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: 8] [Impact Index Per Article: 8.0] [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
|
Chen J, Wang Z, Zhang R, Yin H, Wang P, Wang C, Jiang Y. Heterodimerization of apelin and opioid receptor-like 1 receptors mediates apelin-13-induced G protein biased signaling. Life Sci 2023:121892. [PMID: 37364634 DOI: 10.1016/j.lfs.2023.121892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/17/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
The apelin receptor (APJ) and the opioid-related nociceptin receptor 1 (ORL1) are family A G protein-coupled receptors that participate in a variety of physiological processes. The distribution and function of APJ and ORL1 in the nervous system and peripheral tissues are similar; however, the detailed mechanism of how these two receptors modulate signaling and physiological effects remains unclear. Here, we examined whether APJ and ORL1 form dimers, and investigated signal transduction pathways. The endogenous co-expression of APJ and ORL1 in SH-SY5Y cells was confirmed by western blotting and RT-PCR. Bioluminescence and fluorescence resonance energy transfer assays, as well as a proximity ligation assay and co-immunoprecipitation experiments, demonstrated that APJ and ORL1 heterodimerize in HEK293 cells. We found that the APJ-ORL1 heterodimer is selectively activated by apelin-13, which causes the dimer to couple to Gαi proteins and reduce the recruitment of GRKs and β-arrestins to the dimer. We showed that the APJ-ORL1 dimer exhibits biased signaling, in which G protein-dependent signaling pathways override β-arrestin-dependent signaling pathways. Our results demonstrate that the structural interface of the APJ-ORL1 dimer switches from transmembrane domain TM1/TM2 in the inactive state to TM5 in the active state. We used mutational analysis and BRET assays to identify key residues in TM5 (APJ L2185.55, APJ I2245.61, and ORL1 L2295.52) responsible for the receptor-receptor interaction. These results provide important information on the APJ-ORL1 heterodimer and may assist the design of new drugs targeting biased signaling pathways for treatment of pain and cardiovascular and metabolic diseases.
Collapse
Affiliation(s)
- Jing Chen
- Neurobiology Institute, Jining Medical University, Jining, China; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
| | - Zhengwen Wang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Rumin Zhang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Haiyan Yin
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Peixiang Wang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Chunmei Wang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Yunlu Jiang
- Neurobiology Institute, Jining Medical University, Jining, China.
| |
Collapse
|
4
|
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
|
5
|
Gómez-Cañas M, Rodríguez-Cueto C, Satta V, Hernández-Fisac I, Navarro E, Fernández-Ruiz J. Endocannabinoid-Binding Receptors as Drug Targets. Methods Mol Biol 2023; 2576:67-94. [PMID: 36152178 DOI: 10.1007/978-1-0716-2728-0_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Cannabis plant has been used from ancient times with therapeutic purposes for treating human pathologies, but the identification of the cellular and molecular mechanisms underlying the therapeutic properties of the phytocannabinoids, the active compounds in this plant, occurred in the last years of the past century. In the late 1980s and early 1990s, seminal studies demonstrated the existence of cannabinoid receptors and other elements of the so-called endocannabinoid system. These G protein-coupled receptors (GPCRs) are a key element in the functions assigned to endocannabinoids and appear to serve as promising pharmacological targets. They include CB1, CB2, and GPR55, but also non-GPCRs can be activated by endocannabinoids, like ionotropic receptor TRPV1 and even nuclear receptors of the PPAR family. Their activation, inhibition, or simply modulation have been associated with numerous physiological effects at both central and peripheral levels, which may have therapeutic value in different human pathologies, then providing a solid experimental explanation for both the ancient medicinal uses of Cannabis plant and the recent advances in the development of cannabinoid-based specific therapies. This chapter will review the scientific knowledge generated in the last years around the research on the different endocannabinoid-binding receptors and their signaling mechanisms. Our intention is that this knowledge may help readers to understand the relevance of these receptors in health and disease conditions, as well as it may serve as the theoretical basis for the different experimental protocols to investigate these receptors and their signaling mechanisms that will be described in the following chapters.
Collapse
Affiliation(s)
- María Gómez-Cañas
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Carmen Rodríguez-Cueto
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Valentina Satta
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Inés Hernández-Fisac
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Elisa Navarro
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Javier Fernández-Ruiz
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain.
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
| |
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] [Key Words] [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
| | - 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
| |
Collapse
|
7
|
Zhang R, Li D, Mao H, Wei X, Xu M, Zhang S, Jiang Y, Wang C, Xin Q, Chen X, Li G, Ji B, Yan M, Cai X, Dong B, Randeva HS, Liu C, Chen J. Disruption of 5-hydroxytryptamine 1A receptor and orexin receptor 1 heterodimer formation affects novel G protein-dependent signaling pathways and has antidepressant effects in vivo. Transl Psychiatry 2022; 12:122. [PMID: 35338110 PMCID: PMC8956632 DOI: 10.1038/s41398-022-01886-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/25/2022] [Accepted: 03/08/2022] [Indexed: 01/28/2023] Open
Abstract
G protein-coupled receptor (GPCR) heterodimers are new targets for the treatment of depression. Increasing evidence supports the importance of serotonergic and orexin-producing neurons in numerous physiological processes, possibly via a crucial interaction between 5-hydroxytryptamine 1A receptor (5-HT1AR) and orexin receptor 1 (OX1R). However, little is known about the function of 5-HT1AR/OX1R heterodimers. It is unclear how the transmembrane domains (TMs) of the dimer affect its function and whether its modulation mediates antidepressant-like effects. Here, we examined the mechanism of 5-HT1AR/OX1R dimerization and downstream G protein-dependent signaling. We found that 5-HT1AR and OX1R form constitutive heterodimers that induce novel G protein-dependent signaling, and that this heterodimerization does not affect recruitment of β-arrestins to the complex. In addition, we found that the structural interface of the active 5-HT1AR/OX1R dimer transforms from TM4/TM5 in the basal state to TM6 in the active conformation. We also used mutation analyses to identify key residues at the interface (5-HT1AR R1514.40, 5-HT1AR Y1985.41, and OX1R L2305.54). Injection of chronic unpredictable mild stress (CUMS) rats with TM4/TM5 peptides improved their depression-like emotional status and decreased the number of endogenous 5-HT1AR/OX1R heterodimers in the rat brain. These antidepressant effects may be mediated by upregulation of BDNF levels and enhanced phosphorylation and activation of CREB in the hippocampus and medial prefrontal cortex. This study provides evidence that 5-HT1AR/OX1R heterodimers are involved in the pathological process of depression. Peptides including TMs of the 5-HT1AR/OX1R heterodimer interface are candidates for the development of compounds with fast-acting antidepressant-like effects.
Collapse
Affiliation(s)
- Rumin Zhang
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Dandan Li
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Huiling Mao
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Xiaonan Wei
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - MingDong Xu
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Shengnan Zhang
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Yunlu Jiang
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Chunmei Wang
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Qing Xin
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Xiaoyu Chen
- Department of Physiology, Shandong First Medical University, Taian, China
| | - Guorong Li
- grid.410585.d0000 0001 0495 1805School of Life Sciences, Shandong Normal University, Jinan, China
| | - Bingyuan Ji
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Maocai Yan
- grid.449428.70000 0004 1797 7280School of Pharmacy, Jining Medical University, Shandong, China
| | - Xin Cai
- grid.268079.20000 0004 1790 6079Department of Physiology, Weifang Medical University, Weifang, China
| | - Bo Dong
- grid.460018.b0000 0004 1769 9639Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Harpal S. Randeva
- grid.7372.10000 0000 8809 1613Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Chuanxin Liu
- grid.449428.70000 0004 1797 7280Neurobiology Institute, Jining Medical University, Jining, China
| | - Jing Chen
- Neurobiology Institute, Jining Medical University, Jining, China. .,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK.
| |
Collapse
|
8
|
Sionov RV, Steinberg D. Anti-Microbial Activity of Phytocannabinoids and Endocannabinoids in the Light of Their Physiological and Pathophysiological Roles. Biomedicines 2022; 10:biomedicines10030631. [PMID: 35327432 PMCID: PMC8945038 DOI: 10.3390/biomedicines10030631] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 12/12/2022] Open
Abstract
Antibiotic resistance has become an increasing challenge in the treatment of various infectious diseases, especially those associated with biofilm formation on biotic and abiotic materials. There is an urgent need for new treatment protocols that can also target biofilm-embedded bacteria. Many secondary metabolites of plants possess anti-bacterial activities, and especially the phytocannabinoids of the Cannabis sativa L. varieties have reached a renaissance and attracted much attention for their anti-microbial and anti-biofilm activities at concentrations below the cytotoxic threshold on normal mammalian cells. Accordingly, many synthetic cannabinoids have been designed with the intention to increase the specificity and selectivity of the compounds. The structurally unrelated endocannabinoids have also been found to have anti-microbial and anti-biofilm activities. Recent data suggest for a mutual communication between the endocannabinoid system and the gut microbiota. The present review focuses on the anti-microbial activities of phytocannabinoids and endocannabinoids integrated with some selected issues of their many physiological and pharmacological activities.
Collapse
|
9
|
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: 21] [Impact Index Per Article: 10.5] [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
|
10
|
Askari-Zahabi K, Abbasnejad M, Kooshki R, Raoof M, Esmaeili-Mahani S, Pourrahimi AM, Zamyad M. The role of basolateral amygdala orexin 1 receptors on the modulation of pain and psychosocial deficits in nitroglycerin-induced migraine model in adult male rats. Korean J Pain 2022; 35:22-32. [PMID: 34966009 PMCID: PMC8728545 DOI: 10.3344/kjp.2022.35.1.22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022] Open
Abstract
Background Migraine headaches have been associated with sensory hyperactivity and anomalies in social/emotional responses. The main objective of this study was to evaluate the potential involvement of orexin 1 receptors (Orx1R) within the basolateral amygdala (BLA) in the modulation of pain and psychosocial dysfunction in a nitroglycerin (NTG)-induced rat model of migraine. Methods Adult male Wistar rats were injected with NTG (5 mg/kg, intraperitoneal) every second day over nine days to induce migraine. The experiments were done in the following six groups (6 rats per group) untreated control, NTG, NTG plus vehicle, and NTG groups that were post-treated with intra-BLA microinjection of Orx1R antagonist SB-334867 (10, 20, and 40 nM). Thermal hyperalgesia was assessed using the hot plate and tail-flick tests. Moreover, the elevated plus maze (EPM) and open field (OF) tests were used to assess anxiety-like behaviors. The animals’ sociability was evaluated using the three-chamber social task. The NTG-induced photophobia was assessed using a light-dark box. Results We observed no change in NTG-induced thermal hyperalgesia following administration of SB-334867 (10, 20, and 40 nM). However, SB-334867 (20 and 40 nM) aggravated the NTG-induced anxiogenic responses in both the EPM and OF tasks. The NTG-induced social impairment was overpowered by SB-334867 at all doses. Time spent in the dark chamber of light-dark box was significantly increased in rats treated with SB-334867 (20 and 40 nM/rat). Conclusions The findings suggest a role for Orx1R within the BLA in control comorbid affective complaints with migraine in rats.
Collapse
Affiliation(s)
- Khadijeh Askari-Zahabi
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Razieh Kooshki
- Department of Biology, Faculty of Sciences, Lorestan University, Khorramabad, Iran
| | - Maryam Raoof
- Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Endodontology Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Ali Mohammad Pourrahimi
- Kerman Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mahnaz Zamyad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| |
Collapse
|
11
|
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
|
12
|
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
|
13
|
Morris G, Walder K, Kloiber S, Amminger P, Berk M, Bortolasci CC, Maes M, Puri BK, Carvalho AF. The endocannabinoidome in neuropsychiatry: Opportunities and potential risks. Pharmacol Res 2021; 170:105729. [PMID: 34119623 DOI: 10.1016/j.phrs.2021.105729] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/31/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023]
Abstract
The endocannabinoid system (ECS) comprises two cognate endocannabinoid receptors referred to as CB1R and CB2R. ECS dysregulation is apparent in neurodegenerative/neuro-psychiatric disorders including but not limited to schizophrenia, major depressive disorder and potentially bipolar disorder. The aim of this paper is to review mechanisms whereby both receptors may interact with neuro-immune and neuro-oxidative pathways, which play a pathophysiological role in these disorders. CB1R is located in the presynaptic terminals of GABAergic, glutamatergic, cholinergic, noradrenergic and serotonergic neurons where it regulates the retrograde suppression of neurotransmission. CB1R plays a key role in long-term depression, and, to a lesser extent, long-term potentiation, thereby modulating synaptic transmission and mediating learning and memory. Optimal CB1R activity plays an essential neuroprotective role by providing a defense against the development of glutamate-mediated excitotoxicity, which is achieved, at least in part, by impeding AMPA-mediated increase in intracellular calcium overload and oxidative stress. Moreover, CB1R activity enables optimal neuron-glial communication and the function of the neurovascular unit. CB2R receptors are detected in peripheral immune cells and also in central nervous system regions including the striatum, basal ganglia, frontal cortex, hippocampus, amygdala as well as the ventral tegmental area. CB2R upregulation inhibits the presynaptic release of glutamate in several brain regions. CB2R activation also decreases neuroinflammation partly by mediating the transition from a predominantly neurotoxic "M1" microglial phenotype to a more neuroprotective "M2" phenotype. CB1R and CB2R are thus novel drug targets for the treatment of neuro-immune and neuro-oxidative disorders including schizophrenia and affective disorders.
Collapse
Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Ken Walder
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, Centre for Molecular and Medical Research, School of Medicine, Geelong, Australia
| | - Stefan Kloiber
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 33 Ursula Franklin Street, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Paul Amminger
- Orygen, Parkville, Victoria, Australia; Centre for Youth Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael Berk
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, Centre for Youth Mental Health, Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, The University of Melbourne, Melbourne, Australia
| | - Chiara C Bortolasci
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Maes
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria
| | | | - Andre F Carvalho
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia.
| |
Collapse
|
14
|
Riquelme-Sandoval A, de Sá-Ferreira CO, Miyakoshi LM, Hedin-Pereira C. New Insights Into Peptide Cannabinoids: Structure, Biosynthesis and Signaling. Front Pharmacol 2020; 11:596572. [PMID: 33362550 PMCID: PMC7759141 DOI: 10.3389/fphar.2020.596572] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/19/2020] [Indexed: 01/01/2023] Open
Abstract
Classically, the endocannabinoid system (ECS) consists of endogenous lipids, of which the best known are anandamide (AEA) and 2 arachidonoylglycerol (2-AG), their enzyme machinery for synthesis and degradation and their specific receptors, cannabinoid receptor one (CB1) and cannabinoid receptor two (CB2). However, endocannabinoids also bind to other groups of receptors. Furthermore, another group of lipids are considered to be endocannabinoids, such as the fatty acid ethanolamides, the fatty acid primary amides and the monoacylglycerol related molecules. Recently, it has been shown that the hemopressin peptide family, derived from α and β chains of hemoglobins, is a new family of cannabinoids. Some studies indicate that hemopressin peptides are expressed in the central nervous system and peripheral tissues and act as ligands of these receptors, thus suggesting that they play a physiological role. In this review, we examine new evidence on lipid endocannabinoids, cannabinoid receptors and the modulation of their signaling pathways. We focus our discussion on the current knowledge of the pharmacological effects, the biosynthesis of the peptide cannabinoids and the new insights on the activation and modulation of cannabinoid receptors by these peptides. The novel peptide compounds derived from hemoglobin chains and their non-classical activation of cannabinoid receptors are only starting to be uncovered. It will be exciting to follow the ensuing discoveries, not only in reference to what is already known of the classical lipid endocannabinoids revealing more complex aspects of endocannabinoid system, but also as to its possibilities as a future therapeutic tool.
Collapse
Affiliation(s)
- Agustín Riquelme-Sandoval
- Laboratory of Cellular Neuroanatomy, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Caio O de Sá-Ferreira
- Laboratory of Cellular Neuroanatomy, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leo M Miyakoshi
- Laboratory of Cellular Neuroanatomy, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Cecilia Hedin-Pereira
- Laboratory of Cellular Neuroanatomy, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,VPPCB-Fiocruz, Rio de Janeiro, Brazil.,National Institute of Science and Technology in Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
| |
Collapse
|
15
|
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
|
16
|
Narouze S. Antinociception mechanisms of action of cannabinoid-based medicine: an overview for anesthesiologists and pain physicians. Reg Anesth Pain Med 2020; 46:240-250. [PMID: 33239391 DOI: 10.1136/rapm-2020-102114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/25/2020] [Accepted: 10/29/2020] [Indexed: 12/19/2022]
Abstract
Cannabinoid-based medications possess unique multimodal analgesic mechanisms of action, modulating diverse pain targets. Cannabinoids are classified based on their origin into three categories: endocannabinoids (present endogenously in human tissues), phytocannabinoids (plant derived) and synthetic cannabinoids (pharmaceutical). Cannabinoids exert an analgesic effect, peculiarly in hyperalgesia, neuropathic pain and inflammatory states. Endocannabinoids are released on demand from postsynaptic terminals and travels retrograde to stimulate cannabinoids receptors on presynaptic terminals, inhibiting the release of excitatory neurotransmitters. Cannabinoids (endogenous and phytocannabinoids) produce analgesia by interacting with cannabinoids receptors type 1 and 2 (CB1 and CB2), as well as putative non-CB1/CB2 receptors; G protein-coupled receptor 55, and transient receptor potential vanilloid type-1. Moreover, they modulate multiple peripheral, spinal and supraspinal nociception pathways. Cannabinoids-opioids cross-modulation and synergy contribute significantly to tolerance and antinociceptive effects of cannabinoids. This narrative review evaluates cannabinoids' diverse mechanisms of action as it pertains to nociception modulation relevant to the practice of anesthesiologists and pain medicine physicians.
Collapse
Affiliation(s)
- Samer Narouze
- Center for Pain Medicine, Western Reserve Hospital, Cuyahoga Falls, Ohio, USA
| |
Collapse
|
17
|
Perin P, Mabou Tagne A, Enrico P, Marino F, Cosentino M, Pizzala R, Boselli C. Cannabinoids, Inner Ear, Hearing, and Tinnitus: A Neuroimmunological Perspective. Front Neurol 2020; 11:505995. [PMID: 33329293 PMCID: PMC7719758 DOI: 10.3389/fneur.2020.505995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
Cannabis has been used for centuries for recreational and therapeutic purposes. Whereas, the recreative uses are based on the psychotropic effect of some of its compounds, its therapeutic effects range over a wide spectrum of actions, most of which target the brain or the immune system. Several studies have found cannabinoid receptors in the auditory system, both at peripheral and central levels, thus raising the interest in cannabinoid signaling in hearing, and especially in tinnitus, which is affected also by anxiety, memory, and attention circuits where cannabinoid effects are well described. Available studies on animal models of tinnitus suggest that cannabinoids are not likely to be helpful in tinnitus treatment and could even be harmful. However, the pharmacology of cannabinoids is very complex, and most studies focused on neural CB1R-based responses. Cannabinoid effects on the immune system (where CB2Rs predominate) are increasingly recognized as essential in understanding nervous system pathological responses, and data on immune cannabinoid targets have emerged in the auditory system as well. In addition, nonclassical cannabinoid targets (such as TRP channels) appear to play an important role in the auditory system as well. This review will focus on neuroimmunological mechanisms for cannabinoid effects and their possible use as protective and therapeutic agents in the ear and auditory system, especially in tinnitus.
Collapse
Affiliation(s)
- Paola Perin
- Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy
| | | | | | | | | | - Roberto Pizzala
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Cinzia Boselli
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| |
Collapse
|
18
|
Chruścicka B, Cowan CSM, Wallace Fitzsimons SE, Borroto-Escuela DO, Druelle CM, Stamou P, Bergmann CA, Dinan TG, Slattery DA, Fuxe K, Cryan JF, Schellekens H. Molecular, biochemical and behavioural evidence for a novel oxytocin receptor and serotonin 2C receptor heterocomplex. Neuropharmacology 2020; 183:108394. [PMID: 33188842 DOI: 10.1016/j.neuropharm.2020.108394] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 10/11/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022]
Abstract
The complexity of oxytocin-mediated functions is strongly associated with its modulatory effects on other neurotransmission systems, including the serotonin (5-hydroxytryptamine, 5-HT) system. Signalling between oxytocin (OT) and 5-HT has been demonstrated during neurodevelopment and in the regulation of specific emotion-based behaviours. It is suggested that crosstalk between neurotransmitters is driven by interaction between their specific receptors, particularly the oxytocin receptor (OTR) and the 5-hydroxytryptamine 2C receptor (5-HTR2C), but evidence for this and the downstream signalling consequences that follow are lacking. Considering the overlapping central expression profiles and shared involvement of OTR and 5-HTR2C in certain endocrine functions and behaviours, including eating behaviour, social interaction and locomotor activity, we investigated the existence of functionally active OTR/5-HTR2C heterocomplexes. Here, we demonstrate evidence for a potential physical interaction between OTR and 5-HTR2Cin vitro in a cellular expression system using flow cytometry-based FRET (fcFRET). We could recapitulate this finding under endogenous expression levels of both receptors via in silico analysis of single cell transcriptomic data and ex vivo proximity ligation assay (PLA). Next, we show that co-expression of the OTR/5-HTR2C pair resulted in a significant depletion of OTR-mediated Gαq-signalling and significant changes in receptor trafficking. Of note, attenuation of OTR-mediated downstream signalling was restored following pharmacological blockade of the 5-HTR2C. Finally, we demonstrated a functional relevance of this novel heterocomplex, in vivo, as 5-HTR2C antagonism increased OT-mediated hypoactivity in mice. Overall, we provide compelling evidence for the formation of functionally active OTR/5-HTR2C heterocomplexes, adding another level of complexity to OTR and 5-HTR2C signalling functionality. This article is part of the special issue on Neuropeptides.
Collapse
Affiliation(s)
- Barbara Chruścicka
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Małopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | | | | | | | | | | | | | - Timothy G Dinan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - David A Slattery
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital Frankfurt, Frankfurt, Germany
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Harriët Schellekens
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
| |
Collapse
|
19
|
Chruścicka B, Wallace Fitzsimons SE, Borroto-Escuela DO, Druelle C, Stamou P, Nally K, Dinan TG, Cryan JF, Fuxe K, Schellekens H. Attenuation of Oxytocin and Serotonin 2A Receptor Signaling through Novel Heteroreceptor Formation. ACS Chem Neurosci 2019; 10:3225-3240. [PMID: 31038917 DOI: 10.1021/acschemneuro.8b00665] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The oxytocin receptor (OTR) and the 5-hydroxytryptamine 2A receptor (5-HTR2A) are expressed in similar brain regions modulating central pathways critical for social and cognition-related behaviors. Signaling crosstalk between their endogenous ligands, oxytocin (OT) and serotonin (5-hydroxytryptamine, 5-HT), highlights the complex interplay between these two neurotransmitter systems and may be indicative of the formation of heteroreceptor complexes with subsequent downstream signaling changes. In this study, we assess the possible formation of OTR-5HTR2A heteromers in living cells and the functional downstream consequences of this receptor-receptor interaction. First, we demonstrated the existence of a physical interaction between the OTR and 5-HTR2A in vitro, using a flow cytometry-based FRET approach and confocal microscopy. Furthermore, we investigated the formation of this specific heteroreceptor complex ex vivo in the brain sections using the Proximity Ligation Assay (PLA). The OTR-5HTR2A heteroreceptor complexes were identified in limbic regions (including hippocampus, cingulate cortex, and nucleus accumbens), key regions associated with cognition and social-related behaviors. Next, functional cellular-based assays to assess the OTR-5HTR2A downstream signaling crosstalk showed a reduction in potency and efficacy of OT and OTR synthetic agonists, carbetocin and WAY267464, on OTR-mediated Gαq signaling. Similarly, the activation of 5-HTR2A by the endogenous agonist, 5-HT, also revealed attenuation in Gαq-mediated signaling. Finally, altered receptor trafficking within the cell was demonstrated, indicative of cotrafficking of the OTR/5-HTR2A pair. Overall, these results constitute a novel mechanism of specific interaction between the OT and 5-HT neurotransmitters via OTR-5HTR2A heteroreceptor formation and provide potential new therapeutic strategies in the treatment of social and cognition-related diseases.
Collapse
Affiliation(s)
- Barbara Chruścicka
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Shauna E. Wallace Fitzsimons
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | | | - Clémentine Druelle
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | | | - Kenneth Nally
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Timothy G. Dinan
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - John F. Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Retzius väg 8, 17177 Stockholm, Sweden
| | - Harriët Schellekens
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| |
Collapse
|
20
|
A ghrelin receptor and oxytocin receptor heterocomplex impairs oxytocin mediated signalling. Neuropharmacology 2019; 152:90-101. [DOI: 10.1016/j.neuropharm.2018.12.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/21/2018] [Accepted: 12/18/2018] [Indexed: 12/31/2022]
|
21
|
Karimi S, Hamidi G, Fatahi Z, Haghparast A. Orexin 1 receptors in the anterior cingulate and orbitofrontal cortex regulate cost and benefit decision-making. Prog Neuropsychopharmacol Biol Psychiatry 2019; 89:227-235. [PMID: 30222989 DOI: 10.1016/j.pnpbp.2018.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 08/07/2018] [Accepted: 09/09/2018] [Indexed: 12/16/2022]
Abstract
Orexin neurons are discretely localized within the lateral hypothalamus and have widespread projections into all areas of the brain. In addition, several lines of evidence specify that orexins may also participate in the regulation of a variety of affective and cognitive processes. The Orexin-1 receptor (OX1r) is distributed extensively throughout the prefrontal cortex (PFC). Delay-based decision- making is mediated largely by the orbitofrontal cortex (OFC) while effort- based decision-making is controlled by the anterior cingulated cortex (ACC). Hence, in the present study, a series of experiments were conducted to clarify the role of OX1r in the mPFC (ACC and/or OFC) in cost and benefit decision-making. The rats were trained in a delay and/or effort-based form of cost-benefit T-maze decision-making task. Two goal arms were different in the amount of accessible reward and cost. Before surgery, all animals were selecting the high reward arm and pay the cost on almost every trial. During the test days, the rats received local injections of either DMSO 20% /0.5 μl, as a vehicle, or SB334867 (3, 30 and 300 nM/0.5 μl), as a selective OX1r antagonist, within the ACC and/or OFC. The results of this study showed that the bilateral microinjection of SB334867 into ACC and/or OFC changed the preference to a low reward arm with no cost, indicating the role of OX1 receptors in cost and benefit decision- making. From these results, it can be implied that OX1 receptors in the mPFC play a crucial role for allowing the animal to evaluate and pay the cost to acquire greater rewards.
Collapse
Affiliation(s)
- Sara Karimi
- Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran
| | - Gholamali Hamidi
- Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran.
| | - Zahra Fatahi
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Haghparast
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
22
|
Tóth KF, Ádám D, Bíró T, Oláh A. Cannabinoid Signaling in the Skin: Therapeutic Potential of the "C(ut)annabinoid" System. Molecules 2019; 24:E918. [PMID: 30845666 PMCID: PMC6429381 DOI: 10.3390/molecules24050918] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 02/06/2023] Open
Abstract
The endocannabinoid system (ECS) has lately been proven to be an important, multifaceted homeostatic regulator, which influences a wide-variety of physiological processes all over the body. Its members, the endocannabinoids (eCBs; e.g., anandamide), the eCB-responsive receptors (e.g., CB₁, CB₂), as well as the complex enzyme and transporter apparatus involved in the metabolism of the ligands were shown to be expressed in several tissues, including the skin. Although the best studied functions over the ECS are related to the central nervous system and to immune processes, experimental efforts over the last two decades have unambiguously confirmed that cutaneous cannabinoid ("c[ut]annabinoid") signaling is deeply involved in the maintenance of skin homeostasis, barrier formation and regeneration, and its dysregulation was implicated to contribute to several highly prevalent diseases and disorders, e.g., atopic dermatitis, psoriasis, scleroderma, acne, hair growth and pigmentation disorders, keratin diseases, various tumors, and itch. The current review aims to give an overview of the available skin-relevant endo- and phytocannabinoid literature with a special emphasis on the putative translational potential, and to highlight promising future research directions as well as existing challenges.
Collapse
Affiliation(s)
- Kinga Fanni Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - Dorottya Ádám
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - Tamás Bíró
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
- HCEMM Nonprofit Ltd., 6720 Szeged, Hungary.
| | - Attila Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| |
Collapse
|
23
|
Therapeutic targeting of HER2-CB 2R heteromers in HER2-positive breast cancer. Proc Natl Acad Sci U S A 2019; 116:3863-3872. [PMID: 30733293 DOI: 10.1073/pnas.1815034116] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Although human epidermal growth factor receptor 2 (HER2)-targeted therapies have dramatically improved the clinical outcome of HER2-positive breast cancer patients, innate and acquired resistance remains an important clinical challenge. New therapeutic approaches and diagnostic tools for identification, stratification, and treatment of patients at higher risk of resistance and recurrence are therefore warranted. Here, we unveil a mechanism controlling the oncogenic activity of HER2: heteromerization with the cannabinoid receptor CB2R. We show that HER2 physically interacts with CB2R in breast cancer cells, and that the expression of these heteromers correlates with poor patient prognosis. The cannabinoid Δ9-tetrahydrocannabinol (THC) disrupts HER2-CB2R complexes by selectively binding to CB2R, which leads to (i) the inactivation of HER2 through disruption of HER2-HER2 homodimers, and (ii) the subsequent degradation of HER2 by the proteasome via the E3 ligase c-CBL. This in turn triggers antitumor responses in vitro and in vivo. Selective targeting of CB2R transmembrane region 5 mimicked THC effects. Together, these findings define HER2-CB2R heteromers as new potential targets for antitumor therapies and biomarkers with prognostic value in HER2-positive breast cancer.
Collapse
|
24
|
Müskens FM, Ward RJ, Herkt D, van de Langemheen H, Tobin AB, Liskamp RMJ, Milligan G. Design, Synthesis, and Evaluation of a Diazirine Photoaffinity Probe for Ligand-Based Receptor Capture Targeting G Protein-Coupled Receptors. Mol Pharmacol 2019; 95:196-209. [PMID: 30514721 PMCID: PMC6324650 DOI: 10.1124/mol.118.114249] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/27/2018] [Indexed: 12/21/2022] Open
Abstract
Chemoproteomic approaches to identify ligand-receptor interactions have gained popularity. However, identifying transmembrane receptors remains challenging. A new trifunctional probe to aid the nonbiased identification of such receptors was developed and synthesized using a convenient seven-step synthesis. This probe contained three functional groups: 1) an N-hydroxysuccinimide ester for ligand-coupling through free amines, 2) a diazirine moiety to capture the receptor of interest upon irradiation with UV light, and 3) a biotin group which allowed affinity purification of the final adduct using streptavidin. The interaction between the G protein-coupled tachykinin neurokinin 1 (NK1) receptor, expressed in an inducible manner, and the peptidic ligand substance P was used as a test system. Liquid chromatography-mass spectrometry analysis confirmed successful coupling of the probe to substance P, while inositol monophosphate accumulation assays demonstrated that coupling of the probe did not interfere substantially with the substance P-NK1 receptor interaction. Confocal microscopy and western blotting provided evidence of the formation of a covalent bond between the probe and the NK1 receptor upon UV activation. As proof of concept, the probe was used in full ligand-based receptor-capture experiments to identify the substance P-binding receptor via liquid chromatography-tandem mass spectrometry, resulting in the successful identification of only the NK1 receptor. This provides proof of concept toward general utilization of this probe to define interactions between ligands and previously unidentified plasma-membrane receptors.
Collapse
Affiliation(s)
- Frederike M Müskens
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| | - Richard J Ward
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| | - Dominik Herkt
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| | - Helmus van de Langemheen
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| | - Andrew B Tobin
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| | - Rob M J Liskamp
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| | - Graeme Milligan
- School of Chemistry, College of Science and Engineering (F.M.M., D.H., H.L., R.M.J.L.) and Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences (F.M.M., R.J.W., A.B.T., G.M.), University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
25
|
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]
|
26
|
Xue Q, Bai B, Ji B, Chen X, Wang C, Wang P, Yang C, Zhang R, Jiang Y, Pan Y, Cheng B, Chen J. Ghrelin Through GHSR1a and OX1R Heterodimers Reveals a Gαs-cAMP-cAMP Response Element Binding Protein Signaling Pathway in Vitro. Front Mol Neurosci 2018; 11:245. [PMID: 30065627 PMCID: PMC6056640 DOI: 10.3389/fnmol.2018.00245] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 06/25/2018] [Indexed: 01/19/2023] Open
Abstract
Growth hormone secretagogue receptor 1α (GHSR1a) and Orexin 1 receptor (OX1R) are involved in various important physiological processes, and have many similar characteristics in function and distribution in peripheral tissues and the central nervous system. We explored the possibility of heterodimerization between GHSR1a and OX1R and revealed a signal transduction pathway mechanism. In this study, bioluminescence and fluorescence resonance energy transfer and co-immunoprecipitation (Co-IP) analyses were performed to demonstrate the formation of functional GHSR1a/OX1R heterodimers. This showed that a peptide corresponding to the 5-transmembrane domain of OX1R impaired heterodimer construction. We found that ghrelin stimulated GHSR1a/OX1R heterodimer cells to increase the activation of Gαs protein, compared to the cells that express GHSR1a. Stimulation of GHSR1a/OX1R heterodimers with orexin-A did not alter GPCR interactions with Gα protein subunits. GHSR1a/OX1R heterodimers induced Gαs and downstream signaling pathway activity, including increase of cAMP-response element luciferase reporter activity and cAMP levels. In addition, ghrelin induced a higher proliferation rate in SH-SY5Y cells than in controls. This suggests that ghrelin GHSR1a/OX1R heterodimers promotes an upregulation of a Gαs-cAMP-cAMP-responsive element signaling pathway in vitro and an increase in neuroblastoma cell proliferation.
Collapse
Affiliation(s)
- Qingjie Xue
- Neurobiology Institute, Jining Medical University, Jining, China.,Department of Pathogenic Biology, Jining Medical University, Jining, China
| | - Bo Bai
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Bingyuan Ji
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Xiaoyu Chen
- Department of Physiology, Taishan Medical University, Taian, China
| | - Chunmei Wang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Peixiang Wang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Chunqing Yang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Rumin Zhang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Yunlu Jiang
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Yanyou Pan
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Baohua Cheng
- Neurobiology Institute, Jining Medical University, Jining, China
| | - Jing Chen
- Neurobiology Institute, Jining Medical University, Jining, China.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| |
Collapse
|
27
|
Liu Y, Zeng H, Pediani JD, Ward RJ, Chen LY, Wu N, Ma L, Tang M, Yang Y, An S, Guo XX, Hao Q, Xu TR. Visualization of the activation of the histamine H3 receptor (H3R) using novel fluorescence resonance energy transfer biosensors and their potential application to the study of H3R pharmacology. FEBS J 2018; 285:2319-2336. [PMID: 29701013 DOI: 10.1111/febs.14484] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 03/24/2018] [Accepted: 04/20/2018] [Indexed: 12/14/2022]
Abstract
Activation of the histamine-3 receptor (H3R) is involved in memory processes and cognitive action, while blocking H3R activation can slow the progression of neurological disorders, such as Alzheimer's disease, schizophrenia and narcolepsy. To date, however, no direct way to examine the activation of H3R has been utilized. Here, we describe a novel biosensor that can visualize the activation of H3R through an intramolecular fluorescence resonance energy transfer (FRET) signal. To achieve this, we constructed an intramolecular H3R FRET sensor with cyan fluorescent protein (CFP) attached at the C terminus and yellow fluorescent protein (YFP) inserted into the third intracellular loop. The sensor was found to internalize normally on agonist treatment. We measured FRET signals between the donor CFP and the acceptor YFP in living cells in real time, the results of which indicated that H3R agonist treatment (imetit or histamine) increases the FRET signal in a time- and concentration-dependent manner with Kon and Koff values consistent with published data and which maybe correlated with decreasing cAMP levels and the promotion of ERK1/2 phosphorylation. The FRET signal was inhibited by H3R antagonists, and the introduction of mutations at F419A, F423A, L426A and L427A, once again, the promotion of ERK1/2 phosphorylation, was diminished. Thus, we have built a H3R biosensor which can visualize the activation of receptor through real-time structure changes and which can obtain pharmacological kinetic data at the same time. The FRET signals may allow the sensor to become a useful tool for screening compounds and optimizing useful ligands.
Collapse
Affiliation(s)
- Ying Liu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Hong Zeng
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - John D Pediani
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Richard J Ward
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Lu-Yao Chen
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Nan Wu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Li Ma
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Mei Tang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Yang Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Su An
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Xiao-Xi Guo
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Qian Hao
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Tian-Rui Xu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| |
Collapse
|
28
|
Oláh A, Szekanecz Z, Bíró T. Targeting Cannabinoid Signaling in the Immune System: "High"-ly Exciting Questions, Possibilities, and Challenges. Front Immunol 2017; 8:1487. [PMID: 29176975 PMCID: PMC5686045 DOI: 10.3389/fimmu.2017.01487] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 10/23/2017] [Indexed: 12/21/2022] Open
Abstract
It is well known that certain active ingredients of the plants of Cannabis genus, i.e., the "phytocannabinoids" [pCBs; e.g., (-)-trans-Δ9-tetrahydrocannabinol (THC), (-)-cannabidiol, etc.] can influence a wide array of biological processes, and the human body is able to produce endogenous analogs of these substances ["endocannabinoids" (eCB), e.g., arachidonoylethanolamine (anandamide, AEA), 2-arachidonoylglycerol (2-AG), etc.]. These ligands, together with multiple receptors (e.g., CB1 and CB2 cannabinoid receptors, etc.), and a complex enzyme and transporter apparatus involved in the synthesis and degradation of the ligands constitute the endocannabinoid system (ECS), a recently emerging regulator of several physiological processes. The ECS is widely expressed in the human body, including several members of the innate and adaptive immune system, where eCBs, as well as several pCBs were shown to deeply influence immune functions thereby regulating inflammation, autoimmunity, antitumor, as well as antipathogen immune responses, etc. Based on this knowledge, many in vitro and in vivo studies aimed at exploiting the putative therapeutic potential of cannabinoid signaling in inflammation-accompanied diseases (e.g., multiple sclerosis) or in organ transplantation, and to dissect the complex immunological effects of medical and "recreational" marijuana consumption. Thus, the objective of the current article is (i) to summarize the most recent findings of the field; (ii) to highlight the putative therapeutic potential of targeting cannabinoid signaling; (iii) to identify open questions and key challenges; and (iv) to suggest promising future directions for cannabinoid-based drug development.
Collapse
Affiliation(s)
- Attila Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Szekanecz
- Department of Internal Medicine, Division of Rheumatology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bíró
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| |
Collapse
|
29
|
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
|
30
|
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: 123] [Impact Index Per Article: 17.6] [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
|
31
|
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
|
32
|
Medrano M, Aguinaga D, Reyes-Resina I, Canela EI, Mallol J, Navarro G, Franco R. Orexin A/Hypocretin Modulates Leptin Receptor-Mediated Signaling by Allosteric Modulations Mediated by the Ghrelin GHS-R1A Receptor in Hypothalamic Neurons. Mol Neurobiol 2017; 55:4718-4730. [DOI: 10.1007/s12035-017-0670-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/20/2017] [Indexed: 12/16/2022]
|
33
|
Dual-agonist occupancy of orexin receptor 1 and cholecystokinin A receptor heterodimers decreases G-protein–dependent signaling and migration in the human colon cancer cell line HT-29. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1153-1164. [DOI: 10.1016/j.bbamcr.2017.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 01/14/2023]
|
34
|
Tian H, Fürstenberg A, Huber T. Labeling and Single-Molecule Methods To Monitor G Protein-Coupled Receptor Dynamics. Chem Rev 2016; 117:186-245. [DOI: 10.1021/acs.chemrev.6b00084] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- He Tian
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New York 10065, United States
| | - Alexandre Fürstenberg
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New York 10065, United States
| | - Thomas Huber
- Laboratory of Chemical Biology
and Signal Transduction, The Rockefeller University, 1230 York
Avenue, New York, New York 10065, United States
| |
Collapse
|
35
|
Simkins TJ, Fried D, Parikh K, Galligan JJ, Goudreau JL, Lookingland KJ, Kaplan BLF. Reduced Noradrenergic Signaling in the Spleen Capsule in the Absence of CB 1 and CB 2 Cannabinoid Receptors. J Neuroimmune Pharmacol 2016; 11:669-679. [PMID: 27287619 DOI: 10.1007/s11481-016-9689-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/02/2016] [Indexed: 11/27/2022]
Abstract
The spleen is a visceral organ that contracts during hypoxia to expel erythrocytes and immune cells into the circulation. Spleen contraction is under the control of noradrenergic sympathetic innervation. The activity of noradrenergic neurons terminating in the spleen capsule is regulated by α2-adrenergic receptors (AR). Interactions between endogenous cannabinoid signaling and noradrenergic signaling in other organ systems suggest endocannabinoids might also regulate spleen contraction. Spleens from mice congenitally lacking both CB1 and CB2 cannabinoid receptors (Cnr1 -/- /Cnr2 -/- mice) were used to explore the role of endocannabinoids in spleen contraction. Spleen contraction in response to exogenous norepinephrine (NE) was found to be significantly lower in Cnr1 -/- /Cnr2 -/- mouse spleens, likely due to decreased expression of capsular α1AR. The majority of splenic Cnr1 mRNA expression is by cells of the spleen capsule, suggestive of post-synaptic CB1 receptor signaling. Thus, these studies demonstrate a role for CB1 and/or CB2 in noradrenergic splenic contraction.
Collapse
Affiliation(s)
- Tyrell J Simkins
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - David Fried
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Kevin Parikh
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - James J Galligan
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - John L Goudreau
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Keith J Lookingland
- Neuroscience Program, Michigan State University, East Lansing, MI, USA
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Barbara L F Kaplan
- Neuroscience Program, Michigan State University, East Lansing, MI, USA.
- Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA.
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA.
- Department of Basic Sciences, Mississippi State University, PO Box 6100, Mississippi State, MS, 39762, USA.
| |
Collapse
|
36
|
Iannotti FA, Di Marzo V, Petrosino S. Endocannabinoids and endocannabinoid-related mediators: Targets, metabolism and role in neurological disorders. Prog Lipid Res 2016; 62:107-28. [DOI: 10.1016/j.plipres.2016.02.002] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/25/2016] [Accepted: 02/26/2016] [Indexed: 12/19/2022]
|
37
|
Yazdi F, Jahangirvand M, Pirasteh AH, Moradi M, Haghparast A. Functional interaction between OX2 and CB1 receptors in the ventral tegmental area and the nucleus accumbens in response to place preference induced by chemical stimulation of the lateral hypothalamus. Pharmacol Biochem Behav 2015; 139:39-46. [DOI: 10.1016/j.pbb.2015.10.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 10/16/2015] [Accepted: 10/17/2015] [Indexed: 10/22/2022]
|
38
|
Sergeev E, Hansen AH, Pandey SK, MacKenzie AE, Hudson BD, Ulven T, Milligan G. Non-equivalence of Key Positively Charged Residues of the Free Fatty Acid 2 Receptor in the Recognition and Function of Agonist Versus Antagonist Ligands. J Biol Chem 2015; 291:303-17. [PMID: 26518871 PMCID: PMC4697166 DOI: 10.1074/jbc.m115.687939] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Indexed: 01/22/2023] Open
Abstract
Short chain fatty acids (SCFAs) are produced in the gut by bacterial fermentation of poorly digested carbohydrates. A key mediator of their actions is the G protein-coupled free fatty acid 2 (FFA2) receptor, and this has been suggested as a therapeutic target for the treatment of both metabolic and inflammatory diseases. However, a lack of understanding of the molecular determinants dictating how ligands bind to this receptor has hindered development. We have developed a novel radiolabeled FFA2 antagonist to probe ligand binding to FFA2, and in combination with mutagenesis and molecular modeling studies, we define how agonist and antagonist ligands interact with the receptor. Although both agonist and antagonist ligands contain negatively charged carboxylates that interact with two key positively charged arginine residues in transmembrane domains V and VII of FFA2, there are clear differences in how these interactions occur. Specifically, although agonists require interaction with both arginine residues to bind the receptor, antagonists require an interaction with only one of the two. Moreover, different chemical series of antagonist interact preferentially with different arginine residues. A homology model capable of rationalizing these observations was developed and provides a tool that will be invaluable for identifying improved FFA2 agonists and antagonists to further define function and therapeutic opportunities of this receptor.
Collapse
Affiliation(s)
- Eugenia Sergeev
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Anders Højgaard Hansen
- the Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Sunil K Pandey
- the Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Amanda E MacKenzie
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Brian D Hudson
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Trond Ulven
- the Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Graeme Milligan
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| |
Collapse
|
39
|
Robinson JD, McDonald PH. The orexin 1 receptor modulates kappa opioid receptor function via a JNK-dependent mechanism. Cell Signal 2015; 27:1449-56. [PMID: 25857454 PMCID: PMC5549559 DOI: 10.1016/j.cellsig.2015.03.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/23/2015] [Accepted: 03/30/2015] [Indexed: 10/23/2022]
Abstract
The orexin 1 receptor (OX1R) and the kappa opioid receptor (KOR) are two G protein-coupled receptors (GPCRs) previously demonstrated to play important roles in modulating the rewarding effects of drugs of abuse such as cocaine. Using cells heterologously expressing both receptors, we investigated whether OX1R can regulate the function of KOR and vice versa. Activation of OX1R was found to attenuate agonist-activated KOR-mediated inhibition of cAMP production. In contrast, agonist-activated KOR-mediated β-arrestin recruitment and p38 activation were enhanced in the presence of activated OX1R. These effects are independent of OX1R internalization but are blocked in the presence of the JNK inhibitor SP-600125. OX1R signaling does not affect ligand binding by KOR. Taken together, these data suggest that OX1R signaling can modulate KOR function in a JNK-dependent manner, promoting preferential signaling of KOR via β-arrestin/p38 rather than Gαi. Conversely, Gαq coupling of OX1R is unaffected by activation of KOR, suggesting that this crosstalk is unidirectional. Given that KOR Gαi-mediated signaling events and β-arrestin-mediated signaling events are thought to promote distinct cellular responses and physiological outcomes downstream of KOR activation, this mechanism may have important implications on the behavioral effects of KOR activity.
Collapse
Affiliation(s)
- James D Robinson
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Patricia H McDonald
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA.
| |
Collapse
|
40
|
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
|
41
|
Marsango S, Caltabiano G, Pou C, Varela Liste MJ, Milligan G. Analysis of Human Dopamine D3 Receptor Quaternary Structure. J Biol Chem 2015; 290:15146-62. [PMID: 25931118 PMCID: PMC4463457 DOI: 10.1074/jbc.m114.630681] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 04/23/2015] [Indexed: 01/11/2023] Open
Abstract
The dopamine D3 receptor is a class A, rhodopsin-like G protein-coupled receptor that can form dimers and/or higher order oligomers. However, the molecular basis for production of these complexes is not well defined. Using combinations of molecular modeling, site-directed mutagenesis, and homogenous time-resolved FRET, the interfaces that allow dopamine D3 receptor monomers to interact were defined and used to describe likely quaternary arrangements of the receptor. These were then compared with published crystal structures of dimeric β1-adrenoreceptor, μ-opioid, and CXCR4 receptors. The data indicate important contributions of residues from within each of transmembrane domains I, II, IV, V, VI, and VII as well as the intracellular helix VIII in the formation of D3-D3 receptor interfaces within homo-oligomers and are consistent with the D3 receptor adopting a β1-adrenoreceptor-like quaternary arrangement. Specifically, results suggest that D3 protomers can interact with each other via at least two distinct interfaces: the first one comprising residues from transmembrane domains I and II along with those from helix VIII and a second one involving transmembrane domains IV and V. Moreover, rather than existing only as distinct dimeric species, the results are consistent with the D3 receptor also assuming a quaternary structure in which two transmembrane domain I-II-helix VIII dimers interact to form a "rhombic" tetramer via an interface involving residues from transmembrane domains VI and VII. In addition, the results also provide insights into the potential contribution of molecules of cholesterol to the overall organization and potential stability of the D3 receptor and possibly other GPCR quaternary structures.
Collapse
Affiliation(s)
- Sara Marsango
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Gianluigi Caltabiano
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Chantevy Pou
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - María José Varela Liste
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Graeme Milligan
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| |
Collapse
|
42
|
Chen J, Zhang R, Chen X, Wang C, Cai X, Liu H, Jiang Y, Liu C, Bai B. Heterodimerization of human orexin receptor 1 and kappa opioid receptor promotes protein kinase A/cAMP-response element binding protein signaling via a Gαs-mediated mechanism. Cell Signal 2015; 27:1426-38. [PMID: 25866368 DOI: 10.1016/j.cellsig.2015.03.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/26/2015] [Accepted: 03/27/2015] [Indexed: 01/14/2023]
Abstract
Orexin and dynorphin are co-expressed in the same synaptic vesicles of hypothalamic neurons and play opposing roles in cocaine self-administration, brain stimulation reward, and impulsivity in ventral tegmental area (VTA), where dopamine neurons express both OX1R and KORs. However, detailed mechanisms of how the coreleased peptides and both receptors fine-tune their signalings and physiological/behavioral effects together remain unclear. Here we explore the possibility of heterodimerization between OX1R and KOR and reveal novel signal transduction mechanisms. First, we demonstrated co-expression of OX1R and KOR in rat hippocampal neurons by single-cell PCR. Furthermore, heterodimerization between OX1R and KOR was examined using bioluminescence and fluorescence resonance energy transfer (BRET and FRET). Our data revealed that human OX1R and KOR heterodimerize, and this heterodimer associates with Gαs, leading to increased protein kinase A (PKA) signaling pathway activity, including upregulation of intracellular cAMP levels and cAMP-response element (CRE) luciferase reporter activity, resulting in increased cAMP-response element binding protein (CREB) phosphorylation. These results support the view that OX1R and KOR heterodimerization might have an anti-depressive role.
Collapse
Affiliation(s)
- Jing Chen
- Division of Translational and Systems Medicine, Warwick Medical School, University of Warwick, Coventry, UK; Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
| | - Rumin Zhang
- Neurobiology Institute, Jining Medical University, Jining 272067, PR China
| | - Xiaoyu Chen
- Department of Physiology, Taishan Medical University, Taian 271000, PR China
| | - Chunmei Wang
- Neurobiology Institute, Jining Medical University, Jining 272067, PR China
| | - Xin Cai
- Neurobiology Institute, Jining Medical University, Jining 272067, PR China
| | - Haiqing Liu
- Department of Physiology, Taishan Medical University, Taian 271000, PR China
| | - Yunlu Jiang
- Neurobiology Institute, Jining Medical University, Jining 272067, PR China
| | - Chuanxin Liu
- Neurobiology Institute, Jining Medical University, Jining 272067, PR China
| | - Bo Bai
- Neurobiology Institute, Jining Medical University, Jining 272067, PR China.
| |
Collapse
|
43
|
Kilpatrick LE, Humphrys LJ, Holliday ND. A G protein-coupled receptor dimer imaging assay reveals selectively modified pharmacology of neuropeptide Y Y1/Y5 receptor heterodimers. Mol Pharmacol 2015; 87:718-32. [PMID: 25637604 DOI: 10.1124/mol.114.095356] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ability of G protein-coupled receptors (GPCRs) to form dimers, and particularly heterodimers, offers potential for targeted therapeutics with improved selectivity. However, studying dimer pharmacology is challenging, because of signaling cross-talk or because dimerization may often be transient in nature. Here we develop a system to isolate the pharmacology of precisely defined GPCR dimers, trapped by bimolecular fluorescence complementation (BiFC). Specific effects of agonist activation on such dimers are quantified using automated imaging and analysis of their internalization, controlled for by simultaneous assessment of endocytosis of one coexpressed protomer population. We applied this BiFC system to study example neuropeptide Y (NPY) Y1 receptor dimers. Incorporation of binding-site or phosphorylation-site mutations into just one protomer of a Y1/Y1 BiFC homodimer had no impact on efficient NPY-stimulated endocytosis, demonstrating that single-site agonist occupancy, and one phosphorylated monomer within this dimer, was sufficient. For two Y1 receptor heterodimer combinations (with the Y4 receptor or β2-adrenoceptor), agonist and antagonist pharmacology was explained by independent actions on the respective orthosteric binding sites. However, Y1/Y5 receptor BiFC dimers, compared with the constituent subtypes, were characterized by reduced potency and efficacy of Y5-selective peptide agonists, the inactivity of Y1-selective antagonists, and a change from surmountable to nonsurmountable antagonism for three unrelated Y5 antagonists. Thus, allosteric interactions between Y1 and Y5 receptors modify the pharmacology of the heterodimer, with implications for potential antiobesity agents that target centrally coexpressed Y1 and Y5 receptors to suppress appetite.
Collapse
Affiliation(s)
- Laura E Kilpatrick
- School of Life Sciences, University of Nottingham, The Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| | - Laura J Humphrys
- School of Life Sciences, University of Nottingham, The Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| | - Nicholas D Holliday
- School of Life Sciences, University of Nottingham, The Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| |
Collapse
|
44
|
Marsango S, Varela MJ, Milligan G. Approaches to Characterize and Quantify Oligomerization of GPCRs. Methods Mol Biol 2015; 1335:95-105. [PMID: 26260596 DOI: 10.1007/978-1-4939-2914-6_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Fluorescence resonance energy transfer (FRET) is an approach widely used to detect protein-protein interactions in live cells. This approach is based on the sensitization of an "acceptor" molecule by the energy transfer from a "donor" when there is an overlap between the emission spectrum of the "donor" and the excitation spectrum of the "acceptor" and close proximity between the two fluorophore species (in the region of 8 nm). Various methods exist to quantify FRET signals: here, we describe the application of homogeneous time-resolved FRET (htrFRET) combined with Tag-lite™ technology and its application to determine not only protein-protein interactions but also the capability of GPCR mutant variants to form homomers compared to the wild type GPCR within the plasma membrane of transfected cells.
Collapse
Affiliation(s)
- Sara Marsango
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, University Avenue, Glasgow, G12 8QQ, Scotland, UK
| | | | | |
Collapse
|
45
|
Kukkonen JP, Leonard CS. Orexin/hypocretin receptor signalling cascades. Br J Pharmacol 2014; 171:314-31. [PMID: 23902572 DOI: 10.1111/bph.12324] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 07/18/2013] [Accepted: 07/28/2013] [Indexed: 12/16/2022] Open
Abstract
Orexin (hypocretin) peptides and their two known G-protein-coupled receptors play essential roles in sleep-wake control and powerfully influence other systems regulating appetite/metabolism, stress and reward. Consequently, drugs that influence signalling by these receptors may provide novel therapeutic opportunities for treating sleep disorders, obesity and addiction. It is therefore critical to understand how these receptors operate, the nature of the signalling cascades they engage and their physiological targets. In this review, we evaluate what is currently known about orexin receptor signalling cascades, while a sister review (Leonard & Kukkonen, this issue) focuses on tissue-specific responses. The evidence suggests that orexin receptor signalling is multifaceted and is substantially more diverse than originally thought. Indeed, orexin receptors are able to couple to members of at least three G-protein families and possibly other proteins, through which they regulate non-selective cation channels, phospholipases, adenylyl cyclase, and protein and lipid kinases. In the central nervous system, orexin receptors produce neuroexcitation by postsynaptic depolarization via activation of non-selective cation channels, inhibition of K⁺ channels and activation of Na⁺/Ca²⁺ exchange, but they also can stimulate the release of neurotransmitters by presynaptic actions and modulate synaptic plasticity. Ca²⁺ signalling is also prominently influenced by these receptors, both via the classical phospholipase C-Ca²⁺ release pathway and via Ca²⁺ influx, mediated by several pathways. Upon longer-lasting stimulation, plastic effects are observed in some cell types, while others, especially cancer cells, are stimulated to die. Thus, orexin receptor signals appear highly tunable, depending on the milieu in which they are operating.
Collapse
Affiliation(s)
- J P Kukkonen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | | |
Collapse
|
46
|
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
|
47
|
Cristino L, Palomba L, Di Marzo V. New horizons on the role of cannabinoid CB1 receptors in palatable food intake, obesity and related dysmetabolism. INTERNATIONAL JOURNAL OF OBESITY SUPPLEMENTS 2014; 4:S26-30. [PMID: 27152162 DOI: 10.1038/ijosup.2014.8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Excessive consumption of high-energy, palatable food contributes to obesity, which results in the metabolic syndrome, heart disease, type-2 diabetes and death. Current knowledge on the function of the hypothalamus as the brain 'feeding centre' recognizes this region as the main regulator of body weight in the central nervous system. Because of their intrinsically fast and adaptive activities, feeding-controlling neural circuitries are endowed with synaptic plasticity modulated by neurotransmitters and hormones that act at different hierarchical levels of integration. In the hypothalamus, among the chemical mediators involved in this integration, endocannabinoids (eCBs) are ideal candidates for the fast (that is, non-genomic), stress-related fine-tuning of neuronal functions. In this article, we overview the role of the eCB system (ECS) in the control of energy intake, and particularly in the consumption of high-energy, palatable food, and discuss how such a role is affected in the brain by changes in the levels of feeding-regulated hormones, such as the adipose tissue-derived anorexigenic mediator leptin, as well as by high-fat diets. The understanding of the molecular mechanisms underlying the neuronal control of feeding behaviours by eCBs offers many potential opportunities for novel therapeutic approaches against obesity. Highlights of the latest advances in the development of strategies that minimize central ECS overactivity in 'western diet'-driven obesity are discussed.
Collapse
Affiliation(s)
- L Cristino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche , Pozzuoli, Italy
| | - L Palomba
- Department of Biomolecular Sciences, University 'Carlo Bo' , Urbino, Italy
| | - V Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche , Pozzuoli, Italy
| |
Collapse
|
48
|
Tovo-Rodrigues L, Roux A, Hutz MH, Rohde LA, Woods AS. Functional characterization of G-protein-coupled receptors: a bioinformatics approach. Neuroscience 2014; 277:764-79. [PMID: 24997265 DOI: 10.1016/j.neuroscience.2014.06.049] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 05/22/2014] [Accepted: 06/18/2014] [Indexed: 12/18/2022]
Abstract
Complex molecular and cellular mechanisms regulate G protein-coupled receptors (GPCRs). It is suggested that proteins intrinsically disordered regions (IDRs) are to play a role in GPCR's intra and extracellular regions plasticity, due to their potential for post-translational modification and interaction with other proteins. These regions are defined as lacking a stable three-dimensional (3D) structure. They are rich in hydrophilic and charged, amino acids and are capable to assume different conformations which allow them to interact with multiple partners. In this study we analyzed 75 GPCR involved in synaptic transmission using computational tools for sequence-based prediction of IDRs within a protein. We also evaluated putative ligand-binding motifs using receptor sequences. The disorder analysis indicated that neurotransmitter GPCRs have a significant amount of disorder in their N-terminus, third intracellular loop (3IL) and C-terminus. About 31%, 39% and 53% of human GPCR involved in synaptic transmission are disordered in these regions. Thirty-three percent of receptors show at least one predicted PEST motif, this being statistically greater than the estimate for the rest of human GPCRs. About 90% of the receptors had at least one putative site for dimerization in their 3IL or C-terminus. ELM instances sampled in these domains were 14-3-3, SH3, SH2 and PDZ motifs. In conclusion, the increased flexibility observed in GPCRs, added to the enrichment of linear motifs, PEST and heteromerization sites, may be critical for the nervous system's functional plasticity.
Collapse
Affiliation(s)
- L Tovo-Rodrigues
- Department of Genetics, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; Structural Biology Unit, Integrative Neuroscience Branch, NIDA IRP, NIH, MD, United States
| | - A Roux
- Structural Biology Unit, Integrative Neuroscience Branch, NIDA IRP, NIH, MD, United States
| | - M H Hutz
- Department of Genetics, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - L A Rohde
- Child and Adolescent Psychiatric Division, Department of Psychiatry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - A S Woods
- Structural Biology Unit, Integrative Neuroscience Branch, NIDA IRP, NIH, MD, United States.
| |
Collapse
|
49
|
Zakrys L, Ward RJ, Pediani JD, Godin AG, Graham GJ, Milligan G. Roundabout 1 exists predominantly as a basal dimeric complex and this is unaffected by binding of the ligand Slit2. Biochem J 2014; 461:61-73. [PMID: 24673457 DOI: 10.1042/bj20140190] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Robo (Roundabout) receptors and their Slit polypeptide ligands are known to play key roles in neuronal development and have been implicated in both angiogenesis and cancer. Like the other family members, Robo1 is a large single transmembrane domain polypeptide containing a series of well-defined extracellular elements. However, the intracellular domain lacks structural definition and little is known about the quaternary structure of Robo receptors or how binding of a Slit might affect this. To address these questions combinations of both autofluorescent protein-based FRET imaging and time-resolved FRET were employed. Both approaches identified oligomeric organization of Robo1 that did not require the presence of the intracellular domain. SpIDA (spatial intensity distribution analysis) of eGFP-tagged forms of Robo1 indicated that for a C-terminally deleted version approximately two-thirds of the receptor was present as a dimer and one-third as a monomer. By contrast, full-length Robo1 was present almost exclusively as a dimer. In each case this was unaffected by the addition of Slit2, although parallel studies demonstrated the biological activity of Slit2 and its interaction with Robo1. Deletion of both the immunoglobulin and fibronectin type III extracellular repeats prevented dimer formation, with the immunoglobulin repeats providing the bulk of the protein-protein interaction affinity.
Collapse
Affiliation(s)
| | - Richard J Ward
- *Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| | - John D Pediani
- *Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| | - Antoine G Godin
- ‡Laboratoire Photonique, Numérique et Nanosciences (LP2N) Institut d'Optique Graduate School, CNRS and Université Bordeaux, 351 cours de la libération, 33405 Talence Cedex, France
| | - Gerard J Graham
- †Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| | - Graeme Milligan
- *Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| |
Collapse
|
50
|
Heterodimerization of mouse orexin type 2 receptor variants and the effects on signal transduction. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:652-63. [PMID: 24368186 DOI: 10.1016/j.bbamcr.2013.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 12/09/2013] [Accepted: 12/13/2013] [Indexed: 02/03/2023]
Abstract
Orexin-A and Orexin-B play important roles in many physiological processes in which Orexins orchestrate diverse downstream effects via two G-protein coupled receptors: Orexin1R and Orexin2R. Two alternative C-terminus splice variants of the mouse Orexin receptors mOX2alphaR and mOX2betaR have recently been identified. This study explored the possibility of heterodimerization between mOX2alphaR and mOX2betaR, and investigated novel signal transduction characteristics after stimulation. The dimerization of mOX2alphaR and mOX2betaR was confirmed by BRET and co-immunoprecipitation assays. Meanwhile, in HEK293 cells, co-expression of mOX2alphaR and mOX2betaR resulted in a strengthened increase in activation of ERK1/2, with maximal activation at 5 min and 100 nM. Furthermore, heterodimerization also elicits stronger intracellular Ca2+ elevation after Orexin(s) stimulation, followed by a slower decline in intracellular Ca2+ to a steady endpoint Protein Kinase C Inhibitor significantly inhibited these downstream effects. In addition, the cAMP response element reporter activities were significantly reduced, whereas the serum response element luciferase and the T-lymphocyte activation of nuclear factor-responsive element reporter activity were significantly up-regulated after Orexin(s) stimulation. Besides, Orexin-A/-B induced a significantly higher rate of HEK293 cell proliferation in cells co-expressing mOX2alphaR/mOX2betaR compared to the control group. Taken together, we provide conclusive evidence that mOX2alphaR can form a functional heterodimer with mOX2betaR and this leads to increased PKC and decreased protein kinase A activity by ERK signal pathway leading to a significant increase in cell proliferation. The nature of this signaling pathway has significant implications for the role of Orexin in the regulation of physiological processes including the homeostasis of feeding.
Collapse
|