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Anethole and eugenol reduce in vitro and in vivo leukocyte migration induced by fMLP, LTB4, and carrageenan. J Nat Med 2014; 68:567-75. [PMID: 24789168 DOI: 10.1007/s11418-014-0839-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 04/03/2014] [Indexed: 12/25/2022]
Abstract
The aim of this study was to investigate the effect of anethole (AN) and eugenol (EUG) on leukocyte migration using in vitro chemotaxis and in situ microcirculation assays. BALB/c mice were used for the in vitro chemotaxis assay, and Wistar rats for the in situ microcirculation assay. We evaluated (a) the in vitro leukocyte migration in response to chemotactic factors (formyl-methionyl-leucyl-phenylalanine [fMLP] and leukotriene B4 [LTB4]) and (b) the rolling, adhesion, and migration of leukocytes induced by an injection of carrageenan (100 µg/cavity) into the scrotum of the animal. In the in vitro chemotaxis assay, AN and EUG at doses of 1, 3, 9, and 27 µg/ml significantly inhibited leukocyte migration when stimulated by the chemotactic agents fMLP and LTB4. In the in situ microcirculation assay, AN at doses of 125 and 250 mg/kg and EUG at a dose of 250 mg/kg significantly decreased the number of leukocytes that rolled, adhered, and migrated to perivascular tissue. The results indicate that AN and EUG exert inhibitory effects on leukocyte migration, highlighting their possible use to diminish excessive leukocyte migration in the inflammatory process.
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Bertin J, Barat C, Bélanger D, Tremblay MJ. Leukotrienes inhibit early stages of HIV-1 infection in monocyte-derived microglia-like cells. J Neuroinflammation 2012; 9:55. [PMID: 22424294 PMCID: PMC3334677 DOI: 10.1186/1742-2094-9-55] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 03/16/2012] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Microglia are one of the main cell types to be productively infected by HIV-1 in the central nervous system (CNS). Leukotriene B4 (LTB4) and cysteinyl-leukotrienes such as LTC4 are some of the proinflammatory molecules produced in infected individuals that contribute to neuroinflammation. We therefore sought to investigate the role of leukotrienes (LTs) in HIV-1 infection of microglial cells. METHODS To evaluate the role of LTs on HIV-1 infection in the CNS, monocyte-derived microglial-like cells (MDMis) were utilized in this study. Leukotriene-treated MDMis were infected with either fully replicative brain-derived HIV-1 isolates (YU2) or R5-tropic luciferase-encoding particles in order to assess viral production and expression. The efficacy of various steps of the replication cycle was evaluated by means of p24 quantification by ELISA, luciferase activity determination and quantitative real-time polymerase chain reaction (RT-PCR). RESULTS We report in this study that virus replication is reduced upon treatment of MDMis with LTB4 and LTC4. Additional experiments indicate that these proinflammatory molecules alter the pH-independent entry and early post-fusion events of the viral life cycle. Indeed, LT treatment induced a diminution in integrated proviral DNA while reverse-transcribed viral products remained unaffected. Furthermore, decreased C-C chemokine receptor type 5 (CCR5) surface expression was observed in LT-treated MDMis. Finally, the effect of LTs on HIV-1 infection in MDMis appears to be mediated partly via a signal transduction pathway involving protein kinase C. CONCLUSIONS These data show for the first time that LTs influence microglial cell infection by HIV-1, and may be a factor in the control of viral load in the CNS.
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Affiliation(s)
- Jonathan Bertin
- Centre de Recherche en Infectiologie, RC709, Centre Hospitalier Universitaire de Québec-CHUL, 2705 Boul, Laurier, Québec, QC G1V 4G2, Canada
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Affiliation(s)
- Motonao Nakamura
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
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Galli A, Kearney M, Nikolaitchik OA, Yu S, Chin MPS, Maldarelli F, Coffin JM, Pathak VK, Hu WS. Patterns of Human Immunodeficiency Virus type 1 recombination ex vivo provide evidence for coadaptation of distant sites, resulting in purifying selection for intersubtype recombinants during replication. J Virol 2010; 84:7651-61. [PMID: 20504919 PMCID: PMC2897624 DOI: 10.1128/jvi.00276-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 05/20/2010] [Indexed: 11/20/2022] Open
Abstract
High-frequency recombination is a hallmark of HIV-1 replication. Recombination can occur between two members of the same subtype or between viruses from two different subtypes, generating intra- or intersubtype recombinants, respectively. Many intersubtype recombinants have been shown to circulate in human populations. We hypothesize that sequence diversity affects the emergence of viable recombinants by decreasing recombination events and reducing the ability of the recombinants to replicate. To test our hypothesis, we compared recombination between two viruses containing subtype B pol genes (B/B) and between viruses with pol genes from subtype B or F (B/F). Recombination events generated during a single cycle of infection without selection pressure on pol gene function were analyzed by single-genome sequencing. We found that recombination occurred slightly ( approximately 30%) less frequently in B/F than in B/B viruses, and the overall distribution of crossover junctions in pol was similar for the two classes of recombinants. We then examined the emergence of recombinants in a multiple cycle assay, so that functional pol gene products were selected. We found that the emerging B/B recombinants had complex patterns, and the crossover junctions were distributed throughout the pol gene. In contrast, selected B/F recombinants had limited recombination patterns and restricted crossover junction distribution. These results provide evidence for the evolved coadapted sites in variants from different subtypes; these sites may be segregated by recombination events, causing the newly generated intersubtype recombinants to undergo purifying selection. Therefore, the ability of the recombinants to replicate is the major barrier for many of these viruses.
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Affiliation(s)
- Andrea Galli
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Mary Kearney
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Olga A. Nikolaitchik
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Sloane Yu
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Mario P. S. Chin
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Frank Maldarelli
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - John M. Coffin
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Vinay K. Pathak
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
| | - Wei-Shau Hu
- HIV Drug Resistance Program, National Cancer Institute—Frederick, Frederick, Maryland 21702, Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111
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Horrillo R, González-Périz A, Martínez-Clemente M, López-Parra M, Ferré N, Titos E, Morán-Salvador E, Deulofeu R, Arroyo V, Clària J. 5-lipoxygenase activating protein signals adipose tissue inflammation and lipid dysfunction in experimental obesity. THE JOURNAL OF IMMUNOLOGY 2010; 184:3978-87. [PMID: 20207999 DOI: 10.4049/jimmunol.0901355] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The presence of the so-called low-grade inflammatory state is recognized as a critical event in adipose tissue dysfunction, leading to altered secretion of adipokines and free fatty acids (FFAs), insulin resistance, and development of hepatic complications associated with obesity. This study was designed to investigate the potential contribution of the proinflammatory 5-lipoxygenase (5-LO) pathway to adipose tissue inflammation and lipid dysfunction in experimental obesity. Constitutive expression of key components of the 5-LO pathway, as well as leukotriene (LT) receptors, was detected in adipose tissue as well as in adipocyte and stromal vascular fractions. Adipose tissue from obese mice, compared with that from lean mice, exhibited increased 5-LO activating protein (FLAP) expression and LTB(4) levels. Incubation of adipose tissue with 5-LO products resulted in NF-kappaB activation and augmented secretion of proinflammatory adipokines such as MCP-1, IL-6, and TNF-alpha. In addition, LTB(4), but not LTD(4), reduced FFA uptake in primary adipocytes, whereas 5-LO inhibition suppressed isoproterenol-induced adipose tissue lipolysis. In mice with dietary obesity, elevated FLAP expression in adipose tissue was paralleled with macrophage infiltration, increased circulating FFA levels, and hepatic steatosis, phenomena that were reversed by FLAP inhibition with Bay-X-1005. Interestingly, FLAP inhibition induced AMP-activated protein kinase phosphorylation in parallel with decreases in hormone-sensitive lipase activity and the expression and secretion of TNF-alpha and IL-6. Similar effects were observed in differentiated 3T3-L1 adipocytes incubated with either Bay-X-1005 or the selective LTB(4) receptor antagonist U-75302. Taken together, these findings indicate that the 5-LO pathway signals the adipose tissue low-grade inflammatory state and steatogenic potential in experimental obesity.
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Affiliation(s)
- Raquel Horrillo
- Department of Biochemistry and Molecular Genetics, Hospital Clinic, August Pi i Sunyer Biomedical Research Institute, Esther Koplowitz Biomedical Research Center, University of Barcelona, Barcelona, Spain
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Peres CM, Aronoff DM, Serezani CH, Flamand N, Faccioli LH, Peters-Golden M. Specific leukotriene receptors couple to distinct G proteins to effect stimulation of alveolar macrophage host defense functions. THE JOURNAL OF IMMUNOLOGY 2007; 179:5454-61. [PMID: 17911632 DOI: 10.4049/jimmunol.179.8.5454] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Leukotrienes (LTs) are lipid mediators implicated in asthma and other inflammatory diseases. LTB(4) and LTD(4) also participate in antimicrobial defense by stimulating phagocyte functions via ligation of B leukotriene type 1 (BLT1) receptor and cysteinyl LT type 1 (cysLT1) receptor, respectively. Although both Galpha(i) and Galpha(q) proteins have been shown to be coupled to both BLT1 and cysLT1 receptors in transfected cell systems, there is little known about specific G protein subunit coupling to LT receptors, or to other G protein-coupled receptors, in primary cells. In this study we sought to define the role of specific G proteins in pulmonary alveolar macrophage (AM) innate immune responses to LTB(4) and LTD(4). LTB(4) but not LTD(4) reduced cAMP levels in rat AM by a pertussis toxin (PTX)-sensitive mechanism. Enhancement of FcgammaR-mediated phagocytosis and bacterial killing by LTB(4) was also PTX-sensitive, whereas that induced by LTD(4) was not. LTD(4) and LTB(4) induced Ca(2+) and intracellular inositol monophosphate accumulation, respectively, highlighting the role of Galpha(q) protein in mediating PTX-insensitive LTD(4) enhancement of phagocytosis and microbicidal activity. Studies with liposome-delivered G protein blocking Abs indicated a dependency on specific Galpha(q/11) and Galpha(i3) subunits, but not Galpha(i2) or G(beta)gamma, in LTB(4)-enhanced phagocytosis. The selective importance of Galpha(q/11) protein was also demonstrated in LTD(4)-enhanced phagocytosis. The present investigation identifies differences in specific G protein subunit coupling to LT receptors in antimicrobial responses and highlights the importance of defining the specific G proteins coupled to heptahelical receptors in primary cells, rather than simply using heterologous expression systems.
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MESH Headings
- Animals
- Cells, Cultured
- Cyclic AMP/antagonists & inhibitors
- Cyclic AMP/metabolism
- Down-Regulation/immunology
- Female
- GTP-Binding Protein alpha Subunit, Gi2/biosynthesis
- GTP-Binding Protein alpha Subunit, Gi2/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/biosynthesis
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Proteins/biosynthesis
- GTP-Binding Proteins/metabolism
- GTP-Binding Proteins/physiology
- Intracellular Fluid/metabolism
- Leukotriene B4/antagonists & inhibitors
- Leukotriene B4/physiology
- Leukotriene D4/antagonists & inhibitors
- Leukotriene D4/physiology
- Macrophage Activation/immunology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Rats
- Rats, Wistar
- Receptors, Leukotriene/metabolism
- Receptors, Leukotriene/physiology
- Toxoids/pharmacology
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Affiliation(s)
- Camila M Peres
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109, USA
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St-Onge M, Flamand N, Biarc J, Picard S, Bouchard L, Dussault AA, Laflamme C, James MJ, Caughey GE, Cleland LG, Borgeat P, Pouliot M. Characterization of prostaglandin E2 generation through the cyclooxygenase (COX)-2 pathway in human neutrophils. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1771:1235-45. [PMID: 17643350 PMCID: PMC2891965 DOI: 10.1016/j.bbalip.2007.06.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Revised: 06/01/2007] [Accepted: 06/18/2007] [Indexed: 01/08/2023]
Abstract
In the present study, we characterized the generation of prostaglandin (PG)E2 in human neutrophils. We found that the Ca2+-dependent type IV cytosolic phospholipase A2 (cPLA2) was pivotally involved in the COX-2-mediated generation of PGE2 in response to a calcium ionophore, as determined by the use of selected PLA2 inhibitors. PGE2 biosynthesis elicited by bacterial-derived peptides or by phagocytic stimuli acting on cell surface receptors also showed to be dependent on cPLA2 activity. We then assessed metabolism of unesterified arachidonic acid (AA), and observed that PGE2 production becomes favored over that of LTB4 with higher AA concentrations. Withdrawal of calcium prevented the generation of PGE2 in response to a calcium ionophore but did not affect the up-regulation of COX-2 or its capacity to convert AA, thus limiting its implication at the level of cPLA2 activation. Of the main eicosanoids produced by neutrophils, only LTB4 was able to up-regulate COX-2 expression. Finally, the only PGE synthase isoform found in neutrophils is microsomal PGE synthase-1; it co-localized with COX-2 and its expression appeared mainly constitutive. These results highlight key differences in regulatory processes of the 5-LO and COX pathways, and enhance our knowledge at several levels in the PGE2 biosynthesis in neutrophils.
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Affiliation(s)
- Mireille St-Onge
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Nicolas Flamand
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109-0642, USA
| | - Jordane Biarc
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Serge Picard
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Line Bouchard
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Andrée-Anne Dussault
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Cynthia Laflamme
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Michael J. James
- Rheumatology Unit, Royal Adelaide Hospital, North Terrace, Adelaide, SA 5000, Australia
| | - Gillian E. Caughey
- Rheumatology Unit, Royal Adelaide Hospital, North Terrace, Adelaide, SA 5000, Australia
| | - Leslie G. Cleland
- Rheumatology Unit, Royal Adelaide Hospital, North Terrace, Adelaide, SA 5000, Australia
| | - Pierre Borgeat
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
| | - Marc Pouliot
- Centre de Recherche en Rhumatologie et Immunologie du CHUQ (CHUL), 2705 Laurier Boulevard, Office T1-49, Sainte-Foy, and Department of Anatomy-Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1V 4G2
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8
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Zhu P, Liu X, Labelle EF, Freedman BD. Mechanisms of hypotonicity-induced calcium signaling and integrin activation by arachidonic acid-derived inflammatory mediators in B cells. THE JOURNAL OF IMMUNOLOGY 2005; 175:4981-9. [PMID: 16210600 DOI: 10.4049/jimmunol.175.8.4981] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We previously characterized the initial steps in the activation of novel (calcium-permeant) nonselective cation channels (NSCCs) and calcium release-activated calcium channels in primary murine B lymphocytes. Phospholipase C products, namely diacylglycerol and d-myo-inositol 1,4,5-trisphosphate, were identified as proximal intracellular agonists of these respective channels following mechanical stimulation of B cells. However, neither the distal steps in NSCC activation nor the contribution of these channels to sustained mechanical signaling were defined in these previous studies. In this study, single cell measurements of intracellular Ca(2+) were used to define the mechanisms of NSCC activation and demonstrate a requirement for arachidonic acid liberated from diacylglycerol. Several arachidonic acid-derived derivatives were identified that trigger Ca(2+) entry into B cells, including the lipoxygenase product 5-hydroperoxyeicosatetranenoic acid and the cytochrome P450 hydroxylase product 20-hydroxyeicosatetraenoic; however, the cytochrome P450 epoxygenase product 5,6-epoxyeicosatrienoic acid is primarily responsible for hypotonicity-induced responses. In addition to regulating calcium entry, our data suggest that eicosanoid-activated NSCCs have a separate and direct role in regulating the avidity of integrins on B cells for extracellular matrix proteins, including ICAM-1 and VCAM-1. Thus, in addition to defining a novel osmotically activated signal transduction pathway in B cells, our results have broad implications for understanding how inflammatory mediators dynamically and rapidly regulate B cell adhesion and trafficking.
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Affiliation(s)
- Peimin Zhu
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
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9
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Andersson TPM, Sköld HN, Svensson SPS. Phosphoinositide 3-kinase is involved in Xenopus and Labrus melanophore aggregation. Cell Signal 2004; 15:1119-27. [PMID: 14575867 DOI: 10.1016/s0898-6568(03)00111-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Melanophores are pigmented cells capable of quick colour changes through coordinated transport of their intracellular pigment granules. We demonstrate the involvement of phosphoinositide 3-kinase (PI3-K) in Xenopus and Labrus aggregation by the use of the PI3-K inhibitor, LY-294002. In Xenopus, wortmannin-insensitive PI3-K was found to be essential for the aggregation, mitogen-activated protein kinase (MAPK) activation and tyrosine phosphorylation of a 280-kDa protein, and for the maintenance of low cyclic adenosine 3':5'-monophosphate (cAMP) during the aggregated state. Pre-aggregated cells disperse completely to LY-294002 at 50-100 muM, involving a transient elevation in cAMP due to adenylate cyclase (AC) stimulation or to inhibition of cyclic nucleotide phosphodiesterase (PDE). The inactive analogue LY-303511 did not induce dispersion at the same concentrations. PDE4 and/or PDE2 was found to be involved in melanosome aggregation. The similar kinetics of LY-294002 and various PDE inhibitors indicates that the elevation of cAMP might be due to inhibition of PDE. In Labrus melanophores, LY-294002 had a less dramatic effect, probably due to less dependence on PDE in regulation of cAMP levels. In Xenopus aggregation, we suggest that melatonin stimulation of the Mel1c receptor via G(beta gamma) activates PI3-K that, directly or indirectly via MAPK, activates PDE.
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Affiliation(s)
- Tony P M Andersson
- Division of Pharmacology, Department of Medicine and Care, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden.
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10
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Abstract
Two receptors for leukotriene B(4) (LTB(4)) have been molecularly identified: BLT1 and BLT2. Both receptors are G protein-coupled seven transmembrane domain receptors, whose genes are located in very close proximity to each other in the human and mouse genomes. The two receptors differ in their affinity and specificity for LTB(4): BLT1 is a high-affinity receptor specific for LTB(4), whereas BLT2 is a low-affinity receptor that also binds other eicosanoids. The two receptors also differ in their pattern of expression with BLT1 being expressed primarily in leukocytes, whereas BLT2 is expressed more ubiquitously. By mediating the activities of LTB(4), these receptors participate both in host immune responses and in the pathogenesis of inflammatory diseases. Reduced disease severity in animal inflammatory models seen with LTB(4) receptor antagonists and in mice with targeted deletion of BLT1 have revealed important roles for LTB(4) and its receptors in regulating pathologic inflammation.
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Affiliation(s)
- Andrew M Tager
- Division of Rheumatology, Allergy and Immunology, Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Building 149-8301, 13th Street, Charlestown, MA 02129, USA
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11
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Andersson TPM, Svensson SPS, Karlsson AM. Regulation of melanosome movement by MAP kinase. PIGMENT CELL RESEARCH 2003; 16:215-21. [PMID: 12753388 DOI: 10.1034/j.1600-0749.2003.00048.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Our objectives were to further characterize the signaling pathways in melatonin-induced aggregation in Xenopus melanophores, specifically to investigate a possible role of mitogen-activated protein kinase (MAPK). By Western blotting we found that melatonin activates MAPK, which precedes melanosome aggregation measured in a microplate reader. Activation of MAPK, tyrosine phosphorylation of a previously described 280-kDa protein, and melanosome aggregation are sensitive to PD98059, a selective inhibitor of MAPK kinase. The MAPK activation is also decreased by the adenylate cyclase stimulant forskolin. In summary, we found that MAPK is activated during melatonin-induced melanosome aggregation. Activation was decreased by an inhibitor of MAPK kinase, and by forskolin. In addition to inhibition of cyclic adenosine 3',5'-monophosphate (cAMP), reduction in protein kinase A activity (PKA), and activation of protein phosphatase 2A, we suggest that melatonin receptors activate the MAPK cascade and tyrosine phosphorylation of the 280-kDa protein. Although the cAMP/PKA signaling pathway is the most prominent, our data suggest that simultaneous activation of the MAPK cascade is of importance to obtain a completely aggregated state. This new regulatory mechanism of organelle transport by the MAPK cascade might be important in other eukaryotic cells.
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Affiliation(s)
- Tony P M Andersson
- Department of Medicine and Care, Division of Pharmacology, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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Brink C, Dahlén SE, Drazen J, Evans JF, Hay DWP, Nicosia S, Serhan CN, Shimizu T, Yokomizo T. International Union of Pharmacology XXXVII. Nomenclature for leukotriene and lipoxin receptors. Pharmacol Rev 2003; 55:195-227. [PMID: 12615958 DOI: 10.1124/pr.55.1.8] [Citation(s) in RCA: 224] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The leukotrienes and lipoxins are biologically active metabolites derived from arachidonic acid. Their diverse and potent actions are associated with specific receptors. Recent molecular techniques have established the nucleotide and amino acid sequences and confirmed the evidence that suggested the existence of different G-protein-coupled receptors for these lipid mediators. The nomenclature for these receptors has now been established for the leukotrienes. BLT receptors are activated by leukotriene B(4) and related hydroxyacids and this class of receptors can be subdivided into BLT(1) and BLT(2). The cysteinyl-leukotrienes (LT) activate another group called CysLT receptors, which are referred to as CysLT(1) and CysLT(2). A provisional nomenclature for the lipoxin receptor has also been proposed. LXA(4) and LXB(4) activate the ALX receptor and LXB(4) may also activate another putative receptor. However this latter receptor has not been cloned. The aim of this review is to provide the molecular evidence as well as the properties and significance of the leukotriene and lipoxin receptors, which has lead to the present nomenclature.
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Affiliation(s)
- Charles Brink
- Centre National de la Recherche Scientifique UMR 7131, Hôpital Broussais, Bâtiment René Leriche, Paris, France.
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Abstract
Inflammation is a process culminated by cellular components and soluble mediators act in concert to evolve a sustainable process to impart distress in vascularized tissue. The role of thrombin receptors in neutrophil degranulation is not fully understood. Thrombin-mediated signaling has been shown to occur at least in part by a family of G protein-coupled protease-activated receptors (PARs). Protease-activated receptors-1 (PAR1) is the prototype for understanding on the fundamental signaling mechanism and related characterization. The inference of thrombin receptors and various synthetic ligand formulations on neutrophil degranulation ascertained an enormous disparity in the response by human donors. Based on the previous reports and supposition in perpetuity, it is hypothesized that thrombin through its receptor, and its subtypes, may very improbably have any functional role in PMN degranulation.
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Affiliation(s)
- S Kannan
- Department of Physiology, School of Medicine, Temple University, Philadelphia, USA.
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14
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de la Fuente C, Santiago F, Deng L, Eadie C, Zilberman I, Kehn K, Maddukuri A, Baylor S, Wu K, Lee CG, Pumfery A, Kashanchi F. Gene expression profile of HIV-1 Tat expressing cells: a close interplay between proliferative and differentiation signals. BMC BIOCHEMISTRY 2002; 3:14. [PMID: 12069692 PMCID: PMC116586 DOI: 10.1186/1471-2091-3-14] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2002] [Accepted: 06/10/2002] [Indexed: 11/15/2022]
Abstract
BACKGROUND Expression profiling holds great promise for rapid host genome functional analysis. It is plausible that host expression profiling in an infection could serve as a universal phenotype in virally infected cells. Here, we describe the effect of one of the most critical viral activators, Tat, in HIV-1 infected and Tat expressing cells. We utilized microarray analysis from uninfected, latently HIV-1 infected cells, as well as cells that express Tat, to decipher some of the cellular changes associated with this viral activator. RESULTS Utilizing uninfected, HIV-1 latently infected cells, and Tat expressing cells, we observed that most of the cellular host genes in Tat expressing cells were down-regulated. The down-regulation in Tat expressing cells is most apparent on cellular receptors that have intrinsic receptor tyrosine kinase (RTK) activity and signal transduction members that mediate RTK function, including Ras-Raf-MEK pathway. Co-activators of transcription, such as p300/CBP and SRC-1, which mediate gene expression related to hormone receptor genes, were also found to be down-regulated. Down-regulation of receptors may allow latent HIV-1 infected cells to either hide from the immune system or avoid extracellular differentiation signals. Some of the genes that were up-regulated included co-receptors for HIV-1 entry, translation machinery, and cell cycle regulatory proteins. CONCLUSIONS We have demonstrated, through a microarray approach, that HIV-1 Tat is able to regulate many cellular genes that are involved in cell signaling, translation and ultimately control the host proliferative and differentiation signals.
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Affiliation(s)
- Cynthia de la Fuente
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Francisco Santiago
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Longwen Deng
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Carolyne Eadie
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Irene Zilberman
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Kylene Kehn
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Anil Maddukuri
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Shanese Baylor
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Kaili Wu
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Chee Gun Lee
- Department of Biochemistry and Molecular Biology UMDNJ-New Jersey Medical School Newark, NJ 07103, USA
| | - Anne Pumfery
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
| | - Fatah Kashanchi
- Department of Biochemistry and Molecular Biology George Washington University School of Medicine Washington DC, 20037, USA
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15
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Tafalla C, Figueras A, Novoa B. Possible role of LTB4 in the antiviral activity of turbot (Scophthalmus maximus) leukocyte-derived supernatants against viral hemorrhagic septicemia virus (VHSV). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2002; 26:283-293. [PMID: 11755677 DOI: 10.1016/s0145-305x(01)00076-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Turbot (Scophthalmus maximus) blood leukocyte-derived supernatants were tested for antiviral activity against viral hemorrhagic septicemia virus (VHSV). The assays were performed by quantifying the effect of the supernatants on the replication of VHSV in the rainbow trout (Oncorhynchus mykiss) cell line, RTG-2. Supernatants were obtained by incubating the leukocytes for 17 h at 18 degrees C in L-15 medium supplemented with 5% fetal calf serum (FCS). Testing of leukocyte supernatants indicated that antiviral activity against VHSV resulted in a viral titer reduction of 72.1%. After the supernatants were extracted with calcium ionophore A23187 treatment, the antiviral activity significantly increased, resulting in a viral titer reduction of 99.9%. In order to determine the nature of this antiviral activity, supernatants were produced from leukocytes treated for 17 h with inhibitors of eicosanoid biosynthesis, reactive oxygen intermediates and nitric oxide (NO) production. None of the inhibitors significantly suppressed the supernatant antiviral activity. The presence of oxygen radicals and NO was measured in the case of co-cultures of leukocytes and RTG-2 cells, but no significant differences were found in the VHSV-infected co-cultures compared to non-infected controls. Since previous work demonstrated that leukotriene B4 (LTB4) was present in turbot blood leukocyte-derived supernatants, we assessed the effect of the VHSV in vitro infection on turbot leukocyte LTB4 production by high performance liquid chromatography (HPLC). The levels of LTB4 were significantly increased in the supernatants after VHSV infection. Furthermore, exogenous LTB4 significantly inhibited VHSV replication in RTG-2 cells. These findings suggest that LTB4 may play a significant role in VHSV replication.
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Affiliation(s)
- Carolina Tafalla
- Instituto de Investigaciones Marinas, CSIC, Eduardo Cabello, 6, 36208 Vigo, Spain
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16
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Woo CH, You HJ, Cho SH, Eom YW, Chun JS, Yoo YJ, Kim JH. Leukotriene B(4) stimulates Rac-ERK cascade to generate reactive oxygen species that mediates chemotaxis. J Biol Chem 2002; 277:8572-8. [PMID: 11756405 DOI: 10.1074/jbc.m104766200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukotriene B(4) is a potent chemoattractant known to be involved mainly in inflammation, immune responses, and host defense against infection, although the exact signaling mechanisms by which it exerts its effects are not well understood. Here we show that exogenous leukotriene B(4) induces reactive oxygen species (ROS) generation via a Rac-dependent pathway, and that stable expression of Rac(N17), a dominant negative Rac1 mutant, completely blocks leukotriene B(4)-induced ROS generation. In addition, leukotriene B(4)-induced ROS generation is selectively blocked by inhibition of ERK or cytosolic phospholipase A(2), but not p38 kinase, which is indicative of its dependence on ERK activation and synthesis of arachidonic acid. Consistent with those findings, leukotriene B(4) Rac-dependently stimulates ERK and cytosolic phospholipase A(2) activity, and transient transfection with plasmid expressing Rac(V12), a constitutively activated Rac1 mutant, also dose-dependently stimulates ERK activity. Our findings suggest that ERK and cytosolic phospholipase A(2) are situated downstream of Rac, and we conclude that Rac, ERK, and cytosolic phospholipase A(2) all play pivotal roles in mediating the ROS generation that appears to be a prerequisite for leukotriene B(4)-induced chemotaxis and cell proliferation.
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Affiliation(s)
- Chang-Hoon Woo
- Graduate School of Biotechnology, Korea University, 5-1 Anam-dong, Seoul 136-701, Korea
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17
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Abstract
Leukotriene B4 (LTB4) is known as one of the most potent chemoattractants and activators of leukocytes and is involved in inflammatory diseases. Enzymes involved in the biosynthesis and metabolism of LTB4 have been cloned, and their properties are well understood. Two G-protein-coupled receptors (BLT1 and BLT2) have been cloned and characterized. BLT1 and BLT2 are high- and low-affinity LTB4 receptors, respectively, and form a gene cluster in human and mouse. In this article recent findings on the metabolism of and the receptors for LTB4 are reviewed. We also discuss briefly a coreceptor role of BLT in HIV infection, and ion channel modification by LTB4.
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Affiliation(s)
- T Yokomizo
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, CREST of Japan, Science and Technology Corporation.
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18
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Yokomizo T, Kato K, Hagiya H, Izumi T, Shimizu T. Hydroxyeicosanoids bind to and activate the low affinity leukotriene B4 receptor, BLT2. J Biol Chem 2001; 276:12454-9. [PMID: 11278893 DOI: 10.1074/jbc.m011361200] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Leukotriene B(4), an arachidonate metabolite, is a potent chemoattractant of leukocytes involved in various inflammatory diseases. Two G-protein-coupled receptors for leukotriene B(4) have been cloned and characterized. BLT1 (Yokomizo, T., Izumi, T., Chang, K., Takuwa, Y., and Shimizu, T. (1997) Nature 387, 620-624) is a high affinity receptor exclusively expressed in leukocytes, and BLT2 (Yokomizo, T., Kato, K., Terawaki, K., Izumi, T., and Shimizu, T. (2000) J. Exp. Med. 192, 421-432) is a low affinity receptor expressed more ubiquitously. Here we report the binding profiles of various BLT antagonists and eicosanoids to either BLT1 or BLT2 using the membrane fractions of Chinese hamster ovary cells stably expressing the receptor. BLT antagonists are grouped into three classes: BLT1-specific U-75302, BLT2-specific LY255283, and BLT1/BLT2 dual-specific ZK 158252 and CP 195543. We also show that 12(S)-hydroxyeicosatetraenoic acid, 12(S)-hydroperxyeicosatetraenoic acid, and 15(S)-hydroxyeicosatetraenoic acid competed with [(3)H]LTB(4) binding to BLT2, but not BLT1, dose dependently. These eicosanoids also cause calcium mobilization and chemotaxis through BLT2, again in contrast to BLT1. These findings suggest that BLT2 functions as a low affinity receptor, with broader ligand specificity for various eicosanoids, and mediates distinct biological and pathophysiological roles from BLT1.
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Affiliation(s)
- T Yokomizo
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo and the Japan Science and Technology Corporation (CREST), Tokyo 113-0033, Japan.
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19
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Yokomizo T, Kato K, Terawaki K, Izumi T, Shimizu T. A second leukotriene B(4) receptor, BLT2. A new therapeutic target in inflammation and immunological disorders. J Exp Med 2000; 192:421-32. [PMID: 10934230 PMCID: PMC2193217 DOI: 10.1084/jem.192.3.421] [Citation(s) in RCA: 391] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Leukotriene B(4) (LTB(4)) is a potent chemoattractant and activator of both granulocytes and macrophages. The actions of LTB(4) appear to be mediated by a specific G protein-coupled receptor (GPCR) BLT1, originally termed BLT (Yokomizo, T., T. Izumi, K. Chang, Y. Takuwa, and T. Shimizu. 1997. Nature. 387:620-624). Here, we report the molecular cloning of a novel GPCR for LTB(4), designated BLT2, which binds LTB(4) with a Kd value of 23 nM compared with 1.1 nM for BLT1, but still efficiently transduces intracellular signaling. BLT2 is highly homologous to BLT1, with an amino acid identity of 45.2%, and its open reading frame is located in the promoter region of the BLT1 gene. BLT2 is expressed ubiquitously, in contrast to BLT1, which is expressed predominantly in leukocytes. Chinese hamster ovary cells expressing BLT2 exhibit LTB(4)-induced chemotaxis, calcium mobilization, and pertussis toxin-insensitive inhibition of adenylyl cyclase. Several BLT1 antagonists, including U 75302, failed to inhibit LTB(4) binding to BLT2. Thus, BLT2 is a pharmacologically distinct receptor for LTB(4), and may mediate cellular functions in tissues other than leukocytes. BLT2 provides a novel target for antiinflammatory therapy and promises to expand our knowledge of LTB(4) function. The location of the gene suggests shared transcriptional regulation of these two receptors.
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Affiliation(s)
- Takehiko Yokomizo
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
| | - Kazuhiko Kato
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Pharmaceutical Research Center, Meiji Seika Kaisha, Limited, Yokohama 222-8567, Japan
| | - Kan Terawaki
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
| | - Takashi Izumi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
| | - Takao Shimizu
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
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20
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Kato K, Yokomizo T, Izumi T, Shimizu T. Cell-specific transcriptional regulation of human leukotriene B(4) receptor gene. J Exp Med 2000; 192:413-20. [PMID: 10934229 PMCID: PMC2193224 DOI: 10.1084/jem.192.3.413] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2000] [Accepted: 04/18/2000] [Indexed: 11/04/2022] Open
Abstract
Leukotriene B(4) (LTB(4)) is a lipid mediator that activates leukocytes and is involved in host defense and inflammation. BLT1, a high-affinity receptor for LTB(4) (originally termed BLT), is expressed exclusively in inflammatory cells and is inducible in macrophages upon activation. The mechanisms of tissue-specific expression and induction of BLT1 are important for the understanding of mechanism of onset and the potential treatment of inflammatory disorders. Here, we report the genomic structure and a promoter analysis of the human BLT1 gene, with an emphasis on the mechanism of cell-specific transcription. No TATA or CAAT elements exist around the transcription initiation sites, but a GC-rich sequence is observed in this region. A reporter gene assay revealed that a region approximately 80 basepair upstream from the initiator sequence is required for the basal transcription of the BLT1 gene. Sp1 was found to be a major activator of basal transcription by electrophoretic mobility shift assays and site-directed mutagenesis. The CpG sites of the BLT1 promoter region were highly methylated in BLT1-nonexpressing cells, but not methylated in BLT1-expressing cells. Further, methylation of this region in vitro inhibited the promoter activity to approximately 15% of the control. Thus, methylation at CpG sites in the promoter region is important for cell-specific transcription of the BLT1 gene. The promoter region of the BLT1 gene is localized within the open reading frame (ORF) of the BLT2 gene, which encodes a low-affinity receptor for LTB(4) (Yokomizo, T., K. Kato, K. Terawaki, T. Izumi, and T. Shimizu. 2000. J. Exp. Med. 192:421-431). To our knowledge, this is the first example of "promoter in ORF" in higher eukaryotes.
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Affiliation(s)
- Kazuhiko Kato
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Pharmaceutical Research Center, Meiji Seika Kaisha, Limited, Yokohama 222-8567, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
| | - Takashi Izumi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
| | - Takao Shimizu
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Tokyo 113-0033, Japan
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21
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Haribabu B, Verghese MW, Steeber DA, Sellars DD, Bock CB, Snyderman R. Targeted disruption of the leukotriene B(4) receptor in mice reveals its role in inflammation and platelet-activating factor-induced anaphylaxis. J Exp Med 2000; 192:433-8. [PMID: 10934231 PMCID: PMC2193219 DOI: 10.1084/jem.192.3.433] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Leukotrienes are derived from arachidonic acid and serve as mediators of inflammation and immediate hypersensitivity. Leukotriene B(4) (LTB(4)) and leukotriene C(4) (LTC(4)) act through G protein-coupled receptors LTB(4) receptor (BLTR) and Cys-LTR, respectively. To investigate the physiological role of BLTR, we produced mice with a targeted disruption of the BLTR gene. Mice deficient for BLTR (BLTR(-/-)) developed normally and had no apparent hematopoietic abnormalities. Peritoneal neutrophils from BLTR(-/-) mice displayed normal responses to the inflammatory mediators C5a and platelet-activating factor (PAF) but did not respond to LTB(4) for calcium mobilization or chemotaxis. Additionally, LTB(4) elicited peritoneal neutrophil influx in control but not in BLTR(-/-) mice. Thus, BLTR is the sole receptor for LTB(4)-induced inflammation in mice. Neutrophil influx in a peritonitis model and acute ear inflammation in response to arachidonic acid was significantly reduced in BLTR(-/-) mice. In mice, intravenous administration of PAF induces immediate lethal anaphylaxis. Surprisingly, female BLTR(-/-) mice displayed selective survival (6 of 9; P = 0.002) relative to male (1 of 11) mice of PAF-induced anaphylaxis. These results demonstrate the role of BLTR in leukotriene-mediated acute inflammation and an unexpected sex-related involvement in PAF-induced anaphylaxis.
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Affiliation(s)
- B Haribabu
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
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22
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Zhang Y, Lou B, Lal RB, Gettie A, Marx PA, Moore JP. Use of inhibitors to evaluate coreceptor usage by simian and simian/human immunodeficiency viruses and human immunodeficiency virus type 2 in primary cells. J Virol 2000; 74:6893-910. [PMID: 10888629 PMCID: PMC112207 DOI: 10.1128/jvi.74.15.6893-6910.2000] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have used coreceptor-targeted inhibitors to investigate which coreceptors are used by human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency viruses (SIV), and human immunodeficiency virus type 2 (HIV-2) to enter peripheral blood mononuclear cells (PBMC). The inhibitors are TAK-779, which is specific for CCR5 and CCR2, aminooxypentane-RANTES, which blocks entry via CCR5 and CCR3, and AMD3100, which targets CXCR4. We found that for all the HIV-1 isolates and all but one of the HIV-2 isolates tested, the only relevant coreceptors were CCR5 and CXCR4. However, one HIV-2 isolate replicated in human PBMC even in the presence of TAK-779 and AMD3100, suggesting that it might use an undefined, alternative coreceptor that is expressed in the cells of some individuals. SIV(mac)239 and SIV(mac)251 (from macaques) were also able to use an alternative coreceptor to enter PBMC from some, but not all, human and macaque donors. The replication in human PBMC of SIV(rcm) (from a red-capped mangabey), a virus which uses CCR2 but not CCR5 for entry, was blocked by TAK-779, suggesting that CCR2 is indeed the paramount coreceptor for this virus in primary cells.
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MESH Headings
- Amides/pharmacology
- Animals
- Anti-HIV Agents/pharmacology
- Benzylamines
- CD4 Antigens/metabolism
- Cell Line
- Chemokine CCL5/analogs & derivatives
- Chemokine CCL5/pharmacology
- Cyclams
- HIV-1/drug effects
- HIV-1/pathogenicity
- HIV-1/physiology
- HIV-2/drug effects
- HIV-2/pathogenicity
- HIV-2/physiology
- Heterocyclic Compounds/pharmacology
- Humans
- Leukocytes, Mononuclear/virology
- Lymphocytes
- Macaca
- Quaternary Ammonium Compounds/pharmacology
- Receptors, CCR2
- Receptors, CCR3
- Receptors, CCR5/metabolism
- Receptors, Chemokine/metabolism
- Receptors, HIV/antagonists & inhibitors
- Receptors, HIV/metabolism
- Receptors, Virus/antagonists & inhibitors
- Receptors, Virus/metabolism
- Simian Immunodeficiency Virus/drug effects
- Simian Immunodeficiency Virus/pathogenicity
- Simian Immunodeficiency Virus/physiology
- Transfection
- Tumor Cells, Cultured
- Virus Replication/drug effects
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Affiliation(s)
- Y Zhang
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York 10016, USA
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23
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Dasari VR, Jin J, Kunapuli SP. Distribution of leukotriene B4 receptors in human hematopoietic cells. IMMUNOPHARMACOLOGY 2000; 48:157-63. [PMID: 10936513 DOI: 10.1016/s0162-3109(00)00201-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Leukotriene B4 (LTB4), a product of arachidonic acid metabolism, plays an important role in inflammatory responses. We have cloned from human erythroleukemia cells, a G protein-coupled receptor, designated P2Y(7), which was later identified as the receptor for LTB4 (B-LTR). We have investigated the distribution of LTB4 receptors in various hematopoietic cells. Northern blotting and reverse transcription-coupled polymerase chain reaction (RT-PCR) analyses using radiolabeled LTB4 receptor cDNA as a probe indicated the presence of LTB4 receptor mRNA in peripheral blood leukocytes but not in platelets. Flow cytometry analysis of peripheral blood cells using specific LTB4 receptor antibodies revealed that monocytes, granulocytes, and lymphocytes, but not platelets, express LTB4 receptors. RT-PCR-Southern hybridization analysis revealed that peripheral blood leukocytes and human umbilical vein endothelial cells express the LTB4 receptor. Of the hematopoietic cell lines tested, promonocytic U937 cells, promyelocytic HL-60 cells, K562 cells, and human erythroleukemia cells express the LTB4 receptor. These results suggest a physiological role for the LTB4 receptor in the stimulation of monocytes, neutrophils, and endothelial cells.
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Affiliation(s)
- V R Dasari
- Department of Physiology, Temple University School of Medicine, 3420 North Broad Street, Philadelphia, PA 19140, USA
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24
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Karlsson AM, Lerner MR, Unett D, Lundström I, Svensson SP. Melatonin-induced organelle movement in melanophores is coupled to tyrosine phosphorylation of a high molecular weight protein. Cell Signal 2000; 12:469-74. [PMID: 10989282 DOI: 10.1016/s0898-6568(00)00089-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Melanophores, brown to black pigment cells from, for example, Xenopus laevis, contain mobile melanin filled organelles, and are well suited for studies on organelle movement. The intracellular regulation of the movement seems to be controlled by serine and threonine phosphorylations and dephosphorylations. Melatonin induces aggregation of the melanosomes to the cell centre through a G(i/o)-protein-coupled receptor, Mel1c, which leads to an inhibition of PKA and a stimulation of PP2A. However, this study shows that the melatonin-induced aggregation of melanosomes is also accompanied by tyrosine phosphorylation of a protein with a molecular weight of approximately 280 kDa. Cells pre-incubated with genistein, an inhibitor of tyrosine phosphorylations, showed inhibited melanosome movement after melatonin stimulation, and a lower degree of tyrosine phosphorylation of the approximately 280 kDa protein. The adenylyl cyclase activator forskolin, and the G(i/o) protein inhibitor pertussis toxin, also inhibited tyrosine phosphorylation of the approximately 280 kDa protein. The results indicate that melatonin stimulation generates tyrosine phosphorylation of a high molecular weight protein, an event that seems to be essential for melanosome aggregation.
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Affiliation(s)
- A M Karlsson
- Department of Medicine and Care, Pharmacology, Faculty of Health Sciences, Linköpings universitet, SE-581 85, Linköping, Sweden.
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25
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Maccarrone M, Bari M, Corasaniti MT, Nisticó R, Bagetta G, Finazzi-Agrò A. HIV-1 coat glycoprotein gp120 induces apoptosis in rat brain neocortex by deranging the arachidonate cascade in favor of prostanoids. J Neurochem 2000; 75:196-203. [PMID: 10854262 DOI: 10.1046/j.1471-4159.2000.0750196.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human immunodeficiency virus type-1 coat glycoprotein gp 120 causes delayed programmed cell death (apoptosis) in rat brain neocortex. Here, we investigated the possible role of the arachidonate cascade and membrane peroxidation in this process. It is shown that gp 120 causes a rapid increase in the activity and expression of the arachidonate-metabolizing enzyme prostaglandin H synthase, paralleled by increased prostaglandin E(2) levels. The selective inhibitor of prostaglandin H synthase indomethacin inhibited enzyme activity, reduced prostaglandin E(2) content, and partially protected neocortex against gp 120-induced apoptosis. Conversely, the activity and expression of the arachidonate-metabolizing enzyme 5-lipoxygenase decreased upon gp 120 treatment, as well as the level of its product, leukotriene B(4). Treatment with gp 120 also reduced membrane lipid peroxidation, and this may be implicated in the execution of programmed cell death. These results suggest that early derangement of the arachidonate cascade in favor of prostanoids may be instrumental in the execution of delayed apoptosis in the brain neocortex of rats.
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Affiliation(s)
- M Maccarrone
- Department of Experimental Medicine and Biochemical Sciences. "Mondino-Tor Vergata" Center for Experimental Neurobiology, University of Rome "Tor Vergata," Rome, Italy
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26
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Yokomizo T, Masuda K, Kato K, Toda A, Izumi T, Shimizu T. Leukotriene B4 receptor. Cloning and intracellular signaling. Am J Respir Crit Care Med 2000; 161:S51-5. [PMID: 10673227 DOI: 10.1164/ajrccm.161.supplement_1.ltta-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- T Yokomizo
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
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27
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Rao S, Garrett-Sinha LA, Yoon J, Simon MC. The Ets factors PU.1 and Spi-B regulate the transcription in vivo of P2Y10, a lymphoid restricted heptahelical receptor. J Biol Chem 1999; 274:34245-52. [PMID: 10567398 DOI: 10.1074/jbc.274.48.34245] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To investigate the in vivo functions of PU.1 and Spi-B, two highly related Ets transcription factors, we previously generated PU. 1(+/+)Spi-B(-/-) and PU.1(+/-)Spi-B(-/-) mice and demonstrated a significant decrease in B-cell receptor (BCR) signaling in mutants. Major components of BCR signaling appear to be expressed at normal levels in these mice, implying that PU.1 and Spi-B cooperate in the transcription of additional target genes important for antigen receptor signaling. We used subtractive hybridization to identify novel in vivo PU.1/Spi-B target genes and determined that the expression of a heptahelical receptor, P2Y10, is dramatically reduced in PU.1(+/-)Spi-B(-/-) B-cells. Further analysis shows that P2Y10 expression is restricted to lymphoid cells and parallels that of Spi-B in B-lymphocytes. Lastly, the P2Y10 promoter contains a PU. 1/Spi-B binding site functionally required for efficient transcription in B-cells. Thus, P2Y10 is likely to be a direct in vivo transcriptional target for PU.1 and Spi-B and provides a unique model to explore transcriptional regulation by this Ets factor subfamily. Furthermore, P2Y10 suggests an intriguing connection between heterotrimeric G-proteins and BCR signaling.
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MESH Headings
- 3T3 Cells
- Amino Acid Sequence
- Animals
- B-Lymphocytes/metabolism
- Binding Sites
- Binding, Competitive
- Blotting, Northern
- Cell Lineage
- DNA/genetics
- DNA/metabolism
- DNA, Complementary/genetics
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- DNA-Binding Proteins/physiology
- Gene Expression
- Mice
- Mice, Knockout
- Molecular Sequence Data
- Promoter Regions, Genetic
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins/physiology
- RNA, Messenger/genetics
- RNA, Messenger/isolation & purification
- RNA, Messenger/metabolism
- Receptors, Antigen, B-Cell/genetics
- Receptors, Antigen, B-Cell/metabolism
- Sequence Homology, Amino Acid
- Tissue Distribution
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Trans-Activators/physiology
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription Factors/physiology
- Transcription, Genetic
- Tumor Cells, Cultured
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Affiliation(s)
- S Rao
- Department of Pathology, The University of Chicago, Chicago, Illinois 60637, USA
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Chiang N, Gronert K, Clish CB, O'Brien JA, Freeman MW, Serhan CN. Leukotriene B4 receptor transgenic mice reveal novel protective roles for lipoxins and aspirin-triggered lipoxins in reperfusion. J Clin Invest 1999; 104:309-16. [PMID: 10430612 PMCID: PMC408424 DOI: 10.1172/jci7016] [Citation(s) in RCA: 171] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Polymorphonuclear neutrophil (PMN) activation is pivotal in acute inflammation and injury from reperfusion. To elucidate components controlling PMNs in vivo, we prepared novel transgenic mice with the human leukotriene (LT) B4 receptor (BLTR) for functional characterization. Overexpression of BLTR in leukocytes dramatically increased PMN trafficking to skin microabscesses and lungs after ischemia-reperfusion, whereas mice deficient in 5-lipoxygenase (5-LO) showed diminished PMN accumulation in reperfused lungs. Hence, both BLTR expression and LT biosynthesis are critical for PMN infiltration in reperfusion-initiated second-organ injury. Also, in BLTR transgenic mice, 5-LO expression and product formation were selectively increased in exudates, demonstrating that receptor overexpression amplifies proinflammatory circuits. Endogenous lipoxin (LX) A4 was produced in ischemic lungs and elevated by reperfusion. Because LXA4 and aspirin-triggered 15-epimeric LXA4 (ATL) selectively regulate leukocyte responses, they were tested in BLTR transgenic mice. Despite excessive PMN recruitment in BLTR transgenic mice, intravenous injection of ATL sharply diminished reperfusion-initiated PMN trafficking to remote organs, and topical application of LX was protective in acute dermal inflammation. These results demonstrate a direct role for BLTR with positive feedback, involving BLTR and 5-LO signaling in controlling PMNs. Moreover, LXA4 and ATL counter BLTR-amplified networks, revealing a novel protective role for LX and ATL in stress responses that has applications in perioperative medicine.
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MESH Headings
- Animals
- Arachidonate 5-Lipoxygenase/deficiency
- Arachidonate 5-Lipoxygenase/genetics
- Aspirin/pharmacology
- Cell Line
- Cell Movement
- Crosses, Genetic
- Ear, External
- Exudates and Transudates
- Female
- HL-60 Cells
- Hindlimb
- Humans
- Hydroxyeicosatetraenoic Acids/biosynthesis
- Hydroxyeicosatetraenoic Acids/physiology
- Lipoxins
- Male
- Mice
- Mice, Transgenic
- Neutrophils/pathology
- Peritonitis/metabolism
- Peritonitis/pathology
- RNA, Messenger/biosynthesis
- Receptors, Cell Surface/physiology
- Receptors, Formyl Peptide
- Receptors, Leukotriene B4/biosynthesis
- Receptors, Leukotriene B4/genetics
- Receptors, Leukotriene B4/physiology
- Receptors, Lipoxin
- Reperfusion Injury/genetics
- Reperfusion Injury/metabolism
- Reperfusion Injury/pathology
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Affiliation(s)
- N Chiang
- Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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29
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Sprietsma JE. Modern diets and diseases: NO-zinc balance. Under Th1, zinc and nitrogen monoxide (NO) collectively protect against viruses, AIDS, autoimmunity, diabetes, allergies, asthma, infectious diseases, atherosclerosis and cancer. Med Hypotheses 1999; 53:6-16. [PMID: 10499817 DOI: 10.1054/mehy.1999.0867] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Thanks to progress in zinc research, it is now possible to describe in more detail how zinc ions (Zn++) and nitrogen monoxide (NO), together with glutathione (GSH) and its oxidized form, GSSG, help to regulate immune responses to antigens. NO appears to be able to liberate Zn++ from metallothionein (MT), an intracellular storage molecule for metal ions such as zinc (Zn++) and copper (Cu++). Both Zn++ and Cu++ show a concentration-dependent inactivation of a protease essential for the proliferation of the AIDS virus HIV-1, while zinc can help prevent diabetes complications through its intracellular activation of the enzyme sorbitol dehydrogenase (SDH). A Zn++ deficiency can lead to a premature transition from efficient Th1-dependent cellular antiviral immune functions to Th2-dependent humoral immune functions. Deficiencies of Zn++, NO and/or GSH shift the Th1/Th2 balance towards Th2, as do deficiencies of any of the essential nutrients (ENs) - a group that includes methionine, cysteine, arginine, vitamins A, B, C and E, zinc and selenium (Se) - because these are necessary for the synthesis and maintenance of sufficient amounts of GSH, MT and NO. Via the Th1/Th2 balance, Zn++, NO, MT and GSH collectively determine the progress and outcome of many diseases. Disregulation of the Th1/Th2 balance is responsible for autoimmune disorders such as diabetes mellitus. Under Th2, levels of interleukin-4 (II-4), II-6, II-10, leukotriene B4 (LTB4) and prostaglandin E2 (PGE2) are raised, while levels of II-2, Zn++, NO and other substances are lowered. This makes things easier for viruses like HIV-1 which multiply in Th2 cells but rarely, if ever, in Th1 cells. AIDS viruses (HIVs) enter immune cells with the aid of the CD4 cell surface receptor in combination with a number of co-receptors which include CCR3, CCR5 and CXCR4. Remarkably, the cell surface receptor for LTB4 (BLTR) also seems to act as a co-receptor for CD4, which helps HIVs to infect immune cells. The Th2 cytokine II-4 increases the number of CXCR4 and BLTR co-receptors, as a result of which, under Th2, the HIV strains that infect immune cells are precisely those that are best able to accelerate the AIDS disease process. The II-4 released under Th2 therefore not only promotes the production of more HIVs and the rate at which they infect immune cells, it also stimulates selection for the more virulent strains. Zn++ inhibit LTB4 production and numbers of LTB4 receptors (BLTRs) in a concentration-dependent way. Zn++ help cells to keep their LTB4 'doors' shut against the more virulent strains of HIV. Moreover, a sufficiency of Zn++ and NO prevents a shift of the Th1/Th2 balance towards Th2 and thereby slows the proliferation of HIV, which it also does by inactivating the HIV protease. Research makes it look likely that deficiencies of ENs such as zinc promote the proliferation of Th2 cells at the expense of Th1 cells. Zinc deficiency also promotes cancer. Under the influence of Th1 cells, zinc inhibits the growth of tumours by activating the endogenous tumour-suppressor endostatin, which inhibits angiogenesis. The modern Western diet, with its excess of refined products such as sugar, alcohol and fats, often contains, per calorie, a deficiency of ENs such as zinc, selenium and vitamins A, B, C and E, which results in disturbed immune functions, a shifted Th1/Th2 balance, chronic (viral) infections, obesity, atherosclerosis, autoimmunity, allergies and cancer. In view of this, an optimization of dietary composition would seem to give the best chance of beating (viral) epidemics and common (chronic) diseases at a realistic price.
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Lynch KR, O'Neill GP, Liu Q, Im DS, Sawyer N, Metters KM, Coulombe N, Abramovitz M, Figueroa DJ, Zeng Z, Connolly BM, Bai C, Austin CP, Chateauneuf A, Stocco R, Greig GM, Kargman S, Hooks SB, Hosfield E, Williams DL, Ford-Hutchinson AW, Caskey CT, Evans JF. Characterization of the human cysteinyl leukotriene CysLT1 receptor. Nature 1999; 399:789-93. [PMID: 10391245 DOI: 10.1038/21658] [Citation(s) in RCA: 795] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The cysteinyl leukotrienes-leukotriene C4(LTC4), leukotriene D4(LTD4) and leukotriene E4(LTE4)-are important mediators of human bronchial asthma. Pharmacological studies have determined that cysteinyl leukotrienes activate at least two receptors, designated CysLT1 and CysLT2. The CysLT1-selective antagonists, such as montelukast (Singulair), zafirlukast (Accolate) and pranlukast (Onon), are important in the treatment of asthma. Previous biochemical characterization of CysLT1 antagonists and the CysLT1 receptor has been in membrane preparations from tissues enriched for this receptor. Here we report the molecular and pharmacological characterization of the cloned human CysLT1 receptor. We describe the functional activation (calcium mobilization) of this receptor by LTD4 and LTC4, and competition for radiolabelled LTD4 binding to this receptor by the cysteinyl leukotrienes and three structurally distinct classes of CysLT1-receptor antagonists. We detected CysLT1-receptor messenger RNA in spleen, peripheral blood leukocytes and lung. In normal human lung, expression of the CysLT1-receptor mRNA was confined to smooth muscle cells and tissue macrophages. Finally, we mapped the human CysLT1-receptor gene to the X chromosome.
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Affiliation(s)
- K R Lynch
- Department of Pharmacology, University of Virginia Health Sciences Center, Charlottesville 22908, USA
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