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Horio Y, Isegawa Y, Shichiri M. Daidzein phosphorylates and activates 5-lipoxygenase via the MEK/ERK pathway: a mechanism for inducing the production of 5-lipoxygenase metabolite that inhibit influenza virus intracellular replication. J Nutr Biochem 2023; 114:109276. [PMID: 36682398 DOI: 10.1016/j.jnutbio.2023.109276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 12/01/2022] [Accepted: 01/13/2023] [Indexed: 01/22/2023]
Abstract
We previously reported that the soy isoflavone daidzein (Dz) suppresses the intracellular replication of influenza virus and that arachidonic acid-derived oxidation product via lipid oxidase 5-lipoxygenase (5-LOX) is involved in its antiviral effect. The activation of 5-LOX by Dz triggers anti-influenza activity; however, the mechanism of activation of 5-LOX remains unclear. Therefore, in this study, we aimed to clarify the activation mechanism using human monocyte-derived THP-1 cells differentiated using phorbol 12-myristate 13-acetate. THP-1 cells expressed 5-LOX endogenously and Dz did not induce 5-LOX expression. However, 8 h after treatment with Dz, the amount of 5-hydroxyeicosatetraenoic acid (5-HETE), an arachidonic acid oxidation product via 5-LOX, increased significantly suggesting that the enzyme is activated regardless of changes in 5-LOX protein levels. Intracellular Ca2+ content, ATP concentration, 5-LOX protein phosphorylation, and 5-LOX intracellular localization are known 5-LOX activation factors. The intracellular Ca2+ and ATP concentrations were not affected by Dz treatment. The enzymatic activity of 5-LOX is regulated by the phosphorylation of three serine residues and four tyrosine residues. Pretreatment with inhibitors of each kinase revealed that Dz-induced 5-HETE production was suppressed by the MEK/ERK inhibitor. 5-LOX in which the Ser663 residue was phosphorylated was found to be increased in the nuclear fraction of Dz-treated THP-1 cells. Furthermore, immunocytochemistry showed that 5-LOX translocates to the nuclear envelope following Dz treatment. These results indicate that Dz activates 5-LOX by phosphorylating Ser663 via the MEK/ERK pathway. Thus, these results demonstrate that Dz exerts anti-influenza virus activity via the MEK/ERK signal transduction pathway.
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Affiliation(s)
- Yuka Horio
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka, Japan; Department of Food Sciences and Nutrition, Mukogawa Women's University, Nishinomiya, Hyogo, Japan
| | - Yuji Isegawa
- Department of Food Sciences and Nutrition, Mukogawa Women's University, Nishinomiya, Hyogo, Japan.
| | - Mototada Shichiri
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka, Japan.
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2
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Narzt MS, Kremslehner C, Golabi B, Nagelreiter IM, Malikovic J, Hussein AM, Plasenzotti R, Korz V, Lubec G, Gruber F, Lubec J. Molecular species of oxidized phospholipids in brain differentiate between learning- and memory impaired and unimpaired aged rats. Amino Acids 2022; 54:1311-1326. [PMID: 35817992 PMCID: PMC9372013 DOI: 10.1007/s00726-022-03183-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 06/17/2022] [Indexed: 02/08/2023]
Abstract
Loss of cognitive function is a typical consequence of aging in humans and rodents. The extent of decline in spatial memory performance of rats, assessed by a hole-board test, reaches from unimpaired and comparable to young individuals to severely memory impaired. Recently, proteomics identified peroxiredoxin 6, an enzyme important for detoxification of oxidized phospholipids, as one of several synaptosomal proteins discriminating between aged impaired and aged unimpaired rats. In this study, we investigated several components of the epilipidome (modifications of phospholipids) of the prefrontal cortex of young, aged memory impaired (AI) and aged unimpaired (AU) rats. We observed an age-related increase in phospholipid hydroperoxides and products of phospholipid peroxidation, including reactive aldehydophospholipids. This increase went in hand with cortical lipofuscin autofluorescence. The memory impairment, however, was paralleled by additional specific changes in the aged rat brain epilipidome. There was a profound increase in phosphocholine hydroxides, and a significant decrease in phosphocholine-esterified azelaic acid. As phospholipid-esterified fatty acid hydroxides, and especially those deriving from arachidonic acid are both markers and effectors of inflammation, the findings suggest that in addition to age-related reactive oxygen species (ROS) accumulation, age-related impairment of spatial memory performance has an additional and distinct (neuro-) inflammatory component.
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Affiliation(s)
- Marie-Sophie Narzt
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, AUVA Research Center, Linz/Vienna, Austria
| | | | - Bahar Golabi
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Ionela-Mariana Nagelreiter
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
- Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria
| | - Jovana Malikovic
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Ahmed M Hussein
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
- Programme for Proteomics, Paracelsus Private Medical University, Salzburg, Austria
- Department of Zoology, Faculty of Science, Al-Azhar University, Assiut, Egypt
| | - Roberto Plasenzotti
- Center for Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Himberg, Austria
| | - Volker Korz
- Programme for Proteomics, Paracelsus Private Medical University, Salzburg, Austria
| | - Gert Lubec
- Programme for Proteomics, Paracelsus Private Medical University, Salzburg, Austria
| | - Florian Gruber
- Department of Dermatology, Medical University of Vienna, Vienna, Austria.
| | - Jana Lubec
- Programme for Proteomics, Paracelsus Private Medical University, Salzburg, Austria.
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3
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Serbulea V, DeWeese D, Leitinger N. The effect of oxidized phospholipids on phenotypic polarization and function of macrophages. Free Radic Biol Med 2017; 111:156-168. [PMID: 28232205 PMCID: PMC5511074 DOI: 10.1016/j.freeradbiomed.2017.02.035] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/09/2017] [Accepted: 02/15/2017] [Indexed: 12/26/2022]
Abstract
Oxidized phospholipids are products of lipid oxidation that are found on oxidized low-density lipoproteins and apoptotic cell membranes. These biologically active lipids were shown to affect a variety of cell types and attributed pro-as well as anti-inflammatory effects. In particular, macrophages exposed to oxidized phospholipids drastically change their gene expression pattern and function. These 'Mox,'macrophages were identified in atherosclerotic lesions, however, it remains unclear how lipid oxidation products are sensed by macrophages and how they influence their biological function. Here, we review recent developments in the field that provide insight into the structure, recognition, and downstream signaling of oxidized phospholipids in macrophages.
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Affiliation(s)
- Vlad Serbulea
- Robert M. Berne Cardiovascular Research Center and Department of Pharmacology, University of Virginia, USA
| | - Dory DeWeese
- Robert M. Berne Cardiovascular Research Center and Department of Pharmacology, University of Virginia, USA
| | - Norbert Leitinger
- Robert M. Berne Cardiovascular Research Center and Department of Pharmacology, University of Virginia, USA
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4
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The role of mid-chain hydroxyeicosatetraenoic acids in the pathogenesis of hypertension and cardiac hypertrophy. Arch Toxicol 2015; 90:119-36. [PMID: 26525395 DOI: 10.1007/s00204-015-1620-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/19/2015] [Indexed: 12/16/2022]
Abstract
The incidence, prevalence, and hospitalization rates associated with cardiovascular diseases (CVDs) are projected to increase substantially in the world. Understanding of the biological and pathophysiological mechanisms of survival can help the researchers to develop new management modalities. Numerous experimental studies have demonstrated that mid-chain HETEs are strongly involved in the pathogenesis of the CVDs. Mid-chain HETEs are biologically active eicosanoids that result from the metabolism of arachidonic acid (AA) by both lipoxygenase and CYP1B1 (lipoxygenase-like reaction). Therefore, identifying the localizations and expressions of the lipoxygenase and CYP1B1 and their associated AA metabolites in the cardiovascular system is of major importance in understanding their pathological roles. Generally, the expression of these enzymes is shown to be induced during several CVDs, including hypertension and cardiac hypertrophy. The induction of these enzymes is associated with the generation of mid-chain HETEs and subsequently causation of cardiovascular events. Of interest, inhibiting the formation of mid-chain HETEs has been reported to confer a protection against different cardiac hypertrophy and hypertension models such as angiotensin II, Goldblatt, spontaneously hypertensive rat and deoxycorticosterone acetate (DOCA)-salt-induced models. Although the exact mechanisms of mid-chain HETEs-mediated cardiovascular dysfunction are not fully understood, the present review proposes several mechanisms which include activating G-protein-coupled receptor, protein kinase C, mitogen-activated protein kinases, and nuclear factor kappa B. This review provides a clear understanding of the role of mid-chain HETEs in the pathogenesis of cardiovascular diseases and their importance as novel targets in the treatment for hypertension and cardiac hypertrophy.
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5
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Thomas CP, O'Donnell VB. Oxidized phospholipid signaling in immune cells. Curr Opin Pharmacol 2012; 12:471-7. [PMID: 22445283 DOI: 10.1016/j.coph.2012.02.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/17/2012] [Accepted: 02/22/2012] [Indexed: 01/18/2023]
Abstract
Oxidized phospholipids (oxPLs) that can be generated either enzymatically or non-enzymatically are fast becoming recognized as important signaling mediators of the immune system. Hundreds of structures exist, but only a small fraction have been studied in detail. Their known activities include regulation of adhesion molecule expression, pro-coagulant activity and inhibition of Toll-like receptor signaling, and several have been detected in models of human and animal disease. In this review, the most studied structures of oxPLs will be summarized, along with descriptions of their known biological actions. Subsequently, the focus will be on the more recently described forms generated acutely by lipoxygenases (LOX) in human and murine immune cells.
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Affiliation(s)
- Christopher P Thomas
- Institute of Infection and Immunity, School of Medicine, Heath Park, Cardiff University, CF14 4XN, UK
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6
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O'Donnell VB. Mass spectrometry analysis of oxidized phosphatidylcholine and phosphatidylethanolamine. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:818-26. [PMID: 21835265 DOI: 10.1016/j.bbalip.2011.07.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 06/30/2011] [Accepted: 07/26/2011] [Indexed: 10/17/2022]
Abstract
Oxidized phospholipids (OxPLs) are rapidly becoming recognized as important mediators of cellular and immune signaling. They are generated either enzymatically or non-enzymatically and 100s of structures exist of which only a small fraction have been analyzed to date. Pleiotropic activities, including regulation of adhesion molecule expression, pro-coagulant activity and inhibition of Toll-like receptor signaling have been observed and some are detected in models of human and animal disease, including atherosclerosis and infection. More recently, the acute generation of specific oxidized phospholipids by cellular enzymes in immune cells was reported. Assays for analysis and quantification of OxPLs were first developed approx 15years ago, primarily for hydro(pero)xy-species. Many were based on monitoring a single precursor ion with/without LC separation, based on the PL headgroup. Others combined LC with monitoring precursor to product transitions, but were unable to provide information regarding position of oxidation on unsaturated sn-2 fatty acid due to sensitivity issues. More recently, LC/MS/MS methods for specific OxPLs have been reported that enable high sensitivity quantitation in biological samples. In this review, widely used methods for detecting and quantifying various classes of OxPL will be summarized, along with practical advice for their use. In particular, the focus will be on LC/MS/MS, which today is almost universally the method of choice.
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7
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Esterified eicosanoids are acutely generated by 5-lipoxygenase in primary human neutrophils and in human and murine infection. Blood 2010; 117:2033-43. [PMID: 21177434 DOI: 10.1182/blood-2010-04-278887] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
5-Lipoxygenase (5-LOX) plays key roles in infection and allergic responses. Herein, four 5-LOX-derived lipids comprising 5-hydroxyeicosatetraenoic acid (HETE) attached to phospholipids (PLs), either phosphatidylethanolamine (PE) or phosphatidylcholine (18:0p/5-HETE-PE, 18:1p/5-HETE-PE, 16:0p/5-HETE-PE, and 16:0a/5-HETE-PC), were identified in primary human neutrophils. They formed within 2 minutes in response to serum-opsonized Staphylococcus epidermidis or f-methionine-leucine-phenylalanine, with priming by lipopolysaccharide, granulocyte macrophage colony-stimulating factor, or cytochalasin D. Levels generated were similar to free 5-HETE (0.37 ± 0.14 ng vs 0.55 ± 0.18 ng/10(6) cells, esterified vs free 5-HETE, respectively). They remained cell associated, localizing to nuclear and extranuclear membrane, and were formed by fast esterification of newly synthesized free 5-HETE. Generation also required Ca(2+), phospholipase C, cytosolic and secretory phospholipase A(2), 5-LOX activating protein, and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1. 5-HETE-PLs were detected in murine S epidermidis peritonitis, paralleling neutrophil influx, and in effluent from Gram-positive human bacterial peritonitis. Formation of neutrophil extracellular traps was significantly enhanced by 5-LOX inhibition but attenuated by HETE-PE, whereas 5-HETE-PE enhanced superoxide and interleukin-8 generation. Thus, new molecular species of oxidized PL formed by human neutrophils during bacterial infection are identified and characterized.
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8
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Bochkov VN, Oskolkova OV, Birukov KG, Levonen AL, Binder CJ, Stöckl J. Generation and biological activities of oxidized phospholipids. Antioxid Redox Signal 2010; 12:1009-59. [PMID: 19686040 PMCID: PMC3121779 DOI: 10.1089/ars.2009.2597] [Citation(s) in RCA: 403] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glycerophospholipids represent a common class of lipids critically important for integrity of cellular membranes. Oxidation of esterified unsaturated fatty acids dramatically changes biological activities of phospholipids. Apart from impairment of their structural function, oxidation makes oxidized phospholipids (OxPLs) markers of "modified-self" type that are recognized by soluble and cell-associated receptors of innate immunity, including scavenger receptors, natural (germ line-encoded) antibodies, and C-reactive protein, thus directing removal of senescent and apoptotic cells or oxidized lipoproteins. In addition, OxPLs acquire novel biological activities not characteristic of their unoxidized precursors, including the ability to regulate innate and adaptive immune responses. Effects of OxPLs described in vitro and in vivo suggest their potential relevance in different pathologies, including atherosclerosis, acute inflammation, lung injury, and many other conditions. This review summarizes current knowledge on the mechanisms of formation, structures, and biological activities of OxPLs. Furthermore, potential applications of OxPLs as disease biomarkers, as well as experimental therapies targeting OxPLs, are described, providing a broad overview of an emerging class of lipid mediators.
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Affiliation(s)
- Valery N Bochkov
- Department of Vascular Biology and Thrombosis Research, Center for Biomolecular Medicine and Pharmacology, Medical University of Vienna, Vienna, Austria.
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9
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Fujishita S, Inaba C, Tada S, Gemmei-Ide M, Kitano H, Saruwatari Y. Effect of zwitterionic polymers on wound healing. Biol Pharm Bull 2009; 31:2309-15. [PMID: 19043218 DOI: 10.1248/bpb.31.2309] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of a thin film of a zwitterionic random copolymer composed of carboxybetaine [1-carboxy-N,N-dimethyl-N-(2'-methacryloyloxyethyl)methanaminium inner salt] (CMB) and n-butyl methacrylate (BMA), poly(CMB-r-BMA) (CMB, 30 mol%), on the healing of a full-thickness excisional and incisional wound in hairless rats was examined. The poly(CMB-r-BMA) film significantly enhanced wound closure and complete healing of a full-thickness excisional wound compared with the effect of the poly(n-butyl methacrylate) (PBMA) and the poly(ethylene terephthalate) (PET) films. However, the poly(CMB-r-BMA) film did not enhance healing of a full-thickness incisional wound in hairless rats. The amount of proteins adsorbed and that of neutrophiles adhered onto the poly(CMB-r-BMA) film were significantly smaller than those onto the PBMA and PET films. The results suggested that various cells and growth factors in the wound exudate are utilized effectively by covering an excisional wound with the poly(CMB-r-BMA) film, resulting in acceleration of healing. In addition, the poly(CMB-r-BMA) film significantly enhanced healing of a full-thickness excisional wound in hairless rats compared with the effect of Tegaderm as wound dressings. The poly(CMB-r-BMA) film has potential as a new wound dressing.
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Affiliation(s)
- Shigeto Fujishita
- Department of Applied Chemistry, Graduate School of Science and Engineering, University of Toyama, Japan
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10
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Maskrey BH, Bermúdez-Fajardo A, Morgan AH, Stewart-Jones E, Dioszeghy V, Taylor GW, Baker PRS, Coles B, Coffey MJ, Kühn H, O'Donnell VB. Activated Platelets and Monocytes Generate Four Hydroxyphosphatidylethanolamines via Lipoxygenase. J Biol Chem 2007; 282:20151-63. [PMID: 17519227 DOI: 10.1074/jbc.m611776200] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
12/15-Lipoxygenase (LOX) mediates immune-regulatory activities not accounted for by its known free acid eicosanoids, suggesting that additional lipids may be generated by activated cells. To characterize novel LOX-derived lipids, a lipidomic approach was utilized. Ionophore-activated interleukin-4-treated human peripheral monocytes generated up to 10-fold more esterified 15-hydroxyeicosatetraenoic acid (15-HETE) than free in a phosphatidylinositol 3-kinase- and protein kinase C-sensitive manner. Precursor scanning electrospray ionization/tandem spectroscopy for m/z 319 (HETE, [M-H](-)) showed 4 ions at m/z 738, 764, 766, and 782 that were identified using tandem spectroscopy and MS3 as specific diacyl and plasmalogen 15-HETE phosphatidylethanolamines. Using H (18)(2)O water, the compounds were shown to form by direct oxidation of endogenous phosphatidylethanolamine (PE) by 15-LOX, with PE being the preferred phospholipid pool containing 15-HETE. Similarly, human platelets generated 4 analogous PE lipids that contained 12-HETE and increased significantly in response to ionophore, collagen, or convulxin. These products were retained in the cells, in contrast to free acids, which are primarily secreted. Precursor scanning of platelet extracts for the major platelet-derived prostanoid, thromboxane B2 (m/z 369.2), did not reveal PE esters, indicating that this modification is restricted to the LOX pathway. In summary, we show formation of PE-esterified HETEs in immune cells that may contribute to LOX signaling in inflammation.
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Affiliation(s)
- Benjamin H Maskrey
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff, Wales, United Kingdom
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Abstract
Major advances have been made over the last decade towards the elucidation of the molecular mechanisms involved in the endothelium-dependent regulation of vascular tone and blood flow. While the primary endothelium-derived vasodilator autacoid is nitric oxide, it is clear that epoxyeicosatrienoic acids and other endothelium-derived hyperpolarising factors, as well as endothelin-1 and reactive oxygen species, play a significant role in the regulation of vascular tone and gene expression. This review is intended as an overview of the signalling mechanisms that link haemodynamic stimuli (such as shear stress and cyclic stretch) and endothelial cell perturbation to the activation of enzymes generating vasoactive autacoids.
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Affiliation(s)
- R Busse
- Vascular Signalling Group, Institut für Kardiovaskuläre Physiologie, Klinikum der J.W. Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
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12
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Hattori H, Imai H, Hanamoto A, Furuhama K, Nakagawa Y. Up-regulation of phospholipid hydroperoxide glutathione peroxidase in rat casein-induced polymorphonuclear neutrophils. Biochem J 2005; 389:279-87. [PMID: 15757501 PMCID: PMC1175104 DOI: 10.1042/bj20050006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Antioxidant enzymes play key roles in the protection of cells from oxidative damage. Little is known, however, about the expression of antioxidants and/or their roles in PMNs (polymorphonuclear leucocytes), which are thought to suffer from oxidative stress in an inflammation site. In the present paper, we report on the regulation of expression of PHGPx (phospholipid hydroperoxide glutathione peroxidase) and cGPx (cytosolic glutathione peroxidase) in rat PMNs in the inflammation site. PHGPx mRNA levels were much lower in casein-induced peritoneal and carrageenan-induced pleural PMNs just after their collection than in peripheral PMNs. cGPx mRNA was also reduced in the casein-induced PMNs, but not in carrageenan-induced PMNs. Both enzymes with decreased levels in the casein-induced PMNs were up-regulated during further 24 h cultivation in vitro and in vivo, with elevation of their protein levels and activities, and reduction of intracellular peroxides. Up-regulation of PHGPx mRNA was attenuated by cycloheximide, a protein synthesis inhibitor, and this effect was cancelled by culturing the cells in the conditioned medium of the cultured casein-induced PMNs. This latter effect was attenuated by pre-treatment with anti-GRO (growth-regulated oncogene) antibody. Recombinant rat GRO could also induce the up-regulation in the presence of cycloheximide, demonstrating that GRO may play an important role in the PHGPx up-regulation of casein-induced PMNs. Production of the lipid mediators leukotriene B4 and 5-HETE (5-hydroxyeicosatetraenoic acid) was decreased in the cultured casein-induced PMNs exhibiting PHGPx up-regulation. The evidence obtained indicates that PHGPx activity in the activated PMNs would be related to the appearance of the intrinsic function of PMNs in the inflammatory site.
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Affiliation(s)
- Hiroyuki Hattori
- *School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
- †Drug Safety Research Laboratory, Daiichi Pharmaceutical Co. Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
| | - Hirotaka Imai
- *School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Akiharu Hanamoto
- *School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Kazuhisa Furuhama
- †Drug Safety Research Laboratory, Daiichi Pharmaceutical Co. Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
| | - Yasuhito Nakagawa
- *School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
- To whom correspondence should be addressed (email )
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13
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Imai H, Nakagawa Y. Biological significance of phospholipid hydroperoxide glutathione peroxidase (PHGPx, GPx4) in mammalian cells. Free Radic Biol Med 2003; 34:145-69. [PMID: 12521597 DOI: 10.1016/s0891-5849(02)01197-8] [Citation(s) in RCA: 529] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reactive oxygen species (ROS) are known mediators of intracellular signal cascades. Excessive production of ROS may lead to oxidative stress, loss of cell function, and cell death by apoptosis or necrosis. Lipid hydroperoxides are one type of ROS whose biological function has not yet been clarified. Phospholipid hydroperoxide glutathione peroxidase (PHGPx, GPx4) is a unique antioxidant enzyme that can directly reduce phospholipid hydroperoxide in mammalian cells. This contrasts with most antioxidant enzymes, which cannot reduce intracellular phospholipid hydroperoxides directly. In this review, we focus on the structure and biological functions of PHGPx in mammalian cells. Recently, molecular techniques have allowed overexpression of PHGPx in mammalian cell lines, from which it has become clear that lipid hydroperoxides also have an important function as activators of lipoxygenase and cyclooxygenase, participate in inflammation, and act as signal molecules for apoptotic cell death and receptor-mediated signal transduction at the cellular level.
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Affiliation(s)
- Hirotaka Imai
- School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo, Japan
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14
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Li J, Wurtman RJ. Heterogeneous long chain acyl-CoA synthetases control distribution of individual fatty acids in newly-formed glycerolipids of neuronal cells undergoing neurite outgrowth. Neurochem Res 1999; 24:739-50. [PMID: 10447457 DOI: 10.1023/a:1020727429052] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using PC12 cells undergoing neurite outgrowth, we studied the activation of various fatty acids, of different chain lengths and degrees of saturation, by long chain acyl-CoA synthetases (LCASs). Cells treated with nerve growth factor (NGF) were labeled with [3H]glycerol, [3H]oleic acid (OA) or [3H]arachidonic acid (AA) in the presence of other unlabeled fatty acids of endogenous or exogenous origin. Triacsin C (4.8 microM), an inhibitor of acyl-CoA synthetase, decreased the incorporation of exogenous [3H]OA into glycerolipids by 30-90%, and increased by about 60% the accumulation of free [3H]OA in the cells. However it did not affect the incorporation of endogenous fatty acids nor of exogenous [3H]AA into phospholipids, suggesting that LCASs which activate exogenous AA and at least some endogenous fatty acids are relatively insensitive to this drug. Activities of the LCAS that is specific for AA (ACS), or of the non-specific LCAS which activates OA and other fatty acids (OCS), were much higher in microsomal and cytoplasmic fractions than in mitochondria or nuclei. The Vmax and Km values of ACS and OCS in microsomes were 12 and 0.7 nmol/min/mg protein and 70 and 37 microM, respectively; and in cytoplasm, 6 and 0.6 nmol/min/mg protein and 38 and 60 microM, respectively. Triacsin C (2-33 microM) did not affect ACS activity in microsomal or cytoplasmal fractions, but inhibited OCS activities dose-dependently and competitively: IC50 and apparent Ki values were 13.5 microM and 14 microM in microsomes, and 3.8 microM and 4 microM in cytoplasm. NGF stimulated the activities of the LCASs, and, consistently, the incorporation of the various fatty acids into glycerolipids. These data indicate that LCASs are heterogeneous with respect to their intracellular locations, substrate specificities, kinetic characteristics and sensitivities to triacsin C; and that this heterogeneity affects the extents to which individual fatty acids are utilized to form glycerolipids.
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Affiliation(s)
- J Li
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139, USA
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15
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O'Flaherty JT, Taylor JS, Thomas MJ. Receptors for the 5-oxo class of eicosanoids in neutrophils. J Biol Chem 1998; 273:32535-41. [PMID: 9829988 DOI: 10.1074/jbc.273.49.32535] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
5-Hydroxy- and 5-oxo-eicosatetraenoate (5-HETE and 5-oxoETE) activate polymorphonuclear neutrophils (PMNs) through a common, receptor-like recognition system. To define this system, we examined the interaction of these eicosanoids with human PMNs. PMNs esterified 5-[3H]HETE to glycerolipids at 37 and 4 degreesC. At 37 but not 4 degreesC, the cells also hydroxylated the label to 5, 20-[3H]diHETE. The acyl:CoA synthetase blocker, triacsin C, inhibited esterification but also led to an increase in the hydroxylation of the label. PMNs processed 5-[3H]oxoETE through the same pathways but only or principally after reducing it to 5-[3H]HETE (37 or 4 degreesC). In the presence of these varying metabolic reactions, PMNs (37 or 4 degreesC; +/- triacsin C) could not be shown to receptor bind either radiolabel. Plasma membranes isolated from PMNs esterified but unlike whole cells did not reduce or hydroxylate 5-[3H]oxoETE. Triacsin C blocked esterification, thereby rendering the membranes unable to metabolize this radiolabel. Indeed, triacsin C-treated membranes bound (Kd = 3.8 nM) 5-[3H]oxoETE specifically and reversibly to 86 pmol of sites per 25 micrograms of membrane protein. 5-OxoETE, 5-HETE, and 5,15-diHETE displaced this binding at concentrations correlating with their potency in eliciting PMN Ca2+ transients. GTP and GTPgammaS, but not ATP or ATPgammaS, also reduced 5-[3H]oxoETE binding, whereas 15-HETE, leukotriene B4, platelet-activating factor, IL-8, C5a, and N-formyl-Met-Leu-Phe lacked this effect. We conclude that PMNs and their plasma membranes use an acyl:CoA synthetase-dependent route to esterify 5-HETE and 5-oxoETE into lipids. Blockade of the synthetase uncovers cryptic plasmalemma sites that bind 5-oxoETE with exquisite specificity. These sites apparently mediate responses to the 5-oxo class of eicosanoids and are likely members of the serpentine superfamily of G protein-linked receptors.
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Affiliation(s)
- J T O'Flaherty
- Departments of Internal Medicine, Wake Forest University Medical Center, Winston-Salem, North Carolina 27157, USA.
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Imai H, Narashima K, Arai M, Sakamoto H, Chiba N, Nakagawa Y. Suppression of leukotriene formation in RBL-2H3 cells that overexpressed phospholipid hydroperoxide glutathione peroxidase. J Biol Chem 1998; 273:1990-7. [PMID: 9442035 DOI: 10.1074/jbc.273.4.1990] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The overexpression of phospholipid hydroperoxide glutathione peroxidase (PHGPx) by RBL-2H3 cells was used as the basis for an investigation of the effects of PHGPx on the formation of leukotrienes. The rates of production of leukotriene C4 (LTC4) and leukotriene B4 (LTB4) in cells that overexpressed PHGPx were 8 times lower than those in a control line of cells. The reduction in rates of production of leukotrienes apparently resulted from the increase in the PHGPx activity since control rates of formation of leukotrienes could be achieved in PHGPx-overexpressing cells upon inhibition of PHGPx activity by diethyl malate. The conversion of radioactively labeled arachidonic acid to intermediates in the lipoxygenase pathway, such as 5-hydroxyeicosatetraenoic acid (5-HETE), LTC4, and LTB4, was strongly inhibited in PHGPx-overexpressing cells that had been prelabeled with [14C]arachidonic acid. PHGPx apparently inactivated the 5-lipoxygenase that catalyzed the conversion of arachidonic acid to 5-hydroperoxyeicosatetraenoic acid (5-HPETE) since 5-HPETE is a common precursor of 5-HETE, LTC4, and LTB4. The rates of formation of LTC4 and LTB4 in PHGPx-overexpressing cells returned to control rates upon the addition of a small amount of 12-HPETE. Flow cytometric analysis revealed that the rapid burst of formation of lipid hydroperoxides induced by A23187 was suppressed in PHGPx-overexpressing cells as compared with the control lines of cells. Subcellular fractionation analysis showed that the amount of PHGPx associated with nuclear fractions from PHGPx-overexpressing cells was 3.5 times higher than that from the control line of cells. These results indicate that PHGPx might be involved in inactivation of 5-lipoxygenase via reductions in levels of the fatty acid hydroperoxides that are required for the full activation of 5-lipoxygenase. Thus, in addition to its role as an antioxidant enzyme, PHGPx appears to have a novel function as a modulator of the production of leukotrienes.
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Affiliation(s)
- H Imai
- School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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