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Nicolaou A, Kendall AC. Bioactive lipids in the skin barrier mediate its functionality in health and disease. Pharmacol Ther 2024; 260:108681. [PMID: 38897295 DOI: 10.1016/j.pharmthera.2024.108681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/11/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
Our skin protects us from external threats including ultraviolet radiation, pathogens and chemicals, and prevents excessive trans-epidermal water loss. These varied activities are reliant on a vast array of lipids, many of which are unique to skin, and that support physical, microbiological and immunological barriers. The cutaneous physical barrier is dependent on a specific lipid matrix that surrounds terminally-differentiated keratinocytes in the stratum corneum. Sebum- and keratinocyte-derived lipids cover the skin's surface and support and regulate the skin microbiota. Meanwhile, lipids signal between resident and infiltrating cutaneous immune cells, driving inflammation and its resolution in response to pathogens and other threats. Lipids of particular importance include ceramides, which are crucial for stratum corneum lipid matrix formation and therefore physical barrier functionality, fatty acids, which contribute to the acidic pH of the skin surface and regulate the microbiota, as well as the stratum corneum lipid matrix, and bioactive metabolites of these fatty acids, involved in cell signalling, inflammation, and numerous other cutaneous processes. These diverse and complex lipids maintain homeostasis in healthy skin, and are implicated in many cutaneous diseases, as well as unrelated systemic conditions with skin manifestations, and processes such as ageing. Lipids also contribute to the gut-skin axis, signalling between the two barrier sites. Therefore, skin lipids provide a valuable resource for exploration of healthy cutaneous processes, local and systemic disease development and progression, and accessible biomarker discovery for systemic disease, as well as an opportunity to fully understand the relationship between the host and the skin microbiota. Investigation of skin lipids could provide diagnostic and prognostic biomarkers, and help identify new targets for interventions. Development and improvement of existing in vitro and in silico approaches to explore the cutaneous lipidome, as well as advances in skin lipidomics technologies, will facilitate ongoing progress in skin lipid research.
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Affiliation(s)
- Anna Nicolaou
- Laboratory for Lipidomics and Lipid Biology, Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9NT, UK; Lydia Becker Institute of Immunology and Inflammation; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9NT, UK.
| | - Alexandra C Kendall
- Laboratory for Lipidomics and Lipid Biology, Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9NT, UK
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2
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Cebo M, Fu X, Gawaz M, Chatterjee M, Lämmerhofer M. Enantioselective ultra-high performance liquid chromatography-tandem mass spectrometry method based on sub-2µm particle polysaccharide column for chiral separation of oxylipins and its application for the analysis of autoxidized fatty acids and platelet releasates. J Chromatogr A 2020; 1624:461206. [DOI: 10.1016/j.chroma.2020.461206] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022]
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3
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Kolmert J, Fauland A, Fuchs D, Säfholm J, Gómez C, Adner M, Dahlén SE, Wheelock CE. Lipid Mediator Quantification in Isolated Human and Guinea Pig Airways: An Expanded Approach for Respiratory Research. Anal Chem 2018; 90:10239-10248. [PMID: 30056696 DOI: 10.1021/acs.analchem.8b01651] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The clinical importance of prostaglandins and leukotrienes in asthma is well recognized; however, the biochemical role of other lipid mediators (often termed oxylipins) in the regulation of airway tone and inflammation remains unclear. We therefore developed a workflow to investigate oxylipin physiology and pharmacology in two in vitro models, the intact human bronchus and the guinea pig trachea. Airways were isolated and smooth muscle contraction was measured in an organ bath following stimulation with either anti-IgE or ovalbumin. The associated release of oxylipins over time into the organ bath was quantified using three developed LC-MS/MS methods capable of collectively measuring 130 compounds. Oxylipin extraction recoveries were 71% on average, method accuracy was 90-98%, coefficient of variation was 4.3-9.4%, and matrix effects were on average 11%. At baseline, low levels of primarily prostaglandins and associated metabolites were observed in both tissue preparations. The mast cell-induced airway constriction caused release of leukotrienes and further elevations in prostaglandin levels. In total, 57 oxylipins from the human bronchus, and 42 from guinea pig trachea, were detected at 60 min post-stimulation in the organ bath. Chiral analysis demonstrated that 5-hydroxyeicosatetraenoic acid (5-HETE) in the human bronchus preparation was not produced by 5-LOX enzymatic activity (enantiomeric excess [ee] = 10%), as opposed to 12( S)-HETE, 14( S)-, and 17( S)-hydroxy docosahexaenoic acid (HDoHE; ee = 100%), highlighting that chiral chromatography is necessary for correct biological interpretation. Unexpectedly, prostaglandin D2 and its metabolites remained elevated 24 h after the challenges, suggesting a sustained activation of mast cells not previously described. The reported translational methodology provides a new platform for comprehensive studies to elucidate the origin and functions of individual oxylipins in various airway responses.
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Affiliation(s)
- Johan Kolmert
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics , Karolinska Institutet , 17177 Stockholm , Sweden.,Institute of Environmental Medicine, Experimental Asthma and Allergy Research Unit , Karolinska Institutet , 17177 Stockholm , Sweden
| | - Alexander Fauland
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics , Karolinska Institutet , 17177 Stockholm , Sweden
| | - David Fuchs
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics , Karolinska Institutet , 17177 Stockholm , Sweden
| | - Jesper Säfholm
- Institute of Environmental Medicine, Experimental Asthma and Allergy Research Unit , Karolinska Institutet , 17177 Stockholm , Sweden
| | - Cristina Gómez
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics , Karolinska Institutet , 17177 Stockholm , Sweden
| | - Mikael Adner
- Institute of Environmental Medicine, Experimental Asthma and Allergy Research Unit , Karolinska Institutet , 17177 Stockholm , Sweden
| | - Sven-Erik Dahlén
- Institute of Environmental Medicine, Experimental Asthma and Allergy Research Unit , Karolinska Institutet , 17177 Stockholm , Sweden
| | - Craig E Wheelock
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics , Karolinska Institutet , 17177 Stockholm , Sweden
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Araújo AC, Wheelock CE, Haeggström JZ. The Eicosanoids, Redox-Regulated Lipid Mediators in Immunometabolic Disorders. Antioxid Redox Signal 2018; 29:275-296. [PMID: 28978222 DOI: 10.1089/ars.2017.7332] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE The oxidation of arachidonic acid via cyclooxygenase (COX) and lipoxygenase (LOX) activity to produce eicosanoids during inflammation is a well-known biosynthetic pathway. These lipid mediators are involved in fever, pain, and thrombosis and are produced from multiple cells as well as cell/cell interactions, for example, immune cells and epithelial/endothelial cells. Metabolic disorders, including hyperlipidemia, hypertension, and diabetes, are linked with chronic low-grade inflammation, impacting the immune system and promoting a variety of chronic diseases. Recent Advances: Multiple studies have corroborated the important function of eicosanoids and their receptors in (non)-inflammatory cells in immunometabolic disorders (e.g., insulin resistance, obesity, and cardiovascular and nonalcoholic fatty liver diseases). In this context, LOX and COX products are involved in both pro- and anti-inflammatory responses. In addition, recent work has elucidated the potent function of specialized proresolving mediators (i.e., lipoxins and resolvins) in resolving inflammation, protecting organs, and stimulating tissue repair and remodeling. CRITICAL ISSUES Inhibiting/stimulating selected eicosanoid pathways may result in anti-inflammatory and proresolution responses leading to multiple beneficial effects, including the abrogation of reactive oxygen species production, increased speed of resolution, and overall improvement of diseases related to immunometabolic perturbations. FUTURE DIRECTIONS Despite many achievements, it is crucial to understand the molecular and cellular mechanisms underlying immunological/metabolic cross talk to offer substantial therapeutic promise. Antioxid. Redox Signal. 29, 275-296.
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Affiliation(s)
- Ana Carolina Araújo
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
| | - Craig E Wheelock
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
| | - Jesper Z Haeggström
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
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5
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Mazaleuskaya LL, Salamatipour A, Sarantopoulou D, Weng L, FitzGerald GA, Blair IA, Mesaros C. Analysis of HETEs in human whole blood by chiral UHPLC-ECAPCI/HRMS. J Lipid Res 2018; 59:564-575. [PMID: 29301865 PMCID: PMC5832923 DOI: 10.1194/jlr.d081414] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/03/2018] [Indexed: 12/30/2022] Open
Abstract
The biosynthesis of eicosanoids occurs enzymatically via lipoxygenases, cyclooxygenases, and cytochrome P450, or through nonenzymatic free radical reactions. The enzymatic routes are highly enantiospecific. Chiral separation and high-sensitivity detection methods are required to differentiate and quantify enantioselective HETEs in complex biological fluids. We report here a targeted chiral lipidomics analysis of human blood using ultra-HPLC-electron capture (EC) atmospheric pressure chemical ionization/high-resolution MS. Monitoring the high-resolution ions formed by the fragmentation of pentafluorobenzyl derivatives of oxidized lipids during the dissociative EC, followed by in-trap fragmentation, increased sensitivity by an order of magnitude when compared with the unit resolution MS. The 12(S)-HETE, 12(S)-hydroxy-(5Z,8E,10E)-heptadecatrienoic acid [12(S)-HHT], and 15(S)-HETE were the major hydroxylated nonesterified chiral lipids in serum. Stimulation of whole blood with zymosan and lipopolysaccharide (LPS) resulted in stimulus- and time-dependent effects. An acute exposure to zymosan induced ∼80% of the chiral plasma lipids, including 12(S)-HHT, 5(S)-HETE, 15(R)-HETE, and 15(S)-HETE, while a maximum response to LPS was achieved after a long-term stimulation. The reported method allows for a rapid quantification with high sensitivity and specificity of enantiospecific responses to in vitro stimulation or coagulation of human blood.
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Affiliation(s)
- Liudmila L Mazaleuskaya
- Institute for Translational Medicine and Therapeutics University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
| | - Ashkan Salamatipour
- Penn Superfund Research Program (SRP) Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
| | - Dimitra Sarantopoulou
- Institute for Translational Medicine and Therapeutics University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
| | - Liwei Weng
- Penn Superfund Research Program (SRP) Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
| | - Garret A FitzGerald
- Institute for Translational Medicine and Therapeutics University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
| | - Ian A Blair
- Institute for Translational Medicine and Therapeutics University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160.,Penn Superfund Research Program (SRP) Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
| | - Clementina Mesaros
- Institute for Translational Medicine and Therapeutics University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160 .,Penn Superfund Research Program (SRP) Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6160
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6
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Paes MC, Silveira AB, Ventura-Martins G, Luciano M, Coelho MGP, Todeschini AR, Bianconi ML, Atella GC, Silva-Neto MAC. CALCIUM-INDUCED LIPID PEROXIDATION IS MEDIATED BY RHODNIUS HEME-BINDING PROTEIN (RHBP) AND PREVENTED BY VITELLIN. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2015; 90:104-115. [PMID: 26111116 DOI: 10.1002/arch.21248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Lipid peroxidation is promoted by the quasi-lipoxygenase (QL) activity of heme proteins and enhanced by the presence of free calcium. Unlike mammalian plasma, the hemolymph of Rhodnius prolixus, a vector of Chagas disease, contains both a free heme-binding protein (RHBP) and circulating lipoproteins. RHBP binds and prevents the heme groups of the proteins from participating in lipid peroxidation reactions. Herein, we show that despite being bound to RHBP, heme groups promote lipid peroxidation through a calcium-dependent QL reaction. This reaction is readily inhibited by the presence of ethylene glycol tetraacetic acid (EGTA), the antioxidant butylated hydroxytoluene or micromolar levels of the main yolk phosphoprotein vitellin (Vt). The inhibition of lipid peroxidation is eliminated by the in vitro dephosphorylation of Vt, indicating that this reaction depends on the interaction of free calcium ions with negatively charged phosphoamino acids. Our results demonstrate that calcium chelation mediated by phosphoproteins occurs via an antioxidant mechanism that protects living organisms from lipid peroxidation.
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Affiliation(s)
- Marcia C Paes
- Laboratório de Interação Tripanossomatídeos e Vetores, Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes (IBRAG), Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil
- Laboratório de Bioquímica de Lipídios e Lipoproteínas, Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
| | - Alan B Silveira
- Laboratório de Sinalização Celular, Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Prédio do Centro de Ciências da Saúde, Bloco D, Subsolo, Sala 05, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brasil
| | - Guilherme Ventura-Martins
- Laboratório de Sinalização Celular, Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Prédio do Centro de Ciências da Saúde, Bloco D, Subsolo, Sala 05, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brasil
| | - Monalisa Luciano
- Laboratório de Interação Tripanossomatídeos e Vetores, Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes (IBRAG), Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil
| | - Marsen G P Coelho
- Laboratório de Interação Tripanossomatídeos e Vetores, Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes (IBRAG), Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil
- Laboratório de Bioquímica Aplicada e Bioquímica de Proteínas e Produtos Naturais, Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes (IBRAG), Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil
| | - Adriane R Todeschini
- Instituto Nacional de Ciência e Tecnologia -em Entomologia Molecular (INCT-EM), Universidade Federal, Prédio do Centro de Ciências da Saúde, Bloco H, Segundo andar, Sala 30, Cidade Universitária, Ilha do Fundão, Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brasil
| | - M Lucia Bianconi
- Laboratório de Glicobiologia Estrutural e Funcional, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
| | - Georgia C Atella
- Laboratório de Biocalorimetria, Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Prédio do Centro de Ciências da Saúde, Bloco E, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brasil
| | - Mário A C Silva-Neto
- Laboratório de Sinalização Celular, Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Prédio do Centro de Ciências da Saúde, Bloco D, Subsolo, Sala 05, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brasil
- Laboratório de Bioquímica de Lipídios e Lipoproteínas, Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
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7
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Muñoz-Garcia A, Thomas CP, Keeney DS, Zheng Y, Brash AR. The importance of the lipoxygenase-hepoxilin pathway in the mammalian epidermal barrier. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1841:401-8. [PMID: 24021977 PMCID: PMC4116325 DOI: 10.1016/j.bbalip.2013.08.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/27/2013] [Accepted: 08/30/2013] [Indexed: 01/22/2023]
Abstract
This review covers the background to discovery of the two key lipoxygenases (LOX) involved in epidermal barrier function, 12R-LOX and eLOX3, and our current views on their functioning. In the outer epidermis, their consecutive actions oxidize linoleic acid esterified in ω-hydroxy-ceramide to a hepoxilin-related derivative. The relevant background to hepoxilin and trioxilin biochemistry is briefly reviewed. We outline the evidence that linoleate in the ceramide is the natural substrate of the two LOX enzymes and our proposal for its importance in construction of the epidermal water barrier. Our hypothesis is that the oxidation promotes hydrolysis of the oxidized linoleate moiety from the ceramide. The resulting free ω-hydroxyl of the ω-hydroxyceramide is covalently bound to proteins on the surface of the corneocytes to form the corneocyte lipid envelope, a key barrier component. Understanding the role of the LOX enzymes and their hepoxilin products should provide rational approaches to ameliorative therapy for a number of the congenital ichthyoses involving compromised barrier function. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.
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Affiliation(s)
- Agustí Muñoz-Garcia
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Christopher P Thomas
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Diane S Keeney
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yuxiang Zheng
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alan R Brash
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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8
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Lagarde M, Bernoud-Hubac N, Calzada C, Véricel E, Guichardant M. Lipidomics of essential fatty acids and oxygenated metabolites. Mol Nutr Food Res 2013; 57:1347-58. [PMID: 23818385 DOI: 10.1002/mnfr.201200828] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 05/02/2013] [Accepted: 05/02/2013] [Indexed: 01/12/2023]
Abstract
Polyunsaturated fatty acids in mammals may be oxygenated into a myriad of bioactive products through di- and monooxygenases, products that are rapidly degraded to control their action. To evaluate the phenotypes of biological systems regarding this wide family of compounds, a lipidomics approach in function of time and compartments would be relevant. The current review takes into consideration most of the diverse oxygenated metabolites of essential fatty acids at large and their immediate degradation products. Their biological function and life span are considered. Overall, this is a fluxolipidomics approach that is emerging.
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Affiliation(s)
- Michel Lagarde
- Université de Lyon, UMR 1060 Inserm, IMBL, INSA-Lyon, Villeurbanne, France.
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Mesaros C, Blair IA. Targeted chiral analysis of bioactive arachidonic Acid metabolites using liquid-chromatography-mass spectrometry. Metabolites 2012; 2:337-65. [PMID: 24957514 PMCID: PMC3901208 DOI: 10.3390/metabo2020337] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/02/2012] [Accepted: 04/09/2012] [Indexed: 02/06/2023] Open
Abstract
A complex structurally diverse series of eicosanoids arises from the metabolism of arachidonic acid. The metabolic profile is further complicated by the enantioselectivity of eicosanoid formation and the variety of regioisomers that arise. In order to investigate the metabolism of arachidonic acid in vitro or in vivo, targeted methods are advantageous in order to distinguish between the complex isomeric mixtures that can arise by different metabolic pathways. Over the last several years this targeted approach has become more popular, although there are still relatively few examples where chiral targeted approaches have been employed to directly analyze complex enantiomeric mixtures. To efficiently conduct targeted eicosanoid analyses, LC separations are coupled with collision induced dissociation (CID) and tandem mass spectrometry (MS/MS). Product ion profiles are often diagnostic for particular regioisomers. The highest sensitivity that can be achieved involves the use of selected reaction monitoring/mass spectrometry (SRM/MS); whereas the highest specificity is obtained with an SRM transitions between an intense parent ion, which contains the intact molecule (M) and a structurally significant product ion. This review article provides an overview of arachidonic acid metabolism and targeted chiral methods that have been utilized for the analysis of the structurally diverse eicosanoids that arise.
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Affiliation(s)
- Clementina Mesaros
- Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Ian A Blair
- Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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10
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Jin J, Boeglin WE, Cha JK, Brash AR. 8R-Lipoxygenase-catalyzed synthesis of a prominent cis-epoxyalcohol from dihomo-γ-linolenic acid: a distinctive transformation compared with S-lipoxygenases. J Lipid Res 2011; 53:292-9. [PMID: 22158855 DOI: 10.1194/jlr.m022863] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conversion of fatty acid hydroperoxides to epoxyalcohols is a well known secondary reaction of lipoxygenases, described for S-specific lipoxygenases forming epoxyalcohols with a trans-epoxide configuration. Here we report on R-specific lipoxygenase synthesis of a cis-epoxyalcohol. Although arachidonic and dihomo-γ-linolenic acids are metabolized by extracts of the Caribbean coral Plexaura homomalla via 8R-lipoxygenase and allene oxide synthase activities, 20:3ω6 forms an additional prominent product, identified using UV, GC-MS, and NMR in comparison to synthetic standards as 8R,9S-cis-epoxy-10S-erythro-hydroxy-eicosa-11Z,14Z-dienoic acid. Both oxygens of (18)O-labeled 8R-hydroperoxide are retained in the product, indicating a hydroperoxide isomerase activity. Recombinant allene oxide synthase formed only allene epoxide from 8R-hydroperoxy-20:3ω6, whereas two different 8R-lipoxygenases selectively produced the epoxyalcohol.A biosynthetic scheme is proposed in which a partial rotation of the reacting intermediate is required to give the observed erythro epoxyalcohol product. This characteristic and the synthesis of cis-epoxy epoxyalcohol may be a feature of R-specific lipoxygenases.
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Affiliation(s)
- Jing Jin
- Department of Pharmacology, and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
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11
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Neilson AP, Ren J, Hong YH, Sen A, Smith WL, Brenner DE, Djuric Z. Effect of fish oil on levels of R- and S-enantiomers of 5-, 12-, and 15-hydroxyeicosatetraenoic acids in mouse colonic mucosa. Nutr Cancer 2011; 64:163-72. [PMID: 22149144 DOI: 10.1080/01635581.2012.630168] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The balance of putative pro- and antiinflammatory lipoxygenase (LOX)-derived S-hydroxyeicosatetraenoic acids (S-HETEs) in colon mucosa is a potential target for modulating colon cancer risk and progression. The biological effects of S-HETEs and R-hydroxyeicosatetraenoic acids (produced by distinct pathways) may differ, but levels of these compounds in the colon are unknown. The objective of this study was to develop chiral methods to characterize hydroxyeicosatetraenoic (HETE) enantiomers in colonic mucosa and evaluate the effects of fish oil on HETE formation. C57BL/6 mice (COX-1 null, COX-2 null, wild-type) were fed a diet supplemented with either olive oil or menhaden oil for 11 wk, and R-/S-HETEs in colonic mucosa were quantified by chiral LC-MS/MS. The R-enantiomer comprised 60-72% of 5-HETE, 18-58% of 15-HETE, and 1-16% of 12-HETE in colonic mucosa, suggesting that non-LOX sources contribute to HETE profiles. Fish oil reduced levels of both R- and S-HETEs, and increased the preponderance of the R-enantiomers (particularly 12- and 15-HETEs). There was apparent shunting of arachidonic acid to 12-/15-LOX in the COX-1 null animals. This is the first report of the enantiomeric composition of HETEs in the colon in vivo and shows large effects of fish oil in the normal colon.
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Affiliation(s)
- Andrew P Neilson
- Department of Family Medicine, University of Michigan Medical School, University of Michigan, Ann Arbor, Michigan 48197, USA
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12
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Félétou M. The Endothelium, Part I: Multiple Functions of the Endothelial Cells -- Focus on Endothelium-Derived Vasoactive Mediators. ACTA ACUST UNITED AC 2011. [DOI: 10.4199/c00031ed1v01y201105isp019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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13
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14
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Comba A, Pasqualini ME. Primers on molecular pathways - lipoxygenases: their role as an oncogenic pathway in pancreatic cancer. Pancreatology 2009; 9:724-8. [PMID: 20016244 DOI: 10.1159/000235623] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Different evidence supports a functional role of enzymes involved in lipid metabolic pathways, such as lipoxygenases (LOXs) and their metabolite derivatives, in carcinogenesis. LOX enzymes catalyze the dioxygenation of arachidonic acid into hydroxyperoxyeicosatetraenoic acids, which is followed by their conversion to their corresponding eicosanoids as hydroxyeicosatetraenoic acids, leukotrienes, lipoxins and hepoxilins, which in turn act as cellular messengers. Subcellular LOX enzyme localization varies according to the LOX and cellular type regulating different cell functions. LOX enzymes or their products may exert their biological effects in different modes, either intracellular or in other cells. Numerous clinical studies on expression of LOXs in human tumors as well as in animal models indicate different roles of distinct LOX isoforms in carcinogenesis. In fact, different LOXs exhibit either protumorigenic or antitumorigenic activities and modulate the tumor response in a tissue-specific manner. Moreover, the LOX pathways are involved in the spread and metastasis of several cancers, including pancreas, through the activation of several cellular signaling pathways which modify gene expression affecting cellular proliferation, survival, migration and extracellular matrix production. In this review we focus on the important role and different mechanisms of action of LOX pathways in the regulation of pancreatic cancer initiation and progression. A novel approach for pancreatic cancer chemoprevention would involve targeting LOX activities, alone or in combination with other pathways as a major anticancer strategy.
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Affiliation(s)
- A Comba
- Ia Cátedra de Biología Celular, Histología y Embriología, Instituto de Biología Celular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Niknami M, Dong Q, Witting PK. Pitfalls in the use of arachidonic acid oxidation products to assign lipoxygenase activity in cancer cells. Free Radic Res 2009; 43:951-6. [PMID: 19680997 DOI: 10.1080/10715760903145013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Arachidonic acid (AA) reaction with cyclooxygenase (COX) and lipoxygenases (LOX) yield eicosanoids that can mediate prostate cancer proliferation and enhance both tumour vascularization and metastasis. Increasingly measurement of eicosanoids with liquid chromatography is employed to implicate LOX activity in different biological systems and in particular link LOX activity to the progression of cancer in experimental models. This study demonstrates that simply identifying patterns of eicosanoid regio-isomerism is insufficient to designate LOX activity in prostate cancer cells and the analysis must include complete stereochemical assignment of the various isomers in order to validate the assignment of LOX activity.
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Affiliation(s)
- Marzieh Niknami
- Cancer Biology Group, Department of Endocrinology and Sydney Cancer Centre, Central Clinical School, The University of Sydney, NSW, Australia
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16
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Garscha U, Nilsson T, Oliw EH. Enantiomeric separation and analysis of unsaturated hydroperoxy fatty acids by chiral column chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 872:90-8. [DOI: 10.1016/j.jchromb.2008.07.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 07/10/2008] [Accepted: 07/14/2008] [Indexed: 11/25/2022]
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Zheng Y, Boeglin WE, Schneider C, Brash AR. A 49-kDa mini-lipoxygenase from Anabaena sp. PCC 7120 retains catalytically complete functionality. J Biol Chem 2007; 283:5138-47. [PMID: 18070874 DOI: 10.1074/jbc.m705780200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Anabaena sp. PCC 7120 is one of the few prokaryotes harboring a lipoxygenase (LOX) gene. The sequence resides in an open reading frame encoding a fusion protein of a catalase-like hemoprotein with an unusually short LOX (approximately 49 kDa) at the C terminus. The recombinant mini-LOX contains a non-heme iron in the active site and is highly active with linoleic and alpha-linolenic acids (which occur naturally in Anabaena) giving the respective 9R-hydroperoxides, the mirror image of the 9S-LOX products of plants. Using stereospecifically labeled [11-(3)H]linoleic acids we show that reaction is catalyzed via a typical antarafacial relationship of initial hydrogen abstraction and oxygenation. The mini-LOX oxygenated C16/C18:2-phosphatidylcholine with 9R specificity, suggesting a "tail first" mode of fatty acid binding. Site-directed mutagenesis of an active site Ala (Ala215), typically conserved as Gly in R-LOX, revealed that substitution with Gly retained 9R specificity, whereas the larger Val substitution switched oxygenation to 13S, implying that Ala215 represents the functional equivalent of the Gly in other R-LOX. Metabolism studies using a synthetic fatty acid with extended double bond conjugation, 9E,11Z,14Z-20:3omega6, showed that the mini-LOX can control oxygenation two positions further along the fatty acid carbon chain. We conclude that the mini-LOX, despite lacking the beta-barrel domain and much additional sequence, is catalytically complete. Interestingly, animal and plant LOX, which undoubtedly share a common ancestor, are related in sequence only in the catalytic domain; it is possible that the prokaryotic LOX represents a common link and that the beta-barrel domain was then acquired independently in the animal and plant kingdoms.
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Affiliation(s)
- Yuxiang Zheng
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA
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18
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Schneider C, Pratt DA, Porter NA, Brash AR. Control of oxygenation in lipoxygenase and cyclooxygenase catalysis. ACTA ACUST UNITED AC 2007; 14:473-88. [PMID: 17524979 PMCID: PMC2692746 DOI: 10.1016/j.chembiol.2007.04.007] [Citation(s) in RCA: 222] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 04/03/2007] [Accepted: 04/10/2007] [Indexed: 12/16/2022]
Abstract
Lipoxygenases (LOX) and cyclooxygenases (COX) react an achiral polyunsaturated fatty acid with oxygen to form a chiral peroxide product of high regio- and stereochemical purity. Both enzymes employ free radical chemistry reminiscent of hydrocarbon autoxidation but execute efficient control during catalysis to form a specific product over the multitude of isomers found in the nonenzymatic reaction. Exactly how both dioxygenases achieve this positional and stereo control is far from clear. We present four mechanistic models, not mutually exclusive, that could account for the specific reactions of molecular oxygen with a fatty acid in the LOX or COX active site.
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Affiliation(s)
- Claus Schneider
- Department of Pharmacology, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, U.S.A
| | - Derek A. Pratt
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, U.S.A
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - Ned A. Porter
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, U.S.A
| | - Alan R. Brash
- Department of Pharmacology, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, U.S.A
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19
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Gaquerel E, Hervé C, Labrière C, Boyen C, Potin P, Salaün JP. Evidence for oxylipin synthesis and induction of a new polyunsaturated fatty acid hydroxylase activity in Chondrus crispus in response to methyljasmonate. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:565-75. [PMID: 17428728 DOI: 10.1016/j.bbalip.2007.02.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Revised: 02/01/2007] [Accepted: 02/13/2007] [Indexed: 11/29/2022]
Abstract
Signaling cascades involving oxygenated derivatives (oxylipins) of polyunsaturated fatty acids (PUFAs) are known to operate in response to external stimuli. The marine red alga Chondrus crispus uses both oxygenated derivatives of C18 (octadecanoids) and C20 (eicosanoids) PUFAs as developmental or defense hormones. The present study demonstrates that methyljasmonate (MeJA) triggers a cascade of oxidation of PUFAs leading to the synthesis of prostaglandins and other oxygenated fatty acids. As a result of a lipoxygenase-like activation, MeJA induces a concomitant accumulation of 13-hydroxy-9Z,11E-octadecadienoic acid (13-HODE) and 13-oxo-9Z,11E-octadecadienoic acid (13-oxo-ODE) in a dose-dependent manner in C. crispus. Furthermore, MeJA increases the level of mRNA encoding a gluthatione S-transferase and induces the activity of a new enzyme catalyzing the regio- and stereoselective bisallylic hydroxylation of polyunsaturated fatty acids from C(18) to C(22). The enzyme selectively oxidized the omega minus 7 carbon position (omega-7) and generated the stereoselective (R)-hydroxylated metabolites with a large enantiomeric excess. The enzyme specificity for the fatty acid recognition was not dependent of the position of double bonds but at least requires a methylene interrupted double bond 1,4-pentadiene motif involving the omega-7 carbon.
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Affiliation(s)
- Emmanuel Gaquerel
- Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris6, Laboratoire International Associé-Dispersal and Adaptation in Marine Species, Unité Mixte de Recherche 7139, Station Biologique, F-29682 Roscoff Cedex, France
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20
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Yu Z, Schneider C, Boeglin WE, Brash AR. Human and mouse eLOX3 have distinct substrate specificities: implications for their linkage with lipoxygenases in skin. Arch Biochem Biophys 2006; 455:188-96. [PMID: 17045234 PMCID: PMC2636205 DOI: 10.1016/j.abb.2006.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 09/01/2006] [Accepted: 09/02/2006] [Indexed: 11/23/2022]
Abstract
Genetic and biochemical evidence suggests a functional link between human 12R-lipoxygenase (12R-LOX) and epidermal lipoxygenase-3 (eLOX3) in normal differentiation of the epidermis; LOX-derived fatty acid hydroperoxide is isomerized by the atypical eLOX3 into a specific epoxyalcohol that is a potential mediator in the pathway. Mouse epidermis expresses a different complement of LOX enzymes, and therefore this metabolic linkage could differ. To test this concept, we compared the substrate specificities of recombinant mouse and human eLOX3 toward sixteen hydroperoxy stereoisomers of arachidonic and linoleic acids. Both enzymes metabolized R-hydroperoxides 2-3 times faster than the corresponding S enantiomers. Whereas 12R-hydroperoxyeicosatetraenoic acid (12R-HPETE) is the best substrate for human eLOX3 (2.4 s(-1); at 30 microM substrate), mouse eLOX3 shows the highest turnover with 8R-HPETE (2.9 s(-1)) followed by 8S-HPETE (1.3 s(-1)). Novel product structures were characterized from reactions of mouse eLOX3 with 5S-, 8R-, and 8S-HPETEs. 8S-HPETE is converted specifically to a single epoxyalcohol, identified as 10R-hydroxy-8S,9S-epoxyeicosa-5Z,11Z,14Z-trienoic acid. The substrate preference of mouse eLOX3 and the unique occurrence of an 8S-LOX enzyme in mouse skin point to a potential LOX pathway for the production of epoxyalcohol in murine epidermal differentiation.
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Affiliation(s)
| | | | | | - Alan R. Brash
- Corresponding author: Alan R. Brash, Department of Pharmacology, Vanderbilt University School of Medicine, 23rd Ave. at Pierce, Nashville, TN 37232-6602. Tel.: 615-343-4495; Fax: 615-322-4707; E-mail:
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21
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Affiliation(s)
- Bradley S Moore
- Scripps Institution of Oceanography and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
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22
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Lloyd T, Krol A, Campanaro D, Malkowski M. Purification, crystallization and preliminary X-ray diffraction analysis of pathogen-inducible oxygenase (PIOX) from Oryza sativa. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:365-7. [PMID: 16582486 PMCID: PMC2222573 DOI: 10.1107/s1744309106007305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2006] [Accepted: 02/28/2006] [Indexed: 05/08/2023]
Abstract
Pathogen-inducible oxygenase (PIOX) is a heme-containing membrane-associated protein found in monocotyledon and dicotyledon plants that utilizes molecular oxygen to convert polyunsaturated fatty acids into their corresponding 2R-hydroperoxides. PIOX is a member of a larger family of fatty-acid alpha-dioxygenases that includes the mammalian cyclooxygenase enzymes cyclooxygenase 1 and 2 (COX-1 and COX-2). Single crystals of PIOX from rice (Oryza sativa) have been grown from MPD using recombinant protein expressed in Escherichia coli and subsequently extracted utilizing decyl maltoside as the solubilizing detergent. Crystals diffract to 3.0 angstroms resolution using a rotating-anode generator and R-AXIS IV detector, and belong to space group P1. Based on the Matthews coefficient and self-rotation function analyses, there are presumed to be four molecules in the asymmetric unit related by noncrystallographic 222 symmetry.
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Affiliation(s)
- Tracy Lloyd
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
| | - Adam Krol
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
| | - Danielle Campanaro
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
- Department of Structural Biology, SUNY at Buffalo, Buffalo, New York 14203, USA
| | - Michael Malkowski
- Hauptman–Woodward Medical Research Institute, Buffalo, New York 14203, USA
- Department of Structural Biology, SUNY at Buffalo, Buffalo, New York 14203, USA
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23
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Maskrey BH, Taylor GW, Rowley AF. The identification and role of a novel eicosanoid in the reproductive behaviour of barnacles (Balanus balanus). J Exp Biol 2006; 209:558-66. [PMID: 16424106 DOI: 10.1242/jeb.02037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
SUMMARY
Post-copulatory behaviour in barnacles involves a violent rocking movement of the opercular valves, which is thought to contribute to the expulsion of oocytes through the oviduct into the mantle cavity where they are fertilised. We demonstrate in this study that the seminal vesicles/testis of the subtidal barnacle Balanus balanus produce a biologically active factor,barnacle muscle stimulatory factor (BMSF), which causes a significant increase in cirral and body muscular activity. BMSF was identified using a combination of high performance liquid chromatography and mass spectrometry as a novel eicosanoid/oxylipin, 8,13-dihydroxyeicosapentaenoic acid. This is rapidly inactivated under mild acid conditions to form a complex range of triene and pentaene chromophore-containing products that have only been partially identified. Injection of purified BMSF into the mantle cavity of barnacles caused the rocking movements of the opercular valves as reported following fertilisation. In excised barnacles, it also caused muscular contractions of the whole body mass. The breakdown products of BMSF, however, were without such activities. The function of BMSF in facilitating fertilisation in barnacles is comparable to the role of other eicosanoids in human reproduction, reinforcing the view that these compounds have conserved activities in both invertebrates and vertebrates.
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Affiliation(s)
- Ben H Maskrey
- Department of Biological Sciences and Institute of Environmental Sustainability, University of Wales Swansea, Swansea, SA2 8PP, UK
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Mortimer M, Järving R, Brash AR, Samel N, Järving I. Identification and characterization of an arachidonate 11R-lipoxygenase. Arch Biochem Biophys 2006; 445:147-55. [PMID: 16321357 DOI: 10.1016/j.abb.2005.10.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 10/22/2005] [Accepted: 10/28/2005] [Indexed: 11/16/2022]
Abstract
11R-Lipoxygenase (11R-LOX) activity has been detected in several marine invertebrates, and here we report the first cloning and expression of the enzyme. The cDNA encoding a protein of 77kDa was isolated by RT-PCR from the soft coral Gersemia fruticosa and expressed in Escherichia coli. Incubations of recombinant enzyme with arachidonic acid yielded a single product, identified by RP-HPLC, GC-MS, and chiral phase-HPLC as 11R-hydroperoxyeicosatetraenoic acid. Other C18, C20, and C22 substrates are also oxygenated, preferentially at the omega10 position. Significantly, both Ca(2+)-ions and a membrane fraction are required for catalytic activity. Calcium effects translocation of the soluble 11R-LOX to the membrane and this association is reversible by Ca(2+) chelation. The enzyme sequence contains some conserved amino acids implicated in calcium activation of mammalian 5-LOX, and with its obligate requirement for membrane interaction the 11R-LOX may thus provide a new model for further analysis of this aspect of lipoxygenase activation.
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Affiliation(s)
- Monika Mortimer
- Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
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Coffa G, Brash AR. A single active site residue directs oxygenation stereospecificity in lipoxygenases: stereocontrol is linked to the position of oxygenation. Proc Natl Acad Sci U S A 2004; 101:15579-84. [PMID: 15496467 PMCID: PMC524819 DOI: 10.1073/pnas.0406727101] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lipoxygenases are a class of dioxygenases that form hydroperoxy fatty acids with distinct positional and stereo configurations. Several amino acid residues influencing regiospecificity have been identified, whereas the basis of stereocontrol is not understood. We have now identified a single residue in the lipoxygenase catalytic domain that is important for stereocontrol; it is conserved as an Ala in S lipoxygenases and a Gly in R lipoxygenases. Our results with mutation of the conserved Ala to Gly in two S lipoxygenases (mouse 8S-LOX and human 15-LOX-2) and the corresponding Gly-Ala substitution in two R lipoxygenases (human 12R-LOX and coral 8R-LOX) reveal that the basis for R or S stereo-control also involves a switch in the position of oxygenation on the substrate. After the initial hydrogen abstraction, antarafacial oxygenation at one end or the other of the activated pair of double bonds (pentadiene) gives, for example, 8S or 12R product. The Ala residue promotes oxygenation on the reactive pentadiene at the end deep in the substrate binding pocket and S stereochemistry of the product hydroperoxide, and a Gly residue promotes oxygenation at the proximal end of the reactive pentadiene resulting in R stereochemistry. A model of lipoxygenase reaction specificity is proposed in which product regiochemistry and stereochemistry are determined by fixed relationships between substrate orientation, hydrogen abstraction, and the Gly or Ala residue we have identified.
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Affiliation(s)
- Gianguido Coffa
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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