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Dewitte A, Tanga A, Villeneuve J, Lepreux S, Ouattara A, Desmoulière A, Combe C, Ripoche J. New frontiers for platelet CD154. Exp Hematol Oncol 2015; 4:6. [PMID: 25763299 PMCID: PMC4355125 DOI: 10.1186/s40164-015-0001-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 02/03/2015] [Indexed: 02/07/2023] Open
Abstract
The role of platelets extends beyond hemostasis. The pivotal role of platelets in inflammation has shed new light on the natural history of conditions associated with acute or chronic inflammation. Beyond the preservation of vascular integrity, platelets are essential to tissue homeostasis and platelet-derived products are already used in the clinics. Unanticipated was the role of platelets in the adaptative immune response, allowing a renewed conceptual approach of auto-immune diseases. Platelets are also important players in cancer growth and dissemination. Platelets fulfill most of their functions through the expression of still incompletely characterized membrane-bound or soluble mediators. Among them, CD154 holds a peculiar position, as platelets represent a major source of CD154 and as CD154 contributes to most of these new platelet attributes. Here, we provide an overview of some of the new frontiers that the study of platelet CD154 is opening, in inflammation, tissue homeostasis, immune response, hematopoiesis and cancer.
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Affiliation(s)
- Antoine Dewitte
- INSERM U1026, and Université de Bordeaux, F-33000 Bordeaux, France ; Service d'Anesthésie-Réanimation II, CHU de Bordeaux, F-33600 Pessac, France
| | - Annabelle Tanga
- INSERM U1026, and Université de Bordeaux, F-33000 Bordeaux, France
| | - Julien Villeneuve
- Cell and Developmental Biology Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain ; Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3200 USA
| | | | - Alexandre Ouattara
- Service d'Anesthésie-Réanimation II, CHU de Bordeaux, F-33600 Pessac, France
| | | | - Christian Combe
- INSERM U1026, and Université de Bordeaux, F-33000 Bordeaux, France ; Service de Néphrologie Transplantation Dialyse, CHU de Bordeaux, F-33076 Bordeaux, France
| | - Jean Ripoche
- INSERM U1026, and Université de Bordeaux, F-33000 Bordeaux, France
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Schepetkin IA, Khlebnikov AI, Giovannoni MP, Kirpotina LN, Cilibrizzi A, Quinn MT. Development of small molecule non-peptide formyl peptide receptor (FPR) ligands and molecular modeling of their recognition. Curr Med Chem 2015; 21:1478-504. [PMID: 24350845 DOI: 10.2174/0929867321666131218095521] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 10/14/2013] [Accepted: 12/10/2013] [Indexed: 02/07/2023]
Abstract
Formyl peptide receptors (FPRs) are G protein-coupled receptors (GPCRs) expressed on a variety of cell types. These receptors play an important role in the regulation of inflammatory reactions and sensing cellular damage. They have also been implicated in the pathogenesis of various diseases, including neurodegenerative diseases, cataract formation, and atherogenesis. Thus, FPR ligands, both agonists and antagonists, may represent novel therapeutics for modulating host defense and innate immunity. A variety of molecules have been identified as receptor subtype-selective and mixed FPR agonists with potential therapeutic value during last decade. This review describes our efforts along with recent advances in the identification, optimization, biological evaluation, and structure-activity relationship (SAR) analysis of small molecule non-peptide FPR agonists and antagonists, including chiral molecules. Questions regarding the interaction at the molecular level of benzimidazoles, pyrazolones, pyridazin-3(2H)-ones, N-phenylureas and other derivatives with FPR1 and FPR2 are discussed. Application of computational models for virtual screening and design of FPR ligands is also considered.
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Affiliation(s)
| | | | | | | | | | - M T Quinn
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, MT 59717, USA.
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Ortiz-Muñoz G, Mallavia B, Bins A, Headley M, Krummel MF, Looney MR. Aspirin-triggered 15-epi-lipoxin A4 regulates neutrophil-platelet aggregation and attenuates acute lung injury in mice. Blood 2014; 124:2625-34. [PMID: 25143486 PMCID: PMC4208278 DOI: 10.1182/blood-2014-03-562876] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 08/05/2014] [Indexed: 01/14/2023] Open
Abstract
Evidence is emerging that platelets are major contributors to innate immune responses in conditions such as acute lung injury (ALI). Platelets form heterotypic aggregates with neutrophils, and we hypothesized that lipoxin mediators regulate formation of neutrophil-platelet aggregates (NPA) and that NPA significantly contribute to ALI. Lipopolysaccharide (LPS)-induced lung injury was accompanied by platelet sequestration, activation, intra-alveolar accumulation, and NPA formation within both blood and alveolar compartments. Using lung intravital microscopy, we observed the dynamic formation of NPA during physiologic conditions, which sharply increased with ALI. Aspirin (ASA) treatment significantly reduced lung platelet sequestration and activation, NPA formation, and lung injury. ASA treatment increased levels of ASA-triggered lipoxin (ATL; 15-epi-lipoxin A4), and blocking the lipoxin A4 receptor (ALX) with a peptide antagonist (Boc2) or using ALX knockouts (Fpr2/3(-/-)) reversed this protection. LPS increased NPA formation in vitro, which was reduced by ATL, and engagement of ALX by ATL on both neutrophils and platelets was necessary to prevent aggregation. In a model of transfusion-related acute lung injury (TRALI), Boc2 also reversed ASA protection, and treatment with ATL in both LPS and TRALI models protected from ALI. We conclude that ATL regulates neutrophil-platelet aggregation and that platelet-neutrophil interactions are a therapeutic target in lung injury.
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Affiliation(s)
| | - Beñat Mallavia
- Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Adriaan Bins
- Department of Immunology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | | | - Mark R Looney
- Department of Medicine, University of California, San Francisco, San Francisco, CA; Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA
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Deficiency of formyl peptide receptor 1 and 2 is associated with increased inflammation and enhanced liver injury after LPS-stimulation. PLoS One 2014; 9:e100522. [PMID: 24956481 PMCID: PMC4067326 DOI: 10.1371/journal.pone.0100522] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 05/28/2014] [Indexed: 12/30/2022] Open
Abstract
Introduction Formyl peptide-receptor 1 and 2 (FPR1 and FPR2) in mice were identified as receptors with contrary affinity for the PAMP fMLF. Formyl-methionyl-leucyl-phenylalanine is either part of the bacterial membrane and is secreted by the mitochondria of eukaryotic ceslls during apoptosis. Furthermore FPR1 and 2 are described as highly relevant factors for the chemotaxis of immune cells. Their role during the acute liver injury has not been investigated yet. Materials and Methods Constitutive knockout mice for FPR1 (mFPR1-/-), FPR2 (mFPR2-/-) and wild type (WT) mice were challenged with LPS i.p. for 3 h and 6 h. Liver and serum were sampled for further analysis. Results Liver transaminases were elevated in all mice 3 h and 6 h post LPS stimulation. Gene expression analysis displayed a reduced expression of the pro-inflammatory cytokines IL-6 and CXCL1 after 3 h in the mFPR1-/- compared to wild type and mFPR2-/- mice. After 6 h, IL-6, TNF-α and CXCL1 were significantly higher in mice lacking mFPR1 or 2. Consistent to these findings the numbers of CD11b+ and Ly6G+ immune cells were altered in the livers. The analysis of TLR2 and TLR4 revealed time and genotype specific changes in theirs gene expression. Additionally, the liver in mFPR1- and mFPR2-deficient mice seem to be more susceptible to apoptosis by showing a significant higher number of TUNEL+-cells in the liver than WT-mice and displayed less Ki67-positive nuclei in the liver. Conclusion The results suggest a prominent role of FPRs in the regulation of the hepatic inflammatory response after LPS induced liver injury. Deletion of mFPR1 or mFPR2 leads to deregulation of the inflammatory response compared to WT mice, associated with more severe liver injury represented by higher levels of transaminases, apoptotic cells and a reduced regenerative capacity.
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Zang Q, Wolf SE, Minei JP. Sepsis-induced Cardiac Mitochondrial Damage and Potential Therapeutic Interventions in the Elderly. Aging Dis 2014; 5:137-49. [PMID: 24729939 DOI: 10.14336/ad.2014.0500137] [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: 12/16/2013] [Revised: 02/11/2014] [Accepted: 02/11/2014] [Indexed: 12/13/2022] Open
Abstract
The incidence of sepsis and its attendant mortality risk are significantly increased with aging. Thus, severe sepsis in the elderly is likely to become an emerging concern in critical care units. Cardiac dysfunction is an important component of multi-organ failure after sepsis. In our laboratory, utilizing a pneumonia-related sepsis animal model, our research has been focused on the mechanisms underlying sepsis-induced cardiac failure. In this review, based on findings from others and ours, we discussed age-dependent decay in mitochondria and the role of mitochondrial reactive oxygen species (mtROS) in sepsis-induced cardiac inflammation and autophagy. Our recent discovery of a potential signal transduction pathway that triggers myocardial mitochondrial damage is also discussed. Because of the significance of mitochondria damage in the aging process and in sepsis pathogenesis, we hypothesize that specific enhancing mitochondrial antioxidant defense by mitochondria-targeted antioxidants (MTAs) may provide important therapeutic potential in treating elder sepsis patients. In this review, we summarized the categories of currently published MTA molecules and the results of preclinical evaluation of MTAs in sepsis and aging models.
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Affiliation(s)
| | - Steven E Wolf
- Departments of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
| | - Joseph P Minei
- Departments of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA
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Yao X, Wigginton JG, Maass DL, Ma L, Carlson D, Wolf SE, Minei JP, Zang QS. Estrogen-provided cardiac protection following burn trauma is mediated through a reduction in mitochondria-derived DAMPs. Am J Physiol Heart Circ Physiol 2014; 306:H882-94. [PMID: 24464748 DOI: 10.1152/ajpheart.00475.2013] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mitochondria-derived danger-associated molecular patterns (DAMPs) play important roles in sterile inflammation after acute injuries. This study was designed to test the hypothesis that 17β-estradiol protects the heart via suppressing myocardial mitochondrial DAMPs after burn injury using an animal model. Sprague-Dawley rats were given a third-degree scald burn comprising 40% total body surface area (TBSA). 17β-Estradiol, 0.5 mg/kg, or control vehicle was administered subcutaneously 15 min following burn. The heart was harvested 24 h postburn. Estradiol showed significant inhibition on the productivity of H2O2 and oxidation of lipid molecules in the mitochondria. Estradiol increased mitochondrial antioxidant defense via enhancing the activities and expression of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Estradiol also protected mitochondrial respiratory function and structural integrity. In parallel, estradiol remarkably decreased burn-induced release of mitochondrial cytochrome c and mitochondrial DNA (mtDNA) into cytoplasm. Further, estradiol inhibited myocardial apoptosis, shown by its suppression on DNA laddering and downregulation of caspase 1 and caspase 3. Estradiol's anti-inflammatory effect was demonstrated by reduction in systemic and cardiac cytokines (TNF-α, IL-1β, and IL-6), decrease in NF-κB activation, and attenuation of the expression of inflammasome component ASC in the heart of burned rats. Estradiol-provided cardiac protection was shown by reduction in myocardial injury marker troponin-I, amendment of heart morphology, and improvement of cardiac contractility after burn injury. Together, these data suggest that postburn administration of 17β-estradiol protects the heart via an effective control over the generation of mitochondrial DAMPs (mtROS, cytochrome c, and mtDNA) that incite cardiac apoptosis and inflammation.
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Affiliation(s)
- Xiao Yao
- Departments of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
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Speth C, Löffler J, Krappmann S, Lass-Flörl C, Rambach G. Platelets as immune cells in infectious diseases. Future Microbiol 2013; 8:1431-51. [DOI: 10.2217/fmb.13.104] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Platelets have been shown to cover a broad range of functions. Besides their role in hemostasis, they have immunological functions and thus participate in the interaction between pathogens and host defense. Platelets have a broad repertoire of receptor molecules that enable them to sense invading pathogens and infection-induced inflammation. Consequently, platelets exert antimicrobial effector mechanisms, but also initiate an intense crosstalk with other arms of the innate and adaptive immunity, including neutrophils, monocytes/macrophages, dendritic cells, B cells and T cells. There is a fragile balance between beneficial antimicrobial effects and detrimental reactions that contribute to the pathogenesis, and many pathogens have developed mechanisms to influence these two outcomes. This review aims to highlight aspects of the interaction strategies between platelets and pathogenic bacteria, viruses, fungi and parasites, in addition to the subsequent networking between platelets and other immune cells, and the relevance of these processes for the pathogenesis of infections.
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Affiliation(s)
- Cornelia Speth
- Division of Hygiene & Medical Microbiology, Innsbruck Medical University Fritz-Pregl-Straße 3, A-6020 Innsbruck, Austria
| | - Jürgen Löffler
- Laboratory of Innate Immunity, Infection, Inflammation, University Hospital Würzburg, Würzburg, Germany
| | - Sven Krappmann
- Microbiology Institute – Clinical Microbiology, Immunology & Hygiene, University Hospital of Erlangen & Friedrich-Alexander-University Erlangen-Nürnberg, Germany
| | - Cornelia Lass-Flörl
- Division of Hygiene & Medical Microbiology, Innsbruck Medical University Fritz-Pregl-Straße 3, A-6020 Innsbruck, Austria
| | - Günter Rambach
- Division of Hygiene & Medical Microbiology, Innsbruck Medical University Fritz-Pregl-Straße 3, A-6020 Innsbruck, Austria
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59
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Wong CHY, Jenne CN, Petri B, Chrobok NL, Kubes P. Nucleation of platelets with blood-borne pathogens on Kupffer cells precedes other innate immunity and contributes to bacterial clearance. Nat Immunol 2013; 14:785-92. [PMID: 23770641 PMCID: PMC4972575 DOI: 10.1038/ni.2631] [Citation(s) in RCA: 260] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/25/2013] [Indexed: 12/13/2022]
Abstract
Using intravital imaging of the liver, we unveil a collaborative role for platelets with Kupffer cells (KCs) in eradicating bloodborne bacterial infections. Under basal conditions, platelets via glycoprotein Ib (GPIb) formed transient “touch-and-go” interactions with von Willebrand factor (vWF) constitutively expressed on KCs. Bacteria, such as Bacillus cereus and Methicillin-resistant Staphylococcus aureus (MRSA), were rapidly caught by KCs and triggered platelets to switch from “touch-and-go” to sustained GPIIb-mediated adhesion on the KC surface to encase the bacterium. Infected GpIbα−/− mice demonstrated increased endothelial and KC damage, leading to increased fluid leakage, significant polycythemia and rapid mortality. This study identifies a novel surveillance mechanism of intravascular macrophage by platelets that rapidly converts to a critical host response against bloodborne bacteria.
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Affiliation(s)
- Connie H Y Wong
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Alberta, Canada
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60
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Aktan Í, Dunkel B, Cunningham F. Equine platelets inhibit E. coli growth and can be activated by bacterial lipopolysaccharide and lipoteichoic acid although superoxide anion production does not occur and platelet activation is not associated with enhanced production by neutrophils. Vet Immunol Immunopathol 2013; 152:209-17. [DOI: 10.1016/j.vetimm.2012.12.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 12/12/2012] [Accepted: 12/13/2012] [Indexed: 12/20/2022]
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63
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Krysko DV, Garg AD, Kaczmarek A, Krysko O, Agostinis P, Vandenabeele P. Immunogenic cell death and DAMPs in cancer therapy. Nat Rev Cancer 2012; 12:860-75. [PMID: 23151605 DOI: 10.1038/nrc3380] [Citation(s) in RCA: 1815] [Impact Index Per Article: 151.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although it was thought that apoptotic cells, when rapidly phagocytosed, underwent a silent death that did not trigger an immune response, in recent years a new concept of immunogenic cell death (ICD) has emerged. The immunogenic characteristics of ICD are mainly mediated by damage-associated molecular patterns (DAMPs), which include surface-exposed calreticulin (CRT), secreted ATP and released high mobility group protein B1 (HMGB1). Most DAMPs can be recognized by pattern recognition receptors (PRRs). In this Review, we discuss the role of endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) in regulating the immunogenicity of dying cancer cells and the effect of therapy-resistant cancer microevolution on ICD.
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Affiliation(s)
- Dmitri V Krysko
- Molecular Signalling and Cell Death Unit, Department for Molecular Biomedical Research, VIB, VIB-Ghent University Technologiepark 927, B-9052 Ghent (Zwijnaarde), Belgium. Dmitri.Krysko@dmbr. ugent.be
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64
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Harding M, Kubes P. Innate immunity in the vasculature: interactions with pathogenic bacteria. Curr Opin Microbiol 2012; 15:85-91. [DOI: 10.1016/j.mib.2011.11.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 11/19/2011] [Accepted: 11/23/2011] [Indexed: 12/20/2022]
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65
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Amison R, Page C, Pitchford S. Pharmacological modulation of the inflammatory actions of platelets. Handb Exp Pharmacol 2012:447-468. [PMID: 22918742 DOI: 10.1007/978-3-642-29423-5_18] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Patients with inflammatory diseases often exhibit a change in platelet function, with these alterations being clearly distinct from the well-characterized role of platelets in haemostasis and thrombosis. It has recently been revealed that platelets can behave as innate inflammatory cells in immune responses with roles in leukocyte recruitment, migration into tissues, release of cytotoxic mediators, and in tissue remodelling following injury.Platelets exhibit a wide range of receptors for mediators involved in the inflammatory pathway and the immune response (Fig. 1). These include purinergic receptors, selectins, integrins, toll-like receptors, immunoglobulins, and chemokine receptors, but the precise role platelets play in the inflammatory process is still under investigation. Nevertheless, given that many of these receptors are distinct from those involved in thrombosis and haemostasis, this raises the real possibility of targeting these receptors to regulate inflammatory diseases without compromising haemostasis.
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Affiliation(s)
- Richard Amison
- Sackler Institute of Pulmonary Pharmacology, King's College London, 150 Stamford Street, Room 5.44, 5th Floor, Franklin-Wilkins Building, Waterloo Campus, London, SE1 9NH, UK
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66
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Schmidt EM, Münzer P, Borst O, Kraemer BF, Schmid E, Urban B, Lindemann S, Ruth P, Gawaz M, Lang F. Ion channels in the regulation of platelet migration. Biochem Biophys Res Commun 2011; 415:54-60. [PMID: 22005466 DOI: 10.1016/j.bbrc.2011.10.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 10/02/2011] [Indexed: 10/16/2022]
Abstract
Platelets have been shown to migrate and thus to invade the vascular wall. Platelet migration is stimulated by SDF-1. In other cell types, migration is dependent on Ca(2+) entry via Ca(2+) channels. Ca(2+) influx is sensitive to cell membrane potential which is maintained by K(+) channel activity and/or Cl(-) channel activity. The present study explored the role of ion channels in the regulation of SDF-1 induced migration. Platelets were isolated from human volunteers as well as from gene targeted mice lacking the Ca(2+) activated K(+) channel SK4 (sk4(-/-)) and their wild type littermates (sk4(+/+)). According to confocal microscopy human platelets expressed the Ca(2+) channel Orai1 and the Ca(2+)-activated K(+) channel K(Ca)3.1 (SK4). SDF-1 (100 ng/ml) stimulated migration in human platelets, an effect blunted by Orai1 inhibitors 2-aminoethoxydiphenyl borate 2-APB (10 μM) and SKF-96365 (10 μM), by unspecific K(+) channel inhibitor TEA (30 mM), by SK4 specific K(+) channel blocker clotrimazole (10 μM), but not by Cl(-) channel inhibitor 5-nitro-2-(3-phenylpropylamino) benzoic acid NPPB (100 μM). Significant stimulation of migration by SDF-1 was further observed in sk4(+/+) platelets but was virtually absent in sk4(-/-) platelets. In conclusion, platelet migration requires activity of the Ca(2+) channel Orai1 and of the Ca(2+) activated K(+) channel SK4, but not of NPPB-sensitive Cl(-) channels.
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67
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Morley AD, Cook A, King S, Roberts B, Lever S, Weaver R, Macdonald C, Unitt J, Fagura M, Phillips T, Lewis R, Wenlock M. Discovery of pyrazoles as novel FPR1 antagonists. Bioorg Med Chem Lett 2011; 21:6456-60. [PMID: 21955939 DOI: 10.1016/j.bmcl.2011.08.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 08/15/2011] [Accepted: 08/17/2011] [Indexed: 10/17/2022]
Abstract
A series of pyrazole inhibitors of the human FPR1 receptor have been identified from high throughput screening. The compounds demonstrate potent inhibition in human neutrophils and attractive physicochemical and in vitro DMPK profiles to be of further interest.
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Affiliation(s)
- Andrew D Morley
- AstraZeneca R&D Charnwood, Chemistry, Bakewell Road, Loughborough LE11 5RH, UK.
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Unitt J, Fagura M, Phillips T, King S, Perry M, Morley A, MacDonald C, Weaver R, Christie J, Barber S, Mohammed R, Paul M, Cook A, Baxter A. Discovery of small molecule human FPR1 receptor antagonists. Bioorg Med Chem Lett 2011; 21:2991-7. [DOI: 10.1016/j.bmcl.2011.03.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 03/11/2011] [Accepted: 03/13/2011] [Indexed: 10/18/2022]
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Ripoche J. Blood platelets and inflammation: their relationship with liver and digestive diseases. Clin Res Hepatol Gastroenterol 2011; 35:353-7. [PMID: 21482218 DOI: 10.1016/j.clinre.2011.02.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/17/2011] [Accepted: 02/22/2011] [Indexed: 02/04/2023]
Abstract
An expansion of knowledge from basic and clinical research has highlighted the critical role of platelets in inflammation and tissue repair in addition to their established contribution to hemostasis. Activated platelets are a rich source of mediators participating to inflammation and tissue regeneration. Platelet-derived microparticles recapitulate essential platelet functions and their contribution to the pathogenesis of inflammatory diseases has been emphasized. Recent findings suggest that platelets are both friends and foes for the liver. Platelets are essential to liver regeneration, platelet-derived serotonin being critical. However platelets can also exacerbate liver damage, as in immune-mediated injury. The dual role of platelets has recently been exemplified in animal models of liver fibrosis. Platelets release profibrogenic mediators, such as CXC Chemokine Ligand 4, that is instrumental in the progression of liver fibrosis. On the other hand, thrombocytopenia aggravates liver fibrosis, an outcome linked to the downregulation of hepatic stellate cell collagen production by platelet derived hepatocyte growth factor. CD154, a key molecule in inflammation, is expressed by platelets and is a pathogenic mediator in inflammatory bowel disease. Here, we summarize some of the mechanisms linking platelets with inflammation and comment few recent articles indicating why platelets may prove to be important pathogenic mediators in liver and gastrointestinal diseases.
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Affiliation(s)
- J Ripoche
- Inserm U889, université Victor-Segalen-Bordeaux, 146, rue Léo-Saignat, 33076 Bordeaux, France.
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70
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Krysko DV, Agostinis P, Krysko O, Garg AD, Bachert C, Lambrecht BN, Vandenabeele P. Emerging role of damage-associated molecular patterns derived from mitochondria in inflammation. Trends Immunol 2011; 32:157-64. [PMID: 21334975 DOI: 10.1016/j.it.2011.01.005] [Citation(s) in RCA: 491] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 01/19/2011] [Accepted: 01/19/2011] [Indexed: 02/08/2023]
Abstract
Cell death and injury often lead to release or exposure of intracellular molecules called damage-associated molecular patterns (DAMPs) or cell death-associated molecules. These molecules are recognized by the innate immune system by pattern recognition receptors - the same receptors that detect pathogen-associated molecular patterns, thus revealing similarities between pathogen-induced and non-infectious inflammatory responses. Many DAMPs are derived from the plasma membrane, nucleus, endoplasmic reticulum and cytosol. Recently, mitochondria have emerged as other organelles that function as a source of DAMPs. Here, we highlight the significance of mitochondrial DAMPs and discuss their contribution to inflammation and development of human pathologies.
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Affiliation(s)
- Dmitri V Krysko
- Molecular Signaling and Cell Death Unit, Department for Molecular Biomedical Research, VIB, Belgium.
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Hernández AM, Rodríguez N, González JE, Reyes E, Rondón T, Griñán T, Macías A, Alfonso S, Vázquez AM, Pérez R. Anti-NeuGcGM3 antibodies, actively elicited by idiotypic vaccination in nonsmall cell lung cancer patients, induce tumor cell death by an oncosis-like mechanism. THE JOURNAL OF IMMUNOLOGY 2011; 186:3735-44. [PMID: 21300821 DOI: 10.4049/jimmunol.1000609] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
1E10 is a murine anti-idiotypic mAb specific for an idiotypic mAb that reacts with NeuGc-containing gangliosides, sulfatides, and Ags expressed in some human tumors. In melanoma, breast, and lung cancer patients, this anti-idiotypic Ab was able to induce a specific Ab response against N-glycosylated gangliosides, attractive targets for cancer immunotherapy as these glycolipids are not naturally expressed in humans. A clinical study with nonsmall cell lung cancer patients showed encouraging clinical benefits. Immunological studies performed in 20 of these patients suggested a correlation between the induction of Abs against NeuGcGM3 and longer survival times. The induced anti-NeuGcGM3 Abs recognized and directly killed tumor cells expressing the Ag, by a mechanism independent of complement activation. In the present work, we show that this cytotoxicity differs from apoptosis because it is temperature independent, no chromatin condensation or caspase 3 induction are detected, and the DNA fragmentation induced has a different pattern than the one characteristic for apoptosis. It is a very quick process and involves cytosqeleton reorganization. The Abs induce cellular swelling and the formation of big membrane lesions that allow the leakage of cytoplasm and the loss of the cell membrane integrity. All of these characteristics resemble a process of oncotic necrosis. To our knowledge, this is the first report of the active induction in cancer patients of NeuGcGM3-specific Abs able to induce complement independent oncotic necrosis to tumor cells. These results contribute to reinforcing the therapeutic potential of anti-idiotypic vaccines and the importance of NeuGcGM3 ganglioside as antitumor target.
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Affiliation(s)
- Ana María Hernández
- Department of Antibody Engineering, Center of Molecular Immunology, Havana 11600, Cuba.
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72
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Pallen MJ. Time to recognise that mitochondria are bacteria? Trends Microbiol 2010; 19:58-64. [PMID: 21123072 DOI: 10.1016/j.tim.2010.11.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 10/19/2010] [Accepted: 11/02/2010] [Indexed: 01/16/2023]
Abstract
The scientific community is comfortable with recognising mitochondria as organelles that happen to be descendants of bacteria. Here, I playfully explore the arguments for and against a phylogenetic fundamentalism that states that mitochondria are bacteria and should be given their own taxonomic family, the Mitochondriaceae. I also explore the consequences of recognizing mitochondria as bacteria for our understanding of the systemic response to trauma and for the prospects of creating transgenic mitochondria.
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Affiliation(s)
- Mark J Pallen
- Centre for Systems Biology, School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
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73
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Kraemer BF, Borst O, Gehring EM, Schoenberger T, Urban B, Ninci E, Seizer P, Schmidt C, Bigalke B, Koch M, Martinovic I, Daub K, Merz T, Schwanitz L, Stellos K, Fiesel F, Schaller M, Lang F, Gawaz M, Lindemann S. PI3 kinase-dependent stimulation of platelet migration by stromal cell-derived factor 1 (SDF-1). J Mol Med (Berl) 2010; 88:1277-88. [PMID: 20852838 DOI: 10.1007/s00109-010-0680-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 08/10/2010] [Accepted: 08/12/2010] [Indexed: 01/02/2023]
Abstract
Platelets have been regarded as static cells that do not move once they adhere to a matrix. The present study explored, whether platelets are able to migrate. In contrast to the current opinion, we found that platelets were mobile, able to migrate over a surface, and transmigrate through a transwell membrane and endothelium toward a source of stromal cell-derived factor 1 (SDF-1). Platelet migration was stimulated by SDF-1, which led to the downstream activation and phosphorylation of Wiskott-Aldrich syndrome protein. SDF-1 signaling and subsequent platelet migration could be inhibited by CXCR4-receptor blocker AMD3100, pertussis toxin, inhibition of phosphoinositol 3-kinase (PI3 kinase) with LY294002 or wortmannin, and disruption of actin polymerization with cytochalasin B. The potential of platelets to migrate in an SDF-1-mediated fashion may redefine the role of platelets in the pathophysiology of vascular inflammation, subsequent atherosclerotic degeneration, and vascular regeneration.
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Affiliation(s)
- Bjoern F Kraemer
- Abteilung III, Kardiologie und Kreislauferkrankungen, Medizinische Klinik, Universitätsklinikum Tübingen, Otfried-Müller-Strasse 10, 72076, Tübingen, Germany
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Die unterschätzte Rolle von Thrombozyten bei der Herztransplantation. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2010. [DOI: 10.1007/s00398-010-0788-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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75
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Saihkay HNS, Rickards KJ, Page CP, Ballinger JR. Validating 123I-metaiodobenzylguanidine as a platelet marker for non-invasive imaging in rabbits. J Pharmacol Toxicol Methods 2010; 63:69-78. [PMID: 20646985 DOI: 10.1016/j.vascn.2010.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 04/20/2010] [Accepted: 05/20/2010] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Recent in vitro studies in our laboratory have demonstrated that platelets are necessary for leukocyte recruitment and airway remodelling in models of allergic airway inflammation, and also migrate to lung tissues in response to anti-IgE or relevant allergens in allergic asthma. Non-invasive imaging of platelet migration in vivo would provide a further insight into the roles of platelets in inflammatory diseases such as asthma, and metaiodobenzylguanidine (MIBG) was considered as a suitable platelet marker. METHODS The kinetics of MIBG uptake into rabbit platelets, the effect of MIBG on platelet function and the effect of platelet activation on MIBG uptake and retention were investigated. MIBG-labelled platelets were administered intravenously into rabbits and the time course of radioactivity in the lung and blood was monitored as a function of stimulation. RESULTS Following a 4h incubation of MIBG in rabbit PRP, a near maximal MIBG uptake (52.4 ± 20.2%) in platelets occurred. This time point was chosen for subsequent in vitro studies. In vitro platelet function studies showed that MIBG has no effect on ADP or PAF-induced platelet aggregation, PAF-induced thromboxane production or fMLP-induced platelet chemotaxis. However, serotonin showed a significant effect on MIBG uptake and retention, but only at high concentrations. Stimulation of rabbit platelets with ADP and PAF caused a significant release of stored MIBG in vitro. Following i.v. administration of MIBG labelled platelets, the response to i.v. ADP and PAF stimulation was small but significant. DISCUSSION The release of MIBG from platelets in vivo, particularly following stimulation, leads to high background levels. Therefore, MIBG may have limited utility as a label for imaging platelets in vivo using PET. However, it may be a useful marker in detecting pathological conditions where platelet migration is involved.
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Affiliation(s)
- Hom N S Saihkay
- The Sackler Institute of Pulmonary Pharmacology, Waterloo Campus, King's College London, London SE1 9NH, UK.
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76
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Yeaman MR. Bacterial-platelet interactions: virulence meets host defense. Future Microbiol 2010; 5:471-506. [PMID: 20210555 DOI: 10.2217/fmb.09.112] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Platelets have historically been viewed as cell fragments that only mediate blood coagulation. Yet, platelets have as - or perhaps even more - important roles in tissue remodeling, modulation of inflammation and antimicrobial host defense. It is evident that platelets interact with prokaryotes directly and indirectly through multiple molecular and cellular mechanisms. The important roles of platelets in antibacterial host defense can be exemplified through contemporary themes in platelet immunobiology. Platelets have unambiguous structures and functions of host defense effector cells. Recent discoveries reveal platelet expression of toll-like and purinonergic receptors, which enable detection and response to bacterial infection, degranulation of an array of microbicidal peptides and coordination of other molecular and cellular host defenses. From multiple perspectives, platelets are now increasingly recognized as critical innate immune effector cells that also bridge and facilitate optimization of adaptive immunity. It follows that clinical deficiencies in platelet quantity or quality are now recognized correlates of increased risk and severity of bacterial and other infections. Along these lines, new evidence suggests that certain prokaryotic organisms may be capable of exploiting platelet interactions to gain a virulence advantage. Indeed, certain bacterial pathogens appear to have evolved highly coordinated means by which to seize opportunities to bind to surfaces of activated platelets, and exploit them to establish or propagate infection. Hence, it is conceivable that certain bacterial pathogens subvert platelet functions. From these perspectives, the net consequences of bacterial virulence versus platelet host defenses likely decide initial steps towards the ultimate result of infection versus immunity.
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Affiliation(s)
- Michael R Yeaman
- Department of Medicine, David Geffen School of Medicine at UCLA, Harbor-UCLA Medical Center, 1124 West Carson Street, RB-2, Torrance, CA 90502, USA.
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77
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Are formyl peptide receptors novel targets for therapeutic intervention in ischaemia-reperfusion injury? Trends Pharmacol Sci 2010; 31:266-76. [PMID: 20483490 PMCID: PMC7112865 DOI: 10.1016/j.tips.2010.04.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 04/06/2010] [Accepted: 04/06/2010] [Indexed: 01/13/2023]
Abstract
Ischaemia–reperfusion (I/R) injury is a common feature of several diseases associated with high morbidity and mortality, such as stroke and myocardial infarction. The damaged tissue displays cardinal signs of inflammation and microvascular injury that, unless resolved, lead to long-term tissue damage with associated dysfunction. Current therapies are limited and are often associated with many side effects. Increasing evidence suggests that members of the formyl peptide receptor (FPR) family, in particular human FPR2/ALX, might have an important role in the pathophysiology of I/R injury. It was recently demonstrated that several peptides and non-peptidyl small-molecule compounds have anti-inflammatory and pro-resolving properties via their action on members of the FPR family. Here I review this evidence and suggest that FPR ligands, particularly in the brain, could be novel and exciting anti-inflammatory therapeutics for the treatment of a variety of clinical conditions, including stroke.
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78
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Abstract
Platelets interact with bacterial pathogens through a wide array of cellular and molecular mechanisms. The consequences of this interaction may significantly influence the balance between infection and immunity. On the one hand, recent data indicate that certain bacteria may be capable of exploiting these interactions to gain a virulence advantage. Indeed, certain bacterial pathogens appear to have evolved specific ways in which to subvert activated platelets. Hence, it is conceivable that some bacterial pathogens exploit platelet responses. On the other hand, platelets are now known to possess unambiguous structures and functions of host defense effector cells. Recent discoveries emphasize critical features enabling such functions, including expression of toll-like receptors that detect hallmark signals of bacterial infection, an array of microbicidal peptides, as well as other host defense molecules and functions. These concepts are consistent with increased risk and severity of bacterial infection as correlates of clinical abnormalities in platelet quantity and quality. In these respects, the molecular and cellular roles of platelets in host defense against bacterial pathogens are explored with attention on advances in platelet immunobiology.
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Affiliation(s)
- Michael R Yeaman
- Division of Infectious Diseases, St. John's Cardiovascular Research Center, Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Torrance, CA 90502, USA.
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79
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Moran N, Kenny D, O’Neill S, Harmon S, Culligan K, Kerrigan S, Meade G, Coleman L, Dunne E, Nolan E, Mckeon K, Foley O. Abstracts presented at the Ireland-UK Platelet Conference, 4–6 September, 2005, Dublin, Ireland. Platelets 2009. [DOI: 10.1080/09537100600982186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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80
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Monocyte activation by necrotic cells is promoted by mitochondrial proteins and formyl peptide receptors. Crit Care Med 2009; 37:2000-9. [PMID: 19384205 DOI: 10.1097/ccm.0b013e3181a001ae] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Necrotic cells evoke potent innate immune responses through unclear mechanisms. The mitochondrial fraction of the cell retains constituents of its bacterial ancestors, including N-formyl peptides, which are potentially immunogenic. Thus, we hypothesized that the mitochondrial fraction of the cell, particularly N-formyl peptides, contributes significantly to the activation of monocytes by necrotic cells. DESIGN Human peripheral blood monocytes were incubated with necrotic cell fractions and mitochondrial proteins to investigate their potential for immune cell activation. SETTING University Medical Center Research Laboratory. SUBJECTS Healthy human adults served as blood donors. MEASUREMENTS AND MAIN RESULTS Human blood monocyte activation was measured after treatment with cytosolic, nuclear and mitochondrial fractions of necrotic HepG2 cells or necrotic HepG2 cells depleted of N-formyl peptides [Rho(0) cells]. The specific role of the high affinity formyl peptide receptor (FPR) was then tested using specific pharmacologic inhibitors and RNA silencing. The capacity of mitochondrial N-formyl peptides to activate monocytes was confirmed using a synthetic peptide conforming to the N-terminus of mitochondrial nicotinamide adenine dinucleotide subunit 6. The results demonstrated that mitochondrial cell fractions most potently activated monocytes, and interleukin (IL)-8 was selectively released at low-protein concentrations. Mitochondria from Rho(0) cells induced minimal monocyte IL-8 release, and specific pharmacologic inhibitors and RNA-silencing confirmed that FPR contributes significantly to monocyte IL-8 responses to both necrotic cells and mitochondrial proteins. N-formyl peptides alone did not induce monocyte IL-8 release; whereas, the combination of mitochondrial N-formyl peptides and mitochondrial transcription factor A (TFAM) dramatically increased IL-8 release from monocytes. Likewise, high mobility group box 1, the nuclear homolog of TFAM, did not induce monocyte IL-8 release unless combined with mitochondrial N-formyl peptides. CONCLUSIONS Interactions between mitochondrial N-formyl peptides and FPR in the presence of other mitochondrial antigens (e.g., TFAM) contributes significantly to the activation of monocytes by necrotic cells.
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81
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Ye RD, Boulay F, Wang JM, Dahlgren C, Gerard C, Parmentier M, Serhan CN, Murphy PM. International Union of Basic and Clinical Pharmacology. LXXIII. Nomenclature for the formyl peptide receptor (FPR) family. Pharmacol Rev 2009; 61:119-61. [PMID: 19498085 DOI: 10.1124/pr.109.001578] [Citation(s) in RCA: 595] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Formyl peptide receptors (FPRs) are a small group of seven-transmembrane domain, G protein-coupled receptors that are expressed mainly by mammalian phagocytic leukocytes and are known to be important in host defense and inflammation. The three human FPRs (FPR1, FPR2/ALX, and FPR3) share significant sequence homology and are encoded by clustered genes. Collectively, these receptors bind an extraordinarily numerous and structurally diverse group of agonistic ligands, including N-formyl and nonformyl peptides of different composition, that chemoattract and activate phagocytes. N-formyl peptides, which are encoded in nature only by bacterial and mitochondrial genes and result from obligatory initiation of bacterial and mitochondrial protein synthesis with N-formylmethionine, is the only ligand class common to all three human receptors. Surprisingly, the endogenous anti-inflammatory peptide annexin 1 and its N-terminal fragments also bind human FPR1 and FPR2/ALX, and the anti-inflammatory eicosanoid lipoxin A4 is an agonist at FPR2/ALX. In comparison, fewer agonists have been identified for FPR3, the third member in this receptor family. Structural and functional studies of the FPRs have produced important information for understanding the general pharmacological principles governing all leukocyte chemoattractant receptors. This article aims to provide an overview of the discovery and pharmacological characterization of FPRs, to introduce an International Union of Basic and Clinical Pharmacology (IUPHAR)-recommended nomenclature, and to discuss unmet challenges, including the mechanisms used by these receptors to bind diverse ligands and mediate different biological functions.
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Affiliation(s)
- Richard D Ye
- Department of Pharmacology, University of Illinois College of Medicine, 835 South Wolcott Avenue, M/C 868, Chicago, Illinois 60612, USA.
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82
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Kirk AD, Morrell C, Baldwin WM. Platelets influence vascularized organ transplants from start to finish. Am J Transplant 2009; 9:14-22. [PMID: 19067663 PMCID: PMC2692406 DOI: 10.1111/j.1600-6143.2008.02473.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This review relates the basic functions of platelets to specific aspects of organ allograft rejection. Platelet activation can occur in the donor or recipient before transplantation as well as during antibody- and cell-mediated rejection. Biopsies taken during organ procurement from cadaver donors have documented that activated platelets are attached to vascular endothelial cells or leukocytes. In addition, many patients waiting for transplants have activated platelets due to the diseases that lead to organ failure or as a result of interventions used to support patients before and during transplantation. The contribution of platelets to hyperacute rejection of both allografts and xenografts is well recognized. Intravascular aggregates of platelets can also be prominent in experimental and clinical transplants that undergo acute antibody or cell-mediated rejection. In acute rejection, platelets can recruit mononuclear cells by secretion of chemokines. After contact, monocytes, macrophages and T cells interact with platelets through receptor/ligand pairs, including P-selectin/PSGL-1 and CD40/CD154. There is a potential for therapy to inhibit platelet mediated immune stimulation, but it is counterbalanced by the need to maintain coagulation in the perioperative period.
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Affiliation(s)
- A. D. Kirk
- Emory Transplant Center, Department of Surgery, Emory University, Atlanta, GA
| | - C.N. Morrell
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - W. M. Baldwin
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
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Pitchford SC, Momi S, Baglioni S, Casali L, Giannini S, Rossi R, Page CP, Gresele P. Allergen induces the migration of platelets to lung tissue in allergic asthma. Am J Respir Crit Care Med 2007; 177:604-12. [PMID: 18096710 DOI: 10.1164/rccm.200702-214oc] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RATIONALE Platelets are essential for pulmonary leukocyte recruitment, airway hyperresponsiveness, and bronchial remodeling in animals with allergic inflammation and can be found in bronchoalveolar lavage of sensitized animals. No studies, however, have explored the direct migration of platelets to lungs. OBJECTIVES To assess whether platelets migrate into lung parenchyma in response to inhaled allergen in ovalbumin-sensitized mice; to assess the role of the FcepsilonRI receptor in this phenomenon; and to evaluate whether platelets from patients with asthma, or from sensitized mice, undergo chemotaxis in vitro in response to relevant antigens. METHODS Ovalbumin-sensitized wild-type (WT) mice, or FcRgamma(-/-) mice lacking the FcepsilonRIgamma, were challenged with aerosolized allergen and lungs analyzed by platelet-specific immunohistochemistry. In some experiments, mice were depleted of platelets and cross-transfused with either WT or FcRgamma(-/-) platelets to assess the role of platelet FcRgamma(-/-). Chemotaxis of platelets from patients with asthma or from sensitized mice was studied in vitro. MEASUREMENTS AND MAIN RESULTS Histology of lungs revealed isolated platelets, migrating out of vessels and localizing underneath the airways after allergen challenge in WT but not in FcRgamma(-/-) mice. Platelets from patients with asthma and from sensitized WT mice, but not from sensitized FcRgamma(-/-) mice, migrated in vitro toward the relevant allergen or an anti-IgE. Platelets from normal mice were found to express FcepsilonRIgamma and platelet-bound IgEs were increased in sensitized mice. CONCLUSIONS Platelets migrate extravascularly in response to a sensitizing allergen via a mechanism dependent on the interaction among allergen, allergen-specific IgE, and the FcepsilonRI, and this may allow them to participate directly in allergic tissue inflammation.
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Affiliation(s)
- Simon C Pitchford
- Department of Internal Medicine, Section of Internal and Cardiovascular Medicine, University of Perugia, Via E. dal Pozzo, I-06126 Perugia, Italy
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Pitchford SC. Novel uses for anti-platelet agents as anti-inflammatory drugs. Br J Pharmacol 2007; 152:987-1002. [PMID: 17603547 PMCID: PMC2095110 DOI: 10.1038/sj.bjp.0707364] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 06/05/2007] [Accepted: 06/05/2007] [Indexed: 12/31/2022] Open
Abstract
An alteration in the character and function of platelets is manifested in patients with inflammatory diseases, and these alterations have been dissociated from the well-characterized involvement of platelets in thrombosis and haemostasis. Recent evidence reveals platelet activation is sometimes critical in the development of inflammation. The mechanisms by which platelets participate in inflammation are diverse, and offer numerous opportunities for future drug intervention. There is now acceptance that platelets act as innate inflammatory cells in immune responses, with roles as sentinel cells undergoing surveillance, responding to microbial invasion, orchestrating leukocyte recruitment, and migrating through tissue, causing damage and influencing repair processes in chronic disease. Some of these processes are targeted by drugs that are being developed to target platelet participation in atherosclerosis. The actions of platelets therefore influence the pathogenesis of diverse inflammatory diseases in various body compartments, encompassing parasitic and bacterial infection, allergic inflammation (especially asthma and rhinitis), and non-atopic inflammatory conditions, for example, chronic obstructive pulmonary disease (COPD), rheumatoid arthritis (RA), inflammatory bowel disease (IBD) and atherosclerosis. This review will first discuss the evidence for platelet activation in these various inflammatory diseases, and secondly discuss the mechanisms by which this pathogenesis occurs and the various anti-platelet agents which have been developed to combat platelet activation in atherosclerosis and their potential future use for the treatment of other inflammatory diseases.
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Affiliation(s)
- S C Pitchford
- Leukocyte Biology Section, National Heart and Lung Institute, Imperial College, London, UK.
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85
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Stenfeldt AL, Karlsson J, Wennerås C, Bylund J, Fu H, Dahlgren C. The non-steroidal anti-inflammatory drug piroxicam blocks ligand binding to the formyl peptide receptor but not the formyl peptide receptor like 1. Biochem Pharmacol 2007; 74:1050-6. [PMID: 17692291 DOI: 10.1016/j.bcp.2007.06.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 06/28/2007] [Accepted: 06/29/2007] [Indexed: 02/02/2023]
Abstract
The anti-inflammatory drug piroxicam has been reported to affect the production of reactive oxygen species in phagocytes. This anti-inflammatory effect is thought to be mediated through inhibition of cyclooxygenase (COX), an enzyme important for prostaglandin synthesis. We have compared the effects of piroxicam on superoxide production mediated by two closely related G-protein coupled receptors expressed on neutrophils, the formyl peptide receptor (FPR) and the formyl peptide receptor like 1 (FPRL1). Neutrophils were stimulated with agonists that bind specifically to FPR (the peptide ligand N-formyl-Met-Leu-Phe, fMLF) or FPRL1 (the peptide ligand Trp-Lys-Tyr-Met-Val-L-Met-NH(2), WKYMVM) or both of these receptors (the peptide ligand Trp-Lys-Tyr-Met-Val-D-Met-NH(2), WKYMVm). Piroxicam reduced the neutrophil superoxide production induced by the FPR agonist but had no significant effect on the FPRL1 induced response. Neutrophil intracellular calcium changes induced by the agonist WKYMVm (that triggers both FPR and FPRL1) were only inhibited by piroxicam when the drug was combined with the FPRL1 specific antagonist, Trp-Arg-Trp-Trp-Trp-Trp (WRW(4)), and this was true also for the inhibition of superoxide anion release. Receptor-binding analysis showed that the fluorescently labelled FPR specific ligand N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys (fNLFNYK), was competed for in a dose-dependent manner, by the FPR ligand fMLF and as well as by piroxicam. We show that piroxicam inhibits the neutrophil responses triggered through FPR, but not through FPRL1 and this inhibition is due to a reduced binding of the activating ligand to its cell surface receptor.
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Affiliation(s)
- A-L Stenfeldt
- Department of Rheumatology and Inflammation Research, Göteborg University, Göteborg, Sweden.
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86
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Chen JH, Yao XH, Gong W, Hu J, Zhou XD, Chen K, Liu H, Ping YF, Wang JM, Bian XW. A novel lipoxygenase inhibitor Nordy attenuates malignant human glioma cell responses to chemotactic and growth stimulating factors. J Neurooncol 2007; 84:223-31. [PMID: 17377739 DOI: 10.1007/s11060-007-9369-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Accepted: 03/01/2007] [Indexed: 11/25/2022]
Abstract
Nordy is a chiral compound synthesized based on the structure of a natural lipoxygenase (LO) inhibitor nordihydroguaiaretic acid (NDGA) from plants. The aim of the present study is to investigate the effect of Nordy on malignant human glioma cell responses to chemoattractants and growth promoting signals. We found that Nordy, in a non-cytotoxic concentration range, potently inhibited the chemotaxis and calcium flux of a human glioblastoma cell line U87 induced by a formylpeptide receptor (FPR) agonist, formyl-methionyl-leucyl-phenylalanine (fMLF) and epidermal growth factor (EGF). U87 cells treated by Nordy also showed a significantly impaired proliferation and expression of mRNA for vascular endothelial growth factor (VEGF) induced by fMLF. The chemotactic and proliferation responses of Nordy treated U87 cells to EGF were concomitantly diminished. Further experiments revealed that Nordy did not significantly affect FPR gene expression in U87 cells, but attenuated the activation of a plethora of signaling molecules including ERK1/2, p38, JNK, and Akt when the cells were stimulated by fMLF. EGF-induced EGF receptor phosphorylation was also inhibited in Nordy-treated U87 cells. Moreover, Nordy significantly reduced the tumorigenicity of U87 cells in nude mice. Our results suggest that Nordy is capable of inhibiting glioma cell responses to signals that promote cell motility, growth and production of VEGF. Thus, Nordy may constitute a molecular basis for the development of novel anti-cancer drugs.
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Affiliation(s)
- Jian-hong Chen
- Institute of Pathology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
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Pitchford SC, Page CP. Platelet activation in asthma: integral to the inflammatory response. Clin Exp Allergy 2006; 36:399-401. [PMID: 16630144 DOI: 10.1111/j.1365-2222.2006.02462.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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88
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Cognasse F, Garraud O. Human platelets exhibit infectious-pathogen-binding ligands and participate to inflammation (and more?). Exp Hematol 2005; 33:1081-2. [PMID: 16219529 DOI: 10.1016/j.exphem.2005.06.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 06/22/2005] [Accepted: 06/29/2005] [Indexed: 11/24/2022]
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89
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Bruno DA, Dhanireddy KK, Kirk AD. Challenges in therapeutic strategies for transplantation: Where now from here? Transpl Immunol 2005; 15:149-55. [PMID: 16412959 DOI: 10.1016/j.trim.2005.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Accepted: 07/12/2005] [Indexed: 10/25/2022]
Abstract
The current standard of care in transplantation reliably achieves acceptable graft and patient survival but still depends on life long immunosuppression in most patients. Current strategies employ medications that, in general, inhibit distal events mediating rejection, namely T cell activation and cytotoxicity. They do not typically interfere with initial allorecognition or the factors that influence the direction of an immune response (towards cytotoxicity as opposed to anergy or regulation). Given the exponential amplification of immune responses, these proximal targets may be more efficient in preventing rejection. Recent laboratory investigations have identified several approaches, e.g., costimulation blockade, depletion, and hematopoietic chimerism, that influence the initial stages of the alloimmune response, or establish self-perpetuating means of eliminating rejection without chronic immunosuppression. This manuscript reviews methods of immune manipulation that the authors view as promising for future exploitation and transfer to the clinic. These therapies are similar in that they are viewed as attempts to influence the ability of the body to mount an immune response and its subsequent direction, as opposed to supplying late effector phase inhibition. While it is recognized as unlikely that any one therapy will universally lead to tolerance, the authors propose that these concepts will make immunosuppressive drug minimization more readily successful.
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Affiliation(s)
- David A Bruno
- Transplantation Branch, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Building 10, Room 5-5750, Bethesda, MD 20892, USA
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