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Gao ZG, Haddad M, Jacobson KA. A 2B adenosine receptor signaling and regulation. Purinergic Signal 2024:10.1007/s11302-024-10025-y. [PMID: 38833181 DOI: 10.1007/s11302-024-10025-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 05/20/2024] [Indexed: 06/06/2024] Open
Abstract
The A2B adenosine receptor (A2BR) is one of the four adenosine-activated G protein-coupled receptors. In addition to adenosine, protein kinase C (PKC) was recently found to activate the A2BR. The A2BR is coupled to both Gs and Gi, as well as Gq proteins in some cell types. Many primary cells and cell lines, such as bladder and breast cancer, bronchial smooth muscle, skeletal muscle, and fat cells, express the A2BR endogenously at high levels, suggesting its potentially important role in asthma, cancer, diabetes, and other conditions. The A2BR has been characterized as both pro- and anti-inflammatory, inducing cell type-dependent secretion of IL-6, IL-8, and IL-10. Theophylline and enprofylline have long been used for asthma treatment, although it is still not entirely clear if their A2BR antagonism contributes to their therapeutic effects or side effects. The A2BR is required in ischemic cardiac preconditioning by adenosine. Both A2BR and protein kinase C (PKC) contribute to cardioprotection, and both modes of A2BR signaling can be blocked by A2BR antagonists. Inhibitors of PKC and A2BR are in clinical cancer trials. Sulforaphane and other isothiocyanates from cruciferous vegetables such as broccoli and cauliflower have been reported to inhibit A2BR signaling via reaction with an intracellular A2BR cysteine residue (C210). A full, A2BR-selective agonist, critical to elucidate many controversial roles of the A2BR, is still not available, although agonist-bound A2BR structures have recently been reported.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
| | - Mansour Haddad
- Faculty of Pharmacy, Yarmouk University, Irbid, 21163, Jordan
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
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A2B Adenosine Receptor in Idiopathic Pulmonary Fibrosis: Pursuing Proper Pit Stop to Interfere with Disease Progression. Int J Mol Sci 2023; 24:ijms24054428. [PMID: 36901855 PMCID: PMC10002355 DOI: 10.3390/ijms24054428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/19/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
Purine nucleotides and nucleosides are involved in various human physiological and pathological mechanisms. The pathological deregulation of purinergic signaling contributes to various chronic respiratory diseases. Among the adenosine receptors, A2B has the lowest affinity such that it was long considered to have little pathophysiological significance. Many studies suggest that A2BAR plays protective roles during the early stage of acute inflammation. However, increased adenosine levels during chronic epithelial injury and inflammation might activate A2BAR, resulting in cellular effects relevant to the progression of pulmonary fibrosis.
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Francucci B, Dal Ben D, Lambertucci C, Spinaci A, Volpini R, Marucci G, Buccioni M. A patent review of adenosine A 2B receptor antagonists (2016-present). Expert Opin Ther Pat 2022; 32:689-712. [PMID: 35387537 DOI: 10.1080/13543776.2022.2057222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION A2B adenosine receptor (A2BAR) plays a crucial role in pathophysiologic conditions associated with high adenosine release, typical of airway inflammatory pathologies, gastrointestinal disorders, cancer, asthma, type 2 diabetes, and atherosclerosis. In some pathologies, simultaneous inactivation of A2A and A2BARs is desirable to have a synergism of action that leads to a greater efficacy of the pharmacological treatment and less side effects due to the dose of drug administered. In this context, it is strongly required to identify molecules capable of selectively antagonizing A2BAR or A2A/A2BARs. AREAS COVERED The review provides a summary of patents, published from 2016 to present, on chemicals and their clinical use. In this paper, information on the biological activity of representative structures of recently developed A2B or A2A/A2B receptor ligands is reported. EXPERT OPINION Among the four P1 receptors, A2BAR is the most inscrutable and the least studied until a few years ago, but its involvement in various inflammatory pathologies has recently made it a pharmacological target of high interest. Many efforts by the academy and pharmaceutical companies have been made to discover potential A2BAR and A2A/A2BARs drugs. Although several compounds have been synthesized only a few molecules have entered clinical trials.
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Affiliation(s)
- Beatrice Francucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Catia Lambertucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Andrea Spinaci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Rosaria Volpini
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Gabriella Marucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Michela Buccioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
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Kanduc D. From Anti-SARS-CoV-2 Immune Response to the Cytokine Storm via Molecular Mimicry. Antibodies (Basel) 2021; 10:36. [PMID: 34698069 PMCID: PMC8544210 DOI: 10.3390/antib10040036] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/20/2021] [Accepted: 09/08/2021] [Indexed: 02/07/2023] Open
Abstract
The aim of this study was to investigate the role of molecular mimicry in the cytokine storms associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human proteins endowed with anti-inflammatory activity were assembled and analyzed for peptide sharing with the SARS-CoV-2 spike glycoprotein (gp) using public databases. It was found that the SARS-CoV-2 spike gp shares numerous pentapeptides with anti-inflammatory proteins that, when altered, can lead to cytokine storms characterized by diverse disorders such as systemic multiorgan hyperinflammation, macrophage activation syndrome, ferritinemia, endothelial dysfunction, and acute respiratory syndrome. Immunologically, many shared peptides are part of experimentally validated epitopes and are also present in pathogens to which individuals may have been exposed following infections or vaccinal routes and of which the immune system has stored memory. Such an immunologic imprint might trigger powerful anamnestic secondary cross-reactive responses, thus explaining the raging of the cytokine storm that can occur following exposure to SARS-CoV-2. In conclusion, the results support molecular mimicry and the consequent cross-reactivity as a potential mechanism in SARS-CoV-2-induced cytokine storms, and highlight the role of immunological imprinting in determining high-affinity, high-avidity, autoimmune cross-reactions as a pathogenic sequela associated with anti-SARS-CoV-2 vaccines.
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Affiliation(s)
- Darja Kanduc
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 70125 Bari, Italy
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Wang W, Chen NY, Ren D, Davies J, Philip K, Eltzschig HK, Blackburn MR, Akkanti B, Karmouty-Quintana H, Weng T. Enhancing Extracellular Adenosine Levels Restores Barrier Function in Acute Lung Injury Through Expression of Focal Adhesion Proteins. Front Mol Biosci 2021; 8:636678. [PMID: 33778007 PMCID: PMC7987656 DOI: 10.3389/fmolb.2021.636678] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/01/2021] [Indexed: 12/23/2022] Open
Abstract
Background: Acute respiratory distress syndrome (ARDS) is a clinical presentation of acute lung injury (ALI) with often fatal lung complication. Adenosine, a nucleoside generated following cellular stress provides protective effects in acute injury. The levels of extracellular adenosine can be depleted by equilibrative nucleoside transporters (ENTs). ENT inhibition by pharmaceutical agent dipyridamole promotes extracellular adenosine accumulation and is protective in ARDS. However, the therapeutic potential of dipyridamole in acute lung injury has not yet been evaluated. Methods: Adenosine acts on three adenosine receptors, the adenosine A1 (Adora1), A2a (Adora2a), the A2b (Adora2b) or the adenosine A3 (Adora 3) receptor. Accumulation of adenosine is usually required to stimulate the low-affinity Adora2b receptor. In order to investigate the effect of adenosine accumulation and the contribution of epithelial-specific ENT2 or adora2b expression in experimental ALI, dipyridamole, and epithelial specific ENT2 or Adora2b deficient mice were utilized. MLE12 cells were used to probe downstream Adora2b signaling. Adenosine receptors, transporters, and targets were determined in ARDS lungs. Results: ENT2 is mainly expressed in alveolar epithelial cells and is negatively regulated by hypoxia following tissue injury. Enhancing adenosine levels with ENT1/ENT2 inhibitor dipyridamole at a time when bleomycin-induced ALI was present, reduced further injury. Mice pretreated with the ADORA2B agonist BAY 60-6583 were protected from bleomycin-induced ALI by reducing vascular leakage (558.6 ± 50.4 vs. 379.9 ± 70.4, p < 0.05), total bronchoalveolar lavage fluid cell numbers (17.9 ± 1.8 to 13.4 ± 1.4 e4, p < 0.05), and neutrophil infiltration (6.42 ± 0.25 vs. 3.94 ± 0.29, p < 0.05). While mice lacking Adora2b in AECs were no longer protected by dipyridamole. We also identified occludin and focal adhesion kinase as downstream targets of ADORA2B, thus providing a novel mechanism for adenosine-mediated barrier protection. Similarly, we also observed similar enhanced ADORA2B (3.33 ± 0.67 to 16.12 ± 5.89, p < 0.05) and decreased occludin (81.2 ± 0.3 to 13.3 ± 0.4, p < 0.05) levels in human Acute respiratory distress syndrome lungs. Conclusion: We have highlighted a role of dipyridamole and adenosine signaling in preventing or treating ALI and identified Ent2 and Adora2b as key mediators in important for the resolution of ALI.
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Affiliation(s)
- Wei Wang
- Department of Thoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ning-yuan Chen
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Dewei Ren
- Houston Methodist J.C. Walter Jr. Transplant Center, Houston Methodist Hospital, Houston, TX, United States
| | - Jonathan Davies
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States
| | - Kemly Philip
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Holger K. Eltzschig
- Department of Anesthesiology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Michael R. Blackburn
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
- UTHealth Pulmonary Center of Excellence, Houston, TX, United States
| | - Bindu Akkanti
- Divisions of Critical Care, Pulmonary and Sleep Medicine, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Harry Karmouty-Quintana
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
- UTHealth Pulmonary Center of Excellence, Houston, TX, United States
- Divisions of Critical Care, Pulmonary and Sleep Medicine, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Tingting Weng
- Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
- UTHealth Pulmonary Center of Excellence, Houston, TX, United States
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Wang M, Guo X, Zhao H, Lv J, Wang H, An Y. Adenosine A 2B receptor activation stimulates alveolar fluid clearance through alveolar epithelial sodium channel via cAMP pathway in endotoxin-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2020; 318:L787-L800. [PMID: 32129084 DOI: 10.1152/ajplung.00195.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Clinical studies have established that the capacity of removing excess fluid from alveoli is impaired in most patients with acute respiratory distress syndrome. Impaired alveolar fluid clearance (AFC) correlates with poor outcomes. Adenosine A2B receptor (A2BAR) has the lowest affinity with adenosine among four adenosine receptors. It is documented that A2BAR can activate adenylyl cyclase (AC) resulting in elevated cAMP. Based on the understanding that cAMP is a key regulator of epithelial sodium channel (ENaC), which is the limited step in sodium transport, we hypothesized that A2BAR signaling may affect AFC in acute lung injury (ALI) through regulating ENaC via cAMP, thus attenuating pulmonary edema. To address this, we utilized pharmacological approaches to determine the role of A2BAR in AFC in rats with endotoxin-induced lung injury and further focused on the mechanisms in vitro. We observed elevated pulmonary A2BAR level in rats with ALI and the similar upregulation in alveolar epithelial cells exposed to LPS. A2BAR stimulation significantly attenuated pulmonary edema during ALI, an effect that was associated with enhanced AFC and increased ENaC expression. The regulatory effects of A2BAR on ENaC-α expression were further verified in cultured alveolar epithelial type II (ATII) cells. More importantly, activation of A2BAR dramatically increased amiloride-sensitive Na+ currents in ATII cells. Moreover, we observed that A2BAR activation stimulated cAMP accumulation, whereas the cAMP inhibitor abolished the regulatory effect of A2BAR on ENaC-α expression, suggesting that A2BAR activation regulates ENaC-α expression via cAMP-dependent mechanism. Together, these findings suggest that signaling through alveolar epithelial A2BAR promotes alveolar fluid balance during endotoxin-induced ALI by regulating ENaC via cAMP pathway, raising the hopes for treatment of pulmonary edema due to ALI.
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Affiliation(s)
- Mengnan Wang
- Department of Critical Care Medicine, Peking University People's Hospital, Beijing, China
| | - Xiaoxia Guo
- Department of Critical Care Medicine, Peking University People's Hospital, Beijing, China
| | - Huiying Zhao
- Department of Critical Care Medicine, Peking University People's Hospital, Beijing, China
| | - Jie Lv
- Department of Critical Care Medicine, Peking University People's Hospital, Beijing, China
| | - Huixia Wang
- Department of Critical Care Medicine, Peking University People's Hospital, Beijing, China
| | - Youzhong An
- Department of Critical Care Medicine, Peking University People's Hospital, Beijing, China
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Abstract
Membrane receptors that are activated by the purine nucleoside adenosine (adenosine receptors) or by purine or pyrimidine nucleotides (P2Y and P2X receptors) transduce extracellular signals to the cytosol. They play important roles in physiology and disease. The G protein-coupled adenosine receptors comprise four subtypes: A1, A2A, A2B, and A3. The G-protein-coupled P2Y receptors are subdivided into eight subtypes: P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and P2Y14, while the P2X receptors represent ATP-gated homomeric or heteromeric ion channels consisting of three subunits; the most important subunits are P2X1, P2X2, P2X3, P2X4, and P2X7. This chapter provides guidance for selecting suitable tool compounds for studying these large and important purine receptor families.
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Affiliation(s)
- Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, Bonn, Germany.
| | - Younis Baqi
- Department of Chemistry, Sultan Qaboos University, Muscat, Oman
| | - Vigneshwaran Namasivayam
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, Bonn, Germany
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Xu X, Zhu Q, Niu F, Zhang R, Wang Y, Wang W, Sun D, Wang X, Wang A. A2BAR activation attenuates acute lung injury by inhibiting alveolar epithelial cell apoptosis both in vivo and in vitro. Am J Physiol Cell Physiol 2018; 315:C558-C570. [PMID: 29898376 DOI: 10.1152/ajpcell.00294.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The epithelial barrier of the lung is destroyed during acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) due to the apoptosis of alveolar epithelial cells (AECs). Therefore, treatments that block AEC apoptosis might be a therapeutic strategy to ameliorate ALI. Based on recent evidence, A2B adenosine receptor (A2BAR) plays an important role in ALI in several different animal models, but its exact function in AECs has not been clarified. We investigated the role of A2BAR in AEC apoptosis in a mouse model of oleic acid (OA)-induced ALI and in hydrogen peroxide (H2O2)-induced AEC (A549 cells and MLE-12 cells) injury. Mice treated with BAY60-6583, a selective A2BAR agonist, showed lower AEC apoptosis rates than mice treated with OA. However, the role of BAY60-6583 in OA-induced ALI was attenuated by a specific blocker of A2BAR, PSB1115. A2BAR activation decreased H2O2-induced cell apoptosis in vitro, as characterized by the translocation of apoptotic proteins, the release of cytochrome c, and the activation of caspase-3 and poly (ADP ribose) polymerase 1 (PARP-1). In addition, apoptosis was required for the phosphorylation of ERK1/2, p38, and JNK. Importantly, compared with cells transfected with the A2BAR-siRNA, an ERK inhibitor or p38 inhibitor exhibited decreased apoptotic ratios and cleaved caspase-9 and cleaved PARP-1 levels, whereas the JNK inhibitor displayed increases in these parameters. In conclusion, A2BAR activation effectively attenuated OA-induced ALI by inhibiting AEC apoptosis and mitigated H2O2-induced AEC injury by suppressing the p38 and ERK1/2-mediated mitochondrial apoptosis pathway.
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Affiliation(s)
- Xiaotao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Qingwei Zhu
- Department of Neurosurgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Fangfang Niu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Rong Zhang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Yan Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Wenying Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Dawei Sun
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Xintao Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Aizhong Wang
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
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Charles EJ, Mehaffey JH, Sharma AK, Zhao Y, Stoler MH, Isbell JM, Lau CL, Tribble CG, Laubach VE, Kron IL. Lungs donated after circulatory death and prolonged warm ischemia are transplanted successfully after enhanced ex vivo lung perfusion using adenosine A2B receptor antagonism. J Thorac Cardiovasc Surg 2017; 154:1811-1820. [PMID: 28483262 DOI: 10.1016/j.jtcvs.2017.02.072] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 12/05/2016] [Accepted: 02/10/2017] [Indexed: 01/10/2023]
Abstract
OBJECTIVE The current supply of acceptable donor lungs is not sufficient for the number of patients awaiting transplantation. We hypothesized that ex vivo lung perfusion (EVLP) with targeted drug therapy would allow successful rehabilitation and transplantation of donation after circulatory death lungs exposed to 2 hours of warm ischemia. METHODS Donor porcine lungs were procured after 2 hours of warm ischemia postcardiac arrest and subjected to 4 hours of cold preservation or EVLP. ATL802, an adenosine A2B receptor antagonist, was administered to select groups. Four groups (n = 4/group) were randomized: cold preservation (Cold), cold preservation with ATL802 during reperfusion (Cold + ATL802), EVLP (EVLP), and EVLP with ATL802 during ex vivo perfusion (EVLP + ATL802). Lungs subsequently were transplanted, reperfused, and assessed by measuring dynamic lung compliance and oxygenation capacity. RESULTS EVLP + ATL802 significantly improved dynamic lung compliance compared with EVLP (25.0 ± 1.8 vs 17.0 ± 2.4 mL/cmH2O, P = .04), and compared with cold preservation (Cold: 12.2 ± 1.3, P = .004; Cold + ATL802: 10.6 ± 2.0 mL/cmH2O, P = .002). Oxygenation capacity was highest in EVLP (440.4 ± 37.0 vs Cold: 174.0 ± 61.3 mm Hg, P = .037). No differences in oxygenation or pulmonary edema were observed between EVLP and EVLP + ATL802. A significant decrease in interleukin-12 expression in tissue and bronchoalveolar lavage was identified between groups EVLP and EVLP + ATL802, along with less neutrophil infiltration. CONCLUSIONS Severely injured donation after circulatory death lungs subjected to 2 hours of warm ischemia are transplanted successfully after enhanced EVLP with targeted drug therapy. Increased use of lungs after uncontrolled donor cardiac death and prolonged warm ischemia may be possible and may improve transplant wait list times and mortality.
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Affiliation(s)
- Eric J Charles
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - J Hunter Mehaffey
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Ashish K Sharma
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Yunge Zhao
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Mark H Stoler
- Department of Pathology, University of Virginia Health System, Charlottesville, Va
| | - James M Isbell
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Christine L Lau
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Curtis G Tribble
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Victor E Laubach
- Department of Surgery, University of Virginia Health System, Charlottesville, Va
| | - Irving L Kron
- Department of Surgery, University of Virginia Health System, Charlottesville, Va.
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Densmore JC, Schaid TR, Jeziorczak PM, Medhora M, Audi S, Nayak S, Auchampach J, Dwinell MR, Geurts AM, Jacobs ER. Lung injury pathways: Adenosine receptor 2B signaling limits development of ischemic bronchiolitis obliterans organizing pneumonia. Exp Lung Res 2017; 43:38-48. [PMID: 28266889 PMCID: PMC5831175 DOI: 10.1080/01902148.2017.1286697] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Purpose/Aim of the Study: Adenosine signaling was studied in bronchiolitis obliterans organizing pneumonia (BOOP) resulting from unilateral lung ischemia. MATERIALS AND METHODS Ischemia was achieved by either left main pulmonary artery or complete hilar ligation. Sprague-Dawley (SD) rats, Dahl salt sensitive (SS) rats and SS mutant rat strains containing a mutation in the A2B adenosine receptor gene (Adora2b) were studied. Adenosine concentrations were measured in bronchoalveolar lavage (BAL) by HPLC. A2A (A2AAR) and A2B adenosine receptor (A2BAR) mRNA and protein were quantified. RESULTS Twenty-four hours after unilateral PA ligation, BAL adenosine concentrations from ischemic lungs were increased relative to contralateral lungs in SD rats. A2BAR mRNA and protein concentrations were increased after PA ligation while miR27a, a negatively regulating microRNA, was decreased in ischemic lungs. A2AAR mRNA and protein concentrations remained unchanged following ischemia. A2BAR protein was increased in PA ligated lungs of SS rats after 7 days, and 4 h after complete hilar ligation in SD rats. SS-Adora2b mutants showed a greater extent of BOOP relative to SS rats, and greater inflammatory changes. CONCLUSION Increased A2BAR and adenosine following unilateral lung ischemia as well as more BOOP in A2BAR mutant rats implicate a protective role for A2BAR signaling in countering ischemic lung injury.
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Affiliation(s)
- John C. Densmore
- Children’s Research Institute, Milwaukee, WI
- Clinical and Translational Science Institute, Milwaukee, WI
- Medical College of Wisconsin, Milwaukee, WI
| | | | - Paul M. Jeziorczak
- Children’s Research Institute, Milwaukee, WI
- Medical College of Wisconsin, Milwaukee, WI
| | | | | | | | | | | | | | - Elizabeth R. Jacobs
- Clinical and Translational Science Institute, Milwaukee, WI
- Medical College of Wisconsin, Milwaukee, WI
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
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11
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Sun Y, Huang P. Adenosine A2B Receptor: From Cell Biology to Human Diseases. Front Chem 2016; 4:37. [PMID: 27606311 PMCID: PMC4995213 DOI: 10.3389/fchem.2016.00037] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/11/2016] [Indexed: 12/26/2022] Open
Abstract
Extracellular adenosine is a ubiquitous signaling molecule that modulates a wide array of biological processes. Recently, significant advances have been made in our understanding of A2B adenosine receptor (A2BAR). In this review, we first summarize some of the general characteristics of A2BAR, and then we describe the multiple binding partners of the receptor, such as newly identified α-actinin-1 and p105, and discuss how these associated proteins could modulate A2BAR's functions, including certain seemingly paradoxical functions of the receptor. Growing evidence indicates a critical role of A2BAR in cancer, renal disease, and diabetes, in addition to its importance in the regulation of vascular diseases, and lung disease. Here, we also discuss the role of A2BAR in cancer, renal disease, and diabetes and the potential of the receptor as a target for treating these three diseases.
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Affiliation(s)
- Ying Sun
- Department of Biology, South University of Science and Technology of ChinaShenzhen, China; Shenzhen Key Laboratory of Cell Microenvironment, South University of Science and Technology of ChinaShenzhen, China
| | - Pingbo Huang
- Division of Life Science, Hong Kong University of Science and TechnologyHong Kong, China; Division of Biomedical Engineering, Hong Kong University of Science and TechnologyHong Kong, China; State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and TechnologyHong Kong, China
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12
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Huerter ME, Sharma AK, Zhao Y, Charles EJ, Kron IL, Laubach VE. Attenuation of Pulmonary Ischemia-Reperfusion Injury by Adenosine A2B Receptor Antagonism. Ann Thorac Surg 2016; 102:385-393. [PMID: 27109193 DOI: 10.1016/j.athoracsur.2016.02.060] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/16/2016] [Accepted: 02/16/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND Ischemia-reperfusion injury (IRI) is a major source of morbidity and mortality after lung transplantation. We previously demonstrated a proinflammatory role of adenosine A2B receptor (A2BR) in lung IR injury. The current study tests the hypothesis that A2BR antagonism is protective of ischemic lungs after in vivo reperfusion or ex vivo lung perfusion (EVLP). METHODS Mice underwent lung IR with or without administration of ATL802, a selective A2BR antagonist. A murine model of EVLP was also used to evaluate rehabilitation of donation after circulatory death (DCD) lungs. DCD lungs underwent ischemia, cold preservation, and EVLP with Steen solution with or without ATL802. A549 human type 2 alveolar epithelial cells were exposed to hypoxia-reoxygenation (HR) (3 hours/1 hour) with or without ATL802 treatment. Cytokines were measured in bronchoalveolar lavage (BAL) fluid and culture media by enzyme-linked immunoassay (ELISA). RESULTS After IR, ATL802 treatment significantly improved lung function (increased pulmonary compliance and reduced airway resistance and pulmonary artery pressure) and significantly attenuated proinflammatory cytokine production, neutrophil infiltration, vascular permeability, and edema. ATL802 also significantly improved the function of DCD lungs after EVLP (increased compliance and reduced pulmonary artery pressure). After HR, A549 cells exhibited robust production of interleukin (IL)-8, a potent neutrophil chemokine, which was significantly attenuated by ATL802. CONCLUSIONS These results demonstrate that A2BR antagonism attenuates lung IRI and augments reconditioning of DCD lungs by EVLP. The protective effects of ATL802 may involve targeting A2BRs on alveolar epithelial cells to prevent IL-8 production. A2BR may be a novel therapeutic target for mitigating IRI to increase the success of lung transplantation.
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Affiliation(s)
- Mary E Huerter
- Department of Surgery, University of Virginia, Charlottesville, VA
| | - Ashish K Sharma
- Department of Surgery, University of Virginia, Charlottesville, VA
| | - Yunge Zhao
- Department of Surgery, University of Virginia, Charlottesville, VA
| | - Eric J Charles
- Department of Surgery, University of Virginia, Charlottesville, VA
| | - Irving L Kron
- Department of Surgery, University of Virginia, Charlottesville, VA
| | - Victor E Laubach
- Department of Surgery, University of Virginia, Charlottesville, VA
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13
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Hoegl S, Brodsky KS, Blackburn MR, Karmouty-Quintana H, Zwissler B, Eltzschig HK. Alveolar Epithelial A2B Adenosine Receptors in Pulmonary Protection during Acute Lung Injury. THE JOURNAL OF IMMUNOLOGY 2015; 195:1815-24. [PMID: 26188061 DOI: 10.4049/jimmunol.1401957] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 06/17/2015] [Indexed: 12/31/2022]
Abstract
Acute lung injury (ALI) is an acute inflammatory lung disease that causes morbidity and mortality in critically ill patients. However, there are many instances where ALI resolves spontaneously through endogenous pathways that help to control excessive lung inflammation. Previous studies have implicated the extracellular signaling molecule adenosine and signaling events through the A2B adenosine receptor in lung protection. In this context, we hypothesized that tissue-specific expression of the A2B adenosine receptor is responsible for the previously described attenuation of ALI. To address this hypothesis, we exposed mice with tissue-specific deletion of Adora2b to ALI, utilizing a two-hit model where intratracheal LPS treatment is followed by injurious mechanical ventilation. Interestingly, a head-to-head comparison of mice with deletion of Adora2b in the myeloid lineage (Adora2b(loxP/loxP) LysM Cre(+)), endothelial cells (Adora2b(loxP/loxP) VE-cadherin Cre(+)), or alveolar epithelial cells (Adora2b(loxP/loxP) SPC Cre(+)) revealed a selective increase in disease susceptibility in Adora2b(loxP/loxP) SPC Cre(+) mice. More detailed analysis of Adora2b(loxP/loxP) SPC Cre(+) mice confirmed elevated lung inflammation and attenuated alveolar fluid clearance. To directly deliver an A2B adenosine receptor-specific agonist to alveolar epithelial cells, we subsequently performed studies with inhaled BAY 60-6583. Indeed, aerosolized BAY 60-6583 treatment was associated with attenuated pulmonary edema, improved histologic lung injury, and dampened lung inflammation. Collectively, these findings suggest that alveolar epithelial A2B adenosine receptor signaling contributes to lung protection, and they implicate inhaled A2B adenosine receptor agonists in ALI treatment.
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Affiliation(s)
- Sandra Hoegl
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO 80045; Department of Anesthesiology, Comprehensive Pneumology Center Munich, German Center for Lung Research, University Hospital, Ludwig Maximilian University, D-81377 Munich, Germany; and
| | - Kelley S Brodsky
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO 80045
| | | | | | - Bernhard Zwissler
- Department of Anesthesiology, Comprehensive Pneumology Center Munich, German Center for Lung Research, University Hospital, Ludwig Maximilian University, D-81377 Munich, Germany; and
| | - Holger K Eltzschig
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO 80045
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14
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Bellingan G, Maksimow M, Howell DC, Stotz M, Beale R, Beatty M, Walsh T, Binning A, Davidson A, Kuper M, Shah S, Cooper J, Waris M, Yegutkin GG, Jalkanen J, Salmi M, Piippo I, Jalkanen M, Montgomery H, Jalkanen S. The effect of intravenous interferon-beta-1a (FP-1201) on lung CD73 expression and on acute respiratory distress syndrome mortality: an open-label study. THE LANCET RESPIRATORY MEDICINE 2013; 2:98-107. [PMID: 24503265 DOI: 10.1016/s2213-2600(13)70259-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Pulmonary vascular leakage occurs early in acute respiratory distress syndrome (ARDS). Mortality is high (35-45%), but no effective pharmacotherapy exists. Production of anti-inflammatory adenosine by ecto-5'-nucleotidase (CD73) helps maintain endothelial barrier function. We tested whether interferon-beta-1a (IFN-beta-1a), which increases CD73 synthesis, can reduce vascular leakage and mortality in patients with ARDS. METHODS In ex-vivo studies, we first established that IFN-beta-1a induced CD73 up-regulation in cultured human lung tissue samples. We then tested the safety, tolerability, and efficacy of intravenous human recombinant IFN-beta-1a (FP-1201) in patients with ARDS in an open-label study (comprising dose-escalation and expansion phases). We recruited patients from eight intensive care units in the UK. Eligible patients were aged 18 years or older, had ARDS, and were being treated with assisted ventilation. We established an optimal tolerated dose (OTD) in the first, dose-escalation phase. Once established, we gave all subsequently enrolled patients the OTD of intravenous FP-1201 for 6 days. We assessed 28-day mortality (our primary endpoint) in all patients receiving the OTD versus 28-day mortality in a group of patients who did not receive treatment (this control group comprised patients in the study but who did not receive treatment because they were screened during the safety windows after dose escalation). This trial is registered with ClinicalTrials.gov, number NCT00789685, and the EU Clinical Trials Register EudraCT, number 2008-000140-13. FINDINGS IFN-beta-1a increased the number of CD73-positive vessels in lung culture by four times on day 1 (p=0·04) and by 14·3 times by day 4 (p=0·004). For the clinical trial, between Feb 23, 2009, and April 7, 2011, we identified 150 patients, of whom 37 were enrolled into the trial and given treatment. The control group consisted of 59 patients who were recruited to take part in the study, but who did not receive treatment. Demographic characteristics and severity of illness did not differ between treatment and control groups. The optimal tolerated FP-1201 dose was 10 μg per day for 6 days. By day 28, 3 (8%) of 37 patients in the treatment cohort and 19 (32%) of 59 patients in the control cohort had died-thus, treatment with FP-1201 was associated with an 81% reduction in odds of 28-day mortality (odds ratio 0·19 [95% CI 0·03-0·72]; p=0·01). INTERPRETATION FP-1201 up-regulates human lung CD73 expression, and is associated with a reduction in 28-day mortality in patients with ARDS. Our findings need to be substantiated in large, prospective randomised trials, but suggest that FP-1201 could be the first effective, mechanistically targeted, disease-specific pharmacotherapy for patients with ARDS.
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Affiliation(s)
- Geoff Bellingan
- Critical Care, University College Hospital, London, UK; Department of Medicine, University College London and NIHR University College London Hospitals Biomedical Research Centre, UK
| | | | | | | | | | | | | | | | | | | | | | - Jackie Cooper
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, UK
| | - Matti Waris
- Department of Virology, University of Turku, Finland
| | - Gennady G Yegutkin
- MediCity Research Laboratory, University of Turku, Finland; Department of Medical Microbiology, University of Turku, Finland
| | - Juho Jalkanen
- Department of Vascular Surgery, Turku University Hospital, Finland
| | - Marko Salmi
- MediCity Research Laboratory, University of Turku, Finland; Department of Medical Biochemistry and Genetics, University of Turku, Finland
| | | | | | - Hugh Montgomery
- Department of Medicine, University College London and NIHR University College London Hospitals Biomedical Research Centre, UK; Whittington Hospital London, UK
| | - Sirpa Jalkanen
- MediCity Research Laboratory, University of Turku, Finland; Department of Medical Microbiology, University of Turku, Finland.
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15
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Isoflurane regulates atypical type-A γ-aminobutyric acid receptors in alveolar type II epithelial cells. Anesthesiology 2013; 118:1065-75. [PMID: 23485993 DOI: 10.1097/aln.0b013e31828e180e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Volatile anesthetics act primarily through upregulating the activity of γ-aminobutyric acid type A (GABAA) receptors. They also exhibit antiinflammatory actions in the lung. Rodent alveolar type II (ATII) epithelial cells express GABAA receptors and the inflammatory factor cyclooxygenase-2 (COX-2). The goal of this study was to determine whether human ATII cells also express GABAA receptors and whether volatile anesthetics upregulate GABAA receptor activity, thereby reducing the expression of COX-2 in ATII cells. METHODS The expression of GABAA receptor subunits and COX-2 in ATII cells of human lung tissue and in the human ATII cell line A549 was studied with immunostaining and immunoblot analyses. Patch clamp recordings were used to study the functional and pharmacological properties of GABAA receptors in cultured A549 cells. RESULTS ATII cells in human lungs and cultured A549 cells expressed GABAA receptor subunits and COX-2. GABA induced currents in A549 cells, with half-maximal effective concentration of 2.5 µM. Isoflurane (0.1-250 µM) enhanced the GABA currents, which were partially inhibited by bicuculline. Treating A549 cells with muscimol or with isoflurane (250 µM) reduced the expression of COX-2, an effect that was attenuated by cotreatment with bicuculline. CONCLUSIONS GABAA receptors expressed by human ATII cells differ pharmacologically from those in neurons, exhibiting a higher affinity for GABA and lower sensitivity to bicuculline. Clinically relevant concentrations of isoflurane increased the activity of GABAA receptors and reduced the expression of COX-2 in ATII cells. These findings reveal a novel mechanism that could contribute to the antiinflammatory effect of isoflurane in the human lung.
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Ntantie E, Gonyo P, Lorimer EL, Hauser AD, Schuld N, McAllister D, Kalyanaraman B, Dwinell MB, Auchampach JA, Williams CL. An adenosine-mediated signaling pathway suppresses prenylation of the GTPase Rap1B and promotes cell scattering. Sci Signal 2013; 6:ra39. [PMID: 23716716 DOI: 10.1126/scisignal.2003374] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During metastasis, cancer cells acquire the ability to dissociate from each other and migrate, which is recapitulated in vitro as cell scattering. The small guanosine triphosphatase (GTPase) Rap1 opposes cell scattering by promoting cell-cell adhesion, a function that requires its prenylation, or posttranslational modification with a carboxyl-terminal isoprenoid moiety, to enable its localization at cell membranes. Thus, signaling cascades that regulate the prenylation of Rap1 offer a mechanism to control the membrane localization of Rap1. We identified a signaling cascade initiated by adenosine A2B receptors that suppressed the prenylation of Rap1B through phosphorylation of Rap1B, which decreased its interaction with the chaperone protein SmgGDS (small GTPase guanosine diphosphate dissociation stimulator). These events promoted the cytosolic and nuclear accumulation of nonprenylated Rap1B and diminished cell-cell adhesion, resulting in cell scattering. We found that nonprenylated Rap1 was more abundant in mammary tumors than in normal mammary tissue in rats and that activation of adenosine receptors delayed Rap1B prenylation in breast, lung, and pancreatic cancer cell lines. Our findings support a model in which high concentrations of extracellular adenosine, such as those that arise in the tumor microenvironment, can chronically activate A2B receptors to suppress Rap1B prenylation and signaling at the cell membrane, resulting in reduced cell-cell contact and promoting cell scattering. Inhibiting A2B receptors may be an effective method to prevent metastasis.
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Affiliation(s)
- Elizabeth Ntantie
- 1Department of Pharmacology and Toxicology, Cancer Center, and Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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17
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Eckle T, Hughes K, Ehrentraut H, Brodsky KS, Rosenberger P, Choi DS, Ravid K, Weng T, Xia Y, Blackburn MR, Eltzschig HK. Crosstalk between the equilibrative nucleoside transporter ENT2 and alveolar Adora2b adenosine receptors dampens acute lung injury. FASEB J 2013; 27:3078-89. [PMID: 23603835 DOI: 10.1096/fj.13-228551] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The signaling molecule adenosine has been implicated in attenuating acute lung injury (ALI). Adenosine signaling is terminated by its uptake through equilibrative nucleoside transporters (ENTs). We hypothesized that ENT-dependent adenosine uptake could be targeted to enhance adenosine-mediated lung protection. To address this hypothesis, we exposed mice to high-pressure mechanical ventilation to induce ALI. Initial studies demonstrated time-dependent repression of ENT1 and ENT2 transcript and protein levels during ALI. To examine the contention that ENT repression represents an endogenous adaptive response, we performed functional studies with the ENT inhibitor dipyridamole. Dipyridamole treatment (1 mg/kg; EC50=10 μM) was associated with significant increases in ALI survival time (277 vs. 395 min; P<0.05). Subsequent studies in gene-targeted mice for Ent1 or Ent2 revealed a selective phenotype in Ent2(-/-) mice, including attenuated pulmonary edema and improved gas exchange during ALI in conjunction with elevated adenosine levels in the bronchoalveolar fluid. Furthermore, studies in genetic models for adenosine receptors implicated the A2B adenosine receptor (Adora2b) in mediating ENT-dependent lung protection. Notably, dipyridamole-dependent attenuation of lung inflammation was abolished in mice with alveolar epithelial Adora2b gene deletion. Our newly identified crosstalk pathway between ENT2 and alveolar epithelial Adora2b in lung protection during ALI opens possibilities for combined therapies targeted to this protein set.
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Affiliation(s)
- Tobias Eckle
- Mucosal Inflammation Program, Department of Anesthesiology, University of Colorado School of Medicine, 12700 E. 19th Ave., Aurora, CO 80045, USA
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18
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Barletta KE, Cagnina RE, Burdick MD, Linden J, Mehrad B. Adenosine A(2B) receptor deficiency promotes host defenses against gram-negative bacterial pneumonia. Am J Respir Crit Care Med 2012; 186:1044-50. [PMID: 22997203 PMCID: PMC3530209 DOI: 10.1164/rccm.201204-0622oc] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 08/31/2012] [Indexed: 12/14/2022] Open
Abstract
RATIONALE Activation of the adenosine A(2B) receptor (A(2B)R) promotes antiinflammatory effects in diverse biological settings, but the role of this receptor in antimicrobial host defense in the lung has not been established. Gram-negative bacillary pneumonia is a common and serious illness associated with high morbidity and mortality, the treatment of which is complicated by increasing rates of antibiotic resistance. OBJECTIVES To test the hypothesis that absence of adenosine A(2B) receptor signaling promotes host defense against bacterial pneumonia. METHODS We used a model of Klebsiella pneumoniae pneumonia in wild-type mice and mice with targeted deletion of the A(2B)R. Host responses were compared in vivo and leukocyte responses to the bacteria were examined in vitro. MEASUREMENTS AND MAIN RESULTS A(2B)R(-/-) mice demonstrated enhanced bacterial clearance from the lung and improved survival after infection with K. pneumoniae compared with wild-type controls, an effect that was mediated by bone marrow-derived cells. Leukocyte recruitment to the lungs and expression of inflammatory cytokines did not differ between A(2B)R(-/-) and wild-type mice, but A(2B)R(-/-) neutrophils exhibited sixfold greater bactericidal activity and enhanced production of neutrophil extracellular traps compared with wild-type neutrophils when incubated with K. pneumoniae. Consistent with this finding, bronchoalveolar lavage fluid from A(2B)R(-/-) mice with Klebsiella pneumonia contained more extracellular DNA compared with wild-type mice with pneumonia. CONCLUSIONS These data suggest that the absence of A(2B)R signaling enhances antimicrobial activity in gram-negative bacterial pneumonia.
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Affiliation(s)
| | - R. Elaine Cagnina
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Marie D. Burdick
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Joel Linden
- La Jolla Institute of Allergy and Immunology, La Jolla, California
| | - Borna Mehrad
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, Virginia
- Department of Microbiology and
- Carter Center for Immunology, University of Virginia, Charlottesville, Virginia
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19
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Konrad FM, Witte E, Vollmer I, Stark S, Reutershan J. Adenosine receptor A2b on hematopoietic cells mediates LPS-induced migration of PMNs into the lung interstitium. Am J Physiol Lung Cell Mol Physiol 2012; 303:L425-38. [DOI: 10.1152/ajplung.00387.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Uncontrolled transmigration of polymorphonuclear leukocytes (PMNs) into the different compartments of the lungs (intravascular, interstitial, alveolar) is a critical event in the early stage of acute lung injury and acute respiratory distress syndrome. Adenosine receptor A2b is highly expressed in the inflamed lungs and has been suggested to mediate cell trafficking. In a murine model of LPS-induced lung inflammation, we investigated the role of A2b on migration of PMNs into the different compartments of the lung. In A2b−/− mice, LPS-induced accumulation of PMNs was significantly higher in the interstitium, but not in the alveolar space. In addition, pulmonary clearance of PMNs was delayed in A2b−/− mice. Using chimeric mice, we identified A2b on hematopoietic cells as crucial for PMN migration. A2b did not affect the release of relevant chemokines into the alveolar space. LPS-induced microvascular permeability was under the control of A2b on both hematopoietic and nonhematopoietic cells. Activation of A2b on endothelial cells also reduced formation of LPS-induced stress fibers, highlighting its role for endothelial integrity. A specific A2b agonist (BAY 60–6583) was effective in decreasing PMN migration into the lung interstitium and microvascular permeability. In addition, in vitro transmigration of human PMNs through a layer of human endothelial or epithelial cells was A2b dependent. Activation of A2b on human PMNs reduced oxidative burst activity. Together, our results demonstrate anti-inflammatory effects of A2b on two major characteristics of acute lung injury, with a distinct role of hematopoietic A2b for cell trafficking and endothelial A2b for microvascular permeability.
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Affiliation(s)
- Franziska M. Konrad
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Esther Witte
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Irene Vollmer
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Stefanie Stark
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Jörg Reutershan
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tübingen, Tübingen, Germany
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20
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Burnstock G, Brouns I, Adriaensen D, Timmermans JP. Purinergic signaling in the airways. Pharmacol Rev 2012; 64:834-68. [PMID: 22885703 DOI: 10.1124/pr.111.005389] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Evidence for a significant role and impact of purinergic signaling in normal and diseased airways is now beyond dispute. The present review intends to provide the current state of knowledge of the involvement of purinergic pathways in the upper and lower airways and lungs, thereby differentiating the involvement of different tissues, such as the epithelial lining, immune cells, airway smooth muscle, vasculature, peripheral and central innervation, and neuroendocrine system. In addition to the vast number of well illustrated functions for purinergic signaling in the healthy respiratory tract, increasing data pointing to enhanced levels of ATP and/or adenosine in airway secretions of patients with airway damage and respiratory diseases corroborates the emerging view that purines act as clinically important mediators resulting in either proinflammatory or protective responses. Purinergic signaling has been implicated in lung injury and in the pathogenesis of a wide range of respiratory disorders and diseases, including asthma, chronic obstructive pulmonary disease, inflammation, cystic fibrosis, lung cancer, and pulmonary hypertension. These ostensibly enigmatic actions are based on widely different mechanisms, which are influenced by the cellular microenvironment, but especially the subtypes of purine receptors involved and the activity of distinct members of the ectonucleotidase family, the latter being potential protein targets for therapeutic implementation.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Royal Free Campus, London, UK.
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21
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Fredholm BB, IJzerman AP, Jacobson KA, Linden J, Müller CE. International Union of Basic and Clinical Pharmacology. LXXXI. Nomenclature and classification of adenosine receptors--an update. Pharmacol Rev 2011; 63:1-34. [PMID: 21303899 PMCID: PMC3061413 DOI: 10.1124/pr.110.003285] [Citation(s) in RCA: 1015] [Impact Index Per Article: 78.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the 10 years since our previous International Union of Basic and Clinical Pharmacology report on the nomenclature and classification of adenosine receptors, no developments have led to major changes in the recommendations. However, there have been so many other developments that an update is needed. The fact that the structure of one of the adenosine receptors has recently been solved has already led to new ways of in silico screening of ligands. The evidence that adenosine receptors can form homo- and heteromultimers has accumulated, but the functional significance of such complexes remains unclear. The availability of mice with genetic modification of all the adenosine receptors has led to a clarification of the functional roles of adenosine, and to excellent means to study the specificity of drugs. There are also interesting associations between disease and structural variants in one or more of the adenosine receptors. Several new selective agonists and antagonists have become available. They provide improved possibilities for receptor classification. There are also developments hinting at the usefulness of allosteric modulators. Many drugs targeting adenosine receptors are in clinical trials, but the established therapeutic use is still very limited.
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Affiliation(s)
- Bertil B Fredholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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22
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Abstract
The natural plant alkaloids caffeine and theophylline were the first adenosine receptor (AR) antagonists described in the literature. They exhibit micromolar affinities and are non-selective. A large number of derivatives and analogues were subsequently synthesized and evaluated as AR antagonists. Very potent antagonists have thus been developed with selectivity for each of the four AR subtypes.
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Affiliation(s)
- Christa Müller
- PharmaCenter Bonn, Pharmaceutical Sciences Bonn (PSB), University of Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, An der Immenburg 4, D-53121 Bonn, Germany, Phone +49-228-73-2301, Fax +49-228-73-2567
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bldg. 8A, Rm. B1A-19, NIH, NIDDK, LBC, Bethesda, MD 20892, United States of America, Phone +1-301-496-9024, Fax +1-301-480-8422
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Feoktistov I, Biaggioni I. Role of adenosine A(2B) receptors in inflammation. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2011; 61:115-44. [PMID: 21586358 PMCID: PMC3748596 DOI: 10.1016/b978-0-12-385526-8.00005-9] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent progress in our understanding of the unique role of A(2B) receptors in the regulation of inflammation, immunity, and tissue repair was considerably facilitated with the introduction of new pharmacological and genetic tools. However, it also led to seemingly conflicting conclusions on the role of A(2B) adenosine receptors in inflammation with some publications indicating proinflammatory effects and others suggesting the opposite. This chapter reviews the functions of A(2B) receptors in various cell types related to inflammation and integrated effects of A(2B) receptor modulation in several animal models of inflammation. It is argued that translation of current findings into novel therapies would require a better understanding of A(2B) receptor functions in diverse types of inflammatory responses in various tissues and at different points of their progression.
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Affiliation(s)
- Igor Feoktistov
- Department of Medicine, Vanderbilt University, Division of Cardiovascular Medicine, Nashville, Tennessee, USA
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24
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Zhou Y, Schneider DJ, Morschl E, Song L, Pedroza M, Karmouty-Quintana H, Le T, Sun CX, Blackburn MR. Distinct roles for the A2B adenosine receptor in acute and chronic stages of bleomycin-induced lung injury. THE JOURNAL OF IMMUNOLOGY 2010; 186:1097-106. [PMID: 21149612 DOI: 10.4049/jimmunol.1002907] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Adenosine is an extracellular signaling molecule that is generated in response to cell injury where it orchestrates tissue protection and repair. Whereas adenosine is best known for promoting anti-inflammatory activities during acute injury responses, prolonged elevations can enhance destructive tissue remodeling processes associated with chronic disease states. The generation of adenosine and the subsequent activation of the adenosine 2B receptor (A(2B)R) is an important processes in the regulation of both acute and chronic lung disease. The goal of this study was to examine the contribution of the A(2B)R in models of bleomycin-induced lung injury that exhibit varying degrees of acute and chronic injury. Intratracheal bleomycin exposure results in substantial acute lung injury followed by progressive fibrosis. In this model, genetic removal of the A(2B)R resulted in enhanced loss of barrier function and increased pulmonary inflammation, with few differences in indexes of pulmonary fibrosis. These results support an anti-inflammatory role for this receptor in this model of acute lung injury. In contrast, systemic exposure of mice to bleomycin resulted in modest acute lung injury together with progressive pulmonary fibrosis. In this model, the effects of A(2B)R removal on acute lung injury were negligible; however, there were substantial reductions in pulmonary fibrosis, supporting a profibrotic role for this receptor. A(2B)R-dependent regulation of IL-6 production was identified as a potential mechanism involved in the diminished pulmonary fibrosis seen in A(2B)R knockout mice exposed to i.p. bleomycin. These studies highlight the distinct roles of A(2B)R signaling during acute and chronic stages of lung injury.
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Affiliation(s)
- Yang Zhou
- Department of Biochemistry and Molecular Biology, University of Texas Medical School at Houston, Houston, TX 77030, USA
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25
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Laubach VE, French BA, Okusa MD. Targeting of adenosine receptors in ischemia-reperfusion injury. Expert Opin Ther Targets 2010; 15:103-18. [PMID: 21110787 DOI: 10.1517/14728222.2011.541441] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
IMPORTANCE OF THE FIELD Ischemia-reperfusion (IR) injury is a common problem after transplantation as well as myocardial infarction and stroke. IR initiates an inflammatory response leading to rapid tissue damage. Adenosine, produced in response to IR, is generally considered a protective signaling molecule and elicits its physiological responses through four distinct adenosine receptors. The short half-life, lack of specificity and rapid metabolism limits the use of adenosine as a therapeutic agent. Thus, intense research efforts have focused on the synthesis and implementation of specific adenosine receptor agonists and antagonists as potential therapeutic agents for a variety of inflammatory conditions including IR injury. AREAS COVERED IN THIS REVIEW Current knowledge on IR injury with a focus on lung, heart and kidney and studies that have advanced our understanding of the role of adenosine receptors and the therapeutic potential of adenosine receptor agonists and antagonists for the prevention of IR injury. WHAT THE READER WILL GAIN Insight into the role of adenosine receptor signaling in IR injury. TAKE HOME MESSAGE No therapies are currently available that specifically target IR injury; however, targeting of specific adenosine receptors may offer therapeutic strategies in this regard.
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Affiliation(s)
- Victor E Laubach
- University of Virginia Health System, Charlottesville, 22908, USA.
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26
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Anvari F, Sharma AK, Fernandez LG, Hranjec T, Ravid K, Kron IL, Laubach VE. Tissue-derived proinflammatory effect of adenosine A2B receptor in lung ischemia-reperfusion injury. J Thorac Cardiovasc Surg 2010; 140:871-7. [PMID: 20659747 DOI: 10.1016/j.jtcvs.2010.06.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 06/14/2010] [Accepted: 06/28/2010] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Ischemia-reperfusion injury after lung transplantation remains a major source of morbidity and mortality. Adenosine receptors have been implicated in both pro- and anti-inflammatory roles in ischemia-reperfusion injury. This study tests the hypothesis that the adenosine A(2B) receptor exacerbates the proinflammatory response to lung ischemia-reperfusion injury. METHODS An in vivo left lung hilar clamp model of ischemia-reperfusion was used in wild-type C57BL6 and adenosine A(2B) receptor knockout mice, and in chimeras created by bone marrow transplantation between wild-type and adenosine A(2B) receptor knockout mice. Mice underwent sham surgery or lung ischemia-reperfusion (1 hour ischemia and 2 hours reperfusion). At the end of reperfusion, lung function was assessed using an isolated buffer-perfused lung system. Lung inflammation was assessed by measuring proinflammatory cytokine levels in bronchoalveolar lavage fluid, and neutrophil infiltration was assessed via myeloperoxidase levels in lung tissue. RESULTS Compared with wild-type mice, lungs of adenosine A(2B) receptor knockout mice were significantly protected after ischemia-reperfusion, as evidenced by significantly reduced pulmonary artery pressure, increased lung compliance, decreased myeloperoxidase, and reduced proinflammatory cytokine levels (tumor necrosis factor-α; interleukin-6; keratinocyte chemoattractant; regulated on activation, normal T-cell expressed and secreted; and monocyte chemotactic protein-1). Adenosine A(2B) receptor knockout → adenosine A(2B) receptor knockout (donor → recipient) and wild-type → adenosine A(2B) receptor knockout, but not adenosine A(2B) receptor knockout → wild-type, chimeras showed significantly improved lung function after ischemia-reperfusion. CONCLUSIONS These results suggest that the adenosine A(2B) receptor plays an important role in mediating lung inflammation after ischemia-reperfusion by stimulating cytokine production and neutrophil chemotaxis. The proinflammatory effects of adenosine A(2B) receptor seem to be derived by adenosine A(2B) receptor activation primarily on resident pulmonary cells and not bone marrow-derived cells. Adenosine A(2B) receptor may provide a therapeutic target for prevention of ischemia-reperfusion-related graft dysfunction in lung transplant recipients.
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Affiliation(s)
- Farshad Anvari
- Department of Surgery, University of Virginia Health System, Charlottesville, VA 22908, USA
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Aherne CM, Kewley EM, Eltzschig HK. The resurgence of A2B adenosine receptor signaling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:1329-39. [PMID: 20546702 DOI: 10.1016/j.bbamem.2010.05.016] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 05/16/2010] [Accepted: 05/17/2010] [Indexed: 01/05/2023]
Abstract
Since its discovery as a low-affinity adenosine receptor (AR), the A2B receptor (A2BAR), has proven enigmatic in its function. The previous discovery of the A2AAR, which shares many similarities with the A2BAR but demonstrates significantly greater affinity for its endogenous ligand, led to the original perception that the A2BAR was not of substantial physiologic relevance. In addition, lack of specific pharmacological agents targeting the A2BAR made its initial characterization challenging. However, the importance of this receptor was reconsidered when it was observed that the A2BAR is highly transcriptionally regulated by factors implicated in inflammatory hypoxia. Moreover, the notion that during ischemia or inflammation extracellular adenosine is dramatically elevated to levels sufficient for A2BAR activation, indicated that A2BAR signaling may be important to dampen inflammation particularly during tissue hypoxia. In addition, the recent advent of techniques for murine genetic manipulation along with development of pharmacological agents with enhanced A2BAR specificity has provided invaluable tools for focused studies on the explicit role of A2BAR signaling in different disease models. Currently, studies performed with combined genetic and pharmacological approaches have demonstrated that A2BAR signaling plays a tissue protective role in many models of acute diseases e.g. myocardial ischemia, or acute lung injury. These studies indicate that the A2BAR is expressed on a wide variety of cell types and exerts tissue/cell specific effects. This is an important consideration for future studies where tissue or cell type specific targeting of the A2BAR may be used as therapeutic approach.
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Affiliation(s)
- Carol M Aherne
- Department of Anesthesiology, University of Colorado, Aurora, CO, USA
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Gazoni LM, Walters DM, Unger EB, Linden J, Kron IL, Laubach VE. Activation of A1, A2A, or A3 adenosine receptors attenuates lung ischemia-reperfusion injury. J Thorac Cardiovasc Surg 2010; 140:440-6. [PMID: 20398911 DOI: 10.1016/j.jtcvs.2010.03.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 12/08/2009] [Accepted: 03/01/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Adenosine and the activation of specific adenosine receptors are implicated in the attenuation of inflammation and organ ischemia-reperfusion injury. We hypothesized that activation of A(1), A(2A), or A(3) adenosine receptors would provide protection against lung ischemia-reperfusion injury. METHODS With the use of an isolated, ventilated, blood-perfused rabbit lung model, lungs underwent 18 hours of cold ischemia followed by 2 hours of reperfusion. Lungs were administered vehicle, adenosine, or selective A(1), A(2A), or A(3) receptor agonists (CCPA, ATL-313, or IB-MECA, respectively) alone or with their respective antagonists (DPCPX, ZM241385, or MRS1191) during reperfusion. RESULTS Compared with the vehicle-treated control group, treatment with A(1), A(2A), or A(3) agonists significantly improved function (increased lung compliance and oxygenation and decreased pulmonary artery pressure), decreased neutrophil infiltration by myeloperoxidase activity, decreased edema, and reduced tumor necrosis factor-alpha production. Adenosine treatment was also protective, but not to the level of the agonists. When each agonist was paired with its respective antagonist, all protective effects were blocked. The A(2A) agonist reduced pulmonary artery pressure and myeloperoxidase activity and increased oxygenation to a greater degree than the A(1) or A(3) agonists. CONCLUSION Selective activation of A(1), A(2A), or A(3) adenosine receptors provides significant protection against lung ischemia-reperfusion injury. The decreased elaboration of the potent proinflammatory cytokine tumor necrosis factor-alpha and decreased neutrophil sequestration likely contribute to the overall improvement in pulmonary function. These results provide evidence for the therapeutic potential of specific adenosine receptor agonists in lung transplant recipients.
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Affiliation(s)
- Leo M Gazoni
- Department of Surgery, University of Virginia Health System, Charlottesville, VA 22908, USA
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Schingnitz U, Hartmann K, Macmanus CF, Eckle T, Zug S, Colgan SP, Eltzschig HK. Signaling through the A2B adenosine receptor dampens endotoxin-induced acute lung injury. THE JOURNAL OF IMMUNOLOGY 2010; 184:5271-9. [PMID: 20348420 DOI: 10.4049/jimmunol.0903035] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sepsis and septic acute lung injury are among the leading causes for morbidity and mortality of critical illness. Extracellular adenosine is a signaling molecule implicated in the cellular adaptation to hypoxia, ischemia, or inflammation. Therefore, we pursued the role of the A2B adenosine receptor (AR) as potential therapeutic target in endotoxin-induced acute lung injury. We gained initial insight from in vitro studies of cultured endothelia or epithelia exposed to inflammatory mediators showing time-dependent induction of the A2BAR (up to 12.9 + or - 3.4-fold, p < 0.05). Similarly, murine studies of endotoxin-induced lung injury identified an almost 4.6-fold induction of A2BAR transcript and corresponding protein induction with LPS exposure. Studies utilizing A2BAR promoter constructs and RNA protection assays indicated that A2BAR induction involved mRNA stability. Functional studies of LPS-induced lung injury revealed that pharmacological inhibition or genetic deletion of the A2BAR was associated with dramatic increases in lung inflammation and histologic tissue injury. Studies of A2BAR bone marrow chimeric mice suggested pulmonary A2BAR signaling in lung protection. Finally, studies with a specific A2BAR agonist (BAY 60-6583) demonstrated attenuation of lung inflammation and pulmonary edema in wild-type but not in gene-targeted mice for the A2BAR. These studies suggest the A2BAR as potential therapeutic target in the treatment of endotoxin-induced forms of acute lung injury.
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Affiliation(s)
- Ulrich Schingnitz
- Department of Anesthesiology and Intensive Care Medicine, Tübingen University Hospital, Tübingen, Germany
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Lu Q, Harrington EO, Newton J, Casserly B, Radin G, Warburton R, Zhou Y, Blackburn MR, Rounds S. Adenosine protected against pulmonary edema through transporter- and receptor A2-mediated endothelial barrier enhancement. Am J Physiol Lung Cell Mol Physiol 2010; 298:L755-67. [PMID: 20228181 DOI: 10.1152/ajplung.00330.2009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously demonstrated that adenosine plus homocysteine enhanced endothelial basal barrier function and protected against agonist-induced barrier dysfunction in vitro through attenuation of RhoA activation by inhibition of isoprenylcysteine-O-carboxyl methyltransferase. In the current study, we tested the effect of elevated adenosine on pulmonary endothelial barrier function in vitro and in vivo. We noted that adenosine alone dose dependently enhanced endothelial barrier function. While adenosine receptor A(1) or A(3) antagonists were ineffective, an adenosine transporter inhibitor, NBTI, or a combination of DPMX and MRS1754, antagonists for adenosine receptors A(2A) and A(2B), respectively, partially attenuated the barrier-enhancing effect of adenosine. Similarly, inhibition of both A(2A) and A(2B) receptors with siRNA also blunted the effect of adenosine on barrier function. Interestingly, inhibition of both transporters and A(2A)/A(2B) receptors completely abolished adenosine-induced endothelial barrier enhancement. The adenosine receptor A(2A) and A(2B) agonist, NECA, also significantly enhanced endothelial barrier function. These data suggest that both adenosine transporters and A(2A) and A(2B) receptors are necessary for exerting maximal effect of adenosine on barrier enhancement. We also found that adenosine enhanced Rac1 GTPase activity and overexpression of dominant negative Rac1 attenuated adenosine-induced increases in focal adhesion complexes. We further demonstrated that elevation of cellular adenosine by inhibition of adenosine deaminase with Pentostatin significantly enhanced endothelial basal barrier function, an effect that was also associated with enhanced Rac1 GTPase activity and with increased focal adhesion complexes and adherens junctions. Finally, using a non-inflammatory acute lung injury (ALI) model induced by alpha-naphthylthiourea, we found that administration of Pentostatin, which elevated lung adenosine level by 10-fold, not only attenuated the development of edema before ALI but also partially reversed edema after ALI. The data suggest that adenosine deaminase inhibition may be useful in treatment of pulmonary edema in settings of ALI.
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Affiliation(s)
- Qing Lu
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island 02908, USA
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Eckle T, Koeppen M, Eltzschig HK. Role of extracellular adenosine in acute lung injury. Physiology (Bethesda) 2009; 24:298-306. [PMID: 19815856 DOI: 10.1152/physiol.00022.2009] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acute lung injury (ALI) is a lung disease characterized by pulmonary edema and severe hypoxia. The past decade hosted a search for endogenous mechanisms controlling lung inflammation and pulmonary edema during ALI. As such, recent evidence indicates extracellular adenosine in orchestrating the resolution of pulmonary edema and inflammation during ALI.
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Affiliation(s)
- Tobias Eckle
- Department of Anesthesiology, Mucosal Inflammation Program, University of Colorado Denver, Aurora, Colorado, USA
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