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Shukla SD, Walters EH, Simpson JL, Keely S, Wark PA, O'Toole RF, Hansbro PM. Hypoxia‐inducible factor and bacterial infections in chronic obstructive pulmonary disease. Respirology 2019; 25:53-63. [DOI: 10.1111/resp.13722] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/25/2019] [Accepted: 10/08/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Shakti D. Shukla
- School of Biomedical Sciences and Pharmacy, Faculty of Health and MedicineUniversity of Newcastle Newcastle NSW Australia
- Priority Research Centre for Healthy Lungs, Hunter Medical Research InstituteUniversity of Newcastle Newcastle NSW Australia
| | - E. Haydn Walters
- School of Medicine, College of Health and MedicineUniversity of Tasmania Hobart TAS Australia
| | - Jodie L. Simpson
- Priority Research Centre for Healthy Lungs, Hunter Medical Research InstituteUniversity of Newcastle Newcastle NSW Australia
- Respiratory and Sleep Medicine, Priority Research Centre for Healthy LungsUniversity of Newcastle Newcastle NSW Australia
| | - Simon Keely
- School of Biomedical Sciences and Pharmacy, Faculty of Health and MedicineUniversity of Newcastle Newcastle NSW Australia
- Priority Research Centre for Digestive Health and Neurogastroenterology, Hunter Medical Research InstituteUniversity of Newcastle Newcastle NSW Australia
| | - Peter A.B. Wark
- Priority Research Centre for Healthy Lungs, Hunter Medical Research InstituteUniversity of Newcastle Newcastle NSW Australia
- Respiratory and Sleep Medicine, Priority Research Centre for Healthy LungsUniversity of Newcastle Newcastle NSW Australia
| | - Ronan F. O'Toole
- School of Molecular Sciences, College of Science, Health and EngineeringLa Trobe University Melbourne VIC Australia
| | - Philip M. Hansbro
- School of Biomedical Sciences and Pharmacy, Faculty of Health and MedicineUniversity of Newcastle Newcastle NSW Australia
- Priority Research Centre for Healthy Lungs, Hunter Medical Research InstituteUniversity of Newcastle Newcastle NSW Australia
- Centenary Institute and School of Life Sciences, Faculty of Science, University of Technology Sydney Sydney NSW Australia
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O'Toole RF, Shukla SD, Walters EH. Does upregulated host cell receptor expression provide a link between bacterial adhesion and chronic respiratory disease? J Transl Med 2016; 14:304. [PMID: 27782846 PMCID: PMC5080759 DOI: 10.1186/s12967-016-1063-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/12/2016] [Indexed: 11/18/2022] Open
Abstract
Expression of the platelet-activating factor receptor is upregulated in the respiratory epithelium of smokers and chronic obstructive pulmonary disease patients. We have recently determined that increased expression of PAFr correlates with higher levels of adhesion to human bronchial epithelial cells by non-typable Haemophilus influenzae and Streptococcus pneumoniae which are major bacterial pathogens in acute exacerbations of COPD. In addition, we found that a PAFr antagonist decreased the adhesion of both respiratory bacterial pathogens to non-cigarette exposure control levels. This highlights the possibility that epithelial receptors, that are upregulated in response to cigarette smoke, could be targeted to specifically block chronic bacterial infections of the lower respiratory tract. In this commentary, we explore the question of whether adhesion to a temporally-upregulated host receptor is a common event in chronic bacterial disease, and as such, could represent a putative therapeutic target for blocking infection by respiratory and other pathogens.
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Affiliation(s)
- Ronan F O'Toole
- School of Medicine, Faculty of Health, University of Tasmania, Medical Science 1, 17 Liverpool Street, Hobart, TAS, 7000, Australia.
| | - Shakti D Shukla
- School of Medicine, Faculty of Health, University of Tasmania, Medical Science 1, 17 Liverpool Street, Hobart, TAS, 7000, Australia
| | - Eugene H Walters
- School of Medicine, Faculty of Health, University of Tasmania, Medical Science 1, 17 Liverpool Street, Hobart, TAS, 7000, Australia
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Dhankher P, Benhamou L, Sheppard TD. Rapid assembly of functionalised spirocyclic indolines by palladium-catalysed dearomatising diallylation of indoles with allyl acetate. Chemistry 2014; 20:13375-81. [PMID: 25171550 PMCID: PMC4304291 DOI: 10.1002/chem.201403940] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Indexed: 11/11/2022]
Abstract
Herein, we report the application of allyl acetate to the palladium-catalysed dearomatising diallylation of indoles. The reaction can be carried out by using a readily available palladium catalyst at room temperature, and can be applied to a wide range of substituted indoles to provide access to the corresponding 3,3-diallylindolinines. These compounds are versatile synthetic intermediates that readily undergo Ugi reactions or proline-catalysed asymmetric Mannich reactions. Alternatively, acylation of the 3,3-diallylindolinines with an acid chloride or a chloroformate, followed by treatment with aluminium chloride, enables 2,3-diallylindoles to be prepared. By using ring-closing metathesis, functionalised spirocyclic indoline scaffolds can be accessed from the Ugi products, and a dihydrocarbazole can be prepared from the corresponding 2,3-diallylindole.
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Affiliation(s)
- Persis Dhankher
- Department of Chemistry, University College London, 20 Gordon St, London, WC1H 0AJ (UK)
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Dhawan S, Cailotto C, Harthoorn LF, de Jonge WJ. Cholinergic signalling in gut immunity. Life Sci 2012; 91:1038-42. [PMID: 22580288 DOI: 10.1016/j.lfs.2012.04.042] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 04/17/2012] [Accepted: 04/24/2012] [Indexed: 12/20/2022]
Abstract
The gut immune system shares many signalling molecules and receptors with the autonomic nervous system. A good example is the vagal neurotransmitter acetylcholine (ACh), for which many immune cell types express cholinergic receptors (AChR). In the last decade the vagal nerve has emerged as an integral part of an immune regulation network via its release of ACh; a system coined "the cholinergic anti-inflammatory reflex". The perspective of cholinergic immune regulation in the gut mucosa has been widened by the recent discovery of populations of ACh producing immune cells in the spleen and other organs. As such, ACh, classically referred to as neurotransmitter, may serve a much broader function as bi-directional signalling molecule between neurons and non-neuronal cell types of the immune system.
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Affiliation(s)
- Shobhit Dhawan
- Tytgat Institute for Liver and GI research, AMC Amsterdam, The Netherlands
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Yasuda M, Kawahara R, Hashimura H, Yamanaka N, Iimori M, Amagase K, Kato S, Takeuchi K. Dopamine D₂-receptor antagonists ameliorate indomethacin-induced small intestinal ulceration in mice by activating α7 nicotinic acetylcholine receptors. J Pharmacol Sci 2011; 116:274-82. [PMID: 21691039 DOI: 10.1254/jphs.11037fp] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have reported that nicotine and the specific α7AChR agonist ameliorate indomethacin-induced intestinal lesions in mice by activating α7 nicotinic acetylcholine receptors (α7nAChR). Dopamine D₂-receptor antagonists, such as domperidone and metoclopramide, enhance the release of ACh from vagal efferent nerves. The present study examined the effects of domperidone and metoclopramide on indomethacin-induced small intestinal ulceration in mice, focusing on the α7AChR. Male C57BL/6 mice were administered indomethacin (10 mg/kg, s.c.) and sacrificed 24 h later. Domperidone (0.1-10 mg/kg) and metoclopramide (0.03-0.3 mg/kg) were administered i.p. twice, at 0.5 h before and 8 h after indomethacin treatment, while methyllycaconitine (a selective antagonist of α7nAChR, 30 mg/kg) was administered twice, at 0.5 h before each domperidone treatment. Indomethacin caused severe hemorrhagic lesions in the small intestine, mostly to the jejunum and ileum, with a concomitant increase in myeloperoxidase (MPO) activity. Domperidone suppressed the severity of lesions and the increase in MPO activity at low doses (0.1-3 mg/kg), but not at a high dose (10 mg/kg). Similar effects were also observed by metoclopramide. The protective effects of domperidone and metoclopramide were totally abolished by prior administration of methyllycaconitine. Indomethacin treatment markedly enhanced inducible nitric oxide synthase and chemokine mRNA expression in the small intestine, but these responses were all significantly attenuated by either domperidone or metoclopramide. These findings suggest that dopamine D₂-receptor antagonists ameliorate indomethacin-induced small intestinal ulceration through the activation of endogenous anti-inflammatory pathways mediated by α7nAChR.
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Affiliation(s)
- Masashi Yasuda
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Kyoto, Japan
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Kawahara R, Yasuda M, Hashimura H, Amagase K, Kato S, Takeuchi K. Activation of α7 nicotinic acetylcholine receptors ameliorates indomethacin-induced small intestinal ulceration in mice. Eur J Pharmacol 2010; 650:411-7. [PMID: 20969854 DOI: 10.1016/j.ejphar.2010.10.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 09/24/2010] [Accepted: 10/06/2010] [Indexed: 02/06/2023]
Abstract
Cholinergic anti-inflammatory actions have been shown to result mainly from the activation of α7 nicotinic acetylcholine receptors. Here, we investigated the possible role of α7 nicotinic acetylcholine receptors in the pathogenesis of indomethacin-induced small intestinal ulceration in mice. Male C57BL/6 mice were given indomethacin (10mg/kg, s.c.), and sacrificed 24h later. Nicotine (0.3-3mg/kg) and PNU-282987 (a selective agonist of α7 nicotinic acetylcholine receptors; 1-10mg/kg) were administered i.p. twice, at 0.5h before and 8h after indomethacin treatment, while methyllycaconitine (a selective antagonist of α7 nicotinic acetylcholine receptors; 10mg/kg was administered twice, at 0.5h before each nicotine treatment. Indomethacin caused severe hemorrhagic lesions in the small intestine with marked increases in myeloperoxidase (MPO) activity and inducible nitric oxide synthase (iNOS) expression in the mucosa. Pretreatment with nicotine reduced the severity of intestinal lesions in a dose-dependent manner. The protective effect of nicotine was mimicked by PNU-282987 and significantly attenuated by methyllycaconitine. The increases in MPO activity and iNOS expression induced by indomethacin were also significantly suppressed by nicotine and PNU-282987. Immunohistochemical study showed that the expression of α7 nicotinic acetylcholine receptors was clearly enhanced in the submucosa of the damaged area following indomethacin treatment. These results suggest that the activation of α7 nicotinic acetylcholine receptors ameliorates indomethacin-induced small intestinal ulceration, and that this effect may result from the inhibition of iNOS expression and neutrophil migration.
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Affiliation(s)
- Ryoji Kawahara
- Division of Pathological Sciences, Department of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical University, Misasagi, Yamashina, Kyoto 607-8414, Japan
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Van Der Zanden EP, Boeckxstaens GE, de Jonge WJ. The vagus nerve as a modulator of intestinal inflammation. Neurogastroenterol Motil 2009; 21:6-17. [PMID: 19140954 DOI: 10.1111/j.1365-2982.2008.01252.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cholinergic nervous system attenuates the production of pro-inflammatory cytokines and inhibits inflammatory processes. Hence, in animal models of intestinal inflammation, such as postoperative ileus and dextran sulfate sodium-induced colitis, vagus nerve stimulation ameliorates disease activity. On the other hand, in infectious models of microbial peritonitis, vagus nerve activation seemingly acts counteractive; it impairs bacterial clearance and increases mortality. It is originally indicated that the key mediator of the cholinergic anti-inflammatory pathway, acetylcholine (ACh), inhibits cytokine release directly via the alpha7 nicotinic ACh receptor (nAChR) expressed on macrophages. However, more recent data also point towards the vagus nerve as an indirect modulator of innate inflammatory processes, exerting its anti-inflammatory effects via postganglionic modulation of immune cells in primary immune organs. This review discusses advances in the possible mechanisms by which the vagus nerve can mediate the immune response, and the role of nAChR activation and signalling on macrophages and other immune cells.
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Affiliation(s)
- E P Van Der Zanden
- Department of Gastroenterology & Hepatology, Academic Medical Center, Amsterdam, The Netherlands
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Aslam R, Saeed SA, Ahmed S, Connor JD. LIPOPROTEINS INHIBIT PLATELET AGGREGATION AND ARACHIDONIC ACID METABOLISM IN EXPERIMENTAL HYPERCHOLESTEROLAEMIA. Clin Exp Pharmacol Physiol 2008; 35:656-62. [DOI: 10.1111/j.1440-1681.2007.04863.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Saeed SA, Ahmad N, Ahmed S. Dual inhibition of cyclooxygenase and lipoxygenase by human haptoglobin: Its polymorphism and relation to hemoglobin binding. Biochem Biophys Res Commun 2007; 353:915-20. [PMID: 17198677 DOI: 10.1016/j.bbrc.2006.12.092] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 12/09/2006] [Indexed: 11/24/2022]
Abstract
Haptoglobin (Hp) binds hemoglobin (Hb) specifically and stoichiometrically. Since Hb stimulates prostaglandin (PG biosynthesis), we investigated if Hp effects arachidonic acid (AA) metabolism. The results showed that Hp (50-250 microg protein) inhibited the biosynthesis of PGs via cyclooxygenase (COX) and 12-HETE via lipoxygenase pathway in human platelets. Additional evidence was obtained by the loss of Hp inhibitory activity upon removal of Hp by affinity chromatography on hemoglobin sepharose and by inhibition of AA or bradykinin-induced bronchoconstriction in the guinea pig. Hb reduced the inhibitory effect of Hp in a concentration-related manner such that all its inhibitory activity was lost when completely bound by Hb. Of the three Hp phenotypes, Hp 1-1 showed maximum binding capacity to Hb indicating its greater protective role. These findings implicate Hp in the regulation of COX and lipoxygenase pathways and show Hp involvement in the body's endogenous defense system against inflammation. This indicates that mammals have dual defense system, i.e., a specific immune system and non-specific Hp defense system.
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Affiliation(s)
- Sheikh Arshad Saeed
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
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Abstract
Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a biologically active phospholipid mediator. Although PAF was named for its potential to induce platelet aggregation, intense investigations have elucidated potent biological actions of PAF in a broad range of cell types and tissues. PAF acts by binding to a unique G-protein-coupled seven transmembrane receptor, and activates multiple intracellular signaling pathways. In the last decade, we have identified the PAF receptor structures, intracellular signaling mechanisms, and genomic organizations. Recently, we found a single nucleotide polymorphism of the human PAF receptor (A224D) with an allele frequency of 7.8% in Japanese. Cells expressing this receptor exhibited the reduced cellular signaling, although the binding parameters remain unchanged. We have established two different types of genetically altered mice, i.e. PAF receptor-overexpressing mouse and PAF receptor-deficient mouse. These mutant mice provide a novel and specific approach for identifying the pathophysiological and physiological functions of PAF in vivo. This review focuses on phenotypes of these mutant mice and summarizes the previous reports regarding PAF and PAF receptor.
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Affiliation(s)
- Satoshi Ishii
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Japan.
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Saeed SA, Rasheed H, Hoodbhoy ZA, Pasha SR, Mapara Z, Kumar H, Shah BH. Involvement of cyclooxygenase, phospholipase C and MAP kinase pathways in human platelet aggregation mediated by the synergistic interaction of adrenaline and PAF. Inflammopharmacology 2001. [DOI: 10.1163/156856001300248425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ishii S, Shimizu T. Platelet-activating factor (PAF) receptor and genetically engineered PAF receptor mutant mice. Prog Lipid Res 2000; 39:41-82. [PMID: 10729607 DOI: 10.1016/s0163-7827(99)00016-8] [Citation(s) in RCA: 279] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a biologically active phospholipid mediator. Although PAF was initially recognized for its potential to induce platelet aggregation and secretion, intense investigations have elucidated potent biological actions of PAF in a broad range of cell types and tissues, many of which also produce the molecule. PAF acts by binding to a unique G-protein-coupled seven transmembrane receptor. PAF receptor is linked to intracellular signal transduction pathways, including turnover of phosphatidylinositol, elevation in intracellular calcium concentration, and activation of kinases, resulting in versatile bioactions. On the basis of numerous pharmacological reports, PAF is thought to have many pathophysiological and physiological functions. Recently advanced molecular technics enable us not only to clone PAF receptor cDNAs and genes, but also generate PAF receptor mutant animals, i.e., PAF receptor-overexpressing mouse and PAF receptor-deficient mouse. These mutant mice gave us a novel and specific approach for identifying the pathophysiological and physiological functions of PAF. This review also describes the phenotypes of these mutant mice and discusses them by referring to previously reported pharmacological and genetical data.
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Affiliation(s)
- S Ishii
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
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