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Mohammadkhani A, Mitchell C, James MH, Borgland SL, Dayas CV. Contribution of hypothalamic orexin (hypocretin) circuits to pathologies of motivation. Br J Pharmacol 2024. [PMID: 39317446 DOI: 10.1111/bph.17325] [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: 07/30/2023] [Revised: 06/17/2024] [Accepted: 06/28/2024] [Indexed: 09/26/2024] Open
Abstract
The orexin (also known as hypocretin) system, consisting of neuropeptides orexin-A and orexin-B, was discovered over 25 years ago and was immediately identified as a central regulator of sleep and wakefulness. These peptides interact with two G-protein coupled receptors, orexin 1 (OX1) and orexin 2 (OX2) receptors which are capable of coupling to all heterotrimeric G-protein subfamilies, but primarily transduce increases in calcium signalling. Orexin neurons are regulated by a variety of transmitter systems and environmental stimuli that signal reward availability, including food and drug related cues. Orexin neurons are also activated by anticipation, stress, cues predicting motivationally relevant information, including those predicting drugs of abuse, and engage neuromodulatory systems, including dopamine neurons of the ventral tegmental area (VTA) to respond to these signals. As such, orexin neurons have been characterized as motivational activators that coordinate a range of functions, including feeding and arousal, that allow the individual to respond to motivationally relevant information, critical for survival. This review focuses on the role of orexins in appetitive motivation and highlights a role for these neuropeptides in pathologies characterized by inappropriately high levels of motivated arousal (overeating, anxiety and substance use disorders) versus those in which motivation is impaired (depression).
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Affiliation(s)
- Aida Mohammadkhani
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, The University of Calgary, Calgary, Alberta, Canada
| | - Caitlin Mitchell
- School of Biomedical Sciences and Pharmacy, University of Newcastle, University Drive, Callaghan, New South Wales, Australia
- The Hunter Medical Research, New Lambton Heights, New South Wales, Australia
| | - Morgan H James
- Department of Psychiatry and Brain Health Institute, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Stephanie L Borgland
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, The University of Calgary, Calgary, Alberta, Canada
| | - Christopher V Dayas
- School of Biomedical Sciences and Pharmacy, University of Newcastle, University Drive, Callaghan, New South Wales, Australia
- The Hunter Medical Research, New Lambton Heights, New South Wales, Australia
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Steiner MA, Botticelli L, Bergamini G, Micioni Di Bonaventura E, Gatfield J, Williams JT, Treiber A, Vaillant C, Cifani C, Micioni Di Bonaventura MV. Evaluating the efficacy of the selective orexin 1 receptor antagonist nivasorexant in an animal model of binge-eating disorder. Int J Eat Disord 2024; 57:1418-1432. [PMID: 38456603 DOI: 10.1002/eat.24181] [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: 11/01/2023] [Revised: 02/15/2024] [Accepted: 02/19/2024] [Indexed: 03/09/2024]
Abstract
OBJECTIVE Test the efficacy of the selective orexin 1 receptor (OX1R) antagonist (SO1RA) nivasorexant in an animal model of binge-eating disorder (BED) and study its dose-response relationship considering free brain concentrations and calculated OX1R occupancy. Compare nivasorexant's profile to that of other, structurally diverse SO1RAs. Gain understanding of potential changes in orexin-A (OXA) neuropeptide and deltaFosB (ΔFosB) protein expression possibly underlying the development of the binge-eating phenotype in the rat model used. METHOD Binge-like eating of highly palatable food (HPF) in rats was induced through priming by intermittent, repeated periods of dieting and access to HPF, followed by an additional challenge with acute stress. Effects of nivasorexant were compared to the SO1RAs ACT-335827 and IDOR-1104-2408. OXA expression in neurons and neuronal fibers as well as ΔFosB and OXA-ΔFosB co-expression was studied in relevant brain regions using immuno- or immunofluorescent histochemistry. RESULTS All SO1RAs dose-dependently reduced binge-like eating with effect sizes comparable to the positive control topiramate, at unbound drug concentrations selectively blocking brain OX1Rs. Nivasorexant's efficacy was maintained upon chronic dosing and under conditions involving more frequent stress exposure. Priming for binge-like eating or nivasorexant treatment resulted in only minor changes in OXA or ΔFosB expression in few brain areas. DISCUSSION Selective OX1R blockade reduced binge-like eating in rats. Neither ΔFosB nor OXA expression proved to be a useful classifier for their binge-eating phenotype. The current results formed the basis for a clinical phase II trial in BED, in which nivasorexant was unfortunately not efficacious compared with placebo. PUBLIC SIGNIFICANCE Nivasorexant is a new investigational drug for the treatment of binge-eating disorder (BED). It underwent clinical testing in a phase II proof of concept trial in humans but was not efficacious compared with placebo. The current manuscript investigated the drug's efficacy in reducing binge-like eating behavior of a highly palatable sweet and fat diet in a rat model of BED, which initially laid the foundation for the clinical trial.
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Affiliation(s)
| | - Luca Botticelli
- Pharmacology Unit, School of Pharmacy, University of Camerino, Camerino, Italy
| | - Giorgio Bergamini
- CNS Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | | | - John Gatfield
- CNS Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Jodi T Williams
- CNS Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Alexander Treiber
- CNS Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | | | - Carlo Cifani
- Pharmacology Unit, School of Pharmacy, University of Camerino, Camerino, Italy
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Zhang VY, O'Connor SL, Welsh WJ, James MH. Machine learning models to predict ligand binding affinity for the orexin 1 receptor. ARTIFICIAL INTELLIGENCE CHEMISTRY 2024; 2:100040. [PMID: 38476266 PMCID: PMC10927255 DOI: 10.1016/j.aichem.2023.100040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
The orexin 1 receptor (OX1R) is a G-protein coupled receptor that regulates a variety of physiological processes through interactions with the neuropeptides orexin A and B. Selective OX1R antagonists exhibit therapeutic effects in preclinical models of several behavioral disorders, including drug seeking and overeating. However, currently there are no selective OX1R antagonists approved for clinical use, fueling demand for novel compounds that act at this target. In this study, we meticulously curated a dataset comprising over 1300 OX1R ligands using a stringent filter and criteria cascade. Subsequently, we developed highly predictive quantitative structure-activity relationship (QSAR) models employing the optimized hyper-parameters for the random forest machine learning algorithm and twelve 2D molecular descriptors selected by recursive feature elimination with a 5-fold cross-validation process. The predictive capacity of the QSAR model was further assessed using an external test set and enrichment study, confirming its high predictivity. The practical applicability of our final QSAR model was demonstrated through virtual screening of the DrugBank database. This revealed two FDA-approved drugs (isavuconazole and cabozantinib) as potential OX1R ligands, confirmed by radiolabeled OX1R binding assays. To our best knowledge, this study represents the first report of highly predictive QSAR models on a large comprehensive dataset of diverse OX1R ligands, which should prove useful for the discovery and design of new compounds targeting this receptor.
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Affiliation(s)
- Vanessa Y Zhang
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
- West Windsor-Plainsboro High School South, West Windsor, NJ, USA
| | - Shayna L O'Connor
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
| | - William J Welsh
- Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA
| | - Morgan H James
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University and Rutgers Biomedical Health Sciences, Piscataway, NJ, USA
- Brain Health Institute, Rutgers University and Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA
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Bergamini G, Durkin S, Steiner MA. Selective orexin 1 receptor antagonism does not affect effort-based responding for sucrose reward in rats. J Psychopharmacol 2024; 38:305-308. [PMID: 38327032 DOI: 10.1177/02698811241229523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
In rodents, orexin neuropeptides regulate motivation and reward-seeking via orexin 1 receptor (OX1R) signaling in the mesolimbic dopaminergic system. This role is clearly established for rewards inherent to drugs of abuse but less so for natural rewards. Reported effects of the selective OX1R antagonist (SO1RA) SB-334867 on motivation for palatable food are ambiguous. In our experimental conditions neither SB-334867, nor two additional, structurally different SO1RAs, ACT-335827 and the clinical development candidate nivasorexant, affected effort-based responding for sucrose in rats. The positive control lisdexamfetamine, approved for psychiatric disorders associated with altered reward sensitivity such as binge eating disorder, increased effort-based responding.
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Affiliation(s)
- Giorgio Bergamini
- CNS Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Sean Durkin
- CNS Pharmacology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
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Treiber A, Seeland S, Haschimi B, Weigel A, Williams JT, Gabillet J. The metabolism of the orexin-1 selective receptor antagonist nivasorexant. Xenobiotica 2024; 54:124-137. [PMID: 38358311 DOI: 10.1080/00498254.2024.2319811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/13/2024] [Indexed: 02/16/2024]
Abstract
Nivasorexant was the first orexin-1 selective receptor antagonist entering clinical development. Despite encouraging preclinical evidence in animal models, a proof-of-concept trial in binge-eating patients recently failed to demonstrate its clinical utility in this population.Across species, nivasorexant clearance was driven by metabolism along seven distinct pathways, five of which were hydroxylation reactions in various locations of the molecule. The exact sites of metabolism were identified by means of mass spectrometry, the use of deuterated analogues, and finally confirmed by chemical references.CYP3A4 was the main cytochrome P450 enzyme involved in nivasorexant metabolism in vitro and accounting for about 90% of turnover in liver microsomes. Minor roles were taken by CYP2C9 and CYP2C19 but individually did not exceed 3-7%.In the rat, nivasorexant was mostly excreted via the bile after extensive metabolism, while urinary excretion was negligible. Only traces of the parent drug were detected in urine, bile, or faeces.
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Affiliation(s)
- Alexander Treiber
- Department of Non-clinical Pharmacokinetics and Drug Metabolism, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Swen Seeland
- Department of Non-clinical Pharmacokinetics and Drug Metabolism, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Belal Haschimi
- Department of Non-clinical Pharmacokinetics and Drug Metabolism, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Aude Weigel
- Department of Non-clinical Pharmacokinetics and Drug Metabolism, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Jodi T Williams
- Department of Medicinal Chemistry, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Jerome Gabillet
- Department of Medicinal Chemistry, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
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