1
|
Soriano-Ursúa MA, Arias-Montaño JA, Ocampo-Néstor AL, Hernández-Martínez CF, Santillán-Torres I, Andrade-Jorge E, Valdez-Ortiz R, Fernández-Del Valle C, Trujillo-Ferrara JG. In silico identification of a biarylamine acting as agonist at human β 3 adrenoceptors and exerting BRL37344-like effects on mouse metabolism. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:2159-2170. [PMID: 37792048 DOI: 10.1007/s00210-023-02753-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/26/2023] [Indexed: 10/05/2023]
Abstract
Human β3-adrenoceptor (β3AR) agonists were considered potential agents for the treatment of metabolic disorders. However, compounds tested as β3AR ligands have shown marked differences in pharmacological profile in rodent and human species, although these compounds remain attractive as they were successfully repurposed for the therapy of urinary incontinence. In this work, some biarylamine compounds were designed and tested in silico as potential β3AR agonists on 3-D models of mouse or human β3ARs. Based on the theoretical results, we identified, synthesized and tested a biarylamine compound (polibegron). In CHO-K1 cells expressing the human β3AR, polibegron and the β3AR agonist BRL 37344 were partial agonists for stimulating cAMP accumulation (50 and 57% of the response to isoproterenol, respectively). The potency of polibegron was 1.71- and 4.5-fold higher than that of isoproterenol and BRL37344, respectively. These results indicate that polibegron acts as a potent, but partial, agonist at human β3ARs. In C57BL/6N mice with obesity induced by a high-fat diet, similar effects of the equimolar intraperitoneal administration of polibegron and BRL37344 were observed on weight, visceral fat and plasma levels of glucose, cholesterol and triglycerides. Similarities and differences between species related to ligand-receptor interactions can be useful for drug designing.
Collapse
Affiliation(s)
- Marvin A Soriano-Ursúa
- Departamentos de Fisiología, Bioquímica y Sección de Estudios de Posgrado E Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, 11340, Mexico City, Mexico.
| | - José-Antonio Arias-Montaño
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del I.P.N., Av. IPN 2508, 07360, Mexico City, Mexico
| | - Ana-Lilia Ocampo-Néstor
- Departamentos de Fisiología, Bioquímica y Sección de Estudios de Posgrado E Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, 11340, Mexico City, Mexico
- Departamento de Nefrología, Hospital General de México "Dr. Eduardo Liceaga", Dr. Balmis 148, Alc. Cuauhtémoc, 06720, Mexico City, Mexico
| | - Christian F Hernández-Martínez
- Departamentos de Fisiología, Bioquímica y Sección de Estudios de Posgrado E Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, 11340, Mexico City, Mexico
| | - Iván Santillán-Torres
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del I.P.N., Av. IPN 2508, 07360, Mexico City, Mexico
| | - Erik Andrade-Jorge
- Departamentos de Fisiología, Bioquímica y Sección de Estudios de Posgrado E Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, 11340, Mexico City, Mexico
| | - Rafael Valdez-Ortiz
- Departamento de Nefrología, Hospital General de México "Dr. Eduardo Liceaga", Dr. Balmis 148, Alc. Cuauhtémoc, 06720, Mexico City, Mexico
| | - Cecilia Fernández-Del Valle
- Área de Investigación Médica, Productos Medix, S.A. de C.V., Calzada del Hueso 39, Ejido Viejo Santa Úrsula Coapa, Coyoacán, 04650, Mexico City, Mexico
| | - José G Trujillo-Ferrara
- Departamentos de Fisiología, Bioquímica y Sección de Estudios de Posgrado E Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, 11340, Mexico City, Mexico.
| |
Collapse
|
2
|
Sundel MH, Sampaio Moura N, Cheng K, Chatain O, Hu S, Drachenberg CB, Xie G, Raufman JP. Selective Activation of M 1 Muscarinic Receptors Attenuates Human Colon Cancer Cell Proliferation. Cancers (Basel) 2023; 15:4766. [PMID: 37835460 PMCID: PMC10571583 DOI: 10.3390/cancers15194766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
M3 muscarinic receptor (M3R) activation stimulates colon cancer cell proliferation, migration, and invasion; M3R expression is augmented in colon cancer and ablating M3R expression in mice attenuates colon neoplasia. Several lines of investigation suggest that in contrast to these pro-neoplastic effects of M3R, M1R plays an opposite role, protecting colon epithelial cells against neoplastic transformation. To pursue these intriguing findings, we examined the relative expression of M1R versus M3R in progressive stages of colon neoplasia and the effect of treating colon cancer cells with selective M1R agonists. We detected divergent expression of M1R and M3R in progressive colon neoplasia, from aberrant crypt foci to adenomas, primary colon cancers, and colon cancer metastases. Treating three human colon cancer cell lines with two selective M1R agonists, we found that in contrast to the effects of M3R activation, selective activation of M1R reversibly inhibited cell proliferation. Moreover, these effects were diminished by pre-incubating cells with a selective M1R inhibitor. Mechanistic insights were gained using selective chemical inhibitors of post-muscarinic receptor signaling molecules and immunoblotting to demonstrate M1R-dependent changes in the activation (phosphorylation) of key downstream kinases, EGFR, ERK1/2, and p38 MAPK. We did not detect a role for drug toxicity, cellular senescence, or apoptosis in mediating M1R agonist-induced attenuated cell proliferation. Lastly, adding M1R-selective agonists to colon cancer cells augmented the anti-proliferative effects of conventional chemotherapeutic agents. Collectively, these results suggest that selective M1R agonism for advanced colon cancer, alone or in combination with conventional chemotherapy, is a therapeutic strategy worth exploring.
Collapse
Affiliation(s)
- Margaret H. Sundel
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Natalia Sampaio Moura
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.S.M.); (K.C.); (O.C.); (S.H.); (G.X.)
| | - Kunrong Cheng
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.S.M.); (K.C.); (O.C.); (S.H.); (G.X.)
| | - Oscar Chatain
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.S.M.); (K.C.); (O.C.); (S.H.); (G.X.)
| | - Shien Hu
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.S.M.); (K.C.); (O.C.); (S.H.); (G.X.)
| | - Cinthia B. Drachenberg
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Guofeng Xie
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.S.M.); (K.C.); (O.C.); (S.H.); (G.X.)
- VA Maryland Healthcare System, Baltimore, MD 21201, USA
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jean-Pierre Raufman
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (N.S.M.); (K.C.); (O.C.); (S.H.); (G.X.)
- VA Maryland Healthcare System, Baltimore, MD 21201, USA
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| |
Collapse
|
3
|
Ferraiolo M, Hermans E. The complex molecular pharmacology of the dopamine D 2 receptor: Implications for pramipexole, ropinirole, and rotigotine. Pharmacol Ther 2023; 245:108392. [PMID: 36958527 DOI: 10.1016/j.pharmthera.2023.108392] [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: 10/27/2022] [Revised: 03/09/2023] [Accepted: 03/20/2023] [Indexed: 03/25/2023]
Abstract
With L-DOPA, dopamine agonists such as pramipexole, ropinirole and rotigotine constitute key therapeutic options for the management of motor symptoms of Parkinson's disease. These compounds exert their beneficial effect on motor behaviours by activating dopamine D2-class receptors and thereby compensating for the declining dopaminergic transmission in the dorsal striatum. Despite a strong similarity in their mechanism of action, these three dopamine agonists present distinct clinical profiles, putatively underpinned by differences in their pharmacological properties. In this context, this review aims at contributing to close the gap between clinical observations and data from molecular neuropharmacology by exploring the properties of pramipexole, ropinirole and rotigotine from both the clinical and molecular perspectives. Indeed, this review first summarizes and compares the clinical features of these three dopamine agonists, and then explores their binding profiles at the different dopamine receptor subtypes. Moreover, the signalling profiles of pramipexole, ropinirole and rotigotine at the D2 receptor are recapitulated, with a focus on biased signalling and the potential therapeutic implications. Overall, this review aims at providing a unifying framework of interpretation for both clinicians and fundamental pharmacologists interested in a deep understanding of the pharmacological properties of pramipexole, ropinirole and rotigotine.
Collapse
Affiliation(s)
- Mattia Ferraiolo
- Neuropharmacology Laboratory, Institute of Neuroscience, UCLouvain, Brussels, Belgium
| | - Emmanuel Hermans
- Neuropharmacology Laboratory, Institute of Neuroscience, UCLouvain, Brussels, Belgium.
| |
Collapse
|
4
|
Ferraiolo M, Ponthot R, Atik H, Koener B, Hanson J, Hermans E. Receptor density influences the recruitment bias of aripiprazole and brexpiprazole at the dopamine D
2L
receptor. Fundam Clin Pharmacol 2022; 36:976-984. [DOI: 10.1111/fcp.12812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 05/26/2022] [Accepted: 06/27/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Mattia Ferraiolo
- Neuropharmacology Laboratory Institute of Neurosciences – UCLouvain Brussels Belgium
| | - Romane Ponthot
- Neuropharmacology Laboratory Institute of Neurosciences – UCLouvain Brussels Belgium
| | - Hicham Atik
- Neuropharmacology Laboratory Institute of Neurosciences – UCLouvain Brussels Belgium
| | - Beryl Koener
- Neuropharmacology Laboratory Institute of Neurosciences – UCLouvain Brussels Belgium
| | - Julien Hanson
- Laboratory of Molecular pharmacology GIGA‐Molecular Biology of Disease – ULiège Liège Belgium
- Laboratory of Medicinal Chemistry CIRM – ULiège Liège Belgium
| | - Emmanuel Hermans
- Neuropharmacology Laboratory Institute of Neurosciences – UCLouvain Brussels Belgium
| |
Collapse
|
5
|
Ferraiolo M, Atik H, Ponthot R, Koener B, Hanson J, Hermans E. Dopamine D 2L receptor density influences the recruitment of β-arrestin2 and G i1 induced by antiparkinsonian drugs. Neuropharmacology 2022; 207:108942. [PMID: 35026287 DOI: 10.1016/j.neuropharm.2022.108942] [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: 10/04/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Brain imaging studies have highlighted that the density of dopamine D2 receptors markedly fluctuates across the stages of Parkinson's disease and in response to pharmacological treatment. Moreover, receptor density constitutes a molecular determinant for the signaling profile of D2 receptor ligands. We therefore hypothesized that variations in receptor expression could influence D2 receptor response to antiparkinsonian drugs, most notably with respect to the recruitment bias between Gi1 and β-arrestin2. METHODS The recruitment bias of dopamine, pramipexole, ropinirole, and rotigotine was examined using a nanoluciferase-based biosensor for probing the interactions of the D2L receptor with either Gi1 or β-arrestin2. The characterization of the functional selectivity of these D2 receptor agonists was performed at two distinct D2L receptor densities by taking advantage of a cell model carrying an inducible system that enables the overexpression of the D2L receptor when exposed to doxycycline. RESULTS A high receptor density oriented the balanced signaling profile of dopamine towards a preferential recruitment of Gi1. It also moderated the marked Gi1 and β-arrestin2 biases of pramipexole and rotigotine, respectively. At variance, the Gi1 bias of ropinirole appeared as not being influenced by D2L receptor density. CONCLUSIONS Taken together, these observations highlight receptor density as a key driver of the signaling transducer recruitment triggered by antiparkinsonian agents. Moreover, given the putative beneficial properties of β-arrestin2 in promoting locomotion, this study provides molecular insights that position the arrestin-biased ligand rotigotine as a putatively more beneficial D2 receptor agonist for the treatment of early and late Parkinson's disease.
Collapse
Affiliation(s)
- Mattia Ferraiolo
- Neuropharmacology Laboratory - Institute of Neurosciences - UCLouvain, Brussels, Belgium
| | - Hicham Atik
- Neuropharmacology Laboratory - Institute of Neurosciences - UCLouvain, Brussels, Belgium
| | - Romane Ponthot
- Neuropharmacology Laboratory - Institute of Neurosciences - UCLouvain, Brussels, Belgium
| | - Beryl Koener
- Neuropharmacology Laboratory - Institute of Neurosciences - UCLouvain, Brussels, Belgium
| | - Julien Hanson
- Laboratory of Molecular Pharmacology - GIGA-Molecular Biology of Disease - ULiège, Liège, Belgium; Laboratory of Medicinal Chemistry - CIRM - ULiège, Liège, Belgium
| | - Emmanuel Hermans
- Neuropharmacology Laboratory - Institute of Neurosciences - UCLouvain, Brussels, Belgium.
| |
Collapse
|
6
|
Receptor density influences ligand-induced dopamine D 2L receptor homodimerization. Eur J Pharmacol 2021; 911:174557. [PMID: 34626593 DOI: 10.1016/j.ejphar.2021.174557] [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: 07/19/2021] [Revised: 09/03/2021] [Accepted: 09/10/2021] [Indexed: 01/23/2023]
Abstract
Chronic treatments with dopamine D2 receptor ligands induce fluctuations in D2 receptor density. Since D2 receptors tend to assemble as homodimers, we hypothesized that receptor density might influence constitutive and ligand-induced homodimerization. Using a nanoluciferase-based complementation assay to monitor dopamine D2L receptor homodimerization in a cellular model enabling the tetracycline-controlled expression of dopamine D2L receptors, we observed that increasing receptor density promoted constitutive dopamine D2L receptor homodimerization. Receptor full agonists promoted homodimerization, while antagonists and partial agonists disrupted dopamine D2L receptor homodimers. High receptor densities enhanced this inhibitory effect only for receptor antagonists. Taken together, our findings indicate that both receptor density and receptor ligands influence dopamine D2L receptor homodimerization, albeit excluding any strict correlation with ligands' intrinsic activity and highlighting further complexity to dopaminergic pharmacology.
Collapse
|
7
|
Affiliation(s)
- Cen Xu
- 7129Amgen Inc., Thousand Oaks, CA, USA
| | | |
Collapse
|
8
|
Li XX, Lee JD, Massey NL, Guan C, Robertson AAB, Clark RJ, Woodruff TM. Pharmacological characterisation of small molecule C5aR1 inhibitors in human cells reveals biased activities for signalling and function. Biochem Pharmacol 2020; 180:114156. [PMID: 32682759 DOI: 10.1016/j.bcp.2020.114156] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 12/17/2022]
Abstract
The complement fragment C5a is a core effector of complement activation. C5a, acting through its major receptor C5aR1, exerts powerful pro-inflammatory and immunomodulatory functions. Dysregulation of the C5a-C5aR1 axis has been implicated in numerous immune disorders, and the therapeutic inhibition of this axis is therefore imperative for the treatment of these diseases. A myriad of small-molecule C5aR1 inhibitors have been developed and independently characterised over the past two decades, however the pharmacological properties of these compounds has been difficult to directly compare due to the wide discrepancies in the model, read-out, ligand dose and instrumentation implemented across individual studies. Here, we performed a systematic characterisation of the most commonly reported and clinically advanced small-molecule C5aR1 inhibitors (peptidic: PMX53, PMX205 and JPE1375; non-peptide: W545011, NDT9513727, DF2593A and CCX168). Through signalling assays measuring C5aR1-mediated cAMP and ERK1/2 signalling, and β-arrestin 2 recruitment, this study highlighted the signalling-pathway dependence of the rank order of potencies of the C5aR1 inhibitors. Functional experiments performed in primary human macrophages demonstrated the high insurmountable antagonistic potencies for the peptidic inhibitors as compared to the non-peptide compounds. Finally, wash-out studies provided novel insights into the duration of inhibition of the C5aR1 inhibitors, and confirmed the long-lasting antagonistic properties of PMX53 and CCX168. Overall, this study revealed the potent and prolonged antagonistic activities of selected peptidic C5aR1 inhibitors and the unique pharmacological profile of CCX168, which thus represent ideal candidates to fulfil diverse C5aR1 research and clinical therapeutic needs.
Collapse
Affiliation(s)
- Xaria X Li
- School of Biomedical Sciences, Australia
| | - John D Lee
- School of Biomedical Sciences, Australia
| | | | - Carolyn Guan
- The University of Queensland, St Lucia 4072, Australia; Department of Chemistry, Princeton University, Princeton, NJ 08544, United States
| | | | | | - Trent M Woodruff
- School of Biomedical Sciences, Australia; Queensland Brain Institute, Australia.
| |
Collapse
|
9
|
Willmann M, Ermert J, Prante O, Hübner H, Gmeiner P, Neumaier B. Radiosynthesis and evaluation of 18F-labeled dopamine D 4-receptor ligands. Nucl Med Biol 2020; 92:43-52. [PMID: 32718750 DOI: 10.1016/j.nucmedbio.2020.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/09/2020] [Indexed: 11/24/2022]
Abstract
INTRODUCTION The dopamine D4 receptor (D4R) has attracted considerable attention as potential target for the treatment of a broad range of central nervous system disorders. Although many efforts have been made to improve the performance of putative radioligand candidates, there is still a lack of D4R selective tracers suitable for in vivo PET imaging. Thus, the objective of this work was to develop a D4-selective PET ligand for clinical applications. METHODS Four compounds based on previous and new lead structures were prepared and characterized with regard to their D4R subtype selectivity and predicted lipophilicity. From these, 3-((4-(2-fluorophenyl)piperazin-1-yl)methyl)-1H-pyrrolo[2,3-b]pyridine I and (S)-4-(3-fluoro-4-methoxybenzyl)-2-(phenoxymethyl)morpholine II were selected for labeling with fluorine-18 and subsequent evaluation by in vitro autoradiography to assess their suitability as D4 radioligand candidates for in vivo imaging. RESULTS The radiosynthesis of [18F]I and [18F]II was successfully achieved by copper-mediated radiofluorination with radiochemical yields of 7% and 66%, respectively. The radioligand [18F]II showed specific binding in areas where D4 expression is expected, whereas [18F]I did not show any uptake in distinct brain regions and exhibited an unacceptable degree of non-specific binding. CONCLUSIONS The compounds studied exhibited high D4R subtype selectivity and logP values compatible with high brain uptake, but only ligand [18F]II showed low non-specific binding and is therefore a good candidate for further evaluation. ADVANCES IN KNOWLEDGE The discovery of new lead structures for high-affinity D4 ligands opens up new possibilities for the development of suitable PET-radioligands. IMPLICATIONS FOR PATIENT PET-imaging of dopamine D4-receptors could facilitate understanding, diagnosis and treatment of neuropsychiatric and neurodegenerative diseases.
Collapse
Affiliation(s)
- Michael Willmann
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen Straße, 52428 Jülich, Germany
| | - Johannes Ermert
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen Straße, 52428 Jülich, Germany.
| | - Olaf Prante
- Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department of Nuclear Medicine, Molecular Imaging and Radiochemistry, Translational Research Center, 91054 Erlangen, Germany
| | - Harald Hübner
- Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department Chemistry and Pharmacy, Medicinal Chemistry, 91058 Erlangen, Germany
| | - Peter Gmeiner
- Friedrich-Alexander University Erlangen-Nürnberg (FAU), Department Chemistry and Pharmacy, Medicinal Chemistry, 91058 Erlangen, Germany
| | - Bernd Neumaier
- Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine, Nuclear Chemistry (INM-5), Wilhelm-Johnen Straße, 52428 Jülich, Germany; University of Colgne, Faculty of Medicine and University Hospital Cologne, Institute of Radiochemistry and Experimental Molecular Imaging, 50937 Cologne, Germany
| |
Collapse
|
10
|
The effects of dopamine D4 receptor ligands on operant alcohol self-administration and cue- and stress-induced reinstatement in rats. Eur J Pharmacol 2020; 867:172838. [DOI: 10.1016/j.ejphar.2019.172838] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 01/04/2023]
|
11
|
Soave M, Cseke G, Hutchings CJ, Brown AJH, Woolard J, Hill SJ. A monoclonal antibody raised against a thermo-stabilised β 1-adrenoceptor interacts with extracellular loop 2 and acts as a negative allosteric modulator of a sub-set of β 1-adrenoceptors expressed in stable cell lines. Biochem Pharmacol 2017; 147:38-54. [PMID: 29102678 PMCID: PMC5770334 DOI: 10.1016/j.bcp.2017.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 10/31/2017] [Indexed: 11/30/2022]
Abstract
Recent interest has focused on antibodies that can discriminate between different receptor conformations. Here we have characterised the effect of a monoclonal antibody (mAb3), raised against a purified thermo-stabilised turkey β1-adrenoceptor (β1AR-m23 StaR), on β1-ARs expressed in CHO-K1 or HEK 293 cells. Immunohistochemical and radioligand-binding studies demonstrated that mAb3 was able to bind to ECL2 of the tβ1-AR, but not its human homologue. Specific binding of mAb3 to tβ1-AR was inhibited by a peptide based on the turkey, but not the human, ECL2 sequence. Studies with [3H]-CGP 12177 demonstrated that mAb3 prevented the binding of orthosteric ligands to a subset (circa 40%) of turkey β1-receptors expressed in both CHO K1 and HEK 293 cells. MAb3 significantly reduced the maximum specific binding capacity of [3H]-CGP-12177 without influencing its binding affinity. Substitution of ECL2 of tβ1-AR with its human equivalent, or mutation of residues D186S, P187D, Q188E prevented the inhibition of [3H]-CGP 12177 binding by mAb3. MAb3 also elicited a negative allosteric effect on agonist-stimulated cAMP responses. The identity of the subset of turkey β1-adrenoceptors influenced by mAb3 remains to be established but mAb3 should become an important tool to investigate the nature of β1-AR conformational states and oligomeric complexes.
Collapse
Affiliation(s)
- Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Gabriella Cseke
- Heptares Therapeutics Ltd., Bio Park, Welwyn Garden City AL7 3AX, UK
| | | | | | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
| |
Collapse
|
12
|
Pediani JD, Ward RJ, Marsango S, Milligan G. Spatial Intensity Distribution Analysis: Studies of G Protein-Coupled Receptor Oligomerisation. Trends Pharmacol Sci 2017; 39:175-186. [PMID: 29032835 PMCID: PMC5783713 DOI: 10.1016/j.tips.2017.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/04/2017] [Accepted: 09/14/2017] [Indexed: 02/08/2023]
Abstract
Spatial intensity distribution analysis (SpIDA) is a recently developed approach for determining quaternary structure information on fluorophore-labelled proteins of interest in situ. It can be applied to live or fixed cells and native tissue. Using confocal images, SpIDA generates fluorescence intensity histograms that are analysed by super-Poissonian distribution functions to obtain density and quantal brightness values of the fluorophore-labelled protein of interest. This allows both expression level and oligomerisation state of the protein to be determined. We describe the application of SpIDA to investigate the oligomeric state of G protein-coupled receptors (GPCRs) at steady state and following cellular challenge, and consider how SpIDA may be used to explore GPCR quaternary organisation in pathophysiology and to stratify medicines. GPCRs may exist and function as monomers: however, abundant evidence suggests they can form dimers/oligomers. This concept has implications for drug discovery as it may offer opportunities to modulate the effects of known pharmaceuticals or identify new drug therapies. A variety of approaches have been applied to this issue from traditional biochemical techniques, via resonance energy transfer approaches to recently developed image analysis-based techniques such as SpIDA. This uses mathematical analysis of confocal microscopy images to generate quantal brightness and density information for a fluorophore-tagged receptor. SpIDA can be applied to live or fixed cells and native tissue. SpIDA has been applied to GPCRs from each of the major subfamilies to explore their oligomerisation status at steady state and their regulation by receptor density and ligand binding.
Collapse
Affiliation(s)
- John D Pediani
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Richard J Ward
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Sara Marsango
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| |
Collapse
|
13
|
Li M, Thapa P, Rajaputra P, Bio M, Peer CJ, Figg WD, You Y, Woo S. Quantitative modeling of the dynamics and intracellular trafficking of far-red light-activatable prodrugs: implications in stimuli-responsive drug delivery system. J Pharmacokinet Pharmacodyn 2017; 44:521-536. [PMID: 28913666 DOI: 10.1007/s10928-017-9543-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 09/08/2017] [Indexed: 12/14/2022]
Abstract
The combination of photodynamic therapy (PDT) with anti-tumor agents is a complimentary strategy to treat local cancers. We developed a unique photosensitizer (PS)-conjugated paclitaxel (PTX) prodrug in which a PS is excited by near-infrared wavelength light to site-specifically release PTX while generating singlet oxygen (SO) to effectively kill cancer cells with both PTX and SO. The aim of the present study was to identify the determinants influencing the combined efficacy of this light-activatable prodrug, especially the bystander killing effects from released PTX. Using PS-conjugated PTX as a model system, we developed a quantitative mathematical model describing the intracellular trafficking. Dynamics of the prodrug and the model predictions were verified with experimental data using human cancer cells in vitro. The sensitivity analysis suggested that parameters related to extracellular concentration of released PTX, prodrug uptake, target engagement, and target abundance are critical in determining the combined killing efficacy of the prodrug. We found that released PTX cytotoxicity was most sensitive to the retention time of the drug in extracellular space. Modulating drug internalization and conjugating the agents targeted to abundant receptors may provide a new strategy for maximizing the killing capacity of the far-red light-activatable prodrug system. These results provide guidance for the design of the PDT combination study in vivo and have implications for other stimuli-responsive drug delivery systems.
Collapse
Affiliation(s)
- Mengjie Li
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA
| | - Pritam Thapa
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA
| | - Pallavi Rajaputra
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA
| | - Moses Bio
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA
| | - Cody J Peer
- Clinical Pharmacology Program, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - William D Figg
- Clinical Pharmacology Program, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Youngjae You
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA.
| | - Sukyung Woo
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73117, USA.
| |
Collapse
|
14
|
Marsango S, Caltabiano G, Jiménez-Rosés M, Millan MJ, Pediani JD, Ward RJ, Milligan G. A Molecular Basis for Selective Antagonist Destabilization of Dopamine D 3 Receptor Quaternary Organization. Sci Rep 2017; 7:2134. [PMID: 28522847 PMCID: PMC5437050 DOI: 10.1038/s41598-017-02249-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/07/2017] [Indexed: 12/17/2022] Open
Abstract
The dopamine D3 receptor (D3R) is a molecular target for both first-generation and several recently-developed antipsychotic agents. Following stable expression of this mEGFP-tagged receptor, Spatial Intensity Distribution Analysis indicated that a substantial proportion of the receptor was present within dimeric/oligomeric complexes and that increased expression levels of the receptor favored a greater dimer to monomer ratio. Addition of the antipsychotics, spiperone or haloperidol, resulted in re-organization of D3R quaternary structure to promote monomerization. This action was dependent on ligand concentration and reversed upon drug washout. By contrast, a number of other antagonists with high affinity at the D3R, did not alter the dimer/monomer ratio. Molecular dynamics simulations following docking of each of the ligands into a model of the D3R derived from the available atomic level structure, and comparisons to the receptor in the absence of ligand, were undertaken. They showed that, in contrast to the other antagonists, spiperone and haloperidol respectively increased the atomic distance between reference α carbon atoms of transmembrane domains IV and V and I and II, both of which provide key interfaces for D3R dimerization. These results offer a molecular explanation for the distinctive ability of spiperone and haloperidol to disrupt D3R dimerization.
Collapse
Affiliation(s)
- Sara Marsango
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
| | - Gianluigi Caltabiano
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Mireia Jiménez-Rosés
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Mark J Millan
- Institut de Recherches Servier, Centre for Innovation in Neuropsychiatry, 125 Chemin de Ronde, Croissy sur Seine, France, 78290
| | - John D Pediani
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Richard J Ward
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
| |
Collapse
|
15
|
Tidball P, Burn HV, Teh KL, Volianskis A, Collingridge GL, Fitzjohn SM. Differential ability of the dorsal and ventral rat hippocampus to exhibit group I metabotropic glutamate receptor-dependent synaptic and intrinsic plasticity. Brain Neurosci Adv 2017; 1. [PMID: 28413831 PMCID: PMC5390859 DOI: 10.1177/2398212816689792] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: The hippocampus is critically involved in learning and memory processes. Although once considered a relatively homogenous structure, it is now clear that the hippocampus can be divided along its longitudinal axis into functionally distinct domains, responsible for the encoding of different types of memory or behaviour. Although differences in extrinsic connectivity are likely to contribute to this functional differentiation, emerging evidence now suggests that cellular and molecular differences at the level of local hippocampal circuits may also play a role. Methods: In this study, we have used extracellular field potential recordings to compare basal input/output function and group I metabotropic glutamate receptor-dependent forms of synaptic and intrinsic plasticity in area CA1 of slices taken from the dorsal and ventral sectors of the adult rat hippocampus. Results: Using two extracellular electrodes to simultaneously record field EPSPs and population spikes, we show that dorsal and ventral hippocampal slices differ in their basal levels of excitatory synaptic transmission, paired-pulse facilitation, and EPSP-to-Spike coupling. Furthermore, we show that slices taken from the ventral hippocampus have a greater ability than their dorsal counterparts to exhibit long-term depression of synaptic transmission and EPSP-to-Spike potentiation induced by transient application of the group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine. Conclusions: Together, our results provide further evidence that the information processing properties of local hippocampal circuits differ in the dorsal and ventral hippocampal sectors, and that these differences may in turn contribute to the functional differentiation that exists along the hippocampal longitudinal axis.
Collapse
Affiliation(s)
- Patrick Tidball
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Hannah V Burn
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Kai Lun Teh
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Arturas Volianskis
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Graham L Collingridge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Stephen M Fitzjohn
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| |
Collapse
|
16
|
Nakazawa S, Nakamichi K, Imai H, Ichihara J. Effect of dopamine D4 receptor agonists on sleep architecture in rats. Prog Neuropsychopharmacol Biol Psychiatry 2015; 63:6-13. [PMID: 25985889 DOI: 10.1016/j.pnpbp.2015.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/28/2015] [Accepted: 05/11/2015] [Indexed: 01/11/2023]
Abstract
Dopamine plays a key role in the regulation of sleep-wake states, as revealed by the observation that dopamine-releasing agents such as methylphenidate have wake-promoting effects. However, the precise mechanisms for the wake-promoting effect produced by the enhancement of dopamine transmission are not fully understood. Although dopamine D1, D2, and D3 receptors are known to have differential effects on sleep architecture, the role of D4 receptors (D4Rs), and particularly the influence of D4R activation on the sleep-wake state, has not been studied so far. In this study, we investigated for the first time the effects of two structurally different D4R agonists, Ro 10-5824 and A-412997, on the sleep-wake states in rats. We found that both D4R agonists generally increased waking duration, and conversely, reduced non-rapid eye movement (NREM) sleep duration in rats. The onset of NREM sleep was also generally delayed. However, only the A-412997 agonist (but not the Ro 10-5824) influenced rapid eye movement sleep onset and duration. Furthermore, these effects were accompanied with an enhancement of EEG spectral power in the theta and the gamma bands. Our results suggest the involvement of dopamine D4R in the regulation of sleep-wake states. The activation of the D4R could enhance the arousal states as revealed by the behavioral and electrophysiological patterns in this study. Dopamine D4R may contribute to the arousal effects of dopamine-releasing agents such as methylphenidate.
Collapse
Affiliation(s)
- Shunsuke Nakazawa
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan.
| | - Keiko Nakamichi
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan
| | - Hideaki Imai
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan
| | - Junji Ichihara
- Drug Development Research Laboratories, Sumitomo Dainippon Pharma, Co., Ltd., Osaka, Japan
| |
Collapse
|
17
|
Janowsky A, Eshleman AJ, Johnson RA, Wolfrum KM, Hinrichs DJ, Yang J, Zabriskie TM, Smilkstein MJ, Riscoe MK. Mefloquine and psychotomimetics share neurotransmitter receptor and transporter interactions in vitro. Psychopharmacology (Berl) 2014; 231:2771-83. [PMID: 24488404 PMCID: PMC4097020 DOI: 10.1007/s00213-014-3446-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 01/07/2014] [Indexed: 11/25/2022]
Abstract
RATIONALE Mefloquine is used for the prevention and treatment of chloroquine-resistant malaria, but its use is associated with nightmares, hallucinations, and exacerbation of symptoms of post-traumatic stress disorder. We hypothesized that potential mechanisms of action for the adverse psychotropic effects of mefloquine resemble those of other known psychotomimetics. OBJECTIVES Using in vitro radioligand binding and functional assays, we examined the interaction of (+)- and (-)-mefloquine enantiomers, the non-psychotomimetic anti-malarial agent, chloroquine, and several hallucinogens and psychostimulants with recombinant human neurotransmitter receptors and transporters. RESULTS Hallucinogens and mefloquine bound stereoselectively and with relatively high affinity (K i = 0.71-341 nM) to serotonin (5-HT) 2A but not 5-HT1A or 5-HT2C receptors. Mefloquine but not chloroquine was a partial 5-HT2A agonist and a full 5-HT2C agonist, stimulating inositol phosphate accumulation, with similar potency and efficacy as the hallucinogen dimethyltryptamine (DMT). 5-HT receptor antagonists blocked mefloquine's effects. Mefloquine had low or no affinity for dopamine D1, D2, D3, and D4.4 receptors, or dopamine and norepinephrine transporters. However, mefloquine was a very low potency antagonist at the D3 receptor and mefloquine but not chloroquine or hallucinogens blocked [(3)H]5-HT uptake by the 5-HT transporter. CONCLUSIONS Mefloquine, but not chloroquine, shares an in vitro receptor interaction profile with some hallucinogens and this neurochemistry may be relevant to the adverse neuropsychiatric effects associated with mefloquine use by a small percentage of patients. Additionally, evaluating interactions with this panel of receptors and transporters may be useful for characterizing effects of other psychotropic drugs and for avoiding psychotomimetic effects for new pharmacotherapies, including antimalarial quinolines.
Collapse
Affiliation(s)
- Aaron Janowsky
- Research Service (R&D22), VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, OR, 97239, USA,
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
A selective role for dopamine D₄ receptors in modulating reward expectancy in a rodent slot machine task. Biol Psychiatry 2014; 75:817-24. [PMID: 24094512 DOI: 10.1016/j.biopsych.2013.08.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 07/15/2013] [Accepted: 08/01/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Cognitive distortions regarding gambling outcomes confer vulnerability to pathological gambling. Using a rat slot machine task (rSMT), we previously demonstrated that the nonspecific D₂ agonist quinpirole enhances erroneous expectations of reward on near-miss trials, suggesting a pivotal role for the D₂ receptor family in mediating the near-miss effect. Identifying which receptor subtype is involved could facilitate treatment development for compulsive slot machine play. METHODS Thirty-two male Long Evans rats learned the rSMT. Three flashing lights could be set to on or off. A win was signaled if all three lights were set to on, whereas any other light pattern indicated a loss. Rats then chose between responding on the collect lever, which delivered 10 sugar pellets on win trials but a 10-second time penalty on loss trials, or to start a new trial instead. Performance was assessed following systemic administration of selective D₂, D₃, and D₄ receptor ligands. RESULTS The selective D₂ antagonist L-741,626, the D₃ antagonist SB-277011-A, and the D₃ agonist PD128,907 had no effect. In contrast, the selective D₄ agonist PD168077 partially mimicked quinpirole's effects, increasing erroneous collect responses on nonwin trials, whereas the D₄ antagonist L-745,870 improved the error rate. L-745,870 was also the only antagonist that could attenuate the deleterious effects of quinpirole. CONCLUSIONS The dopamine D₄ receptor is critically involved in signaling reward expectancy in the rSMT. The ability of L-745,870 to reduce the classification of losses as wins suggests that D₄ antagonists could be effective in treating problematic slot machine play.
Collapse
|
19
|
Functional characterization of the short neuropeptide F receptor in the desert locust, Schistocerca gregaria. PLoS One 2013; 8:e53604. [PMID: 23308260 PMCID: PMC3537624 DOI: 10.1371/journal.pone.0053604] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 11/30/2012] [Indexed: 12/11/2022] Open
Abstract
Whereas short neuropeptide F (sNPF) has already been reported to stimulate feeding behaviour in a variety of insect species, the opposite effect was observed in the desert locust. In the present study, we cloned a G protein-coupled receptor (GPCR) cDNA from the desert locust, Schistocerca gregaria. Cell-based functional analysis of this receptor indicated that it is activated by both known isoforms of Schgr-sNPF in a concentration dependent manner, with EC50 values in the nanomolar range. This Schgr-sNPF receptor constitutes the first functionally characterized peptide GPCR in locusts. The in vivo effects of the sNPF signalling pathway on the regulation of feeding in locusts were further studied by knocking down the newly identified Schgr-sNPF receptor by means of RNA interference, as well as by means of peptide injection studies. While injection of sNPF caused an inhibitory effect on food uptake in the desert locust, knocking down the corresponding peptide receptor resulted in an increase of total food uptake when compared to control animals. This is the first comprehensive study in which a clearly negative correlation is described between the sNPF signalling pathway and feeding, prompting a reconsideration of the diverse roles of sNPFs in the physiology of insects.
Collapse
|
20
|
Koener B, Focant MC, Bosier B, Maloteaux JM, Hermans E. Increasing the density of the D2L receptor and manipulating the receptor environment are required to evidence the partial agonist properties of aripiprazole. Prog Neuropsychopharmacol Biol Psychiatry 2012; 36:60-70. [PMID: 21871520 DOI: 10.1016/j.pnpbp.2011.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/05/2011] [Accepted: 08/10/2011] [Indexed: 11/30/2022]
Abstract
The clinical efficacy of aripiprazole in the treatment of psychosis relies on a partial agonism at D2 receptors. As the expression of this receptor differs physiologically between pre- and post-synaptic sites and is affected by pathological conditions or pharmacological treatments, it appears difficult to predict the clinical response to partial agonists. In addition, the response to this novel antipsychotic was shown to depend on the cell-line and the pathway analyzed, suggesting a functional selective profile at the D2 receptor. This study aims at examining the influence of receptor density and ionic environment on the pharmacological properties of aripiprazole. A cell line was developed in which the expression of the recombinant D2 receptor can be tightly manipulated using doxycycline and sodium butyrate. The potency and efficacy of aripiprazole and other reference D2 receptor ligands were examined in [35S]GTPγS binding assays, in buffers containing either NaCl or N-methyl-D-glucamine (NMDG) which is proposed to enhance G protein coupling. Increasing the density of D2 receptors considerably enhanced the [35S]GTPγS binding induced by dopamine and the full agonist NPA. In maximally induced cells, the agonist properties of the partial agonist (-)-3-PPP was revealed in a buffer containing NaCl, whereas the response to aripiprazole was not evidenced. Substituting NMDG for NaCl promoted the response to dopamine and (-)3-PPP and was proven efficient to reveal the partial agonist profile of aripiprazole. While NMDG substitution for NaCl strongly enhanced receptor-G protein coupling, these ionic manipulations are likely to influence receptor conformations, thereby modulating the activation of signaling pathways. Our data obtained with partial agonists acting at the D2 receptor suggest that these changes in the experimental conditions could contribute to reveal the functional selective profile of GPCR ligands. They also emphasize that the properties of functional selective ligands do not only depend on receptor density but also on the surrounding environment which likely differs between brain structures.
Collapse
Affiliation(s)
- Beryl Koener
- Institute of Neuroscience (Ions), Group of Neuropharmacology, Université Catholique de Louvain, Avenue Mounier 53, bte B1.53.02, B-1200 Brussels, Belgium
| | | | | | | | | |
Collapse
|
21
|
Rondou P, Haegeman G, Van Craenenbroeck K. The dopamine D4 receptor: biochemical and signalling properties. Cell Mol Life Sci 2010; 67:1971-86. [PMID: 20165900 PMCID: PMC11115718 DOI: 10.1007/s00018-010-0293-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 01/19/2010] [Accepted: 01/26/2010] [Indexed: 01/20/2023]
Abstract
Dopamine is an important neurotransmitter that regulates several key functions in the brain, such as motor output, motivation and reward, learning and memory, and endocrine regulation. Dopamine does not mediate fast synaptic transmission, but rather modulates it by triggering slow-acting effects through the activation of dopamine receptors, which belong to the G-protein-coupled receptor superfamily. Besides activating different effectors through G-protein coupling, dopamine receptors also signal through interaction with a variety of proteins, collectively termed dopamine receptor-interacting proteins. We focus on the dopamine D4 receptor, which contains an important polymorphism in its third intracellular loop. This polymorphism has been the subject of numerous studies investigating links with several brain disorders, such as attention-deficit hyperactivity disorder and schizophrenia. We provide an overview of the structure, signalling properties and regulation of dopamine D4 receptors, and briefly discuss their physiological and pathophysiological role in the brain.
Collapse
Affiliation(s)
- Pieter Rondou
- Laboratory of Eukaryotic Gene Expression and Signal Transduction (LEGEST), Ghent University (UGent), K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
- Present Address: Center for Medical Genetics Ghent (CMGG), Ghent University Hospital, Medical Research Building, De Pintelaan 185, 9000 Ghent, Belgium
| | - Guy Haegeman
- Laboratory of Eukaryotic Gene Expression and Signal Transduction (LEGEST), Ghent University (UGent), K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Kathleen Van Craenenbroeck
- Laboratory of Eukaryotic Gene Expression and Signal Transduction (LEGEST), Ghent University (UGent), K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| |
Collapse
|
22
|
Newman-Tancredi A, Heusler P, Martel JC, Ormière AM, Leduc N, Cussac D. Agonist and antagonist properties of antipsychotics at human dopamine D4.4 receptors: G-protein activation and K+ channel modulation in transfected cells. Int J Neuropsychopharmacol 2008; 11:293-307. [PMID: 17897483 DOI: 10.1017/s1461145707008061] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Interaction at dopamine D4 receptors may improve cognitive function, which is highly impaired in individuals with schizophrenia, but comparative studies of recent antipsychotics in cellular models of D4 receptor activation are lacking. Here, we report the in-vitro profile of over 30 ligands at recombinant hD4.4 receptors. In [35S]GTPgammaS binding experiments using membranes of CHO-hD4.4 cells, apomorphine, preclamol and the selective D4 agonists, ABT724, CP226269, Ro-10-5824 and PD168077, behaved as partial agonists (Emax 20-60% vs. dopamine), whereas L745870 and RBI257, displayed antagonist properties. The 'conventional' antipsychotic, haloperidol and the 'atypicals', clozapine and risperidone, exhibited antagonist properties, while 'third generation' compounds bifeprunox, SLV313 and F15063, acted as partial agonists (10-30%). Aripiprazole and SSR181507 slightly stimulated [35S]GTPgammaS binding at micromolar concentrations. In Xenopus laevis oocytes co-expressing hD4.4 receptors with G-protein-coupled inwardly rectifying potassium (GIRK) channels, apomorphine, preclamol, ABT724, CP226269, and PD168077 stimulated GIRK currents (Emax 70-80%). The 5-HT1A receptor ligands, WAY100635 and flibanserin, also exhibited partial agonist activity (30% and 15%, respectively). Haloperidol, clozapine, olanzapine and nemonapride did not stimulate GIRK currents, whereas aripiprazole, bifeprunox, SLV313 and F15063, but not SSR181507, exhibited partial agonism (Emax 20-35%). In-vitro responses depended on experimental conditions: increasing NaCl concentration (30 mm to 100 mm) reduced agonist efficacy in [35S]GTPgammaS binding, whereas decreasing the amount of hD4.4 cRNA injected into oocytes (from 2.0 to 0.5 ng/oocyte) reduced agonist efficacy of several compounds. These data indicate that, unlike conventional or 'atypical' antipsychotics, several 'third generation' agents display D4 receptor partial agonism that may be sufficient to influence physiological D4 receptor activity in vivo.
Collapse
|
23
|
Tietze R, Löber S, Hübner H, Gmeiner P, Kuwert T, Prante O. Discovery of a dopamine D4 selective PET ligand candidate taking advantage of a click chemistry based REM linker. Bioorg Med Chem Lett 2008; 18:983-8. [DOI: 10.1016/j.bmcl.2007.12.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 12/06/2007] [Accepted: 12/11/2007] [Indexed: 11/25/2022]
|
24
|
Holden KG, Tidgewell K, Marquam A, Rothman RB, Navarro H, Prisinzano TE. Synthetic studies of neoclerodane diterpenes from Salvia divinorum: exploration of the 1-position. Bioorg Med Chem Lett 2007; 17:6111-5. [PMID: 17904842 PMCID: PMC2111044 DOI: 10.1016/j.bmcl.2007.09.050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 09/06/2007] [Accepted: 09/11/2007] [Indexed: 10/22/2022]
Abstract
Modification of the C-1 ketone of salvinorin A (2a) produces analogues with opioid antagonist properties. Of particular significance is the finding that 1-deoxo-1,10-dehydrosalvinorin A (11a) is a moderately potent antagonist at all three opioid receptor subtypes, and that herkinorin (2b), a mu agonist, is converted to a weak antagonist by removal of the C-1 ketone (3b and 11b). These observations suggest that the ketone of 2b is a key structural feature responsible for mu agonist activity.
Collapse
MESH Headings
- Binding, Competitive/drug effects
- Diterpenes/chemical synthesis
- Diterpenes/chemistry
- Diterpenes/pharmacology
- Diterpenes, Clerodane/chemical synthesis
- Diterpenes, Clerodane/chemistry
- Diterpenes, Clerodane/pharmacology
- Drug Evaluation, Preclinical
- Furans/chemical synthesis
- Furans/chemistry
- Furans/pharmacology
- Humans
- Molecular Structure
- Pyrones/chemical synthesis
- Pyrones/chemistry
- Pyrones/pharmacology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/genetics
- Recombinant Proteins/agonists
- Recombinant Proteins/antagonists & inhibitors
- Recombinant Proteins/genetics
- Salvia/chemistry
- Structure-Activity Relationship
Collapse
|
25
|
Carato P, Graulich A, Jensen N, Roth BL, Liégeois JF. Synthesis and in vitro binding studies of substituted piperidine naphthamides. Part II: Influence of the substitution on the benzyl moiety on the affinity for D2L, D4.2, and 5-HT2A receptors. Bioorg Med Chem Lett 2007; 17:1570-4. [PMID: 17251022 DOI: 10.1016/j.bmcl.2006.12.106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 12/20/2006] [Accepted: 12/26/2006] [Indexed: 10/23/2022]
Abstract
In continuation of our work on N-(piperidin-4-yl)-naphthamides, the effect of substituted benzyl groups on D(2L), D(4.2), and 5-HT(2A) receptor affinity was evaluated. In the 1-naphthamide series most compounds were highly selective for D(4.2) over D(2L) and 5-HT(2A) receptors. Halogen and methyl substitution in position 3 or 4 of the benzyl group increased D(4.2) affinity. In the 2-naphthamide series a similar high D(4.2) over D(2L) selectivity was retained while 5-HT(2A) affinity was increased. 3-Methoxy, 3-methyl, and 4-methyl substituents were favorable for D(4.2) affinity while halogens reduced affinity. 2-Naphthamides with a 3-bromo- or a 3-methyl group were mixed D(4.2)/5-HT(2A) ligands similar to their unsubstituted parent compound. All compounds from both series with significant affinity for D(4.2) and 5-HT(2A) receptors were antagonists.
Collapse
Affiliation(s)
- Pascal Carato
- Laboratoire de Chimie Thérapeutique, Université du Droit et de la Santé Lille II, rue du Professeur Laguesse 3, BP83, F-59006 Lille, France
| | | | | | | | | |
Collapse
|
26
|
Chen N, Reith MEA. Substrates and inhibitors display different sensitivity to expression level of the dopamine transporter in heterologously expressing cells. J Neurochem 2007; 101:377-88. [PMID: 17250655 DOI: 10.1111/j.1471-4159.2006.04384.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The use of heterologous expression systems for studying dopamine (DA) transporter (DAT) function has provided important information corroborating and complementing in situ obtained knowledge. Preliminary experiments with human embryonic kidney cells (HEK293) heterologously expressing varying amounts of DAT suggested fluctuations in the potency of cocaine in inhibiting DA uptake and led to the present systematic assessment of the impact of the density of DAT on its function. Transiently expressing intact HEK293 cells, transfected with increasing amounts of DAT cDNA, displayed increasing levels of surface DAT, binding of the cocaine analog [(3)H]2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane ([(3)H]CFT), and uptake of [(3)H]DA, [(3)H]N-methyl-4-phenylpyridinium ([(3)H]MPP(+)), [(3)H]norepinephrine, and [(3)H]serotonin. However, the amount of DAT cDNA and the DAT expression level required to produce 50% of maximal activity was threefold higher for CFT binding than for DA uptake. Increased DAT expression was accompanied by weakened potency in inhibiting [(3)H]DA uptake for cocaine, CFT, benztropine, and its analog JHW025, GBR 12909 and mazindol; their potency in inhibiting [(3)H]CFT binding was unaffected. Inhibition of uptake by the substrates DA, m-tyramine, d-amphetamine, or MPP(+) was also unaffected. Increasing DAT in stably expressing HEK293 cells by stimulation of gene expression with sodium butyrate also decreased the uptake inhibitory potency of a number of the above blockers without affecting the interaction between substrates and DAT. The present results prompt discussion of models explaining how factors regulating DAT expression at the plasma membrane can regulate DAT function and pharmacology.
Collapse
Affiliation(s)
- Nianhang Chen
- Department of Psychiatry, Millhauser Laboratories, New York University School of Medicine, New York, New York 10016, USA
| | | |
Collapse
|
27
|
Melis MR, Succu S, Sanna F, Melis T, Mascia MS, Enguehard-Gueiffier C, Hubner H, Gmeiner P, Gueiffier A, Argiolas A. PIP3EA and PD-168077, two selective dopamine D4 receptor agonists, induce penile erection in male rats: site and mechanism of action in the brain. Eur J Neurosci 2006; 24:2021-30. [PMID: 17067298 DOI: 10.1111/j.1460-9568.2006.05043.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PIP3EA (2-[4-(2-methoxyphenyl)piperazin-1-yl-methyl]imidazo[1,2-a]pyridine) and PD-168077 (N-[4-2-cyanophenylpiperazin-1-ylmethyl]-3-methylbenzamide maleate), two selective dopamine D4 agonists, administered systemically, intracerebroventricularly or into the paraventricular nucleus of the hypothalamus induce penile erection in male Sprague-Dawley rats. A U-inverted dose-response curve was found with either compound when given subcutaneously (1-100 microg/kg) or intracerebroventricularly (0.1-20 microg/rat), but not into the paraventricular nucleus (10-200 ng/rat). The pro-erectile effect of PIP3EA and of PD-168077 occurs concomitantly with an increased nitric oxide (NO) production in the paraventricular nucleus, as measured by the increased concentration of nitrites and nitrates found in the dialysate obtained from the paraventricular nucleus by intracerebral microdialysis. These effects of PIP3EA and PD-168077 were reduced by L-745,870 (3-[4-(4-chlorophenyl)piperazin-1-ylmethyl]-1H-pyrrolo[2,3-b]pyridine trihydrochloride), a selective dopamine D4 receptors antagonist, by omega-conotoxin, a blocker of voltage-dependent Ca2+ channels of the N-type, by S-methyl-thiocitrulline, a neuronal nitric oxide synthase inhibitor, and by d(CH2)5Tyr(Me)2-Orn8-vasotocin, an oxytocin receptor antagonist, given into the lateral ventricles, but not into the paraventricular nucleus. Comparison of the dose-response curves of PIP3EA and PD-168077 revealed that PIP3EA is as potent as PD-168077 when given into the paraventricular nucleus, but more potent when given systemically. However, both compounds are less efficacious (e.g. induce a lower number of penile erection episodes) than apomorphine, a classical mixed dopamine receptor agonist, irrespective of the route of administration. These results confirm previous findings showing that central D4 receptors mediate penile erection and show that dopamine D4 receptor agonists act in the paraventricular nucleus to facilitate penile erection by increasing central oxytocinergic neurotransmission.
Collapse
Affiliation(s)
- Maria Rosaria Melis
- Bernard B. Brodie Department of Neuroscience, Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Mueller A, Mahmoud NG, Strange PG. Diverse signalling by different chemokines through the chemokine receptor CCR5. Biochem Pharmacol 2006; 72:739-48. [PMID: 16844091 DOI: 10.1016/j.bcp.2006.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Revised: 05/30/2006] [Accepted: 06/01/2006] [Indexed: 11/20/2022]
Abstract
We have investigated the signalling properties of the chemokine receptor, CCR5, using several assays for agonism: stimulation of changes in intracellular Ca(2+) or CCR5 internalisation in CHO cells expressing CCR5 or stimulation of [(35)S]GTPgammaS binding in membranes of CHO cells expressing CCR5. Four isoforms of the chemokine CCL3 with different amino termini (CCL3, CCL3(2-70), CCL3(5-70), CCL3L1) were tested in these assays in order to probe structure/activity relationships. Each isoform exhibited agonism. The pattern of agonism (potency, maximal effect) was different in the three assays, although the rank order was the same with CCL3L1 being the most potent and efficacious. The data show that the amino terminus of the chemokine is important for signalling. A proline at position 2 (CCL3L1) provides for high potency and efficacy but the isoform with a serine at position 2 (CCL3(2-70)) is as efficacious in some assays showing that the proline is not the only determinant of high efficacy. We also increased the sensitivity of CCR5 signalling by treating cells with sodium butyrate, thus increasing the receptor/G protein ratio. This allowed the detection of a change in intracellular Ca(2+) after treatment with CCL7 and Met-RANTES showing that these ligands possess measurable but low efficacy. This study therefore shows that sodium butyrate treatment increases the sensitivity of signalling assays and enables the detection of efficacy in ligands previously considered as antagonists. The use of different assay systems, therefore, provides different estimates of efficacy for some ligands at this receptor.
Collapse
Affiliation(s)
- Anja Mueller
- School of Animal and Microbial Sciences, University of Reading, PO Box 228, Reading, RG6 6AJ, UK
| | | | | |
Collapse
|
29
|
Löber S, Hübner H, Gmeiner P. Synthesis and biological investigations of dopaminergic partial agonists preferentially recognizing the D4 receptor subtype. Bioorg Med Chem Lett 2006; 16:2955-9. [PMID: 16563764 DOI: 10.1016/j.bmcl.2006.02.075] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 02/24/2006] [Accepted: 02/25/2006] [Indexed: 11/17/2022]
Abstract
Aminomethyl-substituted biaryls bearing a pyrazole or triazole moiety were synthesized and investigated for dopamine and serotonin receptor binding. The N-arylpyrazoles 3b,f,g and 4 revealed Ki values in the subnanomolar range (0.28-0.70 nM) for the dopamine D4 receptor subtype. Employing both mitogenesis and GTPgammaS assays, ligand efficacy was evaluated indicating partial agonist properties. Interestingly, the tetrahydropyrimidine 4 (FAUC 2020) displayed significant intrinsic selectivity for D2(long) over D2(short).
Collapse
Affiliation(s)
- Stefan Löber
- Department of Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D-91052 Erlangen, Germany
| | | | | |
Collapse
|
30
|
Zhang A, Kan Y, Li F. Recent advances towards the discovery of dopamine receptor ligands. Expert Opin Ther Pat 2006. [DOI: 10.1517/13543776.16.5.587] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
31
|
Abstract
Specific protein G-coupled receptors mediate the effects of dopamine in its projection areas. Five dopaminergic receptors have been cloned, characterized and classified in two families, the D1-like family (D1- and D5-receptor subtypes) and the D2-like family (D2-, D3- and D4-receptor subtypes). These five dopamine receptor subtypes are characterized by their diversity in terms of transduction, distribution, pharmacology, functions, and regulation, leading to pleiotropic pathophysiological and pharmacological involvements in neuropsychiatric disorders underlain by a deregulation of the dopaminergic system.
Collapse
Affiliation(s)
- R Bordet
- EA1046, Laboratoire de Pharmacologie, Faculté de Médecine, Université de Lille 2, Lille
| |
Collapse
|
32
|
Nakane M, Cowart MD, Hsieh GC, Miller L, Uchic ME, Chang R, Terranova MA, Donnelly-Roberts DL, Namovic MT, Miller TR, Wetter JM, Marsh K, Stewart AO, Brioni JD, Moreland RB. 2-[4-(3,4-Dimethylphenyl)piperazin-1-ylmethyl]-1H benzoimidazole (A-381393), a selective dopamine D4 receptor antagonist. Neuropharmacology 2005; 49:112-21. [PMID: 15992586 DOI: 10.1016/j.neuropharm.2005.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Revised: 12/24/2004] [Accepted: 02/04/2005] [Indexed: 11/17/2022]
Abstract
2-[4-(3,4-Dimethylphenlyl)piperazin-1-ylmethyl]-1H benzoimidazole (A-381393) was identified as a potent dopamine D4 receptor antagonist with excellent receptor selectivity. [3H]-spiperone competition binding assays showed that A-381393 potently bound to membrane from cells expressing recombinant human dopamine D4.4 receptor (Ki=1.5 nM), which was 20-fold higher than that of clozapine (Ki=30.4 nM). A-381393 exhibited highly selective binding for the dopamine D4.4 receptor (>2700-fold) when compared to D1, D2, D3 and D5 dopamine receptors. Furthermore, in comparison to clozapine and L-745870, A-381393 exhibits better receptor selectivity, showing no affinity up to 10 microM for a panel of more than 70 receptors and channels, with the exception of moderate affinity for 5-HT2A (Ki=370 nM). A-381393 potently inhibited the functional activity of agonist-induced GTP-gamma-S binding assay and 1 microM dopamine induced-Ca2+ flux in human dopamine D4.4 receptor expressing cells, but not in human dopamine D2L or D3 receptor cells. In contrast to L-745870, A-381393 did not exhibit any significant intrinsic activity in a D4.4 receptor. In vivo, A-381393 has good brain penetration after subcutaneous administration. A-381393 inhibited penile erection induced by the selective D4 agonist PD168077 in conscious rats. Thus, A-381393 is a novel selective D4 antagonist that will enhance the ability to study dopamine D4 receptors both in vitro and in vivo.
Collapse
Affiliation(s)
- Masaki Nakane
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Nickolls SA, Strange PG. The influence of G protein subtype on agonist action at D2 dopamine receptors. Neuropharmacology 2005; 47:860-72. [PMID: 15527820 DOI: 10.1016/j.neuropharm.2004.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 05/28/2004] [Accepted: 06/18/2004] [Indexed: 10/26/2022]
Abstract
In previous studies, we have shown that agonists influence the ability of D2 dopamine receptors to couple to G proteins and here we extend this work. The human D2Short dopamine receptor and a natural polymorphism of this D(2Short)(Ser311Cys), have been studied by co-expressing the receptors in insect cells with Gbeta1gamma2 and either Galpha(o), Galpha(i1), Galpha(i2) or Galpha(i3) G protein subunits. These preparations have been used to study the G protein coupling profiles of the two receptors and the influence of agonists. Receptor/G protein coupling was analysed in dopamine/[3H]spiperone competition binding experiments and through stimulation of [35S]GTPgammaS binding. Although the Ser311Cys polymorphism itself had no appreciable effect on the G protein coupling specificity of the D2 receptor, agonist stimulation of [35S]GTPgammaS binding, revealed that both dopamine and (+)-3PPP showed a clear preference for Galpha(o) compared to the Galpha(i) subtypes, but quinpirole did not. These results indicate that agonists are able to stabilise different receptor conformations with different abilities to couple to G proteins.
Collapse
Affiliation(s)
- Sarah A Nickolls
- School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, UK
| | | |
Collapse
|
34
|
Moreland RB, Nakane M, Donnelly-Roberts DL, Miller LN, Chang R, Uchic ME, Terranova MA, Gubbins EJ, Helfrich RJ, Namovic MT, El-Kouhen OF, Masters JN, Brioni JD. Comparative pharmacology of human dopamine D(2)-like receptor stable cell lines coupled to calcium flux through Galpha(qo5). Biochem Pharmacol 2004; 68:761-72. [PMID: 15276084 DOI: 10.1016/j.bcp.2004.05.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Accepted: 05/11/2004] [Indexed: 11/23/2022]
Abstract
The goal of this study was to develop a new approach to study the pharmacology of the dopamine D(4) receptor that could be used in comparative studies with dopamine D(2) and D(3) receptors. Stable HEK-293 cell lines co-expressing recombinant human D(2L), D(3) or D(4) receptors along with Galpha(qo5) cDNA were prepared. Dopamine induced a robust, transient calcium signal in these cell lines with EC(50)s for D(2L), D(3) and D(4) of 18.0, 11.9 and 2.2 nM, respectively. Reported D(4)-selective agonists CP226269 and PD168077 were potent, partial D(4) agonists exhibiting 31-1700-fold selectivity for D(4) over D(3) or D(2). Non-selective D(2)-like agonists apomorphine and quinpirole showed full efficacy but did not discriminate across the three receptors. D(3)-selective agonists 7-hydroxy-DPAT and PD128907 were potent but non-selective D(2)-like agonists. The reported D(3) partial agonist BP-897 exhibited minimal agonist activity at D(3) but was a potent D(3) antagonist and a partial D(4) agonist. Other D(2)-like antagonists, haloperidol, clozapine, and domperidone showed concentration-dependent inhibition of dopamine responses at all three receptors with K(i) ranging from 0.05 to 48.3 nM. The D(3) selective antagonist S33084 and D(4)-selective antagonist L-745870 were highly selective for D(3) and D(4) receptors with K(b) of 0.7 and 0.1 nM, respectively. Stable co-expression of D(2)-like receptors with chimeric Galpha(qo5) proteins in HEK-293 cells is an efficient method to study receptor activation in a common cellular background and an efficient method for direct comparison of ligand affinity and efficacy across human D(2L), D(3) and D(4) receptors.
Collapse
Affiliation(s)
- Robert B Moreland
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Boeckler F, Russig H, Zhang W, Löber S, Schetz J, Hübner H, Ferger B, Gmeiner P, Feldon J. FAUC 213, a highly selective dopamine D4 receptor full antagonist, exhibits atypical antipsychotic properties in behavioural and neurochemical models of schizophrenia. Psychopharmacology (Berl) 2004; 175:7-17. [PMID: 15007532 DOI: 10.1007/s00213-004-1782-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2003] [Accepted: 11/10/2003] [Indexed: 11/25/2022]
Abstract
RATIONALE 2-[4-(4-Chlorophenyl)piperazin-1-ylmethyl]pyrazolo[1,5-a]pyridine (FAUC 213) is a highly selective antagonist at the dopamine D(4) receptor subtype. It was designed as a derivative of two partial antagonists and has been proven to be a complete antagonist in mitogenesis assay. OBJECTIVES In the present study, FAUC 213 was examined for antipsychotic properties in animal models of behavioural neurobiology and neurochemistry. METHODS Different concentrations of FAUC 213 were screened for effects on spontaneous, as well as amphetamine-induced, locomotor activity and apomorphine-induced prepulse disruption. The liability of causing extrapyramidal side effects was investigated in models of catalepsy and by high-performance liquid chromatography (HPLC) detection of dopamine turnover in several brain regions. The application schedule was validated, and the bioavailability of the compound determined, by means of a HPLC-pharmacokinetic study. RESULTS A significant effect in both the reduction of amphetamine-induced locomotor hyperactivity and the restoration of apomorphine-disrupted prepulse inhibition was found at 30 mg/kg. This dose proved not to be high enough to induce catalepsy or to increase dopamine turnover in the dorsal striatum, nucleus accumbens and medial prefrontal cortex. The selective D(4) antagonist FAUC 213, therefore, is not believed to mediate the above-mentioned effects via D(2) receptor antagonism, but a partial involvement of 5-HT(2)- and alpha(1)-receptors cannot be ruled out at present. CONCLUSIONS We have gathered evidence that FAUC 213 exhibits atypical antipsychotic characteristics.
Collapse
Affiliation(s)
- Frank Boeckler
- Laboratory of Behavioural Neurobiology, Swiss Federal Institute of Technology Zürich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Matulenko MA, Hakeem AA, Kolasa T, Nakane M, Terranova MA, Uchic ME, Miller LN, Chang R, Donnelly-Roberts DL, Namovic MT, Moreland RB, Brioni JD, Stewart AO. Synthesis and functional activity of (2-aryl-1-piperazinyl)-N-(3-methylphenyl)acetamides: selective dopamine D4 receptor agonists. Bioorg Med Chem 2004; 12:3471-83. [PMID: 15186832 DOI: 10.1016/j.bmc.2004.04.035] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Revised: 04/23/2004] [Accepted: 04/28/2004] [Indexed: 11/27/2022]
Abstract
Diaryl piperazine acetamides were identified as potent and selective dopamine D(4) receptor agonists. Our strategy is based on an amide bond reversal of an acid sensitive, dopamine D(4) receptor partial agonist, PD 168077. This reversal provided compounds with excellent potency and improved stability. Systematic evaluation of the substitution on the aryl piperazine portion revealed a significant effect on functional activity. The synthesis and biological activity of these new dopamine D(4) agonists is discussed.
Collapse
Affiliation(s)
- Mark A Matulenko
- Neuroscience Research, Global Pharmaceutical Research, Abbott Laboratories, Abbott Park, IL 60064, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Wong AHC, Van Tol HHM. The dopamine D4 receptors and mechanisms of antipsychotic atypicality. Prog Neuropsychopharmacol Biol Psychiatry 2003; 27:1091-9. [PMID: 14642969 DOI: 10.1016/j.pnpbp.2003.09.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The dopamine D4 receptor (D4) is a target for most common neuroleptic medications. After its initial discovery, it was found to possess the highest affinity of all dopamine receptor subtypes for the archetypical, atypical, antipsychotic clozapine. Nevertheless, initial clinical trials have not provided evidence that this receptor is a primary target for antipsychotic drugs. Considering the accumulated in vivo evidence that at least a subgroup of psychotic patients have altered dopamine signaling, all dopamine receptor subtypes likely contribute to the phenotypic expression of schizophrenia. New insights into the function of this receptor and its role in the modulation of excitatory signaling support the view that this dopamine receptor may affect attention and cognition. In this review, the authors outline some recent developments that provide insight into D4 receptor physiology, function and its possible relationship to schizophrenia treatment.
Collapse
Affiliation(s)
- Albert H C Wong
- Laboratory of Molecular Neurobiology, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada M5T 1R8
| | | |
Collapse
|
38
|
Ge H, Olli-Lähdesmäki T, Kallio J, Scheinin M. alpha 2B-Adrenoceptor levels govern agonist and inverse agonist responses in PC12 cells. Biochem Biophys Res Commun 2003; 308:12-8. [PMID: 12890472 DOI: 10.1016/s0006-291x(03)01320-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Receptor density is an important determinant of cellular effector responses to receptor activation. We analysed cytosolic Ca(2+) responses to alpha(2)-adrenergic agents in PC12 cells expressing human alpha(2B)-adrenergic receptors (AR) at two densities (3.8 and 1.3 pmol/mg protein). The efficacy (E(max)) of agonists was greater in cells with higher receptor expression; while the potency (EC(50)) of norepinephrine and oxymetazoline was independent of alpha(2B)-AR levels. Several classical alpha(2)-AR antagonists behaved as either partial or inverse agonists in a receptor density-dependent fashion. No apparent structural similarities were found among the inverse agonists, precluding simple predictions of inverse agonist activity. Transfected PC12 cells expressing alpha(2B)-AR at relatively high density would be a useful approach to screen inverse agonists for this class of receptors. Our results further indicate that receptor density significantly influences the properties of ligands, not only of partial agonists as predicted by classical receptor theory, but also of antagonists and full agonists.
Collapse
Affiliation(s)
- Huifang Ge
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Itäinen Pitkäkatu 4, FIN-20520, Turku, Finland
| | | | | | | |
Collapse
|
39
|
Patel S, Chapman KL, Marston D, Hutson PH, Ragan CI. Pharmacological and functional characterisation of dopamine D4 receptors in the rat retina. Neuropharmacology 2003; 44:1038-46. [PMID: 12763097 DOI: 10.1016/s0028-3908(03)00112-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the retina, activation of dopamine receptors, particularly the D2-like family (D2, D3, D4 receptor subtypes), with quinpirole suppresses the light sensitive cAMP pool and inhibits melatonin synthesis in photoreceptor cells. We have characterised rat retinal D4 receptors using the D4 selective radioligand [(125)I] L-750667 which bound specifically and saturably to rat retinal membranes with high affinity (K(d) 0.06+/-0.02 nM) and exhibited a D4 receptor pharmacology. Comparison of the binding kinetics of [(125)I] L-750667 and [(3)H] spiperone revealed B(max) values of 134+/-27 fmol/mg and 219+/-47 fmol/mg respectively, indicating that the dopamine D4 receptor is a major component of D2-like dopamine receptors in the rat retina. Modulation of retinal cAMP levels by quinpirole was used to evaluate the functional relevance of rat retinal dopamine D4 receptors. Quinpirole (0.03-3 micro ) produced a dose-related decrease of the light sensitive cAMP pool which was reversed by haloperidol, clozapine and the D4 selective antagonist, L-745870 with a rank order of potency suggesting that the quinpirole effect is due to activation of the dopamine D4 receptors. The D2 selective ligand L-741626 had no effect on the quinpirole response confirming that the D4 receptor is the major receptor subtype mediating dopamine induced suppression of adenylate cyclase in the retina.
Collapse
Affiliation(s)
- Smita Patel
- Merck Sharp and Dohme, Neuroscience Research Centre, Terlings Park, Eastwick Rd, Harlow, Essex, UK.
| | | | | | | | | |
Collapse
|
40
|
Boström J, Böhm M, Gundertofte K, Klebe G. A 3D QSAR study on a set of dopamine D4 receptor antagonists. JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES 2003; 43:1020-7. [PMID: 12767161 DOI: 10.1021/ci034004+] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The molecular alignments obtained from a previously reported pharmacophore model have been employed in a three-dimensional quantitative structure-activity relationship (3D QSAR) study, to obtain a more detailed insight into the structure-activity relationships for D(2) and D(4) receptor antagonists. The frequently applied CoMFA method and the related CoMSIA method were used. Statistically significant models have been derived with these two methods, based on a set of 32 structurally diverse D(2) and D(4) receptor antagonists. The CoMSIA and the CoMFA methods produced equally good models expressed in terms of q(2) values. The predictive power of the derived models were demonstrated to be high. Graphical interpretation of the results, provided by the CoMSIA method, brings to light important structural features of the compounds related to either low- or high-affinity D(2) or D(4) antagonism. The results of the 3D QSAR studies indicate that bulky N-substituents decrease D(2) binding, whereas D(4) binding is enhanced. Electrostatically favorable and unfavorable regions exclusive to D(2) receptor binding were identified. Likewise, certain hydrogen-bond acceptors can be used to lower D(2) affinity. These observations may be exploited for the design of novel dopamine D(4) selective antagonists.
Collapse
Affiliation(s)
- Jonas Boström
- H. Lundbeck A/S, Ottiliavej 9, DK-2500 Copenhagen-Valby, Denmark.
| | | | | | | |
Collapse
|
41
|
Nickolls SA, Strange PG. Interaction of the D2short dopamine receptor with G proteins: analysis of receptor/G protein selectivity. Biochem Pharmacol 2003; 65:1139-50. [PMID: 12663049 DOI: 10.1016/s0006-2952(03)00040-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human D(2short) (D(2S)) dopamine receptor has been expressed together with the G proteins Gi2 and Go in insect cells using the baculovirus system. Levels of receptor were determined using [3H]spiperone binding. Levels of G protein heterotrimer were determined using quantitative Western blot and using [35S]GTPgammaS saturation binding experiments. Levels of the receptor and G protein and the receptor/G protein ratio were similar in the two preparations. Stimulation of [35S]GTPgammaS binding by a range of agonists occurred with higher relative efficacy and in some cases higher potency in the preparation expressing Go, indicating that interaction of the D(2S) receptor is more efficient with this G protein. The effects of various G protein-selective agents on 10,11-dihydroxy-N-n-propylnorapomorphine ([3H]NPA) binding were used to examine the receptor/G protein complex in the two preparations. Suramin inhibited [3H]NPA binding with slightly higher potency in the Gi2 preparation, whereas GppNHp inhibited [3H]NPA binding with greater potency ( approximately 6-fold) in the Go preparation. This may imply that the G protein is more readily activated in the D(2S)/Go preparation. [3H]Spiperone binding occurred with an increased B(max) in the presence of suramin in the Go preparation but not in the Gi2 preparation, suggesting a higher affinity interaction between the free receptor and this G protein. It is concluded that the higher efficiency activation of Go by the D(2S) receptor may be a function of higher affinity receptor/G protein interaction as well as a greater ability to activate the G protein.
Collapse
Affiliation(s)
- Sarah A Nickolls
- School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, UK
| | | |
Collapse
|
42
|
Cha MY, Choi BC, Kang KH, Pae AN, Choi KI, Cho YS, Koh HY, Lee HY, Jung D, Kong JY. Design and synthesis of a piperazinylalkylisoxazole library for subtype selective dopamine receptor ligands. Bioorg Med Chem Lett 2002; 12:1327-30. [PMID: 11992769 DOI: 10.1016/s0960-894x(02)00179-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A piperazinylbutylisoxazole libary was designed, synthesized and screened for the binding affinities to dopamine D2, D3, and D4 receptors. Several ligands were identified to possess high binding affinity and selectivity for the D3 and D4 receptors over the D2 receptor. Compounds 6s and 6t showed K(i) values of 2.6 nM and 3.9 nM for the D3 receptor with 46- and 50-fold selectivity over the D2 receptor, respectively.
Collapse
Affiliation(s)
- Mi Young Cha
- Biochemicals Research Center, Korea Institute of Science and Technology, Cheongrayang, 130-650, Seoul, South Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Einsiedel J, Hübner H, Gmeiner P. Benzamide bioisosteres incorporating dihydroheteroazole substructures: EPC synthesis and SAR leading to a selective dopamine D4 receptor partial agonist (FAUC 179). Bioorg Med Chem Lett 2001; 11:2533-6. [PMID: 11549463 DOI: 10.1016/s0960-894x(01)00484-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Conformationally restricted benzamide bioisosteres were investigated when the chiral phenyldihydroimidazole derivative 4e (FAUC 179) showed strong and highly selective dopamine D4 receptor binding (K(i)high=0.95nM). Mitogenesis experiments indicated partial agonist properties (42%). EPC syntheses of the target compounds of type 4 were performed starting from alpha-amino acids.
Collapse
Affiliation(s)
- J Einsiedel
- Department of Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D-91052, Erlangen, Germany
| | | | | |
Collapse
|
44
|
Löber S, Hübner H, Utz W, Gmeiner P. Rationally based efficacy tuning of selective dopamine d4 receptor ligands leading to the complete antagonist 2-[4-(4-chlorophenyl)piperazin-1-ylmethyl]pyrazolo[1,5-a]pyridine (FAUC 213). J Med Chem 2001; 44:2691-4. [PMID: 11495580 DOI: 10.1021/jm015522j] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Structure dependent efficacy studies in the field of selective D4 ligands led to the 2-aminomethyl substituted azaindole 2 (FAUC 213) that displayed strong D4 binding, high subtype selectivity, and complete antagonist properties in ligand-induced mitogenesis experiments. According to our schematic molecular model, the intrinsic activity of the regioisomers investigated is controlled by the ability of the heterocyclic unit to interact with both elements of the D4 binding-site crevice, the aromatic microdomain in TM6, and a serine residue in TM5.
Collapse
Affiliation(s)
- S Löber
- Department of Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D-91052 Erlangen, Germany
| | | | | | | |
Collapse
|
45
|
Nash MS, Selkirk JV, Gaymer CE, Challiss RA, Nahorski SR. Enhanced inducible mGlu1alpha receptor expression in Chinese hamster ovary cells. J Neurochem 2001; 77:1664-7. [PMID: 11413250 DOI: 10.1046/j.1471-4159.2001.00405.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Inducible expression of the group-I metabotropic glutamate receptor (mGlu1alpha) in Chinese hamster ovary cells allows for the study of receptor density dependent effects. However, expression levels attainable with this system are lower than those reported for various brain regions and achieved by conventional (constitutive) transfection. Thus, direct comparison of mGlu1alpha receptor-mediated responses in this inducible expression system with those for receptors expressed heterologously or in vivo is compounded. We show here that inducible expression can be selectively augmented by butyrate pretreatment to levels approaching those reported for cerebral tissue. Enhanced mGlu1alpha receptor protein levels, agonist-induced inositol phosphate accumulation, as well as single-cell inositol 1,4,5-trisphosphate production and intracellular Ca(2+) mobilization occurred following co-induction with butyrate. In contrast, endogenous purinoceptor function was unaffected. Importantly, the ability to titrate receptor expression by varying isopropyl beta-thiogalactoside concentration was retained. Sodium butyrate thus offers a simple and convenient method to enhance inducible gene expression to levels found in vivo.
Collapse
Affiliation(s)
- M S Nash
- Department of Cell Physiology and Pharmacology, University of Leicester, UK.
| | | | | | | | | |
Collapse
|
46
|
Waddington JL, Clifford JJ, McNamara FN, Tomiyama K, Koshikawa N, Croke DT. The psychopharmacology-molecular biology interface: exploring the behavioural roles of dopamine receptor subtypes using targeted gene deletion ('knockout'). Prog Neuropsychopharmacol Biol Psychiatry 2001; 25:925-64. [PMID: 11383985 DOI: 10.1016/s0278-5846(01)00152-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the absence of selective agonists and antagonists able to discriminate between individual members of the D1-like and D2-like families of dopamine receptor subtypes, functional parcellation has remained problematic. 'Knockout' of these subtypes by targeted gene deletion offers a new approach to evaluating their roles in the regulation of behaviour. Like any new technique, 'knockout' has associated with it a number of methodological limitations that are now being addressed in a systematic manner. Studies on the phenotype of D1(A/1), D(1B/5), D2, D3 and D4 'knockouts' at the level of spontaneous and agonist/antagonist-induced behaviour are reviewed, in terms of methodological issues, neuronal implications and potential clinical relevance. Dopamine receptor subtype 'knockout' is a nascent technology that is now beginning to fulfil its potential. It is being complemented by more systematic phenotypic characterisation at the level of behaviour and additional, molecular biologically-based approaches.
Collapse
Affiliation(s)
- J L Waddington
- Department of Clinical Pharmacology, Royal College of Surgeons in Ireland, Dublin
| | | | | | | | | | | |
Collapse
|
47
|
Rowley M, Bristow LJ, Hutson PH. Current and novel approaches to the drug treatment of schizophrenia. J Med Chem 2001; 44:477-501. [PMID: 11170639 DOI: 10.1021/jm0002432] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
MESH Headings
- Animals
- Antipsychotic Agents/adverse effects
- Antipsychotic Agents/pharmacology
- Antipsychotic Agents/therapeutic use
- Cholinergic Agonists/adverse effects
- Cholinergic Agonists/pharmacology
- Cholinergic Agonists/therapeutic use
- Disease Models, Animal
- Dopamine Antagonists/adverse effects
- Dopamine Antagonists/pharmacology
- Dopamine Antagonists/therapeutic use
- Enzyme Inhibitors/adverse effects
- Enzyme Inhibitors/pharmacology
- Enzyme Inhibitors/therapeutic use
- Excitatory Amino Acid Antagonists/adverse effects
- Excitatory Amino Acid Antagonists/pharmacology
- Excitatory Amino Acid Antagonists/therapeutic use
- Humans
- Mice
- Mice, Transgenic
- Nitric Oxide Synthase/antagonists & inhibitors
- Receptor, Serotonin, 5-HT2A
- Receptors, AMPA/antagonists & inhibitors
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D4
- Receptors, Metabotropic Glutamate/antagonists & inhibitors
- Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors
- Receptors, Neurotensin/agonists
- Receptors, Serotonin/drug effects
- Schizophrenia/drug therapy
- Schizophrenia/etiology
- Schizophrenia/metabolism
- Serotonin Antagonists/adverse effects
- Serotonin Antagonists/pharmacology
- Serotonin Antagonists/therapeutic use
Collapse
Affiliation(s)
- M Rowley
- Merck Sharp and Dohme, The Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
| | | | | |
Collapse
|
48
|
Hübner H, Kraxner J, Gmeiner P. Cyanoindole derivatives as highly selective dopamine D(4) receptor partial agonists: solid-phase synthesis, binding assays, and functional experiments. J Med Chem 2000; 43:4563-9. [PMID: 11087581 DOI: 10.1021/jm0009989] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Traceless linking of diethoxymethyl (DEM)-protected 5- and 6-cyanoindoles and subsequent incorporation of phenylpiperazine derivatives led to the 2- and 3-piperazinylmethyl-substituted cyanoindoles 3a-m. Dopamine receptor binding studies on the final products 3a-m clearly indicated strong and selective recognition of the D(4) subtype which is known as a promising target for the treatment of neuropsychiatric disorders. The most interesting binding properties were observed for the 2-aminomethyl-5-cyanoindoles FAUC 299 (3f) and FAUC 316 (3j) (K(i) = 0.52 and 1.0 nM, respectively) when the fluoro derivative 3j proved extraordinary selectivity over D(1), D(2long), D(2short), and D(3) (>8600). To determine ligand efficacy, mitogenesis experiments were performed indicating partial agonist effects for the test compounds 3f,j (35% and 30%, when compared to the full agonist quinpirole).
Collapse
Affiliation(s)
- H Hübner
- Department of Medicinal Chemistry, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D-91052 Erlangen, Germany
| | | | | |
Collapse
|
49
|
Abstract
The last ten years have witnessed the generation of a large amount of information on the neurobiology of dopamine receptors. Molecular biology and pharmacology studies have revealed existence of at least five dopamine receptor subtypes, namely D1, D2, D3, D4 and D5. The discovery of D4 receptors and the putative affinity of clozapine for D4 receptors have kindled development of selective D4 receptor antagonists for the treatment of schizophrenia. Studies on expression of D4 receptor proteins have shown selective localisation of D4 receptors in mesolimbic/mesocortical areas which could probably explain the lack of motor side effects with atypical antipsychotics like clozapine and olanzapine. However, neuropathological and genetic studies on the role of D4 receptors in the pathophysiology of schizophrenia and preliminary clinical studies with selective D4 receptor antagonists have been disappointing. There have been, however, complimentary findings between selective D4 receptor antagonism and genetic approaches such as antisense treatment or gene targeting. The therapeutic potential of D4 receptors as a target for developing antipsychotics will be known only when selective D4 receptor-antagonists with varying D2/D4 and D4/5-HT2A ratios are developed and tested in psychiatric patients.
Collapse
Affiliation(s)
- S K Kulkarni
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India.
| | | |
Collapse
|
50
|
Abstract
Dopamine is an important neurotransmitter involved in motor control, endocrine function, reward, cognition and emotion. Dopamine receptors belong to the superfamily of G protein-coupled receptors and play a crucial role in mediating the diverse effects of dopamine in the central nervous system (CNS). The dopaminergic system is implicated in disorders such as Parkinson's disease and addiction, and is the major target for antipsychotic medication in the treatment of schizophrenia. Molecular cloning studies a decade ago revealed the existence of five different dopamine receptor subtypes in mammalian species. While the presence of the abundantly expressed dopamine D(1) and D(2) receptors was predicted from biochemical and pharmacological work, the cloning of the less abundant dopamine D(3), D(4) and D(5) receptors was not anticipated. The identification of these novel dopamine receptor family members posed a challenge with respect to determining their precise physiological roles and identifying their potential as therapeutic targets for dopamine-related disorders. This review is focused on the accomplishments of one decade of research on the dopamine D(4) receptor. New insights into the biochemistry of the dopamine D(4) receptor include the discovery that this G protein-coupled receptor can directly interact with SH3 domains. At the physiological level, converging evidence from transgenic mouse work and human genetic studies suggests that this receptor has a role in exploratory behavior and as a genetic susceptibility factor for attention deficit hyperactivity disorder.
Collapse
Affiliation(s)
- J N Oak
- Laboratory of Molecular Neurobiology, Centre for Addiction and Mental Health, Clarke Div., 250 College street, M5T 1R8, Toronto, Ontario, Canada
| | | | | |
Collapse
|