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Gheinani AH, Sack BS, Bigger-Allen A, Thaker H, Atta H, Lambrinos G, Costa K, Doyle C, Gharaee-Kermani M, Patalano S, Piper M, Cotellessa JF, Vitko D, Li H, Prabhakaran MK, Cristofaro V, Froehlich J, Lee RS, Yang W, Sullivan MP, Macoska JA, Adam RM. Integrated omics analysis unveils a DNA damage response to neurogenic injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.10.571015. [PMID: 38106029 PMCID: PMC10723451 DOI: 10.1101/2023.12.10.571015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Spinal cord injury (SCI) evokes profound bladder dysfunction. Current treatments are limited by a lack of molecular data to inform novel therapeutic avenues. Previously, we showed systemic inosine treatment improved bladder function following SCI in rats. Here, we applied multi-omics analysis to explore molecular alterations in the bladder and their sensitivity to inosine following SCI. Canonical pathways regulated by SCI included those associated with protein synthesis, neuroplasticity, wound healing, and neurotransmitter degradation. Upstream regulator analysis identified MYC as a key regulator, whereas causal network analysis predicted multiple regulators of DNA damage response signaling following injury, including PARP-1. Staining for both DNA damage (γH2AX) and PARP activity (poly-ADP-ribose) markers in the bladder was increased following SCI, and attenuated in inosine-treated tissues. Proteomics analysis suggested that SCI induced changes in protein synthesis-, neuroplasticity-, and oxidative stress-associated pathways, a subset of which were shown in transcriptomics data to be inosine-sensitive. These findings provide novel insights into the molecular landscape of the bladder following SCI, and highlight a potential role for PARP inhibition to treat neurogenic bladder dysfunction.
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Affiliation(s)
- Ali Hashemi Gheinani
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Functional Urology Research Group, Department for BioMedical Research DBMR, University of Bern, Switzerland
- Department of Urology, Inselspital University Hospital, 3010 Bern, Switzerland
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Bryan S Sack
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Functional Urology Research Group, Department for BioMedical Research DBMR, University of Bern, Switzerland
| | - Alex Bigger-Allen
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Biological & Biomedical Sciences Graduate Program, Division of Medical Sciences, Harvard Medical School, Boston, MA
| | - Hatim Thaker
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Hussein Atta
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - George Lambrinos
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Kyle Costa
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
| | - Claire Doyle
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | | | | | - Mary Piper
- Harvard Chan Bioinformatics Core, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Justin F Cotellessa
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Dijana Vitko
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Haiying Li
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Manubhai Kadayil Prabhakaran
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Vivian Cristofaro
- Division of Urology, VA Boston Healthcare System, Boston, MA, USA
- University of Massachusetts, Boston, MA, USA
| | - John Froehlich
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Richard S Lee
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Wei Yang
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Maryrose P Sullivan
- Division of Urology, VA Boston Healthcare System, Boston, MA, USA
- University of Massachusetts, Boston, MA, USA
| | | | - Rosalyn M Adam
- Urological Diseases Research Center, Boston Children's Hospital, Boston, MA, USA
- Department of Urology, Inselspital University Hospital, 3010 Bern, Switzerland
- Department of Surgery, Harvard Medical School, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
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Jackson EK, Tofovic SP, Chen Y, Birder LA. 8-Aminopurines in the Cardiovascular and Renal Systems and Beyond. Hypertension 2023; 80:2265-2279. [PMID: 37503660 PMCID: PMC10592300 DOI: 10.1161/hypertensionaha.123.20582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Screening of compounds comprising 8-substituted guanine revealed that 8-aminoguanosine and 8-aminoguanine cause diuresis/natriuresis/glucosuria, yet decrease potassium excretion. Subsequent investigations demonstrated that 8-aminoguanosine's effects are mediated by its metabolite 8-aminoguanine. The mechanism by which 8-aminoguanine causes diuresis/natriuresis/glucosuria involves inhibition of PNPase (purine nucleoside phosphorylase), which increases renal interstitial inosine levels. Additional evidence suggests that inosine, via indirect or direct adenosine A2B receptor activation, increases renal medullary blood flow which enhances renal excretory function. Likely, 8-aminoguanine has pleiotropic actions that also alter renal excretory function. Indeed, the antikaliuretic effects of 8-aminoguanine are independent of PNPase inhibition. 8-Aminoguanine is an endogenous molecule; nitrosative stress leads to production of biomolecules containing 8-nitroguanine moieties. Degradation of these biomolecules releases 8-nitroguanosine and 8-nitro-2'-deoxyguanosine which are converted to 8-aminoguanine. Also, guanosine and guanine per se may contribute to 8-aminoguanine formation. 8-Aminoinosine, 8-aminohypoxanthine, and 8-aminoxanthine likewise induce diuresis/natriuresis/glucosuria, yet do not reduce potassium excretion. Thus, there are several pharmacologically active 8-aminopurines with nuanced effects on renal excretory function. Chronic treatment with 8-aminoguanine attenuates hypertension in deoxycorticosterone/salt rats, prevents strokes, and increases lifespan in Dahl salt-sensitive rats on a high salt diet and attenuates the metabolic syndrome in rats; 8-aminoguanosine retards progression of pulmonary hypertension in rats and anemia and organ damage in sickle cell mice. 8-Aminoguanine reverses age-associated lower urinary tract dysfunction and retinal degeneration. 8-Aminopurines represent a new class of agents (and potentially endogenous factors) that have beneficial effects on the cardiovascular system and kidneys and may turn back the clock in age-associated diseases.
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Affiliation(s)
- Edwin K. Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Stevan P. Tofovic
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Yuanyuan Chen
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Lori A. Birder
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
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Shimizu N, Saito T, Wada N, Hashimoto M, Shimizu T, Kwon J, Cho KJ, Saito M, Karnup S, de Groat WC, Yoshimura N. Molecular Mechanisms of Neurogenic Lower Urinary Tract Dysfunction after Spinal Cord Injury. Int J Mol Sci 2023; 24:7885. [PMID: 37175592 PMCID: PMC10177842 DOI: 10.3390/ijms24097885] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/21/2023] [Accepted: 04/22/2023] [Indexed: 05/15/2023] Open
Abstract
This article provides a synopsis of current progress made in fundamental studies of lower urinary tract dysfunction (LUTD) after spinal cord injury (SCI) above the sacral level. Animal models of SCI allowed us to examine the effects of SCI on the micturition control and the underlying neurophysiological processes of SCI-induced LUTD. Urine storage and elimination are the two primary functions of the LUT, which are governed by complicated regulatory mechanisms in the central and peripheral nervous systems. These neural systems control the action of two functional units in the LUT: the urinary bladder and an outlet consisting of the bladder neck, urethral sphincters, and pelvic-floor striated muscles. During the storage phase, the outlet is closed, and the bladder is inactive to maintain a low intravenous pressure and continence. In contrast, during the voiding phase, the outlet relaxes, and the bladder contracts to facilitate adequate urine flow and bladder emptying. SCI disrupts the normal reflex circuits that regulate co-ordinated bladder and urethral sphincter function, leading to involuntary and inefficient voiding. Following SCI, a spinal micturition reflex pathway develops to induce an overactive bladder condition following the initial areflexic phase. In addition, without proper bladder-urethral-sphincter coordination after SCI, the bladder is not emptied as effectively as in the normal condition. Previous studies using animal models of SCI have shown that hyperexcitability of C-fiber bladder afferent pathways is a fundamental pathophysiological mechanism, inducing neurogenic LUTD, especially detrusor overactivity during the storage phase. SCI also induces neurogenic LUTD during the voiding phase, known as detrusor sphincter dyssynergia, likely due to hyperexcitability of Aδ-fiber bladder afferent pathways rather than C-fiber afferents. The molecular mechanisms underlying SCI-induced LUTD are multifactorial; previous studies have identified significant changes in the expression of various molecules in the peripheral organs and afferent nerves projecting to the spinal cord, including growth factors, ion channels, receptors and neurotransmitters. These findings in animal models of SCI and neurogenic LUTD should increase our understanding of pathophysiological mechanisms of LUTD after SCI for the future development of novel therapies for SCI patients with LUTD.
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Affiliation(s)
- Nobutaka Shimizu
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
- Pelvic Floor Center, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Tetsuichi Saito
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Naoki Wada
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Mamoru Hashimoto
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Takahiro Shimizu
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Joonbeom Kwon
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Kang Jun Cho
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Sergei Karnup
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - William C. de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Naoki Yoshimura
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (N.S.)
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Valada P, Hinz S, Vielmuth C, Lopes CR, Cunha RA, Müller CE, Lopes JP. The impact of inosine on hippocampal synaptic transmission and plasticity involves the release of adenosine through equilibrative nucleoside transporters rather than the direct activation of adenosine receptors. Purinergic Signal 2022:10.1007/s11302-022-09899-7. [PMID: 36156760 DOI: 10.1007/s11302-022-09899-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 09/13/2022] [Indexed: 11/24/2022] Open
Abstract
Inosine has robust neuroprotective effects, but it is unclear if inosine acts as direct ligand of adenosine receptors or if it triggers metabolic effects indirectly modifying the activity of adenosine receptors. We now combined radioligand binding studies with electrophysiological recordings in hippocampal slices to test how inosine controls synaptic transmission and plasticity. Inosine was without effect at 30 μM and decreased field excitatory post-synaptic potentials by 14% and 33% at 100 and 300 μM, respectively. These effects were prevented by the adenosine A1 receptor antagonist DPCPX. Inosine at 300 (but not 100) μM also decreased the magnitude of long-term potentiation (LTP), an effect prevented by DPCPX and by the adenosine A2A receptor antagonist SCH58261. Inosine showed low affinity towards human and rat adenosine receptor subtypes with Ki values of > 300 µM; only at the human and rat A1 receptor slightly higher affinities with Ki values of around 100 µM were observed. Affinity of inosine at the rat A3 receptor was higher (Ki of 1.37 µM), while it showed no interaction with the human orthologue. Notably, the effects of inosine on synaptic transmission and plasticity were abrogated by adenosine deaminase and by inhibiting equilibrative nucleoside transporters (ENT) with dipyridamole and NBTI. This shows that the impact of inosine on hippocampal synaptic transmission and plasticity is not due to a direct activation of adenosine receptors but is instead due to an indirect modification of the tonic activation of these adenosine receptors through an ENT-mediated modification of the extracellular levels of adenosine.
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Affiliation(s)
- Pedro Valada
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
| | - Sonja Hinz
- Pharmaceutical & Medicinal Chemistry, University of Bonn, 53121, Bonn, Germany
| | - Christin Vielmuth
- Pharmaceutical & Medicinal Chemistry, University of Bonn, 53121, Bonn, Germany
| | - Cátia R Lopes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal. .,Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
| | - Christa E Müller
- Pharmaceutical & Medicinal Chemistry, University of Bonn, 53121, Bonn, Germany
| | - João Pedro Lopes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal
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Ma Q, Wang D, Li Y, Yang H, Li Y, Wang J, Li J, Sun J, Liu J. Activation of A 2B adenosine receptor protects against demyelination in a mouse model of schizophrenia. Exp Ther Med 2022; 23:396. [PMID: 35495590 PMCID: PMC9047022 DOI: 10.3892/etm.2022.11323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/24/2022] [Indexed: 11/11/2022] Open
Abstract
The purpose of the present study was to explore the effects of A2B adenosine receptor (A2BAR) on learning, memory and demyelination in a dizocilpine maleate (MK-801)-induced mouse model of schizophrenia (SCZ). BAY 60-6583, an agonist of A2BAR, or PSB 603, an antagonist of A2BAR, was used to treat SCZ in this model. The Morris Water Maze (MWM) was utilized to determine changes in cognitive function. Moreover, western blotting, immunohistochemistry and immunofluorescence were conducted to investigate the myelination and oligodendrocyte (OL) alterations at differentiation and maturation stages. The MWM results showed that learning and memory were impaired in SCZ mice, while subsequent treatment with BAY 60-6583 alleviated these impairments. In addition, western blot analysis revealed that myelin basic protein (MBP) and chondroitin sulphate proteoglycan 4 (NG2) expression levels were significantly decreased in MK-801-induced mice, while the expression of G protein-coupled receptor 17 (GPR17) was increased. Additionally, the number of anti-adenomatous polyposis coli clone CC-1/OL transcription factor 2 (CC-1+/Olig2+) cells was also decreased. Notably, BAY 60-6583 administration could reverse these changes, resulting in a significant increase in MBP and NG2 protein expression, and in the number of CC-1+/Olig2+ cells, while GPR17 protein expression levels were decreased. The present study indicated that the selective activation of A2BAR using BAY 60-6583 could improve the impaired learning and memory of SCZ mice, as well as protect the myelin sheath from degeneration by regulating the survival and maturation of OLs.
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Affiliation(s)
- Quanrui Ma
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Dan Wang
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Yunhong Li
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Hao Yang
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Yilu Li
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Junyan Wang
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Jinxia Li
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Jinping Sun
- Department of Pathology, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
| | - Juan Liu
- Department of Human Anatomy and Histo-Embryology, Basic Medical College, Ningxia Medical University, Yinchuan, Ningxia 750004, P.R. China
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Lovászi M, Németh ZH, Gause WC, Gummadova J, Pacher P, Haskó G. Inosine monophosphate and inosine differentially regulate endotoxemia and bacterial sepsis. FASEB J 2021; 35:e21935. [PMID: 34591327 PMCID: PMC9812230 DOI: 10.1096/fj.202100862r] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 01/07/2023]
Abstract
Inosine monophosphate (IMP) is the intracellular precursor for both adenosine monophosphate and guanosine monophosphate and thus plays a central role in intracellular purine metabolism. IMP can also serve as an extracellular signaling molecule, and can regulate diverse processes such as taste sensation, neutrophil function, and ischemia-reperfusion injury. How IMP regulates inflammation induced by bacterial products or bacteria is unknown. In this study, we demonstrate that IMP suppressed tumor necrosis factor (TNF)-α production and augmented IL-10 production in endotoxemic mice. IMP exerted its effects through metabolism to inosine, as IMP only suppressed TNF-α following its CD73-mediated degradation to inosine in lipopolysaccharide-activated macrophages. Studies with gene targeted mice and pharmacological antagonism indicated that A2A , A2B, and A3 adenosine receptors are not required for the inosine suppression of TNF-α production. The inosine suppression of TNF-α production did not require its metabolism to hypoxanthine through purine nucleoside phosphorylase or its uptake into cells through concentrative nucleoside transporters indicating a role for alternative metabolic/uptake pathways. Inosine augmented IL-β production by macrophages in which inflammasome was activated by lipopolysaccharide and ATP. In contrast to its effects in endotoxemia, IMP failed to affect the inflammatory response to abdominal sepsis and pneumonia. We conclude that extracellular IMP and inosine differentially regulate the inflammatory response.
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Affiliation(s)
- Marianna Lovászi
- Department of Anesthesiology, Columbia University, New York, NY, USA
| | - Zoltán H Németh
- Department of Anesthesiology, Columbia University, New York, NY, USA,Department of Surgery, Morristown Medical Center, Morristown, NJ, USA
| | - William C. Gause
- Center for Immunity and Inflammation and Department of Medicine, Rutgers - New Jersey Medical School, Newark, NJ, USA
| | - Jennet Gummadova
- Daresbury Proteins Ltd, Sci-Tech Daresbury, Warrington, United Kingdom
| | - Pál Pacher
- Laboratory of Cardiovascular Physiology and Tissue Injury, National Institutes of Health/NIAAA, Bethesda, MD, USA
| | - György Haskó
- Department of Anesthesiology, Columbia University, New York, NY, USA
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Nascimento FP, Macedo-Júnior SJ, Lapa-Costa FR, Cezar-Dos-Santos F, Santos ARS. Inosine as a Tool to Understand and Treat Central Nervous System Disorders: A Neglected Actor? Front Neurosci 2021; 15:703783. [PMID: 34504414 PMCID: PMC8421806 DOI: 10.3389/fnins.2021.703783] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/20/2021] [Indexed: 11/13/2022] Open
Abstract
Since the 1970s, when ATP was identified as a co-transmitter in sympathetic and parasympathetic nerves, it and its active metabolite adenosine have been considered relevant signaling molecules in biological and pathological processes in the central nervous system (CNS). Meanwhile, inosine, a naturally occurring purine nucleoside formed by adenosine breakdown, was considered an inert adenosine metabolite and remained a neglected actor on the purinergic signaling scene in the CNS. However, this scenario began to change in the 1980s. In the last four decades, an extensive group of shreds of evidence has supported the importance of mediated effects by inosine in the CNS. Also, inosine was identified as a natural trigger of adenosine receptors. This evidence has shed light on the therapeutic potential of inosine on disease processes involved in neurological and psychiatric disorders. Here, we highlight the clinical and preclinical studies investigating the involvement of inosine in chronic pain, schizophrenia, epilepsy, depression, anxiety, and in neural regeneration and neurodegenerative diseases, such as Parkinson and Alzheimer. Thus, we hope that this review will strengthen the knowledge and stimulate more studies about the effects promoted by inosine in neurological and psychiatric disorders.
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Affiliation(s)
- Francisney Pinto Nascimento
- Programa de Pós-Graduação em Biociências, Laboratório de Neurofarmacologia Clínica, Faculdade de Medicina, Universidade Federal da Integração Latino-Americana, Foz do Iguaçu, Brazil
| | | | | | - Fernando Cezar-Dos-Santos
- Programa de Pós-Graduação em Biociências, Laboratório de Neurofarmacologia Clínica, Faculdade de Medicina, Universidade Federal da Integração Latino-Americana, Foz do Iguaçu, Brazil
| | - Adair R S Santos
- Programa de Pós-Graduação em Neurociências, Laboratório de Neurobiologia da Dor e Inflamação, Universidade Federal de Santa Catarina, Florianópolis, Brazil
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8
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Purines: From Diagnostic Biomarkers to Therapeutic Agents in Brain Injury. Neurosci Bull 2020; 36:1315-1326. [PMID: 32542580 DOI: 10.1007/s12264-020-00529-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
The purines constitute a family of inter-related compounds that serve a broad range of important intracellular and extracellular biological functions. In particular, adenosine triphosphate (ATP) and its metabolite and precursor, adenosine, regulate a wide variety of cellular and systems-level physiological processes extending from ATP acting as the cellular energy currency, to the adenosine arising from the depletion of cellular ATP and responding to reduce energy demand and hence to preserve ATP during times of metabolic stress. This inter-relationship provides opportunities for both the diagnosis of energy depletion during conditions such as stroke, and the replenishment of ATP after such events. In this review we address these opportunities and the broad potential of purines as diagnostics and restorative agents.
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Xiao C, Liu N, Jacobson KA, Gavrilova O, Reitman ML. Physiology and effects of nucleosides in mice lacking all four adenosine receptors. PLoS Biol 2019; 17:e3000161. [PMID: 30822301 PMCID: PMC6415873 DOI: 10.1371/journal.pbio.3000161] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/13/2019] [Accepted: 02/07/2019] [Indexed: 11/29/2022] Open
Abstract
Adenosine is a constituent of many molecules of life; increased free extracellular adenosine indicates cell damage or metabolic stress. The importance of adenosine signaling in basal physiology, as opposed to adaptive responses to danger/damage situations, is unclear. We generated mice lacking all four adenosine receptors (ARs), Adora1−/−;Adora2a−/−;Adora2b−/−;Adora3−/− (quad knockout [QKO]), to enable investigation of the AR dependence of physiologic processes, focusing on body temperature. The QKO mice demonstrate that ARs are not required for growth, metabolism, breeding, and body temperature regulation (diurnal variation, response to stress, and torpor). However, the mice showed decreased survival starting at about 15 weeks of age. While adenosine agonists cause profound hypothermia via each AR, adenosine did not cause hypothermia (or bradycardia or hypotension) in QKO mice, indicating that AR-independent signals do not contribute to adenosine-induced hypothermia. The hypothermia elicited by adenosine kinase inhibition (with A134974), inosine, or uridine also required ARs, as each was abolished in the QKO mice. The proposed mechanism for uridine-induced hypothermia is inhibition of adenosine transport by uridine, increasing local extracellular adenosine levels. In contrast, adenosine 5′-monophosphate (AMP)–induced hypothermia was attenuated in QKO mice, demonstrating roles for both AR-dependent and AR-independent mechanisms in this process. The physiology of the QKO mice appears to be the sum of the individual knockout mice, without clear evidence for synergy, indicating that the actions of the four ARs are generally complementary. The phenotype of the QKO mice suggests that, while extracellular adenosine is a signal of stress, damage, and/or danger, it is less important for baseline regulation of body temperature. A study of mice lacking all four adenosine receptors shows that while they mediate effects of uridine, inosine and adenosine, these receptors are dispensable for growth, metabolism, breeding, and body temperature regulation. This suggests that extracellular adenosine is a damage or danger signal, rather than a major regulator of baseline physiology. Elevated extracellular adenosine generally indicates metabolic stress or cell damage and regulates many aspects of physiology. We studied “QKO” mice lacking all four adenosine receptors. Young QKO mice do not appear obviously ill, but do show decreased survival later in life. QKO mice demonstrate that adenosine receptors are not required for growth, metabolism, breeding, and body temperature regulation. QKO mice are missing the pharmacologic effects of adenosine on body temperature, heart rate, and blood pressure. Therefore, all of these effects are mediated by the four adenosine receptors. We also determined that the hypothermic effects of a pharmacologic adenosine kinase inhibitor (A134974), uridine, or inosine each requires adenosine receptors. The uridine-induced hypothermia is likely due to its inhibition of adenosine uptake into cells. QKO mouse physiology appears to be the sum of the individual knockout mice, without evidence for synergy, indicating that the actions of the four adenosine receptors are generally complementary.
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Affiliation(s)
- Cuiying Xiao
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, United States of America
| | - Naili Liu
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, United States of America
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, United States of America
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, United States of America
| | - Marc L. Reitman
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland, United States of America
- * E-mail:
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Doyle C, Cristofaro V, Sullivan MP, Adam RM. Inosine - a Multifunctional Treatment for Complications of Neurologic Injury. Cell Physiol Biochem 2018; 49:2293-2303. [PMID: 30261493 DOI: 10.1159/000493831] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/18/2018] [Indexed: 01/31/2023] Open
Abstract
Spinal cord injury (SCI) caused by trauma or disease leads to motor and sensory abnormalities that depend on the level, severity and duration of the lesion. The most obvious consequence of SCI is paralysis affecting lower and upper limbs. SCI also leads to loss of bladder and bowel control, both of which have a deleterious, life-long impact on the social, psychological, functional, medical and economic well being of affected individuals. Currently, there is neither a cure for SCI nor is there adequate management of its consequences. Although medications provide symptomatic relief for the complications of SCI including muscle spasms, lower urinary tract dysfunction and hyperreflexic bowel, strategies for repair of spinal injuries and recovery of normal limb and organ function are still to be realized. In this review, we discuss experimental evidence supporting the use of the naturally occurring purine nucleoside inosine to improve the devastating sequelae of SCI. Evidence suggests inosine is a safe, novel agent with multifunctional properties that is effective in treating complications of SCI and other neuropathies.
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Affiliation(s)
- Claire Doyle
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Vivian Cristofaro
- Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts, USA.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Maryrose P Sullivan
- Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts, USA.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Rosalyn M Adam
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
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Tritium-labeled agonists as tools for studying adenosine A 2B receptors. Purinergic Signal 2018; 14:223-233. [PMID: 29752618 DOI: 10.1007/s11302-018-9608-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/27/2018] [Indexed: 12/11/2022] Open
Abstract
A selective agonist radioligand for A2B adenosine receptors (A2BARs) is currently not available. Such a tool would be useful for labeling the active conformation of the receptors. Therefore, we prepared BAY 60-6583, a potent and functionally selective A2BAR (partial) agonist, in a tritium-labeled form. Despite extensive efforts, however, we have not been able to establish a radioligand binding assay using [3H]BAY 60-6583. This is probably due to its high non-specific binding and its moderate affinity, which had previously been overestimated based on functional data. As an alternative, we evaluated the non-selective A2BAR agonist [3H]NECA for its potential to label A2BARs. [3H]NECA showed specific, saturable, and reversible binding to membrane preparations of Chinese hamster ovary (CHO) or human embryonic kidney (HEK) cells stably expressing human, rat, or mouse A2BARs. In competition binding experiments, the AR agonists 2-chloroadenosine (CADO) and NECA displayed significantly higher affinity when tested versus [3H]NECA than versus the A2B-antagonist radioligand [3H]PSB-603 while structurally diverse AR antagonists showed the opposite effects. Although BAY 60-6583 is an A2BAR agonist, it displayed higher affinity versus [3H]PSB-603 than versus [3H]NECA. These results indicate that nucleoside and non-nucleoside agonists are binding to very different conformations of the A2BAR. In conclusion, [3H]NECA is currently the only useful radioligand for determining the affinity of ligands for an active A2BAR conformation.
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Doyle C, Cristofaro V, Sack BS, Mahmood F, Sullivan MP, Adam RM. The role of the mucosa in modulation of evoked responses in the spinal cord injured rat bladder. Neurourol Urodyn 2018; 37:1583-1593. [PMID: 29427331 PMCID: PMC6086770 DOI: 10.1002/nau.23512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/09/2018] [Indexed: 11/27/2022]
Abstract
Aims Mounting evidence indicates that a variety of factors released from the urothelium or suburothelium can modulate smooth muscle activity. Although the relationship between the mucosa and smooth muscle has been investigated, little is known about the pathophysiologic changes in detrusor‐mucosa interactions in neurogenic bladders. The goal of the study was to determine the impact of the mucosa on evoked responses in spinal cord injured (SCI) bladders. Methods Urinary bladders were obtained from 6wk SCI rats or age‐matched uninjured controls. Ex vivo isometric tension studies were performed and muscarinic receptor expression was measured in bladder tissue with and without mucosa. Results The magnitude and area of nerve evoked responses in SCI tissue with mucosa was higher than without mucosa. The duration and decay time of nerve‐evoked responses were longer in SCI than control tissue irrespective of the mucosa. The level of the muscarinic M2 receptor was decreased in the mucosa of SCI bladders. Conclusions Detrusor‐mucosa interactions are substantially altered in the neurogenic bladder. After spinal cord injury, an excitatory modulation of smooth muscle contraction by the mucosa emerges, and could be targeted via intravesical treatment in the context of neurogenic bladder dysfunction.
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Affiliation(s)
- Claire Doyle
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts.,Department of Surgery, Harvard Medical School, Boston, Massachusetts
| | - Vivian Cristofaro
- Department of Surgery, Harvard Medical School, Boston, Massachusetts.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Bryan S Sack
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts.,Department of Surgery, Harvard Medical School, Boston, Massachusetts
| | - Fabliha Mahmood
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts
| | - Maryrose P Sullivan
- Department of Surgery, Harvard Medical School, Boston, Massachusetts.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Rosalyn M Adam
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts.,Department of Surgery, Harvard Medical School, Boston, Massachusetts
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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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