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A study of 5-lipoxygenase inhibitors invoking DFT-based descriptor nucleophilicity index. MONATSHEFTE FUR CHEMIE 2022. [DOI: 10.1007/s00706-022-02953-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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2
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A lasting symbiosis: how Vibrio fischeri finds a squid partner and persists within its natural host. Nat Rev Microbiol 2021; 19:654-665. [PMID: 34089008 DOI: 10.1038/s41579-021-00557-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2021] [Indexed: 01/10/2023]
Abstract
As our understanding of the human microbiome progresses, so does the need for natural experimental animal models that promote a mechanistic understanding of beneficial microorganism-host interactions. Years of research into the exclusive symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium Vibrio fischeri have permitted a detailed understanding of those bacterial genes underlying signal exchange and rhythmic activities that result in a persistent, beneficial association, as well as glimpses into the evolution of symbiotic competence. Migrating from the ambient seawater to regions deep inside the light-emitting organ of the squid, V. fischeri experiences, recognizes and adjusts to the changing environmental conditions. Here, we review key advances over the past 15 years that are deepening our understanding of these events.
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Toda K, Tsukayama I, Nagasaki Y, Konoike Y, Tamenobu A, Ganeko N, Ito H, Kawakami Y, Takahashi Y, Miki Y, Yamamoto K, Murakami M, Suzuki-Yamamoto T. Red-kerneled rice proanthocyanidin inhibits arachidonate 5-lipoxygenase and decreases psoriasis-like skin inflammation. Arch Biochem Biophys 2020; 689:108307. [PMID: 32112739 DOI: 10.1016/j.abb.2020.108307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 12/13/2022]
Abstract
5-lipoxygenase is a key enzyme in the synthesis of leukotrienes from arachidonic acid. The produced leukotrienes are involved in inflammatory diseases including psoriasis, asthma, and atherosclerosis. A suitable 5-lipoxygenase inhibitor might be useful for preventing and improving the symptoms of leukotriene-related inflammatory diseases. Here, we investigate the mechanism underlying the anti-inflammatory effect of a proanthocyanidin found in red-kerneled rice. Red-kerneled rice proanthocyanidin exhibited potent mixed noncompetitive inhibition of human and rat 5-lipoxygenases, with an IC50 values of 15.1 μM against human enzyme, and 7.0 μM against rat enzyme, respectively. This compound decreased leukotriene B4 production in rat basophilic leukemia-2H3 cells. In imiquimod-induced psoriasis-like mouse skin, topical application of the proanthocyanidin suppressed hyperplasia, decreased inflammatory cell infiltration, and down-regulated expression of the psoriasis-associated genes Il17a, Il22, S100a9, and Krt1. Lipid metabolome analysis by electrospray ionization mass spectrometry showed that red-kerneled rice proanthocyanidin treatment of psoriasis-like mouse skin dose-dependently decreased the production of leukotriene B4 but no other arachidonate metabolites. Red-kerneled rice proanthocyanidin inhibits 5-lipoxygenase, resulting in a decrease in leukotriene B4 production and psoriasis-like mouse skin inflammation. These results suggest that this proanthocyanidin may be therapeutically effective for treating leukotriene-related diseases.
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Affiliation(s)
- Keisuke Toda
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Izumi Tsukayama
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Yuki Nagasaki
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Yuka Konoike
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan; Department of Nutrition and Life Science, Fukuyama University, Sanzo, Gakuen-cho 1, Fukuyama, Hiroshima, 729-0292, Japan
| | - Asako Tamenobu
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Natsuki Ganeko
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Hideyuki Ito
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Yuki Kawakami
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Yoshitaka Takahashi
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan
| | - Yoshimi Miki
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Kei Yamamoto
- Graduate School of Technology, Industrial and Social Science, Tokushima University, 2-1, Minami-jyosanjima-cho, Tokushima, 770-8513, Japan
| | - Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Toshiko Suzuki-Yamamoto
- Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan.
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Shameera Ahamed T, Rajan VK, Muraleedharan K. QSAR modeling of benzoquinone derivatives as 5-lipoxygenase inhibitors. FOOD SCIENCE AND HUMAN WELLNESS 2019. [DOI: 10.1016/j.fshw.2019.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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5
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A ligand-based comparative molecular field analysis (CoMFA) and homology model based molecular docking studies on 3′, 4′-dihydroxyflavones as rat 5-lipoxygenase inhibitors: Design of new inhibitors. Comput Biol Chem 2017; 71:188-200. [DOI: 10.1016/j.compbiolchem.2017.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/08/2017] [Accepted: 08/16/2017] [Indexed: 12/17/2022]
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6
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Active site characterization and structure based 3D-QSAR studies on non-redox type 5-lipoxygenase inhibitors. Eur J Pharm Sci 2016; 88:26-36. [DOI: 10.1016/j.ejps.2016.03.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 02/11/2016] [Accepted: 03/12/2016] [Indexed: 12/15/2022]
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Smyrniotis CJ, Barbour SR, Xia Z, Hixon MS, Holman TR. ATP allosterically activates the human 5-lipoxygenase molecular mechanism of arachidonic acid and 5(S)-hydroperoxy-6(E),8(Z),11(Z),14(Z)-eicosatetraenoic acid. Biochemistry 2014; 53:4407-19. [PMID: 24893149 PMCID: PMC4215895 DOI: 10.1021/bi401621d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
5-Lipoxygenase
(5-LOX) reacts with arachidonic acid (AA) to first
generate 5(S)-hydroperoxy-6(E),8(Z),11(Z),14(Z)-eicosatetraenoic
acid [5(S)-HpETE] and then an epoxide from 5(S)-HpETE to form leukotriene A4, from a single
polyunsaturated fatty acid. This work investigates the kinetic mechanism
of these two processes and the role of ATP in their activation. Specifically,
it was determined that epoxidation of 5(S)-HpETE
(dehydration of the hydroperoxide) has a rate of substrate capture
(Vmax/Km)
significantly lower than that of AA hydroperoxidation (oxidation of
AA to form the hydroperoxide); however, hyperbolic kinetic parameters
for ATP activation indicate a similar activation for AA and 5(S)-HpETE. Solvent isotope effect results for both hydroperoxidation
and epoxidation indicate that a specific step in its molecular mechanism
is changed, possibly because of a lowering of the dependence of the
rate-limiting step on hydrogen atom abstraction and an increase in
the dependency on hydrogen bond rearrangement. Therefore, changes
in ATP concentration in the cell could affect the production of 5-LOX
products, such as leukotrienes and lipoxins, and thus have wide implications
for the regulation of cellular inflammation.
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Affiliation(s)
- Christopher J Smyrniotis
- Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States
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Abstract
This review describes the design and current development of leukotriene biosynthesis inhibitors as potential antiinflammatory agents. Knowledge of the enzymatic mechanism of 5-lipoxygenase led to specific inhibitors of this enzyme which catalyzes a key step in the leukotriene pathway. Competitive inhibitors include iron chelators, redox agents and alternate substrates. Further, the potential of product inhibitors and mechanism based inactivators of 5-lipoxygenase is discussed.
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Affiliation(s)
- J R Cashman
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, California, 94143
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9
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Ivanov I, Heydeck D, Hofheinz K, Roffeis J, O'Donnell VB, Kuhn H, Walther M. Molecular enzymology of lipoxygenases. Arch Biochem Biophys 2010; 503:161-74. [PMID: 20801095 DOI: 10.1016/j.abb.2010.08.016] [Citation(s) in RCA: 404] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 08/19/2010] [Accepted: 08/20/2010] [Indexed: 10/19/2022]
Abstract
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.
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Affiliation(s)
- Igor Ivanov
- Institute of Biochemistry, University Medicine Berlin - Charité, Germany
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10
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Bedetti C, Cantafora A. Extraction and purification of arachidonic acid metabolites from cell cultures. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2005; 35:47-81. [PMID: 3113186 DOI: 10.1007/bfb0004426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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11
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Venkatachalam TK, Qazi S, Samuel P, Uckun FM. Substituted heterocyclic thiourea compounds as a new class of anti-allergic agents inhibiting IgE/Fc epsilon RI receptor mediated mast cell leukotriene release. Bioorg Med Chem 2003; 11:1095-105. [PMID: 12614897 DOI: 10.1016/s0968-0896(02)00531-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mast cell derived leukotrienes (LT's) play a vital role in pathophysiology of allergy and asthma. We synthesized various analogues of indolyl, naphthyl and phenylethyl substituted halopyridyl, thiazolyl and benzothiazolyl thioureas and examined their in vitro effects on the high affinity IgE receptor/Fc epsilon RI-mediated mast cell leukotriene release. Of the 22 naphthylethyl thiourea compounds tested, there were 7 active compounds and N-[1-(1-naphthyl)ethyl]-N'-[2-(ethyl-4-acetylthiazolyl)]thiourea (17 and 16) (IC(50)=0.002 microM) and N-[1-(1R)-naphthylethyl]-N'-[2-(5-methylpyridyl)]thiourea (compound 5) (IC(50)=0.005 microM) were identified as the lead compounds. Among the 11 indolylethyl thiourea compounds tested, there were seven active compounds and the halopyridyl compounds N-[2-(3-indolylethyl)]-N'-[2-(5-chloropyridyl)]thiourea (24) and N-[2-(3-indolylethyl)]-N'-[2-(5-bromopyridyl)]thiourea (25) were the most active agents and inhibited the LTC(4) release with low micromolar IC(50) values of 4.9 and 6.1 microM, respectively. The hydroxylphenyl substituted compounds N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(5-chloropyridyl)]thiourea (37; IC(50)=12.6 microM), N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(5-bromopyridyl)]thiourea (50; IC(50)=16.8 microM) and N-[2-(4-hydroxyphenyl)ethyl]-N'-[2-(pyridyl)]thiourea (35; IC(50)=8.5 microM) were the most active pyridyl thiourea agents. Notably, the introduction of electron withdrawing or donating groups had a marked impact on the biological activity of these thiourea derivatives and the Hammett sigma values of their substituents were identified as predictors of their potency. In contrast, experimentally determined partition coefficient values did not correlate with the biological activity of the thiourea compounds which demonstrates that their liphophilicity is not an important factor controlling their mast cell inhibitory effects. These results establish the substituted halopyridyl, indolyl and naphthyl thiourea compounds as a new chemical class of anti-allergic agents inhibiting IgE receptor/Fc epsilon RI-mediated mast cell LTC(4) release. Further lead optimization efforts may provide the basis for new and effective treatment as well as prevention programs for allergic asthma in clinical settings.
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Affiliation(s)
- T K Venkatachalam
- Department of Chemistry, Parker Hughes Institute, 2699 Patton Road, Roseville, MN 55113, USA
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12
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Hashizume Y, Asakura T, Oikawa T, Yamauchi T, Soda K, Ohkawa K. Relationship between cytocidal activity and glutathione-S-transferase inhibition using doxorubicin coupled to stereoisomers of glutathione with different substrate specificity. Anticancer Drugs 2001; 12:549-54. [PMID: 11460002 DOI: 10.1097/00001813-200107000-00009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To determine the cytotoxic mode of action of a glutathione (GSH)--doxorubicin (DXR) conjugate, which exhibited potent cytotoxicity against various multidrug-resistant as well as DXR-sensitive cell lines, the molecular interaction between covalent GSH--DXR conjugates and glutathione-S-transferase (GST), a possible molecular target of the conjugates, was investigated. The following four GSH molecules with stereoisomeric forms were prepared: L-Glu--L-Cys--Gly (LL-GSH), D-Glu--L-Cys--Gly (DL-GSH), L-Glu--D-Cys--Gly (LD-GSH) and D-Glu--D-Cys--Gly (DD-GSH). The enzymic activity of GST against each GSH stereoisomer was 88, 38, 8 and 4 nmol/mg/min, respectively, suggesting that the L-form cysteine residue in the molecule was an important substrate of GST. Addition of DXR conjugated with each isomer (10 microM) to a GSH-containing GST assay mixture inhibited the GST activity to 32% for LL-GSH--XR, 16% for DL-GSH-DXR and 61% for LD-GSH-DXR as compared with the solvent control. Moreover, IC50 values for these conjugates were 30, 20 and 250 nM, respectively. The cytocidal activity of each conjugate corresponded to the substrate specificity of GST activity for the GSH isomer. These conjugates bound to the GST molecule, and the binding ability was 0.746, 0.627 and 0.462 mol/mol of GST for LL-GSH--XR, DL-GSH-DXR and LD-GSH--XR, respectively. These findings suggested that GSH--DXR interacted with the substrate-binding site of the GST molecule and inhibition of GST activity exhibited potent cytotoxicity.
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Affiliation(s)
- Y Hashizume
- Departments of Biochemistry I, Jikei University School of Medicine, Tokyo 105-8461, Japan
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López-Nicolás JM, Bru Martìnez R, García-Carmona F. Effect of calcium on the oxidation of linoleic acid by potato (Solanum tuberosum var. Desiree) tuber 5-lipoxygenase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:292-296. [PMID: 10691630 DOI: 10.1021/jf990293j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
When the effect of calcium on the oxidation of linoleic acid by potato tuber 5-lipoxygenase (LOX) was investigated, it was seen to promote the enzyme's activity at pH values higher than the optimum pH of 6.3, resulting in an enzyme activation at alkaline pH. Kinetic analysis of calcium activation at different pH values revealed that the cation abolished the inhibition by high substrate concentration, which occurs in the absence of Ca(2+), thus leading to activation at high substrate concentration. Studies were conducted to investigate the influence of Ca(2+) on the physicochemical nature of the substrate and its effect on the LOX activity expression. It was concluded that the aggregation mode rather than the aggregation state of linoleic acid is responsible for potato 5-LOX changes.
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Affiliation(s)
- J M López-Nicolás
- Area de Tecnología de los Alimentos, ETS Ingenieros Agrónomos, Campus de Cartagena, Universidad de Murcia, Murcia, Spain
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Noguchi M, Miyano M, Matsumoto T. Physiochemical characterization of ATP binding to human 5-lipoxygenase. Lipids 1996; 31:367-71. [PMID: 8743047 DOI: 10.1007/bf02522921] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Human 5-lipoxygenase requires ATP as a stimulatory factor. At the two preferred concentrations of the free Ca2+, 0.02 microM with a resting cell and 20 microM with a stimulated cell, Scatchard analysis revealed that 5-lipoxygenase has one affinity ATP binding site with a Kd of 4.6 microM at the low Ca2+ concentration but has two affinity ATP binding sites with a higher Kd of 4.4 microM and a lower Kd of 14.5 microM at the high Ca2+ concentration. In contrast, in a Tween 20 reaction system, 5-lipoxygenase had similar activation coefficients for ATP at both Ca2+ concentrations; these were 12.7 microM at the low Ca2+ concentration and 12.0 microM at the high Ca2+ concentration. These results showed that 5-lipoxygenase has an ATP binding site and suggest that self-association of 5-lipoxygenase in 20 microM Ca2+ may affect ATP binding affinity as measured by Scatchard analysis.
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Affiliation(s)
- M Noguchi
- Life Science Research Laboratory, Japan Tobacco Inc., Kanagawa, Japan
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15
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Asakura T, Matsuda M, Matsuda S, Shichi H. Synthesis of 12(R)- and 12(S)-hydroxyeicosatetraenoic acid by porcine ocular tissues. JOURNAL OF OCULAR PHARMACOLOGY 1994; 10:525-35. [PMID: 7836861 DOI: 10.1089/jop.1994.10.525] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Microsomal fractions from porcine ocular tissues synthesized 12(S)-5,8,10,14-hydroxyeicosatetraenoic acid [12(S)-HETE] from arachidonic acid by a membrane-bound lipoxygenase and 12(R)-HETE by the cytochrome P450-dependent monooxygenase system. Both activities were the highest in corneal microsomes. The 12(R)-HETE synthesizing activity of corneal microsomes was dependent on NADPH and inhibited by 0.1 mM SKF-525A, an inhibitor of P450 enzymes. The activity to form 12(R)-enantiomer was significantly enhanced by treatment of corneal epithelium with 3-methylcholanthrene or clofibrate. The induced activity was suppressed by cycloheximide, indicating that the induction of enzyme activities involved a translational process. The effect of these inducers on 12(R)-HETE synthesizing activity appeared to be additive. The activity to form 12(S)-enantiomer was markedly stimulated by 3 mM CaCl2. The 12-lipoxygenase of corneal microsomes was capable of oxygenating linoleic acid in addition to arachidonic acid, a characteristic of 12-lipoxygenases of the leukocyte type. 12(R)-HETE at 10(-6) M inhibited almost completely the Na,K-ATPase of corneal epithelium but had little or no effect on ciliary epithelial enzymic activity. 12(S)-HETE at 10(-6) M also inhibited corneal enzymic activity but to a lesser extent, and had no significant effect on ciliary epithelial Na,K-ATPase activity.
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Affiliation(s)
- T Asakura
- Department of Biochemistry, Jikei University School of Medicine, Tokyo, Japan
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Carty TJ, Marfat A, Moore PF, Falkner FC, Twomey TM, Weissman A. Ampiroxicam, an anti-inflammatory agent which is a prodrug of piroxicam. AGENTS AND ACTIONS 1993; 39:157-65. [PMID: 8304243 DOI: 10.1007/bf01998969] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ampiroxicam is a nonacidic ether carbonate prodrug of piroxicam. Our results demonstrate that, in contrast to piroxicam, ampiroxicam does not possess detectable prostaglandin synthesis inhibitory activity in vitro. Ampiroxicam, however, has similar in vivo potency to piroxicam in suppressing paw swelling in rat adjuvant arthritis. In an acute model of paw inflammation in rats, ampiroxicam is less potent than piroxicam itself: the ED50's of ampiroxicam are 9- and 3.5-fold higher than those of piroxicam following a single or multiple (5) daily oral doses, respectively. Using the phenylbenzoquinone stretching test as a method of evaluating acute analgetic activity, the ED50 for ampiroxicam is about 3-fold higher than that of piroxicam. These tests of activity share the property of being partially prostaglandin-dependent. Ampiroxicam itself is not observed in plasma after oral dosing to man, nor in the rat, dog, and monkey as reported here. Bioavailability studies show that conversion to piroxicam is about 100%, 90%, 70%, and 50% in these four species, respectively. These results indicate that ampiroxicam's anti-inflammatory activity is produced in vivo by conversion to piroxicam and support its credentials as an efficacious prodrug of piroxicam.
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Affiliation(s)
- T J Carty
- Department of Immunology and Infectious Disease, Pfizer Inc, Groton, CT 06340
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17
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Malaviya R, Malaviya R, Jakschik B. Reversible translocation of 5-lipoxygenase in mast cells upon IgE/antigen stimulation. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53486-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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18
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Yamamoto S. Mammalian lipoxygenases: molecular structures and functions. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1128:117-31. [PMID: 1420284 DOI: 10.1016/0005-2760(92)90297-9] [Citation(s) in RCA: 457] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- S Yamamoto
- Department of Biochemistry, Tokushima University School of Medicine, Japan
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19
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Natsui K, Ueda N, Yamamoto S, Komatsu N, Watanabe K. Arachidonate 5-lipoxygenase of porcine pancreas: its localization in acinar cells. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1085:241-7. [PMID: 1892894 DOI: 10.1016/0005-2760(91)90100-v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Arachidonate 5-lipoxygenase has been found so far in various types of leukocyte. When a homogenate of porcine pancreas was incubated with arachidonic acid, 5-hydroxy-6,8,11,14-eicosatetraenoic acid was predominantly produced concomitant with small amounts of compounds derived from leukotriene A4. After differential centrifugation of the homogenate, the 5-lipoxygenase activity was found predominantly in the 1000 x g pellet and 105,000 x g supernatant. When porcine pancreas was investigated immunohistochemically with anti-5-lipoxygenase antibody, Langerhans islets were unstained, and infiltration of 5-lipoxygenase-positive leukocytes was hardly observed. In contrast, acinar cells were positively stained. Immunoelectron microscopy demonstrated the localization of the enzyme along the nuclear membranes of the acinar cells.
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Affiliation(s)
- K Natsui
- Department of Biochemistry, Tokushima University School of Medicine, Japan
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20
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Salmon JA, Garland LG. Leukotriene antagonists and inhibitors of leukotriene biosynthesis as potential therapeutic agents. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 1991; 37:9-90. [PMID: 1763186 DOI: 10.1007/978-3-0348-7139-6_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- J A Salmon
- Wellcome Foundation, Beckenham, Kent, England
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Abstract
Lipoxygenase is a dioxygenase which incorporates one molecule of oxygen at a certain position of unsaturated fatty acids such as arachidonic and linolenic acids. The enzymatic oxygenation of unsaturated fatty acids is stereospecific concomitant with a stereoselective abstraction of hydrogen atom. Fatty acid cyclooxygenase is an atypical lipoxygenase incorporating two molecules of oxygen, and initiates the biosynthesis of prostaglandins and thromboxanes. Arachidonate 5-lipoxygenase is responsible for the leukotriene synthesis. No such bioactive compound has been found as a metabolite of the 12- and 15-lipoxygenase pathways, and their physiological roles are still unclarified. These enzymes have been purified, and their molecular and catalytic properties have been investigated. Their cDNA clones have been isolated, and their nucleotide sequences have been determined deducing the primary structures of the enzymes.
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Affiliation(s)
- S Yamamoto
- Department of Biochemistry, Tokushima University, School of Medicine, Japan
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22
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Goldschmidt PL, Vulliez-Le Normand B, Briquet I, Dray F. Effects of N-acetyl-aspartyl glutamic acid and sodium cromoglycate on leukotriene B4 secretion by human leukocytes. Allergy 1990; 45:363-9. [PMID: 2165751 DOI: 10.1111/j.1398-9995.1990.tb00512.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Peripheral leukocytes from allergic subjects were treated for 30 min with sodium cromoglycate (SCG) or with N-acetyl-aspartyl glutamic acid (NAAGA) and challenged for leukotriene B4 (LTB4) production with calcium ionophore A 23187. NAAGA significantly inhibits LTB4 release at concentrations of 10(-2) M (-86%), 5 x 10(-3) M (-49%) and 10(-3) M (-34%), while SCG was not able to block LTB4 production within the range of 10(-2)-10(-4) M. In spite of the fact that SCG and NAAGA are chemically unrelated and that both show antiallergic properties, only NAAGA is able in this model to block production of LTB4, a chemical mediator strongly involved in inflammatory and hypersensitivity reactions.
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Affiliation(s)
- P L Goldschmidt
- Laboratoire Immunosérologie, Hôpital Broussais, Paris, France
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23
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Localization of arachidonate 12-lipoxygenase in parenchymal cells of porcine anterior pituitary. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39977-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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24
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Reddanna P, Whelan J, Burgess JR, Eskew ML, Hildenbrandt G, Zarkower A, Scholz RW, Reddy CC. The role of vitamin E and selenium on arachidonic acid oxidation by way of the 5-lipoxygenase pathway. Ann N Y Acad Sci 1989; 570:136-45. [PMID: 2516998 DOI: 10.1111/j.1749-6632.1989.tb14914.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- P Reddanna
- Department of Veterinary Science, Pennsylvania State University, University Park 16802
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25
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Cochran FR, Finch-Arietta MB. Optimization of cofactors which regulate RBL-1 arachidonate 5-lipoxygenase. Biochem Biophys Res Commun 1989; 161:1327-32. [PMID: 2742590 DOI: 10.1016/0006-291x(89)91388-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The arachidonate lipoxygenase from rat basophilic leukemia cells (RBL-1) is widely utilized as a model to dissect the primary enzymatic reactions leading to leukotriene formation. The purpose of the present study was to optimize the specific activity of 5-lipoxygenase prepared from a high speed supernatant of RBL-1 cell homogenates. Activation of 5-lipoxygenase was observed in the presence of micromolar levels of calcium. A synergistic enhancement of 5-lipoxygenase was observed upon addition of equally low levels of ATP; maximal activation was induced by 5 microM CaCl2 plus 5 microM ATP. Addition of a microsomal-membrane preparation and NADPH further augmented 5-HETE biosynthesis. High concentrations (330 microM) of NADPH reversed the microsomal-induced stimulation of RBL-1 5-lipoxygenase, resulting in enzyme inhibition.
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Affiliation(s)
- F R Cochran
- Department of Allergy and Inflammation, Hoffmann-LaRoche, Nutley, NJ 07110
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26
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Hatzelmann A, Schatz M, Ullrich V. Involvement of glutathione peroxidase activity in the stimulation of 5-lipoxygenase activity by glutathione-depleting agents in human polymorphonuclear leukocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 180:527-33. [PMID: 2496978 DOI: 10.1111/j.1432-1033.1989.tb14678.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We recently demonstrated activation of 5-lipoxygenase activity in human polymorphonuclear leukocytes (PMN) on preincubation of the cells with glutathione-depleting agents, namely 1-chloro-2,4-dinitrobenzene (Dnp-C1) and azodicarboxylic acid bis[dimethylamide] (diamide). In this paper we show that Dnp-C1, but not diamide, impairs the reduction of added organic peroxides in whole PMN. Also, since co-incubation of fatty acid hydroperoxides with arachidonate caused activation of 5-lipoxygenase, we propose that Dnp-C1 increases the peroxide level in PMN which is required for the onset of lipoxygenase activity. This could be substantiated in PMN homogenates by a glutathione-dependent depression of arachidonate 5-lipoxygenation. At higher arachidonate concentrations and in the presence of Ca2+ the glutathione effect was not observed but additional glutathione peroxidase also blocked this maximally stimulated 5-lipoxygenase. Together with other experiments, it became obvious that the formation of leukotrienes, but also of 15-lipoxygenase products, requires a sharply defined threshold level of fatty acid hydroperoxides which are generated by the lipoxygenases and counteracted by glutathione-dependent peroxidase(s). Dnp-C1 influences this equilibrium by removing glutathione and thereby inhibiting glutathione-dependent peroxidase activity. From our data we conclude that it is the physiological function of the peroxidase activity in PMN to determine an efficiently regulated threshold level of hydroperoxide products, below which no activation of 5-lipoxygenase or 15-lipoxygenase can occur.
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Affiliation(s)
- A Hatzelmann
- Faculty of Biology, University of Konstanz, Federal Republic of Germany
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27
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Affiliation(s)
- S Yamamoto
- Department of Biochemistry, Tokushima University, School of Medicine, Japan
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28
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Lagarde M, Gualde N, Rigaud M. Metabolic interactions between eicosanoids in blood and vascular cells. Biochem J 1989; 257:313-20. [PMID: 2494983 PMCID: PMC1135582 DOI: 10.1042/bj2570313] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- M Lagarde
- INSERM U205, INSA Lyon, Villeurbanne, France
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29
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Kimura Y, Okuda H, Okuda T, Arichi S. Effects of chalcones isolated from licorice roots on leukotriene biosynthesis in human polymorphonuclear neutrophls. Phytother Res 1988. [DOI: 10.1002/ptr.2650020308] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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30
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Miller CC, McCreedy CA, Jones AD, Ziboh VA. Oxidative metabolism of dihomogammalinolenic acid by guinea pig epidermis: evidence of generation of anti-inflammatory products. PROSTAGLANDINS 1988; 35:917-38. [PMID: 3141974 DOI: 10.1016/0090-6980(88)90116-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Reports that vegetable oils which contain gamma-linolenic acid (18:3n-6) may exert beneficial effects on cutaneous disorders prompted us to investigate whether epidermis possesses the ability to transform dihomogammalinolenic acid (20:3n-6), the epidermal elongase product of 18:3n-6, into oxidative metabolites with anti-inflammatory potential. Incubations of [1-14C]20:3n-6 with the 105,000 g particulate (microsomal) fraction from guinea pig epidermal homogenate resulted in the formation of the 1-series prostaglandin PGE1. The identity of this product was confirmed by argentation thin-layer chromatography (TLC), reverse phase-HPLC, and conversion with alkali treatment to PGB1. Incubations of [1-14C]20:3n-6 with the 105,000 g supernatant (cytosolic) fraction from guinea pig epidermal homogenate resulted in the formation of the 15-lipoxygenase product 15-hydroxy-8, 11, 13-eicosatrienoic acid (15-OH-20:3n6). The identity of this product was confirmed by normal phase-HPLC and gas chromatography/mass spectrometry (GC/MS). Thus, data from these studies indicate the capacity of enzymes in the microsomal and cytosolic fractions of guinea pig epidermal homogenates to transform 20:3n-6 to the eicosanoids PGE1 and 15-OH 20:3n-6, products which reportedly have anti-inflammatory properties. The in vivo significance of these findings remains to be explored.
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Affiliation(s)
- C C Miller
- Department of Dermatology, School of Medicine, University of California, Davis 95616
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31
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Hatzelmann A, Ullrich V. The omega-hydroxylation of arachidonic acid by human polymorphonuclear leukocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 173:445-52. [PMID: 3129296 DOI: 10.1111/j.1432-1033.1988.tb14019.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Incubations of [1-14C]arachidonic acid with unstimulated human polymorphonuclear leukocytes resulted in the formation of four new metabolites in a previously described reverse-phase HPLC system. Three of these metabolites were largely suppressed in a CO/O2 (80/20, by vol.) atmosphere indicating a cytochrome-P450-dependent monooxygenase reaction. In agreement with this assumption is their NADPH/O2-dependent formation in the microsomal fraction. One metabolite was identified by gas chromatography/mass spectrometry analysis as omega-hydroxy-arachidonic acid and the two others were secondary products identified as omega-carboxy-arachidonic acid and 5,20-dihydroxy-E,Z,Z,Z-6,8,11,14-eicosatetraenoic acid. Since the affinity for arachidonate of the omega-monooxygenase was quite low and the presence of LTB4 suppressed the omega-hydroxylation of arachidonate, we conclude that the known LTB4 omega-monooxygenase is responsible for the formation of omega-hydroxy-arachidonate. It is unlikely, however, that significant concentrations of these metabolites are formed by activated polymorphonuclear leukocytes in vivo. The fourth metabolite remains tightly associated with the leukocytes but has not been further characterized.
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Affiliation(s)
- A Hatzelmann
- Faculty of Biology, University of Konstanz, Federal Republic of Germany
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32
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Affiliation(s)
- F Austen
- Dept. of Rheumatology and Immunology, Brigham and Women's Hospital, Boston, Mass. 02115
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33
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Affiliation(s)
- J L Humes
- Department of Biochemistry and Molecular Biology, Merck Institute for Therapeutic Research, Rahway, New Jersey 07065
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34
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Badwey JA, Robinson JM, Horn W, Soberman RJ, Karnovsky MJ, Karnovsky ML. Synergistic stimulation of neutrophils. Possible involvement of 5-hydroxy-6,8,11,14-eicosatetraenoate in superoxide release. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)69137-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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35
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Affiliation(s)
- A A Spector
- Department of Biochemistry, University of Iowa, Iowa City 52242
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36
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Hatzelmann A, Ullrich V. Regulation of 5-lipoxygenase activity by the glutathione status in human polymorphonuclear leukocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 169:175-84. [PMID: 2824200 DOI: 10.1111/j.1432-1033.1987.tb13595.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The influence of the glutathione status of human polymorphonuclear leukocytes (PMN) on 5-lipoxygenase activity was studied by treating cells with increasing concentrations of 1-chloro-2,4-dinitrobenzene (Dnp-Cl) or azodicarboxylic acid bis(dimethylamide) (Diamide). Subsequent incubation with arachidonate resulted in an up to tenfold-stimulated formation of 5-hydroxyeicosatetraenoic acid, leukotriene B4, leukotriene B4 isomers and omega-hydroxyleukotriene B4. Higher concentrations of the GSH reagents were inhibitory. At maximal stimulation by Dnp-Cl, 5-hydroperoxyeicosatetraenoic acid started to be built up at the expense of 5-HETE at glutathione levels which were diminished by about 50% compared to resting cells. No increase in cytosolic Ca2+ could be measured under these conditions by the fura-2 method. In PMN homogenates Dnp-Cl and Diamide were without effect and even caused inhibition when 5-lipoxygenase was stimulated by Ca2+ and ATP. 15-Lipoxygenase was either unchanged in the case of Diamide, or even increased after pretreatment with Dnp-Cl. The results allow us to conclude that 5-lipoxygenase activity in intact PMN is regulated not only by Ca2+ but in a complex manner also by the glutathione redox status. Conditions of oxidative stress increase the activity which may reflect the in vivo situation under phagocytosis and oxidative burst.
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Affiliation(s)
- A Hatzelmann
- Faculty of Biology, University of Konstanz, Federal Republic of Germany
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37
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Kothari HV, Lee WH, Ku EC. An alternate mechanism for regulation of leukotriene production in leukocytes: studies with an anti-inflammatory drug, sodium diclofenac. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 921:502-11. [PMID: 2822132 DOI: 10.1016/0005-2760(87)90078-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Sodium diclofenac, a potent cyclooxygenase inhibitor, was recently shown to inhibit arachidonic acid conversion to leukotriene products in human leukocytes. This activity was confirmed by radioimmunoassay in calcium ionophore A 23187-stimulated leukocytes isolated from the rat peritoneal cavity and human peripheral blood. Studies with rat peritoneal leukocytes revealed that this effect was not mediated by inhibition of 5-lipoxygenase or phospholipase A2, but rather through modulation of arachidonic acid uptake and release. The potency of this effect was dependent upon cell type; macrophages being more sensitive to the drug than neutrophils. In leukocytes treated with sodium diclofenac, arachidonic acid released from phospholipids in response to A 23187 challenge was reincorporated into triacylglycerols. The drug enhanced the spontaneous uptake of arachidonic acid into the cellular triacylglycerol pool and, in this manner, decreased the availability of intracellular arachidonic acid. Therefore, sodium diclofenac, in addition to inhibition of cyclooxygenase, regulates leukotriene production of inflammatory cells by a mechanism mediated in part through the redistribution of arachidonic acid in lipid pools.
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Affiliation(s)
- H V Kothari
- Research Department, CIBA-GEIGY Corporation, Summit, NJ 07901
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38
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Griswold DE, Marshall PJ, Webb EF, Godfrey R, Newton J, DiMartino MJ, Sarau HM, Gleason JG, Poste G, Hanna N. SK&F 86002: a structurally novel anti-inflammatory agent that inhibits lipoxygenase- and cyclooxygenase-mediated metabolism of arachidonic acid. Biochem Pharmacol 1987; 36:3463-70. [PMID: 2823821 DOI: 10.1016/0006-2952(87)90327-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effects of SK&F 86002 [5-(4-pyridyl)-6 (4-fluorophenyl)-2,3-dihydroimidazo (2,1-b) thiazole] on the generation of eicosanoids in vitro and on inflammatory responses in vivo are described and compared to other non-steroidal anti-inflammatory drugs. SK&F 86002 inhibited prostaglandin H2 (PGH2) synthase activity (IC50 120 microM) as well as prostanoid production by rat basophilic leukemia (RBL-1) cells (IC50 70 microM) and its sonicate (IC50 100 microM) and human monocytes (IC50 1 microM). In addition, SK&F 86002 inhibited the generation of dihydroxyeicosatetraenoic acid (diHETE) and 5-hydroxyeicosatetraenoic acid (5-HETE) by a high speed supernatant fraction of RBL-1 cells (IC50 10 microM). Cellular production of 5-lipoxygenase products was inhibited by SK&F 86002 as measured by leukotriene B4 (LTB4) generation from human neutrophils (IC50 20 microM), leukotriene C4 (LTC4) generation by human monocytes (IC50 20 microM), and 5-HETE production by RBL-1 cells (IC50 40 microM). The in vivo profile of anti-inflammatory activity of SK&F 86002 supports the dual inhibition of arachidonate metabolism as indicated by its activity in inflammation models that are insensitive to selective cyclooxygenase inhibitors. The responses of arachidonic-acid-induced edema in the mouse ear and rat paw, as well as the cell infiltration induced by carrageenan in the mouse peritoneum and by arachidonic acid in the rat air pouch, were inhibited by SK&F 86002 and phenidone but not by the selective cyclooxygenase inhibitors naproxen and indomethacin.
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Affiliation(s)
- D E Griswold
- Smith Kline & French Laboratories, Philadelphia, PA 19101
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39
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Chang WC, Su GW. Stimulation of 5-lipoxygenase activity in polymorphonuclear leukocytes of rats by caseinate treatment. Biochem Pharmacol 1987; 36:3033-6. [PMID: 2820429 DOI: 10.1016/0006-2952(87)90220-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In the present study, the lipoxygenase activity in polymorphonuclear (PMN) leukocytes of rats was characterized, and the change in lipoxygenase activity in peritoneal and peripheral PMN leukocytes challenged by caseinate was investigated. Peritoneal PMN leukocytes produced 5-HETE and LTB4 as the major 5-lipoxygenase metabolites from arachidonic acid. The 5-lipoxygenase activity was calcium dependent. Caseinate treatment in rats significantly stimulated the 5-lipoxygenase activity in peripheral and peritoneal PMN leukocytes. Although it also stimulated the cyclooxygenase metabolic pathway, the effect was not as evident as that on the 5-lipoxygenase pathway. Since LTB4 is a potent chemotactic factor for PMN leukocyte migration, the present results might explain the mechanism on the PMN leukocyte infiltration caused by caseinate treatment.
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40
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Saunders R, Horrocks LA. Eicosanoids, plasma membranes, and molecular mechanisms of spinal cord injury. NEUROCHEMICAL PATHOLOGY 1987; 7:1-22. [PMID: 3328833 DOI: 10.1007/bf02834288] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- R Saunders
- Dept. Physiological Chemistry, Ohio State University, Columbus 43210
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41
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Zor U, Her E, Talmon J, Kohen F, Harell T, Moshonov S, Rivnay B. Hydrocortisone inhibits antigen-induced rise in intracellular free calcium concentration and abolishes leukotriene C4 production in leukemic basophils. PROSTAGLANDINS 1987; 34:29-40. [PMID: 3685396 DOI: 10.1016/0090-6980(87)90260-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Antigenic stimulation of rat basophilic leukemia cells (RBL-3H3) elevates intracellular free Ca2+ concentration ([Ca2+]i) and induces production of leukotriene C4 (LTC4). This model was used to examine the role of Ca2+ in LTC4 formation, and inhibition by hydrocortisone (HC). HC, at a physiological concentration (2 x 10(-7) M), selectively prevented the stimulatory effect of the antigen on LTC4 production whereas the response to calcium ionophore (A23187) remained unimpaired. The inhibition by HC was time-dependent: half maximal response was reached at 2 hour and maximal response at 3 hours. Addition of arachidonic acid (3 micrograms/ml) did not overcome the inhibitory action of HC. An elevated [Ca2+]i is known to be essential for the activation of both 5-lipoxygenase and phospholipase A2. The stimulatory effect of the antigen on LTC4 production was abolished when the cells were incubated in Ca2+-deficient medium. Likewise, calcium ionophore stimulation shows dependence on extracellular Ca2+. Half maximal stimulation by the antigen and calcium ionophore was observed at external Ca2+ concentration of 150 microM and 40 microM respectively. Treatment with HC largely prevented the antigen-induced rise in [Ca2+]i, measured by Quin 2. In addition, HC reduced by 70% the accumulation of 45Ca2+ induced by the antigen. Collectively, these results demonstrate for the first time that HC reduces antigen-induced elevation of [Ca2+]i, and this may be associated with the inhibitory action of HC on LTC4 formation. This property could be partly responsible for the antiallergic and antiinflammatory activities of HC.
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Affiliation(s)
- U Zor
- Department of Hormone, Research, Weizmann Institute of Science, Rehovot, Israel
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42
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Kaneko S, Ueda N, Tonai T, Maruyama T, Yoshimoto T, Yamamoto S. Arachidonate 5-lipoxygenase of porcine leukocytes studied by enzyme immunoassay using monoclonal antibodies. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48306-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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43
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44
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Aharony D, Redkar-Brown DG, Hubbs SJ, Stein RL. Kinetic studies on the inactivation of 5-lipoxygenase by 5(S)-hydroperoxyeicosatetraenoic acid. PROSTAGLANDINS 1987; 33:85-100. [PMID: 3108961 DOI: 10.1016/0090-6980(87)90307-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The oxygenation of arachidonic acid (AA) by guinea-pig neutrophil 5-lipoxygenase terminates prematurely at a substrate utilization of only 50%. In the presence of dithiothreitol (DTT), reaction progress continues longer but still terminates prematurely, at about 70% substrate turnover. The addition of more substrate during the first 60 seconds of the initial reaction resulted in continued product formation. However, at times after 120 seconds, the addition of more AA could not produce additional product formation. Together, these results indicate a time-dependent (t1/2 = 0.5-1.0 min), irreversible loss of enzyme activity. To determine if the product 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HPETE) mediates the inactivation, it was tested for its ability to irreversibly inhibit the enzyme and found to inactivate 5-lipoxygenase with Ki = 0.05 +/- 0.01 microM and ki = 1.4 +/- 0.4 min-1. DTT changed the apparent affinity of 5-HPETE (Ki = 0.33 +/- 0.09 microM) but had no effect on the rate of inactivation (ki = 1.26 +/- 0.62 min-1). In contrast, the hydroxy derivative of 5-HPETE, 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE), is a reversible, time-independent inhibitor with Ki = 6.3 +/- 0.9 microM regardless of DTT. The ability of thiols to protect 5-lipoxygenase from production inactivation is due, at least in part, to a non-enzymatic reaction between DTT and 5-HPETE that converts the hydroperoxy acid to a material that can no longer inactivate the enzyme.
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45
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Okiji T, Morita I, Kobayashi C, Sunada I, Murota S. Arachidonic-acid metabolism in normal and experimentally-inflamed rat dental pulp. Arch Oral Biol 1987; 32:723-7. [PMID: 3128966 DOI: 10.1016/0003-9969(87)90116-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pulp homogenates were incubated with [14C]-arachidonic acid and the metabolites separated by thin-layer chromatography. The main products of normal pulp were 6-keto-prostaglandin (PG) F1 alpha and 12-hydroxy-eicosatetraenoic acid (12-HETE), further identified by high performance-liquid chromatography. Thromboxane (TX) B2, and PGD2, E2 and F2 alpha were also detected at less than 30 per cent of 6-keto-PGF1 alpha. When the pulp was inflamed by applying bacterial lipopolysaccharide, production of all these metabolites increased; in particular, PGE2 was increased 9.3-fold compared with normal, and 6-keto-PGF1 alpha and HETE 3.8- and 2.0-fold, respectively. An unidentified product, slightly more polar than 12-HETE, was also markedly produced by the inflamed pulp. Thus arachidonic-acid metabolites including lipoxygenase products may be involved in the development of pulpal inflammation.
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Affiliation(s)
- T Okiji
- Department of Endodontics, Faculty of Dentistry, Tokyo Medical and Dental University, Japan
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46
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Ono N, Yamasaki Y, Yamamoto N, Sunami A, Miyake H. Pharmacological studies on proglumetacin maleate, a new non-steroidal anti-inflammatory drug (4). Mode of action on anti-inflammatory activity. JAPANESE JOURNAL OF PHARMACOLOGY 1986; 42:431-9. [PMID: 3102823 DOI: 10.1254/jjp.42.431] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The possible mechanism of the anti-inflammatory activity of proglumetacin maleate (PGM), a new indomethacin (IND) derivative interacting with arachidonic acid (AA) metabolism, was investigated to elucidate the contributions of PGM itself and its two major metabolites, desproglumideproglumetacin maleate (DPP) and IND. PGM caused much less inhibition of PGE2 formation by sheep seminal vesicle microsomes (IC50 = 310 microM) and TXB2 formation by a washed rabbit platelet suspension (IC50 = 6.3 microM) than IND. DPP also caused less inhibition of cyclooxygenase than IND. Moreover, PGM had less effect on sodium arachidonate (SAA)-induced rat platelet aggregation ex vivo and AA-induced sudden death in rabbits than IND. These results show that PGM has anti-inflammatory activity after its conversion to the active metabolite IND. However, the inhibitory effects of PGM and DPP were as strong as that of IND on SAA- or collagen-induced rabbit platelet aggregation in vitro. These activities are considered to be associated with platelet membrane interaction. Moreover, unlike IND, PGM (IC50 = 1.5 microM) and DPP (IC50 = 16.3 microM) strongly inhibited 5-HETE formation by the cytosol of guinea pig polymorphonuclear leukocytes. This unique activity of PGM on 5-lipoxygenase may contribute to its anti-inflammatory activity.
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47
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Umezu K, Yuasa S, Ichikawa A. Inhibitory mechanism of tritoqualine on histamine release from mast cells. Biochem Pharmacol 1986; 35:3137-42. [PMID: 2428378 DOI: 10.1016/0006-2952(86)90398-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Tritoqualine (TRQ, (+)-(R*)-7-amino-4,5,6-triethoxy-3-[(R*)-5,6,7, 8-tetrahydro-4-methoxy-6-methyl-1,3-dioxolo[4,5-g]isoquinolin++ +-5-yl] phthalide) strongly inhibited the increased metabolism of [3H]arachidonic acid-labeled phospholipid and 45Ca2+ influx in mast cells stimulated by compound 48/80 (compd 48/80), Concanavalin A (Con A) plus phosphatidylserine (PS), or 2,4-dinitrophenyl-coupled-ascaris extracts (DNP-asc). However, TRQ did not disturb the binding of 14C-labeled compd 48/80 to the mast cell membrane. The activity of calmodulin purified from mastocytoma P-815 cells was inhibited by TRQ at IC50 1.0 microM. From these results, it is concluded that the inhibitory mechanism of TRQ on stimulus-induced histamine release from mast cells may be mediated at least partially by the inhibition of Ca2+ influx and calmodulin activity.
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Purification of arachidonate 5-lipoxygenase from porcine leukocytes and its reactivity with hydroperoxyeicosatetraenoic acids. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(19)57499-3] [Citation(s) in RCA: 159] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Shimizu T, Izumi T, Seyama Y, Tadokoro K, Rådmark O, Samuelsson B. Characterization of leukotriene A4 synthase from murine mast cells: evidence for its identity to arachidonate 5-lipoxygenase. Proc Natl Acad Sci U S A 1986; 83:4175-9. [PMID: 3012557 PMCID: PMC323694 DOI: 10.1073/pnas.83.12.4175] [Citation(s) in RCA: 132] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Leukotriene A4 synthase was purified from the cytosolic fraction of murine mast cells. The enzyme converted 5-hydroperoxy-6-trans-8,11,14-cis-icosatetraenoic acid (5-HPETE) to leukotriene A4. This unstable product was identified by demonstration of two epimers of 6-transleukotriene B4, methanol trapping, as well as further transformation to leukotriene B4 by leukotriene A4 hydrolase. Leukotriene A4 synthase stereospecifically eliminated the D-hydrogen at C-10 (pro-R) in the synthesis of leukotriene A4 when incubated with [10D-3H;3-(14)C]5-HPETE. The purified enzyme also exhibited 5-lipoxygenase activity toward arachidonic acid and 8-lipoxygenase activity towards 8,11,14-cisicosatrienoic acid. All of these activities required Ca2+ and ATP for their maximal velocities. The effects of heat treatment and of several lipoxygenase inhibitors on these enzyme activities as well as coelution in various chromatographic systems strongly suggest that lipoxygenase and leukotriene A4 synthase activities reside in the same enzyme molecule.
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