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Trinh PNH, Baltos JA, Hellyer SD, May LT, Gregory KJ. Adenosine receptor signalling in Alzheimer’s disease. Purinergic Signal 2022; 18:359-381. [PMID: 35870032 PMCID: PMC9391555 DOI: 10.1007/s11302-022-09883-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/02/2022] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common dementia in the elderly and its increasing prevalence presents treatment challenges. Despite a better understanding of the disease, the current mainstay of treatment cannot modify pathogenesis or effectively address the associated cognitive and memory deficits. Emerging evidence suggests adenosine G protein-coupled receptors (GPCRs) are promising therapeutic targets for Alzheimer’s disease. The adenosine A1 and A2A receptors are expressed in the human brain and have a proposed involvement in the pathogenesis of dementia. Targeting these receptors preclinically can mitigate pathogenic β-amyloid and tau neurotoxicity whilst improving cognition and memory. In this review, we provide an accessible summary of the literature on Alzheimer’s disease and the therapeutic potential of A1 and A2A receptors. Although there are no available medicines targeting these receptors approved for treating dementia, we provide insights into some novel strategies, including allosterism and the targeting of oligomers, which may increase drug discovery success and enhance the therapeutic response.
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Affiliation(s)
- Phuc N. H. Trinh
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
- Department of Pharmacology, Monash University, Parkville, VIC 3052 Australia
| | - Jo-Anne Baltos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
- Department of Pharmacology, Monash University, Parkville, VIC 3052 Australia
| | - Shane D. Hellyer
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
| | - Lauren T. May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
- Department of Pharmacology, Monash University, Parkville, VIC 3052 Australia
| | - Karen J. Gregory
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
- Department of Pharmacology, Monash University, Parkville, VIC 3052 Australia
- ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Parkville, 3052 Australia
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2
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Wu DY, Feng L, Hao XY, Huang SB, Wu ZF, Ma S, Yin YL, Tan CQ. Effects of dietary supplementation of gestating sows with adenosine 5 '-monophosphate or adenosine on placental angiogenesis and vitality of their offspring. J Anim Sci 2022; 100:6628671. [PMID: 35781577 DOI: 10.1093/jas/skac237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/01/2022] [Indexed: 11/12/2022] Open
Abstract
Our previous study found that dietary nucleotide supplementation, including adenosine 5 '-monophosphate (AMP), could increase AMP content in sow milk and promote piglet growth, but its effects on placental efficiency and piglet vitality remains unknown. This experiment aimed to investigate the effects of dietary AMP or its metabolite adenosine (ADO) supplementation on sow reproductive performance and placental angiogenesis. A total of 135 sows with a similar farrowing time were blocked by backfat and body weight (BW) at day 65 of gestation, and assigned to 1 of 3 dietary treatment groups (n = 45 per treatment): basal diet, basal diet supplemented with 0.1% AMP, or 0.1% ADO, respectively. Placental analysis and the characteristics of sows and piglets unveiled that compared with control (CON) group, AMP or ADO supplementation could improve sow placental efficiency (P<0.05) and newborn piglet vitality (P<0.05), increase piglet birth weight (P<0.05), and reduce stillbirth rate (P<0.05). More importantly, AMP or ADO supplementation could increase the contents of AMP, ADO, and their metabolites in placentae (P<0.05). Meanwhile, AMP or ADO supplementation could also increase placental vascular density (P<0.05) and the expression of vascular endothelial growth factor A (P<0.05), as well as promote the migration and tube formation of porcine iliac artery endothelial cells (P<0.05). Overall, maternal dietary AMP or ADO supplementation could increase their contents in the placenta, thereby improving placental angiogenesis and neonatal piglet vitality.
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Affiliation(s)
- D Y Wu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - L Feng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - X Y Hao
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - S B Huang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Z F Wu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - S Ma
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Y L Yin
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.,National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China
| | - C Q Tan
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center for Breeding Swine Industry, Institute of Subtropical Animal Nutrition and Feed, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, China
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3
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Gdula AM, Swiatkowska M. A2 A receptor agonists and P2Y 12 receptor antagonists modulate expression of thrombospondin-1 (TSP-1) and its secretion from Human Microvascular Endothelial Cells (HMEC-1). Microvasc Res 2021; 138:104218. [PMID: 34182003 DOI: 10.1016/j.mvr.2021.104218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 05/07/2021] [Accepted: 06/24/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUNDS AND AIMS To address the problem of resistance to standard antiplatelet therapy in some patients, our team proposed a purinoceptor-dependent dual therapy. Its efficacy is also determined by the condition of the vascular endothelium which, by secreting numerous factors, is involved in hemostasis. Among them, thrombospondin-1 is important in the context of thrombotic events. Therefore we sought to determine if the novel dual purinoceptor-dependent concept is associated with TSP-1 changes in vascular endothelial cells. METHODS AND RESULTS TSP-1 expression in human microvascular endothelial cells was determined at transcriptional and protein level. We performed real-time PCR, the Western blot analysis and ELISA test. We found that TSP-1 mRNA and protein expression levels significantly changed in response to P1R agonists treatment. Furthermore, we have observed that co-administration of selective A2AR agonists (UK-432,097 or MRE0094) with P2Y12R antagonists altered TSP-1 expression levels, and the direction of these changes was not synergistic. MRE0094 applied with ARC69931MX or R-138727 increased mRNA expression from 39 to 56 or 57%, respectively (*P < 0.05 vs. MRE0094; ***P < 0.001 vs. control). Also, in the case of the P2Y12R antagonists used together with UK-432,097, there was an increase from 53 to 71 and 70% (*P < 0.05 vs. UK-432,097; ***P < 0.001 vs. control). The observed trends in gene expression were reflected in the protein expression and the level of its secretion from HMEC-1. CONCLUSION The article presents evidence which proves that the purinoceptor-dependent concept is associated with TSP-1 changes in endothelial cells (EC). Moreover, Human Microvascular Endothelial Cells treatment applied together with agonists (MRE0094 or UK-432,097) and P2Y12R antagonist did not result in any synergistic effect, implicating a possible crosstalk between G proteins in GPCRs dependent signaling. Therefore, we suggest that understanding of the specific mechanism underlying TSP-1 alterations in EC in the context of the dual purinoceptor-dependent approach is essential for antiplatelet therapies and should be the subject of future research.
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Affiliation(s)
- Anna M Gdula
- Department of Cytobiology and Proteomics, Medical University of Lodz, 6/8 Mazowiecka St., 92-215 Lodz, Poland.
| | - Maria Swiatkowska
- Department of Cytobiology and Proteomics, Medical University of Lodz, 6/8 Mazowiecka St., 92-215 Lodz, Poland
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Li J, Hong X, Li G, Conti PS, Zhang X, Chen K. PET Imaging of Adenosine Receptors in Diseases. Curr Top Med Chem 2019; 19:1445-1463. [PMID: 31284861 DOI: 10.2174/1568026619666190708163407] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/26/2019] [Accepted: 02/02/2019] [Indexed: 01/08/2023]
Abstract
Adenosine receptors (ARs) are a class of purinergic G-protein-coupled receptors (GPCRs). Extracellular adenosine is a pivotal regulation molecule that adjusts physiological function through the interaction with four ARs: A1R, A2AR, A2BR, and A3R. Alterations of ARs function and expression have been studied in neurological diseases (epilepsy, Alzheimer's disease, and Parkinson's disease), cardiovascular diseases, cancer, and inflammation and autoimmune diseases. A series of Positron Emission Tomography (PET) probes for imaging ARs have been developed. The PET imaging probes have provided valuable information for diagnosis and therapy of diseases related to alterations of ARs expression. This review presents a concise overview of various ARs-targeted radioligands for PET imaging in diseases. The most recent advances in PET imaging studies by using ARs-targeted probes are briefly summarized.
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Affiliation(s)
- Jindian Li
- Department of Radiology, Molecular Imaging Center, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, CSC103, Los Angeles, CA 90033, United States.,State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Xingfang Hong
- Laboratory of Pathogen Biology, School of Basic Medical Sciences, Dali University, Dali 671000, China
| | - Guoquan Li
- Department of Radiology, Molecular Imaging Center, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, CSC103, Los Angeles, CA 90033, United States
| | - Peter S Conti
- Department of Radiology, Molecular Imaging Center, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, CSC103, Los Angeles, CA 90033, United States
| | - Xianzhong Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Kai Chen
- Department of Radiology, Molecular Imaging Center, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, CSC103, Los Angeles, CA 90033, United States
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5
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Treprostinil reduces endothelial damage in murine sinusoidal obstruction syndrome. J Mol Med (Berl) 2018; 97:201-213. [PMID: 30535954 PMCID: PMC6348071 DOI: 10.1007/s00109-018-1726-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/13/2018] [Accepted: 11/21/2018] [Indexed: 12/03/2022]
Abstract
Abstract Sinusoidal obstruction syndrome (SOS) is a major complication after hematopoietic stem cell transplantation and belongs to a group of diseases increasingly identified as transplant-related systemic endothelial disease. Administration of defibrotide affords some protection against SOS, but the effect is modest. Hence, there is unmet medical need justifying the preclinical search for alternative approaches. Prostaglandins exert protective actions on endothelial cells of various vascular beds. Here, we explored the therapeutic potential of the prostacyclin analog treprostinil to prevent SOS. Treprostinil acts via stimulation of IP, EP2, and EP4 receptors, which we detected in murine liver sinusoidal endothelial cells (LSECs). Busulfan-induced cell death was reduced when pretreated with treprostinil in vitro. In a murine in vivo model of SOS, concomitantly administered treprostinil caused lower liver weight-to-body weight ratios indicating liver protection. Histopathological changes were scored to assess damage to liver sinusoidal endothelial cells, to hepatocytes, and to the incipient fibrotic reaction. Treprostinil indeed reduced sinusoidal endothelial cell injury, but this did not translate into reduced liver cell necrosis or fibrosis. In summary, our observations provide evidence for a beneficial effect of treprostinil on damage to LSECs but unexpectedly treprostinil was revealed as a double-edged sword in SOS. Key messages Murine liver sinusoidal endothelial cells (LSECs) express prostanoid receptors. Treprostinil reduces busulfan-induced cell death in vitro. Treprostinil lowers liver weight-to-body weight ratios in mice. Treprostinil positively affects LSECs in mice but not hepatic necrosis/fibrosis.
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6
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Xu Y, Wang Y, Yan S, Zhou Y, Yang Q, Pan Y, Zeng X, An X, Liu Z, Wang L, Xu J, Cao Y, Fulton DJ, Weintraub NL, Bagi Z, Hoda MN, Wang X, Li Q, Hong M, Jiang X, Boison D, Weber C, Wu C, Huo Y. Intracellular adenosine regulates epigenetic programming in endothelial cells to promote angiogenesis. EMBO Mol Med 2018; 9:1263-1278. [PMID: 28751580 PMCID: PMC5582416 DOI: 10.15252/emmm.201607066] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The nucleoside adenosine is a potent regulator of vascular homeostasis, but it remains unclear how expression or function of the adenosine‐metabolizing enzyme adenosine kinase (ADK) and the intracellular adenosine levels influence angiogenesis. We show here that hypoxia lowered the expression of ADK and increased the levels of intracellular adenosine in human endothelial cells. Knockdown (KD) of ADK elevated intracellular adenosine, promoted proliferation, migration, and angiogenic sprouting in human endothelial cells. Additionally, mice deficient in endothelial ADK displayed increased angiogenesis as evidenced by the rapid development of the retinal and hindbrain vasculature, increased healing of skin wounds, and prompt recovery of arterial blood flow in the ischemic hindlimb. Mechanistically, hypomethylation of the promoters of a series of pro‐angiogenic genes, especially for VEGFR2 in ADK KD cells, was demonstrated by the Infinium methylation assay. Methylation‐specific PCR, bisulfite sequencing, and methylated DNA immunoprecipitation further confirmed hypomethylation in the promoter region of VEGFR2 in ADK‐deficient endothelial cells. Accordingly, loss or inactivation of ADK increased VEGFR2 expression and signaling in endothelial cells. Based on these findings, we propose that ADK downregulation‐induced elevation of intracellular adenosine levels in endothelial cells in the setting of hypoxia is one of the crucial intrinsic mechanisms that promote angiogenesis.
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Affiliation(s)
- Yiming Xu
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA .,School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Yong Wang
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,College of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Siyuan Yan
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
| | - Yaqi Zhou
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qiuhua Yang
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yue Pan
- Georgia Prevention Institute, Augusta University, Augusta, GA, USA
| | - Xianqiu Zeng
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xiaofei An
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Zhiping Liu
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Lina Wang
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Jiean Xu
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yapeng Cao
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - David J Fulton
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Neal L Weintraub
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Zsolt Bagi
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Md Nasrul Hoda
- Departments of Medical Laboratory, Imaging & Radiologic Sciences, and Neurology, Augusta University, Augusta, GA, USA
| | - Xiaoling Wang
- Georgia Prevention Institute, Augusta University, Augusta, GA, USA
| | - Qinkai Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Mei Hong
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xuejun Jiang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
| | - Detlev Boison
- Robert S. Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR, USA
| | - Christian Weber
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Chaodong Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Yuqing Huo
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
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Welihinda AA, Kaur M, Raveendran KS, Amento EP. Enhancement of inosine-mediated A 2AR signaling through positive allosteric modulation. Cell Signal 2017; 42:227-235. [PMID: 29126977 DOI: 10.1016/j.cellsig.2017.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 10/20/2017] [Accepted: 11/06/2017] [Indexed: 12/14/2022]
Abstract
Inosine is an endogenous nucleoside that is produced by metabolic deamination of adenosine. Inosine is metabolically more stable (half-life 15h) than adenosine (half-life <10s). Inosine exerts anti-inflammatory and immunomodulatory effects similar to those observed with adenosine. These effects are mediated in part through the adenosine A2A receptor (A2AR). Relative to adenosine inosine exhibits a lower affinity towards the A2AR. Therefore, it is generally believed that inosine is incapable of activating the A2AR through direct engagement, but indirectly activates the A2AR upon metabolic conversion to higher affinity adenosine. A handful of studies, however, have provided evidence for direct inosine engagement at the A2AR leading to activation of downstream signaling events and inhibition of cytokine production. Here, we demonstrate that under conditions devoid of adenosine, inosine as well as an analog of inosine 6-S-[(4-Nitrophenyl)methyl]-6-thioinosine selectively and dose-dependently activated A2AR-mediated cAMP production and ERK1/2 phosphorylation in CHO cells stably expressing the human A2AR. Inosine also inhibited LPS-stimulated TNF-α, CCL3 and CCL4 production by splenic monocytes in an A2AR-dependent manner. In addition, we demonstrate that a positive allosteric modulator (PAM) of the A2AR enhanced inosine-mediated cAMP production, ERK1/2 phosphorylation and inhibition of pro-inflammatory cytokine and chemokine production. The cumulative effects of allosteric enhancement of adenosine-mediated and inosine-mediated A2AR activation may be the basis for the sustained anti-inflammatory and immunomodulatory effects observed in vivo and thereby provide insights into potential therapeutic interventions for inflammation- and immune-mediated diseases.
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Affiliation(s)
- Ajith A Welihinda
- Molecular Medicine Research Institute, 428 Oakmead Parkway, Sunnyvale, CA 94085.
| | - Manmeet Kaur
- Molecular Medicine Research Institute, 428 Oakmead Parkway, Sunnyvale, CA 94085
| | - Kaviya S Raveendran
- Molecular Medicine Research Institute, 428 Oakmead Parkway, Sunnyvale, CA 94085
| | - Edward P Amento
- Molecular Medicine Research Institute, 428 Oakmead Parkway, Sunnyvale, CA 94085
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8
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Bahreyni A, Samani SS, Rahmani F, Behnam-Rassouli R, Khazaei M, Ryzhikov M, Parizadeh MR, Avan A, Hassanian SM. Role of adenosine signaling in the pathogenesis of breast cancer. J Cell Physiol 2017; 233:1836-1843. [PMID: 28383816 DOI: 10.1002/jcp.25944] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 03/30/2017] [Indexed: 01/10/2023]
Abstract
The plasma level of adenosine increases under ischemic and inflamed conditions in tumor microenvironment. Adenosine elicits a range of signaling pathways in tumors, resulting in either inhibition or enhancement of tumor growth depending upon different subtypes of adenosine receptors activation and type of cancer. Metabolism of adenosine-5'-triphosphate (ATP) and its derivatives including adenosine is dysregulated in the breast tumor microenvironment, supporting the role of this metabolite in the pathogenesis of breast cancer. Adenosine regulates inflammation, apoptosis, cell proliferation, and metastasis in breast cancer cells. This review summarizes the role of adenosine in the pathogenesis of breast cancer for a better understanding and hence a better management of this disease.
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Affiliation(s)
- Amirhossein Bahreyni
- Faculty of Medicine, Department of Medical Biochemistry, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Sattar Samani
- Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran
| | - Farzad Rahmani
- Faculty of Medicine, Department of Medical Biochemistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Majid Khazaei
- Faculty of Medicine, Department of Medical Physiology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mikhail Ryzhikov
- Department of Molecular Microbiology and Immunology, School of Medicine, St. Louis University, Saint Louis, Missouri
| | - Mohammad Reza Parizadeh
- Faculty of Medicine, Department of Medical Biochemistry, Mashhad University of Medical Sciences, Mashhad, Iran.,Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amir Avan
- Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Molecular Medicine Group, Department of Modern Sciences and Technologies, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyed Mahdi Hassanian
- Faculty of Medicine, Department of Medical Biochemistry, Mashhad University of Medical Sciences, Mashhad, Iran.,Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Microanatomy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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9
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Kazemi MH, Raoofi Mohseni S, Hojjat-Farsangi M, Anvari E, Ghalamfarsa G, Mohammadi H, Jadidi-Niaragh F. Adenosine and adenosine receptors in the immunopathogenesis and treatment of cancer. J Cell Physiol 2017; 233:2032-2057. [DOI: 10.1002/jcp.25873] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 02/21/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Mohammad H. Kazemi
- Student Research Committee, Department of Immunology, School of Medicine; Iran University of Medical Sciences (IUMS); Tehran Iran
- Immunology Research Center; Tabriz University of Medical Sciences; Tabriz Iran
| | - Sahar Raoofi Mohseni
- Department of Immunology, School of Public Health; Tehran University of Medical Sciences; Tehran 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
| | - Enayat Anvari
- Faculty of Medicine, Department of Physiology; Ilam University of Medical Sciences; Ilam Iran
| | - Ghasem Ghalamfarsa
- Medicinal Plants Research Center; Yasuj University of Medical Sciences; Yasuj Iran
| | - Hamed Mohammadi
- Immunology Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Faculty of Medicine, Department of Immunology; Tabriz University of Medical Sciences; Tabriz Iran
| | - Farhad Jadidi-Niaragh
- Immunology Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Department of Immunology, School of Public Health; Tehran University of Medical Sciences; Tehran Iran
- Faculty of Medicine, Department of Immunology; Tabriz University of Medical Sciences; Tabriz Iran
- Drug Applied Research Center; Tabriz University of Medical Sciences; Tabriz Iran
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10
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Gariboldi V, Vairo D, Guieu R, Marlingue M, Ravis E, Lagier D, Mari A, Thery E, Collart F, Gaudry M, Bonello L, Paganelli F, Condo J, Kipson N, Fenouillet E, Ruf J, Mottola G. Expressions of adenosine A 2A receptors in coronary arteries and peripheral blood mononuclear cells are correlated in coronary artery disease patients. Int J Cardiol 2016; 230:427-431. [PMID: 28041708 DOI: 10.1016/j.ijcard.2016.12.089] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/15/2016] [Accepted: 12/16/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND Altered coronary blood flow occurs in patients with coronary artery disease (CAD). Adenosine strongly impacts blood flow mostly via adenosine A2A receptor (A2AR) expressed in coronary tissues. As part of a systemic regulation of the adenosinergic system, we compared A2AR expression in situ, and on peripheral blood mononuclear cells (PBMC) in CAD patients. METHODS AND RESULTS Aortic and coronary tissues, and PBMC were sampled in 20 CAD patients undergoing coronary artery bypass surgery and consecutively included. Controls were PBMC obtained from 15 healthy subjects. Expression and activity of A2AR were studied by Western blotting and cAMP measurement, respectively. A2AR expression on PBMC was lower in patients than in controls (0.83±0.31 vs 1.2±0.35 arbitrary units; p<0.01), and correlated with A2AR expression in coronary and aortic tissues (Pearson's r: 0.77 and 0.59, p<0.01, respectively). Basal and maximal cAMP productions following agonist stimulation of PBMC were significantly lower in patients than in controls (120±42 vs 191±65 and 360±113 vs 560±215pg/106 cells, p<0.05, respectively). In CAD patients, the increase from basal to maximal cAMP production in PBMC and aortic tissues was similar (+300% and +246%, respectively). CONCLUSION Expression of A2AR on PBMC correlated with those measured in coronary artery and aortic tissues in CAD patients, A2AR activity of PBMC matched that observed in aorta, and A2AR expression and activity in PBMC were found reduced as compared to controls. Measuring the expression level of A2AR on PBMC represents a good tool to address in situ expression in coronary tissues of CAD patients.
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Affiliation(s)
- Vlad Gariboldi
- Department of Cardiac Surgery, Timone University Hospital, Marseille, France
| | - Donato Vairo
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France
| | - Régis Guieu
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France; Laboratory of Biochemistry, Timone University Hospital, Marseille, France.
| | - Marion Marlingue
- Laboratory of Biochemistry, Timone University Hospital, Marseille, France
| | - Eléonore Ravis
- Department of Cardiology, Timone University Hospital, Marseille, France
| | - David Lagier
- Department of Anesthesia, Timone University Hospital, Marseille, France
| | - Alissa Mari
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France
| | - Elsa Thery
- Laboratory of Biochemistry, Timone University Hospital, Marseille, France
| | - Frédéric Collart
- Department of Cardiac Surgery, Timone University Hospital, Marseille, France
| | - Marine Gaudry
- Department of Vascular Surgery, Timone University Hospital, Marseille, France
| | - Laurent Bonello
- Department of Cardiology, North University Hospital, Marseille, France
| | - Franck Paganelli
- Department of Cardiology, North University Hospital, Marseille, France
| | - Jocelyne Condo
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France
| | - Nathalie Kipson
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France
| | | | - Jean Ruf
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France
| | - Giovanna Mottola
- UMR MD2, Aix-Marseille University and IRBA, Marseille, France; Laboratory of Biochemistry, Timone University Hospital, Marseille, France
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11
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Luan H, Wu P, Wang M, Sui H, Fan L, Gu R. Effects of adenosine stimulation on the mRNA expression of CLCNKB in the basolateral medullary thick ascending limb of the rat kidney. Mol Med Rep 2016; 14:4391-4398. [PMID: 27748841 DOI: 10.3892/mmr.2016.5781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 08/06/2016] [Indexed: 11/06/2022] Open
Abstract
Adenosine is a molecule produced by several organs within the body, including the kidneys, where it acts as an autoregulatory factor. It mediates ion transport in several nephron segments, including the proximal tubule and the thick ascending limb (TAL). Ion transport is dictated in part by anionic chloride channels, which regulate crucial kidney functions, including the reabsorption of Na+ and Cl‑, urine concentration, and establishing and maintaining the corticomedullary osmotic gradient. The present study investigated the effects of adenosine on the mRNA expression of chloride voltage‑gated channel Kb (CLCNKB), a candidate gene involved in hypertension, which encodes for the ClC‑Kb channel. Medullary thick ascending limb (mTAL) tubules were isolated from the rat kidney, and primary cultures of mTAL cells from the mTAL tubules were established. The cells were treated with adenosine and the mRNA expression of CLCNKB was detected by reverse transcription‑quantitative polymerase chain reaction. The cells were also treated with pathways inhibitors (H8 and AACOCF3), and the protein expression of cyclic adenosine 3',5'‑monophosphate (cAMP)‑protein kinase A (PKA) and phospholipase A2 (PLA2) by were analyzed by western blotting. The findings indicated that adenosine increased the mRNA expression of CLCNKB in primary cultures of medullary TAL cells, and this stimulatory effect was regulated by the cAMP‑PKA and PLA2‑arachidonic acid (AA) pathways. The present study showed that adenosine affected the mRNA expression of CLCNKB, initially through the cAMP‑PKA pathway and then the PLA2‑AA pathway.
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Affiliation(s)
- Haiyan Luan
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Peng Wu
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Mingxiao Wang
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Hongyu Sui
- Department of Physiology, Basic Medical School, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
| | - Lili Fan
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
| | - Ruimin Gu
- Department of Pharmacology, Harbin Medical University, Harbin, Heilongjiang 150081, P.R. China
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12
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Cunha RA. How does adenosine control neuronal dysfunction and neurodegeneration? J Neurochem 2016; 139:1019-1055. [PMID: 27365148 DOI: 10.1111/jnc.13724] [Citation(s) in RCA: 312] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022]
Abstract
The adenosine modulation system mostly operates through inhibitory A1 (A1 R) and facilitatory A2A receptors (A2A R) in the brain. The activity-dependent release of adenosine acts as a brake of excitatory transmission through A1 R, which are enriched in glutamatergic terminals. Adenosine sharpens salience of information encoding in neuronal circuits: high-frequency stimulation triggers ATP release in the 'activated' synapse, which is locally converted by ecto-nucleotidases into adenosine to selectively activate A2A R; A2A R switch off A1 R and CB1 receptors, bolster glutamate release and NMDA receptors to assist increasing synaptic plasticity in the 'activated' synapse; the parallel engagement of the astrocytic syncytium releases adenosine further inhibiting neighboring synapses, thus sharpening the encoded plastic change. Brain insults trigger a large outflow of adenosine and ATP, as a danger signal. A1 R are a hurdle for damage initiation, but they desensitize upon prolonged activation. However, if the insult is near-threshold and/or of short-duration, A1 R trigger preconditioning, which may limit the spread of damage. Brain insults also up-regulate A2A R, probably to bolster adaptive changes, but this heightens brain damage since A2A R blockade affords neuroprotection in models of epilepsy, depression, Alzheimer's, or Parkinson's disease. This initially involves a control of synaptotoxicity by neuronal A2A R, whereas astrocytic and microglia A2A R might control the spread of damage. The A2A R signaling mechanisms are largely unknown since A2A R are pleiotropic, coupling to different G proteins and non-canonical pathways to control the viability of glutamatergic synapses, neuroinflammation, mitochondria function, and cytoskeleton dynamics. Thus, simultaneously bolstering A1 R preconditioning and preventing excessive A2A R function might afford maximal neuroprotection. The main physiological role of the adenosine modulation system is to sharp the salience of information encoding through a combined action of adenosine A2A receptors (A2A R) in the synapse undergoing an alteration of synaptic efficiency with an increased inhibitory action of A1 R in all surrounding synapses. Brain insults trigger an up-regulation of A2A R in an attempt to bolster adaptive plasticity together with adenosine release and A1 R desensitization; this favors synaptotocity (increased A2A R) and decreases the hurdle to undergo degeneration (decreased A1 R). Maximal neuroprotection is expected to result from a combined A2A R blockade and increased A1 R activation. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
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Affiliation(s)
- Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Zhai W, Chen D, Shen H, Chen Z, Li H, Yu Z, Chen G. A1 adenosine receptor attenuates intracerebral hemorrhage-induced secondary brain injury in rats by activating the P38-MAPKAP2-Hsp27 pathway. Mol Brain 2016; 9:66. [PMID: 27301321 PMCID: PMC4908780 DOI: 10.1186/s13041-016-0247-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 06/02/2016] [Indexed: 12/27/2022] Open
Abstract
Background This study was designed to determine the role of the A1 adenosine receptors in intracerebral hemorrhage (ICH)-induced secondary brain injury and the underlying mechanisms. Methods A collagenase-induced ICH model was established in Sprague–Dawley rats, and cultured primary rat cortical neurons were exposed to oxyhemoglobin at a concentration of 10 μM to mimic ICH in vitro. The A1 adenosine receptor agonist N(6)-cyclohexyladenosine and antagonist 8-phenyl-1,3-dipropylxanthine were used to study the role of A1 adenosine receptor in ICH-induced secondary brain injury, and antagonists of P38 and Hsp27 were used to study the underlying mechanisms of A1 adenosine receptor actions. Results The protein level of A1 adenosine receptor was significantly increased by ICH, while there was no significant change in protein levels of the other 3 adenosine receptors. In addition, the A1 adenosine receptor expression could be increased by N(6)-cyclohexyladenosine and decreased by 8-phenyl-1,3-dipropylxanthine under ICH conditions. Activation of the A1 adenosine receptor attenuated neuronal apoptosis in the subcortex, which was associated with increased phosphorylation of P38, MAPK, MAPKAP2, and Hsp27. Inhibition of the A1 adenosine receptor resulted in opposite effects. Finally, the neuroprotective effect of the A1 adenosine receptor agonist N(6)-cyclohexyladenosine was inhibited by antagonists of P38 and Hsp27. Conclusions This study demonstrates that activation of the A1 adenosine receptor by N(6)-cyclohexyladenosine could prevent ICH-induced secondary brain injury via the P38-MAPKAP2-Hsp27 pathway.
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Affiliation(s)
- Weiwei Zhai
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Dongdong Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Haitao Shen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Zhouqing Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Haiying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Zhengquan Yu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
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Martínez-Ramírez AS, Vázquez-Cuevas FG. Purinergic signaling in the ovary. Mol Reprod Dev 2015; 82:839-48. [PMID: 26275037 DOI: 10.1002/mrd.22537] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 08/05/2015] [Indexed: 01/27/2023]
Abstract
Adenosine triphosphate (ATP) is released from the cell by multiple mechanisms. The extracellular form of this purine is processed by ectonucleotidases, resulting in a variety of dephosphorylated metabolites that can bind to specific receptors found in the membrane of target cells; such purinergic signaling is important as an autocrine-paracrine intercellular communication system that influences tissue physiology. In this review, we summarize the studies analyzing purinergic activity in the ovary, which can modulate cellular physiology-including sensitivity to gonadotropins-in several ovarian cell types, including the cumulus-cell complex, granulosa cells, theca cells, and the ovarian surface epithelium. These functions support a role for ATP as an important intra-ovarian messenger, and open new lines of research that can improve our understanding of mechanisms regulating ovarian function and the fine-tuning of folliculogenesis.
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Affiliation(s)
- Angélica S Martínez-Ramírez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla Querétaro, Querétaro, México
| | - Francisco G Vázquez-Cuevas
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla Querétaro, Querétaro, México
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Ribeiro FF, Neves-Tomé R, Assaife-Lopes N, Santos TE, Silva RFM, Brites D, Ribeiro JA, Sousa MM, Sebastião AM. Axonal elongation and dendritic branching is enhanced by adenosine A2A receptors activation in cerebral cortical neurons. Brain Struct Funct 2015; 221:2777-99. [DOI: 10.1007/s00429-015-1072-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 05/27/2015] [Indexed: 01/09/2023]
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[MUV Researcher of the Month, October 2014]. Wien Klin Wochenschr 2014; 126:663-4. [PMID: 25336182 DOI: 10.1007/s00508-014-0641-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Mediero A, Perez-Aso M, Cronstein BN. Activation of adenosine A(2A) receptor reduces osteoclast formation via PKA- and ERK1/2-mediated suppression of NFκB nuclear translocation. Br J Pharmacol 2014; 169:1372-88. [PMID: 23647065 DOI: 10.1111/bph.12227] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 03/25/2013] [Accepted: 04/12/2013] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE We previously reported that adenosine, acting at adenosine A(2A) receptors (A(2A)R), inhibits osteoclast (OC) differentiation in vitro (A(2A)R activation OC formation reduces by half) and in vivo. For a better understanding how adenosine A(2A)R stimulation regulates OC differentiation, we dissected the signalling pathways involved in A(2A)R signalling. EXPERIMENTAL APPROACH OC differentiation was studied as TRAP+ multinucleated cells following M-CSF/RANKL stimulation of either primary murine bone marrow cells or the murine macrophage line, RAW264.7, in presence/absence of the A(2A)R agonist CGS21680, the A(2A)R antagonist ZM241385, PKA activators (8-Cl-cAMP 100 nM, 6-Bnz-cAMP) and the PKA inhibitor (PKI). cAMP was quantitated by EIA and PKA activity assays were carried out. Signalling events were studied in PKA knockdown (lentiviral shRNA for PKA) RAW264.7 cells (scrambled shRNA as control). OC marker expression was studied by RT-PCR. KEY RESULTS A(2A)R stimulation increased cAMP and PKA activity which and were reversed by addition of ZM241385. The direct PKA stimuli 8-Cl-cAMP and 6-Bnz-cAMP inhibited OC maturation whereas PKI increased OC differentiation. A(2A)R stimulation inhibited p50/p105 NFκB nuclear translocation in control but not in PKA KO cells. A(2A)R stimulation activated ERK1/2 by a PKA-dependent mechanism, an effect reversed by ZM241385, but not p38 and JNK activation. A(2A)R stimulation inhibited OC expression of differentiation markers by a PKA-mechanism. CONCLUSIONS AND IMPLICATIONS A(2A)R activation inhibits OC differentiation and regulates bone turnover via PKA-dependent inhibition of NFκB nuclear translocation, suggesting a mechanism by which adenosine could target bone destruction in inflammatory diseases like rheumatoid arthritis.
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Affiliation(s)
- Aránzazu Mediero
- Department of Medicine, Division of Translational Medicine, NYU School of Medicine, New York, NY 10016, USA
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Huang PC, Hsiao YT, Kao SY, Chen CF, Chen YC, Chiang CW, Lee CF, Lu JC, Chern Y, Wang CT. Adenosine A(2A) receptor up-regulates retinal wave frequency via starburst amacrine cells in the developing rat retina. PLoS One 2014; 9:e95090. [PMID: 24777042 PMCID: PMC4002430 DOI: 10.1371/journal.pone.0095090] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 03/23/2014] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Developing retinas display retinal waves, the patterned spontaneous activity essential for circuit refinement. During the first postnatal week in rodents, retinal waves are mediated by synaptic transmission between starburst amacrine cells (SACs) and retinal ganglion cells (RGCs). The neuromodulator adenosine is essential for the generation of retinal waves. However, the cellular basis underlying adenosine's regulation of retinal waves remains elusive. Here, we investigated whether and how the adenosine A(2A) receptor (A(2A)R) regulates retinal waves and whether A(2A)R regulation of retinal waves acts via presynaptic SACs. METHODOLOGY/PRINCIPAL FINDINGS We showed that A(2A)R was expressed in the inner plexiform layer and ganglion cell layer of the developing rat retina. Knockdown of A(2A)R decreased the frequency of spontaneous Ca²⁺ transients, suggesting that endogenous A(2A)R may up-regulate wave frequency. To investigate whether A(2A)R acts via presynaptic SACs, we targeted gene expression to SACs by the metabotropic glutamate receptor type II promoter. Ca²⁺ transient frequency was increased by expressing wild-type A(2A)R (A2AR-WT) in SACs, suggesting that A(2A)R may up-regulate retinal waves via presynaptic SACs. Subsequent patch-clamp recordings on RGCs revealed that presynaptic A(2A)R-WT increased the frequency of wave-associated postsynaptic currents (PSCs) or depolarizations compared to the control, without changing the RGC's excitability, membrane potentials, or PSC charge. These findings suggest that presynaptic A(2A)R may not affect the membrane properties of postsynaptic RGCs. In contrast, by expressing the C-terminal truncated A(2A)R mutant (A(2A)R-ΔC) in SACs, the wave frequency was reduced compared to the A(2A)R-WT, but was similar to the control, suggesting that the full-length A(2A)R in SACs is required for A(2A)R up-regulation of retinal waves. CONCLUSIONS/SIGNIFICANCE A(2A)R up-regulates the frequency of retinal waves via presynaptic SACs, requiring its full-length protein structure. Thus, by coupling with the downstream intracellular signaling, A(2A)R may have a great capacity to modulate patterned spontaneous activity during neural circuit refinement.
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Affiliation(s)
- Pin-Chien Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Tien Hsiao
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Shao-Yen Kao
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ching-Feng Chen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Chieh Chen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chung-Wei Chiang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chien-fei Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Juu-Chin Lu
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chih-Tien Wang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Thurner P, Gsandtner I, Kudlacek O, Choquet D, Nanoff C, Freissmuth M, Zezula J. A two-state model for the diffusion of the A2A adenosine receptor in hippocampal neurons: agonist-induced switch to slow mobility is modified by synapse-associated protein 102 (SAP102). J Biol Chem 2014; 289:9263-74. [PMID: 24509856 PMCID: PMC3979375 DOI: 10.1074/jbc.m113.505685] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The A2A receptor is a class A/rhodopsin-like G protein-coupled receptor. Coupling to its cognate protein, Gs, occurs via restricted collision coupling and is contingent on the presence of cholesterol. Agonist activation slows diffusion of the A2A adenosine receptor in the lipid bilayer. We explored the contribution of the hydrophobic core and of the extended C terminus by examining diffusion of quantum dot-labeled receptor variants in dissociated hippocampal neurons. Single particle tracking of the A2A receptor(1–311), which lacks the last 101 residues, revealed that agonist-induced confinement was abolished and that the agonist-induced decrease in diffusivity was reduced substantially. A fragment comprising the SH3 domain and the guanylate kinase domain of synapse-associated protein 102 (SAP102) was identified as a candidate interactor that bound to the A2A receptor C terminus. Complex formation between the A2A receptor and SAP102 was verified by coimmunoprecipitation and by tracking its impact on receptor diffusion. An analysis of all trajectories by a hidden Markov model was consistent with two diffusion states where agonist activation reduced the transition between the two states and, thus, promoted the accumulation of the A2A receptor in the compartment with slow mobility. Overexpression of SAP102 precluded the access of the A2A receptor to a compartment with restricted mobility. In contrast, a mutated A2A receptor (with 383DVELL387 replaced by RVRAA) was insensitive to the action of SAP102. These observations show that the hydrophobic core per se does not fully account for the agonist-promoted change in mobility of the A2A receptor. The extended carboxyl terminus allows for regulatory input by scaffolding molecules such as SAP102.
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Affiliation(s)
- Patrick Thurner
- From the Institute for Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Währinger Str. 13a, 1090 Vienna, Austria and
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Antonioli L, Blandizzi C, Pacher P, Haskó G. Immunity, inflammation and cancer: a leading role for adenosine. Nat Rev Cancer 2013; 13:842-57. [PMID: 24226193 DOI: 10.1038/nrc3613] [Citation(s) in RCA: 542] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cancer is a complex disease that is dictated by both cancer cell-intrinsic and cell-extrinsic processes. Adenosine is an ancient extracellular signalling molecule that can regulate almost all aspects of tissue function. As such, several studies have recently highlighted a crucial role for adenosine signalling in regulating the various aspects of cell-intrinsic and cell-extrinsic processes of cancer development. This Review critically discusses the role of adenosine and its receptors in regulating the complex interplay among immune, inflammatory, endothelial and cancer cells during the course of neoplastic disease.
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Affiliation(s)
- Luca Antonioli
- 1] Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy. [2] Department of Surgery and Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA
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Wu YC, Lai HL, Chang WC, Lin JT, Liu YJ, Chern Y. A novel Gαs-binding protein, Gas-2 like 2, facilitates the signaling of the A2A adenosine receptor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3145-3154. [PMID: 23994616 DOI: 10.1016/j.bbamcr.2013.08.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/08/2013] [Accepted: 08/12/2013] [Indexed: 12/13/2022]
Abstract
The A2A adenosine receptor (A2AR) is a G-protein-coupled receptor that contains a long cytoplasmic carboxyl terminus (A2AR-C). We report here that Gas-2 like 2 (G2L2) is a new interacting partner of A2AR-C. The interaction between A2AR and G2L2 was verified by GST pull-down, co-immunoprecipitation, immunocytochemical staining, and fluorescence resonance energy transfer. Expression of G2L2 increased the intracellular cAMP content evoked by A2AR in an A2AR-C-dependent manner. Immunoprecipitation and pull-down assays demonstrated that G2L2 selectively bound to A2AR-C and the inactive form of Gαs to facilitate the recruitment of the trimeric G protein complex to the proximal position of A2AR for efficient activation. Collectively, G2L2 is a new effector that controls the action of A2AR by modulating its ability to regulate the Gαs-mediated cAMP contents.
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Affiliation(s)
- Yi-Chih Wu
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan; Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan; Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hsing-Lin Lai
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Wei-Cheng Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jiun-Tsai Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yu-Ju Liu
- Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Yijuang Chern
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan; Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
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Sakowicz-Burkiewicz M, Kitowska A, Grden M, Maciejewska I, Szutowicz A, Pawelczyk T. Differential effect of adenosine receptors on growth of human colon cancer HCT 116 and HT-29 cell lines. Arch Biochem Biophys 2013; 533:47-54. [PMID: 23454010 DOI: 10.1016/j.abb.2013.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 02/01/2013] [Accepted: 02/18/2013] [Indexed: 11/27/2022]
Abstract
The study aimed to evaluate the impact of adenosine receptors (ARs) on human colon tumor cells (HCT 116, HT-29) growth and sensitivity to 5-Fluorouracil (5-FU) an anticancer chemotherapeutic drug. The exposure of cancer cells to a selective A(3)-AR agonist (IB-MECA) resulted in an increase in HT-29 cells number, whereas the number of HCT 116 cells decreased significantly. In the presence of IB-MECA (1 μM) the percentage of apoptotic HT-29 cells significantly decreased, whereas the number of apoptotic and necrotic HCT 116 cells increased by 3- and 2,5-fold, respectively. The application of a selective A(2A)-AR agonist resulted in the increased survival of HCT 116 cells, but not HT-29 cells. The blockade of A(2A)-AR with ZM 241385 (0.1 μM) significantly increased the cytotoxicity of 5-FU (1 μM) in HCT 116 cells but not in HT-29 cells. The suppression of A(3)-AR with MRS 1523 (1 μM) increased the sensitivity of HT-29 cells to 5-FU while response of HCT 116 cells to 5-FU decreased. The growth promoting effect of IB-MECA in HT-29 cells was associated with the decreased intracellular cAMP level, whereas IB-MECA growth inhibitory effect in HCT 116 cells was abolished by okadaic acid (2 nM) indicating the involvement of protein phosphatase PP2A.
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Keuerleber S, Thurner P, Gruber CW, Zezula J, Freissmuth M. Reengineering the collision coupling and diffusion mode of the A2A-adenosine receptor: palmitoylation in helix 8 relieves confinement. J Biol Chem 2012; 287:42104-18. [PMID: 23071116 PMCID: PMC3516756 DOI: 10.1074/jbc.m112.393579] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The A(2A)-adenosine receptor undergoes restricted collision coupling with its cognate G protein G(s) and lacks a palmitoylation site at the end of helix 8 in its intracellular C terminus. We explored the hypothesis that there was a causal link between the absence of a palmitoyl moiety and restricted collision coupling by introducing a palmitoylation site. The resulting mutant A(2A)-R309C receptor underwent palmitoylation as verified by both mass spectrometry and metabolic labeling. In contrast to the wild type A(2A) receptor, the concentration-response curve for agonist-induced cAMP accumulation was shifted to the left with increasing expression levels of A(2A)-R309C receptor, an observation consistent with collision coupling. Single particle tracking of quantum dot-labeled receptors confirmed that wild type and mutant A(2A) receptor differed in diffusivity and diffusion mode; agonist activation resulted in a decline in mean square displacement of both receptors, but the drop was substantially more pronounced for the wild type receptor. In addition, in the agonist-bound state, the wild type receptor was frequently subject to confinement events (estimated radius 110 nm). These were rarely seen with the palmitoylated A(2A)-R309C receptor, the preferred diffusion mode of which was a random walk in both the basal and the agonist-activated state. Taken together, the observations link restricted collision coupling to diffusion limits imposed by the absence of a palmitoyl moiety in the C terminus of the A(2A) receptor. The experiments allowed for visualizing local confinement of an agonist-activated G protein-coupled receptor in an area consistent with the dimensions of a lipid raft.
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Affiliation(s)
- Simon Keuerleber
- Institute of Pharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Währinger Strasse 13A, 1090 Vienna, Austria
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Tawfeek HA, Abou-Samra AB. Disruption of parathyroid hormone and parathyroid hormone-related peptide receptor phosphorylation prolongs ERK1/2 MAPK activation and enhances c-fos expression. Am J Physiol Endocrinol Metab 2012; 302:E1363-72. [PMID: 22414806 PMCID: PMC3378071 DOI: 10.1152/ajpendo.00034.2012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have demonstrated that parathyroid hormone (PTH) binding to the PTH/PTH-related peptide receptor (PPR) stimulates G protein coupling, receptor phosphorylation, β-arrestin translocation, and internalization of the ligand/receptor complex. The extracellular signal-regulated mitogen-activated protein kinases 1/2 (ERK1/2 MAPK) are downstream effectors of PPR. In the current study, we investigated the role of PPR phosphorylation in the PTH regulation of the ERK1/2 MAPK pathway. Short treatment with PTH (0-40 min) of LLCP-K(1) cells stably expressing a wild-type (WT) or a phosphorylation-deficient (PD) PPR (WT-PPR or PD-PPR cells, respectively) results in similar activation of ERK1/2. Interestingly, PTH stimulation of ERK1/2 in the WT-PPR cells then decreases as a result of longer PTH (60 min) treatment, and inhibition of ERK1/2 by PTH is observed at 90 min. Strikingly, the PD-PPR cells exhibit prolonged ERK1/2 activation up to 90 min of PTH treatment. An ERK1/2-dependent increase in c-fos expression is observed in the PD-PPR cells. Subsequently, c-fos expression in the WT-PPR and PD-PPR cells was markedly attenuated by a specific ERK1/2 pathway inhibitor. Further investigations revealed that PTH treatment causes a robust recruitment of a green fluorescent protein-tagged β-arrestin2 (β-arrestin2-GFP) in the WT-PPR cells. In contrast, β-arrestin2 recruitment was reduced in the PD-PPR cells. Importantly, expression of a receptor phosphorylation-independent β-arrestin2 (R169E) in the PD-PPR cells restored the biphasic effect of PTH on ERK1/2 as in the WT-PPR cells. The study reports a novel role for receptor phosphorylation and β-arrestin2 in the subsequent inhibition of the ERK1/2 pathway and in control of gene expression.
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Affiliation(s)
- Hesham A Tawfeek
- Center for Orthopaedic Research, Columbia University, 650 West 168th St., New York, NY 10032, USA.
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Thauerer B, Zur Nedden S, Baier-Bitterlich G. Purine nucleosides: endogenous neuroprotectants in hypoxic brain. J Neurochem 2012; 121:329-42. [PMID: 22335456 PMCID: PMC3499684 DOI: 10.1111/j.1471-4159.2012.07692.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Even a short blockade of oxygen flow in brain may lead to the inhibition of oxidative phosphorylation and depletion of cellular ATP, which results in profound deficiencies in cellular function. Following ischemia, dying, injured, and hypoxic cells release soluble purine-nucleotide and -nucleoside pools. Growing evidence suggests that purine nucleosides might act as trophic factors in the CNS and PNS. In addition to equilibrative nucleoside transporters (ENTs) regulating purine nucleoside concentrations intra- and extracellularly, specific extracellular receptor subtypes for these compounds are expressed on neurons, glia, and endothelial cells, mediating stunningly diverse effects. Such effects range from induction of cell differentiation, apoptosis, mitogenesis, and morphogenetic changes, to stimulation of synthesis and/or release of cytokines and neurotrophic factors under both physiological and pathological conditions. Multiple signaling pathways regulate the critical balance between cell death and survival in hypoxia-ischemia. A convergent pathway for the regulation of multiple modalities involved in O₂ sensing is the mitogen activated protein kinase (p42/44 MAPK) or (ERK1/2 extracellular signal-regulated kinases) pathway terminating in a variety of transcription factors, for example, hypoxia-inducible factor 1α. In this review, the coherence of purine nucleoside-related pathways and MAPK activation in the endogenous neuroprotective regulation of the nervous system's development and neuroplasticity under hypoxic stress will be discussed.
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Affiliation(s)
- Bettina Thauerer
- Division of Neurobiochemistry, Biocenter Department, Medical University of Innsbruck, Innsbruck, Austria
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Mediero A, Kara FM, Wilder T, Cronstein BN. Adenosine A(2A) receptor ligation inhibits osteoclast formation. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:775-86. [PMID: 22138579 DOI: 10.1016/j.ajpath.2011.10.017] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 10/04/2011] [Accepted: 10/11/2011] [Indexed: 01/25/2023]
Abstract
Adenosine is generated in increased concentrations at sites of injury/hypoxia and mediates a variety of physiological and pharmacological effects via G protein-coupled receptors (A(1), A(2A), A(2B), and A(3)). Because all adenosine receptors are expressed on osteoclasts, we determined the role of A(2A) receptor in the regulation of osteoclast differentiation. Differentiation and bone resorption were studied as the macrophage colony-stimulating factor-1-receptor activator of NF-κB ligand formation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive cells from primary murine bone marrow-derived precursors. A(2A) receptor and osteoclast marker expression levels were studied by RT-PCR. Cytokine secretion was assayed by enzyme-linked immunosorbent assay. In vivo examination of A(2A) knockout (KO)/control bones was determined by TRAP staining, micro-computed tomography, and electron microscopy. The A(2A) receptor agonist, CGS21680, inhibited osteoclast differentiation and function (half maximal inhibitory concentration, 50 nmol/L), increased the percentage of immature osteoclast precursors, and decreased IL-1β and tumor necrosis factor-α secretion, an effect that was reversed by the A(2A) antagonist, ZM241385. Cathepsin K and osteopontin mRNA expression increased in control and ZM241385-pretreated osteoclasts, and this was blocked by CGS21680. Micro-computed tomography of A(2A)KO mouse femurs showed a significantly decreased bone volume/trabecular bone volume ratio, decreased trabecular number, and increased trabecular space. A(2A)KO femurs showed an increased TRAP-positive osteoclast. Electron microscopy in A(2A)KO femurs showed marked osteoclast membrane folding and increased bone resorption. Thus, adenosine, acting via the A(2A) receptor, inhibits macrophage colony-stimulating factor-1-receptor activator of NF-κB ligand-stimulated osteoclast differentiation and may regulate bone turnover under conditions in which adenosine levels are elevated.
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Affiliation(s)
- Aránzazu Mediero
- Division of Translational Medicine, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA
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Activation of adenosine A2A receptor up-regulates BDNF expression in rat primary cortical neurons. Neurochem Res 2011; 36:2259-69. [PMID: 21792677 DOI: 10.1007/s11064-011-0550-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 06/18/2011] [Accepted: 07/14/2011] [Indexed: 01/12/2023]
Abstract
As a member of neurotrophin family, brain derived neurotrophic factor (BDNF) plays critical roles in neuronal development, differentiation, synaptogenesis, and neural protection from the harmful stimuli. There have been reported that adenosine A2(A) receptor subtype is widely distributed in the brain regions, such as hippocampus, striatum, and cortex. Adenosine A2(A) receptor is colocalized with BDNF in brain regions and the functional interaction between A2(A) receptor stimulation and BDNF action has been suggested. In this study, we investigated the possibility that the activation of A2(A) receptor modulates BDNF production in rat primary cortical neuron. CGS21680, an adenosine A2(A) receptor agonist, induced BDNF expression and release. An antagonist against A2(A) receptor, ZM241385, prevented CGS21680-induced increase in BDNF production. A2(A) receptor stimulation induced the activation of Akt-GSK-3β signaling pathway and the blockade of the signaling pathway with specific inhibitors abolished the increase in BDNF production, possibly via modulation of ERK1/2-CREB pathway. The physiological roles of A2(A) receptor-induced BDNF production was demonstrated by the protection of neurons from the excitotoxicity and increased neurite extension as well as synapse formation from immature and mature neurons. Taken together, activation of A2(A) receptor regulates BDNF production in rat cortical neuron, which provides neuro-protective action.
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Wagner MCE. The therapeutic potential of adenosine triphosphate as an immune modulator in the treatment of HIV/AIDS: a combination approach with HAART. Curr HIV Res 2011; 9:209-22. [PMID: 21675943 PMCID: PMC3343418 DOI: 10.2174/157016211796320289] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 04/27/2011] [Accepted: 06/08/2011] [Indexed: 12/11/2022]
Abstract
Extracellular adenosine triphosphate (eATP) is a potent molecule that has the capacity to modulate various aspects of cell functions including gene expression. This element of modulation is essential to the role of ATP as a therapeutic agent. The hypothesis presented is that ATP can have an important impact on the treatment of HIV infection. This is supported in part by published research, although a much greater role for ATP is suggested than prior authors ever thought possible. ATP has the ability to enhance the immune system and could thus improve the host's own defense mechanisms to eradicate the virus-infected cells and restore normal immune function. This could provide effective therapy when used in conjunction with highly active antiretroviral therapies (HAART) to eliminate the latently infected cells. The key lies in applying ATP through the methodology described. This article presents a strategy for using ATP therapeutically along with background evidence to substantiate the importance of using ATP in the treatment of HIV infection.
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Verzijl D, IJzerman AP. Functional selectivity of adenosine receptor ligands. Purinergic Signal 2011; 7:171-92. [PMID: 21544511 PMCID: PMC3146648 DOI: 10.1007/s11302-011-9232-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 04/05/2011] [Indexed: 12/11/2022] Open
Abstract
Adenosine receptors are plasma membrane proteins that transduce an extracellular signal into the interior of the cell. Basically every mammalian cell expresses at least one of the four adenosine receptor subtypes. Recent insight in signal transduction cascades teaches us that the current classification of receptor ligands into agonists, antagonists, and inverse agonists relies very much on the experimental setup that was used. Upon activation of the receptors by the ubiquitous endogenous ligand adenosine they engage classical G protein-mediated pathways, resulting in production of second messengers and activation of kinases. Besides this well-described G protein-mediated signaling pathway, adenosine receptors activate scaffold proteins such as β-arrestins. Using innovative and sensitive experimental tools, it has been possible to detect ligands that preferentially stimulate the β-arrestin pathway over the G protein-mediated signal transduction route, or vice versa. This phenomenon is referred to as functional selectivity or biased signaling and implies that an antagonist for one pathway may be a full agonist for the other signaling route. Functional selectivity makes it necessary to redefine the functional properties of currently used adenosine receptor ligands and opens possibilities for new and more selective ligands. This review focuses on the current knowledge of functionally selective adenosine receptor ligands and on G protein-independent signaling of adenosine receptors through scaffold proteins.
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Affiliation(s)
- Dennis Verzijl
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
| | - Ad P. IJzerman
- Division of Medicinal Chemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
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Gessi S, Merighi S, Sacchetto V, Simioni C, Borea PA. Adenosine receptors and cancer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1400-12. [DOI: 10.1016/j.bbamem.2010.09.020] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 09/14/2010] [Accepted: 09/20/2010] [Indexed: 01/25/2023]
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Ye Y, Perez-Polo JR, Birnbaum Y. Protecting against ischemia-reperfusion injury: antiplatelet drugs, statins, and their potential interactions. Ann N Y Acad Sci 2010; 1207:76-82. [PMID: 20955429 DOI: 10.1111/j.1749-6632.2010.05725.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Statins and antiplatelet agents are currently used as therapeutic agents for patients with acute myocardial infarction. Statins limit myocardial infarct size by activating phosphatidylinositol-3-kinase (PI3K), ecto-5'-nucleotidase, Akt/endothelial nitric oxide synthase (eNOS), and the downstream effectors inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Inhibition of PI3K, adenosine receptors, eNOS, iNOS, or COX-2 abrogates the protective effects of statins. At >5 mg/kg, aspirin attenuates the myocardial infarct-size-limiting effect of statins. In contrast, the combination of low-dose atoravastatin with either the phosphodiesterase-III inhibitor cilostazol or the adenosine reuptake inhibitor dipyridamole synergistically limits infarct size. Low-dose aspirin with dipyridamole started during ischemia augmented the infarct-size-limiting effects of simvastatin. In contrast, high-dose aspirin blocked the protective effect of simvastatin. The combination of dipyridamole with low-dose aspirin and simvastatin resulted in the smallest infarct size. According to the most current data available, we believe that antiplatelet regimens may require modification for patients who are receiving statins.
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Affiliation(s)
- Yumei Ye
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas, USA
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Kominsky DJ, Campbell EL, Colgan SP. Metabolic shifts in immunity and inflammation. THE JOURNAL OF IMMUNOLOGY 2010; 184:4062-8. [PMID: 20368286 DOI: 10.4049/jimmunol.0903002] [Citation(s) in RCA: 297] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Sites of ongoing inflammation and triggered immune responses are characterized by significant changes in metabolic activity. Recent studies have indicated that such shifts in tissue metabolism result from a combination of profound recruitment of inflammatory cells (neutrophils and monocytes) and high proliferation rates among lymphocyte populations. The resultant shifts in energy supply and demand can result in metabolic acidosis and diminished delivery and/or availability of oxygen, leading to hypoxia extensive enough to trigger transcriptional and translation changes in tissue phenotype. Such phenotypic shifts can imprint fundamental changes to tissue metabolism. In this study, we review recent work addressing metabolic changes and metabolic control of inflammation and immunity.
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Affiliation(s)
- Douglas J Kominsky
- Department of Anesthesiology, University of Colorado Denver Health Sciences Center, Aurora, CO 80045, USA
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Safhi MMA, Rutherford C, Ledent C, Sands WA, Palmer TM. Priming of Signal Transducer and Activator of Transcription Proteins for Cytokine-Triggered Polyubiquitylation and Degradation by the A2A Adenosine Receptor. Mol Pharmacol 2010; 77:968-78. [DOI: 10.1124/mol.109.062455] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Negative regulation of diacylglycerol kinase theta mediates adenosine-dependent hepatocyte preconditioning. Cell Death Differ 2010; 17:1059-68. [PMID: 20057501 DOI: 10.1038/cdd.2009.210] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In liver ischemic preconditioning (IP), stimulation of adenosine A2a receptors (A2aR) prevents ischemia/reperfusion injury by promoting diacylglycerol-mediated activation of protein kinase C (PKC). By concerting diacylglycerol to phosphatidic acid, diacylglycerol kinases (DGKs) act as terminator of diacylglycerol signalling. This study investigates the role of DGK in the development of hepatocyte IP. DGK activity and cell viability were evaluated in isolated rat hepatocytes preconditioned by 10 min hypoxia followed by 10 min re-oxygenation or by the treatment with the A2aR agonist, CGS21680, and subsequently exposed to prolonged hypoxia. We observed that after IP or A2aR activation, a decrease in DGK activity was associated with the onset of hepatocyte tolerance to hypoxia. CGS21680-induced stimulation of A2aR specifically inhibited DGK isoform theta by activating RhoA-GTPase. Consistently, both siRNA-mediated downregulation of DGK theta and hepatocyte pretreatment with the DGK inhibitor R59949 induced cell tolerance to hypoxia. The pharmacological inhibition of DGK was associated with the diacylglycerol-dependent activation of PKC delta and epsilon and of their downstream target p38 MAPK. In conclusion, we unveil a novel signalling pathway contributing to the onset of hepatocyte preconditioning, which through RhoA-GTPase, couples A2aR to the downregulation of DGK. Such an inhibition is essential for the sustained accumulation of diacylglycerol required for triggering PKC-mediated survival signals.
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Abstract
Extracellular adenosine is produced in a coordinated manner from cells following cellular challenge or tissue injury. Once produced, it serves as an autocrine- and paracrine-signaling molecule through its interactions with seven-membrane-spanning G-protein-coupled adenosine receptors. These signaling pathways have widespread physiological and pathophysiological functions. Immune cells express adenosine receptors and respond to adenosine or adenosine agonists in diverse manners. Extensive in vitro and in vivo studies have identified potent anti-inflammatory functions for all of the adenosine receptors on many different inflammatory cells and in various inflammatory disease processes. In addition, specific proinflammatory functions have also been ascribed to adenosine receptor activation. The potent effects of adenosine signaling on the regulation of inflammation suggest that targeting specific adenosine receptor activation or inactivation using selective agonists and antagonists could have important therapeutic implications in numerous diseases. This review is designed to summarize the current status of adenosine receptor signaling in various inflammatory cells and in models of inflammation, with an emphasis on the advancement of adenosine-based therapeutics to treat inflammatory disorders.
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Affiliation(s)
- Michael R Blackburn
- Department of Biochemistry and Molecular Biology, The University of Texas-Houston Medical School, Houston, TX 77030, USA.
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Katebi M, Soleimani M, Cronstein BN. Adenosine A2A receptors play an active role in mouse bone marrow-derived mesenchymal stem cell development. J Leukoc Biol 2008; 85:438-44. [PMID: 19056861 DOI: 10.1189/jlb.0908520] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Bone marrow-derived mesenchymal stem cells (BM-MSCs) play a role in wound healing and tissue repair and may also be useful for organ regeneration. As we have demonstrated previously that A(2A) adenosine receptors (A(2A)R) promote tissue repair and wound healing by stimulating local repair mechanisms and enhancing accumulation of endothelial progenitor cells, we investigated whether A(2A)R activation modulates BM-MSC proliferation and differentiation. BM-MSCs were isolated and cultured from A(2A)-deficient and ecto-5'nucleotidase (CD73)-deficient female mice; the MSCs were identified and quantified by a CFU-fibroblast (CFU-F) assay. Procollagen alpha2 type I expression was determined by Western blotting and immunocytochemistry. MSC-specific markers were examined in primary cells and third-passage cells by cytofluorography. PCR and real time-PCR were used to quantitate adenosine receptor and CD73 expression. There were significantly fewer CFU-Fs in cultures of BM-MSCs from A(2A)R knockout (KO) mice or BM-MSCs treated with the A(2A)R antagonist ZM241385, 1 microM. Similarly, there were significantly fewer procollagen alpha2 type I-positive MSCs in cultures from A(2A)R KO and antagonist-treated cultures as well. In late passage cells, there were significantly fewer MSCs from A(2A) KO mice expressing CD90, CD105, and procollagen type I (P<0.05 for all; n=3). These findings indicate that adenosine and adenosine A(2A)R play a critical role in promoting the proliferation and differentiation of mouse BM-MSCs.
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Affiliation(s)
- Majid Katebi
- New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
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Lin CL, Dumont AS, Tsai YJ, Huang JH, Chang KP, Kwan AL, Hong YR, Howng SL. 17Beta-estradiol activates adenosine A(2a) receptor after subarachnoid hemorrhage. J Surg Res 2008; 157:208-15. [PMID: 19181336 DOI: 10.1016/j.jss.2008.08.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 08/15/2008] [Accepted: 08/18/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Our previous study showed that 17beta-estradiol (E2) and an adenosine A(2A) receptor (AR-A(2A)) agonist could attenuate subarachnoid hemorrhage (SAH)-induced cerebral vasospasm via preventing the augmentation of iNOS expression and preserving the normal eNOS expression. This study tests the hypothesis that E2 attenuates SAH-induced vasospasm and apoptosis by activating adenosine AR-A(2A) and extracellular signal-regulated kinase 1 and 2 (ERK1/2), and by altering antiapoptotic and proapoptotic protein expression (Bcl-2 and Bax, respectively). MATERIALS AND METHODS The two-hemorrhage SAH model in rat was used. Animals were treated with E2 with or without a nonselective estrogen receptor (ER) antagonist (ICI182,780). The cross sectional areas of the basilar artery and terminal dUTP nick-end labeling (TUNEL) were used to determine the degree of vasospasm and apoptosis, respectively. The expressions of Bcl-2, Bax, AR-A(2A), and ERK1/2 in the cerebral cortex, hippocampus, and dentate gyrus were investigated. RESULTS E2 significantly attenuated vasospasm. Seven days after the first SAH, TUNEL scores were significantly increased, and protein levels of AR-A(2A), ERK1/2, and Bcl-2 were significantly decreased in the dentate gyrus only but not in the cortex and hippocampus. These changes were reversed by E2 while ICI182,780 abrogated the antiapoptotic and anti-spastic effects of E2. The expression of Bax did not change in the dentate gyrus after SAH with or without treatment. CONCLUSIONS The down-regulated AR-A(2A) and ERK may play a role in vasospasm and apoptosis after SAH. The beneficial effect of E2 in the attenuating SAH-induced vasospasm and apoptosis may be due to an increased expression of AR-A(2A) and ERK via ER-dependent mechanisms. These data may support further investigation of E2 in the treatment of SAH in humans.
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Affiliation(s)
- Chih-Lung Lin
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
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Mazzola A, Amoruso E, Beltrami E, Lecca D, Ferrario S, Cosentino S, Tremoli E, Ceruti S, Abbracchio MP. Opposite effects of uracil and adenine nucleotides on the survival of murine cardiomyocytes. J Cell Mol Med 2008; 12:522-36. [PMID: 18419595 PMCID: PMC3822540 DOI: 10.1111/j.1582-4934.2007.00133.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We previously showed that the human heart expresses all known P2X and P2Y receptors activated by extra-cellular adenine or uracil nucleotides. Despite evidence that, both in humans and rodents, plasma levels of ATP and UTP markedly increase during myocardial infarction, the differential effects mediated by the various adenine- and uracil-preferring myocardial P2 receptors are still largely unknown. Here, we studied the effects of adenine and uracil nucleotides on murine HL-1 cardiomyocytes. RT-PCR analysis showed that HL-1 cardiomyocytes express all known P2X receptors (except for P2X(2)), as well as the P2Y(2,4,6,14) subtypes. Exposure of cardiomyocytes to adenine nucleotides (ATP, ADP or BzATP) induced apoptosis and necrosis, as determined by flow-cytometry. Cell death was exacerbated by tumour necrosis factor (TNF)-alpha, a cytokine implicated in chronic heart failure progression. Conversely, uracil nucleotides (UTP, UDP and UDPglucose) had no effect 'per se', but fully counteracted the deleterious effects induced by adenine nucleotides and TNF-alpha, even if added to cardiomyocytes after beginning exposure to these cell death-inducing agents. Thus, exposure of cardiomyocytes to elevated concentrations of ATP or ADP in the presence of TNF-alpha contributes to cell death, an effect which is counteracted by uracil-preferring P2 receptors. Cardiomyocytes do not need to be 'primed' by uracil nucleotides to become insensitive to adenine nucleotides-induced death, suggesting the existence of a possible 'therapeutic' window for uracil nucleotides-mediated protection. Thus, release of UTP during cardiac ischaemia and in chronic heart failure may protect against myocardial damage, setting the basis for developing novel cardioprotective agents that specifically target uracil-preferring P2Y receptors.
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Affiliation(s)
- Alessia Mazzola
- Laboratory of Molecular and Cellular Pharmacology of Purinergic Transmission, Department of Pharmacological Sciences, University of Milan, Milan, Italy
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Gandia J, Galino J, Amaral OB, Soriano A, Lluís C, Franco R, Ciruela F. Detection of higher-order G protein-coupled receptor oligomers by a combined BRET-BiFC technique. FEBS Lett 2008; 582:2979-84. [PMID: 18675812 DOI: 10.1016/j.febslet.2008.07.045] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 07/01/2008] [Accepted: 07/11/2008] [Indexed: 01/25/2023]
Abstract
Despite some caveats, G protein-coupled receptor oligomerization is a phenomenon that is becoming largely accepted. Within these oligomers, however, stoichiometry remains to be elucidated. Here, by using bimolecular fluorescence complementation, we visualized adenosine A(2A) receptor homodimers in living cells, showing no apparent difference in the subcellular distribution when compared to the YFP-labelled adenosine A(2A) receptor protomer. Interestingly, the combination of bimolecular fluorescence complementation and bioluminescence resonance energy transfer techniques allowed us to detect the occurrence of adenosine A(2A) receptors oligomers containing more than two protomers. These results provide new insights into the molecular composition of G protein-coupled receptor oligomers.
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Affiliation(s)
- Jorge Gandia
- Departament Patologia i Terapèutica Experimental, Facultat de Medicina, Universitat de Barcelona, Pavelló de Govern, L'Hospitalet de Llobregat, 08907 Barcelona, Spain
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Plasma membrane diffusion of G protein-coupled receptor oligomers. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:2262-8. [PMID: 18691614 DOI: 10.1016/j.bbamcr.2008.07.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 07/03/2008] [Accepted: 07/08/2008] [Indexed: 11/23/2022]
Abstract
G protein-coupled receptors are known to form homo-and heteromers at the plasma membrane, but the molecular properties of these oligomers are relatively unknown. Here, we show a method that allows the diffusion of G protein-coupled receptors oligomers in the plasma membrane to be monitored in single cells by combining Bimolecular Fluorescence Complementation and Fluorescence Correlation Spectroscopy. With this approach we have measured, for the first time, the membrane diffusional characteristics of adenosine A(1) and A(2A) receptor homo-and heterodimers in Chinese Hamster Ovary cells. Interestingly, both homodimers display similar diffusion co-efficients (D) when expressed in living cells (D=5.0 and 4.8x10(-9) cm(2)/s, respectively) but the heterodimer formed by these receptors exhibit a significantly faster plasma membrane diffusion co-efficent (D=5.6x10(-9) cm(2)/s) when compared to the adenosine A(1) receptor tagged with the full-length yellow fluorescent protein (D=4.0x10(-9) cm(2)/s). Overall, these results demonstrate differences in plasma membrane diffusion between adenosine receptor homo-and heterodimers, providing new insights into the molecular plasticity of G protein-coupled receptor oligomerization.
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Zezula J, Freissmuth M. The A(2A)-adenosine receptor: a GPCR with unique features? Br J Pharmacol 2008; 153 Suppl 1:S184-90. [PMID: 18246094 DOI: 10.1038/sj.bjp.0707674] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The A(2A)-adenosine receptor is a prototypical G(s)-coupled receptor. However, the A(2A)-receptor has several structural and functional characteristics that make it unique. In contrast to the classical model of collision coupling described for the beta-adrenergic receptors, the A(2A)-receptor couples to adenylyl cyclase by restricted collision coupling and forms a tight complex with G(s). The mechanistic basis for this is not clear; restricted collision coupling may arise from the interaction of the receptor with additional proteins or due to the fact that G protein-coupling is confined to specialized membrane microdomains. The A(2A)-receptor has a long C-terminus (of >120 residues), which is for the most part dispensable for coupling to G(s). It was originally viewed as the docking site for kinases and the beta-arrestin family to initiate receptor desensitization and endocytosis. The A(2A)-receptor is, however, fairly resistant to agonist-induced internalization. Recently, the C-terminus has also been appreciated as a binding site for several additional 'accessory' proteins. Established interaction partners include alpha-actinin, ARNO, USP4 and translin-associated protein-X. In addition, the A(2A)-receptor has also been reported to form a heteromeric complex with the D(2)-dopamine receptor and the metabotropic glutamate receptor-5. It is clear that (i) this list cannot be exhaustive and (ii) that all these proteins cannot bind simultaneously to the receptor. There must be rules of engagement, which allow the receptor to elicit different biological responses, which depend on the cellular context and the nature of the concomitant signal(s). Thus, the receptor may function as a coincidence detector and a signal integrator.
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Affiliation(s)
- J Zezula
- Center of Biomolecular Medicine and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Austria
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43
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Charalambous C, Gsandtner I, Keuerleber S, Milan-Lobo L, Kudlacek O, Freissmuth M, Zezula J. Restricted collision coupling of the A2A receptor revisited: evidence for physical separation of two signaling cascades. J Biol Chem 2008; 283:9276-88. [PMID: 18218631 DOI: 10.1074/jbc.m706275200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The A(2A)-adenosine receptor is a prototypical G(s) protein-coupled receptor but stimulates MAPK/ERK in a G(s)-independent way. The A(2A) receptor has long been known to undergo restricted collision coupling with G(s); the mechanistic basis for this mode of coupling has remained elusive. Here we visualized agonist-induced changes in mobility of the yellow fluorescent protein-tagged receptor by fluorescence recovery after photobleaching microscopy. Stimulation with a specific A(2A) receptor agonist did not affect receptor mobility. In contrast, stimulation with dopamine decreased the mobility of the D(2) receptor. When coexpressed in the same cell, the A(2A) receptor precluded the agonist-induced change in D(2) receptor mobility. Thus, the A(2A) receptor did not only undergo restricted collision coupling, but it also restricted the mobility of the D(2) receptor. Restricted mobility was not due to tethering to the actin cytoskeleton but was, in part, related to the cholesterol content of the membrane. Depletion of cholesterol increased receptor mobility but blunted activation of adenylyl cyclase, which was accounted for by impaired formation of the ternary complex of agonist, receptor, and G protein. These observations support the conclusion that the A(2A) receptor engages G(s) and thus signals to adenylyl cyclase in cholesterol-rich domains of the membrane. In contrast, stimulation of MAPK by the A(2A) receptor was not impaired. These findings are consistent with a model where the recruitment of these two pathways occurs in physically segregated membrane microdomains. Thus, the A(2A) receptor is the first example of a G protein-coupled receptor documented to select signaling pathways in a manner dependent on the lipid microenvironment of the membrane.
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Affiliation(s)
- Christoforos Charalambous
- Institute of Pharmacology, Center of Biomolecular Medicine and Pharmacology, Medical University of Vienna, Währinger Strasse 13a, Vienna, Austria
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44
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Adenosine-stimulated adrenal steroidogenesis involves the adenosine A2A and A2B receptors and the Janus kinase 2–mitogen-activated protein kinase kinase–extracellular signal-regulated kinase signaling pathway. Int J Biochem Cell Biol 2008; 40:2815-25. [DOI: 10.1016/j.biocel.2008.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 05/15/2008] [Accepted: 05/29/2008] [Indexed: 11/22/2022]
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45
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Rivo J, Zeira E, Galun E, Einav S, Linden J, Matot I. Attenuation of reperfusion lung injury and apoptosis by A2A adenosine receptor activation is associated with modulation of Bcl-2 and Bax expression and activation of extracellular signal-regulated kinases. Shock 2007; 27:266-73. [PMID: 17304107 DOI: 10.1097/01.shk.0000235137.13152.44] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Adenosine receptors (AR) and extracellular signal-regulated kinases (ERK) have been implicated in tissue protection and apoptosis regulation during ischemia/reperfusion (I/R) injury. This study tests the hypothesis that reduction of reperfusion lung injury after A2A AR activation is associated with attenuation of apoptosis, modulation of ERK activation, and alterations in antiapoptotic and proapoptotic protein expression (Bcl-2 and Bax, respectively). Experiments were performed in intact-chest, spontaneously breathing cats in which the arterial branch of the left lower lung lobe was occluded for 2 h and reperfused for 3 h (I/R group). Animals were treated with the selective A2A AR agonist ATL313 given 5 min before reperfusion alone or in combination with the selective A2A AR antagonist ZM241385. Western blot analysis showed significant reduction in expression of Bcl-2 and increase in expression of Bax after reperfusion, compared with control lungs. Phosphorylated ERK1/2 levels were also increased after reperfusion. Compared with the I/R group, ATL313 markedly (P < 0.01) attenuated indices of injury and apoptosis including the percentage of injured alveoli, wet-dry weight ratio, myeloperoxidase activity, in situ terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling-positive cells, and caspase 3 activity and expression. Furthermore, compared with reperfused lungs, in ATL313-pretreated lungs, Western blot analysis demonstrated substantial ERK1/2 activation, increased expression of Bcl-2, and attenuated expression of Bax. The protective effects of ATL313 were blocked by pretreatment with ZM241385. In summary, the present study shows that in vivo activation of A2A AR confers protection against reperfusion lung injury. This protection is associated with decreased apoptosis and involves ERK1/2 activation and alterations in antiapoptotic Bcl-2 and proapoptotic Bax proteins.
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Affiliation(s)
- Julia Rivo
- Department of Anesthesiology and Critical Care Medicine, Hadassah University Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel
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46
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Fang Y, Olah ME. Cyclic AMP-dependent, protein kinase A-independent activation of extracellular signal-regulated kinase 1/2 following adenosine receptor stimulation in human umbilical vein endothelial cells: role of exchange protein activated by cAMP 1 (Epac1). J Pharmacol Exp Ther 2007; 322:1189-200. [PMID: 17565009 DOI: 10.1124/jpet.107.119933] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A critical process in angiogenesis is endothelial cell proliferation, which requires activation of extracellular signal-regulated kinase (ERK)1/2. This study analyzed the pathway responsible for adenosine-induced ERK1/2 phosphorylation in human umbilical vein endothelial cells (HUVEC). Characterization with adenosine receptor (AR) agonists and antagonists and the AR mRNA profile demonstrated that stimulation of the A(2B)AR can mediate ERK1/2 phosphorylation in HUVEC. The lack of sensitivity of A(2B)AR-mediated ERK1/2 phosphorylation to 3-[1-[3-(dimethylaminopropyl]-1H-indol-3-yl]-4-(1H-indol-3-yl)-1H-pyrrole-2,5-dione monohydrochloride (GF109203X) and 3-[1-[3-(amidinothio)propyl]-1H-in-dol-3-yl]-3-(1-methyl-1H-indol-3-yl) maleimide (bisindolylmaleimide IX) (Ro31-8220) indicated that protein kinase C stimulation is not required. The response did not involve transactivation of receptors for epidermal growth factor or vascular endothelial growth factor (VEGF). The A(2B)AR-mediated response required functional G(alphas) and was mimicked by forskolin and 8-bromoadenosine 3',5'-cyclic monophosphate. However, ERK1/2 phosphorylation induced by A(2B)AR stimulation and forskolin was insensitive to protein kinase A inhibitors. It was hypothesized that the A(2B)AR-mediated ERK1/2 activation may involve exchange protein activated by cAMP (Epac), a cAMP-activated guanine nucleotide exchange factor for Rap GTPases. Reverse Transcription-polymerase chain reaction analysis detected Epac1 but not Epac2 in HUVEC. 8-(p-Chlorophenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (8CPT-2Me-cAMP), an Epac activator, stimulated ERK1/2 phosphorylation. Overexpression of Epac1 enhanced A(2B)AR-mediated and forskolin-induced ERK1/2 phosphorylation, whereas response to VEGF was unaffected. Inhibition of Epac1 expression with small interfering RNA substantially reduced A(2B)AR-mediated and forskolin-induced ERK1/2 phosphorylation and abolished that by 8CPT-2Me-cAMP. A(2B)AR stimulation and forskolin activated Rap1. Expression of a dominant-negative Ras protein did not affect either forskolin-induced or A(2B)AR-mediated ERK1/2 phosphorylation. In summary, Epac1 activation in HUVEC results in ERK1/2 activation, and this protein, at least in part, mediates response to the physiologically relevant event of A(2B)AR stimulation.
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Affiliation(s)
- Ying Fang
- Department of Pharmacology and Cell Biophysics, College of Medicine, University of Cincinnati, Ohio, USA
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47
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Silva CG, Porciúncula LO, Canas PM, Oliveira CR, Cunha RA. Blockade of adenosine A(2A) receptors prevents staurosporine-induced apoptosis of rat hippocampal neurons. Neurobiol Dis 2007; 27:182-9. [PMID: 17596953 DOI: 10.1016/j.nbd.2007.04.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Accepted: 04/07/2007] [Indexed: 12/20/2022] Open
Abstract
Since adenosine A(2A) receptor (A(2A)Rs) blockade protects against noxious brain insults involving apoptosis, we directly tested if A(2A)R blockade prevents apoptosis induced by staurosporine (STS). Exposure of rat hippocampal neurons to STS (30 nM, 24 h) decreased neuronal viability while increasing the number apoptotic-like neurons and de-localizing mitochondria and cytochrome c immunoreactivities. This was prevented by the selective A(2A)R antagonists, SCH58261 and ZM241385 (50 nM). Shorter incubation periods (6 h) with STS caused no neuronal loss but decreased synaptophysin and MAP-2 immunoreactivities, which was prevented by SCH58261. Furthermore, STS (100 nM) decreased MTT reduction and increased caspase-3 activity in rat hippocampal nerve terminals, which was prevented by SCH58261. These results show that A(2A)R blockade inhibits STS-induced apoptotic-like neuronal cell death. This begins with an apoptotic-like synaptotoxicity, which later evolved into an overt neurotoxicity, and A(2A)Rs effectively control this initial synaptotoxicity, in agreement with their predominant synaptic localization in the hippocampus.
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Affiliation(s)
- Carla G Silva
- Center for Neuroscience of Coimbra, Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
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Fresco P, Oliveira JMA, Kunc F, Soares AS, Rocha-Pereira C, Gonçalves J, Diniz C. A2A adenosine-receptor-mediated facilitation of noradrenaline release in rat tail artery involves protein kinase C activation and betagamma subunits formed after alpha2-adrenoceptor activation. Neurochem Int 2007; 51:47-56. [PMID: 17493708 DOI: 10.1016/j.neuint.2007.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 03/14/2007] [Accepted: 03/19/2007] [Indexed: 11/29/2022]
Abstract
This work aimed to investigate the molecular mechanisms involved in the interaction of alpha2-adrenoceptors and adenosine A2A-receptor-mediated facilitation of noradrenaline release in rat tail artery, namely the type of G-protein involved in this effect and the step or steps where the signalling cascades triggered by alpha2-adrenoceptors and A2A-receptors interact. The selective adenosine A2A-receptor agonist 2-p-(2-carboxy ethyl) phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS 21680; 100 nM) enhanced tritium overflow evoked by trains of 100 pulses at 5 Hz. This effect was abolished by the selective adenosine A2A-receptor antagonist 5-amino-7-(2-phenyl ethyl)-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo [1,5-c]pyrimidine (SCH 58261; 20 nM) and by yohimbine (1 microM). CGS 21680-mediated effects were also abolished by drugs that disrupted G(i/o)-protein coupling with receptors, PTX (2 microg/ml) or NEM (40 microM), by the anti-G(salpha) peptide (2 microg/ml) anti-G(betagamma) peptide (10 microg/ml) indicating coupling of A2A-receptors to G(salpha) and suggesting a crucial role for G(betagamma) subunits in the A(2A)-receptor-mediated enhancement of tritium overflow. Furthermore, phorbol 12-myristate 13-acetate (PMA; 1 microM) or forskolin (1 microM), direct activators of protein kinase C and of adenylyl cyclase, respectively, also enhanced tritium overflow. In addition, PMA-mediated effects were not observed in the presence of either yohimbine or PTX. Results indicate that facilitatory adenosine A2A-receptors couple to G(salpha) subunits which is essential, but not sufficient, for the release facilitation to occur, requiring the involvement of G(i/o)-protein coupling (it disappears after disruption of G(i/o)-protein coupling, PTX or NEM) and/or G(betagamma) subunits (anti-G(betagamma)). We propose a mechanism for the interaction in study suggesting group 2 AC isoforms as a plausible candidate for the interaction site, as these isoforms can integrate inputs from G(salpha) subunits (released after adenosine A2A-receptor activation; prime-activation), G(betagamma) subunits (released after activation of G(i/o)-protein coupled receptors) which can directly synergistically stimulate the prime-activated AC or indirectly via G(betagamma) activation of the PLC-PKC pathway.
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MESH Headings
- Adenylyl Cyclases/drug effects
- Adenylyl Cyclases/metabolism
- Adrenergic Agonists/pharmacology
- Adrenergic Antagonists/pharmacology
- Animals
- Arteries/drug effects
- Arteries/innervation
- Arteries/metabolism
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- GTP-Binding Protein beta Subunits/biosynthesis
- GTP-Binding Protein beta Subunits/drug effects
- GTP-Binding Protein gamma Subunits/biosynthesis
- GTP-Binding Protein gamma Subunits/drug effects
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/innervation
- Muscle, Smooth, Vascular/metabolism
- Norepinephrine/metabolism
- Protein Kinase C/drug effects
- Protein Kinase C/metabolism
- Protein Subunits/drug effects
- Protein Subunits/metabolism
- Rats
- Rats, Wistar
- Receptor Cross-Talk/drug effects
- Receptor Cross-Talk/physiology
- Receptor, Adenosine A2A/drug effects
- Receptor, Adenosine A2A/metabolism
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Sympathetic Fibers, Postganglionic/drug effects
- Sympathetic Fibers, Postganglionic/metabolism
- Tail/blood supply
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Affiliation(s)
- Paula Fresco
- Serviço de Farmacologia, REQUIMTE/FARMA, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 164, P 4050-047 Porto, Portugal.
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Tang LM, Wang YP, Wang K, Pu LY, Zhang F, Li XC, Kong LB, Sun BC, Li GQ, Wang XH. Protective effect of adenosine A2A receptor activation in small-for-size liver transplantation. Transpl Int 2007; 20:93-101. [PMID: 17181659 DOI: 10.1111/j.1432-2277.2006.00394.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The aim of the present study was to investigate the potential role of adenosine A(2A) receptor (A(2A)R) activation in small-for-size liver transplantation. A rat orthotopic liver transplantation model was performed by using 40% (range: 36-46%) liver grafts. Recipients were given either saline (control group) or CGS 21680 (2-p-(2-Carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride, a selective A(2A)R agonist), or CGS 21680+ ZM 241385 (a selective A(2A)R antagonist) immediately after reperfusion for 3 h. Compared with control group, CGS 21680 used at both low dose (0.05 microg/kg/min) and high dose (0.5 microg/kg/min) increased the survival rate from 16.7% (2/12) to 83.3% (10/12) and 66.7% (8/12), respectively. These effects correlated with improved liver function and preserved hepatic architecture. CGS 21680 effectively decreased neutrophil infiltration, suppressed pro-inflammatory (TNF-alpha, IL-1beta and IL-6) expression, promoted expression of antiapoptotic molecules, and inhibited apoptosis. The effects of CGS 21680 were prevented when ZM 241385 was co-administrated. In conclusion, the present study showed that A(2A)R activation alleviated portal hypertension, suppressed inflammatory response, reduced apoptosis, and potentiated the survival of small-for-size liver grafts. Our findings provide the rationale for a novel therapeutic approach using A(2A)R activation to maximize the availability of small-for-size liver grafts.
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Affiliation(s)
- Li-Ming Tang
- The Liver Transplantation Center of the First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, China
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Sahin B, Galdi S, Hendrick J, Greene RW, Snyder GL, Bibb JA. Evaluation of neuronal phosphoproteins as effectors of caffeine and mediators of striatal adenosine A2A receptor signaling. Brain Res 2007; 1129:1-14. [PMID: 17157277 PMCID: PMC1847645 DOI: 10.1016/j.brainres.2006.10.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2006] [Revised: 10/02/2006] [Accepted: 10/26/2006] [Indexed: 11/26/2022]
Abstract
Adenosine A(2A) receptors are predominantly expressed in the dendrites of enkephalin-positive gamma-aminobutyric acidergic medium spiny neurons in the striatum. Evidence indicates that these receptors modulate striatal dopaminergic neurotransmission and regulate motor control, vigilance, alertness, and arousal. Although the physiological and behavioral correlates of adenosine A(2A) receptor signaling have been extensively studied using a combination of pharmacological and genetic tools, relatively little is known about the signal transduction pathways that mediate the diverse biological functions attributed to this adenosine receptor subtype. Using a candidate approach based on the coupling of these receptors to adenylate cyclase-activating G proteins, a number of membranal, cytosolic, and nuclear phosphoproteins regulated by PKA were evaluated as potential mediators of adenosine A(2A) receptor signaling in the striatum. Specifically, the adenosine A(2A) receptor agonist, CGS 21680, was used to determine whether the phosphorylation state of each of the following PKA targets is responsive to adenosine A(2A) receptor stimulation in this tissue: Ser40 of tyrosine hydroxylase, Ser9 of synapsin, Ser897 of the NR1 subunit of the N-methyl-d-aspartate-type glutamate receptor, Ser845 of the GluR1 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid-type glutamate receptor, Ser94 of spinophilin, Thr34 of the dopamine- and cAMP-regulated phosphoprotein, M(r) 32,000, Ser133 of the cAMP-response element-binding protein, Thr286 of Ca(2+)/calmodulin-dependent protein kinase II, and Thr202/Tyr204 and Thr183/Tyr185 of the p44 and p42 isoforms, respectively, of mitogen-activated protein kinase. Although the substrates studied differed considerably in their responsiveness to selective adenosine A(2A) receptor activation, the phosphorylation state of all postsynaptic PKA targets was up-regulated in a time- and dose-dependent manner by treatment with CGS 21680, whereas presynaptic PKA substrates were unresponsive to this agent, consistent with the postsynaptic localization of adenosine A(2A) receptors. Finally, the phosphorylation state of these proteins was further assessed in vivo by systemic administration of caffeine.
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Affiliation(s)
- Bogachan Sahin
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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