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Giakomidi D, Bird MF, Guerrini R, Calo G, Lambert DG. Fluorescent opioid receptor ligands as tools to study opioid receptor function. J Pharmacol Toxicol Methods 2021; 113:107132. [PMID: 34728348 DOI: 10.1016/j.vascn.2021.107132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/12/2021] [Accepted: 10/25/2021] [Indexed: 11/30/2022]
Abstract
Opioid receptors are divided into the three classical types: MOP(μ:mu), DOP(δ:delta) and KOP(κ:kappa) that are naloxone-sensitive and an additional naloxone-insensitive nociceptin/orphanin FQ(N/OFQ) peptide receptor(NOP). Studies to determine opioid receptor location and turnover variably rely on; (i) measuring receptor mRNA, (ii) genetically tagging receptors, (iii) labelling receptors with radioligands, (iv) use of antibodies in immunohistochemistry/Western Blotting or (v) measuring receptor function coupled with the use of selective antagonists. All have their drawbacks with significant issues relating to mRNA not necessarily predicting protein, poor antibody selectivity and utility of radiolabels in low expression systems. In this minireview we discuss use of fluorescently labelled opioid receptor ligands. To maintain the pharmacological properties of the corresponding parent ligand fluorescently labelled ligands must take into account fluorophore (brightness and propensity to bleach), linker length and chemistry, and site to which the linker (and hence probe) will be attached. Use of donor and acceptor fluorophores with spectral overlap facilitates use in FRET type assays to determine proximity of ligand or tagged receptor pairs. There is a wide range of probes of agonist and antagonist nature for all four opioid receptor types; caution is needed with agonist probes due to the possibility for internalization. We have produced two novel ATTO based probes; DermorphinATTO488 (MOP) and N/OFQATTO594 (NOP). These probes label MOP and NOP in a range of preparations and using N/OFQATTO594 we demonstrate internalization and ligand-receptor interaction by FRET. Fluorescent opioid probes offer potential methodological advantages over more traditional use of antibodies and radiolabels.
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Affiliation(s)
- Despina Giakomidi
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Hodgkin Building, Leicester LE1 9HN. UK
| | - Mark F Bird
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Hodgkin Building, Leicester LE1 9HN. UK
| | - Remo Guerrini
- Department of Chemical, Pharmaceutical and Agricultural Sciences and LTTA, University of Ferrara, Italy
| | - Girolamo Calo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy
| | - David G Lambert
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Hodgkin Building, Leicester LE1 9HN. UK.
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Giakomidi D, Bird MF, McDonald J, Marzola E, Guerrini R, Chanoch S, Sabu N, Horley B, Calo G, Lambert DG. Evaluation of [Cys(ATTO 488)8]Dermorphin-NH2 as a novel tool for the study of μ-opioid peptide receptors. PLoS One 2021; 16:e0250011. [PMID: 33891604 PMCID: PMC8064508 DOI: 10.1371/journal.pone.0250011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/29/2021] [Indexed: 11/26/2022] Open
Abstract
The μ-opioid peptide (MOP) receptor is a member of the opioid receptor family and an important clinical target for analgesia. Measuring MOP receptor location and tracking its turnover traditionally used radiolabels or antibodies with attendant problems of utility of radiolabels in whole cells and poor antibody selectivity. To address these issues we have synthesized and characterised a novel ATTO488 based fluorescent Dermorphin analogue; [Cys(ATTO 488)8]Dermorphin-NH2 (DermATTO488). We initially assessed the binding profile of DermATTO488 in HEK cells expressing human MOP and CHO cells expressing human MOP, δ-opioid peptide (DOP), κ-opioid peptide (KOP) and Nociceptin/Orphanin FQ peptide (NOP) receptors using radioligand binding. Functional activity of the conjugated peptide was assessed by measuring (i) the ability of the ligand to engage G-protein by measuring the ability to stimulate GTPγ[35S] binding and (ii) the ability to stimulate phosphorylation of ERK1/2. Receptor location was visualised using confocal scanning laser microscopy. Dermorphin and DermATTO488 bound to HEKMOP (pKi: 8.29 and 7.00; p<0.05), CHOMOP (pKi: 9.26 and 8.12; p<0.05) and CHODOP (pKi: 7.03 and 7.16; p>0.05). Both ligands were inactive at KOP and NOP. Dermorphin and DermATTO488 stimulated the binding of GTPγ[35S] with similar pEC50 (7.84 and 7.62; p>0.05) and Emax (1.52 and 1.34fold p>0.05) values. Moreover, Dermorphin and DermATTO488 produced a monophasic stimulation of ERK1/2 phosphorylation peaking at 5mins (6.98 and 7.64-fold; p>0.05). Finally, in confocal microscopy DermATTO488 bound to recombinant MOP receptors on CHO and HEK cells in a concentration dependent manner that could be blocked by pre-incubation with unlabelled Dermorphin or Naloxone. Collectively, addition to ATTO488 to Dermorphin produced a ligand not dissimilar to Dermorphin; with ~10fold selectivity over DOP. This new ligand DermATTO488 retained functional activity and could be used to visualise MOP receptor location.
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Affiliation(s)
- Despina Giakomidi
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Mark F. Bird
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - John McDonald
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Erika Marzola
- Department of Chemical and Pharmaceutical Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - Remo Guerrini
- Department of Chemical and Pharmaceutical Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - Serena Chanoch
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Nidhuna Sabu
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Barbara Horley
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Girolamo Calo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - David G. Lambert
- Department of Cardiovascular Sciences (Anaesthesia, Critical Care and Pain Management), University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
- * E-mail:
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3
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Machelska H, Celik MÖ. Opioid Receptors in Immune and Glial Cells-Implications for Pain Control. Front Immunol 2020; 11:300. [PMID: 32194554 PMCID: PMC7064637 DOI: 10.3389/fimmu.2020.00300] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 02/06/2020] [Indexed: 11/23/2022] Open
Abstract
Opioid receptors comprise μ (MOP), δ (DOP), κ (KOP), and nociceptin/orphanin FQ (NOP) receptors. Opioids are agonists of MOP, DOP, and KOP receptors, whereas nociceptin/orphanin FQ (N/OFQ) is an agonist of NOP receptors. Activation of all four opioid receptors in neurons can induce analgesia in animal models, but the most clinically relevant are MOP receptor agonists (e.g., morphine, fentanyl). Opioids can also affect the function of immune cells, and their actions in relation to immunosuppression and infections have been widely discussed. Here, we analyze the expression and the role of opioid receptors in peripheral immune cells and glia in the modulation of pain. All four opioid receptors have been identified at the mRNA and protein levels in immune cells (lymphocytes, granulocytes, monocytes, macrophages) in humans, rhesus monkeys, rats or mice. Activation of leukocyte MOP, DOP, and KOP receptors was recently reported to attenuate pain after nerve injury in mice. This involved intracellular Ca2+-regulated release of opioid peptides from immune cells, which subsequently activated MOP, DOP, and KOP receptors on peripheral neurons. There is no evidence of pain modulation by leukocyte NOP receptors. More good quality studies are needed to verify the presence of DOP, KOP, and NOP receptors in native glia. Although still questioned, MOP receptors might be expressed in brain or spinal cord microglia and astrocytes in humans, mice, and rats. Morphine acting at spinal cord microglia is often reported to induce hyperalgesia in rodents. However, most studies used animals without pathological pain and/or unconventional paradigms (e.g., high or ultra-low doses, pain assessment after abrupt discontinuation of chronic morphine treatment). Therefore, the opioid-induced hyperalgesia can be viewed in the context of dependence/withdrawal rather than pain management, in line with clinical reports. There is convincing evidence of analgesic effects mediated by immune cell-derived opioid peptides in animal models and in humans. Together, MOP, DOP, and KOP receptors, and opioid peptides in immune cells can ameliorate pathological pain. The relevance of NOP receptors and N/OFQ in leukocytes, and of all opioid receptors, opioid peptides and N/OFQ in native glia for pain control is yet to be clarified.
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Affiliation(s)
- Halina Machelska
- Department of Experimental Anesthesiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Melih Ö Celik
- Department of Experimental Anesthesiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
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Bird MF, Guerrini R, Willets JM, Thompson JP, Caló G, Lambert DG. Nociceptin/Orphanin FQ (N/OFQ) conjugated to ATTO594: a novel fluorescent probe for the N/OFQ (NOP) receptor. Br J Pharmacol 2018; 175:4496-4506. [PMID: 30276802 PMCID: PMC6255954 DOI: 10.1111/bph.14504] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/31/2018] [Accepted: 09/04/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE The nociceptin/orphanin FQ (N/OFQ) receptor (NOP) is a member of the opioid receptor family and is involved in a number of physiological responses, pain and immune regulation as examples. In this study, we conjugated a red fluorophore-ATTO594 to the peptide ligand N/OFQ (N/OFQATTO594 ) for the NOP receptor and explored NOP receptor function at high (in recombinant systems) and low (on immune cells) expression. EXPERIMENTAL APPROACH We assessed N/OFQATTO594 receptor binding, selectivity and functional activity in recombinant (CHO) cell lines. Live cell N/OFQATTO594 binding was measured in (i) HEK cells expressing NOP and NOPGFP receptors, (ii) CHO cells expressing the hNOPGαqi5 chimera (to force coupling to measurable Ca2+ responses) and (iii) freshly isolated human polymorphonuclear cells (PMN). KEY RESULTS N/OFQATTO594 bound to NOP receptor with nM affinity and high selectivity. N/OFQATTO594 activated NOP receptor by reducing cAMP formation and increasing Ca2+ levels in CHOhNOPGαqi5 cells. N/OFQATTO594 was also able to visualize NOP receptors at low expression levels on PMN cells. In NOP-GFP-tagged receptors, N/OFQATTO594 was used in a FRET protocol where GFP emission activated ATTO, visualizing ligand-receptor interaction. When the NOPGFP receptor is activated by N/OFQATTO594 , movement of ligand and receptor from the cell surface to the cytosol can be measured. CONCLUSIONS AND IMPLICATIONS In the absence of validated NOP receptor antibodies and issues surrounding the use of radiolabels (especially in low expression systems), these data indicate the utility of N/OFQATTO594 to study a wide range of N/OFQ-driven cellular responses.
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Affiliation(s)
- M F Bird
- Department of Cardiovascular Sciences, Anaesthesia, Critical Care and Pain Management, Leicester Royal InfirmaryUniversity of LeicesterLeicesterUK
| | - R Guerrini
- Department of Chemical and Pharmaceutical Sciences and LTTAUniversity of FerraraFerraraItaly
| | - J M Willets
- Department of Molecular and Cell BiologyUniversity of LeicesterLeicesterUK
| | - J P Thompson
- Department of Cardiovascular Sciences, Anaesthesia, Critical Care and Pain Management, Leicester Royal InfirmaryUniversity of LeicesterLeicesterUK
| | - G Caló
- Department of Medical Sciences, Section of Pharmacology and National Institute of NeuroscienceUniversity of FerraraFerraraItaly
| | - D G Lambert
- Department of Cardiovascular Sciences, Anaesthesia, Critical Care and Pain Management, Leicester Royal InfirmaryUniversity of LeicesterLeicesterUK
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Celik MÖ, Labuz D, Henning K, Busch-Dienstfertig M, Gaveriaux-Ruff C, Kieffer BL, Zimmer A, Machelska H. Leukocyte opioid receptors mediate analgesia via Ca(2+)-regulated release of opioid peptides. Brain Behav Immun 2016; 57:227-242. [PMID: 27139929 DOI: 10.1016/j.bbi.2016.04.018] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/25/2016] [Accepted: 04/27/2016] [Indexed: 12/23/2022] Open
Abstract
Opioids are the most powerful analgesics. As pain is driven by sensory transmission and opioid receptors couple to inhibitory G proteins, according to the classical concept, opioids alleviate pain by activating receptors on neurons and blocking the release of excitatory mediators (e.g., substance P). Here we show that analgesia can be mediated by opioid receptors in immune cells. We propose that activation of leukocyte opioid receptors leads to the secretion of opioid peptides Met-enkephalin, β-endorphin and dynorphin A (1-17), which subsequently act at local neuronal receptors, to relieve pain. In a mouse model of neuropathic pain induced by a chronic constriction injury of the sciatic nerve, exogenous agonists of δ-, μ- and κ-opioid receptors injected at the damaged nerve infiltrated by opioid peptide- and receptor-expressing leukocytes, produced analgesia, as assessed with von Frey filaments. The analgesia was attenuated by pharmacological or genetic inactivation of opioid peptides, and by leukocyte depletion. This decrease in analgesia was restored by the transfer of wild-type, but not opioid receptor-lacking leukocytes. Ex vivo, exogenous opioids triggered secretion of opioid peptides from wild-type immune cells isolated from damaged nerves, which was diminished by blockade of Gαi/o or Gβγ (but not Gαs) proteins, by chelator of intracellular (but not extracellular) Ca(2+), by blockers of phospholipase C (PLC) and inositol 1,4,5-trisphosphate (IP3) receptors, and was partially attenuated by protein kinase C inhibitor. Similarly, the leukocyte depletion-induced decrease in exogenous opioid analgesia was re-established by transfer of immune cells ex vivo pretreated with extracellular Ca(2+) chelator, but was unaltered by leukocytes pretreated with intracellular Ca(2+) chelator or blockers of Gαi/o and Gβγ proteins. Thus, both ex vivo opioid peptide release and in vivo analgesia were mediated by leukocyte opioid receptors coupled to the Gαi/o-Gβγ protein-PLC-IP3 receptors-intracellular Ca(2+) pathway. Our findings suggest that opioid receptors in immune cells are important targets for the control of pathological pain.
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Affiliation(s)
- Melih Ö Celik
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany.
| | - Dominika Labuz
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany.
| | - Karen Henning
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany.
| | - Melanie Busch-Dienstfertig
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany.
| | - Claire Gaveriaux-Ruff
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Université de Strasbourg, Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.
| | - Brigitte L Kieffer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Université de Strasbourg, Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France; Douglas Hospital Research Center, McGill University, Montreal H4H 1R3, Canada.
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, University of Bonn, 53105 Bonn, Germany.
| | - Halina Machelska
- Department of Anesthesiology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin, Germany.
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Al-Hashimi M, McDonald J, Thompson JP, Lambert DG. Evidence for nociceptin/orphanin FQ (NOP) but not µ (MOP), δ (DOP) or κ (KOP) opioid receptor mRNA in whole human blood. Br J Anaesth 2016; 116:423-9. [PMID: 26865135 DOI: 10.1093/bja/aev540] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND While it is well known that opioids depress the immune system, the site(s) of action for this depression is highly controversial. Immune modulation could occur directly at the immune cell or centrally via the hypothalamic-pituitary-adrenal axis. In a number of studies using individual enriched immune cell populations we have failed to detect classical µ (MOP), δ (DOP) and κ (KOP) receptors. The non-classical nociceptin/orphanin FQ (N/OFQ) receptor (NOP) is expressed on all cells examined thus far. Our hypothesis was that immune cells do not express classical opioid receptors and that using whole blood would definitively answer this question. METHODS Whole blood (containing all immune cell types) was incubated with opioids (morphine and fentanyl) commonly encountered in anaesthesia and with agents mimicking sepsis [lipopolysaccharide (LPS) and peptidoglycan G (PepG)]. Opioid receptor mRNA expression was assessed by endpoint polymerase chain reaction (PCR) with gel visualisation and quantitative PCR. RESULTS Classical MOP, DOP, and KOP receptors were not detected in any of the samples tested either at rest or when challenged with opioids, LPS or PepG. Commercial primers for DOP did not perform well in quantitative PCR, so the absence of expression was confirmed using a traditional gel-based approach. NOP receptors were detected in all samples; expression was unaffected by opioids and reduced by LPS/PepG combinations. CONCLUSIONS Classical opioid receptors are not expressed on circulating immune cells.
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Affiliation(s)
- M Al-Hashimi
- Department of Cardiovascular Sciences, University of Leicester, Division of Anaesthesia, Critical Care and Pain Management, Leicester Royal Infirmary, Leicester LE2 7LX, UK
| | - J McDonald
- Department of Cardiovascular Sciences, University of Leicester, Division of Anaesthesia, Critical Care and Pain Management, Leicester Royal Infirmary, Leicester LE2 7LX, UK
| | - J P Thompson
- Department of Cardiovascular Sciences, University of Leicester, Division of Anaesthesia, Critical Care and Pain Management, Leicester Royal Infirmary, Leicester LE2 7LX, UK
| | - D G Lambert
- Department of Cardiovascular Sciences, University of Leicester, Division of Anaesthesia, Critical Care and Pain Management, Leicester Royal Infirmary, Leicester LE2 7LX, UK
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Mambretti EM, Kistner K, Mayer S, Massotte D, Kieffer BL, Hoffmann C, Reeh PW, Brack A, Asan E, Rittner HL. Functional and structural characterization of axonal opioid receptors as targets for analgesia. Mol Pain 2016; 12:12/0/1744806916628734. [PMID: 27030709 PMCID: PMC4994859 DOI: 10.1177/1744806916628734] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/10/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Opioids are the gold standard for the treatment of acute pain despite serious side effects in the central and enteric nervous system. µ-opioid receptors (MOPs) are expressed and functional at the terminals of sensory axons, when activated by exogenous or endogenous ligands. However, the presence and function of MOP along nociceptive axons remains controversial particularly in naïve animals. Here, we characterized axonal MOPs by immunofluorescence, ultrastructural, and functional analyses. Furthermore, we evaluated hypertonic saline as a possible enhancer of opioid receptor function. RESULTS Comparative immunolabeling showed that, among several tested antibodies, which all provided specific MOP detection in the rat central nervous system (CNS), only one monoclonal MOP-antibody yielded specificity and reproducibility for MOP detection in the rat peripheral nervous system including the sciatic nerve. Double immunolabeling documented that MOP immunoreactivity was confined to calcitonin gene-related peptide (CGRP) positive fibers and fiber bundles. Almost identical labeling and double labeling patterns were found using mcherry-immunolabeling on sciatic nerves of mice producing a MOP-mcherry fusion protein (MOP-mcherry knock-in mice). Preembedding immunogold electron microscopy on MOP-mcherry knock-in sciatic nerves indicated presence of MOP in cytoplasm and at membranes of unmyelinated axons. Application of [D-Ala(2), N-MePhe(4), Gly-ol]-enkephalin (DAMGO) or fentanyl dose-dependently inhibited depolarization-induced CGRP release from rat sciatic nerve axons ex vivo, which was blocked by naloxone. When the lipophilic opioid fentanyl was applied perisciatically in naïve Wistar rats, mechanical nociceptive thresholds increased. Subthreshold doses of fentanyl or the hydrophilic opioid DAMGO were only effective if injected together with hypertonic saline. In vitro, using β-arrestin-2/MOP double-transfected human embryonic kidney cells, DAMGO as well as fentanyl lead to a recruitment of β-arrestin-2 to the membrane followed by a β-arrestin-2 reappearance in the cytosol and MOP internalization. Pretreatment with hypertonic saline prevented MOP internalization. CONCLUSION MOPs are present and functional in the axonal membrane from naïve animals. Hypertonic saline acutely decreases ligand-induced internalization of MOP and thereby might improve MOP function. Further studies should explore potential clinical applications of opioids together with enhancers for regional analgesia.
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Affiliation(s)
- Egle M Mambretti
- Department of Anesthesiology, University Hospital of Wuerzburg, Germany Institute of Anatomy and Cell Biology, University of Wuerzburg, Germany
| | - Katrin Kistner
- Institute of Physiology and Pathophysiology, University of Erlangen-Nuremberg, Germany
| | - Stefanie Mayer
- Institute for Pharmacology and Toxicology & Bio-Imaging Center/Rudolf-Virchow Center, University of Wuerzburg, Germany
| | - Dominique Massotte
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR, Strasbourg Cedex, France
| | - Brigitte L Kieffer
- Douglas Research Center, Department of Psychiatry, Faculty of Medicine, McGill University, Montreal, Quebec, Canada Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France
| | - Carsten Hoffmann
- Institute for Pharmacology and Toxicology & Bio-Imaging Center/Rudolf-Virchow Center, University of Wuerzburg, Germany
| | - Peter W Reeh
- Institute of Physiology and Pathophysiology, University of Erlangen-Nuremberg, Germany
| | - Alexander Brack
- Department of Anesthesiology, University Hospital of Wuerzburg, Germany
| | - Esther Asan
- Institute of Anatomy and Cell Biology, University of Wuerzburg, Germany
| | - Heike L Rittner
- Department of Anesthesiology, University Hospital of Wuerzburg, Germany
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Talmont F, Moulédous L. Evaluation of commercial antibodies against human sphingosine-1-phosphate receptor 1. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:427-31. [DOI: 10.1007/s00210-014-0957-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/06/2014] [Indexed: 01/06/2023]
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9
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Schmidt Y, Gavériaux-Ruff C, Machelska H. μ-Opioid receptor antibody reveals tissue-dependent specific staining and increased neuronal μ-receptor immunoreactivity at the injured nerve trunk in mice. PLoS One 2013; 8:e79099. [PMID: 24278116 PMCID: PMC3838372 DOI: 10.1371/journal.pone.0079099] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 09/19/2013] [Indexed: 12/22/2022] Open
Abstract
Neuropathic pain is a debilitating chronic disease often resulting from damage to peripheral nerves. Activation of opioid receptors on peripheral sensory neurons can attenuate pain without central nervous system side effects. Here we aimed to analyze the distribution of neuronal μ-opioid receptors, the most relevant opioid receptors in the control of clinical pain, along the peripheral neuronal pathways in neuropathy. Hence, following a chronic constriction injury of the sciatic nerve in mice, we used immunohistochemistry to quantify the μ-receptor protein expression in the dorsal root ganglia (DRG), directly at the injured nerve trunk, and at its peripheral endings in the hind paw skin. We also thoroughly examined the μ-receptor antibody staining specificity. We found that the antibody specifically labeled μ-receptors in human embryonic kidney 293 cells as well as in neuronal processes of the sciatic nerve and hind paw skin dermis, but surprisingly not in the DRG, as judged by the use of μ/δ/κ-opioid receptor knockout mice. Therefore, a reliable quantitative analysis of μ-receptor expression in the DRG was not possible. However, we demonstrate that the μ-receptor immunoreactivity was strongly enhanced proximally to the injury at the nerve trunk, but was unaltered in paws, on days 2 and 14 following injury. Thus, μ-opioid receptors at the site of axonal damage might be a promising target for the control of painful neuropathies. Furthermore, our findings suggest a rigorous tissue-dependent characterization of antibodies' specificity, preferably using knockout animals.
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Affiliation(s)
- Yvonne Schmidt
- Klinik für Anästhesiologie und operative Intensivmedizin, Freie Universität Berlin, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Claire Gavériaux-Ruff
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, UdS Université de Strasbourg, Strasbourg, Inserm, U964; CNRS, UMR7104, Illkirch, France
| | - Halina Machelska
- Klinik für Anästhesiologie und operative Intensivmedizin, Freie Universität Berlin, Charité- Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
- * E-mail:
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10
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Brookes ZLS, Stedman EN, Brown NJ, Hebbes CP, Guerrini R, Calo G, Reilly CS, Lambert DG. The nociceptin/orphanin FQ receptor antagonist UFP-101 reduces microvascular inflammation to lipopolysaccharide in vivo. PLoS One 2013; 8:e74943. [PMID: 24086402 PMCID: PMC3781147 DOI: 10.1371/journal.pone.0074943] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 08/07/2013] [Indexed: 12/23/2022] Open
Abstract
Microvascular inflammation occurs during sepsis and the endogenous opioid-like peptide nociceptin/orphanin FQ (N/OFQ) is known to regulate inflammation. This study aimed to determine the inflammatory role of N/OFQ and its receptor NOP (ORL1) within the microcirculation, along with anti-inflammatory effects of the NOP antagonist UFP-101 (University of Ferrara Peptide-101) in an animal model of sepsis (endotoxemia). Male Wistar rats (220 to 300 g) were administered lipopolysaccharide (LPS) for 24 h (-24 h, 1 mg kg(-1); -2 h, 1 mg kg(-1) i.v., tail vein). They were then either anesthetised for observation of the mesenteric microcirculation using fluorescent in vivo microscopy, or isolated arterioles (~200 µm) were studied in vitro with pressure myography. 200 nM kg(-1) fluorescently labelled N/OFQ (FITC-N/OFQ, i.a., mesenteric artery) bound to specific sites on the microvascular endothelium in vivo, indicating sparse distribution of NOP receptors. In vitro, arterioles (~200 µm) dilated to intraluminal N/OFQ (10(-5)M) (32.6 + 8.4%) and this response was exaggerated with LPS (62.0 +7.9%, p=0.031). In vivo, LPS induced macromolecular leak of FITC-BSA (0.02 g kg(-1) i.v.) (LPS: 95.3 (86.7 to 97.9)%, p=0.043) from post-capillary venules (<40 µm) and increased leukocyte rolling as endotoxemia progressed (p=0.027), both being reduced by 150 nmol kg(-1) UFP-101 (i.v., jugular vein). Firstly, the rat mesenteric microcirculation expresses NOP receptors and secondly, NOP function (ability to induce dilation) is enhanced with LPS. UFP-101 also reduced microvascular inflammation to endotoxemia in vivo. Hence inhibition of the microvascular N/OFQ-NOP pathway may have therapeutic potential during sepsis and warrants further investigation.
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Affiliation(s)
- Zoë L. S. Brookes
- Microcirculation Research Group, Department of Cardiovascular Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Emily N. Stedman
- Microcirculation Research Group, Department of Cardiovascular Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Nicola J. Brown
- Microcirculation Research Group, Department of Cardiovascular Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Christopher P. Hebbes
- Department of Cardiovascular Sciences, Division of Anaesthesia, Critical Care and Pain Management, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
| | - Remo Guerrini
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, Ferrara, Italy
| | - Girolamo Calo
- Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, Ferrara, Italy
- Department of Experimental and Clinical Medicine, Section of Pharmacology, University of Ferrara and Italian Institute of Neuroscience, Ferrara, Italy
| | - Charles S. Reilly
- Microcirculation Research Group, Department of Cardiovascular Sciences, University of Sheffield, Sheffield, United Kingdom
| | - David G. Lambert
- Department of Cardiovascular Sciences, Division of Anaesthesia, Critical Care and Pain Management, University of Leicester, Leicester Royal Infirmary, Leicester, United Kingdom
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11
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Talmont F, Moulédous L, Boué J, Mollereau C, Dietrich G. Denatured G-protein coupled receptors as immunogens to generate highly specific antibodies. PLoS One 2012; 7:e46348. [PMID: 23029489 PMCID: PMC3459905 DOI: 10.1371/journal.pone.0046348] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 08/31/2012] [Indexed: 12/12/2022] Open
Abstract
G-protein coupled receptors (GPCRs) play a major role in a number of physiological and pathological processes. Thus, GPCRs have become the most frequent targets for development of new therapeutic drugs. In this context, the availability of highly specific antibodies may be decisive to obtain reliable findings on localization, function and medical relevance of GPCRs. However, the rapid and easy generation of highly selective anti-GPCR antibodies is still a challenge. Herein, we report that highly specific antibodies suitable for detection of GPCRs in native and unfolded forms can be elicited by immunizing animals against purified full length denatured recombinant GPCRs. Contrasting with the currently admitted postulate, our study shows that an active and well-folded GPCR is not required for the production of specific anti-GPCR antibodies. This new immunizing strategy validated with three different human GPCR (μ-opioid, κ-opioid, neuropeptide FF2 receptors) might be generalized to other members of the GPCR family.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies/immunology
- Antibodies/isolation & purification
- Humans
- Immunization
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/immunology
- Immunoglobulin G/isolation & purification
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Pichia/genetics
- Protein Denaturation
- Protein Folding
- Receptors, Neuropeptide/administration & dosage
- Receptors, Neuropeptide/genetics
- Receptors, Neuropeptide/immunology
- Receptors, Opioid, kappa/administration & dosage
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/immunology
- Receptors, Opioid, mu/administration & dosage
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/immunology
- Recombinant Proteins/administration & dosage
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
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Affiliation(s)
- Franck Talmont
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France.
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12
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Smith TH, Grider JR, Dewey WL, Akbarali HI. Morphine decreases enteric neuron excitability via inhibition of sodium channels. PLoS One 2012; 7:e45251. [PMID: 23028881 PMCID: PMC3448635 DOI: 10.1371/journal.pone.0045251] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 08/14/2012] [Indexed: 12/31/2022] Open
Abstract
Gastrointestinal peristalsis is significantly dependent on the enteric nervous system. Constipation due to reduced peristalsis is a major side-effect of morphine, which limits the chronic usefulness of this excellent pain reliever in man. The ionic basis for the inhibition of enteric neuron excitability by morphine is not well characterized as previous studies have mainly utilized microelectrode recordings from whole mount myenteric plexus preparations in guinea pigs. Here we have developed a Swiss-Webster mouse myenteric neuron culture and examined their electrophysiological properties by patch-clamp techniques and determined the mechanism for morphine-induced decrease in neuronal excitability. Isolated neurons in culture were confirmed by immunostaining with pan-neuronal marker, β-III tubulin and two populations were identified by calbindin and calretinin staining. Distinct neuronal populations were further identified based on the presence and absence of an afterhyperpolarization (AHP). Cells with AHP expressed greater density of sodium currents. Morphine (3 µM) significantly reduced the amplitude of the action potential, increased the threshold for spike generation but did not alter the resting membrane potential. The decrease in excitability resulted from inhibition of sodium currents. In the presence of morphine, the steady-state voltage dependence of Na channels was shifted to the left with almost 50% of channels unavailable for activation from hyperpolarized potentials. During prolonged exposure to morphine (two hours), action potentials recovered, indicative of the development of tolerance in single enteric neurons. These results demonstrate the feasibility of isolating mouse myenteric neurons and establish sodium channel inhibition as a mechanism for morphine-induced decrease in neuronal excitability.
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Affiliation(s)
- Tricia H. Smith
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - John R. Grider
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - William L. Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Hamid I. Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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