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Butler CR, Popiolek M, McAllister LA, LaChapelle EA, Kramer M, Beck EM, Mente S, Brodney MA, Brown M, Gilbert A, Helal C, Ogilvie K, Starr J, Uccello D, Grimwood S, Edgerton J, Garst-Orozco J, Kozak R, Lotarski S, Rossi A, Smith D, O'Connor R, Lazzaro J, Steppan C, Steyn SJ. Design and Synthesis of Clinical Candidate PF-06852231 (CVL-231): A Brain Penetrant, Selective, Positive Allosteric Modulator of the M 4 Muscarinic Acetylcholine Receptor. J Med Chem 2024; 67:10831-10847. [PMID: 38888621 DOI: 10.1021/acs.jmedchem.4c00293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Selective activation of the M4 muscarinic acetylcholine receptor subtype offers a novel strategy for the treatment of psychosis in multiple neurological disorders. Although the development of traditional muscarinic activators has been stymied due to pan-receptor activation, muscarinic receptor subtype selectivity can be achieved through the utilization of a subtype of a unique allosteric site. A major challenge in capitalizing on this allosteric site to date has been achieving a balance of suitable potency and brain penetration. Herein, we describe the design of a brain penetrant series of M4 selective positive allosteric modulators (PAMs), ultimately culminating in the identification of 21 (PF-06852231, now CVL-231/emraclidine), which is under active clinical development as a novel mechanism and approach for the treatment of schizophrenia.
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Affiliation(s)
- Christopher R Butler
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Michael Popiolek
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Laura A McAllister
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Erik A LaChapelle
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Melissa Kramer
- Medicine Design, Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Elizabeth M Beck
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Scot Mente
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Michael A Brodney
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Matthew Brown
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Adam Gilbert
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Chris Helal
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Kevin Ogilvie
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Jeremy Starr
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Daniel Uccello
- Medicine Design, Medicinal Chemistry, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Sarah Grimwood
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Jeremy Edgerton
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | | | - Rouba Kozak
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Susan Lotarski
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Amie Rossi
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Deborah Smith
- Internal Medicine, Pfizer Inc., Cambridge, Massachusetts 02139, United States
| | - Rebecca O'Connor
- Discovery Sciences, Primary Pharmacology, Pfizer Inc., Groton, Connecticut 06340, United States
| | - John Lazzaro
- Discovery Sciences, Primary Pharmacology, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Claire Steppan
- Discovery Sciences, Primary Pharmacology, Pfizer Inc., Groton, Connecticut 06340, United States
| | - Stefanus J Steyn
- Medicine Design, Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc., Groton, Connecticut 06340, United States
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Azargoonjahromi A. Current Findings and Potential Mechanisms of KarXT (Xanomeline-Trospium) in Schizophrenia Treatment. Clin Drug Investig 2024:10.1007/s40261-024-01377-9. [PMID: 38904739 DOI: 10.1007/s40261-024-01377-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2024] [Indexed: 06/22/2024]
Abstract
Standard schizophrenia treatment involves antipsychotic medications that target D2 dopamine receptors. However, these drugs have limitations in addressing all symptoms and can lead to adverse effects such as motor impairments, metabolic effects, sedation, sexual dysfunction, cognitive impairment, and tardive dyskinesia. Recently, KarXT has emerged as a novel drug for schizophrenia. KarXT combines xanomeline, a muscarinic receptor M1 and M4 agonist, with trospium, a nonselective antimuscarinic agent. Of note, xanomeline can readily cross blood-brain barrier (BBB) and, thus, enter into the brain, thereby stimulating muscarinic receptors (M1 and M4). By doing so, xanomeline has been shown to target negative symptoms and potentially improve positive symptoms. Trospium, on the other hand, is not able to cross BBB, thereby not affecting M1 and M4 receptors; instead, it acts as an antimuscarinic agent and, hence, diminishes peripheral activity of muscarinic receptors to minimize side effects probably stemming from xanomeline in other organs. Accordingly, ongoing clinical trials investigating KarXT's efficacy in schizophrenia have demonstrated positive outcomes, including significant improvements in the Positive and Negative Syndrome Scale (PANSS) total score and cognitive function compared with placebo. These findings emphasize the potential of KarXT as a promising treatment for schizophrenia, providing symptom relief while minimizing side effects associated with xanomeline monotherapy. Despite such promising evidence, further research is needed to confirm the efficacy, safety, and tolerability of KarXT in managing schizophrenia. This review article explores the current findings and potential mechanisms of KarXT in the treatment of schizophrenia.
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Affiliation(s)
- Ali Azargoonjahromi
- Shiraz University of Medical Sciences, Janbazan Blv, 14th Alley, Jahrom, Shiraz, 7417773539, Fars, Iran.
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Cadeddu R, Braccagni G, Branca C, van Luik ER, Pittenger C, Thomsen MS, Bortolato M. Activation of M 4 muscarinic receptors in the striatum reduces tic-like behaviours in two distinct murine models of Tourette syndrome. Br J Pharmacol 2024. [PMID: 38689378 DOI: 10.1111/bph.16392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND AND PURPOSE Current pharmacotherapies for Tourette syndrome (TS) are often unsatisfactory and poorly tolerated, underscoring the need for novel treatments. Insufficient striatal acetylcholine has been suggested to contribute to tic ontogeny. Thus, we tested whether activating M1 and/or M4 receptors-the two most abundant muscarinic receptors in the striatum-reduced tic-related behaviours in mouse models of TS. EXPERIMENTAL APPROACH Studies were conducted using CIN-d and D1CT-7 mice, two TS models characterized by early-life depletion of striatal cholinergic interneurons and cortical neuropotentiation, respectively. First, we tested the effects of systemic and intrastriatal xanomeline, a selective M1/M4 receptor agonist, on tic-like and other TS-related responses. Then, we examined whether xanomeline effects were reduced by either M1 or M4 antagonists or mimicked by the M1/M3 agonist cevimeline or the M4 positive allosteric modulator (PAM) VU0467154. Finally, we measured striatal levels of M1 and M4 receptors and assessed the impact of VU0461754 on the striatal expression of the neural marker activity c-Fos. KEY RESULTS Systemic and intrastriatal xanomeline reduced TS-related behaviours in CIN-d and D1CT-7 mice. Most effects were blocked by M4, but not M1, receptor antagonists. VU0467154, but not cevimeline, elicited xanomeline-like ameliorative effects in both models. M4, but not M1, receptors were down-regulated in the striatum of CIN-d mice. Additionally, VU0467154 reduced striatal c-Fos levels in these animals. CONCLUSION AND IMPLICATIONS Activation of striatal M4, but not M1, receptors reduced tic-like manifestations in mouse models, pointing to xanomeline and M4 PAMs as novel putative therapeutic strategies for TS.
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Affiliation(s)
- Roberto Cadeddu
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Giulia Braccagni
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Caterina Branca
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Easton R van Luik
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Christopher Pittenger
- Department of Psychiatry, School of Medicine, Yale University, New Haven, Connecticut, USA
- Department of Psychology, School of Arts and Sciences, Yale University, New Haven, Connecticut, USA
- Child Study Center, School of Medicine, Yale University, New Haven, Connecticut, USA
- Center for Brain and Mind Health, School of Medicine, Yale University, New Haven, Connecticut, USA
| | | | - Marco Bortolato
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
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Kidambi N, Elsayed OH, El-Mallakh RS. Xanomeline-Trospium and Muscarinic Involvement in Schizophrenia. Neuropsychiatr Dis Treat 2023; 19:1145-1151. [PMID: 37193547 PMCID: PMC10183173 DOI: 10.2147/ndt.s406371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/01/2023] [Indexed: 05/18/2023] Open
Abstract
Schizophrenia is a severe mental illness that has its onset in late adolescence or early adulthood and is associated with significant dysfunction across multiple domains. The pathogenesis of schizophrenia remains unknown, but physiologic understanding of the illness has been driven by the dopamine hypothesis. However, acetylcholine (ACh) clearly plays a role with mixed results regarding effect on psychosis. Selective muscarinic M1 and M4 agonists, such as xanomeline, originally developed to aid in cognitive loss with Alzheimer's, showed promise in proof-of-concept study in 20 patients with schizophrenia. Unfortunately, tolerability problems made muscarinic agonists impractical in either condition. However, coadministration of trospium, a lipophobic, non-selective muscarinic antagonist previously used for the treatment of overactive bladder, with xanomeline resulted in a significant reduction of cholinergic adverse effects. A recent randomized, placebo-controlled study of the antipsychotic effects of this combination in 182 patients with acute psychosis revealed improved tolerability with 80% of subjects staying to the end of the 5 weeks study. At the end of the trial, the treatment group saw a -17.4 change in the positive and negative symptom scale (PANSS) score from baseline compared to a -5.9 change in the placebo arm (P < 0.001). Furthermore, the negative symptom subscore, was also superior in the active arm (P < 0.001). These early studies are exciting because they suggest that the cholinergic system may be recruited to treat a severe and disabling disorder with suboptimal treatment options. Xanomeline-trospium combination is currently in phase III studies.
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Affiliation(s)
- Neil Kidambi
- Mood Disorders Research Program, Depression Center, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Omar H Elsayed
- Mood Disorders Research Program, Depression Center, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Rif S El-Mallakh
- Mood Disorders Research Program, Depression Center, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY, 40202, USA
- Correspondence: Rif S El-Mallakh, Mood Disorders Research Program, Depression Center, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY, 40202, USA, Tel +1 502 588 4450, Fax +1 502 588 9539, Email
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Correll CU, Angelov AS, Miller AC, Weiden PJ, Brannan SK. Safety and tolerability of KarXT (xanomeline-trospium) in a phase 2, randomized, double-blind, placebo-controlled study in patients with schizophrenia. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2022; 8:109. [PMID: 36463237 PMCID: PMC9719488 DOI: 10.1038/s41537-022-00320-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
KarXT combines xanomeline, an M1/M4 preferring muscarinic agonist with no direct D2 receptor antagonism, with the peripherally restricted anticholinergic trospium. In EMERGENT-1 (NCT03697252), a 5-week, randomized, double-blind, placebo-controlled, phase 2 study in inpatients with schizophrenia, KarXT met the primary efficacy endpoint, numerous secondary endpoints, and was generally well tolerated. Here, we conducted additional post hoc analyses of safety and tolerability data of KarXT from EMERGENT-1 with a particular focus on adverse events (AEs) that may be associated with muscarinic receptor agonism (nausea or vomiting) or antagonism (dry mouth or constipation). A total of 179 patients received at least one dose of either KarXT (n = 89) or placebo (n = 90) and were included in the analyses. KarXT was associated with a low overall AE burden. The majority of procholinergic and anticholinergic AEs with KarXT were mild, occurred in the first 1-2 weeks of treatment, and were transient with a median duration ranging from 1 day for vomiting to 13 days for dry mouth. No patients in either treatment group discontinued the study due to any procholinergic or anticholinergic AEs. Incidence of somnolence/sedation AEs with KarXT were low and similar to those in the placebo group. KarXT was associated with no significant or clinically relevant changes in body weight, metabolic parameters, or vital signs. KarXT was generally well tolerated with an AE profile consistent with the activity of xanomeline-trospium at muscarinic receptors.
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Affiliation(s)
- Christoph U Correll
- Department of Psychiatry Research, The Zucker Hillside Hospital, Glen Oaks, NY, USA.
- Department of Psychiatry and Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.
- Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin Berlin, Berlin, Germany.
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Myslivecek J. Multitargeting nature of muscarinic orthosteric agonists and antagonists. Front Physiol 2022; 13:974160. [PMID: 36148314 PMCID: PMC9486310 DOI: 10.3389/fphys.2022.974160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/01/2022] [Indexed: 11/16/2022] Open
Abstract
Muscarinic receptors (mAChRs) are typical members of the G protein-coupled receptor (GPCR) family and exist in five subtypes from M1 to M5. Muscarinic receptor subtypes do not sufficiently differ in affinity to orthosteric antagonists or agonists; therefore, the analysis of receptor subtypes is complicated, and misinterpretations can occur. Usually, when researchers mainly specialized in CNS and peripheral functions aim to study mAChR involvement in behavior, learning, spinal locomotor networks, biological rhythms, cardiovascular physiology, bronchoconstriction, gastrointestinal tract functions, schizophrenia, and Parkinson’s disease, they use orthosteric ligands and they do not use allosteric ligands. Moreover, they usually rely on manufacturers’ claims that could be misleading. This review aimed to call the attention of researchers not deeply focused on mAChR pharmacology to this fact. Importantly, limited selective binding is not only a property of mAChRs but is a general attribute of most neurotransmitter receptors. In this review, we want to give an overview of the most common off-targets for established mAChR ligands. In this context, an important point is a mention the tremendous knowledge gap on off-targets for novel compounds compared to very well-established ligands. Therefore, we will summarize reported affinities and give an outline of strategies to investigate the subtype’s function, thereby avoiding ambiguous results. Despite that, the multitargeting nature of drugs acting also on mAChR could be an advantage when treating such diseases as schizophrenia. Antipsychotics are a perfect example of a multitargeting advantage in treatment. A promising strategy is the use of allosteric ligands, although some of these ligands have also been shown to exhibit limited selectivity. Another new direction in the development of muscarinic selective ligands is functionally selective and biased agonists. The possible selective ligands, usually allosteric, will also be listed. To overcome the limited selectivity of orthosteric ligands, the recommended process is to carefully examine the presence of respective subtypes in specific tissues via knockout studies, carefully apply “specific” agonists/antagonists at appropriate concentrations and then calculate the probability of a specific subtype involvement in specific functions. This could help interested researchers aiming to study the central nervous system functions mediated by the muscarinic receptor.
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7
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Paul SM, Yohn SE, Popiolek M, Miller AC, Felder CC. Muscarinic Acetylcholine Receptor Agonists as Novel Treatments for Schizophrenia. Am J Psychiatry 2022; 179:611-627. [PMID: 35758639 DOI: 10.1176/appi.ajp.21101083] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Schizophrenia remains a challenging disease to treat effectively with current antipsychotic medications due to their limited efficacy across the entire spectrum of core symptoms as well as their often burdensome side-effect profiles and poor tolerability. An unmet need remains for novel, mechanistically unique, and better tolerated therapeutic agents for treating schizophrenia, especially those that treat not only positive symptoms but also the negative and cognitive symptoms of the disease. Almost 25 years ago, the muscarinic acetylcholine receptor (mAChR) agonist xanomeline was reported to reduce psychotic symptoms and improve cognition in patients with Alzheimer's disease. The antipsychotic and procognitive properties of xanomeline were subsequently confirmed in a small study of acutely psychotic patients with chronic schizophrenia. These unexpected clinical findings have prompted considerable efforts across academia and industry to target mAChRs as a new approach to potentially treat schizophrenia and other psychotic disorders. The authors discuss recent advances in mAChR biology and pharmacology and the current understanding of the relative roles of the various mAChR subtypes, their downstream cellular effectors, and key neural circuits mediating the reduction in the core symptoms of schizophrenia in patients treated with xanomeline. They also provide an update on the status of novel mAChR agonists currently in development for potential treatment of schizophrenia and other neuropsychiatric disorders.
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8
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Tong LY, Deng YB, Du WH, Zhou WZ, Liao XY, Jiang X. Clemastine Promotes Differentiation of Oligodendrocyte Progenitor Cells Through the Activation of ERK1/2 via Muscarinic Receptors After Spinal Cord Injury. Front Pharmacol 2022; 13:914153. [PMID: 35865954 PMCID: PMC9294397 DOI: 10.3389/fphar.2022.914153] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
The recovery of spinal cord injury (SCI) is closely associated with the obstruction of oligodendrocyte progenitor cell (OPC) differentiation, which ultimately induces the inability to generate newly formed myelin. To address the concern, drug-based methods may be the most practical and feasible way, possibly applying to clinical therapies for patients with SCI. In our previous study, we found that clemastine treatment preserves myelin integrity, decreases the loss of axons, and improves functional recovery in the SCI model. Clemastine acts as an antagonist of the muscarinic acetylcholine receptor (muscarinic receptor, MR) identified from a string of anti-muscarinic drugs that can enhance oligodendrocyte differentiation and myelin wrapping. However, the effects of clemastine on OPC differentiation through MRs in SCI and the underlying mechanism remain unclear. To explore the possibility, a rat model of SCI was established. To investigate if clemastine could promote the differentiation of OPCs in SCI via MR, the expressions of OPC and mature OL were detected at 7 days post injury (dpi) or at 14 dpi. The significant effect of clemastine on encouraging OPC differentiation was revealed at 14 dpi rather than 7 dpi. Under pre-treatment with the MR agonist cevimeline, the positive role of clemastine on OPC differentiation was partially disrupted. Further studies indicated that clemastine increased the phosphorylation level of extracellular signal–regulated kinase 1/2 (p-ERK1/2) and the expressions of transcription factors, Myrf and Olig2. To determine the relationship among clemastine, ERK1/2 signaling, specified transcription factors, and OPC differentiation, the ERK1/2 signaling was disturbed by U0126. The inhibition of ERK1/2 in SCI rats treated with clemastine decreased the expressions of p-ERK 1/2, Myrf, Olig2, and mature OLs, suggesting that ERK1/2 is required for clemastine on promoting OPC differentiation and that specified transcription factors may be affected by the activity of ERK1/2. Moreover, the impact of clemastine on modulating the level of p-ERK 1/2 was restricted following cevimeline pre-injecting, which provides further evidence that the role of clemastine was mediated by MRs. Altogether, our data demonstrated that clemastine, mediated by MRs, promotes OPC differentiation under the enhancement of Myrf and Olig2 by activating ERK1/2 signaling and suggests a novel therapeutic prospect for SCI recovery.
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Affiliation(s)
- Lu-Yao Tong
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Yong-Bing Deng
- Department of Chongqing Emergency Medical Center, Chongqing University Center Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Wei-Hong Du
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Wen-Zhu Zhou
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Xin-Yu Liao
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing, China
| | - Xue Jiang
- Department of Biochemistry and Molecular Biology, Molecular Medicine and Cancer Research Center, College of Basic Medicine, Chongqing Medical University, Chongqing, China
- *Correspondence: Xue Jiang, ,
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9
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Myslivecek J. Dopamine and Dopamine-Related Ligands Can Bind Not Only to Dopamine Receptors. Life (Basel) 2022; 12:life12050606. [PMID: 35629274 PMCID: PMC9147915 DOI: 10.3390/life12050606] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/11/2022] [Accepted: 04/17/2022] [Indexed: 12/13/2022] Open
Abstract
The dopaminergic system is one of the most important neurotransmitter systems in the central nervous system (CNS). It acts mainly by activation of the D1-like receptor family at the target cell. Additionally, fine-tuning of the signal is achieved via pre-synaptic modulation by the D2-like receptor family. Some dopamine drugs (both agonists and antagonists) bind in addition to DRs also to α2-ARs and 5-HT receptors. Unfortunately, these compounds are often considered subtype(s) specific. Thus, it is important to consider the presence of these receptor subtypes in specific CNS areas as the function virtually elicited by one receptor type could be an effect of other—or the co-effect of multiple receptors. However, there are enough molecules with adequate specificity. In this review, we want to give an overview of the most common off-targets for established dopamine receptor ligands. To give an overall picture, we included a discussion on subtype selectivity. Molecules used as antipsychotic drugs are reviewed too. Therefore, we will summarize reported affinities and give an outline of molecules sufficiently specific for one or more subtypes (i.e., for subfamily), the presence of DR, α2-ARs, and 5-HT receptors in CNS areas, which could help avoid ambiguous results.
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Affiliation(s)
- Jaromir Myslivecek
- Institute of Physiology, 1st Faculty of Medicine, Charles University, Albertov 5, 128 00 Prague, Czech Republic
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10
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Design, Synthesis, and Biological Evaluation of 4,4’-Difluorobenzhydrol Carbamates as Selective M1 Antagonists. Pharmaceuticals (Basel) 2022; 15:ph15020248. [PMID: 35215360 PMCID: PMC8879200 DOI: 10.3390/ph15020248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/05/2022] [Accepted: 02/14/2022] [Indexed: 11/17/2022] Open
Abstract
Due to their important role in mediating a broad range of physiological functions, muscarinic acetylcholine receptors (mAChRs) have been a promising target for therapeutic and diagnostic applications alike; however, the list of truly subtype-selective ligands is scarce. Within this work, we have identified a series of twelve 4,4’-difluorobenzhydrol carbamates through a rigorous docking campaign leveraging commercially available amine databases. After synthesis, these compounds have been evaluated for their physico–chemical property profiles, including characteristics such as HPLC-logD, tPSA, logBB, and logPS. For all the synthesized carbamates, these characteristics indicate the potential for BBB permeation. In competitive radioligand binding experiments using Chinese hamster ovary cell membranes expressing the individual human mAChR subtype hM1-hM5, the most promising compound 2 displayed a high binding affinitiy towards hM1R (1.2 nM) while exhibiting modest-to-excellent selectivity versus the hM2-5R (4–189-fold). All 12 compounds were shown to act in an antagonistic fashion towards hM1R using a dose-dependent calcium mobilization assay. The structural eligibility for radiolabeling and their pharmacological and physico–chemical property profiles render compounds 2, 5, and 7 promising candidates for future position emission tomography (PET) tracer development.
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11
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Drug Design Targeting the Muscarinic Receptors and the Implications in Central Nervous System Disorders. Biomedicines 2022; 10:biomedicines10020398. [PMID: 35203607 PMCID: PMC8962391 DOI: 10.3390/biomedicines10020398] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 11/16/2022] Open
Abstract
There is substantial evidence that cholinergic system function impairment plays a significant role in many central nervous system (CNS) disorders. During the past three decades, muscarinic receptors (mAChRs) have been implicated in various pathologies and have been prominent targets of drug-design efforts. However, due to the high sequence homology of the orthosteric binding site, many drug candidates resulted in limited clinical success. Although several advances in treating peripheral pathologies have been achieved, targeting CNS pathologies remains challenging for researchers. Nevertheless, significant progress has been made in recent years to develop functionally selective orthosteric and allosteric ligands targeting the mAChRs with limited side effect profiles. This review highlights past efforts and focuses on recent advances in drug design targeting these receptors for Alzheimer’s disease (AD), schizophrenia (SZ), and depression.
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12
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Tolaymat M, Sundel MH, Alizadeh M, Xie G, Raufman JP. Potential Role for Combined Subtype-Selective Targeting of M 1 and M 3 Muscarinic Receptors in Gastrointestinal and Liver Diseases. Front Pharmacol 2021; 12:786105. [PMID: 34803723 PMCID: PMC8600121 DOI: 10.3389/fphar.2021.786105] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/19/2021] [Indexed: 01/17/2023] Open
Abstract
Despite structural similarity, the five subtypes comprising the cholinergic muscarinic family of G protein-coupled receptors regulate remarkably diverse biological functions. This mini review focuses on the closely related and commonly co-expressed M1R and M3R muscarinic acetylcholine receptor subtypes encoded respectively by CHRM1 and CHRM3. Activated M1R and M3R signal via Gq and downstream initiate phospholipid turnover, changes in cell calcium levels, and activation of protein kinases that alter gene transcription and ultimately cell function. The unexpectedly divergent effects of M1R and M3R activation, despite similar receptor structure, distribution, and signaling, are puzzling. To explore this conundrum, we focus on the gastrointestinal (GI) tract and liver because abundant data identify opposing effects of M1R and M3R activation on the progression of gastric, pancreatic, and colon cancer, and liver injury and fibrosis. Whereas M3R activation promotes GI neoplasia, M1R activation appears protective. In contrast, in murine liver injury models, M3R activation promotes and M1R activation mitigates liver fibrosis. We analyze these findings critically, consider their therapeutic implications, and review the pharmacology and availability for research and therapeutics of M1R and M3R-selective agonists and antagonists. We conclude by considering gaps in knowledge and other factors that hinder the application of these drugs and the development of new agents to treat GI and liver diseases.
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Affiliation(s)
- Mazen Tolaymat
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Margaret H Sundel
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Madeline Alizadeh
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Guofeng Xie
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD, United States.,VA Maryland Healthcare System, Baltimore, MD, United States.,Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jean-Pierre Raufman
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD, United States.,VA Maryland Healthcare System, Baltimore, MD, United States.,Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
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13
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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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14
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Spearing PK, Cho HP, Luscombe VB, Blobaum AL, Boutaud O, Engers DW, Rodriguez AL, Niswender CM, Jeffrey Conn P, Lindsley CW, Bender AM. Discovery of a novel class of heteroaryl-pyrrolidinones as positive allosteric modulators of the muscarinic acetylcholine receptor M 1. Bioorg Med Chem Lett 2021; 47:128193. [PMID: 34118412 DOI: 10.1016/j.bmcl.2021.128193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/31/2021] [Accepted: 06/06/2021] [Indexed: 11/25/2022]
Abstract
This Letter describes the synthesis and optimization of a series of heteroaryl-pyrrolidinone positive allosteric modulators (PAMs) of the muscarinic acetylcholine receptor M1 (mAChR M1). Through the continued optimization of M1 PAM tool compound VU0453595, with a focus on replacement of the 6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one with a wide variety of alternative 4,5-dihydropyrrolo-fused heteroaromatics, the generation of M1 PAMs with structurally novel chemotypes is disclosed. Two compounds from these subseries, 8b (VU6005610) and 20a (VU6005852), show robust selectivity for the M1 mAChR, and no M1 agonism. Both compounds have favorable preliminary PK profiles in vitro;8b additionally demonstrates high brain exposure in a rodent IV cassette model.
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Affiliation(s)
- Paul K Spearing
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Hyekyung P Cho
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Vincent B Luscombe
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Anna L Blobaum
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Olivier Boutaud
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Darren W Engers
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Alice L Rodriguez
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Colleen M Niswender
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States; Vanderbilt Kennedy Center, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - P Jeffrey Conn
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States; Vanderbilt Kennedy Center, Vanderbilt University School of Medicine, Nashville, TN 37232, United States
| | - Craig W Lindsley
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States; Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, United States
| | - Aaron M Bender
- Warren Center for Neuroscience Drug Discovery, Nashville, TN 37232, United States; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, United States.
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15
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Foster DJ, Bryant ZK, Conn PJ. Targeting muscarinic receptors to treat schizophrenia. Behav Brain Res 2021; 405:113201. [PMID: 33647377 PMCID: PMC8006961 DOI: 10.1016/j.bbr.2021.113201] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/02/2021] [Accepted: 02/18/2021] [Indexed: 11/23/2022]
Abstract
Schizophrenia is a severe neuropsychiatric disorder characterized by a diverse range of symptoms that can have profound impacts on the lives of patients. Currently available antipsychotics target dopamine receptors, and while they are useful for ameliorating the positive symptoms of the disorder, this approach often does not significantly improve negative and cognitive symptoms. Excitingly, preclinical and clinical research suggests that targeting specific muscarinic acetylcholine receptor subtypes could provide more comprehensive symptomatic relief with the potential to ameliorate numerous symptom domains. Mechanistic studies reveal that M1, M4, and M5 receptor subtypes can modulate the specific brain circuits and physiology that are disrupted in schizophrenia and are thought to underlie positive, negative, and cognitive symptoms. Novel therapeutic strategies for targeting these receptors are now advancing in clinical and preclinical development and expand upon the promise of these new treatment strategies to potentially provide more comprehensive relief than currently available antipsychotics.
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Affiliation(s)
- Daniel J Foster
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, United States; Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, United States
| | - Zoey K Bryant
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, United States; Warren 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; Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, 37232, United States.
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16
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Bakker C, Tasker T, Liptrot J, Hart EP, Klaassen ES, Prins S, van der Doef TF, Brown GA, Brown A, Congreve M, Weir M, Marshall FH, Cross DM, Groeneveld GJ, Nathan PJ. First-in-man study to investigate safety, pharmacokinetics and exploratory pharmacodynamics of HTL0018318, a novel M 1 -receptor partial agonist for the treatment of dementias. Br J Clin Pharmacol 2021; 87:2945-2955. [PMID: 33351971 PMCID: PMC8359307 DOI: 10.1111/bcp.14710] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/09/2020] [Accepted: 12/16/2020] [Indexed: 12/23/2022] Open
Abstract
AIMS HTL0018318 is a selective M1 receptor partial agonist currently under development for the symptomatic treatment of cognitive and behavioural symptoms in Alzheimer's disease and other dementias. We investigated safety, tolerability, pharmacokinetics and exploratory pharmacodynamics (PD) of HTL0018318 following single ascending doses. METHODS This randomized, double-blind, placebo-controlled study in 40 healthy younger adult and 57 healthy elderly subjects, investigated oral doses of 1-35 mg HTL0018318. Pharmacodynamic assessments were performed using a battery of neurocognitive tasks and electrophysiological measurements. Cerebrospinal fluid concentrations of HTL0018318 and food effects on pharmacokinetics of HTL0018318 were investigated in an open label and partial cross-over design in 14 healthy subjects. RESULTS Pharmacokinetics of HTL0018318 were well-characterized showing dose proportional increases in exposure from 1-35 mg. Single doses of HTL0018318 were associated with mild dose-related adverse events of low incidence in both younger adult and elderly subjects. The most frequently reported cholinergic AEs included hyperhidrosis and increases in blood pressure up to 10.3 mmHg in younger adults (95% CI [4.2-16.3], 35-mg dose) and up to 11.9 mmHg in elderly subjects (95% CI [4.9-18.9], 15-mg dose). There were no statistically significant effects on cognitive function but the study was not powered to detect small to moderate effect sizes of clinical relevance. CONCLUSION HTL0018318 showed well-characterized pharmacokinetics and following single doses were generally well tolerated in the dose range studied. These provide encouraging data in support of the development for HTL0018318 for Alzheimer's disease and other dementias.
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Affiliation(s)
| | | | | | - Ellen P Hart
- Centre for Human Drug Research (CDHR), Leiden, Netherlands
| | | | - Samantha Prins
- Centre for Human Drug Research (CDHR), Leiden, Netherlands
| | | | | | | | | | | | | | | | - Geert Jan Groeneveld
- Centre for Human Drug Research (CDHR), Leiden, Netherlands.,Leiden University Medical Centre, Leiden, The Netherlands
| | - Pradeep J Nathan
- Sosei Heptares, Cambridge, UK.,Department of Psychiatry, University of Cambridge, UK.,School of Psychological Sciences, Monash University, Australia
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17
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Moran SP, Xiang Z, Doyle CA, Maksymetz J, Lv X, Faltin S, Fisher NM, Niswender CM, Rook JM, Lindsley CW, Conn PJ. Biased M 1 receptor-positive allosteric modulators reveal role of phospholipase D in M 1-dependent rodent cortical plasticity. Sci Signal 2019; 12:12/610/eaax2057. [PMID: 31796631 DOI: 10.1126/scisignal.aax2057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Highly selective, positive allosteric modulators (PAMs) of the M1 subtype of muscarinic acetylcholine receptor have emerged as an exciting new approach to potentially improve cognitive function in patients suffering from Alzheimer's disease and schizophrenia. Discovery programs have produced a structurally diverse range of M1 receptor PAMs with distinct pharmacological properties, including different extents of agonist activity and differences in signal bias. This includes biased M1 receptor PAMs that can potentiate coupling of the receptor to activation of phospholipase C (PLC) but not phospholipase D (PLD). However, little is known about the role of PLD in M1 receptor signaling in native systems, and it is not clear whether biased M1 PAMs display differences in modulating M1-mediated responses in native tissue. Using PLD inhibitors and PLD knockout mice, we showed that PLD was necessary for the induction of M1-dependent long-term depression (LTD) in the prefrontal cortex (PFC). Furthermore, biased M1 PAMs that did not couple to PLD not only failed to potentiate orthosteric agonist-induced LTD but also blocked M1-dependent LTD in the PFC. In contrast, biased and nonbiased M1 PAMs acted similarly in potentiating M1-dependent electrophysiological responses that were PLD independent. These findings demonstrate that PLD plays a critical role in the ability of M1 PAMs to modulate certain central nervous system (CNS) functions and that biased M1 PAMs function differently in brain regions implicated in cognition.
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Affiliation(s)
- Sean P Moran
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Zixiu Xiang
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Catherine A Doyle
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - James Maksymetz
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Xiaohui Lv
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Sehr Faltin
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Nicole M Fisher
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Jerri M Rook
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - P Jeffrey Conn
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA. .,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37240, USA
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18
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Petkowski JJ, Bains W, Seager S. An Apparent Binary Choice in Biochemistry: Mutual Reactivity Implies Life Chooses Thiols or Nitrogen-Sulfur Bonds, but Not Both. ASTROBIOLOGY 2019; 19:579-613. [PMID: 30431334 DOI: 10.1089/ast.2018.1831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A fundamental goal of biology is to understand the rules behind life's use of chemical space. Established work focuses on why life uses the chemistry that it does. Given the enormous scope of possible chemical space, we postulate that it is equally important to ask why life largely avoids certain areas of chemical space. The nitrogen-sulfur bond is a prime example, as it rarely appears in natural molecules, despite the very rich N-S bond chemistry applied in various branches of industry (e.g., industrial materials, agrochemicals, pharmaceuticals). We find that, out of more than 200,000 known, unique compounds made by life, only about 100 contain N-S bonds. Furthermore, the limited number of N-S bond-containing molecules that life produces appears to fall into a few very distinctive structural groups. One may think that industrial processes are unrelated to biochemistry because of a greater possibility of solvents, catalysts, and temperatures available to industry than to the cellular environment. However, the fact that life does rarely make N-S bonds, from the plentiful precursors available, and has evolved the ability to do so independently several times, suggests that the restriction on life's use of N-S chemistry is not in its synthesis. We present a hypothesis to explain life's extremely limited usage of the N-S bond: that the N-S bond chemistry is incompatible with essential segments of biochemistry, specifically with thiols. We support our hypothesis by (1) a quantitative analysis of the occurrence of N-S bond-containing natural products and (2) reactivity experiments between selected N-S compounds and key biological molecules. This work provides an example of a reason why life nearly excludes a distinct region of chemical space. Combined with future examples, this potentially new field of research may provide fresh insight into life's evolution through chemical space and its origin and early evolution.
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Affiliation(s)
- Janusz J Petkowski
- 1 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | | | - Sara Seager
- 1 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
- 3 Department of Physics, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
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19
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Thorn CA, Moon J, Bourbonais CA, Harms J, Edgerton JR, Stark E, Steyn SJ, Butter CR, Lazzaro JT, O’Connor RE, Popiolek M. Striatal, Hippocampal, and Cortical Networks Are Differentially Responsive to the M4- and M1-Muscarinic Acetylcholine Receptor Mediated Effects of Xanomeline. ACS Chem Neurosci 2019; 10:1753-1764. [PMID: 30480428 DOI: 10.1021/acschemneuro.8b00625] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Preclinical and clinical data suggest that muscarinic acetylcholine receptor activation may be therapeutically beneficial for the treatment of schizophrenia and Alzheimer's diseases. This is best exemplified by clinical observations with xanomeline, the efficacy of which is thought to be mediated through co-activation of the M1 and M4 muscarinic acetylcholine receptors (mAChRs). Here we examined the impact of treatment with xanomeline and compared it to the actions of selective M1 and M4 mAChR activators on in vivo intracellular signaling cascades in mice, including 3'-5'-cyclic adenosine monophosphate response element binding protein (CREB) phosphorylation and inositol phosphate-1 (IP1) accumulation in the striatum, hippocampus, and prefrontal cortex. We additionally assessed the effects of xanomeline on hippocampal electrophysiological signatures in rats using ex vivo recordings from CA1 (Cornu Ammonis 1) as well as in vivo hippocampal theta. As expected, xanomeline's effects across these readouts were consistent with activation of both M1 and M4 mAChRs; however, differences were observed across different brain regions, suggesting non-uniform activation of these receptor subtypes in the central nervous system. Interestingly, despite having nearly equal in vitro potency at the M1 and the M4 mAChRs, during in vivo assays xanomeline produced M4-like effects at significantly lower brain exposures than those at which M1-like effects were observed. Our results raise the possibility that clinical efficacy observed with xanomeline was driven, in part, through its non-uniform activation of mAChR subtypes in the central nervous system and, at lower doses, through preferential agonism of the M4 mAChR.
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Affiliation(s)
| | | | | | | | | | | | | | | | - John T. Lazzaro
- Primary Pharmacology Group, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
| | - Rebecca E. O’Connor
- Primary Pharmacology Group, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, United States
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20
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GPCR drug discovery-moving beyond the orthosteric to the allosteric domain. ADVANCES IN PHARMACOLOGY 2019; 86:1-20. [DOI: 10.1016/bs.apha.2019.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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21
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Del Bello F, Bonifazi A, Giorgioni G, Cifani C, Micioni Di Bonaventura MV, Petrelli R, Piergentili A, Fontana S, Mammoli V, Yano H, Matucci R, Vistoli G, Quaglia W. 1-[3-(4-Butylpiperidin-1-yl)propyl]-1,2,3,4-tetrahydroquinolin-2-one (77-LH-28-1) as a Model for the Rational Design of a Novel Class of Brain Penetrant Ligands with High Affinity and Selectivity for Dopamine D4 Receptor. J Med Chem 2018; 61:3712-3725. [DOI: 10.1021/acs.jmedchem.8b00265] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Fabio Del Bello
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Alessandro Bonifazi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse−Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Gianfabio Giorgioni
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Carlo Cifani
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | | | - Riccardo Petrelli
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Alessandro Piergentili
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Stefano Fontana
- Center for Drug Discovery and Development-DMPK, Aptuit, an Evotec Company, Via A. Fleming, 4, 37135 Verona, Italy
| | - Valerio Mammoli
- Center for Drug Discovery and Development-DMPK, Aptuit, an Evotec Company, Via A. Fleming, 4, 37135 Verona, Italy
| | - Hideaki Yano
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse−Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Rosanna Matucci
- Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino (NEUROFARBA), Sezione di Farmacologia e Tossicologia, Università degli Studi di Firenze, Viale Pieraccini 6, 50139 Firenze, Italy
| | - Giulio Vistoli
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
| | - Wilma Quaglia
- Scuola di Scienze del Farmaco e dei Prodotti della Salute, Università di Camerino, Via S. Agostino 1, 62032 Camerino, Italy
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22
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Uslaner JM, Kuduk SD, Wittmann M, Lange HS, Fox SV, Min C, Pajkovic N, Harris D, Cilissen C, Mahon C, Mostoller K, Warrington S, Beshore DC. Preclinical to Human Translational Pharmacology of the Novel M1 Positive Allosteric Modulator MK-7622. J Pharmacol Exp Ther 2018; 365:556-566. [DOI: 10.1124/jpet.117.245894] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/16/2018] [Indexed: 11/22/2022] Open
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23
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Wood MW, Martino G, Coupal M, Lindberg M, Schroeder P, Santhakumar V, Valiquette M, Sandin J, Widzowski D, Laird J. Broad analgesic activity of a novel, selective M1 agonist. Neuropharmacology 2017. [PMID: 28623171 DOI: 10.1016/j.neuropharm.2017.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although the muscarinic receptor family has long been a source of potentially compelling targets for small molecule drug discovery, it was difficult to achieve agonist selectivity within the family. A new class of M1 muscarinic agonists has emerged, and these compounds have been characterized as agonists that activate the receptor at an allosteric site. Members of this class of M1 agonists have been shown to be selective across the muscarinic receptors. However, upon introduction of a novel pharmacologic mechanism, it is prudent to ensure that no new off-target activities have arisen, particularly within the context of in vivo experiments. Reported here, is the in vitro and in vivo characterization of a novel M1 agonist tool compound, PPBI, and demonstrations that the primary biological effects of PPBI are mediated through M1. PPBI reverses d-amphetamine locomotor activity, but fails to do so in transgenic mice that do not express M1. PPBI also reverses a natural deficit in a rat cognition model at a level of exposure which also activates cortical circuitry. Most notably, PPBI is analgesic in a variety of rat and mouse models and the analgesic effect of PPBI is reversed by an M1-preferring antagonist and an M1-selective toxin. Finally, the pharmacokinetic/pharmacodynamic measures of PPBI are compared across multiple endpoints which highlights that activity in models of psychosis and pain require higher exposures than that required in the cognition model.
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Affiliation(s)
- Michael W Wood
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States.
| | - Giovanni Martino
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Martin Coupal
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Mattias Lindberg
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Patricia Schroeder
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Vijayaratnam Santhakumar
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Manon Valiquette
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Johan Sandin
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Daniel Widzowski
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
| | - Jennifer Laird
- AstraZeneca, Neuroscience, Innovative Medicines & Early Development, Waltham, MA 02451, United States
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24
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Mitoh Y, Ueda H, Ichikawa H, Fujita M, Kobashi M, Matsuo R. Effects of cevimeline on excitability of parasympathetic preganglionic neurons in the superior salivatory nucleus of rats. Auton Neurosci 2017; 206:1-7. [PMID: 28600120 DOI: 10.1016/j.autneu.2017.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/04/2017] [Accepted: 05/24/2017] [Indexed: 12/11/2022]
Abstract
The superior salivatory nucleus (SSN) contains parasympathetic preganglionic neurons innervating the submandibular and sublingual salivary glands. Cevimeline, a muscarinic acetylcholine receptor (mAChR) agonist, is a sialogogue that possibly stimulates SSN neurons in addition to the salivary glands themselves because it can cross the blood-brain barrier (BBB). In the present study, we examined immunoreactivities for mAChR subtypes in SSN neurons retrogradely labeled with a fluorescent tracer in neonatal rats. Additionally, we examined the effects of cevimeline in labeled SSN neurons of brainstem slices using a whole-cell patch-clamp technique. Mainly M1 and M3 receptors were detected by immunohistochemical staining, with low-level detection of M4 and M5 receptors and absence of M2 receptors. Most (110 of 129) SSN neurons exhibited excitatory responses to application of cevimeline. In responding neurons, voltage-clamp recordings showed that 84% (101/120) of the neurons exhibited inward currents. In the neurons displaying inward currents, the effects of the mAChR antagonists were examined. A mixture of M1 and M3 receptor antagonists most effectively reduced the peak amplitude of inward currents, suggesting that the excitatory effects of cevimeline on SSN neurons were mainly mediated by M1 and M3 receptors. Current-clamp recordings showed that application of cevimeline induced membrane depolarization (9/9 neurons). These results suggest that most SSN neurons are excited by cevimeline via M1 and M3 muscarinic receptors.
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Affiliation(s)
- Yoshihiro Mitoh
- Department of Oral Physiology, Okayama University Graduate School of Medicine and Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan; Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama 700-8525, Japan.
| | - Hirotaka Ueda
- Department of Orthodontics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Hiroyuki Ichikawa
- Division of Oral and Craniofacial Anatomy, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan
| | - Masako Fujita
- Department of Oral Physiology, Okayama University Graduate School of Medicine and Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan
| | - Motoi Kobashi
- Department of Oral Physiology, Okayama University Graduate School of Medicine and Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan
| | - Ryuji Matsuo
- Department of Oral Physiology, Okayama University Graduate School of Medicine and Dentistry and Pharmaceutical Sciences, Okayama 700-8525, Japan.
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25
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Abstract
Xanomeline (1) is an orthosteric muscarinic acetylcholine receptor (mAChR) agonist, often referred to as M1/M4-preferring, that received widespread attention for its clinical efficacy in schizophrenia and Alzheimer's disease (AD) patients. Despite the compound's promising initial clinical results, dose-limiting side effects limited further clinical development. While xanomeline, and related orthosteric muscarinic agonists, have yet to receive approval from the FDA for the treatment of these CNS disorders, interest in the compound's unique M1/M4-preferring mechanism of action is ongoing in the field of chemical neuroscience. Specifically, the promising cognitive and behavioral effects of xanomeline in both schizophrenia and AD have spurred a renewed interest in the development of safer muscarinic ligands with improved subtype selectivity for either M1 or M4. This Review will address xanomeline's overall importance in the field of neuroscience, with a specific focus on its chemical structure and synthesis, pharmacology, drug metabolism and pharmacokinetics (DMPK), and adverse effects.
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Affiliation(s)
- Aaron M. Bender
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Carrie K. Jones
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department
of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department
of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
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26
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Popiolek M, Nguyen DP, Reinhart V, Edgerton JR, Harms J, Lotarski SM, Steyn SJ, Davoren JE, Grimwood S. Inositol Phosphate Accumulation in Vivo Provides a Measure of Muscarinic M 1 Receptor Activation. Biochemistry 2016; 55:7073-7085. [PMID: 27958713 DOI: 10.1021/acs.biochem.6b00688] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The rationale for using M1 selective muscarinic acetylcholine receptor activators for the treatment of cognitive impairment associated with psychiatric and neurodegenerative disease is well-established in the literature. Here, we investigate measurement of inositol phosphate accumulation, an end point immediately downstream of the M1 muscarinic acetylcholine receptor signaling cascade, as an in vivo biochemical readout for M1 muscarinic acetylcholine receptor activation. Five brain penetrant M1-subtype selective activators from three structurally distinct chemical series were pharmacologically profiled for functional activity in vitro using recombinant cell calcium mobilization and inositol phosphate assays, and a native tissue hippocampal slice electrophysiology assay, to show that all five compounds presented a positive allosteric modulator agonist profile, within a narrow range of potencies. In vivo characterization using an amphetamine-stimulated locomotor activity behavioral assay and the inositol phosphate accumulation biochemical assay demonstrated that the latter has utility for assessing functional potency of M1 activators. Efficacy measured by inositol phosphate accumulation in mouse striatum compared favorably to efficacy in reversing amphetamine-induced locomotor activity, suggesting that the inositol phosphate accumulation assay has utility for the evaluation of M1 muscarinic acetylcholine receptor activators in vivo. The benefits of this in vivo biochemical approach include a wide response window, interrogation of specific brain circuit activation, an ability to model responses in the context of brain exposure, an ability to rank order compounds based on in vivo efficacy, and minimization of animal use.
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Affiliation(s)
- Michael Popiolek
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - David P Nguyen
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - Veronica Reinhart
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - Jeremy R Edgerton
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - John Harms
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - Susan M Lotarski
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - Stefanus J Steyn
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - Jennifer E Davoren
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
| | - Sarah Grimwood
- Neuroscience and Pain Research Unit, ‡Pharmacokinetics, Dynamics and Metabolism, and §Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development , Cambridge, Massachusetts 02139, United States
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27
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Odagaki Y, Kinoshita M, Ota T. Comparative analysis of pharmacological properties of xanomeline and N-desmethylclozapine in rat brain membranes. J Psychopharmacol 2016; 30:896-912. [PMID: 27464743 DOI: 10.1177/0269881116658989] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND 3(3-Hexyloxy-1,2,5-thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-methylpyridine (xanomeline) and N-desmethylclozapine are of special interest as promising antipsychotics with better efficacy, especially for negative symptoms and/or cognitive/affective impairment. METHODS The guanosine-5'-O-(3-[(35)S]thio)triphosphate ([(35)S]GTPγS) binding experiments were performed using (1) conventional filtration technique, (2) antibody-capture scintillation proximity assay, and (3) immunoprecipitation method, in brain membranes prepared from rat cerebral cortex, hippocampus, and striatum. RESULTS Xanomeline had agonistic activity at the M1 muscarinic acetylcholine receptor (mAChR) in all brain regions, as well as at the 5-HT1A receptor in the cerebral cortex and hippocampus. On the other hand, N-desmethylclozapine exhibited slight agonistic effects on the M1 mAChR, and agonistic properties at the 5-HT1A receptor in the cerebral cortex and hippocampus. This compound also behaved as an agonist at the δ-opioid receptor in the cerebral cortex and striatum. In addition, the stimulatory effects of N-desmethylclozapine on [(35)S]GTPγS binding to Gαi/o were partially mediated through mAChRs (most likely M4 mAChR subtype), at least in striatum. CONCLUSIONS The agonistic effects on the mAChRs (particularly M1 subtype, and also probably M4 subtype), the 5-HT1A receptor and the δ-opioid receptor expressed in native brain tissues, some of which are common to both compounds and others specific to either, likely shape the unique beneficial effectiveness of both compounds in the treatment for schizophrenic patients. These characteristics provide us with a clue to develop newer antipsychotics, beyond the framework of dopamine D2 receptor antagonism, that are effective not only on positive symptoms but also on negative symptoms and/or cognitive/affective impairment.
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Affiliation(s)
- Yuji Odagaki
- Department of Psychiatry, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Masakazu Kinoshita
- Department of Psychiatry, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Toshio Ota
- Department of Psychiatry, Faculty of Medicine, Saitama Medical University, Saitama, Japan
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Welt T, Kulic L, Hoey SE, McAfoose J, Späni C, Chadha AS, Fisher A, Nitsch RM. Acute Effects of Muscarinic M1 Receptor Modulation on AβPP Metabolism and Amyloid-β Levels in vivo: A Microdialysis Study. J Alzheimers Dis 2016; 46:971-82. [PMID: 25881909 DOI: 10.3233/jad-150152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Indirect modulation of cholinergic activity by cholinesterase inhibition is currently a widely established symptomatic treatment for Alzheimer's disease (AD). Selective activation of certain muscarinic receptor subtypes has emerged as an alternative cholinergic-based amyloid-lowering strategy for AD, as selective muscarinic M1 receptor agonists can reduce amyloid-β (Aβ) production by shifting endoproteolytic amyloid-β protein precursor (AβPP) processing toward non-amyloidogenic pathways. In this study, we addressed the hypothesis that acute stimulation of muscarinic M1 receptors can inhibit Aβ production in awake and freely moving AβPP transgenic mice. By combining intracerebral microdialysis with retrodialysis, we determined hippocampal Aβ concentrations during simultaneous pharmacological modulation of brain M1 receptor function. Infusion with a M1 receptor agonist AF102B resulted in a rapid reduction of interstitial fluid (ISF) Aβ levels while treatment with the M1 antagonist dicyclomine increased ISF Aβ levels reaching significance within 120 minutes of treatment. The reduction in Aβ levels was associated with PKCα and ERK activation resulting in increased levels of the α-secretase ADAM17 and a shift in AβPP processing toward the non-amyloidogenic processing pathway. In contrast, treatment with the M1 receptor antagonist dicyclomine caused a decrease in levels of phosphorylated ERK that was independent of PKCα, and led to an elevation of β-secretase levels associated with increased amyloidogenic AβPP processing. The results of this study demonstrate rapid effects of in vivo M1 receptor modulation on the ISF pool of Aβ and suggest that intracerebral microdialysis with retrodialysis is a useful technical approach for monitoring acute treatment effects of muscarinic receptor modulators on AβPP/Aβ metabolism.
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Affiliation(s)
- Tobias Welt
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | - Luka Kulic
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland
| | - Sarah E Hoey
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | - Jordan McAfoose
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | - Claudia Späni
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
| | | | - Abraham Fisher
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Roger M Nitsch
- Division of Psychiatry Research, University of Zürich Campus Schlieren, Switzerland
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29
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Thal DM, Sun B, Feng D, Nawaratne V, Leach K, Felder CC, Bures MG, Evans DA, Weis WI, Bachhawat P, Kobilka TS, Sexton PM, Kobilka BK, Christopoulos A. Crystal structures of the M1 and M4 muscarinic acetylcholine receptors. Nature 2016; 531:335-40. [PMID: 26958838 DOI: 10.1038/nature17188] [Citation(s) in RCA: 233] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 01/29/2016] [Indexed: 12/19/2022]
Abstract
Muscarinic M1-M5 acetylcholine receptors are G-protein-coupled receptors that regulate many vital functions of the central and peripheral nervous systems. In particular, the M1 and M4 receptor subtypes have emerged as attractive drug targets for treatments of neurological disorders, such as Alzheimer's disease and schizophrenia, but the high conservation of the acetylcholine-binding pocket has spurred current research into targeting allosteric sites on these receptors. Here we report the crystal structures of the M1 and M4 muscarinic receptors bound to the inverse agonist, tiotropium. Comparison of these structures with each other, as well as with the previously reported M2 and M3 receptor structures, reveals differences in the orthosteric and allosteric binding sites that contribute to a role in drug selectivity at this important receptor family. We also report identification of a cluster of residues that form a network linking the orthosteric and allosteric sites of the M4 receptor, which provides new insight into how allosteric modulation may be transmitted between the two spatially distinct domains.
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Affiliation(s)
- David M Thal
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Bingfa Sun
- ConfometRx, 3070 Kenneth Street, Santa Clara, California 95054, USA
| | - Dan Feng
- ConfometRx, 3070 Kenneth Street, Santa Clara, California 95054, USA
| | - Vindhya Nawaratne
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Katie Leach
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | | | - Mark G Bures
- Computational Chemistry and Chemoinformatics, Eli Lilly, Indianapolis, Indiana 46285, USA
| | - David A Evans
- Computational Chemistry and Chemoinformatics, Eli Lilly, Sunninghill Road, Windlesham GU20 6PH, UK
| | - William I Weis
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Priti Bachhawat
- ConfometRx, 3070 Kenneth Street, Santa Clara, California 95054, USA
| | - Tong Sun Kobilka
- ConfometRx, 3070 Kenneth Street, Santa Clara, California 95054, USA
| | - Patrick M Sexton
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Brian K Kobilka
- ConfometRx, 3070 Kenneth Street, Santa Clara, California 95054, USA.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Arthur Christopoulos
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
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30
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Broadley KJ, Buffat MGP, Burnell E, Davies RH, Moreau X, Snee S, Thomas EJ. Stereoselective synthesis of oxazolidinonyl-fused piperidines of interest as selective muscarinic (M1) receptor agonists: a novel M1 allosteric modulator. Org Biomol Chem 2016; 14:2057-89. [PMID: 26768599 DOI: 10.1039/c5ob02588e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Syntheses of (1RS,2SR,6SR)-2-alkoxymethyl-, 2-hetaryl-, and 2-(hetarylmethyl)-7-arylmethyl-4,7-diaza-9-oxabicyclo[4.3.0]nonan-8-ones, of interest as potential muscarinic M1 receptor agonists, are described. A key step in the synthesis of (1RS,2SR,6SR)-7-benzyl-6-cyclobutyl-2-methoxymethyl-4,7-diaza-9-oxabicyclo[4.3.0]nonan-8-one, was the addition of isopropenylmagnesium bromide to 2-benzyloxycarbonylamino-3-tert-butyldimethylsilyloxy-2-cyclobutylpropanal. This gave the 4-tert-butyldimethylsilyloxymethyl-4-cyclobutyl-5-isopropenyloxazolidinone with the 5-isopropenyl and 4-tert-butyldimethylsilyloxymethyl groups cis-disposed about the five-membered ring by chelation controlled addition and in situ cyclisation. This reaction was useful for a range of organometallic reagents. The hydroboration-oxidation of (4SR,5RS)-3-benzyl-4-(tert-butyldimethylsilyloxymethyl)-4-cyclobutyl-5-(1-methoxyprop-2-en-2-yl)-1,3-oxazolidin-2-one gave (4SR,5RS)-3-benzyl-4-(tert-butyldimethylsilyloxymethyl)-4-cyclobutyl-5-[(SR)-1-hydroxy-3-methoxyprop-2-yl]-1,3-oxazolidin-2-one stereoselectively. 4,7-Diaza-9-oxabicyclo[4.3.0]nonan-8-ones with substituents at C2 that could facilitate C2 deprotonation were unstable with respect to oxazolidinone ring-opening and this restricted both the synthetic approach and choice of 2-heteroaryl substituent. The bicyclic system with a 2-furyl substituent at C2 was therefore identified as an important target. The addition of 1-lithio-1-(2-furyl)ethene to 2-benzyloxycarbonylamino-3-tert-butyldimethylsilyloxy-2-cyclobutylpropanal gave (4SR,5RS)-4-tert-butyldimethylsilyloxymethyl-4-cyclobutyl-5-[1-(2-furyl)ethenyl]-1,3-oxazolidinone after chelation controlled addition and in situ cyclisation. Following oxazolidinone N-benzylation, hydroboration at 35 °C, since hydroboration at 0 °C was unexpectedly selective for the undesired isomer, followed by oxidation gave a mixture of side-chain epimeric alcohols that were separated after SEM-protection and selective desilylation. Conversion of the neopentylic alcohols into the corresponding primary amines by reductive amination, was followed by N-nosylation, removal of the SEM-groups and cyclisation using a Mitsunobu reaction. Denosylation then gave the 2-furyloxazolidinonyl-fused piperidines, the (1RS,2SR,6SR)-epimer showing an allosteric agonistic effect on M1 receptors. Further studies resulted in the synthesis of other 2-substituted 4,7-diaza-9-oxabicyclo[4.3.0]nonan-8-ones and an analogous tetrahydropyran.
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Affiliation(s)
- Kenneth J Broadley
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
| | - Maxime G P Buffat
- The School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
| | - Erica Burnell
- The School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
| | | | - Xavier Moreau
- The School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
| | - Stephen Snee
- The School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
| | - Eric J Thomas
- The School of Chemistry, The University of Manchester, Manchester, M13 9PL, UK.
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31
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Alt A, Pendri A, Bertekap RL, Li G, Benitex Y, Nophsker M, Rockwell KL, Burford NT, Sum CS, Chen J, Herbst JJ, Ferrante M, Hendricson A, Cvijic ME, Westphal RS, OConnell J, Banks M, Zhang L, Gentles RG, Jenkins S, Loy J, Macor JE. Evidence for Classical Cholinergic Toxicity Associated with Selective Activation of M1 Muscarinic Receptors. ACTA ACUST UNITED AC 2015; 356:293-304. [DOI: 10.1124/jpet.115.226910] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 11/17/2015] [Indexed: 11/22/2022]
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Improved cognition without adverse effects: novel M1 muscarinic potentiator compares favorably to donepezil and xanomeline in rhesus monkey. Psychopharmacology (Berl) 2015; 232:1859-66. [PMID: 25491927 DOI: 10.1007/s00213-014-3813-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 11/11/2014] [Indexed: 02/05/2023]
Abstract
RATIONALE The standards of care for Alzheimer's disease, acetylcholinesterase inhibitors such as donepezil (Aricept®), are dose-limited due to adverse side-effects. These adverse events lead to significant patient non-compliance, constraining the dose and magnitude of efficacy that can be achieved. Non-selective muscarinic receptor orthosteric agonists such as Xanomeline have been shown to be effective in treating symptoms as well, but were also poorly tolerated. Therefore, there is an unmet medical need for a symptomatic treatment that improves symptoms and is better tolerated. METHODS We compared donepezil, xanomeline, and the novel selective muscarinic 1 receptor positive allosteric modulator PQCA in combination with donepezil in the object retrieval detour (ORD) cognition test in rhesus macaque. Gastrointestinal (GI) side effects (salivation and feces output) were then assessed with all compounds to determine therapeutic window. RESULTS All three compounds significantly reduced a scopolamine-induced deficit in ORD. Consistent with what is observed clinically in patients, both donepezil and xanomeline produced significant GI effects in rhesus at doses equal to or less than a fivefold margin from the minimum effective dose that improves cognition. In stark contrast, PQCA produced no GI side effects when tested at the same dose range. CONCLUSIONS These data suggest M1 positive allosteric modulators have the potential to improve cognition in Alzheimer's disease with a greater therapeutic margin than the current standard of care, addressing an important unmet medical need.
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33
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Aslanoglou D, Alvarez-Curto E, Marsango S, Milligan G. Distinct Agonist Regulation of Muscarinic Acetylcholine M2-M3 Heteromers and Their Corresponding Homomers. J Biol Chem 2015; 290:14785-96. [PMID: 25918156 PMCID: PMC4505543 DOI: 10.1074/jbc.m115.649079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 01/01/2023] Open
Abstract
Each subtype of the muscarinic receptor family of G protein-coupled receptors is activated by similar concentrations of the neurotransmitter acetylcholine or closely related synthetic analogs such as carbachol. However, pharmacological selectivity can be generated by the introduction of a pair of mutations to produce Receptor Activated Solely by Synthetic Ligand (RASSL) forms of muscarinic receptors. These display loss of potency for acetylcholine/carbachol alongside a concurrent gain in potency for the ligand clozapine N-oxide. Co-expression of a form of wild type human M2 and a RASSL variant of the human M3 receptor resulted in concurrent detection of each of M2-M2 and M3-M3 homomers alongside M2-M3 heteromers at the surface of stably transfected Flp-InTM T-RExTM 293 cells. In this setting occupancy of the receptors with a muscarinic antagonist was without detectable effect on any of the muscarinic oligomers. However, selective agonist occupancy of the M2 receptor resulted in enhanced M2-M2 homomer interactions but decreased M2-M3 heteromer interactions. By contrast, selective activation of the M3 RASSL receptor did not significantly alter either M3-M3 homomer or M2-M3 heteromer interactions. Selectively targeting closely related receptor oligomers may provide novel therapeutic opportunities.
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Affiliation(s)
- Despoina Aslanoglou
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Elisa Alvarez-Curto
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Sara Marsango
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Graeme Milligan
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
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34
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Prakash A, Kalra J, Mani V, Ramasamy K, Majeed ABA. Pharmacological approaches for Alzheimer’s disease: neurotransmitter as drug targets. Expert Rev Neurother 2014; 15:53-71. [DOI: 10.1586/14737175.2015.988709] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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35
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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.
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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.)
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M1-muscarinic receptors promote fear memory consolidation via phospholipase C and the M-current. J Neurosci 2014; 34:1570-8. [PMID: 24478341 DOI: 10.1523/jneurosci.1040-13.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Neuromodulators released during and after a fearful experience promote the consolidation of long-term memory for that experience. Because overconsolidation may contribute to the recurrent and intrusive memories of post-traumatic stress disorder, neuromodulatory receptors provide a potential pharmacological target for prevention. Stimulation of muscarinic receptors promotes memory consolidation in several conditioning paradigms, an effect primarily associated with the M1 receptor (M1R). However, neither inhibiting nor genetically disrupting M1R impairs the consolidation of cued fear memory. Using the M1R agonist cevimeline and antagonist telenzepine, as well as M1R knock-out mice, we show here that M1R, along with β2-adrenergic (β2AR) and D5-dopaminergic (D5R) receptors, regulates the consolidation of cued fear memory by redundantly activating phospholipase C (PLC) in the basolateral amygdala (BLA). We also demonstrate that fear memory consolidation in the BLA is mediated in part by neuromodulatory inhibition of the M-current, which is conducted by KCNQ channels and is known to be inhibited by muscarinic receptors. Manipulating the M-current by administering the KCNQ channel blocker XE991 or the KCNQ channel opener retigabine reverses the effects on consolidation caused by manipulating β2AR, D5R, M1R, and PLC. Finally, we show that cAMP and protein kinase A (cAMP/PKA) signaling relevant to this stage of consolidation is upstream of these neuromodulators and PLC, suggesting an important presynaptic role for cAMP/PKA in consolidation. These results support the idea that neuromodulatory regulation of ion channel activity and neuronal excitability is a critical mechanism for promoting consolidation well after acquisition has occurred.
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Liu H, Wang L, Lv M, Pei R, Li P, Pei Z, Wang Y, Su W, Xie XQ. AlzPlatform: an Alzheimer's disease domain-specific chemogenomics knowledgebase for polypharmacology and target identification research. J Chem Inf Model 2014; 54:1050-60. [PMID: 24597646 PMCID: PMC4010297 DOI: 10.1021/ci500004h] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
Alzheimer’s
disease (AD) is one of the most complicated progressive neurodegeneration
diseases that involve many genes, proteins, and their complex interactions.
No effective medicines or treatments are available yet to stop or
reverse the progression of the disease due to its polygenic nature.
To facilitate discovery of new AD drugs and better understand the
AD neurosignaling pathways involved, we have constructed an Alzheimer’s
disease domain-specific chemogenomics knowledgebase, AlzPlatform (www.cbligand.org/AD/) with cloud computing and sourcing
functions. AlzPlatform is implemented with powerful computational
algorithms, including our established TargetHunter, HTDocking, and
BBB Predictor for target identification and polypharmacology analysis
for AD research. The platform has assembled various AD-related chemogenomics
data records, including 928 genes and 320 proteins related to AD,
194 AD drugs approved or in clinical trials, and 405 188 chemicals
associated with 1 023 137 records of reported bioactivities
from 38 284 corresponding bioassays and 10 050 references.
Furthermore, we have demonstrated the application of the AlzPlatform
in three case studies for identification of multitargets and polypharmacology
analysis of FDA-approved drugs and also for screening and prediction
of new AD active small chemical molecules and potential novel AD drug
targets by our established TargetHunter and/or HTDocking programs.
The predictions were confirmed by reported bioactivity data and our
in vitro experimental validation. Overall, AlzPlatform will enrich
our knowledge for AD target identification, drug discovery, and polypharmacology
analyses and, also, facilitate the chemogenomics data sharing and
information exchange/communications in aid of new anti-AD drug discovery
and development.
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Affiliation(s)
- Haibin Liu
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy; Drug Discovery Institute; University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
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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.
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Affiliation(s)
| | | | | | | | | | | | | | | | - V. DOLEŽAL
- Department of Neurochemistry, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Thomsen M, Fulton BS, Caine SB. Acute and chronic effects of the M1/M4-preferring muscarinic agonist xanomeline on cocaine vs. food choice in rats. Psychopharmacology (Berl) 2014; 231:469-79. [PMID: 23995301 PMCID: PMC3947149 DOI: 10.1007/s00213-013-3256-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 08/15/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE We previously showed that the M1/M4-preferring muscarinic agonist xanomeline can acutely attenuate or eliminate cocaine self-administration in mice. OBJECTIVE Medications used to treat addictions will arguably be administered in (sub)chronic or repeated regimens. Tests of acute effects often fail to predict chronic effects, highlighting the need for chronic testing of candidate medications. METHODS Rats were trained to lever press under a concurrent FR5 FR5 schedule of intravenous cocaine and food reinforcement. Once baseline behavior stabilized, the effects of 7 days once-daily injections of xanomeline were evaluated. RESULTS Xanomeline pretreatment dose-dependently (1.8-10 mg/kg/day) shifted the dose-effect curve for cocaine rightward (up to 5.6-fold increase in A 50), with reallocation of behavior to the food-reinforced lever. There was no indication of tolerance, rather effects grew over days. The suppression of cocaine choice appeared surmountable at high cocaine doses, and xanomeline treatment did not significantly decrease total-session cocaine or food intake. CONCLUSIONS In terms of xanomeline's potential for promoting abstinence from cocaine in humans, the findings were mixed. Xanomeline did produce reallocation of behavior from cocaine to food with a robust increase in food reinforcers earned at some cocaine/xanomeline dose combinations. However, effects appeared surmountable, and food-maintained behavior was also decreased at some xanomeline/cocaine dose combinations, suggesting clinical usefulness may be limited. These data nevertheless support the notion that chronic muscarinic receptor stimulation can reduce cocaine self-administration. Future studies should show whether ligands with higher selectivity for M1 or M1/M4 subtypes would be less limited by undesired effects and can achieve higher efficacy.
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Affiliation(s)
- Morgane Thomsen
- Alcohol and Drug Abuse Research Center, McLean Hospital/Harvard Medical School, Belmont, MA, USA,
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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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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.
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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
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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
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Melancon BJ, Tarr JC, Panarese JD, Wood MR, Lindsley CW. Allosteric modulation of the M1 muscarinic acetylcholine receptor: improving cognition and a potential treatment for schizophrenia and Alzheimer's disease. Drug Discov Today 2013; 18:1185-99. [PMID: 24051397 PMCID: PMC3876030 DOI: 10.1016/j.drudis.2013.09.005] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/02/2013] [Accepted: 09/09/2013] [Indexed: 12/13/2022]
Abstract
Allosteric modulation of AMPA, NR2B, mGlu2, mGlu5 and M1, targeting glutamatergic dysfunction, represents a significant area of research for the treatment of schizophrenia. Of these targets, clinical promise has been demonstrated using muscarinic activators for the treatment of Alzheimer's disease (AD) and schizophrenia. These diseases have inspired researchers to determine the effects of modulating cholinergic transmission in the forebrain, which is primarily regulated by one of five subtypes of muscarinic acetylcholine receptor (mAChR), a subfamily of G-protein-coupled receptors (GPCRs). Of these five subtypes, M1 is highly expressed in brain regions responsible for learning, cognition and memory. Xanomeline, an orthosteric muscarinic agonist with modest selectivity, was one of the first compounds that displayed improvements in behavioral disturbances in AD patients and efficacy in schizophrenics. Since these initial clinical results, many scientists, including those in our laboratories, have strived to elucidate the role of M1 with compounds that display improved selectivity for this receptor by targeting allosteric modes of receptor activation. A survey of selected compounds in this area will be presented.
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Affiliation(s)
- Bruce J Melancon
- Vanderbilt Center for Neuroscience Drug Discovery, Department of Pharmacology, Vanderbilt University Medical Center, 1205 Light Hall, Nashville, TN 37232-6600, USA
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Odagaki Y, Kinoshita M, Toyoshima R. Pharmacological characterization of M1 muscarinic acetylcholine receptor-mediated Gq activation in rat cerebral cortical and hippocampal membranes. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:937-47. [DOI: 10.1007/s00210-013-0887-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/27/2013] [Indexed: 11/30/2022]
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Uslaner JM, Eddins D, Puri V, Cannon CE, Sutcliffe J, Chew CS, Pearson M, Vivian JA, Chang RK, Ray WJ, Kuduk SD, Wittmann M. The muscarinic M1 receptor positive allosteric modulator PQCA improves cognitive measures in rat, cynomolgus macaque, and rhesus macaque. Psychopharmacology (Berl) 2013; 225:21-30. [PMID: 22825578 DOI: 10.1007/s00213-012-2788-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 06/20/2012] [Indexed: 12/24/2022]
Abstract
RATIONALE The current standards of care for Alzheimer's disease, acetylcholinesterase inhibitors, have limited efficacy due to a host of mechanism-related side effects arising from indiscriminate activation of muscarinic and nicotinic receptors. The M1 muscarinic receptor is predominantly expressed in the brain in regions involved in cognition, and therefore selective activation of the M1 receptor would be expected to boost cognitive performance with reduced risk of peripheral side effects. OBJECTIVES Here we investigated whether the selective M1 muscarinic receptor positive allosteric modulator, PQCA, improves cognitive performance and cerebral blood flow. RESULTS PQCA attenuated a scopolamine-induced deficit in novel object recognition in rat, self-ordered spatial search in cynomolgus macaque, and the object retrieval detour task in rhesus macaque. Beneficial effects in each of these assays and species were observed at similar plasma drug concentrations. Furthermore, at similar drug concentrations that were effective in the behavioral studies, PQCA increased blood flow in the frontal cortex of mice, providing a translational biomarker that could be used to guide dose selection for clinical studies. CONCLUSIONS These findings provide a framework for appropriately testing an M1 selective compound in patients with Alzheimer's disease.
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Affiliation(s)
- Jason M Uslaner
- Merck Research Laboratories, Merck & Co., Inc., West Point, PA 19486, USA.
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Abstract
INTRODUCTION There is substantial evidence from preclinical and early proof-of-concept studies suggesting that selective modulation of the M(1) muscarinic receptor is efficacious in cognitive models of Alzheimer's disease (AD) and antipsychotic models of schizophrenia. For example, a number of nonselective M(1) muscarinic agonists have previously shown positive effects on cognitive function in AD patients, but were limited due to cholinergic adverse events thought to be mediated by pan activation of the M(2) to M(5) subtypes. Thus, there is a need to identify selective activators of the M(1) receptor to evaluate their potential in cognitive disorders. One strategy to confer selectivity for M(1) is the identification of allosteric agonists or positive allosteric modulators, which would target an allosteric site on the M(1) receptor rather than the highly conserved orthosteric acetylcholine binding site. AREAS COVERED This review discusses the M(1) muscarinic receptor and its potential therapeutic value in the treatment of CNS disorders such as AD and schizophrenia. Specifically, novel allosteric ligands that activate or positively modulate the M(1) receptor are examined and peer-reviewed articles associated with these patents publications are also described. EXPERT OPINION There is substantial evidence supporting activation of the M(1) receptor might be effective in treating symptoms of AD and schizophrenia, but therapeutic success has been elusive and is hypothesized to be due to the lack of selectivity among orthosteric agonists. During the past decade, allosteric modulation of GPCRs has evolved as a viable strategy toward generating subtype selective molecules. A number of novel, selective ligands in the form of allosteric agonists and positive allosteric modulators of the M(1) receptor have been identified offering the potential for clinical evaluation of M(1)-specific receptor activation.
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Affiliation(s)
- Scott D Kuduk
- Department of Medicinal Chemistry, Merck Research Laboratories , Sumneytown Pike, PO Box 4, West Point, PA 19486, USA.
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Melancon BJ, Utley TJ, Sevel C, Mattmann ME, Cheung YY, Bridges TM, Morrison RD, Sheffler DJ, Niswender CM, Daniels JS, Conn PJ, Lindsley CW, Wood MR. Development of novel M1 antagonist scaffolds through the continued optimization of the MLPCN probe ML012. Bioorg Med Chem Lett 2012; 22:5035-40. [PMID: 22749871 PMCID: PMC3883446 DOI: 10.1016/j.bmcl.2012.06.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 05/31/2012] [Accepted: 06/04/2012] [Indexed: 11/24/2022]
Abstract
This Paper describes the continued optimization of an MLPCN probe molecule M(1) antagonist (ML012) through an iterative parallel synthesis approach. After several rounds of modifications of the parent compound, we arrived at a new azetidine scaffold that displayed improved potency while maintaining a desirable level of selectivity over other muscarinic receptor subtypes. Data for representative molecules 7w (VU0452865) and 12a (VU0455691) are presented.
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Affiliation(s)
- Bruce J Melancon
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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Viberg A, Martino G, Lessard E, Laird JMA. Evaluation of an innovative population pharmacokinetic-based design for behavioral pharmacodynamic endpoints. AAPS JOURNAL 2012; 14:657-63. [PMID: 22711220 DOI: 10.1208/s12248-012-9380-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 06/05/2012] [Indexed: 11/30/2022]
Abstract
Pre-clinical behavioral pharmacology studies supporting indications like analgesia typically consist of at least three different studies; dose-finding, duration of effect, and tolerance-development studies. Pharmacokinetic (PK) plasma samples are generally taken from a parallel group of animals to avoid disruption of the behavioral pharmacodynamic (PD) endpoint. Our objective was to investigate if pre-clinical behavioral pharmacology studies in rats could be performed effectively by combining three studies into a single experimental design and using sparse PK sampling in the same animals as for PD. A refined dosing strategy was applied for a muscarinic agonist, AZD6088, using the rat spinal nerve ligation heat hyperalgesia model. PD measurements were performed on day 1, 3, 5 and 8. Two PK samples per day were taken day 2 and 4. In a separate control group, PD measurements were performed on rats without PK sampling. Data was analyzed using a population approach in NONMEM. The animals produced a consistent and reproducible response irrespective of day of testing suggesting that blood sampling on alternate days did not interfere with the PD responses. A direct concentration-effect relationship with good precision was established and no tolerance development was observed. The new design combining three studies into one and eliminating a satellite PK group realized substantial savings compared to the old design; animal use was reduced by 58% and time required to generate results was reduced by 55%. The design described here delivers substantial savings in animal lives, time, and money whilst still delivering a good quality and precise description of the PKPD relationship.
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Affiliation(s)
- Anders Viberg
- Clinical Pharmacology and Pharmacometrics, AstraZeneca R&D Södertälje, 151 85, Södertälje, Sweden.
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Sams AG, Larsen K, Mikkelsen GK, Hentzer M, Christoffersen CT, Jensen KG, Frederiksen K, Bang-Andersen B. Hit-to-lead investigation of a series of novel combined dopamine D2 and muscarinic M1 receptor ligands with putative antipsychotic and pro-cognitive potential. Bioorg Med Chem Lett 2012; 22:5134-40. [PMID: 22677319 DOI: 10.1016/j.bmcl.2012.05.048] [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] [Received: 03/26/2012] [Revised: 05/09/2012] [Accepted: 05/10/2012] [Indexed: 12/22/2022]
Abstract
We describe the discovery of a series of compounds based on 1-{3-[4-(2-oxo-2,3-dihydro-benzoimidazol-1-yl)-piperidin-1-yl]-propyl}-3,4-dihydro-1H-quinolin-2-one (3), showing combined D(2) receptor affinity and M(1) receptor agonism. Based on a strategy of controlling logP, we herein describe a hit-to-lead investigation with the aim of retaining the combined D(2)/M(1) profile, while removing the propensity of the compounds to inhibit the hERG channel, as well as at obtaining acceptable pharmacokinetic properties. Although a SAR was evident for all four parameters in question, it was not possible to separate hERG channel inhibition and D(2) receptor affinity by this effort; whilst it was feasible to obtain compounds with M(1) receptor agonism, acceptable clearance, and weak hERG inhibition.
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Affiliation(s)
- Anette Graven Sams
- Neuroscience Drug Discovery Denmark, H. Lundbeck A/S, Copenhagen-Valby, Denmark.
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Abstract
The physiological role of muscarinic receptors is highly complex and, although not completely understood, has become clearer over the last decade. Recent pharmacological evidence with novel compounds, together with data from transgenic mice, suggests that all five subtypes have defined functions in the nervous system as well as mediating the non neuronal, hormonal actions of acetylcholine. Numerous novel agonists, allosteric regulators, and antagonists have now been identified with authentic subtype specificity in vitro and in vivo. These compounds provide additional pharmacological opportunities for selective subtype modulation as well as a new generation of muscarinic receptor-based therapeutics.
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Affiliation(s)
- Richard M Eglen
- Corning Life Sciences, 900 Chelmsford St., MA 01851, Lowell, USA.
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Abstract
Muscarinic agonists and antagonists are used to treat a handful of gastrointestinal (GI) conditions associated with impaired salivary secretion or altered motility of GI smooth muscle. With regard to exocrine secretion, the major muscarinic receptor expressed in salivary, gastric, and pancreatic glands is the M₃ with a small contribution of the M₁ receptor. In GI smooth muscle, the major muscarinic receptors expressed are the M₂ and M₃ with the M₂ outnumbering the M₃ by a ratio of at least four to one. The antagonism of both smooth muscle contraction and exocrine secretion is usually consistent with an M₃ receptor mechanism despite the major presence of the M₂ receptor in smooth muscle. These results are consistent with the conditional role of the M₂ receptor in smooth muscle. That is, the contractile role of the M₂ receptor depends on that of the M₃ so that antagonism of the M₃ receptor eliminates the response of the M₂. The physiological roles of muscarinic receptors in the GI tract are consistent with their known signaling mechanisms. Some so-called tissue-selective M₃ antagonists may owe their selectivity to a highly potent interaction with a nonmuscarinic receptor target.
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