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Nguyen HTM, van der Westhuizen ET, Langmead CJ, Tobin AB, Sexton PM, Christopoulos A, Valant C. Opportunities and challenges for the development of M 1 muscarinic receptor positive allosteric modulators in the treatment for neurocognitive deficits. Br J Pharmacol 2024; 181:2114-2142. [PMID: 36355830 DOI: 10.1111/bph.15982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/22/2022] [Accepted: 10/18/2022] [Indexed: 11/12/2022] Open
Abstract
Targeting allosteric sites of M1 muscarinic acetylcholine receptors (M1 receptors) is a promising strategy to treat neurocognitive disorders, such as Alzheimer's disease and schizophrenia. Indeed, the last two decades have seen an impressive body of work focussing on the design and development of positive allosteric modulators (PAMs) for the M1 receptor. This has led to the identification of a structurally diverse range of highly selective M1 PAMs. In preclinical models, M1 PAMs have shown rescue of cognitive deficits and improvement of endpoints predictive of symptom domains of schizophrenia. Yet, to date only a few M1 PAMs have reached early-stage clinical trials, with many of them failing to progress further due to on-target mediated cholinergic adverse effects that have plagued the development of this class of ligand. This review covers the recent preclinical and clinical studies in the field of M1 receptor drug discovery for the treatment of Alzheimer's disease and schizophrenia, with a specific focus on M1 PAM, highlighting both the undoubted potential but also key challenges for the successful translation of M1 PAMs from bench-side to bedside. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Huong T M Nguyen
- Drug Discovery Biology, Monash University, Parkville, Melbourne, VIC, Australia
- Department of Biochemistry, Hanoi University of Pharmacy, Hanoi, Vietnam
| | | | - Christopher J Langmead
- Drug Discovery Biology, Monash University, Parkville, Melbourne, VIC, Australia
- Neuromedicines Discovery Centre, Monash University, Parkville, Melbourne, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash University, Parkville, Melbourne, VIC, Australia
| | - Andrew B Tobin
- Centre for Translational Pharmacology, University of Glasgow, Glasgow, UK
| | - Patrick M Sexton
- Drug Discovery Biology, Monash University, Parkville, Melbourne, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash University, Parkville, Melbourne, VIC, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash University, Parkville, Melbourne, VIC, Australia
- Neuromedicines Discovery Centre, Monash University, Parkville, Melbourne, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash University, Parkville, Melbourne, VIC, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash University, Parkville, Melbourne, VIC, Australia
- Neuromedicines Discovery Centre, Monash University, Parkville, Melbourne, VIC, Australia
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2
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Targeting the M1 muscarinic acetylcholine receptor in Alzheimer’s disease. Neuronal Signal 2022; 6:NS20210004. [PMID: 35571495 PMCID: PMC9069568 DOI: 10.1042/ns20210004] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 11/17/2022] Open
Abstract
Alzheimer’s disease (AD) remains a major cause of morbidity and mortality worldwide, and despite extensive research, only a few drugs are available for management of the disease. One strategy has been to up-regulate cholinergic neurotransmission to improve cognitive function, but this approach has dose-limiting adverse effects. To avoid these adverse effects, new drugs that target specific receptor subtypes of the cholinergic system are needed, and the M1 subtype of muscarinic acetylcholine receptor (M1-mAChR) has been shown to be a good target for this approach. By using several strategies, M1-mAChR ligands have been developed and trialled in preclinical animal models and in human studies, with varying degrees of success. This article reviews the different approaches to targeting the M1-mAChR in AD and discusses the advantages and limitations of these strategies. The factors to consider in targeting the M1-mAChR in AD are also discussed.
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3
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Neuropharmacology of Cevimeline and Muscarinic Drugs-Focus on Cognition and Neurodegeneration. Int J Mol Sci 2021; 22:ijms22168908. [PMID: 34445613 PMCID: PMC8396258 DOI: 10.3390/ijms22168908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 12/18/2022] Open
Abstract
At present, Alzheimer’s disease (AD) and related dementias cannot be cured. Therefore, scientists all over the world are trying to find a new approach to prolong an active life of patients with initial dementia. Both pharmacological and non-pharmacological pathways are investigated to improve the key symptom of the disease, memory loss. In this respect, influencing the neuromodulator acetylcholine via muscarinic receptors, such as cevimeline, might be one of the therapeutic alternatives. The purpose of this study is to explore the potential of cevimeline on the cognitive functions of AD patients. The methodology is based on a systematic literature review of available studies found in Web of Science, PubMed, Springer, and Scopus on the research topic. The findings indicate that cevimeline has shown an improvement in experimentally induced cognitive deficits in animal models. Furthermore, it has demonstrated to positively influence tau pathology and reduce the levels of amyloid-β (Aβ) peptide in the cerebral spinal fluid of Alzheimer’s patients. Although this drug has not been approved by the FDA for its use among AD patients and there is a lack of clinical studies confirming and extending this finding, cevimeline might represent a breakthrough in the treatment of AD.
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van der Westhuizen ET, Choy KHC, Valant C, McKenzie-Nickson S, Bradley SJ, Tobin AB, Sexton PM, Christopoulos A. Fine Tuning Muscarinic Acetylcholine Receptor Signaling Through Allostery and Bias. Front Pharmacol 2021; 11:606656. [PMID: 33584282 PMCID: PMC7878563 DOI: 10.3389/fphar.2020.606656] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/30/2020] [Indexed: 12/18/2022] Open
Abstract
The M1 and M4 muscarinic acetylcholine receptors (mAChRs) are highly pursued drug targets for neurological diseases, in particular for Alzheimer's disease and schizophrenia. Due to high sequence homology, selective targeting of any of the M1-M5 mAChRs through the endogenous ligand binding site has been notoriously difficult to achieve. With the discovery of highly subtype selective mAChR positive allosteric modulators in the new millennium, selectivity through targeting an allosteric binding site has opened new avenues for drug discovery programs. However, some hurdles remain to be overcome for these promising new drug candidates to progress into the clinic. One challenge is the potential for on-target side effects, such as for the M1 mAChR where over-activation of the receptor by orthosteric or allosteric ligands can be detrimental. Therefore, in addition to receptor subtype selectivity, a drug candidate may need to exhibit a biased signaling profile to avoid such on-target adverse effects. Indeed, recent studies in mice suggest that allosteric modulators for the M1 mAChR that bias signaling toward specific pathways may be therapeutically important. This review brings together details on the signaling pathways activated by the M1 and M4 mAChRs, evidence of biased agonism at these receptors, and highlights pathways that may be important for developing new subtype selective allosteric ligands to achieve therapeutic benefit.
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Affiliation(s)
- Emma T. van der Westhuizen
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - K. H. Christopher Choy
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Simon McKenzie-Nickson
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Sophie J. Bradley
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Andrew B. Tobin
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Patrick M. Sexton
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
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5
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Teal LB, Gould RW, Felts AS, Jones CK. Selective allosteric modulation of muscarinic acetylcholine receptors for the treatment of schizophrenia and substance use disorders. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2019; 86:153-196. [PMID: 31378251 DOI: 10.1016/bs.apha.2019.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Muscarinic acetylcholine receptor (mAChRs) subtypes represent exciting new targets for the treatment of schizophrenia and substance use disorder (SUD). Recent advances in the development of subtype-selective allosteric modulators have revealed promising effects in preclinical models targeting the different symptoms observed in schizophrenia and SUD. M1 PAMs display potential for addressing the negative and cognitive symptoms of schizophrenia, while M4 PAMs exhibit promise in treating preclinical models predictive of antipsychotic-like activity. In SUD, there is increasing support for modulation of mesocorticolimbic dopaminergic circuitry involved in SUD with selective M4 mAChR PAMs or M5 mAChR NAMs. Allosteric modulators of these mAChR subtypes have demonstrated efficacy in rodent models of cocaine and ethanol seeking, with indications that these ligand may also be useful for other substances of abuse, as well as in various stages in the cycle of addiction. Importantly, allosteric modulators of the different mAChR subtypes may provide viable treatment options, while conferring greater subtype specificity and corresponding enhanced therapeutic index than orthosteric muscarinic ligands and maintaining endogenous temporo-spatial ACh signaling. Overall, subtype specific mAChR allosteric modulators represent important novel therapeutic mechanisms for schizophrenia and SUD.
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Affiliation(s)
- Laura B Teal
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States
| | - Robert W Gould
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States
| | - Andrew S Felts
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States
| | - Carrie K Jones
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, United States.
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6
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Holschneider DP, Guo Y, Wang Z, Vidal M, Scremin OU. Positive Allosteric Modulation of Cholinergic Receptors Improves Spatial Learning after Cortical Contusion Injury in Mice. J Neurotrauma 2019; 36:2233-2245. [PMID: 30688147 DOI: 10.1089/neu.2018.6036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We examined benzyl quinolone carboxylic acid (BQCA), a novel M1 muscarinic-positive allosteric modulator, for improving memory and motor dysfunction after cerebral cortical contusion injury (CCI). Adult mice received unilateral motorsensory cortical CCI or sham injury. Benzyl quinolone carboxylic acid (BQCA; 5, 10, and 20 mg/kg, intraperitoneally [i.p.] × 2/day × 3-4 weeks) or vehicle (Veh) were administered, and weekly evaluations were undertaken using a battery of motor tests, as well as the Morris water maze. Thereafter, cerebral metabolic activation was investigated in awake animals during walking with [14C]-2-deoxygIucose autoradiography, comparing CCI mice previously treated with BQCA (20 mg/kg) or vehicle. Relative changes in local cerebral glucose uptake (rCGU) were evaluated in three-dimensional-reconstructed brains using statistical parametric mapping. CCI resulted in mild hyperactivity in the open field, and modest significant motor deficits, as well as significantly decreased spatial learning at 3 weeks. BQCA in CCI mice resulted in significantly improved spatial recall during the third week, with minimal effects on motor outcomes. CCI significantly decreased rCGU in the ipsilesional basal ganglia-thalamocortical circuit and in somatosensory regions, with relative increases noted contralaterally, as well as in the cerebellum. Significant decreases in rCGU were noted in subregions of the ipsilesional hippocampal formation, with significant increases noted contralesionally. BQCA compared to vehicle-treated mice showed modest, though significantly increased, rCGU in motor regions, as well as a partial reversal of lesion-related rCGU findings in subregions of the hippocampal formation. rCGU in ipsilesional posterior CA1 demonstrated a significant inverse correlation with latency to find the submerged platform. BQCA at 20 mg/kg had no significant effect on general motor activity, body weight, or acute motor, secretory, or respiratory symptoms. Results suggest that BQCA is a candidate compound to improve learning and memory function after brain trauma and may not suffer the associated central nervous system side effects typically associated with even modest doses of other cholinergic enhancers.
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Affiliation(s)
- Daniel P Holschneider
- 1 Department of Psychiatry and the Behavioral Sciences and Biomedical Engineering, University of Southern California, Los Angeles, California.,2 Department of Neurology, Biomedical Engineering, University of Southern California, Los Angeles, California.,3 Greater Los Angeles VA Healthcare System, Los Angeles, California
| | - Yumei Guo
- 1 Department of Psychiatry and the Behavioral Sciences and Biomedical Engineering, University of Southern California, Los Angeles, California
| | - Zhuo Wang
- 1 Department of Psychiatry and the Behavioral Sciences and Biomedical Engineering, University of Southern California, Los Angeles, California
| | - Milagros Vidal
- 1 Department of Psychiatry and the Behavioral Sciences and Biomedical Engineering, University of Southern California, Los Angeles, California
| | - Oscar U Scremin
- 3 Greater Los Angeles VA Healthcare System, Los Angeles, California
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7
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M 1-positive allosteric modulators lacking agonist activity provide the optimal profile for enhancing cognition. Neuropsychopharmacology 2018; 43:1763-1771. [PMID: 29581537 PMCID: PMC6006294 DOI: 10.1038/s41386-018-0033-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/11/2018] [Accepted: 02/16/2018] [Indexed: 11/09/2022]
Abstract
Highly selective positive allosteric modulators (PAMs) of the M1 subtype of muscarinic acetylcholine receptor have emerged as an exciting new approach for improving cognitive function in patients suffering from Alzheimer's disease and schizophrenia. However, excessive activation of M1 is known to induce seizure activity and have actions in the prefrontal cortex (PFC) that could impair cognitive function. We now report a series of pharmacological, electrophysiological, and behavioral studies in which we find that recently reported M1 PAMs, PF-06764427 and MK-7622, have robust agonist activity in cell lines and agonist effects in the mouse PFC, and have the potential to overactivate the M1 receptor and disrupt PFC function. In contrast, structurally distinct M1 PAMs (VU0453595 and VU0550164) are devoid of agonist activity in cell lines and maintain activity dependence of M1 activation in the PFC. Consistent with the previously reported effect of PF-06764427, the ago-PAM MK-7622 induces severe behavioral convulsions in mice. In contrast, VU0453595 does not induce behavioral convulsions at doses well above those required for maximal efficacy in enhancing cognitive function. Furthermore, in contrast to the robust efficacy of VU0453595, the ago-PAM MK-7622 failed to improve novel object recognition, a rodent assay of cognitive function. These findings suggest that in vivo cognition-enhancing efficacy of M1 PAMs can be observed with PAMs lacking intrinsic agonist activity and that intrinsic agonist activity of M1 PAMs may contribute to adverse effects and reduced efficacy in improving cognitive function.
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8
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Yohn SE, Conn PJ. Positive allosteric modulation of M 1 and M 4 muscarinic receptors as potential therapeutic treatments for schizophrenia. Neuropharmacology 2018; 136:438-448. [PMID: 28893562 PMCID: PMC5844786 DOI: 10.1016/j.neuropharm.2017.09.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 01/22/2023]
Abstract
Current antipsychotic drugs provide symptomatic relief for positive symptoms of schizophrenia, but do not offer symptom management for negative and cognitive symptoms. In addition, many patients discontinue treatment due to adverse side effects. Therefore, there is a critical need to develop more effective and safe treatment options. Although the etiology of schizophrenia is unclear, considerable data from post-mortem, neuroimaging and neuropharmacology studies support a role of the muscarinic acetylcholine (mAChRs) in the pathophysiology of schizophrenia. Substantial evidence suggests that activation of mAChRs has the potential to treat all symptom domains of schizophrenia. Despite encouraging results in demonstrating efficacy, clinical trials of nonselective mAChR agonists were limited in their clinical utility due to dose-limiting peripheral side effects. Accordingly, efforts have been made to specifically target centrally located M1 and M4 mAChR subtypes devoid of adverse-effect liability. To circumvent this limitation, there have been tremendous advances in the discovery of ligands that bind at allosteric sites, binding sites distinct from the orthosteric site, which are structurally less conserved and thereby afford high levels of receptor subtype selectivity. The discovery of subtype-specific allosteric modulators has greatly advanced our understanding of the physiological role of various muscarinic receptor subtypes in schizophrenia and the potential utility of M1 and M4 mAChR subtypes as targets for the development of novel treatments for schizophrenia and related disorders. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- Samantha E Yohn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, United States
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, United States.
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9
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Wang M, Bi W, Fan K, Li T, Yan T, Xiao F, He B, Bi K, Jia Y. Ameliorating effect of Alpinia oxyphylla—Schisandra chinensis herb pair on cognitive impairment in a mouse model of Alzheimer’s disease. Biomed Pharmacother 2018; 97:128-135. [DOI: 10.1016/j.biopha.2017.10.088] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/14/2017] [Accepted: 10/18/2017] [Indexed: 12/31/2022] Open
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10
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Kurimoto E, Matsuda S, Shimizu Y, Sako Y, Mandai T, Sugimoto T, Sakamoto H, Kimura H. An Approach to Discovering Novel Muscarinic M1 Receptor Positive Allosteric Modulators with Potent Cognitive Improvement and Minimized Gastrointestinal Dysfunction. J Pharmacol Exp Ther 2017; 364:28-37. [DOI: 10.1124/jpet.117.243774] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/09/2017] [Indexed: 11/22/2022] Open
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11
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Foster DJ, Conn PJ. Allosteric Modulation of GPCRs: New Insights and Potential Utility for Treatment of Schizophrenia and Other CNS Disorders. Neuron 2017; 94:431-446. [PMID: 28472649 PMCID: PMC5482176 DOI: 10.1016/j.neuron.2017.03.016] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/02/2017] [Accepted: 03/09/2017] [Indexed: 01/11/2023]
Abstract
G-protein-coupled receptors (GPCRs) play critical roles in regulating brain function. Recent advances have greatly expanded our understanding of these receptors as complex signaling machines that can adopt numerous conformations and modulate multiple downstream signaling pathways. While agonists and antagonists have traditionally been pursued to target GPCRs, allosteric modulators provide several mechanistic advantages, including the ability to distinguish between closely related receptor subtypes. Recently, the discovery of allosteric ligands that confer bias and modulate some, but not all, of a given receptor's downstream signaling pathways can provide pharmacological modulation of brain circuitry with remarkable precision. In addition, allosteric modulators with unprecedented specificity have been developed that can differentiate between subpopulations of a given receptor subtype based on the receptor's dimerization state. These advances are not only providing insight into the biological roles of specific receptor populations, but hold great promise for treating numerous CNS disorders.
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Affiliation(s)
- Daniel J Foster
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.
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12
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Grannan MD, Mielnik CA, Moran SP, Gould RW, Ball J, Lu Z, Bubser M, Ramsey AJ, Abe M, Cho HP, Nance KD, Blobaum AL, Niswender CM, Conn PJ, Lindsley CW, Jones CK. Prefrontal Cortex-Mediated Impairments in a Genetic Model of NMDA Receptor Hypofunction Are Reversed by the Novel M 1 PAM VU6004256. ACS Chem Neurosci 2016; 7:1706-1716. [PMID: 27617634 DOI: 10.1021/acschemneuro.6b00230] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Abnormalities in the signaling of the N-methyl-d-aspartate subtype of the glutamate receptor (NMDAR) within cortical and limbic brain regions are thought to underlie many of the complex cognitive and affective symptoms observed in individuals with schizophrenia. The M1 muscarinic acetylcholine receptor (mAChR) subtype is a closely coupled signaling partner of the NMDAR. Accumulating evidence suggests that development of selective positive allosteric modulators (PAMs) of the M1 receptor represent an important treatment strategy for the potential normalization of disruptions in NMDAR signaling in patients with schizophrenia. In the present studies, we evaluated the effects of the novel and highly potent M1 PAM, VU6004256, in ameliorating selective prefrontal cortical (PFC)-mediated physiologic and cognitive abnormalities in a genetic mouse model of global reduction in the NR1 subunit of the NMDAR (NR1 knockdown [KD]). Using slice-based extracellular field potential recordings, deficits in muscarinic agonist-induced long-term depression (LTD) in layer V of the PFC in the NR1 KD mice were normalized with bath application of VU6004256. Systemic administration of VU6004256 also reduced excessive pyramidal neuron firing in layer V PFC neurons in awake, freely moving NR1 KD mice. Moreover, selective potentiation of M1 by VU6004256 reversed the performance impairments of NR1 KD mice observed in two preclinical models of PFC-mediated learning, specifically the novel object recognition and cue-mediated fear conditioning tasks. VU6004256 also produced a robust, dose-dependent reduction in the hyperlocomotor activity of NR1 KD mice. Taken together, the current findings provide further support for M1 PAMs as a novel therapeutic approach for the PFC-mediated impairments in schizophrenia.
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Affiliation(s)
- Michael D. 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
| | - Catharine A. Mielnik
- Department
of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Sean P. Moran
- 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
| | - 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
| | - Jacob Ball
- 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
| | - Zhuoyan Lu
- 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 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
| | - Amy J. Ramsey
- Department
of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Masahito Abe
- 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
| | - Hyekyung P. Cho
- 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
| | - Kellie D. Nance
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Anna L. Blobaum
- 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
| | - 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 Kennedy Center, 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 Kennedy Center, 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
- Department
of Chemistry, Vanderbilt University, 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
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13
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Choy KHC, Shackleford DM, Malone DT, Mistry SN, Patil RT, Scammells PJ, Langmead CJ, Pantelis C, Sexton PM, Lane JR, Christopoulos A. Positive Allosteric Modulation of the Muscarinic M1 Receptor Improves Efficacy of Antipsychotics in Mouse Glutamatergic Deficit Models of Behavior. J Pharmacol Exp Ther 2016; 359:354-365. [PMID: 27630144 DOI: 10.1124/jpet.116.235788] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/13/2016] [Indexed: 12/14/2022] Open
Abstract
Current antipsychotics are effective in treating the positive symptoms associated with schizophrenia, but they remain suboptimal in targeting cognitive dysfunction. Recent studies have suggested that positive allosteric modulation of the M1 muscarinic acetylcholine receptor (mAChR) may provide a novel means of improving cognition. However, very little is known about the potential of combination therapies in extending coverage across schizophrenic symptom domains. This study investigated the effect of the M1 mAChR positive allosteric modulator BQCA [1-(4-methoxybenzyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid], alone or in combination with haloperidol (a first-generation antipsychotic), clozapine (a second-generation atypical antipsychotic), or aripiprazole (a third-generation atypical antipsychotic), in reversing deficits in sensorimotor gating and spatial memory induced by the N-methyl-d-aspartate receptor antagonist, MK-801 [(5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine]. Sensorimotor gating and spatial memory induction are two models that represent aspects of schizophrenia modeled in rodents. In prepulse inhibition (an operational measure of sensorimotor gating), BQCA alone had minimal effects but exhibited different levels of efficacy in reversing MK-801-induced prepulse inhibition disruptions when combined with a subeffective dose of each of the three (currently prescribed) antipsychotics. Furthermore, the combined effect of BQCA and clozapine was absent in M1-/- mice. Interestingly, although BQCA alone had no effect in reversing MK-801-induced memory impairments in a Y-maze spatial test, we observed a reversal upon the combination of BQCA with atypical antipsychotics, but not with haloperidol. These findings provide proof of concept that a judicious combination of existing antipsychotics with a selective M1 mAChR positive allosteric modulator can extend antipsychotic efficacy in glutamatergic deficit models of behavior.
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Affiliation(s)
- Kwok H C Choy
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - David M Shackleford
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Daniel T Malone
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Shailesh N Mistry
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Rahul T Patil
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Peter J Scammells
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Christopher J Langmead
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Christos Pantelis
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Patrick M Sexton
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Johnathan R Lane
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
| | - Arthur Christopoulos
- Drug Discovery Biology (K.H.C.C., D.T.M, C.J.L, P.M.S, J.R.L, A.C.), Centre for Drug Candidate Optimization (D.M.S., R.T.P.), and Medicinal Chemistry (S.N.M, P.J.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; and Melbourne Neuropsychiatry Centre, Department of Psychiatry and Centre for Neural Engineering, University of Melbourne, Melbourne, Australia (C.P.)
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14
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Jeon SJ, Lee HJ, Lee HE, Park SJ, Gwon Y, Kim H, Zhang J, Shin CY, Kim DH, Ryu JH. Oleanolic acid ameliorates cognitive dysfunction caused by cholinergic blockade via TrkB-dependent BDNF signaling. Neuropharmacology 2016; 113:100-109. [PMID: 27470063 DOI: 10.1016/j.neuropharm.2016.07.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/22/2016] [Accepted: 07/24/2016] [Indexed: 12/13/2022]
Abstract
Oleanolic acid is a naturally occurring triterpenoid and is widely present in food and medicinal plants. To examine the effect of oleanolic acid on memory deficits, we employed a cholinergic blockade-induced cognitive deficit mouse model. A single administration of oleanolic acid significantly increased the latency on the passive avoidance task and affected the alternation behavior on the Y-maze task and the exploration time on the novel object recognition task, indicating that oleanolic acid reverses the cognitive impairment induced by scopolamine. In accordance with previous reports, oleanolic acid enhanced extracellular-signal-regulated kinase 1/2 (ERK1/2) and cAMP response element-binding protein (CREB) phosphorylation and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. Interestingly, ameliorating effect of oleanolic acid on scopolamine-induced memory impairment was abolished by N2-(2-{[(2-oxoazepan-3-yl)amino]carbonyl}phenyl)benzo[b]thiophene-2-carboxamide (ANA-12), a potent and specific inhibitor of tropomyosin receptor kinase B (TrkB), in the passive avoidance task. Similarly, oleanolic acid significantly evoked long-term potentiation in a dose-dependent manner, which was diminished by ANA-12 treatment as shown in the electrophysiology study. Together, these results imply that oleanolic acid ameliorates scopolamine-induced memory impairment by modulating the BDNF-ERK1/2-CREB pathway through TrkB activation in mice, suggesting that oleanolic acid would be a potential therapeutic agent for the treatment of cognitive deficits.
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Affiliation(s)
- Se Jin Jeon
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Hong Ju Lee
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 604-714, Republic of Korea
| | - Hyung Eun Lee
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Se Jin Park
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Yubeen Gwon
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Haneul Kim
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Jiabao Zhang
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea
| | - Chan Young Shin
- Department of Neuroscience, Center for Neuroscience Research, Institute of Biomedical Science and Technology, Konkuk University School of Medicine, Seoul, 143-701, Republic of Korea
| | - Dong Hyun Kim
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 604-714, Republic of Korea; Institute of Convergence Bio-Health, Dong-A University, Busan 604-714, Republic of Korea.
| | - Jong Hoon Ryu
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea; Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea.
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15
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Newman LA, Gold PE. Attenuation in rats of impairments of memory by scopolamine, a muscarinic receptor antagonist, by mecamylamine, a nicotinic receptor antagonist. Psychopharmacology (Berl) 2016; 233:925-32. [PMID: 26660295 PMCID: PMC4752895 DOI: 10.1007/s00213-015-4174-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/23/2015] [Indexed: 01/08/2023]
Abstract
RATIONALE Scopolamine, a muscarinic antagonist, impairs learning and memory for many tasks, supporting an important role for the cholinergic system in these cognitive functions. The findings are most often interpreted to indicate that a decrease in postsynaptic muscarinic receptor activation mediates the memory impairments. However, scopolamine also results in increased release of acetylcholine in the brain as a result of blocking presynaptic muscarinic receptors. OBJECTIVES The present experiments assess whether scopolamine-induced increases in acetylcholine release may impair memory by overstimulating postsynaptic cholinergic nicotinic receptors, i.e., by reaching the high end of a nicotinic receptor activation inverted-U dose-response function. RESULTS Rats tested in a spontaneous alternation task showed dose-dependent working memory deficits with systemic injections of mecamylamine and scopolamine. When an amnestic dose of scopolamine (0.15 mg/kg) was co-administered with a subamnestic dose of mecamylamine (0.25 mg/kg), this dose of mecamylamine significantly attenuated the scopolamine-induced memory impairments. We next assessed the levels of acetylcholine release in the hippocampus in the presence of scopolamine and mecamylamine. Mecamylamine injections resulted in decreased release of acetylcholine, while scopolamine administration caused a large increase in acetylcholine release. CONCLUSIONS These findings indicate that a nicotinic antagonist can attenuate impairments in memory produced by a muscarinic antagonist. The nicotinic antagonist may block excessive activation of nicotinic receptors postsynaptically or attenuate increases in acetylcholine release presynaptically. Either effect of a nicotinic antagonist-to decrease scopolamine-induced increases in acetylcholine output or to decrease postsynaptic acetylcholine receptor activation-may mediate the negative effects on memory of muscarinic antagonists.
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Affiliation(s)
- L A Newman
- Department of Biology, Syracuse University, 114 Life Sciences Complex, Syracuse, NY, 13244, USA
| | - P E Gold
- Department of Biology, Syracuse University, 114 Life Sciences Complex, Syracuse, NY, 13244, USA.
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16
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Gould RW, Dencker D, Grannan M, Bubser M, Zhan X, Wess J, Xiang Z, Locuson C, Lindsley CW, Conn PJ, Jones CK. Role for the M1 Muscarinic Acetylcholine Receptor in Top-Down Cognitive Processing Using a Touchscreen Visual Discrimination Task in Mice. ACS Chem Neurosci 2015; 6:1683-95. [PMID: 26176846 DOI: 10.1021/acschemneuro.5b00123] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The M1 muscarinic acetylcholine receptor (mAChR) subtype has been implicated in the underlying mechanisms of learning and memory and represents an important potential pharmacotherapeutic target for the cognitive impairments observed in neuropsychiatric disorders such as schizophrenia. Patients with schizophrenia show impairments in top-down processing involving conflict between sensory-driven and goal-oriented processes that can be modeled in preclinical studies using touchscreen-based cognition tasks. The present studies used a touchscreen visual pairwise discrimination task in which mice discriminated between a less salient and a more salient stimulus to assess the influence of the M1 mAChR on top-down processing. M1 mAChR knockout (M1 KO) mice showed a slower rate of learning, evidenced by slower increases in accuracy over 12 consecutive days, and required more days to acquire (achieve 80% accuracy) this discrimination task compared to wild-type mice. In addition, the M1 positive allosteric modulator BQCA enhanced the rate of learning this discrimination in wild-type, but not in M1 KO, mice when BQCA was administered daily prior to testing over 12 consecutive days. Importantly, in discriminations between stimuli of equal salience, M1 KO mice did not show impaired acquisition and BQCA did not affect the rate of learning or acquisition in wild-type mice. These studies are the first to demonstrate performance deficits in M1 KO mice using touchscreen cognitive assessments and enhanced rate of learning and acquisition in wild-type mice through M1 mAChR potentiation when the touchscreen discrimination task involves top-down processing. Taken together, these findings provide further support for M1 potentiation as a potential treatment for the cognitive symptoms associated with schizophrenia.
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Affiliation(s)
| | - D. Dencker
- Laboratory
of Neuropsychiatry, Psychiatric Center Copenhagen, DK-2100 Copenhangen, Denmark
| | | | | | | | - J. Wess
- Laboratory
of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, United States
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17
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Carruthers SP, Gurvich CT, Rossell SL. The muscarinic system, cognition and schizophrenia. Neurosci Biobehav Rev 2015; 55:393-402. [PMID: 26003527 DOI: 10.1016/j.neubiorev.2015.05.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 04/21/2015] [Accepted: 05/12/2015] [Indexed: 12/26/2022]
Abstract
An increasing body of evidence has implicated the central muscarinic system as contributing to a number of symptoms of schizophrenia and serving as a potential target for pharmaceutical interventions. A theoretical review is presented that focuses on the central muscarinic system's contribution to the cognitive symptoms of schizophrenia. The aim is to bridge the void between pertinent neuropsychological and neurobiological research to provide an explanatory account of the role that the central muscarinic system plays in the symptoms of schizophrenia. First, there will be a brief overview of the relevant neuropsychological schizophrenia literature, followed by a concise introduction to the central muscarinic system. Subsequently, we will draw from animal, neuropsychological and pharmacological literature, and discuss the findings in relation to cognition, schizophrenia and the muscarinic system. Whilst unifying the multiple domains of research into a concise review will act as a useful line of enquiry into the central muscarinic systems contribution to the symptoms of schizophrenia, it will be made apparent that more research is needed in this field.
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Affiliation(s)
- Sean P Carruthers
- Brain and Psychological Sciences Research Centre (BPsyC), Faculty of Health, Arts, Design, Swinburne University of Technology, Melbourne 3122, VIC, Australia; Monash Alfred Psychiatry Research Centre (MAPrc), Monash University Central Clinical School and The Alfred Hospital, Melbourne 3004, VIC, Australia.
| | - Caroline T Gurvich
- Monash Alfred Psychiatry Research Centre (MAPrc), Monash University Central Clinical School and The Alfred Hospital, Melbourne 3004, VIC, Australia
| | - Susan L Rossell
- Brain and Psychological Sciences Research Centre (BPsyC), Faculty of Health, Arts, Design, Swinburne University of Technology, Melbourne 3122, VIC, Australia; Monash Alfred Psychiatry Research Centre (MAPrc), Monash University Central Clinical School and The Alfred Hospital, Melbourne 3004, VIC, Australia; Psychiatry, St Vincent's Hospital, Melbourne 3065, VIC, Australia
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18
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Davie BJ, Valant C, White JM, Sexton PM, Capuano B, Christopoulos A, Scammells PJ. Synthesis and pharmacological evaluation of analogues of benzyl quinolone carboxylic acid (BQCA) designed to bind irreversibly to an allosteric site of the M ₁ muscarinic acetylcholine receptor. J Med Chem 2014; 57:5405-18. [PMID: 24856614 DOI: 10.1021/jm500556a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Activation of the M1 muscarinic acetylcholine receptor (mAChR) is a prospective treatment for alleviating cognitive decline experienced in central nervous system (CNS) disorders. Current therapeutics indiscriminately enhance the activity of the endogenous neurotransmitter ACh, leading to side effects. BQCA is a positive allosteric modulator and allosteric agonist at the M1 mAChR that has high subtype selectivity and is a promising template from which to generate higher affinity, more pharmacokinetically viable drug candidates. However, to efficiently guide rational drug design, the binding site of BQCA needs to be conclusively elucidated. We report the synthesis and pharmacological validation of BQCA analogues designed to bind irreversibly to the M1 mAChR. One analogue in particular, 11, can serve as a useful structural probe to confirm the location of the BQCA binding site; ideally, by co-crystallization with the M1 mAChR. Furthermore, this ligand may also be used as a pharmacological tool with a range of applications.
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Affiliation(s)
- Briana J Davie
- Medicinal Chemistry and ‡Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
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19
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Moore NLT, Gauchan S, Genovese RF. Adolescent traumatic stress experience results in less robust conditioned fear and post-extinction fear cue responses in adult rats. Pharmacol Biochem Behav 2014; 120:17-24. [PMID: 24491436 DOI: 10.1016/j.pbb.2014.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/08/2014] [Accepted: 01/26/2014] [Indexed: 12/16/2022]
Abstract
Early exposure to a traumatic event may produce lasting effects throughout the lifespan. Traumatic stress during adolescence may deliver a distinct developmental insult compared with more-often studied neonatal or juvenile traumatic stress paradigms. The present study describes the lasting effects of adolescent traumatic stress upon adulthood fear conditioning. Adolescent rats were exposed to a traumatic stressor (underwater trauma, UWT), then underwent fear conditioning during adulthood. Fear extinction was tested over five conditioned suppression extinction sessions three weeks later. The efficacies of two potential extinction-enhancing compounds, endocannabinoid reuptake inhibitor AM404 (10mg/kg) and M1 muscarinic positive allosteric modulator BQCA (10mg/kg), were also assessed. Finally, post-extinction fear responses were examined using a fear cue (light) as a prepulse stimulus. Rats traumatically stressed during adolescence showed blunted conditioned suppression on day 1 of extinction training, and AM404 reversed this effect. Post-extinction startle testing showed that fear conditioning eliminates prepulse inhibition to the light cue. Startle potentiation was observed only in rats without adolescent UWT exposure. AM404 and BQCA both ameliorated this startle potentiation, while BQCA increased startle in the UWT group. These results suggest that exposure to a traumatic stressor during adolescence alters developmental outcomes related to stress response and fear extinction compared to rats without adolescent traumatic stress exposure, blunting the adulthood fear response and reducing residual post-extinction fear expression. Efficacy of pharmacological interventions may also vary as a factor of developmental traumatic stress exposure.
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Affiliation(s)
- Nicole L T Moore
- Behavioral Biology Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910, USA.
| | - Sangeeta Gauchan
- Behavioral Biology Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910, USA
| | - Raymond F Genovese
- Behavioral Biology Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Ave., Silver Spring, MD 20910, USA
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20
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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.
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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
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21
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Davie BJ, Christopoulos A, Scammells PJ. Development of M1 mAChR allosteric and bitopic ligands: prospective therapeutics for the treatment of cognitive deficits. ACS Chem Neurosci 2013; 4:1026-48. [PMID: 23659787 PMCID: PMC3715844 DOI: 10.1021/cn400086m] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 05/09/2013] [Indexed: 12/22/2022] Open
Abstract
Since the cholinergic hypothesis of memory dysfunction was first reported, extensive research efforts have focused on elucidating the mechanisms by which this intricate system contributes to the regulation of processes such as learning, memory, and higher executive function. Several cholinergic therapeutic targets for the treatment of cognitive deficits, psychotic symptoms, and the underlying pathophysiology of neurodegenerative disorders, such as Alzheimer's disease and schizophrenia, have since emerged. Clinically approved drugs now exist for some of these targets; however, they all may be considered suboptimal therapeutics in that they produce undesirable off-target activity leading to side effects, fail to address the wide variety of symptoms and underlying pathophysiology that characterize these disorders, and/or afford little to no therapeutic effect in subsets of patient populations. A promising target for which there are presently no approved therapies is the M1 muscarinic acetylcholine receptor (M1 mAChR). Despite avid investigation, development of agents that selectively activate this receptor via the orthosteric site has been hampered by the high sequence homology of the binding site between the five muscarinic receptor subtypes and the wide distribution of this receptor family in both the central nervous system (CNS) and the periphery. Hence, a plethora of ligands targeting less structurally conserved allosteric sites of the M1 mAChR have been investigated. This Review aims to explain the rationale behind allosterically targeting the M1 mAChR, comprehensively summarize and critically evaluate the M1 mAChR allosteric ligand literature to date, highlight the challenges inherent in allosteric ligand investigation that are impeding their clinical advancement, and discuss potential methods for resolving these issues.
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Affiliation(s)
- Briana J. Davie
- Medicinal
Chemistry and Drug Discovery Biology, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville VIC 3052, Australia
| | - Arthur Christopoulos
- Medicinal
Chemistry and Drug Discovery Biology, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville VIC 3052, Australia
| | - Peter J. Scammells
- Medicinal
Chemistry and Drug Discovery Biology, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville VIC 3052, Australia
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