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Vuerich M, Nguyen DH, Ferrari D, Longhi MS. Adenosine-mediated immune responses in inflammatory bowel disease. Front Cell Dev Biol 2024; 12:1429736. [PMID: 39188525 PMCID: PMC11345147 DOI: 10.3389/fcell.2024.1429736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 07/16/2024] [Indexed: 08/28/2024] Open
Abstract
Extracellular ATP and its derivates mediate a signaling pathway that might be pharmacologically targeted to treat inflammatory conditions. Extracellular adenosine, the product of ATP hydrolysis by ectonucleotidase enzymes, plays a key role in halting inflammation while promoting immune tolerance. The rate-limiting ectoenzyme ENTPD1/CD39 and the ecto-5'-nucleotidase/CD73 are the prototype members of the ectonucleotidase family, being responsible for ATP degradation into immunosuppressive adenosine. The biological effects of adenosine are mediated via adenosine receptors, a family of G protein-coupled receptors largely expressed on immune cells where they modulate innate and adaptive immune responses. Inflammatory bowel disease (IBD) is a serious inflammatory condition of the gastrointestinal tract, associated with substantial morbidity and often refractory to currently available medications. IBD is linked to altered interactions between the gut microbiota and the immune system in genetically predisposed individuals. A wealth of studies conducted in patients and animal models highlighted the role of various adenosine receptors in the modulation of chronic inflammatory diseases like IBD. In this review, we will discuss the most recent findings on adenosine-mediated immune responses in different cell types, with a focus on IBD and its most common manifestations, Crohn's disease and ulcerative colitis.
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Affiliation(s)
- Marta Vuerich
- Biomedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Du Hanh Nguyen
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
- Department of Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Davide Ferrari
- Department of Life Science and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Maria Serena Longhi
- Department of Anesthesia, Critical Care & Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
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O'Brien BJ, Faraoni EY, Strickland LN, Ma Z, Mota V, Mota S, Chen X, Mills T, Eltzschig HK, DelGiorno KE, Bailey‐Lundberg JM. CD73-generated extracellular adenosine promotes resolution of neutrophil-mediated tissue injury and restrains metaplasia in pancreatitis. FASEB J 2023; 37:e22684. [PMID: 36468677 PMCID: PMC9753971 DOI: 10.1096/fj.202201537r] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/07/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022]
Abstract
Pancreatitis is currently the leading cause of gastrointestinal hospitalizations in the US. This condition occurs in response to abdominal injury, gallstones, chronic alcohol consumption or, less frequently, the cause remains idiopathic. CD73 is a cell surface ecto-5'-nucleotidase that generates extracellular adenosine, which can contribute to resolution of inflammation by binding adenosine receptors on infiltrating immune cells. We hypothesized genetic deletion of CD73 would result in more severe pancreatitis due to decreased generation of extracellular adenosine. CD73 knockout (CD73-/- ) and C57BL/6 (wild type, WT) mice were used to evaluate the progression and response of caerulein-induced acute and chronic pancreatitis. In response to caerulein-mediated chronic or acute pancreatitis, WT mice display resolution of pancreatitis at earlier timepoints than CD73-/- mice. Using immunohistochemistry and analysis of single-cell RNA-seq (scRNA-seq) data, we determined CD73 localization in chronic pancreatitis is primarily observed in mucin/ductal cell populations and immune cells. In murine pancreata challenged with caerulein to induce acute pancreatitis, we compared CD73-/- to WT mice and observed a significant infiltration of Ly6G+, MPO+, and Granzyme B+ cells in CD73-/- compared to WT pancreata and we quantified a significant increase in acinar-to-ductal metaplasia demonstrating sustained metaplasia and inflammation in CD73-/- mice. Using neutrophil depletion in CD73-/- mice, we show neutrophil depletion significantly reduces metaplasia defined by CK19+ cells per field and significantly reduces acute pancreatitis. These data identify CD73 enhancers as a potential therapeutic strategy for patients with acute and chronic pancreatitis as adenosine generation and activation of adenosine receptors is critical to resolve persistent inflammation in the pancreas.
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Affiliation(s)
- Baylee J. O'Brien
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Erika Y. Faraoni
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Lincoln N. Strickland
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Zhibo Ma
- Gene Expression LaboratoryThe Salk Institute for Biological SciencesSan DiegoCaliforniaUSA
| | - Victoria Mota
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Samantha Mota
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
- The Graduate School of Biomedical SciencesThe University of Texas MD Anderson Cancer Center and The University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Xuebo Chen
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Tingting Mills
- Department of Biochemistry, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Holger K. Eltzschig
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Kathleen E. DelGiorno
- Department of Cell and Developmental BiologyVanderbilt UniversityNashvilleTennesseeUSA
| | - Jennifer M. Bailey‐Lundberg
- Center for Perioperative Medicine, Department of Anesthesiology, McGovern Medical SchoolThe University of Texas Health Science Center at HoustonHoustonTexasUSA
- The Graduate School of Biomedical SciencesThe University of Texas MD Anderson Cancer Center and The University of Texas Health Science Center at HoustonHoustonTexasUSA
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3
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Michailidou D, Mustelin T, Lood C. Role of Neutrophils in Systemic Vasculitides. Front Immunol 2020; 11:619705. [PMID: 33391289 PMCID: PMC7774018 DOI: 10.3389/fimmu.2020.619705] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/18/2020] [Indexed: 12/20/2022] Open
Abstract
Neutrophils and neutrophil extracellular traps (NETs) contribute to the pathogenesis of many autoimmune diseases, including vasculitis. Though neutrophils, and NETs, can break self-tolerance by being a source of autoantigens for autoantibodies in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, playing a key role in driving the autoimmune response, the role of neutrophils and NETs in large vessel vasculitis, including giant cell arteritis (GCA), is not well understood. In this review, we summarize the current insight into molecular mechanisms contributing to neutrophil-mediated pathology in small and medium vessel vasculitis, as well as provide potential translational perspectives on how neutrophils, and NETs, may partake in large vessel vasculitis, a rare disease entity of unclear pathogenesis.
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Affiliation(s)
- Despina Michailidou
- Division of Rheumatology, University of Washington, Seattle, WA, United States
| | - Tomas Mustelin
- Division of Rheumatology, University of Washington, Seattle, WA, United States
| | - Christian Lood
- Division of Rheumatology, University of Washington, Seattle, WA, United States
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Carmona-Rivera C, Khaznadar SS, Shwin KW, Irizarry-Caro JA, O'Neil LJ, Liu Y, Jacobson KA, Ombrello AK, Stone DL, Tsai WL, Kastner DL, Aksentijevich I, Kaplan MJ, Grayson PC. Deficiency of adenosine deaminase 2 triggers adenosine-mediated NETosis and TNF production in patients with DADA2. Blood 2019; 134:395-406. [PMID: 31015188 PMCID: PMC6659253 DOI: 10.1182/blood.2018892752] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/08/2019] [Indexed: 12/30/2022] Open
Abstract
Reduction of adenosine deaminase 2 (ADA2) activity due to autosomal-recessive loss-of-function mutations in the ADA2 gene (previously known as CECR1) results in a systemic vasculitis known as deficiency of ADA2 (DADA2). Neutrophils and a subset of neutrophils known as low-density granulocytes (LDGs) have been implicated in the pathogenesis of vasculitis, at least in part, through the formation of neutrophil extracellular traps (NETs). The study objective was to determine whether neutrophils and NETs play a pathogenic role in DADA2. In vivo evidence demonstrated NETs and macrophages in affected gastrointestinal tissue from patients with DADA2. An abundance of circulating LDGs prone to spontaneous NET formation was observed during active disease in DADA2 and were significantly reduced after remission induction by anti-tumor necrosis factor (TNF) therapy. Increased circulating LDGs were identified in unaffected family members with monoallelic ADA2 mutations. Adenosine triggered NET formation, particularly in neutrophils from female patients, by engaging A1 and A3 adenosine receptors (ARs) and through reactive oxygen species- and peptidylarginine deiminase-dependent pathways. Adenosine-induced NET formation was inhibited by recombinant ADA2, A1/A3 AR antagonists, or by an A2A agonist. M1 macrophages incubated with NETs derived from patients with DADA2 released significantly greater amounts of TNF-α. Treatment with an A2AAR agonist decreased nuclear translocation of NF-κB and subsequent production of inflammatory cytokines in DADA2 monocyte-derived macrophages. These results suggest that neutrophils may play a pathogenic role in DADA2. Modulation of adenosine-mediated NET formation may contribute a novel and directed therapeutic approach in the treatment of DADA2 and potentially other inflammatory diseases.
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Affiliation(s)
- Carmelo Carmona-Rivera
- Systemic Autoimmunity Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| | - Sami S Khaznadar
- Molecular Recognition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Kyawt W Shwin
- Division of Rheumatic Diseases, Dallas VA Medical Center, UT Southwestern Medical Center, Dallas, TX
| | - Jorge A Irizarry-Caro
- Systemic Autoimmunity Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| | - Liam J O'Neil
- Systemic Autoimmunity Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| | - Yudong Liu
- Systemic Autoimmunity Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| | - Kenneth A Jacobson
- Molecular Recognition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Amanda K Ombrello
- Inflammatory Disease Section, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD; and
| | - Deborah L Stone
- Inflammatory Disease Section, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD; and
| | - Wanxia L Tsai
- Translational Immunology Section, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| | - Daniel L Kastner
- Inflammatory Disease Section, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD; and
| | - Ivona Aksentijevich
- Inflammatory Disease Section, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD; and
| | - Mariana J Kaplan
- Systemic Autoimmunity Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| | - Peter C Grayson
- Systemic Autoimmunity Branch, Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
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Barletta KE, Ley K, Mehrad B. Regulation of neutrophil function by adenosine. Arterioscler Thromb Vasc Biol 2012; 32:856-64. [PMID: 22423037 DOI: 10.1161/atvbaha.111.226845] [Citation(s) in RCA: 191] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Adenosine is an endogenously released purine nucleoside that signals via 4 widely expressed G protein-coupled receptors: A(1), A(2A), A(2B), and A(3). In the setting of inflammation, the generation and release of adenosine is greatly enhanced. Neutrophils play an important role in host defense against invading pathogens and are the cellular hallmark of acute inflammation. Neutrophils both release adenosine and can respond to it via expression of all 4 adenosine receptor subtypes. At low concentrations, adenosine can act via the A(1) and A(3) adenosine receptor subtypes to promote neutrophil chemotaxis and phagocytosis. At higher concentrations, adenosine acts at the lower-affinity A(2A) and A(2B) receptors to inhibit neutrophil trafficking and effector functions such as oxidative burst, inflammatory mediator production, and granule release. Modulation of neutrophil function by adenosine is relevant in a broad array of disease models, including ischemia reperfusion injury, sepsis, and noninfectious acute lung injury. This review will summarize relevant research in order to provide a framework for understanding how adenosine directly regulates various elements of neutrophil function.
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Affiliation(s)
- Kathryn E Barletta
- Department of Pharmacology, University of Virginia, Charlottesville, USA
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Bours MJL, Swennen ELR, Di Virgilio F, Cronstein BN, Dagnelie PC. Adenosine 5'-triphosphate and adenosine as endogenous signaling molecules in immunity and inflammation. Pharmacol Ther 2006; 112:358-404. [PMID: 16784779 DOI: 10.1016/j.pharmthera.2005.04.013] [Citation(s) in RCA: 775] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 04/20/2005] [Indexed: 02/07/2023]
Abstract
Human health is under constant threat of a wide variety of dangers, both self and nonself. The immune system is occupied with protecting the host against such dangers in order to preserve human health. For that purpose, the immune system is equipped with a diverse array of both cellular and non-cellular effectors that are in continuous communication with each other. The naturally occurring nucleotide adenosine 5'-triphosphate (ATP) and its metabolite adenosine (Ado) probably constitute an intrinsic part of this extensive immunological network through purinergic signaling by their cognate receptors, which are widely expressed throughout the body. This review provides a thorough overview of the effects of ATP and Ado on major immune cell types. The overwhelming evidence indicates that ATP and Ado are important endogenous signaling molecules in immunity and inflammation. Although the role of ATP and Ado during the course of inflammatory and immune responses in vivo appears to be extremely complex, we propose that their immunological role is both interdependent and multifaceted, meaning that the nature of their effects may shift from immunostimulatory to immunoregulatory or vice versa depending on extracellular concentrations as well as on expression patterns of purinergic receptors and ecto-enzymes. Purinergic signaling thus contributes to the fine-tuning of inflammatory and immune responses in such a way that the danger to the host is eliminated efficiently with minimal damage to healthy tissues.
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Affiliation(s)
- M J L Bours
- Maastricht University, Department of Epidemiology, Nutrition and Toxicology Research Institute Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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Weidler C, Holzer C, Harbuz M, Hofbauer R, Angele P, Schölmerich J, Straub RH. Low density of sympathetic nerve fibres and increased density of brain derived neurotrophic factor positive cells in RA synovium. Ann Rheum Dis 2005; 64:13-20. [PMID: 15608299 PMCID: PMC1755208 DOI: 10.1136/ard.2003.016154] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To investigate the correlation between density of nerve fibres and the presence of BDNF(+) cells. METHODS Densities of nerve fibres and BDNF(+) cells were detected by quantitative immunohistochemistry in fresh synovial tissue from 52 patients with RA, 59 with OA, and 26 controls (Co). BDNF was also detected by in situ hybridisation. RESULTS Sympathetic nerve fibre density was similar in Co and OA but markedly reduced in RA (p = 0.002), whereas density of substance P positive (SP(+)) sensory nerve fibres was lower in OA than in Co and RA (p = 0.002). The ratio of sympathetic/SP(+) sensory nerve fibre density was highest in OA and Co, followed by RA. The correlation between density of sympathetic nerve fibres and SP(+) sensory nerve fibres in OA (R = 0.425, p = 0.001) was strongly positive, had a positive trend in Co (R = 0.243, NS), but was negative in RA (R = -0.292, p = 0.040). In RA and OA tissue the density of BDNF(+) cells was high in sublining areas but markedly lower in Co (p = 0.001). BDNF(+) cell density correlated positively with the ratio of sympathetic/SP(+) sensory nerve fibre density in Co (R = 0.433, p = 0.045) and in OA (R = 0.613, p = 0.015), but not in RA (R = 0.101, NS). Immunohistochemical double staining demonstrated that some macrophages and fibroblasts were positive for BDNF. CONCLUSIONS The correlation of density of SP(+) sensory with sympathetic nerve fibres was positive in Co and OA but negative in RA. BDNF may have a stimulatory role on growth of sympathetic in relation to SP(+) sensory nerve fibres in Co and OA, but not in RA.
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Affiliation(s)
- C Weidler
- Department of Internal Medicine I, University Hospital, 93042 Regensburg, Germany
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Thiel M, Caldwell CC, Sitkovsky MV. The critical role of adenosine A2A receptors in downregulation of inflammation and immunity in the pathogenesis of infectious diseases. Microbes Infect 2003; 5:515-26. [PMID: 12758281 DOI: 10.1016/s1286-4579(03)00068-6] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Adenosine can be described as a retaliatory metabolite, the production and release of which is usually enhanced under adverse environmental conditions. Binding via specific receptors, adenosine activates endogenous protective mechanisms aiming at the restoration of tissue homeostasis. While adenosinergic downregulation of tissue damage is beneficial in acute inflammation, chronic suppression of the immune system by adenosine may account for immunoparalysis in long-term septic patients.
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Affiliation(s)
- Manfred Thiel
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 10/11N311, 10 Center Drive, Bethesda, MD 20892-1892, USA
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Abstract
Diabetes mellitus (DM) is associated with platelet and leukocyte dysfunction. Previous observations with regard to insulin effects on platelet and leukocyte function are less than consistent. We thus investigated the effects of insulin on platelets and leukocytes, as well as on platelet-leukocyte interactions in whole blood. Hirudinized whole blood from 20 healthy subjects was preincubated at 37 degrees C in the absence or presence of insulin (30 and 300 microU/ml), and further incubated without or with adenosine diphosphate (ADP) (10(-5) M) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) (10(-7) M), respectively. Platelet P-selectin expression, platelet fibrinogen binding, single platelet and platelet-platelet aggregate (PPA) counts, and leukocyte CD11b expression and superoxide anion production were monitored by flow cytometry. Insulin decreased single platelet counts (P<0.05) and increased PPAs (P<0.01) at 300 microU/ml in unstimulated samples, but did not significantly influence the P-selectin expression or fibrinogen binding of single platelets. Insulin also enhanced ADP-induced platelet aggregation, seen as an augmented decrease of single platelet counts. Insulin (30 microU/ml) increased leukocyte CD11b mean fluorescence intensity (MFI) in unstimulated, as well as fMLP- and ADP-stimulated samples (P<0.05 for all). fMLP-induced superoxide anion (O(2)(-)) production was, however, attenuated by insulin. Furthermore, fMLP-activation of leukocytes was associated with enhanced platelet fibrinogen binding and P-selectin expression. In conclusion, clinically relevant concentrations of insulin enhance platelet aggregability and leukocyte CD11b expression, but attenuate leukocyte respiratory burst activity. Our results suggest that insulin may modulate thrombotic and inflammatory processes in vivo in a complex manner.
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Affiliation(s)
- Hu Hu
- Department of Medicine, Karolinska Hospital, SE-171 76, Stockholm, Sweden.
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Adenosine receptor occupancy suppresses chemoattractant-induced phospholipase D activity by diminishing membrane recruitment of small GTPases. Blood 2000. [DOI: 10.1182/blood.v95.2.519] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adenosine (Ado) is an important autocrine modulator of neutrophil functions. In this study, we determined the effects of endogenous Ado on fMet-Leu-Phe (fMLP)–induced phospholipase D (PLD) activity in neutrophils. The removal of extracellular Ado by Ado deaminase (ADA) or the blockade of its action by the A2a receptor antagonists 8-(3-chlorostyryl) caffeine (CSC) or CGS15943 markedly increased fMLP-induced PLD activation. The concentration-dependent stimulatory effects of CSC and CGS15943 were abolished by a pretreatment of neutrophil suspensionswith ADA. In contrast, the selective A2a receptor agonist CGS21680 suppressed fMLP-induced PLD activation. Furthermore, inhibition by CGS21680 of fMLP-induced PLD activity was reversed by CSC or CGS15943. The removal of Ado by ADA or the blockade of its action by CSC or CGS15943, markedly increased the membrane recruitment of cytosolic protein kinase C (PKC), RhoA, and ADP-ribosylation factor (ARF) in response to fMLP. As shown for PLD activity, the stimulatory effect of Ado receptor antagonists on PLD cofactors translocation was abolished by a pretreatment of the cells with ADA. Moreover, the membrane translocation of both PKC, RhoA, and ARF in response to fMLP was attenuated by CGS21680 and this effect of the A2a receptor agonist was antagonized by CSC or CGS15943. These data demonstrate that Ado released by neutrophils in the extracellular milieu inhibits PLD activation by blocking membrane association of ARF, RhoA, and PKC through Ado A2a receptor occupancy.
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11
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Zalavary S, Bengtsson T. Modulation of the chemotactic peptide- and immunoglobulin G-triggered respiratory burst in human neutrophils by exogenous and endogenous adenosine. Eur J Pharmacol 1998; 354:215-25. [PMID: 9754923 DOI: 10.1016/s0014-2999(98)00461-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The effects of exogenous and endogenous adenosine on the production of oxygen metabolites in neutrophils triggered by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) or immunoglobulin G (IgG)-opsonized yeast particles, were investigated. By using luminol-enhanced chemiluminescence, we found that adenosine A1 receptor activation did not affect, whereas adenosine A receptor activation, through a mechanism involving the cyclic AMP (cAMP)-protein kinase A signalling pathway, both inhibited the fMLP- and IgG-triggered respiratory burst. The adenosine-induced inhibition was however more pronounced after exposure to fMLP than to IgG-yeast. Stimulation with fMLP caused an extracellular accumulation of endogenous adenosine, which indicates that this event is a negative-feedback mechanism preventing an uncontrolled activation of chemoattractant-stimulated neutrophils. On the contrary, exposure of neutrophils to IgG-yeast did not appear to accumulate extracellular adenosine, probably due to increased adenosine deaminase activity during phagocytosis. In conclusion, this work accentuates the importance of adenosine, both exogenously applied and endogenously formed, as an inflammatory agent modulating the respiratory burst during the different phases in neutrophil activation.
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Affiliation(s)
- S Zalavary
- Department of Health and Environment, Faculty of Health Sciences, Linköping University, Sweden.
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12
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Abstract
Extracellular adenosine has pharmacological activity on a wide variety of cell types and may play an important role as an inflammatory modulator with both pro- and anti-inflammatory activities. These studies examine the effects of adenosine on guinea pig pulmonary eosinophils. Adenosine alone did not directly induce superoxide (O2-) production. Pretreatment with adenosine primed the O2- response of guinea pig pulmonary eosinophils following the addition of 1 or 10 microM platelet-activating factor (PAF). Priming was seen at adenosine concentrations greater than 1 microM and was maximal at 100 microM. At this maximal dose, adenosine priming increased the O2- response to 1 microM and 10 microM PAF by 86% and 51%, respectively. Priming by adenosine was not seen when ionomycin or phorbol myristate acid (PMA) were used as agonists. In fura-2 loaded eosinophils, the addition of 100 microM adenosine resulted in a small but significant rise in intracellular calcium of 54.4 +/- 9.2 nM above baseline. In contrast, similar adenosine concentrations had no effect on cytosolic calcium levels in guinea pig neutrophils. These data demonstrate a pro-inflammatory role for adenosine in elicited guinea pig pulmonary eosinophils.
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Affiliation(s)
- B A Walker
- U.B.C. Pulmonary Research Laboratory, University of British Columbia, Vancouver British Columbia, Canada
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13
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Whelan CJ. Is granulocyte or endothelial cell activation responsible for the initiation of granulocyte recruitment during acute inflammation? AGENTS AND ACTIONS 1992; 37:319-24. [PMID: 1295380 DOI: 10.1007/bf02028126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- C J Whelan
- Department of Peripheral Pharmacology, Glaxo Group Research Ltd., Ware, Herts, UK
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14
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Affiliation(s)
- B N Cronstein
- Department of Medicine, NYU Medical Center, New York 10016
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15
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Calcium changes in immune complex-stimulated human neutrophils. Simultaneous measurement of receptor occupancy and activation reveals full population stimulus binding but subpopulation activation. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98799-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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