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Kahremany S, Hofmann L, Gruzman A, Cohen G. Advances in Understanding the Initial Steps of Pruritoceptive Itch: How the Itch Hits the Switch. Int J Mol Sci 2020; 21:ijms21144883. [PMID: 32664385 PMCID: PMC7402353 DOI: 10.3390/ijms21144883] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 02/07/2023] Open
Abstract
Pruritoceptive (dermal) itch was long considered an accompanying symptom of diseases, a side effect of drug applications, or a temporary sensation induced by invading pruritogens, as produced by the stinging nettle. Due to extensive research in recent years, it was possible to provide detailed insights into the mechanism of itch mediation and modulation. Hence, it became apparent that pruritus is a complex symptom or disease in itself, which requires particular attention to improve patients’ health. Here, we summarize recent findings in pruritoceptive itch, including how this sensation is triggered and modulated by diverse endogenous and exogenous pruritogens and their receptors. A differentiation between mediating pruritogen and modulating pruritogen seems to be of great advantage to understand and decipher the molecular mechanism of itch perception. Only a comprehensive view on itch sensation will provide a solid basis for targeting this long-neglected adverse sensation accompanying numerous diseases and many drug side effects. Finally, we identify critical aspects of itch perception that require future investigation.
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Affiliation(s)
- Shirin Kahremany
- Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (A.G.)
- The Skin Research Institute, The Dead Sea and Arava Science Center, Masada 86910, Israel;
- Correspondence:
| | - Lukas Hofmann
- Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (A.G.)
| | - Arie Gruzman
- Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (A.G.)
| | - Guy Cohen
- The Skin Research Institute, The Dead Sea and Arava Science Center, Masada 86910, Israel;
- Ben-Gurion University of the Negev, Eilat Campus, Eilat 8855630, Israel
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2
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Sato A, Yokoyama I, Ebina K. Biotinylated heptapeptides substituted with a D-amino acid as platelet-activating factor inhibitors. Eur J Pharmacol 2015; 764:202-207. [PMID: 26142829 DOI: 10.1016/j.ejphar.2015.06.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/22/2015] [Accepted: 06/30/2015] [Indexed: 10/23/2022]
Abstract
Platelet-activating factor (PAF), a potent lipid mediator, is implicated in many inflammatory diseases, and therefore may serve as a direct target for anti-inflammatory drugs. We previously reported that synthetic biotinylated peptides having a Tyr-Lys-Asp-Gly sequence markedly inhibit PAF-induced inflammation by direct binding, and that two synthetic fluorescence-labelled heptapeptides (Lys-Trp-Tyr-Lys-Asp-Gly-Asp and D-Lys-Trp-Tyr-Lys-Asp-Gly-Asp) with high stability in plasma specifically bind to PAF-like lipids (oxidized- and lyso-phosphatidylchoine). In this study, synthetic heptapeptides (Lys-Trp-Tyr-Lys-Asp-Gly-Asp) coupled to a biotin molecule through the N-terminal amino group and ε-amino group of N-terminus Lys, (Btn)KP6 and K(Btn)P6, respectively, and their biotinylated peptides substituted with D-Lys at the N-terminus, (Btn)dKP6 and dK(Btn)P6, respectively, were investigated for their effects on PAF-induced inflammation. In the experiments using a rat model of hind paw oedema, (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 significantly inhibited PAF-induced paw oedema, with the highest inhibitory effect exhibited by dK(Btn)P6. The inhibitory effect of D-Tyr-D-Lys-D-Asp-Gly tetrapeptide on PAF-induced paw oedema was much lower than that of Tyr-Lys-Asp-Gly tetrapeptide. In the experiments using tryptophan fluorescence spectroscopy, (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 bound to PAF dose-dependently, with dK(Btn)P6 showing the strongest binding affinity, indicating that its affinity appears to be closely correlated with its inhibitory effect on PAF-induced inflammation. These results suggest that direct binding of (Btn)KP6, K(Btn)P6, (Btn)dKP6, and dK(Btn)P6 to PAF can lead to marked inhibition of PAF-induced inflammation, and these agents, particularly dK(Btn)P6, may be useful as anti-inflammatory drugs targeting PAF with high stability in plasma.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan.
| | - Izumi Yokoyama
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
| | - Keiichi Ebina
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1, Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan
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3
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C-reactive protein specifically enhances platelet-activating factor-induced inflammatory activity in vivo. Eur J Pharmacol 2014; 745:46-51. [DOI: 10.1016/j.ejphar.2014.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/16/2014] [Accepted: 10/06/2014] [Indexed: 11/19/2022]
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4
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Sato A, Kumagai T, Ebina K. A synthetic biotinylated peptide, BP21, inhibits the induction of mRNA expression of inflammatory substances by oxidized- and lyso-phosphatidylcholine. Drug Dev Res 2014; 75:246-56. [PMID: 24890951 DOI: 10.1002/ddr.21178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/07/2014] [Indexed: 11/10/2022]
Abstract
Preclinical Research Oxidized low-density lipoprotein (ox-LDL) is implicated in many inflammatory diseases, e.g., type 2 diabetes, obesity, atherosclerosis, and metabolic syndrome. We previously reported that a synthetic biotinylated peptide, BP21, inhibits the bioactivity of ox-LDL via direct binding to ox-LDL. Here, we investigated the effect of BP21 on the mRNA expression of proinflammatory mediators induced by two major components of ox-LDL, oxidized- and lyso-phosphatidylcholine (ox-PC and LPC), in monocytes/macrophages (THP-1 cells) and adipocytes (3T3-L1 cells). In THP-1 cells, BP21 markedly reduced the mRNA expression of interleukin (IL)-6, adipocyte fatty acid-binding protein (aP2), tumor necrosis factor-α, and mitogen-activated protein kinase phosphatase-1, which are induced by one of the major bioactive components of ox-PC, 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), and reduced the mRNA expression of IL-6, the ox-LDL-specific scavenger receptor CD36, and aP2 induced by LPC. In adipocytes, the mRNA expression of IL-1β as an adipokine and aP2 is highly induced by ox-PC and LPC, and BP21 markedly reduced the mRNA expression of IL-1β and aP2 induced by POVPC and LPC. Furthermore, BP21 specifically bound to LPC and POVPC in a dose-dependent manner. These results suggest that BP21 may be useful lead for the potential treatment and prevention of inflammatory diseases caused by ox-PC and LPC.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, Iwaki, Fukushima, 970-8551, Japan
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5
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Common mechanism in endothelin-3 and PAF receptor function for anti-inflammatory responses. Eur J Pharmacol 2013; 718:30-3. [DOI: 10.1016/j.ejphar.2013.09.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 08/20/2013] [Accepted: 09/08/2013] [Indexed: 11/17/2022]
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Sato A, Kumagai T, Aoki J, Ebina K. Synthetic biotinylated peptide compounds derived from Asp-hemolysin: novel potent inhibitors of platelet-activating factor. Eur J Pharmacol 2012; 685:205-12. [PMID: 22542654 DOI: 10.1016/j.ejphar.2012.04.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 03/22/2012] [Accepted: 04/05/2012] [Indexed: 11/29/2022]
Abstract
Platelet-activating factor (PAF: 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine), a potent inflammatory mediator, is implicated in many inflammatory diseases and may possibly serve as a direct target for anti-inflammatory drugs. We have previously reported that Asp-hemolysin-related synthetic peptides (P4-P29) inhibit the bioactivities of oxidized low-density lipoprotein (ox-LDL) containing PAF-like lipids by direct binding to ox-LDL, which plays a key role in the atherosclerotic inflammatory process. In this study, we investigated whether these peptides inhibit the bioactivities of PAF by binding to PAF and its metabolite/precursor lyso-PAF. In in vitro experiments, P21, one of the peptides, bound to both PAF and lyso-PAF in a dose-dependent manner and markedly inhibited PAF-induced apoptosis in human umbilical vein endothelial cells. Moreover, in in vivo experiments, P4 and P21, particularly their N-terminally biotinylated peptide compounds (BP4 and BP21), inhibited PAF-induced rat paw oedema dose dependently and markedly, and showed sufficient inhibition of the oedema even at doses 150-300 times less than the doses of PAF antagonists. These results provide evidence that direct binding of N-terminally biotinylated peptide compounds derived from Asp-hemolysin to PAF and lyso-PAF leads to a dramatic inhibition of the bioactivities of PAF, both in vitro and in vivo, and strongly suggesting that these compounds may be useful as a novel type of anti-inflammatory drug for the treatment of several inflammatory diseases caused by PAF.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima, 970-8551 Japan.
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7
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Ma J, Altomare A, de la Monte S, Tong M, Rieder F, Fiocchi C, Behar J, Shindou H, Biancani P, Harnett KM. HCl-induced inflammatory mediators in esophageal mucosa increase migration and production of H2O2 by peripheral blood leukocytes. Am J Physiol Gastrointest Liver Physiol 2010; 299:G791-8. [PMID: 20616304 PMCID: PMC2950690 DOI: 10.1152/ajpgi.00160.2010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Exposure of esophageal mucosa to hydrochloric acid (HCl) is a crucial factor in the pathogenesis of reflux disease. We examined supernatant of HCl-exposed rabbit mucosa for inflammatory mediators enhancing migration of leukocytes and production of H(2)O(2) as an indicator of leukocyte activation. A tubular segment of rabbit esophageal mucosa was tied at both ends to form a sac, which was filled with HCl-acidified Krebs buffer at pH 5 (or plain Krebs buffer as control) and kept oxygenated at 37 degrees C. The medium around the sac (supernatant) was collected after 3 h. Rabbit peripheral blood leukocytes (PBL) were isolated, and sac supernatant was used to investigate PBL migration and H(2)O(2) production. HCl-exposed esophageal mucosa released substance P (SP), CGRP, platelet-activating factor (PAF), and IL-8 into the supernatant. PBL migration increased in response to IL-8 or to supernatant of the HCl-filled mucosal sac. Supernatant-induced PBL migration was inhibited by IL-8 antibodies and by antagonists for PAF (CV3988) or neurokinin 1 (i.e., SP), but not by a CGRP antagonist. Supernatant of the HCl-filled mucosal sac increased H(2)O(2) release by PBL that was significantly reduced by CV3988 and by a SP antagonist but was not affected by IL-8 antibodies or by a CGRP antagonist. We conclude that IL-8, PAF, and SP are important inflammatory mediators released by esophageal mucosa in response to acid that promote PBL migration. In addition, PAF and SP induce production of H(2)O(2) by PBL. These findings provide a direct link between acid exposure and recruitment and activation of immune cells in esophageal mucosa.
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Affiliation(s)
- Jie Ma
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,2School of Pharmaceutical Sciences, Jilin University, Changchun, Jilin, China;
| | - Annamaria Altomare
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island; ,3Department of Digestive Disease of Campus Bio Medico University of Rome, Rome, Italy;
| | - Suzanne de la Monte
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Ming Tong
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Florian Rieder
- 4Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Claudio Fiocchi
- 4Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; and
| | - Jose Behar
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Hideo Shindou
- 5Department of Biochemistry and Molecular Biology, University of Tokyo, Tokyo, Japan
| | - Piero Biancani
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
| | - Karen M. Harnett
- 1Department of Medicine, Rhode Island Hospital and Brown University, Providence, Rhode Island;
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Schmitz G, Ruebsaamen K. Metabolism and atherogenic disease association of lysophosphatidylcholine. Atherosclerosis 2009; 208:10-8. [PMID: 19570538 DOI: 10.1016/j.atherosclerosis.2009.05.029] [Citation(s) in RCA: 259] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 04/27/2009] [Accepted: 05/25/2009] [Indexed: 10/20/2022]
Abstract
Lysophosphatidylcholine (LPC) is a major plasma lipid that has been recognized as an important cell signalling molecule produced under physiological conditions by the action of phospholipase A(2) on phosphatidylcholine. LPC transports glycerophospholipid components such as fatty acids, phosphatidylglycerol and choline between tissues. LPC is a ligand for specific G protein-coupled signalling receptors and activates several second messengers. LPC is also a major phospholipid component of oxidized low-density lipoproteins (Ox-LDL) and is implicated as a critical factor in the atherogenic activity of Ox-LDL. Hence, LPC plays an important role in atherosclerosis and acute and chronic inflammation. In this review we focus in some detail on LPC function, biochemical pathways, sources and signal-transduction system. Moreover, we outline the detection of LPC by mass spectrometry which is currently the best method for accurate and simultaneous analysis of each individual LPC species and reveal the pathophysiological implication of LPC which makes it an interesting target for biomarker and drug development regarding atherosclerosis and cardiovascular disorders.
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Affiliation(s)
- Gerd Schmitz
- Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany.
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9
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Shindou H, Hishikawa D, Nakanishi H, Harayama T, Ishii S, Taguchi R, Shimizu T. A Single Enzyme Catalyzes Both Platelet-activating Factor Production and Membrane Biogenesis of Inflammatory Cells. J Biol Chem 2007; 282:6532-9. [PMID: 17182612 DOI: 10.1074/jbc.m609641200] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Platelet-activating factor (PAF) is a potent proinflammatory lipid mediator eliciting a variety of cellular functions. Lipid mediators, including PAF are produced from membrane phospholipids by enzymatic cascades. Although a G protein-coupled PAF receptor and degradation enzymes have been cloned and characterized, the PAF biosynthetic enzyme, aceyl-CoA:lyso-PAF acetyltransferase, has not been identified. Here, we cloned lyso-PAF acetyltransferase, which is critical in stimulus-dependent formation of PAF. The enzyme is a 60-kDa microsomal protein with three putative membrane-spanning domains. The enzyme was induced by bacterial endotoxin (lipopolysaccharide), which was suppressed by dexamethasone treatment. Surprisingly, the enzyme catalyzed not only biosynthesis of PAF from lyso-PAF but also incorporation of arachidonoyl-CoA to produce PAF precursor membrane glycerophospholipids (lysophosphatidylcholine acyltransferase activity). Under resting conditions, the enzyme prefers arachidonoyl-CoA and contributes to membrane biogenesis. Upon acute inflammatory stimulation with lipopolysaccharide, the activated enzyme utilizes acetyl-CoA more efficiently and produces PAF. Thus, our findings provide a novel concept that a single enzyme catalyzes membrane biogenesis of inflammatory cells while producing a prophlogistic mediator in response to external stimuli.
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Affiliation(s)
- Hideo Shindou
- Department of Biochemistry and Molecular Biology, University of Tokyo, Hongo, Tokyo, Japan
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10
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Strømgaard K, Saito DR, Shindou H, Ishii S, Shimizu T, Nakanishi K. Ginkgolide derivatives for photolabeling studies: preparation and pharmacological evaluation. J Med Chem 2002; 45:4038-46. [PMID: 12190325 DOI: 10.1021/jm020147w] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The terpene trilactones (TTLs), ginkgolides and bilobalide, are structurally unique constituents of Ginkgo biloba extracts, which exhibit various neuromodulatory properties. Although the TTLs are believed to be responsible for some of these effects, the specific interactions with targets in the central nervous system remain to be elucidated on a molecular level. Ginkgolides are known antagonists of the platelet-activating factor (PAF) receptor. Herein, we describe the first examination of the binding of native TTLs and their derivatives to the cloned PAF receptor, confirming that of the TTLs, ginkgolide B is the most potent PAF receptor antagonist. Ginkgolide derivatives carrying photoactivatable and fluorescent groups for the purpose of performing photolabeling have been prepared and evaluated using the cloned PAF receptor. These studies have shown that ginkgolide derivatives with aromatic photoactivatable substituents are potent PAF receptor antagonists with K(i) values of 0.09-0.79 microM and hence excellent ligands for clarifying the binding of ginkgolides to PAF receptor by photolabeling studies. Ginkgolide derivatives incorporating both fluorescent and photoactivatable groups still retained binding affinity to the PAF receptor and hence should be promising ligands for photolabeling and subsequent sequencing studies.
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Affiliation(s)
- Kristian Strømgaard
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA.
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11
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Sakamoto S, Tezuka K, Tsuji T, Hori N, Tamatani T. AILIM/ICOS: its expression and functional analysis with monoclonal antibodies. HYBRIDOMA AND HYBRIDOMICS 2002; 20:293-303. [PMID: 11839247 DOI: 10.1089/15368590152740699] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Activation-inducible lymphocyte immuno-mediatory molecule (AILIM/ICOS) is the third member of the co-stimulatory molecule CD28/CTLA-4 (CD152) family, and an inducible cell surface glycoprotein expressed on lymphocytes following activation. To determine the expression profile of the molecule, we generated monoclonal antibodies (MAbs) against human, rat, and mouse AILIM/ICOS. None of the MAbs bound to AILIM/ICOS of other species. The numbers of AILIM/ICOS-positive cells among human peripheral blood mononuclear cells (PBMC), and rat and mouse splenocytes were very low (0.5, 0.4, and 1.2%, respectively), and the cells included many CD4-positive T cells except in the case of rat. Rat AILIM/ICOS-positive cells among splenocytes included many CD45RA-positive B cells, although the expression on lymph node cells was similar to that on human PBMC and mouse splenocytes. Among rat thymocytes, the AILIM/ICOS expression was mainly localized on CD4- and CD8-double positive T cells. The binding of AILIM/ICOS to B7h-Ig, which is the ligand-Fc chimeric protein, was inhibited by all AILIM/ICOS-specific MAbs except for SG430. The potency of the co-stimulatory activity of CD3 and AILIM/ICOS as to T-cell proliferation was found to be substantial in human. Interestingly, the levels of stimulation with the two types of MAbs were equal to that with CD3 and CD28 despite the different functions of the two MAbs in the AILIM/ICOS-B7h interaction. On the other hand, the potencies in rat and mouse, although two independent MAbs were tested, were relatively lower than that of CD28-mediated co-stimulation.
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Affiliation(s)
- S Sakamoto
- Pharmaceutical Frontier Research Laboratories, JT Inc., 13-2, Fukuura 1-chome, Kanazawa-ku, Yokohama 236-0004, Japan.
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Ogawa S, Nagamatsu G, Watanabe M, Watanabe S, Hayashi T, Horita S, Nitta K, Nihei H, Tezuka K, Abe R. Opposing effects of anti-activation-inducible lymphocyte-immunomodulatory molecule/inducible costimulator antibody on the development of acute versus chronic graft-versus-host disease. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5741-8. [PMID: 11698447 DOI: 10.4049/jimmunol.167.10.5741] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The functional role of inducible costimulator (ICOS)-mediated costimulation was examined in an in vivo model of alloantigen-driven Th1 or Th2 cytokine responses, the parent-into-F(1) model of acute or chronic graft-vs-host disease (GVHD), respectively. When the Ab specific for mouse ICOS was injected into chronic GVHD-induced mice, activation of B cells, production of autoantibody, and development of glomerulonephritis were strongly suppressed. In contrast, the same treatment enhanced donor T cell chimerism and host B cell depletion in acute GVHD induced host mice. Blocking of B7-CD28 interaction by injection of anti-B7-1 and anti-B7-2 Abs inhibited both acute and chronic GVHD. These observations clearly indicate that the costimulatory signal mediated by CD28 caused the initial allorecognition resulting in the clonal expansion of alloreactive T cells, whereas the costimulatory signal mediated by ICOS played a critical role in the functional differentiation and manifestation of alloreactive T cells. Furthermore, treatment with anti-ICOS Ab selectively suppresses Th2-dominant autoimmune disease.
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Affiliation(s)
- S Ogawa
- Division of Immunobiology, Research Institutes of Biological Sciences, Science University of Tokyo, Chiba, Japan
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Marathe GK, Silva AR, de Castro Faria Neto HC, Tjoelker LW, Prescott SM, Zimmerman GA, McIntyre TM. Lysophosphatidylcholine and lyso-PAF display PAF-like activity derived from contaminating phospholipids. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)30275-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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14
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Shindou H, Ishii S, Uozumi N, Shimizu T. Roles of cytosolic phospholipase A(2) and platelet-activating factor receptor in the Ca-induced biosynthesis of PAF. Biochem Biophys Res Commun 2000; 271:812-7. [PMID: 10814544 DOI: 10.1006/bbrc.2000.2723] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Casein-elicited peritoneal exudate cells (PEC), mainly consisted of neutrophils, were collected from platelet-activating factor receptor-knock-out (PAFR-KO), cytosolic phospholipase A(2) knock-out (cPLA(2)-KO), and wild-type (WT) mice. After stimulation of PEC with calcium ionophore A 23187, PAF levels were measured by radio-ligand binding assay using receptor-rich membrane fraction prepared from the PAF receptor transgenic mice. We found that the level of PAF production by PEC was not different between WT and PAFR-KO mice. On the other hand, cPLA(2)-KO mice were deficient in the PAF production. These results provide the direct evidence while cPLA(2) is essential in the production of PAF, PAF receptor deficiency has little effect on the PAF production.
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Affiliation(s)
- H Shindou
- Department of Biochemistry and Molecular Biology, University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
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15
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Aihara M, Ishii S, Kume K, Shimizu T. Interaction between neurone and microglia mediated by platelet-activating factor. Genes Cells 2000; 5:397-406. [PMID: 10886367 DOI: 10.1046/j.1365-2443.2000.00333.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Platelet-activating factor (PAF) is a potent phospholipid mediator that plays various roles in neuronal function and brain development. The production and release of PAF in the brain has also been reported under various pathological conditions. However, neither the cell types and mechanism responsible for the synthesis of PAF nor its target cells have been fully identified. RESULTS Using primary culture cells derived from rat brain and a very sensitive assay method for PAF, we found that PAF was synthesized in neurones following stimulation with glutamic acid. PAF synthesis required activation of NMDA receptors and subsequent elevation of intracellular calcium ions. Microglia, which express functional PAF receptors to a high level, showed a marked chemotactic response to PAF. This chemotaxis is a receptor-mediated process, as microglia from PAF-receptor-deficient mice did not show such a response. The activation of a pertussis-toxin-sensitive G-protein and mitogen-activated protein kinase presumably plays a role in intracellular signalling leading to chemotaxis. CONCLUSIONS Considering the cytoprotective and cytotoxic roles of microglia, PAF functions as a key messenger in neurone-microglial interactions.
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Affiliation(s)
- M Aihara
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Tokyo, Tokyo 113-0033, and CREST of Japan Science and Technology Incorporation, Japan
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16
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Marathe GK, Davies SS, Harrison KA, Silva AR, Murphy RC, Castro-Faria-Neto H, Prescott SM, Zimmerman GA, McIntyre TM. Inflammatory platelet-activating factor-like phospholipids in oxidized low density lipoproteins are fragmented alkyl phosphatidylcholines. J Biol Chem 1999; 274:28395-404. [PMID: 10497200 DOI: 10.1074/jbc.274.40.28395] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oxidation of human low density lipoprotein (LDL) generates proinflammatory mediators and underlies early events in atherogenesis. We identified mediators in oxidized LDL that induced an inflammatory reaction in vivo, and activated polymorphonuclear leukocytes and cells ectopically expressing human platelet-activating factor (PAF) receptors. Oxidation of a synthetic phosphatidylcholine showed that an sn-1 ether bond confers an 800-fold increase in potency. This suggests that rare ether-linked phospholipids in LDL are the likely source of PAF-like activity in oxidized LDL. Accordingly, treatment of oxidized LDL with phospholipase A(1) greatly reduced phospholipid mass, but did not decrease its PAF-like activity. Tandem mass spectrometry identified traces of PAF, and more abundant levels of 1-O-hexadecyl-2-(butanoyl or butenoyl)-sn-glycero-3-phosphocholines (C(4)-PAF analogs) in oxidized LDL that comigrated with PAF-like activity. Synthesis showed that either C(4)-PAF was just 10-fold less potent than PAF as a PAF receptor ligand and agonist. Quantitation by gas chromatography-mass spectrometry of pentafluorobenzoyl derivatives shows the C(4)-PAF analogs were 100-fold more abundant in oxidized LDL than PAF. Oxidation of synthetic alkyl arachidonoyl phosphatidylcholine generated these C(4)-PAFs in abundance. These results show that quite minor constituents of the LDL phosphatidylcholine pool are the exclusive precursors for PAF-like bioactivity in oxidized LDL.
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Affiliation(s)
- G K Marathe
- Department of Pathology, University of Utah, Salt Lake City, Utah 84112, USA
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17
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Uozumi N, Kume K, Nagase T, Nakatani N, Ishii S, Tashiro F, Komagata Y, Maki K, Ikuta K, Ouchi Y, Miyazaki J, Shimizu T. Role of cytosolic phospholipase A2 in allergic response and parturition. Nature 1997; 390:618-22. [PMID: 9403692 DOI: 10.1038/37622] [Citation(s) in RCA: 544] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Phospholipase A2 (PLA2) comprises a superfamily of enzymes that hydrolyse the ester bond of phospholipids at the sn-2 position. Among the members of this superfamily, cytosolic PLA2 has attracted attention because it preferentially hydrolyses arachidonoyl phospholipids and is activated by submicromolar concentrations of Ca2+ ions and by phosphorylation by mitogen-activated protein kinases (MAP kinases). Here we investigate the function of cytosolic PLA2 in vivo by using homologous recombination to generate mice deficient in this enzyme. These mice showed a marked decrease in their production of eicosanoids and platelet-activating factor in peritoneal macrophages. Their ovalbumin-induced anaphylactic responses were significantly reduced, as was their bronchial reactivity to methacholine. Female mutant mice failed to deliver offspring, but these could be rescued by administration of a progesterone-receptor antagonist to the mother at term. Considered together with previous findings, our results indicate that cytosolic PLA2 plays a non-redundant role in allergic responses and reproductive physiology.
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Affiliation(s)
- N Uozumi
- Department of Biochemistry, University of Tokyo, Japan
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18
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Aoki Y, Nakamura M, Kodama H, Shimizu T. A simple, rapid and specific radioreceptor assay for platelet-activating factor. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 407:459-64. [PMID: 9321990 DOI: 10.1007/978-1-4899-1813-0_67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Y Aoki
- Life Science Research Laboratory, Japan Tobacco Inc., Kanagawa, Japan
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19
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Kume K, Waga I, Shimizu T. Microplate chromatography assay for acetyl-CoA: lysoplatelet-activating factor acetyltransferase. Anal Biochem 1997; 246:118-22. [PMID: 9056192 DOI: 10.1006/abio.1996.9959] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Acetyl-CoA:lysoplatelet-activating factor (1-O-alkyl-sn-glycero-3-phosphocholine) acetyltransferase (lysoPAF-AT) (EC 2.3.1.67) is a key enzyme in the biosynthesis of platelet-activating factor (PAF) and has been shown to be activated by various extracellular stimuli. A novel method to determine the enzyme activity is described here, which enables 96 simultaneous assays in a standard 96-well microplate format. The assay is based on the quantification of the incorporation of [3H]acetyl-CoA into PAF in the presence of lysoPAF. The radioactive products are separated from the substrate with a 96-well-formatted chromatography device using a Multiscreen plate (Millipore) prefilled with octyl-silica gel. As little as 1 mg octyl-silica gel was sufficient for the efficient recovery of the radioactive product, resulting in the very low background and thus high sensitivity. The enzyme activity could be measured directly with whole cell lysates from various cells cultured in 96-well microplate scale. This tailor-made microplate chromatography separation step is readily applicable for other kinds of enzyme assays.
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Affiliation(s)
- K Kume
- Faculty of Medicine, University of Tokyo, Bunkyo, Tokyo , 113, Japan.
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