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Tesmer AL, Li X, Bracey E, Schmandt C, Polania R, Peleg-Raibstein D, Burdakov D. Orexin neurons mediate temptation-resistant voluntary exercise. Nat Neurosci 2024; 27:1774-1782. [PMID: 39107488 PMCID: PMC11374669 DOI: 10.1038/s41593-024-01696-2] [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: 08/02/2023] [Accepted: 06/04/2024] [Indexed: 09/06/2024]
Abstract
Despite the well-known health benefits of physical activity, many people underexercise; what drives the prioritization of exercise over alternative options is unclear. We developed a task that enabled us to study how mice freely and rapidly alternate between wheel running and other voluntary activities, such as eating palatable food. When multiple alternatives were available, mice chose to spend a substantial amount of time wheel running without any extrinsic reward and maintained this behavior even when palatable food was added as an option. Causal manipulations and correlative analyses of appetitive and consummatory processes revealed this preference for wheel running to be instantiated by hypothalamic hypocretin/orexin neurons (HONs). The effect of HON manipulations on wheel running and eating was strongly context-dependent, being the largest in the scenario where both options were available. Overall, these data suggest that HON activity enables an eat-run arbitration that results in choosing exercise over food.
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Affiliation(s)
- Alexander L Tesmer
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Xinyang Li
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Eva Bracey
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Cyra Schmandt
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Rafael Polania
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland
| | - Daria Peleg-Raibstein
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland.
| | - Denis Burdakov
- Neurobehavioural Dynamics Laboratory, Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Schwerzenbach, Switzerland.
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2
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Chen XY, Yang W, Xue Y, Xie AM, Sun XR, Chen L. Orexin increases the neuronal excitability of several brain areas associated with maintaining of arousal. J Neurochem 2024. [PMID: 39092633 DOI: 10.1111/jnc.16195] [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: 04/13/2024] [Revised: 07/01/2024] [Accepted: 07/20/2024] [Indexed: 08/04/2024]
Abstract
Orexin is exclusively produced in neurons localized within the lateral hypothalamic area (LHA) and perifornical area (PFA). Orexin has been identified as a key promotor of arousal. The selective loss of orexinergic neurons results in narcolepsy. It is known that the intrinsic electrophysiological properties are critical for neurons to perform their functions in corresponding brain regions. In addition to hypothalamic orexin, other brain nuclei are involved in the regulation of sleep and wakefulness. Quite a lot of studies focus on elucidating orexin-induced regulation of sleep-wake states and modulation of neuronal electrophysiological properties in several brain regions. Here, we summarize that the orexinergic neurons exhibit spontaneous firing activity which is associated with the states of sleep-wake cycle. Orexin mainly exerts postsynaptic excitatory effects on multiple brain nuclei associated with the process of sleep and wakefulness. This review may provide a background to guide future research about the cellular mechanisms of orexin-induced maintaining of arousal.
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Affiliation(s)
- Xin-Yi Chen
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, China
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Wu Yang
- Department of Geriatrics, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yan Xue
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - An-Mu Xie
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xiang-Rong Sun
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
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3
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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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4
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Braun A, Manavis J, Yamanaka A, Ootsuka Y, Blumbergs P, Bobrovskaya L. The role of orexin in Parkinson's disease. J Neurosci Res 2024; 102:e25322. [PMID: 38520160 DOI: 10.1002/jnr.25322] [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: 09/01/2023] [Revised: 02/28/2024] [Accepted: 03/09/2024] [Indexed: 03/25/2024]
Abstract
Emerging evidence has implicated the orexin system in non-motor pathogenesis of Parkinson's disease. It has also been suggested the orexin system is involved in the modulation of motor control, further implicating the orexin system in Parkinson's disease. Parkinson's disease is the second most common neurodegenerative disease with millions of people suffering worldwide with motor and non-motor symptoms, significantly affecting their quality of life. Treatments are based solely on symptomatic management and no cure currently exists. The orexin system has the potential to be a treatment target in Parkinson's disease, particularly in the non-motor stage. In this review, the most current evidence on the orexin system in Parkinson's disease and its potential role in motor and non-motor symptoms of the disease is summarized. This review begins with a brief overview of Parkinson's disease, animal models of the disease, and the orexin system. This leads into discussion of the possible roles of orexin neurons in Parkinson's disease and levels of orexin in the cerebral spinal fluid and plasma in Parkinson's disease and animal models of the disease. The role of orexin is then discussed in relation to symptoms of the disease including motor control, sleep, cognitive impairment, psychological behaviors, and the gastrointestinal system. The neuroprotective effects of orexin are also summarized in preclinical models of the disease.
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Affiliation(s)
- Alisha Braun
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jim Manavis
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | | | - Youichirou Ootsuka
- College of Medicine and Public Health, Flinders Medical and Health Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Peter Blumbergs
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Larisa Bobrovskaya
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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5
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Williams JT, Bolli MH, Brotschi C, Sifferlen T, Steiner MA, Treiber A, Gatfield J, Boss C. Discovery of Nivasorexant (ACT-539313): The First Selective Orexin-1 Receptor Antagonist (SO1RA) Investigated in Clinical Trials. J Med Chem 2024; 67:2337-2348. [PMID: 38331429 DOI: 10.1021/acs.jmedchem.3c01894] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
The orexin system consists of two neuropeptides (orexins A and B) and two receptors (OX1 and OX2). Selective OX1 receptor antagonists (SO1RA) are gaining interest for their potential use in the treatment of CNS disorders, including substance abuse, eating, obsessive compulsive, or anxiety disorders. While blocking OX2 reduces wakefulness, the expected advantage of selectively antagonizing OX1 is the ability to achieve clinical efficacy without the promotion of sleep. Herein we report our discovery efforts starting from a dual orexin receptor antagonist and describe a serendipitous finding that triggered a medicinal chemistry program that culminated in the identification of the potent SO1RA ACT-539313. Efficacy in a rat model of schedule-induced polydipsia supported the decision to select the compound as a preclinical candidate. Nivasorexant (20) represents the first SO1RA to enter clinical development and completed a first proof of concept phase II clinical trial in binge eating disorder in 2022.
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Affiliation(s)
- Jodi T Williams
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - Martin H Bolli
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - Christine Brotschi
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - Thierry Sifferlen
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - Michel A Steiner
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - Alexander Treiber
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - John Gatfield
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
| | - Christoph Boss
- Drug Discovery, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123 Allschwil, Switzerland
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6
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Kniazkina M, Dyachuk V. Does EGFR Signaling Mediate Orexin System Activity in Sleep Initiation? Int J Mol Sci 2023; 24:ijms24119505. [PMID: 37298454 DOI: 10.3390/ijms24119505] [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: 04/19/2023] [Revised: 05/21/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
Sleep-wake cycle disorders are an important symptom of many neurological diseases, including Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Circadian rhythms and sleep-wake cycles play a key role in maintaining the health of organisms. To date, these processes are still poorly understood and, therefore, need more detailed elucidation. The sleep process has been extensively studied in vertebrates, such as mammals and, to a lesser extent, in invertebrates. A complex, multi-step interaction of homeostatic processes and neurotransmitters provides the sleep-wake cycle. Many other regulatory molecules are also involved in the cycle regulation, but their functions remain largely unclear. One of these signaling systems is epidermal growth factor receptor (EGFR), which regulates the activity of neurons in the modulation of the sleep-wake cycle in vertebrates. We have evaluated the possible role of the EGFR signaling pathway in the molecular regulation of sleep. Understanding the molecular mechanisms that underlie sleep-wake regulation will provide critical insight into the fundamental regulatory functions of the brain. New findings of sleep-regulatory pathways may provide new drug targets and approaches for the treatment of sleep-related diseases.
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Affiliation(s)
- Marina Kniazkina
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok 690041, Russia
| | - Vyacheslav Dyachuk
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok 690041, Russia
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7
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Beckenstrom AC, Coloma PM, Dawson GR, Finlayson AK, Malik A, Post A, Steiner MA, Potenza MN. Use of experimental medicine approaches for the development of novel psychiatric treatments based on orexin receptor modulation. Neurosci Biobehav Rev 2023; 147:105107. [PMID: 36828161 PMCID: PMC10165155 DOI: 10.1016/j.neubiorev.2023.105107] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/08/2023] [Accepted: 02/18/2023] [Indexed: 02/25/2023]
Abstract
Despite progress in understanding the pathological mechanisms underlying psychiatric disorders, translation from animal models into clinical use remains a significant bottleneck. Preclinical studies have implicated the orexin neuropeptide system as a potential target for psychiatric disorders through its role in regulating emotional, cognitive, and behavioral processes. Clinical studies are investigating orexin modulation in addiction and mood disorders. Here we review performance-outcome measures (POMs) arising from experimental medicine research methods which may show promise as markers of efficacy of orexin receptor modulators in humans. POMs provide objective measures of brain function, complementing patient-reported or clinician-observed symptom evaluation, and aid the translation from preclinical to clinical research. Significant challenges include the development, validation, and operationalization of these measures. We suggest that collaborative networks comprising clinical practitioners, academics, individuals working in the pharmaceutical industry, drug regulators, patients, patient advocacy groups, and other relevant stakeholders may provide infrastructure to facilitate validation of experimental medicine approaches in translational research and in the implementation of these approaches in real-world clinical practice.
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Affiliation(s)
- Amy C Beckenstrom
- P1vital Ltd, Manor House, Howbery Business Park, Wallingford OX10 8BA, UK.
| | - Preciosa M Coloma
- Idorsia Pharmaceuticals Ltd, Hegenheimermattweg 91, Allschwil 4123, Switzerland
| | - Gerard R Dawson
- P1vital Ltd, Manor House, Howbery Business Park, Wallingford OX10 8BA, UK
| | - Ailidh K Finlayson
- P1vital Ltd, Manor House, Howbery Business Park, Wallingford OX10 8BA, UK; Department of Psychology, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Asad Malik
- P1vital Ltd, Manor House, Howbery Business Park, Wallingford OX10 8BA, UK
| | - Anke Post
- Corlieve Therapeutics, Swiss Innovation Park, Hegenheimermattweg 167A, 4123 Allschwil, Switzerland
| | | | - Marc N Potenza
- Departments of Psychiatry and Neuroscience and the Child Study Center, Yale School of Medicine, 1 Church Street, Room 726, New Haven, CT 06510, USA; Connecticut Mental Health Center, 34 Park Street, New Haven, CT 06519, USA; Connecticut Council on Problem Gambling, Wethersfield, CT, USA; The Wu Tsai Institute, Yale University, 100 College St, New Haven, CT 06510, USA
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8
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Treiber A, Delahaye S, Weigel A, Aeänismaa P, Gatfield J, Seeland S. The Metabolism of the Dual Orexin Receptor Antagonist Daridorexant. Xenobiotica 2023:1-11. [PMID: 36809238 DOI: 10.1080/00498254.2023.2183159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Daridorexant is a dual orexin receptor antagonist developed for the treatment of insomnia disorder and has shown improvement in sleep outcomes and daytime functioning. The present work describes its biotransformation pathways in vitro and in vivo and provides a cross-species comparison between the animal species used in preclinical safety assessments and man.Daridorexant clearance is driven by metabolism along seven distinct pathways. Metabolic profiles were characterized by downstream products while primary metabolic products were of minor importance. The metabolic pattern differed between rodent species, with the rat reflecting the human pattern better than the mouse.In rodents, daridorexant is mostly excreted via the bile after extensive metabolism while urinary excretion was negligible in the rat. Only traces of parent drug were detected in urine, bile or faeces.Daridorexant has three major metabolites which are well covered in these preclinical safety species. All of them retain some residual affinity towards orexin receptors. However, none of these is considered to contribute to the pharmacological effect of daridorexant as their active concentrations in human brain are too low.
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Affiliation(s)
| | | | - Aude Weigel
- Department of Non-clinical Pharmacokinetics and Metabolism and
| | - Päivi Aeänismaa
- Department of Non-clinical Pharmacokinetics and Metabolism and
| | - John Gatfield
- Department of Biology, Idorsia Pharmaceuticals Ltd, Allschwil, Switzerland
| | - Swen Seeland
- Department of Non-clinical Pharmacokinetics and Metabolism and
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9
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Stoops WW, Strickland JC, Hatton KW, Hays LR, Rayapati AO, Lile JA, Rush CR. Suvorexant maintenance enhances the reinforcing but not subjective and physiological effects of intravenous cocaine in humans. Pharmacol Biochem Behav 2022; 220:173466. [PMID: 36152876 PMCID: PMC9588557 DOI: 10.1016/j.pbb.2022.173466] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/19/2022] [Accepted: 09/19/2022] [Indexed: 10/14/2022]
Abstract
Preclinical research has sought to understand the role of the orexin system in cocaine addiction given the connection between orexin producing cells in the lateral hypothalamus and brain limbic areas. Exogenous administration of orexin peptides increased cocaine self-administration whereas selective orexin-1 receptor antagonists reduced cocaine self-administration in non-human animals. The first clinically available orexin antagonist, suvorexant (a dual orexin-1 and orexin-2 receptor antagonist), attenuated motivation for cocaine and cocaine conditioned place preference, as well as cocaine-associated impulsive responding, in rodents. This study aimed to translate those preclinical findings and determine whether suvorexant maintenance altered the pharmacodynamic effects of cocaine in humans. Seven non-treatment seeking subjects with cocaine use disorder completed this within-subject human laboratory study, and a partial data set was obtained from one additional subject. Subjects were maintained for at least three days on 0, 5, 10 and 20 mg oral suvorexant administered at 2230 h daily in random order. Subjects completed experimental sessions in which cocaine self-administration of 0, 10 and 30 mg/70 kg of intravenous cocaine was evaluated on a concurrent progressive ratio drug versus money choice task. Subjective and physiological effects of cocaine were also determined. Cocaine functioned as a reinforcer and produced prototypic dose-related subjective and physiological effects (e.g., increased ratings of "Stimulated" and heart rate). Suvorexant (10, 20 mg) increased self-administration of 10 mg/70 kg cocaine and decreased oral temperature but did not significantly alter any other effects of cocaine. Future research may seek to evaluate the effects of orexin-1 selective antagonists in combination with cocaine.
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Affiliation(s)
- William W Stoops
- Department of Behavioral Science, University of Kentucky College of Medicine, 1100 Veterans Drive, Medical Behavioral Science Building, Lexington, KY 40536-0086, USA; Department of Psychiatry, University of Kentucky College of Medicine, 245 Fountain Court, Lexington, KY 40509-1810, USA; Department of Psychology, University of Kentucky College of Arts and Sciences, 171 Funkhouser Drive, Lexington, KY 40506-0044, USA; Center on Drug and Alcohol Research, University of Kentucky College of Medicine, 845 Angliana Avenue, Lexington, KY 40508, USA.
| | - Justin C Strickland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 5510 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Kevin W Hatton
- Department of Anesthesiology, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, USA
| | - Lon R Hays
- Department of Psychiatry, University of Kentucky College of Medicine, 245 Fountain Court, Lexington, KY 40509-1810, USA
| | - Abner O Rayapati
- Department of Psychiatry, University of Kentucky College of Medicine, 245 Fountain Court, Lexington, KY 40509-1810, USA
| | - Joshua A Lile
- Department of Behavioral Science, University of Kentucky College of Medicine, 1100 Veterans Drive, Medical Behavioral Science Building, Lexington, KY 40536-0086, USA; Department of Psychiatry, University of Kentucky College of Medicine, 245 Fountain Court, Lexington, KY 40509-1810, USA; Department of Psychology, University of Kentucky College of Arts and Sciences, 171 Funkhouser Drive, Lexington, KY 40506-0044, USA
| | - Craig R Rush
- Department of Behavioral Science, University of Kentucky College of Medicine, 1100 Veterans Drive, Medical Behavioral Science Building, Lexington, KY 40536-0086, USA; Department of Psychiatry, University of Kentucky College of Medicine, 245 Fountain Court, Lexington, KY 40509-1810, USA; Department of Psychology, University of Kentucky College of Arts and Sciences, 171 Funkhouser Drive, Lexington, KY 40506-0044, USA
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10
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Viskaitis P, Arnold M, Garau C, Jensen LT, Fugger L, Peleg-Raibstein D, Burdakov D. Ingested non-essential amino acids recruit brain orexin cells to suppress eating in mice. Curr Biol 2022; 32:1812-1821.e4. [PMID: 35316652 DOI: 10.1016/j.cub.2022.02.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 01/10/2022] [Accepted: 02/23/2022] [Indexed: 12/22/2022]
Abstract
Ingested nutrients are proposed to control mammalian behavior by modulating the activity of hypothalamic orexin/hypocretin neurons (HONs). Previous in vitro studies showed that nutrients ubiquitous in mammalian diets, such as non-essential amino acids (AAs) and glucose, modulate HONs in distinct ways. Glucose inhibits HONs, whereas non-essential (but not essential) AAs activate HONs. The latter effect is of particular interest because its purpose is unknown. Here, we show that ingestion of a dietary-relevant mix of non-essential AAs activates HONs and shifts behavior from eating to exploration. These effects persisted despite ablation of a key neural gut → brain communication pathway, the cholecystokinin-sensitive vagal afferents. The behavioral shift induced by the ingested non-essential AAs was recapitulated by targeted HON optostimulation and abolished in mice lacking HONs. Furthermore, lick microstructure analysis indicated that intragastric non-essential AAs and HON optostimulation each reduce the size, but not the frequency, of consumption bouts, thus implicating food palatability modulation as a mechanism for the eating suppression. Collectively, these results suggest that a key purpose of HON activation by ingested, non-essential AAs is to suppress eating and re-initiate food seeking. We propose and discuss possible evolutionary advantages of this, such as optimizing the limited stomach capacity for ingestion of essential nutrients.
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Affiliation(s)
- Paulius Viskaitis
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse, Schwerzenbach 8603, Switzerland
| | - Myrtha Arnold
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse, Schwerzenbach 8603, Switzerland
| | - Celia Garau
- University of Leicester, Department of Neuroscience, Psychology & Behaviour, University Road, Leicester LE1 9HN, UK
| | - Lise T Jensen
- Aarhus University, Department of Clinical Medicine - Department of Clinical Immunology, Palle Juul-Jensens Boulevard, Aarhus 8200, Denmark
| | - Lars Fugger
- Aarhus University, Department of Clinical Medicine - Department of Clinical Immunology, Palle Juul-Jensens Boulevard, Aarhus 8200, Denmark; University of Oxford, Oxford Centre for Neuroinflammation, Nuffield Department of Clinical Neurosciences, Division of Clinical Neurology, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Daria Peleg-Raibstein
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse, Schwerzenbach 8603, Switzerland
| | - Denis Burdakov
- ETH Zürich, Department of Health Sciences and Technology, Schorenstrasse, Schwerzenbach 8603, Switzerland.
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11
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Ramser A, Dridi S. Avian Orexin: Feed Intake Regulator or Something Else? Vet Sci 2022; 9:vetsci9030112. [PMID: 35324840 PMCID: PMC8950792 DOI: 10.3390/vetsci9030112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/25/2022] [Accepted: 03/02/2022] [Indexed: 02/04/2023] Open
Abstract
Originally named for its expression in the posterior hypothalamus in rats and after the Greek word for “appetite”, hypocretin, or orexin, as it is known today, gained notoriety as a neuropeptide regulating feeding behavior, energy homeostasis, and sleep. Orexin has been proven to be involved in both central and peripheral control of neuroendocrine functions, energy balance, and metabolism. Since its discovery, its ability to increase appetite as well as regulate feeding behavior has been widely explored in mammalian food production animals such as cattle, pigs, and sheep. It is also linked to neurological disorders, leading to its intensive investigation in humans regarding narcolepsy, depression, and Alzheimer’s disease. However, in non-mammalian species, research is limited. In the case of avian species, orexin has been shown to have no central effect on feed-intake, however it was found to be involved in muscle energy metabolism and hepatic lipogenesis. This review provides current knowledge and summarizes orexin’s physiological roles in livestock and pinpoints the present lacuna to facilitate further investigations.
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Affiliation(s)
- Alison Ramser
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA;
- Cell and Molecular Biology Program, Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Sami Dridi
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA;
- Cell and Molecular Biology Program, Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
- Correspondence: ; Tel.: +1-(479)-575-2583; Fax: +1-(479)-575-7139
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12
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Orexin receptors 1 and 2 in serotonergic neurons differentially regulate peripheral glucose metabolism in obesity. Nat Commun 2021; 12:5249. [PMID: 34475397 PMCID: PMC8413382 DOI: 10.1038/s41467-021-25380-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 08/05/2021] [Indexed: 12/02/2022] Open
Abstract
The wake-active orexin system plays a central role in the dynamic regulation of glucose homeostasis. Here we show orexin receptor type 1 and 2 are predominantly expressed in dorsal raphe nucleus-dorsal and -ventral, respectively. Serotonergic neurons in ventral median raphe nucleus and raphe pallidus selectively express orexin receptor type 1. Inactivation of orexin receptor type 1 in serotonin transporter-expressing cells of mice reduced insulin sensitivity in diet-induced obesity, mainly by decreasing glucose utilization in brown adipose tissue and skeletal muscle. Selective inactivation of orexin receptor type 2 improved glucose tolerance and insulin sensitivity in obese mice, mainly through a decrease in hepatic gluconeogenesis. Optogenetic activation of orexin neurons in lateral hypothalamus or orexinergic fibers innervating raphe pallidus impaired or improved glucose tolerance, respectively. Collectively, the present study assigns orexin signaling in serotonergic neurons critical, yet differential orexin receptor type 1- and 2-dependent functions in the regulation of systemic glucose homeostasis. The wake-active orexin system plays a central role in the dynamic regulation of glucose homeostasis. Here the authors report that inactivation of the orexin receptor type 1 or 2 in serotonergic neurons differentially regulate systemic glucose homeostasis in the context of diet induced obesity.
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Li B, Chang L, Peng X. Orexin 2 receptor in the nucleus accumbens is critical for the modulation of acute stress-induced anxiety. Psychoneuroendocrinology 2021; 131:105317. [PMID: 34111776 DOI: 10.1016/j.psyneuen.2021.105317] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/30/2022]
Abstract
Orexin is a neuropeptide mainly synthesized in the lateral hypothalamus/perifornical area and has been traditionally implicated in feeding, sleep-wake cycles, and reward. Intriguingly, patients with anxiety have increased levels of orexin in the cerebrospinal fluid. Pharmacological or genetic manipulation of orexin receptors affects anxiety-like behaviors in rodents, suggesting an involvement of the orexin signaling in the regulation of anxiety. Yet, the neural substrates involved remain largely unknown. The nucleus accumbens (NAc) shell holds a key position in the modulation of anxiety-related behaviors. Therefore, in the present study, by using neuropharmacology, molecular approaches and behavioral tests in rats, the role of orexin/orexin receptors in the NAc shell on the anxiety-like behaviors was investigated. We found that microinjection of orexin-A into the NAc shell induced an anxiogenic-like effect. Quantitative real-time PCR and immunofluorescence showed that the orexin 2 receptor (OX2R) is expressed and distributed in the NAc shell neurons. Activation of OX2R mimicked the anxiogenic effect of orexin-A. Moreover, infusion of an OX2R antagonist had no effect on anxiety-like behaviors in normal rats, but reversed anxiogenic effect induced by acute restraint stress. Finally, we found that downregulation of OX2R in the NAc shell caused an anxiolytic-like effect in acute restraint stressed rats, which was consistent with the pharmacological results. Together, this study suggests that OX2R in the NAc shell is involved in the regulation of acute stress-induced anxiety, and raises the possibility that OX2R antagonist may serve as an effective mean to treat anxiety disorders.
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Affiliation(s)
- Bin Li
- Women & Children Central Laboratory, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
| | - Leilei Chang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Xiaochun Peng
- School of Life Sciences, Nanjing University, Nanjing, China
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Guillaumin MCC, Burdakov D. Neuropeptides as Primary Mediators of Brain Circuit Connectivity. Front Neurosci 2021; 15:644313. [PMID: 33776641 PMCID: PMC7991401 DOI: 10.3389/fnins.2021.644313] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 02/18/2021] [Indexed: 11/21/2022] Open
Abstract
Across sleep and wakefulness, brain function requires inter-neuronal interactions lasting beyond seconds. Yet, most studies of neural circuit connectivity focus on millisecond-scale interactions mediated by the classic fast transmitters, GABA and glutamate. In contrast, neural circuit roles of the largest transmitter family in the brain–the slow-acting peptide transmitters–remain relatively overlooked, or described as “modulatory.” Neuropeptides may efficiently implement sustained neural circuit connectivity, since they are not rapidly removed from the extracellular space, and their prolonged action does not require continuous presynaptic firing. From this perspective, we review actions of evolutionarily-conserved neuropeptides made by brain-wide-projecting hypothalamic neurons, focusing on lateral hypothalamus (LH) neuropeptides essential for stable consciousness: the orexins/hypocretins. Action potential-dependent orexin release inside and outside the hypothalamus evokes slow postsynaptic excitation. This excitation does not arise from modulation of classic neurotransmission, but involves direct action of orexins on their specific G-protein coupled receptors (GPCRs) coupled to ion channels. While millisecond-scale, GABA/glutamate connectivity within the LH may not be strong, re-assessing LH microcircuits from the peptidergic viewpoint is consistent with slow local microcircuits. The sustained actions of neuropeptides on neuronal membrane potential may enable core brain functions, such as temporal integration and the creation of lasting permissive signals that act as “eligibility traces” for context-dependent information routing and plasticity. The slowness of neuropeptides has unique advantages for efficient neuronal processing and feedback control of consciousness.
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Affiliation(s)
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
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15
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Orexin-A differentially modulates inhibitory and excitatory synaptic transmission in rat inner retina. Neuropharmacology 2021; 187:108492. [PMID: 33582153 DOI: 10.1016/j.neuropharm.2021.108492] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/08/2021] [Accepted: 02/06/2021] [Indexed: 11/21/2022]
Abstract
In this work, modulation by orexin-A of the release of glutamate and GABA from bipolar and amacrine cells respectively was studied by examining the effects of the neuropeptide on miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) of rat retinal ganglion cells (GCs). Using RNAscope in situ hybridization in combination with immunohistochemistry, we showed positive signals for orexin receptor-1 (OX1R) mRNA in the bipolar cell terminals and those for orexin receptor-2 (OX2R) mRNA in the amacrine cell terminals. With whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that application of orexin-A reduced the interevent interval of mEPSCs of GCs through OX1R. However, it increased the interevent interval of mIPSCs, mediated by GABAA receptors, through OX2R. Furthermore, orexin-A-induced reduction of mEPSC interevent interval was abolished by the application of PI-PLC inhibitors or PKC inhibitors. In contrast, orexin-A-induced increase of GABAergic mIPSC interevent interval was mimicked by 8-Br-cAMP or an adenylyl cyclase activator, but was eliminated by PKA antagonists. Finally, application of nimodipine, an L-type Ca2+ channel blocker, increased both mEPSC and mIPSC interevent interval, and co-application of orexin-A no longer changed the mEPSCs and mIPSCs. We conclude that orexin-A increases presynaptic glutamate release onto GCs by activating L-type Ca2+ channels in bipolar cells, a process that is mediated by an OX1R/PI-PLC/PKC signaling pathway. However, orexin-A decreases presynaptic GABA release onto GCs by inhibiting L-type Ca2+ channels in amacrine cells, a process that is mediated by an OX2R/cAMP-PKA signaling pathway.
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16
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Orexin-A Intensifies Mouse Pupillary Light Response by Modulating Intrinsically Photosensitive Retinal Ganglion Cells. J Neurosci 2021; 41:2566-2580. [PMID: 33536197 DOI: 10.1523/jneurosci.0217-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 01/16/2021] [Accepted: 01/22/2021] [Indexed: 12/24/2022] Open
Abstract
We show for the first time that the neuropeptide orexin modulates pupillary light response, a non-image-forming visual function, in mice of either sex. Intravitreal injection of the orexin receptor (OXR) antagonist TCS1102 and orexin-A reduced and enhanced pupillary constriction in response to light, respectively. Orexin-A activated OX1Rs on M2-type intrinsically photosensitive retinal ganglion cells (M2 cells), and caused membrane depolarization of these cells by modulating inward rectifier potassium channels and nonselective cation channels, thus resulting in an increase in intrinsic excitability. The increased intrinsic excitability could account for the orexin-A-evoked increase in spontaneous discharges and light-induced spiking rates of M2 cells, leading to an intensification of pupillary constriction. Orexin-A did not alter the light response of M1 cells, which could be because of no or weak expression of OX1Rs on them, as revealed by RNAscope in situ hybridization. In sum, orexin-A is likely to decrease the pupil size of mice by influencing M2 cells, thereby improving visual performance in awake mice via enhancing the focal depth of the eye's refractive system.SIGNIFICANCE STATEMENT This study reveals the role of the neuropeptide orexin in mouse pupillary light response, a non-image-forming visual function. Intravitreal orexin-A administration intensifies light-induced pupillary constriction via increasing the excitability of M2 intrinsically photosensitive retinal ganglion cells by activating the orexin receptor subtype OX1R. Modulation of inward rectifier potassium channels and nonselective cation channels were both involved in the ionic mechanisms underlying such intensification. Orexin could improve visual performance in awake mice by reducing the pupil size and thereby enhancing the focal depth of the eye's refractive system.
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Yuan W, Wang H, Gong Y. Prevention of cisplatin-induced nausea and vomiting by seabuckthorn ( Hippophae rhamnoides L.) seed oil: Insights at the level of orexin-A in rats. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2021; 24:248-255. [PMID: 33953865 PMCID: PMC8061333 DOI: 10.22038/ijbms.2020.47599.10973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 11/24/2020] [Indexed: 12/28/2022]
Abstract
OBJECTIVES Nausea and vomiting are perennial problems in cancer patients undergoing chemotherapy. Orexin-A (OXA) has been shown to regulate feeding and gastric motility. Seabuckthorn (Hippophae rhamnoides L.) seed oil (SSO) has been proved to promote digestion and bowel movements. We investigated whether SSO alleviated cisplatin-induced vomiting and its possible mechanism involved in OXA. MATERIALS AND METHODS Rats were randomly divided into normal control group (NCG), cisplatin group (CG), SSO low-dose group (SLG), SSO middle-dose group (SMG) SSO high-dose group (SHG), and ondansetron group (OG). Rats were pretreated respectively with SSO (0.850, 1.675, and 3.350 g/kg·BW) and ondansetron (2 mg/kg·BW) in SLG, SMG, SHG, and OG for 6 days, and the same volume of saline in NCG and CG groups. On the 6th day, cisplatin (6 mg/kg, IP) was administered in all groups except NCG. The cumulative food and kaolin intake, gastric emptying, plasma OXA level, OX1R mRNA and protein expression in the hypothalamus and brainstem, and OXA expression in the lateral hypothalamic area (LHA) were observed, and the HPLC method was used to analyze the composition of SSO. RESULTS Kaolin intake in cisplatin-induced vomiting rats was significantly reduced (P<0.05) and gastric emptying delayed by cisplatin was improved (P<0.05-0.01) by pretreatment with SSO. Plasma OXA concentration, OX1R expression in the hypothalamus and brainstem increased significantly (P<0.05-0.01). Furthermore, OXA expression in LHA also increased significantly (P<0.05). CONCLUSION SSO prevents cisplatin-induced vomiting in rats, which is possibly involved in increasing peripheral and central OXA and the expression of OX1R in the hypothalamus and brainstem.
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Affiliation(s)
- Wen Yuan
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
- Key Laboratory of Pharmaceutical Research for Metabolic Diseases, Qingdao University of Science and Technology, Qingdao, China
| | - Hongbo Wang
- Qingdao Jimo People’s hospital, Qingdao, China
| | - Yanling Gong
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
- Key Laboratory of Pharmaceutical Research for Metabolic Diseases, Qingdao University of Science and Technology, Qingdao, China
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Boss C, Gatfield J, Brotschi C, Heidmann B, Sifferlen T, von Raumer M, Schmidt G, Williams JT, Treiber A, Roch C. The Quest for the Best Dual Orexin Receptor Antagonist (Daridorexant) for the Treatment of Insomnia Disorders. ChemMedChem 2020; 15:2286-2305. [PMID: 32937014 DOI: 10.1002/cmdc.202000453] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/06/2020] [Indexed: 02/06/2023]
Abstract
Since its discovery in 1998, the orexin system has been of interest to the research community as a potential therapeutic target for the treatment of sleep/wake disorders, stress and anxiety disorders, addiction or eating disorders. It consists of two G protein-coupled receptors, the orexin 1 and orexin 2 receptors, and two neuropeptides with agonistic effects, the orexin A and orexin B peptides. Herein we describe our efforts leading to the identification of a promising set of dual orexin receptor antagonists (DORAs) which subsequently went through physiology-based pharmacokinetic and pharmacodynamic modelling>[1] and finally led to the selection of daridorexant, currently in phase 3 clinical trials for the treatment of insomnia disorders.
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Affiliation(s)
- Christoph Boss
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - John Gatfield
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Christine Brotschi
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Bibia Heidmann
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Thierry Sifferlen
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Markus von Raumer
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Gunther Schmidt
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Jodi T Williams
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Alexander Treiber
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
| | - Catherine Roch
- Drug Discovery and Preclinical Research & Development, Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, 4123, Allschwil, BL, Switzerland
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19
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Han Y, Yuan K, Zheng Y, Lu L. Orexin Receptor Antagonists as Emerging Treatments for Psychiatric Disorders. Neurosci Bull 2020; 36:432-448. [PMID: 31782044 PMCID: PMC7142186 DOI: 10.1007/s12264-019-00447-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 09/27/2019] [Indexed: 12/12/2022] Open
Abstract
Orexins comprise two neuropeptides produced by orexin neurons in the lateral hypothalamus and are released by extensive projections of these neurons throughout the central nervous system. Orexins bind and activate their associated G protein-coupled orexin type 1 receptors (OX1Rs) and OX2Rs and act on numerous physiological processes, such as sleep-wake regulation, feeding, reward, emotion, and motivation. Research on the development of orexin receptor antagonists has dramatically increased with the approval of suvorexant for the treatment of primary insomnia. In the present review, we discuss recent findings on the involvement of the orexin system in the pathophysiology of psychiatric disorders, including sleep disorders, depression, anxiety, and drug addiction. We discuss the actions of orexin receptor antagonists, including selective OX1R antagonists (SORA1s), selective OX2R antagonists (SORA2s), and dual OX1/2R antagonists (DORAs), in the treatment of these disorders based on both preclinical and clinical evidence. SORA2s and DORAs have more pronounced efficacy in the treatment of sleep disorders, whereas SORA1s may be promising for the treatment of anxiety and drug addiction. We also discuss potential challenges and opportunities for the application of orexin receptor antagonists to clinical interventions.
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Affiliation(s)
- Ying Han
- National Institute of Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, 100191, China
| | - Kai Yuan
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, China
- Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China
| | - Yongbo Zheng
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, China
| | - Lin Lu
- National Institute of Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, 100191, China.
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, China.
- Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871, China.
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20
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Zarrabian S, Riahi E, Karimi S, Razavi Y, Haghparast A. The potential role of the orexin reward system in future treatments for opioid drug abuse. Brain Res 2020; 1731:146028. [DOI: 10.1016/j.brainres.2018.11.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/11/2018] [Accepted: 11/15/2018] [Indexed: 12/20/2022]
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21
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Adeghate E, Lotfy M, D'Souza C, Alseiari SM, Alsaadi AA, Qahtan SA. Hypocretin/orexin modulates body weight and the metabolism of glucose and insulin. Diabetes Metab Res Rev 2020; 36:e3229. [PMID: 31655012 DOI: 10.1002/dmrr.3229] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 08/16/2019] [Accepted: 10/06/2019] [Indexed: 12/18/2022]
Abstract
The hypocretin/orexin (Hcrt/orexin) unit affects the functions of the nervous, cardiovascular, gastrointestinal, and reproductive systems. Hcrt/orexin ligands and receptors have been localized to different parts of the central and peripheral nervous systems, cerebrospinal fluid and blood, exocrine (pancreas, salivary, lacrimal) as well as endocrine (pancreatic islets, pituitary, adrenal) glands. Several factors including stress, glucagon-like peptide-1 agonists, glutamate, nicotine, glucose, and hypoglycaemia stimulate the expression of Hcrt/orexin system, but it is inhibited by ageing, bone morphogenetic protein, hypoxia/hypercapnia, melanocortin receptor accessory protein 2, and glucagon. Literature reports show that Hcrt/orexin can significantly increase insulin secretion from normal and diabetic rat pancreata. Hcrt/orexin decreases blood glucose concentration and reduces insulin resistance partly via increased tissue expression of glucose transporter type 4. It reduces obesity by increasing browning of fat cells and energy expenditure. Taken together, Hcrt/orexin modulates obesity and the metabolism of glucose and insulin. The Hcrt/orexin system may thus be a target in the development of new therapies for the treatment of diabetes mellitus.
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Affiliation(s)
- Ernest Adeghate
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mohamed Lotfy
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Crystal D'Souza
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Saleh Meqbel Alseiari
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Abdulla Ali Alsaadi
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Saif Abdo Qahtan
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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Uslaner JM, Herring WJ, Coleman PJ. The Discovery of Suvorexant: Lessons Learned That Can Be Applied to Other CNS Drug Development Efforts. ACS Pharmacol Transl Sci 2020; 3:161-168. [PMID: 32259095 PMCID: PMC7088936 DOI: 10.1021/acsptsci.9b00110] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Indexed: 11/29/2022]
Abstract
The development of therapeutics for central nervous system (CNS) disorders has many challenges that result in low probability of success and longer-than-typical development timelines. Suvorexant (Belsomra), the first dual orexin receptor antagonist used for insomnia, was approved by the United States Food and Drug Administration ∼10 years after the initial high-throughput screen was conducted to identify orexin receptor antagonists. What accounted for this success and speed? Here we suggest that this program was unique and set up for success by (1) having a robust and high-throughput pharmacodynamic readout that was translatable across species, including humans, (2) a well-validated target with a defined product profile, resulting in a highly energized team with a can-do attitude, and (3) a highly executable and streamlined clinical strategy. The utility of Belsomra for insomnia, as well as other neurological and psychiatric diseases, continues to be explored, most recently for insomnia associated with Alzheimer's disease.
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Affiliation(s)
- Jason M. Uslaner
- Discovery Neuroscience, Clinical Neuroscience, and Chemistry, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - William J. Herring
- Discovery Neuroscience, Clinical Neuroscience, and Chemistry, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Paul J. Coleman
- Discovery Neuroscience, Clinical Neuroscience, and Chemistry, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
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Effect of orexin-A in the arcuate nucleus on cisplatin-induced gastric side effects in rats. Neurosci Res 2019; 143:53-60. [DOI: 10.1016/j.neures.2018.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/10/2018] [Accepted: 06/01/2018] [Indexed: 12/12/2022]
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24
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Li GY, Zhuang QX, Zhang XY, Wang JJ, Zhu JN. Ionic Mechanisms Underlying the Excitatory Effect of Orexin on Rat Subthalamic Nucleus Neurons. Front Cell Neurosci 2019; 13:153. [PMID: 31105528 PMCID: PMC6499184 DOI: 10.3389/fncel.2019.00153] [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: 12/11/2018] [Accepted: 04/08/2019] [Indexed: 11/24/2022] Open
Abstract
Central orexinergic system deficiency results in cataplexy, a motor deficit characterized with a sudden loss of muscle tone, highlighting a direct modulatory role of orexin in motor control. However, the neural mechanisms underlying the regulation of orexin on motor function are still largely unknown. The subthalamic nucleus (STN), the only excitatory structure of the basal ganglia, holds a key position in the basal ganglia circuitry and motor control. Previous study has revealed a wide distribution of orexinergic fibers as well as orexin receptors in the basal ganglia including the STN. Therefore, in the present study, by using whole-cell patch clamp recording and immunostaining techniques, the direct effect of orexin on the STN neurons in brain slices, especially the underlying receptor and ionic mechanisms, were investigated. Our results show that orexin-A elicits an excitatory effect on STN neurons in rats. Tetrodotoxin (TTX) does not block the orexin-induced excitation on STN neurons, suggesting a direct postsynaptic action of the neuropeptide. The orexin-A-induced inward current on STN neurons is mediated by the activation of both OX1 and OX2 receptors. Immunofluorescence result shows that OX1 and OX2 receptors are co-expressed and co-localized in STN neurons. Furthermore, Na+-Ca2+ exchangers (NCXs) and inward rectifier K+ channels co-mediate the excitatory effect of orexin-A on STN neurons. These results demonstrate a dual receptor in conjunction with the downstream ionic mechanisms underlying the excitatory action of orexin on STN neurons, suggesting a potential modulation of the central orexinergic system on basal ganglia circuitry as well as its related motor control and motor diseases.
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Affiliation(s)
- Guang-Ying Li
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Qian-Xing Zhuang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Xiao-Yang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Jian-Jun Wang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Jing-Ning Zhu
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, School of Life Sciences, Nanjing University, Nanjing, China
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25
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Wang C, Han X, Sun X, Guo F, Luan X, Xu L. Orexin-A signaling in the paraventricular nucleus promote gastric acid secretion and gastric motility through the activation neuropeptide Y Y 1 receptors and modulated by the hypothalamic lateral area. Neuropeptides 2019; 74:24-33. [PMID: 30700376 DOI: 10.1016/j.npep.2019.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 01/22/2019] [Accepted: 01/22/2019] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Abnormal gastric acid secretion and gastric dyskinesia are common gastroenterological ailments. Our study aims to investigate the effect of orexin-A in the paraventricular nucleus (PVN) gastric motility and gastric acid secretion. METHODS The source of orexin-A neuronal projections to the PVN were explored by retrograde tracing and fluorescence immunohistochemistry experiments. Neuronal discharge recordings of single cells were taken within the PVN. Gastric motility was recorded using a force transducer implanted into the stomach, and gastric acid secretion measured through a pyloric catheter. RESULTS Orexin-A-positive neuronal projections from LHA to PVN were found. Administration of orexin-A to PVN activated the firing of 63.2% NPY-excited/GD-excitatory (GD-E) neurons but suppressed the firing of 55.9% NPY-inhibited/GD-inhibitory (GD-I) neurons, promoted gastric motility and gastric acid secretion in a dose-dependent manner. Responses produced by orexin-A could be partially blocked by Y1 receptor antagonist GR-231118; Electrical stimulation to the the hypothalamic lateral area (LHA) altered NPY-sensitive/GD neuronal activity in the PVN, stimulated gastric motility and gastric acid secretion. Additionally, these effects induced by LHA electrical stimulation were blocked by administration of the OX1R antagonist SB-334867 to the PVN. CONCLUSION Orexin-A from LHA neurons act on the PVN to enhance gastric motility and gastric acid secretion, with Y1 receptor signaling playing a critical role.
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Affiliation(s)
- Cheng Wang
- Qingdao University, School of Basic Medical Sciences, Shandong, Qingdao 266071, China
| | - Xiaohua Han
- Qingdao University, School of Basic Medical Sciences, Shandong, Qingdao 266071, China
| | - Xiangrong Sun
- Qingdao University, School of Basic Medical Sciences, Shandong, Qingdao 266071, China
| | - Feiei Guo
- Qingdao University, School of Basic Medical Sciences, Shandong, Qingdao 266071, China
| | - Xiao Luan
- Qingdao University, School of Basic Medical Sciences, Shandong, Qingdao 266071, China
| | - Luo Xu
- Qingdao University, School of Basic Medical Sciences, Shandong, Qingdao 266071, China.
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Orexin-A Stimulates Insulin Secretion Through the Activation of the OX1 Receptor and Mammalian Target of Rapamycin in Rat Insulinoma Cells. Pancreas 2019; 48:568-573. [PMID: 30946236 DOI: 10.1097/mpa.0000000000001280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The study aimed to investigate the involvement of the mammalian target of rapamycin (mTOR) signaling pathway in orexin-A/OX1 receptor-induced insulin secretion in rat insulinoma INS-1 cells. METHODS Rat insulinoma INS-1 cells were grown and treated with various concentrations of orexin-A, with or without OX1 receptor-selective antagonist SB674042 or the phosphatidylinositol 3-kinase/mTOR antagonist PF-04691502. Insulin release experiments, Western blot analysis, and statistical analysis were conducted using INS-1 cells. RESULTS Our results showed that treating cells with orexin-A increased the expression of the OX1 receptor and the phosphorylation of mTOR in a concentration-dependent manner. An increase in insulin secretion was also observed for cells treated with orexin-A. We further demonstrated that the increase in insulin secretion was dependent on the activation of the OX1 receptor and mTOR signaling pathway by using the OX1 receptor-selective antagonist SB674042 or the phosphatidylinositol 3-kinase/mTOR antagonist PF-04691502, which abolished the effects of orexin-A treatment. CONCLUSIONS Our results concluded that orexin-A/OX1 receptor stimulates insulin secretion by activating AKT and its downstream target, mTOR. Therefore, orexins may regulate the energy balance for cell survival with the involvement of mTOR in this process.
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Guo F, Gao S, Xu L, Sun X, Zhang N, Gong Y, Luan X. Arcuate Nucleus Orexin-A Signaling Alleviates Cisplatin-Induced Nausea and Vomiting Through the Paraventricular Nucleus of the Hypothalamus in Rats. Front Physiol 2018; 9:1811. [PMID: 30618823 PMCID: PMC6304364 DOI: 10.3389/fphys.2018.01811] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 12/04/2018] [Indexed: 01/06/2023] Open
Abstract
The most common side effects of cisplatin chemotherapy are nausea and vomiting, and the overwhelming majority of research studies on the mechanism of cisplatin-induced nausea have been focused on the “vomiting center.” As a modulatory center of gastric motility, the roles of the hypothalamus in nausea and vomiting remain unclear. In the present study, we investigated the effects of exogenous orexin-A injected into the arcuate nucleus (ARC) on cisplatin-induced nausea and vomiting, and the possible underlying mechanism. Kaolin intake was calculated daily in cisplatin-treated and saline-treated rats. Gastric motility recording, injections into the ARC, and lesions of the paraventricular nucleus (PVN) were used to study the effects of orexin-A and the hypothalamic nucleus on disorders of gastrointestinal function in cisplatin-treated rats. The pathway from the ARC to the PVN was observed through Fluoro-Gold retrograde tracing. Furthermore, an NPY Y1 receptor antagonist was administered to explore the possible mechanisms involved in the effects of orexin-A in the ARC. We illustrated that exogenous orexin-A injected into the ARC reduced kaolin intake and promoted gastric motility in cisplatin-treated rats, and these effects could have been blocked by an ipsilateral PVN lesion or co-injected antagonist of orexin-A-SB334867. Additional results showed that orexin-A-activated neurons in the ARC communicated directly with other neurons in the PVN that express neuropeptide Y (NPY). Furthermore, activation of the downstream NPY pathway was required for the observed effects of orexin in the ARC on cisplatin-induced nausea and vomiting. These findings reveal a novel neurobiological circuit from the ARC to the PVN that might provide a potential target for the prevention and treatment of cisplatin-induced nausea and vomiting.
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Affiliation(s)
- Feifei Guo
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Shengli Gao
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Luo Xu
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xiangrong Sun
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Nana Zhang
- Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yanling Gong
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Xiao Luan
- Pathophysiology Department, School of Basic Medicine, Qingdao University, Qingdao, China
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Liu C, Xue Y, Liu MF, Wang Y, Liu ZR, Diao HL, Chen L. Orexins increase the firing activity of nigral dopaminergic neurons and participate in motor control in rats. J Neurochem 2018; 147:380-394. [DOI: 10.1111/jnc.14568] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Cui Liu
- Department of Physiology; Qingdao University; Qingdao China
| | - Yan Xue
- Department of Physiology; Qingdao University; Qingdao China
| | - Mei-Fang Liu
- Department of Physiology; Qingdao University; Qingdao China
| | - Ying Wang
- Department of Physiology; Qingdao University; Qingdao China
| | - Zi-Ran Liu
- Department of Physiology; Qingdao University; Qingdao China
| | - Hui-Ling Diao
- Department of Physiology; Qingdao University; Qingdao China
| | - Lei Chen
- Department of Physiology; Qingdao University; Qingdao China
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Orexin-B modulates synaptic transmission of rod bipolar cells in rat retina. Neuropharmacology 2018; 133:38-50. [PMID: 29325900 DOI: 10.1016/j.neuropharm.2018.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/31/2017] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
Abstract
Orexin-A, -B play a crucial role in arousal and feeding by activating two G-protein-coupled receptors: orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R). Orexins, along with orexin receptors, are expressed in retinal neurons, and they have been shown to differentially modulate excitatory AMPA receptors of amacrine and ganglion cells in the inner retina. In this work we report that orexin-B modulates the activity of rod bipolar cells (RBCs) located in the outer retina of rat. Intravitreal injection of orexin-B increased the amplitude of the scotopic electroretinographic b-wave, a reflection of RBC activity, recorded in vivo. Patch clamp recordings in rat retinal slices showed that orexin-B did not change glutamatergic excitatory component of the RBC response driven by photoreceptors. Effects of orexin-B on GABA receptor-mediated synaptic transmission of RBCs were then examined. In retinal slice preparations orexin-B suppressed GABA receptor-mediated inhibitory postsynaptic currents of RBCs in the inner plexiform layer. Furthermore, using whole-cell recordings in isolated RBCs it was shown that orexin-B suppressed GABAC receptor-, but not GABAA receptor-, mediated currents of the RBCs, an effect that was blocked by OX1R and OX2R antagonists. The orexin-B-induced inhibition of GABAC currents was likely mediated by a Gi/o/PC-PLC/Ca2+-independent PKC signaling pathway, as such inhibition was absent when each step of the above-pathway was blocked with GDP-β-S/pertussis toxin (for Gi/o), D609 (for PLC), bisindolylmaleimide IV (for PKC)/rottlerin (for PKCδ), respectively. The orexin-B-induced potentiation of RBC activity may improve visual acuity and contrast sensitivity of the animal during the dark period (wake phase).
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Nguyen PH, Greene E, Kong BW, Bottje W, Anthony N, Dridi S. Acute Heat Stress Alters the Expression of Orexin System in Quail Muscle. Front Physiol 2017; 8:1079. [PMID: 29311994 PMCID: PMC5742252 DOI: 10.3389/fphys.2017.01079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 12/07/2017] [Indexed: 11/13/2022] Open
Abstract
Accumulating evidences indicate that the hypothalamic neuropeptide orexins or hypocretins are involved in stress-induced responses in mammals. Recently, we found that orexin is expressed and secreted from avian muscle cells, however its regulation is still unknown. In this study, we investigated the effect of heat and oxidative stress, the most challenging stressors in poultry production, on the expression of orexin system in quail muscle tissues and myoblast cell lines. Four week-old genetically selected susceptible and resistant Japanese quail (Coturnix coturnix Japonica) lines were exposed to acute heat stress (HS, 37°C for 1.5 h) or maintained at thermoneutral conditions (24°C). Quail myoblast (QM7) cell line was exposed to heat stress (45°C) for 0.5, 1, 2, or 4 h. The control cells were maintained at 37°C. The cells were also treated with several doses of hydrogen peroxide (H2O2, 10-200 μM) or 4-Hydroxynonenal (4-HNE, 10-30 μM) as oxidative stress. Untreated cells were used as controls. Acute HS significantly induced the expression of HSP70 and down-regulated orexin system in both quail muscle tissue and QM7 cells. Similarly, H2O2 but not 4-HNE treatment significantly increased HSP70 protein levels and dysregulated the expression of orexin and its related receptors in a dose-dependent manner in QM7 cells. Transient overexpression of HSP70 down-regulated the expression of orexin system in QM7 cells. Taken together, these data indicate that orexin may be a key player in stress response in avian muscle by demonstrating that heat and oxidative stress alter the expression of orexin system in quail muscle. This effect might be mediated through HSP70. Unraveling the upstream regulators and downstream effectors of orexin in avian muscle merits further in depth investigations.
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Affiliation(s)
- Phuong H Nguyen
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Elisabeth Greene
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Byung-Whi Kong
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Walter Bottje
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Nicholas Anthony
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Sami Dridi
- Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, United States
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Sánchez-García A, Cabral-Pacheco GA, Zomosa-Signoret VC, Ortiz-López R, Camacho A, Tabera-Tarello PM, Garnica-López JA, Vidaltamayo R. Modular organization of a hypocretin gene minimal promoter. Mol Med Rep 2017; 17:2263-2270. [PMID: 29207107 PMCID: PMC5783473 DOI: 10.3892/mmr.2017.8142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/17/2017] [Indexed: 12/02/2022] Open
Abstract
Orexins or hypocretins are neurotransmitters produced by a small population of neurons in the lateral hypothalamus. This family of peptides modulates sleep-wake cycle, arousal and feeding behaviors; however, the mechanisms regulating their expression remain to be fully elucidated. There is an interest in defining the key molecular elements in orexin regulation, as these may serve to identify targets for generating novel therapies for sleep disorders, obesity and addiction. Our previous studies showed that the expression of orexin was decreased in mice carrying null-mutations of the transcription factor early B-cell factor 2 (ebf2) and that the promoter region of the prepro-orexin (Hcrt) gene contained two putative ebf-binding sites, termed olf-1 sites. In the present study, a minimal promoter region of the murine Hcrt gene was identified, which was able to drive the expression of a luciferase reporter gene in the human 293 cell line. Deletion of the olf1-site proximal to the transcription start site of the Hcrt gene increased reporter gene expression, whereas deletion of the distal olf1-like site decreased its expression. The lentiviral transduction of murine transcription factor ebf2 cDNA into 293 cells increased the gene expression driven by this minimal Hcrt-gene promoter and an electrophoretic mobility shift assays demonstrated that the distal olf1-like sequence was a binding site for ebf2.
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Affiliation(s)
- Adriana Sánchez-García
- Department of Biochemistry and Molecular Medicine, School of Medicine, Universidad Autonoma de Nuevo Leon, Monterrey, NL 64460, Mexico
| | - Griselda A Cabral-Pacheco
- Department of Biochemistry and Molecular Medicine, School of Medicine, Universidad Autonoma de Nuevo Leon, Monterrey, NL 64460, Mexico
| | - Viviana C Zomosa-Signoret
- Department of Biochemistry and Molecular Medicine, School of Medicine, Universidad Autonoma de Nuevo Leon, Monterrey, NL 64460, Mexico
| | - Rocío Ortiz-López
- Genomics Unit, Center for Research and Development in Health Sciences, Universidad Autonoma de Nuevo Leon, Monterrey, NL 64460, Mexico
| | - Alberto Camacho
- Department of Biochemistry and Molecular Medicine, School of Medicine, Universidad Autonoma de Nuevo Leon, Monterrey, NL 64460, Mexico
| | - Paulo M Tabera-Tarello
- Department of Basic Science, School of Health Sciences, Universidad de Monterrey, San Pedro Garzia, NL 66238, Mexico
| | - José A Garnica-López
- Department of Basic Science, School of Health Sciences, Universidad de Monterrey, San Pedro Garzia, NL 66238, Mexico
| | - Román Vidaltamayo
- Department of Basic Science, School of Health Sciences, Universidad de Monterrey, San Pedro Garzia, NL 66238, Mexico
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Matsuda K, Matsumura K, Shimizu SS, Nakamachi T, Konno N. Neuropeptide Y-Induced Orexigenic Action Is Attenuated by the Orexin Receptor Antagonist in Bullfrog Larvae. Front Neurosci 2017; 11:176. [PMID: 28420957 PMCID: PMC5378779 DOI: 10.3389/fnins.2017.00176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 03/16/2017] [Indexed: 11/13/2022] Open
Abstract
In bullfrog larvae at the pre- and pro-metamorphic stages, feeding behavior is regulated by appetite factors such as orexigenic peptides. In fact, food intake is enhanced by intracerebroventricular (ICV) administration of neuropeptide Y (NPY) and orexin A. Using goldfish, our previous study indicated that the orexigenic action of NPY is mediated by orexin A, suggesting the functional interaction between the two. However, there is little information about whether the action of orexin A mediates the orexigenic action of NPY in bullfrog larvae. Therefore, we examined the effect of the orexin receptor antagonist, SB334867 on the orexigenic action of NPY in larvae. The stimulatory effect of ICV injection of NPY at 10 pmol/g body weight (BW) on food intake was abolished by treatment with SB334867 at 60 pmol/g BW. These results suggest that, in bullfrog larvae, there is a neuronal relationship between the NPY and orexin systems, and that the orexigenic action of NPY is mediated by the orexin A-induced orexigenic action.
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Affiliation(s)
- Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan.,Laboratory of Regulatory Biology, Graduate School of Innovative Life Sciences, University of ToyamaToyama, Japan
| | - Kairi Matsumura
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
| | - Syun-Suke Shimizu
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
| | - Tomoya Nakamachi
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
| | - Norifumi Konno
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of ToyamaToyama, Japan
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Rønnestad I, Gomes AS, Murashita K, Angotzi R, Jönsson E, Volkoff H. Appetite-Controlling Endocrine Systems in Teleosts. Front Endocrinol (Lausanne) 2017; 8:73. [PMID: 28458653 PMCID: PMC5394176 DOI: 10.3389/fendo.2017.00073] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/27/2017] [Indexed: 12/15/2022] Open
Abstract
Mammalian studies have shaped our understanding of the endocrine control of appetite and body weight in vertebrates and provided the basic vertebrate model that involves central (brain) and peripheral signaling pathways as well as environmental cues. The hypothalamus has a crucial function in the control of food intake, but other parts of the brain are also involved. The description of a range of key neuropeptides and hormones as well as more details of their specific roles in appetite control continues to be in progress. Endocrine signals are based on hormones that can be divided into two groups: those that induce (orexigenic), and those that inhibit (anorexigenic) appetite and food consumption. Peripheral signals originate in the gastrointestinal tract, liver, adipose tissue, and other tissues and reach the hypothalamus through both endocrine and neuroendocrine actions. While many mammalian-like endocrine appetite-controlling networks and mechanisms have been described for some key model teleosts, mainly zebrafish and goldfish, very little knowledge exists on these systems in fishes as a group. Fishes represent over 30,000 species, and there is a large variability in their ecological niches and habitats as well as life history adaptations, transitions between life stages and feeding behaviors. In the context of food intake and appetite control, common adaptations to extended periods of starvation or periods of abundant food availability are of particular interest. This review summarizes the recent findings on endocrine appetite-controlling systems in fish, highlights their impact on growth and survival, and discusses the perspectives in this research field to shed light on the intriguing adaptations that exist in fish and their underlying mechanisms.
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Affiliation(s)
- Ivar Rønnestad
- Department of Biology, University of Bergen, Bergen, Norway
| | - Ana S. Gomes
- Department of Biology, University of Bergen, Bergen, Norway
| | - Koji Murashita
- Department of Biology, University of Bergen, Bergen, Norway
- Research Center for Aquaculture Systems, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Tamaki, Mie, Japan
| | - Rita Angotzi
- Department of Biology, University of Bergen, Bergen, Norway
| | - Elisabeth Jönsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Hélène Volkoff
- Departments of Biology and Biochemistry, Memorial University of Newfoundland, St John’s, NL, Canada
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Liguori G, Pavone LM, Assisi L, Langella E, Tafuri S, Mirabella N, Costagliola A, Vittoria A. Expression of orexin B and its receptor 2 in rat testis. Gen Comp Endocrinol 2017; 242:66-73. [PMID: 26631456 DOI: 10.1016/j.ygcen.2015.11.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 11/18/2022]
Abstract
The peptides orexin A (OxA) and orexin B (OxB) deriving from a common precursor molecule, prepro-orexin, by proteolytic cleavage, bind the two G-coupled OX1 and OX2 receptors. While OX1 selectively binds OxA, OX2 shows similar affinity for both orexins. Firstly discovered in the hypothalamus, orexins and their receptors have been found in other brain regions as well as in peripheral tissues of mammals, thus resulting involved in the regulation of a broad variety of physiological functions. While the functional localization of OxA and OX1 in the mammalian genital tract has been already described, the expression of OxB and OX2 and their potential role in the reproductive functions remain to be explored. Here, we investigated the presence of OxB and OX2 in the rat testis by immunohistochemical and biochemical analyses. The results definitely demonstrated the localization of OxB and OX2 in pachytene and second spermatocytes as well as in spermatids at all stages of the cycle of the seminiferous epithelium. The expression of both OX2 mRNA and protein in the rat testis was also established by RT-PCR and Western blotting, respectively. The analysis of the molecular mechanism of action of OxB in the rat testis showed that OxB, in contrast with OxA, is unable to promote steroidogenesis. These results translate into the regulation of diverse biological actions by OxA and OxB in the male gonad.
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Affiliation(s)
- Giovanna Liguori
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via F. Delpino 1, 80137 Naples, Italy
| | - Luigi Michele Pavone
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy
| | - Loredana Assisi
- Department of Biology, University of Naples Federico II, Via Mezzocannone 6, 80134 Naples, Italy
| | - Emilia Langella
- School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - Simona Tafuri
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via F. Delpino 1, 80137 Naples, Italy
| | - Nicola Mirabella
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via F. Delpino 1, 80137 Naples, Italy
| | - Anna Costagliola
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via F. Delpino 1, 80137 Naples, Italy
| | - Alfredo Vittoria
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via F. Delpino 1, 80137 Naples, Italy.
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Role of Lateral Hypothalamic Orexin (Hypocretin) Neurons in Alcohol Use and Abuse: Recent Advances. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40495-016-0069-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
INTRODUCTION The orexin (hypocretin) system is an evolutionarily conserved neuropeptide-G-protein-coupled receptor system, consisting of two neuropeptides the orexin-A and the orexin-B peptides as well as two receptors the orexin-1 and the orexin-2 receptors. The orexin system is crucially involved in the regulation of the circadian rhythm, states of wakefulness and arousal and the modulation of emotions and has attracted the interest of many researchers which resulted in an enormous amount of insight, mainly in the field of antagonists. Clinical proof of concept was obtained with dual orexin receptor antagonists in primary insomnia. Merck's suvorexant got FDA approval on 13 August 2014 for the treatment of insomnia. AREAS COVERED The patent applications from Thomson Reuters Integrity Database (covering 2010-August 2014) are summarized, analyzed and discussed in the review. EXPERT OPINION Intense patenting activities have been observed over the past 3 years in the field of orexin antagonists. Several compounds have been investigated in clinical trials mainly for the treatment of primary insomnia. The advantage of orexin antagonists, based on animal pharmacology results, is the promotion and maintenance of physiological sleep which should avoid hangover phenomena reported as side effects of approved treatments. Many other potential treatment options are mentioned for orexin antagonists of different selectivity profiles.
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Affiliation(s)
- Christoph Boss
- Drug Discovery and Preclinical Research, Actelion Pharmaceuticals Ltd , Gewerbestrasse 16, CH-4123 Allschwil/ BL , Switzerland
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Liu F, Weng SJ, Yang XL, Zhong YM. Orexin-A potentiates L-type calcium/barium currents in rat retinal ganglion cells. Neuroscience 2015; 305:225-37. [PMID: 26259903 DOI: 10.1016/j.neuroscience.2015.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/27/2015] [Accepted: 08/04/2015] [Indexed: 01/07/2023]
Abstract
Two neuropeptides, orexin-A and orexin-B (also called hypocretin-1 and -2), have been implicated in sleep/wake regulation, feeding behaviors via the activation of two subtypes of G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). While the expression of orexins and orexin receptors is immunohistochemically revealed in retinal neurons, the function of these peptides in the retina is largely unknown. Using whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that orexin-A increased L-type-like barium currents (IBa,L) in ganglion cells (GCs), and the effect was blocked by the selective OX1R antagonist SB334867, but not by the OX2R antagonist TCS OX2 29. The orexin-A effect was abolished by intracellular dialysis of GDP-β-S/GPAnt-2A, a Gq protein inhibitor, suggesting the mediation of Gq. Additionally, during internal dialysis of the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor U73122, orexin-A did not change the IBa,L of GCs, whereas the orexin-A effect persisted in the presence of the phosphatidylcholine (PC)-PLC inhibitor D609. The orexin-A-induced potentiation was not seen with internal infusion of Ca(2+)-free solution or when inositol 1,4,5-trisphosphate (IP3)-sensitive Ca(2+) release from intracellular stores was blocked by heparin/xestospongins-C. Moreover, the orexin-A effect was mimicked by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, but was eliminated when PKC was inhibited by bisindolylmaleimide IV (Bis-IV)/Gö6976. Neither adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) nor guanosine 3',5'-cyclic monophosphate (cGMP)-protein kinase G (PKG) signaling pathway was likely involved, as orexin-A persisted to potentiate the IBa,L of GCs no matter these two pathways were activated or inhibited. These results suggest that, by activating OX1R, orexin-A potentiates the IBa,L of rat GCs through a distinct Gq/PI-PLC/IP3/Ca(2+)/PKC signaling pathway.
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Affiliation(s)
- F Liu
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - S-J Weng
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - X-L Yang
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Y-M Zhong
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
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Recent trends in orexin research—2010 to 2015. Bioorg Med Chem Lett 2015; 25:2875-87. [DOI: 10.1016/j.bmcl.2015.05.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/08/2015] [Accepted: 05/09/2015] [Indexed: 12/31/2022]
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Zheng C, Deng QQ, Liu LL, Wang MY, Zhang G, Sheng WL, Weng SJ, Yang XL, Zhong YM. Orexin-A differentially modulates AMPA-preferring responses of ganglion cells and amacrine cells in rat retina. Neuropharmacology 2015; 93:80-93. [PMID: 25656479 DOI: 10.1016/j.neuropharm.2015.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/22/2014] [Accepted: 01/20/2015] [Indexed: 01/18/2023]
Abstract
By activating their receptors (OX1R and OX2R) orexin-A/B regulate wake/sleeping states, feeding behaviors, but the function of these peptides in the retina remains unknown. Using patch-clamp recordings and calcium imaging in rat isolated retinal cells, we demonstrated that orexin-A suppressed α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-preferring receptor-mediated currents (AMPA-preferring currents) in ganglion cells (GCs) through OX1R, but potentiated those in amacrine cells (ACs) through OX2R. Consistently, in rat retinal slices orexin-A suppressed light-evoked AMPA-preferring receptor-mediated excitatory postsynaptic currents in GCs, but potentiated those in ACs. Intracellular dialysis of GDP-β-S or preincubation with the Gi/o inhibitor pertussis toxin (PTX) abolished both the effects. Either cAMP/the protein kinase A (PKA) inhibitor Rp-cAMP or cGMP/the PKG blocker KT5823 failed to alter the orexin-A effects. Whilst both of them involved activation of protein kinase C (PKC), the effects on GCs and ACs were respectively eliminated by the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor and phosphatidylcholine (PC)-PLC inhibitor. Moreover, in GCs orexin-A increased [Ca(2+)]i and the orexin-A effect was blocked by intracellular Ca(2+)-free solution and by inositol 1,4,5-trisphosphate (IP3) receptor antagonists. In contrast, orexin-A did not change [Ca(2+)]i in ACs and the orexin-A effect remained in intracellular or extracellular Ca(2+)-free solution. We conclude that a distinct Gi/o/PI-PLC/IP3/Ca(2+)-dependent PKC signaling pathway, following the activation of OX1R, is likely responsible for the orexin-A effect on GCs, whereas a Gi/o/PC-PLC/Ca(2+)-independent PKC signaling pathway, following the activation of OX2R, mediates the orexin-A effect on ACs. These two actions of orexin-A, while working in concert, provide a characteristic way for modulating information processing in the inner retina.
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Affiliation(s)
- Chao Zheng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China; Cell Electrophysiology Laboratory, Wannan Medical College, 22 West Wenchang Road, Wuhu, Anhui 241002, China
| | - Qin-Qin Deng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Lei-Lei Liu
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Meng-Ya Wang
- Cell Electrophysiology Laboratory, Wannan Medical College, 22 West Wenchang Road, Wuhu, Anhui 241002, China
| | - Gong Zhang
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Wen-Long Sheng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Shi-Jun Weng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Xiong-Li Yang
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
| | - Yong-Mei Zhong
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
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40
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Wen J, Zhao Y, Shen Y, Guo L. Effect of orexin A on apoptosis in BGC-823 gastric cancer cells via OX1R through the AKT signaling pathway. Mol Med Rep 2015; 11:3439-44. [PMID: 25586545 DOI: 10.3892/mmr.2015.3190] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 07/22/2014] [Indexed: 01/16/2023] Open
Abstract
Orexins are a class of peptides involved in the regulation of food intake, energy homeostasis, the sleep‑wake cycle and gastrointestinal function. Recent studies have demonstrated that orexin A may influence apoptosis and proliferation in numerous types of cancer cells. However, the effect of orexin A on gastric cancer cells and its mechanisms of action remain elusive. In the present study, BGC‑823 gastric cancer cells were treated with orexin A (10‑10‑10‑6 M) in vitro and the expression levels of orexin receptor 1 (OX1R) protein in cells was then determined. The proliferation, viability and apoptosis of BGC‑823 cells were detected. In addition, BGC‑823 cells were treated with AKT inhibitor PF‑04691502 or OX1R‑specific antagonist SB334867 in combination with orexin A, in order to examine the activation of AKT and caspase‑3. The results showed that orexin A (10‑10‑10‑6 M) stimulated the OX1R protein expression in BGC‑823 cells, which improved the proliferation and viability of the cells as well as protected them from apoptosis. Phosphorylated AKT protein was significantly increased in BGC‑823 cells following treatment with orexin A. Moreover, 10‑8 M orexin A reduced the proapoptotic activity of caspase‑3 (by ≤30%). The OX1R antagonist SB334867 (10‑6 M) and AKT antagonist PF‑04691502 (10‑6 M), when used individually or in combination, abolished the effect of orexin A (10‑8 M) on BGC-823 cells. In conclusion, the results of the present study demonstrated that orexin A inhibited gastric cancer cell apoptosis via OX1R through the AKT signaling pathway.
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Affiliation(s)
- Jing Wen
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yuyan Zhao
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yang Shen
- Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lei Guo
- Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
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41
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Williams JT, Gatfield J, Roch C, Treiber A, Jenck F, Bolli MH, Brotschi C, Sifferlen T, Heidmann B, Boss C. Discovery and optimisation of 1-acyl-2-benzylpyrrolidines as potent dual orexin receptor antagonists. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00074b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The evolution of our lead compound1into thein vivoactive, competitive, dual orexin receptor antagonist27, is described.
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Affiliation(s)
| | - John Gatfield
- Drug Discovery Chemistry
- Actelion Pharmaceuticals Ltd
- Switzerland
| | - Catherine Roch
- Drug Discovery Chemistry
- Actelion Pharmaceuticals Ltd
- Switzerland
| | | | - Francois Jenck
- Drug Discovery Chemistry
- Actelion Pharmaceuticals Ltd
- Switzerland
| | - Martin H. Bolli
- Drug Discovery Chemistry
- Actelion Pharmaceuticals Ltd
- Switzerland
| | | | | | - Bibia Heidmann
- Drug Discovery Chemistry
- Actelion Pharmaceuticals Ltd
- Switzerland
| | - Christoph Boss
- Drug Discovery Chemistry
- Actelion Pharmaceuticals Ltd
- Switzerland
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42
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Hu B, Yang N, Qiao QC, Hu ZA, Zhang J. Roles of the orexin system in central motor control. Neurosci Biobehav Rev 2014; 49:43-54. [PMID: 25511388 DOI: 10.1016/j.neubiorev.2014.12.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/10/2014] [Accepted: 12/03/2014] [Indexed: 12/15/2022]
Abstract
The neuropeptides orexin-A and orexin-B are produced by one group of neurons located in the lateral hypothalamic/perifornical area. However, the orexins are widely released in entire brain including various central motor control structures. Especially, the loss of orexins has been demonstrated to associate with several motor deficits. Here, we first summarize the present knowledge that describes the anatomical and morphological connections between the orexin system and various central motor control structures. In the next section, the direct influence of orexins on related central motor control structures is reviewed at molecular, cellular, circuitry, and motor activity levels. After the summarization, the characteristic and functional relevance of the orexin system's direct influence on central motor control function are demonstrated and discussed. We also propose a hypothesis as to how the orexin system orchestrates central motor control in a homeostatic regulation manner. Besides, the importance of the orexin system's phasic modulation on related central motor control structures is highlighted in this regulation manner. Finally, a scheme combining the homeostatic regulation of orexin system on central motor control and its effects on other brain functions is presented to discuss the role of orexin system beyond the pure motor activity level, but at the complex behavioral level.
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Affiliation(s)
- Bo Hu
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Nian Yang
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Qi-Cheng Qiao
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Zhi-An Hu
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
| | - Jun Zhang
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
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43
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Yu L, Zhang XY, Chen ZP, Zhuang QX, Zhu JN, Wang JJ. Orexin excites rat inferior vestibular nuclear neurons via co-activation of OX1 and OX 2 receptors. J Neural Transm (Vienna) 2014; 122:747-55. [PMID: 25371350 DOI: 10.1007/s00702-014-1330-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 10/28/2014] [Indexed: 12/13/2022]
Abstract
Orexin deficiency results in cataplexy, a motor deficit characterized by sudden loss of muscle tone, strongly indicating an active role of central orexinergic system in motor control. However, effects of orexin on neurons in central motor structures are still largely unknown. Our previous studies have revealed that orexin excites neurons in the cerebellar nuclei and lateral vestibular nucleus, two important subcortical motor centers for control of muscle tone. Here, we report that both orexin-A and orexin-B depolarizes and increases the firing rate of neurons in the inferior vestibular nucleus (IVN), the largest nucleus in the vestibular nuclear complex and holding an important position in integration of information signals in the control of body posture. TTX does not block orexin-induced excitation on IVN neurons, suggesting a direct postsynaptic action of the neuropeptide. Furthermore, bath application of orexin induces an inward current on IVN neurons in a concentration-dependent manner. SB334867 and TCS-OX2-29, specific OX1 and OX2 receptor antagonists, blocked the excitatory effect of orexin, and [Ala(11), D-Leu(15)]-orexin B, a selective OX2 receptor agonist, mimics the orexin-induced inward current on IVN neurons. qPCR and immunofluorescence results show that both OX1 and OX2 receptor mRNAs and proteins are expressed and localized in the rat IVN. These results demonstrate that orexin excites the IVN neurons by co-activation of both OX1 and OX2 receptors, suggesting that via the direct modulation on the IVN, the central orexinergic system may actively participate in the central vestibular-mediated postural and motor control.
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Affiliation(s)
- Lei Yu
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Mailbox 426, 22 Hankou Road, Nanjing, 210093, China
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44
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Chang X, Zhao Y, Ju S, Guo L. Orexin-A stimulates 3β-hydroxysteroid dehydrogenase expression and cortisol production in H295R human adrenocortical cells through the AKT pathway. Int J Mol Med 2014; 34:1523-8. [PMID: 25319929 DOI: 10.3892/ijmm.2014.1959] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 09/23/2014] [Indexed: 11/05/2022] Open
Abstract
Orexin-A is a regulatory peptide involved in the regulation of food intake, sleep-wakefulness, and it has various endocrine and metabolic functions. It orchestrates diverse central and peripheral processes through the stimulation of two G-protein coupled receptors, orexin receptor type 1 (OX1 receptor) and orexin receptor type 2 (OX2 receptor). In this study, human adrenocortical cells (NCI-H295R cells) were incubated with various concentrations of orexin-A (10-10 to 10-6 M) in vitro, and the mRNA and protein expression of OX1 receptor was determined in the cells. In addition, NCI-H295R cells treated with 10-6 M orexin-A were then treated with or without OX1 receptor specific antagonist (SB334867), AKT antagonist (PF-04691502), or a combination of both. Subsequently, cell proliferation, the cortisol content in the medium and the mRNA and protein expression expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) were analyzed. The activity of the AKT signaling pathway was also determined in the NCI-H295R cells. We observed that the increase in the mRNA and protein expression of OX1 receptor was orexin-A concentration-dependent, with 10-6 M orexin-A exerting the most potent effect. Orexin-A enhanced cell proliferation and cortisol production, and increased the mRNA and protein expression of 3β-HSD in the NCI-H295R cells; however, these effects were partly blocked by the OX1 receptor antagonist, the AKT antagonist and the combination of both. Furthermore, orexin-A significantly increased the phosphorylation of AKT, with the levels of total AKT protein remaining unaltered. This effect was blocked in the presence of PF-04691502 (10-6 M), SB334867 (10-6 M) and the combination of both. On the whole, our data demonstrate that the effects of orexin-A on the survival and function of human adrenocortical cells are mediated through the AKT signaling pathway.
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Affiliation(s)
- Xiaocen Chang
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yuyan Zhao
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Shujing Ju
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Lei Guo
- Departments of Endocrinology and Orthopedic Surgery, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China
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45
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Boss C, Roch-Brisbare C, Steiner MA, Treiber A, Dietrich H, Jenck F, von Raumer M, Sifferlen T, Brotschi C, Heidmann B, Williams JT, Aissaoui H, Siegrist R, Gatfield J. Structure-Activity Relationship, Biological, and Pharmacological Characterization of the Proline Sulfonamide ACT-462206: a Potent, Brain-Penetrant Dual Orexin 1/Orexin 2 Receptor Antagonist. ChemMedChem 2014; 9:2486-96. [DOI: 10.1002/cmdc.201402258] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Indexed: 01/16/2023]
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46
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Karasawa H, Yakabi S, Wang L, Taché Y. Orexin-1 receptor mediates the increased food and water intake induced by intracerebroventricular injection of the stable somatostatin pan-agonist, ODT8-SST in rats. Neurosci Lett 2014; 576:88-92. [PMID: 24915296 DOI: 10.1016/j.neulet.2014.05.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/25/2014] [Accepted: 05/31/2014] [Indexed: 11/19/2022]
Abstract
Intracerebroventricular (icv) injection of the stable somatostatin pan-agonist, ODT8-SST induces a somatostatin 2 receptor (sst2) mediated robust feeding response that involves neuropeptide Y and opioid systems in rats. We investigated whether the orexigenic system driven by orexin also plays a role. Food and water intake after icv injection was measured concomitantly in non-fasted and non-water deprived rats during the light phase. In vehicle treated rats (100% DMSO, icv), ODT8-SST (1μg/rat, icv) significantly increased the 2-h food and water intake compared to icv vehicle plus saline (5.1±1.0g vs. 1.2±0.4g and 11.3±1.9mL vs. 2.5±1.2mL, respectively). The orexin-1 receptor antagonist, SB-334867 (16μg/rat, icv) completely inhibited the 2-h food and water intake induced by icv ODT8-SST. In contrast, the icv pretreatment with the selective somatostatin sst2 antagonist, S-406-028, established to block the orexigenic effect of icv ODT8-SST, did not modify the increased food and water intake induced by icv orexin-A (10.7μg/rat). These data indicate that orexin-1 receptor signaling system is part of the brain neurocircuitry contributing to the orexigenic and dipsogenic responses induced by icv ODT8-SST and that orexin-A stimulates food intake independently from brain sst2 activation.
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Affiliation(s)
- Hiroshi Karasawa
- Department of Medicine, CURE/Digestive Diseases Center, and Center for Neurobiology of Stress Digestive Diseases Division, University of California at Los Angeles, Los Angeles, CA 90073, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Seiichi Yakabi
- Department of Medicine, CURE/Digestive Diseases Center, and Center for Neurobiology of Stress Digestive Diseases Division, University of California at Los Angeles, Los Angeles, CA 90073, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Lixin Wang
- Department of Medicine, CURE/Digestive Diseases Center, and Center for Neurobiology of Stress Digestive Diseases Division, University of California at Los Angeles, Los Angeles, CA 90073, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Yvette Taché
- Department of Medicine, CURE/Digestive Diseases Center, and Center for Neurobiology of Stress Digestive Diseases Division, University of California at Los Angeles, Los Angeles, CA 90073, USA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA.
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47
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Heese K. G proteins, p60TRP, and neurodegenerative diseases. Mol Neurobiol 2013; 47:1103-11. [PMID: 23345134 DOI: 10.1007/s12035-013-8410-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 01/13/2013] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a complex brain disorder of the limbic system and association cortices. The disease is characterized by the production and deposition of the amyloid β-peptide (Aβ) in the brain, and the neuropathological mechanisms involved must be deciphered to gain further insights into the fundamental aspects of the protein biology responsible for the development and progression of this disease. Aβ is generated by the intramembranous cleavage of the β-amyloid precursor protein, which is mediated by the proteases β- and γ-secretase. Accumulating evidence suggests the importance of the coupling of this cleavage mechanism to G protein signaling. Heterotrimeric G proteins play pivotal roles as molecular switches in signal transduction pathways mediated by G protein-coupled receptors (GPCRs). Extracellular stimuli activate these receptors, which in turn catalyze guanosine triphosphate-guanosine diphosphate exchange on the G protein α-subunit. The activation-deactivation cycles of G proteins underlie their crucial functions as molecular switches for a vast array of biological responses. The novel transcription regulator protein p60 transcription regulator protein and its related GPCR signaling pathways have recently been described as potential targets for the development of alternative strategies for inhibiting the early signaling mechanisms involved in neurodegenerative diseases such as AD.
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Affiliation(s)
- Klaus Heese
- Department of Biomedical Engineering, College of Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791, Republic of Korea.
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48
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Civelli O, Reinscheid RK, Zhang Y, Wang Z, Fredriksson R, Schiöth HB. G protein-coupled receptor deorphanizations. Annu Rev Pharmacol Toxicol 2012; 53:127-46. [PMID: 23020293 PMCID: PMC5828024 DOI: 10.1146/annurev-pharmtox-010611-134548] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
G protein-coupled receptors (GPCRs) are major regulators of intercellular interactions. They initiate these actions by being activated by a wide variety of natural ligands. Historically, ligands were discovered first, but the advent of molecular biology reversed this trend. Most GPCRs are identified on the basis of their DNA sequences and thus are initially unmatched to known natural ligands. They are termed orphan GPCRs. Discovering their ligands-i.e., "deorphanizing" the GPCRs-gave birth to the field of reverse pharmacology. This review discusses the present status of GPCR deorphanization, presents a few examples of successes and surprises, and highlights difficulties encountered in these efforts.
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Affiliation(s)
- Olivier Civelli
- Department of Pharmacology, University of California, Irvine, Irvine, California 92617, USA.
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49
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Biegańska K, Sokołowska P, Jöhren O, Zawilska JB. Orexin A suppresses the growth of rat C6 glioma cells via a caspase-dependent mechanism. J Mol Neurosci 2012; 48:706-12. [PMID: 22588980 PMCID: PMC3447140 DOI: 10.1007/s12031-012-9799-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 04/30/2012] [Indexed: 01/16/2023]
Abstract
Orexin A and orexin B (also known as hypocretins) are closely related peptides synthesized by hypothalamic neurons. They orchestrate diverse central and peripheral processes by stimulation of two G-protein coupled receptors, OX1R and OX2R. Recent studies have demonstrated the ability of orexins to promote a robust apoptosis in different cancer cells in culture and a potent growth reduction of human colon tumors in mice xenografts. Here we report effects of orexins on survival of rat C6 glioma cells, an experimental model for studies on glioblastoma multiforme (GBM). Quantitative real-time PCR demonstrated the expression of both types of orexin receptors in C6 cells. Orexin A and orexin B did not affect rat C6 glioma cell proliferation as assessed by [3H]thymidine incorporation assay. Incubation of the cells with orexin A (0.001–1 μM) resulted in a marked decrease of cell viability. The observed effect was caspase-dependent, as it was blocked by Z-VAD-fmk, a pan caspase inhibitor. In addition to that, a parallel increase in caspase-3 activity was observed. It is suggested that stimulation of orexin receptors induces death of rat C6 glioma cells through activation of caspase pathway.
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Affiliation(s)
- Kaja Biegańska
- Institute for Medical Biology, Polish Academy of Sciences, 93-232 Lodz, Poland
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50
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Woldan-Tambor A, Biegańska K, Wiktorowska-Owczarek A, Zawilska JB. Activation of orexin/hypocretin type 1 receptors stimulates cAMP synthesis in primary cultures of rat astrocytes. Pharmacol Rep 2011; 63:717-23. [PMID: 21857082 DOI: 10.1016/s1734-1140(11)70583-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 11/29/2010] [Indexed: 01/29/2023]
Abstract
The effects of orexins, which are also named hypocretins, on cAMP formation were examined in primary cultures of rat astrocytes. Orexin A, an agonist of OX₁ and OX₂ receptors, stimulated cAMP production with an EC₅₀ value of 0.68 μM and potentiated the forskolin-induced increase in the nucleotide synthesis. [Ala¹¹-D-Leu¹⁵]orexin B, an agonist of OX₂ receptors, was inactive. The effects of orexin A were antagonized by SB 408124, a selective blocker of OX₁ receptors, but were not affected by TCS OX2 29, a selective antagonist of OX₃ receptors. We hypothesized that the activation of OX₁ receptors stimulated cAMP synthesis in primary rat astrocyte cultures.
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Affiliation(s)
- Agata Woldan-Tambor
- Department of Pharmacodynamics, Medical University of Łódź, Muszyńskiego 1, PL 90-151 Łódź, Poland
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