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Sample records for defense signaling lipoxygenase

  1. Systemic defense signaling in tomato

    Institute of Scientific and Technical Information of China (English)

    LI Changbao; SUN Jiaqiang; JIANG Hongling; WU Xiaoyan; LI Chuanyou

    2005-01-01

    The wound-inducible expression of proteinase inhibitors (PIs) genes in tomato provides a powerful model system to elucidate the signal transduction pathway of sys- temic defense response. An increasing body of evidence indi- cates that systemin and jasmonic acid (JA) work in the same signaling pathway to activate the expression of PIs and other defense-related genes. However, little is known about how systemin and JA interact to regulate cell to cell communica- tion over long distances. Genetic analysis of the systemin/JA signaling pathway in tomato plants provides a unique opportunity to dissect the mechanism by which peptide and oxylipin signals interact to coordinate systemic expression of defense-related genes. Previously, it has been proposed that systemin is the long-distance mobile signal for systemic expression of defense related genes. However, recent genetic approach provided new evidence that jasmonic acid, rather than systemin, functions as the systemic wound signal, and that the peptide systemin works to regulate the biosynthesis of JA.

  2. Role of 9-Lipoxygenase and α-Dioxygenase Oxylipin Pathways as Modulators of Local and Systemic Defense

    Institute of Scientific and Technical Information of China (English)

    Jorge Vicente; Tomás Cascón; Begonya Vicedo; Pilar García-Agustín; Mats Hamberg; Carmen Castresana

    2012-01-01

    Plant 9-lipoxygenases(9-LOX)and α-dioxygenases(α-DOX)initiate the synthesis of oxylipins after bacterial infection.Here,the role of these enzymes in plants' defense was investigated using individual Arabidopsis thaliana lox1 and dox1 mutants and a double lox1 dox1 mutant.Studies with Pseudomonas syringae pv.tomato(Pst)revealed the enhanced susceptibility of lox1 to the virulent strain Pst DC3000 and the partial impairment of lox1 and dox1 mutants to activate systemic acquired resistance.Notably,both defects were enhanced in the lox1 dox1 plants as compared with individual mutants.We found that pre-treatment with 9-LOX- and α-DOX-generated oxylipins protected plant tissues against bacterial infection.The strongest effect in this respect was exerted by 9-ketooctadecatrienoic acid(9-KOT),which is produced from linolenic acid by 9-LOX.Quantification of 9-KOT revealed its accumulation after bacterial infection.The levels were reduced in lox1 and lox1 dox1 plants but strongly increased in the dox1 mutant due to metabolic interaction of the two pathways.Transcriptional analyses indicated that 9-KOT pre-treatment modifies hormone homeostasis during bacterial infection.The nature of the changes detected suggested that 9-KOT interferes with the hormonal changes caused by bacterial effectors.This notion was substantiated by the finding that 9-KOT failed to reduce the growth of PstDC3000hrpA,a mutant compromised in effector secretion,and of the avirulent strain Pst DC3000 avrRpm1.Further support for the action of the 9-LOX- and α-DOX-oxylipin pathways as modulators of hormone homeostasis was the observation that lox1 dox1 seedlings are hypersensitive to the growth-inhibitory effect of ABA and showed enhanced activation of ABA-inducible marker genes as compared with wild-type plants.

  3. Up-regulation of lipoxygenase, phospholipase, and oxylipin-production in the induced chemical defense of the red alga Gracilaria chilensis against epiphytes.

    Science.gov (United States)

    Weinberger, Florian; Lion, Ulrich; Delage, Ludovic; Kloareg, Bernard; Potin, Philippe; Beltrán, Jessica; Flores, Verónica; Faugeron, Sylvain; Correa, Juan; Pohnert, Georg

    2011-07-01

    The red alga Gracilaria chilensis is commercially farmed for the production of agar hydrocolloids, but some susceptible algae in farms suffer from intense epiphyte growth. We investigated the induced chemical defense response of G. chilensis against epiphytes and demonstrated that an extract of an epiphyte-challenged alga can trigger a defense response. The hormonally active metabolites were purified by RP-HPLC. Treatment with the extract or the purified fraction changed the chemical profile of the alga and increased resistance against epiphyte spores. Semi-quantitative RT-PCR and enzyme assays demonstrated that this metabolic response occurs after an increase in lipoxygenase and phospholipase A2 activity. Although this suggests the involvement of regulatory oxylipins, neither jasmonic acid nor the algal metabolite prostaglandin E2 triggers comparable defense responses.

  4. Involvement of Jasmonate- signaling pathway in the herbivore-induced rice plant defense

    Institute of Scientific and Technical Information of China (English)

    XU Tao; ZHOU Qiang; CHEN Wei; ZHANG Guren; HE Guofeng; GU Dexiang; ZHANG Wenqing

    2003-01-01

    The expression patterns of eight defense- related genes in the herbivore-infested and jasmonate- treated (jasmonic acid, JA and its derivative MeJA) rice leaves were analyzed using RT-PCR. The results showed that Spodoptera litura Fabricius (Lepidoptera: Noctuidae) herbivory induced the expression of lipoxygenase (LOX) and allene oxide synthase (AOS) genes that are involved in the jasmonate-signaling pathway. Moreover, S. Litura damage resulted in the expression of farnesyl pyrophosphate synthase (FPS), Bowman-birk proteinase inhibitor (BBPI), phenylalanine ammonia-lyase (PAL) and other rice defense- related genes that were also induced by aqueous JA treatment or gaseous MeJA treatment. These indicated that in rice leaves, the JA-related signaling pathway was involved in the S. Litura-induced chemical defense. Mechanical damage and brown planthopper (BPH), Nilaparvata lugens (Stal) (Homoptera: Delphacidae) damage induced the expression of LOX gene, but both treatments did not induce the expression of AOS gene. However, BPH damage induced the expression of acidic pathogen-related protein 1 (PR-1a), Chitinase (PR-3), and PAL genes, which is involved in the salicylate- signaling pathway. It was suggested that salicylate-related signaling pathway or other pathways, rather than jasmonate-signaling pathway was involved in the BPH-induced rice plant defense.

  5. AA/12-lipoxygenase signaling contributes to inhibitory learning in Hermissenda Type B photoreceptors

    Directory of Open Access Journals (Sweden)

    Tony L Walker

    2010-08-01

    Full Text Available Conditioned inhibition (CI is a major category of associative learning that occurs when an organism learns that one stimulus predicts the absence of another. In addition to being important in its own right, CI is interesting because its occurrence implies that the organism has formed an association between stimuli that are non-coincident. In contrast to other categories of associative learning that are dependent upon temporal contiguity (pairings of stimuli, the neurobiology of CI is virtually unexplored. We have previously described a simple form of CI learning in Hermissenda, whereby animals’ phototactic behavior is increased by repeated exposures to explicitly unpaired (EU presentations of light and rotation. EU conditioning also produces characteristic reductions in the excitability and light response, and increases several somatic K+ currents in Type B photoreceptors. Type B photoreceptors are a major site of plasticity for classical conditioning in Hermissenda. Because arachidonic acid (AA and/or its metabolites open diverse K+ channels in many cell types, we examined the potential contribution of AA to CI. Our results indicate that AA contributes to one of the major effects of EU-conditioning on Type B photoreceptors: decreases in light-evoked spike activity. We find that AA increases the transient (IA somatic K+ current in Type B photoreceptors, further mimicking CI training. In addition, our results indicate that metabolism of AA by a 12-lipoxygenase enzyme is critical for these effects of AA, and further that 12-lipoxygenase metabolites are apparently generated during CI training.

  6. Defensive weapons and defense signals in plants: some metabolites serve both roles.

    Science.gov (United States)

    Maag, Daniel; Erb, Matthias; Köllner, Tobias G; Gershenzon, Jonathan

    2015-02-01

    The defense of plants against herbivores and pathogens involves the participation of an enormous range of different metabolites, some of which act directly as defensive weapons against enemies (toxins or deterrents) and some of which act as components of the complex internal signaling network that insures that defense is timed to enemy attack. Recent work reveals a surprising trend: The same compounds may act as both weapons and signals of defense. For example, two groups of well-studied defensive weapons, glucosinolates and benzoxazinoids, trigger the accumulation of the protective polysaccharide callose as a barrier against aphids and pathogens. In the other direction, several hormones acting in defense signaling (and their precursors and products) exhibit activity as weapons against pathogens. Knowing which compounds are defensive weapons, which are defensive signals and which are both is vital for understanding the functioning of plant defense systems. © 2015 WILEY Periodicals, Inc.

  7. Aboveground to belowground herbivore defense signaling in maize

    Science.gov (United States)

    Gill, Torrence; Zhu, Lixue; Lopéz, Lorena; Pechanova, Olga; Shivaji, Renuka; Ankala, Arunkanth; Williams, W. Paul

    2011-01-01

    Insect pests that attempt to feed on the caterpillar-resistant maize genotype Mp708 encounter a potent, multipronged defense system that thwarts their invasion. First, these plants are on “constant alert” due to constitutively elevated levels of the phytohormone jasmonic acid that signals the plant to activate its defenses. The higher jasmonic acid levels trigger the expression of defense genes prior to herbivore attack so the plants are “primed” and respond with a faster and stronger defense. The second defense is the rapid accumulation of a toxic cysteine protease called Mir1-CP in the maize whorl in response to caterpillar feeding. When caterpillars ingest Mir1-CP, it damages the insect's midgut and retards their growth. In this article, we discuss a third possible defense strategy employed by Mp708. We have shown that foliar caterpillar feeding causes Mir1-CP and defense gene transcripts to accumulate in its roots. We propose that caterpillar feeding aboveground sends a signal belowground via the phloem that results in Mir1-CP accumulation in the roots. We also postulate that the roots serve as a reservoir of Mir1-CP that can be mobilized to the whorl in response to caterpillar assault. PMID:21270535

  8. Ruthenium complexes as inhibitors of 15-lipoxygenase-1

    NARCIS (Netherlands)

    Traven, Katja; Eleftheriadis, Nikolaos; Sersen, Sara; Kljun, Jakob; Bezensek, Jure; Stanovnik, Branko; Turel, Iztok; Dekker, Frans

    2015-01-01

    Lipoxygenases metabolize polyunsaturated fatty acids into signalling molecules such as leukotrienes and lipoxins, which play a regulatory role in several inflammatory lung diseases such as asthma, chronic obstructive pulmonary disease (COPD) and chronic bronchitis. Human 15-lipoxygenase-1 (15-LOX-1)

  9. A cell wall extract from Piriformospora indica promotes tuberization in potato (Solanum tuberosum L.) via enhanced expression of Ca(+2) signaling pathway and lipoxygenase gene.

    Science.gov (United States)

    Upadhyaya, Chandrama Prakash; Gururani, Mayank Anand; Prasad, Ram; Verma, Ajit

    2013-06-01

    Piriformospora indica is an axenically cultivable phytopromotional endosymbiont that mimics capabilities of arbuscular mycorrhizal fungi. This is a basidiomycete of the Sebacinaceae family, which promotes growth, development, and seed production in a variety of plant species. We report that the cell wall extract (CWE) from P. indica induces tuberization in vitro and promotes tuber growth and yield in potato. The CWE altered the calcium signaling pathway that regulates tuberization process. An increase in tuber number and size was correlated with increased transcript expression of the two Ca(2+)-dependant proteins (CaM1 and St-CDPK1) and the lipoxygenase (LOX) mRNA, which are known to play distinct roles in potato tuberization. External supplementation of Ca(2+) ions induced a similar set of tuberization pathway genes, indicating presence of an active Ca(2+) in the CWE of P. indica. Since potato tuberization is directly influenced by the presence of microflora in nature, the present study provides an insight into the novel mechanism of potato tuberization in relation to plant-microbe association. Ours is the first report on an in vitro tuber-inducing beneficial fungus.

  10. Mepivacaine-induced contraction involves phosphorylation of extracellular signal-regulated kinase through activation of the lipoxygenase pathway in isolated rat aortic smooth muscle.

    Science.gov (United States)

    Lee, Hyo Min; Ok, Seong-Ho; Sung, Hui-Jin; Eun, So Young; Kim, Hye Jung; Lee, Soo Hee; Kang, Sebin; Shin, Il-Woo; Lee, Heon Keun; Chung, Young-Kyun; Choi, Mun-Jeoung; Bae, Sung Il; Sohn, Ju-Tae

    2013-04-01

    Mepivacaine is an aminoamide local anesthetic with an intermediate duration that intrinsically produces vasoconstriction both in vivo and in vitro. This study investigated the arachidonic acid metabolic pathways involved in mepivacaine-induced contraction, and elucidated the associated cellular mechanism with a particular focus on extracellular signal-regulated kinase (ERK) in endothelium-denuded rat aorta. Isolated rat thoracic aortic rings were suspended for isometric tension recording. Cumulative mepivacaine concentration-response curves were generated in the presence or absence of the following inhibitors: quinacrine dihydrochloride, nordihydroguaiaretic acid, phenidone, AA-861, indomethacin, NS-398, SC-560, fluconazole, PD 98059, and verapamil. Mepivacaine-induced ERK phosphorylation, 5-lipoxygenase (5-LOX) expression, and cyclooxygenase (COX)-2 expression in rat aortic smooth muscle cells were detected by Western blot analysis in the presence or absence of inhibitors. Mepivacaine produced tonic contraction in isolated endothelium-denuded rat aorta. Quinacrine dihydrochloride, nordihydroguaiaretic acid, phenidone, AA-861, NS-398, PD 98059, and verapamil attenuated mepivacaine-induced contraction in a concentration-dependent manner. However, fluconazole had no effect on mepivacaine-induced contraction. PD 98059, quinacrine dihydrochloride, nordihydroguaiaretic acid, AA-861, phenidone, and indomethacin attenuated mepivacaine-induced ERK phosphorylation. Mepivacaine upregulated 5-LOX and COX-2 expression. These results suggest that mepivacaine-induced contraction involves ERK activation, which is primarily mediated by the 5-LOX pathway and in part by the COX-2 pathway.

  11. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance.

    Science.gov (United States)

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W; Williamson, Valerie M; Schroeder, Frank C; Klessig, Daniel F

    2015-07-23

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture.

  12. Lipoxygenases and their metabolites in formation of plant stress tolerance

    Directory of Open Access Journals (Sweden)

    L. M. Babenko

    2017-02-01

    Full Text Available The review focuses on the analysis of new information concerning molecular enzymology of lipoxygenases – proteins involved in lipid peroxidation and found in animals and plants. Modern concept of structural features, catalytic characteristics and functions of lipoxygenase family enzymes as well as products of their catalytic activity in plants have been discussed and summarized. Issues of enzyme localization in plant cells and tissues, evolution and distribution of lipoxygenases, involvement in production of signaling substances involved in formation of adaptation response to abiotic and biotic stress factors and in regulation of lipoxygenase signal system activity are highlighted. Participants of the elements signaling of LOX-pathway reception and transduction into genome are considered. Special attention is given to jasmonates, metabolites of the allene oxide synthase branch of the lipoxygenase cascade, because these metabolites have high biological activity, are ubiquitously present in all plant organisms, and are involved in regulation of vitally important processes. Data concerning lipoxygenase phylogeny, possible occurrence of a common predecessor for modern isoforms of the enzyme in pro- and eukaryote have been examined. Some results of our studies that open up possibilities of using the lipoxygenase catalytic activity characteristics as biological markers in plant stress tolerance researches are given.

  13. Chemosensory anxiety signals prime defensive behavior in prepubertal girls.

    Science.gov (United States)

    Lübke, Katrin T; Busch, Anne; Hoenen, Matthias; Schaal, Benoist; Pause, Bettina M

    2017-05-01

    Chemosensory anxiety signals effectively prime motor responses related to withdrawal behavior, such as the startle reflex, in adult humans. As the reproductive status strongly affects the response to social chemosignals, the current study examined whether chemosensory anxiety signals would augment the startle response in prepubertal children as it does in adults. Using cotton pads, axillary sweat was collected from 28 men while waiting for an important oral examination (anxiety condition), and during ergometer training (sport control condition). Using a constant-flow olfactometer, sweat samples and pure cotton samples (cotton control) were presented to 10 prepubertal girls aged 9-13years (M=11.25, SD=1.25) for 3000ms during inhalation. White noise bursts of 102dB(A) served as startle probes, and startle responses were recorded via electromyography of the orbicularis oculi muscle. The girls showed larger startle amplitudes to probes presented in the context of chemosensory anxiety signals as compared to a context of sport control sweat (panxiety signals prime defensive motor behavior. This effect appears unrelated to the odorous quality of anxiety sweat, but seems to reflect a specific preparedness to respond to the underlying social alarm signal. Thus, chemosensory communication supporting individual harm protection is independent of the reproductive status in humans. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans

    OpenAIRE

    Heshof, R.; Schayck, van, J.P.; Tamayo Ramos, J.A.; Graaff, de, R.

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesize...

  15. Interconnection between actin cytoskeleton and plant defense signaling.

    Science.gov (United States)

    Janda, Martin; Matoušková, Jindřiška; Burketová, Lenka; Valentová, Olga

    2014-01-01

    Actin cytoskeleton is the fundamental structural component of eukaryotic cells. It has a role in numerous elementary cellular processes such as reproduction, development and also in response to abiotic and biotic stimuli. Remarkably, the role of actin cytoskeleton in plant response to pathogens is getting to be under magnifying glass. Based on microscopic studies, most of the data showed, that actin plays an important role in formation of physiological barrier in the site of infection. Actin dynamics is involved in the transport of antimicrobial compounds and cell wall fortifying components (e.g. callose) to the site of infection. Also the role in PTI (pathogen triggered immunity) and ETI (effector triggered immunity) was recently indicated. On the other hand much less is known about the transcriptome reprogramming upon changes in actin dynamics. Our recently published results showed that drugs inhibiting actin polymerization (latrunculin B, cytochalasin E) cause the induction of genes which are involved in salicylic acid (SA) signaling pathway. In this addendum we would like to highlight in more details current state of knowledge concerning the involvement of actin dynamics in plant defense signaling.

  16. Signal signature in induced defense of Arabidopsis upon pathogen and insect attack

    NARCIS (Netherlands)

    Oosten, V.R. van; Vos, M. de; Pelt, J.A. van; Poecke, R.M.P. van; Loon, L.C. van; Dicke, M.; Pieterse, C.M.J.

    2004-01-01

    Three plant signaling molecules play a dominant role in the regulation of defenses in a number of plant-attacker model systems: salicylic acid (SA), jasmonic acid (JA) and ethylene (ET). In this study, the roles of these signaling compounds were determined in the induced defense responses of Arabido

  17. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance

    National Research Council Canada - National Science Library

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W; Williamson, Valerie M; Schroeder, Frank C; Klessig, Daniel F

    2015-01-01

    .... Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated...

  18. Signaling in plant resistance responses: divergence and cross-talk of defense pathways

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Schaller, A.; Mauch-Mani, B.; Conrath, U.

    2006-01-01

    Plants possess inducible defense mechanisms to protect themselves against attack by microbial pathogens and herbivorous insects. The endogenous signalling molecules salicylic acid, ethylene, and jasmonic acid, and the peptide messenger systemin play important roles in the regulation of these induced

  19. Epigenetic Control of Defense Signaling and Priming in Plants

    Science.gov (United States)

    Espinas, Nino A.; Saze, Hidetoshi; Saijo, Yusuke

    2016-01-01

    Immune recognition of pathogen-associated molecular patterns or effectors leads to defense activation at the pathogen challenged sites. This is followed by systemic defense activation at distant non-challenged sites, termed systemic acquired resistance (SAR). These inducible defenses are accompanied by extensive transcriptional reprogramming of defense-related genes. SAR is associated with priming, in which a subset of these genes is kept at a poised state to facilitate subsequent transcriptional regulation. Transgenerational inheritance of defense-related priming in plants indicates the stability of such primed states. Recent studies have revealed the importance and dynamic engagement of epigenetic mechanisms, such as DNA methylation and histone modifications that are closely linked to chromatin reconfiguration, in plant adaptation to different biotic stresses. Herein we review current knowledge regarding the biological significance and underlying mechanisms of epigenetic control for immune responses in plants. We also argue for the importance of host transposable elements as critical regulators of interactions in the evolutionary “arms race” between plants and pathogens. PMID:27563304

  20. Epigenetic control of defense signaling and priming in plants

    Directory of Open Access Journals (Sweden)

    Nino Asuela Espinas

    2016-08-01

    Full Text Available Immune recognition of pathogen-associated molecular patterns or effectors leads to defense activation at the pathogen challenged sites. This is followed by systemic defense activation at distant non-challenged sites, termed systemic acquired resistance (SAR. These inducible defenses are accompanied by extensive transcriptional reprogramming of defense-related genes. SAR is associated with priming, in which a subset of these genes is kept at a poised state to facilitate subsequent transcriptional regulation. Transgenerational inheritance of defense-related priming in plants indicates the stability of such primed states. Recent studies have revealed the importance and dynamic engagement of epigenetic mechanisms, such as DNA methylation and histone modifications that are closely linked to chromatin reconfiguration, in plant adaptation to different biotic stresses. Herein we review current knowledge regarding the biological significance and underlying mechanisms of epigenetic control for immune responses in plants. We also argue for the importance of host transposable elements (TEs as critical regulators of interactions in the evolutionary arms race between plants and pathogens.

  1. Salivary signals of European corn borer induce indirect defenses in tomato.

    Science.gov (United States)

    Louis, Joe; Luthe, Dawn S; Felton, Gary W

    2013-11-01

    Plants can recognize the insect elicitors and activate its defense mechanisms. European Corn Borer (ECB; Ostrinia nubilalis) saliva, produced from the labial salivary glands and released through the spinneret, is responsible for inducing direct defenses in host plants. Glucose oxidase (GOX) present in the ECB saliva induced direct defenses in tomato. By contrast, GOX activity in ECB saliva was insufficient to trigger defenses in maize, suggesting that host-specific salivary elicitors are responsible for inducing direct defenses in host plants. Our current study further examined whether ECB saliva can trigger indirect defenses in tomato. Relative expression levels of TERPENE SYNTHASE5 (TPS5) and HYDROPEROXIDE LYASE (HPL), marker for indirect defenses in host plants, were monitored. Quantitative real-time PCR analysis revealed that ECB saliva can induce the expression of TPS5 and HPL, suggesting that salivary signals can induce indirect defenses in addition to the direct defenses. Further experiments are required to identify different ECB elicitors that are responsible for inducing direct and indirect defenses in host plants.

  2. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans.

    Science.gov (United States)

    Heshof, Ruud; van Schayck, J Paul; Tamayo-Ramos, Juan Antonio; de Graaff, Leo H

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans.

  3. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance

    OpenAIRE

    Manosalva, P; Manohar, M; von Reuss, S.; Chen, S.; Koch, A; Kaplan, F; Choe, A.; Micikas, R.; X. Wang; Kogel, K.; Sternberg, P.; Williamson, V; Schroeder, D; Klessig, F.

    2015-01-01

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentratio...

  4. Molecular enzymology of lipoxygenases.

    Science.gov (United States)

    Ivanov, Igor; Heydeck, Dagmar; Hofheinz, Katharina; Roffeis, Jana; O'Donnell, Valerie B; Kuhn, Hartmut; Walther, Matthias

    2010-11-15

    Lipoxygenases (LOXs) are lipid peroxidizing enzymes, implicated in the pathogenesis of inflammatory and hyperproliferative diseases, which represent potential targets for pharmacological intervention. Although soybean LOX1 was discovered more than 60years ago, the structural biology of these enzymes was not studied until the mid 1990s. In 1993 the first crystal structure for a plant LOX was solved and following this protein biochemistry and molecular enzymology became major fields in LOX research. This review focuses on recent developments in molecular enzymology of LOXs and summarizes our current understanding of the structural basis of LOX catalysis. Various hypotheses explaining the reaction specificity of different isoforms are critically reviewed and their pros and cons briefly discussed. Moreover, we summarize the current knowledge of LOX evolution by profiling the existence of LOX-related genomic sequences in the three kingdoms of life. Such sequences are found in eukaryotes and bacteria but not in archaea. Although the biological role of LOXs in lower organisms is far from clear, sequence data suggests that this enzyme family might have evolved shortly after the appearance of atmospheric oxygen on earth.

  5. Specificity of lipoxygenase pathways supports species delineation in the marine diatom genus Pseudo-nitzschia.

    Directory of Open Access Journals (Sweden)

    Nadia Lamari

    Full Text Available Oxylipins are low-molecular weight secondary metabolites derived from the incorporation of oxygen into the carbon chains of polyunsaturated fatty acids (PUFAs. Oxylipins are produced in many prokaryotic and eukaryotic lineages where they are involved in a broad spectrum of actions spanning from stress and defense responses, regulation of growth and development, signaling, and innate immunity. We explored the diversity in oxylipin patterns in the marine planktonic diatom Pseudo-nitzschia. This genus includes several species only distinguishable with the aid of molecular markers. Oxylipin profiles of cultured strains were obtained by reverse phase column on a liquid chromatograph equipped with UV photodiode detector and q-ToF mass spectrometer. Lipoxygenase compounds were mapped on phylogenies of the genus Pseudo-nitzschia inferred from the nuclear encoded hyper-variable region of the LSU rDNA and the plastid encoded rbcL. Results showed that the genus Pseudo-nitzschia exhibits a rich and varied lipoxygenase metabolism of eicosapentaenoic acid (EPA, with a high level of specificity for oxylipin markers that generally corroborated the genotypic delineation, even among genetically closely related cryptic species. These results suggest that oxylipin profiles constitute additional identification tools for Pseudo-nitzschia species providing a functional support to species delineation obtained with molecular markers and morphological traits. The exploration of the diversity, patterns and plasticity of oxylipin production across diatom species and genera will also provide insights on the ecological functions of these secondary metabolites and on the selective pressures driving their diversification.

  6. Aboveground to belowground herbivore defense signaling in maize: a two-way street?

    Science.gov (United States)

    Luthe, Dawn S; Gill, Torrence; Zhu, Lixue; Lopéz, Lorena; Pechanova, Olga; Shivaji, Renuka; Ankala, Arunkanth; Williams, W Paul

    2011-01-01

    Insect pests that attempt to feed on the caterpillar-resistant maize genotype Mp708 encounter a potent, multipronged defense system that thwarts their invasion. First, these plants are on "constant alert" due to constitutively elevated levels of the phytohormone jasmonic acid that signals the plant to activate its defenses. The higher jasmonic acid levels trigger the expression of defense genes prior to herbivore attack so the plants are "primed" and respond with a faster and stronger defense. The second defense is the rapid accumulation of a toxic cysteine protease called Mir1-CP in the maize whorl in response to caterpillar feeding. When caterpillars ingest Mir1-CP, it damages the insect's midgut and retards their growth. In this article, we discuss a third possible defense strategy employed by Mp708. We have shown that foliar caterpillar feeding causes Mir1-CP and defense gene transcripts to accumulate in its roots. We propose that caterpillar feeding aboveground sends a signal belowground via the phloem that results in Mir1-CP accumulation in the roots. We also postulate that the roots serve as a reservoir of Mir1-CP that can be mobilized to the whorl in response to caterpillar assault.

  7. Regulation of Arabidopsis defense responses against Spodoptera littoralis by CPK-mediated calcium signaling

    Directory of Open Access Journals (Sweden)

    Ishihama Nobuaki

    2010-05-01

    Full Text Available Abstract Background Plant Ca2+ signals are involved in a wide array of intracellular signaling pathways after pest invasion. Ca2+-binding sensory proteins such as Ca2+-dependent protein kinases (CPKs have been predicted to mediate the signaling following Ca2+ influx after insect herbivory. However, until now this prediction was not testable. Results To investigate the roles CPKs play in a herbivore response-signaling pathway, we screened the characteristics of Arabidopsis CPK mutants damaged by a feeding generalist herbivore, Spodoptera littoralis. Following insect attack, the cpk3 and cpk13 mutants showed lower transcript levels of plant defensin gene PDF1.2 compared to wild-type plants. The CPK cascade was not directly linked to the herbivory-induced signaling pathways that were mediated by defense-related phytohormones such as jasmonic acid and ethylene. CPK3 was also suggested to be involved in a negative feedback regulation of the cytosolic Ca2+ levels after herbivory and wounding damage. In vitro kinase assays of CPK3 protein with a suite of substrates demonstrated that the protein phosphorylates transcription factors (including ERF1, HsfB2a and CZF1/ZFAR1 in the presence of Ca2+. CPK13 strongly phosphorylated only HsfB2a, irrespective of the presence of Ca2+. Furthermore, in vivo agroinfiltration assays showed that CPK3-or CPK13-derived phosphorylation of a heat shock factor (HsfB2a promotes PDF1.2 transcriptional activation in the defense response. Conclusions These results reveal the involvement of two Arabidopsis CPKs (CPK3 and CPK13 in the herbivory-induced signaling network via HsfB2a-mediated regulation of the defense-related transcriptional machinery. This cascade is not involved in the phytohormone-related signaling pathways, but rather directly impacts transcription factors for defense responses.

  8. Synchronization of developmental processes and defense signaling by growth regulating transcription factors.

    Directory of Open Access Journals (Sweden)

    Jinyi Liu

    Full Text Available Growth regulating factors (GRFs are a conserved class of transcription factor in seed plants. GRFs are involved in various aspects of tissue differentiation and organ development. The implication of GRFs in biotic stress response has also been recently reported, suggesting a role of these transcription factors in coordinating the interaction between developmental processes and defense dynamics. However, the molecular mechanisms by which GRFs mediate the overlaps between defense signaling and developmental pathways are elusive. Here, we report large scale identification of putative target candidates of Arabidopsis GRF1 and GRF3 by comparing mRNA profiles of the grf1/grf2/grf3 triple mutant and those of the transgenic plants overexpressing miR396-resistant version of GRF1 or GRF3. We identified 1,098 and 600 genes as putative targets of GRF1 and GRF3, respectively. Functional classification of the potential target candidates revealed that GRF1 and GRF3 contribute to the regulation of various biological processes associated with defense response and disease resistance. GRF1 and GRF3 participate specifically in the regulation of defense-related transcription factors, cell-wall modifications, cytokinin biosynthesis and signaling, and secondary metabolites accumulation. GRF1 and GRF3 seem to fine-tune the crosstalk between miRNA signaling networks by regulating the expression of several miRNA target genes. In addition, our data suggest that GRF1 and GRF3 may function as negative regulators of gene expression through their association with other transcription factors. Collectively, our data provide new insights into how GRF1 and GRF3 might coordinate the interactions between defense signaling and plant growth and developmental pathways.

  9. The model of defense gene expression induced by signaling molecule β-ocimene

    Institute of Scientific and Technical Information of China (English)

    LIU Chunlin; RUAN Ying; GUAN Chunyun

    2004-01-01

    @@ β-ocimene, a kind of monoterpene, was found recently as a plant communication signal molecule[1]. It has two isomeric forms in nature: cis-β-ocimene and trans-β- ocimene. According to recent reports, all investigated plants, such as corn, cotton, lima bean, potato, tobacco, arabidopsis, and Mediterranean pine, could release the chemical component β-ocimene after fed by arthropod herbivores[2-5], suggesting thatβ-ocimene is an important functioal component in the herbivore-induced volatile. Nowadays, we know that β-ocimene can induce the expression of defense genes relative to salicylic acid in detatched leaves. But many problems of β-ocimene, for example, whether β-ocimene can induce the defense gene expression in intact plants, what role it can play in the expression model of defense genes, are elusive[1,6].

  10. Natural polyamines inhibit soybean (Glycine max) lipoxygenase-1, but not the lipoxygenase-2 isozyme.

    Science.gov (United States)

    Maccarrone, M; Baroni, A; Finazzi-Agrò, A

    1998-08-01

    Natural polyamines are shown to inhibit dioxygenase activity of soybean lipoxygenase-1, but they were ineffective toward the lipoxygenase-2 isozyme. The inhibitory power was dependent on the number of basic groups in the molecule, in the order spermine > spermidine > cadaverine >/= putrescine. Both spermidine and spermine acted as uncompetitive inhibitors of lipoxygenase-1 with respect to linoleic acid, the inhibition constants being 2.70 and 0.80 mM, respectively. The inhibitory power apparently correlated with the radical-trapping ability of the polyamines. Spermidine and spermine also inhibited the co-oxidase and peroxidase activities of lipoxygenase-1 and were effective inhibitors of lipoxygenase activity in lentil root protoplasts.

  11. A Lesion-Mimic Syntaxin Double Mutant in Arabidopsis Reveals Novel Complexity of Pathogen Defense Signaling

    Institute of Scientific and Technical Information of China (English)

    Ziguo Zhang; Hans Thordal-Christensen; Andrea Lenk; Mats X. Andersson; Torben Gjetting; Carsten Pedersen; Mads E. Nielsen; Marl-Anne Newman; Bi-Huei Hou; Shauna C. Somerville

    2008-01-01

    The lesion-mimicArabidopsis mutant, syp121 syp122, constitutively expresses the salicylic acid (SA) signaling pathway and has low penetration resistance to powdery mildew fungi. Genetic analyses of the lesion-mimic phenotype have expanded our understanding of programmed cell death (PCD) in plants. Inactivation of SA signaling genes in syp121 syp 122 only partially rescues the lesion-mimic phenotype, indicating that additional defenses contribute to the PCD. Whole genome transcriptome analysis confirmed that SA-induced transcripts, as well as numerous other known pathogenresponse transcripts, are up-regulated after inactivation of the syntaxin genes. A suppressor mutant analysis of syp121 syp122 revealed that FMO1, ALD1, and PAD4 are important for lesion development. Mutant alleles of EDS1, NDR1, RAR1, and SGT1b also partially rescued the lesion-mimic phenotype, suggesting that mutating syntaxin genes stimulates TIR-NB-LRR and CC-NB-LRR-type resistances. The syntaxin double knockout potentiated a powdery mildewinduced HR-like response. This required functional PAD4 but not functional SA signaling. However, SA signaling potentiated the PAD4-dependent HR-like response. Analyses of quadruple mutants suggest that EDS5 and SID2 confer separate SA-independent signaling functions, and that FMO1 and ALD1 mediate SA-independent signals that are NPRl-dependent.These studies highlight the contribution of multiple pathways to defense and point to the complexity of their interactions.

  12. Phosphoinositide-signaling is one component of a robust plant defense response.

    Directory of Open Access Journals (Sweden)

    Imara Yasmin Perera

    2014-06-01

    Full Text Available The phosphoinositide pathway and inositol-1,4,5-triphosphate (InsP3 have been implicated in plant responses to many abiotic stresses; however, their role in response to biotic stress is not well characterized. In the current study, we show that both basal defense and systemic acquired resistance responses are affected in transgenic plants constitutively expressing the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase which have greatly reduced InsP3 levels. Flagellin induced Ca2+-release as well as the expressions of some flg22 responsive genes were attenuated in the InsP 5-ptase plants. Furthermore, the InsP 5-ptase plants were more susceptible to virulent and avirulent strains of Pseudomonas syringae pv. tomato (PstDC3000. The InsP 5-ptase plants had lower basal salicylic acid (SA levels and the induction of SAR in systemic leaves was reduced and delayed. Reciprocal exudate experiments showed that although the InsP 5-ptase plants produced equally effective molecules that could trigger PR-1 gene expression in wild type plants, exudates collected from either wild type or InsP 5-ptase plants triggered less PR-1 gene expression in InsP 5-ptase plants. Additionally, expression profiles indicated that several defense genes including PR-1, PR-2, PR-5 and AIG1 were basally down regulated in the InsP 5-ptase plants compared with wild type. Upon pathogen attack, expression of these genes was either not induced or showed delayed induction in systemic leaves. Our study shows that phosphoinositide signaling is one component of the plant defense network and is involved in both basal and systemic responses. The dampening of InsP3-mediated signaling affects Ca2+ release, modulates defense gene expression and compromises plant defense responses.

  13. Molecular characterization of two lipoxygenases from barley

    NARCIS (Netherlands)

    Mechelen, J.R. van; Schuurink, R.C.; Smits, M.; Graner, A.; Douma, A.C.; Sedee, N.J.A.; Schmitt, N.F.; Valk, B.E.

    1999-01-01

    Two full-length lipoxygenase cDNA sequences (LoxB and LoxC) from barley (Hordeum distichum cv. L. Triumph) are described. The cDNAs share high homology with the barley LoxA cDNA. Southern blotting experiments indicate single copy numbers of the three lipoxygenase genes. RFLP mapping revealed the pre

  14. Sink limitation induces the expression of multiple soybean vegetative lipoxygenase mRNAs while the endogenous jasmonic acid level remains low.

    Science.gov (United States)

    Bunker, T W; Koetje, D S; Stephenson, L C; Creelman, R A; Mullet, J E; Grimes, H D

    1995-08-01

    The response of individual members of the lipoxygenase multigene family in soybeans to sink deprivation was analyzed. RNase protection assays indicated that a novel vegetative lipoxygenase gene, vlxC, and three other vegetative lipoxygenase mRNAs accumulated in mature leaves in response to a variety of sink limitations. These data suggest that several members of the lipoxygenase multigene family are involved in assimilate partitioning. The possible involvement of jasmonic acid as a signaling molecule regulating assimilate partitioning into the vegetative storage proteins and lipoxygenases was directly assessed by determining the endogenous level of jasmonic acid in leaves from plants with their pods removed. There was no rise in the level of endogenous jasmonic acid coincident with the strong increase in both vlxC and vegetative storage protein VspB transcripts in response to sink limitation. Thus, expression of the vegetative lipoxygenases and vegetative storage proteins is not regulated by jasmonic acid in sink-limited leaves.

  15. Nuclear jasmonate and salicylate signaling and crosstalk in defense against pathogens

    Directory of Open Access Journals (Sweden)

    Roberto eSolano

    2013-04-01

    Full Text Available An extraordinary progress has been made over the last two decades on understanding the components and mechanisms governing plant innate immunity. After detection of a pathogen, effective plant resistance depends on the activation of a complex signaling network integrated by small signaling molecules and hormonal pathways, and the balance of these hormone systems determines resistance to particular pathogens. The discovery of new components of hormonal signaling pathways, including plant nuclear hormone receptors, is providing a picture of complex crosstalk and induced hormonal changes that modulate disease and resistance through several protein families that perceive hormones within the nucleus and lead to massive gene induction responses often achieved by de-repression. This review highlights recent advances in our understanding of positive and negative regulators of these hormones signaling pathways that are crucial regulatory targets of hormonal crosstalk in disease and defense. We focus on the most recent discoveries on the jasmonate and salicylate pathway components that explain their crosstalk with other hormonal pathways in the nucleus. We discuss how these components fine-tune defense responses to build a robust plant immune system against a great number of different microbes and, finally, we summarize recent discoveries on specific nuclear hormonal manipulation by microbes which exemplify the ingenious ways by which pathogens can take control over the plant’s hormone signaling network to promote disease.

  16. Target of rapamycin signaling orchestrates growth-defense trade-offs in plants.

    Science.gov (United States)

    De Vleesschauwer, David; Filipe, Osvaldo; Hoffman, Gena; Seifi, Hamed Soren; Haeck, Ashley; Canlas, Patrick; Van Bockhaven, Jonas; De Waele, Evelien; Demeestere, Kristof; Ronald, Pamela; Hofte, Monica

    2017-09-14

    Plant defense to microbial pathogens is often accompanied by significant growth inhibition. How plants merge immune system function with normal growth and development is still poorly understood. Here, we investigated the role of target of rapamycin (TOR), an evolutionary conserved serine/threonine kinase, in the plant defense response. We used rice as a model system and applied a combination of chemical, genetic, genomic and cell-based analyses. We demonstrate that ectopic expression of TOR and Raptor (regulatory-associated protein of mTOR), a protein previously demonstrated to interact with TOR in Arabidopsis, positively regulates growth and development in rice. Transcriptome analysis of rice cells treated with the TOR-specific inhibitor rapamycin revealed that TOR not only dictates transcriptional reprogramming of extensive gene sets involved in central and secondary metabolism, cell cycle and transcription, but also suppresses many defense-related genes. TOR overexpression lines displayed increased susceptibility to both bacterial and fungal pathogens, whereas plants with reduced TOR signaling displayed enhanced resistance. Finally, we found that TOR antagonizes the action of the classic defense hormones salicylic acid and jasmonic acid. Together, these results indicate that TOR acts as a molecular switch for the activation of cell proliferation and plant growth at the expense of cellular immunity. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  17. FGF23 signaling impairs neutrophil recruitment and host defense during CKD.

    Science.gov (United States)

    Rossaint, Jan; Oehmichen, Jessica; Van Aken, Hugo; Reuter, Stefan; Pavenstädt, Hermann J; Meersch, Melanie; Unruh, Mark; Zarbock, Alexander

    2016-03-01

    Chronic kidney disease (CKD) has been associated with impaired host response and increased susceptibility to infections. Leukocyte recruitment during inflammation must be tightly regulated to protect the host against pathogens. FGF23 levels are increased in blood during CKD, and levels of this hormone have been associated with a variety of adverse effects in CKD patients. Here, we have shown that CKD impairs leukocyte recruitment into inflamed tissue and host defense in mice and humans. FGF23 neutralization during CKD in murine models restored leukocyte recruitment and host defense. Intravital microscopy of animals with chronic kidney failure showed that FGF23 inhibits chemokine-activated leukocyte arrest on the endothelium, and downregulation of FGF receptor 2 (FGFR2) on PMNs rescued host defense in these mice. In vitro, FGF23 inhibited PMN adhesion, arrest under flow, and transendothelial migration. Mechanistically, FGF23 binding to FGFR2 counteracted selectin- and chemokine-triggered β2 integrin activation on PMNs by activating protein kinase A (PKA) and inhibiting activation of the small GTPase Rap1. Moreover, knockdown of PKA abolished the inhibitory effect of FGF23 on integrin activation. Together, our data reveal that FGF23 acts directly on PMNs and dampens host defense by direct interference with chemokine signaling and integrin activation.

  18. Signal to Noise Studies on Thermographic Data with Fabricated Defects for Defense Structures

    Science.gov (United States)

    Zalameda, Joseph N.; Rajic, Nik; Genest, Marc

    2006-01-01

    There is a growing international interest in thermal inspection systems for asset life assessment and management of defense platforms. The efficacy of flash thermography is generally enhanced by applying image processing algorithms to the observations of raw temperature. Improving the defect signal to noise ratio (SNR) is of primary interest to reduce false calls and allow for easier interpretation of a thermal inspection image. Several factors affecting defect SNR were studied such as data compression and reconstruction using principal component analysis and time window processing.

  19. Role of tomato lipoxygenase D in wound-induced jasmonate biosynthesis and plant immunity to insect herbivores.

    Directory of Open Access Journals (Sweden)

    Liuhua Yan

    Full Text Available In response to insect attack and mechanical wounding, plants activate the expression of genes involved in various defense-related processes. A fascinating feature of these inducible defenses is their occurrence both locally at the wounding site and systemically in undamaged leaves throughout the plant. Wound-inducible proteinase inhibitors (PIs in tomato (Solanum lycopersicum provide an attractive model to understand the signal transduction events leading from localized injury to the systemic expression of defense-related genes. Among the identified intercellular molecules in regulating systemic wound response of tomato are the peptide signal systemin and the oxylipin signal jasmonic acid (JA. The systemin/JA signaling pathway provides a unique opportunity to investigate, in a single experimental system, the mechanism by which peptide and oxylipin signals interact to coordinate plant systemic immunity. Here we describe the characterization of the tomato suppressor of prosystemin-mediated responses8 (spr8 mutant, which was isolated as a suppressor of (prosystemin-mediated signaling. spr8 plants exhibit a series of JA-dependent immune deficiencies, including the inability to express wound-responsive genes, abnormal development of glandular trichomes, and severely compromised resistance to cotton bollworm (Helicoverpa armigera and Botrytis cinerea. Map-based cloning studies demonstrate that the spr8 mutant phenotype results from a point mutation in the catalytic domain of TomLoxD, a chloroplast-localized lipoxygenase involved in JA biosynthesis. We present evidence that overexpression of TomLoxD leads to elevated wound-induced JA biosynthesis, increased expression of wound-responsive genes and, therefore, enhanced resistance to insect herbivory attack and necrotrophic pathogen infection. These results indicate that TomLoxD is involved in wound-induced JA biosynthesis and highlight the application potential of this gene for crop protection against

  20. A novel class of fungal lipoxygenases.

    Science.gov (United States)

    Heshof, Ruud; Jylhä, Sirpa; Haarmann, Thomas; Jørgensen, Ann Louise Worsøe; Dalsgaard, Trine Kastrup; de Graaff, Leo H

    2014-02-01

    Lipoxygenases (LOXs) are well-studied enzymes in plants and mammals. However, fungal LOXs are less studied. In this study, we have compared fungal LOX protein sequences to all known characterized LOXs. For this, a script was written using Shell commands to extract sequences from the NCBI database and to align the sequences obtained using Multiple Sequence Comparison by Log-Expectation. We constructed a phylogenetic tree with the use of Quicktree to visualize the relation of fungal LOXs towards other LOXs. These sequences were analyzed with respect to the signal sequence, C-terminal amino acid, the stereochemistry of the formed oxylipin, and the metal ion cofactor usage. This study shows fungal LOXs are divided into two groups, the Ile- and the Val-groups. The Ile-group has a conserved WRYAK sequence that appears to be characteristic for fungal LOXs and has as a C-terminal amino acid Ile. The Val-group has a highly conserved WL-L/F-AK sequence that is also found in LOXs of plant and animal origin. We found that fungal LOXs with this conserved sequence have a Val at the C-terminus in contrast to other LOXs of fungal origin. Also, these LOXs have signal sequences implying these LOXs will be expressed extracellularly. Our results show that in this group, in addition to the Gaeumannomyces graminis and the Magnaporthe salvinii LOXs, the Aspergillus fumigatus LOX uses manganese as a cofactor.

  1. Expression of soluble recombinant lipoxygenase from Pleurotus sapidus in Pichia pastoris.

    Science.gov (United States)

    Kelle, Sebastian; Zelena, Katerina; Krings, Ulrich; Linke, Diana; Berger, Ralf G

    2014-03-01

    The first heterologous expression of an iron-containing lipoxygenase from a basidiomycete in Pichia pastoris is reported. Five different expression constructs of the lipoxygenase gene LOX1 from Pleurotus sapidus were cloned and successfully transferred into P. pastoris SMD1168, but only one pPIC9K vector construct was functionally expressed. In this construct the vector-provided α-factor signal sequence was replaced by insertion of a second Kozak sequence between the signal sequence and the LOX1 gene. His(+) transformants were screened for their level of resistance to geneticin (G418). Lox1 was expressed under different culture conditions and purified using the N-terminal His-tag. Relative enzyme activity increased significantly 48h after methanol induction and was highest with 2mll(-1) inducer. The recombinant enzyme showed an optimal lipoxygenase activity at pH 7 and 30-35°C and a vmax like the wild-type enzyme.

  2. Essential role of interleukin-1 signaling in host defenses against group B streptococcus.

    Science.gov (United States)

    Biondo, Carmelo; Mancuso, Giuseppe; Midiri, Angelina; Signorino, Giacomo; Domina, Maria; Lanza Cariccio, Veronica; Venza, Mario; Venza, Isabella; Teti, Giuseppe; Beninati, Concetta

    2014-09-09

    Signal transduction via MyD88, an adaptor protein engaged by the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) family receptors, has a crucial role in host defenses against group B streptococcus (GBS). To examine the contribution of IL-1R signaling to MyD88-dependent host defenses, we analyzed GBS infection in type I IL-1R (IL-1RI)-deficient mice. Most of these animals displayed clinical signs of sepsis and neurological disease and died after a challenge with a bacterial dose that did not cause illness or death in any of the wild-type animals. Moreover, bacterial numbers in the blood and brains of the immunodefective mice were considerably increased. The ability of blood leukocytes or bone marrow-derived macrophages to kill GBS in vitro was not affected by a lack of IL-1RI. However, it was found in a newly developed model of GBS-induced peritoneal inflammation that IL-1 signaling selectively promoted the production of the chemokines KC and MIP-1α and neutrophil recruitment. Moreover, the secretion of KC and MIP-1α, but not tumor necrosis factor alpha, by peritoneal macrophages stimulated with GBS was significantly decreased in the absence of IL-1RI. Accordingly, the number of neutrophils in the blood and the concentration of myeloperoxidase, a neutrophil marker, in infected organs were severely reduced in the immunodefective mice during GBS disease, concomitantly with a reduction in tissue KC and MIP-1α levels. In conclusion, IL-1RI plays a crucial role in host defenses against GBS by inducing the high-level production of chemokines and the subsequent recruitment of neutrophilic polymorphonuclear leukocytes to infection sites. Group B streptococcus (GBS) is a serious and frequent human pathogen. Experimental infection with this bacterium has been widely used to understand the mechanism whereby the body's first line of defense, represented by cells and molecules of the innate immune system, fights infections. In both humans and mice, defective

  3. Phosphorylation of Serine 271 on 5-Lipoxygenase and Its Role in Nuclear Export*

    OpenAIRE

    Flamand, Nicolas; Luo, Ming; Peters-Golden, Marc; Brock, Thomas G.

    2009-01-01

    The enzyme 5-lipoxygenase (5-LO) initiates the biosynthesis of leukotrienes, inflammatory mediators involved in immune diseases and defense. The subcellular localization of 5-LO is regulated, with nuclear import commonly leading to increased leukotriene production. We report here that 5-LO is constitutively phosphorylated on Ser-271 in transfected NIH 3T3 cells. This residue is nested in a classical nuclear export sequence, and phosphorylated Ser-271 5-LO was exclusive...

  4. Modulation of legume defense signaling pathways by native and non-native pea aphid clones

    Directory of Open Access Journals (Sweden)

    Carlos Sanchez-Arcos

    2016-12-01

    Full Text Available The pea aphid (Acyrthosiphon pisum is a complex of at least 15 genetically different host races that are native to specific legume plants, but can all develop on the universal host plant Vicia faba. Despite much research it is still unclear why pea aphid host races (biotypes are able to colonize their native hosts while other host races are not. All aphids penetrate the plant and salivate into plant cells when they test plant suitability. Thus plants might react differently to the various pea aphid host races. To find out whether legume species vary in their defense responses to different pea aphid host races, we measured the amounts of salicylic acid (SA, the jasmonic acid-isoleucine conjugate (JA-Ile, other jasmonate precursors and derivatives, and abscisic acid (ABA in four different species (Medicago sativa, Trifolium pratense, Pisum sativum, V. faba after infestation by native and non-native pea aphid clones of various host races. Additionally, we assessed the performance of the clones on the four plant species. On M. sativa and T. pratense, non-native clones that were barely able to survive or reproduce, triggered a strong SA and JA-Ile response, whereas infestation with native clones led to lower levels of both phytohormones. On P. sativum, non-native clones, which survived or reproduced to a certain extent, induced fluctuating SA and JA-Ile levels, whereas the native clone triggered only a weak SA and JA-Ile response. On the universal host V. faba all aphid clones triggered only low SA levels initially, but induced clone-specific patterns of SA and JA-Ile later on. The levels of the active JA-Ile conjugate and of the other JA-pathway metabolites measured showed in many cases similar patterns, suggesting that the reduction in JA signaling was due to an effect upstream of OPDA. ABA levels were downregulated in all aphid clone-plant combinations and were therefore probably not decisive factors for aphid-plant compatibility. Our results

  5. Impact of embedded endocannabinoids and their oxygenation by lipoxygenase on membrane properties.

    Science.gov (United States)

    Dainese, Enrico; Sabatucci, Annalaura; Angelucci, Clotilde B; Barsacchi, Daniela; Chiarini, Marco; Maccarrone, Mauro

    2012-05-16

    N-Arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol are the best characterized endocannabinoids. Their biological activity is subjected to metabolic control whereby a dynamic equilibrium among biosynthetic, catabolic, and oxidative pathways drives their intracellular concentrations. In particular, lipoxygenases can generate hydroperoxy derivatives of endocannabinoids, endowed with distinct activities within cells. The in vivo interaction between lipoxygenases and endocannabinoids is likely to occur within cell membranes; thus, we sought to ascertain whether a prototypical enzyme like soybean (Glycine max) 15-lipoxygenase-1 is able to oxygenate endocannabinoids embedded in synthetic vesicles and how these substances could affect the binding ability of the enzyme to different lipid bilayers. We show that (i) embedded endocannabinoids increase membrane fluidity; (ii) 15-lipoxygenase-1 preferentially binds to endocannabinoid-containing bilayers; and that (iii) 15-lipoxygenase-1 oxidizes embedded endocannabinoids and thus reduces fluidity and local hydration of membrane lipids. Together, the present findings reveal further complexity in the regulation of endocannabinoid signaling within the central nervous system, disclosing novel control by oxidative pathways.

  6. Cross-Talk between Cancer Cells and the Tumour Microenvironment: The Role of the 5-Lipoxygenase Pathway

    Science.gov (United States)

    Moore, Gillian Y.; Pidgeon, Graham P.

    2017-01-01

    5-lipoxygenase is an enzyme responsible for the synthesis of a range of bioactive lipids signalling molecules known collectively as eicosanoids. 5-lipoxygenase metabolites such as 5-hydroxyeicosatetraenoic acid (5-HETE) and a number of leukotrienes are mostly derived from arachidonic acid and have been shown to be lipid mediators of inflammation in different pathological states including cancer. Upregulated 5-lipoxygenase expression and metabolite production is found in a number of cancer types and has been shown to be associated with increased tumorigenesis. 5-lipoxygenase activity is present in a number of diverse cell types of the immune system and connective tissue. In this review, we discuss potential routes through which cancer cells may utilise the 5-lipoxygenase pathway to interact with the tumour microenvironment during the development and progression of a tumour. Furthermore, immune-derived 5-lipoxygenase signalling can drive both pro- and anti-tumour effects depending on the immune cell subtype and an overview of evidence for these opposing effects is presented. PMID:28125014

  7. Elucidation of defense-related signaling responses to spot blotch infection in bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Sahu, Ranabir; Sharaff, Murali; Pradhan, Maitree; Sethi, Avinash; Bandyopadhyay, Tirthankar; Mishra, Vinod K; Chand, Ramesh; Chowdhury, Apurba K; Joshi, Arun K; Pandey, Shree P

    2016-04-01

    Spot blotch disease, caused by Bipolaris sorokiniana, is an important threat to wheat, causing an annual loss of ~17%. Under epidemic conditions, these losses may be 100%, yet the molecular responses of wheat to spot blotch remain almost uncharacterized. Moreover, defense-related phytohormone signaling genes have been poorly characterized in wheat. Here, we have identified 18 central components of salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and enhanced disease susceptibility 1 (EDS1) signaling pathways as well as the genes of the phenylpropanoid pathway in wheat. In time-course experiments, we characterized the reprogramming of expression of these pathways in two contrasting genotypes: Yangmai #6 (resistant to spot blotch) and Sonalika (susceptible to spot blotch). We further evaluated the performance of a population of recombinant inbred lines (RILs) by crossing Yangmai#6 and Sonalika (parents) and subsequent selfing to F10 under field conditions in trials at multiple locations. We characterized the reprogramming of defense-related signaling in these RILs as a consequence of spot blotch attack. During resistance to spot blotch attack, wheat strongly elicits SA signaling (SA biogenesis as well as the NPR1-dependent signaling pathway), along with WRKY33 transcription factor, followed by an enhanced expression of phenylpropanoid pathway genes. These may lead to accumulation of phenolics-based defense metabolites that may render resistance against spot blotch. JA signaling may synergistically contribute to the resistance. Failure to elicit SA (and possibly JA) signaling may lead to susceptibility against spot blotch infection in wheat.

  8. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling

    Directory of Open Access Journals (Sweden)

    Mina eAziz

    2016-04-01

    Full Text Available Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant’s growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03 transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm. In contrast, a previously-characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against beet armyworm feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense.

  9. Control of antiviral defenses through hepatitis C virus disruption of retinoic acid-inducible gene-I signaling

    Science.gov (United States)

    Foy, Eileen; Li, Kui; Sumpter, Rhea; Loo, Yueh-Ming; Johnson, Cynthia L.; Wang, Chunfu; Fish, Penny Mar; Yoneyama, Mitsutoshi; Fujita, Takashi; Lemon, Stanley M.; Gale, Michael

    2005-01-01

    Hepatitis C virus (HCV) is a major human pathogen that infects 170 million people. A hallmark of HCV is its ability to establish persistent infections reflecting the evasion of host immunity and interference with α/β-IFN innate immune defenses. We demonstrate that disruption of retinoic acid-inducible gene I (RIG-I) signaling by the viral NS3/4A protease contributes to the ability of HCV to control innate antiviral defenses. RIG-I was essential for virus or HCV RNA-induced signaling to the IFN-β promoter in human hepatoma cells. This signaling was disrupted by the protease activity of NS3/4A, which ablates RIG-I signaling of downstream IFN regulatory factor 3 and NF-κB activation, attenuating expression of host antiviral defense genes and interrupting an IFN amplification loop that otherwise suppresses HCV replication. Treatment of cells with an active site inhibitor of the NS3/4A protease relieved this suppression and restored intracellular antiviral defenses. Thus, NS3/4A control of RIG-I supports HCV persistence by preventing IFN regulatory factor 3 and NF-κB activation. Our results demonstrate that these processes are amenable to restoration through pharmacologic inhibition of viral protease function. PMID:15710892

  10. The ubiquitin ligase SEVEN IN ABSENTIA (SINA) ubiquitinates a defense-related NAC transcription factor and is involved in defense signaling.

    Science.gov (United States)

    Miao, Min; Niu, Xiangli; Kud, Joanna; Du, Xinran; Avila, Julian; Devarenne, Timothy P; Kuhl, Joseph C; Liu, Yongsheng; Xiao, Fangming

    2016-07-01

    We recently identified a defense-related tomato (Solanum lycopersicum) NAC (NAM, ATAF1,2, CUC2) transcription factor, NAC1, that is subjected to ubiquitin-proteasome system-dependent degradation in plant cells. In this study, we identified a tomato ubiquitin ligase (termed SEVEN IN ABSENTIA3; SINA3) that ubiquitinates NAC1, promoting its degradation. We conducted coimmunoprecipitation and bimolecular fluorescence complementation to determine that SINA3 specifically interacts with the NAC1 transcription factor in the nucleus. Moreover, we found that SINA3 ubiquitinates NAC1 in vitro and promotes NAC1 degradation via polyubiquitination in vivo, indicating that SINA3 is a ubiquitin ligase that ubiquitinates NAC1, promoting its degradation. Our real-time PCR analysis indicated that, in contrast to our previous finding that NAC1 mRNA abundance increases upon Pseudomonas infection, the SINA3 mRNA abundance decreases in response to Pseudomonas infection. Moreover, using Agrobacterium-mediated transient expression, we found that overexpression of SINA3 interferes with the hypersensitive response cell death triggered by multiple plant resistance proteins. These results suggest that SINA3 ubiquitinates a defense-related NAC transcription factor for degradation and plays a negative role in defense signaling.

  11. A novel class of fungal lipoxygenases

    NARCIS (Netherlands)

    Heshof, R.; Jylhä, S.; Haarmann, T.; Jørgensen, A.L.W.; Dalsgaard, T.K.; Graaff, de L.H.

    2014-01-01

    Lipoxygenases (LOXs) are well-studied enzymes in plants and mammals. However, fungal LOXs are less studied. In this study, we have compared fungal LOX protein sequences to all known characterized LOXs. For this, a script was written using Shell commands to extract sequences from the NCBI database an

  12. Peptides as inhibitors of lipoxygenase and tyrosinase

    NARCIS (Netherlands)

    Minderhout-Schurink, M.

    2007-01-01

    Oxidation reactions catalyzed by enzymes such as lipoxygenase (LOX) and tyrosinase (TYR) initiate food quality decay. Besides their physiological role in the human body, LOX and TYR are involved in certain types of cancer, neurodegenerative diseases and processes of aging. Most common antioxidants a

  13. Opposing roles of Toll-like receptor and cytosolic DNA-STING signaling pathways for Staphylococcus aureus cutaneous host defense

    Science.gov (United States)

    Spreafico, Roberto; Modlin, Robert L.; Smale, Stephen T.

    2017-01-01

    Successful host defense against pathogens requires innate immune recognition of the correct pathogen associated molecular patterns (PAMPs) by pathogen recognition receptors (PRRs) to trigger the appropriate gene program tailored to the pathogen. While many PRR pathways contribute to the innate immune response to specific pathogens, the relative importance of each pathway for the complete transcriptional program elicited has not been examined in detail. Herein, we used RNA-sequencing with wildtype and mutant macrophages to delineate the innate immune pathways contributing to the early transcriptional response to Staphylococcus aureus, a ubiquitous microorganism that can activate a wide variety of PRRs. Unexpectedly, two PRR pathways—the Toll-like receptor (TLR) and Stimulator of Interferon Gene (STING) pathways—were identified as dominant regulators of approximately 95% of the genes that were potently induced within the first four hours of macrophage infection with live S. aureus. TLR signaling predominantly activated a pro-inflammatory program while STING signaling activated an antiviral/type I interferon response with live but not killed S. aureus. This STING response was largely dependent on the cytosolic DNA sensor cyclic guanosine-adenosine synthase (cGAS). Using a cutaneous infection model, we found that the TLR and STING pathways played opposite roles in host defense to S. aureus. TLR signaling was required for host defense, with its absence reducing interleukin (IL)-1β production and neutrophil recruitment, resulting in increased bacterial growth. In contrast, absence of STING signaling had the opposite effect, enhancing the ability to restrict the infection. These results provide novel insights into the complex interplay of innate immune signaling pathways triggered by S. aureus and uncover opposing roles of TLR and STING in cutaneous host defense to S. aureus. PMID:28704551

  14. Bacterial lipoxygenases, a new subfamily of enzymes? A phylogenetic approach.

    Science.gov (United States)

    Hansen, Jhoanne; Garreta, Albert; Benincasa, Maria; Fusté, M Carmen; Busquets, Montserrat; Manresa, Angeles

    2013-06-01

    Lipoxygenases (EC. 1.13.11.12) are a non-heme iron enzymes consisting of one polypeptide chain folded into two domains, the N-terminal domain and the catalytic moiety β-barrel domain. They catalyze the dioxygenation of 1Z,4Z-pentadiene moieties of polyunsaturated fatty acids obtaining hydroperoxy fatty acids. For years, the presence of lipoxygenases was considered a eukaryotic feature, present in mammals, plants, small marine invertebrates, and fungi, but now, some lipoxygenase sequences have been detected on prokaryotic organisms, changing the idea that lipoxygenases are exclusively a eukaryotic affair. Lipoxygenases are involved in different types of reactions on eukaryote organisms where the biological role and the structural characteristics of these enzymes are well studied. However, these aspects of the bacterial lipoxygenases have not yet been elucidated and are unknown. This revision discusses biochemical aspects, biological applications, and some characteristics of these enzymes and tries to determine the existence of a subfamily of bacterial lipoxygenases in the context of the phylogeny of prokaryotic lipoxygenases, supporting the results of phylogenetic analyzes with the comparison and discussion of structural information of the first prokaryotic lipoxygenase crystallized and other eukaryotic lipoxygenases structures.

  15. Zinc hyperaccumulation substitutes for defense failures beyond salicylate and jasmonate signaling pathways of Alternaria brassicicola attack in Noccaea caerulescens.

    Science.gov (United States)

    Gallego, Berta; Martos, Soledad; Cabot, Catalina; Barceló, Juan; Poschenrieder, Charlotte

    2017-04-01

    The hypothesis of metal defense as a substitute for a defective biotic stress signaling system in metal hyperaccumulators was tested using the pathosystem Alternaria brassicicola-Noccaea caerulescens under low (2 µM), medium (12 µM) and high (102 µM) Zn supply. Regardless the Zn supply, N. caerulescens responded to fungal attack with the activation of both HMA4 coding for a Zn transporter, and biotic stress signaling pathways. Salicylate, jasmonate, abscisic acid and indoleacetic acid concentrations, as well as biotic stress marker genes (PDF1.2, CHIB, LOX2, PR1 and BGL2) were activated 24 h upon inoculation. Based on the activation of defense genes 24 h after the inoculation an incompatible fungal-plant interaction could be predicted. Nonetheless, in the longer term (7 days) no effective protection against A. brassicicola was achieved in plants exposed to low and medium Zn supply. After 1 week the biotic stress markers were even further increased in these plants, and this compatible interaction was apparently not caused by a failure in the signaling of the fungal attack, but due to the lack of specificity in the type of the activated defense mechanisms. Only plants receiving high Zn exhibited an incompatible fungal interaction. High Zn accumulation in these plants, possibly in cooperation with high glucosinolate concentrations, substituted for the ineffective defense system and the interaction turned into incompatible. In a threshold-type response, these joint effects efficiently hampered fungal spread and, consequently decreased the biotic stress signaling. © 2016 Scandinavian Plant Physiology Society.

  16. Leucine aminopeptidase regulates defense and wound signaling in tomato downstream of jasmonic acid.

    Science.gov (United States)

    Fowler, Jonathan H; Narváez-Vásquez, Javier; Aromdee, Dale N; Pautot, Véronique; Holzer, Frances M; Walling, Linda L

    2009-04-01

    Leucine aminopeptidase A (LapA) is a late wound-response gene of tomato (Solanum lycopersicum). To elucidate the role of LapA, transgenic plants that overexpressed or abolished LapA gene expression were used. The early wound-response gene RNA levels were similar in wild-type and Lap-silenced (LapA-SI), -antisense (LapA-AS), and -overexpressing (LapA-OX) plants. By contrast, late wound-response gene RNA levels and protection against Manduca sexta damage were influenced by LapA RNA and protein levels. While LapA-OX plants had elevated levels of LapA RNAs and protein, ectopic expression of LapA was not sufficient to induce Pin (Ser proteinase inhibitor) or PPO (polyphenol oxidase) transcripts in nonwounded leaves. M. sexta larvae damaged less foliage and displayed delays in growth and development when feeding on LapA-OX plants. By contrast, LapA-SI and LapA-AS lines had lower levels of Pin and PPO RNAs than wild-type controls. Furthermore, larvae consumed more foliage and attained larger masses when feeding on LapA-SI plants. Jasmonic acid (JA) did not complement the wound-signaling phenotype of LapA-SI plants. Based on root elongation in the presence of JA, JA perception appeared to be intact in LapA-SI lines. Collectively, these data suggested that LAP-A has a role in modulating essential defenses against herbivores by promoting late wound responses and acting downstream of JA biosynthesis and perception.

  17. Leucine Aminopeptidase Regulates Defense and Wound Signaling in Tomato Downstream of Jasmonic Acid[W

    Science.gov (United States)

    Fowler, Jonathan H.; Narváez-Vásquez, Javier; Aromdee, Dale N.; Pautot, Véronique; Holzer, Frances M.; Walling, Linda L.

    2009-01-01

    Leucine aminopeptidase A (LapA) is a late wound-response gene of tomato (Solanum lycopersicum). To elucidate the role of LapA, transgenic plants that overexpressed or abolished LapA gene expression were used. The early wound-response gene RNA levels were similar in wild-type and Lap-silenced (LapA-SI), -antisense (LapA-AS), and -overexpressing (LapA-OX) plants. By contrast, late wound-response gene RNA levels and protection against Manduca sexta damage were influenced by LapA RNA and protein levels. While LapA-OX plants had elevated levels of LapA RNAs and protein, ectopic expression of LapA was not sufficient to induce Pin (Ser proteinase inhibitor) or PPO (polyphenol oxidase) transcripts in nonwounded leaves. M. sexta larvae damaged less foliage and displayed delays in growth and development when feeding on LapA-OX plants. By contrast, LapA-SI and LapA-AS lines had lower levels of Pin and PPO RNAs than wild-type controls. Furthermore, larvae consumed more foliage and attained larger masses when feeding on LapA-SI plants. Jasmonic acid (JA) did not complement the wound-signaling phenotype of LapA-SI plants. Based on root elongation in the presence of JA, JA perception appeared to be intact in LapA-SI lines. Collectively, these data suggested that LAP-A has a role in modulating essential defenses against herbivores by promoting late wound responses and acting downstream of JA biosynthesis and perception. PMID:19376935

  18. Rice Rab11 is required for JA-mediated defense signaling

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Min Ji [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); BK21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714 (Korea, Republic of); Lee, Yun mi [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); Son, Young Sim [Division of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Im, Chak Han [Eco-Friendliness Research Department, Gyeongsangnam-do Agricultural Research and Extension Services, Jinju 660-360 (Korea, Republic of); Yi, Young Byung [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); Rim, Yeong Gil [Systems and Synthetic Agrobiotech Center, Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Bahk, Jeong Dong, E-mail: jdbahk@gnu.ac.kr [Division of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University, Jinju 660-701 (Korea, Republic of); Heo, Jae Bok, E-mail: jbheo72@dau.ac.kr [Department of Molecular Biotechnology, Dong-A University, Busan 604-714 (Korea, Republic of); BK21 Center for Silver-Bio Industrialization, Dong-A University, Busan 604-714 (Korea, Republic of)

    2013-05-17

    Highlights: •OsRab11 interacts with OsOPR8. •OsOPR8 is localized in the cytosol and peroxisome. •OsRab11 enhances the NADPH consumption by OsOPR8. •Transgenic Arabidopsis overexpressing OsRab11 represents a pathogen-resistant phenotype. -- Abstract: Rab proteins play an essential role in regulating vesicular transport in eukaryotic cells. Previously, we characterized OsRab11, which in concert with OsGAP1 and OsGDI3 regulates vesicular trafficking from the trans-Golgi network (TGN) to the plasma membrane or vacuole. To further elucidate the physiological function of OsRab11 in plants, we performed yeast two-hybrid screens using OsRab11 as bait. OsOPR8 was isolated and shown to interact with OsRab11. A co-immunoprecipitation assay confirmed this interaction. The green fluorescent protein-OsOPR8 fusion product was targeted to the cytoplasm and peroxisomes of protoplasts from Arabidopsis thaliana. OsOPR8 exhibited NADPH-dependent reduction activity when 2-cyclohexen-1-one (CyHE) and 12-oxo-phytodienoic acid (OPDA) were supplied as possible substrates. Interestingly, NADPH oxidation by OsOPR8 was increased when wild-type OsRab11 or the constitutively active form of OsRab11 (Q78L) were included in the reaction mix, but not when the dominant negative form of OsRab11 (S28N) was included. OsRab11 was expressed broadly in plants and both OsRab11 and OsOPR8 were induced by jasmonic acid (JA) and elicitor treatments. Overexpressed OsRab11 transgenic plants showed resistance to pathogens through induced expression of JA-responsive genes. In conclusion, OsRab11 may be required for JA-mediated defense signaling by activating the reducing activity of OsOPR8.

  19. OsWRKY03, a rice transcriptional activator that functions in defense signaling pathway upstream of OsNPR1

    Institute of Scientific and Technical Information of China (English)

    Xiao Qiang LIU; Xian Quan BAI; Qian QIAN; Xiu Jie WANG; Ming Sheng CHEN; Cheng Cai CHU

    2005-01-01

    WRKY family proteins are a class of plant specific transcription factors that involve in many stress response pathways.It has been shown that one Arabidopsis WRKY protein, AtWRKY29/22, is activated by MAP kinase signaling cascade and confers resistance to both bacterial and fungal pathogens. However, little is known about the biological roles of WRKY proteins in rice. In this study, we investigated the expression patterns of rice AtWRKY29/22 homolog, OsWRKY03,under different conditions, and also its possible role involved in plant defense. Our results showed that OsWRKY03 was up-regulated by several defense signaling molecules or different treatments. Further analysis revealed that the expression of OsWRKY03 was light dependent. Transcriptional activation activity of OsWRKY03 was also demonstrated by yeast functional assay. Transient expression of OsWRKY03-GFP fusion protein in onion epidermis cells showed that OsWRKY03 was a nuclear localized protein. OsNPR1 as well as several other pathogenesis-related genes, such as OsPR1b, phenylalanine ammonia-lyase (ZB8) and peroxidase (POX22.3), were induced in OsWRKY03-overexpressing transgenic plants. These results indicated that OsWRKY03 is located upstream of OsNPR1 as a transcriptional activator in salicylic acid (SA)-dependent or jasmonic acid (JA)-dependent defense signaling cascades.

  20. Root-expressed maize lipoxygenase 3 negatively regulates induced systemic resistance to Colletotrichum graminicola in shoots.

    Science.gov (United States)

    Constantino, Nasie N; Mastouri, Fatemeh; Damarwinasis, Ramadhika; Borrego, Eli J; Moran-Diez, Maria E; Kenerley, Charley M; Gao, Xiquan; Kolomiets, Michael V

    2013-01-01

    We have previously reported that disruption of a maize root-expressed 9-lipoxygenase (9-LOX) gene, ZmLOX3, results in dramatic increase in resistance to diverse leaf and stalk pathogens. Despite evident economic significance of these findings, the mechanism behind this increased resistance remained elusive. In this study, we found that increased resistance of the lox3-4 mutants is due to constitutive activation of induced systemic resistance (ISR) signaling. We showed that ZmLOX3 lacked expression in leaves in response to anthracnose leaf blight pathogen Colletotrichum graminicola, but was expressed constitutively in the roots, thus, prompting our hypothesis: the roots of lox3-4 mutants are the source of increased resistance in leaves. Supporting this hypothesis, treatment of wild-type plants (WT) with xylem sap of lox3-4 mutant induced resistance to C. graminicola to the levels comparable to those observed in lox3-4 mutant. Moreover, treating mutants with the sap collected from WT plants partially restored the susceptibility to C. graminicola. lox3-4 mutants showed primed defense responses upon infection, which included earlier and greater induction of defense-related PAL and GST genes compared to WT. In addition to the greater expression of the octadecanoid pathway genes, lox3-4 mutant responded earlier and with a greater accumulation of H2O2 in response to C. graminicola infection or treatment with alamethicin. These findings suggest that lox3-4 mutants display constitutive ISR-like signaling. In support of this idea, root colonization by Trichoderma virens strain GV29-8 induced the same level of disease resistance in WT as the treatment with the mutant sap, but had no additional resistance effect in lox3-4 mutant. While treatment with T. virens GV29 strongly and rapidly suppressed ZmLOX3 expression in hydroponically grown WT roots, T. virens Δsml mutant, which is deficient in ISR induction, was unable to suppress expression of ZmLOX3, thus, providing genetic

  1. Functional analysis of chimeric lysin motif domain receptors mediating Nod factor-induced defense signaling in Arabidopsis thaliana and chitin-induced nodulation signaling in Lotus japonicus.

    Science.gov (United States)

    Wang, Wei; Xie, Zhi-Ping; Staehelin, Christian

    2014-04-01

    The expression of chimeric receptors in plants is a way to activate specific signaling pathways by corresponding signal molecules. Defense signaling induced by chitin from pathogens and nodulation signaling of legumes induced by rhizobial Nod factors (NFs) depend on receptors with extracellular lysin motif (LysM) domains. Here, we constructed chimeras by replacing the ectodomain of chitin elicitor receptor kinase 1 (AtCERK1) of Arabidopsis thaliana with ectodomains of NF receptors of Lotus japonicus (LjNFR1 and LjNFR5). The hybrid constructs, named LjNFR1-AtCERK1 and LjNFR5-AtCERK1, were expressed in cerk1-2, an A. thaliana CERK1 mutant lacking chitin-induced defense signaling. When treated with NFs from Rhizobium sp. NGR234, cerk1-2 expressing both chimeras accumulated reactive oxygen species, expressed chitin-responsive defense genes and showed increased resistance to Fusarium oxysporum. In contrast, expression of a single chimera showed no effects. Likewise, the ectodomains of LjNFR1 and LjNFR5 were replaced by those of OsCERK1 (Oryza sativa chitin elicitor receptor kinase 1) and OsCEBiP (O. sativa chitin elicitor-binding protein), respectively. The chimeras, named OsCERK1-LjNFR1 and OsCEBiP-LjNFR5, were expressed in L. japonicus NF receptor mutants (nfr1-1; nfr5-2) carrying a GUS (β-glucuronidase) gene under the control of the NIN (nodule inception) promoter. Upon chitin treatment, GUS activation reflecting nodulation signaling was observed in the roots of NF receptor mutants expressing both chimeras, whereas a single construct was not sufficient for activation. Hence, replacement of ectodomains in LysM domain receptors provides a way to specifically trigger NF-induced defense signaling in non-legumes and chitin-induced nodulation signaling in legumes. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  2. Lipoxygenase Activity Accelerates Programmed Spore Germination in Aspergillus fumigatus

    Directory of Open Access Journals (Sweden)

    Gregory J. Fischer

    2017-05-01

    Full Text Available The opportunistic human pathogen Aspergillus fumigatus initiates invasive growth through a programmed germination process that progresses from dormant spore to swollen spore (SS to germling (GL and ultimately invasive hyphal growth. We find a lipoxygenase with considerable homology to human Alox5 and Alox15, LoxB, that impacts the transitions of programmed spore germination. Overexpression of loxB (OE::loxB increases germination with rapid advance to the GL stage. However, deletion of loxB (ΔloxB or its signal peptide only delays progression to the SS stage in the presence of arachidonic acid (AA; no delay is observed in minimal media. This delay is remediated by the addition of the oxygenated AA oxylipin 5-hydroxyeicosatetraenoic acid (5-HETE that is a product of human Alox5. We propose that A. fumigatus acquisition of LoxB (found in few fungi enhances germination rates in polyunsaturated fatty acid-rich environments.

  3. Methods for identifying lipoxygenase producing microorganisms on agar plates.

    Science.gov (United States)

    Nyyssölä, Antti; Heshof, Ruud; Haarmann, Thomas; Eidner, Jasmin; Westerholm-Parvinen, Ann; Langfelder, Kim; Kruus, Kristiina; de Graaff, Leo; Buchert, Johanna

    2012-03-26

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the β-carotene bleaching method, but the sensitivity of this method was lower than the other two methods. The potassium iodide-starch and indamine dye formation methods were also applied for detecting lipoxygenase production by Trichoderma reesei and Pichia pastoris transformants expressing the lipoxygenase gene of the fungus Gaeumannomyces graminis. In both cases lipoxygenase production in the transformants could be identified. For detection of the G. graminis lipoxygenase produced by Aspergillus nidulans the potassium iodide-starch method was successful. When Escherichia coli was grown on agar and soybean lipoxygenase was applied on the culture lipoxygenase activity could clearly be detected by the indamine dye formation method. This suggests that the method has potential for screening of metagenomic libraries in E. coli for lipoxygenase activity.

  4. Transcellular lipoxygenase metabolism between monocytes and platelets

    Energy Technology Data Exchange (ETDEWEB)

    Bigby, T.D.; Meslier, N. (Univ. of California, San Francisco (USA))

    1989-09-15

    We have examined the effects of co-culture and in vitro co-stimulation on lipoxygenase metabolism in monocytes and platelets. Monocytes were obtained from the peripheral blood of normal volunteers by discontinuous gradient centrifugation and adherence to tissue culture plastic. Platelets were obtained from the platelet-rich plasma of the same donor. When 10(9) platelets and 2.5 x 10(6) monocytes were co-stimulated with 1 microM A23187, these preparations released greater quantities of 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid, 5(S),12-(S)dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid, and leukotriene C4, 5(S)-hydroxy-6(R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic (LTC4) when compared with monocytes alone. Release of arachidonic acid, 5-HETE, delta 6-trans-LTB4, and delta 6-trans-12-epi-LTB4 from monocytes was decreased in the presence of platelets. A dose-response curve was constructed and revealed that the above changes became evident when the platelet number exceeded 10(7). Dual radiolabeling experiments with 3H- and 14C-arachidonic acid revealed that monocytes provided arachidonic acid, 5-HETE, and LTA4 for further metabolism by the platelet. Monocytes did not metabolize platelet intermediates detectably. In addition, as much as 1.2 microM 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid and 12(S)-hydroperoxy-10-trans-5,8,14-cis-eicosatetraenoic acid had no effect on monocyte lipoxygenase metabolism. Platelets were capable of converting LTA4 to LTC4, but conversion of LTA4 to LTB4 was not detected. We conclude that the monocyte and platelet lipoxygenase pathways undergo a transcellular lipoxygenase interaction that differs from the interaction of the neutrophil and platelet lipoxygenase pathways. In this interaction monocytes provide intermediate substrates for further metabolic conversion by platelets in an unidirectional manner.

  5. Transcriptomic profiling of soybean in response to high-intensity UV-B irradiation reveals stress defense signaling

    Directory of Open Access Journals (Sweden)

    Min Young Yoon

    2016-12-01

    Full Text Available The depletion of the ozone layer in the stratosphere has led to a dramatic spike in ultraviolet B (UV-B intensity and increased UV-B light levels. The direct absorption of high-intensity UV-B induces complex abiotic stresses in plants, including excessive light exposure, heat, and dehydration. However, UV-B stress signaling mechanisms in plants including soybean (Glycine max [L.] remain poorly understood. Here, we surveyed the overall transcriptional responses of two soybean genotypes, UV-B-sensitive Cheongja 3 and UV-B-resistant Buseok, to continuous UV-B irradiation for 0 (control, 0.5, and 6 h using RNA-seq analysis. Homology analysis using UV-B-related genes from Arabidopsis thaliana revealed differentially expressed genes (DEGs likely involved in UV-B stress responses. Functional classification of the DEGs showed that the categories of immune response, stress defense signaling, and reactive oxygen species (ROS metabolism were over-represented. UV-B-resistant Buseok utilized phosphatidic acid-dependent signaling pathways (based on subsequent reactions of phospholipase C and diacylglycerol kinase rather than phospholipase D in response to UV-B exposure at high fluence rates, and genes involved in its downstream pathways, such as ABA signaling, mitogen-activated protein kinase cascades, and ROS overproduction, were upregulated in this genotype. In addition, the DEGs for TIR-NBS-LRR and heat shock proteins are positively activated. These results suggest that defense mechanisms against UV-B stress at high fluence rates are separate from the photomorphogenic responses utilized by plants to adapt to low-level UV light. Our study provides valuable information for deep understanding of UV-B stress defense mechanisms and for the development of resistant soybean genotypes that survive under high-intensity UV-B stress.

  6. Resistance to hemi-biotrophic F. graminearum infection is associated with coordinated and ordered expression of diverse defense signaling pathways.

    Directory of Open Access Journals (Sweden)

    Lina Ding

    Full Text Available Fusarium species cause serious diseases in cereal staple food crops such as wheat and maize. Currently, the mechanisms underlying resistance to Fusarium-caused diseases are still largely unknown. In the present study, we employed a combined proteomic and transcriptomic approach to investigate wheat genes responding to F. graminearum infection that causes Fusarium head blight (FHB. We found a total of 163 genes and 37 proteins that were induced by infection. These genes and proteins were associated with signaling pathways mediated by salicylic acid (SA, jasmonic acid (JA, ethylene (ET, calcium ions, phosphatidic acid (PA, as well as with reactive oxygen species (ROS production and scavenging, antimicrobial compound synthesis, detoxification, and cell wall fortification. We compared the time-course expression profiles between FHB-resistant Wangshuibai plants and susceptible Meh0106 mutant plants of a selected set of genes that are critical to the plants' resistance and defense reactions. A biphasic phenomenon was observed during the first 24 h after inoculation (hai in the resistant plants. The SA and Ca(2+ signaling pathways were activated within 6 hai followed by the JA mediated defense signaling activated around 12 hai. ET signaling was activated between these two phases. Genes for PA and ROS synthesis were induced during the SA and JA phases, respectively. The delayed activation of the SA defense pathway in the mutant was associated with its susceptibility. After F. graminearum infection, the endogenous contents of SA and JA in Wangshuibai and the mutant changed in a manner similar to the investigated genes corresponding to the individual pathways. A few genes for resistance-related cell modification and phytoalexin production were also identified. This study provided important clues for designing strategies to curb diseases caused by Fusarium.

  7. Root-Expressed Maize Lipoxygenase 3 Negatively Regulates Induced Systemic Resistance to Colletotrichum graminicola in Shoots

    Directory of Open Access Journals (Sweden)

    Nasie eConstantino

    2013-12-01

    Full Text Available We have previously reported that disruption of a maize root-expressed 9-lipoxygenase (9-LOX gene, ZmLOX3, results in dramatic increase in resistance to diverse leaf and stalk pathogens. Despite evident economic significance of these findings, the mechanism behind this increased resistance remained elusive. In this study, we show that increased resistance of the lox3-4 mutants is due to constitutive activation of induced systemic resistance (ISR signaling. We showed that ZmLOX3 lacked expression in leaves in response to anthracnose leaf blight pathogen Colletotrichum graminicola, but was expressed constitutively in the roots, thus prompting our hypothesis: the roots of lox3-4 mutants are the source of increased resistance in leaves. Supporting this hypothesis, treatment of wild-type plants (WT with xylem sap of lox3-4 mutant induced resistance to C. graminicola to the levels comparable to those observed in lox3-4 mutant. Moreover, treating mutants with the sap collected from WT plants partially restored the susceptibility to C. graminicola. lox3-4 mutants showed primed defense responses upon infection, which included earlier and greater induction of defense-related PAL and GST genes compared to WT. In addition to the greater expression of the octadecanoid pathway genes, lox3-4 mutant responded earlier and with a greater accumulation of H2O2 in response to C. graminicola infection or treatment with alamethicin. These findings suggest that lox3-4 mutants display constitutive ISR-like signaling. In support of this idea, root colonization by Trichoderma virens strain GV29-8 induced the same level of disease resistance in WT as the treatment with the mutant sap, but had no additional resistance effect in lox3-4 mutant. While treatment with T. virens GV29 strongly and rapidly suppressed ZmLOX3 expression in hydroponically grown WT roots, T. virens Δsml mutant, which is deficient in ISR induction, was unable to suppress expression of ZmLOX3, thus

  8. Analysis of rhizosphere bacterial communities in Arabidopsis: impact of plant defense signaling

    NARCIS (Netherlands)

    Doornbos, R.F.

    2009-01-01

    In the rhizosphere, numerous microbial and plant-microbe interactions occur. Of special interest is the ability of specific rhizosphere bacteria to elicit induced systemic resistance (ISR), a state of enhanced defensive capacity of the plant that is effective against a wide range of pathogens. The g

  9. Jasmonate and ethylene signaling mediate whitefly-induced interference with indirect plant defense in Arabidopsis thaliana

    NARCIS (Netherlands)

    Zhang, P.J.; Broekgaarden, C.; Zheng, S.J.; Snoeren, T.A.L.; Loon, van J.J.A.; Gols, R.; Dicke, M.

    2013-01-01

    Upon herbivore attack, plants activate an indirect defense, that is, the release of a complex mixture of volatiles that attract natural enemies of the herbivore. When plants are simultaneously exposed to two herbivore species belonging to different feeding guilds, one herbivore may interfere with th

  10. With anandamide as substrate plant 5-lipoxygenases behave like 11-lipoxygenases

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Zadelhoff, G. van; Veldink, G.A.

    1998-01-01

    Anandamide, an endogenous ligand for cannabinoid receptors CB1 and CB2, was incubated with purified 5-lipoxygenases from barley and tomato. This yielded 11S-hydroperoxy-5,8,12,14-eicosatetraenoylethanolamide (11S-HPANA) as major product (about 70%). This is in contrast with the dioxygenation of arac

  11. Methods for identifying lipoxygenase producing microorganisms on agar plates

    NARCIS (Netherlands)

    Nyyssola, A.; Heshof, R.; Haarmann, T.; Eidner, J.; Westerholm-Parvinen, A.; Langfelder, K.; Kruus, K.; Graaff, de L.H.; Buchert, J.

    2012-01-01

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the beta-carotene bleaching

  12. Expression of lipoxygenase isoenzymes in developing barley grains

    NARCIS (Netherlands)

    Schmitt, N.F.; Mechelen, J.R. van

    1997-01-01

    Expression of lipoxygenase was studied in whole developing barley grains from 5 days after flowering (DAF) to full maturity. Lipoxygenase showed two distinct peaks of activity. The first peak of activity occurred in the early stages of grain development from 5 until 20 DAF, whereas the second peak o

  13. OsHK3 is a crucial regulator of abscisic acid signaling involved in antioxidant defense in rice

    Institute of Scientific and Technical Information of China (English)

    Feng Wen; Tingting Qin; Yao Wang; Wen Dong; Aying Zhang; Mingpu Tan; Mingyi Jiang

    2015-01-01

    In this study, the role of the rice (Oryza sativa L.) histidine kinase OsHK3 in abscisic acid (ABA)‐induced antioxi-dant defense was investigated. Treatments with ABA, H2O2, and polyethylene glycol (PEG) induced the expression of OsHK3 in rice leaves, and H2O2 is required for ABA‐induced increase in the expression of OsHK3 under water stress. Subcel ular localization analysis showed that OsHK3 is located in the cytoplasm and the plasma membrane. The transient expres-sion analysis and the transient RNA interference test in rice protoplasts showed that OsHK3 is required for ABA‐induced upregulation in the expression of antioxidant enzymes genes and the activities of antioxidant enzymes. Further analysis showed that OsHK3 functions upstream of the calcium/calmodulin‐dependent protein kinase OsDMI3 and the mito-gen‐activated protein kinase OsMPK1 to regulate the activities of antioxidant enzymes in ABA signaling. Moreover, OsHK3 was also shown to regulate the expression of nicotinamide adenine dinucleotide phosphate oxidase genes, OsrbohB and OsrbohE, and the production of H2O2 in ABA signaling. Our data indicate that OsHK3 play an important role in the regulation of ABA‐induced antioxidant defense and in the feedback regula-tion of H2O2 production in ABA signaling.

  14. Cyclooxygenases and lipoxygenases in prostate and breast cancers.

    Science.gov (United States)

    Nie, Daotai

    2007-01-01

    Oxidative metabolism of polyunsaturated fatty acids through cyclooxygenases or lipoxygenases can generate various lipid peroxides and bioactive lipids, and regulate cellular proliferation, apoptosis, differentiation and senescence. The role of the second cyclooxygenase isoform (COX-2) has been demonstrated in a number of studies and is regarded as a promising target for chemoprevention and treatment. The involvement for lipoxygenases in tumor initiation and progression has been implicated in several studies but remains controversial. Among the many members of lipoxygenase family, both tumor promoting and suppressing activities have been described. For example, 15-lipoxygenase-1 has been implicated as a tumor promoter in prostate cancer, but it suppresses colon cancer. In this review, the role of cyclooxygenases and lipoxygenases in cancer will be described, with the hope of attracting further research to define their functions in cancer.

  15. SGT1 interacts with the Prf resistance protein and is required for Prf accumulation and Prf-mediated defense signaling.

    Science.gov (United States)

    Kud, Joanna; Zhao, Zhulu; Du, Xinran; Liu, Yule; Zhao, Yun; Xiao, Fangming

    2013-02-15

    The highly conserved eukaryotic co-chaperone SGT1 (suppressor of the G2 allele of skp1) is an important signaling component of plant defense responses and positively regulates disease resistance conferred by many resistance (R) proteins. In this study, we investigated the contribution of SGT1 in the Prf-mediated defense responses in both Nicotiana benthamiana and tomato (Solanum lycopersicum). SGT1 was demonstrated to interact with Prf in plant cells by co-immunoprecipitation. The requirement of SGT1 in the accumulation of Prf or autoactive Prf(D1416V) was determined by the degradation of these proteins in N. benthamiana, in which SGT1 was repressed by virus-induced gene silencing (VIGS). Pseudomonas pathogen assay on the SGT1-silenced tomato plants implicates SGT1 is required for the Prf-mediated full resistance to Pseudomonas syringae pv. tomato (Pst). These results suggest that, in both N. benthamiana and tomato, SGT1 contributes to the Prf-mediated defense responses by stabilizing Prf protein via its co-chaperone activity. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Integration of ethylene and jasmonic acid signaling pathways in the expression of maize defense protein Mir1-CP.

    Science.gov (United States)

    Ankala, A; Luthe, D S; Williams, W P; Wilkinson, J R

    2009-12-01

    In plants, ethylene and jasmonate control the defense responses to multiple stressors, including insect predation. Among the defense proteins known to be regulated by ethylene is maize insect resistance 1-cysteine protease (Mir1-CP). This protein is constitutively expressed in the insect-resistant maize (Zea mays) genotype Mp708; however, its abundance significantly increases during fall armyworm (Spodoptera frugiperda) herbivory. Within 1 h of herbivory by fall armyworm, Mir1-CP accumulates at the feeding site and continues to increase in abundance until 24 h without any increase in its transcript (mir1) levels. To resolve this discrepancy and elucidate the role of ethylene and jasmonate in the signaling of Mir1-CP expression, the effects of phytohormone biosynthesis and perception inhibitors on Mir1-CP expression were tested. Immunoblot analysis of Mir1-CP accumulation and quantitative reverse-transcriptase polymerase chain reaction examination of mir1 levels in these treated plants demonstrate that Mir1-CP accumulation is regulated by both transcript abundance and protein expression levels. The results also suggest that jasmonate functions upstream of ethylene in the Mir1-CP expression pathway, allowing for both low-level constitutive expression and a two-stage defensive response, an immediate response involving Mir1-CP accumulation and a delayed response inducing mir1 transcript expression.

  17. ELR chemokine signaling in host defense and disease in a viral model of central nervous system disease

    Directory of Open Access Journals (Sweden)

    Martin P Hosking

    2014-06-01

    Full Text Available Intracranial infection of the neurotropic JHM strain of mouse hepatitis virus (JHMV into the central nervous system (CNS of susceptible strains of mice results in an acute encephalomyelitis, accompanied by viral replication in glial cells and robust infiltration of virus-specific T cells that contribute to host defense through cytokine secretion and cytolytic activity. Mice that survive the acute stage of disease develop an immune-mediated demyelinating diseases characterized by viral persistence in white matter tracts and a chronic neuroinflammatory response dominated by T cells and macrophages. Early following JHMV infection, there is a dynamic expression of chemokines and chemokine receptors that contribute to neuroinflammation by regulating innate and adaptive immune responses as well influencing glial biology. In response to JHMV infection, we have shown that signaling through the chemokine receptor CXCR2 contributes to host defense through recruitment of polymorphonuclear cells (PMNs to the CNS that enhance permeability of the blood-brain-barrier (BBB and facilitating entry of virus-specific T cells into the parenchyma. Further, CXCR2 promotes the protection of oligodendroglia from cytokine-induced apoptosis and restricts the severity of demyelination. This review covers aspects related to the role of CXCR2 in host defense and disease in response to JHMV infection.

  18. 拉·德方斯观光大厦%La Defense Tour Signal

    Institute of Scientific and Technical Information of China (English)

    大都会建筑事务所

    2008-01-01

    @@ Ambition Post-war Paris is torn between its need.as the nation's capital,to represent its modernity versus its preservation instinct. The construction of the business dist rict of La Defense will begin with the creation of a virgin surface of any new urbanization:the Concentration of critical mass on the outskirts of the city(Paris).whilst protecting the historic centre.

  19. Influences of an acoustic signal with ultrasound components on the acquisition of a defensive conditioned reflex in Wistar rats.

    Science.gov (United States)

    Loseva, E V; Alekseeva, T G

    2007-06-01

    The effects of short (90 sec) exposures to a complex acoustic signal with ultrasound components on the acquisition of a defensive conditioned two-way avoidance reflex using an electric shock as the unconditioned stimulus in a shuttle box were studied in female Wistar rats. This stimulus induced audiogenic convulsions of different severities in 59% of the animals. A scale for assessing the ability of rats to acquire the conditioned two-way avoidance reflex was developed. Presentation of the complex acoustic signal was found to be a powerful stressor for Wistar rats, preventing the acquisition of the reflex in the early stages (four and six days) after presentation. This effect was independent of the presence and severity of audiogenic convulsions in the rats during presentation of the acoustic signal. On repeat training nine days after the acoustic signal (with the first session after four days), acquisition of the reflex was hindered (as compared with controls not presented with the acoustic signal). However, on repeat training at later time points (1.5 months after the complex acoustic signal, with the first session after six days), the rats rapidly achieved the learning criterion (10 correct avoidance responses in a row). On the other hand, if the acoustic signal was presented at different times (immediately or at three or 45 days) after the first training session, the animals' ability to acquire the reflex on repeat training was not impaired at either the early or late periods after exposure to the stressor. These results suggest that the complex acoustic signal impairs short-term memory (the process of acquisition of the conditioned two-way avoidance reflex at the early post-presentation time point) but has no effect on long-term memory or consolidation of the memory trace.

  20. Possible role of glutamine synthetase in the NO signaling response in root nodules by contributing to the antioxidant defenses

    Directory of Open Access Journals (Sweden)

    Liliana Santos Silva

    2013-09-01

    Full Text Available Nitric oxide (NO is emerging as an important regulatory player in the Rhizobium-legume symbiosis. The occurrence of NO during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. The identification of the molecular targets of NO is key for the assembly of the signal transduction cascade that will ultimately help to unravel NO function. We have recently shown that the key nitrogen assimilatory enzyme Glutamine Synthetase (GS is a molecular target of NO in root nodules of Medicago truncatula, being post-translationally regulated by tyrosine nitration in relation to nitrogen fixation. In functional nodules of M. truncatula NO formation has been located in the bacteroid containing cells of the fixation zone, where the ammonium generated by bacterial nitrogenase is released to the plant cytosol and assimilated into the organic pools by plant GS. We propose that the NO-mediated GS post-translational inactivation is connected to nitrogenase inhibition induced by NO and is related to metabolite channeling to boost the nodule antioxidant defenses. Glutamate, a substrate for GS activity is also the precursor for the synthesis of glutathione (GSH, which is highly abundant in root nodules of several plant species and known to play a major role in the antioxidant defense participating in the ascorbate/GSH cycle. Existing evidence suggests that upon NO-mediated GS inhibition, glutamate could be channeled for the synthesis of GSH. According to this hypothesis, GS would be involved in the NO-signaling responses in root nodules and the NO-signaling events would meet the nodule metabolic pathways to provide an adaptive response to the inhibition of symbiotic nitrogen fixation by reactive nitrogen species (RNS.

  1. Specificity of herbivore-induced hormonal signaling and defensive traits in five closely related milkweeds (Asclepias spp.).

    Science.gov (United States)

    Agrawal, Anurag A; Hastings, Amy P; Patrick, Eamonn T; Knight, Anna C

    2014-07-01

    Despite the recognition that phytohormonal signaling mediates induced responses to herbivory, we still have little understanding of how such signaling varies among closely related species and may generate herbivore-specific induced responses. We studied closely related milkweeds (Asclepias) to link: 1) plant damage by two specialist chewing herbivores (milkweed leaf beetles Labidomera clivicolis and monarch caterpillars Danaus plexippus); 2) production of the phytohormones jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA); 3) induction of defensive cardenolides and latex; and 4) impacts on Danaus caterpillars. We first show that A. syriaca exhibits induced resistance following monarch herbivory (i.e., reduced monarch growth on previously damaged plants), while the defensively dissimilar A. tuberosa does not. We next worked with a broader group of five Asclepias, including these two species, that are highly divergent in defensive traits yet from the same clade. Three of the five species showed herbivore-induced changes in cardenolides, while induced latex was found in four species. Among the phytohormones, JA and ABA showed specific responses (although they generally increased) to insect species and among the plant species. In contrast, SA responses were consistent among plant and herbivore species, showing a decline following herbivore attack. Jasmonic acid showed a positive quantitative relationship only with latex, and this was strongest in plants damaged by D. plexippus. Although phytohormones showed qualitative tradeoffs (i.e., treatments that enhanced JA reduced SA), the few significant individual plant-level correlations among hormones were positive, and these were strongest between JA and ABA in monarch damaged plants. We conclude that: 1) latex exudation is positively associated with endogenous JA levels, even among low-latex species; 2) correlations among milkweed hormones are generally positive, although herbivore damage induces a

  2. Biochemical and molecular-genetic characterization of SFD1’s involvement in lipid metabolism and defense signaling

    Directory of Open Access Journals (Sweden)

    Katarzyna eLorenc-Kukula

    2012-02-01

    Full Text Available The Arabidopsis thaliana SFD1 (SUPPRESSOR OF FATTY ACID DESATURASE DEFICIENCY1 gene (also known as GLY1 is required for accumulation of 34:6 (i.e., 18:3-16:3 monogalactosyldiacylglycerol (MGDG and for the activation of systemic acquired resistance (SAR, an inducible defense mechanism that confers resistance against a broad spectrum of pathogens. SFD1, which has been suggested to be involved in lipid-based signaling in SAR, contains a putative chloroplast transit peptide and has glycerol-3-phosphate synthesizing dihydroxyacetone phosphate (DHAP reductase (also referred as glycerol-3-phosphate dehydrogenase activity. The goals of this study were to determine if the DHAP reductase activity and chloroplast localization are required for SFD1’s involvement in galactolipid metabolism and SAR signaling. The crystal structure of a Leishmania mexicana glycerol-3-phosphate dehydrogenase was used to model SFD1 structure and identify Lys194, Lys279 and Asp332 as potential catalytic site residues in SFD1. Mutational analysis of SFD1 confirmed that Lys194, Lys279 and Asp332 are critical for SFD1’s DHAP reductase activity, and its involvement in SAR. SFD1 proteins with these residues individually substituted by Ala lacked DHAP reductase activity and were unable to complement the SAR defect of the sfd1 mutant. SFD1-Ala279 was unable to restore 34:6-MGDG content when expressed in the sfd1 mutant. In vivo imaging of a GFP-tagged SFD1 protein demonstrated that SFD1 is targeted to the chloroplast. The N-terminal 43 amino acids, which are required for proper targeting of SFD1 to the chloroplast, are also required for SFD1’s function in lipid metabolism and SAR. Taken together, these results demonstrate that SFD1s DHAP reductase activity is required in the chloroplast for lipid metabolism and defense signaling.

  3. Lipoxygenase isoenzymes: a spectroscopic and structural characterization of soybean seed enzymes.

    Science.gov (United States)

    Draheim, J E; Carroll, R T; McNemar, T B; Dunham, W R; Sands, R H; Funk, M O

    1989-02-15

    Applying recent developments in protein purification techniques, a number of lipoxygenase isoenzymes have been isolated in satisfactory quantities for a detailed physical and structural characterization. Four seed isoenzymes from two soybean cultivars have been studied by peptide mapping, free thiol and iron content determinations, and C-terminal analysis as well as by uv-visible absorption and EPR spectroscopy. While differences between the type 1 enzyme and the other isoenzymes were readily detected using proteolytic peptide mapping, digestion with dilute hydrochloric acid and C-terminal analysis both revealed structural features which were similar in all of the isoenzymes. One clear difference between the lipoxygenases was in their free sulfhydryl group content. The uv-visible absorption spectrum of each native isoenzyme was consistent with expectations for the experimental aromatic amino acid content. All of the isoenzymes contained one non-heme iron atom per molecule of protein. The oxidation of each isoenzyme with product hydroperoxide resulted in the conversion of the iron from an EPR silent state into several forms with EPR signals characteristic of high spin iron(III). The EPR spectra of all isoenzymes were remarkably similar. A time course EPR and catalytic activity study revealed that the various EPR active states represent a complex equilibrium between iron atoms in different environments. The pH dependence for the EPR and absorption spectroscopy lends support to the hypothesis that acid/base chemistry represents an important aspect of lipoxygenase catalysis.

  4. A chloroplast lipoxygenase is required for wound-induced jasmonic acid accumulation in Arabidopsis.

    Science.gov (United States)

    Bell, E; Creelman, R A; Mullet, J E

    1995-09-12

    Plant lipoxygenases are thought to be involved in the biosynthesis of lipid-derived signaling molecules. The potential involvement of a specific Arabidopsis thaliana lipoxygenase isozyme, LOX2, in the biosynthesis of the plant growth regulators jasmonic acid (JA) and abscisic acid was investigated. Our characterization of LOX2 indicates that the protein is targeted to chloroplasts. The physiological role of this chloroplast lipoxygenase was analyzed in transgenic plants where cosuppression reduced LOX2 accumulation. The reduction in LOX2 levels caused no obvious changes in plant growth or in the accumulation of abscisic acid. However, the wound-induced accumulation of JA observed in control plants was absent in leaves of transgenic plants that lacked LOX2. Thus, LOX2 is required for the wound-induced synthesis of the plant growth regulator JA in leaves. We also examined the expression of a wound- and JA-inducible Arabidopsis gene, vsp, in transgenic and control plants. Leaves of transgenic plants lacking LOX2 accumulated less vsp mRNA than did control leaves in response to wounding. This result suggests that wound-induced JA (or some other LOX2-requiring component of the wound response pathway) is involved in the wound-induced regulation of this gene.

  5. Oxidative stress: molecular perception and transduction of signals triggering antioxidant gene defenses

    Directory of Open Access Journals (Sweden)

    Scandalios J.G.

    2005-01-01

    Full Text Available Molecular oxygen (O2 is the premier biological electron acceptor that serves vital roles in fundamental cellular functions. However, with the beneficial properties of O2 comes the inadvertent formation of reactive oxygen species (ROS such as superoxide (O2·-, hydrogen peroxide, and hydroxyl radical (OH·. If unabated, ROS pose a serious threat to or cause the death of aerobic cells. To minimize the damaging effects of ROS, aerobic organisms evolved non-enzymatic and enzymatic antioxidant defenses. The latter include catalases, peroxidases, superoxide dismutases, and glutathione S-transferases (GST. Cellular ROS-sensing mechanisms are not well understood, but a number of transcription factors that regulate the expression of antioxidant genes are well characterized in prokaryotes and in yeast. In higher eukaryotes, oxidative stress responses are more complex and modulated by several regulators. In mammalian systems, two classes of transcription factors, nuclear factor kB and activator protein-1, are involved in the oxidative stress response. Antioxidant-specific gene induction, involved in xenobiotic metabolism, is mediated by the "antioxidant responsive element" (ARE commonly found in the promoter region of such genes. ARE is present in mammalian GST, metallothioneine-I and MnSod genes, but has not been found in plant Gst genes. However, ARE is present in the promoter region of the three maize catalase (Cat genes. In plants, ROS have been implicated in the damaging effects of various environmental stress conditions. Many plant defense genes are activated in response to these conditions, including the three maize Cat and some of the superoxide dismutase (Sod genes.

  6. Crystallization and preliminary crystallographic analysis of manganese lipoxygenase.

    Science.gov (United States)

    Wennman, Anneli; Oliw, Ernst H; Karkehabadi, Saeid

    2014-04-01

    Lipoxygenases constitute a family of nonhaem metal enzymes with catalytic iron or, occasionally, catalytic manganese. Lipoxygenases oxidize polyunsaturated fatty acids with position specificity and stereospecificity to hydroperoxides, which contribute to inflammation and the development of cancer. Little is known about the structural differences between lipoxygenases with Fe or Mn and the metal-selection mechanism. A Pichia pastoris expression system was used for the production of the manganese lipoxygenase of the take-all fungus of wheat, Gaeumannomyces graminis. The active enzyme was treated with α-mannosidase, purified to apparent homogeneity and subjected to crystal screening and X-ray diffraction. The crystals diffracted to 2.6 Å resolution and belonged to space group C2, with unit-cell parameters a = 226.6, b = 50.6, c = 177.92 Å, β = 91.70°.

  7. Lipoxygenase and carotenoids: A co-oxidation story | Chedea ...

    African Journals Online (AJOL)

    Lipoxygenases (LOXs), widely found in plants, fungi, and animals, are a large ... fungi and plants where they have established functions that include their role as ... as the ability to protect the plant from reactive oxygen species, and coloration.

  8. An iron 13S-lipoxygenase with an α-linolenic acid specific hydroperoxidase activity from Fusarium oxysporum.

    Directory of Open Access Journals (Sweden)

    Florian Brodhun

    Full Text Available Jasmonates constitute a family of lipid-derived signaling molecules that are abundant in higher plants. The biosynthetic pathway leading to plant jasmonates is initiated by 13-lipoxygenase-catalyzed oxygenation of α-linolenic acid into its 13-hydroperoxide derivative. A number of plant pathogenic fungi (e.g. Fusarium oxysporum are also capable of producing jasmonates, however, by a yet unknown biosynthetic pathway. In a search for lipoxygenase in F. oxysporum, a reverse genetic approach was used and one of two from the genome predicted lipoxygenases (FoxLOX was cloned. The enzyme was heterologously expressed in E. coli, purified via affinity chromatography, and its reaction mechanism characterized. FoxLOX was found to be a non-heme iron lipoxygenase, which oxidizes C18-polyunsaturated fatty acids to 13S-hydroperoxy derivatives by an antarafacial reaction mechanism where the bis-allylic hydrogen abstraction is the rate-limiting step. With α-linolenic acid as substrate FoxLOX was found to exhibit a multifunctional activity, because the hydroperoxy derivatives formed are further converted to dihydroxy-, keto-, and epoxy alcohol derivatives.

  9. Influenza Viral Manipulation of Sphingolipid Metabolism and Signaling to Modulate Host Defense System

    Directory of Open Access Journals (Sweden)

    Madhuvanthi Vijayan

    2014-01-01

    Full Text Available Viruses attempt to create a distinctive cellular environment to favor viral replication and spread. Recent studies uncovered new functions of the sphingolipid signaling/metabolism during pathogenic virus infections. While sphingolipids such as sphingomyelin and ceramide were reported to influence the entry step of several viruses, sphingolipid-metabolizing enzymes could directly alter viral replication processes. Influenza virus was shown to increase the level of sphingosine kinase (SK 1 to promote virus propagation. The mechanism involves regulation of intracellular signaling pathways, leading to the amplification of influenza viral RNA synthesis and nuclear export of viral ribonucleoprotein (RNP complex. However, bovine viral diarrhea virus inhibits SK1 to enhance the efficacy of virus replication, demonstrating the presence of virus-specific strategies for modulation of the sphingolipid system. Therefore, investigating the sphingolipid metabolism and signaling in the context of virus replication could help us design innovative therapeutic approaches to improve human health.

  10. Signaling roles of ceramide and its metabolites in cutaneous antimicrobial defense

    Directory of Open Access Journals (Sweden)

    Yoshikazu Uchida

    2015-06-01

    Full Text Available The skin epidermis is a multipurpose barrier (i.e., against epidermal permeability disruption and oxidative/UV irradiation as well as a mechanical barrier and antimicrobial barrier, to protect cells/tissues from external perturbants. When there is a normal barrier, function is restored and/or enhanced in the epidermis in response to external perturbations. Ceramide (Cer is a well-known, key lipid constituent of the epidermal permeability barrier in the extracellular domain of the stratum corneum. Cer and its metabolites also serve as signaling lipids to regulate cellular function (e.g., proliferation, differentiation, and apoptosis. Recent studies from our laboratory demonstrate that the Cer metabolites, sphingosine-1-phosphate (S1P and ceramide-1-phosphate (C1P, generate signaling transcriptionally to stimulate cathelicidin antimicrobial peptide (CAMP, and human beta-defensin (hBD 2 and hBD3 production, respectively, in cells, including in epidermal keratinocytes. S1P and C1P production are increased by external perturbation-induced endoplasmic reticulum stress. These studies illuminate a mechanism through which external perturbations signal to stimulate antimicrobial peptides without evidence of microbial infections. In this work, we describe the signaling roles of Cer, S1P, and C1P in cells.

  11. Fusarium oxysporum f.sp. ciceri race 1 induced redox state alterations are coupled to downstream defense signaling in root tissues of chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Gupta, Sumanti; Bhar, Anirban; Chatterjee, Moniya; Das, Sampa

    2013-01-01

    Reactive oxygen species are known to play pivotal roles in pathogen perception, recognition and downstream defense signaling. But, how these redox alarms coordinate in planta into a defensive network is still intangible. Present study illustrates the role of Fusarium oxysporum f.sp ciceri Race1 (Foc1) induced redox responsive transcripts in regulating downstream defense signaling in chickpea. Confocal microscopic studies highlighted pathogen invasion and colonization accompanied by tissue damage and deposition of callose degraded products at the xylem vessels of infected roots of chickpea plants. Such depositions led to the clogging of xylem vessels in compatible hosts while the resistant plants were devoid of such obstructions. Lipid peroxidation assays also indicated fungal induced membrane injury. Cell shrinkage and gradual nuclear adpression appeared as interesting features marking fungal ingress. Quantitative real time polymerase chain reaction exhibited differential expression patterns of redox regulators, cellular transporters and transcription factors during Foc1 progression. Network analysis showed redox regulators, cellular transporters and transcription factors to coordinate into a well orchestrated defensive network with sugars acting as internal signal modulators. Respiratory burst oxidase homologue, cationic peroxidase, vacuolar sorting receptor, polyol transporter, sucrose synthase, and zinc finger domain containing transcription factor appeared as key molecular candidates controlling important hubs of the defense network. Functional characterization of these hub controllers may prove to be promising in understanding chickpea-Foc1 interaction and developing the case study as a model for looking into the complexities of wilt diseases of other important crop legumes.

  12. Fusarium oxysporum f.sp. ciceri race 1 induced redox state alterations are coupled to downstream defense signaling in root tissues of chickpea (Cicer arietinum L..

    Directory of Open Access Journals (Sweden)

    Sumanti Gupta

    Full Text Available Reactive oxygen species are known to play pivotal roles in pathogen perception, recognition and downstream defense signaling. But, how these redox alarms coordinate in planta into a defensive network is still intangible. Present study illustrates the role of Fusarium oxysporum f.sp ciceri Race1 (Foc1 induced redox responsive transcripts in regulating downstream defense signaling in chickpea. Confocal microscopic studies highlighted pathogen invasion and colonization accompanied by tissue damage and deposition of callose degraded products at the xylem vessels of infected roots of chickpea plants. Such depositions led to the clogging of xylem vessels in compatible hosts while the resistant plants were devoid of such obstructions. Lipid peroxidation assays also indicated fungal induced membrane injury. Cell shrinkage and gradual nuclear adpression appeared as interesting features marking fungal ingress. Quantitative real time polymerase chain reaction exhibited differential expression patterns of redox regulators, cellular transporters and transcription factors during Foc1 progression. Network analysis showed redox regulators, cellular transporters and transcription factors to coordinate into a well orchestrated defensive network with sugars acting as internal signal modulators. Respiratory burst oxidase homologue, cationic peroxidase, vacuolar sorting receptor, polyol transporter, sucrose synthase, and zinc finger domain containing transcription factor appeared as key molecular candidates controlling important hubs of the defense network. Functional characterization of these hub controllers may prove to be promising in understanding chickpea-Foc1 interaction and developing the case study as a model for looking into the complexities of wilt diseases of other important crop legumes.

  13. ERK signaling couples nutrient status to antiviral defense in the insect gut.

    Science.gov (United States)

    Xu, Jie; Hopkins, Kaycie; Sabin, Leah; Yasunaga, Ari; Subramanian, Harry; Lamborn, Ian; Gordesky-Gold, Beth; Cherry, Sara

    2013-09-10

    A unique facet of arthropod-borne virus (arbovirus) infection is that the pathogens are orally acquired by an insect vector during the taking of a blood meal, which directly links nutrient acquisition and pathogen challenge. We show that the nutrient responsive ERK pathway is both induced by and restricts disparate arboviruses in Drosophila intestines, providing insight into the molecular determinants of the antiviral "midgut barrier." Wild-type flies are refractory to oral infection by arboviruses, including Sindbis virus and vesicular stomatitis virus, but this innate restriction can be overcome chemically by oral administration of an ERK pathway inhibitor or genetically via the specific loss of ERK in Drosophila intestinal epithelial cells. In addition, we found that vertebrate insulin, which activates ERK in the mosquito gut during a blood meal, restricts viral infection in Drosophila cells and against viral invasion of the insect gut epithelium. We find that ERK's antiviral signaling activity is likely conserved in Aedes mosquitoes, because genetic or pharmacologic manipulation of the ERK pathway affects viral infection of mosquito cells. These studies demonstrate that ERK signaling has a broadly antiviral role in insects and suggest that insects take advantage of cross-species signals in the meal to trigger antiviral immunity.

  14. Inhibition of SlMPK1, SlMPK2, and SlMPK3 Disrupts Defense Signaling Pathways and Enhances Tomato Fruit Susceptibility to Botrytis cinerea.

    Science.gov (United States)

    Zheng, Yanyan; Yang, Yang; Liu, Can; Chen, Lin; Sheng, Jiping; Shen, Lin

    2015-06-10

    Mitogen-activated protein kinases (MAPKs) are major components of defense signaling pathways that transduce extracellular stimuli into intracellular responses in plants. Our previous study indicated that SlMPK1/2/3 were associated with nitric oxide-induced defense response in tomato fruit. In this study, we determine whether SlMPK1/2/3 influence the tomato fruit's innate immunity and whether plant hormones and reactive oxygen species (ROS) are involved in SlMPK1/2/3 defense signaling pathways. Treatment with 10 μM U0126 significantly inhibited the relative expression of SlMPK1, SlMPK2, and SlMPK3 (P fruit showed higher concentrations of auxin indole acetic acid (IAA), abscisic acid (ABA), and gibberellic acid (GA), but a lower concentration of methyl jasmonate (MeJA). The activities of defense enzymes, including β-1,3-glucanases (GLU), chitinase (CHI), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO), decreased after U0126 treatment. Meanwhile, H2O2 content increased, and catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) activities decreased after U0126 treatment. U0126 treatment enhanced the susceptibility of tomato fruit to Botrytis cinerea and resulted in more severe gray mold rot. These results demonstrate that inhibition of SlMPK1/2/3 disrupts tomato fruit defense signaling pathways and enhances the susceptibility to B. cinerea and also that plant hormones and ROS are associated with SlMPK1/2/3 defense signaling pathways.

  15. Virulent Diuraphis noxia Aphids Over-Express Calcium Signaling Proteins to Overcome Defenses of Aphid-Resistant Wheat Plants.

    Science.gov (United States)

    Sinha, Deepak K; Chandran, Predeesh; Timm, Alicia E; Aguirre-Rojas, Lina; Smith, C Michael

    2016-01-01

    The Russian wheat aphid, Diuraphis noxia, an invasive phytotoxic pest of wheat, Triticum aestivum, and barley, Hordeum vulgare, causes huge economic losses in Africa, South America, and North America. Most acceptable and ecologically beneficial aphid management strategies include selection and breeding of D. noxia-resistant varieties, and numerous D. noxia resistance genes have been identified in T. aestivum and H. vulgare. North American D. noxia biotype 1 is avirulent to T. aestivum varieties possessing Dn4 or Dn7 genes, while biotype 2 is virulent to Dn4 and avirulent to Dn7. The current investigation utilized next-generation RNAseq technology to reveal that biotype 2 over expresses proteins involved in calcium signaling, which activates phosphoinositide (PI) metabolism. Calcium signaling proteins comprised 36% of all transcripts identified in the two D. noxia biotypes. Depending on plant resistance gene-aphid biotype interaction, additional transcript groups included those involved in tissue growth; defense and stress response; zinc ion and related cofactor binding; and apoptosis. Activation of enzymes involved in PI metabolism by D. noxia biotype 2 aphids allows depletion of plant calcium that normally blocks aphid feeding sites in phloem sieve elements and enables successful, continuous feeding on plants resistant to avirulent biotype 1. Inhibition of the key enzyme phospholipase C significantly reduced biotype 2 salivation into phloem and phloem sap ingestion.

  16. FLS2-BAK1 extracellular domain interaction sites required for defense signaling activation.

    Directory of Open Access Journals (Sweden)

    Teresa Koller

    Full Text Available Signaling initiation by receptor-like kinases (RLKs at the plasma membrane of plant cells often requires regulatory leucine-rich repeat (LRR RLK proteins such as SERK or BIR proteins. The present work examined how the microbe-associated molecular pattern (MAMP receptor FLS2 builds signaling complexes with BAK1 (SERK3. We first, using in vivo methods that validate separate findings by others, demonstrated that flg22 (flagellin epitope ligand-initiated FLS2-BAK1 extracellular domain interactions can proceed independent of intracellular domain interactions. We then explored a candidate SERK protein interaction site in the extracellular domains (ectodomains; ECDs of the significantly different receptors FLS2, EFR (MAMP receptors, PEPR1 (damage-associated molecular pattern (DAMP receptor, and BRI1 (hormone receptor. Repeat conservation mapping revealed a cluster of conserved solvent-exposed residues near the C-terminus of models of the folded LRR domains. However, site-directed mutagenesis of this conserved site in FLS2 did not impair FLS2-BAK1 ECD interactions, and mutations in the analogous site of EFR caused receptor maturation defects. Hence this conserved LRR C-terminal region apparently has functions other than mediating interactions with BAK1. In vivo tests of the subsequently published FLS2-flg22-BAK1 ECD co-crystal structure were then performed to functionally evaluate some of the unexpected configurations predicted by that crystal structure. In support of the crystal structure data, FLS2-BAK1 ECD interactions were no longer detected in in vivo co-immunoprecipitation experiments after site-directed mutagenesis of the FLS2 BAK1-interaction residues S554, Q530, Q627 or N674. In contrast, in vivo FLS2-mediated signaling persisted and was only minimally reduced, suggesting residual FLS2-BAK1 interaction and the limited sensitivity of co-immunoprecipitation data relative to in vivo assays for signaling outputs. However, Arabidopsis plants

  17. Programmed chloroplast destruction during leaf senescence involves 13-lipoxygenase (13-LOX).

    Science.gov (United States)

    Springer, Armin; Kang, ChulHee; Rustgi, Sachin; von Wettstein, Diter; Reinbothe, Christiane; Pollmann, Stephan; Reinbothe, Steffen

    2016-03-22

    Leaf senescence is the terminal stage in the development of perennial plants. Massive physiological changes occur that lead to the shut down of photosynthesis and a cessation of growth. Leaf senescence involves the selective destruction of the chloroplast as the site of photosynthesis. Here, we show that 13-lipoxygenase (13-LOX) accomplishes a key role in the destruction of chloroplasts in senescing plants and propose a critical role of its NH2-terminal chloroplast transit peptide. The 13-LOX enzyme identified here accumulated in the plastid envelope and catalyzed the dioxygenation of unsaturated membrane fatty acids, leading to a selective destruction of the chloroplast and the release of stromal constituents. Because 13-LOX pathway products comprise compounds involved in insect deterrence and pathogen defense (volatile aldehydes and oxylipins), a mechanism of unmolested nitrogen and carbon relocation is suggested that occurs from leaves to seeds and roots during fall.

  18. Data on expression of lipoxygenases-5 and -12 in the normal and acetaminophen-damaged liver

    Directory of Open Access Journals (Sweden)

    Maria Suciu

    2016-06-01

    Mice were injected with acetaminophen, and at 48 h their livers were processed for immunohistochemistry with anti-mouse lipoxygenase-5 and -12 antibodies. At the same time point, the RNA was also extracted from the liver to assess the expression of lipoxygenase-5 and -12 genes via qPCR analysis. Our results show that lipoxygenase-5 expression, but not that of lipoxygenase-12, changes significantly in the acetominophen-damaged liver.

  19. Age-related Resistance and the Defense Signaling Pathway of Ph-3 Gene Against Phytophthora infestans in Tomatoes

    Directory of Open Access Journals (Sweden)

    Sayed Rashad Ali Shah

    2015-09-01

    Full Text Available Resistance (R genes against plant pathogens often have age-related resistance (ARR effects. However, the mechanism involved in this phenomenon remains unknown. In this paper, Solanum lycopersicum ‘CLN2037B’ and S. pimpinellifolium ‘L3708’ harboring the Ph-3 gene, as well as S. habrochaites ‘LA2099’, ‘LA1777’ and ‘LA1033’ harboring quantitative trait loci (QTLs, were tested to investigate age-related resistance against late blight (LB; caused by Phytophthora infestans in the three-leaf stage of the plants. The results demonstrated that the QTL-related LB resistance showed the same age-related resistance as the Ph-3-mediated resistance at the six- and nine-leaf stages compared with the three-leaf stage. This indicated that there is a common defense mechanism in tomatoes against P. infestans via ARR. In addition, we combined ethylene (ET, salicylic acid (SA and jasmonic acid (JA mutants with virus-induced gene silencing (VIGS to study the Ph-3-dependent resistance signaling pathway. The results showed that ethylene and salicylic acid, but not jasmonic acid, are involved in the LB resistance mediated by the Ph-3 gene.

  20. Heterogeneity in Signaled Active Avoidance: Substantive and Methodological Relevance of Diversity in Instrumental Defensive Responses to Threat Cues

    Directory of Open Access Journals (Sweden)

    Isaac Robert Galatzer-Levy

    2014-09-01

    Full Text Available Individuals exposed to traumatic stressors follow divergent patterns including resilience and chronic stress. However, researchers utilizing animal models that examine threat responses typically use central tendency statistics that assume population homogeneity, potentially overlooking fundamental differences that can explain human diversity in response to traumatic stressors. The current study tests this assumption by identifying and replicating common heterogeneous patterns of response to signaled active avoidance (AA training where rats are trained to prevent an aversive outcome (shock by performing a instrumental behavior (shuttling between chambers during the presentation of a conditioned threat cue (tone. Study 1 conducted three days of signaled AA training (n = 81 animals and study 2 conducted five days of training (n = 186 animals. Four trajectories were identified in both samples including animals that acquired and retained avoidance behavior on the first day (Rapid Avoiders: 22% & 25%; those who never successfully acquired avoidance (Non-Avoiders; 20% &16%; a modal class who acquired avoidance over three days (Modal Avoiders; 37% & 50%; and a population who demonstrated a slow pattern of avoidance, failed to fully acquire avoidance in study 1 and did acquire avoidance on days 4 and 5 in study 2 (Slow Avoiders; 22.0% & 9%. With the exception of the Slow Avoiders in Study 1, populations that acquired demonstrated rapid step-like increases leading to asymptotic levels of avoidance. These findings indicate that avoidance responses are heterogeneous in a way that may be informative for understanding resilience and chronic stress responses such as PTSD as well as the nature of instrumental behavior acquisition. Characterizing heterogeneous populations based on their response to threat cues would increase the accuracy and translatability of such models and potentially lead to new discoveries that explain diversity in instrumental defensive

  1. Physalis alkekengi carotenoidic extract inhibitor of soybean lipoxygenase-1 activity.

    Science.gov (United States)

    Chedea, Veronica Sanda; Pintea, Adela; Bunea, Andrea; Braicu, Cornelia; Stanila, Andreea; Socaciu, Carmen

    2014-01-01

    The aim of this study was to evaluate the effect of the carotenoidic saponified extract of Physalis alkekengi sepals (PA) towards the lipoxygenase (LOX) oxidation of linoleic acid. Lipoxygenase activity in the presence of carotenoids, standard and from extract, was followed by its kinetic behaviour determining the changes in absorption at 234 nm. The standard carotenoids used were β-carotene (β-car), lutein (Lut), and zeaxanthin (Zea). The calculated enzymatic specific activity (ESA) after 600 s of reaction proves that PA carotenoidic extract has inhibitory effect on LOX oxidation of linoleic acid. A longer polyenic chain of carotenoid structure gives a higher ESA during the first reaction seconds. This situation is not available after 600 s of reaction and may be due to a destruction of this structure by cooxidation of carotenoids, besides the classical LOX reaction. The PA carotenoidic extract inhibiting the LOX-1 reaction can be considered a source of lipoxygenase inhibitors.

  2. 15-Lipoxygenase inhibition of Commelina benghalensis, Tradescantia fluminensis, Tradescantia zebrina

    Institute of Scientific and Technical Information of China (English)

    Cean Socorro M. Alaba

    2014-01-01

    Objective:To evaluate the 15-lipoxygenase inhibitory activity of the methanol leaf extracts of Commelina benghalensis, Tradescantia fluminensis (T. fluminensis) and Tradescantia zebrina. Method: The inhibitory activity was evaluated using a spectrophotometric assay by observing the increase in absorbance at 234 nm due to the formation of the product 13-hydroperoxyoctadecadienoic acid. The extracts were also tested for the presence of terpenoids, saponins, tannins, flavonoids, steroids, phenolic compounds, alkaloids and cardiac glycosides. Results:All the extracts inhibited the action of 15-lipoxygenase at a concentration of 0.2 µg/mL. T. fluminensis and Tradescantia zebrina exhibited higher than 50%inhibition with T. fluminensis at 87.2%. T. fluminensis was partitioned with ethyl acetate and hexane and their IC50 values were determined at 8.72 µg/mL and 98.04 µg/mL, respectively. Conclusions:T. fluminensis is a potentially good source of 15-lipoxygenase inhibitors.

  3. Integration of Ethylene and Jasmonic Acid Signaling Pathways in the Expression of Novel Maize Defense Protein Mir1-CP

    Science.gov (United States)

    In plants, ethylene (ET) and jasmonate (JA) control the defense responses to multiple stressors, including insect predation. Among the defense proteins known to be regulated by ET, is maize insect resistance 1-cysteine protease (Mir1-CP). This protein is constitutively expressed in the insect resi...

  4. Seaweed Polysaccharides and Derived Oligosaccharides Stimulate Defense Responses and Protection Against Pathogens in Plants

    Directory of Open Access Journals (Sweden)

    Alejandra Moenne

    2011-11-01

    Full Text Available Plants interact with the environment by sensing “non-self” molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA, jasmonic acid (JA and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i Pathogenesis-Related (PR proteins with antifungal and antibacterial activities; (ii defense enzymes such as pheylalanine ammonia lyase (PAL and lipoxygenase (LOX which determine accumulation of phenylpropanoid compounds (PPCs and oxylipins with antiviral, antifugal and antibacterial activities and iii enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants.

  5. Subversion of innate defenses by the interplay between DENV and pre-existing enhancing antibodies: TLRs signaling collapse.

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    Naphak Modhiran

    Full Text Available BACKGROUND: The phenomenon of antibody dependent enhancement as a major determinant that exacerbates disease severity in DENV infections is well accepted. While the detailed mechanism of antibody enhanced disease severity is unclear, evidence suggests that it is associated with both increased DENV infectivity and suppression of the type I IFN and pro-inflammatory cytokine responses. Therefore, it is imperative for us to understand the intracellular mechanisms altered during ADE infection to decipher the mechanism of severe pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: In this present work, qRT-PCR, immunoblotting and gene array analysis were conducted to determine whether DENV-antibody complex infection exerts a suppressive effect on the expression and/or function of the pathogen recognition patterns, focusing on the TLR-signaling pathway. We show here that FcγRI and FcγRIIa synergistically facilitated entry of DENV-antibody complexes into monocytic THP-1 cells. Ligation between DENV-antibody complexes and FcR not only down regulated TLRs gene expression but also up regulated SARM, TANK, and negative regulators of the NF-κB pathway, resulting in suppression of innate responses but increased viral production. These results were confirmed by blocking with anti-FcγRI or anti-FcγRIIa antibodies which reduced viral production, up-regulated IFN-β synthesis, and increased gene expression in the TLR-dependent signaling pathway. The negative impact of DENV-ADE infection on the TLR-dependent pathway was strongly supported by gene array screening which revealed that both MyD88-dependent and -independent signaling molecules were down regulated during DENV-ADE infection. Importantly, the same phenomenon was seen in PBMC of secondary DHF/DSS patients but not in PBMC of DF patients. CONCLUSIONS/SIGNIFICANCE: Our present work demonstrates the mechanism by which DENV uses pre-existing immune mediators to defeat the principal activating pathway of innate

  6. Subversion of Innate Defenses by the Interplay between DENV and Pre-Existing Enhancing Antibodies: TLRs Signaling Collapse

    Science.gov (United States)

    Modhiran, Naphak; Kalayanarooj, Siripen; Ubol, Sukathida

    2010-01-01

    Background The phenomenon of antibody dependent enhancement as a major determinant that exacerbates disease severity in DENV infections is well accepted. While the detailed mechanism of antibody enhanced disease severity is unclear, evidence suggests that it is associated with both increased DENV infectivity and suppression of the type I IFN and pro-inflammatory cytokine responses. Therefore, it is imperative for us to understand the intracellular mechanisms altered during ADE infection to decipher the mechanism of severe pathogenesis. Methodology/Principal Findings In this present work, qRT-PCR, immunoblotting and gene array analysis were conducted to determine whether DENV-antibody complex infection exerts a suppressive effect on the expression and/or function of the pathogen recognition patterns, focusing on the TLR-signaling pathway. We show here that FcγRI and FcγRIIa synergistically facilitated entry of DENV-antibody complexes into monocytic THP-1 cells. Ligation between DENV-antibody complexes and FcR not only down regulated TLRs gene expression but also up regulated SARM, TANK, and negative regulators of the NF-κB pathway, resulting in suppression of innate responses but increased viral production. These results were confirmed by blocking with anti-FcγRI or anti-FcγRIIa antibodies which reduced viral production, up-regulated IFN-β synthesis, and increased gene expression in the TLR-dependent signaling pathway. The negative impact of DENV-ADE infection on the TLR-dependent pathway was strongly supported by gene array screening which revealed that both MyD88-dependent and –independent signaling molecules were down regulated during DENV-ADE infection. Importantly, the same phenomenon was seen in PBMC of secondary DHF/DSS patients but not in PBMC of DF patients. Conclusions/Significance Our present work demonstrates the mechanism by which DENV uses pre-existing immune mediators to defeat the principal activating pathway of innate defense resulting in

  7. Anacardic acid derived salicylates are inhibitors or activators of lipoxygenases

    NARCIS (Netherlands)

    Wisastra, Rosalina; Ghizzoni, Massimo; Boltjes, Andre; Haisma, Hidde J.; Dekker, Frank J.

    2012-01-01

    Lipoxygenases catalyze the oxidation of unsaturated fatty acids, such as linoleic acid, which play a crucial role in inflammatory responses. Selective inhibitors may provide a new therapeutic approach for inflammatory diseases. In this study, we describe the identification of a novel soybean lipoxyg

  8. Thermal injury and ozone stress affect soybean lipoxygenases expression

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Maccarrone, M.; Veldink, G.A.

    1992-01-01

    The effects of thermal injury (cold and heat shock) and ozone treatment on lipoxygenases 1 (LOX-1) and 2 (LOX-2) of soybean seedlings have been investigated. Cold stress led to a decrease of the specific activities of both isoenzymes, attributable at least in part to a down-regulation of gene expres

  9. Effect of endocannabinoids on soybean lipoxygenase-1 activity.

    Science.gov (United States)

    Nguyen, Minh Duc; Nguyen, Dang Hung; Yoo, Jae-Myung; Myung, Pyung-Keun; Kim, Mee Ree; Sok, Dai-Eun

    2013-08-01

    Endocannabinoids appear to be involved in a variety of physiological processes. Lipoxygenase activity has been known to be affected by unsaturated fatty acids or phenolic compounds. In this study, we examined whether endocannabinoids containing both N-acyl group and phenolic group can affect the activity of soybean lipoxygenase (LOX)-1, similar to mammalian 15-lipoxygenase in physicochemical properties. First, N-arachidonoyl dopamine and N-oleoyl dopamine were found to inhibit soybean LOX-1-catalyzed oxygenation of linoleic acid in a non-competitive manner with a Ki value of 3.7 μM and 6.2 μM, respectively. Meanwhile, other endocannabinoids failed to show a remarkable inhibition of soybean LOX-1. Separately, N-arachidonoyl dopamine and N-arachidonoyl serotonin were observed to inactivate soybean LOX-1 with Kin value of 27 μM and 24 μM, respectively, and k3 value of 0.12 min(-1) and 0.35 min(-1), respectively. Furthermore, such an inactivation was enhanced by ascorbic acid, but suppressed by 13(S)-hydroperoxy-9,11-octadecadienoic acid. Taken together, it is proposed that endocannabinoids containing polyunsaturated acyl moiety and phenolic group may be efficient for the inhibition as well as inactivation of 15-lipoxygenase.

  10. Melatonin promotes Bax sequestration to mitochondria reducing cell susceptibility to apoptosis via the lipoxygenase metabolite 5-hydroxyeicosatetraenoic acid

    KAUST Repository

    Radogna, Flavia

    2015-03-01

    Extra-neurological functions of melatonin include control of the immune system and modulation of apoptosis. We previously showed that melatonin inhibits the intrinsic apoptotic pathway in leukocytes via stimulation of high affinity MT1/MT2 receptors, thereby promoting re-localization of the anti-apoptotic Bcl-2 protein to mitochondria. Here we show that Bcl-2 sequesters pro-apoptotic Bax into mitochondria in an inactive form after melatonin treatment, thus reducing cell propensity to apoptosis. Bax translocation and the anti-apoptotic effect of melatonin are strictly dependent on the presence of Bcl-2, and on the 5-lipoxygenase (5-LOX) metabolite 5-hydroxyeicosatetraenoic acid (5-HETE), which we have previously shown to be produced as a consequence of melatonin binding to its low affinity target calmodulin. Therefore, the anti-apoptotic effect of melatonin requires the simultaneous, independent interaction with high (MT1/MT2) and low (calmodulin) affinity targets, eliciting two independent signal transduction pathways converging into Bax sequestration and inactivation. MT1/MT2 vs. lipoxygenase pathways are activated by 10-9 vs. 10-5M melatonin, respectively; the anti-apoptotic effect of melatonin is achieved at 10-5M, but drops to 10-9M upon addition of exogenous 5-HETE, revealing that lipoxygenase activation is the rate-limiting pathway. Therefore, in areas of inflammation with increased 5-HETE levels, physiological nanomolar concentrations of melatonin may suffice to maintain leukocyte viability.

  11. Neuroprotection of taurine through inhibition of 12/15 lipoxygenase pathway in cerebral ischemia of rats.

    Science.gov (United States)

    Zhang, Zhe; Yu, Rongbo; Cao, Lei

    2017-05-01

    Cerebral ischemia exhibits a multiplicity of pathophysiological mechanisms. Taurine (Tau), an endogenous substance, possesses a number of cytoprotective properties. The aim of the present study was to examine the neuroprotective effect of Tau, through affecting 12/15 lipoxygenase (12/15-LOX) signal pathway in an acute permanent middle cerebral artery occlusion (MCAO) model of rats. Sprague-Dawley rats were randomly divided into 3 groups (n = 10), namely the sham-operated group, MCAO group and Tau group. Tau was intraperitoneally administrated immediately after cerebral ischemia. At 24 h after MCAO, neurological function score, brain water content and infarct volume were assessed. The expression of 12/15-lipoxygenase (12/15-LOX), p38 mitogen-activated protein kinase (p38 MAPK), and cytosolic phospholipase A2 (cPLA2) was measured by Western blot. Enzyme-linked immunosorbent assay was used to evaluate the inflammatory factors TNF-α, IL-1β and IL-6 in serum. Compared with MCAO group, taurine significantly improved neurological function and significantly reduced brain water content (p Taurine protected the brain from damage caused by MCAO; this effect may be through down-regulation of 12/15-LOX, p38 MAPK, and cPLA2.

  12. The dioxygenation rate in lipoxygenase catalysis is determined by the amount of iron (III) lipoxygenase in solution

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Schilstra, M.J.; Veldink, G.A.

    1994-01-01

    The dioxygenation rate in reactions catalyzed by lipoxygenase- 1 from soybeans has been measured as a function of the enzyme present in the Fe(II1) form with rapid kinetic techniques. The experiments were carried out at pH 10, 25 'C. The product concentration and the fraction of iron(II1)

  13. Mechanisms of Optimal Defense Patterns in Nicotiana attenuata: Flowering Attenuates Herbivory-elicited Ethylene and Jasmonate Signaling

    Institute of Scientific and Technical Information of China (English)

    Celia Diezel; Silke AIImann; lan T. Baldwin

    2011-01-01

    To defend themselves against herbivore attack,plants produce secondary metabolites,which are variously inducible and constitutively deployed,presumably to optimize their fitness benefits in light of their fitness costs.Three phytohormones,jasmonates (JA) and their active forms,the JA-isoleucine (JA-Ile) and ethylene (ET),are known to play central roles in the elicitation of induced defenses,but little is known about how this mediation changes over ontogeny.The Optimal Defense Theory (ODT) predicts changes in the costs and benefits of the different types of defenses and has been usefully extrapolated to their modes of deployment.Here we studied whether the herbivore-induced accumulation of JA,JA-lle and ET changed over ontogeny in Nicotiana attenuata,a native tobacco in which inducible defenses are particularly well studied.Herbivore-elicited ET production changed dramatically during six developmental stages,from rosette through flowering,decreasing with the elongation of the first corollas during flower development.This decrease was largely recovered within a day after flower removal by decapitation.A similar pattern was found for the herbivore-induced accumulation of JA and JA-IIe.These results are consistent with ODT predictions and suggest that the last steps in floral development control the inducibility of at least three plant hormones,optimizing defense-growth tradeoffs.

  14. Exploring the potential of fungal manganese-containing lipoxygenase for pitch control and pulp delignification.

    Science.gov (United States)

    Marques, Gisela; Molina, Setefilla; Babot, Esteban D; Lund, Henrik; del Río, José C; Gutiérrez, Ana

    2011-01-01

    The potential of the lipoxygenase from Gaeumannomyces graminis to remove lipophilic extractives from eucalypt and flax pulps was investigated. Pulp treatments were performed with the lipoxygenase both in the presence and absence of linoleic acid, and were followed by a peroxide bleaching stage. The main lipophilic extractives from eucalypt pulp such as conjugated and free sterols decreased up to 40% and 7%, respectively, by the lipoxygenase treatment in the presence of linoleic acid. Different degradation patterns were observed among the lipophilic compounds present in flax pulp, although a high removal of all the extractives classes, including alkanes (21-55%), fatty alcohols (42-61%), and free (16-55%) and glycosylated (45-71%) sterols, was attained in all the lipoxygenase treatments. Reactions of the lipoxygenase with model lipid mixtures were carried out to better understand the degradation patterns observed in pulps. Finally, pulp delignification by the lipoxygenase treatments was also evaluated.

  15. Evaluation of in vitro urease and lipoxygenase inhibition activity of weight reducing tablets.

    Science.gov (United States)

    Jaffary, Syed Rashid Ali; Ahmed, Syed Waseemuddin; Shakeel, Sadia; Asif, Hafiz Muhammad; Usmanghani, Khan

    2016-07-01

    Enzyme inhibition is a significant part of research in pharmaceutical field in view of the fact that these studies have directed to the innovations of drugs having remarkable performance in diverse physiological conditions. The present study was aimed to assess urease and lipoxygenase inhibitory activity of weight reducing tablets. For evaluating the urease activity indophenol method was employed using Thiourea as the model urease inhibitor. The lipoxygenase inhibition was evaluated by measuring the hydroperoxides produced in lipoxygenation reaction using a purified lipoxygenase with lionoleic acid as substrate. When formulation of the weight reducing tablets was compared at various concentrations (50, 100 and 500µg/ml). The antiurease activity and lipoxygenase inhibition activity increased in a dose dependent manner. The formulations under test have an excellent antiurease and lipoxygenase inhibition potential and prospective to be used in the cure of a variety of complications associated with the production of urease and lipoxygenase enzymes.

  16. Soybean lipoxygenase-3 in complex with 4-nitrocatechol.

    Science.gov (United States)

    Skrzypczak-Jankun, Ewa; Borbulevych, Oleg Y; Jankun, Jerzy

    2004-03-01

    4-Nitrocatechol (4NC) is a known inhibitor of lipoxygenase. This work presents the X-ray structure of soybean lipoxygenase-3 in complex with 4NC refined at 2.15 A resolution. The X-ray analysis shows 4NC near iron with partial occupancy, blocking access to Fe but not covalently bound to it. The two hydroxyl groups interact with the C-terminus (4-OH) and His523 ND1 (3-OH). The residues surrounding the iron cofactor, His518*, His523, His709, Ile857* COO(-) and water, form a trigonal bipyramid with the residues marked with asterisks in the axial positions. The water bound to iron and the presence of the inhibitor seem to be responsible for the rearrangements and changes in the geometry of the ligand distribution and confirm the displacement of His518 from iron coordination. A description of the catechol binding contributes to the understanding of lipoxygenase inhibition and the participation of its co-oxidative activity in the utilization of natural flavonoids.

  17. The Pseudomonas syringae pv. tomato type III effector HopM1 suppresses Arabidopsis defenses independent of suppressing salicylic acid signaling and of targeting AtMIN7.

    Directory of Open Access Journals (Sweden)

    Anju Gangadharan

    Full Text Available Pseudomonas syringae pv tomato strain DC3000 (Pto delivers several effector proteins promoting virulence, including HopM1, into plant cells via type III secretion. HopM1 contributes to full virulence of Pto by inducing degradation of Arabidopsis proteins, including AtMIN7, an ADP ribosylation factor-guanine nucleotide exchange factor. Pseudomonas syringae pv phaseolicola strain NPS3121 (Pph lacks a functional HopM1 and elicits robust defenses in Arabidopsis thaliana, including accumulation of pathogenesis related 1 (PR-1 protein and deposition of callose-containing cell wall fortifications. We have examined the effects of heterologously expressed HopM1Pto on Pph-induced defenses. HopM1 suppresses Pph-induced PR-1 expression, a widely used marker for salicylic acid (SA signaling and systemic acquired resistance. Surprisingly, HopM1 reduces PR-1 expression without affecting SA accumulation and also suppresses the low levels of PR-1 expression apparent in SA-signaling deficient plants. Further, HopM1 enhances the growth of Pto in SA-signaling deficient plants. AtMIN7 contributes to Pph-induced PR-1 expression. However, HopM1 fails to degrade AtMIN7 during Pph infection and suppresses Pph-induced PR-1 expression and callose deposition in wild-type and atmin7 plants. We also show that the HopM1-mediated suppression of PR-1 expression is not observed in plants lacking the TGA transcription factor, TGA3. Our data indicate that HopM1 promotes bacterial virulence independent of suppressing SA-signaling and links TGA3, AtMIN7, and other HopM1 targets to pathways distinct from the canonical SA-signaling pathway contributing to PR-1 expression and callose deposition. Thus, efforts to understand this key effector must consider multiple targets and unexpected outputs of its action.

  18. silencing COI1 in rice increases susceptibility to chewing insects and impairs inducible defense.

    Directory of Open Access Journals (Sweden)

    Mao Ye

    Full Text Available The jasmonic acid (JA pathway plays a key role in plant defense responses against herbivorous insects. CORONATINE INSENSITIVE1 (COI1 is an F-box protein essential for all jasmonate responses. However, the precise defense function of COI1 in monocotyledonous plants, especially in rice (Oryza sativa L. is largely unknown. We silenced OsCOI1 in rice plants via RNA interference (RNAi to determine the role of OsCOI1 in rice defense against rice leaf folder (LF Cnaphalocrocis medinalis, a chewing insect, and brown planthopper (BPH Nilaparvata lugens, a phloem-feeding insect. In wild-type rice plants (WT, the transcripts of OsCOI1 were strongly and continuously up-regulated by LF infestation and methyl jasmonate (MeJA treatment, but not by BPH infestation. The abundance of trypsin protease inhibitor (TrypPI, and the enzymatic activities of polyphenol oxidase (PPO and peroxidase (POD were enhanced in response to both LF and BPH infestation, but the activity of lipoxygenase (LOX was only induced by LF. The RNAi lines with repressed expression of OsCOI1 showed reduced resistance against LF, but no change against BPH. Silencing OsCOI1 did not alter LF-induced LOX activity and JA content, but it led to a reduction in the TrypPI content, POD and PPO activity by 62.3%, 48.5% and 27.2%, respectively. In addition, MeJA-induced TrypPI and POD activity were reduced by 57.2% and 48.2% in OsCOI1 RNAi plants. These results suggest that OsCOI1 is an indispensable signaling component, controlling JA-regulated defense against chewing insect (LF in rice plants, and COI1 is also required for induction of TrypPI, POD and PPO in rice defense response to LF infestation.

  19. PURIFIKASI DAN KARAKTERISASI ENZIM LIPOKSIGENASE KACANG TANAH [Purification and Characterization of Peanut Lipoxygenase Enzime

    Directory of Open Access Journals (Sweden)

    S Widowati1

    2005-08-01

    Full Text Available Fat oxidation of peanut is a serious problem, because it could reduce of peanut quality and form a hydroperoxide compound. Hydroperoxide could be broken down into acid, ketone and low peptide, and resulted in volatile compounds with undersirable aroma. Extraction on enzyme was carried out by water, while purification and fractination were conducted using ammonium sulphate and chromatography. The objective of this research was to evaluate of the protein fraction, lipoxygenase properties, and enzyme activity during fractionation. The result showed that the highest fraction of protein was globulin, i.e 41-48% of total extracted protein, and the activity of lipoxygenase enzyme in the albumin fraction was 40-54% of the total activity. Purification of lipoxygenase enzyme was conducted by using ammonium sulphate (40-60% saturated and this increased its specific activity up to 2.0-4.2 timer from the crude enzyme. Separation of lipoxygenase enzyme using sephadex G-150 revealed 3 (tree peaks of activities, with specific activities 6.0-70.0 fold of the crude enzyme. Lipoxygenase enzyme of gajah variety denatured when heated at 700C during 30 minutes. The activition energy of lipoxygenase enzyme from Gajah variety (19.083 Cal/Mol was relatively lower than 1509 and 1512 which were, 25.446 Cal/Mol and 24.780 Cal/Mol, respectively. The result showed that lipoxygenase enzyme from Gajah variety was relativeky more heat stable as compared to the 1509 and 1512 lines. Lower activation energy of lipoxygenase enzyme indicated that effect of temperature alteration toward 'k' value was smaller. Lipoxygenase enzyme was active at pH higher than 3.0 or lower than 10.0. The data indicated that 'Km' value of lipoxygenase enzyme from Gajah variety was higher than that of 1509 and 1512 lines. It means that lipoxygenase enzyme from 1509 and 1512 lines more reactive that gajah variety.

  20. Epidermis contains platelet-type 12-lipoxygenase that is overexpressed in germinal layer keratinocytes in psoriasis.

    Science.gov (United States)

    Hussain, H; Shornick, L P; Shannon, V R; Wilson, J D; Funk, C D; Pentland, A P; Holtzman, M J

    1994-01-01

    Human epidermal cells exhibited none of the cytosolic lipoxygenase activity that is prominent in mucosal epithelial cells, but instead contained a microsomal activity that converted arachidonic acid to 12-hydroxyeicosatetraenoic acid (12-HETE). Identification of the extractable 12-HETE-forming activity as a 12-lipoxygenase (distinct from cytochrome P-450) included (S)-12-stereospecificity of product formation, trapping of 12-hydroperoxyeicosatetraenoic acid as an intermediate reaction product, and lack of NADPH dependence for activity. Epidermal cell poly(A)+ RNA contained high levels of a 2.3-kb mRNA that selectively hybridized with human platelet 12-lipoxygenase cDNA, and partial cDNA sequence of this mRNA indicated identity to platelet 12-lipoxygenase. The epidermal 12-lipoxygenase was not recognized by antibodies against the leukocyte-type 12- and 15-lipoxygenases (found in leukocytes, reticulocytes, and mucosal epithelial cells) but was detected by an antiplatelet 12-lipoxygenase antibody. The epidermal 12-lipoxygenase antigen was selectively expressed in germinal layer keratinocytes in healthy and psoriatic skin, and these layers exhibited hyperplasia and increased immunostaining in inflamed psoriatic skin. Together with previous results, these observations indicate that 1) epidermis generates 12-HETE by either cytochrome P-450 or lipoxygenase-based mechanisms depending on reaction conditions, and 2) 12-lipoxygenases (originally described in hematopoietic cell types) may be expressed in at least two distinct isoforms in epithelial barriers in humans, and in the case of the skin, a microsomal (platelet-type) 12-lipoxygenase is selectively overexpressed in germinal layer keratinocytes during psoriatic inflammation.

  1. Pithy protection: Nicotiana attenuata's jasmonic acid-mediated defenses are required to resist stem-boring weevil larvae.

    Science.gov (United States)

    Diezel, Celia; Kessler, Danny; Baldwin, Ian T

    2011-04-01

    Folivory is the best studied plant-herbivore interaction, but it is unclear whether the signaling and resistance traits important for the defense of leaves are also important for other plant parts. Larvae of the tobacco stem weevil, Trichobaris mucorea, burrow into stems of Nicotiana attenuata and feed on the pith. Transgenic N. attenuata lines silenced in signaling and foliar defense traits were evaluated in a 2-year field study for resistance against attack by naturally occurring T. mucorea larva. Plants silenced in early jasmonic acid (JA) biosynthesis (antisense [as]-lipoxygenase3 [lox3]; inverted repeat [ir]-allene oxide cyclase), JA perception (as-coronatine insensitive1), proteinase inhibitors (ir-pi), and nicotine (ir-putrescine methyl-transferase) direct defenses and lignin (ir-cad) biosynthesis were infested more frequently than wild-type plants. Plants unable to emit C(6) aldehydes (as-hpl) had lower infestation rates, while plants silenced in late steps in JA biosynthesis (ir-acyl-coenzyme A oxidase, ir-opr) and silenced in diterpene glycoside production (ir-geranylgeranyl pyrophosphate synthase) did not differ from wild type. Pith choice assays revealed that ir-putrescine methyl-transferase, ir-coronatine insensitive1, and ir-lox3 pith, which all had diminished nicotine levels, were preferred by larvae compared to wild-type pith. The lack of preference for ir-lox2 and ir-cad piths, suggest that oviposition attraction and vascular defense, rather than pith palatability accounts for the higher attack rates observed for these plants. We conclude that traits that influence a plant's apparency, stem hardness, and pith direct defenses all contribute to resistance against this herbivore whose attack can be devastating to N. attenuata's fitness.

  2. Genomic and cDNA cloning of a novel mouse lipoxygenase gene

    NARCIS (Netherlands)

    Willems van Dijk, K.; Steketee, K.; Havekes, L.; Frants, R.; Hofker, M.

    1995-01-01

    A novel 12- and 15-lipoxygenase related gene was isolated from a mouse strain 129 genomic phage library in a screen with a human 15-lipoxygenase cDNA probe. The complete genomic sequence revealed 14 exons and 13 introns covering 7.3 kb of DNA. The splice junctions were verified from the cDNA

  3. Epidermis-type lipoxygenase 3 regulates adipocyte differentiation and peroxisome proliferator-activated receptor gamma activity

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Jørgensen, Claus; Petersen, Rasmus K

    2010-01-01

    differentiation has remained enigmatic. Previously, we showed that lipoxygenase (LOX) activity is involved in activation of PPAR gamma during the early stages of adipocyte differentiation. Of the seven known murine LOXs, only the unconventional LOX epidermis-type lipoxygenase 3 (eLOX3) is expressed in 3T3-L1...

  4. WWP-1 is a novel modulator of the DAF-2 insulin-like signaling network involved in pore-forming toxin cellular defenses in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Chang-Shi Chen

    Full Text Available Pore-forming toxins (PFTs are the single largest class of bacterial virulence factors. The DAF-2 insulin/insulin-like growth factor-1 signaling pathway, which regulates lifespan and stress resistance in Caenorhabditis elegans, is known to mutate to resistance to pathogenic bacteria. However, its role in responses against bacterial toxins and PFTs is as yet unexplored. Here we reveal that reduction of the DAF-2 insulin-like pathway confers the resistance of Caenorhabditis elegans to cytolitic crystal (Cry PFTs produced by Bacillus thuringiensis. In contrast to the canonical DAF-2 insulin-like signaling pathway previously defined for aging and pathogenesis, the PFT response pathway diverges at 3-phosphoinositide-dependent kinase 1 (PDK-1 and appears to feed into a novel insulin-like pathway signal arm defined by the WW domain Protein 1 (WWP-1. In addition, we also find that WWP-1 not only plays an important role in the intrinsic cellular defense (INCED against PFTs but also is involved in innate immunity against pathogenic bacteria Pseudomonas aeruginosa and in lifespan regulation. Taken together, our data suggest that WWP-1 and DAF-16 function in parallel within the fundamental DAF-2 insulin/IGF-1 signaling network to regulate fundamental cellular responses in C. elegans.

  5. Polyamine regulates tolerance to water stress in leaves of white clover associated with antioxidant defense and dehydrin genes via involvement in calcium messenger system and hydrogen peroxide signaling

    Directory of Open Access Journals (Sweden)

    Zhou eLi

    2015-10-01

    Full Text Available Endogenous polyamine (PA may play a critical role in tolerance to water stress in plants acting as a signaling molecule activator. Water stress caused increases in endogenous PA content in leaves, including putrescine (Put, spermidine (Spd, and spermine (Spm. Exogenous application of Spd could induce the instantaneous H2O2 burst and accumulation of cytosolic free Ca2+, and activate NADPH oxidase and CDPK gene expression in cells. To a great extent, PA biosynthetic inhibitor reduced the water stress-induced H2O2 accumulation, free cytosolic Ca2+ release, antioxidant enzyme activities and genes expression leading to aggravate water stress-induced oxidative damage, while these suppressing effects were alleviated by the addition of exogenous Spd, indicating PA was involved in water stress-induced H2O2 and cytosolic free Ca2+ production as well as stress tolerance. Dehydrin genes (Y2SK, Y2K, and SK2 were showed to be highly responsive to exogenous Spd. PA-induced antioxidant defense and dehydrin genes expression could be blocked by the scavenger of H2O2 and the inhibitors of H2O2 generation or Ca2+ channels blockers, a calmodulin antagonist, as well as the inhibitor of CDPK. These findings suggested that PA regulated tolerance to water stress in white clover associated with antioxidant defenses and dehydrins via involvement in the calcium messenger system and H2O2 signaling pathways. PA-induced H2O2 production required Ca2+ release, while PA-induced Ca2+ release was also essential for H2O2 production, suggesting an interaction between PA-induced H2O2 and Ca2+ signaling.

  6. Transcriptional responses to polycyclic aromatic hydrocarbon-induced stress in Arabidopsis thaliana reveal the involvement of hormone and defense signaling pathways

    Directory of Open Access Journals (Sweden)

    Colón-Carmona Adán

    2010-04-01

    Full Text Available Abstract Background Polycyclic aromatic hydrocarbons (PAHs are toxic, widely-distributed, environmentally persistent, and carcinogenic byproducts of carbon-based fuel combustion. Previously, plant studies have shown that PAHs induce oxidative stress, reduce growth, and cause leaf deformation as well as tissue necrosis. To understand the transcriptional changes that occur during these processes, we performed microarray experiments on Arabidopsis thaliana L. under phenanthrene treatment, and compared the results to published Arabidopsis microarray data representing a variety of stress and hormone treatments. In addition, to probe hormonal aspects of PAH stress, we assayed transgenic ethylene-inducible reporter plants as well as ethylene pathway mutants under phenanthrene treatment. Results Microarray results revealed numerous perturbations in signaling and metabolic pathways that regulate reactive oxygen species (ROS and responses related to pathogen defense. A number of glutathione S-transferases that may tag xenobiotics for transport to the vacuole were upregulated. Comparative microarray analyses indicated that the phenanthrene response was closely related to other ROS conditions, including pathogen defense conditions. The ethylene-inducible transgenic reporters were activated by phenanthrene. Mutant experiments showed that PAH inhibits growth through an ethylene-independent pathway, as PAH-treated ethylene-insensitive etr1-4 mutants exhibited a greater growth reduction than WT. Further, phenanthrene-treated, constitutive ethylene signaling mutants had longer roots than the untreated control plants, indicating that the PAH inhibits parts of the ethylene signaling pathway. Conclusions This study identified major physiological systems that participate in the PAH-induced stress response in Arabidopsis. At the transcriptional level, the results identify specific gene targets that will be valuable in finding lead compounds and engineering increased

  7. 5-Lipoxygenase-Dependent Recruitment of Neutrophils and Macrophages by Eotaxin-Stimulated Murine Eosinophils

    Directory of Open Access Journals (Sweden)

    Ricardo Alves Luz

    2014-01-01

    Full Text Available The roles of eosinophils in antimicrobial defense remain incompletely understood. In ovalbumin-sensitized mice, eosinophils are selectively recruited to the peritoneal cavity by antigen, eotaxin, or leukotriene(LTB4, a 5-lipoxygenase (5-LO metabolite. 5-LO blockade prevents responses to both antigen and eotaxin. We examined responses to eotaxin in the absence of sensitization and their dependence on 5-LO. BALB/c or PAS mice and their mutants (5-LO-deficient ALOX; eosinophil-deficient GATA-1 were injected i.p. with eotaxin, eosinophils, or both, and leukocyte accumulation was quantified up to 24 h. Significant recruitment of eosinophils by eotaxin in BALB/c, up to 24 h, was accompanied by much larger numbers of recruited neutrophils and monocytes/macrophages. These effects were abolished by eotaxin neutralization and 5-LO-activating protein inhibitor MK886. In ALOX (but not PAS mice, eotaxin recruitment was abolished for eosinophils and halved for neutrophils. In GATA-1 mutants, eotaxin recruited neither neutrophils nor macrophages. Transfer of eosinophils cultured from bone-marrow of BALB/c donors, or from ALOX donors, into GATA-1 mutant recipients, i.p., restored eotaxin recruitment of neutrophils and showed that the critical step dependent on 5-LO is the initial recruitment of eosinophils by eotaxin, not the secondary neutrophil accumulation. Eosinophil-dependent recruitment of neutrophils in naive BALB/c mice was associated with increased binding of bacteria.

  8. 5-Lipoxygenase is not essential in macrophage-mediated oxidation of low-density lipoprotein.

    Science.gov (United States)

    Jessup, W; Darley-Usmar, V; O'Leary, V; Bedwell, S

    1991-08-15

    The concentration-dependent effects of a series of lipoxygenase inhibitors and antioxidants on the macrophage-mediated oxidative modification of low-density lipoprotein (LDL) were measured. Their influence on macrophage 5-lipoxygenase pathway activity was also studied over the same concentration range. No correlation between inhibition of 5-lipoxygenase and of macrophage-mediated oxidation of LDL was observed. The capacity of the compounds to prevent cell-mediated modification of LDL could be explained in terms of their activity as either aqueous- or lipid-peroxyl radical scavengers. Two potent 5-lipoxygenase inhibitors (MK 886 and Revlon 5901), which had no radical-scavenging properties, were unable to block LDL modification. It is concluded that 5-lipoxygenase is not essential for LDL oxidation by macrophages.

  9. Effects of infrared treatment on urease, trypsin inhibitor and lipoxygenase activities of soybean samples.

    Science.gov (United States)

    Yalcin, Seda; Basman, Arzu

    2015-02-15

    In this study, infrared (IR) treatment at different powers (814W, 1003W, 1208W, 1342W) and times (10min, 15min) were applied to unsoaked and soaked (30min, 45min) soybeans (cvs. Adasoy, Nazlican). Effects of IR treatment on urease, trypsin inhibitor, lipoxygenase-1 and lipoxygenase-3 activities were investigated. Infrared treatment caused a substantial reduction in urease and trypsin inhibitor activities and considerable decrease was observed as the IR power increased. Urease inactivation in unsoaked samples was achieved at even lower power (1208W). In contrast to urease activity, IR treatment had a more pronounced effect on trypsin inhibitor and lipoxygenase activities of soaked soybeans as compared to unsoaked counterparts. Maximum trypsin inhibitor reduction in IR-treated samples was 95% for cv. Adasoy and 97% for cv. Nazlican. IR power of 1003W was sufficient for complete inactivation of lipoxygenase-1 and lipoxygenase-3, regardless of the moisture contents of the samples.

  10. Development of the simple and sensitive method for lipoxygenase assay in AOT/isooctane reversed micelles.

    Science.gov (United States)

    Park, Kyung Min; Kim, Yu Na; Choi, Seung Jun; Chang, Pahn-Shick

    2013-06-01

    In this study, we investigated the possibility of reversed micelles, widely used as an enzyme reactor for lipases, for the determination of lipoxygenase activity. Although it is rapid and simple, reversed micelles have some limitations, such as interference by UV-absorbing materials and surfactant. Lipoxygenase activity in the reversed micelles was determined by reading the absorbance of the lipid hydroperoxidation product (conjugated diene) at 234 nm. Among surfactants and organic media, AOT and isooctane were most effective for the dioxygenation of linoleic acid in reversed micelles. The strong absorbance of AOT in the UV region is a major obstacle for the direct application of the AOT/isooctane reversed micelles to lipoxygenase activity determination. To prevent interference by AOT, we added an AOT removal step in the procedure for lipoxygenase activity determination in reversed micelles. The lipoxygenase activity was dependent on water content, and maximum activity was obtained at an R-value of 10.

  11. A modified ferrous oxidation-xylenol orange assay for lipoxygenase activity in rice grains.

    Science.gov (United States)

    Timabud, Tarinee; Sanitchon, Jirawat; Pongdontri, Paweena

    2013-12-01

    Ferrous oxidation-xylenol orange assay reagent was reformulated by using spectral analysis of ferric-xylenol orange complex to detect low concentrations of lipoxygenase rice grain products. Reducing the levels of ferrous sulphate and xylenol orange in the FOX reagent enabled the detection of low concentrations of hydroperoxy fatty acid derived from lipoxygenase activity in the range of 0.1-1.5 μM. Protein, substrate and time courses of the modified FOX assay were studied to determine lipoxygenase activity in rice grain. The assay was also applicable as a high throughput technique for comparisons of lipoxygenase activity from various rice varieties. This has important implications for rapid screening for low-lipoxygenase containing rice cultivars in rice breeding program and grain quality during storage. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. OsDMI3 Is a Novel Component of Abscisic Acid Signaling in the Induction of Antioxidant Defense in Leaves of Rice

    Institute of Scientific and Technical Information of China (English)

    Ben Shi; Lan Ni; Aying Zhang; Jianmei Cao; Hong Zhang; Tingting Qin; Mingpu Tan; Jianhua Zhang; Mingyi Jiang

    2012-01-01

    Ca2+ and calmodulin (CaM) have been shown to play an important role in abscisic acid (ABA)-induced antioxidant defense.However,it is unknown whether Ca2+/CaM-dependent protein kinase (CCaMK) is involved in the process.In the present study,the role of rice CCaMK,OsDMI3,in ABA-induced antioxidant defense was investigated in leaves of rice (Oryza sativa) plants.Treatments with ABA,H2O2,and polyethylene glycol (PEG) induced the expression of OsDMI3 and the activity of OsDMI3,and H2O2 is required for the ABA-induced increases in the expression and the activity of OsDMI3 under water stress.Subcellular localization analysis showed that OsDMI3 is located in the nucleus,the cytoplasm,and the plasma membrane.The analysis of the transient expression of OsDMI3 in rice protoplasts and the RNA interference (RNAi) silencing of OsDMI3 in rice protoplasts showed that OsDMI3 is required for ABA-induced increases in the expression and the activities of superoxide dismutase (SOD) and catalase (CAT).Further,the oxidative damage induced by higher concentrations of PEG and H2O2 was aggravated in the mutant of OsDMI3.Moreover,the analysis of the RNAi silencing of OsDMI3 in protoplasts and the mutant of OsDMI3 showed that higher levels of H2O2 accumulation require OsDMI3 activation in ABA signaling,but the initial H2O2 production induced by ABA is not dependent on the activation of OsDMI3 in leaves of rice plants.Our data reveal that OsDMI3 is an important component in ABA-induced antioxidant defense in rice.

  13. WRKY8 transcription factor functions in the TMV-cg defense response by mediating both abscisic acid and ethylene signaling in Arabidopsis.

    Science.gov (United States)

    Chen, Ligang; Zhang, Liping; Li, Daibo; Wang, Fang; Yu, Diqiu

    2013-05-21

    WRKY transcription factors are key players in the plant immune response, but less is known about their involvement in antiviral defense than about their roles in defense against bacterial or fungi pathogens. Here, we report that Arabidopsis thaliana WRKY DNA-binding protein 8 (WRKY8) has a role in mediating the long-distance movement of crucifer-infecting tobacco mosaic virus (TMV-cg). The expression of WRKY8 was inhibited by TMV-cg infection, and mutation of WRKY8 accelerated the accumulation of TMV-cg in systemically infected leaves. Quantitative RT-PCR analysis showed that the expression of ABA insensitive 4 (ABI4) was reduced and the expression of 1-aminocyclopropane-1-carboxylic acid synthase 6 (ACS6) and ethylene response factor 104 (ERF104) was enhanced in the systemically infected leaves of wrky8. Immunoprecipitation assays demonstrated that WRKY8 could bind selectively to putative W-boxes of the ABI4, ACS6, and ERF104 promoters. Furthermore, TMV-cg infection enhanced WRKY8 binding to the ABI4 promoter but reduced the binding of WRKY8 to the ACS6 and ERF104 promoters, indicating that regulation of ABI4, ACS6, and ERF104 by WRKY8 is at least partially dependent on TMV-cg. Exogenous applications of abscisic acid (ABA) reduced the systemic accumulation of TMV-cg. Mutations in ABA deficient 1, ABA deficient 2, ABA deficient 3, or abi4 accelerated systemic TMV-cg accumulation. In contrast, exogenous application of aminocyclopropane-1-carboxylic acid enhanced the systemic accumulation of TMV-cg, but mutations in acs6, erf104, or an octuple acs mutant inhibited systemic TMV-cg accumulation. Our results demonstrate that WRKY8 is involved in the defense response against TMV-cg through the direct regulation of the expression of ABI4, ACS6, and ERF104 and may mediate the crosstalk between ABA and ethylene signaling during the TMV-cg-Arabidopsis interaction.

  14. Antioxidative defense

    Directory of Open Access Journals (Sweden)

    Stevanović Jelka

    2011-01-01

    Full Text Available Free radicals occur constantly during metabolism and take part in numerous physiological processes, such as: intra-cellular and inter-cellular signalization, gene expression, removal of damaged or senescent cells, and control of the tone of blood vessels. However, there is an increased quantity of free radicals in situations of so-called oxidative stress, when they cause serious damage to cellular membranes (peroxidation of their lipids, damage of membrane proteins, and similar, to interior cellular protein molecules, as well as DNA molecules and carbohydrates. This is precisely why the organism has developed numerous mechanisms for removing free radicals and/or preventing their production. Some of these are enzyme-related and include superoxide-dismutase, catalase, glutathione-peroxidase, and others. Other, non-enzyme mechanisms, imply antioxidative activities of vitamins E and C, provitamin A, coenzyme Q, reduced glutation, and others. Since free radicals can leave the cell that has produced them and become dispersed throughout the body, in addition to antioxidative defense that functions within cellular structures, antioxidant extra-cellular defense has also been developed. This is comprised by: transferrin, lactoferrin, haptoglobin, hemopexin, ceruloplasmin, albumins, extra-cellular isoform SOD, extracellular glutathione-peroxidase, glucose, bilirubin, urates, and many other molecules.

  15. The 9-lipoxygenase Osr9-LOX1 interacts with the 13-lipoxygenase-mediated pathway to regulate resistance to chewing and piercing-sucking herbivores in rice.

    Science.gov (United States)

    Zhou, Guoxin; Ren, Nan; Qi, Jingfeng; Lu, Jing; Xiang, Caiyu; Ju, Hongping; Cheng, Jiaan; Lou, Yonggen

    2014-09-01

    Oxylipins produced by the 13-lipoxygenase (LOX) have been reported to play an important role in plant defense responses to herbivores. Yet, the role of oxylipins produced by the 9-LOX pathway in this process remains largely unknown. Here we cloned a gene encoding a chloroplast-localized 9-LOX, Osr9-LOX1, from rice. Transcriptional analysis revealed that herbivore infestation, mechanical wounding and jasmonic acid (JA) treatment either repressed or did not enhance the level of Osr9-LOX1 transcripts at early stages but did at later stages, whereas salicylic acid (SA) treatment quickly increased the transcript level of Osr9-LOX1. Antisense expression of Osr9-lox1 (as-r9lox1) decreased the amount of wound-induced (Z)-3-hexenal but increased levels of striped stem borer (SSB)-induced linolenic acid, JA, SA and trypsin protease inhibitors. These changes were associated with increased resistance in rice to the larvae of the SSB Chilo suppressalis. In contrast, although no significant differences were observed in the duration of the nymph stage or the number of eggs laid by female adults between the brown planthopper (BPH) Nilaparvata lugens that fed on as-r9lox1 lines and BPH that fed on wild-type (WT) rice plants, the survival rate of BPH nymphs that fed on as-r9lox1 lines was higher than that of nymphs that fed on WT plants, possibly because of a higher JA level. The results demonstrate that Osr9-LOX1 plays an important role in regulating an herbivore-induced JA burst and cross-talk between JA and SA, and in controlling resistance in rice to chewing and phloem-feeding herbivores.

  16. 5-lipoxygenase and 5-lipoxygenase-activating protein gene polymorphisms, dietary linoleic acid, and risk for breast cancer.

    Science.gov (United States)

    Wang, Jun; John, Esther M; Ingles, Sue Ann

    2008-10-01

    The n-6 polyunsaturated fatty acid 5-lipoxygenase pathway has been shown to play a role in the carcinogenesis of breast cancer. We conducted a population-based case-control study among Latina, African-American, and White women from the San Francisco Bay area to examine the association of the 5-lipoxygenase gene (ALOX5) and 5-lipoxygenase-activating protein gene (ALOX5AP) with breast cancer risk. Three ALOX5AP polymorphisms [poly(A) microsatellite, -4900 A>G (rs4076128), and -3472 A>G (rs4073259)] and three ALOX5 polymorphisms [Sp1-binding site (-GGGCGG-) variable number of tandem repeat polymorphism, -1279 G>T (rs6593482), and 760 G>A (rs2228065)] were genotyped in 802 cases and 888 controls. We did not find significant main effects of ALOX5 and ALOX5AP genotypes on breast cancer risk that were consistent across race or ethnicity; however, there was a significant interaction between the ALOX5AP -4900 A>G polymorphism and dietary linoleic acid intake (P=0.03). Among women consuming a diet high in linoleic acid (top quartile of intake, >17.4 g/d), carrying the AA genotype was associated with higher breast cancer risk (age- and race-adjusted odds ratio, 1.8; 95% confidence interval, 1.2-2.9) compared with carrying genotypes AG or GG. Among women consuming

  17. Plant defense against insect herbivores

    DEFF Research Database (Denmark)

    Fürstenberg-Hägg, Joel; Zagrobelny, Mika; Bak, Søren

    2013-01-01

    have adapted to resist plant defenses, and in some cases even sequester the compounds and reuse them in their own defense. Both plant defense and insect adaptation involve metabolic costs, so most plant-insect interactions reach a stand-off, where both host and herbivore survive although......Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar....... Insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. These are perceived in undamaged tissues, which thereafter reinforce their defense by producing different, mostly low molecular weight...

  18. Defense Priming and Jasmonates: A Role for Free Fatty Acids in Insect Elicitor-Induced Long Distance Signaling

    Directory of Open Access Journals (Sweden)

    Ting Li

    2016-01-01

    Full Text Available Green leaf volatiles (GLV prime plants against insect herbivore attack resulting in stronger and faster signaling by jasmonic acid (JA. In maize this response is specifically linked to insect elicitor (IE-induced signaling processes, which cause JA accumulation not only around the damage site, but also in distant tissues, presumably through the activation of electrical signals. Here, we present additional data further characterizing these distal signaling events in maize. Also, we describe how exposure to GLV increases free fatty acid (fFA levels in maize seedlings, but also in other plants, and how increased fFA levels affect IE-induced JA accumulation. Increased fFA, in particular α-linolenic acid (LnA, caused a significant increase in JA accumulation after IE treatment, while JA induced by mechanical wounding (MW alone was not affected. We also identified treatments that significantly decreased certain fFA level including simulated wind and rain. In such treated plants, IE-induced JA accumulation was significantly reduced when compared to un-moved control plants, while MW-induced JA accumulation was not significantly affected. Since only IE-induced JA accumulation was altered by changes in the fFA composition, we conclude that changing levels of fFA affect primarily IE-induced signaling processes rather than serving as a substrate for JA.

  19. Quantitative Structure-property Relationship Studies on Amino Acid Conjugates of Jasmonic Acid as Defense Signaling Molecules

    Institute of Scientific and Technical Information of China (English)

    Zu-Guang Li; Ke-Xian Chen; Hai-Ying Xie; Jian-Rong Gao

    2009-01-01

    Jasmonates and related compounds, including amino acid conjugates of jasmonic acid, have regulatory functions in the signaling pathway for plant developmental processes and responses to the complex equilibrium of biotic and abiotic stress.But the molecular details of the signaling mechanism are still poorly understood. Statistically significant quantitative structure-property relationship models (r2 > 0.990) constructed by genetic function approximation and molecular field analysis were generated for the purpose of deriving structural requirements for lipophilicity of amino acid conjugates of jasmonic acid. The best models derived in the present study provide some valuable academic information in terms of the 213D-descriptors influencing the lipophilicity, which may contribute to further understanding the mechanism of exogenous application of jasmonates in their signaling pathway and designing novel analogs ofjasmonic acid as ecological pesticides.

  20. Sulindac sulfide suppresses 5-lipoxygenase at clinically relevant concentrations.

    Science.gov (United States)

    Steinbrink, Svenja D; Pergola, Carlo; Bühring, Ulrike; George, Sven; Metzner, Julia; Fischer, Astrid S; Häfner, Ann-Kathrin; Wisniewska, Joanna M; Geisslinger, Gerd; Werz, Oliver; Steinhilber, Dieter; Maier, Thorsten J

    2010-03-01

    Sulindac is a non-selective inhibitor of cyclooxygenases (COX) used to treat inflammation and pain. Additionally, non-COX targets may account for the drug's chemo-preventive efficacy against colorectal cancer and reduced gastrointestinal toxicity. Here, we demonstrate that the pharmacologically active metabolite of sulindac, sulindac sulfide (SSi), targets 5-lipoxygenase (5-LO), the key enzyme in the biosynthesis of proinflammatory leukotrienes (LTs). SSi inhibited 5-LO in ionophore A23187- and LPS/fMLP-stimulated human polymorphonuclear leukocytes (IC(50) approximately 8-10 microM). Importantly, SSi efficiently suppressed 5-LO in human whole blood at clinically relevant plasma levels (IC(50) = 18.7 microM). SSi was 5-LO-selective as no inhibition of related lipoxygenases (12-LO, 15-LO) was observed. The sulindac prodrug and the other metabolite, sulindac sulfone (SSo), failed to inhibit 5-LO. Mechanistic analysis demonstrated that SSi directly suppresses 5-LO with an IC(50) of 20 muM. Together, these findings may provide a novel molecular basis to explain the COX-independent pharmacological effects of sulindac under therapy.

  1. OsNPR1 negatively regulates herbivore-induced JA and ethylene signaling and plant resistance to a chewing herbivore in rice.

    Science.gov (United States)

    Li, Ran; Afsheen, Sumera; Xin, Zhaojun; Han, Xiu; Lou, Yonggen

    2013-03-01

    NPR1 (a non-expressor of pathogenesis-related genes1) has been reported to play an important role in plant defense by regulating signaling pathways. However, little to nothing is known about its function in herbivore-induced defense in monocot plants. Here, using suppressive substrate hybridization, we identified a NPR1 gene from rice, OsNPR1, and found that its expression levels were upregulated in response to infestation by the rice striped stem borer (SSB) Chilo suppressalis and rice leaf folder (LF) Cnaphalocrocis medinalis, and to mechanical wounding and treatment with jasmonic acid (JA) and salicylic acid (SA). Moreover, mechanical wounding induced the expression of OsNPR1 quickly, whereas herbivore infestation induced the gene more slowly. The antisense expression of OsNPR1 (as-npr1), which reduced the expression of the gene by 50%, increased elicited levels of JA and ethylene (ET) as well as of expression of a lipoxygenase gene OsHI-LOX and an ACC synthase gene OsACS2. The enhanced JA and ET signaling in as-npr1 plants increased the levels of herbivore-induced trypsin proteinase inhibitors (TrypPIs) and volatiles, and reduced the performance of SSB. Our results suggest that OsNPR1 is an early responding gene in herbivore-induced defense and that plants can use it to activate a specific and appropriate defense response against invaders by modulating signaling pathways.

  2. Defense-Related Calcium Signaling Mutants Uncovered via a Quantitative High-Throughput Screen in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Stefanie Ranf; Julia Grimmer; Yvonne P(o)schl; Pascal Pecher; Delphine Chinchilla; Dierk Scheel; Justin Lee

    2012-01-01

    Calcium acts as a second messenger for signaling to a variety of stimuli including MAMPs (Microbe-Associated Molecular Patterns),such as flg22 and elf18 that are derived from bacterial flagellin and elongation factor Tu,respectively.Here,Arabidopsis thaliana mutants with changed calcium elevation (cce) in response to fig22 treatment were isolated and characterized.Besides novel mutant alleles of the flg22 receptor,FLS2 (Flagellin-Sensitive 2),and the receptor-associated kinase,BAK1 (Brassinosteroid receptor 1-Associated Kinase 1),the new cce mutants can be categorized into two main groups—those with a reduced or an enhanced calcium elevation.Moreover,cce mutants from both groups show differential phenotypes to different sets of MAMPs.Thus,these mutants will facilitate the discovery of novel components in early MAMP signaling and bridge the gaps in current knowledge of calcium signaling during plant-microbe interactions.Last but not least,the screening method is optimized for speed (covering 384 plants in 3 or 10 h) and can be adapted to genetically dissect any other stimuli that induce a change in calcium levels.

  3. Lipoxygenase and cyclooxygenase metabolism: new insights in treatment and chemoprevention of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Adrian Thomas E

    2003-01-01

    Full Text Available Abstract The essential fatty acids, linoleic acid and arachidonic acid play an important role in pancreatic cancer development and progression. These fatty acids are metabolized to eicosanoids by cyclooxygenases and lipoxygenases. Abnormal expression and activities of both cyclooxygenases and lipoxygenases have been reported in pancreatic cancer. In this article, we aim to provide a brief summary of (1 our understanding of the roles of these enzymes in pancreatic cancer tumorigenesis and progression; and (2 the potential of using cyclooxygenase and lipoxygenase inhibitors for pancreatic cancer treatment and prevention.

  4. 5-lipoxygenase expression in a brain damage model induced by chronic oral administration of aluminum

    Institute of Scientific and Technical Information of China (English)

    Yongquan Pan; Peng Zhang; Junqing Yang; Qiang Su

    2010-01-01

    A preliminary study has found that the 5-lipoxygenase inhibitor, caffeic acid, has a marked protective effect on acute brain injury induced by intracerebroventricular microinjection of aluminum.In this experiment, chronic brain injury and neuronal degeneration model was established in rats by chronic oral administration of aluminum, and then intervened using caffeic acid. Results showed that caffeic acid can downregulate chronic aluminum overload-induced 5-lipoxygenase mRNA and protein expression, and repair the aluminum overload-induced hippocampal neuronal damage andspatial orientation impairment. It is suggested that direct intervention of 5-lipoxygenase expression has a neuroprotective role in the degeneration induced by chronic aluminum overload brain injury model.

  5. Plant Defense against Insect Herbivores

    Science.gov (United States)

    Fürstenberg-Hägg, Joel; Zagrobelny, Mika; Bak, Søren

    2013-01-01

    Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar. Insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. These are perceived in undamaged tissues, which thereafter reinforce their defense by producing different, mostly low molecular weight, defense compounds. These bioactive specialized plant defense compounds may repel or intoxicate insects, while defense proteins often interfere with their digestion. Volatiles are released upon herbivory to repel herbivores, attract predators or for communication between leaves or plants, and to induce defense responses. Plants also apply morphological features like waxes, trichomes and latices to make the feeding more difficult for the insects. Extrafloral nectar, food bodies and nesting or refuge sites are produced to accommodate and feed the predators of the herbivores. Meanwhile, herbivorous insects have adapted to resist plant defenses, and in some cases even sequester the compounds and reuse them in their own defense. Both plant defense and insect adaptation involve metabolic costs, so most plant-insect interactions reach a stand-off, where both host and herbivore survive although their development is suboptimal. PMID:23681010

  6. UV-B irradiation changes specifically the secondary metabolite profile in broccoli sprouts: induced signaling overlaps with defense response to biotic stressors.

    Science.gov (United States)

    Mewis, Inga; Schreiner, Monika; Nguyen, Chau Nhi; Krumbein, Angelika; Ulrichs, Christian; Lohse, Marc; Zrenner, Rita

    2012-09-01

    Only a few environmental factors have such a pronounced effect on plant growth and development as ultraviolet light (UV). Concerns have arisen due to increased UV-B radiation reaching the Earth's surface as a result of stratospheric ozone depletion. Ecologically relevant low to moderate UV-B doses (0.3-1 kJ m(-2) d(-1)) were applied to sprouts of the important vegetable crop Brassica oleracea var. italica (broccoli), and eco-physiological responses such as accumulation of non-volatile secondary metabolites were related to transcriptional responses with Agilent One-Color Gene Expression Microarray analysis using the 2×204 k format Brassica microarray. UV-B radiation effects have usually been linked to increases in phenolic compounds. As expected, the flavonoids kaempferol and quercetin accumulated in broccoli sprouts (the aerial part of the seedlings) 24 h after UV-B treatment. A new finding is the specific UV-B-mediated induction of glucosinolates (GS), especially of 4-methylsulfinylbutyl GS and 4-methoxy-indol-3-ylmethyl GS, while carotenoids and Chl levels remained unaffected. Accumulation of defensive GS metabolites was accompanied by increased expression of genes associated with salicylate and jasmonic acid signaling defense pathways and up-regulation of genes responsive to fungal and bacterial pathogens. Concomitantly, plant pre-exposure to moderate UV-B doses had negative effects on the performance of the caterpillar Pieris brassicae (L.) and on the population growth of the aphid Myzus persicae (Sulzer). Moreover, insect-specific induction of GS in broccoli sprouts was affected by UV-B pre-treatment.

  7. Ectopic expression of a Ve homolog VvVe gene from Vitis vinifera enhances defense response to Verticillium dahliae infection in tobacco.

    Science.gov (United States)

    Tang, Juan; Lin, Jing; Yang, Yuwen; Chen, Tianzi; Ling, Xitie; Zhang, Baolong; Chang, Youhong

    2016-01-15

    Verticillium wilt is a soil borne disease that can cause devastating losses to the production of many economically important crops. A Ve1 homologous gene responding to Verticillium dahliae infection was identified in Vitis vinifera cv. "HeiFeng" by semi-quantitative reverse transcription polymerase chain reaction and was designated as VvVe. The overexpression of VvVe in transgenic Nicotiana benthamiana plants significantly enhanced the resistance to isolate V991 of V. dahliae when compared with the wild type plants. The expressions of defense-related genes including the salicylic acid regulated gene pathogen-related 1 (PR1) but not PR2, the ethylene- and jasmonic acid-regulated genes ethylene response factor 1 (ERF1) and lipoxygenase (LOX) were significantly increased due to over expression of VvVe. And greater accumulation of active oxygen, callose and phenylalanine-ammonia lyase were observed in the leaves of transgenic VvVe tobacco plants than the wild type when under infection by V. dahliae. Moreover, the hypersensitive response mimicking cell death was exclusively occurred in the transgenic VvVe tobacco plants but not in the wild type. Taken together, the VvVe gene is a Ve1 like gene which involves in the signal cascade of salicylic acid, jasmonate, and ethylene defense pathways and enhances defense response to V. dahliae infection in the transgenic tobacco. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Antiaggregatory effects of flavonoids in vivo and their influence on lipoxygenase and cyclooxygenase in vitro.

    Science.gov (United States)

    Swies, J; Robak, J; Dabrowski, L; Duniec, Z; Michalska, Z; Gryglewski, R J

    1984-01-01

    Quercetin, rutin and troxerutin were found to inhibit platelet aggregation on collagen strip superfused with blood of anesthetized cats. Quercetin was the most potent acting at the dose of 1 micrograms/kg. Its effect was shortlasting. Troxerutin was a weak inhibitor of platelet aggregation and its effect was delayed. Quercetin inhibited in 50% 15-lipoxygenase and 12-lipoxygenase in vitro at the concentration of 1.3 microm and 13 microM respectively. It stimulated cyclooxygenase when 100 microM of arachidonic acid was applied. Quercetin inhibited cyclooxygenase in the presence of 1.6 microM of substrate. Rutin was a weaker inhibitor of lipoxygenase. Troxerutin was inactive in all experiments in vitro. It is concluded that unusually strong effect of quercetin in vivo can be explained neither by its influence on cyclooxygenase nor on lipoxygenase because the effects in vitro were observed in much higher concentrations.

  9. Cloning and Sequence Analysis of Lipoxygenase Gene cDNA from Cucumber Fruit (Cucumis sativus L.)

    Institute of Scientific and Technical Information of China (English)

    Z.K. Wang; Z.W. Qin; X.Y. Zhou; D.Y. Song

    2007-01-01

    @@ Lipoxygenases are nonheme-iron-containing dioxygenases that catalyze the hydroperoxidation of unsatrated fatty acids containing a cis, cis-1,4-pentadiene structure producing hydroperoxy acids with conjugated dienes.

  10. Catalytic asymmetric total synthesis of (S)-(-)-zearalenone, a novel lipoxygenase inhibitor.

    Science.gov (United States)

    Baggelaar, Marc P; Huang, Yange; Feringa, Ben L; Dekker, Frank J; Minnaard, Adriaan J

    2013-09-01

    A catalytic asymmetric synthesis of (S)-(-)-zearalenone is reported using asymmetric allylic alkylation for the introduction of the stereocenter. (S)-(-)-Zearalenone turned out to be a novel lipoxygenase inhibitor. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Catalytic asymmetric total synthesis of (S)-(-)-zearalenone, a novel lipoxygenase inhibitor

    NARCIS (Netherlands)

    Baggelaar, Marc P.; Huang, Yange; Feringa, Ben L.; Dekker, Frank J.; Minnaard, Adriaan J.

    2013-01-01

    A catalytic asymmetric synthesis of (S)-(-)-zearalenone is reported using asymmetric allylic alkylation for the introduction of the stereocenter. (S)-(-)-Zearalenone turned out to be a novel lipoxygenase inhibitor. (C) 2013 Elsevier Ltd. All rights reserved.

  12. Effects of Lipoxygenase Null Genes of Soybean in Controlling Beany-flavor of Soymilk and Soyflour

    Institute of Scientific and Technical Information of China (English)

    MA Hao; GUAN Chun-yun; HE Xiao-ling; ZHANG Guo-zheng; DIN An-lin

    2002-01-01

    The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chromatography (GC) and gas chromatography-mass spectrometry. Results showed that the same 24 flavor constituents were isolated in both soymilk and soyflour, and most of them were aldehydes and alcohols. Lox2 was most responsible for the production of the volatile and beany-flavor components, and Lox1 less responsible.Lox3 was least responsible and can reduce the yield of hexanal. Either Lx1 or Lx2 could significantly reduce the volatile and beany-flavor, and Lx3 could significantly increase the yield of hexanal. Primary and secondary interactions existed among the null mutant genes, and the major effects and interactions could be affected by processing conditions. The isoline with triple lipoxygenase null genes yielded the least volatile and beany-flavor components, and the isoline without the lipoxygenase gene Lx3 produced the greatest amount of the volatile and beany-flavor components. The amounts of volatile and beany-flavor components produced by the other isolines were between that of the isoline with triple lipoxygenase null genes and the isoline without lipoxygenase gene Lx3. According to the correlation analysis, the hexanal amount could be used as an index in evaluating the importance of lipoxygenase isozymes in the yield of beany-flavor compounds, and the effects of the different types of lipoxygenase null mutants in controlling beany-flavor compounds. The cultivars with triple lipoxygenase null genes will be a quality raw material for soyfood processing.

  13. Reengineering an azaphilone biosynthesis pathway in Aspergillus nidulans to create lipoxygenase inhibitors.

    Science.gov (United States)

    Somoza, Amber D; Lee, Kuan-Han; Chiang, Yi-Ming; Oakley, Berl R; Wang, Clay C C

    2012-02-17

    Sclerotiorin, an azaphilone polyketide, is a bioactive natural product known to inhibit 15-lipoxygenase and many other biological targets. To readily access sclerotiorin and analogs, we developed a 2-3 step semisynthetic route to produce a variety of azaphilones starting from an advanced, putative azaphilone intermediate (5) overproduced by an engineered strain of Aspergillus nidulans. The inhibitory activities of the semisynthetic azaphilones against 15-lipoxygenase were evaluated with several compounds displaying low micromolar potency.

  14. Inhibition of lipoxygenase activity in lentil protoplasts by monoclonal antibodies introduced into the cells via electroporation

    OpenAIRE

    J. F. G. Vliegenthart; Maccarrone, M.; Veldink, G.A.

    1992-01-01

    The isolation of lentil protoplasts and the transfer of anti-lipoxygenase monoclonal antibodies into plant protoplasts by electroporation is reported. The dependence of the efficiency of monoclonal antibody incorporation on the field strength is shown as well. The transferred immunoglobulins retained their functional and structural integrity and were able to inhibit the intracellular target enzyme, with a linear relationship between inhibition of lipoxygenase activity and amount of incorporat...

  15. 15-Lipoxygenase Inhibitory Activity Of The Extracts From Clerodendrum Quadriloculare Blanco Merr. Lamiaceae Leaves

    Directory of Open Access Journals (Sweden)

    Kay Ann J. Tongol

    2015-08-01

    Full Text Available Abstract Clerodendrum quadriloculare Blanco Merr. is an endemic plant species of the genus Clerodendrum in the Philippines. This plant contains phytosterols which may contribute to its biological properties. Results of this present research work established the anti-inflammatory potential by inhibiting 15-lipoxygenase enzyme in an in vitro assay model. The methanolic extract of C. quadriloculare possessed significant inhibition against 15-lipoxygenase enzymes with an IC50 value of 0.38 mgmL.

  16. 5-Lipoxygenase inhibition by acetyl-11-keto-β-boswellic acid (AKBA) by a novel mechanism.

    Science.gov (United States)

    Safayhi, H; Sailer, E R; Ammon, H P

    1996-05-01

    Acetyl-11-keto-β-boswellic acid (AKAB) from Boswellia serrata and B. carterii acts directly on purified 5-lipoxygenase of human blood leukocytes at a selective site for pentacyclic triterpenes that is different from the arachidonate substrate binding site. The pentacyclic triterpene ring is crucial for binding to the enzyme, whereas functional groups (11-keto function in addition to a hydrophilic group on C 4 of ring A) are essential for the 5-lipoxygenase activity.

  17. MAPK-dependent JA and SA signalling in Nicotiana attenuata affects plant growth and fitness during competition with conspecifics

    Directory of Open Access Journals (Sweden)

    Meldau Stefan

    2012-11-01

    Full Text Available Abstract Background Induced defense responses to herbivores are generally believed to have evolved as cost-saving strategies that defer the fitness costs of defense metabolism until these defenses are needed. The fitness costs of jasmonate (JA-mediated defenses have been well documented. Those of the early signaling units mediating induced resistance to herbivores have yet to be examined. Early signaling components that mediate herbivore-induced defense responses in Nicotiana attenuata, have been well characterized and here we examine their growth and fitness costs during competition with conspecifics. Two mitogen-activated protein kinases (MAPKs, salicylic acid (SA-induced protein kinase (SIPK and wound-induced protein kinase (WIPK are rapidly activated after perception of herbivory and both kinases regulate herbivory-induced JA levels and JA-mediated defense metabolite accumulations. Since JA-induced defenses result in resource-based trade-offs that compromise plant productivity, we evaluated if silencing SIPK (irSIPK and WIPK (irWIPK benefits the growth and fitness of plants competiting with wild type (WT plants, as has been shown for plants silenced in JA-signaling by the reduction of Lipoxygenase 3 (LOX3 levels. Results As expected, irWIPK and LOX3-silenced plants out-performed their competing WT plants. Surprisingly, irSIPK plants, which have the largest reductions in JA signaling, did not. Phytohormone profiling of leaves revealed that irSIPK plants accumulated higher levels of SA compared to WT. To test the hypothesis that these high levels of SA, and their presumed associated fitness costs of pathogen associated defenses in irSIPK plants had nullified the JA-deficiency-mediated growth benefits in these plants, we genetically reduced SA levels in irSIPK plants. Reducing SA levels partially recovered the biomass and fitness deficits of irSIPK plants. We also evaluated whether the increased fitness of plants with reduced SA or JA levels

  18. The antimicrobial peptide snakin-2 is upregulated in the defense response of tomatoes (Solanum lycopersicum) as part of the jasmonate-dependent signaling pathway.

    Science.gov (United States)

    Herbel, Vera; Sieber-Frank, Julia; Wink, Michael

    2017-01-01

    Antimicrobial peptides (AMPs) are produced by all living organisms and play an important role in innate immunity because they are readily available and non-specific against invading pathogenic microorganisms. Snakin-2 (SN2) from tomato is a short, cationic peptide that forms lethal pores in biomembranes of microbes. In plant cells, SN2 is produced as a prepeptide with a signal sequence for ER targeting and an acidic region to decrease toxicity in the producing organism. Gene expression analysis by qRT-PCR in tomato plants demonstrated that SN2 is constitutively expressed, mostly in leaves and flowers. After fungal infection, wounding, or external application of phytohormones (such as methyl jasmonate, MeJa) operating in the JA-dependent defense response, a systemic reaction with an elevated expression of the SN2 gene is triggered in all parts of tomato plants. Abiotic stress factors like extreme temperatures or dehydration do not affect SN2 expression. Upon wounding, the expression of SN2 and LoxD are strongly enhanced in tomato fruits. Furthermore, we provide evidence that the protein level of bioactive SN2 is also increased upon application of methyl jasmonate in tomato seedlings. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. A MyD88-dependent IFNγR-CCR2 signaling circuit is required for mobilization of monocytes and host defense against systemic bacterial challenge

    Institute of Scientific and Technical Information of China (English)

    Eric M Pietras; Lloyd S Miller; Carl T Johnson; Ryan M O'Connell; Paul W Dempsey; Genhong Cheng

    2011-01-01

    Monocytes are mobilized to sites of infection via interaction between the chemokine MCP-1 and its receptor, CCR2, at which point they differentiate into macrophages that mediate potent antimicrobial effects. In this study, we investigated the mechanisms by which monocytes are mobilized in response to systemic challenge with the intracellular bacterium Francisella tularensis. We found that mice deficient in MyD88, interferon-γ (IFNγ)R or CCR2 all had defects in the expansion of splenic monocyte populations upon F. tularensis challenge, and in control of F. tularensis infection. Interestingly, MyD88-deficient mice were defective in production of IFNγ, and IFNγR deficient mice exhibited defective production of MCP-1, the ligand for CCR2. Transplantation of IFNγR-deficient bone marrow (BM) into wild-type mice further suggested that mobilization of monocytes in response to F. tularensis challenge required IFNγR expression on BM-derived cells. These studies define a critical host defense circuit wherein MyD88-dependent IFNγ production signals via IFNγR expressed on BM-derived cells, resulting in MCP-1 production and activation of CCR2-dependent mobilization of monocytes in the innate immune response to systemic F. tularensis challenge.

  20. Lipoxygenase inhibitors protect acute lymphoblastic leukemia cells from ferroptotic cell death.

    Science.gov (United States)

    Probst, Lukas; Dächert, Jasmin; Schenk, Barbara; Fulda, Simone

    2017-09-15

    Ferroptosis has recently been identified as a mode of programmed cell death. However, little is yet known about the signaling mechanism. Here, we report that lipoxygenases (LOX) contribute to the regulation of RSL3-induced ferroptosis in acute lymphoblastic leukemia (ALL) cells. We show that the glutathione (GSH) peroxidase 4 (GPX4) inhibitor RSL3 triggers lipid peroxidation, production of reactive oxygen species (ROS) and cell death in ALL cells. All these events are impeded in the presence of Ferrostatin-1 (Fer-1), a small-molecule inhibitor of lipid peroxidation. Also, lipid peroxidation and ROS production precede the induction of cell death, underscoring their contribution to cell death upon exposure to RSL3. Importantly, LOX inhibitors, including the selective 12/15-LOX inhibitor Baicalein and the pan-LOX inhibitor nordihydroguaiaretic acid (NDGA), protect ALL cells from RSL3-stimulated lipid peroxidation, ROS generation and cell death, indicating that LOX contribute to ferroptosis. RSL3 triggers lipid peroxidation and cell death also in FAS-associated Death Domain (FADD)-deficient cells which are resistant to death receptor-induced apoptosis indicating that the induction of ferroptosis may bypass apoptosis resistance. By providing new insights into the molecular regulation of ferroptosis, our study contributes to the development of novel treatment strategies to reactivate programmed cell death in ALL. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Metabolism of anandamide into eoxamides by 15-lipoxygenase-1 and glutathione transferases.

    Science.gov (United States)

    Forsell, Pontus K A; Brunnström, Asa; Johannesson, Malin; Claesson, Hans-Erik

    2012-08-01

    Human 15-lipoxygenase-1 (15-LO-1) can metabolize arachidonic acid (ARA) into pro-inflammatory mediators such as the eoxins, 15-hydroperoxyeicosatetraenoic acid (HPETE), and 15-hydroxyeicosatetraenoyl-phosphatidylethanolamine. We have in this study investigated the formation of various lipid hydroperoxide by either purified 15-LO-1 or in the Hodgkin lymphoma cell line L1236, which contain abundant amount of 15-LO-1. Both purified 15-LO-1 and L1236 cells produced lipid hydroperoxides more efficiently when anandamide (AEA) or 2-arachidonoyl-glycerol ester was used as substrate than with ARA. Furthermore, L1236 cells converted AEA to a novel class of cysteinyl-containing metabolites. Based on RP-HPLC, mass spectrometry and comparison to synthetic products, these metabolites were identified as the ethanolamide of the eoxin (EX) C(4) and EXD(4). By using the epoxide EXA(4)-ethanol amide, it was also found that platelets have the capacity to produce the ethanolamide of EXC(4) and EXD(4). We suggest that the ethanolamides of the eoxins should be referred to as eoxamides, in analogy to the ethanolamides of prostaglandins which are named prostamides. The metabolism of AEA into eoxamides might engender molecules with novel biological effects. Alternatively, it might represent a new mechanism for the termination of AEA signalling.

  2. Physcomitrella patens activates reinforcement of the cell wall, programmed cell death and accumulation of evolutionary conserved defense signals...upon Botrytis cinerea infection

    Science.gov (United States)

    The moss Physcomitrella patens is an evolutionarily basal model system suitable to analyze plant defense responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea (B. cinerea), several defense mechanisms are induced in P. patens, including the fortification of t...

  3. Plant defense against insect herbivores

    DEFF Research Database (Denmark)

    Fürstenberg-Hägg, Joel; Zagrobelny, Mika; Bak, Søren

    2013-01-01

    defense responses. Plants also apply morphological features like waxes, trichomes and latices to make the feeding more difficult for the insects. Extrafloral nectar, food bodies and nesting or refuge sites are produced to accommodate and feed the predators of the herbivores. Meanwhile, herbivorous insects......Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar....... Insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. These are perceived in undamaged tissues, which thereafter reinforce their defense by producing different, mostly low molecular weight...

  4. Expression of 5-Lipoxygenase in human colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Labile Togba Soumaoro; Satoru Iida; Hiroyuki Uetake; Megumi Ishiguro; Yoko Takagi; Tetsuro Higuchi; Masamichi Yasuno; Masayuki Enomoto; Kenichi Sugihara

    2006-01-01

    AIM: To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis.METHODS: The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase (Cox)-2 proteins was also examined using immunohistochemical staining methods.RESULTS: There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples (P < 0.0001). Sixty six (72.5%) tumors showed high 5-Lox mRNA levels. The positivity rate of 5-Lox and Cox-2 protein expression was 68.7% and 79.1%respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size (Rho = 0.392,P = 0.0002), depth or vessel invasion.CONCLUSION: These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.

  5. Lipoxygenase regulation in vivo and in vitro by lipid compounds

    Directory of Open Access Journals (Sweden)

    Skaterna T. D.

    2015-06-01

    Full Text Available Lipoxygenases (LOs are known as one of the enzymes of lipid peroxidation. The majority of LOs are soluble enzymes and have affinity to membranes. The enzyme translocation from a cytosol to a membrane surface is one of the stages of regulation of the amount of LO catalysis products in the cell. A sorption to the membrane surface is described for most LOs from plant and animal sources. This review presents the data about regulation of the LO activity by the lipid compounds – both natural and chemically modified. Lipids might regulate the LO activity through: protein-lipid interactions of C2 domain with the membrane, changes in the enzyme affinity, the LOs translocation, allosteric regulation, increase in the selectivity towards substrates. The regulatory effect of active compound on the enzyme activity depends on the lipophilicity of effectors. Considering the LO activity it is necessary to take into account the enzyme microenvironment and its influence on the range of the LO products.

  6. Lipoxygenase distribution in coffee (Coffea arabica L.) berries.

    Science.gov (United States)

    Patui, Sonia; Peresson, Carlo; Braidot, Enrico; Tubaro, Franco; Colussi, Alessio; Bonnländer, Bernd; Macrì, Francesco; Vianello, Angelo

    2007-10-01

    In this paper lipoxygenase (LOX) presence was investigated in coffee berries to determine its involvement in lipid degradative metabolism of plants grown in organic and conventional cultivations. An immunochemical analysis has evidenced a ca. 80 kDa protein, cross-reacting with an anti-LOX antibody, only in the pulp fraction of berries obtained from plants of both cultivations. LOX activity in this fraction could be monitored either as conjugated diene formation or reaction products (determined by HPLC) and was mainly associated with a heavy membrane fraction (HMF, enriched in tonoplast, endoplasmic reticulum, plasma membrane, and mitochondria) and a light membrane fraction (LMF, enriched in plasma membrane and endoplasmic reticulum, with low levels of tonoplast and mitochondria). The LOX activity of LMF from berries of both cultivations showed an optimum at pH 8.0. The HMF exhibited a different activity peak in samples from conventional (pH 8.0) and organic (pH 5.5) cultures, suggesting the presence of different isoenzymes. These findings were also confirmed by variation of the ratio of 9- and 13-hydroperoxides in organic (1:1) and conventional cultivations (1:10), indicating that the organic one was subjected to an oxidative stress in the coffee pulp fraction leading to the expression of an acidic LOX. Such de novo synthesized LOX activity could be responsible for the production of secondary metabolites, which may interfere with the organoleptic profile of coffee.

  7. Chemical composition and lipoxygenase activity in soybeans (Glycine max L. Merr.) submitted to gamma irradiation

    Science.gov (United States)

    Barros, Érica Amanda de; Broetto, Fernando; Bressan, Dayanne F.; Sartori, Maria M. P.; Costa, Vladimir E.

    2014-05-01

    Soybeans are an important food due to their functional and nutritional characteristics. However, consumption by western populations is limited by the astringent taste of soybeans and their derivatives which results from the action of lipoxygenase, an enzyme activated during product processing. The aim of this study was to evaluate the effect of gamma irradiation on the chemical composition and specific activity of lipoxygenase in different soybean cultivars. Soybeans were stored in plastic bags and irradiated with doses of 2.5, 5 and 10 kGy. The chemical composition (moisture, protein, lipids, ashes, crude fiber, and carbohydrates) and lipoxygenase specific activity were determined for each sample. Gamma irradiation induced a small increase of protein and lipid content in some soybean cultivars, which did not exceed the highest content of 5% and 26%, respectively, when compared to control. Lipoxygenase specific activity decreased in the three cultivars with increasing gamma irradiation dose. In conclusion, the gamma irradiation doses used are suitable to inactivate part of lipoxygenase while not causing expressive changes in the chemical composition of the cultivars studied.

  8. Involvement of a lipoxygenase-like enzyme in abscisic Acid biosynthesis.

    Science.gov (United States)

    Creelman, R A; Bell, E; Mullet, J E

    1992-07-01

    Several lines of evidence indicate that abscisic acid (ABA) is derived from 9'-cis-neoxanthin or 9'-cis-violaxanthin with xanthoxin as an intermediate. (18)O-labeling experiments show incorporation primarily into the side chain carboxyl group of ABA, suggesting that oxidative cleavage occurs at the 11, 12 (11', 12') double bond of xanthophylls. Carbon monoxide, a strong inhibitor of heme-containing P-450 monooxygenases, did not inhibit ABA accumulation, suggesting that the oxygenase catalyzing the carotenoid cleavage step did not contain heme. This observation, plus the ability of lipoxygenase to make xanthoxin from violaxanthin, suggested that a lipoxygenase-like enzyme is involved in ABA biosynthesis. To test this idea, the ability of several soybean (Glycine max L.) lipoxygenase inhibitors (5,8,11-eicosatriynoic acid, 5,8,11,14-eicosatetraynoic acid, nordihydroguaiaretic acid, and naproxen) to inhibit stress-induced ABA accumulation in soybean cell culture and soybean seedlings was determined. All lipoxygenase inhibitors significantly inhibited ABA accumulation in response to stress. These results suggest that the in vivo oxidative cleavage reaction involved in ABA biosynthesis requires activity of a nonheme oxygenase having lipoxygenase-like properties.

  9. Short-Term Regulation of FcγR-Mediated Phagocytosis by TLRs in Macrophages: Participation of 5-Lipoxygenase Products.

    Science.gov (United States)

    Pinheiro, Carla da S; Monteiro, Ana Paula T; Dutra, Fabiano F; Bozza, Marcelo T; Peters-Golden, Marc; Benjamim, Claudia F; Canetti, Claudio

    2017-01-01

    TLRs recognize a broad spectrum of microorganism molecules, triggering a variety of cellular responses. Among them, phagocytosis is a critical process for host defense. Leukotrienes (LTs), lipid mediators produced from 5-lipoxygenase (5-LO) enzyme, increase FcγR-mediated phagocytosis. Here, we evaluated the participation of TLR2, TLR3, TLR4, and TLR9 in FcγR-mediated phagocytosis and whether this process is modulated by LTs. Rat alveolar macrophages (AMs), murine bone marrow-derived macrophages (BMDMs), and peritoneal macrophages (PMs) treated with TLR2, TLR3, and TLR4 agonists, but not TLR9, enhanced IgG-opsonized sheep red blood cell (IgG-sRBC) phagocytosis. Pretreatment of AMs or BMDMs with drugs that block LT synthesis impaired the phagocytosis promoted by TLR ligands, and TLR potentiation was also abrogated in PMs and BMDMs from 5-LO(-/-) mice. LTB4 production induced by IgG engagement was amplified by TLR ligands, while cys-LTs were amplified by activation of TLR2 and TLR4, but not by TLR3. We also noted higher ERK1/2 phosphorylation in IgG-RBC-challenged cells when preincubated with TLR agonists. Furthermore, ERK1/2 inhibition by PD98059 reduced the phagocytic activity evoked by TLR agonists. Together, these data indicate that TLR2, TLR3, and TLR4 ligands, but not TLR9, amplify IgG-mediated phagocytosis by a mechanism which requires LT production and ERK-1/2 pathway activation.

  10. Inhibitors of 5-lipoxygenase inhibit expression of intercellular adhesion molecule-1 in human melanoma cells

    Institute of Scientific and Technical Information of China (English)

    Yin WANG; Bin ZHOU; Ji LI; Yong-bing CAO; Xin-sheng CHEN; Ming-he CHENG; Ming YIN

    2004-01-01

    AIM: To study the effect of 5-lipoxygenase inhibitors on the expression of intercellular adhesion molecule-1 (ICAM-1) in melanoma cells. METHODS: ICAM-1 protein of human melanoma cell a375 was detected by enzyme-linked immunosorbent, flow cytometry and Western blot analysis. Level of ICAM-1 mRNA in a375 was evaluated by Northern blot analysis. Adhesion of a375 to endothelial cell EC304 was analyzed by isotopic tracing. RESULTS:5-Lipoxygenase inhibitors nordihydroguaiaretic acid, AA861 and MK886, could suppress the expression of ICAM-1 protein as well as of its mRNA in a375 cells and reduce the adhesion of a375 to EC304. CONCLUSION:5-Lipoxygenase inhibitors can inhibit the expression of ICAM-1 in human melanoma cells and may be valuable for treatment of melanoma metastasis.

  11. Biochemical and molecular characterization of hazelnut (Corylus avellana) seed lipoxygenases.

    Science.gov (United States)

    Santino, Angelo; De Paolis, Angelo; Gallo, Antonia; Quarta, Angela; Casey, Rod; Mita, Giovanni

    2003-11-01

    Plant lipoxygenases (LOXs) are a class of dioxygenases which display diverse functions in several physiological processes such as growth, development and response to biotic and abiotic stresses. Even though LOXs have been characterized from several plant species, the physiological role of seed LOXs is still unclear. With the aim to better clarify the occurrence of LOXs and their influence on hazelnut seed quality, we carried out the biochemical and molecular characterization of the main LOX isoforms expressed during seed development. A genomic clone containing a complete LOX gene was isolated and fully characterized. The 9887 bp sequence reported contains an open reading frame of 5334 bp encoding a putative polypeptide of 99 kDa. Semiquantitative RT-PCR carried out from RNAs extracted from seeds at different maturation stages showed that LOXs are mainly expressed at early developmental stages. These results were confirmed by LOX activity assays. Biochemical characterization of the reaction products of the hazelnut LOX indicated that it is a 9-LOX. Two cDNAs were isolated by RT-PCR carried out on total RNA from immature hazelnut seeds. Sequence analysis indicated that the two cDNAs are highly homologous (91.9% degree of identity) and one of these corresponded exactly to the genomic clone. The deduced amino acid sequences of the hazelnut LOXs showed that they are closely related to a previously reported almond LOX (79.5% identity) and, to a lesser extent, to some LOXs involved in plant responses to pathogens (cotton and tobacco LOXs, 75.5 and 74.6% identity, respectively). The physiological role of hazelnut LOXs and their role in influencing seed quality are also discussed.

  12. The structural basis for specificity in lipoxygenase catalysis.

    Science.gov (United States)

    Newcomer, Marcia E; Brash, Alan R

    2015-03-01

    Many intriguing facets of lipoxygenase (LOX) catalysis are open to a detailed structural analysis. Polyunsaturated fatty acids with two to six double bonds are oxygenated precisely on a particular carbon, typically forming a single chiral fatty acid hydroperoxide product. Molecular oxygen is not bound or liganded during catalysis, yet it is directed precisely to one position and one stereo configuration on the reacting fatty acid. The transformations proceed upon exposure of substrate to enzyme in the presence of O2 (RH + O2 → ROOH), so it has proved challenging to capture the precise mode of substrate binding in the LOX active site. Beginning with crystal structures with bound inhibitors or surrogate substrates, and most recently arachidonic acid bound under anaerobic conditions, a picture is consolidating of catalysis in a U-shaped fatty acid binding channel in which individual LOX enzymes use distinct amino acids to control the head-to-tail orientation of the fatty acid and register of the selected pentadiene opposite the non-heme iron, suitably positioned for the initial stereoselective hydrogen abstraction and subsequent reaction with O2 . Drawing on the crystal structures available currently, this review features the roles of the N-terminal β-barrel (C2-like, or PLAT domain) in substrate acquisition and sensitivity to cellular calcium, and the α-helical catalytic domain in fatty acid binding and reactions with O2 that produce hydroperoxide products with regio and stereospecificity. LOX structures combine to explain how similar enzymes with conserved catalytic machinery differ in product, but not substrate, specificities.

  13. 5-Lipoxygenase Deficiency Reduces Acetaminophen-Induced Hepatotoxicity and Lethality

    Directory of Open Access Journals (Sweden)

    Miriam S. N. Hohmann

    2013-01-01

    Full Text Available 5-Lipoxygenase (5-LO converts arachidonic acid into leukotrienes (LTs and is involved in inflammation. At present, the participation of 5-LO in acetaminophen (APAP-induced hepatotoxicity and liver damage has not been addressed. 5-LO deficient (5-LO-/- mice and background wild type mice were challenged with APAP (0.3–6 g/kg or saline. The lethality, liver damage, neutrophil and macrophage recruitment, LTB4, cytokine production, and oxidative stress were assessed. APAP induced a dose-dependent mortality, and the dose of 3 g/kg was selected for next experiments. APAP induced LTB4 production in the liver, the primary target organ in APAP toxicity. Histopathological analysis revealed that 5-LO-/- mice presented reduced APAP-induced liver necrosis and inflammation compared with WT mice. APAP-induced lethality, increase of plasma levels of aspartate aminotransferase and alanine aminotransferase, liver cytokine (IL-1β, TNF-α, IFN-γ, and IL-10, superoxide anion, and thiobarbituric acid reactive substances production, myeloperoxidase and N-acetyl-β-D-glucosaminidase activity, Nrf2 and gp91phox mRNA expression, and decrease of reduced glutathione and antioxidant capacity measured by 2,2′-azinobis(3-ethylbenzothiazoline 6-sulfonate assay were prevented in 5-LO-/- mice compared to WT mice. Therefore, 5-LO deficiency resulted in reduced mortality due to reduced liver inflammatory and oxidative damage, suggesting 5-LO is a promising target to reduce APAP-induced lethality and liver inflammatory/oxidative damage.

  14. Effect of Dietary Stilbenes on 5-Lipoxygenase and Cyclooxygenases Activities In Vitro

    OpenAIRE

    Kutil, Z. (Zsófia); Kvasnicová, M.; Temml, V.; Schuster, D; Maršík, P. (Petr); Cusimamani, E.F.; Lou, J.D.; Vaněk, T. (Tomáš); Landa, P.

    2015-01-01

    Stilbenes contained in various foods are associated with health beneficial effects. In this study six natural and one synthetic stilbene were tested for their potential to regulate the activity of lipoxygenase and cyclooxygenase in vitro. The most potent inhibitor of 5-lipoxygenase was pterostilbene (IC50 = 9.32 mu M), whereas the strongest inhibitor of cyclooxygenase-1 and cyclooxygenase-2 was pinostilbene (IC50s = 1.90 and 0.35 mu M, respectively). Pterostilbene (IC50s = 11.70 and 27.04 mu ...

  15. Blockade of TRPM7 channel activity and cell death by inhibitors of 5-lipoxygenase.

    Directory of Open Access Journals (Sweden)

    Hsiang-Chin Chen

    Full Text Available TRPM7 is a ubiquitous divalent-selective ion channel with its own kinase domain. Recent studies have shown that suppression of TRPM7 protein expression by RNA interference increases resistance to ischemia-induced neuronal cell death in vivo and in vitro, making the channel a potentially attractive pharmacological target for molecular intervention. Here, we report the identification of the 5-lipoxygenase inhibitors, NDGA, AA861, and MK886, as potent blockers of the TRPM7 channel. Using a cell-based assay, application of these compounds prevented cell rounding caused by overexpression of TRPM7 in HEK-293 cells, whereas inhibitors of 12-lipoxygenase and 15-lipoxygenase did not prevent the change in cell morphology. Application of the 5-lipoxygenase inhibitors blocked heterologously expressed TRPM7 whole-cell currents without affecting the protein's expression level or its cell surface concentration. All three inhibitors were also effective in blocking the native TRPM7 current in HEK-293 cells. However, two other 5-lipoxygenase specific inhibitors, 5,6-dehydro-arachidonic acid and zileuton, were ineffective in suppressing TRPM7 channel activity. Targeted knockdown of 5-lipoxygenase did not reduce TRPM7 whole-cell currents. In addition, application of 5-hydroperoxyeicosatetraenoic acid (5-HPETE, the product of 5-lipoxygenase, or 5-HPETE's downstream metabolites, leukotriene B4 and leukotriene D4, did not stimulate TRPM7 channel activity. These data suggested that NDGA, AA861, and MK886 reduced the TRPM7 channel activity independent of their effect on 5-lipoxygenase activity. Application of AA861 and NDGA reduced cell death for cells overexpressing TRPM7 cultured in low extracellular divalent cations. Moreover, treatment of HEK-293 cells with AA861 increased cell resistance to apoptotic stimuli to a level similar to that obtained for cells in which TRPM7 was knocked down by RNA interference. In conclusion, NDGA, AA861, and MK886 are potent blockers of

  16. Lipoxygenase-allene oxide synthase pathway in octocoral thermal stress response

    Science.gov (United States)

    Lõhelaid, H.; Teder, T.; Samel, N.

    2015-03-01

    Marine ecosystems are sensitive to elevated seawater temperature, with stony corals serving as model organisms for temperature-imposed declines in population viability and diversity. Several stress markers, including heat shock proteins, have been used for the detection and prediction of stress responses in stony corals. However, the stress indicators in soft corals remain elusive. In higher animals and plants, oxylipins synthesized by fatty acid di- and monooxygenases contribute to stress-induced signaling; however, the role of eicosanoid pathways in corals remains unclear. The eicosanoid gene specific to corals encodes for a natural fusion protein of allene oxide synthase and lipoxygenase ( AOS- LOX). In this work, using the easily cultivated soft coral Capnella imbricata as the stress response model, we monitored the expression of the AOS-LOX and the formation of arachidonic acid metabolites in response to an acute rise in water temperature. Gene expression profiles of two 70 kDa heat shock proteins ( Hsps: Hsp70 and Grp78) were used as a positive control for the stress response. In comparison with normal seawater temperature (23 °C), AOS- LOXa and Hsps were all up-regulated after modest (28 °C) and severe (31 °C) temperature elevation. While the up-regulation of AOS- LOXa and Grp78 was more sensitive to moderate temperature changes, Hsp70s were more responsive to severe heat shock. Concurrently, endogenous and exogenous AOS-LOXa-derived eicosanoids were up-regulated. Thus, together with the up-regulation of AOS- LOX by other abiotic and biotic stress stimuli, these data implicate AOS-LOX as part of the general stress response pathway in corals.

  17. Just in time: circadian defense patterns and the optimal defense hypothesis.

    Science.gov (United States)

    Baldwin, Ian T; Meldau, Stefan

    2013-06-01

    The optimal defense hypothesis (ODH) provides a functional explanation for the inhomogeneous distribution of defensive structures and defense metabolites throughout a plant's body: tissues that are most valuable in terms of fitness and have the highest probability of attack are generally the best defended. In a previous review, we argue that ontogenically-controlled accumulations of defense metabolites are likely regulated through an integration of developmental and defense signaling pathways. In this addendum, we extend the discussion of ODH patterns by including the recent discoveries of circadian clock-controlled defenses in plants.

  18. Hydroperoxide production from linoleic acid by heterologous Gaeumannomyces graminis tritici lipoxygenase: Optimization and scale-up

    NARCIS (Netherlands)

    Villaverde, J.J.; Vlist, van der V.; Santos, S.A.O.; Haarmann, T.; Langfelder, K.; Pirttimaa, M.; Nyyssola, A.; Jylhä, S.; Tamminen, T.; Kruus, K.; Graaff, de L.H.; Pascoal Neto, C.; Simoes, M.M.Q.; Domingues, M.R.M.; Silvestre, A.J.D.; Eidner, J.; Buchert, J.

    2013-01-01

    Linoleic acid was converted into hydroperoxides by a Gaeumannomyces graminis tritici lipoxygenase produced recombinantly in Trichoderma reesei. Hydroperoxide production was optimized using a face-centred experimental design in order to study the effects of pH, temperature and time on the conversion

  19. In vitro screening of Crataegus succulenta extracts for free radical scavenging and 15-lipoxygenase inhibitory activities.

    Science.gov (United States)

    Bedreag, Catrinel Florentina Giurescu; Trifan, Adriana; Vasincu, Al; Miron, S D; Aprotosoaie, Ana Clara; Miron, Anca

    2014-01-01

    Crataegus succulenta Schrad. ex Link is widely spread in North America. A literature survey revealed no studies on the chemical composition and biological effects of this species. The aim of the present study was to investigate the phenolic content, free radical scavenging and 15-lipoxygenase inhibitory effects of Crataegus succulenta leaf and flower extracts. Total phenolic, flavonoid and proanthocyanidin contents were quantified by spectrophotometric methods. Both extracts were evaluated for their ability to scavenge DPPH, superoxide anion and hydroxyl radicals and to inhibit 15-lipoxygenase activity. There were noticed no striking differences in the total phenolic, flavonoid and proanthocyanidin contents between leaf and flower extracts. Both extracts showed similar 15-lipoxygenase inhibitory effects. Flower extract scavenged more effectively DPPH and superoxide radicals while leave extract was more active against hydroxyl radical. In superoxide anion radical scavenging assay, both extracts were more active than (+)-catechin. In hydroxyl radical scavenging and 15-lipoxygenase inhibition assays, the extracts were only 4-5 times less active than (+)-catechin. The high antioxidant potential of Crataegus succulenta extracts suggest a possible use as ingredients in functional foods for the prevention of oxidative stress-related diseases.

  20. Design, synthesis, and computational studies on dihydropyrimidine scaffolds as potential lipoxygenase inhibitors and cancer chemopreventive agents.

    Science.gov (United States)

    Venugopala, Katharigatta N; Govender, Reshme; Khedr, Mohammed A; Venugopala, Rashmi; Aldhubiab, Bandar E; Harsha, Sree; Odhav, Bharti

    2015-01-01

    Dihydropyrimidine scaffold has a wide range of potential pharmacological activities such as antiviral, antitubercular, antimalarial, anti-inflammatory, and anticancer properties. 5-Lipoxygenase enzyme is an enzyme responsible for the metabolism of arachidonic acid to leukotrienes. The elevated levels of this enzyme and its metabolites in cancer cells have a direct relation on the development of cancer when compared to normal cells. The development of novel lipoxygenase inhibitors can have a major role in cancer therapy. A series of substituted 1,4-dihydropyrimidine analogues were synthesized and characterized by (1)H-NMR, (13)C-NMR, and HRMS. Molecular docking against lipoxygenase enzyme (protein data bank code =3V99) was done using Molecular Operating Environment 2013.08 and Leadit 2.1.2 softwares and showed high affinities. The synthesized compounds were tested for their lipoxygenase inhibitory activity and showed inhibition ranging from 59.37%±0.66% to 81.19%±0.94%. The activity was explained by a molecular docking study. The title compounds were also tested for cytotoxic activity against two human cancer cell lines Michigan Cancer Foundation-7 and human melanoma cells and a normal peripheral blood mononuclear cell line.

  1. Modulation of soybean lipoxygenase expression and membrane oxidation by water deficit

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Maccarrone, M.; Veldink, G.A.; Finazzi Agrò, A.

    1995-01-01

    The modulation of the activity and expression of soybean lipoxygenases 1 (LOX-1) [Vliegenthart, J.F.G. and Veldink, G.A. (1982) in: Free Radicals in Biology (Pryor, W.A., Ed.) pp. 29–64, Academic Press, New York] and 2 (LOX-2) by water deficit (osmotic stress) has been investigated, by following gen

  2. THE 5-LIPOXYGENASE PATHWAY IS REQUIRED FOR ACUTE LUNG INJURY FOLLOWING HEMORRHAGIC SHOCK

    Science.gov (United States)

    Eun, John C.; Moore, Ernest E.; Mauchley, David C.; Johnson, Chris A.; Meng, Xianzhong; Banerjee, Anirban; Wohlauer, Max V.; Zarini, Simona; Gijón, Miguel A.; Murphy, Robert C.

    2012-01-01

    The cellular and biochemical mechanisms leading to acute lung injury and subsequent multiple organ failure are only partially understood. In order to study the potential role of eicosanoids, particularly leukotrienes, as possible mediators of acute lung injury, we used a murine experimental model of acute lung injury induced by hemorrhagic shock after blood removal via cardiac puncture. Neutrophil sequestration as shown by immunofluorescence, and protein leakage into the alveolar space, were measured as markers of injury. We used liquid chromatography coupled to tandem mass spectrometry to unequivocally identify several eicosanoids in the bronchoalveolar lavage fluid of experimental animals. MK886, a specific inhibitor of the 5-lipoxygenase pathway, as well as transgenic mice deficient in 5-lipoxygenase, were used to determine the role of this enzymatic pathway in this model. Leukotriene B4 and leukotriene C4 were consistently elevated in shock-treated mice compared to sham-treated mice. MK886 attenuated neutrophil infiltration and protein extravasation induced by hemorrhagic shock. 5-lipoxygenase-deficient mice showed reduced neutrophil infiltration and protein extravasation after shock treatment, indicating greatly reduced lung injury. These results support the hypothesis that 5-lipoxygenase, most likely through the generation of leukotrienes, plays an important role in the pathogenesis of acute lung injury induced by hemorrhagic shock in mice. This pathway could represent a new target for pharmacological intervention to reduce lung damage following severe primary injury. PMID:22392149

  3. Purification and some properties of African oil bean seed lipoxygenase--Part 1.

    Science.gov (United States)

    Anokwulu, M N

    2003-11-01

    Lipoxygenase was extracted from African oil bean seed and purified by ammonium sulphate precipitation, gel filtration on Sephadex G-25 and ion-exchange chromatography on DEAE--cellulose column. The enzyme was purified 79.63 fold and 36% of the enzyme activity was recovered. The molecular weight of the enzyme was 102,000 daltons and the peroxide value was 10.56 x 10(-3) mM. The Vmax was 0.14 OD min-1 while the Km value was 1.92 x 10(-4) M. The enzyme had an optimum pH of 7.0 and optimum temperature of 30 degrees C. While diethyl-dithiocarbamate was the best inhibitor of the enzyme's oxidation of linoleic acid, nordihydroguiaretic acid was the best antioxidant for its oxidation of the fatty acid. African oil bean seed lipoxygenase had high enzyme activity of 86% when compared to soybean lipoxygenase (considered to be the best source of the enzyme). This means that African oil bean seed is a good source of lipoxygenase for biotechnology such as the bleaching of browned yam tubers.

  4. Role of epidermis-type lipoxygenases for skin barrier function and adipocyte differentiation

    DEFF Research Database (Denmark)

    Fürstenberger, Gerhard; Epp, Nikolas; Eckl, Katja-Martina

    2007-01-01

    12R-lipoxygenase (12R-LOX) and epidermis-type LOX-3 (eLOX-3) are novel members of the multigene family of mammalian LOX. A considerable gap exists between the identification of these enzymes and their biologic function. Here, we present evidence that 12R-LOX and eLOX-3, acting in sequence, and e...

  5. N-Substituted pyrazole-3-carboxamides as inhibitors of human 15-lipoxygenase.

    Science.gov (United States)

    Pelcman, Benjamin; Sanin, Andrei; Nilsson, Peter; Schaal, Wesley; Olofsson, Kristofer; Krog-Jensen, Christian; Forsell, Pontus; Hallberg, Anders; Larhed, Mats; Boesen, Thomas; Kromann, Hasse; Claesson, Hans-Erik

    2015-08-01

    High-throughput screening was used to find selective inhibitors of human 15-lipoxygenase-1 (15-LOX-1). One hit, a 1-benzoyl substituted pyrazole-3-carboxanilide (1a), was used as a starting point in a program to develop potent and selective 15-LOX-1 inhibitors.

  6. The pepper GNA-related lectin and PAN domain protein gene, CaGLP1, is required for plant cell death and defense signaling during bacterial infection.

    Science.gov (United States)

    Kim, Nak Hyun; Lee, Dong Hyuk; Choi, Du Seok; Hwang, Byung Kook

    2015-12-01

    Carbohydrate-binding proteins, commonly referred to as lectins or agglutinins, function in defense responses to microbial pathogens. Pepper (Capsicum annuum) GNA-related lectin and PAN-domain protein gene CaGLP1 was isolated and functionally characterized from pepper leaves infected with Xanthomonas campestris pv. vesicatoria (Xcv). CaGLP1 contained an amine-terminus prokaryotic membrane lipoprotein lipid attachment site, a Galanthus nivalis agglutinin (GNA)-related lectin domain responsible for the recognition of high-mannose N-glycans, and a carboxyl-terminus PAN/apple domain. RNA gel blot and immunoblot analyses determined that CaGLP1 was strongly induced in pepper by compatible and incompatible Xcv infection. CaGLP1 protein localized primarily to the plasma membrane and exhibited mannose-binding specificity. CaGLP1-silenced pepper plants were more susceptible to compatible or incompatible Xcv infection compared with that of non-silenced control plants. CaGLP1 silencing in pepper leaves did not accumulate H2O2 and induce cell death during incompatible Xcv infection. Defense-related CaDEF1 (defensin) gene expression was significantly reduced in CaGLP1-silenced pepper plants. CaGLP1-overexpression in Arabidopsis thaliana enhanced resistance to Pseudomonas syringae pv. tomato. Defense-related AtPDF1.2 expression was elevated in CaGLP1-overexpression lines. Together, these results suggest that CaGLP1 is required for plant cell death and defense responses through the reactive oxygen species burst and downstream defense-related gene expression in response to bacterial pathogen challenge.

  7. 植物的防御性萜类挥发信号分子%Plant Terpenoid Volatiles as Defensive Signals

    Institute of Scientific and Technical Information of China (English)

    吴燕; 郭蕴斐; 卢山

    2012-01-01

    植物生长发育过程中会合成大量萜类化合物,其中多数具有挥发性.这些挥发性萜类成分除参与保护光合器官免受光合作用产生的热量灼伤之外,还作为信号分子参与了大量的化学生态过程,例如对昆虫和其他动物的吸引以利于花粉和种子的传播.另一方面,自上世纪80年代以来,逐渐有研究工作表明,挥发性萜类化合物也可以作为信号介导植物对植食性昆虫的防御反应,以及在植物-害虫-天敌的三级营养关系中发挥作用.同时,研究工作还显示萜类化合物可以作为信号在同株植物的不同部位之间及邻近植物之间进行有效传递以促进对虫害的防御,并证明了这些萜类分子在细胞和分子水平上的调控作用.这些工作为利用化学生态学手段对虫害进行有效控制提供了新的策略,文章仅就近年来对植物萜类挥发信号分子在合成、识别、传输及其作用等方面的研究进展做简要回顾.%Plants synthesize and emit a large amount of terpenoid constituents during their growth and development. Most terpenoids are volatile. Their emission functions not only in the protection of photosynthetic organ-elles against overheating, but also in the chemical ecological processes, e.g. the attraction of insects and other animals for the dispersal of seeds and pollens. However, from the 1980s, accumulative evidences showed that plants could use volatile terpenoids in their defensive responses against herbivore insects, and also use them to mediate tritrophic nutritional interactions among plants, herbivores and natural enemies. Other work also proved that volatile terpenoids could carry signals from attacked plant to other plants nearby. It has been deciphered step by step that volatile terpenoids could regulate plant activities at both cellular and molecular levels, and this provides a feasible strategy for effective pest control by chemical ecological methods. The progresses

  8. Leukotrienes and other lipoxygenase products of arachidonic acid synthesized in the kidney.

    Science.gov (United States)

    Ardaillou, R; Baud, L; Sraer, J

    1986-08-25

    Lipoxygenase products are synthesized in the kidney. Rabbit medulla and murine and human glomeruli produce 12- and 15-hydroxy-5,8,10,14-eicosatetraenoic acid (HETE). Minor amounts of leukotrienes are formed under normal conditions, but it is likely that the resident renal cells are capable of synthesizing these metabolites. Rat glomeruli and papillae possess the enzymes necessary to process leukotriene C4 into leukotrienes D4 and E4. However, the enzyme activity of the papillae is masked due to the presence of an inhibitor detected in the 10,000 g supernate of the papillary homogenate. 12-HETE synthesis is markedly increased in glomeruli from rats with nephrotoxic serum nephritis and leukotriene B4 synthesis in glomeruli from rats with cationic bovine gamma-globulin-induced glomerulonephritis. In vivo consequences of the association between the resident glomerular cells and the bone marrow-derived cells have been studied in vitro in co-incubation experiments. Glomeruli release factors that stimulate the cyclo-oxygenase and lipoxygenase pathways in macrophages. Co-incubation of glomeruli, platelets, and polymorphonuclear leukocytes results in the formation of 12,20-diHETE and an excess of 12-HETE. Lipoxygenase products, regardless of their origin, modify the renal functions. Leukotriene C4 binds specifically to rat glomeruli and human cultured glomerular epithelial cells. Leukotrienes C4 or D4 administered in vivo cause renal vasoconstriction and a decline in the glomerular filtration rate. In vitro, these two sulfidopeptide leukotrienes promote epithelial cell proliferation and produce mesangial cell contraction. The lipoxygenase pathway is also implicated in the attachment of macrophages to glomeruli and in the oxidative burst of glomerular mesangial cells during phagocytosis. The future use of specific inhibitors of the synthesis or antagonists of the lipoxygenase products, particularly the leukotrienes, should provide a tool for evaluating the role of these

  9. Genetic ablation and short-duration inhibition of lipoxygenase results in increased macroautophagy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Insook; Park, Sujin; Cho, Jin Won [Department of Integrated OMICS for Biomedical Science, WCU Program of Graduate School, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Yigitkanli, Kazim; Leyen, Klaus van [Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129 (United States); Roth, Jürgen, E-mail: jurgen.roth@bluewin.ch [Department of Integrated OMICS for Biomedical Science, WCU Program of Graduate School, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

    2014-02-15

    12/15-lipoxygenase (12/15-LOX) is involved in organelle homeostasis by degrading mitochondria in maturing red blood cells and by eliminating excess peroxisomes in liver. Furthermore, 12/15-LOX contributes to diseases by exacerbating oxidative stress-related injury, notably in stroke. Nonetheless, it is unclear what the consequences are of abolishing 12/15-LOX activity. Mice in which the alox15 gene has been ablated do not show an obvious phenotype, and LOX enzyme inhibition is not overtly detrimental. We show here that liver histology is also unremarkable. However, electron microscopy demonstrated that 12/15-LOX knockout surprisingly leads to increased macroautophagy in the liver. Not only macroautophagy but also mitophagy and pexophagy were increased in hepatocytes, which otherwise showed unaltered fine structure and organelle morphology. These findings were substantiated by immunofluorescence showing significantly increased number of LC3 puncta and by Western blotting demonstrating a significant increase for LC3-II protein in both liver and brain homogenates of 12/15-LOX knockout mice. Inhibition of 12/15-LOX activity by treatment with four structurally different inhibitors had similar effects in cultured HepG2 hepatoma cells and SH-SY5Y neuroblastoma cells with significantly increased autophagy discernable already after 2 hours. Hence, our study reveals a link between ablation or inhibition of 12/15-LOX and stimulation of macroautophagy. The enhanced macroautophagy may be related to the known tissue-protective effects of LOX ablation or inhibition under various diseased conditions caused by oxidative stress and ischemia. This could provide an important cleaning mechanism of cells and tissues to prevent accumulation of damaged mitochondria and other cellular components. - Highlights: • A relationship between lipoxygenases and autophagy is disclosed. • 12/15-lipoxygenase knockout increases autophagy in mice liver and brain. • Lipoxygenase inhibition boosts

  10. Properties of a complex of Fe(III)-soybean lipoxygenase-1 and 4-nitrocatechol.

    Science.gov (United States)

    Spaapen, L J; Verhagen, J; Veldink, G A; Vliegenthart, J F

    1980-01-18

    Fe(III)-soybean lipoxygenase-1 yields with 4-nitrocatechol a green coloured 1 : 1 complex, which shows at pH 7.0 absorption maxima at 385 nm and 650 nm. The formation of this complex is reversible. The circular dichroism spectrum of the complex of Fe(III)-lipoxygenase-1 and 4-nitrocatechol has a positive band at around 380 nm and a negative band at around 450 nm and is significantly different from that of the Fe(III)-enzyme as such. 4-Nitrocatechol can be displaced from the green complex by 13-L-hydroperoxy-cis-9, trans-11-octadecadienoic acid, resulting in the formation of the blue complex between the Fe(III)-enzyme and 13-L-hydroperoxy-cis-9,trans-11-octadecadienoic acid both under aerobic and anaerobic conditions. Also linoleic acid competes with 4-nitrocatechol for the binding site on the Fe(III)-enzyme, as can be demonstrated under anaerobic conditions, ultimately leading to reduction of the Fe(III)-enzyme. The oxygenation of linoleic acid by Fe(III)-lipoxygenase-1 is inhibited by 4-nitrocatechol. From steady-state kinetics a non-competitive inhibition pattern is obtained. Probably it has to be considered as pseudo non-competitive because of the slow establishment of the complex equilibrium. An inhibition constant (K4NC) of 16.3 microM is found. On prolonged incubation of Fe(III)-lipoxygenase-1 and 4-nitrocatechol the green complex converts into a brown species. This conversion is found to be coupled with a change in the nature of the inhibition from reversible to irreversible. A complex between native lipoxygenase-1 and 4-nitrocatechol is found to be unlikely.

  11. Reactive oxygen species and lipoxygenases regulate the oncogenicity of NPM-ALK-positive anaplastic large cell lymphomas.

    Science.gov (United States)

    Thornber, K; Colomba, A; Ceccato, L; Delsol, G; Payrastre, B; Gaits-Iacovoni, F

    2009-07-23

    The chimera nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), the tyrosine kinase activity of which is constitutively upregulated, is the causative agent of 75% of the anaplastic large-cell lymphomas (ALCLs). We have demonstrated that NPM-ALK induces the production of reactive oxygen species (ROS) by a pathway involving the arachidonic acid-metabolizing enzymes of the lipoxygenase (LOX) family. The use of the LOX inhibitor nordihydroguaiaretic acid (NDGA) and of the anti-oxidant N-acetylcysteine (NAC) demonstrated that ROS are important in maintaining the ALK kinase active. Consistent with this, NDGA treatment resulted in the inhibition of key pathways, such as Akt, signal transducer and activator of transcription factor 3 (STAT3) and extracellular signal-regulated kinase (ERK), which are involved in NPM-ALK antiapoptotic and pro-mitogenic functions. Conversely, the stress-activated kinase p38, described in some instances as a mediator of apoptosis, was activated. Interestingly, 5-LOX, an isoform involved in many cancers, was found to be activated in NPM-ALK(+) cells. Functional studies have shown that transforming properties, namely proliferation and resistance to apoptosis, were abrogated by treatment with either NDGA or the 5-LOX inhibitor (N-(3-phenoxycinnamyl)-acetohydroxamic acid) (BW A4C). Together, these data point to the ROS/LOX pathway as a potential new target for therapy in NPM-ALK-positive tumors.

  12. Prosystemin overexpression induces transcriptional modifications of defense-related and receptor-like kinase genes and reduces the susceptibility to Cucumber mosaic virus and its satellite RNAs in transgenic tomato plants

    Science.gov (United States)

    Bubici, Giovanni; Carluccio, Anna Vittoria; Stavolone, Livia

    2017-01-01

    Systemin is a plant signal peptide hormone involved in the responses to wounding and insect damage in the Solanaceae family. It works in the same signaling pathway of jasmonic acid (JA) and enhances the expression of proteinase inhibitors. With the aim of studying a role for systemin in plant antiviral responses, a tomato (Solanum lycopersicum) transgenic line overexpressing the prosystemin cDNA, i.e. the systemin precursor, was inoculated with Cucumber mosaic virus (CMV) strain Fny supporting either a necrogenic or a non-necrogenic satellite RNA (satRNA) variant. Transgenic plants showed reduced susceptibility to both CMV/satRNA combinations. While symptoms of the non-necrogenic inoculum were completely suppressed, a delayed onset of lethal disease occurred in about half of plants challenged with the necrogenic inoculum. RT-qPCR analysis showed a correlation between the systemin-mediated reduced susceptibility and the JA biosynthetic and signaling pathways (e.g. transcriptional alteration of lipoxygenase D and proteinase inhibitor II). Moreover, transgenically overexpressed systemin modulated the expression of a selected set of receptor-like protein kinase (RLK) genes, including some playing a known role in plant innate immunity. A significant correlation was found between the expression profiles of some RLKs and the systemin-mediated reduced susceptibility to CMV/satRNA. These results show that systemin can increase plant defenses against CMV/satRNA through transcriptional reprogramming of diverse signaling pathways. PMID:28182745

  13. A lipoxygenase from red alga Pyropia haitanensis, a unique enzyme catalyzing the free radical reactions of polyunsaturated fatty acids with triple ethylenic bonds.

    Science.gov (United States)

    Zhu, Zhujun; Qian, Feijian; Yang, Rui; Chen, Juanjuan; Luo, Qijun; Chen, Haimin; Yan, Xiaojun

    2015-01-01

    Lipoxygenases (LOXs) are key enzymes to regulate the production of hormones and defensive metabolites in plants, animals and algae. In this research, a full length LOX gene has been cloned and expressed from the red alga Pyropia haitanensis (Bangiales, Rhodophyta) gametophyte (PhLOX2). Subsequent phylogenetic analysis showed that such LOX enzymes are separated at the early stage of evolution, establishing an independent branch. The LOX activity was investigated at the optimal pH of 8.0. It appears that PhLOX2 is a multifunctional enzyme featuring both lipoxygenase and hydroperoxidase activities. Additionally, PhLOX2 exhibits remarkable substrate and position flexibility, and it can catalyze an array of chemical reactions involving various polyunsaturated fatty acids, ranging from C18 to C22. As a matter of fact, mono-hydroperoxy, di-hydroperoxy and hydroxyl products have been obtained from such transformations, and eicosapentaenoic acid seem to be the most preferred substrate. It was found that at least triple ethylenic bonds are required for PhLOX2 to function as a LOX, and the resulting hydroxy products should be originated from the PhLOX2 mediated reduction of mono-hydroperoxides, in which the hydrogen abstraction occurs on the carbon atom between the second and third double bond. Most of the di-hydroperoxides observed seem to be missing their mono-position precursors. The substrate and position flexibility, as well as the function versatility of PhLOXs represent the ancient enzymatic pathway for organisms to control intracellular oxylipins.

  14. A fungal catalase reacts selectively with the 13S fatty acid hydroperoxide products of the adjacent lipoxygenase gene and exhibits 13S-hydroperoxide-dependent peroxidase activity.

    Science.gov (United States)

    Teder, Tarvi; Boeglin, William E; Schneider, Claus; Brash, Alan R

    2017-03-28

    The genome of the fungal plant pathogen Fusarium graminearum harbors six catalases, one of which has the sequence characteristics of a fatty acid peroxide-metabolizing catalase. We cloned and expressed this hemoprotein (designated as Fg-cat) along with its immediate neighbor, a 13S-lipoxygenase (cf. Brodhun et al., PloS One, e64919, 2013) that we considered might supply a fatty acid hydroperoxide substrate. Indeed, Fg-cat reacts abruptly with the 13S-hydroperoxide of linoleic acid (13S-HPODE) with an initial rate of 700-1300s(-1). By comparison there was no reaction with 9R- or 9S-HPODEs and extremely weak reaction with 13R-HPODE (~0.5% of the rate with 13S-HPODE). Although we considered Fg-cat as a candidate for the allene oxide synthase of the jasmonate pathway in fungi, the main product formed from 13S-HPODE was identified by UV, MS, and NMR as 9-oxo-10E-12,13-cis-epoxy-octadecenoic acid (with no traces of AOS activity). The corresponding analog is formed from the 13S-hydroperoxide of α-linolenic acid along with novel diepoxy-ketones and two C13 aldehyde derivatives, the reaction mechanisms of which are proposed. In a peroxidase assay monitoring the oxidation of ABTS, Fg-cat exhibited robust activity (kcat 550s(-1)) using the 13S-hydroperoxy-C18 fatty acids as the oxidizing co-substrate. There was no detectable peroxidase activity using the corresponding 9S-hydroperoxides, nor with t-butyl hydroperoxide, and very weak activity with H2O2 or cumene hydroperoxide at micromolar concentrations of Fg-cat. Fg-cat and the associated lipoxygenase gene are present together in fungal genera Fusarium, Metarhizium and Fonsecaea and appear to constitute a partnership for oxidations in fungal metabolism or defense.

  15. Calculations of hydrogen tunnelling and enzyme catalysis: a comparison of liver alcohol dehydrogenase, methylamine dehydrogenase and soybean lipoxygenase

    Science.gov (United States)

    Tresadern, Gary; McNamara, Jonathan P.; Mohr, Matthias; Wang, Hong; Burton, Neil A.; Hillier, Ian H.

    2002-06-01

    Although the potential energy barrier for hydrogen transfer is similar for the enzymes liver alcohol dehydrogenase, methylamine dehydrogenase and soybean lipoxygenase, the degree of tunnelling is predicted to differ greatly, and is reflected by their primary kinetic isotope effects.

  16. Bioactivation of aflatoxin B1 by lipoxygenases, prostaglandin H synthase and cytochrome P450 monooxygenase in guinea-pig tissues.

    Science.gov (United States)

    Liu, L; Massey, T E

    1992-04-01

    In the present investigation, we have examined the role of lipoxygenases in the bioactivation of aflatoxin B1 (AFB1) in hepatic and extrahepatic tissues. The enzyme activities were evaluated by determining [3H]AFB1-DNA adduct formation. The results demonstrated that both purified soybean lipoxygenase and guinea-pig tissue cytosolic lipoxygenases were able to activate AFB1 to form [3H]AFB1-DNA adduct(s). The reaction was completely inhibited by nordihydroguaiaretic acid (NDGA, 0.1 mM), a lipoxygenase inhibitor and an antioxidant, but not by indomethacin (0.1 mM), an inhibitor of prostaglandin H synthase (PHS), indicating that this reaction is associated with lipoxygenase activity, and/or is involved in a peroxyl radical process. While purified lipoxygenase showed arachidonic acid (AA)-dependent properties, the omission of AA did not diminish guinea-pig tissue cytosolic [3H]AFB1-DNA adduct formation, possibly because AA was released from lipid particles by AFB1. Within the range of hemoglobin (Hb) concentrations found in lung, kidney and liver cytosols (1.4-11.1 microM) and microsomes (0-0.5 microM), neither pure Hb, nor Hb of cytosols or microsomes from whole blood caused detectable AA-dependent AFB1-DNA binding. This indicates that Hb, as a contaminant with quasi-lipoxygenase activity, did not contribute to AFB1 activation attributed to guinea-pig tissue lipoxygenases. [3H]AFB1 concentrations at half-maximal DNA binding rate of pulmonary cytochrome P450 monooxygenases (P450) and lipoxygenases were similar, though P450 had a much higher maximum DNA binding rate. Pulmonary microsomal PHS activity for AFB1 activation was too low for its half-maximal binding concentrations of [3H]AFB1 and maximum rate to be accurately determined. In kidney, maximum rates for lipoxygenase, PHS and P450 were similar, whereas half-maximal binding concentrations for reactions by lipoxygenase and P450 were lower compared to that of PHS. The half-maximal binding concentration of hepatic

  17. Short-Term Regulation of FcγR-Mediated Phagocytosis by TLRs in Macrophages: Participation of 5-Lipoxygenase Products

    Directory of Open Access Journals (Sweden)

    Carla da S. Pinheiro

    2017-01-01

    Full Text Available TLRs recognize a broad spectrum of microorganism molecules, triggering a variety of cellular responses. Among them, phagocytosis is a critical process for host defense. Leukotrienes (LTs, lipid mediators produced from 5-lipoxygenase (5-LO enzyme, increase FcγR-mediated phagocytosis. Here, we evaluated the participation of TLR2, TLR3, TLR4, and TLR9 in FcγR-mediated phagocytosis and whether this process is modulated by LTs. Rat alveolar macrophages (AMs, murine bone marrow-derived macrophages (BMDMs, and peritoneal macrophages (PMs treated with TLR2, TLR3, and TLR4 agonists, but not TLR9, enhanced IgG-opsonized sheep red blood cell (IgG-sRBC phagocytosis. Pretreatment of AMs or BMDMs with drugs that block LT synthesis impaired the phagocytosis promoted by TLR ligands, and TLR potentiation was also abrogated in PMs and BMDMs from 5-LO−/− mice. LTB4 production induced by IgG engagement was amplified by TLR ligands, while cys-LTs were amplified by activation of TLR2 and TLR4, but not by TLR3. We also noted higher ERK1/2 phosphorylation in IgG-RBC-challenged cells when preincubated with TLR agonists. Furthermore, ERK1/2 inhibition by PD98059 reduced the phagocytic activity evoked by TLR agonists. Together, these data indicate that TLR2, TLR3, and TLR4 ligands, but not TLR9, amplify IgG-mediated phagocytosis by a mechanism which requires LT production and ERK-1/2 pathway activation.

  18. A proposed interplay between peroxidase, amine oxidase and lipoxygenase in the wounding-induced oxidative burst in Pisum sativum seedlings.

    Science.gov (United States)

    Roach, Thomas; Colville, Louise; Beckett, Richard P; Minibayeva, Farida V; Havaux, Michel; Kranner, Ilse

    2015-04-01

    Plant surfaces form the barrier between a plant and its environment. Upon damage, the wound healing process begins immediately and is accompanied by a rapid production of extracellular reactive oxygen species (ROS), essential in deterring pathogens, signalling responses and cell wall restructuring. Although many enzymes produce extracellular ROS, it is unclear if ROS-producing enzymes act synergistically. We characterised the oxidative burst of superoxide (O2(·-)) and hydrogen peroxide (H2O2) that follows wounding in pea (Pisum sativum L.) seedlings. Rates of ROS production were manipulated by exogenous application of enzyme substrates and inhibitors. The results indicate significant roles for di-amine oxidases (DAO) and peroxidases (Prx) rather than NADPH oxidase. The burst of O2(·-) was strongly dependent on the presence of H2O2 produced by DAO. Potential substrates released from wounded seedlings included linoleic acid that, upon exogenous application, strongly stimulated catalase-sensitive O2(·-) production. Moreover, a 65kD plasma membrane (PM) guaiacol Prx was found in the secretome of wounded seedlings and showed dependence on linoleic acid for O2(·-) production. Lipoxygenases are suggested to modulate O2(·-) production by consuming polyunsaturated fatty acids in the apoplast. Overall, a O2(·-)-producing mechanism involving H2O2-derived from DAO, linoleic acid and a PM-associated Prx is proposed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Biological evaluation of potent antioxidant, lipoxygenase inhibitor and antibacterial: A comparative study

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam

    2016-01-01

    Full Text Available Three biologically active new Schiff bases, 2-[(3-hydroxybenzylideneamino]phenol 5, 2-[(4-hydroxybenzylideneamino]phenol 6 and 4-[(2-hydroxyphenyliminomethyl]benzene-1,3-diol 7, were synthesized by the reaction of 2-aminophenol 1 with three different hydroxyl-benzaldehydes 2–4. They were characterized by spectroscopic analysis (IR, 1H NMR, EI-MS along with elemental analyses. The products were biological screened out for antioxidant, lipoxygenase inhibition, antibacterial and urease inhibition activities. The compounds 5 and 6 showed potent while 7 showed moderate antioxidant activity. Compound 6 showed potent whereas 5 and 7 showed significant lipoxygenase inhibition activity. All the target compounds showed excellent activities against Staphylococcus intermedius, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Salmonella typhi bacteria. All the compounds showed non-significant activity against urease enzyme.

  20. Altered gravity modulates 5-lipoxygenase in human erythroleukemia K562 cells.

    Science.gov (United States)

    Maccarrone, M; Putti, S; Finazzi Agro, A

    1998-07-01

    Mammalian lipoxygenases catalyse the first committed step in the so-called "arachidonate cascade", leading to the production of potent bioactive molecules, such as leukotrienes, lipoxins and hepoxilins. Leukotrienes interact with G protein-couple receptors involved in neuronal plasticity and T lymphocyte activation, lipoxins activate leukocytes, hepoxilines control the insulin release and stimulate the phospholipase C. Lipoxygenase (linoleate:oxygen oxidoreductase; E.C. 1.13.11.34; 5-LOX) are responsible for lymphocyte maturation and programmed death (apoptosis) of neuronal cells. Therefore, 5-LOX might be Space relevant, because among the most striking effects of Space enviroment are indeed those on T lymphocyte activation, neuronal cell growth and suspectedly apoptosis. In this study, the possible effects of the force of gravity on the activity and expression of 5-LOX have been investigated by subjecting human erythroleukemia K562 cells to simulated hypogravity or hypergravity.

  1. 5-Lipoxygenase deficiency impairs innate and adaptive immune responses during fungal infection.

    Directory of Open Access Journals (Sweden)

    Adriana Secatto

    Full Text Available 5-Lipoxygenase-derived products have been implicated in both the inhibition and promotion of chronic infection. Here, we sought to investigate the roles of endogenous 5-lipoxygenase products and exogenous leukotrienes during Histoplasma capsulatum infection in vivo and in vitro. 5-LO deficiency led to increased lung CFU, decreased nitric oxide production and a deficient primary immune response during active fungal infection. Moreover, H. capsulatum-infected 5-LO(-/- mice showed an intense influx of neutrophils and an impaired ability to generate and recruit effector T cells to the lung. The fungal susceptibility of 5-LO(-/- mice correlated with a lower rate of macrophage ingestion of IgG-H. capsulatum relative to WT macrophages. Conversely, exogenous LTB4 and LTC4 restored macrophage phagocytosis in 5-LO deficient mice. Our results demonstrate that leukotrienes are required to control chronic fungal infection by amplifying both the innate and adaptive immune response during histoplasmosis.

  2. Isolation and characterization of wild-type lipoxygenase LOX(Psa)1 from Pleurotus sapidus.

    Science.gov (United States)

    Plagemann, Ina; Krings, Ulrich; Berger, Ralf G

    2014-01-01

    The lipoxygenase LOX(Psa) 1 of Pleurotus sapidus, originally investigated because of its ability to oxidize (+)-valencene to the valuable grapefruit aroma (+)-nootkatone, was isolated from the peptidase-rich lyophilisate using a three-step purification scheme including preparative isoelectric focusing and chromatographic techniques. Nano-liquid chromatography electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS) of the purified enzyme and peptide mass fingerprint analysis gave 38 peptides of the lipoxygenase from P. sapidus. Nearly 50% of the 643 amino acids long sequence encoded by the cDNA was covered. Both terminal peptides of the native LOX(Psa) 1 were identified by de novo sequencing, and the postulated molecular mass of 72.5 kDa was confirmed. With linoleic acid as the substrate, the LOX(Psa)1 showed a specific activity of 113 U mg(-1) and maximal activity at pH 7.0 and 30 degrees C, respectively.

  3. Structure and kinetics of formation of catechol complexes of ferric soybean lipoxygenase-1

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, M.J.; Brennan, B.A.; Chase, D.B. [E.I. du Pont de Nemours & Co., Wilmington, DE (United States)]|[Haverford College, PA (United States)] [and others

    1995-11-21

    Ferric soybean lipoxygenase forms stable complexes with 4-substituted catechols. The structure of the complex between the enzyme and 3,4-dihydroxybenzonitrile has been studied by resonance Raman, electron paramagnetic resonance, visible, and X-ray spectroscopies. It is a bidentate iron-catecholate complex with at least one water ligand. The kinetics of formation of complexes between lipoxygenase and 3,4-dihydroxybenzonitrile and 3,4-dihydroxyacetophenone have been studied by stopped-flow spectroscopy. The data are consistent with two kinetically distinct, reversible steps. The pH dependence of the first step suggests that the substrate for the reaction is the catechol monoanion. When these results are combined, plausible mechanisms for the complexation reaction are suggested. 51 refs., 12 figs., 2 tabs.

  4. A trichome-specific linoleate lipoxygenase expressed during pyrethrin biosynthesis in pyrethrum

    DEFF Research Database (Denmark)

    Ramirez, Aldana M; Yang, Ting; Bouwmeester, Harro J

    2013-01-01

    The lipid precursor alcohols of pyrethrins-jasmolone, pyrethrolone and cinerolone-have been proposed as sharing parts of the oxylipin pathway with jasmonic acid. This implies that one of the first committed steps of pyrethrin biosynthesis is catalyzed by a lipoxygenase, catalyzing the hydroperoxi......The lipid precursor alcohols of pyrethrins-jasmolone, pyrethrolone and cinerolone-have been proposed as sharing parts of the oxylipin pathway with jasmonic acid. This implies that one of the first committed steps of pyrethrin biosynthesis is catalyzed by a lipoxygenase, catalyzing...... the hydroperoxidation of linolenic acid at position 13. Previously, we showed that the expression and activity of chrysanthemyl diphosphate synthase (TcCDS), the enzyme catalyzing the first committed step in the biosynthesis of the acid moiety of pyrethrins, is trichome-specific and developmentally regulated in flowers...

  5. Chemoprevention of Prostate Cancer Initiation in a Novel Transgenic Mouse Model by Targeting 15-Lipoxygenase-1

    Science.gov (United States)

    2012-02-01

    chemoprevention studies. Diets rich in either omega (ω)-3 or ω-6 polyunsaturated fatty acids ( PUFAs ) directly impact PCa tumor growth. Furthermore... acids effects on PIN development. 15. SUBJECT TERMS Diet, polyunsaturated fatty acids ( PUFAs ), 15-lipoxygenase-1, cyclooxygenase, prostate cancer...compared to FLiMP+/+ mice fed a normal diet (PIN observed) and, (3) Our study in year 2 provided mechanistic roles of omega (ω)-3 fatty acids in slowing

  6. Helicobacter pylori urease activates blood platelets through a lipoxygenase-mediated pathway.

    Science.gov (United States)

    Wassermann, German E; Olivera-Severo, Deiber; Uberti, Augusto F; Carlini, Célia R

    2010-07-01

    The bacterium Helicobacter pylori causes peptic ulcers and gastric cancer in human beings by mechanisms yet not fully understood. H. pylori produces urease which neutralizes the acidic medium permitting its survival in the stomach. We have previously shown that ureases from jackbean, soybean or Bacillus pasteurii induce blood platelet aggregation independently of their enzyme activity by a pathway requiring platelet secretion, activation of calcium channels and lipoxygenase-derived eicosanoids. We investigated whether H. pylori urease displays platelet-activating properties and defined biochemical pathways involved in this phenomenon. For that the effects of purified recombinant H. pylori urease (HPU) added to rabbit platelets were assessed turbidimetrically. ATP secretion and production of lipoxygenase metabolites by activated platelets were measured. Fluorescein-labelled HPU bound to platelets but not to erythrocytes. HPU induced aggregation of rabbit platelets (ED(50) 0.28 microM) accompanied by ATP secretion. No correlation was found between platelet activation and ureolytic activity of HPU. Platelet aggregation was blocked by esculetin (12-lipoxygenase inhibitor) and enhanced approximately 3-fold by indomethacin (cyclooxygenase inhibitor). A metabolite of 12-lipoxygenase was produced by platelets exposed to HPU. Platelet responses to HPU did not involve platelet-activating factor, but required activation of verapamil-inhibitable calcium channels. Our data show that purified H. pylori urease activates blood platelets at submicromolar concentrations. This property seems to be common to ureases regardless of their source (plant or bacteria) or quaternary structure (single, di- or tri-chain proteins). These properties of HPU could play an important role in pathogenesis of gastrointestinal and associated cardiovascular diseases caused by H. pylori.

  7. The lipoxygenase pathway in tulip (Tulipa gesneriana): detection of the ketol route.

    Science.gov (United States)

    Grechkin, A N; Mukhtarova, L S; Hamberg, M

    2000-01-01

    The in vitro metabolism of [1-(14)C]linoleate, [1-(14)C]linolenate and their 9(S)-hydroperoxides was studied in cell-free preparations from tulip (Tulipa gesneriana) bulbs, leaves and flowers. Linoleate and its 9-hydroperoxide were converted by bulb and leaf preparations into three ketols: (12Z)-9-hydroxy-10-oxo-12-octadecadienoic acid (alpha-ketol), (11E)-10-oxo-13-hydroxy-11-octadecadienoic acid (gamma-ketol) and a novel compound, (12Z)-10-oxo-11-hydroxy-12-octadecadienoic acid (10,11-ketol), in the approximate molar proportions of 10:3:1. The corresponding 15, 16-dehydro alpha- and gamma-ketols were the main metabolites of [1-(14)C]linolenate and its 9-hydroperoxide. Thus bulbs and leaves possessed 9-lipoxygenase and allene oxide synthase activities. Incubations with flower preparations gave alpha-ketol hydro(pero)xides as predominant metabolites. Bulb and leaf preparations possessed a novel enzyme activity, gamma-ketol reductase, which reduces gamma-ketol to 10-oxo-13-hydroxyoctadecanoic acid (dihydro-gamma-ketol) in the presence of NADH. Exogenous linolenate 13(S)-hydroperoxide was converted mostly into chiral (9S,13S)-12-oxo-10-phytodienoate (99.5% optical purity) by bulb preparations, while [1-(14)C]linolenate was a precursor for ketols only. Thus tulip bulbs possess abundant allene oxide cyclase activity, the substrate for which is linolenate 13(S)-hydroperoxide, even though 13(S)-lipoxygenase products were not detectable in the bulbs. The majority of the cyclase activity was found in the microsomes (10(5) g pellet). Cyclase activity was not found in the other tissues examined, but only in the bulbs. The ketol route of the lipoxygenase pathway, mediated by 9-lipoxygenase and allene oxide synthase activities, has not been detected previously in the vegetative organs of any plant species. PMID:11085944

  8. Manassantin A isolated from Saururus chinensis inhibits 5-lipoxygenase-dependent leukotriene C4 generation by blocking mitogen-activated protein kinase activation in mast cells.

    Science.gov (United States)

    Kim, Su Jeong; Lu, Yue; Kwon, Okyun; Hwangbo, Kyoung; Seo, Chang-Seob; Lee, Seung Ho; Kim, Cheorl-Ho; Chang, Young-Chae; Son, Jong Keun; Chang, Hyeun Wook

    2011-01-01

    In this study, manassantin A (Man A), an herbal medicine isolated from Saururus chinensis (S. chinensis), markedly inhibited 5-lipoxygenase (5-LO)-dependent leukotriene C(4) (LTC(4)) generation in bone marrow-derived mast cells (BMMCs) in a concentration-dependent manner. To investigate the molecular mechanisms underlying the inhibition of LTC(4) generation by Man A, we assessed the effects of Man A on phosphorylation of cytosolic phospholipase A(2) (cPLA(2)) and mitogen-activated protein kinases (MAPKs). Inhibition of LTC(4) generation by Man A was accompanied by a decrease in cPLA(2) phosphorylation, which occurred via the MAPKs including extracellular signal-regulated protein kinase-1/2 (ERK1/2) as well as p38 and c-Jun N-terminal kinase (JNK) pathways. Taken together, the present study suggests the Man A represents a potential therapeutic approach for the treatment of airway allergic-inflammatory diseases.

  9. Effects of Tannin Extract from Gongronema latifolium Leaves on Lipoxygenase Cucumeropsis manii Seeds

    Directory of Open Access Journals (Sweden)

    Sabinus O. O. Eze

    2013-01-01

    Full Text Available Lipoxygenase (EC 1.13.11.12 was partially purified from germinated seeds of Cucumeropsis manii to a purification fold of 47.14, enzyme activity recovery of 72.18%, and specific activity of 326.25 units/mg protein, using a three-step process of centrifugation, ammonium sulphate precipitation and gel filtration. Kinetic properties show maximum activity at pH 6.0 and at optimum temperature of 40°C. Inhibitory effects of the extract from Gongronema latifolium and two other known antioxidants: ascorbic acid and propyl gallate on lipoxygenase from Cucumeropsis manii were studied. Result shows presence of inhibition with IC50 of 4.2×10−3 ± 0.09×10−3 g/L, 4.3×10−2 ± 0.11×10−2 g/L and 7.9×10−2 ± 0.11×10−2 g/L for the extract from ascorbic acid and propyl gallate, respectively. The extract when compared to the other antioxidants exhibits a competitive mechanism of inhibition. This tannin extract could be included during food processing as preservative against food deterioration that might be caused by oxidative enzymes such as lipoxygenase.

  10. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans

    NARCIS (Netherlands)

    Heshof, R.; Schayck, van J.P.; Tamayo Ramos, J.A.; Graaff, de L.H.

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain jus

  11. tasselseed1 is a lipoxygenase affecting jasmonic acid signaling in sex determination of maize

    Science.gov (United States)

    Sex determination in maize is controlled by a developmental cascade leading to the formation of unisexual florets derived from an initially bisexual floral meristem. Abortion of pistil primordia in staminate florets is controlled by a tasselseed-mediated cell death process. Here, we describe the pos...

  12. Cell survival signalling through PPARδ and arachidonic acid metabolites in neuroblastoma.

    Directory of Open Access Journals (Sweden)

    Emma Bell

    Full Text Available Retinoic acid (RA has paradoxical effects on cancer cells: promoting cell death, differentiation and cell cycle arrest, or cell survival and proliferation. Arachidonic acid (AA release occurs in response to RA treatment and, therefore, AA and its downstream metabolites may be involved in cell survival signalling. To test this, we inhibited phospholipase A2-mediated AA release, cyclooxygenases and lipoxygenases with small-molecule inhibitors to determine if this would sensitise cells to cell death after RA treatment. The data suggest that, in response to RA, phospholipase A2-mediated release of AA and subsequent metabolism by lipoxygenases is important for cell survival. Evidence from gene expression reporter assays and PPARδ knockdown suggests that lipoxygenase metabolites activate PPARδ. The involvement of PPARδ in cell survival is supported by results of experiments with the PPARδ inhibitor GSK0660 and siRNA-mediated knockdown. Quantitative reverse transcriptase PCR studies demonstrated that inhibition of 5-lipoxygenase after RA treatment resulted in a strong up-regulation of mRNA for PPARδ2, a putative inhibitory PPARδ isoform. Over-expression of PPARδ2 using a tetracycline-inducible system in neuroblastoma cells reduced proliferation and induced cell death. These data provide evidence linking lipoxygenases and PPARδ in a cell survival-signalling mechanism and suggest new drug-development targets for malignant and hyper-proliferative diseases.

  13. [Disease resistance signal transfer between roots of different tomato plants through common arbuscular mycorrhiza networks].

    Science.gov (United States)

    Xie, Li-Jun; Song, Yuan-Yuan; Zeng, Ren-Sen; Wang, Rui-Long; Wei, Xiao-Chen; Ye, Mao; Hu, Lin; Zhang, Hui

    2012-05-01

    Common mycorrhizal networks (CMNs) are the underground conduits of nutrient exchange between plants. However, whether the CMNs can serve as the underground conduits of chemical communication to transfer the disease resistance signals between plants are unknown. By inoculating arbuscular mycorrhizal fungus (AMF) Glomus mosseae to establish CMNs between 'donor' and 'receiver' tomato plants, and by inoculating Alternaria solani, the causal agent of tomato early blight disease, to the 'donor' plants, this paper studied whether the potential disease resistance signals can be transferred between the 'donor' and 'receiver' plants roots. The real time RT-PCR analysis showed that after inoculation with A. solani, the AMF-inoculated 'donor' plants had strong expression of three test defense-related genes in roots, with the transcript levels of the phenylalanine ammonia-lyase (PAL), lipoxygenase (LOX) and chitinase (PR3) being significantly higher than those in the roots of the 'donor' plants only inoculated with A. solani, not inoculated with both A. solani and AMF, and only inoculated with AMF. More importantly, in the presence of CMNs, the expression levels of the three genes in the roots of the 'receiver' plants were significantly higher than those of the 'receiver' plants without CMNs connection, with the connection blocking, and with the connection but the 'donor' plants not A. solani-inoculated. Compared with the control (without CMNs connection), the transcript level of the PAL, LOX and PR3 in the roots of the 'receiver' plants having CMNs connection with the 'donor' plants was 4.2-, 4.5- and 3.5-fold higher, respectively. In addition, the 'donor' plants activated their defensive responses more quickly than the 'receiver' plants (18 and 65 h vs. 100 and 140 h). These findings suggested that the disease resistance signals produced by the pathogen-induced 'donor' tomato plant roots could be transferred to the 'receiver' plant roots through CMNs.

  14. Arabidopsis mitogen-activated protein kinase kinases MKK1 and MKK2 have overlapping functions in defense signaling mediated by MEKK1, MPK4, and MKS1

    DEFF Research Database (Denmark)

    Qiu, Jin-Long; Zhou, Lu; Yun, Byung-Wook

    2008-01-01

    The Arabidopsis thaliana MKK1 and MKK2 MAP kinase kinases have been implicated in biotic and abiotic stress responses as part of a signalling cascade including MEKK1 and MPK4. Here, the double loss-of-function mutant (mkk1/2) of MKK1 and MKK2 is shown to have marked phenotypes in development...

  15. Dry and ripe fruit of Aegle marmelos. L: A potent source of antioxidant, lipoxygenase inhibitors and free radical scavenger.

    Science.gov (United States)

    Rahman, Atiqur; Imran, Hina; Iqbal, Lubna; STaqvi, Syed Intasar Hussain; Fatima, Nudrat; Yaqeen, Zahra

    2016-07-01

    The antioxidant, lipoxygenase inhibitory activities and free radical scavenging capacity of the crude extract, aqueous and some organic fractions of dry and ripe fruit of Aeglemarmelos. L were studied to understand the protective and therapeutic role for the use of the fruit as a remedy in different ailments. All the tested fractions and extracts showed to possess significant antioxidant, free radical scavenging capacity and lipoxygenase inhibitory potential. However, chloroform and aqueous fractions showed significant ability to quench radicals, to reduce ferric chloride and to inhibit soyabean lipoxygenase. Their antioxidant and lipoxygenase inhibition was estimated by IC50 values, for antioxidant ranging from 88-65% activity at concentration of 5-0.15μ/mL and similarly for lipoxygenase inhibition ranging from 89-69% at various concentrations of 5-0.15μ/mL, in chloroform and aqueous fractions respectively. The scavenger molecules in the dry and ripe fruit of A. marmelos may attribute to therapeutic and protective effect during different progressive stages of ailments.

  16. Interaction between Non-Heme Iron of Lipoxygenases and Cumene Hydroperoxide: Basis for Enzyme Activation, Inactivation, and Inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Vahedi-Faridi, Ardeshir; Brault, Pierre-Alexandre; Shah, Priya; Kim, Yong-Wah; Dunham, William R.; Funk, Jr., Max O. (Toledo)

    2010-11-16

    Lipoxygenase catalysis depends in a critical fashion on the redox properties of a unique mononuclear non-heme iron cofactor. The isolated enzyme contains predominantly, if not exclusively, iron(II), but the catalytically active form of the enzyme has iron(III). The activating oxidation of the iron takes place in a reaction with the hydroperoxide product of the catalyzed reaction. In a second peroxide-dependent process, lipoxygenases are also inactivated. To examine the redox activation/inactivation dichotomy in lipoxygenase chemistry, the interaction between lipoxygenase-1 (and -3) and cumene hydroperoxide was investigated. Cumene hydroperoxide was a reversible inhibitor of the reaction catalyzed by lipoxygenase-1 under standard assay conditions at high substrate concentrations. Reconciliation of the data with the currently held kinetic mechanism requires simultaneous binding of substrate and peroxide. The enzyme also was both oxidized and largely inactivated in a reaction with the peroxide in the absence of substrate. The consequences of this reaction for the enzyme included the hydroxylation at C{beta} of two amino acid side chains in the vicinity of the cofactor, Trp and Leu. The modifications were identified by mass spectrometry and X-ray crystallography. The peroxide-induced oxidation of iron was also accompanied by a subtle rearrangement in the coordination sphere of the non-heme iron atom. Since the enzyme retains catalytic activity, albeit diminished, after treatment with cumene hydroperoxide, the structure of the iron site may reflect the catalytically relevant form of the cofactor.

  17. Interaction between non-heme iron of lipoxygenases and cumene hydroperoxide: basis for enzyme activation, inactivation, and inhibition.

    Science.gov (United States)

    Vahedi-Faridi, Ardeshir; Brault, Pierre-Alexandre; Shah, Priya; Kim, Yong-Wah; Dunham, William R; Funk, Max O

    2004-02-25

    Lipoxygenase catalysis depends in a critical fashion on the redox properties of a unique mononuclear non-heme iron cofactor. The isolated enzyme contains predominantly, if not exclusively, iron(II), but the catalytically active form of the enzyme has iron(III). The activating oxidation of the iron takes place in a reaction with the hydroperoxide product of the catalyzed reaction. In a second peroxide-dependent process, lipoxygenases are also inactivated. To examine the redox activation/inactivation dichotomy in lipoxygenase chemistry, the interaction between lipoxygenase-1 (and -3) and cumene hydroperoxide was investigated. Cumene hydroperoxide was a reversible inhibitor of the reaction catalyzed by lipoxygenase-1 under standard assay conditions at high substrate concentrations. Reconciliation of the data with the currently held kinetic mechanism requires simultaneous binding of substrate and peroxide. The enzyme also was both oxidized and largely inactivated in a reaction with the peroxide in the absence of substrate. The consequences of this reaction for the enzyme included the hydroxylation at C beta of two amino acid side chains in the vicinity of the cofactor, Trp and Leu. The modifications were identified by mass spectrometry and X-ray crystallography. The peroxide-induced oxidation of iron was also accompanied by a subtle rearrangement in the coordination sphere of the non-heme iron atom. Since the enzyme retains catalytic activity, albeit diminished, after treatment with cumene hydroperoxide, the structure of the iron site may reflect the catalytically relevant form of the cofactor.

  18. CB1 cannabinoid receptor-mediated anandamide signalling reduces the defensive behaviour evoked through GABAA receptor blockade in the dorsomedial division of the ventromedial hypothalamus.

    Science.gov (United States)

    Dos Anjos-Garcia, Tayllon; Ullah, Farhad; Falconi-Sobrinho, Luiz Luciano; Coimbra, Norberto Cysne

    2017-02-01

    The effects of cannabinoids in brain areas expressing cannabinoid receptors, such as hypothalamic nuclei, are not yet well known. Several studies have demonstrated the role of hypothalamic nuclei in the organisation of behavioural responses induced through innate fear and panic attacks. Panic-prone states are experimentally induced in laboratory animals through a reduction in the GABAergic activity. The aim of the present study was to examine panic-like elaborated defensive behaviour evoked by GABAA receptor blockade with bicuculline (BIC) in the dorsomedial division of the ventromedial hypothalamus (VMHdm). We also aimed to characterise the involvement of endocannabinoids and the CB1 cannabinoid receptor in the modulation of elaborated defence behavioural responses organised with the VMHdm. The guide-cannula was stereotaxicaly implanted in VMHdm and the animals were treated with anandamide (AEA) at different doses, and the effective dose was used after the pre-treatment with the CB1 receptor antagonist AM251, followed by GABAA receptor blockade in VMHdm. The results showed that the intra-hypothalamic administration of AEA at an intermediate dose (5 pmol) attenuated defence responses induced through the intra-VMHdm microinjection of bicuculline (40 ng). This effect, however, was inhibited when applied central microinjection of the CB1 receptor antagonist AM251 in the VMHdm. Moreover, AM251 potentiates de non-oriented escape induced by bicuculline, effect blocked by pre-treatment with the TRPV1 channel antagonist 6-I-CPS. These results indicate that AEA modulates the pro-aversive effects of intra-VMHdm-bicuculline treatment, recruiting CB1 cannabinoid receptors and the TRPV1 channel is involved in the AM251-related potentiation of bicuculline effects on non-oriented escape behaviour.

  19. Synthetic Plant Defense Elicitors

    Directory of Open Access Journals (Sweden)

    Yasemin eBektas

    2015-01-01

    Full Text Available To defend themselves against invading pathogens plants utilize a complex regulatory network that coordinates extensive transcriptional and metabolic reprogramming. Although many of the key players of this immunity-associated network are known, the details of its topology and dynamics are still poorly understood. As an alternative to forward and reverse genetic studies, chemical genetics-related approaches based on bioactive small molecules have gained substantial popularity in the analysis of biological pathways and networks. Use of such molecular probes can allow researchers to access biological space that was previously inaccessible to genetic analyses due to gene redundancy or lethality of mutations. Synthetic elicitors are small drug like molecules that induce plant defense responses, but are distinct from known natural elicitors of plant immunity. While the discovery of the some synthetic elicitors had already been reported in the 1970s, recent breakthroughs in combinatorial chemical synthesis now allow for inexpensive high-throughput screens for bioactive plant defense-inducing compounds. Along with powerful reverse genetics tools and resources available for model plants and crop systems, comprehensive collections of new synthetic elicitors will likely allow plant scientists to study the intricacies of plant defense signaling pathways and networks in an unparalleled fashion. As synthetic elicitors can protect crops from diseases, without the need to be directly toxic for pathogenic organisms, they may also serve as promising alternatives to conventional biocidal pesticides, which often are harmful for the environment, farmers and consumers. Here we are discussing various types of synthetic elicitors that have been used for studies on the plant immune system, their modes-of-action as well as their application in crop protection.

  20. Heterologous Expression and Biochemical Characterization of Two Lipoxygenases in Oriental Melon, Cucumis melo var. makuwa Makino.

    Science.gov (United States)

    Cao, Songxiao; Chen, Hao; Zhang, Chong; Tang, Yufan; Liu, Jieying; Qi, Hongyan

    2016-01-01

    Lipoxygenases (LOXs) are a class of non-heme iron-containing dioxygenases that catalyse oxidation of polyunsaturated fatty acids to produce hydroperoxidation that are in turn converted to oxylipins. Although multiple isoforms of LOXs have been detected in several plants, LOXs in oriental melon have not attracted much attention. Two full-length LOX cDNA clones, CmLOX10 and CmLOX13 which have been isolated from oriental melon (Cucumis melo var. makuwa Makino) cultivar "Yumeiren", encode 902 and 906 amino acids, respectively. Bioinformatics analysis showed that CmLOX10 and CmLOX13 included all of the typical LOX domains and shared 58.11% identity at the amino acid level with each other. The phylogenetic analysis revealed that CmLOX10 and CmLOX13 were members of the type 2 13-LOX subgroup which are known to be involved in biotic and abiotic stress. Heterologous expression of the full-length CmLOX10 and truncated CmLOX13 in Escherichia coli revealed that the encoded exogenous proteins were identical to the predicted molecular weights and possessed the lipoxygenase activities. The purified CmLOX10 and CmLOX13 recombinant enzymes exhibited maximum activity at different temperature and pH and both had higher affinity for linoleic acid than linolenic acid. Chromatogram analysis of reaction products from the CmLOX10 and CmLOX13 enzyme reaction revealed that both enzymes produced 13S-hydroperoxides when linoleic acid was used as substrate. Furthermore, the subcellular localization analysis by transient expression of the two LOX fusion proteins in tobacco leaves showed that CmLOX10 and CmLOX13 proteins were located in plasma membrane and chloroplasts respectively. We propose that the two lipoxygenases may play different functions in oriental melon during plant growth and development.

  1. Effects of heat processing on soya bean fatty acids content and the lipoxygenase activity

    Directory of Open Access Journals (Sweden)

    Žilić Slađana M.

    2010-01-01

    Full Text Available Effects of increased temperatures on the lipoxygenase activity and changes of soya bean fatty acids were observed in the present study. The kernels of soya bean cultivars Bosa and ZPS 015 were subjected to the treatments of extrusion, autoclaving, micronisation and microwave roasting. Depending on the technological processing procedure, the kernels were exposed to temperatures ranging from 60 to 150°C for 25 to 30 seconds during extrusion and for 30 minutes during autoclaving. The temperature that developed in the course of the microwave radiation and autoclaving did not cause statistically significant differences between oil content in heat treated and fresh kernels of soya bean. However, the oil content was higher in soya bean flakes (micronized kernels and lower in grits than in fresh kernels. The heat treatments resulted in the significant decrease of the linolenic fatty acid content. Depending on the temperature and applied heat treatments, the content of linoleic and oleic fatty acid oscillated. High temperatures caused changes in unsaturated fatty acids with 18 carbon atoms resulting in relative increase of the stearic acid content. The lipoxygenase activity decreased in correlation with increased temperatures and the time of heating. The maximum drop of the activity was observed after kernel exposure to the extrusion and micronisation processes at the temperature of 100oC. However, a significant lipoxygenase activity increase was recorded in both studied cultivars after one-minute microwave heating, i.e. at the temperature about 60°C. A further temperature increase led to a gradual denaturation of the enzyme and therefore to its decreased activity.

  2. Bleaching of browned water yam (Dioscorea alata) with African oil bean seed lipoxygenase (Part 2).

    Science.gov (United States)

    Anokwulu, M N

    2004-01-01

    Purified African oil bean seed lipoxygenase was used to bleach water yam tubers that were browned by exposing their cut surfaces to air. The enzyme solution destroyed the polyphenols extracted from the browned water yams and the polyphenols at the browned yam tubers which resulted in the bleaching of the browned yam tubers to their original white colour. The destruction of the polyphenol extract and the bleaching of the browned yam tubers were found to be dependent on the enzyme concentration of the enzyme.

  3. Clicked Cinnamic/Caffeic Esters and Amides as Radical Scavengers and 5-Lipoxygenase Inhibitors

    OpenAIRE

    Doiron, Jérémie A.; Benoît Métayer; Ryan R. Richard; Dany Desjardins; Boudreau, Luc H.; Natalie A. Levesque; Jacques Jean-François; Samuel J. Poirier; Surette, Marc E.; Mohamed Touaibia

    2014-01-01

    5-Lipoxygenase (5-LO) is the key enzyme responsible for the conversion of arachidonic acid to leukotrienes, a class of lipid mediators implicated in inflammatory disorders. In this paper, we describe the design, synthesis, and preliminary activity studies of novel clicked caffeic esters and amides as radical scavengers and 5-LO inhibitors. From known 5-LO inhibitor 3 as a lead, cinnamic esters 8a–h and amides 9a–h as well as caffeic esters 15a–h and amides 16a–h were synthesized by Cu(I)-cata...

  4. Regulation of leukotriene and 5oxoETE synthesis and the effect of 5-lipoxygenase inhibitors: a mathematical modeling approach

    Directory of Open Access Journals (Sweden)

    Karelina Tatiana A

    2012-11-01

    Full Text Available Abstract Background 5-lipoxygenase (5-LO is a key enzyme in the synthesis of leukotrienes and 5-Oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (oxoETE. These inflammatory signaling molecules play a role in the pathology of asthma and so 5-LO inhibition is a promising target for asthma therapy. The 5-LO redox inhibitor zileuton (Zyflo IR/CR® is currently marketed for the treatment of asthma in adults and children, but widespread use of zileuton is limited by its efficacy/safety profile, potentially related to its redox characteristics. Thus, a quantitative, mechanistic description of its functioning may be useful for development of improved anti-inflammatory targeting this mechanism. Results A mathematical model describing the operation of 5-LO, phospholipase A2, glutathione peroxidase and 5-hydroxyeicosanoid dehydrogenase was developed. The catalytic cycles of the enzymes were reconstructed and kinetic parameters estimated on the basis of available experimental data. The final model describes each stage of cys-leukotriene biosynthesis and the reactions involved in oxoETE production. Regulation of these processes by substrates (phospholipid concentration and intracellular redox state (concentrations of reduced glutathione, glutathione (GSH, and lipid peroxide were taken into account. The model enabled us to reveal differences between redox and non-redox 5-LO inhibitors under conditions of oxidative stress. Despite both redox and non-redox inhibitors suppressing leukotriene A4 (LTA4 synthesis, redox inhibitors are predicted to increase oxoETE production, thus compromising efficacy. This phenomena can be explained in terms of the pseudo-peroxidase activity of 5-LO and the ability of lipid peroxides to transform 5-LO into its active form even in the presence of redox inhibitors. Conclusions The mathematical model developed described quantitatively different mechanisms of 5-LO inhibition and simulations revealed differences between the potential

  5. Induction of phenylalanine ammonia-lyase and lipoxygenase in cotton seedlings by mechanical wounding and aphid infestation

    Institute of Scientific and Technical Information of China (English)

    QIN Qiuju; SHI Xueyan; LIANG Pei; GAO Xiwu

    2005-01-01

    It has been suggested that infestation of plants causes increases in the activities of phenylalanine ammonia-lyase (PAL)and lipoxygenase (LOX), key enzymes in the phenolic compounds synthesis pathway and the octadecanoid pathway, respectively. The purpose of this work is to investigate whether the infestation of cotton aphid (Aphis gossypii ) and mechanical wound can cause the induction of PAL and LOX activities in cotton seedlings, and whether the induction occurs in healthy seedlings growing nearby the attacked ones. The specific activities of PAL and LOX were measured using spectrophotometric method after aphid infestation and mechanical wounding. Result indicated that PAL activity and LOX activity were greatly induced by mechanical wounding and aphid infestation in cotton seedlings. The induction of PAL and LOX occurred not only in wounded and infested seedlings but also in intact healthy seedlings growing nearby. After exposed to the aphid infestation-induced volatiles, the specific activity of PAL in cotton seedlings increased by 6 % at 24 h, 80 % at 48 h, 235 % at 72 h compared to the control, and the specific activity of LOX increased by 18 % at 24 h, 34 % at 48 h,24 % at 72 h, respectively. In comparison, the specific activity of PAL in unwounded seedlings exposed to wound-induced volatiles increased by 0.0 at 24 h, 200% at 48 h, 164% at 72 h, respectively and the specific activity of LOX increased by 28% at 24 h, 37% at 48 h, 8 % at 72 h, respectively. It suggests that the induced volatiles are involved in plant-plant communication as airborne transferred signals.

  6. Pigment Epithelium-Derived Factor Inhibits Retinal Microvascular Dysfunction Induced By 12/15-Lipoxygenase-Derived Eicosanoids

    Science.gov (United States)

    Ibrahim, Ahmed S.; Tawfik, Amany M.; Hussein, Khaled A; Elshafey, Sally; Markand, Shanu; Rizk, Nasser; Duh, Elia J.; Smith, Sylvia B.; Al-Shabrawey, Mohamed

    2015-01-01

    We recently demonstrated that 12/15-lipoxygenase (LOX) derived metabolites, hydroxyeicosatetraenoic acids (HETEs), contribute to diabetic retinopathy (DR) via NADPH oxidase (NOX) and disruption of the balance in retinal levels of the vascular endothelial growth factor (VEGF) and Pigment Epithelium-Derived Factor (PEDF). Here, we test whether PEDF ameliorates retinal vascular injury induced by HETEs and the underlying mechanisms. Furthermore, we pursue the causal relationship between LOX-NOX system and regulation of PEDF expression during DR. For these purposes, we used an experimental eye model in which normal mice were injected intravitreally with 12/15HETE with/without PEDF. Thereafter, Fluorescein Angiography (FA) was used to evaluate the vascular leakage, followed by Optical coherence tomography (OCT) to assess the presence of angiogenesis. FA and OCT reported an increased vascular leakage and pre-retinal neovascularization, respectively, in response to 12-HETE that were not observed in PEDF-treated group. Moreover, PEDF significantly attenuated the increased levels of vascular cell and intercellular adhesion molecules, VCAM-1 and ICAM-1, elicited by 12-HETE injection. Accordingly, the direct relationship between HETE and PEDF has been explored through in-vitro studies using Müller cells (rMCs) and human retinal endothelial cells (HRECs). The results showed that HETEs triggered the secretion of TNF-α and IL-6, as well as activation of NFκB in rMCs and significantly increased permeability and reduced zonula occludens protein-1 (ZO-1) immunoreactivity in HRECs. All these effects were prevented in PEDF-treated cells. Furthermore, interest in PEDF regulation during DR has been expanded to include NOX system. Retinal PEDF was significantly restored in diabetic mice treated with NOX inhibitor, apocynin, or lacking NOX2 up to 80% of the control level. Collectively, our findings suggest that interfering with LOX-NOX signaling opens up a new direction for treating DR

  7. Rapid modification of the insect elicitor N-linolenoyl-glutamate via a lipoxygenase-mediated mechanism on Nicotiana attenuata leaves

    Directory of Open Access Journals (Sweden)

    VanDoorn Arjen

    2010-08-01

    Full Text Available Abstract Background Some plants distinguish mechanical wounding from herbivore attack by recognizing specific constituents of larval oral secretions (OS which are introduced into plant wounds during feeding. Fatty acid-amino acid conjugates (FACs are major constituents of Manduca sexta OS and strong elicitors of herbivore-induced defense responses in Nicotiana attenuata plants. Results The metabolism of one of the major FACs in M. sexta OS, N-linolenoyl-glutamic acid (18:3-Glu, was analyzed on N. attenuata wounded leaf surfaces. Between 50 to 70% of the 18:3-Glu in the OS or of synthetic 18:3-Glu were metabolized within 30 seconds of application to leaf wounds. This heat-labile process did not result in free α-linolenic acid (18:3 and glutamate but in the biogenesis of metabolites both more and less polar than 18:3-Glu. Identification of the major modified forms of this FAC showed that they corresponded to 13-hydroxy-18:3-Glu, 13-hydroperoxy-18:3-Glu and 13-oxo-13:2-Glu. The formation of these metabolites occurred on the wounded leaf surface and it was dependent on lipoxygenase (LOX activity; plants silenced in the expression of NaLOX2 and NaLOX3 genes showed more than 50% reduced rates of 18:3-Glu conversion and accumulated smaller amounts of the oxygenated derivatives compared to wild-type plants. Similar to 18:3-Glu, 13-oxo-13:2-Glu activated the enhanced accumulation of jasmonic acid (JA in N. attenuata leaves whereas 13-hydroxy-18:3-Glu did not. Moreover, compared to 18:3-Glu elicitation, 13-oxo-13:2-Glu induced the differential emission of two monoterpene volatiles (β-pinene and an unidentified monoterpene in irlox2 plants. Conclusions The metabolism of one of the major elicitors of herbivore-specific responses in N. attenuata plants, 18:3-Glu, results in the formation of oxidized forms of this FAC by a LOX-dependent mechanism. One of these derivatives, 13-oxo-13:2-Glu, is an active elicitor of JA biosynthesis and differential

  8. The Persimmon 9-lipoxygenase Gene DkLOX3 Plays Positive Roles in Both Promoting Senescence and Enhancing Tolerance to Abiotic Stress.

    Science.gov (United States)

    Hou, Yali; Meng, Kun; Han, Ye; Ban, Qiuyan; Wang, Biao; Suo, Jiangtao; Lv, Jingyi; Rao, Jingping

    2015-01-01

    The lipoxygenase (LOX) pathway is a key regulator for lipid peroxidation, which is crucial for plant senescence and defense pathways. In this study, the transcriptional expression patterns of three persimmon (Diospyros kaki L. 'Fupingjianshi') 9-lipoxygenase genes (DkLOX1, DkLOX3, and DkLOX4) were investigated. DkLOX1 was specifically expressed in fruit, particularly in young fruit, and showed little response to the postharvest environments. DkLOX4 was expressed in all tissues and slightly stimulated by mechanical damage and low temperature. DkLOX3 was expressed mainly in mature fruit, and the expression was extremely high throughout the storage period, apparently up-regulated by mechanical damage and high carbon dioxide treatments. Further functional analysis showed that overexpression of DkLOX3 in tomato (Solanum lycopersicum cv. Micro-Tom) accelerated fruit ripening and softening. This was accompanied by higher malondialdehyde (MDA) content and lycopene accumulation, advanced ethylene release peak and elevated expression of ethylene synthesis genes, including ACS2, ACO1, and ACO3. In addition, DkLOX3 overexpression promoted dark induced transgenic Arabidopsis leaf senescence with more chlorophyll loss, increased electrolyte leakage and MDA content. Furthermore, the functions of DkLOX3 in response to abiotic stresses, including osmotic stress, high salinity and drought were investigated. Arabidopsis DkLOX3 overexpression (DkLOX3-OX) transgenic lines were found to be more tolerant to osmotic stress with higher germination rate and root growth than wild-type. Moreover, DkLOX3-OX Arabidopsis plants also exhibited enhanced resistance to high salinity and drought, with similar decreased O2 (-) and H2O2 accumulation and upregulation of stress-responsive genes expression, including RD22, RD29A, RD29B, and NCED3, except for FRY1, which plays a negative role in stress response. Overall, these results suggested that DkLOX3 plays positive roles both in promoting ripening

  9. Inhibition of 12/15 lipoxygenase by curcumin and an extract from Curcuma longa L.

    Science.gov (United States)

    Bezáková, Lýdia; Košťálová, Daniela; Obložinský, Marek; Hoffman, Peter; Pekárová, Mária; Kollárová, Renáta; Holková, Ivana; Mošovská, Silvia; Sturdík, Ernest

    2014-02-01

    Curcumin (diferuloylmethane) is an orange-yellow secondary metabolic compound from the rhizome of turmeric (Curcuma longa L.), a spice often found in curry powder. It is one of the major curcuminoids of turmeric. For centuries, curcumin has been used in some medicinal preparations or as a food colouring agent. A variety of enzymes that are closely associated with inflammation and cancer were found to be modulated by curcumin. This paper summarized the results of the inhibitory effect of curcumin and a Curcuma longa L. ethanolic extract on lipoxygenase from the rat lung cytosolic fraction. The positional specificity determination of arachidonic acid dioxygenation by RP- and SP-HPLC methods showed that in a purified enzyme preparation from the rat lung cytosol the specific form of lipoxygenase (LOX) is present exhibiting 12/15-LOX dual specificity (with predominant 15-LOX activity). The inhibitory activity of curcumin and Curcuma longa extract on LOX from cytosolic fraction of rat lung was expressed in the percentage of inhibition and as IC50. Lineweaver-Burk plot analysis has indicated that curcumin is the competitive inhibitor of 12/15 LOX from the rat lung cytosolic fraction.

  10. The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

    Directory of Open Access Journals (Sweden)

    Gigot, C.

    2010-01-01

    Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

  11. Differential impact of lipoxygenase 2 and jasmonates on natural and stress-induced senescence in Arabidopsis.

    Science.gov (United States)

    Seltmann, Martin A; Stingl, Nadja E; Lautenschlaeger, Jens K; Krischke, Markus; Mueller, Martin J; Berger, Susanne

    2010-04-01

    Jasmonic acid and related oxylipins are controversially discussed to be involved in regulating the initiation and progression of leaf senescence. To this end, we analyzed profiles of free and esterified oxylipins during natural senescence and upon induction of senescence-like phenotypes by dark treatment and flotation on sorbitol in Arabidopsis (Arabidopsis thaliana). Jasmonic acid and free 12-oxo-phytodienoic acid increased during all three processes, with the strongest increase of jasmonic acid after dark treatment. Arabidopside content only increased considerably in response to sorbitol treatment. Monogalactosyldiacylglycerols and digalactosyldiacylglycerols decreased during these treatments and aging. Lipoxygenase 2-RNA interference (RNAi) plants were generated, which constitutively produce jasmonic acid and 12-oxo-phytodienoic acid but do not exhibit accumulation during natural senescence or upon stress treatment. Chlorophyll loss during aging and upon dark incubation was not altered, suggesting that these oxylipins are not involved in these processes. In contrast, lipoxygenase 2-RNAi lines and the allene oxid synthase-deficient mutant dde2 were less sensitive to sorbitol than the wild type, indicating that oxylipins contribute to the response to sorbitol stress.

  12. Purification and characterization of lipoxygenase from mung bean (Vigna radiata L.) germinating seedlings.

    Science.gov (United States)

    Aanangi, Raveendra; Kotapati, Kasi Viswanath; Palaka, Bhagath Kumar; Kedam, Thyagaraju; Kanika, Nirmala Devi; Ampasala, Dinakara Rao

    2016-06-01

    This study reports purification and characterization of lipoxygenase protein from mung bean germinating seedlings. Lipoxygenases (LOXs) are key enzymes in seed germination. The purified mung bean LOX has resolved into two peaks by chromatofocusing, one has highest LOX activity with an isoelectric point of 5.84 and the other has lowest LOX activity with an isoelectric point of 5.52. The purified LOX has molecular mass of approximately 97 kDa and showed high activity with linoleic acid than linolenic acid and arachidonic acid. The optimal activity of LOX was observed at pH 6.5 and temperature 35 °C. Far-UV circular dichroism (CD) studies revealed that the purified mung bean LOX possess secondary structural elements with significant α-helix and β-strands. Further, the secondary structure of mung bean LOX was stable up to 60 °C at pH 6.5. Biophysical and chemical properties of the mung bean LOX are similar to the other legume LOXs and may be considered as type-1 LOX.

  13. Prokaryotic Expression, Purification and Characterization of a Novel Rice Seed Lipoxygenase Gene OsLOX1

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Lipoxygenase (LOX,EC1.13.11.12) is a key enzyme during the degradation of lipids in animals and even plants,and also the first key enzyme responsible for the biosynthesis of jasmonate.To purify and characterize the OsLOX1 gene from rice seeds,the entire coding region of the OsLOX1 gene was inserted into an expression vector pET30a(+) and transformed into Eschenchia coil BL21 (DE3).Expression of the fusion protein was successfully induced by isopropyl-β-D-thiogalactopyranoside (IPTG) and the purified recombinant protein was obtained by His.Bind(R) Kits.Further assay showed that the purified recombinant protein exhibited the LOX activity.The optimum pH was 4.8 (acetate buffer) and the optimum temperature was 30℃ for the above enzyme.Thus,the recombinant might confer an available usage for the synthesis of jasmonate in vitro,and also provides a possibility for elucidating the inter-relationship between the primary structure of the plant seed lipoxygenase protein and its physiological functions.

  14. Impact of Wines and Wine Constituents on Cyclooxygenase-1, Cyclooxygenase-2, and 5-Lipoxygenase Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Zsofia Kutil

    2014-01-01

    Full Text Available Cyclooxygenases and lipoxygenases are proinflammatory enzymes; the former affects platelet aggregation, vasoconstriction, vasodilatation and later the development of atherosclerosis. Red wines from Georgia and central and western Europe inhibited cyclooxygenase-1 (COX-1 activity in the range of 63–94%, cyclooxygenase-2 (COX-2 activity in the range of 20–44% (tested at a concentration of 5 mL/L, and 5-lipoxygenase (5-LOX activity in the range of 72–84% (at a concentration of 18.87 mL/L. White wines inhibited 5-LOX in the range of 41–68% at a concentration of 18.87 mL/L and did not inhibit COX-1 and COX-2. Piceatannol (IC50 = 0.76 μM was identified as a strong inhibitor of 5-LOX followed by luteolin (IC50 = 2.25 μM, quercetin (IC50 = 3.29 μM, and myricetin (IC50 = 4.02 μM. trans-Resveratrol was identified as an inhibitor of COX-1 (IC50 = 2.27 μM and COX-2 (IC50 = 3.40 μM. Red wine as a complex mixture is a powerful inhibitor of COX-1, COX-2, and 5-LOX, the enzymes involved in eicosanoid biosynthetic pathway.

  15. Molecular characterization of a lipoxygenase from the basidiomycete mushroom Pleurotus ostreatus.

    Science.gov (United States)

    Tasaki, Yuji; Toyama, Shungo; Kuribayashi, Takashi; Joh, Toshio

    2013-01-01

    The full-length cDNA of the gene PoLOX1 encoding a lipoxygenase (LOX) and its corresponding genomic DNA were isolated from the basidiomycete mushroom Pleurotus ostreatus strain H1. The deduced amino acid sequence of PoLOX1 showed similarity to a valencene dioxygenase of Pleurotus sapidus, putative LOX-like proteins from ascomycete, basidiomycete, and deuteromycete fungi, and known LOXs from plants, animals, and bacteria. PoLOX1 also contained the LOX iron-binding catalytic domain in the C-terminal region, but not the polycystin-1, lipoxygenase, alpha-toxin (PLAT) domain, which is usually found in the N-terminal region of eukaryotic LOXs. Genomic sequence analysis revealed that PoLOX1 was interrupted by one intron, and that the promoter region included TATA and CAAT boxes. Southern blot analysis indicated that PoLOX1 is a member of a small gene family comprising highly similar genes. Northern blot analysis revealed that it is transcribed more abundantly in the stipes of the fruit bodies than in the caps.

  16. Signal transducer and activator of transcription 3 (Stat3) regulates host defense and protects mice against herpes simplex virus-1 (HSV-1) infection.

    Science.gov (United States)

    Hsia, Hung-Ching; Stopford, Charles M; Zhang, Zhigang; Damania, Blossom; Baldwin, Albert S

    2016-12-13

    Signal transducer and activator of transcription 3 (STAT3) mediates cellular responses to multiple cytokines, governs gene expression, and regulates the development and activation of immune cells. STAT3 also modulates reactivation of latent herpes simplex virus-1 (HSV-1) in ganglia. However, it is unclear how STAT3 regulates the innate immune response during the early phase of HSV-1 lytic infection. Many cell types critical for the innate immunity are derived from the myeloid lineage. Therefore, in this study, we used myeloid-specific Stat3 knockout mice to investigate the role of STAT3 in the innate immune response against HSV-1. Our results demonstrate that Stat3 knockout bone marrow-derived macrophages (BMMs) expressed decreased levels of interferon-α (IFN-α) and interferon-stimulated genes (ISGs) upon HSV-1 infection. In vivo, knockout mice were more susceptible to HSV-1, as marked by higher viral loads and more significant weight loss. Splenic expression of IFN-α and ISGs was reduced in the absence of STAT3, indicating that STAT3 is required for optimal type I interferon response to HSV-1. Expression of TNF-α and IL-12, cytokines that have been shown to limit HSV-1 replication and pathogenesis, was also significantly lower in knockout mice. Interestingly, Stat3 knockout mice failed to expand the CD8(+) conventional DC (cDC) population upon HSV-1 infection, and this was accompanied by impaired NK and CD8 T cell activation. Collectively, our data demonstrate that myeloid-specific Stat3 deletion causes defects in multiple aspects of the immune system and that STAT3 has a protective role at the early stage of systemic HSV-1 infection.

  17. Cyclic LIPopeptides from Bacillus subtilis ABS-S14 elicit defense-related gene expression in citrus fruit.

    Science.gov (United States)

    Waewthongrak, Waewruedee; Leelasuphakul, Wichitra; McCollum, Greg

    2014-01-01

    Effects of cyclic lipopeptides (CLPs) obtained from Bacillus subtilis ABS-S14 on eliciting defense-related gene transcription and activity of defense-related enzymes; glucanase (GLU), chitinase (CHI), peroxidase (POX) and lipoxygenase (LOX) in Citrus sinensis cv. Valencia fruit were determined. The maximum level of GLU transcripts induced in fruit treated with fengycin was significantly greatest among treatments at 48 h. Surfactin enhanced the LOX and POX transcripts. In parallel, corresponding enzyme activities were correlated with changes in gene expression observed in fruit inoculated with Penicillium digitatum following treatment with individual CLPs. Synergistic effects of fengycin and iturin A, fengycin and surfactin were shown in gene transcript of GLU and CHI, respectively, and surfactin induced POX and LOX gene expression of citrus flavedo without pathogen infection. These results suggest that fengycin and surfactin act as elicitors of defense-related gene expression in "Valencia" fruit following infection.

  18. Cyclic LIPopeptides from Bacillus subtilis ABS-S14 elicit defense-related gene expression in citrus fruit.

    Directory of Open Access Journals (Sweden)

    Waewruedee Waewthongrak

    Full Text Available Effects of cyclic lipopeptides (CLPs obtained from Bacillus subtilis ABS-S14 on eliciting defense-related gene transcription and activity of defense-related enzymes; glucanase (GLU, chitinase (CHI, peroxidase (POX and lipoxygenase (LOX in Citrus sinensis cv. Valencia fruit were determined. The maximum level of GLU transcripts induced in fruit treated with fengycin was significantly greatest among treatments at 48 h. Surfactin enhanced the LOX and POX transcripts. In parallel, corresponding enzyme activities were correlated with changes in gene expression observed in fruit inoculated with Penicillium digitatum following treatment with individual CLPs. Synergistic effects of fengycin and iturin A, fengycin and surfactin were shown in gene transcript of GLU and CHI, respectively, and surfactin induced POX and LOX gene expression of citrus flavedo without pathogen infection. These results suggest that fengycin and surfactin act as elicitors of defense-related gene expression in "Valencia" fruit following infection.

  19. Recognizing plant defense priming

    NARCIS (Netherlands)

    Martinez-Medina, A.; Flors, V.; Heil, M.; Mauch-Mani, B.; Pieterse, C.M.J.; Pozo, M.J.; Ton, J.; Van Dam, N.M.; Conrath, U.

    2016-01-01

    Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in plant

  20. Discovery of a novel dual fungal CYP51/human 5-lipoxygenase inhibitor: implications for anti-fungal therapy.

    Directory of Open Access Journals (Sweden)

    Eric K Hoobler

    Full Text Available We report the discovery of a novel dual inhibitor targeting fungal sterol 14α-demethylase (CYP51 or Erg11 and human 5-lipoxygenase (5-LOX with improved potency against 5-LOX due to its reduction of the iron center by its phenylenediamine core. A series of potent 5-LOX inhibitors containing a phenylenediamine core, were synthesized that exhibit nanomolar potency and >30-fold selectivity against the LOX paralogs, platelet-type 12-human lipoxygenase, reticulocyte 15-human lipoxygenase type-1, and epithelial 15-human lipoxygenase type-2, and >100-fold selectivity against ovine cyclooxygenase-1 and human cyclooxygnease-2. The phenylenediamine core was then translated into the structure of ketoconazole, a highly effective anti-fungal medication for seborrheic dermatitis, to generate a novel compound, ketaminazole. Ketaminazole was found to be a potent dual inhibitor against human 5-LOX (IC50 = 700 nM and CYP51 (IC50 = 43 nM in vitro. It was tested in whole blood and found to down-regulate LTB4 synthesis, displaying 45% inhibition at 10 µM. In addition, ketaminazole selectively inhibited yeast CYP51 relative to human CYP51 by 17-fold, which is greater selectivity than that of ketoconazole and could confer a therapeutic advantage. This novel dual anti-fungal/anti-inflammatory inhibitor could potentially have therapeutic uses against fungal infections that have an anti-inflammatory component.

  1. Cloning and expression of lipoxygenase genes and enzyme activity in ripening persimmon fruit in response to GA and ABA treatment

    Science.gov (United States)

    Two genes of the lipoxygenase (LOX) family, DkLox1 and DkLox3 (GenBank accession No. JF436951 and JF436950), were cloned from persimmon fruit (Diospyros kaki L. ‘Fuping Jianshi’). Sequence analysis indicated that they belong to the 9-LOX sub-group. Heterologous expression of DkLox1 in E. coli produc...

  2. The untranslated leader sequence of the barley lipoxygenase 1 (Lox1) gene confers embryo-specific expression

    NARCIS (Netherlands)

    Rouster, J.; Mechelen J. van; Cameron-Mills, V.

    1998-01-01

    The barley lipoxygenase 1 (Lox1) gene encodes a protein expressed in embryos during grain development and germination and in leaves after methyl-jasmonate (MeJA) treatment. Transient gene expression assays in germinating barley embryos were used to identify cis-regulatory elements involved in the em

  3. Lipoxygenase, a key enzyme in bioconversion of linoleic acid into trihydroxy-octadecenoic acid by Pseudomonas aeruginosa PR3

    Science.gov (United States)

    Lipoxygenases catalyze the oxidation of unsaturated fatty acids with a (1Z,4Z)-pentadiene structure leading to the formation of conjugated (Z,E)-hydroperoxydienoic acids, which in turn result in production of hydroxy lipid. These enzymes are widely distributed in plants, animals, and microorganisms...

  4. Thermostable lipoxygenase, a key enzyme in bioconversion of linoleic acid to trihycroxy-octadecenoic acid by Pseudomonas aeruginosa PR3

    Science.gov (United States)

    Lipoxygenases, enzymes that contain non-heme iron, catalyze the oxidation of unsaturated fatty acids with a (1Z,4Z)-pentadiene moiety leading to conjugated (Z,E)-hydroperoxydienoic acids. These enzymes are widely distributed in plants and animals, and a few microorganisms are reported as well. It ...

  5. Human Lipoxygenase Pathway Gene Variation and Association with Markers of Subclinical Atherosclerosis in the Diabetes Heart Study

    Directory of Open Access Journals (Sweden)

    Kathryn P. Burdon

    2010-01-01

    Conclusions. Polymorphisms within ALOX12, ALOX5, and ALOX5AP are genetically associated with subclinical atherosclerosis and with biomarkers of disease in families with type 2 diabetes. These results suggest that variants in lipoxygenase pathway genes may have pleiotropic effects on multiple components that determine risk of cardiovascular disease.

  6. Maize death acids, 9-lipoxygenase derived cyclopente(a)nones, display activity as cytotoxic phytoalexins and transcriptional mediators

    Science.gov (United States)

    Plant damage promotes the interaction of lipoxygenases (LOX) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed jasmonates. ...

  7. The untranslated leader sequence of the barley lipoxygenase 1 (Lox1) gene confers embryo-specific expression

    NARCIS (Netherlands)

    Rouster, J.; Mechelen J. van; Cameron-Mills, V.

    1998-01-01

    The barley lipoxygenase 1 (Lox1) gene encodes a protein expressed in embryos during grain development and germination and in leaves after methyl-jasmonate (MeJA) treatment. Transient gene expression assays in germinating barley embryos were used to identify cis-regulatory elements involved in the em

  8. Macroevolutionary patterns of glucosinolate defense and tests of defense-escalation and resource availability hypotheses.

    Science.gov (United States)

    Cacho, N Ivalú; Kliebenstein, Daniel J; Strauss, Sharon Y

    2015-11-01

    We explored macroevolutionary patterns of plant chemical defense in Streptanthus (Brassicaceae), tested for evolutionary escalation of defense, as predicted by Ehrlich and Raven's plant-herbivore coevolutionary arms-race hypothesis, and tested whether species inhabiting low-resource or harsh environments invest more in defense, as predicted by the resource availability hypothesis (RAH). We conducted phylogenetically explicit analyses using glucosinolate profiles, soil nutrient analyses, and microhabitat bareness estimates across 30 species of Streptanthus inhabiting varied environments and soils. We found weak to moderate phylogenetic signal in glucosinolate classes and no signal in total glucosinolate production; a trend toward evolutionary de-escalation in the numbers and diversity of glucosinolates, accompanied by an evolutionary increase in the proportion of aliphatic glucosinolates; some support for the RAH relative to soil macronutrients, but not relative to serpentine soil use; and that the number of glucosinolates increases with microhabitat bareness, which is associated with increased herbivory and drought. Weak phylogenetic signal in chemical defense has been observed in other plant systems. A more holistic approach incorporating other forms of defense might be necessary to confidently reject escalation of defense. That defense increases with microhabitat bareness supports the hypothesis that habitat bareness is an underappreciated selective force on plants in harsh environments.

  9. Homology modeling of 5-lipoxygenase and hints for better inhibitor design

    Science.gov (United States)

    Aparoy, P.; Reddy, R. N.; Guruprasad, Lalitha; Reddy, M. R.; Reddanna, P.

    2008-09-01

    Lipoxygenases (LOXs) are a group of enzymes involved in the oxygenation of polyunsaturated fatty acids. Among these 5-lipoxygenase (5-LOX) is the key enzyme leading to the formation of pharmacologically important leukotrienes and lipoxins, the mediators of inflammatory and allergic disorders. In view of close functional similarity to mammalian lipoxygenase, potato 5-LOX is used extensively. In this study, the homology modeling technique has been used to construct the structure of potato 5-LOX. The amino acid sequence identity between the target protein and sequence of template protein 1NO3 (soybean LOX-3) searched from NCBI protein BLAST was 63%. Based on the template structure, the protein model was constructed by using the Homology program in InsightII. The protein model was briefly refined by energy minimization steps and validated using Profile-3D, ERRAT and PROCHECK. The results showed that 99.3% of the amino acids were in allowed regions of Ramachandran plot, suggesting that the model is accurate and its stereochemical quality good. Like all LOXs, 5-LOX also has a two-domain structure, the small N-terminal β-barrel domain and a larger catalytic domain containing a single atom of non-heme iron coordinating with His525, His530, His716 and Ile864. Asn720 is present in the fifth coordination position of iron. The sixth coordination position faces the open cavity occupied here by the ligands which are docked. Our model of the enzyme is further validated by examining the interactions of earlier reported inhibitors and by energy minimization studies which were carried out using molecular mechanics calculations. Four ligands, nordihydroguaiaretic acid (NDGA) having IC50 of 1.5 μM and analogs of benzyl propargyl ethers having IC50 values of 760 μM, 45 μM, and no inhibition respectively were selected for our docking and energy minimization studies. Our results correlated well with the experimental data reported earlier, which proved the quality of the model. This

  10. [Effects of high pulsed electric field on the secondary and tertiary structure of lipoxygenase].

    Science.gov (United States)

    Zhong, Kui; Hu, Xiao-Song; Wu, Ji-Hong; Chen, Fang; Liao, Xiao-Jun

    2009-03-01

    The effect of pulsed electric field (PEF) on the secondary and tertiary structure of lipoxygenase (LOX) in a buffer solution was analyzed using far UV-circular dichroism (CD) and fluorescence spectrophotometry, respectively. The secondary and tertiary structure of LOX changed after PEF treatment. The CD spectra of LOX also changed, with the intensity of two negative peaks and the content of alpha-helix significantly decreased (p electric field strength. The fluorescence intensity of LOX increased, and the relative fluorescence intensity of the two characteristic peaks of LOX emission spectra at 337 nm and 583 nm also showed a good linear correlation with the electric field strength. These results showed that the activity inactivation of LOX may be due to the alteration in secondary structure, and both had a good relation.

  11. Purification of a novel lipoxygenase from eggplant (Solanum melongena) fruit chloroplasts.

    Science.gov (United States)

    Pérez-Gilabert, Manuela; López-Nicolás, José Manuel; García Carmona, Francisco

    2001-03-01

    A novel membrane lipoxygenase (LOX; EC 1.13.11.12) from eggplant (Solanum melongena L. cv. Belleza negra) fruit chloroplasts has been purified 20-fold to a specific activity of 207 enzymatic units per mg of protein with a yield of 72%. The purification was carried out by sonicating the chloroplastic membranes in the presence of Triton X-114 followed by phase partitioning and anion exchange chromatography. The purified membrane LOX preparation consisted of a single major band with an apparent molecular mass of 97 kDa after sodium dodecyl sulfate polyacrylamide gel electrophoresis. The results obtained using intact chloroplasts indicate that the enzyme is not localized in the stroma. When the enzyme reacts with linoleic acid, it produces a single peak, which comigrates with standard 9-hydroperoxy-octadecadienoic acid. A physiological role for this chloroplastic LOX is proposed.

  12. Evaluation of Olive Fruit Lipoxygenase Extraction Protocols on 9- and 13-Z,E-HPODE Formation

    Directory of Open Access Journals (Sweden)

    Barbara Soldo

    2016-04-01

    Full Text Available In plant tissues, enzymes implicated in the lipoxygenase (LOX pathway are responsible for the hydroperoxydation of polyunsaturated fatty acids, ultimately leading to the production of small chemical species involved in several physiological processes. During industrial olive oil production, these enzymes are activated upon crushing and grinding of olive fruit tissue, subsequently leading to the synthesis of volatile compounds responsible for the positive aroma and flavor of the oil. An investigation of LOX activity during olive fruit ripening and malaxation could assist in the production of oils with favorable aroma and taste. Therefore, a reliable method for olive LOX purification is crucial. Here we report a critical review of six LOX extraction protocols, two of which have shown minimum enzyme activity, possibly leading to misconceptions in the interpretation of experimental data. Future research concerning olive LOX should employ extraction methods that preserve enzyme activity.

  13. Evaluation of Olive Fruit Lipoxygenase Extraction Protocols on 9- and 13-Z,E-HPODE Formation.

    Science.gov (United States)

    Soldo, Barbara; Šprung, Matilda; Mušac, Gloria; Pavela-Vrančić, Maja; Ljubenkov, Ivica

    2016-04-20

    In plant tissues, enzymes implicated in the lipoxygenase (LOX) pathway are responsible for the hydroperoxydation of polyunsaturated fatty acids, ultimately leading to the production of small chemical species involved in several physiological processes. During industrial olive oil production, these enzymes are activated upon crushing and grinding of olive fruit tissue, subsequently leading to the synthesis of volatile compounds responsible for the positive aroma and flavor of the oil. An investigation of LOX activity during olive fruit ripening and malaxation could assist in the production of oils with favorable aroma and taste. Therefore, a reliable method for olive LOX purification is crucial. Here we report a critical review of six LOX extraction protocols, two of which have shown minimum enzyme activity, possibly leading to misconceptions in the interpretation of experimental data. Future research concerning olive LOX should employ extraction methods that preserve enzyme activity.

  14. A role for 5-lipoxygenase products in obesity-associated inflammation and insulin resistance.

    Science.gov (United States)

    Neels, Jaap G

    2013-10-01

    There is a growing amount of evidence that obesity-induced low-grade inflammation is an important causative link between obesity and many of its associated pathologies such as type 2 diabetes and atherosclerosis. In the quest to identify the triggers of obesity-associated inflammation of adipose tissue, our laboratory recently demonstrated that adipocytes can secrete leukotrienes, and that these pro-inflammatory lipid mediators contribute to obesity-associated inflammation and insulin resistance in mice. Together with other recent studies, our recent findings identify an important role for the enzyme 5-lipoxygenase and its products in the induction and resolution of adipose tissue inflammation. Therefore, pharmaceutical approaches that target this enzyme or its products should be considered as novel treatments aimed at preventing or resolving obesity-induced inflammation and its associated pathologies.

  15. Intravenous anesthetic propofol binds to 5-lipoxygenase and attenuates leukotriene B4 production.

    Science.gov (United States)

    Okuno, Toshiaki; Koutsogiannaki, Sophia; Ohba, Mai; Chamberlain, Matthew; Bu, Weiming; Lin, Fu-Yan; Eckenhoff, Roderic G; Yokomizo, Takehiko; Yuki, Koichi

    2017-04-01

    Propofol is an intravenous anesthetic that produces its anesthetic effect, largely via the GABAA receptor in the CNS, and also reduces the N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced neutrophil respiratory burst. Because fMLP-stimulated neutrophils produce leukotriene (LT)B4, we examined the effect of propofol on LTB4 production in vivo and in vitro Cecal ligation and puncture surgery was performed in mice, with or without exposure to propofol. Propofol attenuated the production of 5-lipoxygenase (5-LOX)-related arachidonic acid (AA) derivatives in the peritoneal fluid. Also, in the in vitro experiments on fMLP-stimulated neutrophils and 5-LOX-transfected human embryonic kidney cells, propofol attenuated the production of 5-LOX-related AA derivatives. Based on these results, we hypothesized that propofol would directly affect 5-LOX function. Using meta-azi-propofol (AziPm), we photolabeled stable 5-LOX protein, which had been used to solve the X-ray crystallographic structure of 5-LOX, and examined the binding site(s) of propofol on 5-LOX. Two propofol binding pockets were identified near the active site of 5-LOX. Alanine scanning mutagenesis was performed for the residues of 5-LOX in the vicinity of propofol, and we evaluated the functional role of these pockets in LTB4 production. We demonstrated that these pockets were functionally important for 5-LOX activity. These two pockets can be used to explore a novel 5-LOX inhibitor in the future.-Okuno, T., Koutsogiannaki, S., Ohba, M., Chamberlain, M., Bu, W., Lin, F.-Y., Eckenhoff, R. G., Yokomizo T., Yuki, K. Intravenous anesthetic propofol binds to 5-lipoxygenase and attenuates leukotriene B4 production. © FASEB.

  16. Chronic hypoxia promotes pulmonary artery endothelial cell proliferation through H2O2-induced 5-lipoxygenase.

    Directory of Open Access Journals (Sweden)

    Kristi M Porter

    Full Text Available Pulmonary Hypertension (PH is a progressive disorder characterized by endothelial dysfunction and proliferation. Hypoxia induces PH by increasing vascular remodeling. A potential mediator in hypoxia-induced PH development is arachidonate 5-Lipoxygenase (ALOX5. While ALOX5 metabolites have been shown to promote pulmonary vasoconstriction and endothelial cell proliferation, the contribution of ALOX5 to hypoxia-induced proliferation remains unknown. We hypothesize that hypoxia exposure stimulates HPAEC proliferation by increasing ALOX5 expression and activity. To test this, human pulmonary artery endothelial cells (HPAEC were cultured under normoxic (21% O2 or hypoxic (1% O2 conditions for 24-, 48-, or 72 hours. In a subset of cells, the ALOX5 inhibitor, zileuton, or the 5-lipoxygenase activating protein inhibitor, MK-886, was administered during hypoxia exposure. ALOX5 expression was measured by qRT-PCR and western blot and HPAEC proliferation was assessed. Our results demonstrate that 24 and 48 hours of hypoxia exposure have no effect on HPAEC proliferation or ALOX5 expression. Seventy two hours of hypoxia significantly increases HPAEC ALOX5 expression, hydrogen peroxide (H2O2 release, and HPAEC proliferation. We also demonstrate that targeted ALOX5 gene silencing or inhibition of the ALOX5 pathway by pharmacological blockade attenuates hypoxia-induced HPAEC proliferation. Furthermore, our findings indicate that hypoxia-induced increases in cell proliferation and ALOX5 expression are dependent on H2O2 production, as administration of the antioxidant PEG-catalase blocks these effects and addition of H2O2 to HPAEC promotes proliferation. Overall, these studies indicate that hypoxia exposure induces HPAEC proliferation by activating the ALOX5 pathway via the generation of H2O2.

  17. Inhibition of arachidonate 15-lipoxygenase prevents 4-hydroxynonenal-induced protein damage in male germ cells.

    Science.gov (United States)

    Bromfield, Elizabeth G; Mihalas, Bettina P; Dun, Matthew D; Aitken, R John; McLaughlin, Eileen A; Walters, Jessica L H; Nixon, Brett

    2017-03-01

    Lipid peroxidation products, such as 4-hydroxynonenal (4HNE), are causative agents responsible for extensive protein damage within the male and female germlines. Recently, we have demonstrated that 4HNE production can initiate the proteolytic degradation of the molecular chaperone Heat Shock Protein A2 (HSPA2) in male germ cells. These events may be partially responsible for HSPA2 deficiency in the spermatozoa of patients that repeatedly fail in vitro fertilization. Given this, mechanisms that limit the production of 4HNE will be highly advantageous for the preservation of male fertility. The propagation of 4HNE in somatic cells has been linked to the enzymatic actions of arachidonate 15-lipoxygenase (ALOX15), a member of the lipoxygenase family of proteins. In view of this association, this study sought to explore ALOX15 as a physiological target to manipulate the levels of 4HNE produced in the male germline. Herein, we have demonstrated that ALOX15 is markedly upregulated in response to oxidative stress in round spermatids and the GC-2 cell line. Pharmacological inhibition of ALOX15 in GC-2 cells resulted in a significant reduction in both mitochondrial and cytoplasmic reactive oxygen species, as well as a dramatic reduction in 4HNE. Importantly, the reduced bioavailability of this aldehyde appears to confer positive downstream effects to its target proteins such that HSPA2 could be protected from damage by 4HNE. Taken together, these results suggest that the actions of ALOX15 are intimately tied to the production of 4HNE. Thus, the ALOX15 protein may be a promising new target for the mitigation of germline oxidative stress. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Down-regulation of lipoxygenase gene reduces degradation of carotenoids of golden rice during storage.

    Science.gov (United States)

    Gayen, Dipak; Ali, Nusrat; Sarkar, Sailendra Nath; Datta, Swapan K; Datta, Karabi

    2015-07-01

    Down-regulation of lipoxygenase enzyme activity reduces degradation of carotenoids of bio-fortified rice seeds which would be an effective tool to reduce huge post-harvest and economic losses of bio-fortified rice seeds during storage. Bio-fortified provitamin A-enriched rice line (golden rice) expressing higher amounts of β-carotene in the rice endosperm provides vitamin A for human health. However, it is already reported that degradation of carotenoids during storage is a major problem. The gene responsible for degradation of carotenoids during storage has remained largely unexplored till now. In our previous study, it has been shown that r9-LOX1 gene is responsible for rice seed quality deterioration. In the present study, we attempted to investigate if r9-LOX1 gene has any role in degradation of carotenoids in rice seeds during storage. To establish our hypothesis, the endogenous lipoxygenase (LOX) activity of high-carotenoid golden indica rice seed was silenced by RNAi technology using aleurone layer and embryo-specific Oleosin-18 promoter. To check the storage stability, LOX enzyme down-regulated high-carotenoid T3 transgenic rice seeds were subjected to artificial aging treatment. The results obtained from biochemical assays (MDA, ROS) also indicated that after artificial aging, the deterioration of LOX-RNAi lines was considerably lower compared to β-carotene-enriched transgenic rice which had higher LOX activity in comparison to LOX-RNAi lines. Furthermore, it was also observed by HPLC analysis that down-regulation of LOX gene activity decreases co-oxidation of β-carotene in LOX-RNAi golden rice seeds as compared to the β-carotene-enriched transgenic rice, after artificial aging treatment. Therefore, our study substantially establishes and verifies that LOX is a key enzyme for catalyzing co-oxidation of β-carotene and has a significant role in deterioration of β-carotene levels in the carotenoid-enriched golden rice.

  19. Modulation of alveolar macrophage lipoxygenase metabolism by the sulfhydryl-reactive compound

    Energy Technology Data Exchange (ETDEWEB)

    Peters-Golden, M.; Thebert, P.

    1986-03-01

    N-ethylmaleimide (NEM), a sulfhydryl(SH)-reactive compound, has been previously shown to trigger arachidonic acid (AA) release and thromboxane (TxB/sub 2/) synthesis in alveolar macrophages (AMs). The present study was undertaken to characterize the effects of this agent on rat AM lipoxygenase metabolism. NEM caused dose-dependent stimulation of TxB/sub 2/ and, to a lesser extent, PGE/sub 2/ synthesis. However, NEM at either 5 or 10 ..mu..M failed to stimulate production of LTB/sub 4/ (control= 31 + 6, 5 ..mu..M = 36 + 8, 10 ..mu..M = 39 +/- 14 pg/ml; mean + SEM, n = 3) or LTC/sub 4/ (control = 109 +/- 29, 5 ..mu..M = 111 + 27, 10 ..mu..M = 113 +/- 40 pg/ml; n = 4). Indomethacin (5 ..mu..M) failed to shunt AA towards LTB/sub 4/ or LTC/sub 4/ synthesis in response to 10 ..mu..M NEM. In addition, /sup 14/C-5-HETE production by /sup 14/C-AA prelabeled AMs was no greater in NEM-treated cultures (308 +/- 96 cpm) than in control cultures (321 +/- 159 cpm/4 x 10/sup 6/ cells). The effect of NEM on zymosan-induced eicosanoid synthesis was examined by incubating AMs with zymosan (100 ..mu..g/ml) for 1 hour + NEM. NEM (10 ..mu..M) inhibited zymosan-induced LTC/sub 4/ synthesis (control = 122 +/- 43, zymosan = 266 +/- 35, zymosan + NEM = 105 +/- 38 pg/ml; n = 3; p = .05) without cytotoxicity, and while yielding additive increments in TxB/sub 2/ and PGE/sub 2/. Since the actions of both 5-lipoxygenase and glutathione transferase represent SH-dependent steps in the synthesis of LTs, it is postulated that the SH reactivity of NEM explains both its inability to stimulate LT synthesis and its ability to inhibit zymosan-induced LTC/sub 4/ synthesis.

  20. Assessment of lipoxygenase activity in seed extracts from 35 plant species

    Directory of Open Access Journals (Sweden)

    Fauconnier, M. L.

    1995-02-01

    Full Text Available Lipoxygenase activity in 35 seed extracts was determined on the basis of hydroperoxide synthesis using linoleic acid as substrate. The results referring to the extracted protein content show that several species of Vigna (V. unguiculata, V. radiata and V. mungo and one of Trifolium exhibit stronger lipoxygenase activity than soybean enzyme extracts. The pH activity relationship was also established for 4 very active samples. GC-MS analysis revealed equal amounts of 9- and 13- hydroperoxides of linoleic acid in these seed extracts, indicating no enzyme positional specificity.

    Se ha determinado la actividad lipoxigenasa en 35 extractos de semilla en base a la síntesis de hidroperóxido usando ácido linoleico como sustrato. Los resultados referidos al contenido en proteína extraídos mostraron que varias especies de Vigna (V. unguiculata, V. radiata y V. mungo además de una de Trifolium, exhibieron mayor actividad lipoxigenasa que los extractos enzimáticos de soja. La relación entre la actividad-pH se ha establecido para 4 muestras muy activas. El análisis por GC-MS de estos extractos de semillas, mostró cantidades iguales de los hidroperóxidos 9- y 13 del ácido linoleico indicando la no especificidad posicional de la enzima.

  1. In vitro Anti-inflammatory Effects of Edible Igusa Soft Rush (Juncus effusus L.) on Lipoxygenase, Hyaluronidase, and Cellular Nitric Oxide Generation Assays

    National Research Council Canada - National Science Library

    Tatsuhiko Nishimura; Kiyotaka Kabata; Akiko Koike; Masateru Ono; Keiji Igoshi; Shin Yasuda

    2016-01-01

    .... Matcha green tea powder was tested for comparison. Hot-water and ethanol extracts of soft rush as well as matcha showed comparable lipoxygenase inhibition, with IC50 values of 123 to 145 µg/mL...

  2. Moving Target Defense

    CERN Document Server

    Jajodia, Sushil; Swarup, Vipin; Wang, Cliff; Wang, X Sean

    2011-01-01

    Moving Target Defense: Creating Asymmetric Uncertainty for Cyber Threats was developed by a group of leading researchers. It describes the fundamental challenges facing the research community and identifies new promising solution paths. Moving Target Defense which is motivated by the asymmetric costs borne by cyber defenders takes an advantage afforded to attackers and reverses it to advantage defenders. Moving Target Defense is enabled by technical trends in recent years, including virtualization and workload migration on commodity systems, widespread and redundant network connectivity, instr

  3. Dynamic defense workshop :

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, Sean Michael; Doak, Justin E.; Haas, Jason Juedes.; Helinski, Ryan; Lamb, Christopher C.

    2013-02-01

    On September 5th and 6th, 2012, the Dynamic Defense Workshop: From Research to Practice brought together researchers from academia, industry, and Sandia with the goals of increasing collaboration between Sandia National Laboratories and external organizations, de ning and un- derstanding dynamic, or moving target, defense concepts and directions, and gaining a greater understanding of the state of the art for dynamic defense. Through the workshop, we broadened and re ned our de nition and understanding, identi ed new approaches to inherent challenges, and de ned principles of dynamic defense. Half of the workshop was devoted to presentations of current state-of-the-art work. Presentation topics included areas such as the failure of current defenses, threats, techniques, goals of dynamic defense, theory, foundations of dynamic defense, future directions and open research questions related to dynamic defense. The remainder of the workshop was discussion, which was broken down into sessions on de ning challenges, applications to host or mobile environments, applications to enterprise network environments, exploring research and operational taxonomies, and determining how to apply scienti c rigor to and investigating the eld of dynamic defense.

  4. Landscape Variation in Plant Defense Syndromes across a Tropical Rainforest

    Science.gov (United States)

    McManus, K. M.; Asner, G. P.; Martin, R.; Field, C. B.

    2014-12-01

    Plant defenses against herbivores shape tropical rainforest biodiversity, yet community- and landscape-scale patterns of plant defense and the phylogenetic and environmental factors that may shape them are poorly known. We measured foliar defense, growth, and longevity traits for 345 canopy trees across 84 species in a tropical rainforest and examined whether patterns of trait co-variation indicated the existence of plant defense syndromes. Using a DNA-barcode phylogeny and remote sensing and land-use data, we investigated how phylogeny and topo-edaphic properties influenced the distribution of syndromes. We found evidence for three distinct defense syndromes, characterized by rapid growth, growth compensated by defense, or limited palatability/low nutrition. Phylogenetic signal was generally lower for defense traits than traits related to growth or longevity. Individual defense syndromes were organized at different taxonomic levels and responded to different spatial-environmental gradients. The results suggest that a diverse set of tropical canopy trees converge on a limited number of strategies to secure resources and mitigate fitness losses due to herbivory, with patterns of distribution mediated by evolutionary histories and local habitat associations. Plant defense syndromes are multidimensional plant strategies, and thus are a useful means of discerning ecologically-relevant variation in highly diverse tropical rainforest communities. Scaling this approach to the landscape level, if plant defense syndromes can be distinguished in remotely-sensed data, they may yield new insights into the role of plant defense in structuring diverse tropical rainforest communities.

  5. Crystal Structure of 12-Lipoxygenase Catalytic-Domain-Inhibitor Complex Identifies a Substrate-Binding Channel for Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shu; Mueser, Timothy C.; Marnett, Lawrence J.; Funk, Jr., Max O. (Toledo); (Vanderbilt)

    2014-10-02

    Lipoxygenases are critical enzymes in the biosynthesis of families of bioactive lipids including compounds with important roles in the initiation and resolution of inflammation and in associated diseases such as diabetes, cardiovascular disease, and cancer. Crystals diffracting to high resolution (1.9 {angstrom}) were obtained for a complex between the catalytic domain of leukocyte 12-lipoxygenase and the isoform-specific inhibitor, 4-(2-oxapentadeca-4-yne)phenylpropanoic acid (OPP). In the three-dimensional structure of the complex, the inhibitor occupied a new U-shaped channel open at one end to the surface of the protein and extending past the redox-active iron site that is essential for catalysis. In models, the channel accommodated arachidonic acid, defining the binding site for the substrate of the catalyzed reaction. There was a void adjacent to the OPP binding site connecting to the surface of the enzyme and providing a plausible access channel for the other substrate, oxygen.

  6. Structural stability of soybean lipoxygenase-1 in solution as probed by small angle X-ray scattering.

    Science.gov (United States)

    Dainese, Enrico; Sabatucci, Annalaura; van Zadelhoff, Guus; Angelucci, Clotilde Beatrice; Vachette, Patrice; Veldink, Gerrit A; Agrò, Alessandro Finazzi; Maccarrone, Mauro

    2005-05-27

    Soybean lipoxygenase-1 (LOX-1) is used widely as a model for studying the structural and functional properties of the homologous family of lipoxygenases. The crystallographic structure revealed that LOX-1 is organized in a beta-sheet N-terminal domain and a larger, mostly helical, C-terminal domain. Here, we describe the overall structural characterization of native unliganded LOX-1 in solution, using small angle X-ray scattering (SAXS). We show that the scattering pattern of the unliganded enzyme in solution does not display any significant difference compared with that calculated from the crystal structure, and that models of the overall shape of the protein calculated ab initio from the SAXS pattern provide a close envelope to the crystal structure. These data, demonstrating that LOX-1 has a compact structure also in solution, rule out any major motional flexibility of the LOX-1 molecule in aqueous solutions. In addition we show that eicosatetraynoic acid, an irreversible inhibitor of lipoxygenase used to mimic the effect of substrate binding, does not alter the overall conformation of LOX-1 nor its ability to bind to membranes. In contrast, the addition of glycerol (to 5%, v/v) causes an increase in the binding of the enzyme to membranes without altering its catalytic efficiency towards linoleic acid nor its SAXS pattern, suggesting that the global conformation of the enzyme is unaffected. Therefore, the compact structure determined in the crystal appears to be essentially preserved in these various solution conditions. During the preparation of this article, a paper by M. Hammel and co-workers showed instead a sharp difference between crystal and solution conformations of rabbit 15-LOX-1. The possible cause of this difference might be the presence of oligomers in the rabbit lipoxygenase preparations.

  7. Unfolding Green Defense

    DEFF Research Database (Denmark)

    Larsen, Kristian Knus

    2015-01-01

    consumption in military operations, defense expenditure, energy security, and global climate change. The report then proceeds to introduce the NATO Green Defence Framework before exploring specific current uses of green technologies and green strategies for defense. The report concludes that a number...

  8. Avian host defense peptides

    NARCIS (Netherlands)

    Cuperus, Tryntsje; Coorens, M.; van Dijk, A.; Haagsman, H.P.

    2013-01-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense

  9. Defense Mechanisms: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    This bibliography includes studies of defense mechanisms, in general, and studies of multiple mechanisms. Defense mechanisms, briefly and simply defined, are the unconscious ego defendants against unpleasure, threat, or anxiety. Sigmund Freud deserves the clinical credit for studying many mechanisms and introducing them in professional literature.…

  10. 5-Lipoxygenase-activating protein: a potential link between innate and adaptive immunity in atherosclerosis and adipose tissue inflammation.

    Science.gov (United States)

    Bäck, Magnus; Sultan, Ariane; Ovchinnikova, Olga; Hansson, Göran K

    2007-04-13

    Transforming growth factor-beta (TGF-beta) is a major antiinflammatory mediator in atherosclerosis. Transgenic ApoE(-/-) mice with a dominant-negative TGFbeta type II receptor (dnTGFbetaRII) on CD4(+) and CD8(+) T cells display aggravated atherosclerosis. The aim of the present study was to elucidate the mechanisms involved in this enhanced inflammatory response. Gene array analyses identified the 5-lipoxygenase-activating protein (FLAP) among the most upregulated genes in both the aorta and adipose tissue of dnTGFbetaRII transgenic ApoE(-/-) mice compared with their ApoE(-/-) littermates, a finding that was confirmed by real-time quantitative RT-PCR. Aortas from the former mice in addition produced increased amounts of the lipoxygenase product leukotriene B(4) after ex vivo stimulation. FLAP protein expression in both the aorta and adipose tissue was detected in macrophages, but not in T cells. Four weeks of treatment with the FLAP inhibitor MK-886 (10 mg/kg in 1% tylose delivered by osmotic pumps) significantly reduced atherosclerotic lesion size and T-cell content. Finally, FLAP mRNA levels were upregulated approximately 8-fold in adipose tissue derived from obese ob/ob mice. In conclusion, the results of the present study suggest a key role for mediators of the 5-lipoxygenase pathway in inflammatory reactions of atherosclerosis and metabolic disease.

  11. Aryl-acetic and cinnamic acids as lipoxygenase inhibitors with antioxidant, anti-inflammatory, and anticancer activity.

    Science.gov (United States)

    Hadjipavlou-Litina, Dimitra; Pontiki, Eleni

    2015-01-01

    Cinnamic acids have been identified as interesting compounds with cytotoxic, anti-inflammatory, and antioxidant properties. Lipoxygenase pathway, catalyzing the first two steps of the transformation of arachidonic acid into leukotrienes is implicated in several processes such as cell differentiation, inflammation and carcinogenesis. Development of drugs that interfere with the formation or effects of these metabolites would be important for the treatment of various diseases like asthma, psoriasis, ulcerative colitis, rheumatoid arthritis, atherosclerosis, cancer, and blood vessel disorders. Till now, asthma consists of the only pathological case in which improvement has been shown by lipoxygenase LO inhibitors. Thus, the research has been directed towards the development of drugs that interfere with the formation of leukotrienes. In order to explore the anti-inflammatory and cytotoxic effects of antioxidant acrylic/cinnamic acids a series of derivatives bearing the appropriate moieties have been synthesized via the Knoevenagel condensation and evaluated for their biological activities. The compounds have shown important antioxidant activity, anti-inflammatory activity and very good inhibition of soybean lipoxygenase while some of them were tested for their anticancer activity.

  12. Identification of lipoxygenase (LOX) genes from legumes and their responses in wild type and cultivated peanut upon Aspergillus flavus infection

    Science.gov (United States)

    Song, Hui; Wang, Pengfei; Li, Changsheng; Han, Suoyi; Lopez-Baltazar, Javier; Zhang, Xinyou; Wang, Xingjun

    2016-01-01

    Lipoxygenase (LOX) genes are widely distributed in plants and play crucial roles in resistance to biotic and abiotic stress. Although they have been characterized in various plants, little is known about the evolution of legume LOX genes. In this study, we identified 122 full-length LOX genes in Arachis duranensis, Arachis ipaënsis, Cajanus cajan, Cicer arietinum, Glycine max, Lotus japonicus and Medicago truncatula. In total, 64 orthologous and 36 paralogous genes were identified. The full-length, polycystin-1, lipoxygenase, alpha-toxin (PLAT) and lipoxygenase domain sequences from orthologous and paralogous genes exhibited a signature of purifying selection. However, purifying selection influenced orthologues more than paralogues, indicating greater functional conservation of orthologues than paralogues. Neutrality and effective number of codons plot results showed that natural selection primarily shapes codon usage, except for C. arietinum, L. japonicas and M. truncatula LOX genes. GCG, ACG, UCG, CGG and CCG codons exhibited low relative synonymous codon usage (RSCU) values, while CCA, GGA, GCU, CUU and GUU had high RSCU values, indicating that the latter codons are strongly preferred. LOX expression patterns differed significantly between wild-type peanut and cultivated peanut infected with Aspergillus flavus, which could explain the divergent disease resistance of wild progenitor and cultivars. PMID:27731413

  13. Defense Industry Clusters in Turkey

    Directory of Open Access Journals (Sweden)

    Kadir Alpaslan Demir

    2016-06-01

    Full Text Available All countries strive for a capable national defense supported by a strong national defense industry. Supporting national defense with imported defense systems has many limitations and risks because the terms of arms trade agreements between countries may easily be influenced by the political climate of the signatories. As a result, establishing an independent national defense requires a strong national defense industry. Furthermore, exporting defense systems may be an important source of national income. National defense industries mostly consist of large-scale defense firms that have the resources required for big defense contracts. However, small to medium enterprises (SMEs do not have the necessary resources, therefore they are at a disadvantage. To overcome this handicap and be part of the business, defense industry clusters mostly consisting of SMEs are being established. Provided that there is good national planning and support in this area, defense clusters consisting of SMEs may play a significant role in industry. SMEs have a chance to offer specialized services, special or customized products when needed. As a result, large defense firms subcontract certain portions of defense projects to SMEs. Since 2010, Turkey has shown signs of continuous improvement in defense industry clustering. In parallel with these developments, this study discusses the importance of clustering in the defense industry, briefly presents the state of the Turkish defense industry as highlighted by national statistics, and presents the current status of defense clusters in Turkey. The novelty of this article consists in its assessment of Turkish defense clusters.

  14. The shunt from the cyclooxygenase to lipoxygenase pathway in human osteoarthritic subchondral osteoblasts is linked with a variable expression of the 5-lipoxygenase-activating protein.

    Science.gov (United States)

    Maxis, Kelitha; Delalandre, Aline; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Duval, Nicolas; Lajeunesse, Daniel

    2006-01-01

    Osteoarthritis (OA) is characterized by articular cartilage degradation and hypertrophic bone changes with osteophyte formation and abnormal bone remodeling. Two groups of OA patients were identified via the production of variable and opposite levels of prostaglandin E2 (PGE2) or leukotriene B4 (LTB4) by subchondral osteoblasts, PGE2 levels discriminating between low and high subgroups. We studied whether the expression of 5-lipoxygenase (5-LO) or 5-LO-activating protein (FLAP) is responsible for the shunt from prostaglandins to leukotrienes. FLAP mRNA levels varied in low and high OA groups compared with normal, whereas mRNA levels of 5-LO were similar in all osteoblasts. Selective inhibition of cyclooxygenase-2 (COX-2) with NS-398-stimulated FLAP expression in the high OA osteoblasts subgroup, whereas it was without effect in the low OA osteoblasts subgroup. The addition of PGE2 to the low OA osteoblasts subgroup decreased FLAP expression but failed to affect it in the high OA osteoblasts subgroup. LTB4 levels in OA osteoblasts were stimulated about twofold by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plus transforming growth factor-beta (TGF-beta), a situation corresponding to their effect on FLAP mRNA levels. Treatments with 1,25(OH)2D3 and TGF-beta also modulated PGE2 production. TGF-beta stimulated PGE2 production in both OA osteoblast groups, whereas 1,25(OH)2D3 alone had a limited effect but decreased the effect of TGF-beta in the low OA osteoblasts subgroup. This modulation of PGE2 production was mirrored by the synthesis of COX-2. IL-18 levels were only slightly increased in a subgroup of OA osteoblasts compared with normal; however, no relationship was observed overall between IL-18 and PGE2 levels in normal and OA osteoblasts. These results suggest that the shunt from the production of PGE2 to LTB4 is through regulation of the expression of FLAP, not 5-LO, in OA osteoblasts. The expression of FLAP in OA osteoblasts is also modulated differently by 1,25(OH

  15. More JAZ in the orchestration of jasmonate-mediated plant defense

    NARCIS (Netherlands)

    Zhou, Meiliang

    2014-01-01

    Jasmonates (JAs) are plant hormones that regulate defense against microbial pathogens and insect herbivores via two antagonistic branches of the JAs signaling pathway leading to activation of distinct sets of defense genes. In Arabidopsis thaliana defense against herbivores is regulated by JAs alone

  16. Defense and the Economy

    Science.gov (United States)

    1993-01-01

    AD A 66 28 o’py 9of 27 copiesII AD-A266 288-co, .o,,,, I IDA PAPER P-28 10I * DEFENSE AND THE ECONOMY David R. Graham An-Jen Tai Barbara A...TYPE AND DATES COVERED January 1993 4. TITLE AND SUBTITLE S. FUNDING NUMBERS Defense and the Economy C-MDA 903 89C 0003i...Fomr 298 (Rev 2-4g) 3Preserked by ANSI Sid, Z39- 2I0 I I I IDA PAPER P-2810() 3 DEFENSE AND THE ECONOMY I I David R. Graham An-Jen Tai Barbara A

  17. Age-dependent relevance of endogenous 5-lipoxygenase derivatives in anxiety-like behavior in mice.

    Directory of Open Access Journals (Sweden)

    Luciana M Leo

    Full Text Available When 5-lipoxygenase (5-LO is inhibited, roughly half of the CNS effect of the prototypic endocannabinoid anandamide (AEA is lost. Therefore, we decided to investigate whether inhibiting this enzyme would influence physiological functions classically described as being under control of the endocannabinoid system. Although 5-LO inhibition by MK-886 reduced lipoxin A4 levels in the brain, no effect was found in the elevated plus maze (EPM, even at the highest possible doses, via i.p. (10 mg/kg, or i.c.v. (500 pmol/2 µl routes. Accordingly, no alterations in anxiety-like behavior in the EPM test were observed in 5-LO KO mice. Interestingly, aged mice, which show reduced circulating lipoxin A4 levels, were sensitive to MK-886, displaying an anxiogenic-like state in response to treatment. Moreover, exogenous lipoxin A4 induced an anxiolytic-like profile in the EPM test. Our findings are in line with other reports showing no difference between FLAP KO or 5-LO KO and their control strains in adult mice, but increased anxiety-like behavior in aged mice. We also show for the first time that lipoxin A4 affects mouse behavior. In conclusion, we propose an age-dependent relevancy of endogenous 5-LO derivatives in the modulation of anxiety-like behavior, in addition to a potential for exogenous lipoxin A4 in producing an anxiolytic-like state.

  18. 5-lipoxygenase is a key determinant of acute myocardial inflammation and mortality during Trypanosoma cruzi infection.

    Science.gov (United States)

    Pavanelli, Wander R; Gutierrez, Fredy R S; Mariano, Flávia S; Prado, Cibele M; Ferreira, Beatriz Rossetti; Teixeira, Mauro Martins; Canetti, Cláudio; Rossi, Marcos A; Cunha, Fernando Q; Silva, João S

    2010-08-01

    This study provides evidence supporting the idea that although inflammatory cells migration to the cardiac tissue is necessary to control the growth of Trypanosoma cruzi, the excessive influx of such cells during acute myocarditis may be deleterious to the host. Production of lipid mediators of inflammation like leukotrienes (LTs) along with cytokines and chemokines largely influences the severity of inflammatory injury in response to tissue parasitism. T. cruzi infection in mice deficient in 5-lipoxygenase (5-LO), the enzyme responsible for the synthesis of LTs and other lipid inflammatory mediators, resulted in transiently increased parasitemia, and improved survival rate compared with WT mice. Myocardia from 5-LO(-/-) mice exhibited reduced inflammation, collagen deposition, and migration of CD4(+), CD8(+), and IFN-gamma-producer cells compared with WT littermates. Moreover, decreased amounts of TNF-alpha, IFN-gamma, and nitric oxide synthase were found in the hearts of 5-LO(-/-) mice. Interestingly, despite of early higher parasitic load, 5-LO(-/-) mice survived, and controlled T. cruzi infection. These results show that efficient parasite clearance is possible in a context of moderate inflammatory response, as occurred in 5-LO(-/-) mice, in which reduced myocarditis protects the animals during T. cruzi infection. Copyright 2010 Elsevier Masson SAS. All rights reserved.

  19. Crystal structure of linoleate 13R-manganese lipoxygenase in complex with an adhesion protein.

    Science.gov (United States)

    Chen, Yang; Wennman, Anneli; Karkehabadi, Saeid; Engström, Åke; Oliw, Ernst H

    2016-08-01

    The crystal structure of 13R-manganese lipoxygenase (MnLOX) of Gaeumannomyces graminis (Gg) in complex with zonadhesin of Pichia pastoris was solved by molecular replacement. Zonadhesin contains β-strands in two subdomains. A comparison of Gg-MnLOX with the 9S-MnLOX of Magnaporthe oryzae (Mo) shows that the protein fold and the geometry of the metal ligands are conserved. The U-shaped active sites differ mainly due to hydrophobic residues of the substrate channel. The volumes and two hydrophobic side pockets near the catalytic base may sanction oxygenation at C-13 and C-9, respectively. Gly-332 of Gg-MnLOX is positioned in the substrate channel between the entrance and the metal center. Replacements with larger residues could restrict oxygen and substrate to reach the active site. C18 fatty acids are likely positioned with C-11 between Mn(2+)OH2 and Leu-336 for hydrogen abstraction and with one side of the 12Z double bond shielded by Phe-337 to prevent antarafacial oxygenation at C-13 and C-11. Phe-347 is positioned at the end of the substrate channel and replacement with smaller residues can position C18 fatty acids for oxygenation at C-9. Gg-MnLOX does not catalyze the sequential lipoxygenation of n-3 fatty acids in contrast to Mo-MnLOX, which illustrates the different configurations of their substrate channels.

  20. Effects of recombinant lipoxygenase on the rheological properties of dough and the quality of noodles.

    Science.gov (United States)

    Zhang, Chong; Zhang, Shuang; Bie, Xiaomei; Zhao, Haizhen; Lu, Fengxia; Lu, Zhaoxin

    2016-07-01

    The effects of purified recombinant lipoxygenase (ana-rLOX) on the rheological properties of dough and the quality of noodles made from wheat flour with low protein content (Yanmai 15) were studied. The addition of ana-rLOX increased dough stability time, decreased the degree of softening within 12 min, enhanced the resistance to extension, and increased the extensibility with 135 min of resting time. The mechanical spectra of the dough showed an increase in both storage modulus (G') and loss modulus (G″) with increasing ana-rLOX levels. The L(*) values of the noodle sheets increased by 2.34 compared with the control after storing for 1 h at room temperature. The textural parameters of noodles improved after ana-rLOX addition, including hardness, gumminess, chewiness and springiness. The wheat flour treated with the ana-rLOX had a higher cooking yield and lower cooking loss for the resulting noodles. The scanning electron microscopy results revealed that gluten was formed in the noodle samples that were treated with ana-rLOX. In this study, ana-rLOX was applied to noodles during the noodle-making process, and both dough rheological characteristics and noodle quality were improved. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  1. New sterols with anti-inflammatory potentials against cyclooxygenase-2 and 5-lipoxygenase from Paphia malabarica.

    Science.gov (United States)

    Joy, Minju; Chakraborty, Kajal; Raola, Vamshi Krishna

    2017-06-01

    Marine bivalves occupy a leading share in the total edible molluscs at the coastline regions of south-eastern Asia, and are found to possess significant nutritional and biological potential. Various in vitro evaluation (antioxidant and anti-inflammatory) guided purification of ethyl acetate-methanol (EtOAc-MeOH) extract of bivalve clam, Paphia malabarica characterised two new sterol derivatives as 23-gem-dimethylcholesta-5-en-3β-ol (1) and (22E)-24(1),24(2)-methyldihomocholest-5,22-dien-3β-ol (2) collected from the south-west coast of Arabian Sea. Their structures were unambiguously assigned on the basis of 1D, 2D NMR spectroscopy and mass spectrometry. The antioxidant and anti-inflammatory activities of 2 as determined by DPPH/ABTS(+) radical scavenging and anti-cyclooxygenase-2/5-lipoxygenase assays were significantly greater (IC50  1 mg/mL). Structure-activity relationship analysis revealed that the bioactivities of these compounds were directly proportional to the electronic and lipophilic parameters. This is the first report of the occurrence and characterisation of 23-gem-dimethyl-3β-hydroxy-Δ(5)-cholestane nucleus and C-30 dihomosterol from marine organisms.

  2. Association between polymorphisms of arachidonate 12-lipoxygenase (ALOX12 and schizophrenia in a Korean population

    Directory of Open Access Journals (Sweden)

    Park Jin

    2010-07-01

    Full Text Available Abstract Arachidonic acid (AA, an essential polyunsaturated fatty acid, is one of the major components of neural membranes, which show an altered phospholipid composition in schizophrenia. Arachidonate 12-lipoxygenase (ALOX12, an important enzyme, metabolizes AA to 12-HPETE, which affects catecholamine synthesis. However, research has yet to show the genetic association between ALOX12 and schizophrenia. Therefore, we investigated single nucleotide polymorphisms (SNP of the ALOX12 gene in schizophrenia, recruiting patients with schizophrenia (n = 289 and normal controls (n = 306 from a Korean population. We selected three SNPs (rs1126667, rs434473, and rs1042357 of the ALOX12 gene and genotyped them by direct sequencing. We reviewed the schizophrenic patients' medical records and assessed them clinically using the Brief Psychiatric Rating Scale (BPRS, the Scale for the Assessment of Negative Symptoms (SANS, and the Operational Criteria Checklist (OPCRIT. Then we statistically analyzed the genetic associations between the SNPs and schizophrenia, finding a genetic association between both rs1126667 and rs1042357 and schizophrenia, in the recessive model (p = 0.015 and 0.015, respectively. We also found an association between rs434473 and negative symptoms, defined through a factor analysis of the OPCRIT data (p = 0.040. Consequently, we suggest that SNPs of the ALOX12 gene might be associated with schizophrenia and negative symptoms in this Korean population. These weak positives require additional study.

  3. The Acute Phase of Trypanosoma cruzi Infection Is Attenuated in 5-Lipoxygenase-Deficient Mice

    Directory of Open Access Journals (Sweden)

    Adriana M. C. Canavaci

    2014-01-01

    Full Text Available In the present work we examine the contribution of 5-lipoxygenase- (5-LO- derived lipid mediators to immune responses during the acute phase of Trypanosoma cruzi infection in 5-LO gene knockout (5-LO−/− mice and wild-type (WT mice. Compared with WT mice, the 5-LO−/− mice developed less parasitemia/tissue parasitism, less inflammatory cell infiltrates, and a lower mortality. This resistance of 5-LO−/− mice correlated with several differences in the immune response to infection, including reduced PGE2 synthesis; sustained capacity of splenocytes to produce high levels of interleukin (IL-12 early in the infection; enhanced splenocyte production of IL-1β, IL-6, and IFN-γ; rapid T-cell polarization to secrete high quantities of IFN-γ and low quantities of IL-10; and greater numbers of CD8+CD44highCD62Llow memory effector T cells at the end of the acute phase of infection. The high mortality in WT mice was associated with increased production of LTB4/LTC4, T cell bias to produce IFN-γ, high levels of serum nitrite, and marked protein extravasation into the peritoneal cavity, although survival was improved by treatment with a cys-LT receptor 1 antagonist. These data also provide evidence that 5-LO-derived mediators negatively affect host survival during the acute phase of T. cruzi infection.

  4. Structure and interaction with phospholipids of a prokaryotic lipoxygenase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Garreta, Albert; Val-Moraes, Silvana P; García-Fernández, Queralt; Busquets, Montserrat; Juan, Carlos; Oliver, Antonio; Ortiz, Antonio; Gaffney, Betty J; Fita, Ignacio; Manresa, Àngels; Carpena, Xavi

    2013-12-01

    Lipoxygenases (LOXs), which are essential in eukaryotes, have no confirmed function in prokaryotes that are devoid of polyunsaturated fatty acids. The structure of a secretable LOX from Pseudomonas aeruginosa (Pa_LOX), the first available from a prokaryote, presents significant differences with respect to eukaryotic LOXs, including a cluster of helices acting as a lid to the active center. The mobility of the lid and the structural variability of the N-terminal region of Pa_LOX was confirmed by comparing 2 crystal forms. The binding pocket contains a phosphatidylethanolamine phospholipid with branches of 18 (sn-1) and 14/16 (sn-2) carbon atoms in length. Carbon atoms from the sn-1 chain approach the catalytic iron in a manner that sheds light on how the enzymatic reaction might proceed. The findings in these studies suggest that Pa_LOX has the capacity to extract and modify unsaturated phospholipids from eukaryotic membranes, allowing this LOX to play a role in the interaction of P. aeruginosa with host cells.

  5. 15-Lipoxygenase-1 Is Involved in the Effects of Atorvastatin on Endothelial Dysfunction

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2016-01-01

    Full Text Available Statins exert pleiotropic effects on endothelial cells in addition to lowering cholesterol. 15-Lipoxygenase-1 (ALOX15 has been implicated in vascular inflammation and disease. The relationship between atorvastatin and ALOX15 was investigated using a rat carotid artery balloon-injury model. Hematoxylin and eosin (HE staining showed that ALOX15 overexpression increased the thickness of the intima-media (IMT. Immunohistochemistry and western blotting showed that atorvastatin increased the expression of cellular adhesion molecules (CAMs but decreased the expression of endothelial nitric oxide synthase (eNOS; these effects of atorvastatin were blocked by ALOX15 overexpression. In human umbilical venous endothelial cells (HUVECs, silencing of ALOX15 enhanced the effects of atorvastatin on endothelial function. Expression levels of CAMs and Akt/eNOS/NO under oxidized low-density lipoprotein (ox-LDL stimulation were modulated by ALOX15 inhibitor and ALOX15 small interfering RNA (siRNA. Atorvastatin abolished the activation of nuclear factor-kappa B (NF-κB induced by ox-LDL. Exposure to ox-LDL induced upregulation of ALOX15 in HUVECs, but this effect was partially abolished by atorvastatin or the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC. These results demonstrate that regulation of ALOX15 expression might be involved in the effects of atorvastatin on endothelial dysfunction.

  6. Critical role of 5-lipoxygenase and heme oxygenase-1 in wound healing.

    Science.gov (United States)

    Brogliato, Ariane R; Moor, Andrea N; Kesl, Shannon L; Guilherme, Rafael F; Georgii, Janaína L; Peters-Golden, Marc; Canetti, Claudio; Gould, Lisa J; Benjamim, Claudia F

    2014-05-01

    Lipid mediators derived from 5-lipoxygenase (5-LO) metabolism can activate both pro- and anti-inflammatory pathways, but their role in wound healing remains largely unexplored. In this study we show that 5-LO knockout (5-LO(-/-)) mice exhibited faster wound healing than wild-type (WT) animals, and exhibited upregulation of heme oxygenase-1 (HO-1). Furthermore, HO-1 inhibition in 5-LO(-/-) mice abolished the beneficial effect observed. Despite the fact that 5-LO(-/-) mice exhibited faster healing, in in vitro assays both migration and proliferation of human dermal fibroblasts (HDFs) were inhibited by the 5-LO pharmacologic inhibitor AA861. No changes were observed in the expression of fibronectin, transforming growth factor (I and III), and α-smooth muscle actin (α-SMA). Interestingly, AA861 treatment significantly decreased ROS formation by stimulated fibroblasts. Similar to 5-LO(-/-) mice, induction of HO-1, but not superoxide dismutase-2 (SOD-2), was also observed in response to 5-LO (AA861) or 5-LO activating protein (MK886) inhibitors. HO-1 induction was independent of nuclear factor (erythroid derived-2) like2 (Nrf-2), cyclooxygenase 2 (COX-2) products, or lipoxin action. Taken together, our results show that 5-LO disruption improves wound healing and alters fibroblast function by an antioxidant mechanism based on HO-1 induction. Overexpression of HO-1 in wounds may facilitate early wound resolution.

  7. Lipoxygenase activity of soybean and protein evaluation of soy milk produced from irradiated grains

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Erica A., E-mail: ericabarros@fca.unesp.br [UNESP - Fazenda Experimental Lageado, Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas; Broetto, Fernando, E-mail: broetto@ibb.unesp.br [UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Quimica e Bioquimica; Costa, Vladimir E., E-mail: vladimir@ibb.unesp.br [UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica

    2011-07-01

    Soybean and its derivative are considered as a functional food because it has high quality protein and are used for the prevention of chronic degenerative diseases. The irradiation technique is used in soybeans to increase shelf life and avoid problems in plant products consumed raw or processed. However, the controversy in the literature that the irradiation dose up 10 kGy food can alter the functional properties and structures of macronutrients. With the prospect of more information on the use of radiation on soybeans, the objective of this study was to determine the activity of lipoxygenase in soybeans and to evaluate possible changes in the protein content of soymilk processed from grain-BRS 213, BRS 258 and Embrapa 48 subjected to dosages of 2.5 , 5.0 and 10.0 kGy of gamma radiation. The soybean cultivars were wrapped in plastic bags and subjected to gamma radiation source {sup 60}Co, Gammacell 220 (Atomic Energy of Canada Ltd.), except the control. The grains irradiated induced reduction of enzyme activity. The results for the protein content of soymilk were similar, appropriate to that required by ANVISA and showed little protein solubility for cultivars BRS-258 and Embrapa48. It was concluded that the technique of irradiation beyond to keep the nutritional value of soy can contribute to the organoleptic quality of soymilk. (author)

  8. Distribution of β-amylase and lipoxygenase in soy protein products obtained during tofu production

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    Stanojević Slađana P.

    2017-01-01

    Full Text Available Soybean is considered an important source of human food and animal feed. Okara and tofu whey are the main by-products of soymilk and tofu production. The distribution of enzymes β-amylase and lipoxygenase (Lox from six soybean genotypes in protein extracts of okara and tofu as well as in soymilk and tofu whey was assessed. SDS-electrophoretic results showed that production process significantly affected high molecular mass protein fractions of soybean by-products. Low amounts of Lox in soymilk were registered, while in okara protein extracts and tofu whey this enzyme was present in trace. In tofu protein extracts, Lox was registered in higher quantity that might be the result of the aggregation process during formation of the tofu gel. Content of β-amylase in all soy protein products was high and similar to the content in soybean genotype. Content of β-amylase in okara depended on respective soybean genotype. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31022 and the EU FP7 project Grant Agreement No.316004 (REGPOT-AREA

  9. Characterization of a novel lipoxygenase-independent senescence mechanism in Alstroemeria peruviana floral tissue.

    Science.gov (United States)

    Leverentz, Michael K; Wagstaff, Carol; Rogers, Hilary J; Stead, Anthony D; Chanasut, Usawadee; Silkowski, Helena; Thomas, Brian; Weichert, Heiko; Feussner, Ivo; Griffiths, Gareth

    2002-09-01

    The role of lipoxygenase (lox) in senescence of Alstroemeria peruviana flowers was investigated using a combination of in vitro assays and chemical profiling of the lipid oxidation products generated. Phospholipids and galactolipids were extensively degraded during senescence in both sepals and petals and the ratio of saturated/unsaturated fatty acids increased. Lox protein levels and enzymatic activity declined markedly after flower opening. Stereochemical analysis of lox products showed that 13-lox was the major activity present in both floral tissues and high levels of 13-keto fatty acids were also synthesized. Lipid hydroperoxides accumulated in sepals, but not in petals, and sepals also had a higher chlorophyll to carotenoid ratio that favors photooxidation of lipids. Loss of membrane semipermeability was coincident for both tissue types and was chronologically separated from lox activity that had declined by over 80% at the onset of electrolyte leakage. Thus, loss of membrane function was not related to lox activity or accumulation of lipid hydroperoxides per se and differs in these respects from other ethylene-insensitive floral tissues representing a novel pattern of flower senescence.

  10. Cuminaldehyde as a lipoxygenase inhibitor: in vitro and in silico validation.

    Science.gov (United States)

    Tomy, M J; Dileep, K V; Prasanth, S; Preethidan, D S; Sabu, A; Sadasivan, C; Haridas, M

    2014-09-01

    The search for lipoxygenase (LOX) inhibitors has been carried out for decades due to its importance in inflammatory diseases. In the present study, it was observed that the methanolic extract of Cuminum cyminum L. inhibited LOX activity. Activity-guided screening of the C. cyminum crude extracts helped the identification and isolation of cuminaldehyde as a 15-LOX inhibitor. The enzyme kinetics analysis suggested cuminaldehyde to be a competitive inhibitor and the IC 50 value derived from LB plots is 1,370 μM. Binding constants of cuminaldehyde on LOX was deduced by isothermal titration calorimetry. The combined thermodynamics and molecular modeling analyses suggested cuminaldehyde as a competitive LOX inhibitor. It is proposed from the present study that the coordinate bond between the Fe(2+) atom in the active site of the enzyme and the cuminaldehyde may be responsible for the enzyme inhibition. The study suggests that cuminaldehyde may be acting as an anti-inflammatory compound and may be therefore included in the category of leads for developing dual COX-LOX inhibitors as non-steroidal anti-inflammatory drugs (NSAIDs).

  11. Isoflavone composition and antioxidant capacity of modified-lipoxygenase soybeans grown in Maryland.

    Science.gov (United States)

    Whent, Monica; Lv, Junli; Luthria, Devanand L; Kenworthy, William; Yu, Liangli Lucy

    2011-12-28

    Maryland-grown soybean lines modified for low lipoxygenase-1 (LOX-1) content and a traditional nonmodified cultivar were analyzed for fatty acid composition, total phenolic content (TPC), isoflavone composition, relative DPPH• scavenging capacity (RDSC), and hydroxyl radical scavenging capacity (HOSC). Soybean lines included black, brown, and yellow soybeans. TPC of all soybean lines ranged from 2.84 to 4.74 mg gallic acid equiv (GAE)/g flour. Total isoflavones were between 2.78 and 8.66 μmol/g flour. RDSC of all lines was between 0.48 and 14.62 μmol Trolox equiv (TE)/g flour, and HOSC ranged from 53.57 to 135.52 μmol TE/g flour. Some modified-LOX genotypes demonstrated antioxidant capacity and/or isoflavone content similar to or higher than those of the nonmodified cultivar (P soybeans demonstrated higher TPC and RDSC than most yellow soybean lines, although they did not have higher isoflavone content. The results demonstrate that modification of the LOX trait did not necessarily alter the antioxidant capacity or chemical composition of the experimental soybean lines when compared with a nonmodified cultivar. These soybean lines may be studied further for nutraceutical properties and use in functional foods.

  12. Plasmin is a specific stimulus of the 5-lipoxygenase pathway of human peripheral monocytes.

    Science.gov (United States)

    Weide, I; Tippler, B; Syrovets, T; Simmet, T

    1996-10-01

    The objective of this study was to characterize the plasmin-induced stimulation of leukotriene (LT) B4 biosynthesis in human peripheral monocytes (PM). Plasmin up to 175 x 10(-3) CTA U/ml triggers a concentration-dependent release of 5-lipoxygenase-derived LTB4 while release of the cyclooxygenase products thromboxane (TX) B2 and prostaglandin (PG) E2 remained unaffected. The stimulatory effect appeared to be specific in as much as 1) it was found in PM, but not in polymorphonuclear neutrophils (PMN), 2) it requires the lysine binding sites of plasmin molecule since it was inhibited by the lysine analogues 6-aminohexanoic acid (6-AHA) and trans-4(aminomethyl)cyclohexane-1-carboxylic acid (t-AMCA), 3) the intact catalytic center of plasmin is required since neither plasminogen nor catalytic center-blocked plasmin share the stimulatory effect of active plasmin, 4) other serine proteases such as alpha-chymotrypsin, human neutrophil elastase and cathepsin G did not stimulate release of detectable amounts of LTB4 from PM. In addition, catalytic center-blocked plasmin antagonized the stimulatory effect of active plasmin. Plasmin-mediated monocyte activation apparently proceeds via a pertussis toxin-sensitive G protein. Plasmin did not increase inositol (1,4,5) trisphosphate levels, but a time- and concentration-dependent stimulation of cyclic GMP formation was observed. The data show that plasmin is a specific stimulus for human peripheral monocytes. Plasmin may be an important link between the coagulation cascade and inflammatory reactions.

  13. Clicked Cinnamic/Caffeic Esters and Amides as Radical Scavengers and 5-Lipoxygenase Inhibitors

    Directory of Open Access Journals (Sweden)

    Jérémie A. Doiron

    2014-01-01

    Full Text Available 5-Lipoxygenase (5-LO is the key enzyme responsible for the conversion of arachidonic acid to leukotrienes, a class of lipid mediators implicated in inflammatory disorders. In this paper, we describe the design, synthesis, and preliminary activity studies of novel clicked caffeic esters and amides as radical scavengers and 5-LO inhibitors. From known 5-LO inhibitor 3 as a lead, cinnamic esters 8a–h and amides 9a–h as well as caffeic esters 15a–h and amides 16a–h were synthesized by Cu(I-catalyzed [1,3]-dipolar cycloaddition with the appropriate azide precursors and terminal alkynes. All caffeic analogs are proved to be good radical scavengers (IC50: 10–20 μM. Esters 15g and 15f possessed excellent 5-LO inhibition activity in HEK293 cells and were equipotent with the known 5-LO inhibitor CAPE and more potent than Zileuton. Several synthesized esters possess activities rivaling Zileuton in stimulated human polymorphonuclear leukocytes.

  14. Benefits of Neuropsychiatric Phenomics: Example of the 5-Lipoxygenase-Leptin-Alzheimer Connection

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    Hari Manev

    2010-01-01

    Full Text Available Phenomics is a systematic study of phenotypes on a genomewide scale that is expected to unravel, as of yet, unsuspected functional roles of the genome. It remains to be determined how to optimally approach and analyze the available phenomics databases to spearhead innovation in neuropsychiatry. By serendipitously connecting two unrelated phenotypes of increased blood levels of the adipokine leptin, a molecule that regulates appetite, in 5-lipoxygenase- (5-LOX deficient mice and patients with a lower risk for Alzheimer's disease (AD, we postulated a leptin-mediated basis for beneficial effects of ALOX5 (a gene encoding 5-LOX gene-deficiency in AD. We suggest that it might be possible to avoid relying on serendipity and develop data-mining tools capable of extracting from phenomics databases indications for such novel hypotheses. Hence, we provide an example of using a free-access Arrowsmith two-node search interface to identify ALOX5 as unsuspected putative mechanisms for the previously described clinical association between increased plasma levels of leptin and a lower risk of incident dementia and AD.

  15. Antioxidant and lipoxygenase activities of polyphenol extracts from oat brans treated with polysaccharide degrading enzymes

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    Nisita Ratnasari

    2017-07-01

    Full Text Available This study used polysaccharide degrading enzymes and protein precipitation to extract polyphenols from oats and to determine their bioactivity. Duplicate oat brans were treated with viscozyme (Vis, cellulase (Cel or no enzyme (control, CTL then, proteins were removed in one set (Vis1, Cel1, CTL1 and not in the other (Vis2, Cel2, CTL2. HPLC analyses showed that for cellulase treated brans, precipitation of proteins increased phenolic acids and avenanthramides by 14%. Meanwhile, a decreased of 67% and 20% respectively was found for viscozyme and control brans. The effect of protein precipitation on soluble polyphenols is therefore dependent of the carbohydrase, as proteins with different compositions will interact differently with other molecules. Radical scavenging data showed that Cel1 and Vis1 had higher quenching effects on ROO• radicals with activities of 22.1 ± 0.8 and 23.5 ± 1.2 μM Trolox Equivalents/g defatted brans. Meanwhile, CTL2 had the highest HO• radicals inhibition (49.4 ± 2.8% compared to 10.8–32.3% for others. Samples that highly inhibited lipoxygenase (LOX, an enzyme involved in lipid oxidation were Cel1 (23.4 ± 2.3% and CTL1 (18 ± 0.4%.

  16. The 5-lipoxygenase pathway: oxidative and inflammatory contributions to the Alzheimer’s disease pathogenesis

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    Praticò eDomenico

    2015-01-01

    Full Text Available Alzheimer’s disease (AD is the most common, and, arguably, one of the most-well studied, neurodegenerative conditions. Several decades of investigation have revealed that amyloid-β and tau proteins are critical pathological players in this condition. Genetic analyses have revealed specific mutations in the cellular machinery that produces amyloid-β, but these mutations are found in only a small fraction of patients with the early-onset variant of AD. In addition to development of amyloid-β and tau pathology, oxidative damage and inflammation are consistently found in the brains of these patients. The 5-lipoxygenase protein enzyme (5LO and its downstream leukotriene metabolites have long been known to be important modulators of oxidation and inflammation in other disease states. Recent in vivo evidence using murine knock-out models has implicated the 5LO pathway, which also requires the 5LO activating protein (FLAP, in the molecular pathology of AD, including the metabolism of amyloid-β and tau. In this manuscript, we will provide an overview of 5LO and FLAP, discussing their involvement in biochemical pathways relevant to AD pathogenesis. We will also discuss how the 5LO pathway contributes to the molecular and behavioral insults seen in AD and provide an assessment of how targeting these proteins could lead to therapeutics relevant not only for Alzheimer’s disease, but also other related neurodegenerative conditions.

  17. Dormant 5-lipoxygenase in inflammatory macrophages is triggered by exogenous arachidonic acid.

    Science.gov (United States)

    Sorgi, Carlos A; Zarini, Simona; Martin, Sarah A; Sanchez, Raphael L; Scandiuzzi, Rodrigo F; Gijón, Miguel A; Guijas, Carlos; Flamand, Nicolas; Murphy, Robert C; Faccioli, Lucia H

    2017-09-08

    The differentiation of resident tissue macrophages from embryonic precursors and that of inflammatory macrophages from bone marrow cells leads to macrophage heterogeneity. Further plasticity is displayed through their ability to be polarized as subtypes M1 and M2 in a cell culture microenvironment. However, the detailed regulation of eicosanoid production and its involvement in macrophage biology remains unclear. Using a lipidomics approach, we demonstrated that eicosanoid production profiles between bone marrow-derived (BMDM) and peritoneal macrophages differed drastically. In polarized BMDMs, M1 and M2 phenotypes were distinguished by thromboxane B2, prostaglandin (PG) E2, and PGD2 production, in addition to lysophospholipid acyltransferase activity. Although Alox5 expression and the presence of 5-lipoxygenase (5-LO) protein in BMDMs was observed, the absence of leukotrienes production reflected an impairment in 5-LO activity, which could be triggered by addition of exogenous arachidonic acid (AA). The BMDM 5-LO regulatory mechanism was not responsive to PGE2/cAMP pathway modulation; however, treatment to reduce glutathione peroxidase activity increased 5-LO metabolite production after AA stimulation. Understanding the relationship between the eicosanoids pathway and macrophage biology may offer novel strategies for macrophage-associated disease therapy.

  18. Mutagenic, antimutagenic, antioxidant, anti-lipoxygenase and antimicrobial activities of Scandix pecten-veneris L.

    Science.gov (United States)

    Sharifi-Rad, M; Tayeboon, G S; Miri, A; Sharifi-Rad, M; Setzer, W N; Fallah, F; Kuhestani, K; Tahanzadeh, N; Sharifi-Rad, J

    2016-05-30

    Scandix pecten-veneris L. or Shepherd's-needle is a weed species used in some countries for medicinal purposes. In this study S. pecten-veneris leaves were shade dried, powdered and extracted with methanol. The purpose of this study was to assay the in vitro mutagenic, antimutagenic, antioxidant, antilipoxygenase and antimicrobial activities of S. pecten-veneris leaf extract. The methanolic extract indicated no mutagenicity when tested with Salmonella typhimurium strains TA98 and TA100. Antimutagenic activity was reported with inhibition of mutagenicity in a concentration dependent fashion. The methanolic extract demonstrated antioxidant activity in the DPPH radical-scavenging test (IC50 = 4.57 mg/mL), comparable to ascorbic acid and BHT. Moreover, the extract presented a remarkable and potent inhibition against soybean lipoxygenase (IC50 = 641.57 µg/mL). The methanolic extract was examined for its antimicrobial powers against four different bacteria with MIC values >100. Our results introduced this plant as a useful factor for the treatment of cancer, inflammatory and infectious diseases.

  19. Effect of Ethylene on Polygalacturonase,Lipoxygenase and Expansin in Ripening of Tomato Fruits

    Institute of Scientific and Technical Information of China (English)

    XUE Zhaohui; KOU Xiaohong; LUO Yunbo; ZHU Benzhong; XU Wentao

    2009-01-01

    Fruit ripening is a complex process and is regulated by many factors.Ethylene and polygalacturonase (PG),lipoxygenase (LOX),expansin (EXP) are all critical regulating factors in fruit ripening and softening process.With antisense,ACS tomato,Nr mutant tomato and cultivated tomato as materials,Northern blot hybridization showed that PG,LeEXP1 and LOX expressed differently in different parts of cultivated tomato fruit during ripening,which was related to fruit ripening.The ripening process of columella and radial pericarp was faster than pericarp.In both Nr mutant and antisense ACS transgenic tomato fruit,expression levels of PG,LeEXP1 and LOX were generally lower than those in cultivated fruit but still related to fruit ripening.The expression levels of PG,LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene ( 100 μL/L).These results indicate that gene expression of PG,LeEXP1 and LOXwere positively regulated by ethylene.The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene.The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced.PG played a major role in ripening and softening of tomato fruit,and cooperated with the regulation of EXP and LOX.

  20. Inhibition of 5-Lipoxygenase Pathway Attenuates Acute Liver Failure by Inhibiting Macrophage Activation

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    Lu Li

    2014-01-01

    Full Text Available This study aimed to investigate the role of 5-lipoxygenase (5-LO in acute liver failure (ALF and changes in macrophage activation by blocking it. ALF was induced in rats by administration of D-galactosamine (D-GalN/lipopolysaccharide (LPS. Rats were injected intraperitoneally with AA-861 (a specific 5-LO inhibitor, 24 hr before D-GalN/LPS administration. After D-GalN/LPS injection, the liver tissue was collected for assessment of histology, macrophage microstructure, macrophage counts, 5-LO mRNA formation, protein expression, and concentration of leukotrienes. Serum was collected for detecting alanine aminotransferase (ALT, aspartate transaminase (AST, total bilirubin (Tbil, and tumor necrosis factor- (TNF-α. Twenty-four hours after injection, compared with controls, ALF rats were characterized by widespread hepatocyte necrosis and elevated ALT, AST, and Tbil, and 5-LO protein expression reached a peak. Liver leukotriene B4 was also significantly elevated. However, 5-LO mRNA reached a peak 8 hr after D-GalN/LPS injection. Simultaneously, the microstructure of macrophages was changed most significantly and macrophages counts were increased significantly. Moreover, serum TNF-α was also elevated. By contrast, AA-861 pretreatment significantly decreased liver necrosis as well as all of the parameters compared with the rats without pretreatment. Macrophages, via the 5-LO pathway, play a critical role in ALF, and 5-LO inhibitor significantly alleviates ALF, possibly related to macrophage inhibition.

  1. 5-Lipoxygenase negatively regulates Th1 response during Brucella abortus infection in mice.

    Science.gov (United States)

    Fahel, Júlia Silveira; de Souza, Mariana Bueno; Gomes, Marco Túlio Ribeiro; Corsetti, Patricia P; Carvalho, Natalia B; Marinho, Fabio A V; de Almeida, Leonardo A; Caliari, Marcelo V; Machado, Fabiana Simão; Oliveira, Sergio Costa

    2015-03-01

    Brucella abortus is a Gram-negative bacterium that infects humans and cattle, causing a chronic inflammatory disease known as brucellosis. A Th1-mediated immune response plays a critical role in host control of this pathogen. Recent findings indicate contrasting roles for lipid mediators in host responses against infections. 5-Lipoxygenase (5-LO) is an enzyme required for the production of the lipid mediators leukotrienes and lipoxins. To determine the involvement of 5-LO in host responses to B. abortus infection, we intraperitoneally infected wild-type and 5-LO-deficient mice and evaluated the progression of infection and concomitant expression of immune mediators. Here, we demonstrate that B. abortus induced the upregulation of 5-LO mRNA in wild-type mice. Moreover, this pathogen upregulated the production of the lipid mediators leukotriene B4 and lipoxin A4 in a 5-LO-dependent manner. 5-LO-deficient mice displayed lower bacterial burdens in the spleen and liver and less severe liver pathology, demonstrating an enhanced resistance to infection. Host resistance paralleled an increased expression of the proinflammatory mediators interleukin-12 (IL-12), gamma interferon (IFN-γ), and inducible nitric oxide synthase (iNOS) during the course of infection. Moreover, we demonstrated that 5-LO downregulated the expression of IL-12 in macrophages during B. abortus infection. Our results suggest that 5-LO has a major involvement in B. abortus infection, by functioning as a negative regulator of the protective Th1 immune responses against this pathogen.

  2. The 5-Lipoxygenase as a Common Pathway for Pathological Brain and Vascular Aging

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    Jin Chu

    2009-01-01

    Full Text Available Epidemiological studies indicate age as a strong risk factor for developing cardiovascular and neurodegenerative diseases. During the aging process, changes in the expression of particular genes can influence the susceptibility to these diseases. 5-Lipoxygenase (5-LO by oxidizing fatty acids forms leukotrienes, potent mediators of oxidative and inflammatory reactions, two key pathogenic events in both clinical settings. This enzyme is widely distributed in the cardiovascular as well as in the central nervous system, where its expression levels increase with age, suggesting that it may be involved in their diseases of aging. The central theme of this article is that during aging, 5-LO acts as biologic link between different stressors and the development of cardiovascular and neurodegenerative diseases. We hypothesize that the age-dependent upregulation of 5-LO represents a “priming” factor in the vasculature as well as in the brain, where a subsequent exposure to triggering stimuli (i.e., infections leads to an abnormal chronic inflammatory reaction, and ultimately results in increased organ vulnerability and functional deficits.

  3. Effects of recombinated Anabaena sp. lipoxygenase on the protein component and dough property of wheat flour.

    Science.gov (United States)

    Wang, Xiaoming; Lu, Fengxia; Zhang, Chong; Lu, Yingjian; Bie, Xiaomei; Xie, Yajuan; Lu, Zhaoxin

    2014-10-08

    The improvement effect of recombinated Anabaena sp. lipoxygenase (ana-rLOX) on the rheological property of dough was investigated with a farinograph and an extensograph. When 30 U/g ana-rLOX was added to wheat flour, the dough stability time extended from 7 to 9.5 min, the degree of softening increased about 31.1%, and the farinograph index also ascended. The dough with added ana-rLOX showed stronger resistance to extension throughout 135 min of resting time as compared to the dough without ana-rLOX. In addition, the protein component in the dough was varied with ana-rLOX. The glutenin in the dough was increased, whereas the gliadin, albumin, and globulin were decreased after the additino of ana-rLOX to the flours. Ana-rLOX could make globulin-3A, globulin 1a, and S48186 grain softness protein cross-link with gliadin and low-molecular-weight (LMW) glutenin, leading to the formation of the protein polymer. These results based on proteomic analysis might provide evidence that ana-rLOX could affect the gluten protein component and explain why it improved the farinograph and extensograph parameters of wheat flour.

  4. Derivatives form better lipoxygenase inhibitors than piperine: in vitro and in silico study.

    Science.gov (United States)

    Tomy, Muringayil J; Sharanya, Chelankara S; Dileep, Kalarickal V; Prasanth, Shankar; Sabu, Abudulhameed; Sadasivan, Chittalakkottu; Haridas, Madathilkovilakathu

    2015-06-01

    Piperine is a secondary metabolite of black pepper. Its uses in medicine were already studied. However, its derivatives have not gained considerable attention. In the presented study, the Lipoxygenase (LOX) inhibitory activity of piperine and its derivatives, piperonylic acid, piperic acid, and piperonal have been assessed and compared by enzyme kinetics, ITC and molecular modeling experiments. The presented investigations expressed that all the studied compounds inhibited LOX by binding at its active site. The IC(50) values of these compounds were deduced from the kinetics data and found to be 85.79, 43.065, 45.17, and 50.78 μm for piperine, piperonylic acid, piperic acid, and piperonal, respectively. The binding free energies obtained from ITC experiments were -7.47, -8.33, -8.09, and -7.86 kcal/mol for piperine, piperonylic acid, piperic acid, and piperonal, respectively. Similarly, the glide scores obtained for piperine, piperonylic acid, piperic acid, and piperonal were -7.28, -10.32, -10.72, and -9.57 kcal/mol, respectively. The results of ITC and molecular modeling experiments suggested that piperonylic acid and piperonal exhibit stronger binding at the active site than piperine does. From the presented studies, it could be concluded that derivatives of piperine may be of higher significance than piperine for certain medicinal applications, implicating (Ayurvedic) fermented herbal drugs with piperine in them.

  5. Minocycline inhibits 5-lipoxygenase activation and brain inflammation after focal cerebral ischemia in rats

    Institute of Scientific and Technical Information of China (English)

    Li-sheng CHU; San-hua FANG; Yu ZHOU; Guo-hang YU; Meng-ling WANG; Wei-ping ZHANG; Er-qing WEI

    2007-01-01

    Aim: To determine whether the anti-inflanunatory effect of minocycline on postis-chemic brain injury is mediated by the inhibition of 5-lipoxygenase (5-LOX) expression and enzymatic activation in rats.Methods: Focal cerebral ischemia was induced for 30 min with middle cerebral artery occlusion, followed by reperfusion. The ischemic injuries, endogenous IgG exudation, the accumulation of neutrophils and macrophage/microglia, and 5-LOX mRNA expression were determined 72 h after reperfusion. 5-LOX metabolites (leukotriene B4 and cysteinyl leukotrienes) were measured 3 h after reperfusion.Results: Minocycline (22.5 and 45 mg/kg, ip, for 3 d) attenuated ischemic injuries, IgG exudation, and the accumulation of neutrophils and macrophage/microglia 72 h after reperfusion. It also inhibited 5-LOX expression 72 h after reperfusion and the production of leukotrienes 3 h after reperfusion.Conclusion: Minocycline inhibited postis-chemic brain inflammation, which might be partly mediated by the inhibition of 5-LOX expression and enzymatic activation.

  6. Age-dependent relevance of endogenous 5-lipoxygenase derivatives in anxiety-like behavior in mice.

    Science.gov (United States)

    Leo, Luciana M; Almeida-Corrêa, Suellen; Canetti, Claudio A; Amaral, Olavo B; Bozza, Fernando A; Pamplona, Fabricio A

    2014-01-01

    When 5-lipoxygenase (5-LO) is inhibited, roughly half of the CNS effect of the prototypic endocannabinoid anandamide (AEA) is lost. Therefore, we decided to investigate whether inhibiting this enzyme would influence physiological functions classically described as being under control of the endocannabinoid system. Although 5-LO inhibition by MK-886 reduced lipoxin A4 levels in the brain, no effect was found in the elevated plus maze (EPM), even at the highest possible doses, via i.p. (10 mg/kg,) or i.c.v. (500 pmol/2 µl) routes. Accordingly, no alterations in anxiety-like behavior in the EPM test were observed in 5-LO KO mice. Interestingly, aged mice, which show reduced circulating lipoxin A4 levels, were sensitive to MK-886, displaying an anxiogenic-like state in response to treatment. Moreover, exogenous lipoxin A4 induced an anxiolytic-like profile in the EPM test. Our findings are in line with other reports showing no difference between FLAP KO or 5-LO KO and their control strains in adult mice, but increased anxiety-like behavior in aged mice. We also show for the first time that lipoxin A4 affects mouse behavior. In conclusion, we propose an age-dependent relevancy of endogenous 5-LO derivatives in the modulation of anxiety-like behavior, in addition to a potential for exogenous lipoxin A4 in producing an anxiolytic-like state.

  7. A Lipoxygenase Pathway Is Activated in Rice after Infection with the Rice Blast Fungus Magnaporthe grisea.

    Science.gov (United States)

    Ohta, H; Shida, K; Peng, Y L; Furusawa, I; Shishiyama, J; Aibara, S; Morita, Y

    1991-09-01

    Lipoxygenase (LOX) and lipid hydroperoxide-decomposing activity (LHDA) markedly increased in the fifth leaves of rice (Oryza sativa cv Aichiasahi) after infection with the rice blast fungus, Magnaporthe grisea. The increases in the enzyme activities were significantly higher in response to infection with an incompatible strain (race 131) compared with infection with a compatible strain (race 007) of the fungus. Using ion-exchange chromatography, we isolated three LOX activities (leaf LOX-1, -2, -3) from both uninoculated and infected leaves. The activity of leaf LOX-3, in particular, increased in the incompatible race-infected leaves. The leaf LOX-3 had a pH optimum of 5.0 and produced preferentially 13-l-hydroperoxy-9,11 (Z,E)-octadecadienoic acid (13-HPODD) from linoleic acid. 13-HPODD and 13-l-hydroxy-9,11 (Z,E)-octadecadienoic acid, one of the reaction products from 13-HPODD by LHDA, were highly inhibitory to the germination of conidia of the fungus. The present study provides correlative evidence for important roles of LOX and LHDA in the resistance response of rice against the blast fungus.

  8. Rethinking Defensive Information Warfare

    Science.gov (United States)

    2004-06-01

    electronic warfare, and special information operations. Defensive information operations ensure timely, accurate, and relevant information access...information and information systems. IA, physical security, OPSEC, counter-deception, counter-psyops, CI, EW, and special information operations. Ensure

  9. A Mutant of Hepatitis B Virus X Protein (HBxΔ127 Promotes Cell Growth through A Positive Feedback Loop Involving 5-Lipoxygenase and Fatty Acid Synthase

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2010-02-01

    Full Text Available Hepatocellular carcinoma (HCC is one of the most common malignant tumors worldwide. Hepatitis B virus X protein (HBx contributes to the development of HCC, whereas HBx with COOH-terminal deletion is a frequent event in the HCC tissues. Previously, we identified a natural mutant of HBx-truncated 27 amino acids at the COOH-terminal (termed HBxΔ127, which strongly enhanced cell growth. In the present study, we focused on investigating the mechanism. Accordingly, fatty acid synthase (FAS plays a crucial role in cancer cell survival and proliferation; thus, we examined the signaling pathways involving FAS. Our data showed that HBxΔ127 strongly increased the transcriptional activities of FAS in human hepatoma HepG2 and H7402 cells. Moreover, we found that 5-lipoxygenase (5-LOX was responsible for the up-regulation of FAS by using MK886 (an inhibitor of 5-LOX and 5-LOX small interfering RNA. We observed that HBxΔ127 could upregulate 5-LOX through phosphorylated extracellular signal-regulated protein kinases 1/2 and thus resulted in the increase of released leukotriene B4 (LTB4, a metabolite of 5-LOX by ELISA. The additional LTB4 could upregulate the expression of FAS in the cells as well. Interestingly, we found that FAS was able to upregulate the expression of 5-LOX in a feedback manner by using cerulenin (an inhibitor of FAS. Collectively, HBxΔ127 promotes cell growth through a positive feedback loop involving 5-LOX and FAS, in which released LTB4 is involved in the up-regulation of FAS. Thus, our finding provides a new insight into the mechanism involving the promotion of cell growth mediated by HBxΔ127.

  10. Lipoxygenase metabolism and lung cancer:research advances%脂氧合酶代谢与肺癌研究进展

    Institute of Scientific and Technical Information of China (English)

    杨玉花; 魏晓莉; 郑建全

    2012-01-01

    脂氧合酶(LOX)是非血红素铁双加氧酶,能催化底物生成各种类花生酸物质,在肺癌预防和治疗中发挥重要作用,有望成为新的抗肺癌药物作用靶点.根据氧分子插入底物的位点不同,人类LOX主要分为5-LOX、12-LOX和15-LOX,5-LOX和12-LOX具有促进肺癌细胞生长和肿瘤转移的作用,而15-LOX的两种亚型15-LOX-1和15-LOX-2主要具有抗肺癌的作用.本文主要综述了各种LOX代谢通路在肺癌发生发展中的作用特点.此外,还介绍了LOX依赖氧化应激、过氧化物酶体增殖物活化受体和P53的抗肺癌机制及其作为肺癌药物作用靶点的研究进展.%Lipoxygenases constitute a family of non-heme iron dioxygenases that catalize substrates to generate various biologically active eicosanoids. Their roles in chemoprevention and treatment of lung cancer in recent years have become a hot research spot and lipoxygenases have the potential to become a new action spots of anti-lung cancer drugs. The human lipoxygenases are classified into 5-, 12-, and 15-lipoxygenase according to the positional specificity of the introduction of molecular oxygen in the substrates. 5-, and 12-lipoxygenases have the effects of promoting lung cancer cell growth and metastasis, but 15-lipoxygenase-l and -2 (two isoforms of 15-lipoxygenase) possess the anti-lung cancer effect. In this review we focus on action features of lipoxygenase pathways in lung cancers and introduce the anti-lung cancer mechanisms of lipoxygenase pathways by oxidative stress, peroxisome proliferator-activated receptors and P53, as well as their prospects as lung cancer pharmacology targets.

  11. Surfing China's National Defense

    Institute of Scientific and Technical Information of China (English)

    Ji Guilin

    2010-01-01

    @@ Following the start of its first test run on August 20, 2009, the website www.mod.gov.cn of the Ministry of National Defense (MOD) of the People's Republic of China has logged more than 2 billion hits,from many countries and regions including China, the United States,the United Kingdom, Japan, Australia and Singapore. China National Defense News reporters recently interviewed Ji Guilin, the website's Editor in Chief, on its performance and the feedback of netizens.

  12. Antiviral Defense Mechanisms in Honey Bees

    Science.gov (United States)

    Brutscher, Laura M.; Daughenbaugh, Katie F.; Flenniken, Michelle L.

    2015-01-01

    Honey bees are significant pollinators of agricultural crops and other important plant species. High annual losses of honey bee colonies in North America and in some parts of Europe have profound ecological and economic implications. Colony losses have been attributed to multiple factors including RNA viruses, thus understanding bee antiviral defense mechanisms may result in the development of strategies that mitigate colony losses. Honey bee antiviral defense mechanisms include RNA-interference, pathogen-associated molecular pattern (PAMP) triggered signal transduction cascades, and reactive oxygen species generation. However, the relative importance of these and other pathways is largely uncharacterized. Herein we review the current understanding of honey bee antiviral defense mechanisms and suggest important avenues for future investigation. PMID:26273564

  13. 75 FR 76423 - Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting

    Science.gov (United States)

    2010-12-08

    ... of the Secretary Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting AGENCY: National Defense Intelligence College, Defense Intelligence Agency, Department of... a closed meeting of the Defense Intelligence Agency National Defense Intelligence College Board...

  14. 76 FR 28960 - Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting

    Science.gov (United States)

    2011-05-19

    ... of the Secretary Defense Intelligence Agency National Defense Intelligence College Board of Visitors Closed Meeting AGENCY: National Defense Intelligence College, Defense Intelligence Agency, Department of... a closed meeting of the Defense Intelligence Agency National Defense Intelligence College Board...

  15. 76 FR 28757 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Science.gov (United States)

    2011-05-18

    ... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION: Notice of Availability (NOA) of Revised Defense Logistics Agency Regulation. SUMMARY: The Defense Logistics...

  16. [Spectral analysis of polyphenol oxidase (PPO) and lipoxygenase (LOX) treated by pulsed electric field].

    Science.gov (United States)

    Luo, Wei; Zhang, Ruo-Bing; Chen, Jie; Wang, Li-Ming; Guan, Zhi-Cheng; Jia, Zhi-Dong

    2009-08-01

    Inactivation effect of pulsed electric field (PEF) on polyphenol oxidase (PPO) and lipoxygenase (LOX) was investigated using a laboratory PEF system with a coaxial treatment chamber. Circular dichroism (CD) and fluorescence analysis were used to study the conformation change of the protein. The experimental results show that PPO and LOX can be effectively inactivated by the PEF treatment. Inactivation effect of PPO and LOX increases with the increase in the applied electric strength and the treatment time. Activity of PPO and LOX can be reduced by 60.3% and 21.7% at 20 kV x cm(-1) after being treated for 320 micros respectively. The decrease of the negative peaks (208 and 215 nm in PPO spectra, 208 nm and 218 nm in LOX spectra) in CD spectra of PPO and LOX shows that PEF treatment caused a loss of alpha-helix and increase in beta-sheet content, indicating that conformation changes occur in the secondary structure of PPO and LOX enzyme. This effect was strengthened as the applied electric field increased: alpha-helical content of PPO and LOX was 56% and 29% after being treated at 8 kV x cm(-1), however, when the electric field was increased up to 20 kV x cm(-1), alpha-helical content of PPO and LOX decreased to 21% and 16% respectively. The decrease rate of alpha-helix and increase rate of beta-sheet in PPO are higher than LOX, indicating that the second conformation of PPO is less resistant to PEF treatment than LOX. The fluorescence intensity of LOX increases after PEF treatment. At the same time, increasing the applied pulsed electric field increases the fluorescence intensity emitted. Fluorescence measurements confirm that tertiary conformation changes occur in the local structure of LOX. However the possible mechanism of the conformation change induced by the PEF treatment is beyond the scope of the present investigation.

  17. Pivotal role of the 5-lipoxygenase pathway in lung injury after experimental sepsis.

    Science.gov (United States)

    Monteiro, Ana Paula T; Soledade, Erico; Pinheiro, Carla S; Dellatorre-Teixeira, Ludmilla; Oliveira, Gisele P; Oliveira, Mariana G; Peters-Golden, Marc; Rocco, Patricia R M; Benjamim, Claudia F; Canetti, Claudio

    2014-01-01

    Postsepsis lung injury is a common clinical problem associated with significant morbidity and mortality. Leukotrienes (LTs) are important lipid mediators of infection and inflammation derived from the 5-lipoxygenase (5-LO) metabolism of arachidonate with the potential to contribute to lung damage after sepsis. To test the hypothesis that LTs are mediators of lung injury after sepsis, we assessed lung structure, inflammatory mediators, and mechanical changes after cecal ligation and puncture surgery in wild-type (WT) and 5-LO knockout (5-LO(-/-)) mice and in WT mice treated with a pharmacologic LT synthesis inhibitor (MK886) and LT receptor antagonists (CP105,696 and montelukast). Sixteen hours after surgery, WT animals exhibited severe lung injury (by histological analysis), substantial mechanical impairment (i.e., an increase in static lung elastance), an increase in neutrophil infiltration, and high levels of LTB4, cysteinyl-LTs (cys-LTs), prostaglandin E2, IL-1β, IL-6, IL-10, IL-17, KC (CXCL1), and monocyte chemotactic protein-1 (CCL2) in lung tissue and plasma. 5-LO(-/-) mice and WT mice treated with a pharmacologic 5-LO inhibitor were significantly protected from lung inflammation and injury. Selective antagonists for BLT1 or cys-LT1, the high-affinity receptors for LTB4 and cys-LTs, respectively, were insufficient to provide protection when used alone. These results point to an important role for 5-LO products in sepsis-induced lung injury and suggest that the use of 5-LO inhibitors may be of therapeutic benefit clinically.

  18. Manganese lipoxygenase of F. oxysporum and the structural basis for biosynthesis of distinct 11-hydroperoxy stereoisomers.

    Science.gov (United States)

    Wennman, Anneli; Magnuson, Ann; Hamberg, Mats; Oliw, Ernst H

    2015-08-01

    The biosynthesis of jasmonates in plants is initiated by 13S-lipoxygenase (LOX), but details of jasmonate biosynthesis by fungi, including Fusarium oxysporum, are unknown. The genome of F. oxysporum codes for linoleate 13S-LOX (FoxLOX) and for F. oxysporum manganese LOX (Fo-MnLOX), an uncharacterized homolog of 13R-MnLOX of Gaeumannomyces graminis. We expressed Fo-MnLOX and compared its properties to Cg-MnLOX from Colletotrichum gloeosporioides. Electron paramagnetic resonance and metal analysis showed that Fo-MnLOX contained catalytic Mn. Fo-MnLOX oxidized 18:2n-6 mainly to 11R-hydroperoxyoctadecadienoic acid (HPODE), 13S-HPODE, and 9(S/R)-HPODE, whereas Cg-MnLOX produced 9S-, 11S-, and 13R-HPODE with high stereoselectivity. The 11-hydroperoxides did not undergo the rapid β-fragmentation earlier observed with 13R-MnLOX. Oxidation of [11S-(2)H]18:2n-6 by Cg-MnLOX was accompanied by loss of deuterium and a large kinetic isotope effect (>30). The Fo-MnLOX-catalyzed oxidation occurred with retention of the (2)H-label. Fo-MnLOX also oxidized 1-lineoyl-2-hydroxy-glycero-3-phosphatidylcholine. The predicted active site of all MnLOXs contains Phe except for Ser(348) in this position of Fo-MnLOX. The Ser348Phe mutant of Fo-MnLOX oxidized 18:2n-6 to the same major products as Cg-MnLOX. Our results suggest that Fo-MnLOX, with support of Ser(348), binds 18:2n-6 so that the proR rather than the proS hydrogen at C-11 interacts with the metal center, but retains the suprafacial oxygenation mechanism observed in other MnLOXs.

  19. 15-Lipoxygenase-1 Activates Tumor Suppressor p53 Independent of Enzymatic Activity

    Science.gov (United States)

    Zhu, Hong; Glasgow, Wayne; George, Margaret D.; Chrysovergis, Kali; Olden, Kenneth; Roberts, John D.; Eling, Thomas

    2008-01-01

    15-LOX-1 and its metabolites are involved in colorectal cancer. Recently, we reported that 15-LOX-1 overexpression in HCT-116 human colorectal cancer cells inhibited cell growth by induction of p53 phosphorylation (4). To determine whether the 15-LOX-1 protein or its metabolites are responsible for phosphorylation of p53 in HCT-116 cells, we used HCT-116 cells that expressed a mutant 15-LOX-1. The mutant 15-LOX-1 enzyme, with a substitution of Leu at residue His361, was devoid of enzymatic activity. HCT-116 cells transiently transfected with either native or mutant 15-LOX-1 showed an increase in p53 phosphorylation and an increase in the expression of downstream genes. Thus 15-LOX-1 induces p53 phosphorylation independent of enzymatic activity. Treatment of A549 human lung carcinoma cells with IL-4 increased the expression of 15-LOX-1 and also increased the expression of downstream targets of p53. This confirmed that the activation of p53 was also observed in wild type cells expressing physiological 15-LOX-1. Immunoprecipitation experiments revealed that 15-LOX-1 interacts with, and binds to, DNA-dependent protein kinase (DNA-PK). The binding of 15-LOX-1 to DNA-PK caused an approximate 3.0 fold enhancement in kinase activity, resulting in increased p53 phosphorylation at Ser15. Knockdown of DNA-PK by small interfering RNA (siRNA) significantly reduced p53 phosphorylation. Furthermore, confocal microscopy demonstrated a co-localization of 15-LOX and DNA-PK in the cells. We propose that the 15-LOX-1 protein binds to DNA-PK, increasing its kinase activity, and results in downstream activation of the tumor suppressor p53, thus revealing a new mechanism by which lipoxygenases may influence the phenotype of tumor cells. PMID:18785202

  20. Simultaneous determination of the lipoxygenase and hydroperxide lyase specificity in olive fruit pulp

    Directory of Open Access Journals (Sweden)

    Salas, Joaquín J.

    2000-06-01

    Full Text Available Olive pulp lipoxygenase regiospecificity and hydroperoxide lyase substrate specificity are important parameters in order to justify the volatile composition of olive oil. A new radiolabelling method to determine simultaneously these properties using only thin layer chromatography steps is described in the present work. The method involves incubation of an enzyme preparation from olive pulp with radiolabelled linoleate, followed by the fractionation of the resulting lipid products, previously treated with 2,4-dinitrophenyl hydrazine, on thin layer chromatography plates coated with polyethylenglycol 400. The results obtained are in agreement with previous studies carried out by other methods.La regioespecificidad de la lipoxigenasa y la especificidad del sustrato hidroperóxido liasa de pulpa de aceituna son parámetros importantes en la justificación de la composición en volátiles del aceite de oliva. En este trabajo se describe un nuevo método de marcaje radioactivo para determinar simultáneamente estas propiedades, usando solo etapas de cromatografía en capa fina. El método implica la incubación de una preparación enzimática de pulpa de aceituna con linoleato marcado, seguido del fraccionamiento de los productos lipídicos resultantes, previamente tratados con 2,4-dinitrofenil hidrazina, sobre placas de cromatografía en capa fina soportadas con polietilenglicol 400. Los resultados obtenidos están de acuerdo con estudios previos llevados a cabo con otros métodos.

  1. Endocannabinoids and their oxygenation by cyclo-oxygenases, lipoxygenases and other oxygenases.

    Science.gov (United States)

    Urquhart, P; Nicolaou, A; Woodward, D F

    2015-04-01

    The naturally occurring mammalian endocannabinoids possess biological attributes that extend beyond interaction with cannabinoid receptors. These extended biological properties are the result of oxidative metabolism of the principal mammalian endocannabinoids arachidonoyl ethanolamide (anandamide; A-EA) and 2-arachidonoylglycerol (2-AG). Both endocannabinoids are oxidized by cyclo-oxygenase-2 (COX-2), but not by COX-1, to a series of prostaglandin derivatives (PGs) with quite different biological properties from those of the parent substrates. PG ethanolamides (prostamides, PG-EAs) and PG glyceryl esters (PG-Gs) are not only pharmacologically distinct from their parent endocannabinoids, they are distinct from the corresponding acidic PGs, and are differentiated from each other. Ethanolamides and glyceryl esters of the major prostanoids PGD2, PGE2, PGF2α, and PGI2 are formed by the various PG synthases, and thromboxane ethanolamides and glyceryl esters are not similarly produced. COX-2 is also of interest by virtue of its corollary central role in modulating endocannabinoid tone, providing a new therapeutic approach for treating pain and anxiety. Other major oxidative conversion pathways are provided for both A-EA and 2-AG by several lipoxygenases (LOXs), resulting in the formation of numerous hydroxyl metabolites. These do not necessarily represent inactivation pathways for endocannabinoids but may mimic or modulate the endocannabinoids or even display alternative pharmacology. Similarly, A-EA and 2-AG may be oxidized by P450 enzymes. Again a very diverse number of metabolites are formed, with either cannabinoid-like biological properties or an introduction of disparate pharmacology. The biological activity of epoxy and hydroxyl derivatives of the endocannabinoids remains to be fully elucidated. This review attempts to consolidate and compare the findings obtained to date in an increasingly important research area. This article is part of a Special Issue entitled

  2. Antioxidant, 5-lipoxygenase inhibitory and cytotoxic activities of compounds isolated from the Ferula lutea flowers.

    Science.gov (United States)

    Znati, Mansour; Ben Jannet, Hichem; Cazaux, Sylvie; Souchard, Jean Pierre; Harzallah Skhiri, Féthia; Bouajila, Jalloul

    2014-10-22

    A phytochemical investigation of the Ferula lutea (Poir.) Maire flowers has led to the isolation of a new compound, (E)-5-ethylidenefuran-2(5H)-one-5-O-β-d-glucopyranoside (1), designated ferunide, 4-hydroxy-3-methylbut-2-enoic acid (2), reported for the first time as a natural product, together with nine known compounds, verbenone-5-O-β-d-glucopyranoside (3), 5-O-caffeoylquinic acid (4), methyl caffeate (5), methyl 3,5-O-dicaffeoylquinate (6), 3,5-O-dicaffeoylquinic acid (7), isorhamnetin-3-O-α-l-rhamnopyranosyl(1→6)-β-d-glucopyranoside, narcissin (8), (-)-marmesin (9), isoimperatorin (10) and 2,3,6-trimethylbenzaldehyde (11). Compounds 3-10 were identified for the first time in Ferula genus. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR experiments, mass spectroscopy and X-ray diffraction analysis (compound 2), as well as by comparison with literature data. The antioxidant, anti-inflammatory and cytotoxic activities of isolated compounds were evaluated. Results showed that compound 7 exhibited the highest antioxidant activity with IC50 values of 18 ± 0.5 µmol/L and 19.7 ± 0.7 µmol/L by DPPH radical and ABTS radical cation, respectively. The compound 6 exhibited the highest anti-inflammatory activity with an IC50 value of 5.3 ± 0.1 µmol/L against 5-lipoxygenase. In addition, compound 5 was found to be the most cytotoxic, with IC50 values of 22.5 ± 2.4 µmol/L, 17.8 ± 1.1 µmol/L and 25 ± 1.1 µmol/L against the HCT-116, IGROV-1 and OVCAR-3 cell lines, respectively.

  3. Antioxidant, 5-Lipoxygenase Inhibitory and Cytotoxic Activities of Compounds Isolated from the Ferula lutea Flowers

    Directory of Open Access Journals (Sweden)

    Mansour Znati

    2014-10-01

    Full Text Available A phytochemical investigation of the Ferula lutea (Poir. Maire flowers has led to the isolation of a new compound, (E-5-ethylidenefuran-2(5H-one-5-O-β-D-glucopyranoside (1, designated ferunide, 4-hydroxy-3-methylbut-2-enoic acid (2, reported for the first time as a natural product, together with nine known compounds, verbenone-5-O-β-D-glucopyranoside (3, 5-O-caffeoylquinic acid (4, methyl caffeate (5, methyl 3,5-O-dicaffeoylquinate (6, 3,5-O-dicaffeoylquinic acid (7, isorhamnetin-3-O-α-L-rhamnopyranosyl(1→6-β-D-glucopyranoside, narcissin (8, (−-marmesin (9, isoimperatorin (10 and 2,3,6-trimethylbenzaldehyde (11. Compounds 3–10 were identified for the first time in Ferula genus. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR experiments, mass spectroscopy and X-ray diffraction analysis (compound 2, as well as by comparison with literature data. The antioxidant, anti-inflammatory and cytotoxic activities of isolated compounds were evaluated. Results showed that compound 7 exhibited the highest antioxidant activity with IC50 values of 18 ± 0.5 µmol/L and 19.7 ± 0.7 µmol/L by DPPH radical and ABTS radical cation, respectively. The compound 6 exhibited the highest anti-inflammatory activity with an IC50 value of 5.3 ± 0.1 µmol/L against 5-lipoxygenase. In addition, compound 5 was found to be the most cytotoxic, with IC50 values of 22.5 ± 2.4 µmol/L, 17.8 ± 1.1 µmol/L and 25 ± 1.1 µmol/L against the HCT-116, IGROV-1 and OVCAR-3 cell lines, respectively.

  4. The 5-lipoxygenase inhibitor, zileuton, suppresses prostaglandin biosynthesis by inhibition of arachidonic acid release in macrophages

    Science.gov (United States)

    Rossi, A; Pergola, C; Koeberle, A; Hoffmann, M; Dehm, F; Bramanti, P; Cuzzocrea, S; Werz, O; Sautebin, L

    2010-01-01

    BACKGROUND AND PURPOSE Zileuton is the only 5-lipoxygenase (5-LOX) inhibitor marketed as a treatment for asthma, and is often utilized as a selective tool to evaluate the role of 5-LOX and leukotrienes. The aim of this study was to investigate the effect of zileuton on prostaglandin (PG) production in vitro and in vivo. EXPERIMENTAL APPROACH Peritoneal macrophages activated with lipopolysaccharide (LPS)/interferon γ (LPS/IFNγ), J774 macrophages and human whole blood stimulated with LPS were used as in vitro models and rat carrageenan-induced pleurisy as an in vivo model. KEY RESULTS Zileuton suppressed PG biosynthesis by interference with arachidonic acid (AA) release in macrophages. We found that zileuton significantly reduced PGE2 and 6-keto prostaglandin F1α (PGF1α) levels in activated mouse peritoneal macrophages and in J774 macrophages. This effect was not related to 5-LOX inhibition, because it was also observed in macrophages from 5-LOX knockout mice. Notably, zileuton inhibited PGE2 production in LPS-stimulated human whole blood and suppressed PGE2 and 6-keto PGF1α pleural levels in rat carrageenan-induced pleurisy. Interestingly, zileuton failed to inhibit the activity of microsomal PGE2 synthase1 and of cyclooxygenase (COX)-2 and did not affect COX-2 expression. However, zileuton significantly decreased AA release in macrophages accompanied by inhibition of phospholipase A2 translocation to cellular membranes. CONCLUSIONS AND IMPLICATION Zileuton inhibited PG production by interfering at the level of AA release. Its mechanism of action, as well as its use as a pharmacological tool, in experimental models of inflammation should be reassessed. PMID:20880396

  5. The influence of 5-lipoxygenase on cigarette smoke-induced emphysema in mice.

    Science.gov (United States)

    Kennedy-Feitosa, Emanuel; Pinto, Rômulo Fonseca Santos; Pires, Karla Maria Pereira; Monteiro, Ana Paula Teixeira; Machado, Mariana Nascimento; Santos, Juliana Carvalho; Ribeiro, Marcelo Lima; Zin, Walter Araújo; Canetti, Cláudio Azevedo; Romana-Souza, Bruna; Porto, Luís Cristóvão; Valenca, Samuel Santos

    2014-01-01

    Pulmonary emphysema is characterized by the loss of lung architecture. Our hypothesis is that the inhibition of 5-lipoxygenase (5-LO) production may be an important strategy to reduce inflammation, oxidative stress, and metalloproteinases in lung tissue resulting from cigarette smoke (CS)-induced emphysema. 5-LO knockout (129S2-Alox5(tm1Fun)/J) and wild-type (WT) mice (129S2/SvPas) were exposed to CS for 60days. Mice exposed to ambient air were used as Controls. Oxidative, inflammatory, and proteolytic markers were analyzed. The alveolar diameter was decreased in CS 5-LO(-/-) mice when compared with the WT CS group. The CS exposure resulted in less pronounced pulmonary inflammation in the CS 5-LO(-/-) group. The CS 5-LO(-/-) group showed leukotriene B4 values comparable to those of the Control group. The expression of MMP-9 was decreased in the CS 5-LO(-/-) group when compared with the CS WT group. The expression of superoxide dismutase, catalase, and glutathione peroxidase were decreased in the CS 5-LO(-/-) group when compared with the Control group. The protein expression of nuclear factor (erythroid-derived 2)-like 2 was reduced in the CS 5-LO(-/-) group when compared to the CS WT group. In conclusion, we show for the first time that 5-LO deficiency protects 129S2 mice against emphysema caused by CS. We suggest that the main mechanism of pathogenesis in this model involves the imbalance between proteases and antiproteases, particularly the association between MMP-9 and TIMP-1. General significance This study demonstrates the influence of 5-LO mediated oxidative stress, inflammation, and proteolytic markers in CS exposed mice. © 2013.

  6. Regulatory roles of NPR1 in plant defense: regulation and function

    NARCIS (Netherlands)

    Spoel, S.H.; Mou, Z.; Zhang, X.; Pieterse, C.M.J.; Dong, X.

    2006-01-01

    Overcoming infection is a struggle that all eukaryotic organisms have to face in order to survive and evolve among ubiquitous microorganisms. Extensive research on plant defenses has revealed that defense signal transduction pathways form an interconnected network in which the signaling molecules sa

  7. Lipoxygenase activities during development of root and nodule of soybean Atividade de lipoxigenases durante o desenvolvimento da raiz e do nódulo de plantas de soja

    Directory of Open Access Journals (Sweden)

    Tatiana Góes Junghans

    2004-07-01

    Full Text Available The objective of this work was to evaluate root and nodule soybean lipoxygenases in Doko cultivar and in a near isogenic line lacking seed lipoxygenases, inoculated and uninoculated with Bradyrhizobium elkanii. The lipoxygenase activities from roots collected at 3, 5, 9, 13, 18 and 28 days post-inoculation and from nodules collected at 13, 18 and 28 days post-inoculation were measured. The pH-activity profiles from root and nodules suggested that the lipoxygenases pool expressed in these organs from Doko cultivar and triple-null near isogenic lines are similar. The root lipoxygenase activity of Doko and triple-null lines, inoculated and uninoculated, reduced over time. The highest lipoxygenase activity observed at the beginning of root formation suggests the involvement of this enzyme in growth and development of this organ. However, for nodules an expressive increase of lipoxygenase activity was noticed 28 days post-inoculation. Root and nodule showed, at least, two mobility groups for lipoxygenases in immunoblottings, with approximately 94 and 97 kDa.O objetivo deste trabalho foi avaliar lipoxigenases de raízes e nódulos de plantas de soja da variedade Doko e da linhagem triplo nula derivada, desprovida das lipoxigenases da semente, com e sem inoculação de Bradyrhizobium elkanii. A atividade de lipoxigenase foi avaliada em raízes coletadas aos 3, 5, 9, 13, 18 e 28 dias após a inoculação e em nódulos coletados aos 13, 18 e 28 dias após a inoculação. Os perfis de pH-atividade de raiz e nódulo sugerem que o "pool" de lipoxigenases expresso nesses órgãos não difere nos dois genótipos. A atividade de lipoxigenases nas raízes de Doko e Doko triplo nula, com e sem inoculação, declinou com o passar do tempo. A maior atividade de lipoxigenases no início de formação da raiz sugere o envolvimento desta enzima no crescimento e desenvolvimento deste órgão. Nos nódulos houve um aumento acentuado na atividade de lipoxigenase aos 28

  8. Exogenous trehalose induces defenses in wheat before and during a biotic stress caused by powdery mildew.

    Science.gov (United States)

    Tayeh, Christine; Randoux, Béatrice; Vincent, Dorothée; Bourdon, Natacha; Reignault, Philippe

    2014-03-01

    Powdery mildew would be one of the most damaging wheat diseases without the extensive use of conventional fungicides. Some of the alternative control strategies currently emerging are based on the use of resistance inducers. The disacharride trehalose (TR) is classically described as an inducer of defenses in plants to abiotic stress. In this work, the elicitor or priming effect of TR was investigated in wheat both before and during a compatible wheat-powdery mildew interaction through molecular, biochemical, and cytological approaches. In noninoculated conditions, TR elicited the expression of genes encoding chitinase (chi, chi1, and chi4 precursor), pathogenesis-related protein 1, as well as oxalate oxidase (oxo). Moreover, lipid metabolism was shown to be altered by TR spraying via the upregulation of lipoxygenase (lox) and lipid-transfer protein (ltp)-encoding gene expression. On the other hand, the protection conferred by TR to wheat against powdery mildew is associated with the induction of two specific defense markers. Indeed, in infectious conditions following TR spraying, upregulations of chi4 precursor and lox gene expression as well as an induction of the LOX activity were observed. These results are also discussed with regard to the impact of TR on the fungal infectious process, which was shown to be stopped at the appressorial germ tube stage. Our findings strongly suggest that TR is a true inducer of wheat defense and resistance, at least toward powdery mildew.

  9. Regulation of KCa2.3 and endothelium-dependent hyperpolarization (EDH in the rat middle cerebral artery: the role of lipoxygenase metabolites and isoprostanes

    Directory of Open Access Journals (Sweden)

    Kathryn M. Gauthier

    2014-06-01

    Full Text Available Background and Purpose. In rat middle cerebral arteries, endothelium-dependent hyperpolarization (EDH is mediated by activation of calcium-activated potassium (KCa channels specifically KCa2.3 and KCa3.1. Lipoxygenase (LOX products function as endothelium-derived hyperpolarizing factors (EDHFs in rabbit arteries by stimulating KCa2.3. We investigated if LOX products contribute to EDH in rat cerebral arteries.Methods. Arachidonic acid (AA metabolites produced in middle cerebral arteries were measured using HPLC and LC/MS. Vascular tension and membrane potential responses to SLIGRL were simultaneously recorded using wire myography and intracellular microelectrodes.Results. SLIGRL, an agonist at PAR2 receptors, caused EDH that was inhibited by a combination of KCa2.3 and KCa3.1 blockade. Non-selective LOX-inhibition reduced EDH, whereas inhibition of 12-LOX had no effect. Soluble epoxide hydrolase (sEH inhibition enhanced the KCa2.3 component of EDH. Following NO synthase (NOS inhibition, the KCa2.3 component of EDH was absent. Using HPLC, middle cerebral arteries metabolized 14C-AA to 15- and 12-LOX products under control conditions. With NOS inhibition, there was little change in LOX metabolites, but increased F-type isoprostanes. 8-iso-PGF2α inhibited the KCa2.3 component of EDH.Conclusions. LOX metabolites mediate EDH in rat middle cerebral arteries. Inhibition of sEH increases the KCa2.3 component of EDH. Following NOS inhibition, loss of KCa2.3 function is independent of changes in LOX production or sEH inhibition but due to increased isoprostane production and subsequent stimulation of TP receptors. These findings have important implications in diseases associated with loss of NO signaling such as stroke; where inhibition of sEH and/or isoprostane formation may of benefit.

  10. Intraplant communication in maize contributes to defense against insects

    Science.gov (United States)

    The vasculature of plants act as a channel for transport of signal(s) that facilitate long-distance intraplant communication. In maize, Maize insect resistance1-Cysteine Protease (Mir1-CP), which has homology to papain-like proteases, provides defense to different feeding guilds of insect pests. Fur...

  11. Defense styles of pedophilic offenders.

    Science.gov (United States)

    Drapeau, Martin; Beretta, Véronique; de Roten, Yves; Koerner, Annett; Despland, Jean-Nicolas

    2008-04-01

    This pilot study investigated the defense styles of pedophile sexual offenders. Interviews with 20 pedophiles and 20 controls were scored using the Defense Mechanisms Rating Scales. Results showed that pedophiles had a significantly lower overall defensive functioning score than the controls. Pedophiles used significantly fewer obsessional-level defenses but more major image-distorting and action-level defenses. Results also suggested differences in the prevalence of individual defenses where pedophiles used more dissociation, displacement, denial, autistic fantasy, splitting of object, projective identification, acting out, and passive aggressive behavior but less intellectualization and rationalization.

  12. Characterization of the non-heme iron center of human 5-lipoxygenase by electron paramagnetic resonance, fluorescence, and ultraviolet-visible spectroscopy: redox cycling between ferrous and ferric states.

    Science.gov (United States)

    Chasteen, N D; Grady, J K; Skorey, K I; Neden, K J; Riendeau, D; Percival, M D

    1993-09-21

    Purified human 5-lipoxygenase, a non-heme iron containing enzyme, has been characterized by electron paramagnetic resonance, (EPR), ultraviolet (UV)-visible and fluorescence spectroscopy. As isolated, the enzyme is largely in the ferrous state and shows a weak X-band EPR signal extending from 0 to 700 G at 15 K, tentatively ascribed to integer spin Fe(II). Titration of the protein with 13-HPOD (13-hydroperoxyoctadecadienoic acid) generates a strong multicomponent EPR signal in the g' approximately 6 region, a yellow color associated with an increased absorption between 310 and 450 nm (epsilon 330nm = 2400 M-1 cm-1), and a 17% decrease in the intrinsic protein fluorescence. The multiple component nature of the g' approximately 6 signal indicates that the metal center in its oxidized state exists in more than one but related forms. The g' approximately 6 EPR signal and the yellow color reach a maximum when approximately 1 mol of 13-HPOD is added/mol of iron; the resultant EPR spectrum accounts quantitatively for all of the iron in the protein with a signal at g' = 4.3 representing less than 3% of the total iron in the majority of samples. Addition of a hydroxyurea reducing agent abolished the g' approximately 6 signal and yellow color of the protein and also reversed the decrease in fluorescence caused by the oxidant 13-HPOD. The results indicate that the g' approximately 6 EPR signal, the yellow color, and the decreased fluorescence are associated with the formation of the Fe(III) form of the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Defense Research Enterprise Assessment

    Science.gov (United States)

    2017-01-01

    Please review the report findings and recommendations. I am interested in receiving your feedback for inclusion in programs wherever these...needed culture shift to utilize their existing authorities. Finally, expanded coordination among intermural basic research portfolios across the Labs...research portfolios across the Labs without creating additional administrative burdens is needed. The defense research enterprise should

  14. AFRL Defensive IO Programs

    Science.gov (United States)

    2007-11-02

    Wireless Information Assurance • Steganography • Air Force Enterprise Defense (AFED) 10 Distributed Agents for Information Warfare Operational...information (images, documents, overlays, audio , links, etc.) •multi-level data release to coalition forces; key-based access •covert communication...maximize throughput of communication channels Data Hiding/Embedding Steganography Watermarking Steganalysis 14 Payoffs • Integrates existing

  15. Defense Business Transformation

    Science.gov (United States)

    2009-12-01

    other. SCM and ERP systems both contribute to the overall distribution and coordination of resources. Just as an ERP enhances information flow...inventory management system (Thureen 2008). It combines the Army’s disparate wholesale and retail inventories, into one combined system (Sparacino 2002...Studies.............................................................................. 73 1. Defense Integrated Military Human Resource System

  16. Robust Preallocated Preferential Defense.

    Science.gov (United States)

    1985-08-01

    Frye , W.H. and Ullman, L.L., Methodology for Calculating Minuteman Defense Effectiveness, SRD-EGI4, Stanford Research Institute, October 1973. 4. Hogg...Corporation 1500 Wilson Boulevard Arlington, VA 22209 ATTN: Dr. Tucker Battle Dr. James Skouras Dr. Iram Weinstein Northrop Corporation 8900 E. Washington

  17. Differential Impact of Lipoxygenase 2 and Jasmonates on Natural and Stress-Induced Senescence in Arabidopsis1[W

    Science.gov (United States)

    Seltmann, Martin A.; Stingl, Nadja E.; Lautenschlaeger, Jens K.; Krischke, Markus; Mueller, Martin J.; Berger, Susanne

    2010-01-01

    Jasmonic acid and related oxylipins are controversially discussed to be involved in regulating the initiation and progression of leaf senescence. To this end, we analyzed profiles of free and esterified oxylipins during natural senescence and upon induction of senescence-like phenotypes by dark treatment and flotation on sorbitol in Arabidopsis (Arabidopsis thaliana). Jasmonic acid and free 12-oxo-phytodienoic acid increased during all three processes, with the strongest increase of jasmonic acid after dark treatment. Arabidopside content only increased considerably in response to sorbitol treatment. Monogalactosyldiacylglycerols and digalactosyldiacylglycerols decreased during these treatments and aging. Lipoxygenase 2-RNA interference (RNAi) plants were generated, which constitutively produce jasmonic acid and 12-oxo-phytodienoic acid but do not exhibit accumulation during natural senescence or upon stress treatment. Chlorophyll loss during aging and upon dark incubation was not altered, suggesting that these oxylipins are not involved in these processes. In contrast, lipoxygenase 2-RNAi lines and the allene oxid synthase-deficient mutant dde2 were less sensitive to sorbitol than the wild type, indicating that oxylipins contribute to the response to sorbitol stress. PMID:20190093

  18. Chronic adventitial inflammation, vasa vasorum expansion, and 5-lipoxygenase up-regulation in irradiated arteries from cancer survivors

    Science.gov (United States)

    Halle, Martin; Christersdottir, Tinna; Bäck, Magnus

    2016-01-01

    Radiation-induced cardiovascular disease is an emerging problem in a steadily increasing population of survivors of cancer. However, the underlying biology is poorly described, and the late onset, which occurs several years after exposure, precludes adequate investigations in animal and cell culture models. We investigated the role of the 5-lipoxygenase (5-LO)/leukotriene pathway in radiation-induced vascular changes. Use of paired samples of irradiated arteries and nonirradiated internal control arteries from the same patient that were harvested during surgery for cancer reconstruction ≤10 yr after radiotherapy provides a unique human model of chronic radiation–induced vascular changes. Immunohistochemical stainings and perioperative inspection revealed an adventitial inflammatory response, with vasa vasorum expansion and chronic infiltration of CD68+ macrophages. These macrophages stained positive for the leukotriene-forming enzyme 5-LO. Messenger RNA levels of 5-LO and leukotriene B4 receptor 1 were increased in irradiated arterial segments compared with control vessels. These results point to targeting the 5-LO/leukotriene pathway as a therapeutic adjunct to prevent late adverse vascular effects of radiotherapy.—Halle, M., Christersdottir, T., Bäck, M. Chronic adventitial inflammation, vasa vasorum expansion, and 5-lipoxygenase up-regulation in irradiated arteries from cancer survivors. PMID:27530979

  19. Design, synthesis of novel pyranotriazolopyrimidines and evaluation of their anti-soybean lipoxygenase, anti-xanthine oxidase, and cytotoxic activities.

    Science.gov (United States)

    Saïd, Abderrahim Ben; Romdhane, Anis; Elie, Nicolas; Touboul, David; Jannet, Hichem Ben; Bouajila, Jalloul

    2016-12-01

    The synthesis of 14-(aryl)-14H-naphto[2,1-b]pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine-2-yl) acetamidoximes 2a-e has been accomplished by reaction of 2-acetonitrile derivatives 1a-e with hydroxylamine. Cyclocondensation reaction of precursors 2a-e with some elctrophilic species such as ethylorthoformate, acetic anhydride, and methyl-acetoacetate provided the new oxadiazole derivatives 3a-e, 4a-e, and 5a-e, respectively. On the other hand, the reaction of precursors 2a-e with 2-chloropropanoyl chloride afforded the new acetimidamides 6a-e which evolve under reflux of toluene to the new oxadiazoles 7a-e. The synthetic compounds were screened for their anti-xanthine oxidase, anti-soybean lipoxygenase, and cytotoxic activities. Moderate to weak xanthine oxidase and soybean lipoxygenase inhibitions were obtained but significant cytotoxic activities were noted. The most cytotoxic activities were recorded mainly (i) 5a was the most active (IC50 = 4.0 μM) and selective against MCF-7 and (ii) 2a was cytotoxic against the four cell lines with selectivity for MCF-7 and OVCAR-3 (IC50 = 17 and 12 μM, respectively) while 2e is highly selective against OVCAR-3 (IC50 = 10 μM).

  20. Reversal of High dietary fructose-induced PPARα suppression by oral administration of lipoxygenase/cyclooxygenase inhibitors

    Directory of Open Access Journals (Sweden)

    Azhar Salman

    2005-08-01

    Full Text Available Abstract High fructose feeding causes diet-induced alterations of lipid metabolism and decreased insulin sensitivity, hallmark of which is a rapid and profound hypertriglyceridemia. One of the mechanisms that contribute to serum hypertriglyceridemia in this model is suppression of hepatic PPARα. HMG-CoA inhibitors, which reduce serum triglycerides in these animals, also elevate/restore hepatic PPARα. Previously we demonstrated that two known lipoxygenase/cyclooxygenase inhibitors reversed diet-induced hypertriglyceridemia in this model and that reversal of certain inflammatory markers in the liver correlated with the metabolic benefit. In this paper we extended these studies by examining the impact of these compounds on expression of PPARα, both at the level of transcription and expression. Our data show that diet-induced suppression of hepaic PPARα is reversed upon treatment with lipoxygenase/cyclooxygenase compounds. We then tested one of these compounds, BW-755c, over a range of doses from 10 mg/kg to 100 mg/kg to establish a dose-response relationship with the reduction of serum hypertriglyceridemia in this model. These experiments support the concept of using anti-inflammatory medications as one method to correct metabolic dysfunction.

  1. Antioxidant/Prooxidant and Antibacterial/Probacterial Effects of a Grape Seed Extract in Complex with Lipoxygenase

    Directory of Open Access Journals (Sweden)

    Veronica Sanda Chedea

    2014-01-01

    Full Text Available In an attempt to determine the antioxidant/prooxidant, antibacterial/probacterial action of flavan-3-ols and procyanidins from grape seeds, pure catechin (CS, and an aqueous grape seed extract (PE, were applied in the absence and presence of pure lipoxygenase (LS or in extract (LE to leucocyte culture, Escherichia coli B41 and Brevibacterium linens, and observed whether there was any effect on lipid peroxidation, cytotoxicity, or growth rate. Short time periods of coincubation of cells with the polyphenols, followed by the exposure to LS and LE, revealed a high level of lipid peroxidation and a prooxidative effect. Longer coincubation and addition of LS and LE resulted in the reversal of the prooxidant action either to antioxidant activity for CS + LS and PE + LS or to the control level for CS + LE and PE + LE. Lipid peroxidation was significantly reduced when cells were exposed to polyphenols over a longer period. Longer exposure of E. coli to CS or PE followed by addition of LS for 3 h resulted in bactericidal activity. Significant stimulatory effect on microbial growth was observed for PE + LS and PE + LE treatments in B. linens, illustrating the potential probacterial activity in B. linens cultures. Lipoxygenase-polyphenols complex formation was found to be responsible for the observed effects.

  2. Defense Institution Building: An Assessment

    Science.gov (United States)

    2016-01-01

    MoDA and DIILS Support of DIB Activity Objectives . . . . . . . 26 2.8. Overlapping Program Objectives...Wales Initiative Fund–Defense Institution Building (WIF-DIB), the Ministry of Defense Advisors ( MoDA ) program, and the Defense Insti- tute of...other events and activities related to a partner nation’s defense institution capabilities and capacity. One exception is MoDA , where engagements are

  3. Alterations in Lipoxygenase and Cyclooxygenase-2 Catalytic Activity and mRNA Expression in Prostate Carcinoma

    Directory of Open Access Journals (Sweden)

    Scott B. Shappell

    2001-01-01

    Full Text Available Recent studies in prostate tissues and especially cell lines have suggested roles for arachidonic acid (AA metabolizing enzymes in prostate adenocarcinoma (Pca development or progression. The goal of this study was to more fully characterize lipoxygenase (LOX and cyclooxygenase-2 (COX-2 gene expression and AA metabolism in benign and malignant prostate using snap-frozen tissues obtained intraoperatively and mRNA analyses and enzyme assays. Formation of 15-hydroxyeicosatetraenoic acid (15-HETE was detected in 23/29 benign samples and 15-LOX-2 mRNA was detected in 21/25 benign samples. In pairs of pure benign and Pca from the same patients, 15-HETE production and 15-LOX-2 mRNA were reduced in Pca versus benign in 9/14 (P=.04 and 14/17 (P=.002, respectively. Under the same conditions, neither 5HETE nor 12-HETE formation was detectable in 29 benign and 24 tumor samples; with a more sensitive assay, traces were detected in some samples, but there was no clear association with tumor tissue. COX-2 mRNA was detected by nuclease protection assay in 7/16 benign samples and 5/16 tumors. In benign and tumor pairs from 10 patients, COX-2 was higher in tumor versus benign in only 2, with similar results by in situ hybridization. Paraffin immunoperoxidase for COX2 was performed in whole mount sections from 87 additional radical prostatectomy specimens, with strong expression in ejaculatory duct as a positive control and corroboration with in situ hybridization. No immunostaining was detected in benign prostate or tumor in 45% of cases. Greater immunostaining in tumor versus benign was present in only 17% of cases, and correlated with high tumor grade (Gleason score 8 and 9 vs. 5 to 7. In conclusion, reduced 15-LOX-2 expression and 15-HETE formation is the most characteristic alteration of AA metabolism in Pca. Increased 12-HETE and 5-HETE formation in Pca were not discernible. Increased COX-2 expression is not a typical abnormality in Pca in general, but

  4. Alterations in lipoxygenase and cyclooxygenase-2 catalytic activity and mRNA expression in prostate carcinoma.

    Science.gov (United States)

    Shappell, S B; Manning, S; Boeglin, W E; Guan, Y F; Roberts, R L; Davis, L; Olson, S J; Jack, G S; Coffey, C S; Wheeler, T M; Breyer, M D; Brash, A R

    2001-01-01

    Recent studies in prostate tissues and especially cell lines have suggested roles for arachidonic acid (AA) metabolizing enzymes in prostate adenocarcinoma (Pca) development or progression. The goal of this study was to more fully characterize lipoxygenase (LOX) and cyclooxygenase-2 (COX-2) gene expression and AA metabolism in benign and malignant prostate using snap-frozen tissues obtained intraoperatively and mRNA analyses and enzyme assays. Formation of 15-hydroxyeicosatetraenoic acid (15-HETE) was detected in 23/29 benign samples and 15-LOX-2 mRNA was detected in 21/25 benign samples. In pairs of pure benign and Pca from the same patients, 15-HETE production and 15-LOX-2 mRNA were reduced in Pca versus benign in 9/14 (P=.04) and 14/17 (P=.002), respectively. Under the same conditions, neither 5-HETE nor 12-HETE formation was detectable in 29 benign and 24 tumor samples; with a more sensitive assay, traces were detected in some samples, but there was no clear association with tumor tissue. COX-2 mRNA was detected by nuclease protection assay in 7/16 benign samples and 5/16 tumors. In benign and tumor pairs from 10 patients, COX-2 was higher in tumor versus benign in only 2, with similar results by in situ hybridization. Paraffin immunoperoxidase for COX-2 was performed in whole mount sections from 87 additional radical prostatectomy specimens, with strong expression in ejaculatory duct as a positive control and corroboration with in situ hybridization. No immunostaining was detected in benign prostate or tumor in 45% of cases. Greater immunostaining in tumor versus benign was present in only 17% of cases, and correlated with high tumor grade (Gleason score 8 and 9 vs. 5 to 7). In conclusion, reduced 15-LOX-2 expression and 15-HETE formation is the most characteristic alteration of AA metabolism in Pca. Increased 12-HETE and 5-HETE formation in Pca were not discernible. Increased COX-2 expression is not a typical abnormality in Pca in general, but occurs in high

  5. High expression of arachidonate 15-lipoxygenase and proinflammatory markers in human ischemic heart tissue

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, Lisa U.; Lundqvist, Annika [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Asp, Julia [Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg (Sweden); Synnergren, Jane [Systems Biology Research Center, School of Life Sciences, University of Skoevde, Skoevde (Sweden); Johansson, Cecilia Thalen [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Palmqvist, Lars [Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg (Sweden); Jeppsson, Anders [Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg (Sweden); Hulten, Lillemor Mattsson, E-mail: Lillemor.Mattsson@wlab.gu.se [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer We found a 17-fold upregulation of ALOX15 in the ischemic heart. Black-Right-Pointing-Pointer Incubation of human muscle cells in hypoxia showed a 22-fold upregulation of ALOX15. Black-Right-Pointing-Pointer We observed increased levels of proinflammatory markers in ischemic heart tissue. Black-Right-Pointing-Pointer Suggesting a link between ischemia and inflammation in ischemic heart biopsies. -- Abstract: A common feature of the ischemic heart and atherosclerotic plaques is the presence of hypoxia (insufficient levels of oxygen in the tissue). Hypoxia has pronounced effects on almost every aspect of cell physiology, and the nuclear transcription factor hypoxia inducible factor-1{alpha} (HIF-1{alpha}) regulates adaptive responses to low concentrations of oxygen in mammalian cells. In our recent work, we observed that hypoxia increases the proinflammatory enzyme arachidonate 15-lipoxygenase (ALOX15B) in human carotid plaques. ALOX15 has recently been shown to be present in the human myocardium, but the effect of ischemia on its expression has not been investigated. Here we test the hypothesis that ischemia of the heart leads to increased expression of ALOX15, and found an almost 2-fold increase in HIF-1{alpha} mRNA expression and a 17-fold upregulation of ALOX15 mRNA expression in the ischemic heart biopsies from patients undergoing coronary bypass surgery compared with non ischemic heart tissue. To investigate the effect of low oxygen concentration on ALOX15 we incubated human vascular muscle cells in hypoxia and showed that expression of ALOX15 increased 22-fold compared with cells incubated in normoxic conditions. We also observed increased mRNA levels of proinflammatory markers in ischemic heart tissue compared with non-ischemic controls. In summary, we demonstrate increased ALOX15 in human ischemic heart biopsies. Furthermore we demonstrate that hypoxia increases ALOX15 in human muscle cells. Our results yield

  6. X-ray absorption spectroscopy of soybean lipoxygenase-1 : Influence of lipid hydroperoxide activation and lyophilization on the structure of the non-heme iron active site

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Heijdt, L.M. van der; Feiters, M.C.; Navaratnam, S.; Nolting, H.-F.; Hermes, C.; Veldink, G.A.

    1992-01-01

    X-ray absorption spectra at the Fe K-edge of the non-heme iron site in Fe(II) as well as Fe(III) soybean lipoxygenase-1, in frozen solution or lyophilized, are presented; the latter spectra were obtained by incubation of the Fe(II) enzyme with its product hydroperoxide. An edge shift of about 23 eV

  7. On the mechanism of action of soybean lipoxygenase-1. A stopped-flow kinetic study of the formation and conversion of yellow and purple enzyme species

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Egmond, M.R.; Fasella, P.M.; Veldink, G.A.; Boldingh, J.

    1977-01-01

    1. The conversion of the native iron-containing lipoxygenase-1 into yellow and purple ferric enzyme species by 13-L-hydroperoxy-9-cis, 11-trans-octadecadienoic acid (R-13-OOH) was studied by measuring the absorbance changes at 330 nm and 580 nm, respectively in the stopped-flow apparatus. The

  8. Avian host defense peptides.

    Science.gov (United States)

    Cuperus, Tryntsje; Coorens, Maarten; van Dijk, Albert; Haagsman, Henk P

    2013-11-01

    Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense of many organisms. It is becoming increasingly clear that in the animal kingdom the functions of HDPs are not confined to direct antimicrobial actions. Research in mammals has indicated that HDPs have many immunomodulatory functions and are also involved in other physiological processes ranging from development to wound healing. During the past five years our knowledge about avian HDPs has increased considerably. This review addresses our current knowledge on the evolution, regulation and biological functions of HDPs of birds.

  9. A Defense Budget Primer

    Science.gov (United States)

    1998-12-09

    budget practices. See Appendix D for the actual timetable of congressional action on the FY1999 budget.65 See James V. Saturno , The Appropriations...details, see James V. Saturno , The Appropriations Process and the Congressional69 Budget Act, CRS Report 97-947. Table 6. Milestone Votes on the Defense...James V. Saturno , The74 Appropriations Process and the Congressional Budget Act, CRS Report 97-947. The Budget Enforcement Act of 1990 and subsequent

  10. Defensive Minefield Planning

    Science.gov (United States)

    1989-06-01

    Minefield Planning by Carlos Vallejo Game Lieutenant, Ecuadorian Navy B. S., Escuela Superior Naval, Ecuador 1980 Submitted in partial fulfillment of...was a superior open-ocean naval force to the North Koreans, defensive minewarfare was able to, at least temporarily, defeat U.S. Navy objectives in...Oswaldo Rosero 1 Unit 8 Coastal Route 1 Monterey, California 93940 77 11. Office of the N’aval Attache 4 Direccion de Educacion 2535 15th. st. N. W

  11. Research progress in mechanical wounding stimulation signal molecules transduction and defensive reaction for fresh-cut fruits and vegetables%鲜切果蔬机械伤害刺激信号分子转导及防御反应的研究进展

    Institute of Scientific and Technical Information of China (English)

    闫媛媛; 胡文忠; 姜爱丽; 陈晨

    2015-01-01

    鲜切果蔬在加工过程中会使果蔬受到机械损伤,组织结构遭到破坏,极易发生褐变与受到微生物侵染,从而加速果蔬组织的衰老和腐败。机械伤害刺激信号分子的产生、运转、感知、接受和转导,以激活受伤害诱导的防卫基因表达,进而诱发鲜切果蔬整体协调产生防御反应。茉莉酸类、水杨酸、乙烯、脱落酸和系统素信号分子诱导果蔬防御反应可减轻机械损伤对鲜切果蔬品质的影响,能够有效抑制微生物对受伤部位的侵染以及果蔬组织内部的酶促褐变,改善果蔬贮藏品质。本文从机械伤害刺激信号分子茉莉酸类、水杨酸、乙烯、脱落酸和系统素的产生及转导方面综述了鲜切果蔬对机械伤害防御反应机制,并从伤害防御方面介绍了外源施用茉莉酸类、水杨酸和乙烯的作用机制与保鲜效果。%Fresh-cut fruit and vegetables during processing will be subjected to mechanical damage, in which the organization structure is destroyed, and it is easy to become browning and be infected by microbial, as well as the aging and corruption of the organization of fruits and vegetables are accelerated. Mechanical noxious stimulate the production, operation, perception, acceptance and transduction of signaling molecules, to activate the injury-induced defense gene expression, and then induced fresh-cut fruits and vegetables to produce the overall coordination of defense response. Jasmine acid, salicylic acid, ethylene, abscisic acid and system elements signaling molecules to induce defense reactions of fruits and vegetables can reduce the effect of mechanical damage on the quality of fresh-cut fruits and vegetables, and can effectively inhibit microbial infection of injured area and the organization enzymatic browning of fruit and vegetable,whichimprove storage quality of fruits and vegetables. This paper summarized the defensive responds of mechanical wounding and

  12. Riboflavin-induced Priming for Pathogen Defense in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Shujian Zhang; Xue Yang; Maowu Sun; Feng Sun; Sheng Deng; Hansong Dong

    2009-01-01

    Riboflavin (vitamin B2) participates in a variety of redox processes that affect plant defense responses. Previously we have shown that riboflavin induces pathogen resistance in the absence of hypersensitive cell death (HCD) in plants. Herein, we report that riboflavin induces priming of defense responses in Arabidopsis thaliana toward infection by virulent Pseudomonas syringae pv. Tomato DC3000 (Pst). Induced resistance was mechanistically connected with the expression of defense response genes and cellular defense events, including H2O2 burst, HCD, and callose deposition in the plant. Riboflavin treatment and inoculation of plants with Pst were neither active but both synergized to induce defense responses. The priming process needed NPR1 (essential regulator of systemic acquired resistance) and maintenance of H2O2 burst but was independent of salicylic acid, jasmonic acid, ethylene, and abscisic acid. Our results suggest that the role of riboflavin in priming defenses is subject to a signaling process distinct from the known pathways of hormone signal transduction.

  13. The Interaction Between Lipoxygenase-Catalyzed Oxidation and Autoxidation in Dry-Cured Bacon and a Model System.

    Science.gov (United States)

    Zhang, Yingyang; Tang, Jing; Zhao, Jianying; Wu, Haizhou; Ditta, Yasir Allah; Zhang, Jianhao

    2015-12-01

    A model system was conducted to characterize the interaction between lipid autoxidation and enzyme-catalyzed oxidation in dry-cured bacon. This involved the use of a hydroxyl radical (HO•) generating system and the extraction and purification of lipoxygenases (LOX) from pork belly. The results showed that LOX activity rapidly (P bacon. This may be because of the hydroxyl-radical-mediated oxidation from LOX-Fe(2+) to LOX-Fe(3+), which activates LOX. In addition, experiments of the model system also showed that LOX activity could be inhibited by increasing the substrate concentration, although substrate type and concentration had no effect on autoxidation. Moreover, LOX enzyme-catalyzed oxidation and autoxidation could act synergistically to promote lipid oxidation irrespective of the substrate (linoleic or arachidonic acid). These results provide useful information for regulating lipid oxidation during the production of dry-cured pork products.

  14. Design, synthesis and evaluation of semi-synthetic triazole-containing caffeic acid analogues as 5-lipoxygenase inhibitors.

    Science.gov (United States)

    De Lucia, Daniela; Lucio, Oscar Méndez; Musio, Biagia; Bender, Andreas; Listing, Monika; Dennhardt, Sophie; Koeberle, Andreas; Garscha, Ulrike; Rizzo, Roberta; Manfredini, Stefano; Werz, Oliver; Ley, Steven V

    2015-08-28

    In this work the synthesis, structure-activity relationship (SAR) and biological evaluation of a novel series of triazole-containing 5-lipoxygenase (5-LO) inhibitors are described. The use of structure-guided drug design techniques provided compounds that demonstrated excellent 5-LO inhibition with IC50 of 0.2 and 3.2 μm in cell-based and cell-free assays, respectively. Optimization of binding and functional potencies resulted in the identification of compound 13d, which showed an enhanced activity compared to the parent bioactive compound caffeic acid 5 and the clinically approved zileuton 3. Compounds 15 and 16 were identified as lead compounds in inhibiting 5-LO products formation in neutrophils. Their interference with other targets on the arachidonic acid pathway was also assessed. Cytotoxicity tests were performed to exclude a relationship between cytotoxicity and the increased activity observed after structure optimization.

  15. DEFENSE PROGRAMS RISK MANAGEMENT FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Constantin PREDA

    2012-01-01

    Full Text Available For the past years defense programs have faced delays in delivering defense capabilities and budget overruns. Stakeholders are looking for ways to improve program management and the decision making process given the very fluid and uncertain economic and political environment. Consequently, they have increasingly resorted to risk management as the main management tool for achieving defense programs objectives and for delivering the defense capabilities strongly needed for the soldiers on the ground on time and within limited defense budgets. Following a risk management based decision-making approach the stakeholders are expected not only to protect program objectives against a wide range of risks but, at the same time, to take advantage of the opportunities to increase the likelihood of program success. The prerequisite for making risk management the main tool for achieving defense programs objectives is the design and implementation of a strong risk management framework as a foundation providing an efficient and effective application of the best risk management practices. The aim of this paper is to examine the risk management framework for defense programs based on the ISO 31000:2009 standard, best risk management practices and the defense programs’ needs and particularities. For the purposes of this article, the term of defense programs refers to joint defense programs.

  16. Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Anders Bøgh; Raventos, D.; Mundy, John Williams

    2002-01-01

    Jasmonates induce plant-defence responses and act to regulate defence-related genes including positive feedback of the lipoxygenase 2 (LOX2) gene involved in jasmonate synthesis. To identify jasmonate-signalling mutants, we used a fusion genetic strategy in which the firefly luciferase (FLUC...... as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition...

  17. Antioxidant, Anti-5-lipoxygenase and Antiacetylcholinesterase Activities of Essential Oils and Decoction Waters of Some Aromatic Plants

    Directory of Open Access Journals (Sweden)

    Sílvia M. Albano

    2012-01-01

    Full Text Available The scavenging of free radicals and superoxide anion, the inhibition of 5-lipoxygenase and the antiacetylcholinesterase activities of essential oils and decoction waters of eight aromatic plants (Dittrichia viscosa , Foeniculum vulgare, Origanum vulgare, Salvia officinalis, Thymbra capitata , Thymus camphoratus, Thymus carnosus and Thymus mastichina were studied. The essential oils were dominated by 1,8-cineole in S. officinalis (59%, T. mastichina (49% and T. camphoratus (21%; borneol (20% in T. carnosus; carvacrol in Thymbra capitata (68%; γ -terpinene (49% in O. vulgare; α -pinene (26% in F. vulgare; and trans-nerolidol (8% + β -oplopenone (7% in D. viscosa. O. vulgare decoction waters had the highest amount of phenols (4 5 ± 3 mg GAE/mL while F. vulgare only had 5 ± 0 mg GAE/mL. The decoction waters showed higher radical scavenging activity than the essential oils. O. vulgare decoction water showed the best antioxidant activity (IC 50= 3 ± 0 m g/mL, while the most effective essential oils were those of Thymbra capitata (IC 50=61 ± 2 m g/mL and O. vulgare (IC 50=15 6 ± 5 m g/mL. Thymbra capitata (IC 50= 6 ± 0 m g/mL decoction water showed the best superoxide anion scavenging activity. F. vulgare decoction water and essential oil revealed the best 5-lipoxygenase inhibition capacity (IC 50=2 7 ± 1 m g/mL and IC 50=6 8 ± 2 m g/mL, respectively. T. mastichina (IC 50=4 6 ± 4 m g/mL, S. officinalis (IC 50=5 1 ± 4 m g/mL, Thymbra capitata (IC 50=5 2 ± 1 m g/mL and T. camphoratus (IC 50=13 7 ± 2 m g/mL essential oils showed the best antiacetylcholinesterase activity.

  18. In vitro Anti-inflammatory Effects of Edible Igusa Soft Rush (Juncus effusus L.) on Lipoxygenase, Hyaluronidase, and Cellular Nitric Oxide Generation Assays: Comparison with Matcha Green Tea (Camellia sinensis L.)

    National Research Council Canada - National Science Library

    Nishimura, Tatsuhiko; Kabata, Kiyotaka; Koike, Akiko; Ono, Masateru; Igoshi, Keiji; Yasuda, Shin

    2016-01-01

    .... Matcha green tea powder was tested for comparison. Hot-water and ethanol extracts of soft rush as well as matcha showed comparable lipoxygenase inhibition, with IC50 values of 123 to 145 µg/mL...

  19. Hormone defense networking in rice: tales from a different world.

    Science.gov (United States)

    De Vleesschauwer, David; Gheysen, Godelieve; Höfte, Monica

    2013-10-01

    Recent advances in plant immunity research underpin the pivotal role of small-molecule hormones in regulating the plant defense signaling network. Although most of our understanding comes from studies of dicot plants such as Arabidopsis thaliana, new studies in monocots are providing additional insights into the defense-regulatory role of phytohormones. Here, we review the roles of both classical and more recently identified stress hormones in regulating immunity in the model monocot rice (Oryza sativa) and highlight the importance of hormone crosstalk in shaping the outcome of rice-pathogen interactions. We also propose a defense model for rice that does not support a dichotomy between the pathogen lifestyle and the effectiveness of the archetypal defense hormones salicylic acid (SA) and jasmonic acid (JA).

  20. Serine/threonine protein phosphatases: multi-purpose enzymes in control of defense mechanisms.

    Science.gov (United States)

    Bajsa, Joanna; Pan, Zhiqiang; Duke, Stephen O

    2011-12-01

    Depending on the threat to a plant, different pattern recognition receptors, such as receptor-like kinases, identify the stress and trigger action by appropriate defense response development. The plant immunity system primary response to these challenges is rapid accumulation of phytohormones, such as ethylene (ET), salicylic acid (SA), and jasmonic acid (JA) and its derivatives. These phytohormones induce further signal transduction and appropriate defenses against biotic threats. Phytohormones play crucial roles not only in the initiation of diverse downstream signaling events in plant defense but also in the activation of effective defenses through an essential process called signaling pathway crosstalk, a mechanism involved in transduction signals between two or more distinct, "linear signal transduction pathways simultaneously activated in the same cell."

  1. Nanomaterials for Defense Applications

    Science.gov (United States)

    Turaga, Uday; Singh, Vinitkumar; Lalagiri, Muralidhar; Kiekens, Paul; Ramkumar, Seshadri S.

    Nanotechnology has found a number of applications in electronics and healthcare. Within the textile field, applications of nanotechnology have been limited to filters, protective liners for chemical and biological clothing and nanocoatings. This chapter presents an overview of the applications of nanomaterials such as nanofibers and nanoparticles that are of use to military and industrial sectors. An effort has been made to categorize nanofibers based on the method of production. This chapter particularly focuses on a few latest developments that have taken place with regard to the application of nanomaterials such as metal oxides in the defense arena.

  2. Phenomenon of Psychological Defense

    Directory of Open Access Journals (Sweden)

    Elena T. Sokolova

    2011-01-01

    Full Text Available The author discusses the controversial issues of formation and functioning of psy¬chological defense mechanisms in ontogenesis and in personality disorders as they are represented in classical and contemporary psychoanalysis, in cognitivism and communication theory. The paper emphasizes the role of cognitive organi¬zation (style, sign-symbolic mediation, representative system of object relations and attachments in individual typological variability of the level organization of ciency of personal and social adaptation, in maturity and mental health of personality

  3. Overexpression of Poplar PtrWRKY89 in Transgenic Arabidopsis Leads to a Reduction of Disease Resistance by Regulating Defense-Related Genes in Salicylate- and Jasmonate-Dependent Signaling.

    Directory of Open Access Journals (Sweden)

    Yuanzhong Jiang

    Full Text Available The plant hormones jasmonic acid (JA and salicylic acid (SA play key roles in plant defenses against pathogens and several WRKY transcription factors have been shown to have a role in SA/JA crosstalk. In a previous study, overexpression of the poplar WRKY gene PtrWRKY89 enhanced resistance to pathogens in transgenic poplars. In this study, the promoter of PtrWRKY89 (ProPtrWRKY89 was isolated and used to drive GUS reporter gene. High GUS activity was observed in old leaves of transgenic Arabidopsis containing ProPtrWRKY89-GUS construct and GUS expression was extremely induced by SA solution and SA+MeJA mixture but not by MeJA treatment. Subcellular localization and transactivation assays showed that PtrWRKY89 acted as a transcription activator in the nucleus. Constitutive expression of PtrWRKY89 in Arabidopsis resulted in more susceptible to Pseudomonas syringae and Botrytis cinerea compared to wild-type plants. Quantitative real-time PCR (qRT-PCR analysis confirmed that marker genes of SA and JA pathways were down-regulated in transgenic Arabidopsis after pathogen inoculations. Overall, our results indicated that PtrWRKY89 modulates a cross talk in resistance to P. syringe and B. cinerea by negatively regulating both SA and JA pathways in Arabidopsis.

  4. Defensive engagement and perceptual enhancement

    OpenAIRE

    Keil, Andreas; Bradley, Margaret M; Ihssen, Niklas; Heim, Sabine; Vila, Jaime; Guerra, Pedro; Lang, Peter J.

    2010-01-01

    We tested whether visual cortical sensitivity to external cues in the context of an acute defensive reaction is heightened or attenuated. A strong cardiac defense (fear) response was elicited by presenting an abrupt, loud acoustic stimulus following a 10-minute period of quiescence. Electrocortical responses to aversive and neutral pictures following defensive stimulus onset were measured using dense-array EEG. Pictures were flickered at 12.5 Hz to evoke steady-state visual evoked potentials ...

  5. Ballistic Missile Defense System (BMDS)

    Science.gov (United States)

    2015-12-01

    Estimate RDT&E - Research , Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then...all ranges and in all phases of flight. Following guidance from the President, the Secretary of Defense approved the Ballistic Missile Defense (BMD...based Midcourse Defense (GMD) system to enhance our capability against Intercontinental Ballistic Missiles. We are currently sustaining 30

  6. Hydrogen Peroxide Pretreatment Mitigates Cadmium-Induced Oxidative Stress in Brassica napus L.: An Intrinsic Study on Antioxidant Defense and Glyoxalase Systems

    Science.gov (United States)

    Hasanuzzaman, Mirza; Nahar, Kamrun; Gill, Sarvajeet S.; Alharby, Hesham F.; Razafindrabe, Bam H. N.; Fujita, Masayuki

    2017-01-01

    Cadmium (Cd) is considered as one of the most toxic metals for plant growth and development. In the present study, we investigated the role of externally applied hydrogen peroxide (H2O2) in regulating the antioxidant defense and glyoxalase systems in conferring Cd-induced oxidative stress tolerance in rapeseed (Brassica napus L.). Seedlings were pretreated with 50 μM H2O2 for 24 h. These pretreated seedlings as well as non-pretreated seedlings were grown for another 48 h at two concentrations of CdCl2 (0.5 and 1.0 mM). Both the levels of Cd increased MDA and H2O2 levels and lipoxygenase activity while ascorbate (AsA) declined significantly. However, reduced glutathione (GSH) content showed an increase at 0.5 mM CdCl2, but glutathione disulfide (GSSG) increased at any level of Cd with a decrease in GSH/GSSG ratio. The activities of ascorbate peroxidase (APX) and glutathione S-transferase (GST) upregulated due to Cd treatment in dose-dependent manners, while glutathione reductase (GR) and glutathione peroxidase (GPX) increased only at 0.5 mM CdCl2 and decreased at higher dose. The activity of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) decreased under Cd stress. On the other hand, H2O2 pretreated seedlings, when exposed to Cd, AsA and GSH contents and GSH/GSSG ratio increased noticeably. H2O2 pretreatment increased the activities of APX, MDHAR, DHAR, GR, GST, GPX, and CAT of Cd affected seedlings. Thus enhancement of both the non-enzymatic and enzymatic antioxidants helped to decrease the oxidative damage as indicated by decreased levels of H2O2 and MDA. The seedlings which were pretreated with H2O2 also showed enhanced glyoxalase system. The activities of Gly I, and Gly II and the content of GSH increased significantly due to H2O2 pretreatment in Cd affected seedlings, compared to the Cd-stressed plants without H2O2 pretreatment which were vital for methylglyoxal

  7. The MAP kinase substrate MKS1 is a regulator of plant defense responses

    DEFF Research Database (Denmark)

    Andreasson, Erik; Jenkins, Thomas; Brodersen, Peter

    2005-01-01

    Arabidopsis MAP kinase 4 (MPK4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (SA)-dependent resistance and for activation of jasmonate (JA)-dependent defense gene expression. To understand MPK4 signaling mechanisms, we used...

  8. Bacterial gasotransmitters: an innate defense against antibiotics.

    Science.gov (United States)

    Luhachack, Lyly; Nudler, Evgeny

    2014-10-01

    In recent decades, there has been growing interest in the field of gasotransmitters, endogenous gaseous signaling molecules (NO, H2S, and CO), as regulators of a multitude of biochemical pathways and physiological processes. Most of the concerted effort has been on eukaryotic gasotransmitters until the subsequent discovery of bacterial counterparts. While the fundamental aspects of bacterial gasotransmitters remain undefined and necessitate further research, we will discuss a known specific role they play in defense against antibiotics. Considering the current dilemma of multidrug-resistant bacteria we consider it particularly prudent to exploring novel targets and approaches, of which the bacterial gasotransmitters, nitric oxide and hydrogen sulfide represent.

  9. In vitro antioxidant, lipoxygenase and xanthine oxidase inhibitory activities of fractions from Cienfuegosia digitata Cav., Sida alba L. and Sida acuta Burn f. (Malvaceae).

    Science.gov (United States)

    Konaté, K; Souza, A; Coulibaly, A Y; Meda, N T R; Kiendrebeogo, M; Lamien-Meda, A; Millogo-Rasolodimby, J; Lamidi, M; Nacoulma, O G

    2010-11-15

    In this study polyphenol content, antioxidant activity, lipoxygenase (LOX) and Xanthine Oxidase (XO) inhibitory effects of n-hexane, dichloromethane, ethyl acetate and n-butanol fractions of aqueous acetone extracts from S. alba L., S. acuta Burn f and Cienfuegosia digitata Cav. were investigated. The total phenolics, flavonoids, flavonols and total tannins were determined by spectrophotometric methods using Folin-ciocalteu, AlCl3 reagents and tannic acid, respectively. The antioxidant potential was evaluated using three methods: inhibition of free radical 2,2-diphenyl-1-picrylhydramzyl (DPPH), ABTS radical cation decolorization assay and Iron (III) to iron (II) reduction activity (FRAP). For enzymatic activity, lipoxygenase and xanthine oxidase inhibitory activities were used. This study shows a relationship between polyphenol contents, antioxidant and enzymatic activities. Present results showed that ethyl acetate and dichloromethane fractions elicit the highest polyphenol content, antioxidant and enzymatic activities.

  10. Effect of gamma irradiation on lipoxygenases, trypsin inhibitor, raffinose family oligosaccharides and nutritional factors of different seed coat colored soybean (Glycine max L.)

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Dixit, Amit [School of Biochemistry, Devi Ahilya University, Khandwa Road, Indore-452017 (India); Kumar, Vineet; Rani, Anita [National Research Centre for Soybean, Khandwa Road, Indore-452017 (India); Manjaya, J.G. [Board of Research in Nuclear Sciences, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Bhatnagar, Deepak, E-mail: bhatnagarbio@yahoo.co [School of Biochemistry, Devi Ahilya University, Khandwa Road, Indore-452017 (India)

    2011-04-15

    Three soybean genotypes Kalitur, Hara soya and NRC37 with black, green and yellow seed coat color, respectively, were gamma irradiated at 0.5, 2.0 and 5.0 kGy and tested for antinutritional and nutritional factors. Gamma irradiation at all doses reduced the level of lipoxygenase isomers, trypsin inhibitor (TI) and ascorbic acid in all the 3 soybean genotypes as compared to the unirradiated control. However, irradiation dose of 5.0 kGy increased the sucrose content of the soybean genotypes. No significant change was observed in oil, protein fatty acids and total tocopherol content of the 3 genotypes at any irradiation dose. It is suggested that inhibition of lipoxygenase, reduction in TI and ascorbic acid may be due to the breakage or oxidation of protein structure by the gamma irradiation. Similarly, gamma irradiation at higher doses may break glycosidic linkages in oligosaccharides to produce more sucrose and decrease the content of flatulence causing oligosaccharides.

  11. Intelligent systems for strategic power infrastructure defense

    Science.gov (United States)

    Jung, Ju-Hwan

    A fault or disturbance in a power system can be severe due to the sources of vulnerability such as human errors, protection and control system failures, a failure of communication networks to deliver critical control signals, and market and load uncertainties. There have been several catastrophic failures resulting from disturbances involving the sources of vulnerability while power systems are designed to withstand disturbances or faults. To avoid catastrophic failures or minimize the impact of a disturbance(s), the state of the power system has to be analyzed correctly and preventive or corrective self-healing control actions have to be deployed. This dissertation addresses two aspects of power systems: Defense system and diagnosis, both concerned with the power system analysis and operation during events involving faults or disturbances. This study is intended to develop a defense system that is able to assess power system vulnerability and to perform self-healing control actions based on the system-wide analysis. In order to meet the requirements of the system-wide analysis, the defense system is designed with multi-agent system technologies. Since power systems are dynamic and uncertain the self-healing control actions need to be adaptive. This study applies the reinforcement learning technique to provide a theoretical basis for adaptation. One of the important issues in adaptation is the convergence of the learning algorithm. An appropriate convergence criterion is derived and an application with a load-shedding scheme is demonstrated in this study. This dissertation also demonstrates the feasibility of the defense system and self-healing control actions through multi-agent system technologies. The other subject of this research is to investigate the methodology for on-line fault diagnosis using the information from Sequence-of-Events Recorders (SER). The proposed multiple-hypothesis analysis generates one or more hypothetical fault scenarios to interpret the

  12. European Missile Defense and Russia

    Science.gov (United States)

    2014-07-01

    most senior level—the only one that matters in Russian decisionmaking cul - ture—is also of significance today and will also be re- ferred to later in... org /missile-defense/us-ballistic-missile-defense/p30607. 9. Email exchange with author, July 2013. 10. “Safeguard,” Washington, DC: Federation of Ameri

  13. Inhibition of soybean and potato lipoxygenases by bhilawanols from bhilawan (Semecarpus anacardium) nut shell liquid and some synthetic salicylic acid analogues.

    Science.gov (United States)

    Nagabhushana, Kyatanahalli S; Umamaheshwari, S; Tocoli, Felismino E; Prabhu, Sandeep K; Green, Ivan R; Ramadoss, Candadai S

    2002-08-01

    Bhilawanol diene (3) isolated from bhilawan nut shell liquid was found to be a potent inhibitor of both soybean and potato lipoxygenases with IC50 values of 0.85 microM and 1.1 microM, respectively. However, the monoene (2) and saturated (1) bhilawanols exhibited relatively lower inhibitory activity. In addition, inhibition studies with synthetic analogues of salicylic acid (4-8) suggested that the unsaturated lipophilic side chain may be an absolute requirement for inhibitory activity.

  14. Host Defense against Opportunist Microorganisms Following Trauma

    Science.gov (United States)

    1991-09-30

    Involvement of PGE2 and Interferon Gamma in the 14 Depression of Cell-Mediated Immune Responses Induced by Thermal Injury Effects of Lipoxygenase...suggest that the drugs modulate cAMP during this phase. Involvement 2f PGE2 and Interferon Gamma in the Depression of Cell-Mediated Immune Responses...reviewed in 2]. Two mediators that are known to contribute to the induction of T suppressor cells are PGE 2 and interferon gamma (IFN ) [35-42]. These

  15. 32 CFR 935.134 - Arm signals.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Arm signals. 935.134 Section 935.134 National... WAKE ISLAND CODE Motor Vehicle Code § 935.134 Arm signals. (a) Any person operating a motor vehicle and making a turn or coming to a stop shall signal the turn or stop in accordance with this section. (b) A...

  16. Conditional Expression of Human 15-Lipoxygenase-1 in Mouse Prostate Induces Prostatic Intraepithelial Neoplasia: The FLiMP Mouse Model

    Directory of Open Access Journals (Sweden)

    Uddhav P. Kelavkar

    2006-06-01

    Full Text Available The incidence and mortality of prostate cancer (PCa vary greatly in different geographic regions, for which lifestyle factors, such as dietary fat intake, have been implicated. Human 15-lipoxygenase-1 (h15-LO-1, which metabolizes polyunsaturated fatty acids, is a highly regulated, tissue-specific, lipid-peroxidating enzyme that functions in physiological membrane remodeling and in the pathogenesis of atherosclerosis, inflammation, and carcinogenesis. We have shown that aberrant overexpression of 15-LO-1 occurs in human PCa, particularly high-grade PCa, and in high-grade prostatic intraepithelial neoplasia (HGPIN, and that the murine orthologue is increased in SV40-based genetically engineered mouse (GEM models of PCa, such as LADY and TRansgenic Adenocarcinoma of Mouse Prostate. To further define the role of 15-LO-1 in prostate carcinogenesis, we established a novel GEM model with targeted overexpression of h15-LO-1 in the prostate [human fifteen lipoxygenase-1 in mouse prostate (FLiMP]. We used a Cre- mediated and a loxP-mediated recombination strategy to target h15-LO-1 specifically to the prostate of C57BL/6 mice. Wild-type (wt, FLiMP+/-, and FLiMP+/+ mice aged 7 to 21, 24 to 28, and 35 weeks were characterized by histopathology, immunohistochemistry (IHC, and DNA/RNA and enzyme analyses. Compared to wt mice, h15-LO-1 enzyme activity was increased similarly in both homozygous FLiMP+/+ and hemizygous FLiMP+/- prostates. Dorsolateral and ventral prostates of FLiMP mice showed focal and progressive epithelial hyperplasia with nuclear atypia, indicative of the definition of mouse prostatic intraepithelial neoplasia (mPIN according to the National Cancer Institute. These foci showed increased proliferation by Ki-67 IHC. No progression to invasive PCa was noted up to 35 weeks. By IHC, h15-LO-1 expression was limited to luminal epithelial cells, with increased expression in mPIN foci (similar to human HGPIN. In summary, targeted overexpression of h

  17. The effect of linoleic acid on pH inside sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles in isooctane and on the enzymic activity of soybean lipoxygenase.

    Science.gov (United States)

    Rodakiewicz-Nowak, J; Maślakiewicz, P; Haber, J

    1996-06-01

    The effective pH of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles (pHrm), containing buffers of different pH (pHst) and various amounts of linoleic acid, was studied within the range of compositions used to study the activity of soybean lipoxygenase in reverse micelles. Significant shifts of pHrm versus pHst were observed for the solutions of relatively higher pHst, dependent on linoleic acid and buffer concentrations. The effect diminished as pHst became closer to 7. When low-ionic-strength buffers were added to AOT solutions in isooctane, a significant buffering effect of linoleic acid in reverse micelles was observed. Solubilization of > 3 mM linoleic acid in micellar solutions containing 25 mM buffers gave the observed pHrm values almost independent of pHst. This effect diminished with the ionic strength of the buffering solution, but did not vanish even at 200 mM buffer. The observed effects result from the balance between ionization of linoleic acid and its partition between the water pool and the micellar interface. The enzymic activity of soybean lipoxygenase in the AOT reverse micellar solutions of the determined pHrm values was also studied. A significant reduction of the kinetics of the enzymic activity was observed, for all studied reverse micellar solutions. Changes of pHrm, caused by the presence of acidic substrate (linoleic acid) do not explain the observed reduction of activity directly through the effect on the enzyme. Due to unfavourable partition of the substrate between the microphases present in the systems, enhanced by reduction of pH at higher total concentrations of linoleic acid, the saturation of the enzyme with the substrate was not observed in the system and is difficult to attain experimentally in reverse micelles. A shift of the lipoxygenase activity/pHrm profile but negligible shift of the activity/pHst profile, with respect to aqueous buffer solutions, were observed. This indicates that either the information given

  18. Interleukin-4 inhibition of interleukin-1-induced expression of matrix metalloproteinase-3 (MMP-3 is independent of lipoxygenase and PPARγ activation in human gingival fibroblasts

    Directory of Open Access Journals (Sweden)

    Gorski Grzegorz

    2007-02-01

    Full Text Available Abstract Background Interleukin 4 (IL-4 has been shown to suppress interleukin-1 (IL-1 induced expression of matrix metalloproteinase-3 (MMP-3 in human synovial and gingival fibroblasts, but the mechanism of suppression has not been determined. Activators of peroxisome proliferator-activated receptor-γ (PPARγ have been shown to inhibit cytokine induced expression of MMPs in other cell types, and IL-4 has been shown to activate PPARγ by stimulating production of ligands through the lipoxygenase pathway. It has been suggested that PPARγ may inhibit expression of MMPs by competing with transcription factor AP-1 for binding to a putative composite binding element in the promoters. The objective of this study was to determine whether the suppressive effects of IL-4 on the IL-1 induced expression of MMP-3 involve activation of lipoxygenase and/or PPARγ. Results Western blotting revealed the presence of PPARγ in nuclear extract of HGF. IL-1 induced binding of nuclear extract to the putative composite PPRE/AP-1 site was diminished in the presence of pioglitazone, but there was no evidence of any change in the composition of the retarded complexes, and no evidence of PPARγ binding to this site. Nordihydroguaiaretic acid (NDGA, a non-selective lipoxygenase inhibitor, and MK886, a specific inhibitor of 5-lipoxygenase, induced MMP-3 expression synergistically with IL-1. However IL-4 was still able to inhibit MMP-3 expression in the presence of NDGA or MK886 and IL-1. Activation of PPARγ with pioglitazone not only failed to inhibit IL-1 induced expression of MMP-3 mRNA, but rather super-induced MMP-3 in the presence of IL-1. PPARγ antagonist GW9662 failed to abolish the suppressive effects of IL-4. Another PPARγ activator, 15-deoxy-Delta12,14prostaglandin J2 (15dPGJ2, also super-induced MMP-3 mRNA, and this was due at least in part to increased transcription. Conclusion IL-4 suppression of IL-1-induced MMP-3 expression in HGF is independent of

  19. Inhibition of lipoxygenase affects induction of both direct and indirect plant defences against herbivorous insects

    NARCIS (Netherlands)

    Bruinsma, M.; Broekhoven, S.; Poelman, E.H.; Posthumus, M.A.; Müller, M.J.; Loon, van J.J.A.; Dicke, M.

    2010-01-01

    Herbivore-induced plant defences influence the behaviour of insects associated with the plant. For biting–chewing herbivores the octadecanoid signal-transduction pathway has been suggested to play a key role in induced plant defence. To test this hypothesis in our plant—herbivore—parasitoid tritroph

  20. Defense Strategies Against Modern Botnets

    CERN Document Server

    Stankovic, Srdjan

    2009-01-01

    Botnets are networks of compromised computers with malicious code which are remotely controlled and which are used for starting distributed denial of service (DDoS) attacks, sending enormous number of e-mails (SPAM) and other sorts of attacks. Defense against modern Botnets is a real challenge. This paper offers several strategies for defense against Botnets with a list and description of measures and activities which should be carried out in order to establish successful defense. The paper also offers parallel preview of the strategies with their advantages and disadvantages considered in accordance with various criteria.

  1. Quadrennial Defense Review and Ballistic Missile Defense Review

    Science.gov (United States)

    2010-03-11

    global defense posture 3 BMDR Highlights • Outlines a strategy and policy framework to – Defend the homeland against limited ballistic missile attack...abroad – Collaborate closely with allies and partners – Pursue a cooperative and tailored global defense posture – Strengthen US civilian capacity...reviews in 2010 – QDR and BMDR released February 1, 2010 – Nuclear Posture Review to be released this spring – Space Posture Review, with Director of

  2. Molecular strategies of plant defense and insect counter-defense

    Institute of Scientific and Technical Information of China (English)

    KEYANZHU-SALZMAN; JIAN-LONGBI; TONG-XIANLIU

    2005-01-01

    The prediction of human population growth worldwide indicates there will be a need to substantially increase food production in order to meet the demand on food supply.This can be achieved in part by the effective management of insect pests. Since plants have co-evolved with herbivorous insects for millions of years, they have developed an array of defense genes to protect themselves against a wide variety of chewing and sucking insects.Using these naturally-occurring genes via genetic engineering represents an environmentally friendly insect pest-control measure. Insects, however, have been actively evolving adaptive mechanisms to evade natural plant defenses. Such evolved adaptability undoubtedly has helped insects during the last century to rapidly overcome a great many humanimposed management practices and agents, including chemical insecticides and genetically engineered plants. Thus, better understanding of the molecular and genetic basis of plant defense and insect counter-defense mechanisms is imperative, not only from a basic science perspective, but also for biotechnology-based pest control practice. In this review, we emphasize the recent advance and understanding of molecular strategies of attack-counterattack and defense-counter-defense between plants and their herbivores.

  3. Inhibition of 5-lipoxygenase and skin inflammation by the aerial parts of Artemisia capillaris and its constituents.

    Science.gov (United States)

    Kwon, Oh Song; Choi, Jae Sue; Islam, Md Nurul; Kim, Yeong Shik; Kim, Hyun Pyo

    2011-09-01

    The aerial parts of Artemisia capillaris Thunberg (Compositae) have been used in Chinese medicine as a liver protective agent, diuretic, and for amelioration of skin inflammatory conditions. This study was conducted to establish the scientific rationale for treating skin inflammation and to find active principles from A. capillaris. To accomplish these goals, the 70% ethanol extract of the aerial parts of A. capillaris (AR) was prepared and its 5-lipoxygenase (5-LOX) inhibitory action was studied since 5-LOX products are known to be involved in several allergic and skin inflammatory disorders. AR showed potent inhibitory activity against 5-LOX-catalyzed leukotriene production by ionophore-induced rat basophilic leukemia-1 cells, with an IC(50) of scopolin, scoparone, esculetin, quercetin, capillarisin, isorhamnetin, 3-O-robinobioside, isorhamnetin 3-O-galactoside and chlorogenic acid, were isolated from A. capillaris, and their effects were examined to identify the active principle(s). Several coumarin and flavonoid derivatives were found to be 5-LOX inhibitors. In particular, esculetin and quercetin were potent inhibitors, with IC(50) values of 6.6 and 0.7 μM, respectively. Against arachidonic acid-induced ear edema in mice, AR, and esculetin strongly inhibited edematic response. AR and esculetin also inhibited delayed-type hypersensitivity response in mice. In conclusion, AR and some of their major constituents are 5-LOX inhibitors, and these in vitro and in vivo activities may contribute to the therapeutic potential of AR in skin inflammatory disorders in traditional medicine.

  4. Eggplant lipoxygenase (Solanum melongena): product characterization and effect of physicochemical properties of linoleic acid on the enzymatic activity.

    Science.gov (United States)

    López-Nicolás, J M; Pérez-Gilabert, M; García-Carmona, F

    2001-01-01

    Lipoxygenase (LOX) from eggplant (Solanum melongena L. cv. Belleza negra) was partially purified, and the products and kinetics of the enzyme were studied. Linoleic acid (LA) was the best substrate for this enzyme. Product analysis by HPLC and GC/MS revealed that, at its pH optimum (pH 7.0), the enzyme converted LA almost totally into the 9-hydroperoxy isomer, whereas the 13-hydroperoxy isomer was only a minor product. At this pH, the enzyme had K(m) and V(max) values for LA of 1.4 microM and 2.2 micromol min(-1) (mg of protein)(-1), respectively, when the monomeric form of LA was used as substrate. The dependence of eggplant LOX activity on the physicochemical properties of LA was also studied. Experiments revealed that LA aggregates were used more efficiently than monomeric LA as substrate. The apparent substrate cooperativity observed may be due to the different activities exhibited toward monomers and aggregates. This result can be interpreted as a substrate-aggregation dependent activity.

  5. 5-Lipoxygenase-dependent apoptosis of human lymphocytes in the International Space Station: data from the ROALD experiment.

    Science.gov (United States)

    Battista, Natalia; Meloni, Maria A; Bari, Monica; Mastrangelo, Nicolina; Galleri, Grazia; Rapino, Cinzia; Dainese, Enrico; Agrò, Alessandro Finazzi; Pippia, Proto; Maccarrone, Mauro

    2012-05-01

    The functional adaptation of the immune system to the surrounding environment is also a fundamental issue in space. It has been suggested that a decreased number of lymphocytes might be a cause of immunosuppression, possibly due to the induction of apoptosis. Early activation of 5-lipoxygenase (5-LOX) might play a central role in the initiation of the apoptotic program. The goal of the role of apoptosis in lymphocyte depression (ROALD) experiment, flown on the International Space Station as part of the BIO-4 mission of the European Space Agency, was to ascertain the induction of apoptosis in human lymphocytes under authentic microgravity, and to elucidate the possible involvement of 5-LOX. Our results demonstrate that exposure of human lymphocytes to microgravity for 48 h onboard the ISS remarkably increased apoptotic hallmarks such as DNA fragmentation (∼3-fold compared to ground-based controls) and cleaved-poly (ADP-ribose) polymerase (PARP) protein expression (∼3-fold), as well as mRNA levels of apoptosis-related markers such as p53 (∼3-fold) and calpain (∼4-fold); these changes were paralleled by an early increase of 5-LOX activity (∼2-fold). Our findings provide a molecular background for the immune dysfunction observed in astronauts during space missions, and reveal potential new markers to monitor health status of ISS crew members.

  6. Repeated allergen exposure reduce early phase airway response and leukotriene release despite upregulation of 5-lipoxygenase pathways

    Directory of Open Access Journals (Sweden)

    Cui Zhi-Hua

    2012-03-01

    Full Text Available Abstract Background Allergen induced early phase airway response and airway plasma exudation are predominantly mediated by inflammatory mast cell mediators including histamine, cysteinyl leukotrienes (cysLTs and thromboxane A2 (TXA2. The aim of the present study was to evaluate whether repeated allergen exposure affects early phase airway response to allergen challenge. Methods A trimellitic anhydride (TMA sensitized guinea pig model was used to investigate the effects of low dose repeated allergen exposure on cholinergic airway responsiveness, early phase airway response and plasma exudation, as well as local airway production of mast cell derived cysteinyl leukotrienes and thromboxane B2 (TXB2 after allergen challenge. Results Repeated low dose allergen exposure increased cholinergic airway responsiveness. In contrast, early phase airway response and plasma exudation in response to a high-dose allergen challenge were strongly attenuated after repeated low dose allergen exposure. Inhibition of the airway response was unspecific to exposed allergen and independent of histamine receptor blocking. Furthermore, a significant reduction of cysteinyl leukotrienes and TXB2 was found in the airways of animals repeatedly exposed to a low dose allergen. However, in vitro stimulation of airway tissue from animals repeatedly exposed to a low dose allergen with arachidonic acid and calcium ionophore (A23187 induced production of cysteinyl leukotrienes and TXB2, suggesting enhanced activity of 5-lipoxygenase and cyclooxygenase pathways. Conclusions The inhibition of the early phase airway response, cysteinyl leukotriene and TXB2 production after repeated allergen exposure may result from unresponsive effector cells.

  7. Synthesis of green note aroma compounds by biotransformation of fatty acids using yeast cells coexpressing lipoxygenase and hydroperoxide lyase.

    Science.gov (United States)

    Buchhaupt, Markus; Guder, Jan Christopher; Etschmann, Maria Magdalena Walburga; Schrader, Jens

    2012-01-01

    Green notes are substances that characterize the aroma of freshly cut grass, cucumbers, green apples, and foliage. In plants, they are synthesized by conversion of linolenic or linoleic acid via the enzymes lipoxygenase (LOX) and hydroperoxide lyase (HPL) to short-chained aldehydes. Current processes for production of natural green notes rely on plant homogenates as enzyme sources but are limited by low enzyme concentration and low specificity. In an alternative approach, soybean LOX2 and watermelon HPL were overexpressed in Saccharomyces cerevisiae. After optimization of the expression constructs, a yeast strain coexpressing LOX and HPL was applied in whole cell biotransformation experiments. Whereas addition of linolenic acid to growing cultures of this strain yielded no products, we were able to identify high green note concentrations when resting cells were used. The primary biotransformation product was 3(Z)-hexenal, a small amount of which isomerized to 2(E)-hexenal. Furthermore, both aldehydes were reduced to the corresponding green note alcohols by endogenous yeast alcohol dehydrogenase to some extent. As the cosolvent ethanol was the source of reducing equivalents for green note alcohol formation, the hexenal/hexenol ratio could be influenced by the use of alternative cosolvents. Further investigations to identify the underlying mechanism of the rather low biocatalyst stability revealed a high toxicity of linolenic acid to yeast cells. The whole cell catalyst containing LOX and HPL enzyme activity described here can be a promising approach towards a highly efficient microbial green note synthesis process.

  8. The Target of 5-Lipoxygenase is a Novel Strategy over Human Urological Tumors than the Target of Cyclooxygenase-2

    Directory of Open Access Journals (Sweden)

    Masahide Matsuyama

    2008-01-01

    Full Text Available The metabolism of arachidonic acid by either the cyclooxygenase (COX or lipoxygenase (LOX pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. It is now considered that they play important roles in tumor promotion, progression, and metastasis, also, the involvement of COX and LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. In this study, we examined the expression of COX and LOX in human urological tumors (renal cell carcinoma, bladder tumor, prostate cancer, testicular cancer by immunohistochemistry and RT-PCR, and we also examined the effects of COX and LOX (5- and 12-LOX inhibitors in those cells by MTT assay, hoechest staining, and flow cytometry. COX-2, 5-LOX and 12-LOX expressions were significantly more extensive and intense in malignant tissues than in normal tissues. Furthermore, 5-LOX inhibitor induced the reduction of malignant cell viability through early apoptosis. These results demonstrated COX-2 and LOX were induced in urological tumors, and 5-LOX inhibitor may mediate potent antiproliferative effects against urological tumors cells. Thus, 5-LOX may become a new target in the treatment of urological tumors.

  9. The Target of 5-Lipoxygenase is a Novel Strategy over Human Urological Tumors than the Target of Cyclooxygenase-2

    Directory of Open Access Journals (Sweden)

    Masahide Matsuyama

    2008-06-01

    Full Text Available The metabolism of arachidonic acid by either the cyclooxygenase (COX or lipoxygenase (LOX pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. It is now considered that they play important roles in tumor promotion, progression, and metastasis, also, the involvement of COX and LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. In this study, we examined the expression of COX and LOX in human urological tumors (renal cell carcinoma, bladder tumor, prostate cancer, testicular cancer by immunohistochemistry and RT-PCR, and we also examined the effects of COX and LOX (5- and 12-LOX inhibitors in those cells by MTT assay, hoechest staining, and flow cytometry. COX-2, 5-LOX and 12-LOX expressions were significantly more extensive and intense in malignant tissues than in normal tissues. Furthermore, 5-LOX inhibitor induced the reduction of malignant cell viability through early apoptosis. These results demonstrated COX-2 and LOX were induced in urological tumors, and 5-LOX inhibitor may mediate potent antiproliferative effects against urological tumors cells. Thus, 5-LOX may become a new target in the treatment of urological tumors.

  10. Evaluation of 12-Lipoxygenase (12-LOX and Plasminogen Activator Inhibitor 1 (PAI-1 as Prognostic Markers in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Tomasz Gondek

    2014-01-01

    Full Text Available In carcinoma of prostate, a causative role of platelet 12-lipoxygenase (12-LOX and plasminogen activator inhibitor 1 (PAI-1 for tumor progression has been firmly established in tumor and/or adjacent tissue. Our goal was to investigate if 12-LOX and/or PAI-1 in patient’s plasma could be used to predict outcome of the disease. The study comprised 149 patients (age 70±9 divided into two groups: a study group with carcinoma confirmed by positive biopsy of prostate (n=116 and a reference group (n=33 with benign prostatic hyperplasia (BPH. The following parameters were determined by the laboratory test in plasma or platelet-rich plasma: protein level of 12-LOX, PAI-1, thromboglobulin (TGB, prostate specific antigen (PSA, C-reactive protein (CRP, hemoglobin (HGB, and hematocrit (HCT, as well as red (RBC and white blood cells (WBC, number of platelets (PLT, international normalized ratio of blood clotting (INR, and activated partial thromboplastin time (APTT. The only difference of significance was noticed in the concentration of 12-LOX in platelet rich plasma, which was lower in cancer than in BPH group. Standardization to TGB and platelet count increases the sensitivity of the test that might be used as a biomarker to assess risk for prostate cancer in periodically monitored patients.

  11. Hypercholesterolemia Increases the Production of Leukotriene B4 in Neutrophils by Enhancing the Nuclear Localization of 5-Lipoxygenase

    Directory of Open Access Journals (Sweden)

    Xiao-Feng Lai

    2014-11-01

    Full Text Available Aims: Neutrophils can synthesize leukotriene B4 (LTB4 by activating the 5-lipoxygenase (5-LOsignaling pathway. LTB4 is a pro-inflammatory mediator associated with the etiology and progression of atherosclerosis. It can increase function and number of neutrophils in an autocrine manner. Since hypercholesterolemia is associated with an increase in the number and function of neutrophils, we hypothesized that this effect could be mediated through increased production of LTB4 in neutrophils. Methods/Results: Hypercholesterolemia was modeled in Wistar rats by feeding them with a high cholesterol diet. The induction of hypercholesterolemia caused an increase in the plasma levels of LTB4, following lipopolysaccharide stimulation. This effect was recapitulated in vitro, both in the presence and absence of stimulation with the activator of 5-LO, A23187. Neutrophils in hypercholesterolemia rats expressed similar total levels of 5-LO as control rats, but displayed increased nuclear localization of 5-LO, as well as elevated levels of phosphorylated 5-LO and ERK1/2. In vitro, MβCD/cholesterol complexes enriched cholesterol in neutrophils, resulted in similar changes in 5-LO/LTB4. In addition, these alterations could be inhibited with the ERK inhibitor PD98059. Conclusion: Hypercholesterolemia increases LTB4 production in neutrophils by increasing the nuclear localization of 5-LO, which is the result of its phosphorylation by activated ERK1/2.

  12. TALEN-Based Mutagenesis of Lipoxygenase LOX3 Enhances the Storage Tolerance of Rice (Oryza sativa) Seeds.

    Science.gov (United States)

    Ma, Lei; Zhu, Fugui; Li, Zhenwei; Zhang, Jianfu; Li, Xin; Dong, Jiangli; Wang, Tao

    2015-01-01

    The deterioration of rice grain reduces the quality of rice, resulting in serious economic losses for farmers. Lipoxygenases (LOXs) catalyze the dioxygenation of polyunsaturated fatty acids with at least one cis,cis-1,4-pentadiene to form hydroperoxide, which is a major factor influencing seed longevity and viability. Recently, genome editing, an essential tool employed in reverse genetics, has been used experimentally to investigate basic plant biology or to modify crop plants for the improvement of important agricultural traits. In this study, we performed targeted mutagenesis in rice using transcription activator-like effector nucleases (TALENs) to improve seed storability. A modified ligation-independent cloning method (LIC) was employed to allow for the quick and efficient directional insertion of TALEN monomer modules into destination vectors used in plants. We demonstrated the feasibility and flexibility of the technology by developing a set of modular vectors for genome editing. After construction and validation, the TALEN pairs were used to create stable transgenic rice lines via Agrobacterium-mediated transformation. One heterozygous mutant (4%) was recovered from 25 transgenic NPTII-resistant lines, and the mutation was transmitted to the next generation. Further molecular and protein level experiments verified LOX3 deficiency and demonstrated the improvement of seed storability. Our work provides a flexible genome editing tool for improving important agronomic traits, as well as direct evidence that Lox3 has only a limited impact on seed longevity.

  13. TALEN-Based Mutagenesis of Lipoxygenase LOX3 Enhances the Storage Tolerance of Rice (Oryza sativa Seeds.

    Directory of Open Access Journals (Sweden)

    Lei Ma

    Full Text Available The deterioration of rice grain reduces the quality of rice, resulting in serious economic losses for farmers. Lipoxygenases (LOXs catalyze the dioxygenation of polyunsaturated fatty acids with at least one cis,cis-1,4-pentadiene to form hydroperoxide, which is a major factor influencing seed longevity and viability. Recently, genome editing, an essential tool employed in reverse genetics, has been used experimentally to investigate basic plant biology or to modify crop plants for the improvement of important agricultural traits. In this study, we performed targeted mutagenesis in rice using transcription activator-like effector nucleases (TALENs to improve seed storability. A modified ligation-independent cloning method (LIC was employed to allow for the quick and efficient directional insertion of TALEN monomer modules into destination vectors used in plants. We demonstrated the feasibility and flexibility of the technology by developing a set of modular vectors for genome editing. After construction and validation, the TALEN pairs were used to create stable transgenic rice lines via Agrobacterium-mediated transformation. One heterozygous mutant (4% was recovered from 25 transgenic NPTII-resistant lines, and the mutation was transmitted to the next generation. Further molecular and protein level experiments verified LOX3 deficiency and demonstrated the improvement of seed storability. Our work provides a flexible genome editing tool for improving important agronomic traits, as well as direct evidence that Lox3 has only a limited impact on seed longevity.

  14. Two New Monoterpene Glycosides from Qing Shan Lu Shui Tea with Inhibitory Effects on Leukocyte-Type 12-Lipoxygenase Activity

    Directory of Open Access Journals (Sweden)

    Ding Zhi Fang

    2013-04-01

    Full Text Available We evaluated the inhibitory effect of 12 Chinese teas on leukocyte-type 12-lipoxygenase (LOX activity. Tea catechins such as epigallocatechin gallate have been known to exhibit leukocyte-type 12-LOX inhibition. Qing Shan Lu Shui, which contains lower catechin levels than the other tested teas, suppressed leukocyte-type 12-LOX activity. To characterize the bioactive components of Qing Shan Lu Shui, leukocyte-type 12-LOX inhibitory activity–guided fractionation of the aqueous ethanol extract of the tea was performed, resulting in the isolation of two new monoterpene glycosides: liguroside A (1 and B (2. The structures of compounds 1 and 2 were characterized as (2E,5E-7-hydroperoxy-3,7-dimethyl-2,5-octadienyl-O-(α-L-rhamnopyranosyl-(1″→3′-(4′″-O-trans-p-coumaroyl-β-D-glucopyranoside and (2E,5E-7-hydroperoxy-3,7-dimethyl-2,5-octa-dienyl- O-(α-L-rhamnopyranosyl-(1″→3′-(4′″-O-cis-p-coumaroyl-β-D-glucopyranoside, respectively, based on spectral and chemical evidence. Ligurosides A (1 and B (2 showed inhibitory effects on leukocyte-type 12-LOX activity, with IC50 values of 1.7 and 0.7 μM, respectively.

  15. Peroxidation radical formation and regiospecificity of recombinated Anabaena sp. lipoxygenase and its effect on modifying wheat proteins.

    Science.gov (United States)

    Wang, Xiaoming; Lu, Fengxia; Zhang, Chong; Lu, Yingjian; Bie, Xiaomei; Ren, Di; Lu, Zhaoxin

    2014-02-19

    Peroxidation radical formation and the regiospecificity of recombinated lipoxygenase from Anabaena sp. PCC7120 (ana-rLOX) were characterized by using ESR and HPLC-MS. It was found that ana-rLOX oxygenated at the C-13 position of the substrate linoleic acid (LA); at C-13 and C-16 of α-linolenic acid (ALA); at C-9, C-12, and C-15 of arachidonic acid (AA); at C-12, C-15, and C-18 of eicosapentaenoic acid (EPA); and at C-14 and C-16 of docosahexaenoic acid (DHA), respectively. A total of 7, 14, 30, 28, and 18 radical adducts for LA, ALA, AA, EPA, and DHA were respectively identified by HPLC-MS. The functional characteristics of wheat protein, such as foaming capacity (FC), foam stability (FS), emulsifying activity index (EAI), emulsifying stability index (ESI), increased with enzymatic reactions. However, the average particle size of wheat proteins decreased with addition of ana-rLOX/LA. The ana-rLOX was also positivele effective in improving dough properties. These results provided clear evidence that ana-rLOX from Anabaena sp. could effectively improve the quality of wheat flour, which suggested that the enzyme could be applied as flour improver.

  16. Involvement of eicosanoids in the pathogenesis of pancreatic cancer: the roles of cyclooxygenase-2 and 5-lipoxygenase.

    Science.gov (United States)

    Knab, Lawrence M; Grippo, Paul J; Bentrem, David J

    2014-08-21

    The interplay between inflammation and cancer progression is a growing area of research. A combination of clinical, epidemiological, and basic science investigations indicate that there is a relationship between inflammatory changes in the pancreas and neoplastic progression. Diets high in ω-6 polyunsaturated fatty acids provide increased substrate for arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) to form eicosanoids. These eicosanoids directly contribute to pancreatic cancer cell proliferation. Both COX-2 and 5-LOX are upregulated in multiple cancer types, including pancreatic cancer. In vitro studies using pancreatic cancer cell lines have demonstrated upregulation of COX-2 and 5-LOX at both the mRNA and protein levels. When COX-2 and 5-LOX are blocked via a variety of mechanisms, cancer cell proliferation is abrogated both in vitro and in vivo. The mechanism of COX-2 has been shown to include effects on apoptosis as well as angiogenesis. 5-LOX has been implicated in apoptosis. The use of COX-2 and 5-LOX inhibitors in clinical studies in patients with pancreatic cancer has been limited. Patient enrollment has been restricted to those with advanced disease which makes evaluation of these drugs as chemopreventive agents difficult. COX-2 and 5-LOX expression have been shown to be present during the early neoplastic changes of pancreatic cancer, well before progression to invasive disease. This indicates that the ideal role for these interventions is early in the disease process as preventive agents, perhaps in patients with chronic pancreatitis or hereditary pancreatitis.

  17. Zileuton, 5-lipoxygenase inhibitor, acts as a chemopreventive agent in intestinal polyposis, by modulating polyp and systemic inflammation.

    Directory of Open Access Journals (Sweden)

    Elias Gounaris

    Full Text Available Leukotrienes and prostaglandins, products of arachidonic acid metabolism, sustain both systemic and lesion-localized inflammation. Tumor-associated Inflammation can also contribute to the pathogenesis of colon cancer. Patients with inflammatory bowel disease (IBD have increased risk of developing colon cancer. The levels of 5-lipoxygenase (5-LO, the key enzyme for leukotrienes production, are increased in colon cancer specimens and colonic dysplastic lesions. Here we report that Zileuton, a specific 5-LO inhibitor, can prevent polyp formation by efficiently reducing the tumor-associated and systemic inflammation in APCΔ468 mice.In the current study, we inhibited 5-LO by dietary administration of Zileuton in the APCΔ468 mouse model of polyposis and analyzed the effect of in vivo 5-LO inhibition on tumor-associated and systemic inflammation.Zileuton-fed mice developed fewer polyps and displayed marked reduction in systemic and polyp-associated inflammation. Pro-inflammatory cytokines and pro-inflammatory innate and adaptive immunity cells were reduced both in the lesions and systemically. As part of tumor-associated inflammation Leukotriene B4 (LTB4, product of 5-LO activity, is increased focally in human dysplastic lesions. The 5-LO enzymatic activity was reduced in the serum of Zileuton treated polyposis mice.This study demonstrates that dietary administration of 5-LO specific inhibitor in the polyposis mouse model decreases polyp burden, and suggests that Zileuton may be a potential chemo-preventive agent in patients that are high-risk of developing colon cancer.

  18. Mineral elements, lipoxygenase activity, and antioxidant capacity of okara as a byproduct in hydrothermal processing of soy milk.

    Science.gov (United States)

    Stanojevic, Sladjana P; Barac, Miroljub B; Pesic, Mirjana B; Zilic, Sladjana M; Kresovic, Mirjana M; Vucelic-Radovic, Biljana V

    2014-09-10

    Minerals and antioxidative capacity of raw okara that was obtained as a byproduct from six soybean varieties during hydrothermal cooking (HTC) of soy milk were assessed. Lipoxygenase (Lox), an enzyme deteriorating the sensory characteristics of okara, was also investigated. All genotypes had very similar concentrations of Lox (4.32-5.62%). Compared to raw soybeans, the applied HTC significantly reduced Lox content in okara (0.54-0.19%) and lowered its activity to 0.004-0.007 μmol g(-1) min (-1). Correlation between the content of Lox in soybeans and that in okara (r = 0.21;p process than on soybean genotype. Very strong correlation (r = 0.99; p minerals in raw okara were potassium (1.04-1.21 g/100g), phosphorus (0.45-0.50 g/100 g), calcium (0.26-0.39 g/100 g), and iron (5.45-10.95 mg/100 g). A very high antioxidant capacity (19.06-29.36 mmol Trolox kg(-1)) contributes to the nutritional value of raw okara.

  19. Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

    Directory of Open Access Journals (Sweden)

    Chean Hui Ng

    2014-08-01

    Full Text Available The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs and aromatic groups could significantly affect the enzymatic activity.

  20. Defense Meteorological Satellite Program (DMSP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Defense Meteorological Satellite Program (DMSP) satellites collect visible and infrared cloud imagery as well as monitoring the atmospheric, oceanographic,...

  1. Defense Spending and the Economy

    Science.gov (United States)

    1983-12-07

    the first resolution. Our forecast projects continued growth in the economy and moderate inflation for one or possibly two years, despite federal...than provided in the resolution. Additional emphasis on defense would, of course, promote defense-intensive sectors of the economy at the expense of...others, but CBO believes the economy could accommodate such shifts without significant adverse effects on macroeconomic variables such as employment

  2. Theater Missile Defense Integration Issues

    Science.gov (United States)

    1993-06-01

    high endoatmospheric defense interceptor (HEDI) proposed t earlier. EADTB. Extended Air Defense Test Bed. A computer-based analysis center for...for attacking deeper elements of an aggressors’s ground forces. Known in NATO as Follow-on Force Attack ( FOFA ). JSTARS. Joint surveillance target...AFIA/INKS ATTN. INKS AFIS/INT ATTN: INT AIR hORCE CTR FOR STUDIES & ANALYSIS ATTN: AFSAA/SAKI 9 Dist-1 w^mmmm mmmm^-mmmemH

  3. Arabidopsis phospholipase Dδ is involved in basal defense and nonhost resistance to powdery mildew fungi

    DEFF Research Database (Denmark)

    Pinosa, Francesco; Buhot, Nathalie; Kwaaitaal, Mark Adrianus Cornelis J

    2013-01-01

    Plants have evolved a complex array of defensive responses against pathogenic microorganisms. Recognition of microbes initiates signaling cascades that activate plant defenses. The membrane lipid phosphatidic acid, produced by phospholipase D (PLD), has been shown to take part in both abiotic...... and biotic stress signaling. In this study, the involvement of PLD in the interaction between Arabidopsis (Arabidopsis thaliana) and the barley powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh) was investigated. This nonadapted pathogen is normally resisted by a cell wall-based defense, which stops....... In conclusion, we propose that PLD is involved in defense signaling in nonhost resistance against powdery mildew fungi and put PLDδ forward as the main isoform participating in this process....

  4. 76 FR 72391 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Science.gov (United States)

    2011-11-23

    ... Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION: Revised Defense Logistics Agency Regulation (DLAR) 1000.22. SUMMARY: On May 18, 2011, the Defense Logistics Agency (DLA) published a Notice of...

  5. 76 FR 53119 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Science.gov (United States)

    2011-08-25

    ... Office of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION: Comment Addressed on Notice of Availability (NOA) of Revised Defense Logistics Agency Regulation (DLAR...

  6. Technical Soddi Defenses: The Trojan Horse Defense Revisited

    Directory of Open Access Journals (Sweden)

    Chad Steel

    2014-12-01

    Full Text Available In 2004, the Trojan horse defense was at a crossroads, with two child pornography cases where it was successfully employed in the United Kingdom, resulting in acquittals.  The original Trojan horse defense has now become part of the more general “technical SODDI” defense, which includes the possibility of unknown actors using unsecured Wi-Fi connections or having physical access to a computer to perform criminal acts.  In the past ten years, it has failed to be effective in the United States for criminal cases, with no published acquittals in cases where it was the primary defense.  In the criminal cases where it has been used as leverage in plea negotiations, there has been either poor forensics performed by the prosecution or political pressure to resolve a matter.  On the civil side, however, the defense has been wildly successful, effectively shutting down large John Doe copyright infringement litigation against non-commercial violators.  

  7. Modulation of Intestinal Epithelial Defense Responses by Probiotic Bacteria.

    Science.gov (United States)

    Wan, L Y M; Chen, Z J; Shah, N P; El-Nezami, H

    2016-12-09

    Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforce the integrity of intestinal epithelium and/or regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal epithelial cell-mediated defense responses, modulations of intestinal barrier function, innate, and adaptive mucosal immune responses, as well as signaling pathways are considered to play important role in the intestinal defense responses against pathogenic bacteria. This review summarizes the beneficial effects of probiotic bacteria to intestinal health together with the mechanisms affected by probiotic bacteria: barrier function, innate, and adaptive defense responses such as secretion of mucins, defensins, trefoil factors, immunoglobulin A (IgA), Toll-like receptors (TLRs), cytokines, gut associated lymphoid tissues, and signaling pathways.

  8. Jasmonate is essential for insect defense in Arabidopsis.

    Science.gov (United States)

    McConn, M; Creelman, R A; Bell, E; Mullet, J E; Browse, J

    1997-05-13

    The signaling pathways that allow plants to mount defenses against chewing insects are known to be complex. To investigate the role of jasmonate in wound signaling in Arabidopsis and to test whether parallel or redundant pathways exist for insect defense, we have studied a mutant (fad3-2 fad7-2 fad8) that is deficient in the jasmonate precursor linolenic acid. Mutant plants contained negligible levels of jasmonate and showed extremely high mortality ( approximately 80%) from attack by larvae of a common saprophagous fungal gnat, Bradysia impatiens (Diptera: Sciaridae), even though neighboring wild-type plants were largely unaffected. Application of exogenous methyl jasmonate substantially protected the mutant plants and reduced mortality to approximately 12%. These experiments precisely define the role of jasmonate as being essential for the induction of biologically effective defense in this plant-insect interaction. The transcripts of three wound-responsive genes were shown not to be induced by wounding of mutant plants but the same transcripts could be induced by application of methyl jasmonate. By contrast, measurements of transcript levels for a gene encoding glutathione S-transferase demonstrated that wound induction of this gene is independent of jasmonate synthesis. These results indicate that the mutant will be a good genetic model for testing the practical effectiveness of candidate defense genes.

  9. Rhizobacteria induces resistance against Fusarium wilt of tomato by increasing the activity of defense enzymes

    Directory of Open Access Journals (Sweden)

    Hélvio Gledson Maciel Ferraz

    2014-09-01

    Full Text Available Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici (Fol, is one of the most important diseases that affect tomato yield worldwide. This study investigated the potential of three antagonists, Streptomyces setonii (UFV 618, Bacillus cereus (UFV 592 and Serratia marcescens (UFV 252, and as positive control the hormone jasmonic acid (JA, to reduce Fusarium wilt symptoms and to potentiate the defense enzymes in the stem tissues of tomato plants infected by Fol. The seeds were microbiolized with each antagonist, and the soil was also drenched with them. The plants were sprayed with JA 48 h before Fol inoculation. The area under the Fusarium wilt index progress curve was reduced by 54, 48, 47 and 45% for the UFV 618, JA, UFV 592 and UFV 252 treatments, respectively. The three antagonists, and even the JA spray, efficiently reduced the Fusarium wilt symptoms on the tomato plant stems, which can be explained by the lower malondialdehyde concentration (an indication of oxidative damage to lipids in the plasma membranes and the greater activities of peroxidases, polyphenoloxidases, glucanases, chitinases, phenylalanine ammonia-lyases and lipoxygenases, which are commonly involved in host resistance against fungal diseases. These results present a novel alternative that can be used in the integrated management of Fusarium wilt on tomatoes.

  10. Suppression of oxidative stress and 5-lipoxygenase activation by edaravone improves depressive-like behavior after concussion.

    Science.gov (United States)

    Higashi, Youichirou; Hoshijima, Michihiro; Yawata, Toshio; Nobumoto, Atsuya; Tsuda, Masayuki; Shimizu, Takahiro; Saito, Motoaki; Ueba, Tetuya

    2014-10-15

    Brain concussions are a serious public concern and are associated with neuropsychiatric disorders, such as depression. Patients with concussion who suffer from depression often experience distress. Nevertheless, few pre-clinical studies have examined concussion-induced depression, and there is little information regarding its pharmacological management. Edaravone, a free radical scavenger, can exert neuroprotective effects in several animal models of neurological disorders. However, the effectiveness of edaravone in animal models of concussion-induced depression remains unclear. In this study, we examined whether edaravone could prevent concussion-induced depression. Mice were subjected to a weight-drop injury and intravenously administered edaravone (3.0 mg/kg) or vehicle immediately after impact. Serial magnetic resonance imaging showed no abnormalities of the cerebrum on diffusion T1- and T2-weighted images. We found that edaravone suppressed concussion-induced depressive-like behavior in the forced swim test, which was accompanied by inhibition of increased hippocampal and cortical oxidative stress (OS) and suppression of 5-lipoxygenase (5-LOX) translocation to the nuclear envelope in hippocampal astrocytes. Hippocampal OS in concussed mice was also prevented by the nicotinamide adenine dinucleotide phosphate oxidase inhibitor, apocynin, and administration of BWB70C, a 5-LOX inhibitor, immediately and 24 h after injury prevented depressive-like behaviors in concussed mice. Further, antidepressant effects of edaravone were observed in mice receiving 1.0 or 3.0 mg/kg of edaravone immediately after impact, but not at a lower dose of 0.1 mg/kg. This antidepressant effect persisted up to 1 h after impact, whereas edaravone treatment at 3 h after impact had no effect on concussion-induced depressive-like behavior. These results suggest that edaravone protects against concussion-induced depression, and this protection is mediated by suppression of OS and 5

  11. Cyclooxygenase/lipoxygenase shunting lowers the anti-cancer effect of cyclooxygenase-2 inhibition in colorectal cancer cells

    Directory of Open Access Journals (Sweden)

    Ganesh Radhakrishnan

    2012-09-01

    Full Text Available Abstract Background Arachidonic acid metabolite, generated by cyclooxygenase (COX, is implicated in the colorectal cancer (CRC pathogenesis. Inhibiting COX may therefore have anti-carcinogenic effects. Results from use of non-steroidal anti-inflammatory drugs inhibiting only COX have been conflicting. It has been postulated that this might result from the shunting of arachidonic acid metabolism to the 5-lipoxygenase (5-LOX pathway. Cancer cell viability is promoted by 5-LOX through several mechanisms that are similar to those of cyclooxygenase-2 (COX-2. Expression of 5-LOX is upregulated in colorectal adenoma and cancer. The aim of this study was to investigate the shunting of arachidonic acid metabolism to the 5-LOX pathway by cyclooxygenase inhibition and to determine if this process antagonizes the anti-cancer effect in colorectal cancer cells. Methods Three colorectal cancer cell lines (HCA7, HT-29 & LoVo expressing 5-LOX and different levels of COX-2 expression were used. The effects of aspirin (a non-selective COX inhibitor and rofecoxib (COX-2 selective on prostaglandin E2 (PGE2 and leukotriene B4 (LTB4 secretion were quantified by ELISA. Proliferation and viability were studied by quantifying double-stranded DNA (dsDNA content and metabolic activity. Apoptosis was determined by annexin V and propidium iodide staining using confocal microscopy, and caspase-3/7 activity by fluorescent substrate assay. Results COX inhibitors suppressed PGE2 production but enhanced LTB4 secretion in COX-2 expressing cell lines (P  Conclusions This study provides evidence of shunting between COX and 5-LOX pathways in the presence of unilateral inhibition, and may explain the conflicting anti-carcinogenic effects reported with use of COX inhibitors.

  12. Grape seed and red wine polyphenol extracts inhibit cellular cholesterol uptake, cell proliferation, and 5-lipoxygenase activity.

    Science.gov (United States)

    Leifert, Wayne R; Abeywardena, Mahinda Y

    2008-12-01

    Accumulating evidence suggests that grape seed and wine polyphenol extracts possess a diverse array of actions and may be beneficial in the prevention of inflammatory-mediated disease such as cardiovascular disease and cancer. This study aimed to determine whether the reported pleiotropic effects of several polyphenolic extracts from grape seed products or red wine would also include inhibition of cholesterol uptake and cell proliferation, and inhibit a known specific target of the inflammatory process, that is, 5-lipoxygenase (5-LOX). Incubation of HT29, Caco2, HepG2, or HuTu80 cells in a medium containing [(3)H]cholesterol in the presence of a grape seed extract (GSE) or red wine polyphenolic compounds (RWPCs) inhibited [(3)H]cholesterol uptake by up to 66% (which appeared maximal). The estimated IC(50) values were 60 and 83 microg/mL for RWPC and GSE, respectively. Similar cholesterol uptake inhibitory effects were observed using the fluorescent cholesterol analogue NBD cholesterol. The inhibition of cholesterol uptake was independent of the sample's (GSE and RWPC) potent antioxidative capacity. Red wine polyphenolic compound and GSE dose dependently inhibited HT29 colon adenocarcinoma cell proliferation, which was accompanied by an increase in apoptosis. In addition, RWPC and GSE inhibited 5-LOX activity with the IC(50) values being 35 and 13 microg/mL, respectively. Two of 3 other GSEs tested also significantly inhibited 5-LOX activity. Inhibition of cholesterol uptake and proinflammatory 5-LOX activity may be beneficial in preventing the development of chronic degenerative diseases such as cardiovascular disease and cancer.

  13. Cloning and characterization of a 9-lipoxygenase gene induced by pathogen attack from Nicotiana benthamiana for biotechnological application

    Directory of Open Access Journals (Sweden)

    Schwab Wilfried

    2011-03-01

    Full Text Available Abstract Background Plant lipoxygenases (LOXs have been proposed to form biologically active compounds both during normal developmental stages such as germination or growth as well as during responses to environmental stress such as wounding or pathogen attack. In our previous study, we found that enzyme activity of endogenous 9-LOX in Nicotiana benthamiana was highly induced by agroinfiltration using a tobacco mosaic virus (TMV based vector system. Results A LOX gene which is expressed after treatment of the viral vectors was isolated from Nicotiana benthamiana. As the encoded LOX has a high amino acid identity to other 9-LOX proteins, the gene was named as Nb-9-LOX. It was heterologously expressed in yeast cells and its enzymatic activity was characterized. The yeast cells expressed large quantities of stable 9-LOX (0.9 U ml-1 cell cultures which can oxygenate linoleic acid resulting in high yields (18 μmol ml-1 cell cultures of hydroperoxy fatty acid. The product specificity of Nb-9-LOX was examined by incubation of linoleic acid and Nb-9-LOX in combination with a 13-hydroperoxide lyase from watermelon (Cl-13-HPL or a 9/13-hydroperoxide lyase from melon (Cm-9/13-HPL and by LC-MS analysis. The result showed that Nb-9-LOX possesses both 9- and 13-LOX specificity, with high predominance for the 9-LOX function. The combination of recombinant Nb-9-LOX and recombinant Cm-9/13-HPL produced large amounts of C9-aldehydes (3.3 μmol mg-1 crude protein. The yield of C9-aldehydes from linoleic acid was 64%. Conclusion The yeast expressed Nb-9-LOX can be used to produce C9-aldehydes on a large scale in combination with a HPL gene with 9-HPL function, or to effectively produce 9-hydroxy-10(E,12(Z-octadecadienoic acid in a biocatalytic process in combination with cysteine as a mild reducing agent.

  14. PgLOX6 encoding a lipoxygenase contributes to jasmonic acid biosynthesis and ginsenoside production in Panax ginseng

    Science.gov (United States)

    Rahimi, Shadi; Kim, Yu-Jin; Sukweenadhi, Johan; Zhang, Dabing; Yang, Deok-Chun

    2016-01-01

    Ginsenosides, the valuable pharmaceutical compounds in Panax ginseng, are triterpene saponins that occur mainly in ginseng plants. It was shown that in vitro treatment with the phytohormone jasmonic acid (JA) is able to increase ginsenoside production in ginseng plants. To understand the molecular link between JA biosynthesis and ginsenoside biosynthesis, we identified a JA biosynthetic 13-lipoxygenase gene (PgLOX6) in P. ginseng that promotes ginsenoside production. The expression of PgLOX6 was high in vascular bundles, which corresponds with expression of ginsenoside biosynthetic genes. Consistent with the role of PgLOX6 in synthesizing JA and promoting ginsenoside synthesis, transgenic plants overexpressing PgLOX6 in Arabidopsis had increased amounts of JA and methyl jasmonate (MJ), increased expression of triterpene biosynthetic genes such as squalene synthase (AtSS1) and squalene epoxidase (AtSE1), and increased squalene content. Moreover, transgenic ginseng roots overexpressing PgLOX6 had around 1.4-fold increased ginsenoside content and upregulation of ginsenoside biosynthesis-related genes including PgSS1, PgSE1, and dammarenediol synthase (PgDDS), which is similar to that of treatment with MJ. However, MJ treatment of transgenic ginseng significantly enhanced JA and MJ, associated with a 2.8-fold increase of ginsenoside content compared with the non-treated, non-transgenic control plant, which was 1.4 times higher than the MJ treatment effect on non-transgenic plants. These results demonstrate that PgLOX6 is responsible for the biosynthesis of JA and promotion of the production of triterpenoid saponin through up-regulating the expression of ginsenoside biosynthetic genes. This work provides insight into the role of JA in biosynthesizing secondary metabolites and provides a molecular tool for increasing ginsenoside production. PMID:27811076

  15. 32 CFR 707.3 - Yard arm signaling lights.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Yard arm signaling lights. 707.3 Section 707.3... RESPECT TO ADDITIONAL STATION AND SIGNAL LIGHTS § 707.3 Yard arm signaling lights. Naval vessels may display, as a means of visual signaling, white all round lights at the ends of the yard arms. These...

  16. Flexible resource allocation during plant defense responses

    Directory of Open Access Journals (Sweden)

    Jack C. Schultz

    2013-08-01

    Full Text Available Plants are organisms composed of modules connected by xylem and phloem transport streams. Attack by both insects and pathogens elicits sometimes rapid defense responses in the attacked module. We have also known for some time that proteins are often reallocated away from pathogen-infected tissues, while the same infection sites may draw carbohydrates to them. This has been interpreted as a tug of war in which the plant withdraws critical resources to block microbial growth while the microbes attempt to acquire more resources. Sink-source regulated transport among modules of critical resources, particularly carbon and nitrogen, is also altered in response to attack. Insects and jasmonate can increase local sink strength, drawing carbohydrates that support defense production. Shortly after attack, carbohydrates may also be drawn to the root. The rate and direction of movement of photosynthate or signals in phloem in response to attack is subject to constraints that include branching, degree of connection among tissues, distance between sources and sinks, proximity, strength, and number of competing sinks, and phloem loading/unloading regulators. Movement of materials (e.g., amino acids, signals to or from attack sites in xylem is less well understood but is partly driven by transpiration. The root is an influential sink and may regulate sink-source interactions and transport above and below ground as well as between the plant and the rhizosphere and nearby, connected plants. Research on resource translocation in response to pathogens or herbivores has focused on biochemical mechanisms; whole-plant research is needed to determine which, if any, of these plant behaviors actually influence plant fitness.

  17. The Inflammasome in Host Defense

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2009-12-01

    Full Text Available Nod-like receptors have emerged as an important family of sensors in host defense. These receptors are expressed in macrophages, dendritic cells and monocytes and play an important role in microbial immunity. Some Nod-like receptors form the inflammasome, a protein complex that activates caspase-1 in response to several stimuli. Caspase-1 activation leads to processing and secretion of pro-inflammatory cytokines such as interleukin (IL-1β and IL-18. Here, we discuss recent advances in the inflammasome field with an emphasis on host defense. We also compare differential requirements for inflammasome activation in dendritic cells, macrophages and monocytes.

  18. Department of Defense, General/Flag Officer, Worldwide Roster

    Science.gov (United States)

    1998-06-01

    USN 9707 970627 3 GENERAL/FLAG OFFICER WORLDWIDE ROSTER DATE DATE OF DUTY TITLE NAME RANK SERVICE ASSIGNED RANK DEP DIR J-8 CARTWRIGHT JAMES E BG* USMC...SIGNAL BRIGADE - SPARTANBURG,SC COMMANDER (RC) SIMPSON DARWIN H BG ARNG 9603 970303 263RD AIR DEFENSE ARTILLERY BRIGADE - ANDERSON,SC COMMANDER (RC...N ................. 27 CARSKADON BRUCE M ................. 28 CARTWRIGHT JAMES E ................ 04 CASCIANO JOHN P ................... 27 CASE

  19. Overview of Peroxiredoxins in oxidant defense and redox regulation

    OpenAIRE

    Poole, Leslie B.; Hall, Andrea; Nelson, Kimberly J.

    2011-01-01

    Peroxiredoxins are important hydroperoxide detoxification enzymes, yet have only come to the fore in recent years relative to the other major players in peroxide detoxification, heme-containing catalases and peroxidases, and glutathione peroxidases. These cysteine-dependent peroxidases exhibit high reactivity with hydrogen peroxide, organic hydroperoxides and peroxynitrite and play major roles not only in peroxide defense, but also in regulating peroxide-mediated cell signaling. This overview...

  20. A Guide to International Participation in the Strategic Defense Initiative

    Science.gov (United States)

    2007-11-02

    methods , devices, or techniques. Alpha Laser Ground testing of the Alpha laser occurs in a 50-foot tall vacuum chamber on TRW’s Southern California test...Processing Mathematical Methods and Algorithms Self Adaptive Processing and Simulation SENSING, DISCRIMINATION AND SIGNAL PROCESSING Detectors for...Based Laser ( GBL ) Address: Commander U.S. Army Strategic Defense Command P.O. Box 1500 Huntsville, Alabama 35807 Tel: (205) 895-4340 HEDI

  1. Induced disease resistance signaling in plants

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Loon, L.C. van; Pieterse, C.M.J.

    2006-01-01

    To protect themselves from disease, plants have evolved sophisticated inducible defense mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signaling pathways controlling induced disease resistance is a major objective in resea

  2. Cell-specific pattern recognition receptor signaling in antibacterial defense

    NARCIS (Netherlands)

    van Lieshout, M.H.P.

    2015-01-01

    Sepsis, the syndrome that describes infection complicated by acute organ failure, is most frequently caused by bacterial pneumonia and infection originating from the abdominal cavity and is a major cause of morbidity and mortality globally. A brisk and firm initial host response is needed for cleara

  3. Conserved nematode signaling molecules elicit plant defenses and pathogen resistance

    Science.gov (United States)

    Nematodes, which are ubiquitous in soil and are estimated to cause $100 B of agricultural damage annually, produce novel, highly conserved small sugar-based molecules call ascarosides. Ascarosides play critical roles in nematode development and behavior. We report here that plants recognize these un...

  4. Cell-specific pattern recognition receptor signaling in antibacterial defense

    NARCIS (Netherlands)

    van Lieshout, M.H.P.

    2015-01-01

    Sepsis, the syndrome that describes infection complicated by acute organ failure, is most frequently caused by bacterial pneumonia and infection originating from the abdominal cavity and is a major cause of morbidity and mortality globally. A brisk and firm initial host response is needed for

  5. Defense Acquisition Policy and Defense Industrial Base Reinforcement Strategy - Enhancing the International Competitiveness of the Korean National Defense Industry

    Science.gov (United States)

    2008-04-23

    Korea Defense Industry Association (KDIA). (2007). Annual management review of Korean Defense Industry. Seoul: Author. Lee, D.O. (2000...COMPETITIVENESS OF THE KOREAN NATIONAL DEFENSE INDUSTRY Published: 23 April 2008 by Dr. Dae Ok Lee 5th Annual Acquisition Research Symposium of the...International Competitiveness of the Korean National Defense Industry 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  6. Adaptation Mechanisms in the Evolution of Moss Defenses to Microbes.

    Science.gov (United States)

    Ponce de León, Inés; Montesano, Marcos

    2017-01-01

    Bryophytes, including mosses, liverworts and hornworts are early land plants that have evolved key adaptation mechanisms to cope with abiotic stresses and microorganisms. Microbial symbioses facilitated plant colonization of land by enhancing nutrient uptake leading to improved plant growth and fitness. In addition, early land plants acquired novel defense mechanisms to protect plant tissues from pre-existing microbial pathogens. Due to its evolutionary stage linking unicellular green algae to vascular plants, the non-vascular moss Physcomitrella patens is an interesting organism to explore the adaptation mechanisms developed in the evolution of plant defenses to microbes. Cellular and biochemical approaches, gene expression profiles, and functional analysis of genes by targeted gene disruption have revealed that several defense mechanisms against microbial pathogens are conserved between mosses and flowering plants. P. patens perceives pathogen associated molecular patterns by plasma membrane receptor(s) and transduces the signal through a MAP kinase (MAPK) cascade leading to the activation of cell wall associated defenses and expression of genes that encode proteins with different roles in plant resistance. After pathogen assault, P. patens also activates the production of ROS, induces a HR-like reaction and increases levels of some hormones. Furthermore, alternative metabolic pathways are present in P. patens leading to the production of a distinct metabolic scenario than flowering plants that could contribute to defense. P. patens has acquired genes by horizontal transfer from prokaryotes and fungi, and some of them could represent adaptive benefits for resistance to biotic stress. In this review, the current knowledge related to the evolution of plant defense responses against pathogens will be discussed, focusing on the latest advances made in the model plant P. patens.

  7. Adaptation Mechanisms in the Evolution of Moss Defenses to Microbes

    Science.gov (United States)

    Ponce de León, Inés; Montesano, Marcos

    2017-01-01

    Bryophytes, including mosses, liverworts and hornworts are early land plants that have evolved key adaptation mechanisms to cope with abiotic stresses and microorganisms. Microbial symbioses facilitated plant colonization of land by enhancing nutrient uptake leading to improved plant growth and fitness. In addition, early land plants acquired novel defense mechanisms to protect plant tissues from pre-existing microbial pathogens. Due to its evolutionary stage linking unicellular green algae to vascular plants, the non-vascular moss Physcomitrella patens is an interesting organism to explore the adaptation mechanisms developed in the evolution of plant defenses to microbes. Cellular and biochemical approaches, gene expression profiles, and functional analysis of genes by targeted gene disruption have revealed that several defense mechanisms against microbial pathogens are conserved between mosses and flowering plants. P. patens perceives pathogen associated molecular patterns by plasma membrane receptor(s) and transduces the signal through a MAP kinase (MAPK) cascade leading to the activation of cell wall associated defenses and expression of genes that encode proteins with different roles in plant resistance. After pathogen assault, P. patens also activates the production of ROS, induces a HR-like reaction and increases levels of some hormones. Furthermore, alternative metabolic pathways are present in P. patens leading to the production of a distinct metabolic scenario than flowering plants that could contribute to defense. P. patens has acquired genes by horizontal transfer from prokaryotes and fungi, and some of them could represent adaptive benefits for resistance to biotic stress. In this review, the current knowledge related to the evolution of plant defense responses against pathogens will be discussed, focusing on the latest advances made in the model plant P. patens. PMID:28360923

  8. Defense Acquisition Performance Assessment Report

    Science.gov (United States)

    2006-01-01

    Incorporated – “Changing the System” HeLLeR , TRiCiA A., Deputy Director of Congressional Support, Technical and Analytical Support, USAF A-Team...Interview Recorder” HeLLieR, RiCHARD, Director of Air Force Programs, United Technologies – “Joint Stars System” HeRMAN , DR. ROBeRT, Member, Defense

  9. Defense Financial and Investment Review

    Science.gov (United States)

    1985-06-01

    to direct its attention to problems such as profit policy and the management and investment practices of defense contractors. Prorit Study 󈨖 In 1982...I \\-L 10 NO ADJUSTMENT 46- 70 71 72 73 74 75 76 77 78 79 80 81 82 83 Sources: Touche Ross; Prorit 󈨐 V-34

  10. In Defense of Darwin's Theory.

    Science.gov (United States)

    Naylor, Bruce G.; Handford, Paul

    1985-01-01

    Examines issues regarding the defensibility and utility of natural selection as a scientific theory, focusing on the process of population change over time. Topics considered include criticisms of Darwinian theory, tautology and the meaning of fitness, the ability of theories to predict and explain, and the sufficiency of natural selection. (DH)

  11. Soviet debate on missile defense

    Energy Technology Data Exchange (ETDEWEB)

    Parrott, B.

    1987-04-01

    Although the Strategic Defense Initiative (SDI) is meant to cope with the danger of a Soviet nuclear attack, the recent US debate over SDI has paid surprisingly little attention to Soviet views of ballistic missile defense. Despite the existence of a substantial body of pertinent scholarship, the debate has failed to take adequate account of major changes in Soviet ballistic missile defense policy since the mid-1960s. It has also neglected the links between current Soviet military policy and broader Soviet political and economic choices. The Soviets regard SDI not as a novel undertaking to reduce the risks of nuclear war but as an extension of the geopolitical competition between the superpowers. This competition has been dominated in the 1980s, in the Soviet view, by sharply increased US assertiveness and the decline of detente. Viewing SDI as a manifestation of these general trends, Soviet decision makers find the prospect of an unregulated race in ballistic missile defenses and military space technologies deeply unsettling. The deterioration of superpower relations has raised serious doubts in Moscow about the wisdom of Soviet external policy during the 1970s and has provoked sharp internal differences over policy toward the US. Already highly suspicious of the Reagan administration, the elite is united by a general conviction that SDI is an American gambit that may ultimately undercut past Soviet strategic gains and pose a grave new threat to Soviet security. 14 references.

  12. What Happens After the Defense?

    DEFF Research Database (Denmark)

    Feldtmann, Birgit

    2015-01-01

    who has attempted to attack the master’s vessel and whose distress is the direct result of lawful self-defense by PCASP? This is the question at the heart of this article, which argues that there are certain post incident obligations and that it is crucial to address these obligations at the flag...

  13. Multidimensional Perfectionism and Ego Defenses

    Science.gov (United States)

    Dickinson, Wendy L.; Ashby, Jeffrey S.

    2005-01-01

    This study examined the relationship between multidimensional perfectionism and ego defense style among 130 college students. Cluster analysis results facilitated the identification of groups of adaptive perfectionists, maladaptive perfectionists, and non-perfectionists. The researchers found that identified maladaptive perfectionists used…

  14. Multidimensional Perfectionism and Ego Defenses

    Science.gov (United States)

    Dickinson, Wendy L.; Ashby, Jeffrey S.

    2005-01-01

    This study examined the relationship between multidimensional perfectionism and ego defense style among 130 college students. Cluster analysis results facilitated the identification of groups of adaptive perfectionists, maladaptive perfectionists, and non-perfectionists. The researchers found that identified maladaptive perfectionists used…

  15. Analytics for Cyber Network Defense

    Energy Technology Data Exchange (ETDEWEB)

    Plantenga, Todd. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Kolda, Tamara Gibson [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2011-06-01

    This report provides a brief survey of analytics tools considered relevant to cyber network defense (CND). Ideas and tools come from elds such as statistics, data mining, and knowledge discovery. Some analytics are considered standard mathematical or statistical techniques, while others re ect current research directions. In all cases the report attempts to explain the relevance to CND with brief examples.

  16. Inflation Adjustments for Defense Acquisition

    Science.gov (United States)

    2014-10-01

    Airframe Total airframe contractor furnished equipment ( CFE ) Total airframe CFE 9 entries (forward fuselage, center fuselage, wing, empennage...etc.) Avionics Total electronics CFE and government- furnished equipment (GFE) Total avionics 16 entries (radar, integrated processor...Relationship CFE Contractor Furnished Equipment CNI Communication, Navigation, Identification DoD Department of Defense FCCM Facilities Capital Cost

  17. Control of Carbon Assimilation and Partitioning by Jasmonate: An Accounting of Growth-Defense Tradeoffs.

    Science.gov (United States)

    Havko, Nathan E; Major, Ian T; Jewell, Jeremy B; Attaran, Elham; Browse, John; Howe, Gregg A

    2016-01-01

    Plant growth is often constrained by the limited availability of resources in the microenvironment. Despite the continuous threat of attack from insect herbivores and pathogens, investment in defense represents a lost opportunity to expand photosynthetic capacity in leaves and absorption of nutrients and water by roots. To mitigate the metabolic expenditure on defense, plants have evolved inducible defense strategies. The plant hormone jasmonate (JA) is a key regulator of many inducible defenses. Synthesis of JA in response to perceived danger leads to the deployment of a variety of defensive structures and compounds, along with a potent inhibition of growth. Genetic studies have established an important role for JA in mediating tradeoffs between growth and defense. However, several gaps remain in understanding of how JA signaling inhibits growth, either through direct transcriptional control of JA-response genes or crosstalk with other signaling pathways. Here, we highlight recent progress in uncovering the role of JA in controlling growth-defense balance and its relationship to resource acquisition and allocation. We also discuss tradeoffs in the context of the ability of JA to promote increased leaf mass per area (LMA), which is a key indicator of leaf construction costs and leaf life span.

  18. Control of Carbon Assimilation and Partitioning by Jasmonate: An Accounting of Growth–Defense Tradeoffs

    Directory of Open Access Journals (Sweden)

    Nathan E. Havko

    2016-01-01

    Full Text Available Plant growth is often constrained by the limited availability of resources in the microenvironment. Despite the continuous threat of attack from insect herbivores and pathogens, investment in defense represents a lost opportunity to expand photosynthetic capacity in leaves and absorption of nutrients and water by roots. To mitigate the metabolic expenditure on defense, plants have evolved inducible defense strategies. The plant hormone jasmonate (JA is a key regulator of many inducible defenses. Synthesis of JA in response to perceived danger leads to the deployment of a variety of defensive structures and compounds, along with a potent inhibition of growth. Genetic studies have established an important role for JA in mediating tradeoffs between growth and defense. However, several gaps remain in understanding of how JA signaling inhibits growth, either through direct transcriptional control of JA-response genes or crosstalk with other signaling pathways. Here, we highlight recent progress in uncovering the role of JA in controlling growth-defense balance and its relationship to resource acquisition and allocation. We also discuss tradeoffs in the context of the ability of JA to promote increased leaf mass per area (LMA, which is a key indicator of leaf construction costs and leaf life span.

  19. Reduced 15S-Lipoxygenase-2 Expression in Esophageal Cancer Specimens and Cells and Upregulation In Vitro by the Cyclooxygenase-2 Inhibitor, NS398

    Directory of Open Access Journals (Sweden)

    Xiao-Chun Xu

    2003-03-01

    Full Text Available Alterations in arachidonic acid metabolism are involved in human carcinogenesis. Cyclooxygenase (COX and lipoxygenase (LOX are key enzymes in this metabolism. We analyzed the expression of 15S-lipoxygenase-2 (15-LOX-2 mRNA and protein in surgical specimens from normal (N=37 and malignant (63 esophageal tissues using in situ hybridization and immunohistochemistry (IHC, in normal (1, premalignant (1, malignant (5 esophageal cell lines using Northern and Western blotting. 15-LOX-2 was expressed in normal esophageal epithelial cells (EECs at the highest levels, whereas an SV40-immortalized HET-1A line and three of five esophageal cancer cell lines failed to express it at detectable levels. 15-LOX-2 was detected in 76% (28/37 of the normal esophageal mucosae, but only in 46% (29/63 of the cancer specimens using IHC (P<.01. Transient transfection of 15-LOX-2 expression vectors into esophageal cancer cells significantly inhibited the proliferation of 15-LOX-2-negative cancer cells. The COX-2 inhibitor, NS398, induced 15LOX-2 expression in esophageal cancer cells, which is associated with reduced cell viability. This study demonstrated that 15-LOX-2 expression is lost in esophageal cancers and that the induction of 15-LOX-2 can inhibit cancer cell proliferation. Further investigation of the effects of nonsteroidal anti-inflammatory drugs on 15-LOX-2 expression and apoptosis in esophageal cancer cells may be warranted.

  20. Discovery of the first dual inhibitor of the 5-lipoxygenase-activating protein and soluble epoxide hydrolase using pharmacophore-based virtual screening

    Science.gov (United States)

    Temml, Veronika; Garscha, Ulrike; Romp, Erik; Schubert, Gregor; Gerstmeier, Jana; Kutil, Zsofia; Matuszczak, Barbara; Waltenberger, Birgit; Stuppner, Hermann; Werz, Oliver; Schuster, Daniela

    2017-01-01

    Leukotrienes (LTs) are pro-inflammatory lipid mediators derived from arachidonic acid (AA) with roles in inflammatory and allergic diseases. The biosynthesis of LTs is initiated by transfer of AA via the 5-lipoxygenase-activating protein (FLAP) to 5-lipoxygenase (5-LO). FLAP inhibition abolishes LT formation exerting anti-inflammatory effects. The soluble epoxide hydrolase (sEH) converts AA-derived anti-inflammatory epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatetraenoic acids (di-HETEs). Its inhibition consequently also counteracts inflammation. Targeting both LT biosynthesis and the conversion of EETs with a dual inhibitor of FLAP and sEH may represent a novel, powerful anti-inflammatory strategy. We present a pharmacophore-based virtual screening campaign that led to 20 hit compounds of which 4 targeted FLAP and 4 were sEH inhibitors. Among them, the first dual inhibitor for sEH and FLAP was identified, N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N’-(3,4-dichlorophenyl)urea with IC50 values of 200 nM in a cell-based FLAP test system and 20 nM for sEH activity in a cell-free assay. PMID:28218273

  1. Discovery of the first dual inhibitor of the 5-lipoxygenase-activating protein and soluble epoxide hydrolase using pharmacophore-based virtual screening

    Science.gov (United States)

    Temml, Veronika; Garscha, Ulrike; Romp, Erik; Schubert, Gregor; Gerstmeier, Jana; Kutil, Zsofia; Matuszczak, Barbara; Waltenberger, Birgit; Stuppner, Hermann; Werz, Oliver; Schuster, Daniela

    2017-02-01

    Leukotrienes (LTs) are pro-inflammatory lipid mediators derived from arachidonic acid (AA) with roles in inflammatory and allergic diseases. The biosynthesis of LTs is initiated by transfer of AA via the 5-lipoxygenase-activating protein (FLAP) to 5-lipoxygenase (5-LO). FLAP inhibition abolishes LT formation exerting anti-inflammatory effects. The soluble epoxide hydrolase (sEH) converts AA-derived anti-inflammatory epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatetraenoic acids (di-HETEs). Its inhibition consequently also counteracts inflammation. Targeting both LT biosynthesis and the conversion of EETs with a dual inhibitor of FLAP and sEH may represent a novel, powerful anti-inflammatory strategy. We present a pharmacophore-based virtual screening campaign that led to 20 hit compounds of which 4 targeted FLAP and 4 were sEH inhibitors. Among them, the first dual inhibitor for sEH and FLAP was identified, N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N’-(3,4-dichlorophenyl)urea with IC50 values of 200 nM in a cell-based FLAP test system and 20 nM for sEH activity in a cell-free assay.

  2. Civil Defense, U. S. A.: A Programmed Orientation to Civil Defense. Unit 5. Governmental Responsibilities for Civil Defense.

    Science.gov (United States)

    Defense Civil Preparedness Agency (DOD), Battle Creek, MI.

    A description of the laws and orders that provide necessary legal authorization for civil defense activities is provided. In addition, an outline of the responsibilities of all governments and the role of the private sector in civil defense is presented. Topics discussed include: (1) Legal authority for civil defense, (2) Civil defense…

  3. Civil Defense, U. S. A.: A Programmed Orientation to Civil Defense. Unit 1. Civil Defense - Protection Against What?

    Science.gov (United States)

    Defense Civil Preparedness Agency (DOD), Battle Creek, MI.

    An explanation of the need for civil defense in nuclear and natural disasters is presented. A brief historical background of civil defense is given. Major topics include: (1) Types of disasters, (2) Probable objectives of a nuclear attack on the United States, (3) The major defensive measures against a nuclear attack, (4) Some reasons for low…

  4. Targeting multiple signaling pathways as a strategy for managing prostate cancer: multifocal signal modulation therapy.

    Science.gov (United States)

    McCarty, Mark F

    2004-12-01

    The aberrant behavior of cancer reflects upregulation of certain oncogenic signaling pathways that promote proliferation, inhibit apoptosis, and enable the cancer to spread and evoke angiogenesis. Theoretically, it should be feasible to decrease the activity of these pathways-or increase the activity of pathways that oppose them-with noncytotoxic agents. Since multiple pathways are dysfunctional in most cancers, and cancers accumulate new oncogenic mutations as they progress, the greatest and most durable therapeutic benefit will likely be achieved with combination regimens that address several targets. Thus, a multifocal signal modulation therapy (MSMT) of cancer is proposed. This concept has already been documented by researchers who have shown that certain combinations of signal modulators-of limited utility when administered individually-can achieve dramatic suppression of tumor growth in rodent xenograft models. The present essay attempts to guide development of MSMTs for prostate cancer. Androgen ablation is a signal-modulating measure already in standard use in the management of delocalized prostate cancer. The additional molecular targets considered here include the type 1 insulin-like growth factor receptor, the epidermal growth factor receptor, mammalian target of rapamycin, NF-kappaB, hypoxia-inducible factor-1alpha, hsp90, cyclooxygenase-2, protein kinase A type I, vascular endothelial growth factor, 5-lipoxygenase, 12-lipoxygenase, angiotensin II receptor type 1, bradykinin receptor type 1, c-Src, interleukin-6, ras, MDM2, bcl-2/bclxL, vitamin D receptor, estrogen receptor-beta, and PPAR-. Various nutrients and phytochemicals suspected to have potential utility in prostate cancer prevention and therapy, but whose key molecular targets are still unknown, might reasonably be incorporated into MSMTs for prostate cancer; these include lycopene, selenium, green tea polyphenols, genistein, and silibinin. MSMTs can be developed systematically by testing

  5. Department of Defense PERSEREC (DOD PERSEREC)

    Data.gov (United States)

    Social Security Administration — The purpose of this agreement is for SSA to verify SSN information for Defense Manpower Data Center (DMDC) of the Department of Defense. DMDC will use the SSA data...

  6. Function of ABA in Stomatal Defense against Biotic and Drought Stresses

    Directory of Open Access Journals (Sweden)

    Chae Woo Lim

    2015-07-01

    Full Text Available The plant hormone abscisic acid (ABA regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss. Recent studies using a combination of approaches, including genetics, physiology, and molecular biology, have contributed considerably to our understanding of ABA signal transduction. A number of proteins associated with ABA signaling and responses—especially ABA receptors—have been identified. ABA signal transduction initiates signal perception by ABA receptors and transfer via downstream proteins, including protein kinases and phosphatases. In the present review, we focus on the function of ABA in stomatal defense against biotic and abiotic stresses, through analysis of each ABA signal component and the relationships of these components in the complex network of interactions. In particular, two ABA signal pathway models in response to biotic and abiotic stress were proposed, from stress signaling to stomatal closure, involving the pyrabactin resistance (PYR/PYR-like (PYL or regulatory component of ABA receptor (RCAR family proteins, 2C-type protein phosphatases, and SnRK2-type protein kinases.

  7. Multiple signalling pathways mediate fungal elicitor-induced beta-thujaplicin biosynthesis in Cupressus lusitanica cell cultures.

    Science.gov (United States)

    Zhao, Jian; Sakai, Kokki

    2003-02-01

    The biosynthesis of a phytoalexin, beta-thujaplicin, in Cupressus lusitanica cell cultures can be stimulated by a yeast elicitor, H(2)O(2), or methyl jasmonate. Lipoxygenase activity was also stimulated by these treatments, suggesting that the oxidative burst and jasmonate pathway may mediate the elicitor-induced accumulation of beta-thujaplicin. The elicitor signalling pathway involved in beta-thujaplicin induction was further investigated using pharmacological and biochemical approaches. Treatment of the cells with calcium ionophore A23187 alone stimulated the production of beta-thujaplicin. A23187 also enhanced the elicitor-induced production of beta-thujaplicin. EGTA, LaCl(3), and verapamil pretreatments partially blocked A23187- or yeast elicitor-induced accumulation of beta-thujaplicin. These results suggest that Ca(2+) influx is required for elicitor-induced production of beta-thujaplicin. Treatment of cell cultures with mastoparan, melittin or cholera toxin alone or in combination with the elicitor stimulated the production of beta-thujaplicin or enhanced the elicitor-induced production of beta-thujaplicin. The G-protein inhibitor suramin inhibited the elicitor-induced production of beta-thujaplicin, suggesting that receptor-coupled G-proteins are likely to be involved in the elicitor-induced biosynthesis of beta-thujaplicin. Indeed, both GTP-binding activity and GTPase activity of the plasma membrane were stimulated by elicitor, and suramin and cholera toxin affected G-protein activities. In addition, all inhibitors of G-proteins and Ca(2+) flux suppressed elicitor-induced increases in lipoxygenase activity whereas activators of G-proteins and the Ca(2+) signalling pathway increased lipoxygenase activity. These observations suggest that Ca(2+) and G-proteins may mediate elicitor signals to the jasmonate pathway, and the jasmonate signalling pathway may then lead to the production of beta-thujaplicin.

  8. Elevated expression of 12/15-lipoxygenase and cyclooxygenase-2 in a transgenic mouse model of prostate carcinoma.

    Science.gov (United States)

    Shappell, Scott B; Olson, Sandra J; Hannah, S Erin; Manning, Suzanne; Roberts, Richard L; Masumori, Naoya; Jisaka, Mitsuo; Boeglin, William E; Vader, Virginia; Dave, Dhiren S; Shook, M Frances; Thomas, Tania Z; Funk, Colin D; Brash, Alan R; Matusik, Robert J

    2003-05-01

    Changes in expression of arachidonic acid (AA) metabolizing enzymes are implicated in the development and progression of human prostate carcinoma (Pca). Transgenic mouse models of Pca that progress from high-grade prostatic intraepithelial neoplasia (HGPIN) to invasive and metastatic carcinoma could facilitate study of the regulation and function of these genes in Pca progression. Herein we characterize the AA-metabolizing enzymes in transgenic mice established with a prostate epithelial-specific long probasin promoter and the SV40 large T antigen (LPB-Tag mice) that develop extensive HGPIN and invasive and metastatic carcinoma with neuroendocrine (NE) differentiation. Murine 8-lipoxygenase (8-LOX), homologue of the 15-LOX-2 enzyme that is expressed in benign human prostatic epithelium and reduced in Pca, was not detected in wild-type or LPB-Tag prostates as determined by enzyme assay, reverse transcription-PCR, and immunohistochemistry. The most prominent AA metabolite in mouse prostate was 12-HETE. Wild-type prostate (dorsolateral lobe) converted 1.6 +/- 0.5% [(14)C]AA to 12-HETE (n = 7), and this increased to 8.0 +/- 4.4% conversion in LPB-Tag mice with HGPIN (n = 13). Quantitative real-time reverse transcription-PCR and immunostaining correlated the increased 12-HETE synthesis with increased neoplastic epithelial expression of 12/15-LOX, the leukocyte-type (L) of 12-LOX and the murine homologue of human 15-LOX-1. Immunostaining showed increased L12-LOX in invasive carcinoma and approximately one-half of metastatic foci. COX-2 mRNA was detectable in neoplastic prostates with HGPIN but not in wild-type prostate. By immunostaining, COX-2 was increased in the neoplastic epithelium of HGPIN but was absent in foci of invasion and metastases. We conclude that (a) AA metabolism in wild-type mouse prostate differs from humans in the basal expression of LOXs (15-LOX-2 in human, absence of its 8-LOX homologue in mouse prostate); (b) increased expression of 12/15-LOX in

  9. [Effect of herba schizonepetae volatile oil (STO) on activity of 5-lipoxygenase in rat thoracic cavity leukocytes].

    Science.gov (United States)

    Zhao, Lu; Zeng, Nan; Tang, Yong-xin; Liu, Xiao-shuai; Yang, Xuan; Qu, Li-ping

    2008-09-01

    To investigate the effect of herba schizonepetae volatile oil (STO) on the activity of 5-lipoxygenase (5-LO), so as to elucidate its mechanisms of anti-inflammatory action which is related to the arachidonic acid (AA) metabolism. Thoracic cavity leukocytes from the pleurisy model rat induced by injecting 1%-carrageenan into the pleural cavity were collected. Then 0. 4 mL cell suspension including 2 x 10(7) cells per millilitre were used as the reaction system in vitro. STO in different concentrations (final concentration 0.011, 0.022, 0.043, 0.087, 0.179, 0.255, 0.364 g x L(-1)), zileuton (final concentration 0.625 x 10(-3) g x L(-1)), and DMSO in the same volume were added into the reaction tube respectively. The reaction tubes were incubated at 37 degrees C for 20 min and CaCl2 (final concentration 2 mmol x L(-1)), MgCl2 (final concentration 0.5 mmol x L(-1)), exogenous AA (final concentration 200 micromol x L(-1)) and A23187 (final concentration 5 micromol x L(-1)) were added in turns during this period. The reaction tubes were mixed and continuously incubated at 37 degrees C for 30 min. After terminating reaction by adding methanol, the metabolites of 5-LO, leukotriene B4 (LTB4) and 5-hydroxy-6, 8, 11, 14-eicosatetraenoic acid (5-HETE), were extracted, separated and detected by means of RP-HPLC. Compared with control group, STO significantly inhibited the biosynthesis of LTB4 and 5-HETE at final concentration between 0. 022 g x L(-1) and 0.364 g x L(-1) (P STO can inhibited the activity of 5-LO, which is an important enzyme of AA metabolism, in rat thoracic cavity leukocytes in a dose-dependent manner in vitro. It is suggested that the mechanism of anti-inflammatory action of STO is related to its inhibiting the activity of 5-LO and decreasing the level of major inflammatory mediators LTB4.

  10. Interaction of 12/15-lipoxygenase with fatty acids alters the leukocyte kinetics leading to improved postmyocardial infarction healing.

    Science.gov (United States)

    Halade, Ganesh V; Kain, Vasundhara; Ingle, Kevin A; Prabhu, Sumanth D

    2017-07-01

    The metabolic transformation of fatty acids to form oxylipids using 12/15-lipoxygenase (LOX) can promote either resolving or nonresolving inflammation. However, the mechanism of how 12/15-LOX interacts with polyunsaturated fatty acids (PUFA) in postmyocardial infarction (post-MI) healing is unclear. Here, we reported the role of 12/15-LOX in post-MI cardiac remodeling in a PUFA [10% (wt/wt), 22 kcal]-enriched environment. Wild-type (WT; C57BL/6J) and 12/15-LOX-null (12/15-LOX(-/-)) male mice of 8-12 wk of age were fed a PUFA-enriched diet for 1 mo and subjected to permanent coronary artery ligation. Post-MI mice were monitored for day 1 or until day 5 along with standard diet-fed MI controls. No-MI surgery mice served as naïve controls. PUFA-fed WT and 12/15-LOX(-/-) mice improved ejection fraction and reduced lung edema greater than WT mice at day 5 post-MI (P acids (EETs), i.e., 11,12-EpETrE and 14,15-EpETrE, which were further enhanced by acute PUFA intake post-MI. Macrophage density was decreased in WT + PUFA and 12/15-LOX(-/-) mice compared with their respective standard diet-fed WT controls at day 5 post-MI. 12/15-LOX(-/-) + PUFA mice displayed an increased expression of chemokine (C-C motif) ligand 2 and reparative macrophages markers (Ym-1, Mrc-1, and Arg-1, all P acids, the cytochrome P-450-derived metabolites in postmyocardial infarction (post-MI) healing; 2) acute exposure of fatty acids to 12/15-LOX(-/-) mice drives leukocyte (neutrophils and macrophages) clearance post-MI; and 3) metabolic transformation of fats is the significant contributor in leukocyte clearance to drive either resolving or nonresolving inflammation post-MI. Copyright © 2017 the American Physiological Society.

  11. 22 CFR 120.6 - Defense article.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Defense article. 120.6 Section 120.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.6 Defense article. Defense article means any item or technical data designated in § 121.1 of this...

  12. 22 CFR 120.9 - Defense service.

    Science.gov (United States)

    2010-04-01

    ... Defense service. (a) Defense service means: (1) The furnishing of assistance (including training) to foreign persons, whether in the United States or abroad in the design, development, engineering... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Defense service. 120.9 Section 120.9...

  13. Defense Procurement Strategy for a Globalized Industry

    Science.gov (United States)

    2007-11-02

    QDR,” DefenseNews, 8 November 2004, p. 4. 3 Vago Muradain, “Finalizing Transformation,” DefenseNews, 8 November 2004, p. 34. 4 Hugo Posey and Ben...Interavia, Summer 2004, 34-36. Munton, Bob, and Brinley Salzmann. “U.K.’s Growing Contols.” DefenseNews, 25 October 2004, 96. Muradain, Vago

  14. Defense Science Board Task Force Report on Cyber Defense Management

    Science.gov (United States)

    2016-09-01

    posturethrough the CCMDs with measurement feedback to the leadership. The DoD CIO should establishmetrics for this assessment. Include Cyber Preparedness in...DoD should evaluate the effectiveness of the resulting defense posturethrough the CCMDs with measurement feedback to the leadership. The DoD CIO...USCYBERCOM Welcome Maj Keffer, USCYBERCOM Chief of Staff Cyber Portfolio Management Decisions Mr. Terry Carter, Deputy Director, Capabilities and Resource

  15. Homeland Defense: DOD Needs to Address Gaps in Homeland Defense and Civil Support Guidance

    Science.gov (United States)

    2012-10-01

    tornado, storm, high water , wind-driven water , tidal wave, tsunami, earthquake, volcanic eruption , landslide, mudslide, snowstorm, or drought), or...Secretary of Defense and the Office of the Under Secretary of Defense for Policy on homeland defense and civil support matters, among other things. The...Assistant Secretary of Defense for Global Strategic Affairs is the principal advisor to the Under Secretary of Defense for Policy and the Secretary

  16. Evaluating Moving Target Defense with PLADD

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Stephen T. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Outkin, Alexander V. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Gearhart, Jared Lee [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hobbs, Jacob Aaron [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Siirola, John Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Phillips, Cynthia A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Verzi, Stephen Joseph [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Tauritz, Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Mulder, Samuel A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Naugle, Asmeret Bier [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-15

    This project evaluates the effectiveness of moving target defense (MTD) techniques using a new game we have designed, called PLADD, inspired by the game FlipIt [28]. PLADD extends FlipIt by incorporating what we believe are key MTD concepts. We have analyzed PLADD and proven the existence of a defender strategy that pushes a rational attacker out of the game, demonstrated how limited the strategies available to an attacker are in PLADD, and derived analytic expressions for the expected utility of the game’s players in multiple game variants. We have created an algorithm for finding a defender’s optimal PLADD strategy. We show that in the special case of achieving deterrence in PLADD, MTD is not always cost effective and that its optimal deployment may shift abruptly from not using MTD at all to using it as aggressively as possible. We believe our effort provides basic, fundamental insights into the use of MTD, but conclude that a truly practical analysis requires model selection and calibration based on real scenarios and empirical data. We propose several avenues for further inquiry, including (1) agents with adaptive capabilities more reflective of real world adversaries, (2) the presence of multiple, heterogeneous adversaries, (3) computational game theory-based approaches such as coevolution to allow scaling to the real world beyond the limitations of analytical analysis and classical game theory, (4) mapping the game to real-world scenarios, (5) taking player risk into account when designing a strategy (in addition to expected payoff), (6) improving our understanding of the dynamic nature of MTD-inspired games by using a martingale representation, defensive forecasting, and techniques from signal processing, and (7) using adversarial games to develop inherently resilient cyber systems.

  17. Deficiencies in jasmonate-mediated plant defense reveal quantitative variation in Botrytis cinerea pathogenesis.

    Directory of Open Access Journals (Sweden)

    Heather C Rowe

    2010-04-01

    Full Text Available Despite the described central role of jasmonate signaling in plant defense against necrotrophic pathogens, the existence of intraspecific variation in pathogen capacity to activate or evade plant jasmonate-mediated defenses is rarely considered. Experimental infection of jasmonate-deficient and jasmonate-insensitive Arabidopsis thaliana with diverse isolates of the necrotrophic fungal pathogen Botrytis cinerea revealed pathogen variation for virulence inhibition by jasmonate-mediated plant defenses and induction of plant defense metabolites. Comparison of the transcriptional effects of infection by two distinct B. cinerea isolates showed only minor differences in transcriptional responses of wild-type plants, but notable isolate-specific transcript differences in jasmonate-insensitive plants. These transcriptional differences suggest B. cinerea activation of plant defenses that require plant jasmonate signaling for activity in response to only one of the two B. cinerea isolates tested. Thus, similar infection phenotypes observed in wild-type plants result from different signaling interactions with the plant that are likely integrated by jasmonate signaling.

  18. Austere Defense: Challenges and Opportunities

    Science.gov (United States)

    2014-01-01

    military advice while acquiescing to divestitures, and effectively executing the austere defense cuts required by current law through 2019 and...Could it be that our assessments of risk have, over time, become too conservative? In- deed, even with the effects of full sequestration the United... crunch . Look- ing at overhead, as Douglas Macgregor of Politico magazine reminds us, during World War II, only four four-star generals commanded a

  19. Western Hemisphere Defense Policy Statement

    Science.gov (United States)

    2012-10-01

    El Salvador, Guatemala, Honduras , Paraguay, Peru and Uruguay have contributed to or led multi-national security operations and United Nations (UN...impact on regional and global peace and security and reflect the new realities of defense cooperation in the hemisphere. Working with Canada and...Mexico, DoD remains prepared to deter and defeat direct threats to our homeland. We partner with Canada on regional security issues such as an evolving

  20. Application of Defense Technology Commonly Used in Boxing Match

    Institute of Scientific and Technical Information of China (English)

    Zhixiao Li[1; Jianjun Liu[2

    2015-01-01

    Boxing defense technology is a kind of techniques to prevent the opponent from attacking successfully. Boxing is a kind of sports that needs close cooperation between attack and defense. Attack is used for defense, where there is no attack, there will be no defense, and vice versa. Defense technology is the foundation of attack technology, therefore, defense is of vital importance in boxing match.

  1. CSRF Vulnerabilities and Defensive Techniques

    Directory of Open Access Journals (Sweden)

    Rupali D. Kombade

    2012-02-01

    Full Text Available Web applications are now part of day to day life due to their user friendly environment as well as advancement of technology to provide internet facilities, but these web applications brought lot of threats with them and these threats are continuously growing, one of the these threat is Cross Site Request Forgery(CSRF. CSRF attack is immerged as serious threat to web applications which based on the vulnerabilities present in the normal request response pattern of HTTP protocol. It is difficult to detect and hence it is present in most of the existing web applications. CSRF attack occurs when a malicious web site causes a user’s web browser to perform an unwanted action on a trusted site. It is listed in OWASP’s top ten Web Application attacks list. In this survey paper we will study CSRF attack, CSRF vulnerabilities and its defensive measures. We have compared various defense mechanisms to analyse the best defense mechanism. This study will help us to build strong and robust CSRF protection mechanism.

  2. Nicotine's defensive function in nature.

    Directory of Open Access Journals (Sweden)

    Anke Steppuhn

    2004-08-01

    Full Text Available Plants produce metabolites that directly decrease herbivore performance, and as a consequence, herbivores are selected for resistance to these metabolites. To determine whether these metabolites actually function as defenses requires measuring the performance of plants that are altered only in the production of a certain metabolite. To date, the defensive value of most plant resistance traits has not been demonstrated in nature. We transformed native tobacco(Nicotiana attenuata with a consensus fragment of its two putrescine N-methyl transferase (pmt genes in either antisense or inverted-repeat (IRpmt orientations. Only the latter reduced (by greater than 95% constitutive and inducible nicotine. With D(4-nicotinic acid (NA, we demonstrate that silencing pmt inhibits nicotine production, while the excess NA dimerizes to form anatabine. Larvae of the nicotine-adapted herbivore Manduca sexta (tobacco hornworm grew faster and, like the beetle Diabrotica undecimpunctata, preferred IRpmt plants in choice tests. When planted in their native habitat, IRpmt plants were attacked more frequently and, compared to wild-type plants, lost 3-fold more leaf area from a variety of native herbivores, of which the beet armyworm, Spodoptera exigua, and Trimerotropis spp. grasshoppers caused the most damage. These results provide strong evidence that nicotine functions as an efficient defense in nature and highlights the value of transgenic techniques for ecological research.

  3. Priming of antiherbivore defensive responses in plants

    Institute of Scientific and Technical Information of China (English)

    Jinwon Kim; Gary W.Felton

    2013-01-01

    Defense priming is defined as increased readiness of defense induction.A growing body of literature indicates that plants (or intact parts of a plant) are primed in anticipation of impending environmental stresses,both biotic and abiotic,and upon the following stimulus,induce defenses more quickly and strongly.For instance,some plants previously exposed to herbivore-inducible plant volatiles (HIPVs) from neighboring plants under herbivore attack show faster or stronger defense activation and enhanced insect resistance when challenged with secondary insect feeding.Research on priming of antiherbivore defense has been limited to the HIPV-mediated mechanism until recently,but significant advances were made in the past three years,including non-HIPV-mediated defense priming,epigenetic modifications as the molecular mechanism of priming,and others.It is timely to consider the advances in research on defense priming in the plantinsect interactions.

  4. Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction.

    Science.gov (United States)

    Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de Los Santos, Berta; Arroyo, Francisco T; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L

    2016-01-01

    Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen.

  5. Partial activation of SA- and JA-defensive pathways in strawberry upon Colletotrichum acutatum interaction

    Directory of Open Access Journals (Sweden)

    FRANCISCO AMIL-RUIZ

    2016-07-01

    Full Text Available Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5 and FaPR10 were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen.

  6. Partial Activation of SA- and JA-Defensive Pathways in Strawberry upon Colletotrichum acutatum Interaction

    Science.gov (United States)

    Amil-Ruiz, Francisco; Garrido-Gala, José; Gadea, José; Blanco-Portales, Rosario; Muñoz-Mérida, Antonio; Trelles, Oswaldo; de los Santos, Berta; Arroyo, Francisco T.; Aguado-Puig, Ana; Romero, Fernando; Mercado, José-Ángel; Pliego-Alfaro, Fernando; Muñoz-Blanco, Juan; Caballero, José L.

    2016-01-01

    Understanding the nature of pathogen host interaction may help improve strawberry (Fragaria × ananassa) cultivars. Plant resistance to pathogenic agents usually operates through a complex network of defense mechanisms mediated by a diverse array of signaling molecules. In strawberry, resistance to a variety of pathogens has been reported to be mostly polygenic and quantitatively inherited, making it difficult to associate molecular markers with disease resistance genes. Colletotrichum acutatum spp. is a major strawberry pathogen, and completely resistant cultivars have not been reported. Moreover, strawberry defense network components and mechanisms remain largely unknown and poorly understood. Assessment of the strawberry response to C. acutatum included a global transcript analysis, and acidic hormones SA and JA measurements were analyzed after challenge with the pathogen. Induction of transcripts corresponding to the SA and JA signaling pathways and key genes controlling major steps within these defense pathways was detected. Accordingly, SA and JA accumulated in strawberry after infection. Contrastingly, induction of several important SA, JA, and oxidative stress-responsive defense genes, including FaPR1-1, FaLOX2, FaJAR1, FaPDF1, and FaGST1, was not detected, which suggests that specific branches in these defense pathways (those leading to FaPR1-2, FaPR2-1, FaPR2-2, FaAOS, FaPR5, and FaPR10) were activated. Our results reveal that specific aspects in SA and JA dependent signaling pathways are activated in strawberry upon interaction with C. acutatum. Certain described defense-associated transcripts related to these two known signaling pathways do not increase in abundance following infection. This finding suggests new insight into a specific putative molecular strategy for defense against this pathogen. PMID:27471515

  7. Reproduction and love: strategies of the organism's cellular defense system?

    Science.gov (United States)

    De Loof, A; Huybrechts, R; Kotanen, S

    1998-08-01

    A novel view is presented which states that primordial germ cells and their descendants can be regarded as 'cancerous cells' which emit signals that activate a whole array of cellular defensive mechanisms by the somatoplasm. These cells have become unrestrained in response to the lack of typical cell adhesion properties of epithelial cells. From this point of view: (1) the encapsulation of oocytes by follicle cells, vitelline membrane and egg shell; (2) the suppression of gonadal development in larval life; (3) the production of sex steroid hormones and of vitellogenin; and (4) the expulsion of the gametes from the body fit into a general framework for a defense strategy of the somatoplasm against germ line cells. Accordingly, the origin of sexual reproduction appears to be a story of failure and intercellular hostility rather than a 'romantic' and altruistic event. Yet, it has resulted in evolutionary success for the system in which it has evolved; probably through realizing feelings of 'pleasure' associated with reproduction.

  8. Prostate Tumor Growth Can Be Modulated by Dietarily Targeting the 15-Lipoxygenase-1 and Cyclooxygenase-2 Enzymes

    Directory of Open Access Journals (Sweden)

    Uddhav P. Kelavkar

    2009-07-01

    Full Text Available The main objectives of our study were to determine the bioavailability of omega-3 (ω-3 to the tumor, to understand its mechanisms, and to determine the feasibility of targeting the ω-6 polyunsaturated fatty acids (PUFAs metabolizing 15-lipoxygenase-1 (15-LO-1 and cyclooxygenase-2 (COX-2 pathways. Nude mice injected subcutaneously with LAPC-4 prostate cancer cells were randomly divided into three different isocaloric (and same percent [%] of total fat diet groups: high ω-6 linoleic acid (LA, high ω-3 stearidonic acid (SDA PUFAs, and normal (control diets. Tumor growth and apoptosis were examined as end points after administration of short-term (5 weeks ω-3 and ω-6 fatty acid diets. Tumor tissue membranes were examined for growth, lipids, enzyme activities, apoptosis, and proliferation. Tumors from the LA diet-fed mice exhibited the most rapid growth compared with tumors from the control and SDA diet-fed mice. Moreover, a diet switch from LA to SDA caused a dramatic decrease in the growth of tumors in 5 weeks, whereas tumors grew more aggressively when mice were switched from an SDA to an LA diet. Evaluating tumor proliferation (Ki-67 and apoptosis (caspase-3 in mice fed the LA and SDA diets suggested increased percentage proliferation index from the ω-6 diet-fed mice compared with the tumors from the ω-3 SDA-fed mice. Further, increased apoptosis was observed in tumors from ω-3 SDA diet-fed mice versus tumors from ω-6 diet-fed mice. Levels of membrane phospholipids of red blood cells reflected dietary changes and correlated with the levels observed in tumors. Linoleic or arachidonic acid and metabolites (eicosanoid/prostaglandins were analyzed for 15-LO-1 and COX-2 activities by high-performance liquid chromatography. We also examined the percent unsaturated or saturated fatty acids in the total phospholipids, PUFA ω-6/ω-3 ratios, and other major enzymes (elongase, Delta [Δ]-5-desaturase, and Δ-6-desaturase of ω-6 catabolic

  9. Activation of Defense Mechanisms against Pathogens in Mosses and Flowering Plants.

    Science.gov (United States)

    Ponce de León, Inés; Montesano, Marcos

    2013-02-04

    During evolution, plants have developed mechanisms to cope with and adapt to different types of stress, including microbial infection. Once the stress is sensed, signaling pathways are activated, leading to the induced expression of genes with different roles in defense. Mosses (Bryophytes) are non-vascular plants that diverged from flowering plants more than 450 million years ago, allowing comparative studies of the evolution of defense-related genes and defensive metabolites produced after microbial infection. The ancestral position among land plants, the sequenced genome and the feasibility of generating targeted knock-out mutants by homologous recombination has made the moss Physcomitrella patens an attractive model to perform functional studies of plant genes involved in stress responses. This paper reviews the current knowledge of inducible defense mechanisms in P. patens and compares them to those activated in flowering plants after pathogen assault, including the reinforcement of the cell wall, ROS production, programmed cell death, activation of defense genes and synthesis of secondary metabolites and defense hormones. The knowledge generated in P. patens together with comparative studies in flowering plants will help to identify key components in plant defense responses and to design novel strategies to enhance resistance to biotic stress.

  10. The yin and yang of 15-lipoxygenase-1 and delta-desaturases: Dietary omega-6 linoleic acid metabolic pathway in prostate

    Directory of Open Access Journals (Sweden)

    Kelavkar Uddhav

    2006-03-01

    Full Text Available Abstract One of the major components in high-fat diets (Western diet is the omega (ω, n-6 polyunsaturated fatty acid (PUFA called linoleic acid (LA. Linoleic acid is the precursor for arachidonic acid (AA. These fatty acids are metabolized to an array of eicosanoids and prostaglandins depending upon the enzymes in the pathway. Aberrant expression of the catabolic enzymes such as cyclooxygenases (COX-1 and/or -2 or lipoxygenases (5-LO, 12-LO, 15-LO-1, and 15-LO-2 that convert PUFA either AA and/or LA to bioactive lipid metabolites appear to significantly contribute to the development of PCa. However, PUFA and its cellular interactions in PCa are poorly understood. We therefore examined the mRNA levels of key enzymes involved in the LA and AA pathways in 18 human donor (normal prostates compared to 60 prostate tumors using the Affymetrix U95Av2 chips. This comparative (normal donor versus prostate cancer study showed that: 1 the level of 15-LO-1 expression (the key enzyme in the LA pathway is low (P P P = 0.001, elongase (P = 0.16 and 15-lipoxygenase-2 (15-LO-2, P = 0.74 are higher in donor (normal prostates, and 2 Contrary to the observation in the normal tissues, significantly high levels of only 15-LO-1; whereas low levels of delta-6 desaturase, elongase, delta-5 desaturase and 15-LO-2 respectively, were observed in PCa tissues. Although the cyclooxygenase (COX-1 and COX-2 mRNA levels were high in PCa, no significant differences were observed when compared in donor tissues. Our study underscores the importance of promising dietary intervention agents such as the omega-3 fatty acids as substrate competitors of LA/AA, aimed primarily at high 15-LO-1 and COX-2 as the molecular targets in PCa initiation and/or progression.

  11. Bioassay-guided isolation, identification and molecular ligand-target insight of lipoxygenase inhibitors from leaves of Anisomeles malabarica R.Br.

    Directory of Open Access Journals (Sweden)

    A Sudha

    2014-01-01

    Full Text Available Background: Anisomeles malabarica R. Br. (Lamiaceae is extensively used in traditional medicine in major parts of India for several medicinal purposes, including their use in rheumatism. Materials and Methods: The air-dried leaves of A. malabarica were extracted with ethanol, defatted with n-hexane and then successively partitioned into chloroform and n-butanol fractions. Bioassay-guided fractionation and purification of chloroform fraction from A. malabarica lead to the isolation of lipoxygenase (LOX inhibitors. The structures of isolated compounds were elucidated by ultraviolet, infrared, 1 H nuclear magnetic resonance (NMR, 13 C NMR and mass spectrometry spectroscopic techniques and assessed further by in vitro soybean lipoxygenase (sLOX assay. In addition, the enzyme type inhibition was evaluated through molecular docking technique as a part of computational study. Results: The bioactive compounds 3, 4 dihydroxy benzoic acid (1 and 4′, 5, 7-trihydroxyflavone (2 were isolated from chloroform fraction of A. malabarica, whose bioactivity was observed to be dose-dependent compared to n-butanol fraction. Among the compounds, 3, 4 dihydroxy benzoic acid showed significant sLOX inhibitory activity with 74.04% ±2.6% followed by 4′, 5, 7-trihydroxyflavone (34.68% ±1.9%. The computational analysis of compounds showed their molecular interaction with important amino acid residues and nonheme iron atom in the catalytic site of LOX by enlightening their potential binding mode at molecular level. Conclusions: The LOX inhibitory constituents were identified from A. malabarica by means of bioassay-guided fractionation process. The results derived from in vitro and computational experiments confirm the potential of the isolated compounds and provide additional evidence for its traditional use in inflammatory disorders.

  12. Attenuation of cysteamine-induced duodenal ulcer with Cochinchina momordica seed extract through inhibiting cytoplasmic phospholipase A2/5-lipoxygenase and activating γ-glutamylcysteine synthetase.

    Science.gov (United States)

    Choi, Ki-Seok; Kim, Eun-Hee; Hong, Hua; Ock, Chan Young; Lee, Jeong Sang; Kim, Joo-Hyun; Hahm, Ki-Baik

    2012-04-01

    Cysteamine is a reducing aminothiol used for inducing duodenal ulcer through mechanisms of oxidative stress related to thiol-derived H(2)O(2) reaction. Cochinchina momordica saponins have been suggested to be protective against various gastric diseases based on their cytoprotective and anti-inflammatory mechanisms. This study was aimed to document the preventive effects of Cochinchina momordica seed extract against cysteamine-induced duodenal ulcer as well as the elucidation of its pharmacological mechanisms. Cochinchina momordica seed extract (50, 100, 200 mg/kg) was administrated intragastrically before cysteamine administration, after which the incidence of the duodenal ulcer, ulcer size, serum gastrin level, and the ratio of reduced glutathione (GSH)/oxidized glutathione disulfide (GSSG) as well as biochemical and molecular measurements of cytoplasmic phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), 5-lipoxygenase and the expression of proinflammatory genes including IL-1β, IL-6, COX-2 were measured in rat model. Additional experiments of electron spin resonance measurement and the changes of glutathione were performed. Cochinchina momordica seed extract effectively prevented cysteamine-induced duodenal ulcer in a dose-dependent manner as reflected with significant decreases in either duodenal ulcerogenesis or perforation accompanied with significantly decreased in serum gastrin in addition to inflammatory mediators including cPLA(2), COX-2, and 5-lipoxygenase. Cochinchina momordica seed extract induced the expression of γ-glutamylcysteine synthetase (γ-GCS)-related glutathione synthesis as well as significantly reduced the expression of cPLA(2). Cochinchina momordica seed extract preserved reduced glutathione through increased expressions of γ-GCS. Cochinchina momordica seed extracts exerted significantly protective effect against cysteamine-induced duodenal ulcer by either cPLA2 inhibition or glutathione preservation. © 2012 Journal of

  13. Signal Words

    Science.gov (United States)

    SIGNAL WORDS TOPIC FACT SHEET NPIC fact sheets are designed to answer questions that are commonly asked by the ... making decisions about pesticide use. What are Signal Words? Signal words are found on pesticide product labels, ...

  14. Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

    Science.gov (United States)

    Rempt, Martin; Weinberger, Florian; Grosser, Katharina

    2012-01-01

    Summary Chemical defense of the invasive red alga Gracilaria vermiculophylla has been studied and compared to that of the noninvasive but related Gracilaria chilensis. Both species rely on a wound-activated chemical defense that makes them less attractive to the herbivorous sea snail Echinolittorina peruviana. The chemical stress response of both species was monitored by LC–ESIMS-based metabolic profiling and revealed commonalities and differences. Both algae rely on a rapid lipoxygenase mediated transformation of arachidonic acid to known and novel oxylipins. Common products are 7,8-dihydroxyeicosatetraenoic acid and a novel eicosanoid with an unusual γ-lactone moiety. Several prostaglandins were predominantly formed by the invasive species. The role of some of these metabolites was investigated by surveying the attachment of E. peruviana on artificial food containing the respective oxylipins. Both algae species are defended against this general herbivore by 7,8-dihydroxyeicosatetraenoic acid, whereas the prostaglandins and the novel oxylipins were inactive at naturally occurring concentrations. The role of different oxylipins in the invasive potential of Gracilaria spp. is discussed. PMID:22423296

  15. Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

    Directory of Open Access Journals (Sweden)

    Martin Rempt

    2012-02-01

    Full Text Available Chemical defense of the invasive red alga Gracilaria vermiculophylla has been studied and compared to that of the noninvasive but related Gracilaria chilensis. Both species rely on a wound-activated chemical defense that makes them less attractive to the herbivorous sea snail Echinolittorina peruviana. The chemical stress response of both species was monitored by LC–ESIMS-based metabolic profiling and revealed commonalities and differences. Both algae rely on a rapid lipoxygenase mediated transformation of arachidonic acid to known and novel oxylipins. Common products are 7,8-dihydroxyeicosatetraenoic acid and a novel eicosanoid with an unusual γ-lactone moiety. Several prostaglandins were predominantly formed by the invasive species. The role of some of these metabolites was investigated by surveying the attachment of E. peruviana on artificial food containing the respective oxylipins. Both algae species are defended against this general herbivore by 7,8-dihydroxyeicosatetraenoic acid, whereas the prostaglandins and the novel oxylipins were inactive at naturally occurring concentrations. The role of different oxylipins in the invasive potential of Gracilaria spp. is discussed.

  16. Cyber Defense: An International View

    Science.gov (United States)

    2015-09-01

    Protection), available from www.gesetze-im-internet.de/gg/art_65a. html, accessed on July 30, 2014. 36. Christian Kahl, Nachrichten, Vom Kampf in der...www.bundeswehr-journal.de/2013/vom- kampf -in-der-funften- dimension/, accessed on July 30, 2014; “Digitaler Truppenein- satz: Bundeswehr meldet sich...www.bundeswehr-journal. de/2013/vom- kampf -in-der-funften-dimension/. 46. “Spionage- und Hackerabwehr: Bundeswehr baut geheime Cy- berwar-Truppe auf” (“Defense of

  17. Territorial Defense, Education, and Interculturalism

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Sierra Pardo

    2011-10-01

    Full Text Available The article carries out a series of reflections regarding the social and economic conditions in which the cultivation of oil palm affected the Bajo Atrato region of the Department of Chocó at the end of the nineteen nineties. It also discusses the actions carried out by communities, companies, and organizations in solidarity with the region’s cause, since these expressions make it possible to understand the role of organization and education in territorial defense processes. Finally, the article examines the different tensions, struggles, challenges, and contradictions inherent to these types of processes.

  18. Cyber defense and situational awareness

    CERN Document Server

    Kott, Alexander; Erbacher, Robert F

    2015-01-01

    This book is the first publication to give a comprehensive, structured treatment to the important topic of situational awareness in cyber defense. It presents the subject in a logical, consistent, continuous discourse, covering key topics such as formation of cyber situational awareness, visualization and human factors, automated learning and inference, use of ontologies and metrics, predicting and assessing impact of cyber attacks, and achieving resilience of cyber and physical mission. Chapters include case studies, recent research results and practical insights described specifically for th

  19. Department of Defense Expenditure Plans

    Science.gov (United States)

    2009-03-20

    Buxton Rd. 1,879 E 88 Redstone Arsenal AL Replace Water Main Along Paton Rd. from H.U. to Martin Rd. 1,857 E 89 Redstone Arsenal AL Fy 2009 Annual Road... Buxton Road E. from Patton to H.U. 1,312 E 25 American Recovery and Reinvestment Act of 2009 Operation and Maintenance, Defense Health Program, and...Meet AR 190-11 75 O 1100 Billings AFRC MT Mechanical System Improvements 188 E 1101 Billings AFRC MT Install Lighting Controls 45 E 1102 Billings

  20. SQL Injection Attacks and Defense

    CERN Document Server

    Clarke, Justin

    2012-01-01

    SQL Injection Attacks and Defense, First Edition: Winner of the Best Book Bejtlich Read Award "SQL injection is probably the number one problem for any server-side application, and this book unequaled in its coverage." -Richard Bejtlich, Tao Security blog SQL injection represents one of the most dangerous and well-known, yet misunderstood, security vulnerabilities on the Internet, largely because there is no central repository of information available for penetration testers, IT security consultants and practitioners, and web/software developers to turn to for help. SQL Injection Att

  1. Secure and defensive high self-esteem.

    Science.gov (United States)

    Jordan, Christian H; Spencer, Steven J; Zanna, Mark P; Hoshino-Browne, Etsuko; Correll, Joshua

    2003-11-01

    Long-standing theories have suggested high self-esteem (SE) can assume qualitatively different forms that are related to defensiveness. The authors explored whether some high-SE individuals are particularly defensive because they harbor negative self-feelings at less conscious levels, indicated by low implicit SE. In Study 1, participants high in explicit SE but low in implicit SE showed the highest levels of narcissism--an indicator of defensiveness. In Studies 2 and 3, the correspondence between implicit and explicit SE predicted defensive behavior (in-group bias in Study 2 and dissonance reduction in Study 3), such that for high explicit-SE participants, those with relatively low implicit SE behaved more defensively. These results are consistent with the idea that high SE can be relatively secure or defensive.

  2. The methodological defense of realism scrutinized.

    Science.gov (United States)

    Wray, K Brad

    2015-12-01

    I revisit an older defense of scientific realism, the methodological defense, a defense developed by both Popper and Feyerabend. The methodological defense of realism concerns the attitude of scientists, not philosophers of science. The methodological defense is as follows: a commitment to realism leads scientists to pursue the truth, which in turn is apt to put them in a better position to get at the truth. In contrast, anti-realists lack the tenacity required to develop a theory to its fullest. As a consequence, they are less likely to get at the truth. My aim is to show that the methodological defense is flawed. I argue that a commitment to realism does not always benefit science, and that there is reason to believe that a research community with both realists and anti-realists in it may be better suited to advancing science. A case study of the Copernican Revolution in astronomy supports this claim.

  3. Korean Defense Industry: Threat or Ally?

    Science.gov (United States)

    1994-02-22

    framework for defense industrial cooperation with Korea . While Senator Dixon eventually dropped his opposition and the Korean Fighter Program is now...US defense firms to transfer technology to Korean firms, the US Government must recognize two realities: first, Korea will develop indigenous...serious Korean competition in the foreseeable future. 8 It does not appear that the Korea defense industry is poised to take away significant market

  4. Implementing an Integrated Network Defense Construct

    Science.gov (United States)

    2013-06-01

    to create an easily defendable avenue for ingress and egress. In medieval times, castles leveraged this principle. If an attacker was brazen enough...defense mirrors that of the physical world, its application has some significant drawbacks. Whereas the medieval castle defenders had the high ground...defenses. Logically an INDS can and should follow the same premise. 3. Integrated Air Defense To model an INDS after an IADS, it is necessary

  5. THE DEFENSE PLANNING SYSTEMS AND THEIR IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Laszlo STICZ

    2010-01-01

    Full Text Available Defense planning in the Alliance is a fundamental element of the arrangements which enable its member countries to enjoy the crucial political, military and resource advantages of collective defense and other common military efforts to enhance security and stability. In this respect, the aim of this paper is to outline the role of the Armed Forces and the specific processes aiming to achieve the ultimate goal of a nation regarding national security, with focus on defense planning and the PDPS.

  6. Integrated Air and Missile Defense (IAMD)

    Science.gov (United States)

    2013-12-01

    Base Year DAMIR - Defense Acquisition Management Information Retrieval Dev Est - Development Estimate DoD - Department of Defense DSN - Defense...Schedule Milestones SAR Baseline Dev Est Current APB Development Objective/Threshold Current Estimate MS B DEC 2009 DEC 2009 JUN...2010 DEC 2009 CDR AUG 2011 MAY 2012 MAY 2013 MAY 2012 MS C DEC 2014 JUN 2015 JUN 2016 AUG 2016 1 (Ch-1) IOT &E Start JAN 2016 MAR 2016 MAR 2017 OCT 2017

  7. Offset implementations for Turkey's International Defense Acquisitions

    OpenAIRE

    2008-01-01

    MBA Professional Report "Offsets" is the umbrella term for a broad range of industrial and commercial "compensatory" practices. Specifically, offset agreements in the defense environment are increasing globally as a percentage of exports. Developed countries with established defense industries use offsets to channel work or technology to their domestic defense companies. Countries with newly industrialized economies are utilizing both military and commercial related offsets that involv...

  8. SELF-DEFENSE IN KARABAKH CONFLICT?

    Directory of Open Access Journals (Sweden)

    Saeed Bagheri

    2015-01-01

    Full Text Available Use of force is one of the principles of international law which has been banned by the UN Charter and modern constitutions. However, since the enforcement of the UN Charter, self-defense has become the preferred excuse for states to justify their use of force. But applying self-defense requires some conditions. Immediacy is one of the important conditions of self-defense. Immediacy defined as the time span between armed attacks and reaction to it, is the main discourse. This condition requires self defense immediately after the armed conflict or during a rational time span since its occurance.In this respect, the emerging Karabakh Conflict between Armenia and Azerbaijan in the 1990s is important. After Armenia’s armed attacks, Azerbaijan has acted within the scope of legitimate self-defense. But in accordance with UN Security Council cease-fire resolution Azerbaijan has suspended its self-defense actions. However, today, still twenty percent of Azerbaijani territory is still under Armenian occupation. Accordingly, after a long time the validity of Azerbaijan’s right to legitimate self-defense is still subject to arguments.In this article, by comparing two different approaches (strict and board interpretation approaches on the temporal link between the measures of self-defense and the armed attacks (immediacy, the temporal link between the self-defense countermeasures of Azerbaijan and armed attacks by Armenia in Karabakh Conflict will be examined.

  9. An Empirical Investigation of Defense Interpretation Depth, Defensive Functioning, and Alliance Strength in Psychodynamic Psychotherapy.

    Science.gov (United States)

    Petraglia, Jonathan; Bhatia, Maneet; De Roten, Yves; Despland, Jean-Nicolas; Drapeau, Martin

    2015-01-01

    The present study examined the relationship between depth of defense interpretations by therapists, and patient defensive functioning, on the therapeutic alliance in a sample of 36 patients undergoing short-term dynamic psychotherapy. Defense interpretation depth was defined as the degree to which therapist interpretations contained information regarding the motivation for patient defenses and historical origins of the defensive processes (Greensen, 1967). Mean depth of interpretation was compared between sessions that were identified beforehand as either high-alliance or low-alliance sessions using the Helping Alliance Questionnaire (HAq-II: Luborsky et al., 1996). Results indicated that defensive functioning was correlated to defense interpretation depth in low-alliance sessions. Moreover, mean depth of interpretation was also higher in low-alliance sessions, pointing to the possible "destabilizing" effects that these interpretations may have on both defensive functioning and the therapeutic alliance. These results are discussed within the context of previous studies of therapeutic technique in dynamic psychotherapy.

  10. Defense mutualisms enhance plant diversification.

    Science.gov (United States)

    Weber, Marjorie G; Agrawal, Anurag A

    2014-11-18

    The ability of plants to form mutualistic relationships with animal defenders has long been suspected to influence their evolutionary success, both by decreasing extinction risk and by increasing opportunity for speciation through an expanded realized niche. Nonetheless, the hypothesis that defense mutualisms consistently enhance plant diversification across lineages has not been well tested due to a lack of phenotypic and phylogenetic information. Using a global analysis, we show that the >100 vascular plant families in which species have evolved extrafloral nectaries (EFNs), sugar-secreting organs that recruit arthropod mutualists, have twofold higher diversification rates than families that lack species with EFNs. Zooming in on six distantly related plant clades, trait-dependent diversification models confirmed the tendency for lineages with EFNs to display increased rates of diversification. These results were consistent across methodological approaches. Inference using reversible-jump Markov chain Monte Carlo (MCMC) to model the placement and number of rate shifts revealed that high net diversification rates in EFN clades were driven by an increased number of positive rate shifts following EFN evolution compared with sister clades, suggesting that EFNs may be indirect facilitators of diversification. Our replicated analysis indicates that defense mutualisms put lineages on a path toward increased diversification rates within and between clades, and is concordant with the hypothesis that mutualistic interactions with animals can have an impact on deep macroevolutionary patterns and enhance plant diversity.

  11. The insanity defense: Related issues

    Science.gov (United States)

    Asokan, T. V.

    2016-01-01

    For the past 150 years, there is no change in the understanding and knowledge other than autonomy and capacity to choose the right and wrong for criminal liability. The alternative concept that human behavior is the result of an interaction between biological and environmental factors other than free choice failed to impress the criminal justice system because of a direct threat to a society's deep seated need to blame someone than themselves for criminal harms that occur. The insanity defense has a long history, and is evolved after many tests that have been tried and tested. McNaughton's rules stressed on “understandability of right and wrong” and “intellectual” rather than a moral or affective definition dominated in its formulation. Lack of control and irresistible drives or impulses were neglected Going by the current understanding of neurological evidences of compulsion and lack of impulse control, rationality tests without the inclusion of lack of control, seem to be outdated. Separate “Control determination” than the “Rationality determination” by the jurors may improve the accuracy of Juror's categorizations. There is a suggestion that Relevance ratio is ideal for ‘Evidentiary relevance” and there should be a quality control on expert testimonies. With progress in neuroscience, the law may need to abandon or alter some of its current assumptions about the nature of voluntary conduct, which underlies various defenses PMID:28216769

  12. Defensive anality and anal narcissism.

    Science.gov (United States)

    Shengold, L

    1985-01-01

    This paper aims at demonstrating a currently beleaguered assumption: the central importance, the continuing vitality, and the appropriate complexity of Freud's theory of the drives and of his idea of the primacy of the body ego. It is not enough to consider man a thinking machine or a social being; his animal nature must be given a central place in psychology. The paper postulates that 'anal or sphincter defensiveness' is one of the precursors of the repression barrier. Anality has been comparatively neglected in recent psychoanalytic literature, and so has its explorer, Karl Abraham. The paper's thesis is that there is a special defensive importance to anal erogeneity and libido, and to those aspects of ego and superego that are functionally operative (as the 'sadistic-anal organization' (Freud, 1917)) during the so-called 'sadistic-anal' developmental phase. Any of the psychic danger situations can evoke regression to manifestations of 'anal narcissim'--an attempt to master overwhelming feeling by a kind of emotional sphincter action, narrowing down the world to the controllable and the predictable. The basic assumption here is Fliess's idea that the attainment of anal sphincter control functions--with, as-it-were, 'psychic resonance'--as a means to master primal (murderous, cannibalistic) affect. For optimal psychic development, a proper balance must be attained between anal control of, and anal expression of, instinctual derivatives--especially of affect laden with aggression.

  13. Nrf2 and cardiovascular defense.

    Science.gov (United States)

    Howden, Reuben

    2013-01-01

    The cardiovascular system is susceptible to a group of diseases that are responsible for a larger proportion of morbidity and mortality than any other disease. Many cardiovascular diseases are associated with a failure of defenses against oxidative stress-induced cellular damage and/or death, leading to organ dysfunction. The pleiotropic transcription factor, nuclear factor-erythroid (NF-E) 2-related factor 2 (Nrf2), regulates the expression of antioxidant enzymes and proteins through the antioxidant response element. Nrf2 is an important component in antioxidant defenses in cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. Nrf2 is also involved in protection against oxidant stress during the processes of ischemia-reperfusion injury and aging. However, evidence suggests that Nrf2 activity does not always lead to a positive outcome and may accelerate the pathogenesis of some cardiovascular diseases (e.g., atherosclerosis). The precise conditions under which Nrf2 acts to attenuate or stimulate cardiovascular disease processes are unclear. Further studies on the cellular environments related to cardiovascular diseases that influence Nrf2 pathways are required before Nrf2 can be considered a therapeutic target for the treatment of cardiovascular diseases.

  14. Nrf2 and Cardiovascular Defense

    Directory of Open Access Journals (Sweden)

    Reuben Howden

    2013-01-01

    Full Text Available The cardiovascular system is susceptible to a group of diseases that are responsible for a larger proportion of morbidity and mortality than any other disease. Many cardiovascular diseases are associated with a failure of defenses against oxidative stress-induced cellular damage and/or death, leading to organ dysfunction. The pleiotropic transcription factor, nuclear factor-erythroid (NF-E 2-related factor 2 (Nrf2, regulates the expression of antioxidant enzymes and proteins through the antioxidant response element. Nrf2 is an important component in antioxidant defenses in cardiovascular diseases such as atherosclerosis, hypertension, and heart failure. Nrf2 is also involved in protection against oxidant stress during the processes of ischemia-reperfusion injury and aging. However, evidence suggests that Nrf2 activity does not always lead to a positive outcome and may accelerate the pathogenesis of some cardiovascular diseases (e.g., atherosclerosis. The precise conditions under which Nrf2 acts to attenuate or stimulate cardiovascular disease processes are unclear. Further studies on the cellular environments related to cardiovascular diseases that influence Nrf2 pathways are required before Nrf2 can be considered a therapeutic target for the treatment of cardiovascular diseases.

  15. Defense Science Board Task Force on Defense Strategies for Advanced Ballistic and Cruise Missile Threats

    Science.gov (United States)

    2017-01-01

    REPORT OF THE DEFENSE SCIENCE BOARD TASK FORCE ON Defense Strategies for Advanced Ballistic and Cruise Missile Threats January 2017 Office of... Science Board (DSB). The DSB is a Federal Advisory Committee established to provide independent advice to the Secretary of Defense. Statements, opinions... Science Board Task Force on Defense Strategies for Advanced Ballistic and Cruise Missile Threats completed its information-gathering in February 2016

  16. Strategic Defense Initiative: Splendid Defense or Pipe Dream? Headline Series No. 275.

    Science.gov (United States)

    Armstrong, Scott; Grier, Peter

    This pamphlet presents a discussion of the various components of President Reagan's Strategic Defense Initiative (SDI) including the problem of pulling together various new technologies into an effective defensive system and the politics of the so-called "star wars" system. An important part of the defense initiative is the "layered" defense…

  17. 75 FR 65462 - Renewal of Department of Defense Federal Advisory Committee; Department of Defense Military...

    Science.gov (United States)

    2010-10-25

    ... Military Family Readiness Council AGENCY: Department of Defense (DoD). ACTION: Renewal of Federal advisory... Department of Defense Military Family Readiness Council (hereafter referred to as the ``Council''). FOR... military family readiness by the Department of Defense; and (c) evaluate and assess the effectiveness...

  18. 75 FR 3210 - Renewal of Department of Defense Federal Advisory Committee; Defense Business Board

    Science.gov (United States)

    2010-01-20

    ... sector corporations or entities and a wealth of top-level, global business experience in the areas of... of the Secretary Renewal of Department of Defense Federal Advisory Committee; Defense Business Board... gives notice that it is renewing the charter for the Defense Business Board (hereafter referred to...

  19. 75 FR 15695 - Renewal of Department of Defense Federal Advisory Committee; Board of Visitors National Defense...

    Science.gov (United States)

    2010-03-30

    ... Defense gives notice that it is renewing the charter for the Board of Visitors National Defense University (hereafter referred to as the Board). FOR FURTHER INFORMATION CONTACT: Jim Freeman, Deputy Committee... of the Secretary Renewal of Department of Defense Federal Advisory Committee; Board of...

  20. 75 FR 13093 - Renewal of Department of Defense Federal Advisory Committee; Defense Acquisition University Board...

    Science.gov (United States)

    2010-03-18

    ... University Board of Visitors AGENCY: Department of Defense (DoD). ACTION: Renewal of Federal advisory... amended), and 41 CFR 102-3.50(c), the Department of Defense gives notice that it is renewing the charter for the Defense Acquisition University Board of Visitors (hereafter referred to as the Board)....