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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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Hasan AU, Ohmori K, Konishi K, Igarashi J, Hashimoto T, Kamitori K, Yamaguchi F, Tsukamoto I, Uyama T, Ishihara Y, Noma T, Tokuda M, Kohno M. Eicosapentaenoic acid upregulates VEGF-A through both GPR120 and PPARγ mediated pathways in 3T3-L1 adipocytes. Mol Cell Endocrinol 2015; 406:10-8. [PMID: 25697344 DOI: 10.1016/j.mce.2015.02.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/31/2015] [Accepted: 02/13/2015] [Indexed: 01/23/2023]
Abstract
Vascular endothelial growth factor-A (VEGF-A) released from adipocytes promotes angiogenesis; and thereby ameliorates the local hypoxia-induced adipose inflammation and insulin resistance. Here, we newly found that eicosapentaenoic acid (EPA) upregulated both mRNA expression and release of VEGF-A in mature 3T3-L1 adipocytes. Silencing mRNA of G-protein coupled receptor 120 (GPR120) and specific inhibition of peroxisome proliferator-activated receptor γ (PPARγ) by GW9662 respectively attenuated the EPA-induced augmentation of VEGF-A release by adipocytes. Furthermore, transfection of GPR120 gene alone and PPARγ gene alone to HEK293 cells respectively increased the promoter activity of VEGF-A as assessed by luciferase reporter assay, which was further augmented when both genes were co-transfected. Promoter deletion analysis and chromatin immunoprecipitation assay revealed that co-transfection of GPR120 enhanced EPA-induced PPARγ binding to PPAR-response element in VEGF-A promoter region. Thus, by the synchronized activation of a membrane receptor GRP120 and a nuclear receptor PPARγ, EPA enhances VEGF-A production in adipocytes.
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Affiliation(s)
- Arif U Hasan
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Koji Ohmori
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan.
| | - Kumi Konishi
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Junsuke Igarashi
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Takeshi Hashimoto
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Kazuyo Kamitori
- Department of Cell Physiology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Fuminori Yamaguchi
- Department of Cell Physiology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Ikuko Tsukamoto
- Department of Pharmaco-Bio-Informatics, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Toru Uyama
- Department of Biochemistry, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Yasuhiro Ishihara
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Takahisa Noma
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Masaaki Tokuda
- Department of Cell Physiology, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Masakazu Kohno
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, 1750-1, Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
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3
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Agostini S, Chiavacci E, Matteucci M, Torelli M, Pitto L, Lionetti V. Barley beta-glucan promotes MnSOD expression and enhances angiogenesis under oxidative microenvironment. J Cell Mol Med 2014; 19:227-38. [PMID: 25388628 PMCID: PMC4288365 DOI: 10.1111/jcmm.12442] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 08/22/2014] [Indexed: 12/20/2022] Open
Abstract
Manganese superoxide dismutase (MnSOD), a foremost antioxidant enzyme, plays a key role in angiogenesis. Barley-derived (1.3) β-d-glucan (β-d-glucan) is a natural water-soluble polysaccharide with antioxidant properties. To explore the effects of β-d-glucan on MnSOD-related angiogenesis under oxidative stress, we tested epigenetic mechanisms underlying modulation of MnSOD level in human umbilical vein endothelial cells (HUVECs) and angiogenesis in vitro and in vivo. Long-term treatment of HUVECs with 3% w/v β-d-glucan significantly increased the level of MnSOD by 200% ± 2% compared to control and by 50% ± 4% compared to untreated H2O2-stressed cells. β-d-glucan-treated HUVECs displayed greater angiogenic ability. In vivo, 24 hrs-treatment with 3% w/v β-d-glucan rescued vasculogenesis in Tg (kdrl: EGFP) s843Tg zebrafish embryos exposed to oxidative microenvironment. HUVECs overexpressing MnSOD demonstrated an increased activity of endothelial nitric oxide synthase (eNOS), reduced load of superoxide anion (O2−) and an increased survival under oxidative stress. In addition, β-d-glucan prevented the rise of hypoxia inducible factor (HIF)1-α under oxidative stress. The level of histone H4 acetylation was significantly increased by β-d-glucan. Increasing histone acetylation by sodium butyrate, an inhibitor of class I histone deacetylases (HDACs I), did not activate MnSOD-related angiogenesis and did not impair β-d-glucan effects. In conclusion, 3% w/v β-d-glucan activates endothelial expression of MnSOD independent of histone acetylation level, thereby leading to adequate removal of O2−, cell survival and angiogenic response to oxidative stress. The identification of dietary β-d-glucan as activator of MnSOD-related angiogenesis might lead to the development of nutritional approaches for the prevention of ischemic remodelling and heart failure.
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Affiliation(s)
- Silvia Agostini
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
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Sabourin J, Antigny F, Robin E, Frieden M, Raddatz E. Activation of transient receptor potential canonical 3 (TRPC3)-mediated Ca2+ entry by A1 adenosine receptor in cardiomyocytes disturbs atrioventricular conduction. J Biol Chem 2012; 287:26688-701. [PMID: 22692208 DOI: 10.1074/jbc.m112.378588] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Although the activation of the A(1)-subtype of the adenosine receptors (A(1)AR) is arrhythmogenic in the developing heart, little is known about the underlying downstream mechanisms. The aim of this study was to determine to what extent the transient receptor potential canonical (TRPC) channel 3, functioning as receptor-operated channel (ROC), contributes to the A(1)AR-induced conduction disturbances. Using embryonic atrial and ventricular myocytes obtained from 4-day-old chick embryos, we found that the specific activation of A(1)AR by CCPA induced sarcolemmal Ca(2+) entry. However, A(1)AR stimulation did not induce Ca(2+) release from the sarcoplasmic reticulum. Specific blockade of TRPC3 activity by Pyr3, by a dominant negative of TRPC3 construct, or inhibition of phospholipase Cs and PKCs strongly inhibited the A(1)AR-enhanced Ca(2+) entry. Ca(2+) entry through TRPC3 was activated by the 1,2-diacylglycerol (DAG) analog OAG via PKC-independent and -dependent mechanisms in atrial and ventricular myocytes, respectively. In parallel, inhibition of the atypical PKCζ by myristoylated PKCζ pseudosubstrate inhibitor significantly decreased the A(1)AR-enhanced Ca(2+) entry in both types of myocytes. Additionally, electrocardiography showed that inhibition of TRPC3 channel suppressed transient A(1)AR-induced conduction disturbances in the embryonic heart. Our data showing that A(1)AR activation subtly mediates a proarrhythmic Ca(2+) entry through TRPC3-encoded ROC by stimulating the phospholipase C/DAG/PKC cascade provide evidence for a novel pathway whereby Ca(2+) entry and cardiac function are altered. Thus, the A(1)AR-TRPC3 axis may represent a potential therapeutic target.
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Affiliation(s)
- Jessica Sabourin
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, 7 rue du Bugnon, CH-1005 Lausanne, Switzerland
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Constitutive activity of the A2A adenosine receptor and compartmentalised cyclic AMP signalling fine-tune noradrenaline release. Purinergic Signal 2012; 8:677-92. [PMID: 22476939 DOI: 10.1007/s11302-012-9298-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 03/09/2012] [Indexed: 10/28/2022] Open
Abstract
Neuroblastoma SH-SY5Y (SH) cells endogenously express A(2A) adenosine receptors and can be differentiated into a sympathetic neuronal phenotype, capable of depolarisation-dependent noradrenaline release. Using differentiated SH culture, we here explored the link between A(2A)-receptor signalling and neurotransmitter release. In response to the receptor agonist CGS21680, the cells produced cyclic AMP (cAMP), and when depolarised, they released increased amounts of noradrenaline. An A(2A)-receptor antagonist, XAC, as well as an inhibitor of cAMP-dependent protein kinase A (PKA), H89, depressed agonist-dependent release. In the presence of XAC or H89, noradrenaline release was found to be below basal values. This suggested that release facilitation also owes to constitutive receptor activity. We demonstrate that even in the absence of an agonist, the native A(2A)-receptor stimulated cAMP production, leading to the activation of PKA and enhanced noradrenaline release. Ancillary, non-cAMP-dependent effects of the receptor (i.e. phosphorylation of CREB, of Rabphilin3A) were refractory to constitutive activation. PKA-dependent facilitation of noradrenaline release was recapitulated with membrane-permeable 8-Br-cAMP; in addition to facilitation, 8-Br-cAMP caused marked inhibition of release, an effect not observed upon receptor activation. Inhibition by receptor-independent cAMP was likely due to suppression of voltage-dependent calcium current (VDCC) and increased activity of Src-family kinases. Receptor-mediated release facilitation was reproduced in the presence of tetrodotoxin (blocking action potentials); hence, the signalling occurred at the active zone comprising release sites. Our findings thus support (1) presynaptic localisation of the A(2A)-receptor and (2) suggest that compartmentalised pathways transmit cAMP signalling in order to facilitate depolarisation-dependent neurotransmitter release.
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Synthesis and biological evaluation of novel indolocarbazoles with anti-angiogenic activity. Eur J Med Chem 2011; 48:108-13. [PMID: 22182929 DOI: 10.1016/j.ejmech.2011.11.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 11/22/2011] [Accepted: 11/28/2011] [Indexed: 11/23/2022]
Abstract
A novel series of indolocarbazoles were synthesized and their antiproliferative activity against HUVEC, LoVo, DLD-1 and ST-486 cell lines, was investigated. Those staurosporine analogs in which a substituted dimethylaminoalkoxy chain was attached to the indolic nitrogen showed interesting activity and selectivity with respect to HUVEC proliferation. The effect on capillary tube formation in 3-dimensional matrigel matrix was studied using the most active compounds. Evaluation of their in vivo anti-angiogenic activity in a murine Lewis lung cancer model was also analyzed.
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Gammella E, Cairo G, Tacchini L. Adenosine A(2)A receptor but not HIF-1 mediates Tyrosine hydroxylase induction in hypoxic PC12 cells. J Neurosci Res 2010; 88:2007-16. [PMID: 20143408 DOI: 10.1002/jnr.22366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the biosynthesis of catecholamines released by oxygen-sensitive cells in response to hypoxic conditions. Adenosine is released in response to hypoxia in the central nervous system and CGS21680, an adenosine A(2)A receptor agonist, induces TH transcription. As we have previously demonstrated the A(2)A receptor-mediated induction of HIF-1 in macrophages and hepatocytes, we investigated the involvement of HIF-1 in the adenosine-mediated activation of TH expression. Exposure to adenosine or CGS21680 increased TH mRNA and protein levels in PC12 cells. Transcription of a reporter gene under the control of the wild type rat TH promoter was induced 3.5-fold in CGS21680-treated cells, but neither the mutation of the hypoxia responsive element in the TH promoter nor the co-transfection of a dominant negative of the HIF-1 beta subunit prevented the increase in transcription; furthermore, CGS21680 increased CREB binding activity but did not induce HIF-1 DNA binding activity or protein levels. To investigate whether HIF-1 was involved in the hypoxia-mediated induction of TH, PC12 cells were exposed to hypoxia in the presence of the A(2)A receptor antagonist ZM241385, which prevented hypoxia-dependent TH induction despite HIF-1 activation; in line with this finding, the inhibition of HIF-1 did not abolish TH induction in hypoxic PC12 cells. These results indicate that, under hypoxic conditions, TH (a key factor in systemic adaptation to reduced oxygen availability) is not regulated by HIF-1, the primary modulator of the response to hypoxia, but by the adenosine A(2)A receptor-mediated signalling pathway.
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Affiliation(s)
- Elena Gammella
- Department of Human Morphology and Biomedical Sciences, Città Studi, Università degli Studi di Milano, Milan, Italy
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Sun Y, Wu F, Sun F, Huang P. Adenosine promotes IL-6 release in airway epithelia. THE JOURNAL OF IMMUNOLOGY 2008; 180:4173-81. [PMID: 18322229 DOI: 10.4049/jimmunol.180.6.4173] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In the airway epithelia, extracellular adenosine modulates a number of biological processes. However, little is known about adenosine's role in the inflammatory responses of airway epithelial cells. Recent studies suggest that the chronic elevation of extracellular adenosine in mice leads to pulmonary inflammation and fibrosis. Yet, the underlying molecular mechanism has not been well understood and little attention has been paid to the role of airway epithelia in adenosine-triggered inflammation. In the present work, we examined the role of adenosine in releasing IL-6 from airway epithelia. In Calu-3 human airway epithelial cells, apical but not basolateral adenosine elicited robust, apically polarized release of IL-6, along with proinflammatory IL-8. Both protein kinase A and protein kinase C mediated the adenosine-induced IL-6 release, at least partly via phosphorylation of CREB. Protein kinase C appeared to phosphorylate CREB through activating ERK. In addition, A2A but not A2B adenosine receptors were specifically required for the adenosine-induced IL-6 release. Furthermore, in rat bronchoalveolar lavage fluid, adenosine triggered the release of IL-6 as well as proinflammatory IL-1beta. Adenosine also mediated the release of a considerable portion of the LPS-induced IL-6 in rat bronchoalveolar lavage fluid. Our findings provide a possible molecular link between extracellular adenosine elevation and lung inflammation and fibrosis.
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Affiliation(s)
- Ying Sun
- Department of Biology, Hong Kong University of Science and Technology, Hong Kong, People's Republic of China
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Sainz IM, Isordia-Salas I, Espinola RG, Long WK, Pixley RA, Colman RW. Multiple myeloma in a murine syngeneic model:modulation of growth and angiogenesis by a monoclonal antibody to kininogen. Cancer Immunol Immunother 2006; 55:797-807. [PMID: 16187087 PMCID: PMC11030674 DOI: 10.1007/s00262-005-0068-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Accepted: 06/23/2005] [Indexed: 11/28/2022]
Abstract
Multiple myeloma (MM), a B-cell malignancy characterized by proliferation of monoclonal plasma cells remains incurable. Murine plasma cell tumors share common features with human MM. We used two cell lines (B38 and C11C1) derived from P3X63Ag8 myeloma cells. The new cell lines were implanted subcutaneously in the strain of origin (Balb/c mice) and used as a model to monitor the effects of C11C1 monoclonal antibody (mAb) to kininogen (HK). We assessed their behavior by intraperitoneal and subcutaneous implantation, by implanting them together and by treating B38-MM with purified mAb C11C1. We evaluated growth, microvascular density (MVD), and cellular expression of urokinase-type plasminogen activator-receptor (uPAR), fibroblast growth factor-2 (FGF-2), vascular endothelial growth factor (VEGF), bradykinin-1 receptor (B1R), bradykinin-2 receptor (B2R) and HK. We found that both MM-cell-lines are uPAR positive, that mAb C11C1 inhibits its own tumor growth in vivo, slows down B38-MM growth rate when both MM are implanted together and when mAb C11C1 is injected intraperitoneally. MAb C11C1-treated-MM showed decreased MVD and HK binding in vivo without FGF-2, B1R or B2R expression changes. We propose that the B38-extramedullary-myeloma-model is a useful tool to study the interactions of this hematopoietic tumor and its environment and that mAb C11C1 may improve the efficacy of conventional MM treatment with minimal side effects.
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MESH Headings
- Animals
- Antibodies, Monoclonal/therapeutic use
- Antibody Specificity
- Cell Line, Tumor/pathology
- Cell Line, Tumor/transplantation
- Fibroblast Growth Factor 2/biosynthesis
- Fibroblast Growth Factor 2/genetics
- Gene Expression Regulation, Neoplastic/drug effects
- Kininogens/immunology
- Mice
- Mice, Inbred BALB C
- Microcirculation/drug effects
- Multiple Myeloma/blood supply
- Multiple Myeloma/pathology
- Multiple Myeloma/therapy
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neovascularization, Pathologic/physiopathology
- Neovascularization, Pathologic/therapy
- Receptor, Bradykinin B1/biosynthesis
- Receptor, Bradykinin B1/genetics
- Receptor, Bradykinin B2/biosynthesis
- Receptor, Bradykinin B2/genetics
- Receptors, Cell Surface/biosynthesis
- Receptors, Cell Surface/genetics
- Receptors, Urokinase Plasminogen Activator
- Subcutaneous Tissue
- Vascular Endothelial Growth Factor A/biosynthesis
- Vascular Endothelial Growth Factor A/genetics
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Affiliation(s)
- Irma M. Sainz
- The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
| | - Irma Isordia-Salas
- The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
| | - Ricardo G. Espinola
- The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
| | - Walter K. Long
- The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
- Department of Microbiology and Immunology, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
| | - Robin A. Pixley
- The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
| | - Robert W. Colman
- The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street, Philadelphia, PA 19140 USA
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Adair TH, Cotten R, Gu JW, Pryor JS, Bennett KR, McMullan MR, McDonnell P, Montani JP. Adenosine infusion increases plasma levels of VEGF in humans. BMC PHYSIOLOGY 2005; 5:10. [PMID: 15967042 PMCID: PMC1183224 DOI: 10.1186/1472-6793-5-10] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Accepted: 06/20/2005] [Indexed: 11/16/2022]
Abstract
Background Many in vitro studies have shown that adenosine (Ado) can induce vascular endothelial growth factor (VEGF) mRNA and protein expression and stimulate endothelial proliferation. In the present study, we seek to determine whether Ado can increase circulating levels of VEGF protein in the intact human. Methods Five outpatients 49.3 ± 6.7 years of age and weighing 88.2 ± 8.5 kg were selected. They were given a 6 min intravenous infusion of Ado (0.14 mg kg-1 min-1) in conjunction with sestamibi myocardial perfusion scans. Mean blood pressure (MBP, calculated from systolic and diastolic values) and heart rate (HR) were determined before Ado infusion and every 2 min for the next 10 min. Plasma VEGF concentrations (ELISA) were determined immediately before Ado infusion and 1 h, 2 h, and 8 h after the infusion. Results Plasma VEGF concentration averaged 20.3 ± 2.0 pg ml-1 prior to Ado infusion, and increased to 62.7 ± 18.1 pg ml-1 at 1 h post- infusion (p < 0.01). VEGF plasma concentration returned to basal levels 2 h after infusion (23.3 ± 3.4 pg ml-1). MBP averaged 116 ± 7 mmHg and heart rate averaged 70 ± 7 prior to Ado infusion. MBP decreased by a maximum of ~22% and HR increased by a maximum of ~17% during the infusion. Conclusion We conclude from these preliminary findings that intravenous infusion of adenosine can increase plasma levels of VEGF in humans.
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Affiliation(s)
- Thomas H Adair
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Reid Cotten
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Medicine University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Jian-Wei Gu
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Janelle S Pryor
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Kenneth R Bennett
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Medicine University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Michael R McMullan
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Medicine University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Preston McDonnell
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Department of Physiology & Biophysics University of Mississippi Medical Center Jackson, MS 39216, USA
| | - Jean-Pierre Montani
- Angiogenesis Research LaboratoriesCenter for Excellence in Cardiovascular-Renal Research
- Institute of PhysiologyUniversity of Fribourg, 1700 Fribourg, Switzerland
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11
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Canals M, Angulo E, Casadó V, Canela EI, Mallol J, Viñals F, Staines W, Tinner B, Hillion J, Agnati L, Fuxe K, Ferré S, Lluis C, Franco R. Molecular mechanisms involved in the adenosine A1 and A2A receptor-induced neuronal differentiation in neuroblastoma cells and striatal primary cultures. J Neurochem 2005; 92:337-48. [PMID: 15663481 DOI: 10.1111/j.1471-4159.2004.02856.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Adenosine A1 receptors (A1Rs) and adenosine A(2A) receptors (A(2A)Rs) are the major mediators of the neuromodulatory actions of adenosine in the brain. In the striatum A1Rs and A(2A)Rs are mainly co-localized in the GABAergic striatopallidal neurons. In this paper we show that agonist-induced stimulation of A1Rs and A(2A)Rs induces neurite outgrowth processes in the human neuroblastoma cell line SH-SY5Y and also in primary cultures of striatal neuronal precursor cells. The kinetics of adenosine-mediated neuritogenesis was faster than that triggered by retinoic acid. The triggering of the expression of TrkB neurotrophin receptor and the increase of cell number in the G1 phase by the activation of adenosine receptors suggest that adenosine may participate in early steps of neuronal differentiation. Furthermore, protein kinase C (PKC) and extracellular regulated kinase-1/2 (ERK-1/2) are involved in the A1R- and A(2A)R-mediated effects. Inhibition of protein kinase A (PKA) activity results in a total inhibition of neurite outgrowth induced by A(2A)R agonists but not by A1R agonists. PKA activation is therefore necessary for A(2A)R-mediated neuritogenesis. Co-stimulation does not lead to synergistic effects thus indicating that the neuritogenic effects of adenosine are mediated by either A1 or A(2A) receptors depending upon the concentration of the nucleoside. These results are relevant to understand the mechanisms by which adenosine receptors modulate neuronal differentiation and open new perspectives for considering the use of adenosine agonists as therapeutic agents in diseases requiring neuronal repair.
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Affiliation(s)
- Meritxell Canals
- Department de Bioquimica i Biologia Molecular, University of Barcelona, Barcelona, Spain
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Mukhopadhyay D, Datta K. Multiple regulatory pathways of vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) expression in tumors. Semin Cancer Biol 2004; 14:123-30. [PMID: 15018896 DOI: 10.1016/j.semcancer.2003.09.019] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
VPF/VEGF is a multi-functional cytokine with important roles in both vasculogenesis and angiogenesis. Its production is generally regulated by local oxygen concentration. Hypoxia stimulates VPF/VEGF production by increasing its gene transcription and the stability of its mRNA. The increase in transcription in hypoxia occurs mainly through the stabilization and activation of the transcription factor, Hypoxia Inducible Factor (HIF). Cellular oxygen concentration is not the only regulator of VPF/VEGF synthesis. Some cancer cells can produce high levels of VPF/VEGF even in normoxia. Clear cell renal carcinoma cell line (RCC) like 786-0, pancreatic carcinoma cell line, ASPC-1, fibrocarcinoma cell line, HT1080, ovarian cancer cells, etc. produce an elevated level of VPF/VEGF, which is not dependent on hypoxia. In this article, we discuss different regulatory pathways in tumor cells comprised of oncogenes, tumor suppressor genes etc. that play important roles, in both the transcription and stability of VPF/VEGF mRNA.
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Affiliation(s)
- Debabrata Mukhopadhyay
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
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