51
|
Szabo M, Huynh T, Valant C, Lane JR, Sexton PM, Christopoulos A, Capuano B. A structure–activity relationship study of the positive allosteric modulator LY2033298 at the M4 muscarinic acetylcholine receptor. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00334b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Positive allosteric modulators targeting the M4 muscarinic acetylcholine receptor offer greater sub-type selectivity and unique potential as CNS agents through their novel mode of action to traditional orthosteric ligands.
Collapse
Affiliation(s)
- Monika Szabo
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| | - Tracey Huynh
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| | - Celine Valant
- Drug Discovery Biology
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| | - J. Robert Lane
- Drug Discovery Biology
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| | - Patrick M. Sexton
- Drug Discovery Biology
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| | - Arthur Christopoulos
- Drug Discovery Biology
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| | - Ben Capuano
- Medicinal Chemistry
- Monash Institute of Pharmaceutical Sciences
- Monash University
- Parkville 3052
- Australia
| |
Collapse
|
52
|
Opportunities and challenges in the discovery of allosteric modulators of GPCRs for treating CNS disorders. Nat Rev Drug Discov 2014; 13:692-708. [PMID: 25176435 DOI: 10.1038/nrd4308] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Novel allosteric modulators of G protein-coupled receptors (GPCRs) are providing fundamental advances in the development of GPCR ligands with high subtype selectivity and novel modes of efficacy that have not been possible with traditional approaches. As new allosteric modulators are advancing as drug candidates, we are developing an increased understanding of the major advantages and broad range of activities that can be achieved with these agents through selective modulation of specific signalling pathways, differential effects on GPCR homodimers versus heterodimers, and other properties. This understanding creates exciting opportunities, as well as unique challenges, in the optimization of novel therapeutic agents for disorders of the central nervous system.
Collapse
|
53
|
Bubser M, Bridges TM, Dencker D, Gould RW, Grannan M, Noetzel MJ, Lamsal A, Niswender CM, Daniels JS, Poslusney MS, Melancon BJ, Tarr JC, Byers FW, Wess J, Duggan ME, Dunlop J, Wood MW, Brandon NJ, Wood MR, Lindsley CW, Conn PJ, Jones CK. Selective activation of M4 muscarinic acetylcholine receptors reverses MK-801-induced behavioral impairments and enhances associative learning in rodents. ACS Chem Neurosci 2014; 5:920-42. [PMID: 25137629 PMCID: PMC4324418 DOI: 10.1021/cn500128b] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Positive allosteric modulators (PAMs) of the M4 muscarinic acetylcholine receptor (mAChR) represent a novel approach for the treatment of psychotic symptoms associated with schizophrenia and other neuropsychiatric disorders. We recently reported that the selective M4 PAM VU0152100 produced an antipsychotic drug-like profile in rodents after amphetamine challenge. Previous studies suggest that enhanced cholinergic activity may also improve cognitive function and reverse deficits observed with reduced signaling through the N-methyl-d-aspartate subtype of the glutamate receptor (NMDAR) in the central nervous system. Prior to this study, the M1 mAChR subtype was viewed as the primary candidate for these actions relative to the other mAChR subtypes. Here we describe the discovery of a novel M4 PAM, VU0467154, with enhanced in vitro potency and improved pharmacokinetic properties relative to other M4 PAMs, enabling a more extensive characterization of M4 actions in rodent models. We used VU0467154 to test the hypothesis that selective potentiation of M4 receptor signaling could ameliorate the behavioral, cognitive, and neurochemical impairments induced by the noncompetitive NMDAR antagonist MK-801. VU0467154 produced a robust dose-dependent reversal of MK-801-induced hyperlocomotion and deficits in preclinical models of associative learning and memory functions, including the touchscreen pairwise visual discrimination task in wild-type mice, but failed to reverse these stimulant-induced deficits in M4 KO mice. VU0467154 also enhanced the acquisition of both contextual and cue-mediated fear conditioning when administered alone in wild-type mice. These novel findings suggest that M4 PAMs may provide a strategy for addressing the more complex affective and cognitive disruptions associated with schizophrenia and other neuropsychiatric disorders.
Collapse
Affiliation(s)
- Michael Bubser
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Thomas M. Bridges
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Ditte Dencker
- Laboratory
of Neuropsychiatry, Psychiatric Centre Copenhagen, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark
| | - Robert W. Gould
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Michael Grannan
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Meredith J. Noetzel
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Atin Lamsal
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Colleen M. Niswender
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - J. Scott Daniels
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Michael S. Poslusney
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Bruce J. Melancon
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - James C. Tarr
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Frank W. Byers
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Jürgen Wess
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20814, United States
| | - Mark E. Duggan
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - John Dunlop
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Michael W. Wood
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Nicholas J. Brandon
- Neuroscience
Innovative Medicines, AstraZeneca, 141 Portland Street, Cambridge, Massachusetts 02139, United States
| | - Michael R. Wood
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - P. Jeffrey Conn
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| | - Carrie K. Jones
- Department
of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, Tennessee 37232, United States
| |
Collapse
|
54
|
Morris LC, Days EL, Turney M, Mi D, Lindsley CW, Weaver CD, Niswender KD. A Duplexed High-Throughput Screen to Identify Allosteric Modulators of the Glucagon-Like Peptide 1 and Glucagon Receptors. JOURNAL OF BIOMOLECULAR SCREENING 2014; 19:847-58. [PMID: 24525870 PMCID: PMC4306651 DOI: 10.1177/1087057114520971] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/31/2013] [Indexed: 11/16/2022]
Abstract
Injectable, degradation-resistant peptide agonists for the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R), such as exenatide and liraglutide, activate the GLP-1R via a complex orthosteric-binding site and are effective therapeutics for glycemic control in type 2 diabetes. Orally bioavailable orthosteric small-molecule agonists are unlikely to be developed, whereas positive allosteric modulators (PAMs) may offer an improved therapeutic profile. We hypothesize that allosteric modulators of the GLP-1R would increase the potency and efficacy of native GLP-1 in a spatial and temporally preserved manner and/or may improve efficacy or side effects of injectable analogs. We report the design, optimization, and initial results of a duplexed high-throughput screen in which cell lines overexpressing either the GLP-1R or the glucagon receptor were coplated, loaded with a calcium-sensitive dye, and probed in a three-phase assay to identify agonists, antagonists, and potentiators of GLP-1, and potentiators of glucagon. 175,000 compounds were initially screened, and progression through secondary assays yielded 98 compounds with a variety of activities at the GLP-1R. Here, we describe five compounds possessing different patterns of modulation of the GLP-1R. These data uncover PAMs that may offer a drug-development pathway to enhancing in vivo efficacy of both endogenous GLP-1 and peptide analogs.
Collapse
Affiliation(s)
- Lindsey C Morris
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Emily L Days
- Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Maxine Turney
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Dehui Mi
- Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Craig W Lindsley
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, TN, USA Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - C David Weaver
- Vanderbilt Institute for Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kevin D Niswender
- Tennessee Valley Healthcare System, Nashville, TN, USA Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University School of Medicine, Nashville, TN, USA
| |
Collapse
|
55
|
Byun NE, Grannan M, Bubser M, Barry RL, Thompson A, Rosanelli J, Gowrishankar R, Kelm ND, Damon S, Bridges TM, Melancon BJ, Tarr JC, Brogan JT, Avison MJ, Deutch AY, Wess J, Wood MR, Lindsley CW, Gore JC, Conn PJ, Jones CK. Antipsychotic drug-like effects of the selective M4 muscarinic acetylcholine receptor positive allosteric modulator VU0152100. Neuropsychopharmacology 2014; 39:1578-93. [PMID: 24442096 PMCID: PMC4023154 DOI: 10.1038/npp.2014.2] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 12/06/2013] [Accepted: 12/12/2013] [Indexed: 12/18/2022]
Abstract
Accumulating evidence suggests that selective M4 muscarinic acetylcholine receptor (mAChR) activators may offer a novel strategy for the treatment of psychosis. However, previous efforts to develop selective M4 activators were unsuccessful because of the lack of M4 mAChR subtype specificity and off-target muscarinic adverse effects. We recently developed VU0152100, a highly selective M4 positive allosteric modulator (PAM) that exerts central effects after systemic administration. We now report that VU0152100 dose-dependently reverses amphetamine-induced hyperlocomotion in rats and wild-type mice, but not in M4 KO mice. VU0152100 also blocks amphetamine-induced disruption of the acquisition of contextual fear conditioning and prepulse inhibition of the acoustic startle reflex. These effects were observed at doses that do not produce catalepsy or peripheral adverse effects associated with non-selective mAChR agonists. To further understand the effects of selective potentiation of M4 on region-specific brain activation, VU0152100 alone and in combination with amphetamine were evaluated using pharmacologic magnetic resonance imaging (phMRI). Key neural substrates of M4-mediated modulation of the amphetamine response included the nucleus accumbens (NAS), caudate-putamen (CP), hippocampus, and medial thalamus. Functional connectivity analysis of phMRI data, specifically assessing correlations in activation between regions, revealed several brain networks involved in the M4 modulation of amphetamine-induced brain activation, including the NAS and retrosplenial cortex with motor cortex, hippocampus, and medial thalamus. Using in vivo microdialysis, we found that VU0152100 reversed amphetamine-induced increases in extracellular dopamine levels in NAS and CP. The present data are consistent with an antipsychotic drug-like profile of activity for VU0152100. Taken together, these data support the development of selective M4 PAMs as a new approach to the treatment of psychosis and cognitive impairments associated with psychiatric disorders such as schizophrenia.
Collapse
Affiliation(s)
- Nellie E Byun
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael Grannan
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael Bubser
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Robert L Barry
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Analisa Thompson
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John Rosanelli
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Raajaram Gowrishankar
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN, USA,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA,Vanderbilt International Scholars Program, Vanderbilt University, Nashville, TN, USA
| | - Nathaniel D Kelm
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Stephen Damon
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Thomas M Bridges
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Bruce J Melancon
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - James C Tarr
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John T Brogan
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Malcolm J Avison
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ariel Y Deutch
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michael R Wood
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Craig W Lindsley
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Chemistry, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - P Jeffrey Conn
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Carrie K Jones
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, 418B Preston Research Building, Nashville, TN 37232, USA, Tel: +1 615 343 4337, Fax: +1 615 343 3088, E-mail:
| |
Collapse
|
56
|
Chemical-genetic attenuation of focal neocortical seizures. Nat Commun 2014; 5:3847. [PMID: 24866701 PMCID: PMC4050272 DOI: 10.1038/ncomms4847] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 04/08/2014] [Indexed: 01/19/2023] Open
Abstract
Focal epilepsy is commonly pharmacoresistant, and resective surgery is often contraindicated by proximity to eloquent cortex. Many patients have no effective treatment options. Gene therapy allows cell-type specific inhibition of neuronal excitability, but on-demand seizure suppression has only been achieved with optogenetics, which requires invasive light delivery. Here we test a combined chemical–genetic approach to achieve localized suppression of neuronal excitability in a seizure focus, using viral expression of the modified muscarinic receptor hM4Di. hM4Di has no effect in the absence of its selective, normally inactive and orally bioavailable agonist clozapine-N-oxide (CNO). Systemic administration of CNO suppresses focal seizures evoked by two different chemoconvulsants, pilocarpine and picrotoxin. CNO also has a robust anti-seizure effect in a chronic model of focal neocortical epilepsy. Chemical–genetic seizure attenuation holds promise as a novel approach to treat intractable focal epilepsy while minimizing disruption of normal circuit function in untransduced brain regions or in the absence of the specific ligand. Focal epilepsy is difficult to treat with currently available drugs or surgical approaches. Kätzel et al. express mutant inhibitory receptors in the brains of rats with focal epilepsy and selectively activate these receptors by an exogenous compound, which results in region- and time-specific suppression of focal seizures
Collapse
|
57
|
Odagaki Y, Kinoshita M, Toyoshima R. Functional activation of G-proteins coupled with muscarinic acetylcholine receptors in rat brain membranes. J Pharmacol Sci 2014; 125:157-68. [PMID: 24849282 DOI: 10.1254/jphs.14020fp] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The functional activation of Gi/o proteins coupled to muscarinic acetylcholine receptors (mAChRs) was investigated with the conventional guanosine-5'-O-(3-[(35)S]thio) triphosphate ([(35)S]GTPγS) binding assay in rat brain membranes. The most efficacious stimulation elicited by acetylcholine or carbachol (CCh) was obtained in striatal membranes. The pharmacological properties of mAChR-mediated [(35)S]GTPγS binding determined with a series of muscarinic agonists and antagonists were almost identical among the three brain regions investigated, i.e., cerebral cortex, hippocampus, and striatum, except for the apparent partial agonist effects of (αR)-α-cyclopentyl-α-hydroxy-N-[1-(4-methyl-3-pentenyl)-4-piperidinyl]benzeneacetamide fumarate (J 104129) observed only in the hippocampus, but not in the other two regions. Among the muscarinic toxins investigated, only MT3 attenuated CCh-stimulated [(35)S] GTPγS binding. The highly selective allosteric potentiator at the M4 mAChR subtype, 3-amino-N-[(4-chlorophenyl)methyl]-4,6-dimethylthieno[2,3-b]pyridine-2-carboxamide (VU 10010), shifted the concentration-response curve for CCh leftwards as well as upwards. On the other hand, neither thiochrome nor brucine N-oxide was effective. The increases induced by CCh and 5-HT were essentially additive, though not completely, indicating that the mAChRs and 5-HT1A receptors were coupled independently to distinct pools of Gi/o proteins. Collectively, all of the data suggest that functional activation of Gi/o proteins coupled to mAChRs, especially the M4 subtype, is detectable by means of CCh-stimulated [(35)S]GTPγS binding assay in rat discrete brain regions.
Collapse
Affiliation(s)
- Yuji Odagaki
- Department of Psychiatry, Faculty of Medicine, Saitama Medical University, Japan
| | | | | |
Collapse
|
58
|
Croy CH, Schober DA, Xiao H, Quets A, Christopoulos A, Felder CC. Characterization of the novel positive allosteric modulator, LY2119620, at the muscarinic M(2) and M(4) receptors. Mol Pharmacol 2014; 86:106-15. [PMID: 24807965 DOI: 10.1124/mol.114.091751] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The M(4) receptor is a compelling therapeutic target, as this receptor modulates neural circuits dysregulated in schizophrenia, and there is clinical evidence that muscarinic agonists possess both antipsychotic and procognitive efficacy. Recent efforts have shifted toward allosteric ligands to maximize receptor selectivity and manipulate endogenous cholinergic and dopaminergic signaling. In this study, we present the pharmacological characterization of LY2119620 (3-amino-5-chloro-N-cyclopropyl-4-methyl-6-[2-(4-methylpiperazin-1-yl)-2-oxoethoxy] thieno[2,3-b]pyridine-2-carboxamide), a M(2)/M(4) receptor-selective positive allosteric modulator (PAM), chemically evolved from hits identified through a M4 allosteric functional screen. Although unsuitable as a therapeutic due to M(2) receptor cross-reactivity and, thus, potential cardiovascular liability, LY2119620 surpassed previous congeners in potency and PAM activity and broadens research capabilities through its development into a radiotracer. Characterization of LY2119620 revealed evidence of probe dependence in both binding and functional assays. Guanosine 5'-[γ-(35)S]-triphosphate assays displayed differential potentiation depending on the orthosteric-allosteric pairing, with the largest cooperativity observed for oxotremorine M (Oxo-M) LY2119620. Further [(3)H]Oxo-M saturation binding, including studies with guanosine-5'-[(β,γ)-imido]triphosphate, suggests that both the orthosteric and allosteric ligands can alter the population of receptors in the active G protein-coupled state. Additionally, this work expands the characterization of the orthosteric agonist, iperoxo, at the M(4) receptor, and demonstrates that an allosteric ligand can positively modulate the binding and functional efficacy of this high efficacy ligand. Ultimately, it was the M(2) receptor pharmacology and PAM activity with iperoxo that made LY2119620 the most suitable allosteric partner for the M(2) active-state structure recently solved (Kruse et al., 2013), a structure that provides crucial insights into the mechanisms of orthosteric activation and allosteric modulation of muscarinic receptors.
Collapse
Affiliation(s)
- Carrie H Croy
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (C.H.C., D.A.S., H.X., A.Q., C.C.F.); and Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (A.C.)
| | - Douglas A Schober
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (C.H.C., D.A.S., H.X., A.Q., C.C.F.); and Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (A.C.)
| | - Hongling Xiao
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (C.H.C., D.A.S., H.X., A.Q., C.C.F.); and Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (A.C.)
| | - Anne Quets
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (C.H.C., D.A.S., H.X., A.Q., C.C.F.); and Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (A.C.)
| | - Arthur Christopoulos
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (C.H.C., D.A.S., H.X., A.Q., C.C.F.); and Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (A.C.)
| | - Christian C Felder
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana (C.H.C., D.A.S., H.X., A.Q., C.C.F.); and Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria, Australia (A.C.)
| |
Collapse
|
59
|
Schober DA, Croy CH, Xiao H, Christopoulos A, Felder CC. Development of a radioligand, [(3)H]LY2119620, to probe the human M(2) and M(4) muscarinic receptor allosteric binding sites. Mol Pharmacol 2014; 86:116-23. [PMID: 24807966 DOI: 10.1124/mol.114.091785] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In this study, we characterized a muscarinic acetylcholine receptor (mAChR) potentiator, LY2119620 (3-amino-5-chloro-N-cyclopropyl-4-methyl-6-[2-(4-methylpiperazin-1-yl)-2-oxoethoxy]thieno[2,3-b]pyridine-2-carboxamide) as a novel probe of the human M2 and M4 allosteric binding sites. Since the discovery of allosteric binding sites on G protein-coupled receptors, compounds targeting these novel sites have been starting to emerge. For example, LY2033298 (3-amino-5-chloro-6-methoxy-4-methyl-thieno(2,3-b)pyridine-2-carboxylic acid cyclopropylamid) and a derivative of this chemical scaffold, VU152100 (3-amino-N-(4-methoxybenzyl)-4,6-dimethylthieno[2,3-b]pyridine carboxamide), bind to the human M4 mAChR allosteric pocket. In the current study, we characterized LY2119620, a compound similar in structure to LY2033298 and binds to the same allosteric site on the human M4 mAChRs. However, LY2119620 also binds to an allosteric site on the human M2 subtype. [(3)H]NMS ([(3)H]N-methylscopolamine) binding experiments confirm that LY2119620 does not compete for the orthosteric binding pocket at any of the five muscarinic receptor subtypes. Dissociation kinetic studies using [(3)H]NMS further support that LY2119620 binds allosterically to the M2 and M4 mAChRs and was positively cooperative with muscarinic orthosteric agonists. To probe directly the allosteric sites on M2 and M4, we radiolabeled LY2119620. Cooperativity binding of [(3)H]LY2119620 with mAChR orthosteric agonists detects significant changes in Bmax values with little change in Kd, suggesting a G protein-dependent process. Furthermore, [(3)H]LY2119620 was displaced by compounds of similar chemical structure but not by previously described mAChR allosteric compounds such as gallamine or WIN 62,577 (17-β-hydroxy-17-α-ethynyl-δ-4-androstano[3,2-b]pyrimido[1,2-a]benzimidazole). Our results therefore demonstrate the development of a radioligand, [(3)H]LY2119620 to probe specifically the human M2 and M4 muscarinic receptor allosteric binding sites.
Collapse
Affiliation(s)
- Douglas A Schober
- Lilly Neuroscience, Lilly Research Laboratories, Eli Lilly and Co., Lilly Corporate Center, Indianapolis, Indiana (D.A.S., C.H.C., H.X., C.C.F.); and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (A.C.)
| | - Carrie H Croy
- Lilly Neuroscience, Lilly Research Laboratories, Eli Lilly and Co., Lilly Corporate Center, Indianapolis, Indiana (D.A.S., C.H.C., H.X., C.C.F.); and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (A.C.)
| | - Hongling Xiao
- Lilly Neuroscience, Lilly Research Laboratories, Eli Lilly and Co., Lilly Corporate Center, Indianapolis, Indiana (D.A.S., C.H.C., H.X., C.C.F.); and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (A.C.)
| | - Arthur Christopoulos
- Lilly Neuroscience, Lilly Research Laboratories, Eli Lilly and Co., Lilly Corporate Center, Indianapolis, Indiana (D.A.S., C.H.C., H.X., C.C.F.); and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (A.C.)
| | - Christian C Felder
- Lilly Neuroscience, Lilly Research Laboratories, Eli Lilly and Co., Lilly Corporate Center, Indianapolis, Indiana (D.A.S., C.H.C., H.X., C.C.F.); and Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia (A.C.)
| |
Collapse
|
60
|
M5 receptor activation produces opposing physiological outcomes in dopamine neurons depending on the receptor's location. J Neurosci 2014; 34:3253-62. [PMID: 24573284 DOI: 10.1523/jneurosci.4896-13.2014] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Of the five muscarinic receptor subtypes, the M5 receptor is the only one detectable in midbrain dopaminergic neurons, making it an attractive potential therapeutic target for treating disorders in which dopaminergic signaling is disrupted. However, developing an understanding of the role of M5 in regulating midbrain dopamine neuron function has been hampered by a lack of subtype-selective compounds. Here, we extensively characterize the novel compound VU0238429 and demonstrate that it acts as a positive allosteric modulator with unprecedented selectivity for the M5 receptor. We then used VU0238429, along with M5 knock-out mice, to elucidate the role of this receptor in regulating substantia nigra pars compacta (SNc) neuron physiology in both mice and rats. In sagittal brain slices that isolate the SNc soma from their striatal terminals, activation of muscarinic receptors induced Ca2+ mobilization and inward currents in SNc dopamine neurons, both of which were potentiated by VU0238429 and absent in M5 knock-out mice. Activation of M5 also increased the spontaneous firing rate of SNc neurons, suggesting that activation of somatodendritic M5 increases the intrinsic excitability of SNc neurons. However, in coronal slices of the striatum, potentiation of M5 with VU0238429 resulted in an inhibition in dopamine release as monitored with fast scan cyclic voltammetry. Accordingly, activation of M5 can lead to opposing physiological outcomes depending on the location of the receptor. Although activation of somatodendritic M5 receptors on SNc neurons leads to increased neuronal firing, activation of M5 receptors in the striatum induces an inhibition in dopamine release.
Collapse
|
61
|
Pancani T, Bolarinwa C, Smith Y, Lindsley CW, Conn PJ, Xiang Z. M4 mAChR-mediated modulation of glutamatergic transmission at corticostriatal synapses. ACS Chem Neurosci 2014; 5:318-24. [PMID: 24528004 DOI: 10.1021/cn500003z] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The striatum is the main input station of the basal ganglia and is extensively involved in the modulation of motivated behavior. The information conveyed to this subcortical structure through glutamatergic projections from the cerebral cortex and thalamus is processed by the activity of several striatal neuromodulatory systems including the cholinergic system. Acetylcholine potently modulates glutamate signaling in the striatum via activation of muscarinic receptors (mAChRs). It is, however, unclear which mAChR subtype is responsible for this modulatory effect. Here, by using electrophysiological, optogenetic, and immunoelectron microscopic approaches in conjunction with a novel, highly selective M4 positive allosteric modulator VU0152100 (ML108) and M4 knockout mice, we show that M4 is a major mAChR subtype mediating the cholinergic inhibition of corticostriatal glutamatergic input on both striatonigral and striatopallidal medium spiny neurons (MSNs). This effect is due to activation of presynaptic M4 receptors, which, in turn, leads to a decrease in glutamate release from corticostriatal terminals. The findings of the present study raise the interesting possibility that M4 mAChR could be a novel therapeutic target for the treatment of neurological and neuropsychiatric disorders involving hyper-glutamatergic transmission at corticostriatal synapses.
Collapse
Affiliation(s)
- Tristano Pancani
- VCNDD
and Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Caroline Bolarinwa
- Yerkes
National Primate Research Center and Department of Neurology, Emory University, Atlanta, Georgia, 30329, United States
| | - Yoland Smith
- Yerkes
National Primate Research Center and Department of Neurology, Emory University, Atlanta, Georgia, 30329, United States
| | - Craig W. Lindsley
- VCNDD
and Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - P. Jeffrey Conn
- VCNDD
and Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Zixiu Xiang
- VCNDD
and Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| |
Collapse
|
62
|
Bock A, Mohr K. Dualsteric GPCR targeting and functional selectivity: the paradigmatic M(2) muscarinic acetylcholine receptor. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 10:e245-52. [PMID: 24050275 DOI: 10.1016/j.ddtec.2012.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Muscarinic acetylcholine receptors belong to Class Aseven transmembrane helical receptors and serve as important drug targets in the treatment of various diseases such as chronic obstructive pulmonary disease, overactive bladder, bronchial asthma and glaucoma. Despite intensive research the discovery of experimental ligands which activate or block specific muscarinic receptor subtypes has only been successful for the M1 and M4 subtypes but remains a challenging task at the other subtypes. In recent years, ligands have been introduced which bind simultaneously to the acetylcholine binding site, that is, the orthosteric site, and to an allosteric binding site. These so-called dualsteric ligands display M2 subtype preference due to the addressing of the allosteric binding site. As proven recently, dualsteric receptor activation goes along with a pronounced signaling bias which follows clear structure–bias-relationships. Dualsteric receptor targeting might represent a common strategy to generate functional selectivity.
Collapse
|
63
|
Discovery and structure–activity relationships study of novel thieno[2,3-b]pyridine analogues as hepatitis C virus inhibitors. Bioorg Med Chem Lett 2014; 24:1581-8. [DOI: 10.1016/j.bmcl.2014.01.075] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 01/10/2014] [Accepted: 01/23/2014] [Indexed: 11/27/2022]
|
64
|
JAKUBÍK J, ŠANTRŮČKOVÁ E, RANDÁKOVÁ A, JANÍČKOVÁ H, ZIMČÍK P, RUDAJEV V, MICHAL P, EL-FAKAHANY EE, DOLEŽAL V. Outline of Therapeutic Interventions With Muscarinic Receptor-Mediated Transmission. Physiol Res 2014; 63:S177-89. [DOI: 10.33549/physiolres.932675] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Muscarinc receptor-mediated signaling takes part in many physiological functions ranging from complex higher nervous activity to vegetative responses. Specificity of action of the natural muscarinic agonist acetylcholine is effected by action on five muscarinic receptor subtypes with particular tissue and cellular localization, and coupling preference with different G-proteins and their signaling pathways. In addition to physiological roles it is also implicated in pathologic events like promotion of carcinoma cells growth, early pathogenesis of neurodegenerative diseases in the central nervous system like Alzheimer´s disease and Parkinson´s disease, schizophrenia, intoxications resulting in drug addiction, or overactive bladder in the periphery. All of these disturbances demonstrate involvement of specific muscarinic receptor subtypes and point to the importance to develop selective pharmacotherapeutic interventions. Because of the high homology of the orthosteric binding site of muscarinic receptor subtypes there is virtually no subtype selective agonist that binds to this site. Activation of specific receptor subtypes may be achieved by developing allosteric modulators of acetylcholine binding, since ectopic binding domains on the receptor are less conserved compared to the orthosteric site. Potentiation of the effects of acetylcholine by allosteric modulators would be beneficial in cases where acetylcholine release is reduced due to pathological conditions. When presynaptic function is severly compromised, the utilization of ectopic agonists can be a thinkable solution.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - V. DOLEŽAL
- Department of Neurochemistry, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic
| |
Collapse
|
65
|
Galloway CR, Lebois EP, Shagarabi SL, Hernandez NA, Manns JR. Effects of selective activation of M1 and M4 muscarinic receptors on object recognition memory performance in rats. Pharmacology 2014; 93:57-64. [PMID: 24480931 DOI: 10.1159/000357682] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/02/2013] [Indexed: 11/19/2022]
Abstract
Acetylcholine signaling through muscarinic receptors has been shown to benefit memory performance in some conditions, but pan-muscarinic activation also frequently leads to peripheral side effects. Drug therapies that selectively target M1 or M4 muscarinic receptors could potentially improve memory while minimizing side effects mediated by the other muscarinic receptor subtypes. The ability of three recently developed drugs that selectively activate M1 or M4 receptors to improve recognition memory was tested by giving Long-Evans rats subcutaneous injections of three different doses of the M1 agonist VU0364572, the M1 positive allosteric modulator BQCA or the M4 positive allosteric modulator VU0152100 before performing an object recognition memory task. VU0364572 at 0.1 mg/kg, BQCA at 1.0 mg/kg and VU0152100 at 3.0 and 30.0 mg/kg improved the memory performance of rats that performed poorly at baseline, yet the improvements in memory performance were the most statistically robust for VU0152100 at 3.0 mg/kg. The results suggested that selective M1 and M4 receptor activation each improved memory but that the likelihood of obtaining behavioral efficacy at a given dose might vary between subjects even in healthy groups depending on baseline performance. These results also highlighted the potential of drug therapies that selectively target M1 or M4 receptors to improve memory performance in individuals with impaired memory.
Collapse
|
66
|
Foster DJ, Choi DL, Conn PJ, Rook JM. Activation of M1 and M4 muscarinic receptors as potential treatments for Alzheimer's disease and schizophrenia. Neuropsychiatr Dis Treat 2014; 10:183-91. [PMID: 24511233 PMCID: PMC3913542 DOI: 10.2147/ndt.s55104] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Alzheimer's disease (AD) and schizophrenia (SZ) are neurological disorders with overlapping symptomatology, including both cognitive deficits and behavioral disturbances. Current clinical treatments for both disorders have limited efficacy accompanied by dose-limiting side effects, and ultimately fail to adequately address the broad range of symptoms observed. Novel therapeutic options for AD and SZ are needed to better manage the spectrum of symptoms with reduced adverse-effect liability. Substantial evidence suggests that activation of muscarinic acetylcholine receptors (mAChRs) has the potential to treat both cognitive and psychosis-related symptoms associated with numerous central nervous system (CNS) disorders. However, use of nonselective modulators of mAChRs is hampered by dose-limiting peripheral side effects that limit their clinical utility. In order to maintain the clinical efficacy without the adverse-effect liability, efforts have been focused on the discovery of compounds that selectively modulate the centrally located M1 and M4 mAChR subtypes. Previous drug discovery attempts have been thwarted by the highly conserved nature of the acetylcholine site across mAChR subtypes. However, current efforts by our laboratory and others have now focused on modulators that bind to allosteric sites on mAChRs, allowing these compounds to display unprecedented subtype selectivity. Over the past couple of decades, the discovery of small molecules capable of selectively targeting the M1 or M4 mAChR subtypes has allowed researchers to elucidate the roles of these receptors in regulating cognitive and behavioral disturbances in preclinical animal models. Here, we provide an overview of these promising preclinical and clinical studies, which suggest that M1- and M4-selective modulators represent viable novel targets with the potential to successfully address a broad range of symptoms observed in patients with AD and SZ.
Collapse
Affiliation(s)
- Daniel J Foster
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Derrick L Choi
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - P Jeffrey Conn
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jerri M Rook
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| |
Collapse
|
67
|
Nickols HH, Conn PJ. Development of allosteric modulators of GPCRs for treatment of CNS disorders. Neurobiol Dis 2014; 61:55-71. [PMID: 24076101 PMCID: PMC3875303 DOI: 10.1016/j.nbd.2013.09.013] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/13/2013] [Accepted: 09/17/2013] [Indexed: 12/14/2022] Open
Abstract
The discovery of allosteric modulators of G protein-coupled receptors (GPCRs) provides a promising new strategy with potential for developing novel treatments for a variety of central nervous system (CNS) disorders. Traditional drug discovery efforts targeting GPCRs have focused on developing ligands for orthosteric sites which bind endogenous ligands. Allosteric modulators target a site separate from the orthosteric site to modulate receptor function. These allosteric agents can either potentiate (positive allosteric modulator, PAM) or inhibit (negative allosteric modulator, NAM) the receptor response and often provide much greater subtype selectivity than orthosteric ligands for the same receptors. Experimental evidence has revealed more nuanced pharmacological modes of action of allosteric modulators, with some PAMs showing allosteric agonism in combination with positive allosteric modulation in response to endogenous ligand (ago-potentiators) as well as "bitopic" ligands that interact with both the allosteric and orthosteric sites. Drugs targeting the allosteric site allow for increased drug selectivity and potentially decreased adverse side effects. Promising evidence has demonstrated potential utility of a number of allosteric modulators of GPCRs in multiple CNS disorders, including neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, as well as psychiatric or neurobehavioral diseases such as anxiety, schizophrenia, and addiction.
Collapse
Key Words
- (+)-6-(2,4-dimethylphenyl)-2-ethyl-6,7-dihydrobenzo[d]oxazol-4(5H)-one
- (1-(4-cyano-4-(pyridine-2-yl)piperidine-1-yl)methyl-4-oxo-4H-quinolizine-3-carboxylic acid)
- (1S,2S)-N(1)-(3,4-dichlorophenyl)cyclohexane-1,2-dicarboxamide
- (1S,3R,4S)-1-aminocyclo-pentane-1,3,4-tricarboxylic acid
- (3,4-dihydro-2H-pyrano[2,3]b quinolin-7-yl)(cis-4-methoxycyclohexyl) methanone
- (3aS,5S,7aR)-methyl 5-hydroxy-5-(m-tolylethynyl)octahydro-1H-indole-1-carboxylate
- 1-(1′-(2-methylbenzyl)-1,4′-bipiperidin-4-yl)-1H-benzo[d]imidazol-2(3H)-one
- 1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine
- 2-(2-(3-methoxyphenyl)ethynyl)-5-methylpyridine
- 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1Himidazol-4-yl)ethynyl)pyridine
- 2-methyl-6-(2-phenylethenyl)pyridine
- 2-methyl-6-(phenylethynyl)-pyridine
- 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide
- 3-cyclohexyl-5-fluoro-6-methyl-7-(2-morpholin-4-ylethoxy)-4H-chromen-4-one
- 3[(2-methyl-1,3-thiazol-4-yl)ethylnyl]pyridine
- 4-((E)-styryl)-pyrimidin-2-ylamine
- 4-[1-(2-fluoropyridin-3-yl)-5-methyl-1H-1,2,3-triazol-4-yl]-N-isopropyl-N-methyl-3,6-dihydropyridine-1(2H)-carboxamide
- 4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine
- 5-methyl-6-(phenylethynyl)-pyridine
- 5MPEP
- 6-(4-methoxyphenyl)-5-methyl-3-(4-pyridinyl)-isoxazolo[4,5-c]pyridin-4(5H)-one
- 6-OHDA
- 6-hydroxydopamine
- 6-methyl-2-(phenylazo)-3-pyridinol
- 77-LH-28-1
- 7TMR
- AC-42
- ACPT-1
- AChE
- AD
- ADX71743
- AFQ056
- APP
- Allosteric modulator
- Alzheimer's disease
- BINA
- BQCA
- CDPPB
- CFMMC
- CNS
- CPPHA
- CTEP
- DA
- DFB
- DHPG
- Drug discovery
- ERK1/2
- FMRP
- FTIDC
- FXS
- Fragile X syndrome
- GABA
- GPCR
- JNJ16259685
- L-AP4
- L-DOPA
- Lu AF21934
- Lu AF32615
- M-5MPEP
- MMPIP
- MPEP
- MPTP
- MTEP
- Metabotropic glutamate receptor
- Muscarinic acetylcholine receptor
- N-[4-chloro-2[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]phenyl]-2-hydrobenzamide
- N-methyl-d-aspartate
- N-phenyl-7-(hydroxylimino)cyclopropa[b]chromen-1a-carboxamide
- NAM
- NMDA
- PAM
- PCP
- PD
- PD-LID
- PET
- PHCCC
- PQCA
- Parkinson's disease
- Parkinson's disease levodopa-induced dyskinesia
- SAM
- SIB-1757
- SIB-1893
- TBPB
- [(3-fluorophenyl)methylene]hydrazone-3-fluorobenzaldehyde
- acetylcholinesterase
- amyloid precursor protein
- benzylquinolone carboxylic acid
- central nervous system
- dihydroxyphenylglycine
- dopamine
- extracellular signal-regulated kinase 1/2
- fragile X mental retardation protein
- l-(+)-2-amino-4-phosphonobutyric acid
- l-3,4-dihydroxyphenylalanine
- mGlu
- metabotropic glutamate receptor
- negative allosteric modulator
- phencyclidine
- positive allosteric modulator
- positron emission tomography
- potassium 30-([(2-cyclopentyl-6-7-dimethyl-1-oxo-2,3-dihydro-1H-inden-5yl)oxy]methyl)biphenyl l-4-carboxylate
- seven transmembrane receptor
- silent allosteric modulator
- γ-aminobutyric acid
Collapse
Affiliation(s)
- Hilary Highfield Nickols
- Division of Neuropathology, Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, 37232, USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
| |
Collapse
|
68
|
Huynh T, Valant C, Crosby IT, Sexton PM, Christopoulos A, Capuano B. Probing Structural Requirements of Positive Allosteric Modulators of the M4 Muscarinic Receptor. J Med Chem 2013; 56:8196-200. [DOI: 10.1021/jm401032k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tracey Huynh
- Medicinal
Chemistry and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, 381-399
Royal Parade, Parkville VIC 3052, Australia
| | - Celine Valant
- Medicinal
Chemistry and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, 381-399
Royal Parade, Parkville VIC 3052, Australia
| | - Ian T. Crosby
- Medicinal
Chemistry and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, 381-399
Royal Parade, Parkville VIC 3052, Australia
| | - Patrick M. Sexton
- Medicinal
Chemistry and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, 381-399
Royal Parade, Parkville VIC 3052, Australia
| | - Arthur Christopoulos
- Medicinal
Chemistry and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, 381-399
Royal Parade, Parkville VIC 3052, Australia
| | - Ben Capuano
- Medicinal
Chemistry and ‡Drug Discovery Biology, Monash Institute
of Pharmaceutical Sciences, Monash University, 381-399
Royal Parade, Parkville VIC 3052, Australia
| |
Collapse
|
69
|
Lütjens R, Perry B, Schelshorn D, Rocher JP. New technologies enabling the industrialization of allosteric modulator discovery. DRUG DISCOVERY TODAY. TECHNOLOGIES 2013; 10:e253-60. [PMID: 24050276 DOI: 10.1016/j.ddtec.2013.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Allosteric modulators (AMs) are a promising avenue towards safe and selective drugs. AMs can interact selectively with unique domains distinct from the endogenous ligand binding site of receptors, up- or downregulating the response to receptor activation. Emphasis is placed in this article on the latest development in high-sensitivity technologies designed to identify AMs of G-protein coupled receptors. In addition to new pharmacological approaches, encouraging results in the crystal resolution of these targets enable use of more rational approaches to identification and optimization of AMs.
Collapse
|
70
|
Nikkhoo AR, Miri R, Arianpour N, Firuzi O, Ebadi A, Salarian AA. Cytotoxic activity assessment and c-Src tyrosine kinase docking simulation of thieno[2,3-b] pyridine-based derivatives. Med Chem Res 2013. [DOI: 10.1007/s00044-013-0729-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
71
|
Bell LA, Bell KA, McQuiston AR. Synaptic muscarinic response types in hippocampal CA1 interneurons depend on different levels of presynaptic activity and different muscarinic receptor subtypes. Neuropharmacology 2013; 73:160-73. [PMID: 23747570 DOI: 10.1016/j.neuropharm.2013.05.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 05/22/2013] [Accepted: 05/27/2013] [Indexed: 10/26/2022]
Abstract
Depolarizing, hyperpolarizing and biphasic muscarinic responses have been described in hippocampal inhibitory interneurons, but the receptor subtypes and activity patterns required to synaptically activate muscarinic responses in interneurons have not been completely characterized. Using optogenetics combined with whole cell patch clamp recordings in acute slices, we measured muscarinic responses produced by endogenously released acetylcholine (ACh) from cholinergic medial septum/diagonal bands of Broca inputs in hippocampal CA1. We found that depolarizing responses required more cholinergic terminal stimulation than hyperpolarizing ones. Furthermore, elevating extracellular ACh with the acetylcholinesterase inhibitor physostigmine had a larger effect on depolarizing versus hyperpolarizing responses. Another subpopulation of interneurons responded biphasically, and periodic release of ACh entrained some of these interneurons to rhythmically burst. M4 receptors mediated hyperpolarizing responses by activating inwardly rectifying K(+) channels, whereas the depolarizing responses were inhibited by the nonselective muscarinic antagonist atropine but were unaffected by M1, M4 or M5 receptor modulators. In addition, activation of M4 receptors significantly altered biphasic interneuron firing patterns. Anatomically, interneuron soma location appeared predictive of muscarinic response types but response types did not correlate with interneuron morphological subclasses. Together these observations suggest that the hippocampal CA1 interneuron network will be differentially affected by cholinergic input activity levels. Low levels of cholinergic activity will preferentially suppress some interneurons via hyperpolarization and increased activity will recruit other interneurons to depolarize, possibly because of elevated extracellular ACh concentrations. These data provide important information for understanding how cholinergic therapies will affect hippocampal network function in the treatment of some neurodegenerative diseases.
Collapse
Affiliation(s)
- L Andrew Bell
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298, USA
| | | | | |
Collapse
|
72
|
Le U, Melancon BJ, Bridges TM, Vinson PN, Utley TJ, Lamsal A, Rodriguez AL, Venable D, Sheffler DJ, Jones CK, Blobaum AL, Wood MR, Daniels JS, Conn PJ, Niswender CM, Lindsley CW, Hopkins CR. Discovery of a selective M₄ positive allosteric modulator based on the 3-amino-thieno[2,3-b]pyridine-2-carboxamide scaffold: development of ML253, a potent and brain penetrant compound that is active in a preclinical model of schizophrenia. Bioorg Med Chem Lett 2013; 23:346-50. [PMID: 23177787 PMCID: PMC3535830 DOI: 10.1016/j.bmcl.2012.10.073] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/10/2012] [Accepted: 10/15/2012] [Indexed: 11/28/2022]
Abstract
Herein we report a next generation muscarinic receptor 4 (M(4)) positive allosteric modulator (PAM), ML253 which exhibits nanomolar activity at both the human (EC(50)=56 nM) and rat (EC(50)=176 nM) receptors and excellent efficacy by the left-ward shift of the ACh concentration response curve (fold shift, human=106; rat=50). In addition, ML253 is selective against the four other muscarinic subtypes, displays excellent CNS exposure and is active in an amphetamine-induced hyperlocomotion assay.
Collapse
Affiliation(s)
- Uyen Le
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
73
|
Gannon RL, Millan MJ. LY2033298, a positive allosteric modulator at muscarinic M₄ receptors, enhances inhibition by oxotremorine of light-induced phase shifts in hamster circadian activity rhythms. Psychopharmacology (Berl) 2012; 224:231-40. [PMID: 22610522 DOI: 10.1007/s00213-012-2743-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 05/05/2012] [Indexed: 12/29/2022]
Abstract
RATIONALE Entrainment of circadian rhythms to the light-dark cycle is essential for restorative sleep, and abnormal sleep timing is implicated in central nervous system (CNS) disorders like depression, schizophrenia, and Alzheimer's disease. Many transmitters, including acetylcholine, that exerts its actions via muscarinic receptors modulate the suprachiasmatic nucleus, the master pacemaker. OBJECTIVES Since positive allosteric modulators of muscarinic M(4) receptors are candidates for treatment of mood and cognitive deficits of CNS disorders, it is important to evaluate their circadian actions. MATERIALS AND METHODS The effects of intraperitoneally applied muscarinic agents on circadian wheel-running rhythms were measured employing hamsters, a model organism for studying activity rhythms. RESULTS Systemic administration of the muscarinic receptor agonist oxotremorine (0.01-0.04 mg/kg) inhibited light-induced phase delays and advances of hamster circadian wheel-running rhythms. The M₄ positive allosteric modulator, LY2033298 (10-40 mg/kg), had no effect on light-induced phase shifts when administered alone, yet significantly enhanced (at 20 mg/kg) the inhibitory influence of oxotremorine on light-induced phase delays. In addition, the muscarinic receptor antagonist, scopolamine, which was without effect on light-induced phase shifts when administered alone (0.001-0.1 mg/kg), antagonized (at 0.1 mg/kg) the inhibitory effect of oxotremorine and LY2033298 on light-induced phase delays. CONCLUSIONS These results are the first to demonstrate that systemically applied muscarinic receptor agonists modulate circadian activity rhythms, and they also reveal a specific role for M₄ receptors. It will be of importance to evaluate circadian actions of psychotropic drugs acting via M₄ receptors, since they may display beneficial properties under pathological conditions.
Collapse
Affiliation(s)
- Robert L Gannon
- Department of Biology, Valdosta State University, Valdosta, GA, 31602, USA.
| | | |
Collapse
|
74
|
Abstract
In this article, we will describe the malignant synaptic growth hypothesis of Alzheimer's disease. Originally presented in 1994, the hypothesis remains a viable model of the functional and biophysical mechanisms underlying the development and progression of Alzheimer's disease. In this article, we will refresh the model with references to relevant empirical support that has been generated in the intervening two decades since it's original presentation. We will include discussion of its relationship, in terms of points of alignment and points of contention, to other models of Alzheimer's disease, including the cholinergic hypothesis and the tau and β-amyloid models of Alzheimer's disease. Finally, we propose several falsifiable predictions made by the malignant synaptic growth hypothesis and describe the avenues of treatment that hold the greatest promise under this hypothesis.
Collapse
Affiliation(s)
- Ehren L Newman
- Center for Memory & Brain, Boston University, 2 Cummington St, Boston, MA 02215, USA
| | - Christopher F Shay
- Center for Memory & Brain, Boston University, 2 Cummington St, Boston, MA 02215, USA
| | - Michael E Hasselmo
- Center for Memory & Brain, Boston University, 2 Cummington St, Boston, MA 02215, USA
| |
Collapse
|
75
|
Allosteric modulators of rhodopsin-like G protein-coupled receptors: opportunities in drug development. Pharmacol Ther 2012; 135:292-315. [PMID: 22728155 DOI: 10.1016/j.pharmthera.2012.06.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 06/07/2012] [Indexed: 11/21/2022]
Abstract
Rhodopsin-like (class A) G protein-coupled receptors (GPCRs) are one of the most important classes of drug targets. The discovery that these GPCRs can be allosterically modulated by small drug molecules has opened up new opportunities in drug development. It will allow the drugability of "difficult targets", such as GPCRs activated by large (glyco)proteins, or by very polar or highly lipophilic physiological agonists. Receptor subtype selectivity should be more easily achievable with allosteric than with orthosteric ligands. Allosteric modulation will allow a broad spectrum of pharmacological effects largely expanding that of orthosteric ligands. Furthermore, allosteric modulators may show an improved safety profile as compared to orthosteric ligands. Only recently, the explicit search for allosteric modulators has been started for only a few rhodopsin-like GPCRs. The first negative allosteric modulators (allosteric antagonists) of chemokine receptors, maraviroc (CCR5 receptor), used in HIV therapy, and plerixafor (CXCR4 receptor) for stem cell mobilization, have been approved as drugs. The development of allosteric modulators for rhodopsin-like GPCRs as novel drugs is still at an early stage; it appears highly promising.
Collapse
|
76
|
Newman EL, Gupta K, Climer JR, Monaghan CK, Hasselmo ME. Cholinergic modulation of cognitive processing: insights drawn from computational models. Front Behav Neurosci 2012; 6:24. [PMID: 22707936 PMCID: PMC3374475 DOI: 10.3389/fnbeh.2012.00024] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 05/21/2012] [Indexed: 11/20/2022] Open
Abstract
Acetylcholine plays an important role in cognitive function, as shown by pharmacological manipulations that impact working memory, attention, episodic memory, and spatial memory function. Acetylcholine also shows striking modulatory influences on the cellular physiology of hippocampal and cortical neurons. Modeling of neural circuits provides a framework for understanding how the cognitive functions may arise from the influence of acetylcholine on neural and network dynamics. We review the influences of cholinergic manipulations on behavioral performance in working memory, attention, episodic memory, and spatial memory tasks, the physiological effects of acetylcholine on neural and circuit dynamics, and the computational models that provide insight into the functional relationships between the physiology and behavior. Specifically, we discuss the important role of acetylcholine in governing mechanisms of active maintenance in working memory tasks and in regulating network dynamics important for effective processing of stimuli in attention and episodic memory tasks. We also propose that theta rhythm plays a crucial role as an intermediary between the physiological influences of acetylcholine and behavior in episodic and spatial memory tasks. We conclude with a synthesis of the existing modeling work and highlight future directions that are likely to be rewarding given the existing state of the literature for both empiricists and modelers.
Collapse
Affiliation(s)
- Ehren L. Newman
- Center for Memory and Brain, Boston University, BostonMA, USA
| | | | | | | | | |
Collapse
|
77
|
Stelly CE, Cronin J, Daniel JM, Schrader LA. Long-term oestradiol treatment enhances hippocampal synaptic plasticity that is dependent on muscarinic acetylcholine receptors in ovariectomised female rats. J Neuroendocrinol 2012; 24:887-96. [PMID: 22313316 DOI: 10.1111/j.1365-2826.2012.02287.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Short-term oestradiol treatment modulates hippocampus-dependent memory and synaptic plasticity in the hippocampus. Long-term oestradiol treatment can also enhance hippocampus- dependent memory, although the effects of long-term oestradiol treatment on synaptic plasticity are unknown. We investigated the effects of long-term oestradiol treatment on synaptic plasticity at the Schaeffer Collateral/CA1 synapse in 8-month-old female rats. In addition, we determined the role of endogenous activation of muscarinic acetylcholine receptors (mAChRs) in synaptic transmission and plasticity using scopolamine (1 μm), an antagonist of mAChRs. Hippocampus slices from ovariectomised rats that were treated with oestradiol-containing capsules for 5 months were compared with slices from ovariectomised rats that received cholesterol-containing capsules. Unexpectedly, scopolamine application significantly increased the baseline field excitatory postsynaptic potentials (fEPSP) and decreased paired pulse facilitation (PPF) in slices from cholesterol-treated rats. Baseline fEPSPs and PPF were not significantly modulated in slices from oestradiol-treated rats by scopolamine. Slices from oestradiol-treated rats showed enhanced long-term potentiation relative to slices from cholesterol-treated rats. Scopolamine significantly reduced the magnitude of plasticity in slices from oestradiol-treated rats. Taken together, these results suggest that mAChRs have a significant effect on baseline synaptic transmission through a decrease in the probability of glutamate release in slices from cholesterol-treated rats. Long-term oestradiol treatment blocks this effect and enhances theta-burst stimulation-induced synaptic plasticity in the middle-aged female rat, and this effect is mediated by activation of mAChRs.
Collapse
Affiliation(s)
- C E Stelly
- Neuroscience Program, Tulane University, New Orleans, LA, USA
| | | | | | | |
Collapse
|
78
|
Upreti C, Zhang XL, Alford S, Stanton PK. Role of presynaptic metabotropic glutamate receptors in the induction of long-term synaptic plasticity of vesicular release. Neuropharmacology 2012; 66:31-9. [PMID: 22626985 DOI: 10.1016/j.neuropharm.2012.05.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/07/2012] [Accepted: 05/09/2012] [Indexed: 11/24/2022]
Abstract
While postsynaptic ionotropic and metabotropic glutamate receptors have received the lions share of attention in studies of long-term activity-dependent synaptic plasticity, it is becoming clear that presynaptic metabotropic glutamate receptors play critical roles in both short-term and long-term plasticity of vesicular transmitter release, and that they act both at the level of voltage-dependent calcium channels and directly on proteins of the vesicular release machinery. Activation of G protein-coupled receptors can transiently inhibit vesicular release through the release of Gβγ which binds to both voltage-dependent calcium channels to reduce calcium influx, and directly to the C-terminus region of the SNARE protein SNAP-25. Our recent work has revealed that the binding of Gβγ to SNAP-25 is necessary, but not sufficient, to elicit long-term depression (LTD) of vesicular glutamate release, and that the concomitant release of Gα(i) and the second messenger nitric oxide are also necessary steps in the presynaptic LTD cascade. Here, we review the current state of knowledge of the molecular steps mediating short-term and long-term plasticity of vesicular release at glutamatergic synapses, and the many gaps that remain to be addressed. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.
Collapse
Affiliation(s)
- Chirag Upreti
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA
| | | | | | | |
Collapse
|
79
|
Zheng RL, Zeng XX, He HY, He J, Yang SY, Yu LT, Yang L. Facile Synthesis of 6-Aryl-3-cyanopyridine-2-(1H)-thiones from Aryl Ketones. SYNTHETIC COMMUN 2012. [DOI: 10.1080/00397911.2010.541964] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Ren-Lin Zheng
- a State Key Laboratory of Biotherapy and Cancer Center , West China Hospital, West China Medical School, Sichuan University , Chengdu , China
| | - Xiu-Xiu Zeng
- a State Key Laboratory of Biotherapy and Cancer Center , West China Hospital, West China Medical School, Sichuan University , Chengdu , China
- b Department of Pharmaceutical and Bioengineering , School of Chemical Engineering, Sichuan University , Chengdu , China
| | - Hai-Yun He
- a State Key Laboratory of Biotherapy and Cancer Center , West China Hospital, West China Medical School, Sichuan University , Chengdu , China
| | - Jun He
- b Department of Pharmaceutical and Bioengineering , School of Chemical Engineering, Sichuan University , Chengdu , China
| | - Sheng-Yong Yang
- a State Key Laboratory of Biotherapy and Cancer Center , West China Hospital, West China Medical School, Sichuan University , Chengdu , China
| | - Luo-Ting Yu
- a State Key Laboratory of Biotherapy and Cancer Center , West China Hospital, West China Medical School, Sichuan University , Chengdu , China
| | - Li Yang
- a State Key Laboratory of Biotherapy and Cancer Center , West China Hospital, West China Medical School, Sichuan University , Chengdu , China
| |
Collapse
|
80
|
Melancon BJ, Hopkins CR, Wood MR, Emmitte KA, Niswender CM, Christopoulos A, Conn PJ, Lindsley CW. Allosteric modulation of seven transmembrane spanning receptors: theory, practice, and opportunities for central nervous system drug discovery. J Med Chem 2012; 55:1445-64. [PMID: 22148748 DOI: 10.1021/jm201139r] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bruce J Melancon
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | | | | | | | | | | | | | | |
Collapse
|
81
|
Abstract
Schizophrenia is a devastating disease with several broad symptom clusters and the current monoamine-based treatments do not adequately treat the disease, especially negative and cognitive symptoms. A proposed alternative approach for treating schizophrenia is through the use of compounds that activate certain muscarinic receptor subtypes, the so-called muscarinic cholinergic hypothesis theory. This theory has been revitalized with a number of recent and provocative findings including postmortem reports in schizophrenia patients showing decreased numbers of muscarinic M(1) and M(4) receptors in brain regions associated with schizophrenia as well as decreased muscarinic receptors in an in vivo imaging study. Studies with M(4) knockout mice have shown that there is a reciprocal relationship between M(4) and dopamine receptor function, and a number of muscarinic agonists have shown antidopaminergic activity in a variety of preclinical assays predictive of antipsychotic efficacy in the clinic. Furthermore, the M(1)/M(4) preferring partial agonist xanomeline has been shown to have antipsychotic-like and pro-cognitive activity in preclinical models and in clinical trials to decrease psychotic-like behaviors in Alzheimer's patients and positive, negative, and cognitive symptoms in patients with schizophrenia. Therefore, we propose that an agonist with M(1) and M(4) interactions would effectively treat core symptom clusters associated with schizophrenia. Currently, research is focused on developing subtype-selective muscarinic agonists and positive allosteric modulators that have reduced propensity for parasympathetic side-effects, but retain the therapeutic benefit observed with their less selective predecessors.
Collapse
Affiliation(s)
- David L McKinzie
- Lilly Research Laboratories, Eli Lilly and Co., Indianapolis, IN 46285, USA.
| | | |
Collapse
|
82
|
Muscarinic and nicotinic acetylcholine receptor agonists and allosteric modulators for the treatment of schizophrenia. Neuropsychopharmacology 2012; 37:16-42. [PMID: 21956443 PMCID: PMC3238081 DOI: 10.1038/npp.2011.199] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Muscarinic and nicotinic acetylcholine (ACh) receptors (mAChRs and nAChRs) are emerging as important targets for the development of novel treatments for the symptoms associated with schizophrenia. Preclinical and early proof-of-concept clinical studies have provided strong evidence that activators of specific mAChR (M(1) and M(4)) and nAChR (α(7) and α(2)β(4)) subtypes are effective in animal models of antipsychotic-like activity and/or cognitive enhancement, and in the treatment of positive and cognitive symptoms in patients with schizophrenia. While early attempts to develop selective mAChR and nAChR agonists provided important preliminary findings, these compounds have ultimately failed in clinical development due to a lack of true subtype selectivity and subsequent dose-limiting adverse effects. In recent years, there have been major advances in the discovery of highly selective activators for the different mAChR and nAChR subtypes with suitable properties for optimization as potential candidates for clinical trials. One novel strategy has been to identify ligands that activate a specific receptor subtype through actions at sites that are distinct from the highly conserved ACh-binding site, termed allosteric sites. These allosteric activators, both allosteric agonists and positive allosteric modulators, of mAChR and nAChR subtypes demonstrate unique mechanisms of action and high selectivity in vivo, and may provide innovative treatment strategies for schizophrenia.
Collapse
|
83
|
Bolbecker AR, Shekhar A. Muscarinic agonists and antagonists in schizophrenia: recent therapeutic advances and future directions. Handb Exp Pharmacol 2012:167-190. [PMID: 22222699 DOI: 10.1007/978-3-642-23274-9_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Existing therapies for schizophrenia have limited efficacy, and significant residual positive, negative, and cognitive symptoms remain in many individuals with the disorder even after treatment with the current arsenal of antipsychotic drugs. Preclinical and clinical data suggest that selective activation of the muscarinic cholinergic system may represent novel therapeutic mechanisms for the treatment of schizophrenia. The therapeutic relevance of earlier muscarinic agonists was limited by their lack of receptor selectivity and adverse event profile arising from activation of nontarget muscarinic receptors. Recent advances in developing compounds that are selective to muscarinic receptor subtypes or activate allosteric receptor sites offer tremendous promise for therapeutic targeting of specific muscarinic receptor subtypes in schizophrenia.
Collapse
Affiliation(s)
- Amanda R Bolbecker
- Psychological and Brain Sciences, Indiana University, 1101 East Tenth Street, Bloomington, IN 47405-7007, USA
| | | |
Collapse
|
84
|
Dencker D, Thomsen M, Wörtwein G, Weikop P, Cui Y, Jeon J, Wess J, Fink-Jensen A. Muscarinic Acetylcholine Receptor Subtypes as Potential Drug Targets for the Treatment of Schizophrenia, Drug Abuse and Parkinson's Disease. ACS Chem Neurosci 2011; 3:80-89. [PMID: 22389751 DOI: 10.1021/cn200110q] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The neurotransmitter dopamine plays important roles in modulating cognitive, affective, and motor functions. Dysregulation of dopaminergic neurotransmission is thought to be involved in the pathophysiology of several psychiatric and neurological disorders, including schizophrenia, Parkinson's disease and drug abuse. Dopaminergic systems are regulated by cholinergic, especially muscarinic, input. Not surprisingly, increasing evidence implicates muscarinic acetylcholine receptor-mediated pathways as potential targets for the treatment of these disorders classically viewed as "dopamine based". There are five known muscarinic receptor subtypes (M(1) to M(5)). Due to their overlapping expression patterns and the lack of receptor subtype-specific ligands, the roles of the individual muscarinic receptors have long remained elusive. During the past decade, studies with knock-out mice lacking specific muscarinic receptor subtypes have greatly advanced our knowledge of the physiological roles of the M(1)-M(5) receptors. Recently, new ligands have been developed that can interact with allosteric sites on different muscarinic receptor subtypes, rather than the conventional (orthosteric) acetylcholine binding site. Such agents may lead to the development of novel classes of drugs useful for the treatment of psychosis, drug abuse and Parkinson's disease. The present review highlights recent studies carried out using muscarinic receptor knock-out mice and new subtype-selective allosteric ligands to assess the roles of M(1), M(4), and M(5) receptors in various central processes that are under strong dopaminergic control. The outcome of these studies opens new perspectives for the use of novel muscarinic drugs for several severe disorders of the CNS.
Collapse
Affiliation(s)
- Ditte Dencker
- Laboratory of Neuropsychiatry,
Psychiatric Centre Copenhagen, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Morgane Thomsen
- Alcohol and Drug Abuse Research
Center, McLean Hospital, Harvard Medical School, Belmont, Massachusetts 02478, United States
| | - Gitta Wörtwein
- Laboratory of Neuropsychiatry,
Psychiatric Centre Copenhagen, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, DK-1014 Copenhagen, Denmark
| | - Pia Weikop
- Laboratory of Neuropsychiatry,
Psychiatric Centre Copenhagen, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Yinghong Cui
- Molecular Signaling Section,
National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892, United States
| | - Jongrye Jeon
- Molecular Signaling Section,
National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892, United States
| | - Jürgen Wess
- Molecular Signaling Section,
National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892, United States
| | - Anders Fink-Jensen
- Laboratory of Neuropsychiatry,
Psychiatric Centre Copenhagen, University of Copenhagen, DK-2100 Copenhagen, Denmark
| |
Collapse
|
85
|
da Silva DC, de Medeiros WAA, Batista IDFC, Pimenta DC, Lebrun I, Abdalla FMF, Sandoval MRL. Characterization of a new muscarinic toxin from the venom of the Brazilian coral snake Micrurus lemniscatus in rat hippocampus. Life Sci 2011; 89:931-8. [PMID: 22005021 DOI: 10.1016/j.lfs.2011.09.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 08/08/2011] [Accepted: 09/28/2011] [Indexed: 11/29/2022]
Abstract
AIMS We have isolated a new muscarinic protein (MT-Mlα) from the venom of the Brazilian coral snake Micrurus lemniscatus. MAIN METHODS This small protein, which had a molecular mass of 7,048Da, shared high sequence homology with three-finger proteins that act on cholinergic receptors. The first 12 amino acid residues of the N-terminal sequence were determined to be: Leu-Ile-Cys-Phe-Ile-Cys-Phe-Ser-Pro-Thr-Ala-His. KEY FINDINGS The MT-Mlα was able to displace the [(3)H]QNB binding in the hippocampus of rats. The binding curve in competition experiments with MT-Mlα was indicative of two types of [(3)H]QNB-binding site with pK(i) values of 9.08±0.67 and 6.17±0.19, n=4, suggesting that various muscarinic acetylcholine receptor (mAChR) subtypes may be the target proteins of MT-Mlα. The MT-Mlα and the M(1) antagonist pirenzepine caused a dose-dependent block on total [(3)H]inositol phosphate accumulation induced by carbachol. The IC(50) values for MT-Mlα and pirenzepine were, respectively, 33.1 and 2.26 nM. Taken together, these studies indicate that the MT-Mlα has antagonist effect on mAChRs in rat hippocampus. SIGNIFICANCE The results of the present study show, for the first time, that mAChRs function is drastically affected by MT-Mlα since it not only has affinity for mAChRs but also has the ability to inhibit mAChRs.
Collapse
|
86
|
Field JR, Walker AG, Conn PJ. Targeting glutamate synapses in schizophrenia. Trends Mol Med 2011; 17:689-98. [PMID: 21955406 DOI: 10.1016/j.molmed.2011.08.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/12/2011] [Accepted: 08/19/2011] [Indexed: 12/25/2022]
Abstract
Although early clinical observations implicated dopamine dysfunction in the neuropathology of schizophrenia, accumulating evidence suggests that multiple neurotransmitter pathways are dysregulated. The psychotomimetic actions of NMDA receptor antagonists point to an imbalance of glutamatergic signaling. Encouragingly, numerous preclinical and clinical studies have elucidated several potential targets for increasing NMDA receptor function and equilibrating glutamatergic tone, including the metabotropic glutamate receptors 2, 3 and 5, the muscarinic acetylcholine receptors M(1) and M(4), and the glycine transporter GlyT1. Highly specific allosteric and orthosteric ligands have been developed that modify the activity of these novel target proteins, and in this review we summarize both the glutamatergic mechanisms and the novel compounds that are increasing the promise for a multifaceted pharmacological approach to treat schizophrenia.
Collapse
Affiliation(s)
- Julie R Field
- Department of Pharmacology and Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | | | | |
Collapse
|
87
|
Adams R, Worth CL, Guenther S, Dunkel M, Lehmann R, Preissner R. Binding sites in membrane proteins--diversity, druggability and prospects. Eur J Cell Biol 2011; 91:326-39. [PMID: 21872966 DOI: 10.1016/j.ejcb.2011.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 06/22/2011] [Accepted: 06/22/2011] [Indexed: 11/27/2022] Open
Abstract
The identification of novel drug targets is one of the major challenges in proteomics. Computational methods developed over the last decade have enhanced the process of drug design in both terms of time and quality. The main task is the design of selective compounds, which bind targets more specifically, dependent on the desired mode of action of the particular drug. This makes it necessary to create compounds, which either exhibit their functions on one single protein to exclude undesired cross-reactivity or to use the advantageous effect of less selective drugs that target numerous proteins and therefore exhibit their functions on whole protein classes. Main aspects in the assignment of interactions between ligands and putative targets involve the amino acid composition of the binding site, evolutionary conservation and similarity in sequence and structure of known targets. Similarities or differences within classified protein families can be the key to their function and give first hints to functional drug design. Hereby, binding site-based classification outnumbers sequence-based classifications since similar binding sites can also be found in more distant proteins. Membrane proteins are 'difficult targets', because of their special physicochemical characteristics and the general lack of structural information. Here, we describe recent advances in modeling methods dedicated to membrane proteins. Different descriptors of similarity between compounds and the similarity between binding sites are under development and elucidate important aspects like dynamics or entropy. The importance of computational drug design is undisputable. Nevertheless, the process of design is complicated by increasing complexity, which underlines the importance of accurate knowledge about the addressed target class(es) and particularly their binding sites. One main objective by considering named topics is to predict putative side effects and errant functions (off-target effects) of novel drugs, which requires a holistic (systems biology) view on drug-target-pathway relations. In the following, we give a brief summary about the recent discussion on drug-target interactions with emphasis on membrane proteins.
Collapse
Affiliation(s)
- Robert Adams
- Charité-Universitätsklinikum Berlin, Structural Bioinformatics Group, Lindenberger Weg 80, 13125 Berlin, Germany
| | | | | | | | | | | |
Collapse
|
88
|
Schmidt LS, Thomsen M, Weikop P, Dencker D, Wess J, Woldbye DP, Wortwein G, Fink-Jensen A. Increased cocaine self-administration in M4 muscarinic acetylcholine receptor knockout mice. Psychopharmacology (Berl) 2011; 216:367-78. [PMID: 21373792 PMCID: PMC3899540 DOI: 10.1007/s00213-011-2225-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 02/08/2011] [Indexed: 11/30/2022]
Abstract
RATIONALE The reinforcing effects of cocaine are mediated by the mesolimbic dopamine system. Behavioral and neurochemical studies have shown that the cholinergic muscarinic M(4) receptor subtype plays an important role in regulation of dopaminergic neurotransmission. OBJECTIVES Here we investigated for the first time the involvement of M(4) receptors in the reinforcing effects of cocaine using chronic intravenous cocaine self-administration in extensively backcrossed M(4) receptor knockout (M(4) (-/-)) mice. METHODS We evaluated acquisition of cocaine self-administration in experimentally naïve mice. Both cocaine self-administration and food-maintained operant behavior were evaluated under fixed ratio 1 (FR 1) and progressive ratio (PR) schedules of reinforcement. In addition, cocaine-induced dopamine release and cocaine-induced hyperactivity were evaluated. RESULTS M(4) (-/-) mice earned significantly more cocaine reinforcers and reached higher breaking points than their wild-type littermates (M(4) (+/+)) at intermediate doses of cocaine under both FR 1 and PR schedules of reinforcement. Under the PR schedule, M(4) (-/-) mice exhibited significantly higher response rates at the lowest liquid food concentration. In accordance with these results, cocaine-induced dopamine efflux in the nucleus accumbens and hyperlocomotion were increased in M(4) (-/-) mice compared to M(4) (+/+) mice. CONCLUSIONS Our data suggest that M(4) receptors play an important role in regulation of the reward circuitry and may serve as a new target in the medical treatment of drug addiction.
Collapse
Affiliation(s)
- Lene S. Schmidt
- Laboratory of Neuropsychiatry, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Morgane Thomsen
- Alcohol and Drug Abuse Research Center, McLean Hospital, Harvard Medical School, Belmont, MA, USA
| | - Pia Weikop
- Laboratory of Neuropsychiatry, Rigshospitalet University Hospital, Copenhagen, Denmark,Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark
| | - Ditte Dencker
- Laboratory of Neuropsychiatry, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, NIDDK, NIH, Bethesda, MD, USA
| | - David P.D. Woldbye
- Laboratory of Neuropsychiatry, Rigshospitalet University Hospital, Copenhagen, Denmark,Department of Neuroscience and Pharmacology, University of Copenhagen, Denmark
| | - Gitta Wortwein
- Laboratory of Neuropsychiatry, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Anders Fink-Jensen
- Laboratory of Neuropsychiatry, Rigshospitalet University Hospital, Copenhagen, Denmark,Psychiatric Centre Copenhagen, University Hospital Copenhagen, Denmark
| |
Collapse
|
89
|
Stahl E, Elmslie G, Ellis J. Allosteric modulation of the M₃ muscarinic receptor by amiodarone and N-ethylamiodarone: application of the four-ligand allosteric two-state model. Mol Pharmacol 2011; 80:378-88. [PMID: 21602476 DOI: 10.1124/mol.111.072991] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
We have reported previously that amiodarone interacts with muscarinic receptors via a novel allosteric site. This study presents mechanistic details on the nature of that interaction. Amiodarone enhanced the maximal level of agonist-stimulated release of arachidonic acid (AA) from Chinese hamster ovary cells that expressed M₃ muscarinic receptors; this enhancement was observed for acetylcholine and for the partial agonist pilocarpine. A similar effect of amiodarone was observed when pilocarpine was used to stimulate inositol phosphate (IP) metabolism, but not when acetylcholine was used. Subsequent studies showed that the IP response exhibited a much larger receptor reserve than the AA response, and reduction of that reserve by receptor alkylation unmasked amiodarone's enhancement of the maximal IP response to acetylcholine. Modulating the receptor reserve also revealed acetylcholine's greater affinity (K(A)) for the conformation of the receptor that mediates the AA response. The amiodarone analog N-ethylamiodarone (NEA) did not alter maximal agonist response but merely reduced agonist potency (that is, it appeared to be an antagonist). However, the action of NEA could be clearly distinguished from the action of the orthosteric antagonist NMS. Demonstration of this point was facilitated by an elaboration of Hall's allosteric two-state model; this new model represents a system composed of two ligands that compete with each other at the orthosteric site and two ligands that compete with each other at the allosteric site. In conclusion, amiodarone competes with NEA at a novel, extracellular, allosteric site to enhance the maximal stimulation evoked by acetylcholine and pilocarpine in two different responses.
Collapse
Affiliation(s)
- Edward Stahl
- Department of Psychiatry, the Penn State University College of Medicine, Hershey, Pennsylvania, USA
| | | | | |
Collapse
|
90
|
Iron-Ligand Coordination in Tandem Radical Cyclizations: Synthesis of Benzo[b]thiophenes by a One-pot Reaction of Iron 1,3-Diketone Complexes with 2-Thiosalicylic Acids. Chemistry 2011; 17:4709-14. [DOI: 10.1002/chem.201100377] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Indexed: 11/07/2022]
|
91
|
Abstract
As indicated by the profound cognitive impairments caused by cholinergic receptor antagonists, cholinergic neurotransmission has a vital role in cognitive function, specifically attention and memory encoding. Abnormally regulated cholinergic neurotransmission has been hypothesized to contribute to the cognitive symptoms of neuropsychiatric disorders. Loss of cholinergic neurons enhances the severity of the symptoms of dementia. Cholinergic receptor agonists and acetylcholinesterase inhibitors have been investigated for the treatment of cognitive dysfunction. Evidence from experiments using new techniques for measuring rapid changes in cholinergic neurotransmission provides a novel perspective on the cholinergic regulation of cognitive processes. This evidence indicates that changes in cholinergic modulation on a timescale of seconds is triggered by sensory input cues and serves to facilitate cue detection and attentional performance. Furthermore, the evidence indicates cholinergic induction of evoked intrinsic, persistent spiking mechanisms for active maintenance of sensory input, and planned responses. Models have been developed to describe the neuronal mechanisms underlying the transient modulation of cortical target circuits by cholinergic activity. These models postulate specific locations and roles of nicotinic and muscarinic acetylcholine receptors and that cholinergic neurotransmission is controlled in part by (cortical) target circuits. The available evidence and these models point to new principles governing the development of the next generation of cholinergic treatments for cognitive disorders.
Collapse
|
92
|
Dasari S, Gulledge AT. M1 and M4 receptors modulate hippocampal pyramidal neurons. J Neurophysiol 2010; 105:779-92. [PMID: 21160001 DOI: 10.1152/jn.00686.2010] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acetylcholine (ACh), acting at muscarinic ACh receptors (mAChRs), modulates the excitability and synaptic connectivity of hippocampal pyramidal neurons. CA1 pyramidal neurons respond to transient ("phasic") mAChR activation with biphasic responses in which inhibition is followed by excitation, whereas prolonged ("tonic") mAChR activation increases CA1 neuron excitability. Both phasic and tonic mAChR activation excites pyramidal neurons in the CA3 region, yet ACh suppresses glutamate release at the CA3-to-CA1 synapse (the Schaffer-collateral pathway). Using mice genetically lacking specific mAChRs (mAChR knockout mice), we identified the mAChR subtypes responsible for cholinergic modulation of hippocampal pyramidal neuron excitability and synaptic transmission. Knockout of M1 receptors significantly reduced, or eliminated, most phasic and tonic cholinergic responses in CA1 and CA3 pyramidal neurons. On the other hand, in the absence of other G(q)-linked mAChRs (M3 and M5), M1 receptors proved sufficient for all postsynaptic cholinergic effects on CA1 and CA3 pyramidal neuron excitability. M3 receptors were able to participate in tonic depolarization of CA1 neurons, but otherwise contributed little to cholinergic responses. At the Schaffer-collateral synapse, bath application of the cholinergic agonist carbachol suppressed stratum radiatum-evoked excitatory postsynaptic potentials (EPSPs) in wild-type CA1 neurons and in CA1 neurons from mice lacking M1 or M2 receptors. However, Schaffer-collateral EPSPs were not significantly suppressed by carbachol in neurons lacking M4 receptors. We therefore conclude that M1 and M4 receptors are the major mAChR subtypes responsible for direct cholinergic modulation of the excitatory hippocampal circuit.
Collapse
Affiliation(s)
- Sameera Dasari
- Dartmouth Medical School, Department of Physiology and Neurobiology, One Medical Center Drive, Lebanon, NH 03756-0001, USA
| | | |
Collapse
|
93
|
Coyle JT, Balu D, Benneyworth M, Basu A, Roseman A. Beyond the dopamine receptor: novel therapeutic targets for treating schizophrenia. DIALOGUES IN CLINICAL NEUROSCIENCE 2010. [PMID: 20954431 PMCID: PMC3181979 DOI: 10.31887/dcns.2010.12.3/jcoyle] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
All current drugs approved to treat schizophrenia appear to exert their antipsychotic effects through blocking the dopamine D2 receptor. Recent meta-analyses and comparative efficacy studies indicate marginal differences in efficacy of newer atypical antipsychotics and the older drugs, and little effects on negative and cognitive symptoms. This review integrates findings from postmortem, imaging, and drug-challenge studies to elucidate a corticolimbic “pathologic circuit” in schizophrenia that may be particularly relevant to the negative symptoms and cognitive impairments of schizophrenia. Potential sites for pharmacologic intervention targeting glutatatergic, GABAergic, and cholinergic neurotransmission to treat these symptoms of schizophrenia are discussed.
Collapse
Affiliation(s)
- Joseph T Coyle
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA.
| | | | | | | | | |
Collapse
|
94
|
Zeng XX, Zheng RL, Zhou T, He HY, Liu JY, Zheng Y, Tong AP, Xiang ML, Song XR, Yang SY, Yu LT, Wei YQ, Zhao YL, Yang L. Novel thienopyridine derivatives as specific anti-hepatocellular carcinoma (HCC) agents: Synthesis, preliminary structure–activity relationships, and in vitro biological evaluation. Bioorg Med Chem Lett 2010; 20:6282-5. [PMID: 20846862 DOI: 10.1016/j.bmcl.2010.08.088] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 07/27/2010] [Accepted: 08/18/2010] [Indexed: 10/19/2022]
|
95
|
Swaminath G, Jaeckel P, Guo Q, Cardozo M, Weiszmann J, Lindberg R, Wang Y, Schwandner R, Li Y. Allosteric rescuing of loss-of-function FFAR2 mutations. FEBS Lett 2010; 584:4208-14. [PMID: 20837008 DOI: 10.1016/j.febslet.2010.09.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 08/08/2010] [Accepted: 09/03/2010] [Indexed: 10/19/2022]
Abstract
FFAR2 (GPR43) is a receptor for short-chain fatty acids (SCFAs), acetate and propionate. In the current study, we investigate the molecular determinants contributing to receptor activation by endogenous ligands. Mutational analysis revealed several important residues located in transmembrane domains (TM) 3, 4, 5, 6, and 7 for acetate binding. Interestingly, mutations that abolished acetate activity, including the mutation in the well-conserved D(E)RY motif, could be rescued by a recently identified synthetic allosteric agonist. These findings provide additional insight into agonist binding and activation which may aid in designing allosteric ligands for targeting receptor function in various diseases.
Collapse
|
96
|
Jakubík J, El-Fakahany EE. Allosteric Modulation of Muscarinic Acetylcholine Receptors. Pharmaceuticals (Basel) 2010; 3:2838-2860. [PMID: 27713379 PMCID: PMC4034100 DOI: 10.3390/ph3092838] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 08/17/2010] [Accepted: 08/18/2010] [Indexed: 11/16/2022] Open
Abstract
An allosteric modulator is a ligand that binds to an allosteric site on the receptor and changes receptor conformation to produce increase (positive cooperativity) or decrease (negative cooperativity) in the binding or action of an orthosteric agonist (e.g., acetylcholine). Since the identification of gallamine as the first allosteric modulator of muscarinic receptors in 1976, this unique mode of receptor modulation has been intensively studied by many groups. This review summarizes over 30 years of research on the molecular mechanisms of allosteric interactions of drugs with the receptor and for new allosteric modulators of muscarinic receptors with potential therapeutic use. Identification of positive modulators of acetylcholine binding and function that enhance neurotransmission and the discovery of highly selective allosteric modulators are mile-stones on the way to novel therapeutic agents for the treatment of schizophrenia, Alzheimer’s disease and other disorders involving impaired cognitive function.
Collapse
Affiliation(s)
- Jan Jakubík
- Institute of Physiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 00 Praha, Czech Republic.
| | - Esam E El-Fakahany
- Division of Neuroscience Research in Psychiatry, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| |
Collapse
|
97
|
Digby GJ, Shirey JK, Conn PJ. Allosteric activators of muscarinic receptors as novel approaches for treatment of CNS disorders. MOLECULAR BIOSYSTEMS 2010; 6:1345-54. [PMID: 20582339 PMCID: PMC4780333 DOI: 10.1039/c002938f] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Muscarinic acetylcholine receptors (mAChRs) represent exciting therapeutic targets for the treatment of multiple CNS disorders. The high degree of conservation of amino acids comprising the orthosteric acetylcholine (ACh) binding site between individual mAChR subtypes has hindered the development of subtype-selective compounds that bind to this site. As a result, many academic and industry researchers are now focusing on developing allosteric activators of mAChRs including both positive allosteric modulators (PAMs) and allosteric agonists. In the past 10 years major advances have been achieved in the discovery of allosteric ligands that possess much greater selectivity for individual mAChR subtypes when compared to previously developed orthosteric agents. These novel allosteric modulators of mAChRs may provide therapeutic potential for treatment of a number of CNS disorders such as Alzheimer's disease and schizophrenia.
Collapse
Affiliation(s)
- Gregory J. Digby
- 1215 Light Hall, 2215B Garland Ave., Nashville, TN 37237-0575, USA. ; Fax: +1 615 343 3088; Tel: +1 615 322 6730
| | - Jana K. Shirey
- 8410E Medical Research Building IV, 2215B Garland Ave., Nashville, TN 37237-0575, USA. ; Fax: +1 615 936-2661; Tel: +1 615 936-8424
| | - P. Jeffrey Conn
- 2215B Garland Ave., Nashville, TN 37237-0575, USA. ; Fax: +1 615 343 3088; Tel: +1 615 322 6730
| |
Collapse
|
98
|
De Amici M, Dallanoce C, Holzgrabe U, Tränkle C, Mohr K. Allosteric ligands for G protein-coupled receptors: a novel strategy with attractive therapeutic opportunities. Med Res Rev 2010; 30:463-549. [PMID: 19557759 DOI: 10.1002/med.20166] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Allosteric receptor ligands bind to a recognition site that is distinct from the binding site of the endogenous messenger molecule. As a consequence, allosteric agents may attach to receptors that are already transmitter-bound. Ternary complex formation opens an avenue to qualitatively new drug actions at G protein-coupled receptors (GPCRs), in particular receptor subtype selective potentiation of endogenous transmitter action. Consequently, suitable exploitation of allosteric recognition sites as alternative molecular targets could pave the way to a drug discovery paradigm different from those aimed at mimicking or blocking the effects of endogenous (orthosteric) receptor activators. The number of allosteric ligands reported to modulate GPCR function is steadily increasing and some have already reached routine clinical use. This review aims at introducing into this fascinating field of drug discovery and at providing an overview about the achievements that have already been made. Various case examples will be discussed in the framework of GPCR classification (family A, B, and C receptors). In addition, the behavior at muscarinic receptors of hybrid derivatives incorporating both an allosteric and an orthosteric fragment in a common molecular skeleton will be illustrated.
Collapse
Affiliation(s)
- Marco De Amici
- Department of Pharmaceutical Sciences Pietro Pratesi, University of Milan, via Mangiagalli 25, 20133 Milano, Italy.
| | | | | | | | | |
Collapse
|
99
|
Kumar A. Carbachol-induced long-term synaptic depression is enhanced during senescence at hippocampal CA3-CA1 synapses. J Neurophysiol 2010; 104:607-16. [PMID: 20505129 DOI: 10.1152/jn.00278.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Dysregulation of the cholinergic transmitter system is a hallmark of Alzheimer's disease and contributes to an age-associated decline in memory performance. The current study examined the influence of carbachol, a cholinergic receptor agonist, on synaptic transmission over the course of aging. Extracellular excitatory postsynaptic field potentials were recorded from CA3-CA1 synapses in acute hippocampal slices obtained from young adult (5-8 mo) and aged (22-24 mo) male Fischer 344 rats. Bath application of carbachol elicited a transient depression of synaptic transmission, which was followed by a long-lasting depression (CCh-LTD) observed 90 min after carbachol cessation in both age groups. However, the magnitude of CCh-LTD was significantly larger in senescent animals and was attenuated by N-methyl-D-aspartate receptor blockade in aged animals. Blockade of L-type Ca(2+) channels inhibited CCh-LTD to a greater extent in aged animals compared to young adults. Finally, the expression of CCh-LTD was dependent on protein synthesis. The results indicate that altered Ca(2+) homeostasis or muscarinic activation of Ca(2+) signaling contribute to the enhanced CCh-LTD during senescence.
Collapse
Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, USA.
| |
Collapse
|
100
|
Bridges TM, LeBois EP, Hopkins CR, Wood MR, Jones CK, Conn PJ, Lindsley CW. The antipsychotic potential of muscarinic allosteric modulation. DRUG NEWS & PERSPECTIVES 2010; 23:229-40. [PMID: 20520852 PMCID: PMC4780339 DOI: 10.1358/dnp.2010.23.4.1416977] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The cholinergic hypothesis of schizophrenia emerged over 50 years ago based on clinical observations with both anticholinergics and pan-muscarinic agonists. Not until the 1990s did the cholinergic hypothesis of schizophrenia receive renewed enthusiasm based on clinical data with xanomeline, a muscarinic acetylcholine receptor M(1)/M(4)-preferring orthosteric agonist. In a clinical trial with Alzheimer's patients, xanomeline not only improved cognitive performance, but also reduced psychotic behaviors. This encouraging data spurred a second clinical trial in schizophrenic patients, wherein xanomeline significantly improved the positive, negative and cognitive symptom clusters. However, the question remained: Was the antipsychotic efficacy due to activation of M(1), M(4) or both M(1)/M(4)? Classical orthosteric ligands lacked the muscarinic receptor subtype selectivity required to address this key question. More recently, functional assays have allowed for the discovery of ligands that bind at allosteric sites, binding sites distinct from the orthosteric (acetylcholine) site, which are structurally less conserved and thereby afford high levels of receptor subtype selectivity. Recently, allosteric ligands, with unprecedented selectivity for either M(1) or M(4), have been discovered and have demonstrated comparable efficacy to xanomeline in preclinical antipsychotic and cognition models. These data suggest that selective allosteric activation of either M(1) or M(4) has antipsychotic potential through distinct, yet complimentary mechanisms.
Collapse
Affiliation(s)
- Thomas M. Bridges
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Evan P. LeBois
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Corey R. Hopkins
- Department of Pharmacology, Vanderbilt Program in Drug Discovery and Vanderbilt Specialized Chemistry Center (MLPCN), Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michael R. Wood
- Department of Pharmacology, Vanderbilt Program in Drug Discovery and Vanderbilt Specialized Chemistry Center (MLPCN), Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Carrie K. Jones
- Department of Pharmacology, Vanderbilt Program in Drug Discovery and Vanderbilt Specialized Chemistry Center (MLPCN), Vanderbilt University Medical Center, and U.S. Department of Veterans Affairs, Tennessee Valley Healthcare System (TVHS), Nashville, Tennessee, USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt Program in Drug Discovery and Vanderbilt Specialized Chemistry Center (MLPCN), Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Craig W. Lindsley
- Department of Pharmacology, Vanderbilt Program in Drug Discovery and Vanderbilt Specialized Chemistry Center (MLPCN), Vanderbilt University Medical Center, and Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
| |
Collapse
|