1
|
Li W, Zhang X, Ma J, Zhou J, Di X, Huang D, Zhou K, Zhang J, Wang L, Fu H, Cui M. Preclinical Evaluation of Dihydropyrazole-Cored Positron Emission Tomography (PET) Ligands for Imaging of Receptor-Interacting Serine/Threonine Protein Kinase 1 (RIPK1) in the Brain. J Med Chem 2024. [PMID: 39259669 DOI: 10.1021/acs.jmedchem.4c01263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2024]
Abstract
Receptor-interacting serine/threonine protein kinase 1 (RIPK1) has emerged as an important regulator of pathologic cell death and inflammation and is implicated in the pathologies of various central nervous system diseases. In this study, we reported the development of three potent dihydropyrazole-cored RIPK1 positron emission tomography (PET) ligands [18F]WL1-3. Among these, [18F]WL1 showed specific binding to RIPK1 in mouse brain sections in vitro through autoradiography and exhibited favorable brain kinetics in mice, characterized by a high initial uptake (brain2 min = 4.89% ID/g) and rapid washout (brain60 min = 0.21% ID/g). PET studies in rat brains revealed that [18F]WL1 could readily penetrate the brain with specific binding confirmed by inhibition effects of unlabeled WL1 and GSK'547. Notably, [18F]WL1 showed significant potential in imaging the alterations of RIPK1 in a rat brain of tumor necrosis factor α-induced systemic inflammatory response syndrome model. These findings may pave the way for the future design of potent RIPK1 PET ligands.
Collapse
Affiliation(s)
- Wanqing Li
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Xiaojun Zhang
- Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, P. R. China
| | - Jie Ma
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P. R. China
| | - Jingyin Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Xuan Di
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Donglan Huang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Kaixiang Zhou
- Center for Advanced Materials Research, Beijing Normal University at Zhuhai, Zhuhai 519087, P. R. China
| | - Jinming Zhang
- Department of Nuclear Medicine, Chinese PLA General Hospital, Beijing 100853, P. R. China
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P. R. China
| | - Hualong Fu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
- Center for Advanced Materials Research, Beijing Normal University at Zhuhai, Zhuhai 519087, P. R. China
| |
Collapse
|
2
|
Belov V, Guehl NJ, Duvvuri S, Iredale P, Moon SH, Dhaynaut M, Chakilam S, MacDonagh AC, Rice PA, Yokell DL, Renger JJ, El Fakhri G, Normandin MD. PET imaging of M4 muscarinic acetylcholine receptors in rhesus macaques using [ 11C]MK-6884: Quantification with kinetic modeling and receptor occupancy by CVL-231 (emraclidine), a novel positive allosteric modulator. J Cereb Blood Flow Metab 2024; 44:1329-1342. [PMID: 38477292 PMCID: PMC11342722 DOI: 10.1177/0271678x241238820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 03/14/2024]
Abstract
Stimulation of the M4 muscarinic acetylcholine receptor reduces striatal hyperdopaminergia, suggesting its potential as a therapeutic target for schizophrenia. Emraclidine (CVL-231) is a novel, highly selective, positive allosteric modulator (PAM) of M4 muscarinic acetylcholine receptors i.e. acts as a modulator that increases the response of these receptors. First, we aimed to further characterize the positron emission tomography (PET) imaging and quantification performance of a recently developed M4 PAM radiotracer, [11C]MK-6884, in non-human primates (NHPs). Second, we applied these results to determine the receptor occupancy of CVL-231 as a function of dose. Using paired baseline-blocking PET scans, we quantified total volume of distribution, binding potential, and receptor occupancy. Both blood-based and reference region-based methods quantified M4 receptor levels across brain regions. The 2-tissue 4-parameter kinetic model best fitted regional [11C]MK-6884-time activity curves. Only the caudate nucleus and putamen displayed statistically significant [11C]MK-6884 uptake and dose-dependent blocking by CVL-231. For binding potential and receptor occupancy quantification, the simplified reference tissue model using the grey cerebellum as a reference region was employed. CVL-231 demonstrated dose-dependent M4 receptor occupancy in the striatum of the NHP brain and shows promise for further development in clinical trials.
Collapse
Affiliation(s)
- Vasily Belov
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Maeva Dhaynaut
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Alexander C MacDonagh
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Peter A Rice
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniel L Yokell
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Georges El Fakhri
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
3
|
Liu B, Thompson G, Jörg M, Barnes N, Thal DM, Christopoulos A, Capuano B, Valant C, Scammells PJ. Discovery of 2-Methyl-5-(1 H-pyrazol-4-yl)pyridines and Related Heterocycles as Promising M 4 mAChR Positive Allosteric Modulators for the Treatment of Neurocognitive Disorders. J Med Chem 2024. [PMID: 39023902 DOI: 10.1021/acs.jmedchem.4c01207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
The M4 muscarinic acetylcholine receptor (mAChR) is a biological target for neurocognitive disorders. Compound 1 is an ago-PAM for the M4 mAChR. Herein, we report the design, synthesis, and evaluation of novel putative M4 mAChR PAMs based on 1. These analogs were screened and then fully characterized in two functional assays (GoB protein activation and CAMYEL activation) to quantify their allosteric and ago-PAM properties against ACh. A selection of 7 M4 PAMs were assessed for their ability to modulate ACh-mediated β-arrestin recruitment and revealed 4 distinct clusters of M4 PAM activity: (1) analogs similar to 1 (24d), (2) analogs demonstrating only allosteric agonism (23d), (3) analogs with increased allosteric properties in CAMYEL activation (23b/23f and 24a/24b), and (4) analogs with a biased modulatory effect toward β-arrestin recruitment (23i). These novel M4 chemical tools disclose discrete molecular determinants, allowing further interrogation of the therapeutic roles of cAMP and β-arrestin pathways in neurocognitive disorders.
Collapse
Affiliation(s)
- Boqun Liu
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Geoff Thompson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Manuela Jörg
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Nicholas Barnes
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David M Thal
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Ben Capuano
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| |
Collapse
|
4
|
Qi A, Kling HE, Billard N, Rodriguez AL, Peng L, Dickerson JW, Engers JL, Bender AM, Moehle MS, Lindsley CW, Rook JM, Niswender CM. Development of a Selective and High Affinity Radioligand, [ 3H]VU6013720, for the M 4 Muscarinic Receptor. Mol Pharmacol 2023; 104:195-202. [PMID: 37595966 PMCID: PMC10586508 DOI: 10.1124/molpharm.122.000643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 08/20/2023] Open
Abstract
M4 muscarinic receptors are highly expressed in the striatum and cortex, brain regions that are involved in diseases such as Parkinson's disease, schizophrenia, and dystonia. Despite potential therapeutic advantages of specifically targeting the M4 receptor, it has been historically challenging to develop highly selective ligands, resulting in undesired off-target activity at other members of the muscarinic receptor family. Recently, we have reported first-in-class, potent, and selective M4 receptor antagonists. As an extension of that work, we now report the development and characterization of a radiolabeled M4 receptor antagonist, [3H]VU6013720, with high affinity (pKd of 9.5 ± 0.2 at rat M4, 9.7 at mouse M4, and 10 ± 0.1 at human M4 with atropine to define nonspecific binding) and no significant binding at the other muscarinic subtypes. Binding assays using this radioligand in rodent brain tissues demonstrate loss of specific binding in Chrm4 knockout animals. Dissociation kinetics experiments with various muscarinic ligands show differential effects on the dissociation of [3H]VU6013720 from M4 receptors, suggesting a binding site that is overlapping but may be distinct from the orthosteric site. Overall, these results demonstrate that [3H]VU6013720 is the first highly selective antagonist radioligand for the M4 receptor, representing a useful tool for studying the basic biology of M4 as well for the support of M4 receptor-based drug discovery. SIGNIFICANCE STATEMENT: This manuscript describes the development and characterization of a novel muscarinic (M) acetylcholine subtype 4 receptor antagonist radioligand, [3H]VU6013720. This ligand binds to or overlaps with the acetylcholine binding site, providing a highly selective radioligand for the M4 receptor that can be used to quantify M4 protein expression in vivo and probe the selective interactions of acetylcholine with M4 versus the other members of the muscarinic receptor family.
Collapse
Affiliation(s)
- Aidong Qi
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Haley E Kling
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Natasha Billard
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Alice L Rodriguez
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Li Peng
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Jonathan W Dickerson
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Julie L Engers
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Aaron M Bender
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Mark S Moehle
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Craig W Lindsley
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Jerri M Rook
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| | - Colleen M Niswender
- Department of Pharmacology and Warren Center for Neuroscience Drug Discovery (A.Q., H.E.K., N.B., A.L.R., L.P., J.W.D., J.L.E., A.M.B., C.W.L., J.M.R., C.M.N.) and Department of Chemistry (C.W.L.), Vanderbilt University, Nashville, Tennessee; Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee (C.M.N); Vanderbilt Brain Institute (C.M.N.) and Vanderbilt Institute of Chemical Biology (C.W.L., C.M.N.),Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Pharmacology and Therapeutics and Center for Translational Research in Neurodegeneration (M.S.M.), University of Florida, Gainesville, Florida
| |
Collapse
|
5
|
Jörg M, van der Westhuizen ET, Lu Y, Christopher Choy KH, Shackleford DM, Khajehali E, Tobin AB, Thal DM, Capuano B, Christopoulos A, Valant C, Scammells PJ. Design, synthesis and evaluation of novel 2-phenyl-3-(1H-pyrazol-4-yl)pyridine positive allosteric modulators for the M 4 mAChR. Eur J Med Chem 2023; 258:115588. [PMID: 37423123 PMCID: PMC7616163 DOI: 10.1016/j.ejmech.2023.115588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/15/2023] [Accepted: 06/20/2023] [Indexed: 07/11/2023]
Abstract
Translation of muscarinic acetylcholine receptor (mAChR) agonists into clinically used therapeutic agents has been difficult due to their poor subtype selectivity. M4 mAChR subtype-selective positive allosteric modulators (PAMs) may provide better therapeutic outcomes, hence investigating their detailed pharmacological properties is crucial to advancing them into the clinic. Herein, we report the synthesis and comprehensive pharmacological evaluation of M4 mAChR PAMs structurally related to 1e, Me-C-c, [11C]MK-6884 and [18F]12. Our results show that small structural changes to the PAMs can result in pronounced differences to baseline, potency (pEC50) and maximum effect (Emax) measures in cAMP assays when compared to the endogenous ligand acetylcholine (ACh) without the addition of the PAMs. Eight selected PAMs were further assessed to determine their binding affinity and potential signalling bias profile between cAMP and β-arrestin 2 recruitment. These rigorous analyses resulted in the discovery of the novel PAMs, 6k and 6l, which exhibit improved allosteric properties compared to the lead compound, and probative in vivo exposure studies in mice confirmed that they maintain the ability to cross the blood-brain barrier, making them more suitable for future preclinical assessment.
Collapse
Affiliation(s)
- Manuela Jörg
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Emma T van der Westhuizen
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Yao Lu
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - K H Christopher Choy
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Elham Khajehali
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - David M Thal
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Ben Capuano
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia; ARC Industrial Transformation Training Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia; Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia.
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia.
| |
Collapse
|
6
|
Xie X, Yu T, Li X, Zhang N, Foster LJ, Peng C, Huang W, He G. Recent advances in targeting the "undruggable" proteins: from drug discovery to clinical trials. Signal Transduct Target Ther 2023; 8:335. [PMID: 37669923 PMCID: PMC10480221 DOI: 10.1038/s41392-023-01589-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/22/2023] [Accepted: 08/02/2023] [Indexed: 09/07/2023] Open
Abstract
Undruggable proteins are a class of proteins that are often characterized by large, complex structures or functions that are difficult to interfere with using conventional drug design strategies. Targeting such undruggable targets has been considered also a great opportunity for treatment of human diseases and has attracted substantial efforts in the field of medicine. Therefore, in this review, we focus on the recent development of drug discovery targeting "undruggable" proteins and their application in clinic. To make this review well organized, we discuss the design strategies targeting the undruggable proteins, including covalent regulation, allosteric inhibition, protein-protein/DNA interaction inhibition, targeted proteins regulation, nucleic acid-based approach, immunotherapy and others.
Collapse
Affiliation(s)
- Xin Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Medical Technology and School of Pharmacy, Chengdu University of Traditional Chinese Medicine, 611137, Chengdu, China
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Tingting Yu
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Medical Technology and School of Pharmacy, Chengdu University of Traditional Chinese Medicine, 611137, Chengdu, China
| | - Xiang Li
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Medical Technology and School of Pharmacy, Chengdu University of Traditional Chinese Medicine, 611137, Chengdu, China
| | - Nan Zhang
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Medical Technology and School of Pharmacy, Chengdu University of Traditional Chinese Medicine, 611137, Chengdu, China
- Department of Dermatology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, China
| | - Leonard J Foster
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Medical Technology and School of Pharmacy, Chengdu University of Traditional Chinese Medicine, 611137, Chengdu, China.
| | - Wei Huang
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Medical Technology and School of Pharmacy, Chengdu University of Traditional Chinese Medicine, 611137, Chengdu, China.
| | - Gu He
- Department of Dermatology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, 610041, Chengdu, China.
| |
Collapse
|
7
|
Cools R, Kerkhofs K, Leitao RCF, Bormans G. Preclinical Evaluation of Novel PET Probes for Dementia. Semin Nucl Med 2023; 53:599-629. [PMID: 37149435 DOI: 10.1053/j.semnuclmed.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/24/2023] [Indexed: 05/08/2023]
Abstract
The development of novel PET imaging agents that selectively bind specific dementia-related targets can contribute significantly to accurate, differential and early diagnosis of dementia causing diseases and support the development of therapeutic agents. Consequently, in recent years there has been a growing body of literature describing the development and evaluation of potential new promising PET tracers for dementia. This review article provides a comprehensive overview of novel dementia PET probes under development, classified by their target, and pinpoints their preclinical evaluation pathway, typically involving in silico, in vitro and ex/in vivo evaluation. Specific target-associated challenges and pitfalls, requiring extensive and well-designed preclinical experimental evaluation assays to enable successful clinical translation and avoid shortcomings observed for previously developed 'well-established' dementia PET tracers are highlighted in this review.
Collapse
Affiliation(s)
- Romy Cools
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Kobe Kerkhofs
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; NURA, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Renan C F Leitao
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
| |
Collapse
|
8
|
Zhang JJ, Fu H, Lin R, Zhou J, Haider A, Fang W, Elghazawy NH, Rong J, Chen J, Li Y, Ran C, Collier TL, Chen Z, Liang SH. Imaging Cholinergic Receptors in the Brain by Positron Emission Tomography. J Med Chem 2023; 66:10889-10916. [PMID: 37583063 PMCID: PMC10461233 DOI: 10.1021/acs.jmedchem.3c00573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Indexed: 08/17/2023]
Abstract
Cholinergic receptors represent a promising class of diagnostic and therapeutic targets due to their significant involvement in cognitive decline associated with neurological disorders and neurodegenerative diseases as well as cardiovascular impairment. Positron emission tomography (PET) is a noninvasive molecular imaging tool that has helped to shed light on the roles these receptors play in disease development and their diverse functions throughout the central nervous system (CNS). In recent years, there has been a notable advancement in the development of PET probes targeting cholinergic receptors. The purpose of this review is to provide a comprehensive overview of the recent progress in the development of these PET probes for cholinergic receptors with a specific focus on ligand structure, radiochemistry, and pharmacology as well as in vivo performance and applications in neuroimaging. The review covers the structural design, pharmacological properties, radiosynthesis approaches, and preclinical and clinical evaluations of current state-of-the-art PET probes for cholinergic receptors.
Collapse
Affiliation(s)
- Jing-Jing Zhang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Hualong Fu
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ruofan Lin
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key
Laboratory of Radiopharmaceuticals, Ministry of Education, College
of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ahmed Haider
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Weiwei Fang
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Nehal H. Elghazawy
- Department
of Pharmaceutical, Chemistry, Faculty of Pharmacy & Biotechnology, German University in Cairo, 11835 Cairo, Egypt
| | - Jian Rong
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Jiahui Chen
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Yinlong Li
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Chongzhao Ran
- Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02114, United States
| | - Thomas L. Collier
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| | - Zhen Chen
- Jiangsu
Co-Innovation Center of Efficient Processing and Utilization of Forest
Resources, Jiangsu Provincial Key Lab for the Chemistry and Utilization
of Agro-Forest Biomass, Jiangsu Key Lab of Biomass-Based Green Fuels
and Chemicals, International Innovation Center for Forest Chemicals
and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
| | - Steven H. Liang
- Division
of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital
& Department of Radiology, Harvard Medical
School, Boston, Massachusetts 02114, United States
- Department
of Radiology and Imaging Sciences, Emory
University, 1364 Clifton Road, Atlanta, Georgia 30322, United States
| |
Collapse
|
9
|
Dean B. Muscarinic M1 and M4 receptor agonists for schizophrenia: promising candidates for the therapeutic arsenal. Expert Opin Investig Drugs 2023; 32:1113-1121. [PMID: 37994870 DOI: 10.1080/13543784.2023.2288074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 11/22/2023] [Indexed: 11/24/2023]
Abstract
INTRODUCTION Successful phase 3 trials of KarXT in people with schizophrenia herald a new era of treating the disorder with drugs that do not target the dopamine D2 receptor. The active component of KarXT is xanomeline, a muscarinic (CHRM) M1 and M4 agonist, making muscarinic receptors a viable target for treating schizophrenia. AREAS COVERED This review covers the process of taking drugs that activate the muscarinic M1 and M4 receptors from conceptualization to the clinic and details the mechanisms by which activating the CHRM1 and 4 can affect the broad spectrum of symptoms experienced by people with schizophrenia. EXPERT OPINION Schizophrenia is a syndrome which means drugs that activate muscarinic M1 and M4 receptors, as was the case for antipsychotic drugs acting on the dopamine D2 receptor, will not give optimal outcomes in everyone within the syndrome. Thus, it would be ideal to identify people who are responsive to drugs activating the CHRM1 and 4. Given knowledge of the actions of these receptors, it is possible treatment non-response could be restricted to sub-groups within the syndrome who have deficits in cortical CHRM1 or those with one of the cognitive endophenotypes that may be identifiable by changes in the blood transcriptome.
Collapse
Affiliation(s)
- Brian Dean
- The Synaptic Biology and Cognition Laboratory, The Florey, Parkville, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, Parkville, Victoria, Australia
| |
Collapse
|
10
|
Nag S, Arakawa R, Jia Z, Lachapelle E, Zhang L, Maresca K, Chen L, Jahan M, Mccarthy T, Halldin C. Characterization of a Novel M4 PAM PET Radioligand [11C]PF06885190 in Nonhuman Primates (NHP). Molecules 2023; 28:4612. [PMID: 37375167 DOI: 10.3390/molecules28124612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/01/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Muscarinic acetylcholine receptors (mAChR), including M4, draw attention as therapeutic targets for several neurodegenerative diseases including Alzheimer's disease (AD). PET imaging of M4 positive allosteric modulator (PAM) allows qualification of the distribution as well as the expression of this receptor under physiological conditions and thereby helps to assess the receptor occupancy (RO) of a drug candidate. In this study, our aims were (a) to synthesize a novel M4 PAM PET radioligand [11C]PF06885190 (b) to evaluate the brain distribution of [11C]PF06885190 in nonhuman primates (NHP) and (c) to analyze its radiometabolites in the blood plasma of NHP. Radiolabeling of [11C]PF06885190 was accomplished via N-methylation of the precursor. Six PET measurements were performed using two male cynomolgus monkeys, where three PET measurements were at baseline, two after pretreatment with a selective M4 PAM compound CVL-231 and one after pretreatment with donepezil. The total volume of distribution (VT) of [11C]PF06885190 was examined using Logan graphical analysis with arterial input function. Radiometabolites were analyzed in monkey blood plasma using gradient HPLC system. Radiolabeling of [11C]PF06885190 was successfully accomplished and the radioligand was found to be stable in the formulation, with radiochemical purity exceeding 99% 1 h after the end of the synthesis. [11C]PF06885190 was characterized in the cynomolgus monkey brain where a moderate brain uptake was found at the baseline condition. However, it showed fast wash-out as it dropped to half of the peak at around 10 min. Change of VT from baseline was around -10% after pretreatment with a M4 PAM, CVL-231. Radiometabolite studies showed relatively fast metabolism. Although sufficient brain uptake of [11C]PF06885190 was observed, these data suggest that [11C]PF06885190 might have too low specific binding in the NHP brain to be further applied in PET imaging.
Collapse
Affiliation(s)
- Sangram Nag
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 17164 Stockholm, Sweden
| | - Ryosuke Arakawa
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 17164 Stockholm, Sweden
| | - Zhisheng Jia
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 17164 Stockholm, Sweden
| | - Erik Lachapelle
- Worldwide Research, Development and Medical, Pfizer Inc., Groton, CT 06340, USA
| | - Lei Zhang
- Worldwide Research, Development and Medical, Pfizer Inc., Cambridge, MA 02139, USA
| | - Kevin Maresca
- Worldwide Research, Development and Medical, Pfizer Inc., Cambridge, MA 02139, USA
| | - Laigao Chen
- Worldwide Research, Development and Medical, Pfizer Inc., Cambridge, MA 02139, USA
| | - Mahabuba Jahan
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 17164 Stockholm, Sweden
| | - Timothy Mccarthy
- Worldwide Research, Development and Medical, Pfizer Inc., Cambridge, MA 02139, USA
| | - Christer Halldin
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, 17164 Stockholm, Sweden
| |
Collapse
|
11
|
Shen S, Zhao C, Wu C, Sun S, Li Z, Yan W, Shao Z. Allosteric modulation of G protein-coupled receptor signaling. Front Endocrinol (Lausanne) 2023; 14:1137604. [PMID: 36875468 PMCID: PMC9978769 DOI: 10.3389/fendo.2023.1137604] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
G protein-coupled receptors (GPCRs), the largest family of transmembrane proteins, regulate a wide array of physiological processes in response to extracellular signals. Although these receptors have proven to be the most successful class of drug targets, their complicated signal transduction pathways (including different effector G proteins and β-arrestins) and mediation by orthosteric ligands often cause difficulties for drug development, such as on- or off-target effects. Interestingly, identification of ligands that engage allosteric binding sites, which are different from classic orthosteric sites, can promote pathway-specific effects in cooperation with orthosteric ligands. Such pharmacological properties of allosteric modulators offer new strategies to design safer GPCR-targeted therapeutics for various diseases. Here, we explore recent structural studies of GPCRs bound to allosteric modulators. Our inspection of all GPCR families reveals recognition mechanisms of allosteric regulation. More importantly, this review highlights the diversity of allosteric sites and presents how allosteric modulators control specific GPCR pathways to provide opportunities for the development of new valuable agents.
Collapse
Affiliation(s)
| | | | | | | | | | - Wei Yan
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhenhua Shao
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| |
Collapse
|
12
|
Structure-activity relationship of pyrazol-4-yl-pyridine derivatives and identification of a radiofluorinated probe for imaging the muscarinic acetylcholine receptor M 4. Acta Pharm Sin B 2023; 13:213-226. [PMID: 36815036 PMCID: PMC9939360 DOI: 10.1016/j.apsb.2022.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 05/13/2022] [Accepted: 06/22/2022] [Indexed: 11/21/2022] Open
Abstract
There is an accumulating body of evidence implicating the muscarinic acetylcholine receptor 4 (M4) in schizophrenia and dementia with Lewy bodies, however, a clinically validated M4 positron emission tomography (PET) radioligand is currently lacking. As such, the aim of this study was to develop a suitable M4 PET ligand that allows the non-invasive visualization of M4 in the brain. Structure-activity relationship studies of pyrazol-4-yl-pyridine derivates led to the discovery of target compound 12 - a subtype-selective positive allosteric modulator (PAM). The radiofluorinated analogue, [18F]12, was synthesized in 28 ± 10% radiochemical yield, >37 GBq/μmol and an excellent radiochemical purity >99%. Initial in vitro autoradiograms on rodent brain sections were performed in the absence of carbachol and showed moderate specificity as well as a low selectivity of [18F]12 for the M4-rich striatum. However, in the presence of carbachol, a significant increase in tracer binding was observed in the rat striatum, which was reduced by >60% under blocking conditions, thus indicating that orthosteric ligand interaction is required for efficient binding of [18F]12 to the allosteric site. Remarkably, however, the presence of carbachol was not required for high specific binding in the non-human primate (NHP) and human striatum, and did not further improve the specificity and selectivity of [18F]12 in higher species. These results pointed towards significant species-differences and paved the way for a preliminary PET study in NHP, where peak brain uptake of [18F]12 was found in the putamen and temporal cortex. In conclusion, we report on the identification and preclinical development of the first radiofluorinated M4 PET radioligand with promising attributes. The availability of a clinically validated M4 PET radioligand harbors potential to facilitate drug development and provide a useful diagnostic tool for non-invasive imaging.
Collapse
|
13
|
Fu H, Rong J, Chen Z, Zhou J, Collier T, Liang SH. Positron Emission Tomography (PET) Imaging Tracers for Serotonin Receptors. J Med Chem 2022; 65:10755-10808. [PMID: 35939391 DOI: 10.1021/acs.jmedchem.2c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) and 5-HT receptors (5-HTRs) have crucial roles in various neuropsychiatric disorders and neurodegenerative diseases, making them attractive diagnostic and therapeutic targets. Positron emission tomography (PET) is a noninvasive nuclear molecular imaging technique and is an essential tool in clinical diagnosis and drug discovery. In this context, numerous PET ligands have been developed for "visualizing" 5-HTRs in the brain and translated into human use to study disease mechanisms and/or support drug development. Herein, we present a comprehensive repertoire of 5-HTR PET ligands by focusing on their chemotypes and performance in PET imaging studies. Furthermore, this Perspective summarizes recent 5-HTR-focused drug discovery, including biased agonists and allosteric modulators, which would stimulate the development of more potent and subtype-selective 5-HTR PET ligands and thus further our understanding of 5-HTR biology.
Collapse
Affiliation(s)
- Hualong Fu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jian Rong
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Zhen Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Jingyin Zhou
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Thomas Collier
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Steven H Liang
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114, United States.,Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, United States
| |
Collapse
|
14
|
|
15
|
Tiepolt S, Meyer PM, Patt M, Deuther-Conrad W, Hesse S, Barthel H, Sabri O. PET Imaging of Cholinergic Neurotransmission in Neurodegenerative Disorders. J Nucl Med 2022; 63:33S-44S. [PMID: 35649648 DOI: 10.2967/jnumed.121.263198] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/06/2022] [Indexed: 12/13/2022] Open
Abstract
As a neuromodulator, the neurotransmitter acetylcholine plays an important role in cognitive, mood, locomotor, sleep/wake, and olfactory functions. In the pathophysiology of most neurodegenerative diseases, such as Alzheimer disease (AD) or Lewy body disorder (LBD), cholinergic receptors, transporters, or enzymes are involved and relevant as imaging targets. The aim of this review is to summarize current knowledge on PET imaging of cholinergic neurotransmission in neurodegenerative diseases. For PET imaging of presynaptic vesicular acetylcholine transporters (VAChT), (-)-18F-fluoroethoxybenzovesamicol (18F-FEOBV) was the first PET ligand that could be successfully translated to clinical application. Since then, the number of 18F-FEOBV PET investigations on patients with AD or LBD has grown rapidly and provided novel, important findings concerning the pathophysiology of AD and LBD. Regarding the α4β2 nicotinic acetylcholine receptors (nAChRs), various second-generation PET ligands, such as 18F-nifene, 18F-AZAN, 18F-XTRA, (-)-18F-flubatine, and (+)-18F-flubatine, were developed and successfully translated to human application. In neurodegenerative diseases such as AD and LBD, PET imaging of α4β2 nAChRs is of special value for monitoring disease progression and drugs directed to α4β2 nAChRs. For PET of α7 nAChR, 18F-ASEM and 11C-MeQAA were successfully applied in mild cognitive impairment and AD, respectively. The highest potential for α7 nAChR PET is seen in staging, in evaluating disease progression, and in therapy monitoring. PET of selective muscarinic acetylcholine receptors (mAChRs) is still in an early stage, as the development of subtype-selective radioligands is complicated. Promising radioligands to image mAChR subtypes M1 (11C-LSN3172176), M2 (18F-FP-TZTP), and M4 (11C-MK-6884) were developed and successfully translated to humans. PET imaging of mAChRs is relevant for the assessment and monitoring of therapies in AD and LBD. PET of acetylcholine esterase activity has been investigated since the 1990s. Many PET studies with 11C-PMP and 11C-MP4A demonstrated cortical cholinergic dysfunction in dementia associated with AD and LBD. Recent studies indicated a solid relationship between subcortical and cortical cholinergic dysfunction and noncognitive dysfunctions such as balance and gait in LBD. Taken together, PET of distinct components of cholinergic neurotransmission is of great interest for diagnosis, disease monitoring, and therapy monitoring and to gain insight into the pathophysiology of different neurodegenerative disorders.
Collapse
Affiliation(s)
- Solveig Tiepolt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Philipp M Meyer
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | | | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany; and
| |
Collapse
|
16
|
Chen B, Marquez-Nostra B, Belitzky E, Toyonaga T, Tong J, Huang Y, Cai Z. PET Imaging in Animal Models of Alzheimer’s Disease. Front Neurosci 2022; 16:872509. [PMID: 35685772 PMCID: PMC9171374 DOI: 10.3389/fnins.2022.872509] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
The successful development and translation of PET imaging agents targeting β-amyloid plaques and hyperphosphorylated tau tangles have allowed for in vivo detection of these hallmarks of Alzheimer’s disease (AD) antemortem. Amyloid and tau PET have been incorporated into the A/T/N scheme for AD characterization and have become an integral part of ongoing clinical trials to screen patients for enrollment, prove drug action mechanisms, and monitor therapeutic effects. Meanwhile, preclinical PET imaging in animal models of AD can provide supportive information for mechanistic studies. With the recent advancement of gene editing technologies and AD animal model development, preclinical PET imaging in AD models will further facilitate our understanding of AD pathogenesis/progression and the development of novel treatments. In this study, we review the current state-of-the-art in preclinical PET imaging using animal models of AD and suggest future research directions.
Collapse
|
17
|
Synthesis, Biological Evaluation, and Docking Studies of Antagonistic Hydroxylated Arecaidine Esters Targeting mAChRs. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27103173. [PMID: 35630651 PMCID: PMC9145622 DOI: 10.3390/molecules27103173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/05/2022] [Accepted: 05/14/2022] [Indexed: 11/17/2022]
Abstract
The muscarinic acetylcholine receptor family is a highly sought-after target in drug and molecular imaging discovery efforts aimed at neurological disorders. Hampered by the structural similarity of the five subtypes’ orthosteric binding pockets, these efforts largely failed to deliver subtype-selective ligands. Building on our recent successes with arecaidine-derived ligands targeting M1, herein we report the synthesis of a related series of 11 hydroxylated arecaidine esters. Their physicochemical property profiles, expressed in terms of their computationally calculated CNS MPO scores and HPLC-logD values, point towards blood–brain barrier permeability. By means of a competitive radioligand binding assay, the binding affinity values towards each of the individual human mAChR subtypes hM1–hM5 were determined. The most promising compound of this series 17b was shown to have a binding constant towards hM1 in the single-digit nanomolar region (5.5 nM). Similar to our previously reported arecaidine-derived esters, the entire series was shown to act as hM1R antagonists in a calcium flux assay. Overall, this study greatly expanded our understanding of this recurring scaffolds’ structure–activity relationship and will guide the development towards highly selective mAChRs ligands.
Collapse
|
18
|
Pomilio AB, Vitale AA, Lazarowski AJ. Neuroproteomics Chip-Based Mass Spectrometry and Other Techniques for Alzheimer´S Disease Biomarkers – Update. Curr Pharm Des 2022; 28:1124-1151. [DOI: 10.2174/1381612828666220413094918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 02/25/2022] [Indexed: 11/22/2022]
Abstract
Background:
Alzheimer's disease (AD) is a progressive neurodegenerative disease of growing interest given that there is cognitive damage and symptom onset acceleration. Therefore, it is important to find AD biomarkers for early diagnosis, disease progression, and discrimination of AD and other diseases.
Objective:
To update the relevance of mass spectrometry for the identification of peptides and proteins involved in AD useful as discriminating biomarkers.
Methods:
Proteomics and peptidomics technologies that show the highest possible specificity and selectivity for AD biomarkers are analyzed, together with the biological fluids used. In addition to positron emission tomography and magnetic resonance imaging, MALDI-TOF mass spectrometry is widely used to identify proteins and peptides involved in AD. The use of protein chips in SELDI technology and electroblotting chips for peptides makes feasible small amounts (L) of samples for analysis.
Results:
Suitable biomarkers are related to AD pathology, such as intracellular neurofibrillary tangles; extraneuronal senile plaques; neuronal and axonal degeneration; inflammation and oxidative stress. Recently, peptides were added to the candidate list, which are not amyloid-b or tau fragments, but are related to coagulation, brain plasticity, and complement/neuroinflammation systems involving the neurovascular unit.
Conclusion:
The progress made in the application of mass spectrometry and recent chip techniques is promising for discriminating between AD, mild cognitive impairment, and matched healthy controls. The application of this technique to blood samples from patients with AD has shown to be less invasive and fast enough to determine the diagnosis, stage of the disease, prognosis, and follow-up of the therapeutic response.
Collapse
Affiliation(s)
- Alicia B. Pomilio
- Departamento de Bioquímica Clínica, Área Hematología, Hospital de Clínicas “José de San Martín”, Universidad de Buenos Aires, Av. Córdoba 2351, C1120AAF Buenos Aires, Argentina
| | - Arturo A. Vitale
- Departamento de Bioquímica Clínica, Área Hematología, Hospital de Clínicas “José de San Martín”, Universidad de Buenos Aires, Av. Córdoba 2351, C1120AAF Buenos Aires, Argentina
| | - Alberto J. Lazarowski
- Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica, Instituto de Fisiopatología y Bioquímica Clínica (INFIBIOC), Universidad de Buenos Aires, Córdoba 2351, C1120AAF Buenos Aires, Argentina
| |
Collapse
|
19
|
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.
Collapse
|
20
|
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: 21] [Impact Index Per Article: 10.5] [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.
Collapse
|
21
|
Li W, Wang Y, Lohith TG, Zeng Z, Tong L, Mazzola R, Riffel K, Miller P, Purcell M, Holahan M, Haley H, Gantert L, Hesk D, Ren S, Morrow J, Uslaner J, Struyk A, Wai JMC, Rudd MT, Tellers DM, McAvoy T, Bormans G, Koole M, Van Laere K, Serdons K, de Hoon J, Declercq R, De Lepeleire I, Pascual MB, Zanotti-Fregonara P, Yu M, Arbones V, Masdeu JC, Cheng A, Hussain A, Bueters T, Anderson MS, Hostetler ED, Basile AS. The PET tracer [ 11C]MK-6884 quantifies M4 muscarinic receptor in rhesus monkeys and patients with Alzheimer's disease. Sci Transl Med 2022; 14:eabg3684. [PMID: 35020407 DOI: 10.1126/scitranslmed.abg3684] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Wenping Li
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | - Yuchuan Wang
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | - Zhizhen Zeng
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | - Ling Tong
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | - Kerry Riffel
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | - Mona Purcell
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | - Hyking Haley
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | - Liza Gantert
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | - David Hesk
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | - Sumei Ren
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | - John Morrow
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | - Arie Struyk
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | | | | | | | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, 3001 Leuven, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, KU Leuven and University Hospital Leuven, 3001 Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, KU Leuven and University Hospital Leuven, 3001 Leuven, Belgium
| | - Kim Serdons
- Nuclear Medicine and Molecular Imaging, KU Leuven and University Hospital Leuven, 3001 Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, KU Leuven, 3001 Leuven, Belgium
| | - Ruben Declercq
- Translational Pharmacology Europe, MSD (Europe) Inc., 1200 Brussels, Belgium
| | - Inge De Lepeleire
- Translational Pharmacology Europe, MSD (Europe) Inc., 1200 Brussels, Belgium
| | - Maria B Pascual
- Nantz National Alzheimer Center, Houston Methodist Neurological Institute, Houston, TX 77030, USA.,Department of Neurology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Paolo Zanotti-Fregonara
- Nantz National Alzheimer Center, Houston Methodist Neurological Institute, Houston, TX 77030, USA.,Department of Neurology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Meixiang Yu
- Nantz National Alzheimer Center, Houston Methodist Neurological Institute, Houston, TX 77030, USA.,Department of Neurology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Victoria Arbones
- Nantz National Alzheimer Center, Houston Methodist Neurological Institute, Houston, TX 77030, USA
| | - Joseph C Masdeu
- Nantz National Alzheimer Center, Houston Methodist Neurological Institute, Houston, TX 77030, USA.,Department of Neurology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Amy Cheng
- MRL, Merck & Co. Inc., Kenilworth, NJ 07033, USA
| | | | | | | | | | | |
Collapse
|
22
|
Ni R. Positron Emission Tomography in Animal Models of Alzheimer's Disease Amyloidosis: Translational Implications. Pharmaceuticals (Basel) 2021; 14:1179. [PMID: 34832961 PMCID: PMC8623863 DOI: 10.3390/ph14111179] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Animal models of Alzheimer's disease amyloidosis that recapitulate cerebral amyloid-beta pathology have been widely used in preclinical research and have greatly enabled the mechanistic understanding of Alzheimer's disease and the development of therapeutics. Comprehensive deep phenotyping of the pathophysiological and biochemical features in these animal models is essential. Recent advances in positron emission tomography have allowed the non-invasive visualization of the alterations in the brain of animal models and in patients with Alzheimer's disease. These tools have facilitated our understanding of disease mechanisms and provided longitudinal monitoring of treatment effects in animal models of Alzheimer's disease amyloidosis. In this review, we focus on recent positron emission tomography studies of cerebral amyloid-beta accumulation, hypoglucose metabolism, synaptic and neurotransmitter receptor deficits (cholinergic and glutamatergic system), blood-brain barrier impairment, and neuroinflammation (microgliosis and astrocytosis) in animal models of Alzheimer's disease amyloidosis. We further propose the emerging targets and tracers for reflecting the pathophysiological changes and discuss outstanding challenges in disease animal models and future outlook in the on-chip characterization of imaging biomarkers towards clinical translation.
Collapse
Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, ETH & University of Zurich, 8093 Zurich, Switzerland;
- Institute for Regenerative Medicine, University of Zurich, 8952 Zurich, Switzerland
| |
Collapse
|
23
|
Neef J, Palacios DS. Progress in mechanistically novel treatments for schizophrenia. RSC Med Chem 2021; 12:1459-1475. [PMID: 34671731 PMCID: PMC8459322 DOI: 10.1039/d1md00096a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/18/2021] [Indexed: 11/21/2022] Open
Abstract
Currently available pharmacological treatments for schizophrenia derive their activity mainly by directly modulating the D2 receptor. This mode of action can alleviate the positive symptoms of schizophrenia but do not address the negative or cognitive symptoms of the disease and carry a heavy side effect burden that leads to high levels of patient non-compliance. Novel mechanisms to treat the positive symptoms of schizophrenia with improved tolerability, as well as medicines to treat negative and cognitive symptoms are urgently required. Recent efforts to identify small molecules for schizophrenia with non-D2 mechanisms will be highlighted, with a focus on those that have reached clinical development. Finally, the potential for disease modifying treatments for schizophrenia will also be discussed.
Collapse
Affiliation(s)
- James Neef
- Novartis Institutes for BioMedical Research Inc 22 Windsor St Cambridge MA 02139 USA
| | - Daniel S Palacios
- Novartis Institutes for BioMedical Research Inc 22 Windsor St Cambridge MA 02139 USA
| |
Collapse
|
24
|
Ozenil M, Aronow J, Millard M, Langer T, Wadsak W, Hacker M, Pichler V. Update on PET Tracer Development for Muscarinic Acetylcholine Receptors. Pharmaceuticals (Basel) 2021; 14:530. [PMID: 34199622 PMCID: PMC8229778 DOI: 10.3390/ph14060530] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 02/07/2023] Open
Abstract
The muscarinic cholinergic system regulates peripheral and central nervous system functions, and, thus, their potential as a therapeutic target for several neurodegenerative diseases is undoubted. A clinically applicable positron emission tomography (PET) tracer would facilitate the monitoring of disease progression, elucidate the role of muscarinic acetylcholine receptors (mAChR) in disease development and would aid to clarify the diverse natural functions of mAChR regulation throughout the nervous system, which still are largely unresolved. Still, no mAChR PET tracer has yet found broad clinical application, which demands mAChR tracers with improved imaging properties. This paper reviews strategies of mAChR PET tracer design and summarizes the binding properties and preclinical evaluation of recent mAChR tracer candidates. Furthermore, this work identifies the current major challenges in mAChR PET tracer development and provides a perspective on future developments in this area of research.
Collapse
Affiliation(s)
- Marius Ozenil
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, 1090 Wien, Austria; (M.O.); (J.A.); (W.W.); (M.H.)
| | - Jonas Aronow
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, 1090 Wien, Austria; (M.O.); (J.A.); (W.W.); (M.H.)
| | - Marlon Millard
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, 1090 Wien, Austria; (M.M.); (T.L.)
| | - Thierry Langer
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, 1090 Wien, Austria; (M.M.); (T.L.)
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, 1090 Wien, Austria; (M.O.); (J.A.); (W.W.); (M.H.)
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, 1090 Wien, Austria; (M.O.); (J.A.); (W.W.); (M.H.)
| | - Verena Pichler
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, 1090 Wien, Austria; (M.M.); (T.L.)
| |
Collapse
|
25
|
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.
Collapse
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.
| |
Collapse
|
26
|
Bao W, Xie F, Zuo C, Guan Y, Huang YH. PET Neuroimaging of Alzheimer's Disease: Radiotracers and Their Utility in Clinical Research. Front Aging Neurosci 2021; 13:624330. [PMID: 34025386 PMCID: PMC8134674 DOI: 10.3389/fnagi.2021.624330] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/23/2021] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's Disease (AD), the leading cause of senile dementia, is a progressive neurodegenerative disorder affecting millions of people worldwide and exerting tremendous socioeconomic burden on all societies. Although definitive diagnosis of AD is often made in the presence of clinical manifestations in late stages, it is now universally believed that AD is a continuum of disease commencing from the preclinical stage with typical neuropathological alterations appearing decades prior to its first symptom, to the prodromal stage with slight symptoms of amnesia (amnestic mild cognitive impairment, aMCI), and then to the terminal stage with extensive loss of basic cognitive functions, i.e., AD-dementia. Positron emission tomography (PET) radiotracers have been developed in a search to meet the increasing clinical need of early detection and treatment monitoring for AD, with reference to the pathophysiological targets in Alzheimer's brain. These include the pathological aggregations of misfolded proteins such as β-amyloid (Aβ) plagues and neurofibrillary tangles (NFTs), impaired neurotransmitter system, neuroinflammation, as well as deficient synaptic vesicles and glucose utilization. In this article we survey the various PET radiotracers available for AD imaging and discuss their clinical applications especially in terms of early detection and cognitive relevance.
Collapse
Affiliation(s)
- Weiqi Bao
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Fang Xie
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Chuantao Zuo
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Yihui Guan
- PET Center, Huanshan Hospital, Fudan University, Shanghai, China
| | - Yiyun Henry Huang
- Department of Radiology and Biomedical Imaging, PET Center, Yale University School of Medicine, New Haven, CT, United States
| |
Collapse
|
27
|
Preparation of a First 18F-Labeled Agonist for M 1 Muscarinic Acetylcholine Receptors. Molecules 2020; 25:molecules25122880. [PMID: 32585815 PMCID: PMC7355535 DOI: 10.3390/molecules25122880] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/15/2020] [Accepted: 06/17/2020] [Indexed: 01/24/2023] Open
Abstract
M1 muscarinic acetylcholine receptors (mAChRs) are abundant in postsynaptic nerve terminals of all forebrain regions and have been implicated in the cognitive decline associated with Alzheimer's disease and other CNS pathologies. Consequently, major efforts have been spent in the development of subtype-selective positron emission tomography (PET) tracers for mAChRs resulting in the development of several 11C-labeled probes. However, protocols for the preparation of 18F-labeled mAChR-ligands have not been published so far. Here, we describe a straightforward procedure for the preparation of an 18F-labeled M1 mAChR agonist and its corresponding pinacol boronate radiolabeling precursor and the non-radioactive reference compound. The target compounds were prepared from commercially available aryl fluorides and Boc protected 4-aminopiperidine using a convergent reaction protocol. The radiolabeling precursor was prepared by a modification of the Miyaura reaction and labeled via the alcohol-enhanced Cu-mediated radiofluorination. The developed procedure afforded the radiotracer in a non-decay-corrected radiochemical yield of 17 ± 3% (n = 3) and in excellent radiochemical purity (>99%) on a preparative scale. Taken together, we developed a straightforward protocol for the preparation of an 18F-labeled M1 mAChR agonist that is amenable for automation and thus provides an important step towards the routine production of a 18F-labeled M1 selective PET tracer for experimental and diagnostic applications.
Collapse
|