title: The Coagulant Factor Xa Induces Protease-Activated Receptor-1 and Annexin A2-Dependent Airway Smooth Muscle Cytokine Production and Cell Proliferation.
abstract: During asthma exacerbation, plasma circulating coagulant factor X (FX) enters the inflamed airways and is activated (FXa). FXa may have an important role in asthma, being involved in thrombin activation and an agonist of protease-activated receptor-1 (PAR-1). Extracellular annexin A2 and integrins are also implicated in PAR-1 signaling. In this study, the potential role of PAR-1 in mediating the effects of FXa on human airway smooth muscle (ASM) cell cytokine production and proliferation was investigated. FXa (5-50 nM), but not FX, stimulated increases in ASM IL-6 production and cell number after 24- and 48-hour incubation, respectively (P < 0.05; n = 5). FXa (15 nM) also stimulated increases in the levels of mRNA for cytokines (IL-6), cell cycle-related protein (cyclin D1), and proremodeling proteins (FGF-2, PDGF-B, CTGF, SM22, and PAI-1) after 3-hour incubation (P < 0.05; n = 4). The actions of FXa were insensitive to inhibition by hirudin (1 U/ml), a selective thrombin inhibitor, but were attenuated by SCH79797 (100 nM), a PAR-1 antagonist, or Cpd 22 (1 μM), an inhibitor of integrin-linked kinase. The selective targeting of PAR-1, annexin A2, or β1-integrin by small interfering RNA and/or by functional blocking antibodies also attenuated FXa-evoked responses. In contrast, the targeting of annexin A2 did not inhibit thrombin-stimulated ASM function. In airway biopsies of patients with asthma, FXa and annexin A2 were detected in the ASM bundle by immunohistochemistry. These findings establish FXa as a potentially important asthma mediator, stimulating ASM function through actions requiring PAR-1 and annexin A2 and involving integrin coactivation.
authors.affiliation: 1 Lung Health Research Centre, Department Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; and.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0001-6742-5028
authors.initials: M
authors.lastname: Schuliga
authors.affiliation: 2 Department Pharmacology, Monash University, Clayton, Victoria, Australia.
authors.forename: Simon G
authors.initials: SG
authors.lastname: Royce
authors.affiliation: 1 Lung Health Research Centre, Department Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; and.
authors.forename: Shenna
authors.initials: S
authors.lastname: Langenbach
authors.affiliation: 1 Lung Health Research Centre, Department Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; and.
authors.forename: Asres
authors.initials: A
authors.lastname: Berhan
authors.affiliation: 1 Lung Health Research Centre, Department Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; and.
authors.forename: Trudi
authors.initials: T
authors.lastname: Harris
authors.affiliation: 1 Lung Health Research Centre, Department Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; and.
authors.forename: Christine R
authors.initials: CR
authors.lastname: Keenan
authors.affiliation: 1 Lung Health Research Centre, Department Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria, Australia; and.
authors.forename: Alastair G
authors.initials: AG
authors.lastname: Stewart
mesh_terms: D056151:Airway Remodeling / Q000187:drug effects*; D017306:Annexin A2 / Q000235:genetics / Q000378:metabolism*; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D001706:Biopsy; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015951:Factor Xa / Q000494:pharmacology*; D005786:Gene Expression Regulation; D006801:Humans; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D011758:Pyrroles / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D044463:Receptor, PAR-1 / Q000235:genetics / Q000378:metabolism*; D012137:Respiratory System / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects; D013917:Thrombin / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D010975:Platelet Aggregation Inhibitors
chemical_list: C472822:ANXA2 protein, human; D017306:Annexin A2; D016207:Cytokines; D019012:Integrin beta1; C415424:N3-cyclopropyl-7-((4-(1-methylethyl)phenyl)methyl)-7H-pyrrolo(3, 2-f)quinazoline-1,3-diamine; D011758:Pyrroles; D011799:Quinazolines; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D013917:Thrombin; D015951:Factor Xa; D010975:Platelet Aggregation Inhibitors
keywords: airway wall remodeling; annexin A2 hetero-tetramer; asthma; intergin; thrombin