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Qin H, Sun C, Kong D, Zhu Y, Shao B, Ren S, Wang H, Zhang J, Xu Y, Wang H. CD73 mediates the therapeutic effects of endometrial regenerative cells in concanavalin A-induced hepatitis by regulating CD4 + T cells. Stem Cell Res Ther 2023; 14:277. [PMID: 37775797 PMCID: PMC10543328 DOI: 10.1186/s13287-023-03505-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023] Open
Abstract
BACKGROUND As a kind of mesenchymal-like stromal cells, endometrial regenerative cells (ERCs) have been demonstrated effective in the treatment of Concanavalin A (Con A)-induced hepatitis. However, the therapeutic mechanism of ERCs is not fully understood. Ecto-5`-nucleotidase (CD73), an enzyme that could convert immune-stimulative adenosine monophosphate (AMP) to immune-suppressive adenosine (ADO), was identified highly expressed on ERCs. The present study was conducted to investigate whether the expression of CD73 on ERCs is critical for its therapeutic effects in Con A-induced hepatitis. METHODS ERCs knocking out CD73 were generated with lentivirus-mediated CRISPR-Cas9 technology and identified by flow cytometry, western blot and AMPase activity assay. CD73-mediated immunomodulatory effects of ERCs were investigated by CD4+ T cell co-culture assay in vitro. Besides, Con A-induced hepatitis mice were randomly assigned to the phosphate-buffered saline treated (untreated), ERC-treated, negative lentiviral control ERC (NC-ERC)-treated, and CD73-knockout-ERC (CD73-KO-ERC)-treated groups, and used to assess the CD73-mediated therapeutic efficiency of ERCs. Hepatic histopathological analysis, serum transaminase concentrations, and the proportion of CD4+ T cell subsets in the liver and spleen were performed to assess the progression degree of hepatitis. RESULTS Expression of CD73 on ERCs could effectively metabolize AMP to ADO, thereby inhibiting the activation and function of conventional CD4+ T cells was identified in vitro. In addition, ERCs could markedly reduce levels of serum and liver transaminase and attenuate liver damage, while the deletion of CD73 on ERCs dampens these effects. Furthermore, ERC-based treatment achieved less infiltration of CD4+ T and Th1 cells in the liver and reduced the population of systemic Th1 and Th17 cells and the levels of pro-inflammatory cytokines such as IFN-γ and TNF-α, while promoting the generation of Tregs in the liver and spleen, while deletion of CD73 on ERCs significantly impaired their immunomodulatory effects locally and systemically. CONCLUSION Taken together, it is concluded that CD73 is critical for the therapeutic efficiency of ERCs in the treatment of Con A-induced hepatitis.
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Affiliation(s)
- Hong Qin
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Chenglu Sun
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Dejun Kong
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Yanglin Zhu
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Bo Shao
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Shaohua Ren
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Hongda Wang
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Jingyi Zhang
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yini Xu
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Hao Wang
- Department of General Surgery, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, Tianjin, 300052, China.
- Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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Normalizing Tumor Vasculature to Reduce Hypoxia, Enhance Perfusion, and Optimize Therapy Uptake. Cancers (Basel) 2021; 13:cancers13174444. [PMID: 34503254 PMCID: PMC8431369 DOI: 10.3390/cancers13174444] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 08/26/2021] [Accepted: 09/01/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary In order for solid tumors to grow, they need to develop new blood vessels in order to support their increasing metabolic requirements. To facilitate the novel vessel formation, the tumor initiates an aggressive pro-angiogenic program. As a result of the aggressive angiogenesis, blood vessels form very rapidly and are often malformed and dysfunctional. There is a reduction in perfusion to the tumor, and often the tumors exhibit significant areas of tumor hypoxia. This review paper discusses the pro-tumorigenic environment induced by tumor hypoxia and how this can be targeted through normalization of the tumor vasculature. Here, we review tumor angiogenesis, the development of a hypoxic phenotype, and how this contributes to sustained tumorigenesis and resistance to therapy. We further discuss the potential of vascular normalization to reduce tumor hypoxia and facilitate uptake and efficacy of a variety of therapies. Abstract A basic requirement of tumorigenesis is the development of a vascular network to support the metabolic requirements of tumor growth and metastasis. Tumor vascular formation is regulated by a balance between promoters and inhibitors of angiogenesis. Typically, the pro-angiogenic environment created by the tumor is extremely aggressive, resulting in the rapid vessel formation with abnormal, dysfunctional morphology. The altered morphology and function of tumor blood and lymphatic vessels has numerous implications including poor perfusion, tissue hypoxia, and reduced therapy uptake. Targeting tumor angiogenesis as a therapeutic approach has been pursued in a host of different cancers. Although some preclinical success was seen, there has been a general lack of clinical success with traditional anti-angiogenic therapeutics as single agents. Typically, following anti-angiogenic therapy, there is remodeling of the tumor microenvironment and widespread tumor hypoxia, which is associated with development of therapy resistance. A more comprehensive understanding of the biology of tumor angiogenesis and insights into new clinical approaches, including combinations with immunotherapy, are needed to advance vascular targeting as a therapeutic area.
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CD73 Maintains Hepatocyte Metabolic Integrity and Mouse Liver Homeostasis in a Sex-Dependent Manner. Cell Mol Gastroenterol Hepatol 2021; 12:141-157. [PMID: 33516905 PMCID: PMC8082562 DOI: 10.1016/j.jcmgh.2021.01.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Metabolic imbalance and inflammation are common features of chronic liver diseases. Molecular factors controlling these mechanisms represent potential therapeutic targets. CD73 is the major enzyme that dephosphorylates extracellular adenosine monophosphate (AMP) to form the anti-inflammatory adenosine. CD73 is expressed on pericentral hepatocytes, which are important for long-term liver homeostasis. We aimed to determine if CD73 has nonredundant hepatoprotective functions. METHODS Liver-specific CD73 knockout (CD73-LKO) mice were generated by targeting the Nt5e gene in hepatocytes. The CD73-LKO mice and hepatocytes were characterized using multiple approaches. RESULTS Deletion of hepatocyte Nt5e resulted in an approximately 70% reduction in total liver CD73 protein (P < .0001). Male and female CD73-LKO mice developed normally during the first 21 weeks without significant liver phenotypes. Between 21 and 42 weeks, the CD73-LKO mice developed spontaneous-onset liver disease, with significant severity in male mice. Middle-aged male CD73-LKO mice showed hepatocyte swelling and ballooning (P < .05), inflammation (P < .01), and variable steatosis. Female CD73-LKO mice had lower serum albumin levels (P < .05) and increased inflammatory genes (P < .01), but did not show the spectrum of histopathologic changes in male mice, potentially owing to compensatory induction of adenosine receptors. Serum analysis and proteomic profiling of hepatocytes from male CD73-LKO mice showed significant metabolic imbalance, with increased blood urea nitrogen (P < .0001) and impairments in major metabolic pathways, including oxidative phosphorylation and AMP-activated protein kinase (AMPK) signaling. There was significant hypophosphorylation of AMPK substrates in CD73-LKO livers (P < .0001), while in isolated hepatocytes treated with AMP, soluble CD73 induced AMPK activation (P < .001). CONCLUSIONS Hepatocyte CD73 supports long-term metabolic liver homeostasis through AMPK in a sex-dependent manner. These findings have implications for human liver diseases marked by CD73 dysregulation.
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Boknik P, Eskandar J, Hofmann B, Zimmermann N, Neumann J, Gergs U. Role of Cardiac A 2A Receptors Under Normal and Pathophysiological Conditions. Front Pharmacol 2021; 11:627838. [PMID: 33574762 PMCID: PMC7871008 DOI: 10.3389/fphar.2020.627838] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022] Open
Abstract
This review presents an overview of cardiac A2A-adenosine receptors The localization of A2A-AR in the various cell types that encompass the heart and the role they play in force regulation in various mammalian species are depicted. The putative signal transduction systems of A2A-AR in cells in the living heart, as well as the known interactions of A2A-AR with membrane-bound receptors, will be addressed. The possible role that the receptors play in some relevant cardiac pathologies, such as persistent or transient ischemia, hypoxia, sepsis, hypertension, cardiac hypertrophy, and arrhythmias, will be reviewed. Moreover, the cardiac utility of A2A-AR as therapeutic targets for agonistic and antagonistic drugs will be discussed. Gaps in our knowledge about the cardiac function of A2A-AR and future research needs will be identified and formulated.
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Affiliation(s)
- P. Boknik
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Westfälische Wilhelms-Universität, Münster, Germany
| | - J. Eskandar
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Westfälische Wilhelms-Universität, Münster, Germany
| | - B. Hofmann
- Cardiac Surgery, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
| | - N. Zimmermann
- Bundesinstitut für Arzneimittel und Medizinprodukte, Bonn, Germany
| | - J. Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
| | - U. Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
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Hatfield SM, Sitkovsky MV. Antihypoxic oxygenation agents with respiratory hyperoxia to improve cancer immunotherapy. J Clin Invest 2020; 130:5629-5637. [PMID: 32870821 PMCID: PMC7598059 DOI: 10.1172/jci137554] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Hypoxia/HIF-1α- and extracellular adenosine/A2 adenosine receptor-mediated immunosuppression protects tissues from collateral damage by antipathogen immune cells. However, this mechanism also protects cancerous tissues by inhibiting antitumor immune cells in hypoxic and extracellular adenosine-rich tumors that are the most resistant to current therapies. Here, we explain a potentially novel, antiimmunosuppressive reasoning to justify strategies using respiratory hyperoxia and oxygenation agents in cancer treatment. Earlier attempts to use oxygenation of tumors as a monotherapy or to improve radiotherapy have failed because oxygenation protocols were not combined with immunotherapies of cancer. In contrast, the proposal for therapeutic use of antihypoxic oxygenation described here was motivated by the need to prevent the hypoxia/HIF-1α-driven accumulation of extracellular adenosine to (a) unleash antitumor immune cells from inhibition by intracellular cAMP and (b) prevent immunosuppressive transcription of cAMP response element- and hypoxia response element-containing immunosuppressive gene products (e.g., TGF-β). Use of oxygenation agents together with inhibitors of the A2A adenosine receptor may be required to enable the most effective cancer immunotherapy. The emerging outcomes of clinical trials of cancer patients refractory to all other treatments provide support for the molecular and immunological mechanism-based approach to cancer immunotherapy described here.
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Wang P, Jia J, Zhang D. Purinergic signalling in liver diseases: Pathological functions and therapeutic opportunities. JHEP Rep 2020; 2:100165. [PMID: 33103092 PMCID: PMC7575885 DOI: 10.1016/j.jhepr.2020.100165] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/24/2020] [Accepted: 07/22/2020] [Indexed: 12/12/2022] Open
Abstract
Extracellular nucleotides, including ATP, are essential regulators of liver function and serve as danger signals that trigger inflammation upon injury. Ectonucleotidases, which are expressed by liver-resident cells and recruited immune cells sequentially hydrolyse nucleotides to adenosine. The nucleotide/nucleoside balance orchestrates liver homeostasis, tissue repair, and functional restoration by regulating the crosstalk between liver-resident cells and recruited immune cells. In this review, we discuss our current knowledge on the role of purinergic signals in liver homeostasis, restriction of inflammation, stimulation of liver regeneration, modulation of fibrogenesis, and regulation of carcinogenesis. Moreover, we discuss potential targeted therapeutic strategies for liver diseases based on purinergic signals involving blockade of nucleotide receptors, enhancement of ectonucleoside triphosphate diphosphohydrolase activity, and activation of adenosine receptors.
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Key Words
- A1, adenosine receptor A1
- A2A, adenosine receptor A2A
- A2B, adenosine receptor A2B
- A3, adenosine receptor A3
- AIH, autoimmune hepatitis
- ALT, alanine aminotransferase
- APAP, acetaminophen
- APCP, α,β-methylene ADP
- Adenosine receptors
- BDL, bile duct ligation
- CCl4, carbon tetrachloride
- CD73, ecto-5ʹ-nucleotidase
- ConA, concanavalin A
- DCs, dendritic cells
- DMN, dimethylnitrosamine
- Ecto-5ʹ-nucleotidase
- Ectonucleoside triphosphate diphosphohydrolases 1
- HCC, hepatocellular carcinoma
- HFD, high-fat diet
- HGF, hepatocyte growth factor
- HSCs, hepatic stellate cells
- IFN, interferon
- IL-, interleukin-
- IPC, ischaemic preconditioning
- IR, ischaemia-reperfusion
- Liver
- MAPK, mitogen-activating protein kinase
- MCDD, methionine- and choline-deficient diet
- MHC, major histocompatibility complex
- NAFLD, non-alcoholic fatty liver disease
- NK, natural killer
- NKT, natural killer T
- NTPDases, ectonucleoside triphosphate diphosphohydrolases
- Nucleotide receptors
- P1, purinergic type 1
- P2, purinergic type 2
- PBC, primary biliary cholangitis
- PH, partial hepatectomy
- PKA, protein kinase A
- PPADS, pyridoxal-phosphate-6-azophenyl-2′,4′-disulphonate
- Purinergic signals
- ROS, reactive oxygen species
- TAA, thioacetamide
- TNF, tumour necrosis factor
- Tregs, regulatory T cells
- VEGF, vascular endothelial growth factor
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Affiliation(s)
- Ping Wang
- Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis & National Clinical Research Center for Digestive Diseases, Beijing 100050, China
| | - Jidong Jia
- Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis & National Clinical Research Center for Digestive Diseases, Beijing 100050, China
| | - Dong Zhang
- Experimental and Translational Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Tolerance Induction and Organ Protection in Transplantation & National Clinical Research Center for Digestive Diseases, Beijing 100050, China
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Stryjak I, Warmuzińska N, Bogusiewicz J, Łuczykowski K, Bojko B. Monitoring of the influence of long-term oxidative stress and ischemia on the condition of kidneys using solid-phase microextraction chemical biopsy coupled with liquid chromatography-high-resolution mass spectrometry. J Sep Sci 2020; 43:1867-1878. [PMID: 32068348 DOI: 10.1002/jssc.202000032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 12/28/2022]
Abstract
The limiting factor in conventional quality assessments of transplanted organs, namely the invasiveness of tissue sample collection, has prompted much research on the field of transplantology to focus on the development of alternative evaluation methods of organ quality. In the present project, we undertake the challenge to address the need for a new analytical solution for graft quality assessments by using a novel metabolomic diagnostic protocol based on low-invasive solid-phase microextraction. Solid-phase microextraction probes of ca. 0.2 mm coated with 4 mm long mixed-mode extraction phase were inserted into rabbit kidneys immediately following euthanasia and after 2, 4, 6, and 21 h of preservation. Liquid chromatography-mass spectrometry analysis of the extracts was performed with the use of a reversed phase column and a Q-Exactive Focus mass spectrometer operated in positive ionization mode. Statistical analysis of significantly changing compounds revealed metabolic profile changes in kidneys induced by ischemia and oxidative stress as a function of the duration of cold storage. The most pronounced alterations were reflected in levels of essential amino acids and purine nucleosides. Our findings demonstrate that the proposed approach may be successfully used to monitor changes in the metabolic profile of organs over time of preservation.
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Affiliation(s)
- Iga Stryjak
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Natalia Warmuzińska
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Joanna Bogusiewicz
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Kamil Łuczykowski
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
| | - Barbara Bojko
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń, Poland
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Ohta A. Oxygen-dependent regulation of immune checkpoint mechanisms. Int Immunol 2019; 30:335-343. [PMID: 29846615 DOI: 10.1093/intimm/dxy038] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/27/2018] [Indexed: 12/21/2022] Open
Abstract
Immunotherapy of cancer has finally materialized following the success of immune checkpoint blockade. Since down-regulation of immune checkpoint mechanisms is beneficial in cancer treatment, it is important to ask why tumors are infamously filled with the immunosuppressive mechanisms. Indeed, immune checkpoints are physiological negative feedback mechanisms of immune activities, and the induction of such mechanisms is important in preventing excessive destruction of inflamed normal tissues. A condition commonly found in tumors and inflamed tissues is tissue hypoxia. Oxygen deprivation under hypoxic conditions by itself is immunosuppressive because proper oxygen supply could support bioenergetic demands of immune cells for optimal immune responses. However, importantly, hypoxia has been found to up-regulate a variety of immune checkpoints and to be able to drive a shift toward a more immunosuppressive environment. Moreover, extracellular adenosine, which accumulates due to tissue hypoxia, also contributes to the up-regulation of other immune checkpoints. Taken together, tissue oxygen is a key regulator of the immune response by directly affecting the energy status of immune effectors and by regulating the intensity of immunoregulatory activity in the environment. The regulators of various immune checkpoint mechanisms may represent the next focus to modulate the intensity of immune responses and to improve cancer immunotherapy.
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Affiliation(s)
- Akio Ohta
- Department of Immunology, Foundation for Biomedical Research and Innovation at Kobe, Minatojima-Minamimachi, Kobe, Japan
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Vuerich M, Harshe RP, Robson SC, Longhi MS. Dysregulation of Adenosinergic Signaling in Systemic and Organ-Specific Autoimmunity. Int J Mol Sci 2019; 20:ijms20030528. [PMID: 30691212 PMCID: PMC6386992 DOI: 10.3390/ijms20030528] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 12/15/2022] Open
Abstract
Exact causes for autoimmune diseases remain unclear and no cures are available. Breakdown of immunotolerance could set the stage for unfettered immune responses that target self-antigens. Impaired regulatory immune mechanisms could have permissive roles in autoreactivity. Abnormal regulatory immune cell function, therefore, might be a major determinant of the pathogenesis of autoimmune disease. All current treatments are associated with some level of clinical toxicity. Treatment to specifically target dysregulated immunity in these diseases would be a great advance. Extracellular adenosine is a signaling mediator that suppresses inflammation through activation of P1 receptors, most active under pathological conditions. Mounting evidence has linked alterations in the generation of adenosine from extracellular nucleotides by ectonucleotidases, and associated perturbations in purinergic signaling, to the immunological disruption and loss of immunotolerance in autoimmunity. Targeted modulation of the purinergic signaling by either targeting ectonucleotidases or modulating P1 purinergic receptors could therefore restore the balance between autoreactive immune responses; and thereby allow reestablishment of immunotolerance. We review the roles of CD39 and CD73 ectoenzymes in inflammatory states and with the dysregulation of P1 receptor signaling in systemic and organ-specific autoimmunity. Correction of such perturbations could be exploited in potential therapeutic applications.
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Affiliation(s)
- Marta Vuerich
- Department of Anesthesia, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
| | - Rasika P Harshe
- Department of Anesthesia, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
| | - Simon C Robson
- Department of Anesthesia, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
| | - Maria Serena Longhi
- Department of Anesthesia, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
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Feuerecker M, Crucian BE, Quintens R, Buchheim J, Salam AP, Rybka A, Moreels M, Strewe C, Stowe R, Mehta S, Schelling G, Thiel M, Baatout S, Sams C, Choukèr A. Immune sensitization during 1 year in the Antarctic high-altitude Concordia Environment. Allergy 2019; 74:64-77. [PMID: 29978486 DOI: 10.1111/all.13545] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 06/04/2018] [Accepted: 06/05/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND Antarctica is a challenging environment for humans. It serves as a spaceflight ground analog, reflecting some conditions of long-duration exploration class space missions. The French-Italian Concordia station in interior Antarctica is a high-fidelity analog, located 1000 km from the coast, at an altitude of 3232 m. The aim of this field study was to characterize the extent, dynamics, and key mechanisms of the immune adaptation in humans overwintering at Concordia for 1 year. METHODS This study assessed immune functions in fourteen crewmembers. Quantitative and phenotypic analyses from human blood were performed using onsite flow cytometry together with specific tests on receptor-dependent and receptor-independent functional innate and adaptive immune responses. Transcriptome analyses and quantitative identification of key response genes were assessed. RESULTS Dynamic immune activation and a two-step escalation/activation pattern were observed. The early phase was characterized by moderately sensitized global immune responses, while after 3-4 months, immune responses were highly upregulated. The cytokine responses to an ex vivo stimulation were markedly raised above baseline levels. These functional observations were reflected at the gene transcriptional level in particular through the modulation of hypoxia-driven pathways. CONCLUSIONS This study revealed unique insights into the extent, dynamics, and genetics of immune dysfunctions in humans exposed for 1 year to the Antarctic environment at the Concordia station. The scale of immune function was imbalanced toward a sensitizing of inflammatory pathways.
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Affiliation(s)
- Matthias Feuerecker
- Department of Anaesthesiology Laboratory of Translational Research “Stress and Immunity” University Hospital LMU Munich Munich Germany
| | | | - Roel Quintens
- Radiobiology Unit Belgian Nuclear Research Centre (SCK CEN) Mol Belgium
| | - Judith‐Irina Buchheim
- Department of Anaesthesiology Laboratory of Translational Research “Stress and Immunity” University Hospital LMU Munich Munich Germany
| | | | - Ales Rybka
- IPEV/PNRA‐ESA Antarctic Program Dome C Antarctica
| | - Marjan Moreels
- Radiobiology Unit Belgian Nuclear Research Centre (SCK CEN) Mol Belgium
| | - Claudia Strewe
- Department of Anaesthesiology Laboratory of Translational Research “Stress and Immunity” University Hospital LMU Munich Munich Germany
| | | | | | - Gustav Schelling
- Department of Anaesthesiology Laboratory of Translational Research “Stress and Immunity” University Hospital LMU Munich Munich Germany
| | - Manfred Thiel
- Department of Anaesthesiology and Intensive Care Medical Faculty at Mannheim University of Heidelberg Mannheim Germany
| | - Sarah Baatout
- Radiobiology Unit Belgian Nuclear Research Centre (SCK CEN) Mol Belgium
| | | | - Alexander Choukèr
- Department of Anaesthesiology Laboratory of Translational Research “Stress and Immunity” University Hospital LMU Munich Munich Germany
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Hatfield S, Veszeleiova K, Steingold J, Sethuraman J, Sitkovsky M. Mechanistic Justifications of Systemic Therapeutic Oxygenation of Tumors to Weaken the Hypoxia Inducible Factor 1α-Mediated Immunosuppression. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1136:113-121. [PMID: 31201720 DOI: 10.1007/978-3-030-12734-3_8] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Long-term studies of anti-pathogen and anti-tumor immunity have provided complementary genetic and pharmacological evidence for the immunosuppressive and immunomodulatory effects of Hypoxia-HIF-1α and adenosine-mediated suppression via the A2A adenosine receptor signaling pathway (Hypoxia-A2A-adenosinergic). This pathway is life saving when it protects inflamed tissues of vital organs from collateral damage by overactive anti-pathogen immune cells or enables the differentiation of cells of adaptive immunity. However, the Hypoxia-A2A-adenosinergic immunosuppression can also prevent tumor rejection by inhibiting the anti-tumor effects of T and NK cells. In addition, this suppressive pathway has been shown to mask tumors due to the hypoxia-HIF-α-mediated loss of MHC Class I molecules on tumor cells. It is suggested that it will be impossible to realize the full anti-tumor capacities of current cancer immunotherapies without simultaneous administration of anti-Hypoxia-A2A-Adenosinergic drugs that inactivate this tumor-protecting mechanism in hypoxic and adenosine-rich tumors.Here, we overview the supporting evidence for the conceptually novel immunotherapeutic motivation to breathe supplemental oxygen (40-60%) or to repurpose already available oxygenation agents in combination with current immunotherapies. Preclinical studies provide strong support for oxygen immunotherapy to enable much stronger tumor regression by weakening immunosuppression by A2A adenosine receptors and by the Hypoxia➔HIF-1α axis. The results of these studies emphasize the value of systemic oxygenation as clinically feasible, promising, and as a valuable tool for mechanistic investigations of tumor biology and cancer immunology. Perhaps the most effective and feasible among individual members of this novel class of anti-tumor drugs are oxygenation agents.
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Affiliation(s)
- Stephen Hatfield
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA, USA
| | - Katarina Veszeleiova
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA, USA
| | - Joe Steingold
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA, USA
| | - Jyothi Sethuraman
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA, USA
| | - Michail Sitkovsky
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA, USA.
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Ghalamfarsa G, Rastegari A, Atyabi F, Hassannia H, Hojjat‐Farsangi M, Ghanbari A, Anvari E, Mohammadi J, Azizi G, Masjedi A, Yousefi M, Yousefi B, Hadjati J, Jadidi‐Niaragh F. Anti‐angiogenic effects of CD73‐specific siRNA‐loaded nanoparticles in breast cancer‐bearing mice. J Cell Physiol 2018; 233:7165-7177. [DOI: 10.1002/jcp.26743] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/13/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Ghasem Ghalamfarsa
- Cellular and Molecular Research Center Yasuj University of Medical Sciences Yasuj Iran
| | - Ali Rastegari
- Drug Applied Research Center Tabriz University of Medical Sciences Tabriz Iran
- Nanotechnology Research Centre, Faculty of Pharmacy Tehran University of Medical Sciences Tehran Iran
| | - Fatemeh Atyabi
- Nanotechnology Research Centre, Faculty of Pharmacy Tehran University of Medical Sciences Tehran Iran
| | - Hadi Hassannia
- Immunogenetic Research Center, Faculty of Medicine Mazandaran University of Medical Sciences Sari Iran
- Amol Faculty of Paramedical Sciences Mazandaran University of Medical Sciences Sari Iran
| | - Mohammad Hojjat‐Farsangi
- Department of Oncology‐Pathology, Immune and Gene therapy Lab, Cancer Center Karolinska (CCK) Karolinska University Hospital Solna and Karolinska Institute Stockholm Sweden
- Department of Immunology, School of Medicine Bushehr University of Medical Sciences Bushehr Iran
| | - Amir Ghanbari
- Cellular and Molecular Research Center Yasuj University of Medical Sciences Yasuj Iran
| | - Enayat Anvari
- Department of Physiology, Faculty of Medicine Ilam University of Medical Sciences Ilam Iran
| | - Jamshid Mohammadi
- Medicinal Plants Research Center Yasuj University of Medical Sciences Yasuj Iran
| | - Gholamreza Azizi
- Non‐Communicable Diseases Research Center Alborz University of Medical Sciences Karaj Iran
| | - Ali Masjedi
- Immunology Research Center Tabriz University of Medical Sciences Tabriz Iran
- Department of Immunology, Faculty of Medicine Tabriz University of Medical Sciences Tabriz Iran
| | - Mehdi Yousefi
- Drug Applied Research Center Tabriz University of Medical Sciences Tabriz Iran
| | - Bahman Yousefi
- Immunology Research Center Tabriz University of Medical Sciences Tabriz Iran
| | - Jamshid Hadjati
- Department of Immunology, Faculty of Medicine Tehran University of Medical Sciences Tehran Iran
| | - Farhad Jadidi‐Niaragh
- Immunology Research Center Tabriz University of Medical Sciences Tabriz Iran
- Department of Immunology, Faculty of Medicine Tabriz University of Medical Sciences Tabriz Iran
- Department of Immunology, Faculty of Medicine Tehran University of Medical Sciences Tehran Iran
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13
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Strewe C, Zeller R, Feuerecker M, Hoerl M, Matzel S, Kumprej I, Crispin A, Johannes B, Debevec T, Mekjavic IB, Eiken O, Thiel M, Schelling G, Choukèr A. PlanHab Study: Consequences of combined normobaric hypoxia and bed rest on adenosine kinetics. Sci Rep 2018; 8:1762. [PMID: 29379127 PMCID: PMC5788919 DOI: 10.1038/s41598-018-20045-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/20/2017] [Indexed: 12/24/2022] Open
Abstract
Adenosine plays a role in the energy supply of cells and provokes differential, hormone-like functions in circulating cells and various tissues. Its release is importantly regulated by oxygen tension. This renders adenosine and its kinetics interesting to investigate in humans subjected to low oxygen conditions. Especially for space exploration scenarios, hypoxic conditions - together with reduced gravity - represent two foreseen living conditions when planning manned long-duration space missions or planetary habitats. The PlanHab study investigated microgravity through inactivity in bed rest and normobaric hypoxia to examine their independent or combined effect on adenosine and its kinetics. Healthy male subjects (n = 14) completed three 21-day interventions: hypoxic bed rest (HBR); hypoxic ambulatory confinement (HAMB); normoxic bed rest (NBR). The interventions were separated by 4 months. Our hypothesis of a hypoxia-triggered increase in adenosine was confirmed in HAMB but unexpectedly also in NBR. However, the highest adenosine levels were noted following HBR. Furthermore, the percentage of hemolysis was elevated in HBR whereas endothelial integrity markers stayed low in all three interventions. In summary, these data suggest that neocytolysis accounts for these effects while we could reduce evidence for microcirculatory changes.
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Affiliation(s)
- C Strewe
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany
| | - R Zeller
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany
| | - M Feuerecker
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany
| | - M Hoerl
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany
| | - S Matzel
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany
| | - I Kumprej
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany.,Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - A Crispin
- Institute for Medical Information Processing, Biometry and Epidemiology, Klinikum Großhadern, University of Munich, Munich, Germany
| | - B Johannes
- Division of Space Physiology, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - T Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - I B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.,Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - O Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Center, School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden
| | - M Thiel
- Department of Anaesthesiology and Surgical Intensive Care Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - G Schelling
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany
| | - A Choukèr
- Department of Anaesthesiology, University Hospital, LMU Munich, Laboratory of Translational Research "Stress and Immunity", Munich, Germany.
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14
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Early immune anergy towards recall antigens and mitogens in patients at onset of septic shock. Sci Rep 2018; 8:1754. [PMID: 29379043 PMCID: PMC5788998 DOI: 10.1038/s41598-018-19976-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 01/10/2018] [Indexed: 12/25/2022] Open
Abstract
The pathology of sepsis is typically characterized by an infection and excessive initial inflammation including a cytokine storm, followed by a state of immune suppression or paralysis. This classical view of a two peak kinetic immune response is currently controversially discussed. This study was a sub-study of the randomized clinical Trial SISPCT registered with www.clinicaltrials.gov (NCT00832039, Registration date: 29/01/2009). Blood samples from 76 patients with severe sepsis and septic shock were incubated for 48 h at 37 °C in vitro with bacterial or fungal recall-antigens or specific mitogen antigens within 24 hours of sepsis onset. Recall-antigen stimulation led to a severe dampening of normal cytokine release. This immunologic anergy was similarly observed after mitogen stimulation. Moreover, patients under hydrocortisone therapy or with lowered arterial oxygen tension had further reductions in cytokine levels upon B- and T-cell mitogen stimulation. This investigation reveals an early onset of immunoparalysis during sepsis. This immune incompetence in mounting an adequate response to further infections includes previously sensitized pathogens, as seen with recall-antigens. Also, the immune-suppressive role of hydrocortisone and low PaO2 is highlighted. Aside from early broad-spectrum antimicrobial therapy, our findings reinforce the need for maximal immunological support and protection against further infections at the onset of sepsis.
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15
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Abstract
Autoimmune diseases are characterized by the abnormal immune response against self-tissue, which are caused by the failure of nature immune homeostasis. Nature immune homeostasis represents the normal state of appropriate immune response to nonself-antigen and unresponsiveness to self-antigens. In normal situation, immune homeostasis is regulated by immunosuppressive signal and immunostimulating signal together. Accumulating data have demonstrated that the adenosinergic pathway played key roles in immune suppression and shield body from an excessive inflammatory response. The deficiency of adenosinergic pathway results in the imbalance between the pro- and anti-inflammatory activities. Thus, researchers pay much attention to the role of adenosinergic pathway in autoimmune diseases development. To date, accumulating data have suggested an important role of adenosinergic pathway-related molecules (i.e., CD39, CD73, ADA, adenosine receptors, etc.) in many types of human autoimmune diseases. More importantly, these findings have presented potential value of adenosinergic pathway analysis to be used for autoimmune diseases diagnosis, monitoring and treatment. In this review, we will provide a comprehensive description of the role of adenosinergic pathway in human autoimmune diseases.
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Affiliation(s)
- Ke Dong
- Department of Clinical Diagnosis, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
| | - Zhao-Wei Gao
- Department of Clinical Diagnosis, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Hui-Zhong Zhang
- Department of Clinical Diagnosis, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
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16
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de Andrade Mello P, Coutinho-Silva R, Savio LEB. Multifaceted Effects of Extracellular Adenosine Triphosphate and Adenosine in the Tumor-Host Interaction and Therapeutic Perspectives. Front Immunol 2017; 8:1526. [PMID: 29184552 PMCID: PMC5694450 DOI: 10.3389/fimmu.2017.01526] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 10/27/2017] [Indexed: 12/20/2022] Open
Abstract
Cancer is still one of the world's most pressing health-care challenges, leading to a high number of deaths worldwide. Immunotherapy is a new developing therapy that boosts patient's immune system to fight cancer by modifying tumor-immune cells interaction in the tumor microenvironment (TME). Extracellular adenosine triphosphate (eATP) and adenosine (Ado) are signaling molecules released in the TME that act as modulators of both immune and tumor cell responses. Extracellular adenosine triphosphate and Ado activate purinergic type 2 (P2) and type 1 (P1) receptors, respectively, triggering the so-called purinergic signaling. The concentration of eATP and Ado within the TME is tightly controlled by several cell-surface ectonucleotidases, such as CD39 and CD73, the major ecto-enzymes expressed in cancer cells, immune cells, stromal cells, and vasculature, being CD73 also expressed on tumor-associated fibroblasts. Once accumulated in the TME, eATP boosts antitumor immune response, while Ado attenuates or suppresses immunity against the tumor. In addition, both molecules can mediate growth stimulation or inhibition of the tumor, depending on the specific receptor activated. Therefore, purinergic signaling is able to modulate both tumor and immune cells behavior and, consequently, the tumor-host interaction and disease progression. In this review, we discuss the role of purinergic signaling in the host-tumor interaction detailing the multifaceted effects of eATP and Ado in the inflammatory TME. Moreover, we present recent findings into the application of purinergic-targeting therapy as a potential novel option to boost antitumor immune responses in cancer.
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Affiliation(s)
- Paola de Andrade Mello
- Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
| | - Robson Coutinho-Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz Eduardo Baggio Savio
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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17
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Fluorinated Adenosine A 2A Receptor Antagonists Inspired by Preladenant as Potential Cancer Immunotherapeutics. INTERNATIONAL JOURNAL OF MEDICINAL CHEMISTRY 2017; 2017:4852537. [PMID: 29201461 PMCID: PMC5671725 DOI: 10.1155/2017/4852537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/31/2017] [Accepted: 09/13/2017] [Indexed: 12/18/2022]
Abstract
Antagonism of the adenosine A2A receptor on T cells blocks the hypoxia-adenosinergic pathway to promote tumor rejection. Using an in vivo immunoassay based on the Concanavalin A mouse model, a series of A2A antagonists were studied and identified preladenant as a potent lead compound for development. Molecular modeling was employed to assist drug design and subsequent synthesis of analogs and those of tozadenant, including fluorinated polyethylene glycol PEGylated derivatives. The efficacy of the analogs was evaluated using two in vitro functional bioassays, and compound 29, a fluorinated triethylene glycol derivative of preladenant, was confirmed as a potential immunotherapeutic agent.
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18
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Burnstock G. Purinergic Signalling: Therapeutic Developments. Front Pharmacol 2017; 8:661. [PMID: 28993732 PMCID: PMC5622197 DOI: 10.3389/fphar.2017.00661] [Citation(s) in RCA: 263] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022] Open
Abstract
Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical SchoolLondon, United Kingdom
- Department of Pharmacology and Therapeutics, The University of Melbourne, MelbourneVIC, Australia
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19
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Schmiel SE, Yang JA, Jenkins MK, Mueller DL. Cutting Edge: Adenosine A2a Receptor Signals Inhibit Germinal Center T Follicular Helper Cell Differentiation during the Primary Response to Vaccination. THE JOURNAL OF IMMUNOLOGY 2016; 198:623-628. [PMID: 27986907 DOI: 10.4049/jimmunol.1601686] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/27/2016] [Indexed: 12/15/2022]
Abstract
Adenosine A2a receptor (A2aR) signaling acts as a barrier to autoimmunity by promoting anergy, inducing regulatory T cells, and inhibiting effector T cells. However, in vivo effects of A2aR signaling on polyclonal CD4 T cells during a primary response to foreign Ag has yet to be determined. To address this problem, we immunized mice with peptide Ag 2W1S coupled to PE in CFA and treated with the selective A2aR agonist CGS-21680 (CGS). 2W1S:I-Ab-specific tetramer-binding CD4 T cells did not become anergic or differentiate into Foxp3+ regulatory T cells. Additionally, CGS treatment did not inhibit Th1 or Th17 differentiation. However, CGS did abrogate germinal center T follicular helper cells, and blunted PE-specific germinal center B cell responses. The use of A2aR-deficient CD4 T cells established that this CGS effect was T cell intrinsic. Therefore, this study has identified a unique role for A2aRs in regulating CD4 T cell differentiation during vaccination.
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Affiliation(s)
- Shirdi E Schmiel
- Department of Medicine, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455; and
| | - Jessica A Yang
- Department of Microbiology and Immunology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Marc K Jenkins
- Department of Microbiology and Immunology, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Daniel L Mueller
- Department of Medicine, Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455; and
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20
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Cronstein BN, Sitkovsky M. Adenosine and adenosine receptors in the pathogenesis and treatment of rheumatic diseases. Nat Rev Rheumatol 2016; 13:41-51. [PMID: 27829671 DOI: 10.1038/nrrheum.2016.178] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Adenosine, a nucleoside derived primarily from the extracellular hydrolysis of adenine nucleotides, is a potent regulator of inflammation. Adenosine mediates its effects on inflammatory cells by engaging one or more cell-surface receptors. The expression and function of adenosine receptors on different cell types change during the course of rheumatic diseases, such as rheumatoid arthritis (RA). Targeting adenosine receptors directly for the treatment of rheumatic diseases is currently under study; however, indirect targeting of adenosine receptors by enhancing adenosine levels at inflamed sites accounts for most of the anti-inflammatory effects of methotrexate, the anchor drug for the treatment of RA. In this Review, we discuss the regulation of extracellular adenosine levels and the role of adenosine in regulating the inflammatory and immune responses in rheumatic diseases such as RA, psoriasis and other types of inflammatory arthritis. In addition, adenosine and its receptors are involved in promoting fibrous matrix production in the skin and other organs, and the role of adenosine in fibrosis and fibrosing diseases is also discussed.
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Affiliation(s)
- Bruce N Cronstein
- NYU-HHC Clinical and Translational Science Institute, NYU School of Medicine, 550 First Avenue, New York, New York 10016, USA
| | - Michail Sitkovsky
- New England Inflammation and Tissue Protection Institute, Northeastern University, 360 Huntington Avenue, 312 MU, Boston, Massachusetts 02115, USA
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21
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Zhang Y, Ertl HCJ. Starved and Asphyxiated: How Can CD8(+) T Cells within a Tumor Microenvironment Prevent Tumor Progression. Front Immunol 2016; 7:32. [PMID: 26904023 PMCID: PMC4748049 DOI: 10.3389/fimmu.2016.00032] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/22/2016] [Indexed: 01/08/2023] Open
Abstract
Although cancer immunotherapy has achieved significant breakthroughs in recent years, its overall efficacy remains limited in the majority of patients. One major barrier is exhaustion of tumor antigen-specific CD8(+) tumor-infiltrating lymphocytes (TILs), which conventionally has been attributed to persistent stimulation with antigen within the tumor microenvironment (TME). A series of recent studies have highlighted that the TME poses significant metabolic challenges to TILs, which may contribute to their functional exhaustion. Hypoxia increases the expression of coinhibitors on activated CD8(+) T cells, which in general reduces the T cells' effector functions. It also impairs the cells' ability to gain energy through oxidative phosphorylation. Glucose limitation increases the expression of programed cell death protein-1 and reduces functions of activated CD8(+) T cells. A combination of hypoxia and hypoglycemia, as is common in solid tumors, places CD8(+) TILs at dual metabolic jeopardy by affecting both major pathways of energy production. Recently, a number of studies addressed the effects of metabolic stress on modulating CD8(+) T cell metabolism, differentiation, and functions. Here, we discuss recent findings on how different types of metabolic stress within the TME shape the tumor-killing capacity of CD8(+) T cells. We propose that manipulating the metabolism of TILs to more efficiently utilize nutrients, especially during intermittent periods of hypoxia could maximize their performance, prolong their survival and improve the efficacy of active cancer immunotherapy.
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Affiliation(s)
- Ying Zhang
- Gene Therapy and Vaccines Program, University of Pennsylvania School of Medicine, Philadelphia, PA, USA; The Wistar Institute Vaccine Center, Philadelphia, PA, USA
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22
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Hypoxia impairs anti-viral activity of natural killer (NK) cells but has little effect on anti-fibrotic NK cell functions in hepatitis C virus infection. J Hepatol 2015; 63:1334-44. [PMID: 26297916 DOI: 10.1016/j.jhep.2015.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 06/30/2015] [Accepted: 08/01/2015] [Indexed: 01/04/2023]
Abstract
BACKGROUND & AIMS Natural killer (NK) cells have been shown to exert anti-viral as well as anti-fibrotic functions in hepatitis C virus (HCV) infection. Previous studies, however, analyzed NK cell functions exclusively under atmospheric oxygen conditions despite the fact that the liver microenvironment is hypoxic. Here, we analyzed the effects of low oxygen tension on anti-viral and anti-fibrotic NK cell activity. METHODS Peripheral (n=34) and intrahepatic (n=15) NK cells from HCV(+) patients as well as circulating NK cells from healthy donors (n=20) were studied with respect to anti-viral and anti-fibrotic activity via co-culture experiments with HuH7 replicon cells and hepatic stellate cells, respectively. RESULTS Anti-viral activity of resting NK cells from healthy controls was not affected by hypoxia. However, hypoxia significantly reduced the response of healthy NK cells to cytokine stimulation. In contrast to healthy controls, we observed resting and cytokine activated peripheral NK cells from HCV patients to display a significantly decreased anti-viral activity when cultured at 5% or 1% oxygen, suggesting HCV NK cells to be very sensitive to hypoxia. These findings could be confirmed when intrahepatic NK cells were tested. Finally, we show that anti-fibrotic NK cell activity was not affected by low oxygen tension. CONCLUSIONS Our results show that anti-viral function of NK cells from HCV(+) patients is critically affected by a hypoxic microenvironment and, therefore, indicate that in order to obtain an accurate understanding of intrahepatic NK cell anti-HCV activity, the laboratory modelling should take into account the liver specific levels of oxygen.
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23
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Pedata F, Dettori I, Coppi E, Melani A, Fusco I, Corradetti R, Pugliese AM. Purinergic signalling in brain ischemia. Neuropharmacology 2015; 104:105-30. [PMID: 26581499 DOI: 10.1016/j.neuropharm.2015.11.007] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/04/2015] [Accepted: 11/06/2015] [Indexed: 12/18/2022]
Abstract
Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia a primary damage due to the early massive increase of extracellular glutamate is followed by activation of resident immune cells, i.e microglia, and production or activation of inflammation mediators. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression. Extracellular concentrations of ATP and adenosine in the brain increase dramatically during ischemia in concentrations able to stimulate their respective specific P2 and P1 receptors. Both ATP P2 and adenosine P1 receptor subtypes exert important roles in ischemia. Although adenosine exerts a clear neuroprotective effect through A1 receptors during ischemia, the use of selective A1 agonists is hampered by undesirable peripheral effects. Evidence up to now in literature indicate that A2A receptor antagonists provide protection centrally by reducing excitotoxicity, while agonists at A2A (and possibly also A2B) and A3 receptors provide protection by controlling massive infiltration and neuroinflammation in the hours and days after brain ischemia. Among P2X receptors most evidence indicate that P2X7 receptor contribute to the damage induced by the ischemic insult due to intracellular Ca(2+) loading in central cells and facilitation of glutamate release. Antagonism of P2X7 receptors might represent a new treatment to attenuate brain damage and to promote proliferation and maturation of brain immature resident cells that can promote tissue repair following cerebral ischemia. Among P2Y receptors, antagonists of P2Y12 receptors are of value because of their antiplatelet activity and possibly because of additional anti-inflammatory effects. Moreover strategies that modify adenosine or ATP concentrations at injury sites might be of value to limit damage after ischemia. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Felicita Pedata
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy.
| | - Ilaria Dettori
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Elisabetta Coppi
- Department of Health Sciences, University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Alessia Melani
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Irene Fusco
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Renato Corradetti
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Anna Maria Pugliese
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
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24
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Dold S, Richter S, Kollmar O, von Heesen M, Scheuer C, Laschke MW, Vollmar B, Schilling MK, Menger MD. Portal Hyperperfusion after Extended Hepatectomy Does Not Induce a Hepatic Arterial Buffer Response (HABR) but Impairs Mitochondrial Redox State and Hepatocellular Oxygenation. PLoS One 2015; 10:e0141877. [PMID: 26523932 PMCID: PMC4629903 DOI: 10.1371/journal.pone.0141877] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 10/14/2015] [Indexed: 01/24/2023] Open
Abstract
Background & Aims Portal hyperperfusion after extended hepatectomy or small-for-size liver transplantation may induce organ dysfunction and failure. The underlying mechanisms, however, are still not completely understood. Herein, we analysed whether hepatectomy-associated portal hyperperfusion induces a hepatic arterial buffer response, i.e., an adaptive hepatic arterial constriction, which may cause hepatocellular hypoxia and organ dysfunction. Methods Sprague-Dawley rats underwent 30%, 70% and 90% hepatectomy. Baseline measurements before hepatectomy served as controls. Hepatic arterial and portal venous flows were analysed by ultrasonic flow measurement. Microvascular blood flow and mitochondrial redox state were determined by intravital fluorescence microscopy. Hepatic tissue pO2 was analysed by polarographic techniques. Hepatic function and integrity were studied by bromosulfophthalein bile excretion and liver histology. Results Portal blood flow was 2- to 4-fold increased after 70% and 90% hepatectomy. This, however, did not provoke a hepatic arterial buffer response. Nonetheless, portal hyperperfusion and constant hepatic arterial blood flow were associated with a reduced mitochondrial redox state and a decreased hepatic tissue pO2 after 70% and 90% hepatectomy. Microvascular blood flow increased significantly after hepatectomy and functional sinusoidal density was found only slightly reduced. Major hepatectomy further induced a 2- to 3-fold increase of bile flow. This was associated with a 2-fold increase of bromosulfophthalein excretion. Conclusions Portal hyperperfusion after extended hepatectomy does not induce a hepatic arterial buffer response but reduces mitochondrial redox state and hepatocellular oxygenation. This is not due to a deterioration of microvascular perfusion, but rather due to a relative hypermetabolism of the remnant liver after major resection.
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Affiliation(s)
- Stefan Dold
- Department of General-, Visceral-, Vascular- and Pediatric Surgery, University of Saarland, Homburg/Saar, Germany
| | - Sven Richter
- Department of General-, Visceral-, Vascular- and Pediatric Surgery, University of Saarland, Homburg/Saar, Germany
| | - Otto Kollmar
- Department of General-, Visceral-, Vascular- and Pediatric Surgery, University of Saarland, Homburg/Saar, Germany
| | - Maximilian von Heesen
- Department of General-, Visceral-, Vascular- and Pediatric Surgery, University of Saarland, Homburg/Saar, Germany
- * E-mail:
| | - Claudia Scheuer
- Institute for Clinical & Experimental Surgery, University of Saarland, Homburg/Saar, Germany
| | - Matthias W. Laschke
- Institute for Clinical & Experimental Surgery, University of Saarland, Homburg/Saar, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, University of Rostock, Rostock, Germany
| | - Martin K. Schilling
- Department of General-, Visceral-, Vascular- and Pediatric Surgery, University of Saarland, Homburg/Saar, Germany
| | - Michael D. Menger
- Institute for Clinical & Experimental Surgery, University of Saarland, Homburg/Saar, Germany
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Aherne CM, Saeedi B, Collins CB, Masterson JC, McNamee EN, Perrenoud L, Rapp CR, Curtis VF, Bayless A, Fletcher A, Glover LE, Evans CM, Jedlicka P, Furuta GT, de Zoeten EF, Colgan SP, Eltzschig HK. Epithelial-specific A2B adenosine receptor signaling protects the colonic epithelial barrier during acute colitis. Mucosal Immunol 2015; 8:1324-38. [PMID: 25850656 PMCID: PMC4598274 DOI: 10.1038/mi.2015.22] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 02/17/2015] [Indexed: 02/04/2023]
Abstract
Central to inflammatory bowel disease (IBD) pathogenesis is loss of mucosal barrier function. Emerging evidence implicates extracellular adenosine signaling in attenuating mucosal inflammation. We hypothesized that adenosine-mediated protection from intestinal barrier dysfunction involves tissue-specific signaling through the A2B adenosine receptor (Adora2b) at the intestinal mucosal surface. To address this hypothesis, we combined pharmacologic studies and studies in mice with global or tissue-specific deletion of the Adora2b receptor. Adora2b(-/-) mice experienced a significantly heightened severity of colitis, associated with a more acute onset of disease and loss of intestinal epithelial barrier function. Comparison of mice with Adora2b deletion on vascular endothelial cells (Adora2b(fl/fl)VeCadCre(+)) or intestinal epithelia (Adora2b(fl/fl)VillinCre(+)) revealed a selective role for epithelial Adora2b signaling in attenuating colonic inflammation. In vitro studies with Adora2b knockdown in intestinal epithelial cultures or pharmacologic studies highlighted Adora2b-driven phosphorylation of vasodilator-stimulated phosphoprotein (VASP) as a specific barrier repair response. Similarly, in vivo studies in genetic mouse models or treatment studies with an Adora2b agonist (BAY 60-6583) recapitulate these findings. Taken together, our results suggest that intestinal epithelial Adora2b signaling provides protection during intestinal inflammation via enhancing mucosal barrier responses.
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Affiliation(s)
- CM Aherne
- Department of Anesthesiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - B Saeedi
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - CB Collins
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Section of Pediatric Gastroenterology, Hepatology and Nutrition, Digestive Health Institute, Children’s Hospital Colorado, Aurora, Colorado, USA
| | - JC Masterson
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Gastrointestinal Eosinophilic Diseases Program, Section of Pediatric Gastroenterology, Hepatology and Nutrition, Digestive Health Institute, Children’s Hospital Colorado, Aurora, Colorado, USA
| | - EN McNamee
- Department of Anesthesiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - L Perrenoud
- Department of Anesthesiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - CR Rapp
- Department of Anesthesiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - VF Curtis
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - A Bayless
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - A Fletcher
- Division of Pulmonary Sciences and Critical Care Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - LE Glover
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - CM Evans
- Division of Pulmonary Sciences and Critical Care Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - P Jedlicka
- Department of Pathology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - GT Furuta
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Gastrointestinal Eosinophilic Diseases Program, Section of Pediatric Gastroenterology, Hepatology and Nutrition, Digestive Health Institute, Children’s Hospital Colorado, Aurora, Colorado, USA
| | - EF de Zoeten
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,Section of Pediatric Gastroenterology, Hepatology and Nutrition, Digestive Health Institute, Children’s Hospital Colorado, Aurora, Colorado, USA
| | - SP Colgan
- Mucosal Inflammation Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - HK Eltzschig
- Department of Anesthesiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Hyperbaric hyperoxia alters innate immune functional properties during NASA Extreme Environment Mission Operation (NEEMO). Brain Behav Immun 2015; 50:52-57. [PMID: 26116982 DOI: 10.1016/j.bbi.2015.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Spaceflight is associated with immune dysregulation which is considered as risk factor for the performance of exploration-class missions. Among the consequences of confinement and other environmental factors of living in hostile environments, the role of different oxygen concentrations is of importance as either low (e.g. as considered for lunar or Martian habitats) or high (e.g. during extravehicular activities) can trigger immune dysfunction. The aim of this study was to investigate the impact of increased oxygen availability--generated through hyperbaricity--on innate immune functions in the course of a 14 days NEEMO mission. METHODS 6 male subjects were included into a 14 days undersea deployment at the Aquarius station (Key Largo, FL, USA). The underwater habitat is located at an operating depth of 47 ft. The 2.5 times higher atmospheric pressure in the habitat leads to hyperoxia. The collection of biological samples occurred 6 days before (L-6), at day 7 (MD7) and 11/13 (MD11/13) during the mission, and 90 days thereafter (R). Blood analyses included differential blood cell count, ex vivo innate immune activation status and inhibitory competences of granulocytes. RESULTS The absolute leukocyte count showed an increase during deployment as well as the granulocyte and monocyte count. Lymphocyte count was decreased on MD7. The assessments of native adhesion molecules on granulocytes (CD11b, CD62L) indicated a highly significant cellular activation (L-6 vs. MD7/MD13) during mission. In contrast, granulocytes were more sensitive towards anti-inflammatory stimuli (adenosine) on MD13. CONCLUSION Living in the NEEMO habitat for 14 days induced significant immune alterations as seen by an activation of adhesion molecules and vice versa higher sensitivity towards inhibition. This investigation under hyperbaric hyperoxia is important especially for Astronauts' immune competence during extravehicular activities when exposed to similar conditions.
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Early Adaption to the Antarctic Environment at Dome C: Consequences on Stress-Sensitive Innate Immune Functions. High Alt Med Biol 2014; 15:341-8. [DOI: 10.1089/ham.2013.1128] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Adenosine A2A receptors modulate acute injury and neuroinflammation in brain ischemia. Mediators Inflamm 2014; 2014:805198. [PMID: 25165414 PMCID: PMC4138795 DOI: 10.1155/2014/805198] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/26/2014] [Accepted: 07/10/2014] [Indexed: 01/07/2023] Open
Abstract
The extracellular concentration of adenosine in the brain increases dramatically during ischemia. Adenosine A2A receptor is expressed in neurons and glial cells and in inflammatory cells (lymphocytes and granulocytes). Recently, adenosine A2A receptor emerged as a potential therapeutic attractive target in ischemia. Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia the early massive increase of extracellular glutamate is followed by activation of resident immune cells, that is, microglia, and production or activation of inflammation mediators. Proinflammatory cytokines, which upregulate cell adhesion molecules, exert an important role in promoting recruitment of leukocytes that in turn promote expansion of the inflammatory response in ischemic tissue. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression. A2A receptors present on central cells and on blood cells account for important effects depending on the time-related evolution of the pathological condition. Evidence suggests that A2A receptor antagonists provide early protection via centrally mediated control of excessive excitotoxicity, while A2A receptor agonists provide protracted protection by controlling massive blood cell infiltration in the hours and days after ischemia. Focus on inflammatory responses provides for adenosine A2A receptor agonists a wide therapeutic time-window of hours and even days after stroke.
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Melani A, Corti F, Cellai L, Giuliana Vannucchi M, Pedata F. Low doses of the selective adenosine A2A receptor agonist CGS21680 are protective in a rat model of transient cerebral ischemia. Brain Res 2014; 1551:59-72. [DOI: 10.1016/j.brainres.2014.01.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/17/2013] [Accepted: 01/14/2014] [Indexed: 12/18/2022]
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Burnstock G, Vaughn B, Robson SC. Purinergic signalling in the liver in health and disease. Purinergic Signal 2014; 10:51-70. [PMID: 24271096 PMCID: PMC3944046 DOI: 10.1007/s11302-013-9398-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 12/18/2022] Open
Abstract
Purinergic signalling is involved in both the physiology and pathophysiology of the liver. Hepatocytes, Kupffer cells, vascular endothelial cells and smooth muscle cells, stellate cells and cholangiocytes all express purinoceptor subtypes activated by adenosine, adenosine 5'-triphosphate, adenosine diphosphate, uridine 5'-triphosphate or UDP. Purinoceptors mediate bile secretion, glycogen and lipid metabolism and indirectly release of insulin. Mechanical stress results in release of ATP from hepatocytes and Kupffer cells and ATP is also released as a cotransmitter with noradrenaline from sympathetic nerves supplying the liver. Ecto-nucleotidases play important roles in the signalling process. Changes in purinergic signalling occur in vascular injury, inflammation, insulin resistance, hepatic fibrosis, cirrhosis, diabetes, hepatitis, liver regeneration following injury or transplantation and cancer. Purinergic therapeutic strategies for the treatment of these pathologies are being explored.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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Subramanian M, Kini R, Madasu M, Ohta A, Nowak M, Exley M, Sitkovsky M, Ohta A. Extracellular adenosine controls NKT-cell-dependent hepatitis induction. Eur J Immunol 2014; 44:1119-29. [PMID: 24448964 DOI: 10.1002/eji.201343866] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 12/19/2013] [Accepted: 01/17/2014] [Indexed: 01/18/2023]
Abstract
Extracellular adenosine regulates inflammatory responses via the A2A adenosine receptor (A2AR). A2AR deficiency results in much exaggerated acute hepatitis, indicating nonredundancy of adenosine-A2AR pathway in inhibiting immune activation. To identify a critical target of immunoregulatory effect of extracellular adenosine, we focused on NKT cells, which play an indispensable role in hepatitis. An A2AR agonist abolished NKT-cell-dependent induction of acute hepatitis by concanavalin A (Con A) or α-galactosylceramide in mice, corresponding to downregulation of activation markers and cytokines in NKT cells and of NK-cell co-activation. These results show that A2AR signaling can downregulate NKT-cell activation and suppress NKT-cell-triggered inflammatory responses. Next, we hypothesized that NKT cells might be under physiological control of the adenosine-A2AR pathway. Indeed, both Con A and α-galactosylceramide induced more severe hepatitis in A2AR-deficient mice than in WT controls. Transfer of A2AR-deficient NKT cells into A2AR-expressing recipients resulted in exaggeration of Con A-induced liver damage, suggesting that NKT-cell activation is controlled by endogenous adenosine via A2AR, and this physiological regulatory mechanism of NKT cells is critical in the control of tissue-damaging inflammation. The current study suggests the possibility to manipulate NKT-cell activity in inflammatory disorders through intervention to the adenosine-A2AR pathway.
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Affiliation(s)
- Meenakshi Subramanian
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA, USA
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Bruzzese L, Fromonot J, By Y, Durand-Gorde JM, Condo J, Kipson N, Guieu R, Fenouillet E, Ruf J. NF-κB enhances hypoxia-driven T-cell immunosuppression via upregulation of adenosine A(2A) receptors. Cell Signal 2014; 26:1060-7. [PMID: 24486403 DOI: 10.1016/j.cellsig.2014.01.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/20/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
Hypoxia affects inflammation by modulating T-cell activation via the adenosinergic system. We supposed that, in turn, inflammation influences cell hypoxic behavior and that stimulation of T-cells in inflammatory conditions involves the concerted action of the nuclear factor κB (NF-κB) and the related hypoxia-inducible factor 1α (HIF-1α) on the adenosinergic system. We addressed this hypothesis by monitoring both transcription factors and four adenosinergic signaling parameters - namely adenosine, adenosine deaminase (ADA), adenosine A2A receptor (A2AR) and cAMP - in T-cells stimulated using phorbol myristate acetate and phytohemagglutinin and submitted to hypoxic conditions which were mimicked using CoCl2 treatment. We found that cell viability was more altered in stimulated than in resting cells under hypoxia. Detailed analysis showed that: i) NF-κB activation remained at basal level in resting hypoxic cells but greatly increased following stimulation, stimulated hypoxic cells exhibiting the higher level; ii) HIF-1α production induced by hypoxia was boosted via NF-κB activation in stimulated cells whereas hypoxia increased HIF-1α production in resting cells without further activating NF-κB; iii) A2AR expression and cAMP production increased in stimulated hypoxic cells whereas adenosine level remained unchanged due to ADA regulation; and iv) the presence of H2S, an endogenous signaling molecule in inflammation, reversed the effect of stimulation on cell viability by down-regulating the activity of transcription factors and adenosinergic immunosuppression. We also found that: i) the specific A2AR agonist CGS-21680 increased the suppressive effect of hypoxia on stimulated T-cells, the antagonist ZM-241385 exhibiting the opposite effect; and ii) Rolipram, a selective inhibitor of cAMP-specific phosphodiesterase 4, and 8-Br-cAMP, a cAMP analog which preferentially activates cAMP-dependent protein kinase A (PKA), increased T-cell immunosuppression whereas H-89, a potent and selective inhibitor of cAMP-dependent PKA, restored cell viability. Together, these data indicate that inflammation enhances T-cell sensitivity to hypoxia via NF-κB activation. This process upregulates A2AR expression and enhances cAMP production and PKA activation, resulting in adenosinergic T-cell immunosuppression that can be modulated via H2S.
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Affiliation(s)
- Laurie Bruzzese
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Julien Fromonot
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Youlet By
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Josée-Martine Durand-Gorde
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Jocelyne Condo
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Nathalie Kipson
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Régis Guieu
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France
| | - Emmanuel Fenouillet
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France; Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Biologiques, France
| | - Jean Ruf
- Aix-Marseille Université (AMU) and Institut de Recherche Biomédicale des Armées (IRBA), UMR MD2, Faculté de Médecine Nord, Marseille, France; Institut National de la Santé et de la Recherche Médicale (INSERM), France.
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Ohta A, Madasu M, Subramanian M, Kini R, Jones G, Choukèr A, Ohta A, Sitkovsky M. Hypoxia-induced and A2A adenosine receptor-independent T-cell suppression is short lived and easily reversible. Int Immunol 2013; 26:83-91. [PMID: 24150242 DOI: 10.1093/intimm/dxt045] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Tissue hypoxia plays a key role in establishing an immunosuppressive environment in vivo by, among other effects, increasing the level of extracellular adenosine, which then signals through A2A adenosine receptor (A2AR) to elicit its immunosuppressive effect. Although the important role of the adenosine--A2AR interaction in limiting inflammation has been established, the current study revisited this issue by asking whether hypoxia can also exert its T-cell inhibitory effects even without A2AR. A similar degree of hypoxia-triggered inhibition was observed in wild-type and A2AR-deficient T cells both in vitro and, after exposure of mice to a hypoxic atmosphere, in vivo. This A2AR-independent hypoxic T-cell suppression was qualitatively and mechanistically different from immunosuppression by A2AR stimulation. The A2AR-independent hypoxic immunosuppression strongly reduced T-cell proliferation, while IFN-γ-producing activity was more susceptible to the A2AR-dependent inhibition. In contrast to the sustained functional impairment after A2AR-mediated T-cell inhibition, the A2AR-independent inhibition under hypoxia was short lived, as evidenced by the quick recovery of IFN-γ-producing activity upon re-stimulation. These data support the view that T-cell inhibition by hypoxia can be mediated by multiple mechanisms and that both A2AR and key molecules in the A2AR-independent T-cell inhibition should be targeted to overcome the hypoxia-related immunosuppression in infected tissues and tumors.
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Affiliation(s)
- Akio Ohta
- New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, MA 02115, USA
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Chhabra P, Linden J, Lobo P, Okusa MD, Brayman KL. The immunosuppressive role of adenosine A2A receptors in ischemia reperfusion injury and islet transplantation. Curr Diabetes Rev 2012; 8:419-33. [PMID: 22934547 PMCID: PMC4209001 DOI: 10.2174/157339912803529878] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 06/15/2012] [Accepted: 06/18/2012] [Indexed: 02/08/2023]
Abstract
Activation of adenosine A2A receptors (A2AR) reduces inflammation by generally inhibiting the activation of pro-inflammatory cells, decreasing endothelial adhesion molecule expression and reducing the release of proinflammatory cytokine mediators. Numerous preclinical studies using selective A2AR agonists, antagonists, A2AR knockout as well as chimeric mice have suggested the therapeutic potential of A2AR agonists for the treatment of ischemia reperfusion injury (IRI) and autoimmune diseases. This review summarizes the immunosuppressive actions of A2AR agonists in murine IRI models of liver, kidney, heart, lung and CNS, and gives details on the cellular effects of A2AR activation in neutrophils, macrophages, dendritic cells, natural killer cells, NKT cells, T effector cells and CD4+CD25+FoxP3+ T regulatory cells. This is discussed in the context of cytokine mediators involved in inflammatory cascades. Whilst the role of adenosine receptor agonists in various models of autoimmune disease has been well-documented, very little information is available regarding the role of A2AR activation in type 1 diabetes mellitus (T1DM). An overview of the pathogenesis of T1DM as well as early islet graft rejection in the immediate peri-transplantation period offers insight regarding the use of A2AR agonists as a beneficial intervention in clinical islet transplantation, promoting islet graft survival, minimizing early islet loss and reducing the number of islets required for successful transplantation, thereby increasing the availability of this procedure to a greater number of recipients. In summary, the use of A2AR agonists as a clinical intervention in IRI and as an adjunct to clinical immunesuppressive regimen in islet transplantation is highlighted.
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Affiliation(s)
- Preeti Chhabra
- Department of Surgery, University of Virginia School of Medicine, P.O. Box 800709, Charlottesville, VA 22908-0709, USA.
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By Y, Jacquin L, Franceschi F, Durand-Gorde JM, Condo J, Michelet P, Guieu R, Ruf J. Fall in oxygen tension of culture medium stimulates the adenosinergic signalling of a human T cell line. Purinergic Signal 2012; 8:661-7. [PMID: 22331499 DOI: 10.1007/s11302-012-9295-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 02/01/2012] [Indexed: 10/28/2022] Open
Abstract
We examined the short-course expression of various parameters involved in the adenosinergic signalling of a human T cell line during in vitro decrease of the medium culture oxygen tension mimicking in vivo hypoxia. Fall of 92 mmHg in oxygen tension of culture medium induced in CEM, a CD4+ human T cell line, a continuous production of hypoxia-inducing factor-1α with a plateau value at 9 h, a rapid increase in adenosine production peaking at 3 h and a decrease in adenosine deaminase peaking at 6 h. The adenosine A(2A) receptor (A(2A)R) protein level of CEM cells was enhanced with a peak at 6 h. Intracellular 3',5'-cyclic adenosine monophosphate accumulated in CEM cells with a maximal level at 9 h. These results show that a human-cultured T cells line can upregulate its own adenosine production and A(2A)R expression during exposure to acute hypoxia. Hypoxia-increased stimulation of the adenosinergic signalling of T cells may have immunosuppressive properties and, consequently, A(2A)R agonists may have therapeutic relevance.
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Affiliation(s)
- Youlet By
- UMR MD2 P2COE, Aix-Marseille Univ, Faculté de Médecine, Timone, 27, Boulevard Jean Moulin, F-13385, Marseille Cedex 5, France
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Reichelt ME, Ashton KJ, Tan XL, Mustafa SJ, Ledent C, Delbridge LMD, Hofmann PA, Headrick JP, Morrison RR. The adenosine A₂A receptor - myocardial protectant and coronary target in endotoxemia. Int J Cardiol 2011; 166:672-80. [PMID: 22192288 DOI: 10.1016/j.ijcard.2011.11.075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 11/07/2011] [Accepted: 11/26/2011] [Indexed: 11/27/2022]
Abstract
BACKGROUND Cardiac injury and dysfunction are contributors to disease progression and mortality in sepsis. This study evaluated the cardiovascular role of intrinsic A₂A adenosine receptor (A₂AAR) activity during lipopolysaccharide (LPS)-induced inflammation. METHODS We assessed the impact of 24 h of LPS challenge (20 mg/kg, IP) on cardiac injury, coronary function and inflammatory mediator levels in Wild-Type (WT) mice and mice lacking functional A₂AARs (A₂AAR KO). RESULTS Cardiac injury was evident in LPS-treated WTs, with ~7-fold elevation in serum cardiac troponin I (cTnI), and significant ventricular and coronary dysfunction. Absence of A₂AARs increased LPS-provoked cTnI release at 24 h by 3-fold without additional demise of contraction function. Importantly, A₂AAR deletion per se emulated detrimental effects of LPS on coronary function, and LPS was without effect in coronary vessels lacking A₂AARs. Effects of A₂AAR KO were independent of major shifts in circulating C-reactive protein (CRP) and haptoglobin. Cytokine responses were largely insensitive to A₂AAR deletion; substantial LPS-induced elevations (up to 100-fold) in IFN-γ and IL-10 were unaltered in A₂AAR KO mice, as were levels of IL-4 and TNF-α. However, late elevations in IL-2 and IL-5 were differentially modulated by A₂AAR KO (IL-2 reduced, IL-5 increased). Data demonstrate that in the context of LPS-triggered cardiac and coronary injury, A₂AAR activity protects myocardial viability without modifying contractile dysfunction, and selectively modulates cytokine (IL-2, IL-5) release. A₂AARs also appear to be targeted by LPS in the coronary vasculature. CONCLUSIONS These experimental data suggest that preservation of A₂AAR functionality might provide therapeutic benefit in human sepsis.
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Affiliation(s)
- Melissa E Reichelt
- Heart Foundation Research Center, Griffith University, Southport QLD, Australia.
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Verrier JD, Exo JL, Jackson TC, Ren J, Gillespie DG, Dubey RK, Kochanek PM, Jackson EK. Expression of the 2',3'-cAMP-adenosine pathway in astrocytes and microglia. J Neurochem 2011; 118:979-87. [PMID: 21777245 PMCID: PMC3166383 DOI: 10.1111/j.1471-4159.2011.07392.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many organs express the extracellular 3',5'-cAMP-adenosine pathway (conversion of extracellular 3',5'-cAMP to 5'-AMP and 5'-AMP to adenosine). Some organs release 2',3'-cAMP (isomer of 3',5'-cAMP) and convert extracellular 2',3'-cAMP to 2'- and 3'-AMP and convert these AMPs to adenosine (extracellular 2',3'-cAMP-adenosine pathway). As astrocytes and microglia are important participants in the response to brain injury and adenosine is an endogenous neuroprotectant, we investigated whether these extracellular cAMP-adenosine pathways exist in these cell types. 2',3'-, 3',5'-cAMP, 5'-, 3'-, and 2'-AMP were incubated with mouse primary astrocytes or primary microglia for 1 h and purine metabolites were measured in the medium by mass spectrometry. There was little evidence of a 3',5'-cAMP-adenosine pathway in either astrocytes or microglia. In contrast, both cell types converted 2',3'-cAMP to 2'- and 3'-AMP (with 2'-AMP being the predominant product). Although both cell types converted 2'- and 3'-AMP to adenosine, microglia were five- and sevenfold, respectively, more efficient than astrocytes in this regard. Inhibitor studies indicated that the conversion of 2',3'-cAMP to 2'-AMP was mediated by a different ecto-enzyme than that involved in the metabolism of 2',3'-cAMP to 3'-AMP and that although CD73 mediates the conversion of 5'-AMP to adenosine, an alternative ecto-enzyme metabolizes 2'- or 3'-AMP to adenosine.
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Affiliation(s)
- Jonathan D. Verrier
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jennifer L. Exo
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Travis C. Jackson
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jin Ren
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Delbert G. Gillespie
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Raghvendra K. Dubey
- Department of Obstetrics & Gynecology, University Hospital Zurich, Switzerland
| | - Patrick M. Kochanek
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Edwin K. Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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39
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Ohta A, Diwanji R, Kini R, Subramanian M, Ohta A, Sitkovsky M. In vivo T cell activation in lymphoid tissues is inhibited in the oxygen-poor microenvironment. Front Immunol 2011; 2:27. [PMID: 22566817 PMCID: PMC3342240 DOI: 10.3389/fimmu.2011.00027] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 06/21/2011] [Indexed: 11/13/2022] Open
Abstract
Activation of immune cells is under control of immunological and physiological regulatory mechanisms to ensure adequate destruction of pathogens with the minimum collateral damage to “innocent” bystander cells. The concept of physiological negative regulation of immune response has been advocated based on the finding of the critical immunoregulatory role of extracellular adenosine. Local tissue oxygen tension was proposed to function as one of such physiological regulatory mechanisms of immune responses. In the current study, we utilized in vivo marker of local tissue hypoxia pimonidazole hydrochloride (Hypoxyprobe-1) in the flowcytometric analysis of oxygen levels to which lymphocytes are exposed in vivo. The level of exposure to hypoxia in vivo was low in B cells and the levels increased in the following order: T cells < NKT cells < NK cells. The thymus was more hypoxic than the spleen and lymph nodes, suggesting the variation in the degree of oxygenation among lymphoid organs and cell types in normal mice. Based on in vitro studies, tissue hypoxia has been assumed to be suppressive to T cell activation in vivo, but there was no direct evidence demonstrating that T cells exposed to hypoxic environment in vivo are less activated. We tested whether the state of activation of T cells in vivo changes due to their exposure to hypoxic tissue microenvironments. The parallel analysis of more hypoxic and less hypoxic T cells in the same mouse revealed that the degree of T cell activation was significantly stronger in better-oxygenated T cells. These observations suggest that the extent of T cell activation in vivo is dependent on their localization and is decreased in environment with low oxygen tension.
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Affiliation(s)
- Akio Ohta
- New England Inflammation and Tissue Protection Institute, Northeastern University Boston, MA, USA.
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Paterniti I, Melani A, Cipriani S, Corti F, Mello T, Mazzon E, Esposito E, Bramanti P, Cuzzocrea S, Pedata F. Selective adenosine A2A receptor agonists and antagonists protect against spinal cord injury through peripheral and central effects. J Neuroinflammation 2011; 8:31. [PMID: 21486435 PMCID: PMC3096915 DOI: 10.1186/1742-2094-8-31] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 04/12/2011] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Permanent functional deficits following spinal cord injury (SCI) arise both from mechanical injury and from secondary tissue reactions involving inflammation. Enhanced release of adenosine and glutamate soon after SCI represents a component in the sequelae that may be responsible for resulting functional deficits. The role of adenosine A2A receptor in central ischemia/trauma is still to be elucidated. In our previous studies we have demonstrated that the adenosine A2A receptor-selective agonist CGS21680, systemically administered after SCI, protects from tissue damage, locomotor dysfunction and different inflammatory readouts. In this work we studied the effect of the adenosine A2A receptor antagonist SCH58261, systemically administered after SCI, on the same parameters. We investigated the hypothesis that the main action mechanism of agonists and antagonists is at peripheral or central sites. METHODS Spinal trauma was induced by extradural compression of SC exposed via a four-level T5-T8 laminectomy in mouse. Three drug-dosing protocols were utilized: a short-term systemic administration by intraperitoneal injection, a chronic administration via osmotic minipump, and direct injection into the spinal cord. RESULTS SCH58261, systemically administered (0.01 mg/kg intraperitoneal. 1, 6 and 10 hours after SCI), reduced demyelination and levels of TNF-α, Fas-L, PAR, Bax expression and activation of JNK mitogen-activated protein kinase (MAPK) 24 hours after SCI. Chronic SCH58261 administration, by mini-osmotic pump delivery for 10 days, improved the neurological deficit up to 10 days after SCI. Adenosine A2A receptors are physiologically expressed in the spinal cord by astrocytes, microglia and oligodendrocytes. Soon after SCI (24 hours), these receptors showed enhanced expression in neurons. Both the A2A agonist and antagonist, administered intraperitoneally, reduced expression of the A2A receptor, ruling out the possibility that the neuroprotective effects of the A2A agonist are due to A2A receptor desensitization. When the A2A antagonist and agonist were centrally injected into injured SC, only SCH58261 appeared neuroprotective, while CGS21680 was ineffective. CONCLUSIONS Our results indicate that the A2A antagonist protects against SCI by acting on centrally located A2A receptors. It is likely that blockade of A2A receptors reduces excitotoxicity. In contrast, neuroprotection afforded by the A2A agonist may be primarily due to peripheral effects.
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Ohta A, Ohta A, Madasu M, Kini R, Subramanian M, Goel N, Sitkovsky M. A2A adenosine receptor may allow expansion of T cells lacking effector functions in extracellular adenosine-rich microenvironments. THE JOURNAL OF IMMUNOLOGY 2009; 183:5487-93. [PMID: 19843934 DOI: 10.4049/jimmunol.0901247] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Immunosuppressive signaling via the A2A adenosine receptor (A2AR) provokes a mechanism that protects inflamed tissues from excessive damage by immune cells. This mechanism is desirable not only for preventing uncontrolled tissue destruction by overactive immune responses, but also for protecting tumor tissues from antitumor immune responses. In aforementioned circumstances, T cell priming may occur in an environment containing high concentrations of extracellular adenosine. To examine qualitative changes in T cells activated in the presence of adenosine, we asked whether different functional responses of T cells are equally susceptible to A2AR agonists. In this study, we demonstrate that A2AR signaling during T cell activation strongly inhibited development of cytotoxicity and cytokine-producing activity in T cells, whereas the inhibition of T cell proliferation was only marginal. Both CD8(+) and CD4(+) T cells proliferated well in the presence of A2AR agonists, but their IFN-gamma-producing activities were susceptible to inhibition by cAMP-elevating A2AR. Importantly, the impaired effector functions were maintained in T cells even after removal of the A2AR agonist, reflecting T cell memory of the immunoregulatory effect of adenosine. Thus, although the adenosine-rich environment may allow for the expansion of T cells, the functional activation of T cells may be critically impaired. This physiological mechanism could explain the inefficiency of antitumor T cells in the tumor microenvironment.
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Affiliation(s)
- Akio Ohta
- New England Inflammation and Tissue Protection Institute, Northeastern University, 360 Huntington Avenue, 113 Mugar Health Sciences Building, Boston, MA 02115, USA.
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Ohta A, Sitkovsky M. The adenosinergic immunomodulatory drugs. Curr Opin Pharmacol 2009; 9:501-6. [PMID: 19539527 DOI: 10.1016/j.coph.2009.05.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 04/28/2009] [Accepted: 05/15/2009] [Indexed: 12/22/2022]
Abstract
Hypoxia-driven increase of extracellular adenosine in local tissue microenvironments of inflamed and cancerous tissues plays a critical role in the regulation of tissue destruction by activated immune cells. Accumulated data suggest that injection or consumption of A2A adenosine receptor (A2AR) antagonists may represent a drug treatment that diminishes adenosine-mediated immunosuppression. Since this, in turn, enhances the immune response, inhibition of adenosine-A2AR signaling may be a promising approach to enhance anti-tumor or anti-pathogen immune response. Patients with disorders characterized by excessive inflammation may be at risk to A2AR antagonists (e.g. caffeine) because of the effect to increase inflammatory damage secondary to enhanced immunity. On the other hand, enhancement of hypoxia-adenosinergic immunomodulatory pathways may be beneficial to prevent inflammatory tissue destruction.
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Affiliation(s)
- Akio Ohta
- New England Inflammation and Tissue Protection Institute, Northeastern University, 113 Mugar Health Science Building, 360 Huntington Avenue, Boston, MA 02115, United States.
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The expanding universe of hypoxia. J Mol Med (Berl) 2008; 86:739-46. [PMID: 18551266 DOI: 10.1007/s00109-008-0364-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 04/23/2008] [Accepted: 04/24/2008] [Indexed: 10/22/2022]
Abstract
Reduced oxygen availability (hypoxia) is sensed and transduced into changes in the activity or expression of cellular macromolecules. These responses impact on virtually all areas of biology and medicine. In this meeting report, we summarize major developments in the field that were presented at the 2008 Keystone Symposium on Cellular, Physiological, and Pathogenic Responses to Hypoxia.
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