediated protein transduction behavior and to explore its potential in delivering biopharmaceutic drugs, we prepared four TAT-EGFP conjugates: TAT(+)-EGFP, TAT(-)-EGFP, EGFP-TAT(+) and EGFP-TAT(-), where TAT(+) and TAT(-) represent the original and the reversed TAT sequence, respectively. These four TAT-EGFP conjugates were incubated with HeLa and PC12 cells for in vitro study as well as injected intraperitoneally to mice for in vivo study. Flow cytometric results showed that four TAT-EGFP conjugates were able to traverse HeLa and PC12 cells with almost equal transduction efficiency. The in vivo study showed that the TAT-EGFP conjugates could be delivered into different organs of mice with different transduction capabilities. Bioinformatic analyses and CD spectroscopic data revealed that the TAT peptide has no defined secondary structure, and conjugating the TAT peptide to the EGFP cargo protein would not alter the native structure and the function of the EGFP protein. These results conclude that the sequence orientation, the spatial structure, and the relative location of the TAT peptide have much less effect on the TAT-mediated protein transduction. Thus, the TAT-fused conjugates could be constructed in more convenient and flexible formats for a wide range of biopharmaceutical applications. © 2011 John Wiley & Sons A/S.

  3. Discovery of intramolecular signal transduction network based on a new protein dynamics model of energy dissipation.

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Ma

    Full Text Available A novel approach to reveal intramolecular signal transduction network is proposed in this work. To this end, a new algorithm of network construction is developed, which is based on a new protein dynamics model of energy dissipation. A key feature of this approach is that direction information is specified after inferring protein residue-residue interaction network involved in the process of signal transduction. This enables fundamental analysis of the regulation hierarchy and identification of regulation hubs of the signaling network. A well-studied allosteric enzyme, E. coli aspartokinase III, is used as a model system to demonstrate the new method. Comparison with experimental results shows that the new approach is able to predict all the sites that have been experimentally proved to desensitize allosteric regulation of the enzyme. In addition, the signal transduction network shows a clear preference for specific structural regions, secondary structural types and residue conservation. Occurrence of super-hubs in the network indicates that allosteric regulation tends to gather residues with high connection ability to collectively facilitate the signaling process. Furthermore, a new parameter of propagation coefficient is defined to determine the propagation capability of residues within a signal transduction network. In conclusion, the new approach is useful for fundamental understanding of the process of intramolecular signal transduction and thus has significant impact on rational design of novel allosteric proteins.

  4. Rapid lentiviral transduction preserves the engraftment potential of Fanca(-/-) hematopoietic stem cells.

    Science.gov (United States)

    Müller, Lars U W; Milsom, Michael D; Kim, Mi-Ok; Schambach, Axel; Schuesler, Todd; Williams, David A

    2008-06-01

    Fanconi anemia (FA) is a rare recessive syndrome, characterized by congenital anomalies, bone marrow failure, and predisposition to cancer. Two earlier clinical trials utilizing gamma-retroviral vectors for the transduction of autologous FA hematopoietic stem cells (HSCs) required extensive in vitro manipulation and failed to achieve detectable long-term engraftment of transduced HSCs. As a strategy for minimizing ex vivo manipulation, we investigated the use of a "rapid" lentiviral transduction protocol in a murine Fanca(-/-) model. Importantly, while this and most murine models of FA fail to completely mimic the human hematopoietic phenotype, we observed a high incidence of HSC transplant engraftment failure and low donor chimerism after conventional transduction (CT) of Fanca(-/-) donor cells. In contrast, rapid transduction (RT) of Fanca(-/-) HSCs preserved engraftment to the level achieved in wild-type cells, resulting in long-term multilineage engraftment of gene-modified cells. We also demonstrate the correction of the characteristic hypersensitivity of FA cells against the cross-linking agent mitomycin C (MMC), and provide evidence for the advantage of using pharmacoselection as a means of further increasing gene-modified cells after RT. Collectively, these data support the use of rapid lentiviral transduction for gene therapy in FA.

  5. From stress to inflammation and major depressive disorder: a social signal transduction theory of depression.

    Science.gov (United States)

    Slavich, George M; Irwin, Michael R

    2014-05-01

    Major life stressors, especially those involving interpersonal stress and social rejection, are among the strongest proximal risk factors for depression. In this review, we propose a biologically plausible, multilevel theory that describes neural, physiologic, molecular, and genomic mechanisms that link experiences of social-environmental stress with internal biological processes that drive depression pathogenesis. Central to this social signal transduction theory of depression is the hypothesis that experiences of social threat and adversity up-regulate components of the immune system involved in inflammation. The key mediators of this response, called proinflammatory cytokines, can in turn elicit profound changes in behavior, which include the initiation of depressive symptoms such as sad mood, anhedonia, fatigue, psychomotor retardation, and social-behavioral withdrawal. This highly conserved biological response to adversity is critical for survival during times of actual physical threat or injury. However, this response can also be activated by modern-day social, symbolic, or imagined threats, leading to an increasingly proinflammatory phenotype that may be a key phenomenon driving depression pathogenesis and recurrence, as well as the overlap of depression with several somatic conditions including asthma, rheumatoid arthritis, chronic pain, metabolic syndrome, cardiovascular disease, obesity, and neurodegeneration. Insights from this theory may thus shed light on several important questions including how depression develops, why it frequently recurs, why it is strongly predicted by early life stress, and why it often co-occurs with symptoms of anxiety and with certain physical disease conditions. This work may also suggest new opportunities for preventing and treating depression by targeting inflammation.

  6. From Stress to Inflammation and Major Depressive Disorder: A Social Signal Transduction Theory of Depression

    Science.gov (United States)

    Slavich, George M.; Irwin, Michael R.

    2014-01-01

    Major life stressors, especially those involving interpersonal stress and social rejection, are among the strongest proximal risk factors for depression. In this review, we propose a biologically plausible, multilevel theory that describes neural, physiologic, molecular, and genomic mechanisms that link experiences of social-environmental stress with internal biological processes that drive depression pathogenesis. Central to this social signal transduction theory of depression is the hypothesis that experiences of social threat and adversity up-regulate components of the immune system involved in inflammation. The key mediators of this response, called proinflammatory cytokines, can in turn elicit profound changes in behavior, which include the initiation of depressive symptoms such as sad mood, anhedonia, fatigue, psychomotor retardation, and social-behavioral withdrawal. This highly conserved biological response to adversity is critical for survival during times of actual physical threat or injury. However, this response can also be activated by modern-day social, symbolic, or imagined threats, leading to an increasingly proinflammatory phenotype that may be a key phenomenon driving depression pathogenesis and recurrence, as well as the overlap of depression with several somatic conditions including asthma, rheumatoid arthritis, chronic pain, metabolic syndrome, cardiovascular disease, obesity, and neurodegeneration. Insights from this theory may thus shed light on several important questions including how depression develops, why it frequently recurs, why it is strongly predicted by early life stress, and why it often co-occurs with symptoms of anxiety and with certain physical disease conditions. This work may also suggest new opportunities for preventing and treating depression by targeting inflammation. PMID:24417575

  7. Deubiquitinase inhibitor b-AP15 activates endoplasmic reticulum (ER) stress and inhibits Wnt/Notch1 signaling pathway leading to the reduction of cell survival in hepatocellular carcinoma cells.

    Science.gov (United States)

    Ding, Youming; Chen, Xiaoyan; Wang, Bin; Yu, Bin; Ge, Jianhui

    2018-04-15

    b-AP15, a potent and selective inhibitor of the ubiquitin-specific peptidase 14 (USP14), displays in vitro and in vivo antitumor abilities on some types of cancer cells. However, the mechanism underlying its action is not well elucidated. The purposes of the present study are to observe the potential impacts of b-AP15 on cell survival of hepatocellular carcinoma cells and to investigate whether and how this compound inhibits some survival-promoting signaling pathways. We found that b-AP15 significantly decreased cell viability and increased cell apoptosis in a dose-dependent manner in hepatocellular carcinoma cells, along with the perturbation of cell cycle and the decreased expressions of cell cycle-related proteins. We also demonstrated that the endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) were enhanced by b-AP15 supplementation. The inhibition of ER stress/UPR only partly attenuated the cytotoxicity of b-AP15 on hepatocellular carcinoma cells. In addition, b-AP15 treatment inhibited Wnt/β-catenin and Notch1 signaling pathways, and suppressed phosphorylation of STAT3, Akt, and Erk1/2, which were not restored by the inhibition of ER stress/UPR. Furthermore, the expression levels of signaling molecules in Notch1 were reduced by specific inhibitor of Wnt/β-catenin pathway. Notably, either Wnt or Notch1 signaling inhibitor mitigated phosphorylation of STAT3, Akt, and Erk1/2, and mimicked the cytotoxicity of b-AP15 on hepatocellular carcinoma cells. These results clearly indicate that b-AP15 induced cytotoxic response to hepatocellular carcinoma cells by augmenting ER stress/UPR and inhibiting Wnt/Notch1 signaling pathways. This new finding provides a novel mechanism by which b-AP15 produces its antitumor therapeutic effects. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Increased entropy of signal transduction in the cancer metastasis phenotype

    Directory of Open Access Journals (Sweden)

    Teschendorff Andrew E

    2010-07-01

    Full Text Available Abstract Background The statistical study of biological networks has led to important novel biological insights, such as the presence of hubs and hierarchical modularity. There is also a growing interest in studying the statistical properties of networks in the context of cancer genomics. However, relatively little is known as to what network features differ between the cancer and normal cell physiologies, or between different cancer cell phenotypes. Results Based on the observation that frequent genomic alterations underlie a more aggressive cancer phenotype, we asked if such an effect could be detectable as an increase in the randomness of local gene expression patterns. Using a breast cancer gene expression data set and a model network of protein interactions we derive constrained weighted networks defined by a stochastic information flux matrix reflecting expression correlations between interacting proteins. Based on this stochastic matrix we propose and compute an entropy measure that quantifies the degree of randomness in the local pattern of information flux around single genes. By comparing the local entropies in the non-metastatic versus metastatic breast cancer networks, we here show that breast cancers that metastasize are characterised by a small yet significant increase in the degree of randomness of local expression patterns. We validate this result in three additional breast cancer expression data sets and demonstrate that local entropy better characterises the metastatic phenotype than other non-entropy based measures. We show that increases in entropy can be used to identify genes and signalling pathways implicated in breast cancer metastasis and provide examples of de-novo discoveries of gene modules with known roles in apoptosis, immune-mediated tumour suppression, cell-cycle and tumour invasion. Importantly, we also identify a novel gene module within the insulin growth factor signalling pathway, alteration of which may

  9. Cloning of a two-component signal transduction system of Xanthomonas campestris pv. phaseoli var. fuscans strain BXPF65

    DEFF Research Database (Denmark)

    Chan, JWYF; Maynard, Scott; Goodwin, PH

    1998-01-01

    A putative two-component signal transduction system was amplified and cloned from the plant pathogenic bacterium Xanthomonas campestris pv. phaseoli var. fuscans isolate BXPF65. The 620 bp amplified fragment was sequenced and analyzed with the BLAST Enhanced Alignment Utility (BEAUTY). BEAUTY...... that the putative histidine kinase has homology with conserved “transmitter” domains of sensor proteins in two-component signal transduction systems. RFLP analysis using the putative signal transduction system showed polymorphisms among the strains....

  10. Genetic incorporation of the protein transduction domain of Tat into Ad5 fiber enhances gene transfer efficacy

    Directory of Open Access Journals (Sweden)

    Siegal Gene P

    2007-10-01

    Full Text Available Abstract Background Human adenovirus serotype 5 (Ad5 has been widely explored as a gene delivery vector for a variety of diseases. Many target cells, however, express low levels of Ad5 native receptor, the Coxsackie-Adenovirus Receptor (CAR, and thus are resistant to Ad5 infection. The Protein Transduction Domain of the HIV Tat protein, namely PTDtat, has been shown to mediate protein transduction in a wide range of cells. We hypothesize that re-targeting Ad5 vector via the PTDtat motif would improve the efficacy of Ad5-mediated gene delivery. Results In this study, we genetically incorporated the PTDtat motif into the knob domain of Ad5 fiber, and rescued the resultant viral vector, Ad5.PTDtat. Our data showed the modification did not interfere with Ad5 binding to its native receptor CAR, suggesting Ad5 infection via the CAR pathway is retained. In addition, we found that Ad5.PTDtat exhibited enhanced gene transfer efficacy in all of the cell lines that we have tested, which included both low-CAR and high-CAR decorated cells. Competitive inhibition assays suggested the enhanced infectivity of Ad5.PTDtat was mediated by binding of the positively charged PTDtat peptide to the negatively charged epitopes on the cells' surface. Furthermore, we investigated in vivo gene delivery efficacy of Ad5.PTDtat using subcutaneous tumor models established with U118MG glioma cells, and found that Ad5.PTDtat exhibited enhanced gene transfer efficacy compared to unmodified Ad5 vector as analyzed by a non-invasive fluorescence imaging technique. Conclusion Genetic incorporation of the PTDtat motif into Ad5 fiber allowed Ad5 vectors to infect cells via an alternative PTDtat targeting motif while retaining the native CAR-mediated infection pathway. The enhanced infectivity was demonstrated in both cultured cells and in in vivo tumor models. Taken together, our study identifies a novel tropism expanded Ad5 vector that may be useful for clinical gene therapy

  11. Notch2 transduction by feline leukemia virus in a naturally infected cat.

    Science.gov (United States)

    Watanabe, Shinya; Ito, Jumpei; Baba, Takuya; Hiratsuka, Takahiro; Kuse, Kyohei; Ochi, Haruyo; Anai, Yukari; Hisasue, Masaharu; Tsujimoto, Hajime; Nishigaki, Kazuo

    2014-04-01

    Feline leukemia virus (FeLV) induces neoplastic and nonneoplastic diseases in cats. The transduction of cellular genes by FeLV is sometimes observed and associated with neoplastic diseases including lymphoma and sarcoma. Here, we report the first natural case of feline Notch2 transduction by FeLV in an infected cat with multicentric lymphoma and hypercalcemia. We cloned recombinant FeLVs harboring Notch2 in the env gene. Notch2 was able to activate expression of a reporter gene, similar to what was previously reported in cats with experimental FeLV-induced thymic lymphoma. Our findings suggest that the transduction of Notch2 strongly correlates with FeLV-induced lymphoma.

  12. Effects of pergolide mesylate on transduction efficiency of PEP-1-catalase protein

    International Nuclear Information System (INIS)

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi; Lim, Soon Sung; Kang, Tae-Cheon; Kwon, Hyeok Yil; Kim, Duk-Soo; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Hwang, Hyun Sook; Choi, Soo Young

    2011-01-01

    Research highlights: → We studied effects of pergolide mesylate (PM) on in vitro and in vivo transduction of PEP-1-catalase. → PEP-1-catatase inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation. → PM enhanced the transduction of PEP-1-catalase into HaCaT cells and skin tissue. → PM increased anti-inflammatory activity of PEP-1-catalase. → PM stimulated therapeutic action of anti-oxidant enzyme catalase in oxidative-related diseases. -- Abstract: The low transduction efficiency of various proteins is an obstacle to their therapeutic application. However, protein transduction domains (PTDs) are well-known for a highly effective tool for exogenous protein delivery to cells. We examined the effects of pergolide mesylate (PM) on the transduction of PEP-1-catalase into HaCaT human keratinocytes and mice skin and on the anti-inflammatory activity of PEP-1-catatase against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation using Western blot and histological analysis. PM enhanced the time- and dose-dependent transduction of PEP-1-catalase into HaCaT cells without affecting the cellular toxicity. In a mouse edema model, PEP-1-catalase inhibited the increased expressions of inflammatory mediators and cytokines such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1β, and tumor necrosis factor-α induced by TPA. On the other hand, PM alone failed to exert any significant anti-inflammatory effects. However, the anti-inflammatory effect of co-treatment with PEP-1-catalase and PM was more potent than that of PEP-1-catalase alone. Our results indicate that PM may enhance the delivery of PTDs fusion therapeutic proteins to target cells and tissues and has potential to increase their therapeutic effects of such drugs against various diseases.

  13. Effects of pergolide mesylate on transduction efficiency of PEP-1-catalase protein

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Lim, Soon Sung [Department of Food Science and Nutrition and RIC Center, Hallym University, Chunchon 200-702 (Korea, Republic of); Kang, Tae-Cheon [Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Kwon, Hyeok Yil [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Kim, Duk-Soo [Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan-Si 330-090 (Korea, Republic of); Cho, Sung-Woo [Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Hwang, Hyun Sook, E-mail: wazzup@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Choi, Soo Young, E-mail: sychoi@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)

    2011-03-18

    Research highlights: {yields} We studied effects of pergolide mesylate (PM) on in vitro and in vivo transduction of PEP-1-catalase. {yields} PEP-1-catatase inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation. {yields} PM enhanced the transduction of PEP-1-catalase into HaCaT cells and skin tissue. {yields} PM increased anti-inflammatory activity of PEP-1-catalase. {yields} PM stimulated therapeutic action of anti-oxidant enzyme catalase in oxidative-related diseases. -- Abstract: The low transduction efficiency of various proteins is an obstacle to their therapeutic application. However, protein transduction domains (PTDs) are well-known for a highly effective tool for exogenous protein delivery to cells. We examined the effects of pergolide mesylate (PM) on the transduction of PEP-1-catalase into HaCaT human keratinocytes and mice skin and on the anti-inflammatory activity of PEP-1-catatase against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation using Western blot and histological analysis. PM enhanced the time- and dose-dependent transduction of PEP-1-catalase into HaCaT cells without affecting the cellular toxicity. In a mouse edema model, PEP-1-catalase inhibited the increased expressions of inflammatory mediators and cytokines such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1{beta}, and tumor necrosis factor-{alpha} induced by TPA. On the other hand, PM alone failed to exert any significant anti-inflammatory effects. However, the anti-inflammatory effect of co-treatment with PEP-1-catalase and PM was more potent than that of PEP-1-catalase alone. Our results indicate that PM may enhance the delivery of PTDs fusion therapeutic proteins to target cells and tissues and has potential to increase their therapeutic effects of such drugs against various diseases.

  14. Inflammation activates the interferon signaling pathways in taste bud cells.

    Science.gov (United States)

    Wang, Hong; Zhou, Minliang; Brand, Joseph; Huang, Liquan

    2007-10-03

    Patients with viral and bacterial infections or other inflammatory illnesses often experience taste dysfunctions. The agents responsible for these taste disorders are thought to be related to infection-induced inflammation, but the mechanisms are not known. As a first step in characterizing the possible role of inflammation in taste disorders, we report here evidence for the presence of interferon (IFN)-mediated signaling pathways in taste bud cells. IFN receptors, particularly the IFN-gamma receptor IFNGR1, are coexpressed with the taste cell-type markers neuronal cell adhesion molecule and alpha-gustducin, suggesting that both the taste receptor cells and synapse-forming cells in the taste bud can be stimulated by IFN. Incubation of taste bud-containing lingual epithelia with recombinant IFN-alpha and IFN-gamma triggered the IFN-mediated signaling cascades, resulting in the phosphorylation of the downstream STAT1 (signal transducer and activator of transcription protein 1) transcription factor. Intraperitoneal injection of lipopolysaccharide or polyinosinic:polycytidylic acid into mice, mimicking bacterial and viral infections, respectively, altered gene expression patterns in taste bud cells. Furthermore, the systemic administration of either IFN-alpha or IFN-gamma significantly increased the number of taste bud cells undergoing programmed cell death. These findings suggest that bacterial and viral infection-induced IFNs can act directly on taste bud cells, affecting their cellular function in taste transduction, and that IFN-induced apoptosis in taste buds may cause abnormal cell turnover and skew the representation of different taste bud cell types, leading to the development of taste disorders. To our knowledge, this is the first study providing direct evidence that inflammation can affect taste buds through cytokine signaling pathways.

  15. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    Science.gov (United States)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  16. Cancer classification through filtering progressive transductive support vector machine based on gene expression data

    Science.gov (United States)

    Lu, Xinguo; Chen, Dan

    2017-08-01

    Traditional supervised classifiers neglect a large amount of data which not have sufficient follow-up information, only work with labeled data. Consequently, the small sample size limits the advancement of design appropriate classifier. In this paper, a transductive learning method which combined with the filtering strategy in transductive framework and progressive labeling strategy is addressed. The progressive labeling strategy does not need to consider the distribution of labeled samples to evaluate the distribution of unlabeled samples, can effective solve the problem of evaluate the proportion of positive and negative samples in work set. Our experiment result demonstrate that the proposed technique have great potential in cancer prediction based on gene expression.

  17. Proteomic analysis of the signaling pathway mediated by the heterotrimeric G? protein Pga1 of Penicillium chrysogenum

    OpenAIRE

    Carrasco-Navarro, Ulises; Vera-Estrella, Rosario; Barkla, Bronwyn J.; Z??iga-Le?n, Eduardo; Reyes-Vivas, Horacio; Fern?ndez, Francisco J.; Fierro, Francisco

    2016-01-01

    Background The heterotrimeric G? protein Pga1-mediated signaling pathway regulates the entire developmental program in Penicillium chrysogenum, from spore germination to the formation of conidia. In addition it participates in the regulation of penicillin biosynthesis. We aimed to advance the understanding of this key signaling pathway using a proteomics approach, a powerful tool to identify effectors participating in signal transduction pathways. Results Penicillium chrysogenum mutants with ...

  18. 2R and remodeling of vertebrate signal transduction engine

    Directory of Open Access Journals (Sweden)

    Huminiecki Lukasz

    2010-12-01

    Full Text Available Abstract Background Whole genome duplication (WGD is a special case of gene duplication, observed rarely in animals, whereby all genes duplicate simultaneously through polyploidisation. Two rounds of WGD (2R-WGD occurred at the base of vertebrates, giving rise to an enormous wave of genetic novelty, but a systematic analysis of functional consequences of this event has not yet been performed. Results We show that 2R-WGD affected an overwhelming majority (74% of signalling genes, in particular developmental pathways involving receptor tyrosine kinases, Wnt and transforming growth factor-β ligands, G protein-coupled receptors and the apoptosis pathway. 2R-retained genes, in contrast to tandem duplicates, were enriched in protein interaction domains and multifunctional signalling modules of Ras and mitogen-activated protein kinase cascades. 2R-WGD had a fundamental impact on the cell-cycle machinery, redefined molecular building blocks of the neuronal synapse, and was formative for vertebrate brains. We investigated 2R-associated nodes in the context of the human signalling network, as well as in an inferred ancestral pre-2R (AP2R network, and found that hubs (particularly involving negative regulation were preferentially retained, with high connectivity driving retention. Finally, microarrays and proteomics demonstrated a trend for gradual paralog expression divergence independent of the duplication mechanism, but inferred ancestral expression states suggested preferential subfunctionalisation among 2R-ohnologs (2ROs. Conclusions The 2R event left an indelible imprint on vertebrate signalling and the cell cycle. We show that 2R-WGD preferentially retained genes are associated with higher organismal complexity (for example, locomotion, nervous system, morphogenesis, while genes associated with basic cellular functions (for example, translation, replication, splicing, recombination; with the notable exception of cell cycle tended to be excluded. 2R

  19. Gene transfer to pre-hematopoietic and committed hematopoietic precursors in the early mouse Yolk Sac: a comparative study between in situ electroporation and retroviral transduction

    Directory of Open Access Journals (Sweden)

    Lécluse Yann

    2007-07-01

    Full Text Available Abstract Background Hematopoietic development in vertebrate embryos results from the sequential contribution of two pools of precursors independently generated. While intra-embryonic precursors harbour the features of hematopoietic stem cells (HSC, precursors formed earlier in the yolk sac (YS display limited differentiation and self-renewal potentials. The mechanisms leading to the generation of the precursors in both sites are still largely unknown, as are the molecular basis underlying their different potential. A possible approach to assess the role of candidate genes is to transfer or modulate their expression/activity in both sites. We thus designed and compared transduction protocols to target either native extra-embryonic precursors, or hematopoietic precursors. Results One transduction protocol involves transient modification of gene expression through in situ electroporation of the prospective blood islands, which allows the evolution of transfected mesodermal cells in their "normal" environment, upon organ culture. Following in situ electroporation of a GFP reporter construct into the YS cavity of embryos at post-streak (mesodermal/pre-hematopoietic precursors or early somite (hematopoietic precursors stages, high GFP expression levels as well as a good preservation of cell viability is observed in YS explants. Moreover, the erythro-myeloid progeny typical of the YS arises from GFP+ mesodermal cells or hematopoietic precursors, even if the number of targeted precursors is low. The second approach, based on retroviral transduction allows a very efficient transduction of large precursor numbers, but may only be used to target 8 dpc YS hematopoietic precursors. Again, transduced cells generate a progeny quantitatively and qualitatively similar to that of control YS. Conclusion We thus provide two protocols whose combination may allow a thorough study of both early and late events of hematopoietic development in the murine YS. In situ

  20. Signal transduction in the development of pulmonary arterial hypertension

    Science.gov (United States)

    Malenfant, Simon; Neyron, Anne-Sophie; Paulin, Roxane; Potus, François; Meloche, Jolyane; Provencher, Steeve; Bonnet, Sébastien

    2013-01-01

    Pulmonary arterial hypertension (PAH) is a unique disease. Properly speaking, it is not a disease of the lung. It can be seen more as a microvascular disease occurring mainly in the lungs and affecting the heart. At the cellular level, the PAH paradigm is characterized by inflammation, vascular tone imbalance, pulmonary arterial smooth muscle cell proliferation and resistance to apoptosis and the presence of in situ thrombosis. At a clinical level, the aforementioned abnormal vascular properties alter physically the pulmonary circulation and ventilation, which greatly influence the right ventricle function as it highly correlates with disease severity. Consequently, right heart failure remains the principal cause of death within this cohort of patients. While current treatment modestly improve patients’ conditions, none of them are curative and, as of today, new therapies are lacking. However, the future holds potential new therapies that might have positive influence on the quality of life of the patient. This article will first review the clinical presentation of the disease and the different molecular pathways implicated in the pathobiology of PAH. The second part will review tomorrow's future putative therapies for PAH. PMID:24015329

  1. Responsive Hydrogels for Label-Free Signal Transduction within Biosensors

    Directory of Open Access Journals (Sweden)

    Kamila Gawel

    2010-04-01

    Full Text Available Hydrogels have found wide application in biosensors due to their versatile nature. This family of materials is applied in biosensing either to increase the loading capacity compared to two-dimensional surfaces, or to support biospecific hydrogel swelling occurring subsequent to specific recognition of an analyte. This review focuses on various principles underpinning the design of biospecific hydrogels acting through various molecular mechanisms in transducing the recognition event of label-free analytes. Towards this end, we describe several promising hydrogel systems that when combined with the appropriate readout platform and quantitative approach could lead to future real-life applications.

  2. The Lipopolysaccharide-Induced Metabolome Signature in Arabidopsis thaliana Reveals Dynamic Reprogramming of Phytoalexin and Phytoanticipin Pathways

    Science.gov (United States)

    Finnegan, Tarryn; Steenkamp, Paul A.; Piater, Lizelle A.

    2016-01-01

    Lipopolysaccharides (LPSs), as MAMP molecules, trigger the activation of signal transduction pathways involved in defence. Currently, plant metabolomics is providing new dimensions into understanding the intracellular adaptive responses to external stimuli. The effect of LPS on the metabolomes of Arabidopsis thaliana cells and leaf tissue was investigated over a 24 h period. Cellular metabolites and those secreted into the medium were extracted with methanol and liquid chromatography coupled to mass spectrometry was used for quantitative and qualitative analyses. Multivariate statistical data analyses were used to extract interpretable information from the generated multidimensional LC-MS data. The results show that LPS perception triggered differential changes in the metabolomes of cells and leaves, leading to variation in the biosynthesis of specialised secondary metabolites. Time-dependent changes in metabolite profiles were observed and biomarkers associated with the LPS-induced response were tentatively identified. These include the phytohormones salicylic acid and jasmonic acid, and also the associated methyl esters and sugar conjugates. The induced defensive state resulted in increases in indole—and other glucosinolates, indole derivatives, camalexin as well as cinnamic acid derivatives and other phenylpropanoids. These annotated metabolites indicate dynamic reprogramming of metabolic pathways that are functionally related towards creating an enhanced defensive capacity. The results reveal new insights into the mode of action of LPS as an activator of plant innate immunity, broadens knowledge about the defence metabolite pathways involved in Arabidopsis responses to LPS, and identifies specialised metabolites of functional importance that can be employed to enhance immunity against pathogen infection. PMID:27656890

  3. Nobiletin Stimulates Chloride Secretion in Human Bronchial Epithelia via a cAMP/PKA-Dependent Pathway

    Directory of Open Access Journals (Sweden)

    Yuan Hao

    2015-08-01

    Full Text Available Background/Aims: Nobiletin, a citrus flavonoid isolated from tangerines, alters ion transport functions in intestinal epithelia, and has antagonistic effects on eosinophilic airway inflammation of asthmatic rats. The present study examined the effects of nobiletin on basal short-circuit current (ISC in a human bronchial epithelial cell line (16HBE14o-, and characterized the signal transduction pathways that allowed nobiletin to regulate electrolyte transport. Methods: The ISC measurement technique was used for transepithelial electrical measurements. Intracellular calcium ([Ca2+]i and cAMP were also quantified. Results: Nobiletin stimulated a concentration-dependent increase in ISC, which was due to Cl- secretion. The increase in ISC was inhibited by a cystic fibrosis transmembrane conductance regulator inhibitor (CFTRinh-172, but not by 4,4'-diisothiocyano-stilbene-2,2'-disulphonic acid (DIDS, Chromanol 293B, clotrimazole, or TRAM-34. Nobiletin-stimulated ISC was also sensitive to a protein kinase A (PKA inhibitor, H89, and an adenylate cyclase inhibitor, MDL-12330A. Nobiletin could not stimulate any increase in ISC in a cystic fibrosis (CF cell line, CFBE41o-, which lacked a functional CFTR. Nobiletin stimulated a real-time increase in cAMP, but not [Ca2+]i. Conclusion: Nobiletin stimulated transepithelial Cl- secretion across human bronchial epithelia. The mechanisms involved activation of adenylate cyclase- and cAMP/PKA-dependent pathways, leading to activation of apical CFTR Cl- channels.

  4. Gravity sensing and signal transduction in vascular plant primary roots.

    Science.gov (United States)

    Baldwin, Katherine L; Strohm, Allison K; Masson, Patrick H

    2013-01-01

    During gravitropism, the potential energy of gravity is converted into a biochemical signal. How this transfer occurs remains one of the most exciting mysteries in plant cell biology. New experiments are filling in pieces of the puzzle. In this review, we introduce gravitropism and give an overview of what we know about gravity sensing in roots of vascular plants, with special highlight on recent papers. When plant roots are reoriented sideways, amyloplast resedimentation in the columella cells is a key initial step in gravity sensing. This process somehow leads to cytoplasmic alkalinization of these cells followed by relocalization of auxin efflux carriers (PINs). This changes auxin flow throughout the root, generating a lateral gradient of auxin across the cap that upon transmission to the elongation zone leads to differential cell elongation and gravibending. We will present the evidence for and against the following players having a role in transferring the signal from the amyloplast sedimentation into the auxin signaling cascade: mechanosensitive ion channels, actin, calcium ions, inositol trisphosphate, receptors/ligands, ARG1/ARL2, spermine, and the TOC complex. We also outline auxin transport and signaling during gravitropism.

  5. Hypoxia-inducible factor-1α mediates the toll-like receptor 4 signaling pathway leading to anti-tumor effects in human hepatocellular carcinoma cells under hypoxic conditions.

    Science.gov (United States)

    Zhang, Xiaoyu; Li, Shuchen; Li, Mingrong; Huang, Haiying; Li, Jingyuan; Zhou, Changwei

    2016-08-01

    Hypoxia-inducible factor-1α (HIF-1α) and toll-like receptor 4 (TLR4) are involved in numerous mechanisms of cancer biology, including cell proliferation and survival; however the interaction of the two factors under hypoxic conditions remains unclear. The present study investigated the in vitro mechanism that results in the suppression of tumor cell growth and cellular functions when HIF-1α is silenced. In the present study, the human hepatocellular carcinoma HepG2 cell line was transfected with short hairpin RNA (shRNA) against HIF-1α and cultured under hypoxic conditions (1% O 2 for 24 h). The expression of HIF-1α and various growth factors, including epidermal growth factor (EGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2), were examined using quantitative polymerase chain reaction and immunoblotting. Tumor growth was measured using a Cell Counting Kit-8 assay and tumor activity was measured using tumor cell invasion and migration assays. Lipopolysaccharide and TAK-242 were used to activate and inhibit TLR4, respectively, to observe the role of TLR4 in the HIF-1α silenced tumor cells. The expression of TLR4 signaling pathway associates, including myeloid differentiation primary response gene 88 (MyD88), apoptosis signal-regulating kinase 1 (ASK1), p38 mitogen-activated protein kinases and HIF-1α, were analyzed by western blot assay. Under hypoxic conditions, silencing of HIF-1α expression suppressed tumor cell growth and regulated the expression of tumor growth-associated genes, including EGF, HGF, VEGF and FG2. Suppression of tumor cell invasion and migration was also observed in the HIF-1α silenced HepG2 cell line. In addition, TLR4 was identified to be involved in HIF-1α and MyD88 accumulation, and activation of ASK1 and p38 were demonstrated to be critical for TLR4-mediated HIF-1α pathway. In conclusion, silencing of HIF-1α expression may induce anti-tumor effects under hypoxic

  6. Endogenous protection derived from activin A/Smads transduction loop stimulated via ischemic injury in PC12 cells.

    Science.gov (United States)

    Mang, Jing; Mei, Chun-Li; Wang, Jiao-Qi; Li, Zong-Shu; Chu, Ting-Ting; He, Jin-Ting; Xu, Zhong-Xin

    2013-10-17

    Activin A (ActA), a member of transforming growth factor-beta (TGF-b) super- family, affects many cellular processes, including ischemic stroke. Though the neuroprotective effects of exogenous ActA on oxygen-glucose deprivation (OGD) injury have already been reported by us, the endogenous role of ActA remains poorly understood. To further define the role and mechanism of endogenous ActA and its signaling in response to acute ischemic damage, we used an OGD model in PC12 cells to simulate ischemic injury on neurons in vitro. Cells were pre-treated by monoclonal antibody against activin receptor type IIA (ActRII-Ab). We found that ActRII-Ab augments ischemic injury in PC12 cells. Further, the extracellular secretion of ActA as well as phosphorylation of smad3 in PC12 cells was also up-regulated by OGD, but suppressed by ActRII-Ab. Taken together, our results show that ActRII-Ab may augment ischemic injury via blocking of transmembrane signal transduction of ActA, which confirmed the existence of endogenous neuroprotective effects derived from the ActA/Smads pathway. ActRIIA plays an important role in transferring neuronal protective signals inside. It is highly possible that ActA transmembrance signaling is a part of the positive feed-back loop for extracellular ActA secretion.

  7. Endogenous Protection Derived from Activin A/Smads Transduction Loop Stimulated via Ischemic Injury in PC12 Cells

    Directory of Open Access Journals (Sweden)

    Zhong-Xin Xu

    2013-10-01

    Full Text Available Activin A (ActA, a member of transforming growth factor-beta (TGF-b super- family, affects many cellular processes, including ischemic stroke. Though the neuroprotective effects of exogenous ActA on oxygen-glucose deprivation (OGD injury have already been reported by us, the endogenous role of ActA remains poorly understood. To further define the role and mechanism of endogenous ActA and its signaling in response to acute ischemic damage, we used an OGD model in PC12 cells to simulate ischemic injury on neurons in vitro. Cells were pre-treated by monoclonal antibody against activin receptor type IIA (ActRII-Ab. We found that ActRII-Ab augments ischemic injury in PC12 cells. Further, the extracellular secretion of ActA as well as phosphorylation of smad3 in PC12 cells was also up-regulated by OGD, but suppressed by ActRII-Ab. Taken together, our results show that ActRII-Ab may augment ischemic injury via blocking of transmembrane signal transduction of ActA, which confirmed the existence of endogenous neuroprotective effects derived from the ActA/Smads pathway. ActRIIA plays an important role in transferring neuronal protective signals inside. It is highly possible that ActA transmembrance signaling is a part of the positive feed-back loop for extracellular ActA secretion.

  8. Multifaceted effects of oligodendroglial exosomes on neurons: impact on neuronal firing rate, signal transduction and gene regulation.

    Science.gov (United States)

    Fröhlich, Dominik; Kuo, Wen Ping; Frühbeis, Carsten; Sun, Jyh-Jang; Zehendner, Christoph M; Luhmann, Heiko J; Pinto, Sheena; Toedling, Joern; Trotter, Jacqueline; Krämer-Albers, Eva-Maria

    2014-09-26

    Exosomes are small membranous vesicles of endocytic origin that are released by almost every cell type. They exert versatile functions in intercellular communication important for many physiological and pathological processes. Recently, exosomes attracted interest with regard to their role in cell-cell communication in the nervous system. We have shown that exosomes released from oligodendrocytes upon stimulation with the neurotransmitter glutamate are internalized by neurons and enhance the neuronal stress tolerance. Here, we demonstrate that oligodendroglial exosomes also promote neuronal survival during oxygen-glucose deprivation, a model of cerebral ischaemia. We show the transfer from oligodendrocytes to neurons of superoxide dismutase and catalase, enzymes which are known to help cells to resist oxidative stress. Additionally, we identify various effects of oligodendroglial exosomes on neuronal physiology. Electrophysiological analysis using in vitro multi-electrode arrays revealed an increased firing rate of neurons exposed to oligodendroglial exosomes. Moreover, gene expression analysis and phosphorylation arrays uncovered differentially expressed genes and altered signal transduction pathways in neurons after exosome treatment. Our study thus provides new insight into the broad spectrum of action of oligodendroglial exosomes and their effects on neuronal physiology. The exchange of extracellular vesicles between neural cells may exhibit remarkable potential to impact brain performance. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  9. Efficient direct conversion of human fibroblasts into myogenic lineage induced by co-transduction with MYCL and MYOD1.

    Science.gov (United States)

    Wakao, Junko; Kishida, Tsunao; Fumino, Shigehisa; Kimura, Koseki; Yamamoto, Kenta; Kotani, Shin-Ichiro; Mizushima, Katsura; Naito, Yuji; Yoshikawa, Toshikazu; Tajiri, Tatsuro; Mazda, Osam

    2017-06-24

    The skeletal muscle consists of contractile myofibers and plays essential roles for maintenance of body posture, movement, and metabolic regulation. During the development and regeneration of the skeletal muscle tissue, the myoblasts fuse into multinucleated myotubes that subsequently form myofibers. Transplantation of myoblasts may make possible a novel regenerative therapy against defects or dysfunction of the skeletal muscle. It is reported that rodent fibroblasts are converted into myoblast-like cells and fuse to form syncytium after forced expression of exogenous myogenic differentiation 1 (MYOD1) that is a key transcription factor for myoblast differentiation. But human fibroblasts are less efficiently converted into myoblasts and rarely fused by MYOD1 alone. Here we found that transduction of v-myc avian myelocytomatosis viral oncogene lung carcinoma derived homolog (MYCL) gene in combination with MYOD1 gene induced myoblast-like phenotypes in human fibroblasts more strongly than MYOD1 gene alone. The rate of conversion was approximately 90%. The directly converted myoblasts (dMBs) underwent fusion in an ERK5 pathway-dependent manner. The dMBs also formed myofiber-like structure in vivo after an inoculation into mice at the subcutaneous tissue. The present results strongly suggest that the combination of MYCL plus MYOD1 may promote direct conversion of human fibroblasts into functional myoblasts that could potentially be used for regenerative therapy for muscle diseases and congenital muscle defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Signal transduction profile of chemical sensitisers in dendritic cells: An endpoint to be included in a cell-based in vitro alternative approach to hazard identification?

    International Nuclear Information System (INIS)

    Neves, Bruno Miguel; Goncalo, Margarida; Figueiredo, Americo; Duarte, Carlos B.; Lopes, Maria Celeste; Cruz, Maria Teresa

    2011-01-01

    The development of non-animal testing methods for the assessment of skin sensitisation potential is an urgent challenge within the framework of existing and forthcoming legislation. Efforts have been made to replace current animal tests, but so far no alternative methods have been developed. It is widely recognised that alternatives to animal testing cannot be accomplished with a single approach, but rather will require the integration of results obtained from different in vitro and in silico assays. The argument subjacent to the development of in vitro dendritic cell (DC)-based assays is that sensitiser-induced changes in the DC phenotype can be differentiated from those induced by irritants. This assumption is derived from the unique capacity of DC to convert environmental signals encountered at the skin into a receptor expression pattern (MHC class II molecules, co-stimulatory molecules, chemokine receptors) and a soluble mediator release profile that will stimulate T lymphocytes. Since signal transduction cascades precede changes in surface marker expression and cytokine/chemokine secretion, these phenotypic modifications are a consequence of a signal transduction profile that is specifically triggered by sensitisers and not by irritants. A limited number of studies have addressed this subject and the present review attempts to summarise and highlight all of the signalling pathways modulated by skin sensitisers and irritants. Furthermore, we conclude this review by focusing on the most promising strategies suitable for inclusion into a cell-based in vitro alternative approach to hazard identification.

  11. Antitumor Activity of Tenacissoside H on Esophageal Cancer through Arresting Cell Cycle and Regulating PI3K/Akt-NF-κB Transduction Cascade

    Directory of Open Access Journals (Sweden)

    Yong-sen Jia

    2015-01-01

    Full Text Available Objective. The purpose of the study was to elucidate the molecular mechanism of tenacissoside H (TDH inhibiting esophageal carcinoma infiltration and proliferation. Methods. In vitro, EC9706 cells were treated with TDH. Cells proliferation and cell cycle were assayed. PI3K and NF-κB mRNAs expression were determined by real time PCR. In vivo, model of nude mice with tumor was established. Mice were treated with TDH. Inhibition ratio of tumor volume was calculated. PCNA expression was examined. Protein expression in PI3K/Akt-NF-κB signaling pathway was determined. Results. In vitro, TDH significantly inhibited cells proliferation in a time-and-dose-dependent manner. TDH arrested the cell cycle in S phase and significantly inhibited PI3K and NF-κB mRNA expression, compared with blank controlled group (P<0.05. In vivo, TDH strongly inhibits tumor growth and volume. PCNA expression was significantly decreased after treatment of TDH. TDH downregulated proteins expression in PI3K/Akt-NF-κB transduction cascade (P<0.05. Conclusion. TDH inhibited esophageal carcinoma infiltration and proliferation both in vitro and in vivo. The anticancer activity has relation to arresting the cell cycle at the S phase, inhibited the PCNA expression of transplanted tumors in nude mice, and regulated the protein expression in the PI3K/Akt-NF-κB transduction cascade.

  12. Characterization of adenoviral transduction profile in prostate cancer cells and normal prostate tissue.

    Science.gov (United States)

    Ai, Jianzhong; Tai, Phillip W L; Lu, Yi; Li, Jia; Ma, Hong; Su, Qin; Wei, Qiang; Li, Hong; Gao, Guangping

    2017-09-01

    Prostate diseases are common in males worldwide with high morbidity. Gene therapy is an attractive therapeutic strategy for prostate diseases, however, it is currently underdeveloped. As well known, adeno virus (Ad) is the most widely used gene therapy vector. The aims of this study are to explore transduction efficiency of Ad in prostate cancer cells and normal prostate tissue, thus further providing guidance for future prostate pathophysiological studies and therapeutic development of prostate diseases. We produced Ad expressing enhanced green fluorescence protein (EGFP), and characterized the transduction efficiency of Ad in both human and mouse prostate cancer cell lines in vitro, as well as prostate tumor xenograft, and wild-type mouse prostate tissue in vivo. Ad transduction efficiency was determined by EGFP fluorescence using microscopy and flow cytometry. Cell type-specific transduction was examined by immunofluorescence staining of cell markers. Our data showed that Ad efficiently transduced human and mouse prostate cancer cells in vitro in a dose dependent manner. Following intratumoral and intraprostate injection, Ad could efficiently transduce prostate tumor xenograft and the major prostatic cell types in vivo, respectively. Our findings suggest that Ad can efficiently transduce prostate tumor cells in vitro as well as xenograft and normal prostate tissue in vivo, and further indicate that Ad could be a potentially powerful toolbox for future gene therapy of prostate diseases. © 2017 Wiley Periodicals, Inc.

  13. Signal transduction events in aluminum-induced cell death in tomato suspension cells

    NARCIS (Netherlands)

    Iakimova, E.T.; Kapchina-Toteva, V.M.; Woltering, E.J.

    2007-01-01

    In this study, some of the signal transduction events involved in AlCl3-induced cell death in tomato (Lycopersicon esculentum Mill.) suspension cells were elucidated. Cells treated with 100 ¿M AlCl3 showed typical features of programmed cell death (PCD) such as nuclear and cytoplasmic condensation.

  14. Sensory cilia and integration of signal transduction in human health and disease

    DEFF Research Database (Denmark)

    Christensen, Søren T; Pedersen, Lotte B; Schneider, Linda

    2007-01-01

    The primary cilium is a hallmark of mammalian tissue cells. Recent research has shown that these organelles display unique sets of selected signal transduction modules including receptors, ion channels, effector proteins and transcription factors that relay chemical and physical stimuli from the ...

  15. CRISPR-cas-mediated phage resistance enhances horizontal gene transfer by transduction

    NARCIS (Netherlands)

    Watson, Bridget N.J.; Staals, Raymond H.J.; Fineran, Peter C.

    2018-01-01

    A powerful contributor to prokaryotic evolution is horizontal gene transfer (HGT) through transformation, conjugation, and transduction, which can be advantageous, neutral, or detrimental to fitness. Bacteria and archaea control HGT and phage infection through CRISPR-Cas (clustered regularly

  16. Efficient transduction of neurons using Ross River glycoprotein-pseudotyped lentiviral vectors

    DEFF Research Database (Denmark)

    Jakobsson, J; Nielsen, T Tolstrup; Staflin, K

    2006-01-01

    , including the possibility to establish stable producer cell lines. After injection of RRV-LV expressing green fluorescent protein into different structures in the rat brain we found efficient transduction of both neurons and glial cells. By using two cell-type-specific promoters, neuron-specific enolase...

  17. The role of Ryk and Ror receptor tyrosine kinases in Wnt signal transduction

    NARCIS (Netherlands)

    Green, J.; Nusse, R.; van Amerongen, R.

    2014-01-01

    Receptor tyrosine kinases of the Ryk and Ror families were initially classified as orphan receptors because their ligands were unknown. They are now known to contain functional extracellular Wnt-binding domains and are implicated in Wnt-signal transduction in multiple species. Although their

  18. Semi-Supervised Transductive Hot Spot Predictor Working on Multiple Assumptions

    KAUST Repository

    Wang, Jim Jing-Yan; Almasri, Islam; Shi, Yuexiang; Gao, Xin

    2014-01-01

    of the transductive semi-supervised algorithms takes all the three semisupervised assumptions, i.e., smoothness, cluster and manifold assumptions, together into account during learning. In this paper, we propose a novel semi-supervised method for hot spot residue

  19. Intrapulmonary Versus Nasal Transduction of Murine Airways With GP64-pseudotyped Viral Vectors

    Directory of Open Access Journals (Sweden)

    Mayumi Oakland

    2013-01-01

    Full Text Available Persistent viral vector-mediated transgene expression in the airways requires delivery to cells with progenitor capacity and avoidance of immune responses. Previously, we observed that GP64-pseudotyped feline immunodeficiency virus (FIV-mediated gene transfer was more efficient in the nasal airways than the large airways of the murine lung. We hypothesized that in vivo gene transfer was limited by immunological and physiological barriers in the murine intrapulmonary airways. Here, we systematically investigate multiple potential barriers to lentiviral gene transfer in the airways of mice. We show that GP64-FIV vector transduced primary cultures of well-differentiated murine nasal epithelia with greater efficiency than primary cultures of murine tracheal epithelia. We further demonstrate that neutrophils, type I interferon (IFN responses, as well as T and B lymphocytes are not the major factors limiting the transduction of murine conducting airways. In addition, we observed better transduction of GP64-pseudotyped vesicular stomatitis virus (VSV in the nasal epithelia compared with the intrapulmonary airways in mice. VSVG glycoprotein pseudotyped VSV transduced intrapulmonary epithelia with similar efficiency as nasal epithelia. Our results suggest that the differential transduction efficiency of nasal versus intrapulmonary airways by FIV vector is not a result of immunological barriers or surface area, but rather differential expression of cellular factors specific for FIV vector transduction.

  20. The fibronectin III-1 domain activates a PI3-Kinase/Akt signaling pathway leading to αvβ5 integrin activation and TRAIL resistance in human lung cancer cells

    International Nuclear Information System (INIS)

    Cho, Christina; Horzempa, Carol; Jones, David; McKeown-Longo, Paula J.

    2016-01-01

    Fibronectin is a mechanically sensitive protein which is organized in the extracellular matrix as a network of interacting fibrils. The lung tumor stroma is enriched for fibronectin which is thought to contribute to metastasis and drug resistance. Fibronectin is an elastic, multi-modular protein made up of individually folded domains, some of which can stretch in response to increased mechanical tension. Very little is known about the relationship of fibronectin’s unfolded domains to lung cancer resistance to chemotherapy. In the present study, we evaluated the impact of unfolding the first Type III domain of fibronectin (FnIII-1c) on TNF-related apoptosis inducing ligand (TRAIL) resistance. NCI-H460 non-small cell lung cancer cells were treated with FnIII-1c then assessed for TRAIL-induced apoptosis. Subsequent analysis of FnIII-1c-mediated signaling pathways was also completed. Human non-small cell lung cancer tissue sections were assessed for the expression of vitronectin by immunohistochemistry. FnIII-1c inhibited TRAIL-induced activation of caspase 8 and subsequent apoptosis in NCI-H460 lung cancer cells. FnIII-1c treatment was associated with the activation of the phosphatidylinositol-3-kinase/alpha serine/threonine kinase (PI3K/Akt) pathway and the αvβ5 integrin receptor for vitronectin, both of which were required for TRAIL resistance. Immunohistochemical staining of sections from non-small cell lung cancers showed that vitronectin was localized around blood vessels and in the tumor-stroma interface. Unfolding of Type III domains within the fibronectin matrix may promote TRAIL resistance through the activation of a PI3K/Akt/αvβ5 signaling axis and point to a novel mechanism by which changes in secondary structure of fibronectin contribute to cancer cell resistance to apoptosis

  1. FASEB summer research conference on signal transduction in plants. Final report, June 16, 1996--June 21, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Lomax, T.L.; Quatrano, R.S.

    1996-12-31

    This is the program from the second FASEB conference on Signal Transduction in Plants. Topic areas included the following: environmental signaling; perception and transduction of light signals; signaling in plant microbe interactions; signaling in plant pathogen interactions; cell, cell communication; cytoskeleton, plasma membrane, and cellwall continuum; signaling molecules in plant growth and development I and II. A list of participants is included.

  2. Structure-function relationships of Na+, K+, ATP, or Mg2+ binding and energy transduction in Na,K-ATPase

    DEFF Research Database (Denmark)

    Jorgensen, Peter L.; Pedersen, Per Amstrup

    2000-01-01

    Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction......Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction...

  3. Enrichment of human hematopoietic stem/progenitor cells facilitates transduction for stem cell gene therapy.

    Science.gov (United States)

    Baldwin, Kismet; Urbinati, Fabrizia; Romero, Zulema; Campo-Fernandez, Beatriz; Kaufman, Michael L; Cooper, Aaron R; Masiuk, Katelyn; Hollis, Roger P; Kohn, Donald B

    2015-05-01

    Autologous hematopoietic stem cell (HSC) gene therapy for sickle cell disease has the potential to treat this illness without the major immunological complications associated with allogeneic transplantation. However, transduction efficiency by β-globin lentiviral vectors using CD34-enriched cell populations is suboptimal and large vector production batches may be needed for clinical trials. Transducing a cell population more enriched for HSC could greatly reduce vector needs and, potentially, increase transduction efficiency. CD34(+) /CD38(-) cells, comprising ∼1%-3% of all CD34(+) cells, were isolated from healthy cord blood CD34(+) cells by fluorescence-activated cell sorting and transduced with a lentiviral vector expressing an antisickling form of beta-globin (CCL-β(AS3) -FB). Isolated CD34(+) /CD38(-) cells were able to generate progeny over an extended period of long-term culture (LTC) compared to the CD34(+) cells and required up to 40-fold less vector for transduction compared to bulk CD34(+) preparations containing an equivalent number of CD34(+) /CD38(-) cells. Transduction of isolated CD34(+) /CD38(-) cells was comparable to CD34(+) cells measured by quantitative PCR at day 14 with reduced vector needs, and average vector copy/cell remained higher over time for LTC initiated from CD34(+) /38(-) cells. Following in vitro erythroid differentiation, HBBAS3 mRNA expression was similar in cultures derived from CD34(+) /CD38(-) cells or unfractionated CD34(+) cells. In vivo studies showed equivalent engraftment of transduced CD34(+) /CD38(-) cells when transplanted in competition with 100-fold more CD34(+) /CD38(+) cells. This work provides initial evidence for the beneficial effects from isolating human CD34(+) /CD38(-) cells to use significantly less vector and potentially improve transduction for HSC gene therapy. © 2015 AlphaMed Press.

  4. An algorithm for modularization of MAPK and calcium signaling pathways: comparative analysis among different species.

    Science.gov (United States)

    Nayak, Losiana; De, Rajat K

    2007-12-01

    Signaling pathways are large complex biochemical networks. It is difficult to analyze the underlying mechanism of such networks as a whole. In the present article, we have proposed an algorithm for modularization of signal transduction pathways. Unlike studying a signaling pathway as a whole, this enables one to study the individual modules (less complex smaller units) easily and hence to study the entire pathway better. A comparative study of modules belonging to different species (for the same signaling pathway) has been made, which gives an overall idea about development of the signaling pathways over the taken set of species of calcium and MAPK signaling pathways. The superior performance, in terms of biological significance, of the proposed algorithm over an existing community finding algorithm of Newman [Newman MEJ. Modularity and community structure in networks. Proc Natl Acad Sci USA 2006;103(23):8577-82] has been demonstrated using the aforesaid pathways of H. sapiens.

  5. Intervention of electroacupuncture on spinal p38 MAPK/ATF-2/VR-1 pathway in treating inflammatory pain induced by CFA in rats.

    Science.gov (United States)

    Fang, Jian-Qiao; Du, Jun-Ying; Liang, Yi; Fang, Jun-Fan

    2013-03-22

    Previous studies have demonstrated that p38 MAPK signal transduction pathway plays an important role in the development and maintenance of inflammatory pain. Electroacupuncture (EA) can suppress the inflammatory pain. However, the relationship between EA effect and p38 MAPK signal transduction pathway in inflammatory pain remains poorly understood. It is our hypothesis that p38 MAPK/ATF-2/VR-1 and/or p38 MAPK/ATF-2/COX-2 signal transduction pathway should be activated by inflammatory pain in CFA-injected model. Meanwhile, EA may inhibit the activation of p38 MAPK signal transduction pathway. The present study aims to investigate that anti-inflammatory and analgesic effect of EA and its intervention on the p38 MAPK signal transduction pathway in a rat model of inflammatory pain. EA had a pronounced anti-inflammatory and analgesic effect on CFA-induced chronic inflammatory pain in rats. EA could quickly raise CFA-rat's paw withdrawal thresholds (PWTs) and maintain good and long analgesic effect, while it subdued the ankle swelling of CFA rats only at postinjection day 14. EA could down-regulate the protein expressions of p-p38 MAPK and p-ATF-2, reduced the numbers of p-p38 MAPK-IR cells and p-ATF-2-IR cells in spinal dorsal horn in CFA rats, inhibited the expressions of both protein and mRNA of VR-1, but had no effect on the COX-2 mRNA expression. The present study indicates that inhibiting the activation of spinal p38 MAPK/ATF-2/VR-1 pathway may be one of the main mechanisms via central signal transduction pathway in the process of anti-inflammatory pain by EA in CFA rats.

  6. Proteomic analysis of the signaling pathway mediated by the heterotrimeric Gα protein Pga1 of Penicillium chrysogenum.

    Science.gov (United States)

    Carrasco-Navarro, Ulises; Vera-Estrella, Rosario; Barkla, Bronwyn J; Zúñiga-León, Eduardo; Reyes-Vivas, Horacio; Fernández, Francisco J; Fierro, Francisco

    2016-10-06

    The heterotrimeric Gα protein Pga1-mediated signaling pathway regulates the entire developmental program in Penicillium chrysogenum, from spore germination to the formation of conidia. In addition it participates in the regulation of penicillin biosynthesis. We aimed to advance the understanding of this key signaling pathway using a proteomics approach, a powerful tool to identify effectors participating in signal transduction pathways. Penicillium chrysogenum mutants with different levels of activity of the Pga1-mediated signaling pathway were used to perform comparative proteomic analyses by 2D-DIGE and LC-MS/MS. Thirty proteins were identified which showed differences in abundance dependent on Pga1 activity level. By modifying the intracellular levels of cAMP we could establish cAMP-dependent and cAMP-independent pathways in Pga1-mediated signaling. Pga1 was shown to regulate abundance of enzymes in primary metabolic pathways involved in ATP, NADPH and cysteine biosynthesis, compounds that are needed for high levels of penicillin production. An in vivo phosphorylated protein containing a pleckstrin homology domain was identified; this protein is a candidate for signal transduction activity. Proteins with possible roles in purine metabolism, protein folding, stress response and morphogenesis were also identified whose abundance was regulated by Pga1 signaling. Thirty proteins whose abundance was regulated by the Pga1-mediated signaling pathway were identified. These proteins are involved in primary metabolism, stress response, development and signal transduction. A model describing the pathways through which Pga1 signaling regulates different cellular processes is proposed.

  7. Hydration status regulates sodium flux and inflammatory pathways through epithelial sodium channel (ENaC) in the skin.

    Science.gov (United States)

    Xu, Wei; Hong, Seok Jong; Zeitchek, Michael; Cooper, Garry; Jia, Shengxian; Xie, Ping; Qureshi, Hannan A; Zhong, Aimei; Porterfield, Marshall D; Galiano, Robert D; Surmeier, D James; Mustoe, Thomas A

    2015-03-01

    Although it is known that the inflammatory response that results from disruption of epithelial barrier function after injury results in excessive scarring, the upstream signals remain unknown. It has also been observed that epithelial disruption results in reduced hydration status and that the use of occlusive dressings that prevent water loss from wounds decreases scar formation. We hypothesized that hydration status changes sodium homeostasis and induces sodium flux in keratinocytes, which result in activation of pathways responsible for keratinocyte-fibroblast signaling and ultimately lead to activation of fibroblasts. Here, we demonstrate that perturbations in epithelial barrier function lead to increased sodium flux in keratinocytes. We identified that sodium flux in keratinocytes is mediated by epithelial sodium channels (ENaCs) and causes increased secretion of proinflammatory cytokines, which activate fibroblast via the cyclooxygenase 2 (COX-2)/prostaglandin E2 (PGE2) pathway. Similar changes in signal transduction and sodium flux occur by increased sodium concentration, which simulates reduced hydration, in the media in epithelial cultures or human ex vivo skin cultures. Blockade of ENaC, prostaglandin synthesis, or PGE2 receptors all reduce markers of fibroblast activation and collagen synthesis. In addition, employing a validated in vivo excessive scar model in the rabbit ear, we demonstrate that utilization of either an ENaC blocker or a COX-2 inhibitor results in a marked reduction in scarring. Other experiments demonstrate that the activation of COX-2 in response to increased sodium flux is mediated through the PIK3/Akt pathway. Our results indicate that ENaC responds to small changes in sodium concentration with inflammatory mediators and suggest that the ENaC pathway is a potential target for a strategy to prevent fibrosis.

  8. Transduction of skin-migrating dendritic cells by human adenovirus 5 occurs via an actin-dependent phagocytic pathway.

    Science.gov (United States)

    Guzman, Efrain; Taylor, Geraldine; Hope, Jayne; Herbert, Rebecca; Cubillos-Zapata, Carolina; Charleston, Bryan

    2016-10-01

    Dendritic cells (DC) are central to the initiation of immune responses, and various approaches have been used to target vaccines to DC in order to improve immunogenicity. Cannulation of lymphatic vessels allows for the collection of DC that migrate from the skin. These migrating DC are involved in antigen uptake and presentation following vaccination. Human replication-deficient adenovirus (AdV) 5 is a promising vaccine vector for delivery of recombinant antigens. Although the mechanism of AdV attachment and penetration has been extensively studied in permissive cell lines, few studies have addressed the interaction of AdV with DC. In this study, we investigated the interaction of bovine skin-migrating DC and replication-deficient AdV-based vaccine vectors. We found that, despite lack of expression of Coxsackie B-Adenovirus Receptor and other known adenovirus receptors, AdV readily enters skin-draining DC via an actin-dependent endocytosis. Virus exit from endosomes was pH independent, and neutralizing antibodies did not prevent virus entry but did prevent virus translocation to the nucleus. We also show that combining adenovirus with adjuvant increases the absolute number of intracellular virus particles per DC but not the number of DC containing intracellular virus. This results in increased trans-gene expression and antigen presentation. We propose that, in the absence of Coxsackie B-Adenovirus Receptor and other known receptors, AdV5-based vectors enter skin-migrating DC using actin-dependent endocytosis which occurs in skin-migrating DC, and its relevance to vaccination strategies and vaccine vector targeting is discussed.

  9. Similar activation of signal transduction pathways by the herpesvirus-encoded chemokine receptors US28 and ORF74

    DEFF Research Database (Denmark)

    McLean, Katherine A; Holst, Peter J; Martini, Lene

    2004-01-01

    The virally encoded chemokine receptors US28 from human cytomegalovirus and ORF74 from human herpesvirus 8 are both constitutively active. We show that both receptors constitutively activate the transcription factors nuclear factor of activated T cells (NFAT) and cAMP response element binding...

  10. BAG3 promotes tumour cell proliferation by regulating EGFR signal transduction pathways in triple negative breast cancer.

    Science.gov (United States)

    Shields, Sarah; Conroy, Emer; O'Grady, Tony; McGoldrick, Alo; Connor, Kate; Ward, Mark P; Useckaite, Zivile; Dempsey, Eugene; Reilly, Rebecca; Fan, Yue; Chubb, Anthony; Matallanas, David Gomez; Kay, Elaine W; O'Connor, Darran; McCann, Amanda; Gallagher, William M; Coppinger, Judith A

    2018-03-20

    Triple-negative breast cancer (TNBC), is a heterogeneous disease characterised by absence of expression of the estrogen receptor (ER), progesterone receptor (PR) and lack of amplification of human epidermal growth factor receptor 2 (HER2). TNBC patients can exhibit poor prognosis and high recurrence stages despite early response to chemotherapy treatment. In this study, we identified a pro-survival signalling protein BCL2- associated athanogene 3 (BAG3) to be highly expressed in a subset of TNBC cell lines and tumour tissues. High mRNA expression of BAG3 in TNBC patient cohorts significantly associated with a lower recurrence free survival. The epidermal growth factor receptor (EGFR) is amplified in TNBC and EGFR signalling dynamics impinge on cancer cell survival and disease recurrence. We found a correlation between BAG3 and EGFR expression in TNBC cell lines and determined that BAG3 can regulate tumour cell proliferation, migration and invasion in EGFR expressing TNBC cells lines. We identified an interaction between BAG3 and components of the EGFR signalling networks using mass spectrometry. Furthermore, BAG3 contributed to regulation of proliferation in TNBC cell lines by reducing the activation of components of the PI3K/AKT and FAK/Src signalling subnetworks. Finally, we found that combined targeting of BAG3 and EGFR was more effective than inhibition of EGFR with Cetuximab alone in TNBC cell lines. This study demonstrates a role for BAG3 in regulation of distinct EGFR modules and highlights the potential of BAG3 as a therapeutic target in TNBC.

  11. Molecular Pathways

    Science.gov (United States)

    Lok, Benjamin H.; Powell, Simon N.

    2012-01-01

    The Rad52 protein was largely ignored in humans and other mammals when the mouse knockout revealed a largely “no-effect” phenotype. However, using synthetic lethal approaches to investigate context dependent function, new studies have shown that Rad52 plays a key survival role in cells lacking the function of the BRCA1-BRCA2 pathway of homologous recombination. Biochemical studies also showed significant differences between yeast and human Rad52, in which yeast Rad52 can promote strand invasion of RPA-coated single-stranded DNA in the presence of Rad51, but human Rad52 cannot. This results in the paradox of how is human Rad52 providing Rad51 function: presumably there is something missing in the biochemical assays that exists in-vivo, but the nature of this missing factor is currently unknown. Recent studies have suggested that Rad52 provides back-up Rad51 function for all members of the BRCA1-BRCA2 pathway, suggesting that Rad52 may be a target for therapy in BRCA pathway deficient cancers. Screening for ways to inhibit Rad52 would potentially provide a complementary strategy for targeting BRCA-deficient cancers in addition to PARP inhibitors. PMID:23071261

  12. Effects of osmotic stress on the activity of MAPKs and PDGFR-beta-mediated signal transduction in NIH-3T3 fibroblasts

    DEFF Research Database (Denmark)

    Nielsen, M-B; Christensen, Søren Tvorup; Hoffmann, E K

    2008-01-01

    Signaling in cell proliferation, cell migration, and apoptosis is highly affected by osmotic stress and changes in cell volume, although the mechanisms underlying the significance of cell volume as a signal in cell growth and death are poorly understood. In this study, we used NIH-3T3 fibroblasts...... in a serum- and nutrient-free inorganic medium (300 mosM) to analyze the effects of osmotic stress on MAPK activity and PDGF receptor (PDGFR)-beta-mediated signal transduction. We found that hypoosmolarity (cell swelling at 211 mosM) induced the phosphorylation and nuclear translocation of ERK1/2, most...... likely via a pathway independent of PDGFR-beta and MEK1/2. Conversely, hyperosmolarity (cell shrinkage at 582 mosM) moved nuclear and phosphorylated ERK1/2 to the cytoplasm and induced the phosphorylation and nuclear translocation of p38 and phosphorylation of JNK1/2. In a series of parallel experiments...

  13. Bridging from Cells to Cognition in Autism Pathophysiology: Biological Pathways to Defective Brain Function and Plasticity

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Matthew; Hooker, Brian S.; Herbert, Martha

    2008-01-01

    We review evidence to support the model that autism may begin when a maternal environmental, infectious, or autoantibody insult causes inflammation which increases reactive oxygen species (ROS) production in the fetus, leading to fetal DNA damage (nuclear and mitochondrial), and that these inflammatory and oxidative stressors persist beyond early development (with potential further exacerbations), producing ongoing functional consequences. In organs with a high metabolic demand such as the central nervous system, the continued use of mitochondria with DNA damage may generate additional ROS which will activate the innate immune system leading to more ROS production. Such a mechanism would self-sustain and possibly progressively worsen. The mitochondrial dysfunction and altered redox signal transduction pathways found in autism would conspire to activate both astroglia and microglia. These activated cells can then initiate a broad-spectrum proinflammatory gene response. Neurons may have acquired receptors for these inflammatory signals to inhibit neuronal signaling as a protection from excitotoxic damage during various pathologic insults (e.g., infection). In autism, over-zealous neuroinflammatory responses could not only influence neural developmental processes, but may more significantly impair neural signaling involved in cognition in an ongoing fashion. This model makes specific predictions in patients and experimental animal models and suggests a number of targets sites of intervention. Our model of potentially reversible pathophysiological mechanisms in autism motivates our hope that effective therapies may soon appear on the horizon.

  14. Gli2a protein localization reveals a role for Iguana/DZIP1 in primary ciliogenesis and a dependence of Hedgehog signal transduction on primary cilia in the zebrafish

    Directory of Open Access Journals (Sweden)

    van Eeden Freek

    2010-04-01

    Full Text Available Abstract Background In mammalian cells, the integrity of the primary cilium is critical for proper regulation of the Hedgehog (Hh signal transduction pathway. Whether or not this dependence on the primary cilium is a universal feature of vertebrate Hedgehog signalling has remained contentious due, in part, to the apparent divergence of the intracellular transduction pathway between mammals and teleost fish. Results Here, using a functional Gli2-GFP fusion protein, we show that, as in mammals, the Gli2 transcription factor localizes to the primary cilia of cells in the zebrafish embryo and that this localization is modulated by the activity of the Hh pathway. Moreover, we show that the Igu/DZIP1protein, previously implicated in the modulation of Gli activity in zebrafish, also localizes to the primary cilium and is required for its proper formation. Conclusion Our findings demonstrate a conserved role of the primary cilium in mediating Hedgehog signalling activity across the vertebrate phylum and validate the use of the zebrafish as a representative model for the in vivo analysis of vertebrate Hedgehog signalling.

  15. Primary cilia modulate Ihh signal transduction in response to hydrostatic loading of growth plate chondrocytes.

    Science.gov (United States)

    Shao, Yvonne Y; Wang, Lai; Welter, Jean F; Ballock, R Tracy

    2012-01-01

    Indian hedgehog (Ihh) is a key component of the regulatory apparatus governing chondrocyte proliferation and differentiation in the growth plate. Recent studies have demonstrated that the primary cilium is the site of Ihh signaling within the cell, and that primary cilia are essential for bone and cartilage formation. Primary cilia are also postulated to act as mechanosensory organelles that transduce mechanical forces acting on the cell into biological signals. In this study, we used a hydrostatic compression system to examine Ihh signal transduction under the influence of mechanical load. Our results demonstrate that hydrostatic compression increased both Ihh gene expression and Ihh-responsive Gli-luciferase activity. These increases were aborted by disrupting the primary cilia structure with chloral hydrate. These results suggest that growth plate chondrocytes respond to hydrostatic loading by increasing Ihh signaling, and that the primary cilium is required for this mechano-biological signal transduction to occur. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Experimental demonstration of high fidelity entanglement distribution over decoherence channels via qubit transduction.

    Science.gov (United States)

    Lim, Hyang-Tag; Hong, Kang-Hee; Kim, Yoon-Ho

    2015-10-21

    Quantum coherence and entanglement, which are essential resources for quantum information, are often degraded and lost due to decoherence. Here, we report a proof-of-principle experimental demonstration of high fidelity entanglement distribution over decoherence channels via qubit transduction. By unitarily switching the initial qubit encoding to another, which is insensitive to particular forms of decoherence, we have demonstrated that it is possible to avoid the effect of decoherence completely. In particular, we demonstrate high-fidelity distribution of photonic polarization entanglement over quantum channels with two types of decoherence, amplitude damping and polarization-mode dispersion, via qubit transduction between polarization qubits and dual-rail qubits. These results represent a significant breakthrough in quantum communication over decoherence channels as the protocol is input-state independent, requires no ancillary photons and symmetries, and has near-unity success probability.

  17. Lipid rafts generate digital-like signal transduction in cell plasma membranes.

    Science.gov (United States)

    Suzuki, Kenichi G N

    2012-06-01

    Lipid rafts are meso-scale (5-200 nm) cell membrane domains where signaling molecules assemble and function. However, due to their dynamic nature, it has been difficult to unravel the mechanism of signal transduction in lipid rafts. Recent advanced imaging techniques have revealed that signaling molecules are frequently, but transiently, recruited to rafts with the aid of protein-protein, protein-lipid, and/or lipid-lipid interactions. Individual signaling molecules within the raft are activated only for a short period of time. Immobilization of signaling molecules by cytoskeletal actin filaments and scaffold proteins may facilitate more efficient signal transmission from rafts. In this review, current opinions of how the transient nature of molecular interactions in rafts generates digital-like signal transduction in cell membranes, and the benefits this phenomenon provides, are discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Primary Cilia Modulate IHH Signal Transduction in Response to Hydrostatic Loading of Growth Plate Chondrocytes

    Science.gov (United States)

    Shao, Y, Yvonne Y.; Wang, Lai; Welter, J, Jean F.; Ballock, R. Tracy

    2011-01-01

    Indian Hedgehog (Ihh) is a key component of the regulatory apparatus governing chondrocyte proliferation and differentiation in the growth plate. Recent studies have demonstrated that the primary cilium is the site of Ihh signaling within the cell, and that primary cilia are essential for bone and cartilage formation. Primary cilia are also postulated to act as mechanosensory organelles that transduce mechanical forces acting on the cell into biological signals. In this study, we used a hydrostatic compression system to examine Ihh signal transduction under the influence of mechanical load. Our results demonstrate that hydrostatic compression increased both Ihh gene expression and Ihh-responsive Gli-luciferase activity. These increases were aborted by disrupting the primary cilia structure with chloral hydrate. These results suggest that growth plate chondrocytes respond to hydrostatic loading by increasing Ihh signaling, and that the primary cilium is required for this mechano-biological signal transduction to occur. PMID:21930256

  19. Effect of insulin resistance on intracellular signal transduction of vessels in diabetic

    International Nuclear Information System (INIS)

    Cen Rongguang; Wei Shaoying; Mo Xingju

    2003-01-01

    To investigate the relationship between the insulin resistance (IR) and the intracellular signal transduction of vessels, changes in fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG), total cholesterol (TC), inositol triphosphate (IP 3 ), protein kinase C(PKC) and intracellular total calcium concentration in 31 diabetic patients were compared with those of 39 normal controls. The levels of FBG, FINS, TG and TC in diabetic patients were significantly higher than those of normal controls (P 3 and PKC in diabetic patients were significantly lower than those of normal controls (P<0.01). The results suggest that there is a causal relation between insulin resistance and abnormalities of cellular calcium metabolism and intracellular signal transduction of vessels

  20. Adeno-associated viral vector transduction of human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Stender, Stefan; Murphy, Mary; O'Brien, Tim

    2007-01-01

    Mesenchymal stem cells (MSCs) have received considerable attention in the emerging field of regenerative medicine. One aspect of MSC research focuses on genetically modifying the cells with the aim of enhancing their regenerative potential. Adeno-associated virus (AAV) holds promise as a vector...... in human MSCs and to assess whether AAV transduction affects MSC multipotentiality. The results indicated that human MSCs could indeed be transiently transduced in vitro by the AAV2 vector with efficiencies of up to 65%. The percentage of GFP-positive cells peaked at 4 days post-transduction and declined...... rapidly towards 0% after day 8. The level of transgene expression in the GFP-positive population increased 4-fold over a 10,000 fold viral dose increase. This dose-response contrasted with the 200-fold increase observed in similarly transduced 293-cells, indicating a relatively restricted transgene...

  1. Information flow during gene activation by signaling molecules: ethylene transduction in Arabidopsis cells as a study system

    Directory of Open Access Journals (Sweden)

    Díaz José

    2009-05-01

    Full Text Available Abstract Background We study root cells from the model plant Arabidopsis thaliana and the communication channel conformed by the ethylene signal transduction pathway. A basic equation taken from our previous work relates the probability of expression of the gene ERF1 to the concentration of ethylene. Results The above equation is used to compute the Shannon entropy (H or degree of uncertainty that the genetic machinery has during the decoding of the message encoded by the ethylene specific receptors embedded in the endoplasmic reticulum membrane and transmitted into the nucleus by the ethylene signaling pathway. We show that the amount of information associated with the expression of the master gene ERF1 (Ethylene Response Factor 1 can be computed. Then we examine the system response to sinusoidal input signals with varying frequencies to determine if the cell can distinguish between different regimes of information flow from the environment. Our results demonstrate that the amount of information managed by the root cell can be correlated with the frequency of the input signal. Conclusion The ethylene signaling pathway cuts off very low and very high frequencies, allowing a window of frequency response in which the nucleus reads the incoming message as a sinusoidal input. Out of this window the nucleus reads the input message as an approximately non-varying one. From this frequency response analysis we estimate: a the gain of the system during the synthesis of the protein ERF1 (~-5.6 dB; b the rate of information transfer (0.003 bits during the transport of each new ERF1 molecule into the nucleus and c the time of synthesis of each new ERF1 molecule (~21.3 s. Finally, we demonstrate that in the case of the system of a single master gene (ERF1 and a single slave gene (HLS1, the total Shannon entropy is completely determined by the uncertainty associated with the expression of the master gene. A second proposition shows that the Shannon entropy

  2. Discharges of copper, zinc and lead to water and soil. Analysis of the emission pathways and possible emission reduction measures; Eintraege von Kuper, Zink und Blei in Gewaesser und Boeden. Analyse der Emissionspfade und moeglicher Emissionsminderungsmassnahmen

    Energy Technology Data Exchange (ETDEWEB)

    Hillenbrand, Thomas; Toussaint, Dominik; Boehm, Eberhard [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany); Fuchs, Stephan; Scherer, Ulrike [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Siedlungswasserwirtschaft; Rudolphi, Alexander; Hoffmann, Martin [Gesellschaft fuer Oekologische Bautechnik Berlin mbH (GFOeB) (Germany)

    2005-08-15

    Because of the pollution situation for copper, zinc and lead and due to the significance of non-point sources, there is a basic need for action to reduce the environmental burden due to non-point emissions of these heavy metals. Therefore the aim of the project was first to quantify the application-related discharges of these heavy metals into water and soil. Based on this, specific strategies to reduce the emissions to water were developed. Additionally a guideline for architects and builders for the outdoor use of the substances in the building sector was drawn up with the objective of supplying information and aids on the environmentally-compatible use of these substances. Furthermore, existing life cycle assessment methods were examined for the use of various roofing materials as well as the possibilities to further develop these methods. The results of the emission calculations show the great significancy of the application areas vehicles, building sector, water supply and other specific sources (i.e. galvanized products). The examination of different measures to reduce the emissions gives a review and an assessment of the possibilities, taking into account the relevant boundary conditions. This information can also serve as the basis for elaborating a programme of measures within the scope of a future river basin management. (orig.)

  3. TRANSDUCTION OF BACILLUS LICHENIFORMIS AND BACILLUS SUBTILIS BY EACH OF TWO PHAGES1

    Science.gov (United States)

    Taylor, Martha J.; Thorne, Curtis B.

    1963-01-01

    Taylor, Martha J. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.) and Curtis B. Thorne. Transduction of Bacillus licheniformis and Bacillus subtilis by each of two phages. J. Bacteriol. 86:452–461. 1963.—A second transducing bacteriophage, designated SP-15, was isolated from the same soil-sample culture filtrate that supplied the Bacillus subtilis transducing phage, SP-10, reported earlier from this laboratory. SP-10 and SP-15 differ serologically and in several other respects, but share the ability to propagate on B. subtilis W-23-Sr (streptomycin-resistant) and B. licheniformis ATCC 9945a, and to mediate general transduction in either species when propagated homologously. Attempts to transduce between the species have failed. SP-10 forms plaques readily on both W-23-Sr and 9945a; SP-15 forms minute plaques on W-23-Sr and has shown no evidence of any lytic activity on 9945a. Maximal recoveries of prototrophic colonies from mixtures of SP-10 with auxotrophs of either W-23-Sr or 9945a were obtained only when excess phage was neutralized by post-transduction treatment with specific phage antiserum. Such treatment was not necessary for maximal recovery of transductants effected by SP-15. Unlike SP-10, SP-15 propagated on W-23-Sr did not transduce B. subtilis 168 (indole−). SP-15 transduced B. licheniformis more efficiently than did SP-10. Neither phage was able to transduce B. licheniformis as efficiently as it transduced B. subtilis. The differing influences of multiplicity of infection were compared for the two phages in both species. PMID:14066421

  4. Tapping of Love waves in an isotropic surface waveguide by surface-to-bulk wave transduction.

    Science.gov (United States)

    Tuan, H.-S.; Chang, C.-P.

    1972-01-01

    A theoretical study of tapping a Love wave in an isotropic microacoustic surface waveguide is given. The surface Love wave is tapped by partial transduction into a bulk wave at a discontinuity. It is shown that, by careful design of the discontinuity, the converted bulk wave power and the radiation pattern may be controlled. General formulas are derived for the calculation of these important characteristics from a relatively general surface contour deformation.

  5. Efficient biotechnological approach for lentiviral transduction of induced pluripotent stem cells.

    Science.gov (United States)

    Zare, Mehrak; Soleimani, Masoud; Mohammadian, Mozhdeh; Akbarzadeh, Abolfazl; Havasi, Parvaneh; Zarghami, Nosratollah

    2016-01-01

    Induced pluripotent stem (iPS) cells are generated from differentiated adult somatic cells by reprogramming them. Unlimited self-renewal, and the potential to differentiate into any cell type, make iPS cells very promising candidates for basic and clinical research. Furthermore, iPS cells can be genetically manipulated for use as therapeutic tools. DNA can be introduced into iPS cells, using lentiviral vectors, which represent a helpful choice for efficient transduction and stable integration of transgenes. In this study, we compare two methods of lentiviral transduction of iPS cells, namely, the suspension method and the hanging drop method. In contrast to the conventional suspension method, in the hanging drop method, embryoid body (EB) formation and transduction occur concurrently. The iPS cells were cultured to form EBs, and then transduced with lentiviruses, using the conventional suspension method and the hanging drop method, to express miR-128 and green fluorescent protein (GFP). The number of transduced cells were assessed by fluorescent microscopy and flow cytometry. MTT assay and real-time PCR were performed to determine the cell viability and transgene expression, respectively. Morphologically, GFP+ cells were more detectable in the hanging drop method, and this finding was quantified by flow cytometric analysis. According to the results of the MTT assay, cell viability was considerably higher in the hanging drop method, and real-time PCR represented a higher relative expression of miR-128 in the iPS cells introduced with lentiviruses in drops. Altogether, it seems that lentiviral transduction of challenging iPS cells using the hanging drop method offers a suitable and sufficient strategy in their gene transfer, with less toxicity than the conventional suspension method.

  6. Role of Glycolytic Intermediates in Global Regulation and Signal Transduction. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J.C.

    2000-05-08

    The goal of this project is to determine the role of glycolytic intermediates in regulation of cell physiology. It is known that many glycolytic intermediates are involved in regulation of enzyme activities at the kinetic level. However, little is known regarding the role of these metabolites in global regulation and signal transduction. This project aims to investigate the role of glycolytic intermediates in the regulation of gene expression.

  7. Recombinant adeno-associated virus: efficient transduction of the rat VMH and clearance from blood.

    Directory of Open Access Journals (Sweden)

    Margriet A van Gestel

    Full Text Available To promote the efficient and safe application of adeno-associated virus (AAV vectors as a gene transfer tool in the central nervous system (CNS, transduction efficiency and clearance were studied for serotypes commonly used to transfect distinct areas of the brain. As AAV2 was shown to transduce only small volumes in several brain regions, this study compares the transduction efficiency of three AAV pseudotyped vectors, namely AAV2/1, AAV2/5 and AAV2/8, in the ventromedial nucleus of the hypothalamus (VMH. No difference was found between AAV2/1 and AAV2/5 in transduction efficiency. Both AAV2/1 and AAV2/5 achieved a higher transduction rate than AAV2/8. One hour after virus administration to the brain, no viral particles could be traced in blood, indicating that no or negligible numbers of virions crossed the blood-brain barrier. In order to investigate survival of AAV in blood, clearance was determined following systemic AAV administration. The half-life of AAV2/1, AAV2/2, AAV2/5 and AAV2/8 was calculated by determining virus clearance rates from blood after systemic injection. The half-life of AAV2/2 was 4.2 minutes, which was significantly lower than the half-lives of AAV2/1, AAV2/5 and AAV2/8. With a half-life of more than 11 hours, AAV2/8 particles remained detectable in blood significantly longer than AAV2/5. We conclude that application of AAV in the CNS is relatively safe as no AAV particles are detectable in blood after injection into the brain. With a half-life of 1.67 hours of AAV2/5, a systemic injection with 1×109 genomic copies of AAV would be fully cleared from blood after 2 days.

  8. The third helix of the murine Hoxc8 homeodomain facilitates protein transduction in mammalian cells

    International Nuclear Information System (INIS)

    Kong, Kyoung-Ah; Gadi, Jogeswar; Park, Hyoung Woo; Bok, Jinwoong; Kim, Myoung Hee

    2008-01-01

    Previously, we have demonstrated that purified Hoxc8 homeoprotein has the ability to penetrate the cellular membrane and can be transduced efficiently into COS-7 cells. Moreover, the Hoxc8 protein is able to form a complex with DNA molecules in vitro and helps the DNA be delivered intracellularly, serving as a gene delivery vehicle. Here, we further analyzed the membrane transduction activity of Hoxc8 protein and provide the evidence that the 16 amino acid (a.a.191-206, 2.23 kDa) third helix of murine Hoxc8 protein is an efficient protein transduction domain (PTD). When the 16 amino acid peptide was fused at the carboxyl terminal of enhanced green fluorescence protein (EGFP), the fusion proteins were transduced efficiently into the primary pig fetal fibroblast cells. The transduction efficiency increased in a concentration-dependent manner up to 1 μM, and appeared to plateau above a concentration of 1 μM. When tandem multimers of PTD, EGFP-PTD(2), EGFP-PTD(3), EGFP-PTD(4), and EGFP-PTD(5), were analyzed at 500 nM of concentration, the penetrating efficiency increased in a dose-dependent manner. As the number of PTDs increased, the EGFP signal also increased, although the signal maintained plateau after EGFP-PTD(3). These results indicate that the 16 amino acid third helix is the key element responsible for the membrane transduction activity of Hoxc8 proteins, and further suggest that the small peptide could serve as a therapeutic delivery vehicle for large cargo proteins

  9. Decision Aggregation in Distributed Classification by a Transductive Extension of Maximum Entropy/Improved Iterative Scaling

    Directory of Open Access Journals (Sweden)

    George Kesidis

    2008-06-01

    Full Text Available In many ensemble classification paradigms, the function which combines local/base classifier decisions is learned in a supervised fashion. Such methods require common labeled training examples across the classifier ensemble. However, in some scenarios, where an ensemble solution is necessitated, common labeled data may not exist: (i legacy/proprietary classifiers, and (ii spatially distributed and/or multiple modality sensors. In such cases, it is standard to apply fixed (untrained decision aggregation such as voting, averaging, or naive Bayes rules. In recent work, an alternative transductive learning strategy was proposed. There, decisions on test samples were chosen aiming to satisfy constraints measured by each local classifier. This approach was shown to reliably correct for class prior mismatch and to robustly account for classifier dependencies. Significant gains in accuracy over fixed aggregation rules were demonstrated. There are two main limitations of that work. First, feasibility of the constraints was not guaranteed. Second, heuristic learning was applied. Here, we overcome these problems via a transductive extension of maximum entropy/improved iterative scaling for aggregation in distributed classification. This method is shown to achieve improved decision accuracy over the earlier transductive approach and fixed rules on a number of UC Irvine datasets.

  10. Adeno-associated virus vector-mediated transduction in the cat brain.

    Science.gov (United States)

    Vite, Charles H; Passini, Marco A; Haskins, Mark E; Wolfe, John H

    2003-10-01

    Adeno-associated virus (AAV) vectors are capable of delivering a therapeutic gene to the mouse brain that can result in long-term and widespread protein production. However, the human infant brain is more than 1000 times larger than the mouse brain, which will make the treatment of global neurometabolic disorders in children more difficult. In this study, we evaluated the ability of three AAV serotypes (1,2, and 5) to transduce cells in the cat brain as a model of a large mammalian brain. The human lysosomal enzyme beta-glucuronidase (GUSB) was used as a reporter gene, because it can be distinguished from feline GUSB by heat stability. The vectors were injected into the cerebral cortex, caudate nucleus, thalamus, corona radiata, internal capsule, and centrum semiovale of 8-week-old cats. The brains were evaluated for gene expression using in situ hybridization and enzyme histochemistry 10 weeks after surgery. The AAV2 vector was capable of transducing cells in the gray matter, while the AAV1 vector resulted in greater transduction of the gray matter than AAV2 as well as transduction of the white matter. AAV5 did not result in detectable transduction in the cat brain.

  11. Progestins alter photo-transduction cascade and circadian rhythm network in eyes of zebrafish (Danio rerio)

    Science.gov (United States)

    Zhao, Yanbin; Fent, Karl

    2016-02-01

    Environmental progestins are implicated in endocrine disruption in vertebrates. Additional targets that may be affected in organisms are poorly known. Here we report that progesterone (P4) and drospirenone (DRS) interfere with the photo-transduction cascade and circadian rhythm network in the eyes of zebrafish. Breeding pairs of adult zebrafish were exposed to P4 and DRS for 21 days with different measured concentrations of 7-742 ng/L and 99-13´650 ng/L, respectively. Of totally 10 key photo-transduction cascade genes analyzed, transcriptional levels of most were significantly up-regulated, or normal down-regulation was attenuated. Similarly, for some circadian rhythm genes, dose-dependent transcriptional alterations were also observed in the totally 33 genes analyzed. Significant alterations occurred even at environmental relevant levels of 7 ng/L P4. Different patterns were observed for these transcriptional alterations, of which, the nfil3 family displayed most significant changes. Furthermore, we demonstrate the importance of sampling time for the determination and interpretation of gene expression data, and put forward recommendations for sampling strategies to avoid false interpretations. Our results suggest that photo-transduction signals and circadian rhythm are potential targets for progestins. Further studies are required to assess alterations on the protein level, on physiology and behavior, as well as on implications in mammals.

  12. Mechano-Signal Transduction in Mesenchymal Stem Cells Induces Prosaposin Secretion to Drive the Proliferation of Breast Cancer Cells.

    Science.gov (United States)

    Ishihara, Seiichiro; Inman, David R; Li, Wan-Ju; Ponik, Suzanne M; Keely, Patricia J

    2017-11-15

    In response to chemical stimuli from cancer cells, mesenchymal stem cells (MSC) can differentiate into cancer-associated fibroblasts (CAF) and promote tumor progression. How mechanical stimuli such as stiffness of the extracellular matrix (ECM) contribute to MSC phenotype in cancer remains poorly understood. Here, we show that ECM stiffness leads to mechano-signal transduction in MSC, which promotes mammary tumor growth in part through secretion of the signaling protein prosaposin. On a stiff matrix, MSC cultured with conditioned media from mammary cancer cells expressed increased levels of α-smooth muscle actin, a marker of CAF, compared with MSC cultured on a soft matrix. By contrast, MSC cultured on a stiff matrix secreted prosaposin that promoted proliferation and survival of mammary carcinoma cells but inhibited metastasis. Our findings suggest that in addition to chemical stimuli, increased stiffness of the ECM in the tumor microenvironment induces differentiation of MSC to CAF, triggering enhanced proliferation and survival of mammary cancer cells. Cancer Res; 77(22); 6179-89. ©2017 AACR . ©2017 American Association for Cancer Research.

  13. Astrocyte reactivity to unconjugated bilirubin requires TNF-α and IL-1β receptor signaling pathways.

    Science.gov (United States)

    Fernandes, Adelaide; Barateiro, Andreia; Falcão, Ana Sofia; Silva, Sandra Leit-Ao; Vaz, Ana Rita; Brito, Maria Alexandra; Silva, Rui Fernando Marques; Brites, Dora

    2011-01-01

    Jaundice and sepsis are common neonatal conditions that can lead to neurodevelopment sequelae, namely if present at the same time. We have reported that tumor necrosis factor (TNF)-α and interleukin (IL)-1β are produced by cultured neurons and mainly by glial cells exposed to unconjugated bilirubin (UCB). The effects of these cytokines are mediated by cell surface receptors through a nuclear factor (NF)-κB-dependent pathway that we have showed to be activated by UCB. The present study was designed to evaluate the role of TNF-α and IL-1β signaling on astrocyte reactivity to UCB in rat cortical astrocytes. Exposure of astrocytes to UCB increased the expression of both TNF-α receptor (TNFR)1 and IL-1β receptor (IL-1R)1, but not TNFR2, as well as their activation, observed by augmented binding of receptors' molecular adaptors, TRAF2 and TRAF6, respectively. Silencing of TNFR1, using siRNA technology, or blockade of IL-1β cascade, using its endogenous antagonist, IL-1 receptor antagonist (IL-1ra), prevented UCB-induced cytokine release and NF-κB activation. Interestingly, lack of TNF-α signal transduction reduced UCB-induced cell death for short periods of incubation, although an increase was observed after extended exposure; in contrast, inhibition of IL-1β cascade produced a sustained blockade of astrocyte injury by UCB. Together, our data show that inflammatory pathways are activated during in vitro exposure of rat cortical astrocytes to UCB and that this activation is prolonged in time. This supports the co