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Zhai M, Huang J, Yang S, Li N, Zeng J, Zheng Y, Sun W, Wu B. Transcriptomic analysis of differentially alternative splicing patterns in mice with inflammatory and neuropathic pain. Mol Pain 2024; 20:17448069241249455. [PMID: 38597175 PMCID: PMC11084985 DOI: 10.1177/17448069241249455] [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: 12/11/2023] [Revised: 03/12/2024] [Accepted: 04/01/2024] [Indexed: 04/11/2024] Open
Abstract
Although the molecular mechanisms of chronic pain have been extensively studied, a global picture of alternatively spliced genes and events in the peripheral and central nervous systems of chronic pain is poorly understood. The current study analyzed the changing pattern of alternative splicing (AS) in mouse brain, dorsal root ganglion, and spinal cord tissue under inflammatory and neuropathic pain. In total, we identified 6495 differentially alternatively spliced (DAS) genes. The molecular functions of shared DAS genes between these two models are mainly enriched in calcium signaling pathways, synapse organization, axon regeneration, and neurodegeneration disease. Additionally, we identified 509 DAS in differentially expressed genes (DEGs) shared by these two models, accounting for a small proportion of total DEGs. Our findings supported the hypothesis that the AS has an independent regulation pattern different from transcriptional regulation. Taken together, these findings indicate that AS is one of the important molecular mechanisms of chronic pain in mammals. This study presents a global description of AS profile changes in the full path of neuropathic and inflammatory pain models, providing new insights into the underlying mechanisms of chronic pain and guiding genomic clinical diagnosis methods and rational medication.
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Affiliation(s)
- Mingzhu Zhai
- Southern University of Science and Technology Yantian Hospital, Shenzhen, China
- Benqing Laboratory, Shenzhen Guangming District People’s Hospital, Shenzhen, China
| | - Jiabin Huang
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Shaomin Yang
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Na Li
- Southern University of Science and Technology Yantian Hospital, Shenzhen, China
| | - Jun Zeng
- Center for Medical Experiments (CME), Shenzhen Guangming District People’s Hospital, Shenzhen, China
| | - Yi Zheng
- Center for Medical Experiments (CME), Shenzhen Guangming District People’s Hospital, Shenzhen, China
| | - Wuping Sun
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Shenzhen Nanshan People’s Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Benqing Wu
- Benqing Laboratory, Shenzhen Guangming District People’s Hospital, Shenzhen, China
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2
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Varga B, Streicher JM, Majumdar S. Strategies towards safer opioid analgesics-A review of old and upcoming targets. Br J Pharmacol 2023; 180:975-993. [PMID: 34826881 PMCID: PMC9133275 DOI: 10.1111/bph.15760] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 10/08/2021] [Accepted: 11/05/2021] [Indexed: 11/30/2022] Open
Abstract
Opioids continue to be of use for the treatment of pain. Most clinically used analgesics target the μ opioid receptor whose activation results in adverse effects like respiratory depression, addiction and abuse liability. Various approaches have been used by the field to separate receptor-mediated analgesic actions from adverse effects. These include biased agonism, opioids targeting multiple receptors, allosteric modulators, heteromers and splice variants of the μ receptor. This review will focus on the current status of the field and some upcoming targets of interest that may lead to a safer next generation of analgesics. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.
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Affiliation(s)
- Balazs Varga
- Center for Clinical Pharmacology, University of Health Sciences and Pharmacy in St Louis and Washington University School of Medicine, St Louis, MO, USA
| | - John M. Streicher
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Susruta Majumdar
- Center for Clinical Pharmacology, University of Health Sciences and Pharmacy in St Louis and Washington University School of Medicine, St Louis, MO, USA
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3
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Rahman SN, McNaught-Flores DA, Huppelschoten Y, da Costa Pereira D, Christopoulos A, Leurs R, Langmead CJ. Structural and Molecular Determinants for Isoform Bias at Human Histamine H 3 Receptor Isoforms. ACS Chem Neurosci 2023; 14:645-656. [PMID: 36702158 DOI: 10.1021/acschemneuro.2c00425] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The human histamine H3 receptor (hH3R) is predominantly expressed in the CNS, where it regulates the synthesis and release of histamine and other neurotransmitters. Due to its neuromodulatory role, the hH3R has been associated with various CNS disorders, including Alzheimer's and Parkinson's disease. Markedly, the hH3R gene undergoes extensive splicing, resulting in 20 isoforms, of which 7TM isoforms exhibit variations in the intracellular loop 3 (IL3) and/or C-terminal tail. Particularly, hH3R isoforms that display variations in IL3 (e.g., hH3R-365) are shown to differentially signal via Gαi-dependent pathways upon binding of biased agonists (e.g., immepip, proxifan, imetit). Nevertheless, the mechanisms underlying biased agonism at hH3R isoforms remain unknown. Using a structure-function relationship study with a broad range of H3R agonists, we thereby explored determinants underlying isoform bias at hH3R isoforms that exhibit variations in IL3 (i.e., hH3R-445, -415, -365, and -329) in a Gαi-dependent pathway (cAMP inhibition). Hence, we systematically characterized hH3R isoforms on isoform bias by comparing various ligand properties (i.e., structural and molecular) to the degree of isoform bias. Importantly, our study provides novel insights into the structural and molecular basis of receptor isoform bias, highlighting the importance to study GPCRs with multiple isoforms to better tailor drugs.
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Affiliation(s)
- Sabrina N Rahman
- Amsterdam Institute for Molecular Life Sciences, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZAmsterdam, The Netherlands.,Drug Discovery Biology and Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Melbourne, 3052VIC, Australia
| | - Daniel A McNaught-Flores
- Amsterdam Institute for Molecular Life Sciences, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZAmsterdam, The Netherlands
| | - Yara Huppelschoten
- Amsterdam Institute for Molecular Life Sciences, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZAmsterdam, The Netherlands
| | - Daniel da Costa Pereira
- Amsterdam Institute for Molecular Life Sciences, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZAmsterdam, The Netherlands
| | - Arthur Christopoulos
- Drug Discovery Biology and Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Melbourne, 3052VIC, Australia
| | - Rob Leurs
- Amsterdam Institute for Molecular Life Sciences, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZAmsterdam, The Netherlands
| | - Christopher J Langmead
- Drug Discovery Biology and Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Melbourne, 3052VIC, Australia
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Exploring Pharmacological Functions of Alternatively Spliced Variants of the Mu Opioid Receptor Gene, Oprm1, via Gene-Targeted Animal Models. Int J Mol Sci 2022; 23:ijms23063010. [PMID: 35328429 PMCID: PMC8950057 DOI: 10.3390/ijms23063010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/19/2022] [Accepted: 02/21/2022] [Indexed: 02/01/2023] Open
Abstract
The mu opioid receptor has a distinct place in the opioid receptor family, since it mediates the actions of most opioids used clinically (e.g., morphine and fentanyl), as well as drugs of abuse (e.g., heroin). The single-copy mu opioid receptor gene, OPRM1, goes through extensive alternative pre-mRNA splicing to generate numerous splice variants that are conserved from rodents to humans. These OPRM1 splice variants can be classified into three structurally distinct types: (1) full-length 7 transmembrane (TM) carboxyl (C)-terminal variants; (2) truncated 6TM variants; and (3) single TM variants. Distinct pharmacological functions of these splice variants have been demonstrated by both in vitro and in vivo studies, particularly by using several unique gene-targeted mouse models. These studies provide new insights into our understanding of the complex actions of mu opioids with regard to OPRM1 alternative splicing. This review provides an overview of the studies that used these gene-targeted mouse models for exploring the functional importance of Oprm1 splice variants.
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Chakraborty S, Uprety R, Daibani AE, Rouzic VL, Hunkele A, Appourchaux K, Eans SO, Nuthikattu N, Jilakara R, Thammavong L, Pasternak GW, Pan YX, McLaughlin JP, Che T, Majumdar S. Kratom Alkaloids as Probes for Opioid Receptor Function: Pharmacological Characterization of Minor Indole and Oxindole Alkaloids from Kratom. ACS Chem Neurosci 2021; 12:2661-2678. [PMID: 34213886 PMCID: PMC8328003 DOI: 10.1021/acschemneuro.1c00149] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Dry leaves of kratom (mitragyna speciosa) are anecdotally consumed as pain relievers and antidotes against opioid withdrawal and alcohol use disorders. There are at least 54 alkaloids in kratom; however, investigations to date have focused around mitragynine, 7-hydroxy mitragynine (7OH), and mitragynine pseudoindoxyl (MP). Herein, we probe a few minor indole and oxindole based alkaloids, reporting the receptor affinity, G-protein activity, and βarrestin-2 signaling of corynantheidine, corynoxine, corynoxine B, mitraciliatine, and isopaynantheine at mouse and human opioid receptors. We identify corynantheidine as a mu opioid receptor (MOR) partial agonist, whereas its oxindole derivative corynoxine was an MOR full agonist. Similarly, another alkaloid mitraciliatine was found to be an MOR partial agonist, while isopaynantheine was a KOR agonist which showed reduced βarrestin-2 recruitment. Corynantheidine, corynoxine, and mitraciliatine showed MOR dependent antinociception in mice, but mitraciliatine and corynoxine displayed attenuated respiratory depression and hyperlocomotion compared to the prototypic MOR agonist morphine in vivo when administered supraspinally. Isopaynantheine on the other hand was identified as the first kratom derived KOR agonist in vivo. While these minor alkaloids are unlikely to play the majority role in the biological actions of kratom, they represent excellent starting points for further diversification as well as distinct efficacy and signaling profiles with which to probe opioid actions in vivo.
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Affiliation(s)
- Soumen Chakraborty
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Rajendra Uprety
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Amal E Daibani
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Valerie L Rouzic
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Amanda Hunkele
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Kevin Appourchaux
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Shainnel O Eans
- Department of Pharmacodynamics, University of Florida, Gainesville, Florida 032610, United States
| | - Nitin Nuthikattu
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Rahul Jilakara
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Lisa Thammavong
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Gavril W Pasternak
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Ying-Xian Pan
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, New Jersey 07103, United States
| | - Jay P McLaughlin
- Department of Pharmacodynamics, University of Florida, Gainesville, Florida 032610, United States
| | - Tao Che
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Susruta Majumdar
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy at St. Louis and Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
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6
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Rossi GC, Bodnar RJ. Interactive Mechanisms of Supraspinal Sites of Opioid Analgesic Action: A Festschrift to Dr. Gavril W. Pasternak. Cell Mol Neurobiol 2021; 41:863-897. [PMID: 32970288 DOI: 10.1007/s10571-020-00961-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/03/2020] [Indexed: 12/30/2022]
Abstract
Almost a half century of research has elaborated the discoveries of the central mechanisms governing the analgesic responses of opiates, including their receptors, endogenous peptides, genes and their putative spinal and supraspinal sites of action. One of the central tenets of "gate-control theories of pain" was the activation of descending supraspinal sites by opiate drugs and opioid peptides thereby controlling further noxious input. This review in the Special Issue dedicated to the research of Dr. Gavril Pasternak indicates his contributions to the understanding of supraspinal mediation of opioid analgesic action within the context of the large body of work over this period. This review will examine (a) the relevant supraspinal sites mediating opioid analgesia, (b) the opioid receptor subtypes and opioid peptides involved, (c) supraspinal site analgesic interactions and their underlying neurophysiology, (d) molecular (particularly AS) tools identifying opioid receptor actions, and (e) relevant physiological variables affecting site-specific opioid analgesia. This review will build on classic initial studies, specify the contributions that Gavril Pasternak and his colleagues did in this specific area, and follow through with studies up to the present.
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Affiliation(s)
- Grace C Rossi
- Department of Psychology, C.W. Post College, Long Island University, Post Campus, Brookville, NY, USA.
| | - Richard J Bodnar
- Department of Psychology, Queens College of the City University of New York, Flushing, NY, USA
- CUNY Neuroscience Collaborative, Graduate Center, CUNY, New York, NY, USA
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7
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Muralidharan A, Samoshkin A, Convertino M, Piltonen MH, Gris P, Wang J, Jiang C, Klares R, Linton A, Ji RR, Maixner W, Dokholyan NV, Mogil JS, Diatchenko L. Identification and characterization of novel candidate compounds targeting 6- and 7-transmembrane μ-opioid receptor isoforms. Br J Pharmacol 2021; 178:2709-2726. [PMID: 33782947 PMCID: PMC10697213 DOI: 10.1111/bph.15463] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 03/15/2021] [Accepted: 03/18/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE The μ-opioid receptor (μ receptor) is the primary target for opioid analgesics. The 7-transmembrane (TM) and 6TM μ receptor isoforms mediate inhibitory and excitatory cellular effects. Here, we developed compounds selective for 6TM- or 7TM-μ receptors to further our understanding of the pharmacodynamic properties of μ receptors. EXPERIMENTAL APPROACH We performed virtual screening of the ZINC Drug Now library of compounds using in silico 7TM- and 6TM-μ receptor structural models and identified potential compounds that are selective for 6TM- and/or 7TM-μ receptors. Subsequently, we characterized the most promising candidate compounds in functional in vitro studies using Be2C neuroblastoma transfected cells, behavioural in vivo pain assays using various knockout mice and in ex vivo electrophysiology studies. KEY RESULTS Our virtual screen identified 30 potential candidate compounds. Subsequent functional in vitro cellular assays shortlisted four compounds (#5, 10, 11 and 25) that demonstrated 6TM- or 7TM-μ receptor-dependent NO release. In in vivo pain assays these compounds also produced dose-dependent hyperalgesic responses. Studies using mice that lack specific opioid receptors further established the μ receptor-dependent nature of identified novel ligands. Ex vivo electrophysiological studies on spontaneous excitatory postsynaptic currents in isolated spinal cord slices also validated the hyperalgesic properties of the most potent 6TM- (#10) and 7TM-μ receptor (#5) ligands. CONCLUSION AND IMPLICATIONS Our novel compounds represent a new class of ligands for μ receptors and will serve as valuable research tools to facilitate the development of opioids with significant analgesic efficacy and fewer side-effects.
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Affiliation(s)
- Arjun Muralidharan
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Department of Psychology, McGill University, Montreal, Quebec, Canada
| | - Alexander Samoshkin
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Marino Convertino
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Marjo Hannele Piltonen
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Pavel Gris
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Jian Wang
- Department of Pharmacology, and Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Changyu Jiang
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Richard Klares
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Alexander Linton
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Ru-Rong Ji
- Center for Translational Pain Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
| | - William Maixner
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Nikolay V. Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, USA
- Department of Pharmacology, and Biochemistry & Molecular Biology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Jeffrey S. Mogil
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Department of Psychology, McGill University, Montreal, Quebec, Canada
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
| | - Luda Diatchenko
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
- Department of Anesthesia, McGill University, Montreal, Quebec, Canada
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
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Webster L, Schmidt WK. Dilemma of Addiction and Respiratory Depression in the Treatment of Pain: A Prototypical Endomorphin as a New Approach. PAIN MEDICINE 2021; 21:992-1004. [PMID: 31165885 DOI: 10.1093/pm/pnz122] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Although mu-opioid receptor agonists have been the mainstay of analgesic regimens for moderate to severe pain, they are associated with serious side effects, risks, and limitations. We evaluate the most serious risks associated with conventional opioids and compare these with the pharmacology of CYT-1010, a prototypical endomorphin and mu-opioid receptor agonist. RESULTS Addiction and respiratory depression are serious risks of traditional mu-opioid analgesics. Mitigation strategies have been inadequate at addressing the opioid crisis and may interfere with the effective treatment of pain. Improved understanding of mu-opioid receptor biology and the discovery in 1997 of an additional and unique family of endogenous opioid peptides (endomorphins) have provided a pathway for dissociating analgesia from opioid-related adverse events and developing new classes of mu-opioid receptor agonists that use biased signaling and/or target novel sites to produce analgesia with reduced side effect liability. Endomorphin-1 and -2 are endogenous opioid peptides highly selective for mu-opioid receptors that exhibit potent analgesia with reduced side effects. CYT-1010 is a cyclized, D-lysine-containing analog of endomorphin-1 with a novel mechanism of action targeting traditional mu- and exon 11/truncated mu-opioid receptor 6TM variants. CYT-1010 preclinical data have demonstrated reduced abuse potential and analgesic potency exceeding that of morphine. In an initial phase 1 clinical study, CYT-1010 demonstrated significant analgesia vs baseline and no respiratory depression at the dose levels tested. CONCLUSIONS CYT-1010 and other novel mu-opioid receptor agonists in clinical development are promising alternatives to conventional opioids that may offer the possibility of safer treatment of moderate to severe pain.
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Abstract
The management of pain, particularly chronic pain, is still an area of medical need. In this context, opioids remain a gold standard for the treatment of pain. However, significant side effects, mainly of central origin, limit their clinical use. Here, we review recent progress to improve the therapeutic and safety profiles of opioids for pain management. Characterization of peripheral opioid-mediated pain mechanisms have been a key component of this process. Several studies identified peripheral µ, δ, and κ opioid receptors (MOR, DOR, and KOR, respectively) and nociceptin/orphanin FQ (NOP) receptors as significant players of opioid-mediated antinociception, able to achieve clinically significant effects independently of any central action. Following this, particularly from a medicinal chemistry point of view, main efforts have been directed towards the peripheralization of opioid receptor agonists with the objective of optimizing receptor activity and minimizing central exposure and the associated undesired effects. These activities have allowed the characterization of a great variety of compounds and investigational drugs that show low central nervous system (CNS) penetration (and therefore a reduced side effect profile) yet maintaining the desired opioid-related peripheral antinociceptive activity. These include highly hydrophilic/amphiphilic and massive molecules unable to easily cross lipid membranes, substrates of glycoprotein P (a extrusion pump that avoids CNS penetration), nanocarriers that release the analgesic agent at the site of inflammation and pain, and pH-sensitive opioid agonists that selectively activate at those sites (and represent a new pharmacodynamic paradigm). Hopefully, patients with pain will benefit soon from the incorporation of these new entities.
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Mizoguchi H, Fujii H. Exploring μ-Opioid Receptor Splice Variants as a Specific Molecular Target for New Analgesics. Curr Top Med Chem 2020; 20:2866-2877. [PMID: 32962616 DOI: 10.2174/1568026620666200922113430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/29/2020] [Accepted: 09/03/2020] [Indexed: 11/22/2022]
Abstract
Since a μ-opioid receptor gene containing multiple exons has been identified, the variety of splice variants for μ-opioid receptors have been reported in various species. Amidino-TAPA and IBNtxA have been discovered as new analgesics with different pharmacological profiles from morphine. These new analgesics show a very potent analgesic effect but do not have dependence liability. Interestingly, these analgesics show the selectivity to the morphine-insensitive μ-opioid receptor splice variants. The splice variants, sensitive to these new analgesics but insensitive to morphine, may be a better molecular target to develop the analgesics without side effects.
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Affiliation(s)
- Hirokazu Mizoguchi
- Department of Physiology and Anatomy, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Hideaki Fujii
- Laboratory of Medicinal Chemistry and Medical Research Laboratories, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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11
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Pacifico S, Albanese V, Illuminati D, Fantinati A, Marzola E, Ferrari F, Neto JA, Sturaro C, Ruzza C, Calò G, Preti D, Guerrini R. Tetrabranched Hetero-Conjugated Peptides as Bifunctional Agonists of the NOP and Mu Opioid Receptors. Bioconjug Chem 2019; 30:2444-2451. [DOI: 10.1021/acs.bioconjchem.9b00519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Salvatore Pacifico
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
| | - Valentina Albanese
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
| | - Davide Illuminati
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
| | - Anna Fantinati
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
| | - Erika Marzola
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
| | - Federica Ferrari
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara Via Fossato di Mortara 17/19, Ferrara 44121, Italy
| | - Joaquim Azevedo Neto
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara Via Fossato di Mortara 17/19, Ferrara 44121, Italy
| | - Chiara Sturaro
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara Via Fossato di Mortara 17/19, Ferrara 44121, Italy
| | - Chiara Ruzza
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara Via Fossato di Mortara 17/19, Ferrara 44121, Italy
| | - Girolamo Calò
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara Via Fossato di Mortara 17/19, Ferrara 44121, Italy
| | - Delia Preti
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
| | - Remo Guerrini
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Luigi Borsari 46, Ferrara 44121, Italy
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12
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Abstract
This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and CUNY Neuroscience Collaborative, Queens College, City University of New York, Flushing, NY 11367, United States.
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