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Seibel-Ehlert U, Plank N, Inoue A, Bernhardt G, Strasser A. Label-Free Investigations on the G Protein Dependent Signaling Pathways of Histamine Receptors. Int J Mol Sci 2021; 22:9739. [PMID: 34575903 PMCID: PMC8467282 DOI: 10.3390/ijms22189739] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 01/14/2023] Open
Abstract
G protein activation represents an early key event in the complex GPCR signal transduction process and is usually studied by label-dependent methods targeting specific molecular events. However, the constrained environment of such "invasive" techniques could interfere with biological processes. Although histamine receptors (HRs) represent (evolving) drug targets, their signal transduction is not fully understood. To address this issue, we established a non-invasive dynamic mass redistribution (DMR) assay for the human H1-4Rs expressed in HEK cells, showing excellent signal-to-background ratios above 100 for histamine (HIS) and higher than 24 for inverse agonists with pEC50 values consistent with literature. Taking advantage of the integrative nature of the DMR assay, the involvement of endogenous Gαq/11, Gαs, Gα12/13 and Gβγ proteins was explored, pursuing a two-pronged approach, namely that of classical pharmacology (G protein modulators) and that of molecular biology (Gα knock-out HEK cells). We showed that signal transduction of hH1-4Rs occurred mainly, but not exclusively, via their canonical Gα proteins. For example, in addition to Gαi/o, the Gαq/11 protein was proven to contribute to the DMR response of hH3,4Rs. Moreover, the Gα12/13 was identified to be involved in the hH2R mediated signaling pathway. These results are considered as a basis for future investigations on the (patho)physiological role and the pharmacological potential of H1-4Rs.
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Affiliation(s)
- Ulla Seibel-Ehlert
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (N.P.); (G.B.)
| | - Nicole Plank
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (N.P.); (G.B.)
| | - Asuka Inoue
- Department of Pharmacological Sciences, Tohoku University, Sendai 980-8578, Japan;
| | - Guenther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (N.P.); (G.B.)
| | - Andrea Strasser
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany; (N.P.); (G.B.)
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2
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Quantitative Determination and Imaging of Gα q Signaling in Live Cells via Split-Luciferase Complementation. Methods Mol Biol 2021. [PMID: 34050463 DOI: 10.1007/978-1-0716-1258-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
G Protein-coupled receptors (GPCRs) transduce signals elicited by bioactive chemical agents (ligands), such as hormones, neurotransmitters, or cytokines, across the cellular membrane. Upon ligand binding, the receptor undergoes structural rearrangements, which cause the activation of G proteins. This triggers the activation of signaling cascades involving amplification, which takes place after every stage of the cascade. Consequently, signals from early stages can be masked when the activation of the signaling cascade is probed remote (distal) from the receptor. This led to the development of several techniques, which probe the activation of such signaling cascades as proximal to the receptor as possible. However, these methods often require specialized equipment or are limited in throughput. By applying split-luciferase complementation to the interaction between the Gαq protein and its effector the phospholipase C-β3 (PLC-β3), we introduce a protocol with a conventional plate reader at high throughput. The method is applicable to live cells and additionally allows imaging of the probe by bioluminescence microscopy.
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3
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Höring C, Seibel U, Tropmann K, Grätz L, Mönnich D, Pitzl S, Bernhardt G, Pockes S, Strasser A. A Dynamic, Split-Luciferase-Based Mini-G Protein Sensor to Functionally Characterize Ligands at All Four Histamine Receptor Subtypes. Int J Mol Sci 2020; 21:ijms21228440. [PMID: 33182741 PMCID: PMC7698210 DOI: 10.3390/ijms21228440] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/06/2020] [Accepted: 11/08/2020] [Indexed: 02/06/2023] Open
Abstract
In drug discovery, assays with proximal readout are of great importance to study target-specific effects of potential drug candidates. In the field of G protein-coupled receptors (GPCRs), the determination of GPCR-G protein interactions and G protein activation by means of radiolabeled GTP analogs ([35S]GTPγS, [γ-32P]GTP) has widely been used for this purpose. Since we were repeatedly faced with insufficient quality of radiolabeled nucleotides, there was a requirement to implement a novel proximal functional assay for the routine characterization of putative histamine receptor ligands. We applied the split-NanoLuc to the four histamine receptor subtypes (H1R, H2R, H3R, H4R) and recently engineered minimal G (mini-G) proteins. Using this method, the functional response upon receptor activation was monitored in real-time and the four mini-G sensors were evaluated by investigating selected standard (inverse) agonists and antagonists. All potencies and efficacies of the studied ligands were in concordance with literature data. Further, we demonstrated a significant positive correlation of the signal amplitude and the mini-G protein expression level in the case of the H2R, but not for the H1R or the H3R. The pEC50 values of histamine obtained under different mini-G expression levels were consistent. Moreover, we obtained excellent dynamic ranges (Z’ factor) and the signal spans were improved for all receptor subtypes in comparison to the previously performed [35S]GTPγS binding assay.
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Affiliation(s)
- Carina Höring
- Correspondence: (C.H.); , (A.S.); Tel.: +49-941-943-4748 (C.H.); +49-941-943-4821 (A.S.)
| | | | | | | | | | | | | | | | - Andrea Strasser
- Correspondence: (C.H.); , (A.S.); Tel.: +49-941-943-4748 (C.H.); +49-941-943-4821 (A.S.)
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4
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Reiner D, Seifert L, Deck C, Schüle R, Jung M, Stark H. Epigenetics meets GPCR: inhibition of histone H3 methyltransferase (G9a) and histamine H 3 receptor for Prader-Willi Syndrome. Sci Rep 2020; 10:13558. [PMID: 32782417 PMCID: PMC7419559 DOI: 10.1038/s41598-020-70523-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/28/2020] [Indexed: 02/08/2023] Open
Abstract
The role of epigenetic regulation is in large parts connected to cancer, but additionally, its therapeutic claim in neurological disorders has emerged. Inhibition of histone H3 lysine N-methyltransferase, especially G9a, has been recently shown to restore candidate genes from silenced parental chromosomes in the imprinting disorder Prader-Willi syndrome (PWS). In addition to this epigenetic approach, pitolisant as G-protein coupled histamine H3 receptor (H3R) antagonist has demonstrated promising therapeutic effects for Prader-Willi syndrome. To combine these pioneering principles of drug action, we aimed to identify compounds that combine both activities, guided by the pharmacophore blueprint for both targets. However, pitolisant as selective H3R inverse agonist with FDA and EMA-approval did not show the required inhibition at G9a. Pharmacological characterization of the prominent G9a inhibitor A-366, that is as well an inhibitor of the epigenetic reader protein Spindlin1, revealed its high affinity at H3R while showing subtype selectivity among subsets of the histaminergic and dopaminergic receptor families. This work moves prominent G9a ligands forward as pharmacological tools to prove for a potentially combined, symptomatic and causal, therapy in PWS by bridging the gap between drug development for G-protein coupled receptors and G9a as an epigenetic effector in a multi-targeting approach.
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Affiliation(s)
- David Reiner
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany
| | - Ludwig Seifert
- Institute of Pharmaceutical Sciences, University of Freiburg, 79104, Freiburg, Germany
| | - Caroline Deck
- Institute of Pharmaceutical Sciences, University of Freiburg, 79104, Freiburg, Germany
| | - Roland Schüle
- Department of Urology, Center for Clinical Research, Medical Center, Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79106, Freiburg, Germany
| | - Manfred Jung
- Institute of Pharmaceutical Sciences, University of Freiburg, 79104, Freiburg, Germany
| | - Holger Stark
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225, Duesseldorf, Germany.
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5
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Bartole E, Grätz L, Littmann T, Wifling D, Seibel U, Buschauer A, Bernhardt G. UR-DEBa242: A Py-5-Labeled Fluorescent Multipurpose Probe for Investigations on the Histamine H3 and H4 Receptors. J Med Chem 2020; 63:5297-5311. [DOI: 10.1021/acs.jmedchem.0c00160] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Edith Bartole
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Lukas Grätz
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Timo Littmann
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - David Wifling
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Ulla Seibel
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Armin Buschauer
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
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6
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Ligand-induced activation of ERK1/2 signaling by constitutively active G s-coupled 5-HT receptors. Acta Pharmacol Sin 2019; 40:1157-1167. [PMID: 30833707 DOI: 10.1038/s41401-018-0204-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/08/2018] [Indexed: 01/14/2023] Open
Abstract
5-HT4R, 5-HT6R, and 5-HT7AR are three constitutively active Gs-coupled 5-HT receptors that have key roles in brain development, learning, memory, cognition, and other physiological processes in the central nervous system. In addition to Gs signaling cascade mediated by these three 5-HT receptors, the ERK1/2 signaling which is dependent on cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activation downstream of Gs signaling has also been widely studied. In this study, we investigated these two signaling pathways originating from the three Gs-coupled 5-HT receptors in AD293 cells. We found that the phosphorylation and activation of ERK1/2 are ligand-induced, in contrast to the constitutively active Gs signaling. This indicates that Gs signaling alone is not sufficient for ERK1/2 activation in these three 5-HT receptors. In addition to Gs, we found that β-arrestin and Fyn are essential for the activation of ERK1/2. Together, these results put forth a novel mechanism for ERK1/2 activation involving the cooperative action of Gs, β-arrestin, and Fyn.
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7
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Bartole E, Littmann T, Tanaka M, Ozawa T, Buschauer A, Bernhardt G. [ 3H]UR-DEBa176: A 2,4-Diaminopyrimidine-Type Radioligand Enabling Binding Studies at the Human, Mouse, and Rat Histamine H 4 Receptors. J Med Chem 2019; 62:8338-8356. [PMID: 31469288 DOI: 10.1021/acs.jmedchem.9b01342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Differences in sequence homology between human (h), mouse (m), and rat (r) histamine H4 receptors (H4R) cause discrepancies regarding affinities, potencies, and/or efficacies of ligands and therefore compromise translational animal models and the applicability of radioligands. Aiming at a radioligand enabling robust and comparative binding studies at the h/m/rH4Rs, 2,4-diaminopyrimidines were synthesized and pharmacologically investigated. The most notable compounds identified were two (partial) agonists with comparable potencies at the h/m/rH4Rs: UR-DEBa148 (N-neopentyl-4-(1,4,6,7-tetrahydro-5H-imidazo[4,5-c]pyridin-5-yl)pyrimidin-2-amine bis(2,2,2-trifluoroacetate), 43), the most potent [pEC50 (reporter gene assay) = 9.9/9.6/10.3] compound in the series being slightly G-protein biased and UR-DEBa176 [(R)-4-[3-(dimethylamino)pyrrolidin-1-yl]-N-neopentylpyrimidin-2-amine bis(2,2,2-trifluoroacetate), 46, pEC50 (reporter gene assay) = 8.7/9.0/9.2], a potential "cold" form of a tritiated H4R ligand. After radiolabeling, binding studies with [3H]UR-DEBa176 ([3H]46) at the h/m/rH4Rs revealed comparable Kd values (41/17/22 nM), low nonspecific binding (11-17%, ∼Kd), and fast associations/dissociations (25-30 min) and disclosed [3H]UR-DEBa176 as useful molecular tool to determine h/m/rH4R binding affinities for H4R ligands.
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Affiliation(s)
- Edith Bartole
- Institute of Pharmacy , University of Regensburg , D-93053 Regensburg , Germany
| | - Timo Littmann
- Institute of Pharmacy , University of Regensburg , D-93053 Regensburg , Germany
| | - Miho Tanaka
- Department of Chemistry, School of Science , University of Tokyo , 7-3-1 Bunkyo-ku , Hongo , Tokyo 113-0033 , Japan
| | - Takeaki Ozawa
- Department of Chemistry, School of Science , University of Tokyo , 7-3-1 Bunkyo-ku , Hongo , Tokyo 113-0033 , Japan
| | - Armin Buschauer
- Institute of Pharmacy , University of Regensburg , D-93053 Regensburg , Germany
| | - Günther Bernhardt
- Institute of Pharmacy , University of Regensburg , D-93053 Regensburg , Germany
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8
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Littmann T, Ozawa T, Hoffmann C, Buschauer A, Bernhardt G. A split luciferase-based probe for quantitative proximal determination of Gα q signalling in live cells. Sci Rep 2018; 8:17179. [PMID: 30464299 PMCID: PMC6249299 DOI: 10.1038/s41598-018-35615-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/08/2018] [Indexed: 01/04/2023] Open
Abstract
The earlier an activation of a G protein-dependent signalling cascade at a G protein-coupled receptor (GPCR) is probed, the less amplificatory effects contribute to the measured signal. This is especially useful in case of a precise quantification of agonist efficacies, and is of paramount importance, when determining agonist bias in relation to the β-arrestin pathway. As most canonical assays with medium to high throughput rely on the quantification of second messengers, and assays affording more proximal readouts are often limited in throughput, we developed a technique with a proximal readout and sufficiently high throughput that can be used in live cells. Split luciferase complementation (SLC) was applied to assess the interaction of Gαq with its effector phospholipase C-β3. The resulting probe yielded an excellent Z' value of 0.7 and offers a broad and easy applicability to various Gαq-coupling GPCRs (hH1R, hM1,3,5R, hNTS1R), expressed in HEK293T cells, allowing the functional characterisation of agonists and antagonists. Furthermore, the developed sensor enabled imaging of live cells by luminescence microscopy, as demonstrated for the hM3R. The versatile SLC-based probe is broadly applicable e.g. to the screening and the pharmacological characterisation of GPCR ligands as well as to molecular imaging.
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Affiliation(s)
- Timo Littmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany.
| | - Takeaki Ozawa
- Department of Chemistry, School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Carsten Hoffmann
- Institute of Molecular Cell Biology, University Hospital Jena, University of Jena, Hans-Knöll-Str. 2, D-07745, Jena, Germany
| | - Armin Buschauer
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany.
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9
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Differential effects of functionally different histamine H 4 receptor ligands on acute irritant dermatitis in mice. Naunyn Schmiedebergs Arch Pharmacol 2018; 391:1387-1397. [PMID: 30145688 DOI: 10.1007/s00210-018-1553-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/31/2018] [Indexed: 10/28/2022]
Abstract
The anti-inflammatory effects of histamine H4 receptor (H4R) antagonists opened new therapeutic options for the treatment of inflammatory/allergic diseases, but the role of H4R in inflammation is far from being solved. Aim of the present study was to investigate the role of structurally related H4R ligands of the aminopyrimidine class with different efficacies and functionalities (neutral antagonist ST-994, partial agonist ST-1006, inverse agonist ST-1012, and partial inverse agonist ST-1124) on croton oil-induced ear edema and pruritus in mice. The H4R ligands were administered subcutaneously before topical application of croton oil. While ST-1006 and ST-1124 were ineffective at any dose tested (10-100 mg/kg), both ST-994 and ST-1012 (30 and 100 mg/kg) significantly reduced croton oil-induced ear edema. Moreover, ST-994, ST-1006, and ST-1124, but not ST-1012, significantly inhibited croton oil-induced ear pruritus at 30 mg/kg. In accordance with results obtained with the reference H4R antagonist JNJ7777120 (100 mg/kg), histological examination of inflamed ear tissue indicated that treatment with ST-994 (30 mg/kg) led to a significant reduction in the inflammatory severity score and in the number of eosinophils infiltrating the tissue, while the number of degranulated mast cells in inflamed tissues was increased in comparison with the number of intact mast cells. These data indicate that croton oil-induced ear inflammation and pruritus seem to be clearly, but variably, affected by the H4R ligands tested. The potential advantage of dual effect of the H4R neutral antagonist ST-994 has to be carefully considered as a new therapeutic approach to the treatment of inflammatory diseases.
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10
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Kuhn K, Littmann T, Dukorn S, Tanaka M, Keller M, Ozawa T, Bernhardt G, Buschauer A. In Search of NPY Y 4R Antagonists: Incorporation of Carbamoylated Arginine, Aza-Amino Acids, or d-Amino Acids into Oligopeptides Derived from the C-Termini of the Endogenous Agonists. ACS OMEGA 2017; 2:3616-3631. [PMID: 30023699 PMCID: PMC6044894 DOI: 10.1021/acsomega.7b00451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/04/2017] [Indexed: 06/08/2023]
Abstract
The cross-linked pentapeptides (2R,7R)-diaminooctanedioyl-bis(Tyr-Arg-Leu-Arg-Tyr-amide) ((2R,7R)-BVD-74D, (2R,7R)-1) and octanedioyl-bis(Tyr-Arg-Leu-Arg-Tyr-amide) (2) as well as the pentapeptide Ac-Tyr-Arg-Leu-Arg-Tyr-amide (3) were previously described as neuropeptide Y Y4 receptor (Y4R) partial agonists. Here, we report on a series of analogues of (2R,7R)-1 and 2 in which Arg2, Leu3, or Arg4 were replaced by the respective aza-amino acids. The replacement of Arg2 in 3 with a carbamoylated arginine building block and the extension of the N-terminus by an additional arginine led to the high-affinity hexapeptide Ac-Arg-Tyr-Nω-[(4-aminobutyl)aminocarbonyl]Arg-Leu-Arg-Tyr-amide (35), which was used as a precursor for a d-amino acid scan. The target compounds were investigated for Y4R functional activity in assays with complementary readouts: aequorin Ca2+ and β-arrestin 1 or β-arrestin 2 assays. In contrast to the parent compounds, which are Y4R agonists, several ligands were able to suppress the effect elicited by the endogenous ligand pancreatic polypeptide and therefore represent a novel class of peptide Y4R antagonists.
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Affiliation(s)
- Kilian
K. Kuhn
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany
| | - Timo Littmann
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany
| | - Stefanie Dukorn
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany
| | - Miho Tanaka
- Department
of Chemistry, School of Science, University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Max Keller
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany
| | - Takeaki Ozawa
- Department
of Chemistry, School of Science, University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Günther Bernhardt
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany
| | - Armin Buschauer
- Institute
of Pharmacy, University of Regensburg, Universitätsstraße 31, Regensburg D-93053, Germany
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11
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Lieb S, Littmann T, Plank N, Felixberger J, Tanaka M, Schäfer T, Krief S, Elz S, Friedland K, Bernhardt G, Wegener J, Ozawa T, Buschauer A. Label-free versus conventional cellular assays: Functional investigations on the human histamine H 1 receptor. Pharmacol Res 2016; 114:13-26. [PMID: 27751876 DOI: 10.1016/j.phrs.2016.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/11/2016] [Accepted: 10/11/2016] [Indexed: 01/07/2023]
Abstract
A set of histamine H1 receptor (H1R) agonists and antagonists was characterized in functional assays, using dynamic mass redistribution (DMR), electric cell-substrate impedance sensing (ECIS) and various signaling pathway specific readouts (Fura-2 and aequorin calcium assays, arrestin recruitment (luciferase fragment complementation) assay, luciferase gene reporter assay). Data were gained from genetically engineered HEK293T cells and compared with reference data from GTPase assays and radioligand binding. Histamine and the other H1R agonists gave different assay-related pEC50 values, however, the order of potency was maintained. In the luciferase fragment complementation assay, the H1R preferred β-arrestin2 over β-arrestin1. The calcium and the impedimetric assay depended on Gq coupling of the H1R, as demonstrated by complete inhibition of the histamine-induced signals in the presence of the Gq inhibitor FR900359 (UBO-QIC). Whereas partial inhibition by FR900359 was observed in DMR and the gene reporter assay, pertussis toxin substantially decreased the response in DMR, but increased the luciferase signal, reflecting the contribution of both, Gq and Gi, to signaling in these assays. For antagonists, the results from DMR were essentially compatible with those from conventional readouts, whereas the impedance-based data revealed a trend towards higher pKb values. ECIS and calcium assays apparently only reflect Gq signaling, whereas DMR and gene reporter assays appear to integrate both, Gq and Gi mediated signaling. The results confirm the value of the label-free methods, DMR and ECIS, for the characterization of H1R ligands. Both noninvasive techniques are complementary to each other, but cannot fully replace reductionist signaling pathway focused assays.
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Affiliation(s)
- S Lieb
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - T Littmann
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - N Plank
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - J Felixberger
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - M Tanaka
- Department of Chemistry, School of Science, University of Tokyo, Tokyo, Japan
| | - T Schäfer
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - S Krief
- Bioprojet Biotech, 35762 Saint-Grégoire, France
| | - S Elz
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - K Friedland
- Department of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - G Bernhardt
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany
| | - J Wegener
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany
| | - T Ozawa
- Department of Chemistry, School of Science, University of Tokyo, Tokyo, Japan
| | - A Buschauer
- Institute of Pharmacy, University of Regensburg, D-93040 Regensburg, Germany.
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12
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Schaper K, Rossbach K, Köther B, Stark H, Kietzmann M, Werfel T, Gutzmer R. Stimulation of the histamine 4 receptor upregulates thymic stromal lymphopoietin (TSLP) in human and murine keratinocytes. Pharmacol Res 2016; 113:209-215. [PMID: 27491560 DOI: 10.1016/j.phrs.2016.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/08/2016] [Accepted: 08/01/2016] [Indexed: 01/23/2023]
Abstract
The cytokine thymic stromal lymphopoietin (TSLP) is involved in the development and the progression of allergic diseases. It is mainly released by epithelial cells at barriers such as skin and gut in response to danger signals. Overexpression of TSLP in keratinocytes (KC) can provoke the development of a type 2 inflammatory response. Additionally, TSLP directly acts on sensory neurons and thereby triggers itch. Since histamine is also increased in lesions of inflammatory skin diseases, the aim of this study was to investigate possible effects of histamine as well as different histamine receptor subtype agonists and antagonists on TSLP production in KC. We therefore stimulated human KC with histamine in the presence or absence of the known TSLP-inductor poly I:C and measured TSLP production at protein as well as mRNA level. Histamine alone did not induce TSLP production in human KC, but pre-incubation with histamine prior to challenge with poly I:C resulted in a significant increase of TSLP production compared to stimulation with poly I:C alone. Experiments with different histamine receptor agonists (H1R: 2-pyridylethylamine; H2R: amthamine; H2R/H4R: 4-methylhistamine (4MH)) revealed a dominant role for the H4R receptor, as 4-MH in combination with poly I:C displayed a significant increase of TSLP secretion, while the other agonists did not show any effect. The increase in TSLP production by 4MH was blocked with the H4R antagonist JNJ7777120. This effect was reproducible also in the murine KC cell line MSC. Taken together, our study indicates a new role for the H4 receptor in the regulation of TSLP in keratinocytes. Therefore, blocking of the H4R receptor in allergic diseases might be promising to alleviate inflammation and pruritus via TSLP.
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Affiliation(s)
- Katrin Schaper
- Division of Immunodermatology and Allergy Research, Department of Dermatology and Allergy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Kristine Rossbach
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, Hannover, Germany
| | - Brigitta Köther
- Division of Immunodermatology and Allergy Research, Department of Dermatology and Allergy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Holger Stark
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Universitaetsstr. 1, 40225 Duesseldorf, Germany
| | - Manfred Kietzmann
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, Hannover, Germany
| | - Thomas Werfel
- Division of Immunodermatology and Allergy Research, Department of Dermatology and Allergy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Ralf Gutzmer
- Division of Immunodermatology and Allergy Research, Department of Dermatology and Allergy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
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Kuhn KK, Ertl T, Dukorn S, Keller M, Bernhardt G, Reiser O, Buschauer A. High Affinity Agonists of the Neuropeptide Y (NPY) Y4 Receptor Derived from the C-Terminal Pentapeptide of Human Pancreatic Polypeptide (hPP): Synthesis, Stereochemical Discrimination, and Radiolabeling. J Med Chem 2016; 59:6045-58. [DOI: 10.1021/acs.jmedchem.6b00309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Kilian K. Kuhn
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Thomas Ertl
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße
31, 93053 Regensburg, Germany
| | - Stefanie Dukorn
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Oliver Reiser
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße
31, 93053 Regensburg, Germany
| | - Armin Buschauer
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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14
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Label-free analysis of GPCR-stimulation: The critical impact of cell adhesion. Pharmacol Res 2016; 108:65-74. [DOI: 10.1016/j.phrs.2016.04.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 01/09/2023]
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15
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Geyer R, Nordemann U, Strasser A, Wittmann HJ, Buschauer A. Conformational Restriction and Enantioseparation Increase Potency and Selectivity of Cyanoguanidine-Type Histamine H4 Receptor Agonists. J Med Chem 2016; 59:3452-70. [PMID: 27007611 DOI: 10.1021/acs.jmedchem.6b00120] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
2-Cyano-1-[4-(1H-imidazol-4-yl)butyl]-3-[2-(phenylsulfanyl)ethyl]guanidine (UR-PI376, 1) is a potent and selective agonist of the human histamine H4 receptor (hH4R). To gain information on the active conformation, we synthesized analogues of 1 with a cyclopentane-1,3-diyl linker. Affinities and functional activities were determined at recombinant hHxR (x: 1-4) subtypes on Sf9 cell membranes (radioligand binding, [(35)S]GTPγS, or GTPase assays) and in part in luciferase assays on human or mouse H4R (HEK-293 cells). The most potent H4R agonists among 14 racemates were separated by chiral HPLC, yielding eight enantiomerically pure compounds. Configurations were assigned based on X-ray structures of intermediates and a stereocontrolled synthetic pathway. (+)-2-Cyano-1-{[trans-(1S,3S)-3-(1H-imidazol-4-yl)cyclopentyl]methyl}-3-[2-(phenylsulfanyl)ethyl]guanidine ((1S,3S)-UR-RG98, 39a) was the most potent H4R agonist in this series (EC50 11 nM; H4R vs H3R, >100-fold selectivity; H1R, H2R, negligible activities), whereas the optical antipode proved to be an H4R antagonist ([(35)S]GTPγS assay). MD simulations confirmed differential stabilization of the active and inactive H4R state by the enantiomers.
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Affiliation(s)
- Roland Geyer
- Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Uwe Nordemann
- Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Andrea Strasser
- Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Hans-Joachim Wittmann
- Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Armin Buschauer
- Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany
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Kyriakidis K, Zampeli E, Palaiologou M, Tiniakos D, Tiligada E. Histamine H3 and H4 receptor ligands modify vascular histamine levels in normal and arthritic large blood vessels in vivo. Inflammation 2016; 38:949-58. [PMID: 25359709 DOI: 10.1007/s10753-014-0057-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Growing evidence associates histamine with arthritis, but its implication in shaping vascular function in chronic inflammation remains largely elusive. This study explored the involvement of vascular histamine in the extra-articular responses in peripheral large blood vessels using a rat model of adjuvant-induced arthritis. Histamine levels were increased in the abdominal aorta and the inferior vena cava of arthritic animals. Contrary to the H1 receptor antagonist dimetindene, histamine induction was observed following administration of the H3 and H4 receptor ligands GSK334429 and JNJ7777120, respectively. In arthritis, prophylactic treatment with GSK334429 partially attenuated the clinical signs and restored basal histamine levels only in the abdominal aorta. This study is the first to implicate the H3 and H4 receptors in a concerted constitutive regulation of basal vascular histamine in the rat large blood vessels and to identify the H3 receptor as a component that may influence arterial histamine during the onset of arthritis.
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Affiliation(s)
- Konstantinos Kyriakidis
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, 11527, Athens, Greece
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17
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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: 362] [Impact Index Per Article: 45.3] [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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18
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Sadek B, Stark H. Cherry-picked ligands at histamine receptor subtypes. Neuropharmacology 2015; 106:56-73. [PMID: 26581501 DOI: 10.1016/j.neuropharm.2015.11.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/05/2015] [Accepted: 11/06/2015] [Indexed: 12/17/2022]
Abstract
Histamine, a biogenic amine, is considered as a principle mediator of multiple physiological effects through binding to its H1, H2, H3, and H4 receptors (H1-H4Rs). Currently, the HRs have gained attention as important targets for the treatment of several diseases and disorders ranging from allergy to Alzheimer's disease and immune deficiency. Accordingly, medicinal chemistry studies exploring histamine-like molecules and their physicochemical properties by binding and interacting with the four HRs has led to the development of a diversity of agonists and antagonists that display selectivity for each HR subtype. An overview on H1-R4Rs and developed ligands representing some key steps in development is provided here combined with a short description of structure-activity relationships for each class. Main chemical diversities, pharmacophores, and pharmacological profiles of most innovative H1-H4R agonists and antagonists are highlighted. Therefore, this overview should support the rational choice for the optimal ligand selection based on affinity, selectivity and efficacy data in biochemical and pharmacological studies. This article is part of the Special Issue entitled 'Histamine Receptors'.
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Affiliation(s)
- Bassem Sadek
- Department of Pharmacology and Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, PO Box 17666, Al Ain, United Arab Emirates.
| | - Holger Stark
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Universitaetsstr. 1, 40225 Düsseldorf, Germany
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Selective breeding for high anxiety introduces a synonymous SNP that increases neuropeptide S receptor activity. J Neurosci 2015; 35:4599-613. [PMID: 25788677 DOI: 10.1523/jneurosci.4764-13.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Neuropeptide S (NPS) has generated substantial interest due to its anxiolytic and fear-attenuating effects in rodents, while a corresponding receptor polymorphism associated with increased NPS receptor (NPSR1) surface expression and efficacy has been implicated in an increased risk of panic disorder in humans. To gain insight into this paradox, we examined the NPS system in rats and mice bred for high anxiety-related behavior (HAB) versus low anxiety-related behavior, and, thereafter, determined the effect of central NPS administration on anxiety- and fear-related behavior. The HAB phenotype was accompanied by lower basal NPS receptor (Npsr1) expression, which we could confirm via in vitro dual luciferase promoter assays. Assessment of shorter Npsr1 promoter constructs containing a sequence mutation that introduces a glucocorticoid receptor transcription factor binding site, confirmed via oligonucleotide pull-down assays, revealed increased HAB promoter activity-an effect that was prevented by dexamethasone. Analogous to the human NPSR1 risk isoform, functional analysis of a synonymous single nucleotide polymorphism in the coding region of HAB rodents revealed that it caused a higher cAMP response to NPS stimulation. Assessment of the behavioral consequence of these differences revealed that intracerebroventricular NPS reversed the hyperanxiety of HAB rodents as well as the impaired cued-fear extinction in HAB rats and the enhanced fear expression in HAB mice, respectively. These results suggest that alterations in the NPS system, conserved across rodents and humans, contribute to innate anxiety and fear, and that HAB rodents are particularly suited to resolve the apparent discrepancy between the preclinical and clinical findings to date.
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Wifling D, Löffel K, Nordemann U, Strasser A, Bernhardt G, Dove S, Seifert R, Buschauer A. Molecular determinants for the high constitutive activity of the human histamine H4 receptor: functional studies on orthologues and mutants. Br J Pharmacol 2015; 172:785-98. [PMID: 24903527 PMCID: PMC4301689 DOI: 10.1111/bph.12801] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 05/19/2014] [Accepted: 05/27/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Some histamine H4 receptor ligands act as inverse agonists at the human H4 receptor (hH4 R), a receptor with exceptionally high constitutive activity, but as neutral antagonists or partial agonists at the constitutively inactive mouse H4 receptor (mH4 R) and rat H4 receptor (rH4 R). To study molecular determinants of constitutive activity, H4 receptor reciprocal mutants were constructed: single mutants: hH4 R-F169V, mH4 R-V171F, hH4 R-S179A, hH4 R-S179M; double mutants: hH4 R-F169V+S179A, hH4 R-F169V+S179M and mH4 R-V171F+M181S. EXPERIMENTAL APPROACH Site-directed mutagenesis with pVL1392 plasmids containing hH4 or mH4 receptors were performed. Wild-type or mutant receptors were co-expressed with Gαi2 and Gβ1 γ2 in Sf9 cells. Membranes were studied in saturation and competition binding assays ([(3) H]-histamine), and in functional [(35) S]-GTPγS assays with inverse, partial and full agonists of the hH4 receptor. KEY RESULTS Constitutive activity decreased from the hH4 receptor via the hH4 R-F169V mutant to the hH4 R-F169V+S179A and hH4 R-F169V+S179M double mutants. F169 alone or in concert with S179 plays a major role in stabilizing a ligand-free active state of the hH4 receptor. Partial inverse hH4 receptor agonists like JNJ7777120 behaved as neutral antagonists or partial agonists at species orthologues with lower or no constitutive activity. Some partial and full hH4 receptor agonists showed decreased maximal effects and potencies at hH4 R-F169V and double mutants. However, the mutation of S179 in the hH4 receptor to M as in mH4 receptor or A as in rH4 receptor did not significantly reduce constitutive activity. CONCLUSIONS AND IMPLICATIONS F169 and S179 are key amino acids for the high constitutive activity of hH4 receptors and may also be of relevance for other constitutively active GPCRs. LINKED ARTICLES This article is part of a themed issue on Histamine Pharmacology Update published in volume 170 issue 1. To view the other articles in this issue visit http://onlinelibrary.wiley.com/doi/10.1111/bph.2013.170.issue-1/issuetoc.
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Affiliation(s)
- D Wifling
- Institute of Pharmacy, University of Regensburg, Regensburg, Germany
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Dimeric carbamoylguanidine-type histamine H2 receptor ligands: A new class of potent and selective agonists. Bioorg Med Chem 2015; 23:3957-69. [PMID: 25639885 DOI: 10.1016/j.bmc.2015.01.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 12/21/2014] [Accepted: 01/07/2015] [Indexed: 11/23/2022]
Abstract
The bioisosteric replacement of the acylguanidine moieties in dimeric histamine H2 receptor (H2R) agonists by carbamoylguanidine groups resulted in compounds with retained potencies and intrinsic activities, but considerably improved stability against hydrolytic cleavage. These compounds achieved up to 2500 times the potency of histamine when studied in [(35)S]GTPγS assays on recombinant human and guinea pig H2R. Unlike 3-(imidazol-4-yl)propyl substituted carbamoylguanidines, the corresponding 2-amino-4-methylthiazoles revealed selectivity over histamine receptor subtypes H1R, H3R and H4R in radioligand competition binding studies. H2R binding studies with three fluorescent compounds and one tritium-labeled ligand, synthesized from a chain-branched precursor, failed due to pronounced cellular accumulation and high non-specific binding. However, the dimeric H2R agonists proved to be useful pharmacological tools for functional studies on native cells, as demonstrated for selected compounds by cAMP accumulation and inhibition of fMLP-stimulated generation of reactive oxygen species in human monocytes.
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Baumeister P, Erdmann D, Biselli S, Kagermeier N, Elz S, Bernhardt G, Buschauer A. [(3) H]UR-DE257: development of a tritium-labeled squaramide-type selective histamine H2 receptor antagonist. ChemMedChem 2014; 10:83-93. [PMID: 25320025 DOI: 10.1002/cmdc.201402344] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Indexed: 11/08/2022]
Abstract
A series of new piperidinomethylphenoxypropylamine-type histamine H2 receptor (H2 R) antagonists with different substituted "urea equivalents" was synthesized and characterized in functional in vitro assays. Based on these data as selection criteria, radiosynthesis of N-[6-(3,4-dioxo-2-{3-[3-(piperidin-1-ylmethyl)phenoxy]propylamino}cyclobut-1-enylamino)hexyl]-(2,3-(3) H2 )propionic amide ([(3) H]UR-DE257) was performed. The radioligand (specific activity: 63 Ci mmol(-1) ) had high affinity for human, rat, and guinea pig H2 R (hH2 R, Sf9 cells: Kd , saturation binding: 31 nM, kinetic studies: 20 nM). UR-DE257 revealed high H2 R selectivity on membranes of Sf9 cells, expressing the respective hHx R subtype (Ki values: hH1 R: >10000 nM, hH2 R: 28 nM, hH3 R: 3800 nM, hH4 R: >10000 nM). In spite of insurmountable antagonism, probably due to rebinding of [(3) H]UR-DE257 to the H2 R (extended residence time), the title compound proved to be a valuable pharmacological tool for the determination of H2 R affinities in competition binding assays.
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Affiliation(s)
- Paul Baumeister
- Institut für Pharmazie, Pharmazeutische/Medizinische Chemie, Universität Regensburg, Universitätsstr. 31, 93053 Regensburg (Germany)
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Werner K, Neumann D, Buschauer A, Seifert R. No evidence for histamine H4 receptor in human monocytes. J Pharmacol Exp Ther 2014; 351:519-26. [PMID: 25273276 DOI: 10.1124/jpet.114.218107] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The histamine H4 receptor (H4R) is a classic pertussis toxin-sensitive Gi protein-coupled receptor that mediates increases in intracellular calcium concentration ([Ca(2+)]i). The presence of H4R in human eosinophils has been rigorously documented by several independent groups. It has also been suggested that H4R is expressed in human monocytes, but this suggestion hinges in part on H4R antibodies with questionable specificity. This situation prompted us to reinvestigate H4R expression in human monocytes. As positive control, we studied human embryonic kidney 293T cells stably expressing the human H4R (hH4R). In these cells, histamine (HA) and the H4R agonist UR-PI376 (2-cyano-1-[4-(1H-imidazol-4-yl)butyl]-3-[(2-phenylthio)ethyl]guanidine) induced pertussis toxin-sensitive [Ca(2+)]i increases. However, in quantitative real-time polymerase chain reaction studies we failed to detect hH4R mRNA in human monocytes and U937 promonocytes. In human monocytes, ATP and N-formyl-l-methionyl-l-leucyl-l-phenylalanine increased [Ca(2+)]i, but HA, UR-PI376, and 5-methylhistamine (a dual H4R/H2 receptor agonist) did not. In U937 promonocytes and differentiated U937 cells, HA increased [Ca(2+)]i, but this increase was mediated via HA H1 receptor. In conclusion, there is no evidence for the presence of H4R in human monocytes.
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Affiliation(s)
- Kristin Werner
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany (K.W., D.N., R.S.); and Department of Pharmaceutical and Medicinal Chemistry II, University of Regensburg, Regensburg, Germany (A.B.)
| | - Detlef Neumann
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany (K.W., D.N., R.S.); and Department of Pharmaceutical and Medicinal Chemistry II, University of Regensburg, Regensburg, Germany (A.B.)
| | - Armin Buschauer
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany (K.W., D.N., R.S.); and Department of Pharmaceutical and Medicinal Chemistry II, University of Regensburg, Regensburg, Germany (A.B.)
| | - Roland Seifert
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany (K.W., D.N., R.S.); and Department of Pharmaceutical and Medicinal Chemistry II, University of Regensburg, Regensburg, Germany (A.B.)
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