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Schiff HV, Rivas CM, Pederson WP, Sandoval E, Gillman S, Prisco J, Kume M, Dussor G, Vagner J, Ledford JG, Price TJ, DeFea KA, Boitano S. β-Arrestin-biased proteinase-activated receptor-2 antagonist C781 limits allergen-induced airway hyperresponsiveness and inflammation. Br J Pharmacol 2023; 180:667-680. [PMID: 35735078 PMCID: PMC10311467 DOI: 10.1111/bph.15903] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 06/13/2022] [Accepted: 06/18/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Asthma is a heterogenous disease strongly associated with inflammation that has many different causes and triggers. Current asthma treatments target symptoms such as bronchoconstriction and airway inflammation. Despite recent advances in biological therapies, there remains a need for new classes of therapeutic agents with novel, upstream targets. The proteinase-activated receptor-2 (PAR2) has long been implicated in allergic airway inflammation and asthma and it remains an intriguing target for novel therapies. Here, we describe the actions of C781, a newly developed low MW PAR2 biased antagonist, in vitro and in vivo in the context of acute allergen exposure. EXPERIMENTAL APPROACH A human bronchial epithelial cell line expressing PAR2 (16HBE14o- cells) was used to evaluate the modulation in vitro, by C781, of physiological responses to PAR2 activation and downstream β-arrestin/MAPK and Gq/Ca2+ signalling. Acute Alternaria alternata sensitized and challenged mice were used to evaluate C781 as a prophylactically administered modulator of airway hyperresponsiveness, inflammation and mucus overproduction in vivo. KEY RESULTS C781 reduced in vitro physiological signalling in response to ligand and proteinase activation. C781 effectively antagonized β-arrestin/MAPK signalling without significant effect on Gq/Ca2+ signalling in vitro. Given prophylactically, C781 modulated airway hyperresponsiveness, airway inflammation and mucus overproduction of the small airways in an acute allergen-challenged mouse model. CONCLUSION AND IMPLICATIONS Our work demonstrates the first biased PAR2 antagonist for β-arrestin/MAPK signalling. C781 is efficacious as a prophylactic treatment for allergen-induced airway hyperresponsiveness and inflammation in mice. It exemplifies a key pharmacophore for PAR2 that can be optimized for clinical development.
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Affiliation(s)
- Hillary V. Schiff
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
- Bio5 Collaborative Research Center, University of Arizona
| | - Candy M. Rivas
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
- Bio5 Collaborative Research Center, University of Arizona
- Physiological Sciences Graduate Interdisciplinary Program, University of Arizona
| | - William P. Pederson
- Physiological Sciences Graduate Interdisciplinary Program, University of Arizona
| | - Estevan Sandoval
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
- Bio5 Collaborative Research Center, University of Arizona
| | - Samuel Gillman
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
- Bio5 Collaborative Research Center, University of Arizona
- Physiological Sciences Graduate Interdisciplinary Program, University of Arizona
| | - Joy Prisco
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
| | - Moeno Kume
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, TX
| | - Gregory Dussor
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, TX
| | - Josef Vagner
- Bio5 Collaborative Research Center, University of Arizona
| | - Julie G. Ledford
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
- Department of Cellular and Molecular Medicine, University of Arizona
| | - Theodore J. Price
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, TX
| | - Kathryn A. DeFea
- University of California Riverside, Biomedical Sciences and PARMedics, Incorporated
| | - Scott Boitano
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences Center
- Bio5 Collaborative Research Center, University of Arizona
- Department of Physiology, University of Arizona
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Lee-Rivera I, López E, López-Colomé AM. Diversification of PAR signaling through receptor crosstalk. Cell Mol Biol Lett 2022; 27:77. [PMID: 36088291 PMCID: PMC9463773 DOI: 10.1186/s11658-022-00382-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/02/2022] [Indexed: 11/17/2022] Open
Abstract
Protease activated receptors (PARs) are among the first receptors shown to transactivate other receptors: noticeably, these interactions are not limited to members of the same family, but involve receptors as diverse as receptor kinases, prostanoid receptors, purinergic receptors and ionic channels among others. In this review, we will focus on the evidence for PAR interactions with members of their own family, as well as with other types of receptors. We will discuss recent evidence as well as what we consider as emerging areas to explore; from the signalling pathways triggered, to the physiological and pathological relevance of these interactions, since this additional level of molecular cross-talk between receptors and signaling pathways is only beginning to be explored and represents a novel mechanism providing diversity to receptor function and play important roles in physiology and disease.
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Carroll EL, Bailo M, Reihill JA, Crilly A, Lockhart JC, Litherland GJ, Lundy FT, McGarvey LP, Hollywood MA, Martin SL. Trypsin-Like Proteases and Their Role in Muco-Obstructive Lung Diseases. Int J Mol Sci 2021; 22:5817. [PMID: 34072295 PMCID: PMC8199346 DOI: 10.3390/ijms22115817] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/20/2022] Open
Abstract
Trypsin-like proteases (TLPs) belong to a family of serine enzymes with primary substrate specificities for the basic residues, lysine and arginine, in the P1 position. Whilst initially perceived as soluble enzymes that are extracellularly secreted, a number of novel TLPs that are anchored in the cell membrane have since been discovered. Muco-obstructive lung diseases (MucOLDs) are characterised by the accumulation of hyper-concentrated mucus in the small airways, leading to persistent inflammation, infection and dysregulated protease activity. Although neutrophilic serine proteases, particularly neutrophil elastase, have been implicated in the propagation of inflammation and local tissue destruction, it is likely that the serine TLPs also contribute to various disease-relevant processes given the roles that a number of these enzymes play in the activation of both the epithelial sodium channel (ENaC) and protease-activated receptor 2 (PAR2). More recently, significant attention has focused on the activation of viruses such as SARS-CoV-2 by host TLPs. The purpose of this review was to highlight key TLPs linked to the activation of ENaC and PAR2 and their association with airway dehydration and inflammatory signalling pathways, respectively. The role of TLPs in viral infectivity will also be discussed in the context of the inhibition of TLP activities and the potential of these proteases as therapeutic targets.
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Affiliation(s)
- Emma L. Carroll
- School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK; (E.L.C.); (J.A.R.)
| | - Mariarca Bailo
- Institute for Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Paisley PA1 2BE, UK; (M.B.); (A.C.); (J.C.L.); (G.J.L.)
| | - James A. Reihill
- School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK; (E.L.C.); (J.A.R.)
| | - Anne Crilly
- Institute for Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Paisley PA1 2BE, UK; (M.B.); (A.C.); (J.C.L.); (G.J.L.)
| | - John C. Lockhart
- Institute for Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Paisley PA1 2BE, UK; (M.B.); (A.C.); (J.C.L.); (G.J.L.)
| | - Gary J. Litherland
- Institute for Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Paisley PA1 2BE, UK; (M.B.); (A.C.); (J.C.L.); (G.J.L.)
| | - Fionnuala T. Lundy
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University, Belfast BT9 7BL, UK; (F.T.L.); (L.P.M.)
| | - Lorcan P. McGarvey
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University, Belfast BT9 7BL, UK; (F.T.L.); (L.P.M.)
| | - Mark A. Hollywood
- Smooth Muscle Research Centre, Dundalk Institute of Technology, A91 HRK2 Dundalk, Ireland;
| | - S. Lorraine Martin
- School of Pharmacy, Queen’s University, Belfast BT9 7BL, UK; (E.L.C.); (J.A.R.)
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Yee MC, Nichols HL, Polley D, Saifeddine M, Pal K, Lee K, Wilson EH, Daines MO, Hollenberg MD, Boitano S, DeFea KA. Protease-activated receptor-2 signaling through β-arrestin-2 mediates Alternaria alkaline serine protease-induced airway inflammation. Am J Physiol Lung Cell Mol Physiol 2018; 315:L1042-L1057. [PMID: 30335499 PMCID: PMC6337008 DOI: 10.1152/ajplung.00196.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/06/2018] [Accepted: 08/22/2018] [Indexed: 01/01/2023] Open
Abstract
Alternaria alternata is a fungal allergen associated with severe asthma and asthma exacerbations. Similarly to other asthma-associated allergens, Alternaria secretes a serine-like trypsin protease(s) that is thought to act through the G protein-coupled receptor protease-activated receptor-2 (PAR2) to induce asthma symptoms. However, specific mechanisms underlying Alternaria-induced PAR2 activation and signaling remain ill-defined. We sought to determine whether Alternaria-induced PAR2 signaling contributed to asthma symptoms via a PAR2/β-arrestin signaling axis, identify the protease activity responsible for PAR2 signaling, and determine whether protease activity was sufficient for Alternaria-induced asthma symptoms in animal models. We initially used in vitro models to demonstrate Alternaria-induced PAR2/β-arrestin-2 signaling. Alternaria filtrates were then used to sensitize and challenge wild-type, PAR2-/- and β-arrestin-2-/- mice in vivo. Intranasal administration of Alternaria filtrate resulted in a protease-dependent increase of airway inflammation and mucin production in wild-type but not PAR2-/- or β-arrestin-2-/- mice. Protease was isolated from Alternaria preparations, and select in vitro and in vivo experiments were repeated to evaluate sufficiency of the isolated Alternaria protease to induce asthma phenotype. Administration of a single isolated serine protease from Alternaria, Alternaria alkaline serine protease (AASP), was sufficient to fully activate PAR2 signaling and induce β-arrestin-2-/--dependent eosinophil and lymphocyte recruitment in vivo. In conclusion, Alternaria filtrates induce airway inflammation and mucus hyperplasia largely via AASP using the PAR2/β-arrestin signaling axis. Thus, β-arrestin-biased PAR2 antagonists represent novel therapeutic targets for treating aeroallergen-induced asthma.
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Affiliation(s)
- Michael C Yee
- Biomedical Sciences, Graduate Program, University of California Riverside , Riverside, California
| | - Heddie L Nichols
- Biomedical Sciences, Graduate Program, University of California Riverside , Riverside, California
| | - Danny Polley
- Cumming School of Medicine, Department of Physiology and Pharmacology and Department of Medicine, University of Calgary , Calgary, Alberta , Canada
| | - Mahmoud Saifeddine
- Cumming School of Medicine, Department of Physiology and Pharmacology and Department of Medicine, University of Calgary , Calgary, Alberta , Canada
| | - Kasturi Pal
- Biomedical Sciences, Graduate Program, University of California Riverside , Riverside, California
- Cell Molecular and Developmental Biology and Biochemistry Graduate Program, University of California Riverside , Riverside, California
| | - Kyu Lee
- Biomedical Sciences, Graduate Program, University of California Riverside , Riverside, California
- Molecular Biology Graduate Program, University of California Riverside , Riverside, California
| | - Emma H Wilson
- Biomedical Sciences, Graduate Program, University of California Riverside , Riverside, California
| | - Michael O Daines
- Department of Pediatrics, University of Arizona Health Sciences , Tucson, Arizona
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences , Tucson, Arizona
| | - Morley D Hollenberg
- Cumming School of Medicine, Department of Physiology and Pharmacology and Department of Medicine, University of Calgary , Calgary, Alberta , Canada
| | - Scott Boitano
- Asthma and Airway Disease Research Center, University of Arizona Health Sciences , Tucson, Arizona
- Department of Physiology, University of Arizona Health Sciences , Tucson, Arizona
| | - Kathryn A DeFea
- Biomedical Sciences, Graduate Program, University of California Riverside , Riverside, California
- Cell Molecular and Developmental Biology and Biochemistry Graduate Program, University of California Riverside , Riverside, California
- Molecular Biology Graduate Program, University of California Riverside , Riverside, California
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5
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Menou A, Duitman J, Flajolet P, Sallenave JM, Mailleux AA, Crestani B. Human airway trypsin-like protease, a serine protease involved in respiratory diseases. Am J Physiol Lung Cell Mol Physiol 2017; 312:L657-L668. [DOI: 10.1152/ajplung.00509.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/15/2017] [Accepted: 02/15/2017] [Indexed: 01/12/2023] Open
Abstract
More than 2% of all human genes are coding for a complex system of more than 700 proteases and protease inhibitors. Among them, serine proteases play extraordinary, diverse functions in different physiological and pathological processes. The human airway trypsin-like protease (HAT), also referred to as TMPRSS11D and serine 11D, belongs to the emerging family of cell surface proteolytic enzymes, the type II transmembrane serine proteases (TTSPs). Through the cleavage of its four major identified substrates, HAT triggers specific responses, notably in epithelial cells, within the pericellular and extracellular environment, including notably inflammatory cytokine production, inflammatory cell recruitment, or anticoagulant processes. This review summarizes the potential role of this recently described protease in mediating cell surface proteolytic events, to highlight the structural features, proteolytic activity, and regulation, including the expression profile of HAT, and discuss its possible roles in respiratory physiology and disease.
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Affiliation(s)
- Awen Menou
- Inserm UMR1152, Medical School Xavier Bichat, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodeling) and LabEx Inflamex, Paris, France; and
| | - JanWillem Duitman
- Inserm UMR1152, Medical School Xavier Bichat, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodeling) and LabEx Inflamex, Paris, France; and
| | - Pauline Flajolet
- Inserm UMR1152, Medical School Xavier Bichat, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodeling) and LabEx Inflamex, Paris, France; and
| | - Jean-Michel Sallenave
- Inserm UMR1152, Medical School Xavier Bichat, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodeling) and LabEx Inflamex, Paris, France; and
| | - Arnaud André Mailleux
- Inserm UMR1152, Medical School Xavier Bichat, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodeling) and LabEx Inflamex, Paris, France; and
| | - Bruno Crestani
- Inserm UMR1152, Medical School Xavier Bichat, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Département Hospitalo-Universitaire FIRE (Fibrosis, Inflammation and Remodeling) and LabEx Inflamex, Paris, France; and
- APHP, Hôpital Bichat, Service de Pneumologie A, Paris, France
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6
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Cosimi E, Saadi J, Wennemers H. Stereoselective Synthesis of α-Fluoro-γ-nitro Thioesters under Organocatalytic Conditions. Org Lett 2016; 18:6014-6017. [PMID: 27934387 DOI: 10.1021/acs.orglett.6b02795] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fluorinated monothiomalonates (F-MTMs) were used as building blocks for the stereoselective synthesis of organofluorine compounds. We present conjugate addition reactions between F-MTMs with nitroolefins that proceed under mild organocatalytic conditions and provide access to α-fluoro-γ-nitro thioesters with adjacent tetrasubstituted and tertiary stereogenic centers. Only 1 mol % of a cinchona alkaloid-urea catalyst is necessary to obtain the addition products in excellent yields and stereoselectivities. The methodology allowed for the straightforward synthesis of a fluorinated analogue of the PAR-2 agonist AC-264613.
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Affiliation(s)
- Elena Cosimi
- Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Jakub Saadi
- Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
| | - Helma Wennemers
- Laboratory of Organic Chemistry, ETH Zurich , Vladimir-Prelog-Weg 3, CH-8093 Zurich, Switzerland
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7
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Sherwood CL, Daines MO, Price TJ, Vagner J, Boitano S. A highly potent agonist to protease-activated receptor-2 reveals apical activation of the airway epithelium resulting in Ca2+-regulated ion conductance. Am J Physiol Cell Physiol 2014; 307:C718-26. [PMID: 25143347 DOI: 10.1152/ajpcell.00257.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The airway epithelium provides a barrier that separates inhaled air and its various particulates from the underlying tissues. It provides key physiological functions in both sensing the environment and initiating appropriate innate immune defenses to protect the lung. Protease-activated receptor-2 (PAR2) is expressed both apically and basolaterally throughout the airway epithelium. One consequence of basolateral PAR2 activation is the rapid, Ca(2+)-dependent ion flux that favors secretion in the normally absorptive airway epithelium. However, roles for apically expressed PAR2 activation have not been demonstrated, in part due to the lack of specific, high-potency PAR2 ligands. In the present study, we used the newly developed PAR2 ligand 2at-LIGRLO(PEG3-Pam)-NH2 in combination with well-differentiated, primary cultured airway epithelial cells from wild-type and PAR2 (-/-) mice to examine the physiological role of PAR2 in the conducting airway after apical activation. Using digital imaging microscopy of intracellular Ca(2+) concentration changes, we verified ligand potency on PAR2 in primary cultured airway cells. Examination of airway epithelial tissue in an Ussing chamber showed that apical activation of PAR2 by 2at-LIGRLO(PEG3-Pam)-NH2 resulted in a transient decrease in transepithelial resistance that was due to increased apical ion efflux. We determined pharmacologically that this increase in ion conductance was through Ca(2+)-activated Cl(-) and large-conductance K(+) channels that were blocked with a Ca(2+)-activated Cl(-) channel inhibitor and clotrimazole, respectively. Stimulation of Cl(-) efflux via PAR2 activation at the airway epithelial surface can increase airway surface liquid that would aid in clearing the airway of noxious inhaled agents.
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Affiliation(s)
- Cara L Sherwood
- Arizona Respiratory Center, University of Arizona, Tucson, Arizona; The BIO5 Collaborative Research Institute, University of Arizona, Tucson, Arizona
| | - Michael O Daines
- Arizona Respiratory Center, University of Arizona, Tucson, Arizona; Department of Pediatrics, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona; The BIO5 Collaborative Research Institute, University of Arizona, Tucson, Arizona
| | - Theodore J Price
- Department of Pharmacology, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona; and The BIO5 Collaborative Research Institute, University of Arizona, Tucson, Arizona
| | - Josef Vagner
- The BIO5 Collaborative Research Institute, University of Arizona, Tucson, Arizona
| | - Scott Boitano
- Arizona Respiratory Center, University of Arizona, Tucson, Arizona; Department of Physiology, Arizona Health Sciences Center, University of Arizona, Tucson, Arizona; The BIO5 Collaborative Research Institute, University of Arizona, Tucson, Arizona
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Gieseler F, Ungefroren H, Settmacher U, Hollenberg MD, Kaufmann R. Proteinase-activated receptors (PARs) - focus on receptor-receptor-interactions and their physiological and pathophysiological impact. Cell Commun Signal 2013; 11:86. [PMID: 24215724 PMCID: PMC3842752 DOI: 10.1186/1478-811x-11-86] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 10/25/2013] [Indexed: 02/07/2023] Open
Abstract
Proteinase-activated receptors (PARs) are a subfamily of G protein-coupled receptors (GPCRs) with four members, PAR1, PAR2, PAR3 and PAR4, playing critical functions in hemostasis, thrombosis, embryonic development, wound healing, inflammation and cancer progression. PARs are characterized by a unique activation mechanism involving receptor cleavage by different proteinases at specific sites within the extracellular amino-terminus and the exposure of amino-terminal “tethered ligand“ domains that bind to and activate the cleaved receptors. After activation, the PAR family members are able to stimulate complex intracellular signalling networks via classical G protein-mediated pathways and beta-arrestin signalling. In addition, different receptor crosstalk mechanisms critically contribute to a high diversity of PAR signal transduction and receptor-trafficking processes that result in multiple physiological effects. In this review, we summarize current information about PAR-initiated physical and functional receptor interactions and their physiological and pathological roles. We focus especially on PAR homo- and heterodimerization, transactivation of receptor tyrosine kinases (RTKs) and receptor serine/threonine kinases (RSTKs), communication with other GPCRs, toll-like receptors and NOD-like receptors, ion channel receptors, and on PAR association with cargo receptors. In addition, we discuss the suitability of these receptor interaction mechanisms as targets for modulating PAR signalling in disease.
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Affiliation(s)
| | | | | | | | - Roland Kaufmann
- Department of General, Visceral and Vascular Surgery, Experimental Transplantation Surgery, Jena University Hospital, Drackendorfer Str, 1, D-07747, Jena, Germany.
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9
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KOMATSU H, ENJOUJI S, ITO A, OHAMA T, SATO K. Prostaglandin E 2 Inhibits Proteinase-Activated Receptor 2-Signal Transduction through Regulation of Receptor Internalization. J Vet Med Sci 2013; 75:255-61. [DOI: 10.1292/jvms.12-0365] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Hiroyuki KOMATSU
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677–1 Yoshida, Yamaguchi 753–8515, Japan
| | - Shuhei ENJOUJI
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677–1 Yoshida, Yamaguchi 753–8515, Japan
| | - Akihiro ITO
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677–1 Yoshida, Yamaguchi 753–8515, Japan
| | - Takashi OHAMA
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677–1 Yoshida, Yamaguchi 753–8515, Japan
| | - Koichi SATO
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677–1 Yoshida, Yamaguchi 753–8515, Japan
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Nichols HL, Saffeddine M, Theriot BS, Hegde A, Polley D, El-Mays T, Vliagoftis H, Hollenberg MD, Wilson EH, Walker JKL, DeFea KA. β-Arrestin-2 mediates the proinflammatory effects of proteinase-activated receptor-2 in the airway. Proc Natl Acad Sci U S A 2012; 109:16660-5. [PMID: 23012429 PMCID: PMC3478622 DOI: 10.1073/pnas.1208881109] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Proteinase-Activated receptor-2 (PAR(2)), a G-protein-coupled Receptor, activated by serine proteinases, is reported to have both protective and proinflammatory effects in the airway. Given these opposing actions, both inhibitors and activators of PAR(2) have been proposed for treating asthma. PAR(2) can signal through two independent pathways: a β-arrestin-dependent one that promotes leukocyte migration, and a G-protein/Ca(2+) one that is required for prostaglandin E(2) (PGE(2)) production and bronchiolar smooth muscle relaxation. We hypothesized that the proinflammatory responses to PAR(2) activation are mediated by β-arrestins, whereas the protective effects are not. Using a mouse ovalbumin model for PAR(2)-modulated airway inflammation, we observed decreased leukocyte recruitment, cytokine production, and mucin production in β-arrestin-2(-/-) mice. In contrast, PAR(2)-mediated PGE(2) production, smooth muscle relaxation, and decreased baseline airway resistance (measures of putative PAR(2) "protective" effects) were independent of β-arrestin-2. Flow cytometry and cytospins reveal that lung eosinophil and CD4 T-cell infiltration, and production of IL-4, IL-6, IL-13, and TNFα, were enhanced in wild-type but not β-arrestin-2(-/-) mice. Using the forced oscillation technique to measure airway resistance reveals that PAR(2) activation protects against airway hyperresponsiveness by an unknown mechanism, possibly involving smooth muscle relaxation. Our data suggest that the PAR(2)-enhanced inflammatory process is β-arrestin-2 dependent, whereas the protective anticonstrictor effect of bronchial epithelial PAR(2) may be β-arrestin independent.
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Affiliation(s)
- Heddie L. Nichols
- Division of Biomedical Sciences, University of California, Riverside, CA 92521
| | | | - Barbara S. Theriot
- Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center, Durham, NC 27710; and
| | - Akhil Hegde
- Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center, Durham, NC 27710; and
| | | | - Tamer El-Mays
- Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada T2N 1N4
| | | | | | - Emma H. Wilson
- Division of Biomedical Sciences, University of California, Riverside, CA 92521
| | - Julia K. L. Walker
- Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center, Durham, NC 27710; and
| | - Kathryn A. DeFea
- Division of Biomedical Sciences, University of California, Riverside, CA 92521
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11
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Role of PGE2 in asthma and nonasthmatic eosinophilic bronchitis. Mediators Inflamm 2012; 2012:645383. [PMID: 22529528 PMCID: PMC3316983 DOI: 10.1155/2012/645383] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/09/2012] [Accepted: 01/09/2012] [Indexed: 11/17/2022] Open
Abstract
Eosinophilic bronchitis is a common cause of chronic cough, which like asthma is characterized by sputum eosinophilia, but unlike asthma there is no variable airflow obstruction or airway hyperresponsiveness. Several studies suggest that prostaglandins may play an important role in orchestrating interactions between different cells in several inflammatory diseases such as asthma. PGE2 is important because of the multiplicity of its effects on immune response in respiratory diseases; however, respiratory system appears to be unique in that PGE2 has beneficial effects. We described that the difference in airway function observed in patients with eosinophilic bronchitis and asthma could be due to differences in PGE2 production. PGE2 present in induced sputum supernatant from NAEB patients decreases BSMC proliferation, probably due to simultaneous stimulation of EP2 and EP4 receptors with inhibitory activity. This protective effect of PGE2 may not only be the result of a direct action exerted on airway smooth-muscle proliferation but may also be attributable to the other anti-inflammatory actions.
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12
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Stoermer MJ, Flanagan B, Beyer RL, Madala PK, Fairlie DP. Structures of peptide agonists for human protease activated receptor 2. Bioorg Med Chem Lett 2012; 22:916-9. [PMID: 22209488 DOI: 10.1016/j.bmcl.2011.12.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Revised: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 10/14/2022]
Abstract
Protease activated receptor 2 (PAR2) is an unusual G-protein coupled receptor in being self-activated, after pruning of the N-terminus by serine proteases like trypsin and tryptase. Short synthetic peptides corresponding to the newly exposed N-terminal hexapeptide sequence also activate PAR2 on immunoinflammatory, cancer and many normal cell types. (1)H nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopy were used here to search for structural clues to activating mechanisms of the hexapeptide agonists SLIGRL (rat), SLIGKV (human) and the peptidomimetic analogue, 2-furoyl-LIGRLO. Either with a free or acetyl capped N-terminus, these agonist peptides display significant propensity in aprotic (DMSO) or lipidic (water-SDS) solvents for turn-like conformations, which are predicted to be receptor-binding conformations in the transmembrane or loops region of PAR2. These motifs may be valuable for the design of small molecule PAR2 agonists and antagonists as prospective new drugs for regulating inflammatory and proliferative diseases.
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Affiliation(s)
- Martin J Stoermer
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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Boitano S, Flynn AN, Sherwood CL, Schulz SM, Hoffman J, Gruzinova I, Daines MO. Alternaria alternata serine proteases induce lung inflammation and airway epithelial cell activation via PAR2. Am J Physiol Lung Cell Mol Physiol 2011; 300:L605-14. [PMID: 21296894 DOI: 10.1152/ajplung.00359.2010] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Allergens are diverse proteins from mammals, birds, arthropods, plants, and fungi. Allergens associated with asthma (asthmagens) share a common protease activity that may directly impact respiratory epithelial biology and lead to symptoms of asthma. Alternaria alternata is a strong asthmagen in semiarid regions. We examined the impact of proteases from A. alternata on lung inflammation in vivo and on cleaving protease-activated receptor-2 (PAR(2)) in vitro. A. alternata filtrate applied to the airway in nonsensitized Balb/c mice induced a protease-dependent lung inflammation. Moreover, A. alternata filtrate applied to human bronchial epithelial cells (16HBE14o-) induced changes in intracellular Ca(2+) concentration ([Ca(2+)](i)), consistent with PAR(2) activation. These effects were blocked by heat inactivation or by serine protease inhibition of A. alternata filtrates, and mimicked by PAR(2) specific ligands SLIGRL-NH(2) or 2-furoyl-LIGRLO-NH(2), but not the PAR(1)-specific ligand TFLLR-NH(2). Desensitization of PAR(2) in 16HBE14o- cells with 2-furoyl-LIGRLO-NH(2) or trypsin prevented A. alternata-induced [Ca(2+)](i) changes while desensitization of PAR(1), PAR(3), and PAR(4) with thrombin had no effect on A. alternata-induced Ca(2+) responses. Furthermore, the Ca(2+) response to A. alternata filtrates was dependent on PAR(2) expression in stably transfected HeLa cell models. These data demonstrate that A. alternata proteases act through PAR(2) to induce rapid increases in human airway epithelial [Ca(2+)](i) in vitro and cell recruitment in vivo. These responses are likely critical early steps in the development of allergic asthma.
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Affiliation(s)
- Scott Boitano
- Dept. of Physiology, Arizona Respiratory Center, Arizona Health Sciences Center, 1501 N. Campbell Ave., Tucson, AZ, USA.
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Davydova ON, Yakovlev AA, Lyzhin AA, Khaspekov LG, Gulyaeva NV. Growth factors deprivation induces a specific increase in PAR2 receptor mRNA expression in primary cerebellar cultures. NEUROCHEM J+ 2010. [DOI: 10.1134/s1819712410040069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Georas SN, Rezaee F, Lerner L, Beck L. Dangerous allergens: why some allergens are bad actors. Curr Allergy Asthma Rep 2010; 10:92-8. [PMID: 20425500 DOI: 10.1007/s11882-010-0090-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Immune responses can be compartmentalized into innate versus adaptive components. This relatively recent dichotomy positioned the innate immune system at the interface between the host and the external environment and provided a new conceptual framework with which to view allergic diseases, including asthma. Airway epithelial cells and dendritic cells are key components of the innate immune system in the nose and lung and are now known to be intimately involved in allergen recognition and in modulating allergic immune responses. Here we review current thinking about how these two key cell types sense and respond to inhaled allergens, and emphasize how an understanding of "allergic innate immunity" can translate into new thinking about mechanisms of allergen sensitization and potentially lead to new therapeutic targets.
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Affiliation(s)
- Steve N Georas
- Division of Pulmonary and Critical Care Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 692, Rochester, NY 14642-8692, USA.
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Georas SN, Beck L. Dangerous allergens: innate immunity, dendritic cells and allergic asthma. Expert Rev Clin Immunol 2010; 4:777-85. [PMID: 20477127 DOI: 10.1586/1744666x.4.6.777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Immune responses can be compartmentalized into innate versus adaptive components. This relatively recent dichotomy positioned the innate immune system at the interface between the host and the external environment, and provided a new conceptual framework with which to view allergic diseases, including asthma. Among the cells of the innate immune system, antigen-presenting dendritic cells are now thought to be intimately involved in allergen recognition, as well as modulating allergic immune responses. This review summarizes current thinking regarding the role of dendritic cells in allergic asthma and concludes with a summary of emerging concepts in the field.
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Affiliation(s)
- Steve N Georas
- University of Rochester Medical Center, 601 Elmwood Avenue, Box 692, Rochester, NY 14642-8692, USA.
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Bhatt DK, Ploug KB, Ramachandran R, Olesen J, Gupta S. Activation of PAR-2 Elicits NO-Dependent and CGRP-Independent Dilation of the Dural Artery. Headache 2010; 50:1017-30. [DOI: 10.1111/j.1526-4610.2010.01679.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Ewen D, Clarke S, Smith J, Berger C, Salmon G, Trevethick M, Shute J. The role of protease-activated receptors PAR-1 and PAR-2 in the repair of 16HBE 14o−epithelial cell monolayersin vitro. Clin Exp Allergy 2010; 40:435-49. [DOI: 10.1111/j.1365-2222.2010.03453.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Peters T, Henry PJ. Protease-activated receptors and prostaglandins in inflammatory lung disease. Br J Pharmacol 2009; 158:1017-33. [PMID: 19845685 PMCID: PMC2785524 DOI: 10.1111/j.1476-5381.2009.00449.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 06/11/2009] [Accepted: 07/08/2009] [Indexed: 12/17/2022] Open
Abstract
Protease-activated receptors (PARs) are a novel family of G protein-coupled receptors. Signalling through PARs typically involves the cleavage of an extracellular region of the receptor by endogenous or exogenous proteases, which reveals a tethered ligand sequence capable of auto-activating the receptor. A considerable body of evidence has emerged over the past 20 years supporting a prominent role for PARs in a variety of human physiological and pathophysiological processes, and thus substantial attention has been directed towards developing drug-like molecules that activate or block PARs via non-proteolytic pathways. PARs are widely expressed within the respiratory tract, and their activation appears to exert significant modulatory influences on the level of bronchomotor tone, as well as on the inflammatory processes associated with a range of respiratory tract disorders. Nevertheless, there is debate as to whether the principal response to PAR activation is an augmentation or attenuation of airways inflammation. In this context, an important action of PAR activators may be to promote the generation and release of prostanoids, such as prostglandin E(2), which have well-established anti-inflammatory effects in the lung. In this review, we primarily focus on the relationship between PARs, prostaglandins and inflammatory processes in the lung, and highlight their potential role in selected respiratory tract disorders, including pulmonary fibrosis, asthma and chronic obstructive pulmonary disease.
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Affiliation(s)
- Terence Peters
- School of Medicine and Pharmacology, University of Western Australia, Nedlands, Australia
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Lin CB, Chen N, Scarpa R, Guan F, Babiarz-Magee L, Liebel F, Li WH, Kizoulis M, Shapiro S, Seiberg M. LIGR, a protease-activated receptor-2-derived peptide, enhances skin pigmentation without inducing inflammatory processes. Pigment Cell Melanoma Res 2008; 21:172-83. [PMID: 18426410 DOI: 10.1111/j.1755-148x.2008.00441.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The protease-activated receptor-2 (PAR-2) is a seven transmembrane G-protein-coupled receptor that could be activated by serine protease cleavage or by synthetic peptide agonists. We showed earlier that activation of PAR-2 with Ser-Leu-Ile-Gly-Arg-Leu-NH(2) (SLIGRL), a known PAR-2 activating peptide, induces keratinocyte phagocytosis and increases skin pigmentation, indicating that PAR-2 regulates pigmentation by controlling phagocytosis of melanosomes. Here, we show that Leu-Ile-Gly-Arg-NH(2) (LIGR) can also induce skin pigmentation. Both SLIGRL and LIGR increased melanin deposition in vitro and in vivo, and visibly darkened human skins grafted onto severe combined immuno-deficient (SCID) mice. Both SLIGRL and LIGR stimulated Rho-GTP activation resulting in keratinocyte phagocytosis. Interestingly, LIGR activates only a subset of the PAR-2 signaling pathways, and unlike SLIGRL, it does not induce inflammatory processes. LIGR did not affect many PAR-2 signaling pathways, including [Ca(2+)] mobilization, cAMP induction, the induction of cyclooxgenase-2 (COX-2) expression and the secretion of prostaglandin E2, interleukin-6 and -8. PAR-2 siRNA inhibited LIGR-induced phagocytosis, indicating that LIGR signals via PAR-2. Our data suggest that LIGR is a more specific regulator of PAR-2-induced pigmentation relative to SLIGRL. Therefore, enhancing skin pigmentation by topical applications of LIGR may result in a desired tanned-like skin color, without enhancing inflammatory processes, and without the need of UV exposure.
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Affiliation(s)
- Connie B Lin
- The Johnson & Johnson Skin Research Center, Consumer Product Worldwide, A division of Johnson & Johnson Consumer Companies, Inc., 199 Grandview Rd., Skillman, NJ 08558, USA
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Gardell LR, Ma JN, Seitzberg JG, Knapp AE, Schiffer HH, Tabatabaei A, Davis CN, Owens M, Clemons B, Wong KK, Lund B, Nash NR, Gao Y, Lameh J, Schmelzer K, Olsson R, Burstein ES. Identification and characterization of novel small-molecule protease-activated receptor 2 agonists. J Pharmacol Exp Ther 2008; 327:799-808. [PMID: 18768780 DOI: 10.1124/jpet.108.142570] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We report the first small-molecule protease-activated receptor (PAR) 2 agonists, AC-55541 [N-[[1-(3-bromo-phenyl)-eth-(E)-ylidene-hydrazinocarbonyl]-(4-oxo-3,4-dihydro-phthalazin-1-yl)-methyl]-benzamide] and AC-264613 [2-oxo-4-phenylpyrrolidine-3-carboxylic acid [1-(3-bromo-phenyl)-(E/Z)-ethylidene]-hydrazide], each representing a distinct chemical series. AC-55541 and AC-264613 each activated PAR2 signaling in cellular proliferation assays, phosphatidylinositol hydrolysis assays, and Ca(2+) mobilization assays, with potencies ranging from 200 to 1000 nM for AC-55541 and 30 to 100 nM for AC-264613. In comparison, the PAR2-activating peptide 2-furoyl-LIGRLO-NH(2) had similar potency, whereas SLIGRL-NH(2) was 30 to 300 times less potent. Neither AC-55541 nor AC-264613 had activity at any of the other PAR receptor subtypes, nor did they have any significant affinity for over 30 other molecular targets involved in nociception. Visualization of EYFP-tagged PAR2 receptors showed that each compound stimulated internalization of PAR2 receptors. AC-55541 and AC-264613 were well absorbed when administered intraperitoneally to rats, each reaching micromolar peak plasma concentrations. AC-55541 and AC-264613 were each stable to metabolism by liver microsomes and maintained sustained exposure in rats, with elimination half-lives of 6.1 and 2.5 h, respectively. Intrapaw administration of AC-55541 or AC-264613 elicited robust and persistent thermal hyperalgesia and edema. Coadministration of either a tachykinin 1 (neurokinin 1) receptor antagonist or a transient receptor potential vanilloid (TRPV) 1 antagonist completely blocked these effects. Systemic administration of either AC-55541 or AC-264613 produced a similar degree of hyperalgesia as was observed when the compounds were administered locally. These compounds represent novel small-molecule PAR2 agonists that will be useful in probing the physiological functions of PAR2 receptors.
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Seitzberg JG, Knapp AE, Lund BW, Mandrup Bertozzi S, Currier EA, Ma JN, Sherbukhin V, Burstein ES, Olsson R. Discovery of potent and selective small-molecule PAR-2 agonists. J Med Chem 2008; 51:5490-3. [PMID: 18720984 DOI: 10.1021/jm800754r] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proteinase activated receptor-2 plays a crucial role in a wide variety of conditions with a strong inflammatory component. We present the discovery and characterization of two structurally different, potent, selective, and metabolically stable small-molecule PAR-2 agonists. These ligands may be useful as pharmacological tools for elucidating the complex physiological role of the PAR-2 receptors as well as for the development of PAR-2 antagonists.
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Affiliation(s)
- Jimmi Gerner Seitzberg
- ACADIA Pharmaceuticals AB, Medeon Science Park, Per Albin Hanssons Väg 35, S-205 12 Malmö, Sweden
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Hatazawa R, Tanaka A, Tanigami M, Amagase K, Kato S, Ashida Y, Takeuchi K. Cyclooxygenase-2/prostaglandin E2 accelerates the healing of gastric ulcers via EP4 receptors. Am J Physiol Gastrointest Liver Physiol 2007; 293:G788-97. [PMID: 17673547 DOI: 10.1152/ajpgi.00131.2007] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We examined the involvement of cyclooxygenase (COX)-1 as well as COX-2 in the healing of gastric ulcers and investigated which prostaglandin (PG) EP receptor subtype is responsible for the healing-promoting action of PGE2. Male SD rats and C57BL/6 mice, including wild-type, COX-1(-/-), and COX-2(-/-), were used. Gastric ulcers were produced by thermocauterization under ether anesthesia. Gastric ulcer healing was significantly delayed in both rats and mice by indomethacin and rofecoxib but not SC-560 given for 14 days after ulceration. The impaired healing was also observed in COX-2(-/-) but not COX-1(-/-) mice. Mucosal PGE2 content increased after ulceration, and this response was significantly suppressed by indomethacin and rofecoxib but not SC-560. The delayed healing in mice caused by indomethacin was significantly reversed by the coadministration of 11-deoxy-PGE1 (EP3/EP4 agonist) but not other prostanoids, including the EP1, EP2, and EP3 agonists. By contrast, CJ-42794 (selective EP(4) antagonist) significantly delayed the ulcer healing in rats and mice. VEGF expression and angiogenesis were both upregulated in the ulcerated mucosa, and these responses were suppressed by indomethacin, rofocoxib, and CJ-42794. The expression of VEGF in primary rat gastric fibroblasts was increased by PGE2 or AE1-329 (EP4 agonist), and these responses were both attenuated by coadministration of CJ-42794. These results confirmed the importance of COX-2/PGE2 in the healing mechanism of gastric ulcers and further suggested that the healing-promoting action of PGE2 is mediated by the activation of EP4 receptors and is associated with VEGF expression.
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Affiliation(s)
- Ryo Hatazawa
- Dept. of Pharmacology and Experimental Therapeutics, Kyoto Pharmaceutical Univ., Misasagi, Yamashina, Kyoto 607, Japan
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Barry GD, Suen JY, Low HB, Pfeiffer B, Flanagan B, Halili M, Le GT, Fairlie DP. A refined agonist pharmacophore for protease activated receptor 2. Bioorg Med Chem Lett 2007; 17:5552-7. [PMID: 17765542 DOI: 10.1016/j.bmcl.2007.08.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 08/10/2007] [Accepted: 08/13/2007] [Indexed: 11/20/2022]
Abstract
Protease activated receptor 2 (PAR(2)) is a G protein-coupled receptor implicated in inflammation and cancer. Only a few peptide agonists are known with greater potency than the native agonist SLIGRL-NH(2). Here we report 52 peptide agonists of PAR(2), 26 with activity at sub-micromolar concentrations, and one being iodinated for radioligand experiments. Potency was highest when the N- or C-termini of SLIGRL-NH(2) were modified, pointing to a new ligand pharmacophore model that may aid development of drug-like PAR(2) modulators.
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Affiliation(s)
- Grant D Barry
- Centre for Drug Design and Development, Institute for Molecular Bioscience, University of Queensland, Brisbane, Qld. 4072, Australia
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Bushell T. The emergence of proteinase-activated receptor-2 as a novel target for the treatment of inflammation-related CNS disorders. J Physiol 2007; 581:7-16. [PMID: 17347265 PMCID: PMC2075212 DOI: 10.1113/jphysiol.2007.129577] [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] [Indexed: 12/27/2022] Open
Abstract
The signalling molecules that are involved in inflammatory pathways are now thought to play a part in many disorders of the central nervous system (CNS). In common with peripheral chronic inflammatory diseases such a rheumatoid arthritis and ulcerative colitis, evidence now exists for the involvement of inflammatory cytokines, for example tumour necrosis factor (TNF) and interleukins (IL), in neurological disorders. A common factor observed with the up-regulation of these cytokines in peripheral inflammatory diseases, is the increased expression of the proteinase-activated receptor (PAR) subtype PAR-2. Indeed, recent evidence suggests that targeting PAR-2 helps reduce joint swelling observed in animal models of arthritis. So could targeting this receptor prove to be useful in treating those CNS disorders where inflammatory processes are thought to play an intrinsic role? The aim of this review is to summarize the emerging data regarding the role of PAR-2 in neuroinflammation and ischaemic injury and discuss its potential as an exciting new target for the prevention and/or treatment of CNS disorders.
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Affiliation(s)
- Trevor Bushell
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 NR, UK.
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