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Schilter HC, Collison A, Russo RC, Foot JS, Yow TT, Vieira AT, Tavares LD, Mattes J, Teixeira MM, Jarolimek W. Effects of an anti-inflammatory VAP-1/SSAO inhibitor, PXS-4728A, on pulmonary neutrophil migration. Respir Res 2015; 16:42. [PMID: 25889951 PMCID: PMC4389443 DOI: 10.1186/s12931-015-0200-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 02/27/2015] [Indexed: 12/13/2022] Open
Abstract
Background and purpose The persistent influx of neutrophils into the lung and subsequent tissue damage are characteristics of COPD, cystic fibrosis and acute lung inflammation. VAP-1/SSAO is an endothelial bound adhesion molecule with amine oxidase activity that is reported to be involved in neutrophil egress from the microvasculature during inflammation. This study explored the role of VAP-1/SSAO in neutrophilic lung mediated diseases and examined the therapeutic potential of the selective inhibitor PXS-4728A. Methods Mice treated with PXS-4728A underwent intra-vital microscopy visualization of the cremaster muscle upon CXCL1/KC stimulation. LPS inflammation, Klebsiella pneumoniae infection, cecal ligation and puncture as well as rhinovirus exacerbated asthma models were also assessed using PXS-4728A. Results Selective VAP-1/SSAO inhibition by PXS-4728A diminished leukocyte rolling and adherence induced by CXCL1/KC. Inhibition of VAP-1/SSAO also dampened the migration of neutrophils to the lungs in response to LPS, Klebsiella pneumoniae lung infection and CLP induced sepsis; whilst still allowing for normal neutrophil defense function, resulting in increased survival. The functional effects of this inhibition were demonstrated in the RV exacerbated asthma model, with a reduction in cellular infiltrate correlating with a reduction in airways hyperractivity. Conclusions and implications This study demonstrates that the endothelial cell ligand VAP-1/SSAO contributes to the migration of neutrophils during acute lung inflammation, pulmonary infection and airway hyperractivity. These results highlight the potential of inhibiting of VAP-1/SSAO enzymatic function, by PXS-4728A, as a novel therapeutic approach in lung diseases that are characterized by neutrophilic pattern of inflammation.
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Affiliation(s)
- Heidi C Schilter
- Drug Discovery Department, Pharmaxis Ltd, 20 Rodborough Road, Frenchs Forest, Sydney, NSW, 2086, Australia.
| | - Adam Collison
- The University of Newcastle & Vaccines, Infection, Viruses & Asthma, Newcastle, Australia.
| | - Remo C Russo
- Laboratório de Imunologia e Mecânica Pulmonar, Departamento de Fisiologia e Biofísica, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil. .,Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil.
| | - Jonathan S Foot
- Drug Discovery Department, Pharmaxis Ltd, 20 Rodborough Road, Frenchs Forest, Sydney, NSW, 2086, Australia.
| | - Tin T Yow
- Drug Discovery Department, Pharmaxis Ltd, 20 Rodborough Road, Frenchs Forest, Sydney, NSW, 2086, Australia.
| | - Angelica T Vieira
- Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil.
| | - Livia D Tavares
- Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil.
| | - Joerg Mattes
- The University of Newcastle & Vaccines, Infection, Viruses & Asthma, Newcastle, Australia.
| | - Mauro M Teixeira
- Laboratório de Imunofarmacologia, Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, MG, Brazil.
| | - Wolfgang Jarolimek
- Drug Discovery Department, Pharmaxis Ltd, 20 Rodborough Road, Frenchs Forest, Sydney, NSW, 2086, Australia. .,School of Medical & Molecular Biosciences, University of Technology Sydney, City Campus, PO Box 123 Broadway, 2007, Sydney, NSW, Australia.
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Characterization of the in vitro binding and inhibition kinetics of primary amine oxidase/vascular adhesion protein-1 by glucosamine. Biochim Biophys Acta Gen Subj 2011; 1820:482-7. [PMID: 22202180 DOI: 10.1016/j.bbagen.2011.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 11/15/2011] [Accepted: 12/09/2011] [Indexed: 02/07/2023]
Abstract
BACKGROUND Primary-amine oxidase (PrAO) catalyzes the oxidative deamination of endogenous and exogenous primary amines and also functions, in some tissues, as an inflammation-inducible endothelial factor, known as vascular adhesion protein-1. VAP-1 mediates the slow rolling and adhesion of lymphocytes to endothelial cells in a number of inflammatory conditions, including inflammation of the synovium. METHODS Glucosamine binding to the enzyme was assessed spectrofluorometrically and the kinetics of inhibition of PrAO were determined spectrophotometrically through the use of direct or coupled assays, in the presence of different substrates. RESULTS Glucosamine is not a substrate for PrAO, but acts as a time-dependent inhibitor of PrAO activity, displaying mixed inhibition kinetics. The observed inhibition and binding were augmented in the presence of H(2)O(2). CONCLUSIONS Significant in vitro effects on PrAO require glucosamine in the millimolar concentration range and it is not clear at this stage whether a low but persistent level of PrAO inhibition might contribute to the anti-arthritic response. GENERAL SIGNIFICANCE This work was aimed at characterizing the interactions of PrAO/VAP-1 with glucosamine, a widely used "over-the-counter" supplement for the treatment of osteoarthritis.
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Heuts DPHM, Gummadova JO, Pang J, Rigby SEJ, Scrutton NS. Reaction of vascular adhesion protein-1 (VAP-1) with primary amines: mechanistic insights from isotope effects and quantitative structure-activity relationships. J Biol Chem 2011; 286:29584-93. [PMID: 21737458 DOI: 10.1074/jbc.m111.232850] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human vascular adhesion protein-1 (VAP-1) is an endothelial copper-dependent amine oxidase involved in the recruitment and extravasation of leukocytes at sites of inflammation. VAP-1 is an important therapeutic target for several pathological conditions. We expressed soluble VAP-1 in HEK293 EBNA1 cells at levels suitable for detailed mechanistic studies with model substrates. Using the model substrate benzylamine, we analyzed the steady-state kinetic parameters of VAP-1 as a function of solution pH. We found two macroscopic pK(a) values that defined a bell-shaped plot of turnover number k(cat,app) as a function of pH, representing ionizable groups in the enzyme-substrate complex. The dependence of (k(cat)/K(m))(app) on pH revealed a single pK(a) value (∼9) that we assigned to ionization of the amine group in free benzylamine substrate. A kinetic isotope effect (KIE) of 6 to 7.6 on (k(cat)/K(m))(app) over the pH range of 6 to 10 was observed with d(2)-benzylamine. Over the same pH range, the KIE on k(cat) was found to be close to unity. The unusual KIE values on (k(cat)/K(m))(app) were rationalized using a mechanistic scheme that includes the possibility of multiple isotopically sensitive steps. We also report the analysis of quantitative structure-activity relationships (QSAR) using para-substituted protiated and deuterated phenylethylamines. With phenylethylamines we observed a large KIE on k(cat,app) (8.01 ± 0.28 with phenylethylamine), indicating that C-H bond breakage is limiting for 2,4,5-trihydroxyphenylalanine quinone reduction. Poor correlations were observed between steady-state rate constants and QSAR parameters. We show the importance of combining KIE, QSAR, and structural studies to gain insight into the complexity of the VAP-1 steady-state mechanism.
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Affiliation(s)
- Dominic P H M Heuts
- Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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Olivieri A, Rico D, Khiari Z, Henehan G, O'Sullivan J, Tipton K. From caffeine to fish waste: amine compounds present in food and drugs and their interactions with primary amine oxidase. J Neural Transm (Vienna) 2011; 118:1079-89. [PMID: 21373760 DOI: 10.1007/s00702-011-0611-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 02/16/2011] [Indexed: 12/29/2022]
Abstract
Tissue bound primary amine oxidase (PrAO) and its circulating plasma-soluble form are involved, through their catalytic activity, in important cellular roles, including the adhesion of lymphocytes to endothelial cells during various inflammatory conditions, the regulation of cell growth and maturation, extracellular matrix deposition and maturation and glucose transport. PrAO catalyses the oxidative deamination of several xenobiotics and has been linked to vascular toxicity, due to the generation of cytotoxic aldehydes. In this study, a series of amines and aldehydes contained in food and drugs were tested via a high-throughput assay as potential substrates or inhibitors of bovine plasma PrAO. Although none of the compounds analyzed were found to be substrates for the enzyme, a series of molecules, including caffeine, the antidiabetics phenformin and tolbutamide and the antimicrobial pentamidine, were identified as PrAO inhibitors. Although the inhibition observed was in the millimolar and micromolar range, these data show that further work will be necessary to elucidate whether the interaction of ingested biogenic or xenobiotic amines with PrAO might adversely affect its biological roles.
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Affiliation(s)
- Aldo Olivieri
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland.
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