1
|
Rebassa JB, Capó T, Lillo J, Raïch I, Reyes-Resina I, Navarro G. Cannabinoid and Orexigenic Systems Interplay as a New Focus of Research in Alzheimer's Disease. Int J Mol Sci 2024; 25:5378. [PMID: 38791416 PMCID: PMC11121409 DOI: 10.3390/ijms25105378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
Alzheimer's disease (AD) remains a significant health challenge, with an increasing prevalence globally. Recent research has aimed to deepen the understanding of the disease pathophysiology and to find potential therapeutic interventions. In this regard, G protein-coupled receptors (GPCRs) have emerged as novel potential therapeutic targets to palliate the progression of neurodegenerative diseases such as AD. Orexin and cannabinoid receptors are GPCRs capable of forming heteromeric complexes with a relevant role in the development of this disease. On the one hand, the hyperactivation of the orexins system has been associated with sleep-wake cycle disruption and Aβ peptide accumulation. On the other hand, cannabinoid receptor overexpression takes place in a neuroinflammatory environment, favoring neuroprotective effects. Considering the high number of interactions between cannabinoid and orexin systems that have been described, regulation of this interplay emerges as a new focus of research. In fact, in microglial primary cultures of APPSw/Ind mice model of AD there is an important increase in CB2R-OX1R complex expression, while OX1R antagonism potentiates the neuroprotective effects of CB2R. Specifically, pretreatment with the OX1R antagonist has been shown to strongly potentiate CB2R signaling in the cAMP pathway. Furthermore, the blockade of OX1R can also abolish the detrimental effects of OX1R overactivation in AD. In this sense, CB2R-OX1R becomes a new potential therapeutic target to combat AD.
Collapse
Affiliation(s)
- Joan Biel Rebassa
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), National Institute of Health Carlos, 28029 Madrid, Spain; (J.B.R.); (T.C.); (J.L.); (I.R.)
- Institut de Neurociències UB, Campus Mundet, 08035 Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Science, University of Barcelona, 08028 Barcelona, Spain
| | - Toni Capó
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), National Institute of Health Carlos, 28029 Madrid, Spain; (J.B.R.); (T.C.); (J.L.); (I.R.)
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Science, University of Barcelona, 08028 Barcelona, Spain
| | - Jaume Lillo
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), National Institute of Health Carlos, 28029 Madrid, Spain; (J.B.R.); (T.C.); (J.L.); (I.R.)
- Institut de Neurociències UB, Campus Mundet, 08035 Barcelona, Spain
- Departament de Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain
| | - Iu Raïch
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), National Institute of Health Carlos, 28029 Madrid, Spain; (J.B.R.); (T.C.); (J.L.); (I.R.)
- Institut de Neurociències UB, Campus Mundet, 08035 Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Science, University of Barcelona, 08028 Barcelona, Spain
| | - Irene Reyes-Resina
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), National Institute of Health Carlos, 28029 Madrid, Spain; (J.B.R.); (T.C.); (J.L.); (I.R.)
- Institut de Neurociències UB, Campus Mundet, 08035 Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Science, University of Barcelona, 08028 Barcelona, Spain
| | - Gemma Navarro
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), National Institute of Health Carlos, 28029 Madrid, Spain; (J.B.R.); (T.C.); (J.L.); (I.R.)
- Institut de Neurociències UB, Campus Mundet, 08035 Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Science, University of Barcelona, 08028 Barcelona, Spain
| |
Collapse
|
2
|
Bonifazi A, Del Bello F, Giorgioni G, Piergentili A, Saab E, Botticelli L, Cifani C, Micioni Di Bonaventura E, Micioni Di Bonaventura MV, Quaglia W. Targeting orexin receptors: Recent advances in the development of subtype selective or dual ligands for the treatment of neuropsychiatric disorders. Med Res Rev 2023; 43:1607-1667. [PMID: 37036052 DOI: 10.1002/med.21959] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 04/11/2023]
Abstract
Orexin-A and orexin-B, also named hypocretin-1 and hypocretin-2, are two hypothalamic neuropeptides highly conserved across mammalian species. Their effects are mediated by two distinct G protein-coupled receptors, namely orexin receptor type 1 (OX1-R) and type 2 (OX2-R), which share 64% amino acid identity. Given the wide expression of OX-Rs in different central nervous system and peripheral areas and the several pathophysiological functions in which they are involved, including sleep-wake cycle regulation (mainly mediated by OX2-R), emotion, panic-like behaviors, anxiety/stress, food intake, and energy homeostasis (mainly mediated by OX1-R), both subtypes represent targets of interest for many structure-activity relationship (SAR) campaigns carried out by pharmaceutical companies and academies. However, before 2017 the research was predominantly directed towards dual-orexin ligands, and limited chemotypes were investigated. Analytical characterizations, including resolved structures for both OX1-R and OX2-R in complex with agonists and antagonists, have improved the understanding of the molecular basis of receptor recognition and are assets for medicinal chemists in the design of subtype-selective ligands. This review is focused on the medicinal chemistry aspects of small molecules acting as dual or subtype selective OX1-R/OX2-R agonists and antagonists belonging to different chemotypes and developed in the last years, including radiolabeled OX-R ligands for molecular imaging. Moreover, the pharmacological effects of the most studied ligands in different neuropsychiatric diseases, such as sleep, mood, substance use, and eating disorders, as well as pain, have been discussed. Poly-pharmacology applications and multitarget ligands have also been considered.
Collapse
Affiliation(s)
- Alessandro Bonifazi
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, Maryland, United States
| | - Fabio Del Bello
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Gianfabio Giorgioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | | | - Elizabeth Saab
- Medicinal Chemistry Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, Maryland, United States
| | - Luca Botticelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
| | | | | | - Wilma Quaglia
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| |
Collapse
|
3
|
Dual Cannabinoid and Orexin Regulation of Anhedonic Behaviour Caused by Prolonged Restraint Stress. Brain Sci 2023; 13:brainsci13020314. [PMID: 36831860 PMCID: PMC9954020 DOI: 10.3390/brainsci13020314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/28/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
The endocannabinoid and orexin systems share many biological functions, including wakefulness, stress response, reward processing, and mood. While these systems work against one another with respect to arousal, chronic stress-induced downregulation of both systems often leads to anhedonia or the inability to experience pleasure from natural rewards. In the current study, a 24 h restraint stress test (24 h RST) reduced sucrose preference in adult male and female C57BL/6 mice. Prior to the stressor, subsets of mice were intraperitoneally administered cannabinoid and orexin receptor agonists, antagonists, and combinations of these drugs. Restraint mice that received the cannabinoid receptor type 1 (CB1R) antagonist SR141716A, orexin receptor type 2 (OX2R) agonist YNT-185, and the combination of SR141716A and YNT-185, exhibited less anhedonia compared to vehicle/control mice. Thus, the 24 h RST likely decreased orexin signaling, which was then restored by YNT-185. Receptor colocalization analysis throughout mesocorticolimbic brain regions revealed increased CB1R-OX1R colocalization from SR141716A and YNT-185 treatments. Although a previous study from our group showed additive cataleptic effects between CP55,940 and the dual orexin receptor antagonist (TCS-1102), the opposite combination of pharmacological agents proved additive for sucrose preference. Taken together, these results reveal more of the complex interactions between the endocannabinoid and orexin systems.
Collapse
|
4
|
Nasudi G, Elahdadi Salmani M, Hosseinmardi N, Moradpour F, Lashkarbolouki T, Goudarzi I. Hippocampal orexin-1 and endocannabinoid-1 receptors underlie the kainate-induced occlusion in theta-burst long- term potentiation. Neuropeptides 2022; 95:102263. [PMID: 35716469 DOI: 10.1016/j.npep.2022.102263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 06/02/2022] [Accepted: 06/02/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Seizures may result from the hyperexcitable neuronal activity of the brain. Multiple neurotransmitter receptors, including orexin (OX) and endocannabinoids interfere with forming the synaptic responses linked to the seizures. Therefore, this study investigates the involvement of OX-1 (OX1R) and endocannbinoid-1 (CB1R) receptors in the kainate- induced excitability in the synaptic field responses. MATERIAL AND METHODS Theta pattern used to stimulate Schaffer collaterals and then metal microelectrodes to record the CA1 field excitatory postsynaptic potentials (fEPSPs). Input/ output stimulation and responses and paired- pulse (PP) stimuli employed to measure the state of synaptic activity in normal and kainate- induced seizure-like hyperexcitable activities and the slope of fEPSPs used as a measure of the change in the synaptic activity. Furthermore, agonists and antagonists of OX and endocannabinoids infused to investigate the involvement of their receptors. RESULT The results showed that kainate application increased the fEPSP slope either in input stimuli with different intensities/output synaptic responses (I/O), or test pulse stimulated baseline synaptic responses (BSR) and, hence, increased the excitability of field responses in the CA1 region. However, neither kainate nor theta burst stimulation (TBS) could alter the PP stimuli -induced synaptic responses. TBS increased the fEPSP slope of the kainate-applied I/O and BSR, however, the increase was not high enough in BSR to be classified as long-term potentiation (LTP). The single-antagonist OX1R and CB1R administration prevented TBS- induced potentiation and partially recovered the effect by adding eCB or OX agonists in kainate-injected animals. In contrast, OX or combined eCB-OX antagonist application group demonstrated nearly full recovery of LTP induction. CONCLUSION Our study concludes that blockade of OX1 or CB1 prevents the induction of LTP, and OX infusion or both receptor blockade recovers the LTP.
Collapse
Affiliation(s)
- Giti Nasudi
- School of Biology, Damghan University, Damghan, Iran
| | | | - Narges Hosseinmardi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Iran
| | - Farshad Moradpour
- Department of Physiology, Faculty of Medicine, Kermanshah University of Medical Sciences, Iran
| | | | - Iran Goudarzi
- School of Biology, Damghan University, Damghan, Iran
| |
Collapse
|
5
|
Deli SB, Bonab SI, Khakpay R, Khakpai F, Feyzi MH. An interaction between basolateral amygdala orexinergic and endocannabinoid systems in inducing anti-nociception in the rat formalin test. Psychopharmacology (Berl) 2022; 239:3171-3184. [PMID: 35918531 DOI: 10.1007/s00213-022-06199-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 07/22/2022] [Indexed: 11/29/2022]
Abstract
The amygdala has emerged as the main brain center for the emotional affective dimension of pain and pain modulation. In the amygdala, orexin and cannabinoid receptors are expressed in relatively high concentrations. To investigate the possible interaction between the amygdala orexin and cannabinoid systems on the modulation of inflammatory pain, we conducted formalin, rotarod, and plethysmometer tests, as well as analyzing mRNA expression of orexin and cannabinoid receptors in male rats. The basolateral amygdala (BLA) was unilaterally implanted by a guide cannula. Our results showed that, compared to saline and DMSO/saline, intra-BLA microinjection of orexin-A (50 and 100 µM) decreased flinch response in the early phase, but not in the late phase of the formalin test. However, these injections had no significant effect on the mRNA expression level of BLA, orexin receptor type-1 (Orx1), and cannabinoid receptor type-1 (Cb1). Moreover, intra-BLA administration of Orx1 receptor antagonist (SB-334867; 50 nM) and Cb1 receptor antagonist (AM251; 250 and 500 nM) decreased flinch response only in the early phase of the formalin test as compared to the DMSO group. Although the intra-BLA infusion of orexin-A alone and along with SB-334867 or AM251 decreased flinch response in the early phase of the formalin test, intra-BLA co-microinjection of SB-334867/AM251/OrxA increased flinch response in both early and late phases of the formalin test when compared to the DMSO/OrxA group. Interestingly, in the SB-334867/AM251/OrxA group, the Cb1 receptor was upregulated in all groups in comparison to Orx1 receptors. Our results revealed an interaction between BLA, orexin-A, and Cb1 receptors in inducing anti-nociception in the formalin test.
Collapse
Affiliation(s)
- Soghra Borneh Deli
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Samira Iman Bonab
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Roghaieh Khakpay
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.
| | - Fatemeh Khakpai
- Cognitive and Neuroscience Research Center (CNRC), Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | | |
Collapse
|
6
|
Dale NC, Hoyer D, Jacobson LH, Pfleger KDG, Johnstone EKM. Orexin Signaling: A Complex, Multifaceted Process. Front Cell Neurosci 2022; 16:812359. [PMID: 35496914 PMCID: PMC9044999 DOI: 10.3389/fncel.2022.812359] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/07/2022] [Indexed: 11/15/2022] Open
Abstract
The orexin system comprises two G protein-coupled receptors, OX1 and OX2 receptors (OX1R and OX2R, respectively), along with two endogenous agonists cleaved from a common precursor (prepro-orexin), orexin-A (OX-A) and orexin-B (OX-B). For the receptors, a complex array of signaling behaviors has been reported. In particular, it becomes obvious that orexin receptor coupling is very diverse and can be tissue-, cell- and context-dependent. Here, the early signal transduction interactions of the orexin receptors will be discussed in depth, with particular emphasis on the direct G protein interactions of each receptor. In doing so, it is evident that ligands, additional receptor-protein interactions and cellular environment all play important roles in the G protein coupling profiles of the orexin receptors. This has potential implications for our understanding of the orexin system’s function in vivo in both central and peripheral environments, as well as the development of novel agonists, antagonists and possibly allosteric modulators targeting the orexin system.
Collapse
Affiliation(s)
- Natasha C. Dale
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Melbourne, VIC, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
| | - Daniel Hoyer
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Laura H. Jacobson
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Melbourne, VIC, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
- Dimerix Limited, Nedlands, WA, Australia
- *Correspondence: Kevin D. G. Pfleger,
| | - Elizabeth K. M. Johnstone
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Melbourne, VIC, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
- School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
- Elizabeth K. M. Johnstone,
| |
Collapse
|
7
|
Papa A, Pasquini S, Contri C, Gemma S, Campiani G, Butini S, Varani K, Vincenzi F. Polypharmacological Approaches for CNS Diseases: Focus on Endocannabinoid Degradation Inhibition. Cells 2022; 11:cells11030471. [PMID: 35159280 PMCID: PMC8834510 DOI: 10.3390/cells11030471] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/21/2022] [Accepted: 01/27/2022] [Indexed: 01/27/2023] Open
Abstract
Polypharmacology breaks up the classical paradigm of “one-drug, one target, one disease” electing multitarget compounds as potential therapeutic tools suitable for the treatment of complex diseases, such as metabolic syndrome, psychiatric or degenerative central nervous system (CNS) disorders, and cancer. These diseases often require a combination therapy which may result in positive but also negative synergistic effects. The endocannabinoid system (ECS) is emerging as a particularly attractive therapeutic target in CNS disorders and neurodegenerative diseases including Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), stroke, traumatic brain injury (TBI), pain, and epilepsy. ECS is an organized neuromodulatory network, composed by endogenous cannabinoids, cannabinoid receptors type 1 and type 2 (CB1 and CB2), and the main catabolic enzymes involved in the endocannabinoid inactivation such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). The multiple connections of the ECS with other signaling pathways in the CNS allows the consideration of the ECS as an optimal source of inspiration in the development of innovative polypharmacological compounds. In this review, we focused our attention on the reported polypharmacological examples in which FAAH and MAGL inhibitors are involved.
Collapse
Affiliation(s)
- Alessandro Papa
- Department of Biotechnology, Chemistry and Pharmacy, DoE Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (A.P.); (S.G.); (G.C.)
| | - Silvia Pasquini
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara 17-19, 44121 Ferrara, Italy; (S.P.); (C.C.); (K.V.); (F.V.)
| | - Chiara Contri
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara 17-19, 44121 Ferrara, Italy; (S.P.); (C.C.); (K.V.); (F.V.)
| | - Sandra Gemma
- Department of Biotechnology, Chemistry and Pharmacy, DoE Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (A.P.); (S.G.); (G.C.)
| | - Giuseppe Campiani
- Department of Biotechnology, Chemistry and Pharmacy, DoE Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (A.P.); (S.G.); (G.C.)
| | - Stefania Butini
- Department of Biotechnology, Chemistry and Pharmacy, DoE Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (A.P.); (S.G.); (G.C.)
- Correspondence: ; Tel.: +39-0577-234161
| | - Katia Varani
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara 17-19, 44121 Ferrara, Italy; (S.P.); (C.C.); (K.V.); (F.V.)
| | - Fabrizio Vincenzi
- Department of Translational Medicine, University of Ferrara, Via Fossato di Mortara 17-19, 44121 Ferrara, Italy; (S.P.); (C.C.); (K.V.); (F.V.)
| |
Collapse
|
8
|
Kim HJJ, Zagzoog A, Smolyakova AM, Ezeaka UC, Benko MJ, Holt T, Laprairie RB. In vivo Evidence for Brain Region-Specific Molecular Interactions Between Cannabinoid and Orexin Receptors. Front Neurosci 2021; 15:790546. [PMID: 34992518 PMCID: PMC8724524 DOI: 10.3389/fnins.2021.790546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/02/2021] [Indexed: 11/25/2022] Open
Abstract
The endocannabinoid and orexin neuromodulatory systems serve key roles in many of the same biological functions such as sleep, appetite, pain processing, and emotional behaviors related to reward. The type 1 cannabinoid receptor (CB1R) and both subtypes of the orexin receptor, orexin receptor type 1 (OX1R) and orexin receptor type 2 (OX2R) are not only expressed in the same brain regions modulating these functions, but physically interact as heterodimers in recombinant and neuronal cell cultures. In the current study, male and female C57BL/6 mice were co-treated with the cannabinoid receptor agonist CP55,940 and either the OX2R antagonist TCS-OX2-29 or the dual orexin receptor antagonist (DORA) TCS-1102. Mice were then evaluated for catalepsy, body temperature, thermal anti-nociception, and locomotion, after which their brains were collected for receptor colocalization analysis. Combined treatment with the DORA TCS-1102 and CP55,940 potentiated catalepsy more than CP55,940 alone, but this effect was not observed for changes in body temperature, nociception, locomotion, or via selective OX2R antagonism. Co-treatment with CP55,940 and TCS-1102 also led to increased CB1R-OX1R colocalization in the ventral striatum. This was not seen following co-treatment with TCS-OX2-29, nor in CB1R-OX2R colocalization. The magnitude of effects following co-treatment with CP55,940 and either the DORA or OX2R-selective antagonist was greater in males than females. These data show that CB1R-OX1R colocalization in the ventral striatum underlies cataleptic additivity between CP55,940 and the DORA TCS-1102. Moreover, cannabinoid-orexin receptor interactions are sex-specific with regards to brain region and functionality. Physical or molecular interactions between these two systems may provide valuable insight into drug-drug interactions between cannabinoid and orexin drugs for the treatment of insomnia, pain, and other disorders.
Collapse
Affiliation(s)
- Hye Ji J. Kim
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ayat Zagzoog
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Anna Maria Smolyakova
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Udoka C. Ezeaka
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Michael J. Benko
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Teagan Holt
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Robert B. Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Pharmacology, College of Medicine, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
9
|
Oyagawa CRM, Grimsey NL. Cannabinoid receptor CB 1 and CB 2 interacting proteins: Techniques, progress and perspectives. Methods Cell Biol 2021; 166:83-132. [PMID: 34752341 DOI: 10.1016/bs.mcb.2021.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cannabinoid receptors 1 and 2 (CB1 and CB2) are implicated in a range of physiological processes and have gained attention as promising therapeutic targets for a number of diseases. Protein-protein interactions play an integral role in modulating G protein-coupled receptor (GPCR) expression, subcellular distribution and signaling, and the identification and characterization of these will not only improve our understanding of GPCR function and biology, but may provide a novel avenue for therapeutic intervention. A variety of techniques are currently being used to investigate GPCR protein-protein interactions, including Förster/fluorescence and bioluminescence resonance energy transfer (FRET and BRET), proximity ligation assay (PLA), and bimolecular fluorescence complementation (BiFC). However, the reliable application of these methodologies is dependent on the use of appropriate controls and the consideration of the physiological context. Though not as extensively characterized as some other GPCRs, the investigation of CB1 and CB2 interacting proteins is a growing area of interest, and a range of interacting partners have been identified to date. This review summarizes the current state of the literature regarding the cannabinoid receptor interactome, provides commentary on the methodologies and techniques utilized, and discusses future perspectives.
Collapse
Affiliation(s)
- Caitlin R M Oyagawa
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Natasha L Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
| |
Collapse
|
10
|
Fartootzadeh R, Alaei H, Reisi P. Mutual assistance of nucleus accumbens cannabinoid receptor-1 and orexin receptor-2 in response to nicotine: a single-unit study. Res Pharm Sci 2021; 16:173-181. [PMID: 34084204 PMCID: PMC8102922 DOI: 10.4103/1735-5362.310524] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/22/2020] [Accepted: 01/24/2021] [Indexed: 11/28/2022] Open
Abstract
Background and purpose: The nucleus accumbens (NAc) express both orexin-2 receptor (OX2R) and cannabinoid receptor type 1 (CB1R). Orexin and cannabinoid regulate the addictive properties of nicotine. In this study, the effect of the CB1R blockade on the electrical activity of NAc neurons in response to nicotine, and its probable interaction with the OX2R in this event, within this area, were examined via the single-unit recording. Experimental approach: The spontaneous firing rate of NAc was initially recorded for 15 min, and then 5 min before subcutaneous injection of nicotine (0.5 mg/kg)/saline, AM251 and TCS-OX2-29 were injected into the NAc. Neuronal responses were recorded for 70 min, after nicotine administration. Findings/Results: Nicotine excited the NAc neurons significantly and intra-NAc microinjection of AM251 (25 and 125 ng/rat), as a selective CB1R antagonist, prevented the nicotine-induced increases of NAc neuronal responses. Moreover, microinjection of AM251 (125 ng/rat), before saline injection, could not affect the percentage of change of the neuronal response. Finally, simultaneous intra-NAc administration of the effective or ineffective doses of AM251 and TCS-OX2-29 (a selective antagonist of OX2R) prevented the nicotine- induced increases of NAc neuronal responses, so that there was a significant difference between the group received ineffective doses of both antagonists and the AM251 ineffective dose. Conclusion and implications: The results suggest that the CB1R can modulate the NAc reaction to the nicotine, and it can be concluded that there is a potential interplay between the OX2R and CB1R in the NAc, in relation to nicotine.
Collapse
Affiliation(s)
- Reza Fartootzadeh
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Hojjatallah Alaei
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Parham Reisi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| |
Collapse
|
11
|
Yaeger JD, Krupp KT, Gale JJ, Summers CH. Counterbalanced microcircuits for Orx1 and Orx2 regulation of stress reactivity. MEDICINE IN DRUG DISCOVERY 2020. [DOI: 10.1016/j.medidd.2020.100059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
|
12
|
Allosteric interactions via the orthosteric ligand binding sites in a constitutive G-protein-coupled receptor homodimer. Pharmacol Res 2020; 166:105116. [PMID: 32783977 DOI: 10.1016/j.phrs.2020.105116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/26/2020] [Accepted: 07/27/2020] [Indexed: 11/23/2022]
Abstract
I interpret some recent data to indicate that co-operative effects take place between the (identical) orthosteric binding sites in a G-protein-coupled receptor dimer. In the current study, the reasonability of this concept was tested by creating a mathematical model. The model is composed of a symmetrical constitutive receptor dimer in which the protomers are able to affect each other allosterically, and it includes binding, receptor activation and signal amplification steps. The model was utilized for analyses of previous data as well as simulations of predicted behaviour. The model demonstrates the behaviour stated in the hypotheses, i.e. even an apparently neutral receptor ligand can allosterically affect agonist binding or receptor activation by binding to the normal orthosteric ligand binding site. Therewith the speculated allosteric action originating from the orthosteric binding site of the dimeric receptor is a realistic possibility. The results of the simulations and curve fitting constitute a reasonable starting point for further studies, and the model can be utilized to design meaningful experiments to investigate these questions.
Collapse
|
13
|
Li T, Xu W, Ouyang J, Lu X, Sherchan P, Lenahan C, Irio G, Zhang JH, Zhao J, Zhang Y, Tang J. Orexin A alleviates neuroinflammation via OXR2/CaMKKβ/AMPK signaling pathway after ICH in mice. J Neuroinflammation 2020; 17:187. [PMID: 32539736 PMCID: PMC7294616 DOI: 10.1186/s12974-020-01841-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 05/14/2020] [Indexed: 02/07/2023] Open
Abstract
Background Orexins are two neuropeptides (orexin A, OXA; orexin B, OXB) secreted mainly from the lateral hypothalamus, which exert a wide range of physiological effects by activating two types of receptors (orexin receptor 1, OXR1; orexin receptor 2, OXR2). OXA has equal affinity for OXR1 and OXR2, whereas OXB binds preferentially to OXR2. OXA rapidly crosses the blood-brain barrier by simple diffusion. Many studies have reported OXA’s protective effect on neurological diseases via regulating inflammatory response which is also a fundamental pathological process in intracerebral hemorrhage (ICH). However, neuroprotective mechanisms of OXA have not been explored in ICH. Methods ICH models were established using stereotactic injection of autologous arterial blood into the right basal ganglia of male CD-1 mice. Exogenous OXA was administered intranasally; CaMKKβ inhibitor (STO-609), OXR1 antagonist (SB-334867), and OXR2 antagonist (JNJ-10397049) were administered intraperitoneally. Neurobehavioral tests, hematoma volume, and brain water content were evaluated after ICH. Western blot and ELISA were utilized to evaluate downstream mechanisms. Results OXA, OXR1, and OXR2 were expressed moderately in microglia and astrocytes and abundantly in neurons. Expression of OXA decreased whereas OXR1 and OXR2 increased after ICH. OXA treatment significantly improved not only short-term but also long-term neurofunctional outcomes and reduced brain edema in ipsilateral hemisphere. OXA administration upregulated p-CaMKKβ, p-AMPK, and anti-inflammatory cytokines while downregulated p-NFκB and pro-inflammatory cytokines after ICH; this effect was reversed by STO-609 or JNJ-10397049 but not SB-334867. Conclusions OXA improved neurofunctional outcomes and mitigated brain edema after ICH, possibly through alleviating neuroinflammation via OXR2/CaMKKβ/AMPK pathway.
Collapse
Affiliation(s)
- Tao Li
- Department of Neurosurgery, The First People's Hospital of Yunnan Province (Kunhua Hospital/The Affiliated Hospital of Kunming University of Science and Technology), Yunnan, 650032, China.,Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA.,Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang, 310009, Hangzhou, China
| | - Weilin Xu
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA.,Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang, 310009, Hangzhou, China
| | - Jinsong Ouyang
- Department of Neurosurgery, The First People's Hospital of Yunnan Province (Kunhua Hospital/The Affiliated Hospital of Kunming University of Science and Technology), Yunnan, 650032, China
| | - Xiaoyang Lu
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang, 310009, Hangzhou, China
| | - Prativa Sherchan
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Cameron Lenahan
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA.,Burrell College of Osteopathic Medicine, 3501 Arrowhead Dr, Las Cruces, NM, 88001, USA
| | - Giselle Irio
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA.,Burrell College of Osteopathic Medicine, 3501 Arrowhead Dr, Las Cruces, NM, 88001, USA
| | - John H Zhang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA
| | - Jianhua Zhao
- Department of Neurosurgery, The First People's Hospital of Yunnan Province (Kunhua Hospital/The Affiliated Hospital of Kunming University of Science and Technology), Yunnan, 650032, China
| | - Yongfa Zhang
- Department of Neurosurgery, The First People's Hospital of Yunnan Province (Kunhua Hospital/The Affiliated Hospital of Kunming University of Science and Technology), Yunnan, 650032, China.
| | - Jiping Tang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, 11041 Campus St, Loma Linda, CA, 92354, USA.
| |
Collapse
|
14
|
Esteban PF, Garcia-Ovejero D, Paniagua-Torija B, Moreno-Luna R, Arredondo LF, Zimmer A, Arevalo-Martin A, Molina-Holgado E. Revisiting CB1 cannabinoid receptor detection and the exploration of its interacting partners. J Neurosci Methods 2020; 337:108680. [DOI: 10.1016/j.jneumeth.2020.108680] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 12/31/2022]
|
15
|
Berrendero F, Flores Á, Robledo P. When orexins meet cannabinoids: Bidirectional functional interactions. Biochem Pharmacol 2018; 157:43-50. [DOI: 10.1016/j.bcp.2018.08.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 08/23/2018] [Indexed: 01/11/2023]
|
16
|
Gut microbiota, cannabinoid system and neuroimmune interactions: New perspectives in multiple sclerosis. Biochem Pharmacol 2018; 157:51-66. [PMID: 30171835 DOI: 10.1016/j.bcp.2018.08.037] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/22/2018] [Indexed: 02/07/2023]
Abstract
The gut microbiota plays a fundamental role on the education and function of the host immune system. Immunological dysregulation is the cause of numerous human disorders such as autoimmune diseases and metabolic disorders frequently associated with inflammatory processes therefore is critical to explore novel mechanisms involved in maintaining the immune system homeostasis. The cannabinoid system and related bioactive lipids participate in multiple central and peripheral physiological processes that affect metabolic, gastrointestinal and neuroimmune regulatory mechanisms displaying a modulatory role and contributing to the maintenance of the organism's homeostasis. In this review, we gather the knowledge on the gut microbiota-endocannabinoids interactions and their impact on autoimmune disorders such as inflammatory bowel disease, rheumatoid arthritis and particularly, multiple sclerosis (MS) as the best example of a CNS autoimmune disorder. Furthermore, we contribute to this field with new data on changes in many elements of the cannabinoid system in a viral model of MS after gut microbiota manipulation by both antibiotics and probiotics. Finally, we highlight new therapeutic opportunities, under an integrative view, targeting the eCBS and the commensal microbiota in the context of neuroinflammation and MS.
Collapse
|
17
|
Wang C, Wang Q, Ji B, Pan Y, Xu C, Cheng B, Bai B, Chen J. The Orexin/Receptor System: Molecular Mechanism and Therapeutic Potential for Neurological Diseases. Front Mol Neurosci 2018; 11:220. [PMID: 30002617 PMCID: PMC6031739 DOI: 10.3389/fnmol.2018.00220] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/06/2018] [Indexed: 12/25/2022] Open
Abstract
Orexins, also known as hypocretins, are two neuropeptides secreted from orexin-containing neurons, mainly in the lateral hypothalamus (LH). Orexins orchestrate their effects by binding and activating two G-protein–coupled receptors (GPCRs), orexin receptor type 1 (OX1R) and type 2 (OX2R). Orexin/receptor pathways play vital regulatory roles in many physiological processes, especially feeding behavior, sleep–wake rhythm, reward and addiction and energy balance. Furthermore several reports showed that orexin/receptor pathways are involved in pathological processes of neurological diseases such as narcolepsy, depression, ischemic stroke, drug addiction and Alzheimer’s disease (AD). This review article summarizes the expression patterns, physiological functions and potential molecular mechanisms of the orexin/receptor system in neurological diseases, providing an overall framework for considering these pathways from the standpoints of basic research and clinical treatment of neurological diseases.
Collapse
Affiliation(s)
- Chunmei Wang
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Qinqin Wang
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Bingyuan Ji
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Yanyou Pan
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Chao Xu
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Baohua Cheng
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Bo Bai
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Jing Chen
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| |
Collapse
|
18
|
Thompson MD, Sakurai T, Rainero I, Maj MC, Kukkonen JP. Orexin Receptor Multimerization versus Functional Interactions: Neuropharmacological Implications for Opioid and Cannabinoid Signalling and Pharmacogenetics. Pharmaceuticals (Basel) 2017; 10:ph10040079. [PMID: 28991183 PMCID: PMC5748636 DOI: 10.3390/ph10040079] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/29/2017] [Accepted: 09/29/2017] [Indexed: 12/17/2022] Open
Abstract
Orexins/hypocretins are neuropeptides formed by proteolytic cleavage of a precursor peptide, which are produced by neurons found in the lateral hypothalamus. The G protein-coupled receptors (GPCRs) for these ligands, the OX₁ and OX₂ orexin receptors, are more widely expressed throughout the central nervous system. The orexin/hypocretin system has been implicated in many pathways, and its dysregulation is under investigation in a number of diseases. Disorders in which orexinergic mechanisms are being investigated include narcolepsy, idiopathic sleep disorders, cluster headache and migraine. Human narcolepsy has been associated with orexin deficiency; however, it has only rarely been attributed to mutations in the gene encoding the precursor peptide. While gene variations within the canine OX₂ gene hcrtr2 have been directly linked with narcolepsy, the majority of human orexin receptor variants are weakly associated with diseases (the idiopathic sleep disorders, cluster headache and polydipsia-hyponatremia in schizophrenia) or are of potential pharmacogenetic significance. Evidence for functional interactions and/or heterodimerization between wild-type and variant orexin receptors and opioid and cannabinoid receptors is discussed in the context of its relevance to depression and epilepsy.
Collapse
Affiliation(s)
- Miles D Thompson
- Department of Pediatrics, University of California, San Diego 92093, CA, USA.
| | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University, Kanazawa 920-8620, Japan.
| | - Innocenzo Rainero
- Department of Neuroscience, University of Turin, Torino 10124, Italy.
| | - Mary C Maj
- Department of Biochemistry, School of Medicine, Saint George's University, Saint George's 11739, Grenada.
| | - Jyrki P Kukkonen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, Helsinki 11739, Finland.
- Department of Physiology, Institute of Biomedicine, Biomedicum Helsinki, University of Helsinki, Helsinki 00100, Finland.
| |
Collapse
|
19
|
Morales P, Reggio PH. An Update on Non-CB 1, Non-CB 2 Cannabinoid Related G-Protein-Coupled Receptors. Cannabis Cannabinoid Res 2017; 2:265-273. [PMID: 29098189 PMCID: PMC5665501 DOI: 10.1089/can.2017.0036] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The endocannabinoid system (ECS) has been shown to be of great importance in the regulation of numerous physiological and pathological processes. To date, two Class A G-protein-coupled receptors (GPCRs) have been discovered and validated as the main therapeutic targets of this system: the cannabinoid receptor type 1 (CB1), which is the most abundant neuromodulatory receptor in the brain, and the cannabinoid receptor type 2 (CB2), predominantly found in the immune system among other organs and tissues. Endogenous cannabinoid receptor ligands (endocannabinoids) and the enzymes involved in their synthesis, cell uptake, and degradation have also been identified as part of the ECS. However, its complex pharmacology suggests that other GPCRs may also play physiologically relevant roles in this therapeutically promising system. In the last years, GPCRs such as GPR18 and GPR55 have emerged as possible missing members of the cannabinoid family. This categorization still stimulates strong debate due to the lack of pharmacological tools to validate it. Because of their close phylogenetic relationship, the Class A orphan GPCRs, GPR3, GPR6, and GPR12, have also been associated with the cannabinoids. Moreover, certain endo-, phyto-, and synthetic cannabinoid ligands have displayed activity at other well-established GPCRs, including the opioid, adenosine, serotonin, and dopamine receptor families. In addition, the cannabinoid receptors have also been shown to form dimers with other GPCRs triggering cross-talk signaling under specific conditions. In this mini review, we aim to provide insight into the non-CB1, non-CB2 cannabinoid-related GPCRs that have been reported thus far. We consider the physiological relevance of these molecular targets in modulating the ECS.
Collapse
Affiliation(s)
- Paula Morales
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, North Carolina
| | - Patricia H. Reggio
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, North Carolina
| |
Collapse
|
20
|
Abstract
Orexin/hypocretin peptide (orexin-A and orexin-B) signaling is believed to take place via the two G-protein-coupled receptors (GPCRs), named OX1 and OX2 orexin receptors, as described in the previous chapters. Signaling of orexin peptides has been investigated in diverse endogenously orexin receptor-expressing cells - mainly neurons but also other types of cells - and in recombinant cells expressing the receptors in a heterologous manner. Findings in the different systems are partially convergent but also indicate cellular background-specific signaling. The general picture suggests an inherently high degree of diversity in orexin receptor signaling.In the current chapter, I present orexin signaling on the cellular and molecular levels. Discussion of the connection to (potential) physiological orexin responses is only brief since these are in focus of other chapters in this book. The same goes for the post-synaptic signaling mechanisms, which are dealt with in Burdakov: Postsynaptic actions of orexin. The current chapter is organized according to the tissue type, starting from the central nervous system. Finally, receptor signaling pathways are discussed across tissues, cell types, and even species.
Collapse
Affiliation(s)
- Jyrki P Kukkonen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, POB 66, FIN-00014, Helsinki, Finland.
| |
Collapse
|
21
|
Role of orexin-2 and CB1 receptors within the periaqueductal gray matter in lateral hypothalamic-induced antinociception in rats. Behav Pharmacol 2017; 28:83-89. [DOI: 10.1097/fbp.0000000000000277] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
22
|
Imperatore R, Palomba L, Morello G, Spiezio AD, Piscitelli F, Marzo VD, Cristino L. Formation of OX-1R/CB 1 R heteromeric complexes in embryonic mouse hypothalamic cells: Effect on intracellular calcium, 2-arachidonoyl-glycerol biosynthesis and ERK phosphorylation. Pharmacol Res 2016; 111:600-609. [DOI: 10.1016/j.phrs.2016.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/27/2016] [Accepted: 07/06/2016] [Indexed: 12/16/2022]
|
23
|
Flores Á, Julià-Hernández M, Maldonado R, Berrendero F. Involvement of the orexin/hypocretin system in the pharmacological effects induced by Δ(9) -tetrahydrocannabinol. Br J Pharmacol 2016; 173:1381-92. [PMID: 26799708 DOI: 10.1111/bph.13440] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 01/12/2016] [Accepted: 01/17/2016] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND AND PURPOSE Anatomical, biochemical and pharmacological evidence suggest the existence of a crosstalk between the orexinergic and endocannabinoid systems. While the orexin receptor 1 (OX1 receptor) modulates the reinforcing properties of cannabinoids, the participation of orexins in the acute pharmacological effects of Δ(9) -tetrahydrocannabinol (THC) remains unexplored. EXPERIMENTAL APPROACH We assessed the possible role of orexins in THC-induced hypolocomotion, hypothermia, antinociception, anxiolytic- and anxiogenic-like effects and memory impairment. Selective OX1 and OX2 receptor antagonists and OX1 knockout (KO) mice as well as prepro-orexin (PPO) KO mice were used as pharmacological and genetic approaches. CB1 receptor levels in control and PPO KO mice were evaluated by immunoblot analysis. The expression of c-Fos after THC treatment was analysed in several brain areas in wild-type mice and in mice lacking the PPO gene. KEY RESULTS The hypothermia, supraspinal antinociception and anxiolytic-like effects induced by THC were modulated by orexins through OX2 receptor signalling. OX1 receptors did not seem to be involved in these THC responses. No differences in CB1 receptor levels were found between wild-type and PPO KO mice. THC-induced increase in c-Fos expression was reduced in the central amygdala, medial preoptic area and lateral septum in these mutant mice. CONCLUSIONS AND IMPLICATIONS Our results provide new findings to further clarify the interaction between orexins and cannabinoids. OX1 and OX2 receptors are differently implicated in the pharmacological effects of cannabinoids.
Collapse
Affiliation(s)
- África Flores
- Laboratory of Neuropharmacology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Barcelona, Spain
| | - Marina Julià-Hernández
- Laboratory of Neuropharmacology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Barcelona, Spain
| | - Rafael Maldonado
- Laboratory of Neuropharmacology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Barcelona, Spain
| | - Fernando Berrendero
- Laboratory of Neuropharmacology, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Barcelona, Spain
| |
Collapse
|
24
|
Davies J, Chen J, Pink R, Carter D, Saunders N, Sotiriadis G, Bai B, Pan Y, Howlett D, Payne A, Randeva H, Karteris E. Orexin receptors exert a neuroprotective effect in Alzheimer's disease (AD) via heterodimerization with GPR103. Sci Rep 2015; 5:12584. [PMID: 26223541 PMCID: PMC4519789 DOI: 10.1038/srep12584] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 05/29/2015] [Indexed: 12/22/2022] Open
Abstract
Orexins are neuropeptides that regulate the sleep-wake cycle and feeding behaviour. QRFP is a newly discovered neuropeptide which exerts similar orexigenic activity, thus playing an important role in energy homeostasis and regulation of appetite. The exact expression and signalling characteristics and physiological actions of QRFP and its receptor GPR103 are poorly understood. Alzheimer's disease (AD) patients experience increased nocturnal activity, excessive daytime sleepiness, and weight loss. We hypothesised therefore that orexins and QRFP might be implicated in the pathophysiology of AD. We report that the down-regulation of hippocampal orexin receptors (OXRs) and GPR103 particularly in the cornu ammonis (CA) subfield from AD patients suffering from early onset familial AD (EOFAD) and late onset familial AD (LOAD). Using an in vitro model we demonstrate that this downregulation is due to to Aβ-plaque formation and tau hyper-phosphorylation. Transcriptomics revealed a neuroprotective role for both orexins and QRFP. Finally we provide conclusive evidence using BRET and FRET that OXRs and GPR103 form functional hetero-dimers to exert their effects involving activation of ERK1/2. Pharmacological intervention directed at the orexigenic system may prove to be an attractive avenue towards the discovery of novel therapeutics for diseases such as AD and improving neuroprotective signalling pathways.
Collapse
Affiliation(s)
- Julie Davies
- Biosciences, College of Health and Life Sciences, Brunel University, Uxbridge, UB8 3PH, UK
| | - Jing Chen
- Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
- Neurobiology Institute, Jining Medical University, Jining, Shandong, 272067, P.R. China
| | - Ryan Pink
- Department of Biological and Medical Sciences, Oxford Brookes University, UK
| | - David Carter
- Department of Biological and Medical Sciences, Oxford Brookes University, UK
| | - Nigel Saunders
- Centre for Systems and Synthetic Biology, Brunel University, Uxbridge UB83PH, UK
| | - Georgios Sotiriadis
- Biosciences, College of Health and Life Sciences, Brunel University, Uxbridge, UB8 3PH, UK
| | - Bo Bai
- Neurobiology Institute, Jining Medical University, Jining, Shandong, 272067, P.R. China
| | - Yanyou Pan
- Neurobiology Institute, Jining Medical University, Jining, Shandong, 272067, P.R. China
| | - David Howlett
- Wolfson Centre for Age Related Diseases, King’s College London, London, SE11UL, UK
| | - Annette Payne
- Department of Computer Science, College of Engineering, Design and Physical Sciences, Brunel University, Uxbridge UB8 3PH, UK
| | - Harpal Randeva
- Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK
| | - Emmanouil Karteris
- Biosciences, College of Health and Life Sciences, Brunel University, Uxbridge, UB8 3PH, UK
| |
Collapse
|
25
|
Orexin-corticotropin-releasing factor receptor heteromers in the ventral tegmental area as targets for cocaine. J Neurosci 2015; 35:6639-53. [PMID: 25926444 DOI: 10.1523/jneurosci.4364-14.2015] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R-OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R-OX1R heteromer. Cocaine binding to the σ1R-CRF1R-OX1R complex promotes a long-term disruption of the orexin-A-CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking.
Collapse
|
26
|
Ibrahim BM, Abdel-Rahman AA. A pivotal role for enhanced brainstem Orexin receptor 1 signaling in the central cannabinoid receptor 1-mediated pressor response in conscious rats. Brain Res 2015; 1622:51-63. [PMID: 26096126 DOI: 10.1016/j.brainres.2015.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 01/02/2023]
Abstract
Orexin receptor 1 (OX1R) signaling is implicated in cannabinoid receptor 1 (CB1R) modulation of feeding. Further, our studies established the dependence of the central CB1R-mediated pressor response on neuronal nitric oxide synthase (nNOS) and extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation in the RVLM. Here, we tested the novel hypothesis that brainstem orexin-A/OX1R signaling plays a pivotal role in the central CB1R-mediated pressor response. Our multiple labeling immunofluorescence findings revealed co-localization of CB1R, OX1R and the peptide orexin-A within the C1 area of the rostral ventrolateral medulla (RVLM). Activation of central CB1R following intracisternal (i.c.) WIN55,212-2 (15μg/rat) in conscious rats caused significant increases in BP and orexin-A level in RVLM neuronal tissue. Additional studies established a causal role for orexin-A in the central CB1R-mediated pressor response because (i) selective blockade of central CB1R (AM251, 30μg/rat; i.c.) abrogated WIN55,212-2-evoked increases in RVLM orexin-A level, (ii) the selective OX1R antagonist SB-408124 (10nmol/rat; i.c.) attenuated orexin-A (3nmol/rat; i.c.) or WIN55,212-2 (15μg/rat; i.c.)-evoked pressor response while selective CB1R blockade (AM251) had no effect on orexin-A (3nmol/rat; i.c.)-evoked pressor response, (iii) direct CB1R activation in the RVLM (WIN55,212-2; 0.1μg/rat) increased RVLM orexin-A and BP. Finally, SB-408124 attenuated WIN55,212-2-evoked increases in RVLM nNOS and ERK1/2 phosphorylation and BP. Our findings suggest that orexin-A/OX1R dependent activation of the RVLM nNOS/ERK1/2 cascade is essential neurochemical mechanism for the central CB1R-mediated pressor response in conscious rats.
Collapse
Affiliation(s)
- Badr Mostafa Ibrahim
- Department of Pharmacology & Toxicology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27858, United States
| | - Abdel A Abdel-Rahman
- Department of Pharmacology & Toxicology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27858, United States.
| |
Collapse
|
27
|
Abstract
Addiction is a chronic relapsing disorder which presents a significant global health burden and unmet medical need. The orexin/hypocretin system is an attractive potential therapeutic target as demonstrated by the successful clinical trials of antagonist medications like Suvorexant for insomnia. It is composed of two neuropeptides, orexin-A and orexin-B and two excitatory and promiscuous G-protein coupled receptors, OX1 and OX2. Orexins are known to have a variety of functions, most notably in regulating arousal, appetite and reward. The orexins have been shown to have a role in mediating the effects of several drugs of abuse, such as cocaine, morphine and alcohol via projections to key brain regions such as the ventral tegmental area, nucleus accumbens and prefrontal cortex. However, it has not yet been demonstrated whether the dual orexin receptor antagonists (DORAs) under development for insomnia are ideal drugs for the treatment of addiction. The question of whether to use a DORA or single orexin receptor antagonist (SORA) for the treatment of addiction is a key question that will need to be answered in order to maximize the clinical utility of orexin receptor antagonists. This review will examine the role of the orexin/hypocretin system in addiction, orexin-based pharmacotherapies under development and factors affecting the selection of one or both orexin receptors as drug targets for the treatment of addiction.
Collapse
|
28
|
Thompson MD, Xhaard H, Sakurai T, Rainero I, Kukkonen JP. OX1 and OX2 orexin/hypocretin receptor pharmacogenetics. Front Neurosci 2014; 8:57. [PMID: 24834023 PMCID: PMC4018553 DOI: 10.3389/fnins.2014.00057] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 03/12/2014] [Indexed: 01/01/2023] Open
Abstract
Orexin/hypocretin peptide mutations are rare in humans. Even though human narcolepsy is associated with orexin deficiency, this is only extremely rarely due to mutations in the gene coding prepro-orexin, the precursor for both orexin peptides. In contrast, coding and non-coding variants of the OX1 and OX2 orexin receptors have been identified in many human populations; sometimes, these have been associated with disease phenotype, although most confer a relatively low risk. In most cases, these studies have been based on a candidate gene hypothesis that predicts the involvement of orexins in the relevant pathophysiological processes. In the current review, the known human OX1/HCRTR1 and OX2/HCRTR2 genetic variants/polymorphisms as well as studies concerning their involvement in disorders such as narcolepsy, excessive daytime sleepiness, cluster headache, polydipsia-hyponatremia in schizophrenia, and affective disorders are discussed. In most cases, the functional cellular or pharmacological correlates of orexin variants have not been investigated—with the exception of the possible impact of an amino acid 10 Pro/Ser variant of OX2 on orexin potency—leaving conclusions on the nature of the receptor variant effects speculative. Nevertheless, we present perspectives that could shape the basis for further studies. The pharmacology and other properties of the orexin receptor variants are discussed in the context of GPCR signaling. Since orexinergic therapeutics are emerging, the impact of receptor variants on the affinity or potency of ligands deserves consideration. This perspective (pharmacogenetics) is also discussed in the review.
Collapse
Affiliation(s)
- Miles D Thompson
- University of Toronto Epilepsy Research Program, Department of Pharmacology, University of Toronto Toronto, ON, Canada
| | - Henri Xhaard
- Faculty of Pharmacy, Centre for Drug Research, University of Helsinki Helsinki, Finland
| | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University Kanazawa, Japan
| | | | - Jyrki P Kukkonen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki Helsinki, Finland
| |
Collapse
|