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Chen D, Zeng R, Teng G, Cai C, Pan T, Tu H, Lin H, Du Q, Wang H, Chen Y. Menstrual blood-derived mesenchymal stem cells attenuate inflammation and improve the mortality of acute liver failure combining with A2AR agonist in mice. J Gastroenterol Hepatol 2021; 36:2619-2627. [PMID: 33729623 PMCID: PMC8518829 DOI: 10.1111/jgh.15493] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 03/06/2021] [Accepted: 03/08/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND AIM Acute liver failure (ALF) poses a serious public health issue. The menstrual blood-derived mesenchymal stem cells (MenSCs) have been applied to cure various liver-related diseases. However, the efficacy and mechanism are far from clear. This study aims to explore the efficacy and potential mechanism of MenSCs to cure ALF. METHODS We investigate the potential mechanism of MenSCs on the ALF in vitro and in vivo. A2A adenosine receptor (A2AR) activation was investigated as the potential reinforcer for MenSCs treatment. Lipid polysaccharide/d-galactosamine (d-GalN) was employed to induce ALF. Diverse techniques were used to measure the inflammatory cytokines and key signaling molecules. Hematoxylin-eosin stain and aminotransaminases were applied to evaluate the liver injury. Flow cytometry was employed to assess the T cells. RESULTS The MenSCs can decrease the lipid polysaccharide-induced inflammatory cytokine elevation and related signaling molecules in ALF, including TLR4, phosphorylated-NF-kBp65 (p-NF-kBp65), PI3K, and p-AKT, p-mTOR and p-IKK in vitro. Moreover, MenSCs also can significantly reverse the liver injury, inflammatory cytokines elevation and related signaling molecules increase, and Treg/Th17 ratio decrease in vivo. In addition, MenSCs plus A2AR agonist can enhance the above changes. CONCLUSIONS The MenSCs can attenuate the ALF-induced liver injury via inhibition of TLR4-mediated PI3K/Akt/mTOR/IKK signaling. Then, this inhibits the p-NF-κBp65 translocate into nuclear, which causes a decrease of inflammatory cytokines release. Moreover, A2AR agonist can play a synergic role with MenSCs and enhance the above-mentioned effects.
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Affiliation(s)
- Dazhi Chen
- Department of GastroenterologyPeking University First HospitalBeijingChina
| | - Ruichao Zeng
- Department of Oncological SurgeryThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhouChina,Precision and Systems BiomedicineQIMR Berghofer Medical Research InstituteBrisbaneQueenslandAustralia,Faculty of MedicineThe University of QueenslandWoolloongabbaQueenslandAustralia
| | - Guigen Teng
- Department of GastroenterologyPeking University First HospitalBeijingChina
| | - Chao Cai
- Department of Infectious Diseases, Wenzhou Key Laboratory of HepatologyThe First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical UniversityWenzhouChina
| | - Tongtong Pan
- Department of Infectious Diseases, Wenzhou Key Laboratory of HepatologyThe First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical UniversityWenzhouChina
| | - Hanxiao Tu
- Department of Infectious Diseases, Wenzhou Key Laboratory of HepatologyThe First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical UniversityWenzhouChina
| | - Hongwei Lin
- Department of Infectious Diseases, Wenzhou Key Laboratory of HepatologyThe First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical UniversityWenzhouChina
| | - Qingjing Du
- Department of Infectious Diseases, Wenzhou Key Laboratory of HepatologyThe First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical UniversityWenzhouChina
| | - Huahong Wang
- Department of GastroenterologyPeking University First HospitalBeijingChina
| | - Yongping Chen
- Department of Infectious Diseases, Wenzhou Key Laboratory of HepatologyThe First Affiliated Hospital of Wenzhou Medical University, Hepatology Institute of Wenzhou Medical UniversityWenzhouChina
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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: 22] [Impact Index Per Article: 5.5] [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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Peng X, Pan X, Tan J, Li Y, Li M. Protective effect of interleukin-36 receptor antagonist on liver injury induced by concanavalin A in mice. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2020; 23:623-628. [PMID: 32742600 PMCID: PMC7374990 DOI: 10.22038/ijbms.2020.35614.8492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Objective(s): Interleukin-36 receptor antagonist (IL-36Ra) is a new member of the IL-1 family that exhibits anti-inflammatory activity in a variety of inflammatory and immune diseases. Our purpose was to determine the effect of IL-36Ra on liver injury in a mouse hepatitis model induced by concanavalin A (ConA). Materials and Methods: Mice were treated with IL-36Ra DNA or pcDNA3.1 control plasmid using a hydrodynamic gene delivery approach. Results: Our data reveal that treatment with IL-36Ra decreased liver inflammation and serum level of aminotransferases. Furthermore, IL-36Ra reduced ConA-induced pro-inflammatory cytokines (interferon-γ, tumor necrosis factor-α, and IL-17A) production when compared to control plasmid. Conclusion: Our results demonstrated that IL-36Ra is a critical protector against ConA-induced liver injury.
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Affiliation(s)
- Xiao Peng
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| | - Xiuhe Pan
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| | - Jun Tan
- Department of Hepatology, HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo 315010, China
| | - Yan Li
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
| | - Mingcai Li
- Department of Immunology, Medical School of Ningbo University, Ningbo 315211, China
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Dal Ben D, Antonioli L, Lambertucci C, Fornai M, Blandizzi C, Volpini R. Purinergic Ligands as Potential Therapeutic Tools for the Treatment of Inflammation-Related Intestinal Diseases. Front Pharmacol 2018; 9:212. [PMID: 29593540 PMCID: PMC5861216 DOI: 10.3389/fphar.2018.00212] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/26/2018] [Indexed: 12/13/2022] Open
Abstract
Inflammation-related intestinal diseases are a set of various conditions presenting an overactive enteric immune system. A continuous overproduction of pro-inflammatory cytokines and a decreased production of anti-inflammatory modulators are generally observed, while morpho-functional alterations of the enteric nervous system lead to intestinal secretory and motor dysfunctions. The factors at the basis of these conditions are still to be totally identified and current therapeutic strategies are aimed only at achieving and maintaining remission states, by using therapeutic tools like aminosalicylates, corticosteroids, immunomodulators, biological drugs (i.e., monoclonal antibodies), and eventually surgery. Recent reports described a key role of purinergic mediators (i.e., adenosine and its nucleotides ATP and ADP) in the regulation of the activity of immune cells and enteric nervous system, showing also that alterations of the purinergic signaling are linked to pathological conditions of the intestinal tract. These data prompted to a series of investigations to test the therapeutic potential for inflammation-related intestinal conditions of compounds able to restore or modulate an altered purinergic signaling within the gut. This review provides an overview on these investigations, describing the results of preclinical and/or clinical evaluation of compounds able to stimulate or inhibit specific P2 (i.e., P2X7) or P1 (i.e., A2A or A3) receptor signaling and to modify the adenosine levels through the modulation of enzymes activity (i.e., Adenosine Deaminase) or nucleoside transporters. Recent developments in the field are also reported and the most promising purine-based therapeutic strategies for the treatment of inflammation-related gastrointestinal disorders are schematically summarized.
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Affiliation(s)
- Diego Dal Ben
- Medicinal Chemistry Unit, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Luca Antonioli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Catia Lambertucci
- Medicinal Chemistry Unit, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Matteo Fornai
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Corrado Blandizzi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Rosaria Volpini
- Medicinal Chemistry Unit, School of Pharmacy, University of Camerino, Camerino, Italy
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van Waarde A, Dierckx RAJO, Zhou X, Khanapur S, Tsukada H, Ishiwata K, Luurtsema G, de Vries EFJ, Elsinga PH. Potential Therapeutic Applications of Adenosine A 2A Receptor Ligands and Opportunities for A 2A Receptor Imaging. Med Res Rev 2017; 38:5-56. [PMID: 28128443 DOI: 10.1002/med.21432] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/31/2016] [Accepted: 11/14/2016] [Indexed: 12/13/2022]
Abstract
Adenosine A2A receptors (A2A Rs) are highly expressed in the human striatum, and at lower densities in the cerebral cortex, the hippocampus, and cells of the immune system. Antagonists of these receptors are potentially useful for the treatment of motor fluctuations, epilepsy, postischemic brain damage, or cognitive impairment, and for the control of an immune checkpoint during immunotherapy of cancer. A2A R agonists may suppress transplant rejection and graft-versus-host disease; be used to treat inflammatory disorders such as asthma, inflammatory bowel disease, and rheumatoid arthritis; be locally applied to promote wound healing and be employed in a strategy for transient opening of the blood-brain barrier (BBB) so that therapeutic drugs and monoclonal antibodies can enter the brain. Increasing A2A R signaling in adipose tissue is also a potential strategy to combat obesity. Several radioligands for positron emission tomography (PET) imaging of A2A Rs have been developed in recent years. This review article presents a critical overview of the potential therapeutic applications of A2A R ligands, the use of A2A R imaging in drug development, and opportunities and limitations of PET imaging in future research.
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Affiliation(s)
- Aren van Waarde
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands
| | - Rudi A J O Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands.,Department of Nuclear Medicine, University Hospital, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium
| | - Xiaoyun Zhou
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands
| | - Shivashankar Khanapur
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands
| | - Hideo Tsukada
- Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita, Hamamatsu, Shizuoka 434-8601, Japan
| | - Kiichi Ishiwata
- Research Institute of Cyclotron and Drug Discovery Research, Southern TOHOKU Research Institute for Neuroscience, 7-115 Yatsuyamada, Koriyama, 963-8052, Japan.,Department of Biofunctional Imaging, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.,Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Gert Luurtsema
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands
| | - Erik F J de Vries
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands
| | - Philip H Elsinga
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, 1, 9713 GZ, Groningen, The Netherlands
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Critical Contribution of Adenosine A2AReceptors in Bone Marrow–Derived Cells to White Matter Lesions Induced by Chronic Cerebral Hypoperfusion. J Neuropathol Exp Neurol 2015; 74:305-18. [DOI: 10.1097/nen.0000000000000174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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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: 70] [Impact Index Per Article: 7.0] [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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8
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Pommey S, Lu B, McRae J, Stagg J, Hill P, Salvaris E, Robson SC, d'Apice AJF, Cowan PJ, Dwyer KM. Liver grafts from CD39-overexpressing rodents are protected from ischemia reperfusion injury due to reduced numbers of resident CD4+ T cells. Hepatology 2013; 57:1597-606. [PMID: 22829222 DOI: 10.1002/hep.25985] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 07/14/2012] [Indexed: 12/17/2022]
Abstract
UNLABELLED Ischemia-reperfusion injury (IRI) is a major limiting event for successful liver transplantation, and CD4+ T cells and invariant natural killer T (iNKT) cells have been implicated in promoting IRI. We hypothesized that hepatic overexpression of CD39, an ectonucleotidase with antiinflammatory functions, will protect liver grafts after prolonged cold ischemia. CD39-transgenic (CD39tg) and wildtype (WT) mouse livers were transplanted into WT recipients after 18 hours cold storage and pathological analysis was performed 6 hours after transplantation. Serum levels of alanine aminotransferase and interleukin (IL)-6 were significantly reduced in recipients of CD39tg livers compared to recipients of WT livers. Furthermore, less severe histopathological injury was demonstrated in the CD39tg grafts. Immune analysis revealed that CD4+ T cells and iNKT cells were significantly decreased in number in the livers of untreated CD39tg mice. This was associated with a peripheral CD4+ T cell lymphopenia due to defective thymocyte maturation. To assess the relative importance of liver-resident CD4+ T cells and iNKT cells in mediating liver injury following extended cold preservation and transplantation, WT mice depleted of CD4+ T cells or mice genetically deficient in iNKT cells were used as donors. The absence of CD4+ T cells, but not iNKT cells, protected liver grafts from early IRI. CONCLUSION Hepatic CD4+ T cells, but not iNKT cells, play a critical role in early IRI following extended cold preservation in a liver transplant model.
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Affiliation(s)
- Sandra Pommey
- Immunology Research Centre, St Vincent's Hospital, Melbourne, Australia
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Zhou YC, Chen S, Cao JJ, Chen SY, Xie YF, Niu QX. Adenovirus-mediated viral interleukin-10 gene transfer prevents concanavalin A-induced liver injury. Dig Liver Dis 2012; 44:398-405. [PMID: 22209949 DOI: 10.1016/j.dld.2011.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 11/14/2011] [Accepted: 11/25/2011] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND AIM Liver injury is closely associated with immune inflammation. Lacking immunostimulatory functions, viral interleukin-10 (vIL-10), a cellular IL-10 homologue, has been an attractive molecule for immunomodulatory therapy. We aimed to reveal a protective effect of the gene transfer of an adenoviral vector encoding vIL-10 on liver injury induced by concanavalin A. METHODS C57BL/6J mice were intravenously injected with adenoviral vector encoding vIL-10 before concanavalin A challenge. Liver injury was assessed. Interferon-γ and interleukin-4 levels were measured by ELISA. The activation of splenic and hepatic immune cells was analysed using an MTT assay. RESULTS Adenoviral vector encoding vIL-10 pretreatment significantly decreased concanavalin A-mediated elevations in serum alanine aminotransaminase and aspartate aminotransaminase activity, and necrotic area in liver tissues. The protective effect of adenoviral vector encoding vIL-10 was attributed to its inhibition of T cell activation, and production of interferon-γ and interleukin-4 by the immune cells. Recombinant mouse IL-10, a high homologous cytokine to vIL-10, effectively downregulated interferon-γ and interleukin-4 release by hepatic mononuclear cells. CONCLUSION Adenovirus vector-mediated vIL-10 gene transfer can prevent concanavalin A-induced hepatic injury, minimise pro-inflammatory cytokine release, and inhibit the activation of T lymphocytes.
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Affiliation(s)
- Yan-Chun Zhou
- Institute of Inflammation and Immune Diseases, Shantou University Medical College, Shantou, Guangdong, China
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10
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Adenosine A2A receptor contributes to the anti-inflammatory effect of the fixed herbal combination STW 5 (Iberogast®) in rat small intestinal preparations. Naunyn Schmiedebergs Arch Pharmacol 2011; 385:411-21. [PMID: 22160002 DOI: 10.1007/s00210-011-0714-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 11/16/2011] [Indexed: 12/18/2022]
Abstract
STW 5 (Iberogast®), an established herbal combination, was effective in randomized, double blind clinical studies in functional dyspepsia and irritable bowel syndrome. Since STW 5 was found to influence intestinal motility and has anti-inflammatory properties, this study investigated the expression of adenosine receptors and characterized their role in the control of the anti-inflammatory action of STW 5 and its fresh plant component STW 6 in inflammation-disturbed rat small intestinal preparations. The inflammation was induced by intraluminal instillation of 2,4,6-trinitrobenzene sulfonic acid (TNBS, 0.01 M). The effects of coincubation with selective receptor agonists and antagonists, STW 5, STW 6, or combinations of these compounds on acetylcholine (ACh)-evoked contraction of ileum/jejunum preparations were tested. Adenosine receptor mRNA expression was examined by reverse transcription-polymerase chain reaction (RT-PCR). In untreated preparations, RT-PCR revealed the presence of all adenosine receptor subtypes. Suppressed expression was detected for all subtypes in inflamed tissues, except for A(2B)R mRNA, which was unaffected. STW 5 reversed these effects and enhanced A(2A)R expression above control levels. Radioligand binding assays confirm the affinity of STW 5 to the A(2A)R, and the A(2A)R antagonist was able to prevent the effect of STW 5 on TNBS-induced attenuation of the ACh contraction. Our findings provide evidence that STW 5, but not STW 6 interacts with A(2A)R, which is involved in the anti-inflammatory action of STW 5. STW 6 did not contribute to adenosine A(2A)R-mediated anti-inflammatory effect of STW 5. Other signaling pathways could be involved in the mechanism of action of STW 6.
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Drygiannakis I, Ernst PB, Lowe D, Glomski IJ. Immunological alterations mediated by adenosine during host-microbial interactions. Immunol Res 2011; 50:69-77. [PMID: 21479929 DOI: 10.1007/s12026-011-8207-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Adenosine accumulates in inflammation and ischemia but it is more than an end-product of ATP catabolism. Signaling through different receptors with distinct, cell-specific cytoplasmic pathways, adenosine is now recognized as an inducible switch that regulates the immune system. By acting through the A(2A)AR, adenosine shapes T cell function, largely by conferring an anti-inflammatory tone on effector Th cells (Teff) and natural killer (NK)T cells. In contrast, both the A(2A)AR and A(2B)AR are expressed by antigen-presenting cells (APC) which have been shown to regulate innate responses and the transition to adaptive immunity. There is also emerging evidence that adenosine production is one mechanism that allows some pathogens as well as neoplasms to evade host defenses. This review discusses the immunoregulatory functions of adenosine and some of the interactions it may have in regulating host-microbial interactions.
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Affiliation(s)
- Ioannis Drygiannakis
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Virginia, Charlottesville, 22908-0708, USA
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12
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Kolachala VL, Bajaj R, Chalasani M, Sitaraman SV. Purinergic receptors in gastrointestinal inflammation. Am J Physiol Gastrointest Liver Physiol 2008; 294:G401-10. [PMID: 18063703 DOI: 10.1152/ajpgi.00454.2007] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Purinergic receptors comprise a family of transmembrane receptors that are activated by extracellular nucleosides and nucleotides. The two major classes of purinergic receptors, P1 and P2, are expressed widely in the gastrointestinal tract as well as immune cells. The purinergic receptors serve a variety of functions from acting as neurotransmitters, to autocoid and paracrine signaling, to cell activation and immune response. Nucleosides and nucleotide agonist of purinergic receptors are released by many cell types in response to specific physiological signals, and their levels are increased during inflammation. In the past decade, the advent of genetic knockout mice and the development of highly potent and selective agonists and antagonists for the purinergic receptors have significantly advanced the understanding of purinergic receptor signaling in health and inflammation. In fact, agonist/antagonists of purinergic receptors are emerging as therapeutic modalities to treat intestinal inflammation. In this article, the distribution of the purinergic receptors in the gastrointestinal tract and their physiological and pathophysiological role in intestinal inflammation will be reviewed.
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Affiliation(s)
- Vasantha L Kolachala
- Division of Digestive Diseases, Emory University School of Medicine, Atlanta, GA 30322, USA
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Palmer TM, Trevethick MA. Suppression of inflammatory and immune responses by the A(2A) adenosine receptor: an introduction. Br J Pharmacol 2007; 153 Suppl 1:S27-34. [PMID: 18026131 DOI: 10.1038/sj.bjp.0707524] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The purine nucleoside adenosine has been described as a 'retaliatory metabolite' by virtue of its ability to function in an autocrine manner to modify the activity of a range of cell types following its extracellular accumulation during cell stress or injury. These effects are largely protective and are triggered by the binding of adenosine to any of four G-protein-coupled adenosine receptors. Most of the anti-inflammatory effects of adenosine have been assigned to the adenosine A(2A) receptor subtype, which is expressed in many immune and inflammatory cells. In this brief article, we will outline the growing evidence to support the hypothesis that the development of agonists selective for the A(2A) receptor is an effective strategy for suppressing the exaggerated inflammatory responses associated with many diseases by virtue of the receptor's ability to inhibit multiple pro-inflammatory signalling cascades.
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Affiliation(s)
- T M Palmer
- Molecular Pharmacology Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
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Caldwell CC, Tschoep J, Lentsch AB. Lymphocyte function during hepatic ischemia/reperfusion injury. J Leukoc Biol 2007; 82:457-64. [PMID: 17470532 DOI: 10.1189/jlb.0107062] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The liver is the primary organ affected by ischemia/reperfusion (I/R) injury after shock, surgical resection, or transplantation. The actions of myeloid leukocytes have been well studied and are thought to be the primary cells responsible for propagating the injury response. However, there is an emerging view that T lymphocytes can also regulate liver I/R-induced inflammation. Resident lymphocytes found within the liver include conventional alphabeta TCR cells as well as unconventional NK and gammadelta T cells. These lymphocytes can alter inflammation through the secretion of soluble mediators such as cytokines and chemokines or through cognate interactions in an antigen-dependent manner. Expression of these mediators will then result in the recruitment of more lymphocytes and neutrophils. There is evidence to suggest that T cell activation in the liver during I/R can be driven by antigenic or nonantigenic mechanisms. Finally, immune cells are exposed to different oxygen tensions, including hypoxia, as they migrate and function within tissues. The hypoxic environment during liver ischemia likely modulates T cell function, at least in part through the actions of hypoxia-inducible factor-1alpha. Further, this hypoxic environment leads to the increased concentration of extracellular adenosine, which is generally known to suppress T cell proinflammatory function. Altogether, the elucidation of T lymphocyte actions during liver I/R will likely allow for novel targets for therapeutic intervention.
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Affiliation(s)
- Charles C Caldwell
- The Laboratory of Trauma, Sepsis and Inflammation Research, Department of Surgery, University of Cincinnati, Cincinnati, Ohio, USA
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