1
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Eliasof A, Liu-Chen LY, Li Y. Peptide-derived ligands for the discovery of safer opioid analgesics. Drug Discov Today 2024; 29:103950. [PMID: 38514040 PMCID: PMC11127667 DOI: 10.1016/j.drudis.2024.103950] [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: 12/08/2023] [Revised: 03/03/2024] [Accepted: 03/13/2024] [Indexed: 03/23/2024]
Abstract
Drugs targeting the μ-opioid receptor (MOR) remain the most efficacious analgesics for the treatment of pain, but activation of MOR with current opioid analgesics also produces harmful side effects, notably physical dependence, addiction, and respiratory depression. Opioid peptides have been accepted as promising candidates for the development of safer and more efficacious analgesics. To develop peptide-based opioid analgesics, strategies such as modification of endogenous opioid peptides, development of multifunctional opioid peptides, G protein-biased opioid peptides, and peripherally restricted opioid peptides have been reported. This review seeks to provide an overview of the opioid peptides that produce potent antinociception with much reduced side effects in animal models and highlight the potential advantages of peptides as safer opioid analgesics.
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Affiliation(s)
- Abbe Eliasof
- College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Lee-Yuan Liu-Chen
- Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Yangmei Li
- College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA.
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2
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Zhang YZ, Wang SY, Guo XC, Liu XH, Wang XF, Wang MM, Qiu TT, Han FT, Zhang Y, Wang CL. Novel endomorphin analogues CEMR-1 and CEMR-2 produce potent and long-lasting antinociception with a favourable side effect profile at the spinal level. Br J Pharmacol 2024; 181:1268-1289. [PMID: 37990825 DOI: 10.1111/bph.16287] [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: 12/22/2022] [Revised: 10/09/2023] [Accepted: 11/08/2023] [Indexed: 11/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Endomorphins have shown great promise as pharmaceutics for the treatment of pain. We have previously confirmed that novel endomorphin analogues CEMR-1 and CEMR-2 behaved as potent μ agonists and displayed potent antinociceptive activities at the supraspinal and peripheral levels. The present study was undertaken to evaluate the antinociceptive properties of CEMR-1 and CEMR-2 following intrathecal (i.t.) administration. Furthermore, their antinociceptive tolerance and opioid-like side effects were also determined. EXPERIMENTAL APPROACH The spinal antinociceptive effects of CEMR-1 and CEMR-2 were determined in a series of pain models, including acute radiant heat paw withdrawal test, spared nerve injury-induced neuropathic pain, complete Freund's adjuvant-induced inflammatory pain, visceral pain and formalin pain. Antinociceptive tolerance was evaluated in radiant heat paw withdrawal test. KEY RESULTS Spinal administration of CEMR-1 and CEMR-2 produced potent and prolonged antinociceptive effects in acute pain. CEMR-1 and CEMR-2 may produce their antinociception through distinct μ receptor subtypes. These two analogues also exhibited significant analgesic activities in neuropathic, inflammatory, visceral and formalin pain at the spinal level. It is noteworthy that CEMR-1 showed non-tolerance-forming analgesic properties, while CEMR-2 exhibited substantially reduced antinociceptive tolerance. Furthermore, both analogues displayed no or reduced side effects on conditioned place preference response, physical dependence, locomotor activity and gastrointestinal transit. CONCLUSIONS AND IMPLICATIONS The present investigation demonstrated that CEMR-1 and CEMR-2 displayed potent and long-lasting antinociception with a favourable side effect profile at the spinal level. Therefore, CEMR-1 and CEMR-2 might serve as promising analgesic compounds with minimal opioid-like side effects.
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Affiliation(s)
- Yu-Zhe Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Si-Yu Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Xue-Ci Guo
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Xiao-Han Liu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | | | - Meng-Meng Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Ting-Ting Qiu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Feng-Tong Han
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Yao Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Chang-Lin Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University, Guilin, China
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ten Barge JA, Baudat M, Meesters NJ, Kindt A, Joosten EA, Reiss IK, Simons SH, van den Bosch GE. Biomarkers for assessing pain and pain relief in the neonatal intensive care unit. FRONTIERS IN PAIN RESEARCH 2024; 5:1343551. [PMID: 38426011 PMCID: PMC10902154 DOI: 10.3389/fpain.2024.1343551] [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: 11/23/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Newborns admitted to the neonatal intensive care unit (NICU) regularly undergo painful procedures and may face various painful conditions such as postoperative pain. Optimal management of pain in these vulnerable preterm and term born neonates is crucial to ensure their comfort and prevent negative consequences of neonatal pain. This entails accurate and timely identification of pain, non-pharmacological pain treatment and if needed administration of analgesic therapy, evaluation of treatment effectiveness, and monitoring of adverse effects. Despite the widely recognized importance of pain management, pain assessment in neonates has thus far proven to be a challenge. As self-report, the gold standard for pain assessment, is not possible in neonates, other methods are needed. Several observational pain scales have been developed, but these often rely on snapshot and largely subjective observations and may fail to capture pain in certain conditions. Incorporation of biomarkers alongside observational pain scores holds promise in enhancing pain assessment and, by extension, optimizing pain treatment and neonatal outcomes. This review explores the possibilities of integrating biomarkers in pain assessment in the NICU.
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Affiliation(s)
- Judith A. ten Barge
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Erasmus MC—Sophia Children’s Hospital, Rotterdam, Netherlands
| | - Mathilde Baudat
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, Netherlands
- Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Naomi J. Meesters
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Erasmus MC—Sophia Children’s Hospital, Rotterdam, Netherlands
| | - Alida Kindt
- Metabolomics and Analytics Center, Leiden Academic Centre for Drug Research, Leiden University, Leiden, Netherlands
| | - Elbert A. Joosten
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, Netherlands
- Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Irwin K.M. Reiss
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Erasmus MC—Sophia Children’s Hospital, Rotterdam, Netherlands
| | - Sinno H.P. Simons
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Erasmus MC—Sophia Children’s Hospital, Rotterdam, Netherlands
| | - Gerbrich E. van den Bosch
- Department of Neonatal and Pediatric Intensive Care, Division of Neonatology, Erasmus MC—Sophia Children’s Hospital, Rotterdam, Netherlands
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4
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Johnson SM, Gumnit MG, Johnson SM, Baker TL, Watters JJ. Disinhibition does not play a role in endomorphin-2-induced changes in inspiratory motoneuron output produced by in vitro neonatal rat preparations. Respir Physiol Neurobiol 2024; 320:104186. [PMID: 37944625 PMCID: PMC10843717 DOI: 10.1016/j.resp.2023.104186] [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: 08/09/2023] [Revised: 10/23/2023] [Accepted: 11/04/2023] [Indexed: 11/12/2023]
Abstract
Low level activation of mu-opioid receptors (MORs) in neonatal rat brainstem-spinal cord preparations increases inspiratory burst amplitude recorded on cervical spinal roots. We tested whether: (1) MOR activation with an endogenous ligand, such as endomorphin-2, increases inspiratory burst amplitude, (2) disinhibition of GABAergic or glycinergic inhibitory synaptic transmission is involved, and (3) inflammation alters endomorphin-2 effects. Using neonatal rat (P0-P3) brainstem-spinal cord preparations, bath-applied endomorphin-2 (10-200 nM) increased inspiratory burst amplitude and decreased burst frequency. Blockade of GABAA receptors (picrotoxin), glycine receptors (strychnine), or both (picrotoxin and strychnine) did not abolish endomorphin-2-induced effects. In preparations isolated from neonatal rats injected 3 h previously with lipopolysaccharide (LPS, 0.1 mg/kg), endomorphin-2 continued to decrease burst frequency but abolished the burst amplitude increase. Collectively, these data indicate that disinhibition of inhibitory synaptic transmission is unlikely to play a role in endomorphin-2-induced changes in inspiratory motor output, and that different mechanisms underlie the endomorphin-2-induced increases in inspiratory burst amplitude and decreases in burst frequency.
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Affiliation(s)
- Stephen M Johnson
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Maia G Gumnit
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Sarah M Johnson
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Tracy L Baker
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Jyoti J Watters
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
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5
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A Novel Multi-Target Mu/Delta Opioid Receptor Agonist, HAGD, Produced Potent Peripheral Antinociception with Limited Side Effects in Mice and Minimal Impact on Human Sperm Motility In Vitro. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28010427. [PMID: 36615612 PMCID: PMC9824695 DOI: 10.3390/molecules28010427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/23/2022] [Accepted: 12/28/2022] [Indexed: 01/06/2023]
Abstract
Pain is a common clinical symptom among patients. Although various opioid analgesics have been developed, their side effects hinder their application. This study aimed to develop a novel opioid analgesic, HAGD (H-Tyr-D-AIa-GIy-Phe-NH2), with limited side effects. In vivo studies on mouse models as well as in vitro studies on Chinese hamster ovary (CHO) cells expressing human mu, delta, or kappa opioid receptors (CHOhMOP, CHOhDOP, and CHOhKOP, respectively) and human sperm were conducted. Compared with subcutaneous morphine (10 mg/kg), subcutaneous HAGD (10 mg/kg) produced equipotent or even greater antinociception with a prolonged duration by activating mu/delta opioid receptors in preclinical mouse pain models. The analgesic tolerance, rewarding effects (i.e., conditioned place preference and acute hyperlocomotion), and gastrointestinal transit inhibition of HAGD were significantly reduced compared with those of morphine. Both HAGD and morphine exhibited a withdrawal response and had no impacts on motor coordination. In CHOhMOP and CHOhDOP, HAGD showed specific and efficient intracellular Ca2+ stimulation. HAGD had minimal impact on human sperm motility in vitro, whereas 1 × 10-7 and 1 × 10-8 mol/L of morphine significantly declined sperm motility at 3.5 h. Overall, HAGD may serve as a promising antinociceptive compound.
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6
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Piekielna-Ciesielska J, Malfacini D, Djeujo FM, Marconato C, Wtorek K, Calo' G, Janecka A. Functional selectivity of EM-2 analogs at the mu-opioid receptor. Front Pharmacol 2023; 14:1133961. [PMID: 36909169 PMCID: PMC9998502 DOI: 10.3389/fphar.2023.1133961] [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: 12/29/2022] [Accepted: 02/13/2023] [Indexed: 02/26/2023] Open
Abstract
The mu opioid receptor agonists are the most efficacious pain controlling agents but their use is accompanied by severe side effects. More recent developments indicate that some ligands can differentially activate receptor downstream pathways, possibly allowing for dissociation of analgesia mediated through the G protein from the opioid-related side effects mediated by β-arrestin pathway. In an effort to identify such biased ligands, here we present a series of thirteen endomorphin-2 (EM-2) analogs with modifications in positions 1, 2, and/or 3. All obtained analogs behaved as mu receptor selective agonists in calcium mobilization assay carried out on cells expressing opioid receptors and chimeric G proteins. A Bioluminescence Resonance Energy Transfer (BRET) approach was employed to determine the ability of analogs to promote the interaction of the mu opioid receptor with G protein or β-arrestin 2. Nearly half of the developed analogs showed strong bias towards G protein, in addition four compounds were nearly inactive towards β-arrestin 2 recruitment while blocking the propensity of EM-2 to evoke mu-β-arrestin 2 interaction. The data presented here contribute to our understanding of EM-2 interaction with the mu opioid receptor and of the transductional propagation of the signal. In addition, the generation of potent and selective mu receptor agonists strongly biased towards G protein provides the scientific community with novel tools to investigate the in vivo consequences of biased agonism at this receptor.
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Affiliation(s)
| | - Davide Malfacini
- Department of Pharmaceutical and Pharmacological Sciences, Section of Pharmacology, University of Padova, Padova, Italy
| | - Francine Medjiofack Djeujo
- Department of Pharmaceutical and Pharmacological Sciences, Section of Pharmacology, University of Padova, Padova, Italy
| | - Chantal Marconato
- Department of Pharmaceutical and Pharmacological Sciences, Section of Pharmacology, University of Padova, Padova, Italy
| | - Karol Wtorek
- Department of Biomolecular Chemistry, Medical University of Lodz, Lodz, Poland
| | - Girolamo Calo'
- Department of Pharmaceutical and Pharmacological Sciences, Section of Pharmacology, University of Padova, Padova, Italy
| | - Anna Janecka
- Department of Biomolecular Chemistry, Medical University of Lodz, Lodz, Poland
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7
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Lee YS. Peptidomimetics and Their Applications for Opioid Peptide Drug Discovery. Biomolecules 2022; 12:biom12091241. [PMID: 36139079 PMCID: PMC9496382 DOI: 10.3390/biom12091241] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Despite various advantages, opioid peptides have been limited in their therapeutic uses due to the main drawbacks in metabolic stability, blood-brain barrier permeability, and bioavailability. Therefore, extensive studies have focused on overcoming the problems and optimizing the therapeutic potential. Currently, numerous peptide-based drugs are being marketed thanks to new synthetic strategies for optimizing metabolism and alternative routes of administration. This tutorial review briefly introduces the history and role of natural opioid peptides and highlights the key findings on their structure-activity relationships for the opioid receptors. It discusses details on opioid peptidomimetics applied to develop therapeutic candidates for the treatment of pain from the pharmacological and structural points of view. The main focus is the current status of various mimetic tools and the successful applications summarized in tables and figures.
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Affiliation(s)
- Yeon Sun Lee
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
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8
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Gumnit MG, Watters JJ, Baker TL, Johnson SM, Johnson SM. Mu-opioid receptor-dependent transformation of respiratory motor pattern in neonates in vitro. Front Physiol 2022; 13:921466. [PMID: 35936900 PMCID: PMC9353126 DOI: 10.3389/fphys.2022.921466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/30/2022] [Indexed: 11/29/2022] Open
Abstract
Endogenous opioid peptides activating mu-opioid receptors (MORs) are part of an intricate neuromodulatory system that coordinates and optimizes respiratory motor output to maintain blood-gas homeostasis. MOR activation is typically associated with respiratory depression but also has excitatory effects on breathing and respiratory neurons. We hypothesized that low level MOR activation induces excitatory effects on the respiratory motor pattern. Thus, low concentrations of an MOR agonist drug (DAMGO, 10–200 nM) were bath-applied to neonatal rat brainstem-spinal cord preparations while recording inspiratory-related motor output on cervical spinal roots (C4-C5). Bath-applied DAMGO (50–200 nM) increased inspiratory motor burst amplitude by 40–60% during (and shortly following) drug application with decreased burst frequency and minute activity. Reciprocal changes in inspiratory burst amplitude and frequency were balanced such that 20 min after DAMGO (50–200 nM) application, minute activity was unaltered compared to pre-DAMGO levels. The DAMGO-induced inspiratory burst amplitude increase did not require crossed cervical spinal pathways, was expressed on thoracic ventral spinal roots (T4-T8) and remained unaltered by riluzole pretreatment (blocks persistent sodium currents associated with gasping). Split-bath experiments showed that the inspiratory burst amplitude increase was induced only when DAMGO was bath-applied to the brainstem and not the spinal cord. Thus, MOR activation in neonates induces a respiratory burst amplitude increase via brainstem-specific mechanisms. The burst amplitude increase counteracts the expected MOR-dependent frequency depression and may represent a new mechanism by which MOR activation influences respiratory motor output.
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9
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Zhang YZ, Wang MM, Wang SY, Wang XF, Yang WJ, Zhao YN, Han FT, Zhang Y, Gu N, Wang CL. Novel Cyclic Endomorphin Analogues with Multiple Modifications and Oligoarginine Vector Exhibit Potent Antinociception with Reduced Opioid-like Side Effects. J Med Chem 2021; 64:16801-16819. [PMID: 34781680 DOI: 10.1021/acs.jmedchem.1c01631] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Endomorphins (EMs) are potent pharmaceuticals for the treatment of pain. Herein, we investigated several novel EM analogues with multiple modifications and oligoarginine conjugation. Our results showed that analogues 1-6 behaved as potent μ-opioid agonists and enhanced stability and lipophilicity. Analogues 5 and 6 administered centrally and peripherally induced significant and prolonged antinociceptive effects in acute pain. Both analogues also produced long-acting antiallodynic effects against neuropathic and inflammatory pain. Furthermore, they showed a reduced acute antinociceptive tolerance. Analogue 6 decreased the extent of chronic antinociceptive tolerance, and analogue 5 exhibited no tolerance at the supraspinal level. Particularly, they displayed nontolerance-forming antinociception at the peripheral level. In addition, analogues 5 and 6 exhibited reduced or no opioid-like side effects on gastrointestinal transit, conditioned place preference (CPP), and motor impairment. The present investigation established that multiple modifications and oligoarginine-vector conjugation of EMs would be helpful in developing novel analgesics with fewer side effects.
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Affiliation(s)
- Yu-Zhe Zhang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Meng-Meng Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Si-Yu Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Xiao-Fang Wang
- Jiangxi University of Chinese Medicine, Nanchang 330004, China
| | - Wen-Jiao Yang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Ya-Nan Zhao
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Feng-Tong Han
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Yao Zhang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Ning Gu
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Chang-Lin Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China.,Stake Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China
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10
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Zhou J, Zhao L, Wei S, Wang Y, Zhang X, Ma M, Wang K, Liu X, Wang R. Contribution of the μ opioid receptor and enkephalin to the antinociceptive actions of endomorphin-1 analogs with unnatural amino acid modifications in the spinal cord. Peptides 2021; 141:170543. [PMID: 33794284 DOI: 10.1016/j.peptides.2021.170543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/08/2021] [Accepted: 03/22/2021] [Indexed: 01/20/2023]
Abstract
Endomorphin analogs containing unnatural amino acids have demonstrated potent analgesic effects in our previous studies. In the present study, the differences in antinociception and the mechanisms thereof for analogs 1-3 administered intracerebroventricularly and intrathecally were explored. All analogs at different routes of administration produced potent analgesia compared to the parent peptide endomorphin-1. Multiple antagonists and antibodies were used to explore the mechanisms of action of these analogs, and it was inferred that analogs 1-3 stimulated the μ opioid receptor to induce antinociception. Moreover, the antibody data suggested that analog 2 may induce the release of immunoreactive [Leu5]-enkephaline and [Met5]-enkephaline to produce a secondary component of antinociception at the spinal level and analog 3 may stimulate the the release of immunoreactive [Met5]-enkephaline at the spinal level. Finally, analogs 2 and 3 produced no acute tolerance in the spinal cord. We hypothesize that the unique characteristics of the endomorphin analogs result from their capacities to stimulate the release of endogenous antinociceptive substances.
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Affiliation(s)
- Jingjing Zhou
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Long Zhao
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Shuang Wei
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Yuan Wang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China.
| | - Xianghui Zhang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Mengtao Ma
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Kairong Wang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Xin Liu
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China.
| | - Rui Wang
- Department of Pharmacology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Institute of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, 730000, PR China.
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11
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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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12
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Wojciechowski P, Kleczkowska P, Mollica A, Stefanucci A, Kaczyńska K. Vagal apnea and hypotension evoked by systemic injection of an antinociceptive analogue of endomorphin-2. Eur J Pharmacol 2020; 885:173514. [PMID: 32860810 DOI: 10.1016/j.ejphar.2020.173514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 08/03/2020] [Accepted: 08/26/2020] [Indexed: 12/17/2022]
Abstract
PK20M (Dmt-D-Lys-Phe-Phe-OH) is a novel modified endomorphin-2 (EM-2) peptide producing strong dose- and time-dependent antinociceptive activity. Yet its prototype, endogenous EM-2, has been reported to trigger respiratory and vascular effects such as apnea and hypotension. The purpose of this study was to investigate the potency of the PK20M to evoke respiratory and cardiovascular responses in comparison to endogenous endomorphins. The engagement of the vagal pathway and μ opioid receptors in mediation of these responses was investigated. The effects of intravenous injections of PK20M, EM-1, and EM-2 were studied in anaesthetized, spontaneously breathing rats. The main dose-dependent effect of all endomorphins in the intact rats was immediate apnea, blood pressure and heart rate decrease. PK20M produced apnea in at least half of the intact animals in a much smaller dose than EM-1 and EM-2. The effects of all compounds were abrogated by pre-treatment with MNLX, a peripherally acting μ receptor antagonist. Cervical vagotomy eliminated arrest of breathing in the case of each tested compound. Hypotension was reduced by vagi section only after EM-1 and EM-2 administration. Our results demonstrated that apnea and bradycardia caused by systemic injection of all endomorphins were mediated via activation of μ vagal opioid receptors. The hypotension depended on intact vagi nerves only in the case of EM-1 and EM-2, whereas PK20M decreased blood pressure via other mechanisms outside vagal innervation. Modified opioid agonist is more potent in evoking extended hypotension; at the same time, it produces an arrest of breathing less frequently than its prototype EM-2.
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Affiliation(s)
- Piotr Wojciechowski
- Department of Respiration Physiology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Patrycja Kleczkowska
- Department of Pharmacodynamics, The Centre for Preclinical Research (CBP), Medical University of Warsaw, Poland
| | - Adriano Mollica
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, 66100, Chieti, Italy
| | - Azzurra Stefanucci
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, 66100, Chieti, Italy
| | - Katarzyna Kaczyńska
- Department of Respiration Physiology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
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Zarezin DP, Nenajdenko VG. Diazocarbonyl derivatives of amino acids: unique chiral building blocks for the synthesis of biologically active compounds. RUSSIAN CHEMICAL REVIEWS 2019. [DOI: 10.1070/rcr4852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This review deals with applications of chiral α-amino diazoketones, α-amino acid derivatives, in the synthesis of various biologically active compounds. General approaches to the synthesis of chiral α-amino diazoketones, including the Arndt – Eistert reaction, acylation of trimethylsilyldiazomethanes, etc., are discussed. Due to the presence of three functional groups, these building blocks can be used to produce a wide range of organic compounds with potential physiological activity, ranging from various heterocyclic compounds to peptidomimetics. Methods for the synthesis of β-amino acid-containing peptides and depsipeptides, amino acid derivatives and heterocyclic compounds with three- to seven-membered rings are considered.
The bibliography includes 226 references.
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Zhang T, Zhang N, Zhang R, Zhao W, Chen Y, Wang Z, Xu B, Zhang M, Shi X, Zhang Q, Guo Y, Xiao J, Chen D, Fang Q. Preemptive intrathecal administration of endomorphins relieves inflammatory pain in male mice via inhibition of p38 MAPK signaling and regulation of inflammatory cytokines. J Neuroinflammation 2018; 15:320. [PMID: 30442166 PMCID: PMC6236886 DOI: 10.1186/s12974-018-1358-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/02/2018] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Preemptive administration of analgesic drugs reduces perceived pain and prolongs duration of antinociceptive action. Whereas several lines of evidence suggest that endomorphins, the endogenous mu-opioid agonists, attenuate acute and chronic pain at the spinal level, their preemptive analgesic effects remain to be determined. In this study, we evaluated the anti-allodynic activities of endomorphins and explored their mechanisms of action after preemptive administration in a mouse model of inflammatory pain. METHODS The anti-allodynic activities of preemptive intrathecal administration of endomorphin-1 and endomorphin-2 were investigated in complete Freund's adjuvant (CFA)-induced inflammatory pain model and paw incision-induced postoperative pain model. The modulating effects of endomorphins on the expression of p38 mitogen-activated protein kinase (p38 MAPK) and inflammatory mediators in dorsal root ganglion (DRG) of CFA-treated mice were assayed by real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, or immunofluorescence staining. RESULTS Preemptive intrathecal injection of endomorphins dose-dependently attenuated CFA-induced mechanical allodynia via the mu-opioid receptor and significantly reversed paw incision-induced allodynia. In addition, CFA-caused increase of phosphorylated p38 MAPK in DRG was dramatically reduced by preemptive administration of endomorphins. Repeated intrathecal application of the specific p38 MAPK inhibitor SB203580 reduced CFA-induced mechanical allodynia as well. Further RT-PCR assay showed that endomorphins regulated the mRNA expression of inflammatory cytokines in DRGs induced by peripheral inflammation. CONCLUSIONS Our findings reveal a novel mechanism by which preemptive treatment of endomorphins attenuates inflammatory pain through regulating the production of inflammatory cytokines in DRG neurons via inhibition of p38 MAPK phosphorylation.
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Affiliation(s)
- Ting Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Nan Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Run Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Weidong Zhao
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Yong Chen
- Department of Neurology, School of Medicine, Duke University, Durham, North Carolina, 27710, USA
| | - Zilong Wang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Biao Xu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Mengna Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Xuerui Shi
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Qinqin Zhang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Yuanyuan Guo
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Jian Xiao
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Dan Chen
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China
| | - Quan Fang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou, 730000, People's Republic of China.
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15
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Yuan BY, Liu WZ, Wang XF, Zhang YZ, Yang DJ, Wang CL. Endomorphin-1 analogs with oligoarginine-conjugation at C-terminus produce potent antinociception with reduced opioid tolerance in paw withdrawal test. Peptides 2018; 106:96-101. [PMID: 30016700 DOI: 10.1016/j.peptides.2018.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/01/2018] [Accepted: 07/13/2018] [Indexed: 12/13/2022]
Abstract
For clinical use, it is essential to develop potent endomorphin (EM) analogs with reduced antinociceptive tolerance. In the present study, the antinociceptive activities and tolerance development of four potent EM-1 analogs with C-terminal oligoarginine-conjugation was evaluated and compared in the radiant heat paw withdrawal test. Following intracerebroventricular (i.c.v.) administration, all analogs 1-4 produced potent and prolonged antinociceptive effects. Notably, analogs 2 and 4 with the introduction of D-Ala in position 2 exhibited relatively higher analgesic potencies than those of analogs 1 and 3 with β-Pro substitution, consistent with their μ-opioid binding characteristic. In addition, at a dose of 50 μmol/kg, endomorphin-1 (EM-1) failed to produce any significant antinociceptive activity after peripheral administration, whereas analogs 1-4 induced potent antinociceptive effects with an increased duration of action. Herein, our results indicated the development of antinociceptive tolerance to EM-1 and morphine at the supraspinal level on day 7. By contrast, analogs 1-4 decreased the antinociceptive tolerance. Furthermore, subcutaneous (s.c.) administration of morphine at 50 μmol/kg also developed the antinociceptive tolerance, whereas the extent of tolerance developed to analogs 1-4 was largely reduced. Especially, analog 4 exhibited non-tolerance-forming antinociception after peripheral administration. The present investigation gave the evidence that C-terminal conjugation of EM-1 with oligoarginine vector will facilitate the development of novel opioid analgesics with reduced opioid tolerance.
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Affiliation(s)
- Bi-Yu Yuan
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Wei-Zhe Liu
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Xiao-Fang Wang
- Jiangxi University of traditional Chinese Medicine, Nanchang, China
| | - Yu-Zhe Zhang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Dai-Jun Yang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Chang-Lin Wang
- School of Life Science and Technology, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
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16
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Piekielna-Ciesielska J, Mollica A, Pieretti S, Fichna J, Szymaszkiewicz A, Zielińska M, Kordek R, Janecka A. Antinociceptive potency of a fluorinated cyclopeptide Dmt-c[D-Lys-Phe-p-CF 3-Phe-Asp]NH 2. J Enzyme Inhib Med Chem 2018. [PMID: 29513114 PMCID: PMC6010070 DOI: 10.1080/14756366.2018.1441839] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Opioid peptides and opiate drugs such as morphine, mediate their analgesic effects, but also undesired side effects, mostly through activation of the mu opioid receptor. However, delta- and kappa-opioid receptors can also contribute to the analgesic effects of opioids. Recent findings showed that simultaneous activation of multiple opioid receptors may result in additional analgesia with fewer side effects. Here, we evaluated the pharmacological profile of our formerly developed mixed mu/kappa-opioid receptor ligands, Dmt-c[D-Lys-Phe-Phe-Asp]NH2 (C-36) and Dmt-c[D-Lys-Phe-p-CF3-Phe-Asp]NH2 (F-81). The ability of these peptides to cross the blood–brain barrier was tested in the parallel artificial membrane permeability (PAMPA) assay. On the basis of the hot-plate test in mice after central and peripheral administration, analog F-81 was selected for the anti-nociceptive and anti-inflammatory activity assessment after peripheral administration.
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Affiliation(s)
| | - Adriano Mollica
- b Department of Pharmacy , University "'G. d'Annunzio"' of Chieti-Pescara , Chieti , Italy
| | - Stefano Pieretti
- c Istituto Superiore di Sanità , National Center for Drug Research and Evaluation , Rome , Italy
| | - Jakub Fichna
- d Department of Biochemistry, Faculty of Medicine , Medical University of Lodz , Poland
| | - Agata Szymaszkiewicz
- d Department of Biochemistry, Faculty of Medicine , Medical University of Lodz , Poland
| | - Marta Zielińska
- d Department of Biochemistry, Faculty of Medicine , Medical University of Lodz , Poland
| | - Radzisław Kordek
- e Department of Pathology, Faculty of Medicine , Medical University of Lodz , Lodz , Poland
| | - Anna Janecka
- a Department of Biomolecular Chemistry, Faculty of Medicine , Medical University of Lodz , Lodz , Poland
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Piekielna-Ciesielska J, Ferrari F, Calo' G, Janecka A. Cyclopeptide Dmt-[D-Lys-p-CF 3-Phe-Phe-Asp]NH 2, a novel G protein-biased agonist of the mu opioid receptor. Peptides 2018; 101:227-233. [PMID: 29196181 DOI: 10.1016/j.peptides.2017.11.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 01/14/2023]
Abstract
Opioid peptides and alkaloid drugs such as morphine, mediate their analgesic effects, but also undesired side effects, mostly through activation of the mu opioid receptor which belongs to the G protein-coupled receptor (GPCR) family. A new important pharmacological concept in the field of GPCRs is biased agonism. Two mu receptor ligands, Dmt-c[D-Lys-Phe-Phe-Asp]NH2 (C-36) and Dmt-c[D-Lys-Phe-p-CF3-Phe-Asp]NH2 (F-81), were evaluated in terms of their ability to promote or block mu receptor/G protein and mu receptor/β-arrestin interactions. Using the bioluminescence resonance energy transfer (BRET) assay it was shown that C-36 activated both, G protein and β-arrestin pathways. Incorporation of trifluoromethyl group into the aromatic ring of phenylalanine in the sequence of F-81 led to activation of G-protein pathway rather than β-arrestin recruitment. Opioid cyclopeptide F-81 turned out to be a biased G protein mu receptor agonist. Such biased ligands are able to separate the biological actions of an activated receptor and have the potential to become more effective drug candidates with fewer side effects.
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Affiliation(s)
| | - Federica Ferrari
- Department of Medical Sciences, Section of Pharmacology and Italian Institute of Neuroscience, University of Ferrara, 44121 Ferrara, Italy
| | - Girolamo Calo'
- Department of Medical Sciences, Section of Pharmacology and Italian Institute of Neuroscience, University of Ferrara, 44121 Ferrara, Italy
| | - Anna Janecka
- Department of Biomolecular Chemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland.
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Wang CL, Yang DJ, Yuan BY, Wang Y. C-terminal hydrazide modification changes the spinal antinociceptive profiles of endomorphins in mice. Peptides 2018; 99:128-133. [PMID: 28888771 DOI: 10.1016/j.peptides.2017.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/24/2017] [Accepted: 08/28/2017] [Indexed: 01/11/2023]
Abstract
Previously, we have demonstrated that endomorphins (EMs) analogs with C-terminal hydrazide modification retained the μ-opioid receptor affinity and selectivity, and exhibited potent antinociception after intracerebroventricular (i.c.v.) administration. In the present study, we extended our studies to evaluate the antinociceptive profiles of EMs and their analogs EM-1-NHNH2, EM-2-NHNH2 given spinally in the radiant heat paw withdrawal test. Following intrathecal (i.t.) administration, EM-1, EM-2, EM-1-NHNH2 and EM-2-NHNH2 dose-dependently increased the latency for paw withdrawal response. EM-1-NHNH2 displayed the highest antinociceptive effects, with the ED50 values being 1.63 nmol, more potent than the parent EM-1 (1.96 nmol), but with no significant difference. By contrast, the analgesic activities of EM-2 and its analog EM-2-NHNH2 were almost equivalent (P>0.05). Naloxone and β-funaltrexamine (β-FNA) almost completely attenuated the antinociceptive effects of EMs and their analogs EM-1-NHNH2, EM-2-NHNH2 (10 nmol, i.t.), indicating the involvement of μ-opioid receptors. Notably, the antinociception of EM-1 was not significantly antagonized by naloxonazine, a selective μ1-opioid receptor antagonist, but partially reversed the effects of EM-2, suggesting that EM-1 and EM-2 may produce antinociception through distinct μ1- and μ2-opioid receptor subtypes. Moreover, naloxonazine didn't significantly block the antinociceptive effects of EM-1-NHNH2 and EM-2-NHNH2, and nor-BNI, the κ-opioid receptor antagonist, attenuated the analgesic effects of EM-2, but not EM-1, EM-1-NHNH2 or EM-2-NHNH2. These results indicated that C-terminal amide to hydrazide conversion changed the antinociceptive opioid mechanisms of EM-2 but not EM-1 at the spinal level. Herein, the acute antinociceptive tolerance were further determined and compared. EM-1-NHNH2 and EM-2-NHNH2 shifted the dose-response curve rightward by only 2.8 and 1.5-fold as determined by tolerance ratio, whereas EM-1 and EM-2 by 3.4 and 4.6-fold, respectively, indicating substantially reduced antinociceptive tolerance. The present study demonstrated that C-terminal hydrazide modification changes the spinal antinociceptive profiles of EMs.
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Affiliation(s)
- Chang-Lin Wang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
| | - Dai-Jun Yang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Bi-Yu Yuan
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Yu Wang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
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Wang CL, Yang DJ, Yuan BY, Qiu TT. Antiallodynic Effects of Endomorphin-1 and Endomorphin-2 in the Spared Nerve Injury Model of Neuropathic Pain in Mice. Anesth Analg 2017; 125:2123-2133. [PMID: 28787346 DOI: 10.1213/ane.0000000000002318] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND The spared nerve injury (SNI) model is a new animal model that can mimic several characteristics of clinical neuropathic pain. Opioids are recommended as treatment of neuropathic pain. Therefore, the present study was conducted to investigate the antinociceptive effects of endomorphin-1 (EM-1) and endomorphin-2 (EM-2) given centrally and peripherally in the SNI model of neuropathic pain in mice. METHODS The SNI model was made in mice by sparing the sural nerve intact, when the other 2 of 3 terminal branches of the sciatic nerve (common peroneal and tibial nerves) were tightly ligated and cut. Von Frey monofilaments were used to measure the SNI-induced mechanical allodynia-like behavior. The antiallodynic effects of EM-1 and EM-2 were determined after central and peripheral administration in the SNI model of neuropathic pain. Also, the specific opioid receptor antagonists were used to determine the opioid mechanisms of EMs involved in neuropathic pain. Values were expressed as the mean ± standard deviation. RESULTS Our results showed that the SNI mice developed prolonged mechanical allodynia-like behavior in ipsilateral paw after surgery, with the withdrawal threshold value being 0.061 ± 0.02 g after 14 days. EM-1 and EM-2 produced significant antiallodynic effects in ipsilateral paw after intracerebroventricular (i.c.v.) administration, more effective than that of morphine. The peak withdrawal thresholds of 10 nmol EM-1 and EM-2 determined at 5 minutes after injection were 0.92 ± 0.36 and 0.87 ± 0.33 g, respectively, higher than that of morphine (0.46 ± 0.20 g). Moreover, both EMs (10 nmol, i.c.v.) exerted significant antiallodynic effects in the contralateral paw, whereas no significant antinociceptive activity was seen after i.c.v. administration of morphine with equimolar dose. It was noteworthy that EM-1 and EM-2 produced antinociception through distinct μ1- and μ2-opioid receptor subtypes, and the EM-2-induced antiallodynia contained an additional component that was mediated by the release of endogenous dynorphin A, acting on κ-opioid receptor. In addition, the antiallodynic activities of peripheral administration of EM-1, EM-2, and morphine were also investigated. Intraplantar, but not subcutaneous administration of EM-1 and EM-2 also exhibited potent antinociception, establishing the peripheral and local effects. Both μ1- and μ2-opioid receptor subtypes, but not the δ- or κ-opioid receptors were involved in the peripheral antiallodynia of EMs. CONCLUSIONS The present investigation demonstrated that both EM-1 and EM-2 given centrally and peripherally produced potent antiallodynic activities in SNI mice, and differential opioid mechanisms were involved.
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Affiliation(s)
- Chang-Lin Wang
- From the School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China
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20
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Kaczyńska K, Zając D, Wojciechowski P, Kogut E, Szereda-Przestaszewska M. Neuropeptides and breathing in health and disease. Pulm Pharmacol Ther 2017; 48:217-224. [PMID: 29223509 DOI: 10.1016/j.pupt.2017.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/20/2017] [Accepted: 12/05/2017] [Indexed: 12/18/2022]
Abstract
Regulatory neuropeptides control and regulate breathing in physiological and pathophysiological conditions. While they have been identified in the neurons of major respiratory areas, they can be active not only at the central level, but also at the periphery via chemoreceptors, vagal afferents, or locally within lungs and airways. Some neuropeptides, such as leptin or substance P, are respiratory stimulants; others, such as neurotensin, produce variable effects on respiration depending on the site of application. Some neuropeptides have been implicated in pathological states, such as obstructive sleep apnea or asthma. This article provides a concise review of the possible role and functions of several selected neuropeptides in the process of breathing in health and disease and in lung pathologies.
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Affiliation(s)
- Katarzyna Kaczyńska
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland.
| | - Dominika Zając
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Piotr Wojciechowski
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Ewelina Kogut
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
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Wu ZY, Lu YC, Feng B, Chen YB, Bai Y, Zhang T, Zhang H, Chen T, Dong YL, Li H, Li YQ. Endomorphin-2 Decreases Excitatory Synaptic Transmission in the Spinal Ventral Horn of the Rat. Front Neural Circuits 2017; 11:55. [PMID: 28848403 PMCID: PMC5550698 DOI: 10.3389/fncir.2017.00055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 07/26/2017] [Indexed: 01/20/2023] Open
Abstract
Motor impairment is one of the serious side-effects of morphine, which is an exogenous agonist of the μ-opioid receptor (MOR) as well as a widely used analgesic drug in clinical practice for chronic pain treatment. Endomorphins (EMs, including EM-1 and EM-2), the most effective and specific endogenous agonists of the MOR, exert more potent analgesia in acute and neuropathic pain than other opiates, such as morphine. Although EMs had fewer side-effects comparing to other opiates, motor impairment was still one unwanted reaction which limited its clinical application. In order to prevent and treat the motor impairment, it is critical to reveal the neural mechanisms underlying such locomotion disorder. The purpose of the present study was to reveal the neural mechanisms underlying the effects of EM-2 on the activity of motoneurons in the spinal ventral horn. First, we examine the distribution of EM-2-immunoreactive (IR) primary afferent fibers and their synaptic connections with the motoneurons innervating the skeletal muscles of the lower limb revealed by sciatic nerve retrograde tracing. The results showed that EM-2-IR fibers and terminals were sparsely observed in lamina IX and they formed symmetric synaptic connections with the motoneurons within lamina IX of the spinal ventral horn. Then, whole-cell patch-clamp technique was used to observe the effects of EM-2 on the spontaneous excitatory postsynaptic current (sEPSC) of motoneurons in lamina IX. The results showed that EM-2 could decrease both the frequency and amplitude of the sEPSC of the motoneurons in lamina IX, which was reversed by the MOR antagonist CTOP. These results indicate that EM-2-IR fibers originated from primary afferent fibers form symmetric synaptic connections with motoneurons innervating skeletal muscles of the lower limbs in lamina IX of the spinal ventral horn and EM-2 might exert inhibitory effects on the activities of these motoneurons through both presynaptic and postsynaptic mechanisms.
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Affiliation(s)
- Zhen-Yu Wu
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Ya-Cheng Lu
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Ban Feng
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Ying-Biao Chen
- Department of Anatomy, Fujian Health CollegeMinhou, China
| | - Yang Bai
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Ting Zhang
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Hua Zhang
- Department of Geriatrics, Xijing Hospital, The Fourth Military Medical UniversityXi'an, China
| | - Tao Chen
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Yu-Ling Dong
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Hui Li
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China
| | - Yun-Qing Li
- Department of Anatomy and K. K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China.,Collaborative Innovation Center for Brain Science, Fudan UniversityShanghai, China
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Original endomorphin-1 analogues exhibit good analgesic effects. Bioorg Med Chem Lett 2017; 27:1557-1560. [DOI: 10.1016/j.bmcl.2017.02.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 01/21/2023]
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Endomorphin-2 analogs with C-terminal esterification produce potent systemic antinociception with reduced tolerance and gastrointestinal side effects. Neuropharmacology 2017; 116:98-109. [DOI: 10.1016/j.neuropharm.2016.12.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/19/2016] [Accepted: 12/29/2016] [Indexed: 01/28/2023]
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Kaczyńska K, Wojciechowski P, Jampolska M, Lipkowski AW, Kleczkowska P. Cardiovascular and respiratory activity of PK20, opioid and neurotensin hybrid peptide in anesthetized and awake rats. Eur J Pharmacol 2017; 797:20-25. [PMID: 28089918 DOI: 10.1016/j.ejphar.2017.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 01/09/2017] [Accepted: 01/11/2017] [Indexed: 10/20/2022]
Abstract
AIM Chimeric compound - PK20 despite its therapeutic activity on nociceptive and inflammatory processes may affect respiration and blood pressure. Our objective was to evaluate influence of the hybrid composed of endomorphin-2 and neurotensin fragments on ventilation, heart rate and blood pressure in anesthetized and awake rats. METHODS The effects of PK20 (1mg/kg) were studied either after its intravenous administration in anesthetized rats or intraperitoneal injection in awake state. Tidal volume and the timing components of the breathing pattern, arterial blood pressure, and heart rate were recorded. RESULTS Intravenous administration of PK20 in the neurally intact rats evoked a dose-dependent apnoea followed by a transient insignificant increase in tidal volume and breathing rate. The blood pressure changes were biphasic: transient increase was replaced by prolonged hypotension. Midcervical vagotomy abrogated all post-PK20 respiratory effects. Hypotension was eliminated after blockade of neurotensin NTS1 receptor, while respiratory changes were reduced by blockade of both: NTS1 and μ opioid receptors. After PK20 intraperitoneal injection awake rats did not show any significant changes in ventilation and blood pressure. CONCLUSION This chimeric peptide should be used with care via intravenous administration in anesthetized animals since PK20 may evoke respiratory apnoea and hypotension. Nevertheless, applied intraperitoneally in the same dose in conscious rats induced no adverse effects.
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Affiliation(s)
- Katarzyna Kaczyńska
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland.
| | - Piotr Wojciechowski
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Monika Jampolska
- Laboratory of Respiration Physiology, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Andrzej W Lipkowski
- Department of Neuropeptides, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland
| | - Patrycja Kleczkowska
- Department of Neuropeptides, Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland; Department of Pharmacodynamics, Centre for Preclinical Research and Technology, Medical University of Warsaw, Poland
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Wan FP, Bai Y, Kou ZZ, Zhang T, Li H, Wang YY, Li YQ. Endomorphin-2 Inhibition of Substance P Signaling within Lamina I of the Spinal Cord Is Impaired in Diabetic Neuropathic Pain Rats. Front Mol Neurosci 2017; 9:167. [PMID: 28119567 PMCID: PMC5223733 DOI: 10.3389/fnmol.2016.00167] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/22/2016] [Indexed: 12/15/2022] Open
Abstract
Opiate analgesia in the spinal cord is impaired in diabetic neuropathic pain (DNP), but until now the reason is unknown. We hypothesized that it resulted from a decreased inhibition of substance P (SP) signaling within the dorsal horn of the spinal cord. To investigate this possibility, we evaluated the effects of endomorphin-2 (EM2), an endogenous ligand of the μ-opioid receptor (MOR), on SP release within lamina I of the spinal dorsal horn (SDH) in rats with DNP. We established the DNP rat model and compared the analgesic efficacy of EM2 between inflammation pain and DNP rat models. Behavioral results suggested that the analgesic efficacy of EM2 was compromised in the condition of painful diabetic neuropathy. Then, we measured presynaptic SP release induced by different stimulating modalities via neurokinin-1 receptor (NK1R) internalization. Although there was no significant change in basal and evoked SP release between control and DNP rats, EM2 failed to inhibit SP release by noxious mechanical and thermal stimuli in DNP but not in control and inflammation pain model. We also observed that EM2 decreased the number of FOS-positive neurons within lamina I of the SDH but did not change the amount of FOS/NK1R double-labeled neurons. Finally, we identified a remarkable decrease in MORs within the primary afferent fibers and dorsal root ganglion (DRG) neurons by Western blot (WB) and immunohistochemistry (IHC). Taken together, these data suggest that reduced presynaptic MOR expression might account for the loss of the inhibitory effect of EM2 on SP signaling, which might be one of the neurobiological foundations for decreased opioid efficacy in the treatment of DNP.
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Affiliation(s)
- Fa-Ping Wan
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Yang Bai
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Zhen-Zhen Kou
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Ting Zhang
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Hui Li
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Ya-Yun Wang
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Yun-Qing Li
- Department of Anatomy and Histology and Embryology, K.K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China; Collaborative Innovation Center for Brain Science, Fudan UniversityShanghai, China
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26
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Kou ZZ, Wan FP, Bai Y, Li CY, Hu JC, Zhang GT, Zhang T, Chen T, Wang YY, Li H, Li YQ. Decreased Endomorphin-2 and μ-Opioid Receptor in the Spinal Cord Are Associated with Painful Diabetic Neuropathy. Front Mol Neurosci 2016; 9:80. [PMID: 27656127 PMCID: PMC5013037 DOI: 10.3389/fnmol.2016.00080] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 08/24/2016] [Indexed: 12/17/2022] Open
Abstract
Painful diabetic neuropathy (PDN) is one of the most common complications in the early stage of diabetes mellitus (DM). Endomorphin-2 (EM2) selectively activates the μ-opioid receptor (MOR) and subsequently induces antinociceptive effects in the spinal dorsal horn. However, the effects of EM2-MOR in PDN have not yet been clarified in the spinal dorsal horn. Therefore, we aimed to explore the role of EM2-MOR in the pathogenesis of PDN. The main findings were the following: (1) streptozotocin (STZ)-induced diabetic rats exhibited hyperglycemia, body weight loss and mechanical allodynia; (2) in the spinal dorsal horn, the expression levels of EM2 and MOR decreased in diabetic rats; (3) EM2 protein concentrations decreased in the brain, lumbar spinal cord and cerebrospinal fluid (CSF) in diabetic rats but were unchanged in the plasma; (4) the frequency but not the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) was significantly higher in diabetic rats than in control rats; and (5) intrathecal injection of EM2 for 14 days in the early stage of PDN partially alleviated mechanical allodynia and reduced MOR expression in diabetic rats. Our results demonstrate that the EM2-MOR signal may be involved in the early stage of PDN.
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Affiliation(s)
- Zhen-Zhen Kou
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Fa-Ping Wan
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Yang Bai
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Chun-Yu Li
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Jia-Chen Hu
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Guo-Tao Zhang
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Ting Zhang
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Tao Chen
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Ya-Yun Wang
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Hui Li
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University Xi'an, China
| | - Yun-Qing Li
- Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical UniversityXi'an, China; Collaborative Innovation Center for Brain Science, Fudan UniversityShanghai, China
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Inhibitory Effect of Endomorphin-2 Binding to the μ-Opioid Receptor in the Rat Pre-Bötzinger Complex on the Breathing Activity. Mol Neurobiol 2016; 54:461-469. [DOI: 10.1007/s12035-015-9624-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/08/2015] [Indexed: 12/13/2022]
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Zadina JE, Nilges MR, Morgenweck J, Zhang X, Hackler L, Fasold MB. Endomorphin analog analgesics with reduced abuse liability, respiratory depression, motor impairment, tolerance, and glial activation relative to morphine. Neuropharmacology 2015; 105:215-227. [PMID: 26748051 DOI: 10.1016/j.neuropharm.2015.12.024] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 12/18/2015] [Accepted: 12/28/2015] [Indexed: 11/20/2022]
Abstract
Opioids acting at the mu opioid receptor (MOR) are the most effective analgesics, however adverse side effects severely limit their use. Of particular importance, abuse liability results in major medical, societal, and economic problems, respiratory depression is the cause of fatal overdoses, and tolerance complicates treatment and increases the risk of side effects. Motor and cognitive impairment are especially problematic for older adults. Despite the host of negative side effects, opioids such as morphine are commonly used for acute and chronic pain conditions. Separation of analgesia from unwanted effects has long been an unmet goal of opioid research. Novel MOR agonist structures may prove critical for greater success. Here we tested metabolically stable analogs of the endomorphins, endogenous opioids highly selective for the MOR. Compared to morphine, the analogs showed dramatically improved analgesia-to-side-effect ratios. At doses providing equal or greater antinociception than morphine in the rat, the analogs showed reduced a) respiratory depression, b) impairment of motor coordination, c) tolerance and hyperalgesia, d) glial p38/CGRP/P2X7 receptor signaling, and e) reward/abuse potential in both conditioned place preference and self-administration tests. Differential effects on glial activation indicate a mechanism for the relative lack of side effects by the analogs compared to morphine. The results suggest that endomorphin analogs described here could provide gold standard pain relief mediated by selective MOR activation, but with remarkably safer side effect profiles compared to opioids like morphine.
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Affiliation(s)
- James E Zadina
- SE LA Veterans Affairs Health Care System, Tulane University School of Medicine, New Orleans, LA 70112, USA; Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA; Neuroscience Program, Tulane University School of Medicine, New Orleans, LA 70112, USA; Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
| | - Mark R Nilges
- Neuroscience Program, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jenny Morgenweck
- Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Xing Zhang
- SE LA Veterans Affairs Health Care System, Tulane University School of Medicine, New Orleans, LA 70112, USA; Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Laszlo Hackler
- SE LA Veterans Affairs Health Care System, Tulane University School of Medicine, New Orleans, LA 70112, USA; Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Melita B Fasold
- SE LA Veterans Affairs Health Care System, Tulane University School of Medicine, New Orleans, LA 70112, USA; Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
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Wang Y, Liu X, Wang D, Yang J, Zhao L, Yu J, Wang R. Endomorphin-1 analogues (MELs) penetrate the blood–brain barrier and exhibit good analgesic effects with minimal side effects. Neuropharmacology 2015; 97:312-21. [DOI: 10.1016/j.neuropharm.2015.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 06/11/2015] [Accepted: 06/15/2015] [Indexed: 12/12/2022]
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Cyclic endomorphin analogs in targeting opioid receptors to achieve pain relief. Future Med Chem 2015; 6:2093-101. [PMID: 25531970 DOI: 10.4155/fmc.14.132] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Endomorphins, the endogenous ligands of the µ-opioid receptor, are attractive candidates for opioid-based pain-relieving agents. These tetrapeptides, with their remarkable affinity for the µ-opioid receptor, display favorable antinociceptive activity when injected directly into the brain of experimental animals. However, the application of endomorphins as clinical analgesics has been impeded by their instability in body fluids and inability to reach the brain after systemic administration. Among numerous modifications of the endomorphin structure aimed at improving their pharmacological properties, cyclization can be viewed as an interesting option. Here, we have summarized recent advances in obtaining endomorphin-based cyclic peptide analogs.
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Wang CL, Qiu TT, Diao YX, Zhang Y, Gu N. Novel endomorphin-1 analogs with C-terminal oligoarginine-conjugation display systemic antinociceptive activity with less gastrointestinal side effects. Biochimie 2015; 116:24-33. [PMID: 26115815 DOI: 10.1016/j.biochi.2015.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 06/13/2015] [Indexed: 10/23/2022]
Abstract
In recent study, in order to improve the bioavailability of endomorphin-1 (EM-1), we designed and synthesized a series of novel EM-1 analogs by replacement of L-Pro(2) by β-Pro, D-Ala or Sar, together with C-terminal oligoarginine-conjugation. Our results indicated that the introduction of D-Ala and β-Pro in position 2, along with oligoarginine-conjugation, didn't significantly decrease the μ-affinity and in vitro bioactivity, and the enhancement of arginine residues did not markedly influence the μ-affinity of these analogs. All analogs displayed a significant enhancement of stability, which may be due to increased resistance to proline-specific enzymatic degradation. Moreover, following intracerebroventricular (i.c.v.) administration, analogs 1, 2, 4 and 5 produced significant antinociception and increased duration of action, with the ED50 values being about 1.8- to 4.2-fold less potent than that of EM-1. In addition, our results indicated that no significant antinociceptive activity of EM-1 was seen following subcutaneous (s.c.) injection, whereas analogs 1, 2, 4 and 5 with equimolar dose induced significant and prolonged antinociception by an opioid and central mechanism. Herein, we further examined the gastrointestinal transit and colonic propulsive latencies of EM-1 and its four analogs administered centrally and peripherally. I.c.v. administration of EM-1 and analogs 1, 2, 4 and 5 significantly delayed gastrointestinal transit and colonic bead propulsion in mice, but the inhibitory effects induced by these analogs were largely attenuated. It is noteworthy that no significant gastrointestinal side effects induced by these four analogs were observed after s.c. administration. Our results demonstrated that combined modifications of EM-1 with unnatural amino acid substitutions and oligoarginine-conjugation gave an efficient strategy to improve the analgesic profile of EM-1 analogs but with less gastrointestinal side effects when administered peripherally.
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Affiliation(s)
- Chang-lin Wang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China.
| | - Ting-ting Qiu
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Yu-xiang Diao
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Yao Zhang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
| | - Ning Gu
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China
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Biondi DM, Xiang J, Etropolski M, Moskovitz B. Evaluation of blood pressure and heart rate in patients with hypertension who received tapentadol extended release for chronic pain: a post hoc, pooled data analysis. Clin Drug Investig 2015; 34:565-76. [PMID: 24916058 PMCID: PMC4102827 DOI: 10.1007/s40261-014-0209-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background and Objectives Hypertension is one of the most common co-existing conditions in patients with chronic pain, and the potential effects of an analgesic on heart rate and blood pressure are of particular concern for patients with hypertension. The purpose of this analysis was to evaluate changes in blood pressure and heart rate with tapentadol extended release (ER) treatment in patients with hypertension. Methods We performed a post hoc analysis of data pooled from three randomized, placebo- and active-controlled, phase III studies of tapentadol ER for managing chronic osteoarthritis knee (NCT00421928, NCT00486811) or low back (NCT00449176) pain (15-week, double-blind treatment period). Data were independently analyzed for patients with a listed medical history of hypertension at baseline and patients with at least one listed concomitant antihypertensive medication at baseline. Heart rate, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured at each visit. Results In patients with a listed medical history of hypertension (n = 1,464), least-squares mean (LSM [standard error (SE)]) changes from baseline to endpoint with placebo, tapentadol ER, and oxycodone HCl controlled release (CR), respectively, were −0.7 (0.44), 0.2 (0.43), and −0.9 (0.45) beats per minute (bpm) for heart rate; −2.4 (0.64), −2.7 (0.64), and −3.7 (0.67) mmHg for SBP; and −1.0 (0.39), −1.3 (0.39), and −2.3 (0.41) mmHg for DBP; in patients with at least one listed concomitant antihypertensive medication (n = 1,376), the LSM (SE) changes from baseline to endpoint were −0.6 (0.45), 0.1 (0.44), and −0.7 (0.47) bpm for heart rate; −1.8 (0.66), −3.3 (0.65), and −3.7 (0.69) mmHg for SBP; and −0.7 (0.40), −1.4 (0.40), and −2.3 (0.42) mmHg for DBP. Conclusion No clinically meaningful mean changes in heart rate or blood pressure were observed for the evaluated cohorts of patients with hypertension who were treated with tapentadol ER (100–250 mg twice daily).
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Affiliation(s)
- David M Biondi
- US Medical Affairs, Janssen Scientific Affairs, LLC, 1125 Trenton Harbourton Road, Titusville, NJ, 08560, USA,
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Liu H, Zhang W, Ma L, Fan L, Gao F, Ni J, Wang R. The improved blood–brain barrier permeability of endomorphin-1 using the cell-penetrating peptide synB3 with three different linkages. Int J Pharm 2014; 476:1-8. [DOI: 10.1016/j.ijpharm.2014.08.045] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 08/14/2014] [Accepted: 08/21/2014] [Indexed: 11/28/2022]
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Role of neurotensin and opioid receptors in the cardiorespiratory effects of [Ile9]PK20, a novel antinociceptive chimeric peptide. Eur J Pharm Sci 2014; 63:8-13. [DOI: 10.1016/j.ejps.2014.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 06/10/2014] [Accepted: 06/26/2014] [Indexed: 12/20/2022]
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Cai J, Song B, Cai Y, Ma Y, Lam AL, Magiera J, Sekar S, Wyse BD, Ambo A, Sasaki Y, Lazarus LH, Smith MT, Li T. Endomorphin analogues with mixed μ-opioid (MOP) receptor agonism/δ-opioid (DOP) receptor antagonism and lacking β-arrestin2 recruitment activity. Bioorg Med Chem 2014; 22:2208-19. [PMID: 24613457 DOI: 10.1016/j.bmc.2014.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 02/11/2014] [Accepted: 02/13/2014] [Indexed: 11/16/2022]
Abstract
Analogues of endomorphin (Dmt-Pro-Xaa-Xaa-NH2) modified at position 4 or at positions 4 and 3, and tripeptides (Dmt-Pro-Xaa-NH2) modified at position 3, with various phenylalanine analogues (Xaa=Trp, 1-Nal, 2-Nal, Tmp, Dmp, Dmt) were synthesized and their effects on in vitro opioid activity were investigated. Most of the peptides exhibited high μ-opioid (MOP) receptor binding affinity (KiMOP=0.13-0.81nM), modest MOP-selectivity (Kiδ-opioid (DOP)/KiMOP=3.5-316), and potent functional MOP agonism (GPI, IC50=0.274-249nM) without DOP and κ-opioid (KOP) receptor agonism. Among them, compounds 7 (Dmt-Pro-Tmp-Tmp-NH2) and 9 (Dmt-Pro-1-Nal-NH2) were opioids with potent mixed MOP receptor agonism/DOP receptor antagonism and devoid of β-arrestin2 recruitment activity. They may offer a unique template for the discovery of potent analgesics that produce less respiratory depression, less gastrointestinal dysfunction and that have a lower propensity to induce tolerance and dependence compared with morphine.
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Affiliation(s)
- Jun Cai
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Bowen Song
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Yunxin Cai
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Yu Ma
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Ai-Leen Lam
- Centre for Integrated Preclinical Drug Development, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Julia Magiera
- Centre for Integrated Preclinical Drug Development, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sunder Sekar
- Centre for Integrated Preclinical Drug Development, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bruce D Wyse
- Centre for Integrated Preclinical Drug Development, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Akihiro Ambo
- Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-ku, Sendai 981-8558, Japan
| | - Yusuke Sasaki
- Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-ku, Sendai 981-8558, Japan
| | - Lawrence H Lazarus
- Medicinal Chemistry Group, Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Science, Research Triangle Park, NC 27709, USA
| | - Maree T Smith
- Centre for Integrated Preclinical Drug Development, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Tingyou Li
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China; Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing 211166, China.
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Wang C, Xiang Q, Diao Y, Ren Y, Gu N. Differential antinociceptive effects of intrathecal administration of C-terminal esterified endomorphin-2 analogues in mice. Eur J Pain 2014; 18:1157-64. [DOI: 10.1002/j.1532-2149.2014.00462.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2014] [Indexed: 11/09/2022]
Affiliation(s)
- C.L. Wang
- School of Life Science and Technology; State Key Laboratory of Urban Water Resource and Environment; Instrumental Science and Technology; School of Electrical Engineering and Automation; Harbin Institute of Technology; China
| | - Q. Xiang
- School of Life Science and Technology; State Key Laboratory of Urban Water Resource and Environment; Instrumental Science and Technology; School of Electrical Engineering and Automation; Harbin Institute of Technology; China
| | - Y.X. Diao
- School of Life Science and Technology; State Key Laboratory of Urban Water Resource and Environment; Instrumental Science and Technology; School of Electrical Engineering and Automation; Harbin Institute of Technology; China
| | - Y.K. Ren
- School of Mechatronics Engineering; Harbin Institute of Technology; China
| | - N. Gu
- School of Life Science and Technology; State Key Laboratory of Urban Water Resource and Environment; Instrumental Science and Technology; School of Electrical Engineering and Automation; Harbin Institute of Technology; China
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Varamini P, Toth I. Lipid- and sugar-modified endomorphins: novel targets for the treatment of neuropathic pain. Front Pharmacol 2013; 4:155. [PMID: 24379782 PMCID: PMC3862115 DOI: 10.3389/fphar.2013.00155] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 11/27/2013] [Indexed: 12/29/2022] Open
Abstract
Endomorphins are endogenous opioid peptides that cause potent antinociception in rodent models of acute and neuropathic pain with less undesirable side effects than opioid alkaloids. However, endomorphins are poorly suited to clinical applications because of low membrane permeability and a susceptibility to enzymatic degradation. Glycosylation and lipidation have proven to be two of the most robust approaches for the generation of new therapeutic endomorphin derivatives. Conjugation with lipoamino acids (LAA) confers an amphipathic character to the peptide, which improved interaction between the peptide and the lipid bilayer of the cell membranes, increasing permeability. Glycosylation can also improve peptide stability and blood brain barrier (BBB) transport. It is believed that an endocytotic mechanism (transcytosis) is responsible for the systemic delivery of water-soluble glycopeptides. This review discusses the application of glycosylation and lipidation strategies to improve the drug-like properties of endomorphins. Pharmacologically active endomorphin analogs with less adverse effects are also discussed.
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Affiliation(s)
- Pegah Varamini
- Medicinal Chemistry Department, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia
| | - Istvan Toth
- Medicinal Chemistry Department, School of Chemistry and Molecular Biosciences, The University of Queensland Brisbane, QLD, Australia ; Medicinal Chemistry Department, School of Pharmacy, The University of Queensland Brisbane, QLD, Australia
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Wang CL, Ren YK, Xiang Q, Wang Y, Gu N, Lu C, Wang R. Characterization of opioid activities of endomorphin analogs with C-terminal amide to hydrazide conversion. Neuropeptides 2013; 47:297-304. [PMID: 24084335 DOI: 10.1016/j.npep.2013.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/31/2013] [Accepted: 09/09/2013] [Indexed: 11/29/2022]
Abstract
Previously, we have synthesized an endomorphin-2 (EM-2) analog with C-terminal amide to hydrazide conversion, exhibiting slightly lower μ-affinity than EM-2. In the present study, the influence of C-terminal amide group to hydrazide conversion on the in vitro and in vivo opioid activities of EMs was evaluated. Our results demonstrated that C-terminal amide to hydrazide conversion of EMs did not markedly change their μ-opioid receptor binding affinities. Nevertheless, EM-2-NHNH2 decreased guinea pig ileum (GPI) and mouse vas deferens (MVD) potencies by about 10- and 5-fold compared to the parent compound, respectively. It is noteworthy that EM-1-NHNH2 exhibited the highest antinociception after intracerebroventricular (i.c.v.) injection, about 1.5-fold more potent than EM-1, but with moderate colonic contractile and expulsive effects, comparable with EM-1. Additionally, though EM-2-NHNH2 showed a slightly lower antinociceptive effect than EM-2, at higher doses (i.c.v., 1.5 and 5 nmol/mouse) the inhibitory effects of colonic propulsion were significantly attenuated, which would be helpful in the development of suitable μ-opioid therapeutics, but without some undesirable side effects. Therefore, the present results gave the evidence that C-terminal amide to hydrazide conversion of EMs may play an important role in the regulation of opioid activities.
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Affiliation(s)
- Chang-Lin Wang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, China.
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39
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Eskandari S, Varamini P, Toth I. Formulation, characterization and permeability study of nano particles of lipo-endomorphin-1 for oral delivery. J Liposome Res 2013; 23:311-7. [DOI: 10.3109/08982104.2013.805339] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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40
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Peripherally acting novel lipo-endomorphin-1 peptides in neuropathic pain without producing constipation. Bioorg Med Chem 2013; 21:1898-904. [DOI: 10.1016/j.bmc.2013.01.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/09/2013] [Accepted: 01/15/2013] [Indexed: 11/24/2022]
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41
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Liu X, Wang Y, Xing Y, Yu J, Ji H, Kai M, Wang Z, Wang D, Zhang Y, Zhao D, Wang R. Design, synthesis, and pharmacological characterization of novel endomorphin-1 analogues as extremely potent μ-opioid agonists. J Med Chem 2013; 56:3102-14. [PMID: 23477419 DOI: 10.1021/jm400195y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Recently we reported the synthesis and structure-activity study of endomorphin-1 (EM-1) analogues containing novel, unnatural α-methylene-β-aminopropanoic acids (Map). In the present study, we describe new EM-1 analogues containing Dmt(1), (R/S)-βPro(2), and (ph)Map(4)/(2-furyl)Map(4). All of the analogues showed a high affinity for the μ-opioid receptor (MOR) and increased stability in mouse brain homogenates. Of the new compounds, Dmt(1)-(R)-βPro(2)-Trp(3)-(2-furyl)Map(4) (analogue 12) displayed the highest affinity toward MOR, in the picomolar range (Ki(μ) = 3.72 pM). Forskolin-induced cAMP accumulation assays indicated that this analogue displayed an extremely high agonistic potency, in the subpicomolar range (EC50 = 0.0421 pM, Emax = 99.5%). This compound also displayed stronger in vivo antinociceptive activity after iv administration when compared to morphine in the tail-flick test, which indicates that this analogue was able to cross the blood-brain barrier.
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Affiliation(s)
- Xin Liu
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, and Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou 730000, PR China
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42
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Co-activation of μ- and δ-opioid receptors elicits tolerance to morphine-induced ventilatory depression via generation of peroxynitrite. Respir Physiol Neurobiol 2013; 186:255-64. [PMID: 23473921 DOI: 10.1016/j.resp.2013.02.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 02/25/2013] [Accepted: 02/26/2013] [Indexed: 11/20/2022]
Abstract
We determined whether pretreatment with (1) the μ-/δ-opioid receptor (μ-/δ-OR) antagonist, naloxone, (2) the δ1,2-OR antagonist, naltrindole, or (3) the peroxynitrite scavenger, d-penicillamine, affects the development of tolerance to the ventilatory depressant effects of morphine in rats. The injection of morphine in vehicle-pretreated rats decreased minute ventilation predominantly via decreases in tidal volume. Pretreatment with naloxone blunted the responses to morphine whereas pretreatment with naltrindole or d-penicillamine did not. A second injection of morphine, given one day later, elicited markedly smaller responses in vehicle rats whereas it elicited pronounced ventilatory depression in rats that were pretreated with naloxone, naltrindole or d-penicillamine (prior to morphine) the day before. Moreover, the ventilatory responses elicited by subsequent exposure to a hypoxic-hypercapnic challenge were markedly depressed in naloxone- or d-penicillamine-pretreated rats compared to vehicle-pretreated rats. These findings suggest that activation of μ- and δ-ORs causes tolerance to the ventilatory depressant effects of morphine at least partly via the generation of peroxynitrite.
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43
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Wang Y, Xing Y, Liu X, Ji H, Kai M, Chen Z, Yu J, Zhao D, Ren H, Wang R. A new class of highly potent and selective endomorphin-1 analogues containing α-methylene-β-aminopropanoic acids (map). J Med Chem 2012; 55:6224-36. [PMID: 22724433 DOI: 10.1021/jm300664y] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A new class of endomorphin-1 (EM-1) analogues were synthesized by introduction of novel unnatural α-methylene-β-amino acids (Map) at position 3 or/and position 4. Their binding and functional activity, metabolic stability, and antinociceptive activity were determined and compared. Most of these analogues showed high affinities for the μ-opioid receptor and an increased stability in mouse brain homogenates compared with EM-1. Examination of cAMP accumulation and ERK1/2 phosphorylation in HEK293 cells confirmed the agonist properties of these analogues. Among these new analogues, H-Tyr-Pro-Trp-(2-furyl)Map-NH(2) (analogue 12) exhibited the highest binding potency (K(i)(μ) = 0.221 nM) and efficacy (EC(50) = 0.0334 nM, E(max) = 97.14%). This analogue also displayed enhanced antinociceptive activity in vivo in comparison to EM-1. Molecular modeling approaches were then carried out to demonstrate the interaction pattern of these analogues with the opioid receptors. We found that, compared to EM-1, the incorporation of our synthesized Map at position 4 would bring the analogue to a closer binding mode with the μ-opioid receptor.
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Affiliation(s)
- Yuan Wang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, P. R. China.
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44
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Varamini P, Mansfeld FM, Blanchfield JT, Wyse BD, Smith MT, Toth I. Synthesis and Biological Evaluation of an Orally Active Glycosylated Endomorphin-1. J Med Chem 2012; 55:5859-67. [DOI: 10.1021/jm300418d] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | | | | | - Bruce D. Wyse
- School of Pharmacy, The University
of Queensland, Brisbane, QLD 4102, Australia
| | - Maree T. Smith
- School of Pharmacy, The University
of Queensland, Brisbane, QLD 4102, Australia
| | - Istvan Toth
- School of Pharmacy, The University
of Queensland, Brisbane, QLD 4102, Australia
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45
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Cravezic A, Fichna J, Gach K, Wyrebska A, Perlikowska R, Costentin J, Bonnet JJ, Janecka A, do Rego JC. Effect of potent endomorphin degradation blockers on analgesic and antidepressant-like responses in mice. Neuropharmacology 2011; 61:1229-38. [DOI: 10.1016/j.neuropharm.2011.07.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 06/27/2011] [Accepted: 07/12/2011] [Indexed: 11/16/2022]
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46
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Perlikowska R, Fichna J, do-Rego JC, Gach K, Janecka A. Kinetic studies of novel inhibitors of endomorphin degrading enzymes. Med Chem Res 2011; 21:1445-1450. [PMID: 22707871 PMCID: PMC3359464 DOI: 10.1007/s00044-011-9666-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 05/07/2011] [Indexed: 11/20/2022]
Abstract
Endomorphins (EMs), two endogenous μ-opioid receptor selective ligands, are attractive lead compounds for opioid-based pain management studies. However, these peptides are quickly degraded by peptidases, in particular by dipeptidylpeptidase IV (DPP IV) and aminopeptidase M (APM). Targeting enzymatic degradation is one approach to prolong endomorphin activity. In this study we characterized the action of two new inhibitors of similar to endomorphins structure, Tyr-Pro-Ala-NH2 (EMDB-2) and Tyr-Pro-Ala-OH (EMDB-3), which were designed earlier in our laboratory. The presented data give evidence that EMDB-2 and EMDB-3 are potent inhibitors of enzymes responsible for endomorphin cleavage. These compounds are stable and easily synthesized. EMDB-2 and EMDB-3 are competitive inhibitors of both, DPP IV and APM, with Ki values in micromolar range. They are less potent than diprotin A in protecting EMs against DPP IV but more potent than actinonin in protecting these peptides against APM.
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47
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Koganezawa T, Okada Y, Terui N, Paton JFR, Oku Y. A μ-opioid receptor agonist DAMGO induces rapid breathing in the arterially perfused in situ preparation of rat. Respir Physiol Neurobiol 2011; 177:207-11. [PMID: 21513819 DOI: 10.1016/j.resp.2011.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 04/05/2011] [Accepted: 04/05/2011] [Indexed: 10/18/2022]
Abstract
Ventilatory responses to opioids are complex and not yet fully understood. We evaluated concentration-dependent effects of a selective μ-opioid receptor agonist [D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO) on respiratory output in the arterially perfused in situ rat preparation, which preserves the integrity of the ponto-medullary respiratory network. DAMGO (300-3400 nM) was added accumulatively to the perfusate. DAMGO increased inspiratory time and diminished central vagal post-inspiratory activity. At 300-500 nM DAMGO caused rapid breathing with shortening of expiratory time. The change of breathing pattern occurred within a single breath. Bilateral vagotomy did not affect the change in respiratory pattern, suggesting that it was of central origin. Additional DAMGO up to 1800 nM did not affect the rapid breathing pattern, and further elevated concentrations (up to 3400 nM) caused inconsistent results. Since the rapid breathing pattern was associated with the obliteration of vagal post-inspiratory activity, we conclude that DAMGO reconfigures the respiratory output to an inspiratory phase-dominant, rapidly alternating inspiration-expiration pattern.
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Affiliation(s)
- Tadachika Koganezawa
- Department of Physiology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
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48
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Liu WX, Wang R. Endomorphins: potential roles and therapeutic indications in the development of opioid peptide analgesic drugs. Med Res Rev 2011; 32:536-80. [DOI: 10.1002/med.20222] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
| | - Rui Wang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province; School of Basic Medical Sciences; Institute of Biochemistry and Molecular Biology; State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou China
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49
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Wang CL, Guo C, Wang YQ, Zhou Y, Li Q, Ni JM, Wang R. Synthesis and antinociceptive effects of endomorphin-1 analogs with C-terminal linked by oligoarginine. Peptides 2011; 32:293-9. [PMID: 21055434 DOI: 10.1016/j.peptides.2010.10.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/25/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
Abstract
Endomorphins (EMs) cannot be delivered into the central nervous system (CNS) in sufficient quantity to elicit antinociception when given systemically because they are severely restricted by the blood-brain barrier (BBB). In the present study, we investigated herein a series of EM-1 analogs with C-terminal linked by oligoarginine in order to improve the brain delivery and antinociception after systemic administration. Indeed, all these analogs decreased the opioid receptor affinity and in vitro pharmacological activity. Moreover, analogs 4, 7-9 produced a less potent antinociceptive activity after intracerebroventricular (i.c.v.) administration, with the ED(50) values about 11- to 13-fold lower potencies than that of EM-1. Nevertheless, our results revealed that EM-1 failed to induce any significant antinociception at a dose of 50μmol/kg after subcutaneous (s.c.) administration, whereas equimolar dose of these four analogs produced a little low but significant antinociceptive effects. Naloxone (10nmol/kg, i.c.v.) significantly blocked the antinociceptive effects, indicating an opioid and central mechanism. These results demonstrated that C-terminal of EM-1 linked to oligoarginine improved the brain delivery, eliciting potent antinociception following peripheral administration.
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MESH Headings
- Analgesics, Opioid/chemical synthesis
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/metabolism
- Analgesics, Opioid/pharmacology
- Animals
- Arginine/chemistry
- Brain/metabolism
- Chromatography, High Pressure Liquid
- Female
- Guinea Pigs
- Ileum/drug effects
- Male
- Mice
- Mice, Inbred Strains
- Muscle Contraction/drug effects
- Naloxone/pharmacology
- Oligopeptides/chemical synthesis
- Oligopeptides/chemistry
- Oligopeptides/metabolism
- Oligopeptides/pharmacology
- Pain/prevention & control
- Pain Measurement
- Radioligand Assay
- Rats
- Rats, Wistar
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/metabolism
- Spectrometry, Mass, Electrospray Ionization
- Vas Deferens/drug effects
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Affiliation(s)
- Chang-lin Wang
- Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou 730000, China
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50
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Fichna J, Perlikowska R, Gach K, Do-Rego JC, Cravezic A, Janecka A, Storr MA. The Novel Endomorphin Degradation Blockers Tyr-Pro-DClPhe-Phe-NH2 (EMDB-1) and Tyr-Pro-Ala-NH2 (EMDB-2) Prolong Endomorphin-2 Action in Rat Ileum In Vitro. Chem Biol Drug Des 2010; 76:77-81. [DOI: 10.1111/j.1747-0285.2010.00977.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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