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Yang L, Wang Y, Chen Z. Central histaminergic signalling, neural excitability and epilepsy. Br J Pharmacol 2021; 179:3-22. [PMID: 34599508 DOI: 10.1111/bph.15692] [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: 12/22/2020] [Revised: 09/07/2021] [Accepted: 09/12/2021] [Indexed: 12/31/2022] Open
Abstract
Epilepsy is a common neurological disorder characterized by repeated and spontaneous epileptic seizures and is not well controlled by current medication. Traditional theory suggests that epilepsy results from an imbalance of excitatory glutamate neurons and inhibitory GABAergic neurons. However, new evidence from clinical and preclinical research suggests that histamine in the CNS plays an important role in the modulation of neural excitability and in the pathogenesis of epilepsy. Many histamine receptor ligands have achieved curative effects in animal epilepsy models, among which the histamine H3 receptor antagonist pitolisant has shown anti-epileptic effects in clinical trials. Recent studies, therefore, have focused on the potential action of histamine receptors to control and treat epilepsy. In this review, we summarize the findings from animal and clinical epilepsy research on the role of brain histamine and its receptors. We also identify current gaps in the research and suggest where further studies are most needed.
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Affiliation(s)
- Lin Yang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China.,Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China.,Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.,Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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2
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Grätz L, Tropmann K, Bresinsky M, Müller C, Bernhardt G, Pockes S. NanoBRET binding assay for histamine H 2 receptor ligands using live recombinant HEK293T cells. Sci Rep 2020; 10:13288. [PMID: 32764682 PMCID: PMC7414126 DOI: 10.1038/s41598-020-70332-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 07/24/2020] [Indexed: 01/12/2023] Open
Abstract
Fluorescence/luminescence-based techniques play an increasingly important role in the development of test systems for the characterization of future drug candidates, especially in terms of receptor binding in the field of G protein-coupled receptors (GPCRs). In this article, we present the establishment of a homogeneous live cell-based BRET binding assay for the histamine H2 receptor with different fluorescently labeled squaramide-type compounds synthesized in the course of this study. Py-1-labeled ligand 8 (UR-KAT478) was found to be most suitable in BRET saturation binding experiments with respect to receptor affinity (pKd = 7.35) and signal intensity. Real-time kinetic experiments showed a full association of 8 within approximately 30 min and a slow dissociation of the ligand from the receptor. Investigation of reference compounds in BRET-based competition binding with 8 yielded pKi values in agreement with radioligand binding data. This study shows that the BRET binding assay is a versatile test system for the characterization of putative new ligands at the histamine H2 receptor and represents a valuable fluorescence-based alternative to canonical binding assays.
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Affiliation(s)
- Lukas Grätz
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Katharina Tropmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Merlin Bresinsky
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Christoph Müller
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany.
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3
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Hattori Y, Seifert R. Pharmacological Characterization of Human Histamine Receptors and Histamine Receptor Mutants in the Sf9 Cell Expression System. Handb Exp Pharmacol 2017; 241:63-118. [PMID: 28233175 PMCID: PMC7120522 DOI: 10.1007/164_2016_124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A large problem of histamine receptor research is data heterogeneity. Various experimental approaches, the complex signaling pathways of mammalian cells, and the use of different species orthologues render it difficult to compare and interpret the published results. Thus, the four human histamine receptor subtypes were analyzed side-by-side in the Sf9 insect cell expression system, using radioligand binding assays as well as functional readouts proximal to the receptor activation event (steady-state GTPase assays and [35S]GTPγS assays). The human H1R was co-expressed with the regulators of G protein signaling RGS4 or GAIP, which unmasked a productive interaction between hH1R and insect cell Gαq. By contrast, functional expression of the hH2R required the generation of an hH2R-Gsα fusion protein to ensure close proximity of G protein and receptor. Fusion of hH2R to the long (GsαL) or short (GsαS) splice variant of Gαs resulted in comparable constitutive hH2R activity, although both G protein variants show different GDP affinities. Medicinal chemistry studies revealed profound species differences between hH1R/hH2R and their guinea pig orthologues gpH1R/gpH2R. The causes for these differences were analyzed by molecular modeling in combination with mutational studies. Co-expression of the hH3R with Gαi1, Gαi2, Gαi3, and Gαi/o in Sf9 cells revealed high constitutive activity and comparable interaction efficiency with all G protein isoforms. A comparison of various cations (Li+, Na+, K+) and anions (Cl-, Br-, I-) revealed that anions with large radii most efficiently stabilize the inactive hH3R state. Potential sodium binding sites in the hH3R protein were analyzed by expressing specific hH3R mutants in Sf9 cells. In contrast to the hH3R, the hH4R preferentially couples to co-expressed Gαi2 in Sf9 cells. Its high constitutive activity is resistant to NaCl or GTPγS. The hH4R shows structural instability and adopts a G protein-independent high-affinity state. A detailed characterization of affinity and activity of a series of hH4R antagonists/inverse agonists allowed first conclusions about structure/activity relationships for inverse agonists at hH4R. In summary, the Sf9 cell system permitted a successful side-by-side comparison of all four human histamine receptor subtypes. This chapter summarizes the results of pharmacological as well as medicinal chemistry/molecular modeling approaches and demonstrates that these data are not only important for a deeper understanding of HxR pharmacology, but also have significant implications for the molecular pharmacology of GPCRs in general.
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Affiliation(s)
- Yuichi Hattori
- Department of Molecular and Medical Pharmacology, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Roland Seifert
- Institute of Pharmacology, Medical School of Hannover, Hannover, Germany
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4
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Panula P, Chazot PL, Cowart M, Gutzmer R, Leurs R, Liu WLS, Stark H, Thurmond RL, Haas HL. International Union of Basic and Clinical Pharmacology. XCVIII. Histamine Receptors. Pharmacol Rev 2016; 67:601-55. [PMID: 26084539 DOI: 10.1124/pr.114.010249] [Citation(s) in RCA: 372] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Histamine is a developmentally highly conserved autacoid found in most vertebrate tissues. Its physiological functions are mediated by four 7-transmembrane G protein-coupled receptors (H1R, H2R, H3R, H4R) that are all targets of pharmacological intervention. The receptors display molecular heterogeneity and constitutive activity. H1R antagonists are long known antiallergic and sedating drugs, whereas the H2R was identified in the 1970s and led to the development of H2R-antagonists that revolutionized stomach ulcer treatment. The crystal structure of ligand-bound H1R has rendered it possible to design new ligands with novel properties. The H3R is an autoreceptor and heteroreceptor providing negative feedback on histaminergic and inhibition on other neurons. A block of these actions promotes waking. The H4R occurs on immuncompetent cells and the development of anti-inflammatory drugs is anticipated.
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Affiliation(s)
- Pertti Panula
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Paul L Chazot
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Marlon Cowart
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Ralf Gutzmer
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Rob Leurs
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Wai L S Liu
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Holger Stark
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Robin L Thurmond
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
| | - Helmut L Haas
- Department of Anatomy, and Neuroscience Center, University of Helsinki, Finland (P.P.); School of Biological and Biomedical Sciences, University of Durham, United Kingdom (P.L.C.); AbbVie, Inc. North Chicago, Illinois (M.C.); Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany (R.G.); Department of Medicinal Chemistry, Amsterdam Institute of Molecules, Medicines and Systems, VU University Amsterdam, The Netherlands (R.L.); Ziarco Pharma Limited, Canterbury, United Kingdom (W.L.S.L.); Institute of Pharmaceutical and Medical Chemistry and Institute of Neurophysiology, Medical Faculty, Westfalische-Wilhelms-University, Muenster, Germany (H.L.H.); Heinrich-Heine-University Duesseldorf, Germany (H.S.); and Janssen Research & Development, LLC, San Diego, California (R.L.T.)
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5
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Abstract
Histamine is one of the best-characterized pruritogens in humans. It is known to play a role in pruritus associated with urticaria as well as ocular and nasal allergic reactions. Histamine mediates its effect via four receptors. Antihistamines that block the activation of the histamine H₁receptor, H₁R, have been shown to be effective therapeutics for the treatment of pruritus associated with urticaria, allergic rhinitis, and allergic conjunctivitis. However, their efficacy in other pruritic diseases such as atopic dermatitis and psoriasis is limited. The other histamine receptors may also play a role in pruritus, with the exception of the histamine H₂receptor, H₂R. Preclinical evidence indicates that local antagonism of the histamine H₃receptor, H₃R, can induce scratching perhaps via blocking inhibitory neuronal signals. The histamine H₄receptor, H₄R, has received a significant amount of attention as to its role in mediating pruritic signals. Indeed, it has now been shown that a selective H₄R antagonist can inhibit histamine-induced itch in humans. This clinical result, in conjunction with efficacy in various preclinical pruritus models, points to the therapeutic potential of H₄R antagonists for the treatment of pruritus not controlled by antihistamines that target the H₁R.
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Affiliation(s)
- Robin L Thurmond
- Janssen Research and Development, L.L.C., San Diego, CA, 92121, USA,
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6
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Seifert R, Strasser A, Schneider EH, Neumann D, Dove S, Buschauer A. Molecular and cellular analysis of human histamine receptor subtypes. Trends Pharmacol Sci 2013; 34:33-58. [PMID: 23254267 PMCID: PMC3869951 DOI: 10.1016/j.tips.2012.11.001] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/03/2012] [Accepted: 11/05/2012] [Indexed: 01/08/2023]
Abstract
The human histamine receptors hH(1)R and hH(2)R constitute important drug targets, and hH(3)R and hH(4)R have substantial potential in this area. Considering the species-specificity of pharmacology of H(x)R orthologs, it is important to analyze hH(x)Rs. Here, we summarize current knowledge of hH(x)Rs endogenously expressed in human cells and hH(x)Rs recombinantly expressed in mammalian and insect cells. We present the advantages and disadvantages of the various systems. We also discuss problems associated with the use of hH(x)R antibodies, an issue of general relevance for G-protein-coupled receptors (GPCRs). There is much greater overlap in activity of 'selective' ligands for other hH(x)Rs than the cognate receptor subtype than generally appreciated. Studies with native and recombinant systems support the concept of ligand-specific receptor conformations, encompassing agonists and antagonists. It is emerging that for characterization of hH(x)R ligands, one cannot rely on a single test system and a single parameter. Rather, multiple systems and parameters have to be studied. Although such studies are time-consuming and expensive, ultimately, they will increase drug safety and efficacy.
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Affiliation(s)
- Roland Seifert
- Institute of Pharmacology, Medical School of Hannover, Hannover, Germany.
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7
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Strasser A, Wittmann HJ, Buschauer A, Schneider EH, Seifert R. Species-dependent activities of G-protein-coupled receptor ligands: lessons from histamine receptor orthologs. Trends Pharmacol Sci 2012; 34:13-32. [PMID: 23228711 DOI: 10.1016/j.tips.2012.10.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 10/26/2012] [Accepted: 10/31/2012] [Indexed: 12/26/2022]
Abstract
Histamine is a biogenic amine that exerts its biological effects as a neurotransmitter and local mediator via four histamine receptor (HR) subtypes (H(x)Rs) - H(1)R, H(2)R, H(3)R, and H(4)R - belonging to the superfamily of G-protein-coupled receptors (GPCRs). All four H(x)Rs exhibit pronounced differences in agonist and/or antagonist pharmacology among various species orthologs. The species differences constitute a problem for animal experiments and drug development. This problem applies to GPCRs with diverse ligands. Here, we summarize our current knowledge on H(x)R orthologs as a case study for species-dependent activity of GPCR ligands. We show that species-specific pharmacology also provides unique opportunities to study important aspects of GPCR pharmacology in general, including ligand-binding sites, the roles of extracellular domains in ligand binding and receptor activation, agonist-independent (constitutive) receptor activity, thermodynamics of ligand/receptor interaction, receptor-activation mechanisms, and ligand-specific receptor conformations.
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Affiliation(s)
- Andrea Strasser
- Department of Pharmaceutical/Medicinal Chemistry II, University of Regensburg, Regensburg, Germany.
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8
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Birnkammer T, Spickenreither A, Brunskole I, Lopuch M, Kagermeier N, Bernhardt G, Dove S, Seifert R, Elz S, Buschauer A. The Bivalent Ligand Approach Leads to Highly Potent and Selective Acylguanidine-Type Histamine H2 Receptor Agonists. J Med Chem 2012; 55:1147-60. [DOI: 10.1021/jm201128q] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Tobias Birnkammer
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Anja Spickenreither
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Irena Brunskole
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Miroslaw Lopuch
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Nicole Kagermeier
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Günther Bernhardt
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Stefan Dove
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Roland Seifert
- Institute
of Pharmacology, Medical School of Hannover, D-30625 Hannover, Germany
| | - Sigurd Elz
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
| | - Armin Buschauer
- Department of Pharmaceutical/Medicinal
Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053
Regensburg, Germany
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9
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Sun X, Li Y, Li W, Xu Z, Tang Y. Computational investigation of interactions between human H2 receptor and its agonists. J Mol Graph Model 2011; 29:693-701. [DOI: 10.1016/j.jmgm.2010.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 11/23/2010] [Accepted: 12/04/2010] [Indexed: 11/16/2022]
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10
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Comparison of the pharmacological properties of human and rat histamine H(3)-receptors. Biochem Pharmacol 2010; 80:1437-49. [PMID: 20688049 DOI: 10.1016/j.bcp.2010.07.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/20/2010] [Accepted: 07/23/2010] [Indexed: 11/20/2022]
Abstract
Ligand pharmacology of histamine H(3)-receptors is species-dependent. In previous studies, two amino acids in transmembrane domain 3 (TM III) were shown to play a significant role. In this study, we characterized human and rat histamine H(3)-receptors (hH(3)R and rH(3)R, respectively), co-expressed with mammalian G proteins in Sf9 insect cell membranes. We compared a series of imidazole-containing H(3)R ligands in radioligand binding and steady-state GTPase assays. H(3)Rs similarly coupled to Gα(i/o)-proteins. Affinities and potencies of the agonists histamine, N(α)-methylhistamine and R-(α)-methylhistamine were in the same range. Imetit was only a partial agonist. The pharmacology of imetit and proxifan was similar at both species. However, impentamine was more potent and efficacious at rH(3)R. The inverse agonists ciproxifan and thioperamide showed higher potency but lower efficacy at rH(3)R. Clobenpropit was not species-selective. Strikingly, imoproxifan was almost full agonist at hH(3)R, but an inverse agonist at rH(3)R. Imoproxifan was docked into the binding pocket of inactive and active hH(3)R- and rH(3)R-models and molecular dynamic simulations were performed. Imoproxifan bound to hH(3)R and rH(3)R in E-configuration, which represents the trans-isomer of the oxime-moiety as determined in crystallization studies, and stabilized active hH(3)R-, but inactive rH(3)R-conformations. Large differences in electrostatic surfaces between TM III and TM V cause differential orientation of the oxime-moiety of imoproxifan, which then differently interacts with the rotamer toggle switch Trp(6.48) in TM VI. Collectively, the substantial species differences at H(3)Rs are explained at a molecular level by the use of novel H(3)R active-state models.
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11
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Igel P, Geyer R, Strasser A, Dove S, Seifert R, Buschauer A. Synthesis and structure-activity relationships of cyanoguanidine-type and structurally related histamine H4 receptor agonists. J Med Chem 2009; 52:6297-313. [PMID: 19791743 DOI: 10.1021/jm900526h] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently, we identified high-affinity human histamine H3 (hH3R) and H4 receptor (hH4R) ligands among a series of NG-acylated imidazolylpropylguanidines, which were originally designed as histamine H2 receptor (H2R) agonists. Aiming at selectivity for hH4R, the acylguanidine group was replaced with related moieties. Within a series of cyanoguanidines, 2-cyano-1-[4-(1H-imidazol-4-yl)butyl]-3-[(2-phenylthio)ethyl]guanidine (UR-PI376, 67) was identified as the most potent hH4R agonist (pEC50 = 7.47, alpha = 0.93) showing negligible hH1R and hH2R activities and significant selectivity over the hH3R (pKB = 6.00, alpha = -0.28), as determined in steady-state GTPase assays using membrane preparations of hH(x)R-expressing Sf9 cells. In contrast to previously described selective H4R agonists, this compound and other 3-substituted derivatives are devoid of agonistic activity at the other HR subtypes. Modeling of the binding mode of 67 suggests that the cyanoguanidine moiety forms charge-assisted hydrogen bonds not only with the conserved Asp-94 but also with the hH4R-specific Arg-341 residue. 2-Carbamoyl-1-[2-(1H-imidazol-4-yl)ethyl]-3-(3-phenylpropyl)guanidine (UR-PI97, 88) was unexpectedly identified as a highly potent and selective hH3R inverse agonist (pKB = 8.42, >300-fold selectivity over the other HR subtypes).
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Affiliation(s)
- Patrick Igel
- Department of Pharmaceutical/Medicinal Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitatsstrasse 31, D-93053 Regensburg, Germany
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12
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Straßer A, Wittmann HJ, Kunze M, Elz S, Seifert R. Molecular Basis for the Selective Interaction of Synthetic Agonists with the Human Histamine H1-Receptor Compared with the Guinea Pig H1-Receptor. Mol Pharmacol 2008; 75:454-65. [DOI: 10.1124/mol.108.053009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Ghorai P, Kraus A, Keller M, Götte C, Igel P, Schneider E, Schnell D, Bernhardt G, Dove S, Zabel M, Elz S, Seifert R, Buschauer A. Acylguanidines as Bioisosteres of Guanidines: NG-Acylated Imidazolylpropylguanidines, a New Class of Histamine H2 Receptor Agonists. J Med Chem 2008; 51:7193-204. [DOI: 10.1021/jm800841w] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Prasanta Ghorai
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Anja Kraus
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Max Keller
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Carsten Götte
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Patrick Igel
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Erich Schneider
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - David Schnell
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Stefan Dove
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Manfred Zabel
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Sigurd Elz
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Roland Seifert
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Armin Buschauer
- Departments of Pharmaceutical/Medicinal Chemistry, Pharmacology and Toxicology, Center for Chemical Analysis, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
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Generation of an agonistic binding site for blockers of the M(3) muscarinic acetylcholine receptor. Biochem J 2008; 412:103-12. [PMID: 18237275 DOI: 10.1042/bj20071366] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
GPCRs (G-protein-coupled receptors) exist in a spontaneous equilibrium between active and inactive conformations that are stabilized by agonists and inverse agonists respectively. Because ligand binding of agonists and inverse agonists often occurs in a competitive manner, one can assume an overlap between both binding sites. Only a few studies report mutations in GPCRs that convert receptor blockers into agonists by unknown mechanisms. Taking advantage of a genetically modified yeast strain, we screened libraries of mutant M(3)Rs {M(3) mAChRs [muscarinic ACh (acetylcholine) receptors)]} and identified 13 mutants which could be activated by atropine (EC50 0.3-10 microM), an inverse agonist on wild-type M(3)R. Many of the mutations sensitizing M(3)R to atropine activation were located at the junction of intracellular loop 3 and helix 6, a region known to be involved in G-protein coupling. In addition to atropine, the pharmacological switch was found for other M(3)R blockers such as scopolamine, pirenzepine and oxybutynine. However, atropine functions as an agonist on the mutant M(3)R only when expressed in yeast, but not in mammalian COS-7 cells, although high-affinity ligand binding was comparable in both expression systems. Interestingly, we found that atropine still blocks carbachol-induced activation of the M(3)R mutants in the yeast expression system by binding at the high-affinity-binding site (Ki approximately 10 nM). Our results indicate that blocker-to-agonist converting mutations enable atropine to function as both agonist and antagonist by interaction with two functionally distinct binding sites.
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Preuss H, Ghorai P, Kraus A, Dove S, Buschauer A, Seifert R. Point mutations in the second extracellular loop of the histamine H2 receptor do not affect the species-selective activity of guanidine-type agonists. Naunyn Schmiedebergs Arch Pharmacol 2007; 376:253-64. [DOI: 10.1007/s00210-007-0204-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 10/15/2007] [Indexed: 12/23/2022]
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Preuss H, Ghorai P, Kraus A, Dove S, Buschauer A, Seifert R. Constitutive activity and ligand selectivity of human, guinea pig, rat, and canine histamine H2 receptors. J Pharmacol Exp Ther 2007; 321:983-95. [PMID: 17332265 DOI: 10.1124/jpet.107.120014] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies revealed pharmacological differences between human and guinea pig histamine H(2) receptors (H(2)Rs) with respect to the interaction with guanidine-type agonists. Because H(2)R species variants are structurally very similar, comparative studies are suited to relate different properties of H(2)R species isoforms to few molecular determinants. Therefore, we systematically compared H(2)Rs of human (h), guinea pig (gp), rat (r), and canine (c). Fusion proteins of hH(2)R, gpH(2)R, rH(2)R, and cH(2)R, respectively, and the short splice variant of G(salpha), G(salphaS), were expressed in Sf9 insect cells. In the membrane steady-state GTPase activity assay, cH(2)R-G(salphaS) but neither gpH(2)R-G(salphaS) nor rH(2)R-G(salphaS) showed the hallmarks of increased constitutive activity compared with hH(2)R-G(salphaS), i.e., increased efficacies of partial agonists, increased potencies of agonists with the extent of potency increase being correlated with the corresponding efficacies at hH(2)R-G(salphaS), increased inverse agonist efficacies, and decreased potencies of antagonists. Furthermore, in membranes expressing nonfused H(2)Rs without or together with mammalian G(salphaS) or H(2)R-G(salpha) fusion proteins, the highest basal and GTP-dependent increases in adenylyl cyclase activity were observed for cH(2)R. An example of ligand selectivity is given by metiamide, acting as an inverse agonist at hH(2)R-G(salphaS), gpH(2)R-G(salphaS), and rH(2)R-G(salphaS) in the GTPase assay in contrast to being a weak partial agonist with decreased potency at cH(2)R-G(salphaS). In conclusion, the cH(2)R exhibits increased constitutive activity compared with hH(2)R, gpH(2)R, and rH(2)R, and there is evidence for ligand-specific conformations in H(2)R species isoforms.
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Affiliation(s)
- Hendrik Preuss
- Department of Pharmaceutical/Medicinal Chemistry II, Institute of Pharmacy, University of Regensburg, Regensburg, Germany
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