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Xu J, Morisseau C, Yang J, Mamatha DM, Hammock BD. Epoxide hydrolase activities and epoxy fatty acids in the mosquito Culex quinquefasciatus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 59:41-9. [PMID: 25686802 PMCID: PMC4387068 DOI: 10.1016/j.ibmb.2015.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/05/2015] [Accepted: 02/05/2015] [Indexed: 05/27/2023]
Abstract
Culex mosquitoes have emerged as important model organisms for mosquito biology, and are disease vectors for multiple mosquito-borne pathogens, including West Nile virus. We characterized epoxide hydrolase activities in the mosquito Culex quinquefasciatus, which suggested multiple forms of epoxide hydrolases were present. We found EH activities on epoxy eicosatrienoic acids (EETs). EETs and other eicosanoids are well-established lipid signaling molecules in vertebrates. We showed EETs can be synthesized in vitro from arachidonic acids by mosquito lysate, and EETs were also detected in vivo both in larvae and adult mosquitoes by LC-MS/MS. The EH activities on EETs can be induced by blood feeding, and the highest activity was observed in the midgut of female mosquitoes. The enzyme activities on EETs can be inhibited by urea-based inhibitors designed for mammalian soluble epoxide hydrolases (sEH). The sEH inhibitors have been shown to play diverse biological roles in mammalian systems, and they can be useful tools to study the function of EETs in mosquitoes. Besides juvenile hormone metabolism and detoxification, insect epoxide hydrolases may also play a role in regulating lipid signaling molecules, such as EETs and other epoxy fatty acids, synthesized in vivo or obtained from blood feeding by female mosquitoes.
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Affiliation(s)
- Jiawen Xu
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California, Davis, CA 95616, USA
| | - Christophe Morisseau
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California, Davis, CA 95616, USA
| | - Jun Yang
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California, Davis, CA 95616, USA
| | - Dadala M Mamatha
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California, Davis, CA 95616, USA
| | - Bruce D Hammock
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California, Davis, CA 95616, USA.
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Oesch F, Fabian E, Guth K, Landsiedel R. Xenobiotic-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models. Arch Toxicol 2014; 88:2135-90. [PMID: 25370008 PMCID: PMC4247477 DOI: 10.1007/s00204-014-1382-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/02/2014] [Indexed: 02/01/2023]
Abstract
The exposure of the skin to medical drugs, skin care products, cosmetics, and other chemicals renders information on xenobiotic-metabolizing enzymes (XME) in the skin highly interesting. Since the use of freshly excised human skin for experimental investigations meets with ethical and practical limitations, information on XME in models comes in the focus including non-human mammalian species and in vitro skin models. This review attempts to summarize the information available in the open scientific literature on XME in the skin of human, rat, mouse, guinea pig, and pig as well as human primary skin cells, human cell lines, and reconstructed human skin models. The most salient outcome is that much more research on cutaneous XME is needed for solid metabolism-dependent efficacy and safety predictions, and the cutaneous metabolism comparisons have to be viewed with caution. Keeping this fully in mind at least with respect to some cutaneous XME, some models may tentatively be considered to approximate reasonable closeness to human skin. For dermal absorption and for skin irritation among many contributing XME, esterase activity is of special importance, which in pig skin, some human cell lines, and reconstructed skin models appears reasonably close to human skin. With respect to genotoxicity and sensitization, activating XME are not yet judgeable, but reactive metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the “Overview and Conclusions” section in the end of this review.
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Affiliation(s)
- F Oesch
- Oesch-Tox Toxicological Consulting and Expert Opinions GmbH&Co.KG, Rheinblick 21, 55263, Wackernheim, Germany
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Wagner K, Vito S, Inceoglu B, Hammock BD. The role of long chain fatty acids and their epoxide metabolites in nociceptive signaling. Prostaglandins Other Lipid Mediat 2014; 113-115:2-12. [PMID: 25240260 PMCID: PMC4254344 DOI: 10.1016/j.prostaglandins.2014.09.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 12/15/2022]
Abstract
Lipid derived mediators contribute to inflammation and the sensing of pain. The contributions of omega-6 derived prostanoids in enhancing inflammation and pain sensation are well known. Less well explored are the opposing anti-inflammatory and analgesic effects of the omega-6 derived epoxyeicosatrienoic acids. Far less has been described about the epoxidized metabolites derived from omega-3 long chain fatty acids. The epoxide metabolites are turned over rapidly with enzymatic hydrolysis by the soluble epoxide hydrolase being the major elimination pathway. Despite this, the overall understanding of the role of lipid mediators in the pathology of chronic pain is growing. Here, we review the role of long chain fatty acids and their metabolites in alleviating both acute and chronic pain conditions. We focus specifically on the epoxidized metabolites of omega-6 and omega-3 long chain fatty acids as well as a novel strategy to modulate their activity in vivo.
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Affiliation(s)
- Karen Wagner
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Steve Vito
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Bora Inceoglu
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Bruce D Hammock
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States.
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El-Sherbeni AA, El-Kadi AOS. The role of epoxide hydrolases in health and disease. Arch Toxicol 2014; 88:2013-32. [PMID: 25248500 DOI: 10.1007/s00204-014-1371-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 09/11/2014] [Indexed: 01/09/2023]
Abstract
Epoxide hydrolases (EH) are ubiquitously expressed in all living organisms and in almost all organs and tissues. They are mainly subdivided into microsomal and soluble EH and catalyze the hydration of epoxides, three-membered-cyclic ethers, to their corresponding dihydrodiols. Owning to the high chemical reactivity of xenobiotic epoxides, microsomal EH is considered protective enzyme against mutagenic and carcinogenic initiation. Nevertheless, several endogenously produced epoxides of fatty acids function as important regulatory mediators. By mediating the formation of cytotoxic dihydrodiol fatty acids on the expense of cytoprotective epoxides of fatty acids, soluble EH is considered to have cytotoxic activity. Indeed, the attenuation of microsomal EH, achieved by chemical inhibitors or preexists due to specific genetic polymorphisms, is linked to the aggravation of the toxicity of xenobiotics, as well as the risk of cancer and inflammatory diseases, whereas soluble EH inhibition has been emerged as a promising intervention against several diseases, most importantly cardiovascular, lung and metabolic diseases. However, there is reportedly a significant overlap in substrate selectivity between microsomal and soluble EH. In addition, microsomal and soluble EH were found to have the same catalytic triad and identical molecular mechanism. Consequently, the physiological functions of microsomal and soluble EH are also overlapped. Thus, studying the biological effects of microsomal or soluble EH alterations needs to include the effects on both the metabolism of reactive metabolites, as well as epoxides of fatty acids. This review focuses on the multifaceted role of EH in the metabolism of xenobiotic and endogenous epoxides and the impact of EH modulations.
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Affiliation(s)
- Ahmed A El-Sherbeni
- Faculty of Pharmacy and Pharmaceutical Sciences, 2142J Katz Group-Rexall Centre for Pharmacy and Health Research, University of Alberta, Edmonton, AB, T6G 2E1, Canada
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Spector AA, Kim HY. Cytochrome P450 epoxygenase pathway of polyunsaturated fatty acid metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:356-65. [PMID: 25093613 DOI: 10.1016/j.bbalip.2014.07.020] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/22/2014] [Accepted: 07/25/2014] [Indexed: 12/19/2022]
Abstract
Polyunsaturated fatty acids (PUFA) are oxidized by cytochrome P450 epoxygenases to PUFA epoxides which function as potent lipid mediators. The major metabolic pathways of PUFA epoxides are incorporation into phospholipids and hydrolysis to the corresponding PUFA diols by soluble epoxide hydrolase. Inhibitors of soluble epoxide hydrolase stabilize PUFA epoxides and potentiate their functional effects. The epoxyeicosatrienoic acids (EETs) synthesized from arachidonic acid produce vasodilation, stimulate angiogenesis, have anti-inflammatory actions, and protect the heart against ischemia-reperfusion injury. EETs produce these functional effects by activating receptor-mediated signaling pathways and ion channels. The epoxyeicosatetraenoic acids synthesized from eicosapentaenoic acid and epoxydocosapentaenoic acids synthesized from docosahexaenoic acid are potent inhibitors of cardiac arrhythmias. Epoxydocosapentaenoic acids also inhibit angiogenesis, decrease inflammatory and neuropathic pain, and reduce tumor metastasis. These findings indicate that a number of the beneficial functions of PUFA may be due to their conversion to PUFA epoxides. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".
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Affiliation(s)
- Arthur A Spector
- Laboratory of Molecular Signaling, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA.
| | - Hee-Yong Kim
- Laboratory of Molecular Signaling, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
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Bishop-Bailey D, Thomson S, Askari A, Faulkner A, Wheeler-Jones C. Lipid-metabolizing CYPs in the regulation and dysregulation of metabolism. Annu Rev Nutr 2014; 34:261-79. [PMID: 24819323 DOI: 10.1146/annurev-nutr-071813-105747] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The cytochrome P450s (CYPs) represent a highly divergent class of enzymes involved in the oxidation of organic compounds. A subgroup of CYPs metabolize ω3-arachidonic and linoleic acids and ω6-docosahexaenoic and eicosapentaenoic polyunsaturated fatty acids (PUFAs) into a series of related biologically active mediators. Over the past 20 years, increasing evidence has emerged for a role of these PUFA-derived mediators in physiological and pathophysiological processes in the vasculature, during inflammation, and in the regulation of metabolism. With recent technological advances and increased availability of lipid mass spectroscopy, we are now starting to discern the patterns of these CYP-PUFA products in health and disease. These analyses not only are revealing the diverse spectrum of lipid nutrients regulated by CYPs, but also clearly indicate that the balance of these mediators changes with dietary intake of different PUFA classes. These findings suggest that we are only just beginning to understand all of the relevant lipid species produced by CYP pathways. Moreover, we are still a long way from understanding the nature and presence of their receptors, their tissue expression, and the pathophysiological processes they regulate. This review highlights these future issues in the context of lipid-metabolizing CYP enzymes, focusing particularly on the CYP450 family of epoxygenases and the lipid mediators they produce.
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Affiliation(s)
- David Bishop-Bailey
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, London NW1 0TU, United Kingdom;
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Gundert-Remy U, Bernauer U, Blömeke B, Döring B, Fabian E, Goebel C, Hessel S, Jäckh C, Lampen A, Oesch F, Petzinger E, Völkel W, Roos PH. Extrahepatic metabolism at the body's internal–external interfaces. Drug Metab Rev 2014; 46:291-324. [DOI: 10.3109/03602532.2014.900565] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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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: 80] [Impact Index Per Article: 8.0] [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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59
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Lord CC, Thomas G, Brown JM. Mammalian alpha beta hydrolase domain (ABHD) proteins: Lipid metabolizing enzymes at the interface of cell signaling and energy metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:792-802. [PMID: 23328280 DOI: 10.1016/j.bbalip.2013.01.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 12/07/2012] [Accepted: 01/02/2013] [Indexed: 11/16/2022]
Abstract
Dysregulation of lipid metabolism underlies many chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Therefore, understanding enzymatic mechanisms controlling lipid synthesis and degradation is imperative for successful drug discovery for these human diseases. Genes encoding α/β hydrolase fold domain (ABHD) proteins are present in virtually all reported genomes, and conserved structural motifs shared by these proteins predict common roles in lipid synthesis and degradation. However, the physiological substrates and products for these lipid metabolizing enzymes and their broader role in metabolic pathways remain largely uncharacterized. Recently, mutations in several members of the ABHD protein family have been implicated in inherited inborn errors of lipid metabolism. Furthermore, studies in cell and animal models have revealed important roles for ABHD proteins in lipid metabolism, lipid signal transduction, and metabolic disease. The purpose of this review is to provide a comprehensive summary surrounding the current state of knowledge regarding mammalian ABHD protein family members. In particular, we will discuss how ABHD proteins are ideally suited to act at the interface of lipid metabolism and signal transduction. Although, the current state of knowledge regarding mammalian ABHD proteins is still in its infancy, this review highlights the potential for the ABHD enzymes as being attractive targets for novel therapies targeting metabolic disease.
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Affiliation(s)
- Caleb C Lord
- Department of Pathology, Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - Gwynneth Thomas
- Department of Pathology, Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
| | - J Mark Brown
- Department of Pathology, Section on Lipid Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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