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Cai L, Liow JS, Morse CL, Telu S, Davies R, Manly LS, Zoghbi SS, Chin FT, Innis RB, Pike VW. Candidate 3-benzazepine-1-ol type GluN2B receptor radioligands ( 11C-NR2B-Me enantiomers) have high binding in cerebellum but not to σ1 receptors. EJNMMI Res 2023; 13:28. [PMID: 37017827 PMCID: PMC10076467 DOI: 10.1186/s13550-023-00975-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/12/2023] [Indexed: 04/06/2023] Open
Abstract
INTRODUCTION We recently reported 11C-NR2B-SMe ([S-methyl-11C](R,S)-7-thiomethoxy-3-(4-(4-methyl-phenyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepin-1-ol) and its enantiomers as candidate radioligands for imaging the GluN2B subunit within rat N-methyl-D-aspartate receptors. However, these radioligands gave unexpectedly high and displaceable binding in rat cerebellum, possibly due to cross-reactivity with sigma-1 (σ1) receptors. This study investigated 11C-labeled enantiomers of a close analogue (7-methoxy-3-(4-(p-tolyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepin-1-ol; NR2B-Me) of 11C-NR2B-SMe as new candidate GluN2B radioligands. PET was used to evaluate these radioligands in rats and to assess potential cross-reactivity to σ1 receptors. METHODS NR2B-Me was assayed for binding affinity and selectivity to GluN2B in vitro. 11C-NR2B-Me and its enantiomers were prepared by Pd-mediated treatment of boronic ester precursors with 11C-iodomethane. Brain PET scans were conducted after radioligand intravenous injection into rats. Various ligands for GluN2B receptors or σ1 receptors were administered at set doses in pre-blocking or displacement experiments to assess their impact on imaging data. 18F-FTC146 and enantiomers of 11C-NR2B-SMe were used for comparison. Radiometabolites from brain and plasma were measured ex vivo and in vitro. RESULTS NR2B-Me enantiomers showed high GluN2B affinity and selectivity in vitro. 11C-NR2B-Me enantiomers gave high early whole rat brain uptake of radioactivity, including high uptake in cerebellum, followed by slower decline. Radioactivity in brain at 30 min ex vivo was virtually all unchanged radioligand. Only less lipophilic radiometabolites appeared in plasma. When 11C-(R)-NR2B-Me was used, three high-affinity GluN2B ligands-NR2B-SMe, Ro25-6981, and CO101,244-showed increasing pre-block of whole brain radioactivity retention with increasing dose. Two σ1 receptor antagonists, FTC146 and BD1407, were ineffective pre-blocking agents. Together, these results strongly resemble those obtained with 11C-NR2B-SMe enantiomers, except that 11C-NR2B-Me enantiomers showed faster reversibility of binding. When 18F-FTC146 was used as a radioligand, FTC146 and BD1407 showed strong pre-blocking effects whereas GluN2B ligands showed only weak blocking effects. CONCLUSION 11C-NR2B-Me enantiomers showed specific binding to GluN2B receptors in rat brain in vivo. High unexpected specific binding in cerebellum was not due to σ1 receptors. Additional investigation is needed to identify the source of the high specific binding.
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Affiliation(s)
- Lisheng Cai
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA.
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Riley Davies
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Lester S Manly
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Frederick T Chin
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University, 1201 Welch Road, Rm. PS049, Stanford, CA, 94305-584, USA
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Dr, Bldg 10, Room B3 C346, Bethesda, MD, 20892, USA
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2
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Gao RD, Taylor M, McInnis T, Chen Z, Gori SS, LaPorte HM, Siegler MA, Neisewander JL, Mach RH, Singh M, Slusher BS, Rais R, Luedtke RR, Tsukamoto T. Synthesis and Pharmacological Characterization of a Difluorinated Analogue of Reduced Haloperidol as a Sigma-1 Receptor Ligand. ACS Chem Neurosci 2023; 14:947-957. [PMID: 36780706 DOI: 10.1021/acschemneuro.2c00791] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Reduced haloperidol (1) was previously reported to act as a potent sigma-1 receptor (S1R) ligand with substantially lower affinity to the dopamine D2 receptor (D2R) compared to haloperidol. It was also found to facilitate brain-derived neurotrophic factor (BDNF) secretion from astrocytic glial cell lines in a sigma-1 receptor (S1R)-dependent manner. Although an increase in BDNF secretion may have beneficial effects in some neurological conditions, the therapeutic utility of reduced haloperidol (1) is limited because it can be oxidized back to haloperidol in the body, a potent dopamine D2 receptor antagonist associated with well-documented adverse effects. A difluorinated analogue of reduced haloperidol, (±)-4-(4-chlorophenyl)-1-(3,3-difluoro-4-(4-fluorophenyl)-4-hydroxybutyl)piperidin-4-ol (2), was synthesized in an attempt to minimize the oxidation. Compound (±)-2 was found to exhibit high affinity to S1R and facilitate BDNF release from mouse brain astrocytes. It was also confirmed that compound 2 cannot be oxidized back to the corresponding haloperidol analogue in liver microsomes. Furthermore, compound 2 was distributed to the brain following intraperitoneal administration in mice and reversed the learning deficits in active avoidance tasks. These findings suggest that compound 2 could serve as a promising S1R ligand with therapeutic potential for the treatment of cognitive impairments.
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Affiliation(s)
- Run-Duo Gao
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Michelle Taylor
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - Tamara McInnis
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - Zhenglan Chen
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - Sadakatali S Gori
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Heather M LaPorte
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153, United States
| | - Maxime A Siegler
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Janet L Neisewander
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Robert H Mach
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Meharvan Singh
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153, United States
| | - Barbara S Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Rana Rais
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Robert R Luedtke
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - Takashi Tsukamoto
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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3
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Samanta D. Fenfluramine: A Review of Pharmacology, Clinical Efficacy, and Safety in Epilepsy. CHILDREN 2022; 9:children9081159. [PMID: 36010049 PMCID: PMC9406381 DOI: 10.3390/children9081159] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 11/29/2022]
Abstract
Despite the availability of more than 30 antiseizure medications (ASMs), the proportion of patients who remain refractory to ASMs remains static. Refractory seizures are almost universal in patients with epileptic encephalopathies. Since many of these patients are not candidates for curative surgery, there is always a need for newer ASMs with better efficacy and safety profile. Recently, the anti-obesity medication fenfluramine (FFA) has been successfully repurposed, and various regulatory agencies approved it for seizures associated with Dravet and Lennox–Gastaut syndromes. However, there is a limited in-depth critical review of FFA to facilitate its optimal use in a clinical context. This narrative review discusses and summarizes the antiseizure mechanism of action of FFA, clinical pharmacology, and clinical studies related to epilepsy, focusing on efficacy and adverse effects.
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, 1 Children's Way, Little Rock, AR 72202, USA
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4
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Martin P, Maurice T, Gammaitoni A, Farfel G, Boyd B, Galer B. Fenfluramine modulates the anti-amnesic effects induced by sigma-1 receptor agonists and neuro(active)steroids in vivo. Epilepsy Behav 2022; 127:108526. [PMID: 35007961 DOI: 10.1016/j.yebeh.2021.108526] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 12/15/2022]
Abstract
Fenfluramine (N-ethyl-α-methl-3-(trifluoromethyl)phenethylamine) is an anti-seizure medication (ASM) particularly effective in patients with Dravet syndrome, a severe treatment-resistant epileptic encephalopathy. Fenfluramine acts not only as neuronal serotonin (5-HT) releaser but also as a positive modulator of the sigma-1 receptor (S1R). We here examined the modulatory activity of Fenfluramine on the S1R-mediated anti-amnesic response in mice using combination analyses. Fenfluramine and Norfenfluramine, racemate and isomers, were combined with either the S1R agonist (PRE-084) or the S1R-acting neuro(active)steroids, pregnenolone sulfate (PREGS), Dehydroepiandrosterone sulfate (DHEAS), or progesterone. We report that Fenfluramine racemate or (+)-Fenfluramine, in the 0.1-1 mg/kg dose range, attenuated the dizocilpine-induced learning deficits in spontaneous alternation and passive avoidance, and showed low-dose synergies in combination with PRE-084. These effects were blocked by the S1R antagonist NE-100. Dehydroepiandrosterone sulfate or PREGS attenuated dizocilpine-induced learning deficits in the 5-20 mg/kg dose range. Co-treatments at low dose between steroids and Fenfluramine or (+)-Fenfluramine were synergistic. Progesterone blocked Fenfluramine effect. Finally, Fenfluramine and (+)-Fenfluramine effects were prevented by the 5-HT1A receptor antagonist WAY-100635 or 5-HT2A antagonist RS-127445, but not by the 5-HT1B/1D antagonist GR 127935 or the 5-HT2C antagonist SB 242084, confirming a 5-HT1A and 5-HT2A receptor involvement in the drug effect on memory. We therefore confirmed the positive modulation of Fenfluramine racemate or dextroisomer on S1R and showed that, in physiological conditions, the drug potentiated the low dose effects of neuro(active)steroids, endogenous S1R modulators. The latter are potent modulators of the excitatory/inhibitory balance in the brain, and their levels must be considered in the antiepileptic action of Fenfluramine.
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Affiliation(s)
| | - Tangui Maurice
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France.
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Martin P, Reeder T, Sourbron J, de Witte PAM, Gammaitoni AR, Galer BS. An Emerging Role for Sigma-1 Receptors in the Treatment of Developmental and Epileptic Encephalopathies. Int J Mol Sci 2021; 22:8416. [PMID: 34445144 PMCID: PMC8395113 DOI: 10.3390/ijms22168416] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are complex conditions characterized primarily by seizures associated with neurodevelopmental and motor deficits. Recent evidence supports sigma-1 receptor modulation in both neuroprotection and antiseizure activity, suggesting that sigma-1 receptors may play a role in the pathogenesis of DEEs, and that targeting this receptor has the potential to positively impact both seizures and non-seizure outcomes in these disorders. Recent studies have demonstrated that the antiseizure medication fenfluramine, a serotonin-releasing drug that also acts as a positive modulator of sigma-1 receptors, reduces seizures and improves everyday executive functions (behavior, emotions, cognition) in patients with Dravet syndrome and Lennox-Gastaut syndrome. Here, we review the evidence for sigma-1 activity in reducing seizure frequency and promoting neuroprotection in the context of DEE pathophysiology and clinical presentation, using fenfluramine as a case example. Challenges and opportunities for future research include developing appropriate models for evaluating sigma-1 receptors in these syndromic epileptic conditions with multisystem involvement and complex clinical presentation.
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Affiliation(s)
- Parthena Martin
- Zogenix, Inc., Emeryville, CA 94608, USA; (P.M.); (T.R.); (A.R.G.)
| | - Thadd Reeder
- Zogenix, Inc., Emeryville, CA 94608, USA; (P.M.); (T.R.); (A.R.G.)
| | - Jo Sourbron
- University Hospital KU Leuven, 3000 Leuven, Belgium;
| | - Peter A. M. de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences at KU Leuven, 3000 Leuven, Belgium;
| | | | - Bradley S. Galer
- Zogenix, Inc., Emeryville, CA 94608, USA; (P.M.); (T.R.); (A.R.G.)
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6
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Odi R, Invernizzi RW, Gallily T, Bialer M, Perucca E. Fenfluramine repurposing from weight loss to epilepsy: What we do and do not know. Pharmacol Ther 2021; 226:107866. [PMID: 33895186 DOI: 10.1016/j.pharmthera.2021.107866] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/26/2021] [Accepted: 04/12/2021] [Indexed: 12/21/2022]
Abstract
In 2020, racemic-fenfluramine was approved in the U.S. and Europe for the treatment of seizures associated with Dravet syndrome, through a restricted/controlled access program aimed at minimizing safety risks. Fenfluramine had been used extensively in the past as an appetite suppressant, but it was withdrawn from the market in 1997 when it was found to cause cardiac valvulopathy. Available evidence indicates that appetite suppression and cardiac valvulopathy are mediated by different serotonergic mechanisms. In particular, appetite suppression can be ascribed mainly to the enantiomers d-fenfluramine and d-norfenfluramine, the primary metabolite of d-fenfluramine, whereas cardiac valvulopathy can be ascribed mainly to d-norfenfluramine. Because of early observations of markedly improved seizure control in some forms of epilepsy, fenfluramine remained available in Belgium through a Royal Decree after 1997 for use in a clinical trial in patients with Dravet syndrome at average dosages lower than those generally prescribed for appetite suppression. More recently, double-blind placebo-controlled trials established its efficacy in the treatment of convulsive seizures associated with Dravet syndrome and of drop seizures associated with Lennox-Gastaut syndrome, at doses up to 0.7 mg/kg/day (maximum 26 mg/day). Although no cardiovascular toxicity has been associated with the use of fenfluramine in epilepsy, the number of patients exposed to date has been limited and only few patients had duration of exposure longer than 3 years. This article analyzes available evidence on the mechanisms involved in fenfluramine-induced appetite suppression, antiseizure effects and cardiovascular toxicity. Despite evidence that stimulation of 5-HT2B receptors (the main mechanism leading to cardiac valvulopathy) is not required for antiseizure activity, there are many critical gaps in understanding fenfluramine's properties which are relevant to its use in epilepsy. Particular emphasis is placed on the remarkable lack of publicly accessible information about the comparative activity of the individual enantiomers of fenfluramine and norfenfluramine in experimental models of seizures and epilepsy, and on receptors systems considered to be involved in antiseizure effects. Preliminary data suggest that l-fenfluramine retains prominent antiseizure effects in a genetic zebrafish model of Dravet syndrome. If these findings are confirmed and extended to other seizure/epilepsy models, there would be an incentive for a chiral switch from racemic-fenfluramine to l-fenfluramine, which could minimize the risk of cardiovascular toxicity and reduce the incidence of adverse effects such as loss of appetite and weight loss.
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Affiliation(s)
- Reem Odi
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Tamar Gallily
- Yissum Technology Transfer Company of the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Meir Bialer
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel; David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Emilio Perucca
- Division of Clinical and Experimental Pharmacology, Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
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7
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Cai L, Liow JS, Morse CL, Telu S, Davies R, Frankland MP, Zoghbi SS, Cheng K, Hall MD, Innis RB, Pike VW. Evaluation of 11C-NR2B-SMe and Its Enantiomers as PET Radioligands for Imaging the NR2B Subunit Within the NMDA Receptor Complex in Rats. J Nucl Med 2020; 61:1212-1220. [PMID: 31924728 DOI: 10.2967/jnumed.119.235143] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/19/2019] [Indexed: 01/01/2023] Open
Abstract
[S-methyl-11C](±)-7-methoxy-3-(4-(4-(methylthio)phenyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepin-1-ol (11C-NR2B-SMe) and its enantiomers were synthesized as candidates for imaging the NR2B subunit within the N-methyl-d-aspartate receptor with PET. Methods: Brains were scanned with PET for 90 min after intravenous injection of one of the candidate radioligands into rats. To detect any NR2B-specific binding of radioligand in brain, various preblocking or displacing agents were evaluated for their impact on the PET brain imaging data. Radiometabolites from brain and other tissues were measured ex vivo and in vitro. Results: Each radioligand gave high early whole-brain uptake of radioactivity, followed by a brief fast decline and then a slow final decline. 11C-(S)-NR2B-SMe was studied extensively. Ex vivo measurements showed that radioactivity in rat brain at 30 min after radioligand injection was virtually unchanged radioligand. Only less lipophilic radiometabolites appeared in plasma. High-affinity NR2B ligands, Ro-25-6981, ifenprodil, and CO101244, showed increasing preblocking of whole-brain radioactivity retention with increasing dose (0.01-3.00 mg/kg, intravenously). Five σ1 antagonists (FTC146, BD1407, F3, F4, and NE100) and 4 σ1 agonists ((+)-pentazocine, (±)-PPCC, PRE-084, and (+)-SKF10047) were ineffective preblocking agents, except FTC146 and F4 at a high dose. Two potent σ1 receptor agonists, TC1 and SA4503, showed dose-dependent preblocking effects in the presence or absence of pharmacologic σ1 receptor blockade with FTC146. Conclusion: 11C-(S)-NR2B-SMe has adequate NR2B-specific PET signal in rat brain to warrant further evaluation in higher species. TC1 and SA4503 likely have off-target binding to NR2B in vivo.
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Affiliation(s)
- Lisheng Cai
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Riley Davies
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Michael P Frankland
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Ken Cheng
- NCATS Chemical Genomics Center, National Institutes of Health, Rockville, Maryland
| | - Matthew D Hall
- NCATS Chemical Genomics Center, National Institutes of Health, Rockville, Maryland
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland; and
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8
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Analysis of Sigma-1 Receptor Binding Ability Under Emotional Stress and Upon Administration of the Anxiolytic Afobazole. Pharm Chem J 2019. [DOI: 10.1007/s11094-019-02060-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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9
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Berizzi AE, Perry CJ, Shackleford DM, Lindsley CW, Jones CK, Chen NA, Sexton PM, Christopoulos A, Langmead CJ, Lawrence AJ. Muscarinic M 5 receptors modulate ethanol seeking in rats. Neuropsychopharmacology 2018; 43:1510-1517. [PMID: 29483658 PMCID: PMC5983544 DOI: 10.1038/s41386-017-0007-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/26/2017] [Accepted: 12/29/2017] [Indexed: 12/16/2022]
Abstract
Despite the cost to both individual and society, alcohol use disorders (AUDs) remain a major health risk within society, and both relapse and heavy drinking are still poorly controlled with current medications. Here we demonstrate for the first time that a centrally active and selective negative allosteric modulator for the rat M5 muscarinic acetylcholine receptor (mAChR), ML375, decreases ethanol self-administration and attenuates cue-induced reinstatement of ethanol seeking in ethanol-preferring (iP) rats. Importantly, ML375 did not affect sucrose self-administration or general locomotor activity indicative of a selective effect on ethanol seeking. Based on the expression profile of M5 mAChRs in the brain and the distinct roles different aspects of the dorsal striatum have on long-term and short-term ethanol use, we studied whether intra-striatal microinjection of ML375 modulated ethanol intake in rats. We show in iP rats with an extensive history of ethanol intake that intra-dorsolateral (DL), but not intra-dorsomedial, striatal injections of ML375 reduced ethanol self-administration to a similar extent as the nicotinic acetylcholine receptor ligand varenicline, which has preclinical and clinical efficacy in reducing the reinforcing effects of ethanol. These data implicate the DL striatum as a locus for the effects of cholinergic-acting drugs on ethanol seeking in rats with a history of long-term ethanol use. Accordingly, we demonstrate in rats that selectively targeting the M5 mAChR can modulate both voluntary ethanol intake and cue-induced ethanol seeking and thereby provide direct evidence that the M5 mAChR is a potential novel target for pharmacotherapies aimed at treating AUDs.
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Affiliation(s)
- Alice E. Berizzi
- 0000 0004 1936 7857grid.1002.3Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
| | - Christina J. Perry
- 0000 0004 0606 5526grid.418025.aThe Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052 Australia
| | - David M. Shackleford
- 0000 0004 1936 7857grid.1002.3Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
| | - Craig W. Lindsley
- 0000 0001 2264 7217grid.152326.1Departments of Pharmacology and Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232 USA
| | - Carrie K. Jones
- 0000 0001 2264 7217grid.152326.1Departments of Pharmacology and Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232 USA
| | - Nicola A. Chen
- 0000 0004 0606 5526grid.418025.aThe Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052 Australia
| | - Patrick M. Sexton
- 0000 0004 1936 7857grid.1002.3Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.
| | - Christopher J. Langmead
- 0000 0004 1936 7857grid.1002.3Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052 Australia
| | - Andrew J. Lawrence
- 0000 0004 0606 5526grid.418025.aThe Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052 Australia ,0000 0001 2179 088Xgrid.1008.9Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3010 Australia
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Penke B, Fülöp L, Szűcs M, Frecska E. The Role of Sigma-1 Receptor, an Intracellular Chaperone in Neurodegenerative Diseases. Curr Neuropharmacol 2018; 16:97-116. [PMID: 28554311 PMCID: PMC5771390 DOI: 10.2174/1570159x15666170529104323] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 04/15/2017] [Accepted: 05/25/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Widespread protein aggregation occurs in the living system under stress or during aging, owing to disturbance of endoplasmic reticulum (ER) proteostasis. Many neurodegenerative diseases may have a common mechanism: the failure of protein homeostasis. Perturbation of ER results in unfolded protein response (UPR). Prolonged chronical UPR may activate apoptotic pathways and cause cell death. METHODS Research articles on Sigma-1 receptor were reviewed. RESULTS ER is associated to mitochondria by the mitochondria-associated ER-membrane, MAM. The sigma-1 receptor (Sig-1R), a well-known ER-chaperone localizes in the MAM. It serves for Ca2+-signaling between the ER and mitochondria, involved in ion channel activities and especially important during neuronal differentiation. Sig-1R acts as central modulator in inter-organelle signaling. Sig-1R helps cell survival by attenuating ER-stress. According to sequence based predictions Sig-1R is a 223 amino acid protein with two transmembrane (2TM) domains. The X-ray structure of the Sig-1R [1] showed a membrane-bound trimeric assembly with one transmembrane (1TM) region. Despite the in vitro determined assembly, the results of in vivo studies are rather consistent with the 2TM structure. The receptor has unique and versatile pharmacological profile. Dimethyl tryptamine (DMT) and neuroactive steroids are endogenous ligands that activate Sig-1R. The receptor has a plethora of interacting client proteins. Sig-1R exists in oligomeric structures (dimer-trimer-octamer-multimer) and this fact may explain interaction with diverse proteins. CONCLUSION Sig-1R agonists have been used in the treatment of different neurodegenerative diseases, e.g. Alzheimer's and Parkinson's diseases (AD and PD) and amyotrophic lateral sclerosis. Utilization of Sig-1R agents early in AD and similar other diseases has remained an overlooked therapeutic opportunity.
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Affiliation(s)
- Botond Penke
- University of Szeged, Department of Medical Chemistry, Faculty of Medicine, Szeged, Hungary
| | - Lívia Fülöp
- University of Szeged, Department of Medical Chemistry, Faculty of Medicine, Szeged, Hungary
| | - Mária Szűcs
- University of Szeged, Department of Medical Chemistry, Faculty of Medicine, Szeged, Hungary
| | - Ede Frecska
- University of Debrecen, Department of Psychiatry, Faculty of Medicine, Debrecen, Hungary
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11
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Franchini S, Sorbi C, Battisti UM, Tait A, Bencheva LI, Cichero E, Fossa P, Cilia A, Prezzavento O, Ronsisvalle S, Aricò G, Benassi L, Vaschieri C, Azzoni P, Magnoni C, Brasili L. Structure-Activity Relationships within a Series of σ1
and σ2
Receptor Ligands: Identification of a σ2
Receptor Agonist (BS148) with Selective Toxicity against Metastatic Melanoma. ChemMedChem 2017; 12:1893-1905. [DOI: 10.1002/cmdc.201700427] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/20/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Silvia Franchini
- Dipartimento di Scienze della Vita; Università degli Studi di Modena e Reggio Emilia; Via Campi 103 41125 Modena Italy
| | - Claudia Sorbi
- Dipartimento di Scienze della Vita; Università degli Studi di Modena e Reggio Emilia; Via Campi 103 41125 Modena Italy
| | - Umberto Maria Battisti
- Dipartimento di Scienze della Vita; Università degli Studi di Modena e Reggio Emilia; Via Campi 103 41125 Modena Italy
| | - Annalisa Tait
- Dipartimento di Scienze della Vita; Università degli Studi di Modena e Reggio Emilia; Via Campi 103 41125 Modena Italy
| | - Leda Ivanova Bencheva
- Dipartimento di Scienze della Vita; Università degli Studi di Modena e Reggio Emilia; Via Campi 103 41125 Modena Italy
| | - Elena Cichero
- Dipartimento di Farmacia; Università degli Studi di Genova; Viale Benedetto XV 3 16132 Genova Italy
| | - Paola Fossa
- Dipartimento di Farmacia; Università degli Studi di Genova; Viale Benedetto XV 3 16132 Genova Italy
| | - Antonio Cilia
- Divisione Ricerca e Sviluppo; Recordati S.p.A.; Via Civitali 1 20148 Milano Italy
| | - Orazio Prezzavento
- Dipartimento di Scienze del Farmaco; Università degli Studi di Catania; Viale Andrea Doria 6 95125 Catania Italy
| | - Simone Ronsisvalle
- Dipartimento di Scienze del Farmaco; Università degli Studi di Catania; Viale Andrea Doria 6 95125 Catania Italy
| | - Giuseppina Aricò
- Dipartimento di Scienze del Farmaco; Università degli Studi di Catania; Viale Andrea Doria 6 95125 Catania Italy
| | - Luisa Benassi
- Dipartimento Chirurgico, Medico, Odontoiatrico e di Scienze Morfologiche con interesse Trapiantologico, Oncologico e di Medicina Rigenerativa; Università degli Studi di Modena e Reggio Emilia; via del Pozzo 71 41124 Modena Italy
| | - Cristina Vaschieri
- Dipartimento Chirurgico, Medico, Odontoiatrico e di Scienze Morfologiche con interesse Trapiantologico, Oncologico e di Medicina Rigenerativa; Università degli Studi di Modena e Reggio Emilia; via del Pozzo 71 41124 Modena Italy
| | - Paola Azzoni
- Dipartimento Chirurgico, Medico, Odontoiatrico e di Scienze Morfologiche con interesse Trapiantologico, Oncologico e di Medicina Rigenerativa; Università degli Studi di Modena e Reggio Emilia; via del Pozzo 71 41124 Modena Italy
| | - Cristina Magnoni
- Dipartimento Chirurgico, Medico, Odontoiatrico e di Scienze Morfologiche con interesse Trapiantologico, Oncologico e di Medicina Rigenerativa; Università degli Studi di Modena e Reggio Emilia; via del Pozzo 71 41124 Modena Italy
| | - Livio Brasili
- Dipartimento di Scienze della Vita; Università degli Studi di Modena e Reggio Emilia; Via Campi 103 41125 Modena Italy
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12
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Dasargyri A, Kümin CD, Leroux JC. Targeting Nanocarriers with Anisamide: Fact or Artifact? ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1603451. [PMID: 27885719 DOI: 10.1002/adma.201603451] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/08/2016] [Indexed: 05/19/2023]
Abstract
Encapsulating chemotherapeutics in nanoparticles can reduce the side effects of intravenous administration and improve their antitumor efficacy. Additionally, surface decoration of the nanocarriers with tumor-targeting ligands may enhance their specificity for cancer cells overexpressing the corresponding ligand-binding counterpart. The focus here is on anisamide, a low-molecular-weight benzamide derivative used as a tumor-directing moiety in functionalized nanosystems, based on its alleged interaction with Sigma receptors. The scintigraphic agents that initially inspired the use of anisamide for tumor targeting are described, and the published anisamide-tethered nanocarrier formulations are reviewed, together with a critical overview of the ligand's tumor-targeting properties. Moreover, anisamide's putative but dubious cellular target, the Sigma-1 receptor, is discussed with regard to its subcellular localization and implications in cancer. Data from in vivo studies reveal that the effect of anisamide on the antitumor efficacy of the decorated nanosystems varies considerably among the published reports. Together with the evidence questioning the interaction of anisamide with the Sigma receptors, the variability of anisamide's effect on the tumor deposition and the antitumor efficacy of the decorated drug carriers calls into question the extent of the ligand's tumor-targeting effect. Further research is necessary to elucidate the ligand's utility in tumor targeting.
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Affiliation(s)
- Athanasia Dasargyri
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich, 8093, Switzerland
| | - Carole D Kümin
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich, 8093, Switzerland
| | - Jean-Christophe Leroux
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich, 8093, Switzerland
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13
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Mysona B, Kansara N, Zhao J, Bollinger K. The Role of Sigma 1 Receptor as a Neuroprotective Target in Glaucoma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 964:299-307. [PMID: 28315279 DOI: 10.1007/978-3-319-50174-1_20] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The role of sigma 1 receptor (S1R) in glaucoma is emerging as a promising field of study. Glaucoma is an optic neuropathy that shares common pathogenic mechanisms with other neurodegenerative diseases such as Alzheimer's and Parkinson's disease . S1R modulates multiple cellular functions associated with neurodegeneration . These include Ca2+ ion homeostasis, endoplasmic reticulum (ER) and oxidative stress , survival signaling pathways, neurotrophin secretion, and glial activation. S1R may also have neurorestorative properties including enhancement of neuronal plasticity and neurite outgrowth. Recent studies using agonists for S1R within the eye provide hope that it could be a therapeutic target for glaucoma. Understanding the role of S1R in glaucoma may help us to stop the progression of this sight threatening disease.
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Affiliation(s)
- Barbara Mysona
- Departments of Cellular Biology and Anatomy and Ophthalmology and the James and Jean Culver Vision Discovery Institute, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Neil Kansara
- Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
- The James and Jean Culver Vision Discovery Institute, Augusta, GA, 30912, USA
| | - Jing Zhao
- The James and Jean Culver Vision Discovery Institute, Augusta, GA, 30912, USA
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Kathryn Bollinger
- Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
- The James and Jean Culver Vision Discovery Institute, Augusta, GA, 30912, USA.
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA.
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14
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Abstract
This chapter presents the three-dimensional (3D) model of the Sigma1 receptor protein as obtained from homology modeling techniques. We show the applicability of this structure to docking-based virtual screening and discuss combined in silico/in vitro mutagenesis studies performed to validate the structural features of the Sigma1 receptor model and to qualify/quantify the prominent role of specific amino acid residues in ligand binding. The validation of the virtual 3D Sigma1 receptor model and its reliable applicability to docking-based virtual screening is of significance for rational ligand design, even in light of the recently reported crystal structure for the Sigma1 receptor.
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Affiliation(s)
- Erik Laurini
- Molecular Simulation Engineering (MOSE) Laboratory, Department of Engineering and Architecture (DEA), University of Trieste, Via Valerio 6, 34127, Trieste, Italy
| | - Domenico Marson
- Molecular Simulation Engineering (MOSE) Laboratory, Department of Engineering and Architecture (DEA), University of Trieste, Via Valerio 6, 34127, Trieste, Italy
| | - Maurizio Fermeglia
- Molecular Simulation Engineering (MOSE) Laboratory, Department of Engineering and Architecture (DEA), University of Trieste, Via Valerio 6, 34127, Trieste, Italy
| | - Sabrina Pricl
- Molecular Simulation Engineering (MOSE) Laboratory, Department of Engineering and Architecture (DEA), University of Trieste, Via Valerio 6, 34127, Trieste, Italy.
- National Interuniversity Consortium for Material Science and Technology (INSTM), Research Unit MOSE-DEA, University of Trieste, Via Valerio 6, 34127, Trieste, Italy.
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15
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Scouting new sigma receptor ligands: Synthesis, pharmacological evaluation and molecular modeling of 1,3-dioxolane-based structures and derivatives. Eur J Med Chem 2016; 112:1-19. [DOI: 10.1016/j.ejmech.2016.01.059] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/13/2016] [Accepted: 01/30/2016] [Indexed: 11/23/2022]
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16
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Dasargyri A, Hervella P, Christiansen A, Proulx ST, Detmar M, Leroux JC. Findings questioning the involvement of Sigma-1 receptor in the uptake of anisamide-decorated particles. J Control Release 2016; 224:229-238. [PMID: 26774218 DOI: 10.1016/j.jconrel.2016.01.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 01/09/2016] [Accepted: 01/11/2016] [Indexed: 11/22/2022]
Abstract
Anisamide is a small benzamide previously suggested as a tumor-targeting ligand for nanocarriers and it has been shown to enhance tumor uptake in vitro as well as in vivo when grafted on the nanoparticle surface. Anisamide has been hypothesized to interact with the Sigma-1 receptor, based on the binding of larger benzamides, which contain anisamide in their structure, to this receptor. However, the interaction between anisamide and Sigma-1 receptor has never been thoroughly studied. We developed fluorescent PEGylated particles decorated with anisamide, which were preferentially taken up in vitro by melanoma cells compared to macrophages. The anisamide-decorated particles were used to study their interaction with the Sigma-1 receptor. The absence of competition of Sigma-1 receptor ligands for the particle uptake was a first indication that the receptor might not be involved in the uptake process. In addition, the extent of particle uptake did not correlate with the levels of cellular expression of Sigma-1 receptor in the cell models tested. Immunostaining of the receptor on melanoma cells revealed intracellular localization, indirectly excluding the possibility of anisamide binding to the receptor when grafted on the particles. All these data question the previously suggested Sigma-1 receptor-mediated uptake of the anisamide-decorated particles, a finding which may have an impact on the use of anisamide as a targeting ligand.
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Affiliation(s)
- Athanasia Dasargyri
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich 8093, Switzerland
| | - Pablo Hervella
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich 8093, Switzerland
| | - Ailsa Christiansen
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich 8093, Switzerland
| | - Steven T Proulx
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich 8093, Switzerland
| | - Michael Detmar
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich 8093, Switzerland
| | - Jean-Christophe Leroux
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology Zurich (ETHZ), Zurich 8093, Switzerland.
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17
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Romero L, Merlos M, Vela JM. Antinociception by Sigma-1 Receptor Antagonists: Central and Peripheral Effects. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 75:179-215. [PMID: 26920013 DOI: 10.1016/bs.apha.2015.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There is plenty of evidence supporting the modulatory role of sigma-1 receptors (σ1Rs) in nociception, mainly based on the pain-attenuated phenotype of σ1R knockout mice and on the antinociceptive effect exerted by σ1R antagonists, particularly in nonacute sensitizing conditions involving sustained afferent drive, activity-dependent plasticity/sensitization, and ultimately pain hypersensitivity, as it is the case in chronic pains of different etiology. Antinociceptive effects of σ1R antagonists both when acting alone and in combination with opioids (to enhance opioid analgesia) have been reported at both central and peripheral sites. At the central level, findings at the behavioral (animal pain models), electrophysiological (spinal wind-up recordings), neurochemical (spinal release of neurotransmitters) and molecular (NMDAR function) level supports a role for σ1R antagonists in inhibiting augmented excitability secondary to sustained afferent input. Attenuation of activity-induced plastic changes (central sensitization) following tissue injury/inflammation or nerve damage could thus underlie the central inhibitory effect of σ1R antagonists. Moreover, recent pieces of information confirm the involvement of σ1R in mechanisms regulating pain at the periphery, where σ1Rs are highly expressed, particularly in dorsal root ganglia. Indeed, local peripheral administration of σ1R antagonists reduces inflammatory hyperalgesia. Potentiation of opioid analgesia is also supported, particularly at supraspinal sites and at the periphery, where locally administered σ1R antagonists unmask opioid analgesia. Altogether, whereas σ1R activation is coupled to pain facilitation and inhibition of opioid antinociception, σ1R antagonism inhibits pain hypersensitivity and "releases the brake" enabling opioids to exert enhanced antinociceptive effects, both at the central nervous system and at the periphery.
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Affiliation(s)
- Luz Romero
- Drug Discovery and Preclinical Development, ESTEVE, Parc Científic de Barcelona, Baldiri Reixac 4-8, Barcelona, Spain
| | - Manuel Merlos
- Drug Discovery and Preclinical Development, ESTEVE, Parc Científic de Barcelona, Baldiri Reixac 4-8, Barcelona, Spain
| | - José Miguel Vela
- Drug Discovery and Preclinical Development, ESTEVE, Parc Científic de Barcelona, Baldiri Reixac 4-8, Barcelona, Spain.
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18
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García-Martínez BA, Jaramillo-Morales OA, Espinosa-Juárez JV, Navarrete-Vázquez G, Melo-Hernández LA, Medina-López JR, Domínguez-Ramírez AM, Schepmann D, Wünsch B, López-Muñoz FJ. Antinociceptive effects of a new sigma-1 receptor antagonist (N-(2-morpholin-4-yl-ethyl)-2-(1-naphthyloxy)acetamide) in two types of nociception. Eur J Pharmacol 2016; 771:10-7. [PMID: 26683636 DOI: 10.1016/j.ejphar.2015.12.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 11/18/2015] [Accepted: 12/07/2015] [Indexed: 12/12/2022]
Abstract
Pain has become an active clinical challenge due its etiological heterogeneity, symptoms and mechanisms of action. In the search for new pharmacological therapeutic alternatives, sigma receptors have been proposed as drug targets. This family consists of sigma-1 and sigma-2 receptors. The sigma-1 system is involved in nociception through its chaperone activity. Additionally, it has been shown that agonist to these receptors promote related sensitisation and pain hypersensitisation, suggesting the possible use of antagonists for sigma-1 receptors as an alternative therapy. The aim of this study was to evaluate the antinociceptive effect of a new sigma-1 receptor antagonist N-(2-morpholin-4-yl-ethyl)-2-(1-naphthyloxy)acetamida (NMIN) in two types of pain (arthritic and neuropathic) and to compare its efficacy and potency with reference drugs. The antinociceptive effects of NMIN were quantitatively evaluated using the pain-induced functional impairment model in the rat and the acetone test in a rat model of neuropathic pain. NMIN (sigma-1 receptor affinity of 324nM) did not show any antinociceptive activity in the arthritic pain model but showed a dose-dependent anti-allodynic effect in neuropathic pain. NMIN showed a similar efficacy compared to the effects obtained with morphine and the sigma-1 antagonist BD-1063. However, these reference drugs showed increased potency compared with NMIN. Our results suggest that sigma-1 receptors may play an important direct role in neuropathic pain but not in arthritic pain, supporting the hypothesis that NMIN may be useful for the treatment of neuropathic pain.
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Affiliation(s)
- Betzabeth Anali García-Martínez
- Maestría en Cs. Farmacéuticas, Div. de CBS, Universidad Autónoma Metropolitana, Unidad Xochimilco, C.P. 04960 Delegación Coyoacán, México D.F., Mexico.
| | | | | | | | | | - José Raúl Medina-López
- Departamento Sistemas Biológicos, Universidad Autónoma Metropolitana, Unidad Xochimilco, México, D.F. 04960, Mexico.
| | | | - Dirk Schepmann
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms-Universität Münster, Germany.
| | - Bernhard Wünsch
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms-Universität Münster, Germany.
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19
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Miyata K, Schepmann D, Wünsch B. Synthesis and σ receptor affinity of regioisomeric spirocyclic furopyridines. Eur J Med Chem 2014; 83:709-16. [PMID: 25016157 DOI: 10.1016/j.ejmech.2014.06.073] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/23/2014] [Accepted: 06/29/2014] [Indexed: 11/25/2022]
Abstract
In order to investigate systematically the effect of the position of the pyridine N-atom on the σ1 receptor affinity four regioisomeric furopyridines 2a-d were synthesized and pharmacologically evaluated. The key steps of the synthesis comprise bromine/lithium exchange at regioisomeric bromopyridinecarbaldehyde acetals 7a-d, subsequent addition to 1-benzylpiperidin-4-one and cyclization. The regioisomeric acetals 7a-d were obtained either by o-metalation of bromopyridines 5b and 5c or by oxidation of bromopicolines 3a and 3d. In radioligand binding studies the regioisomeric furopyridines 2a-d showed 7- to 12-fold lower σ1 affinity than the benzofuran analog 1. The reduced σ1 affinity of the furopyridines 2a-d is explained with the reduced electron density of the pyridine ring. Since the four regioisomeric furopyridines show almost the same σ1 affinity (Ki = 4.9-10 nM), a directed interaction of the pyridine N-atom with the receptor protein can be excluded.
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Affiliation(s)
- Kengo Miyata
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms - Universität Münster, Corrensstraße 48, D-48149 Münster, Germany; Research Center for Materials Science and Department of Chemistry, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Dirk Schepmann
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms - Universität Münster, Corrensstraße 48, D-48149 Münster, Germany
| | - Bernhard Wünsch
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms - Universität Münster, Corrensstraße 48, D-48149 Münster, Germany; Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University Münster, Germany.
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20
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Abstract
The exact 3D structure of the enigmatic σ1 receptor is unknown, as the crystal structure of this protein has not been solved so far. Many efforts have been devoted to unveiling the structure of the σ1 receptor and specifically its binding site, which include photoaffinity labeling, site directed mutagenesis, and homology modeling. The aim of the present miniperspective is to give a short overview of all results that contribute to the current knowledge of the σ1 receptor and its ligand binding site.
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Affiliation(s)
- Stefanie Brune
- Institut für Pharmazeutische und Medizinische Chemie der Westfälischen Wilhelms-Universität Münster , Corrensstraße 48, D-48149 Münster, Germany
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21
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Guo L, Zhao J, Jin G, Zhao B, Wang G, Zhang A, Zhen X. SKF83959 is a potent allosteric modulator of sigma-1 receptor. Mol Pharmacol 2013; 83:577-86. [PMID: 23295385 DOI: 10.1124/mol.112.083840] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
SKF83959 (3-methyl-6-chloro-7,8-hydroxy-1-[3-methylphenyl]-2,3,4,5-tetrahydro-1H-3-benzazepine), an atypical dopamine receptor-1 (D(1) receptor) agonist, has shown many D(1) receptor-independent effects, such as neuroprotection, blockade of Na(+) channel, and promotion of spontaneous glutamate release, which resemble the effects of the sigma-1 receptor activation. In the present work, we explored the potential modulation of SKF83959 on the sigma-1 receptor. The results indicated that SKF83959 dramatically promoted the binding of (3)H(+)-pentazocine (a selective sigma-1 receptor agonist) to the sigma-1 receptor in brain and liver tissues but produced no effect on (3)H-progesterone binding (a sigma-1 receptor antagonist). The saturation assay and the dissociation kinetics assay confirmed the allosteric effect. We further demonstrated that the SKF83959 analogs, such as SCH22390 [(R)-(1)-7-chloro-8- hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride] and SKF38393 [(+/-)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol hydrobromide], also showed the similar allosteric effect on the sigma-1 receptor in the liver tissue but not in the brain tissue. Moreover, all three tested chemicals elicited no significant effect on (3)H-1,3-di(2-tolyl)-guanidine ((3)H-DTG) binding to the sigma-2 receptor. The present data uncovered a new role of SKF83959 and its analogs on the sigma-1 receptor, which, in turn, may reveal the underlying mechanism for the D(1) receptor-independent effect of the drug.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/analogs & derivatives
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Allosteric Regulation/drug effects
- Animals
- Brain/drug effects
- Brain/metabolism
- Cell Line
- Drug Synergism
- HEK293 Cells
- Humans
- Liver/drug effects
- Liver/metabolism
- Male
- Pentazocine/pharmacology
- Progesterone/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Dopamine D1/agonists
- Receptors, Dopamine D1/metabolism
- Receptors, sigma/agonists
- Receptors, sigma/antagonists & inhibitors
- Receptors, sigma/metabolism
- Sigma-1 Receptor
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Affiliation(s)
- Lin Guo
- Department of Pharmacology II, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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Zhang CL, Feng ZJ, Liu Y, Ji XH, Peng JY, Zhang XH, Zhen XC, Li BM. Methylphenidate enhances NMDA-receptor response in medial prefrontal cortex via sigma-1 receptor: a novel mechanism for methylphenidate action. PLoS One 2012; 7:e51910. [PMID: 23284812 PMCID: PMC3527396 DOI: 10.1371/journal.pone.0051910] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 11/07/2012] [Indexed: 01/09/2023] Open
Abstract
Methylphenidate (MPH), commercially called Ritalin or Concerta, has been widely used as a drug for Attention Deficit Hyperactivity Disorder (ADHD). Noteworthily, growing numbers of young people using prescribed MPH improperly for pleasurable enhancement, take high risk of addiction. Thus, understanding the mechanism underlying high level of MPH action in the brain becomes an important goal nowadays. As a blocker of catecholamine transporters, its therapeutic effect is explained as being due to proper modulation of D1 and α2A receptor. Here we showed that higher dose of MPH facilitates NMDA-receptor mediated synaptic transmission via a catecholamine-independent mechanism, in layer V∼VI pyramidal cells of the rat medial prefrontal cortex (PFC). To indicate its postsynaptic action, we next found that MPH facilitates NMDA-induced current and such facilitation could be blocked by σ1 but not D1/5 and α2 receptor antagonists. And this MPH eliciting enhancement of NMDA-receptor activity involves PLC, PKC and IP3 receptor mediated intracellular Ca(2+) increase, but does not require PKA and extracellular Ca(2+) influx. Our additional pharmacological studies confirmed that higher dose of MPH increases locomotor activity via interacting with σ1 receptor. Together, the present study demonstrates for the first time that MPH facilitates NMDA-receptor mediated synaptic transmission via σ1 receptor, and such facilitation requires PLC/IP3/PKC signaling pathway. This novel mechanism possibly explains the underlying mechanism for MPH induced addictive potential and other psychiatric side effects.
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Affiliation(s)
- Chun-Lei Zhang
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ze-Jun Feng
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yue Liu
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Xiao-Hua Ji
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ji-Yun Peng
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Xue-Han Zhang
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Xue-Chu Zhen
- Neuropharmacological Laboratory, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Bao-Ming Li
- Institute of Neurobiology and State Key laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, China
- Center for Neuropsychiatric Disorders, Institute of Life Science, Nanchang University, Nanchang, China
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23
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A 96-well filtration method for radioligand binding analysis of σ receptor ligands. J Pharm Biomed Anal 2012; 71:157-61. [PMID: 22910107 DOI: 10.1016/j.jpba.2012.07.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 07/18/2012] [Accepted: 07/22/2012] [Indexed: 11/24/2022]
Abstract
σ receptors represent a potential drug target for numerous therapeutic indications including cancer, depression, psychostimulant abuse, and stroke. Most published radioligand binding studies for σ receptors utilize a low throughput method employing a "cell harvester." Higher throughput methods are required to facilitate efficient screening of large numbers of novel compounds. In this study, a series of reference compounds was analyzed with a new medium-throughput 96-well filtration method and the results were compared to those obtained using the conventional cell harvester-based method. The 96-well assay utilized rat liver membranes for the determination of both known σ receptor subtypes (σ(1) and σ(2)) because this tissue contains high densities of both subtypes and fulfills criteria required for reliable use with the 96-well format. The new method gave comparable K(i) values for reference ligands analyzed in parallel with samples prepared in rat brain membranes and processed on the traditional cell harvester. For σ(1) receptors, equivalent affinity values were observed for both methods/tissues. For σ(2) receptors, approximately 2-fold higher affinities were observed for most compounds in liver, as compared to brain membranes, but excellent correlation with brain-derived values was maintained. To further demonstrate the utility of the new method it was used to screen a novel series of 2(3H)-benzothiazolone compounds, resulting in the identification of several analogues with nanomolar affinity and greater than 50-fold specificity for σ(1) versus σ(2) receptors.
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24
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Su TP, Hayashi T, Maurice T, Buch S, Ruoho AE. The sigma-1 receptor chaperone as an inter-organelle signaling modulator. Trends Pharmacol Sci 2010; 31:557-66. [PMID: 20869780 PMCID: PMC2993063 DOI: 10.1016/j.tips.2010.08.007] [Citation(s) in RCA: 359] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 08/19/2010] [Accepted: 08/26/2010] [Indexed: 01/13/2023]
Abstract
Inter-organelle signaling plays important roles in many physiological functions. Endoplasmic reticulum (ER)-mitochondrion signaling affects intramitochondrial calcium (Ca(2+)) homeostasis and cellular bioenergetics. ER-nucleus signaling attenuates ER stress. ER-plasma membrane signaling regulates cytosolic Ca(2+) homeostasis and ER-mitochondrion-plasma membrane signaling regulates hippocampal dendritic spine formation. Here, we propose that the sigma-1 receptor (Sig-1R), an ER chaperone protein, acts as an inter-organelle signaling modulator. Sig-1Rs normally reside at the ER-mitochondrion contact called the MAM (mitochondrion-associated ER membrane), where Sig-1Rs regulate ER-mitochondrion signaling and ER-nucleus crosstalk. When cells are stimulated by ligands or undergo prolonged stress, Sig-1Rs translocate from the MAM to the ER reticular network and plasmalemma/plasma membrane to regulate a variety of functional proteins, including ion channels, receptors and kinases. Thus, the Sig-1R serves as an inter-organelle signaling modulator locally at the MAM and remotely at the plasmalemma/plasma membrane. Many pharmacological/physiological effects of Sig-1Rs might relate to this unique action of Sig-1Rs.
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Affiliation(s)
- Tsung-Ping Su
- Cellular Pathobiology Section, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, suite 3304, 333 Cassell Drive, Baltimore, MD 21224, USA.
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25
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Cobos EJ, Entrena JM, Nieto FR, Cendán CM, Del Pozo E. Pharmacology and therapeutic potential of sigma(1) receptor ligands. Curr Neuropharmacol 2010; 6:344-66. [PMID: 19587856 PMCID: PMC2701284 DOI: 10.2174/157015908787386113] [Citation(s) in RCA: 287] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 07/18/2008] [Accepted: 07/09/2008] [Indexed: 11/22/2022] Open
Abstract
Sigma (σ) receptors, initially described as a subtype of opioid receptors, are now considered unique receptors. Pharmacological studies have distinguished two types of σ receptors, termed σ1 and σ2. Of these two subtypes, the σ1 receptor has been cloned in humans and rodents, and its amino acid sequence shows no homology with other mammalian proteins. Several psychoactive drugs show high to moderate affinity for σ1 receptors, including the antipsychotic haloperidol, the antidepressant drugs fluvoxamine and sertraline, and the psychostimulants cocaine and methamphetamine; in addition, the anticonvulsant drug phenytoin allosterically modulates σ1 receptors. Certain neurosteroids are known to interact with σ1 receptors, and have been proposed to be their endogenous ligands. These receptors are located in the plasma membrane and in subcellular membranes, particularly in the endoplasmic reticulum, where they play a modulatory role in intracellular Ca2+ signaling. Sigma1 receptors also play a modulatory role in the activity of some ion channels and in several neurotransmitter systems, mainly in glutamatergic neurotransmission. In accordance with their widespread modulatory role, σ1 receptor ligands have been proposed to be useful in several therapeutic fields such as amnesic and cognitive deficits, depression and anxiety, schizophrenia, analgesia, and against some effects of drugs of abuse (such as cocaine and methamphetamine). In this review we provide an overview of the present knowledge of σ1 receptors, focussing on σ1 ligand neuropharmacology and the role of σ1 receptors in behavioral animal studies, which have contributed greatly to the potential therapeutic applications of σ1 ligands.
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Affiliation(s)
- E J Cobos
- Department of Pharmacology and Institute of Neuroscience, Faculty of Medicine, University of Granada, Granada, Spain
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26
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Hayashi T, Su T. The sigma receptor: evolution of the concept in neuropsychopharmacology. Curr Neuropharmacol 2010; 3:267-80. [PMID: 18369400 DOI: 10.2174/157015905774322516] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 06/17/2005] [Indexed: 11/22/2022] Open
Abstract
Although originally proposed as a subtype of opioid receptors, the sigma receptor is now confirmed to be a non-opioid receptor that binds diverse classes of psychotropic drugs. Sigma receptors are subdivided into two subtypes, sigma-1 and sigma-2. The sigma-1 receptor is a 25-kDa protein possessing one putative transmembrane domain and an endoplasmic reticulum retention signal. Sigma-1 receptors are highly expressed in deeper laminae of the cortex, olfactory bulb, nuclei of mesencephalon, hypothalamus, and Purkinje cells in the brain. Sigma-1 receptors are predominantly localized at the endoplasmic reticulum of both neurons and oligodendrocytes. From behavioral studies, sigma-1 receptors were shown to be involved in higher-ordered brain functions including memory and drug dependence. The actions mediated by sigma-1 receptors at the cellular level can be considered either as acute or chronic. The acute actions include the modulation of ion channels (i.e., K+ channel, NMDA receptors, IP3 receptors) and the sigma-1 receptor translocation. Chronic actions of sigma-1 receptors are basically considered to be the result of an up- or down regulation of the sigma-1 receptor itself. For example, the upregulation of sigma-1 receptors per se, even without exogenous ligands, promotes cellular differentiation and reconstitution of lipid microdomains (lipid rafts) in cultured cells. These findings together suggest that sigma-1 receptors might possess a constitutive biological activity, and that sigma-1 receptor ligands might merely work as modulators of the innate activity of this protein. Recent in vitro and in vitro studies strongly point to the possibility that sigma-1 receptors participate in membrane remodeling and cellular differentiation in the nervous system.
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Affiliation(s)
- T Hayashi
- Cellular Pathobiology Unit/DPS, Cellular Neurobiology Research Branch, National Institute on Drug Abuse, National Institutes of Health, DHHS., 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
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27
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Rybczynska AA, Dierckx RA, Ishiwata K, Elsinga PH, van Waarde A. Cytotoxicity of σ-Receptor Ligands Is Associated with Major Changes of Cellular Metabolism and Complete Occupancy of the σ-2 Subpopulation. J Nucl Med 2008; 49:2049-56. [DOI: 10.2967/jnumed.108.053876] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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28
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Colabufo NA, Berardi F, Abate C, Contino M, Niso M, Perrone R. Is the σ2Receptor a Histone Binding Protein? J Med Chem 2006; 49:4153-8. [PMID: 16821775 DOI: 10.1021/jm0600592] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Starting from the high affinity sigma(2) receptor ligand 2, (PB28), we synthesized amino derivative 4 and coupled it to an NHS-ester activated sepharose stationary phase column to elute a crude protein prepared by lysed human SK-N-SH neuroblastoma cells. We characterized the SDS-PAGE gel electrophoresis stained bands by MALDI-MS and LC-MS-MS analysis. The MASCOT MS-MS ion search program led to the identification of the protein components. The six eluted proteins had a molecular weight ranging from 13 kDa to 26 kDa and were human histone proteins. A human 40S ribosomal protein S3 (SwissProt accession number: P23396) was also identified as a comigrated band. The human histone proteins that were characterized were H3.3A histone (NCBI accession number: 51859376), H2B histone (NCBI accession number: 1568557), H2A.5 histone (NCBI accession number: 70686), H1 (NCBI accession number: 22770677), and H2.1 histone (SwissProt accession number: P16403). These results disclosed a dual hypothesis about the sigma(2) receptor, that is, that it is formed by histones or that the sigma(2) ligands also bind histone proteins.
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Affiliation(s)
- Nicola Antonio Colabufo
- Dipartimento Farmacochimico, Università degli Studi di Bari, via Orabona 4, 70125 Bari, Italy.
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29
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Hirata M, Mori T, Soga S, Umeda T, Ohmomo Y. Synthesis and in Vitro Evaluation of Iodinated Derivatives of Piperazine as a New Ligand for Sigma Receptor Imaging by Single Photon Emission Computed Tomography. Chem Pharm Bull (Tokyo) 2006; 54:470-5. [PMID: 16595947 DOI: 10.1248/cpb.54.470] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new series of radioiodinated analogues of 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(3-phenylpropyl)piperazine (SA4503) was synthesized and evaluated as a potential brain sigma-1 receptor imaging ligands by single photon emission computed tomography (SPECT). Iodinated analogues of SA4503 (4a-c) were prepared from piperazine in a high yield. The in vitro competition binding studies using [3H] DTG (sigma-1, 2), [3H] (+)-pentazocine (sigma-1), and [3H] DTG in the presence of carbetapentane (sigma-2) as sigma receptor selective radioligands were revealed that iodinated analogues 4a-c possess high affinities to sigma receptors (IC50: 4a=7.1, 4b=31.0, and 4c=77.3 nM). In particular, the affinity of 4a, bearing iodine at ortho position on the phenyl ring, was 4.4 times greater than SA4503, and 3 times greater than that of haloperidol. The meta-iodo analogue 4b was the same to SA4503, the lead compound. The radioiodinated derivatives, [125I] 4a, 4b were synthesized no-carrier-added from the corresponding tributyltin precursors by the iododestannylation reaction with high yields. The binding of [125I] 4a, 4b have been characterized in the rat brain membranes. These compounds were indicated single population binding to sigma receptor with high affinity (4a: Kd=1.86+/-0.34 nM, Bmax=205+/-28.9 fmol/mg protein, 4b: Kd=3.30+/-0.51 nM, Bmax=231.5+/-13.8 fmol/mg protein). In vitro blocking studies were confirmed that the high specificity of 4a, 4b. These results suggest that radioiodinated 4a and 4b are promising sigma receptors imaging ligand for pursuing further in vivo studies.
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30
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Klouz A, Tillement JP, Boussard MF, Wierzbicki M, Berezowski V, Cecchelli R, Labidalle S, Onténiente B, Morin D. [3H]BHDP as a novel and selective ligand for sigma1 receptors in liver mitochondria and brain synaptosomes of the rat. FEBS Lett 2003; 553:157-62. [PMID: 14550565 DOI: 10.1016/s0014-5793(03)01011-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The binding profile of [(3)H]BHDP ([(3)H]N-benzyl-N'-(2-hydroxy-3,4-dimethoxybenzyl)-piperazine) was evaluated. [(3)H]BHDP labelled a single class of binding sites with high affinity (K(d)=2-3 nM) in rat liver mitochondria and synaptic membranes. The pharmacological characterization of these sites using sigma reference compounds revealed that these sites are sigma receptors and, more particularly, sigma1 receptors. Indeed, BHDP inhibited [(3)H]pentazocine binding, a marker for sigma1 receptors, with high affinity in a competitive manner. BHDP is selective for sigma1 receptors since it did not show any relevant affinity for most of the other receptors, ion channels or transporters tested. Moreover, in an in vitro model of cellular hypoxia, BHDP prevented the fall in adenosine triphosphate (ATP) levels caused by 24 h hypoxia in cultured astrocytes. Taken together, these results demonstrate that [(3)H]BHDP is a potent and selective ligand for sigma1 receptors showing cytoprotective effects in astrocytes.
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Affiliation(s)
- Anis Klouz
- Laboratoire de Pharmacologie, EA427, Faculté de Médecine, Créteil, France
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31
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Kawamura K, Kobayashi T, Matsuno K, Ishiwata K. Different brain kinetics of two sigma 1 receptor ligands, [3H](+)-pentazocine and [11C]SA4503, by P-glycoprotein modulation. Synapse 2003; 48:80-6. [PMID: 12619041 DOI: 10.1002/syn.10190] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We compared the brain kinetics of radiolabeled (+)-pentazocine and SA4503, which have a high and selective affinity for sigma(1) receptors. Brain uptake of [(11)C]SA4503 was high after intravenous injection followed by a gradual decrease in mice, whereas that of [(3)H](+)-pentazocine rapidly decreased. The brain uptake of the two radioligands was dose-dependently reduced, but the reduction of [(3)H](+)-pentazocine was found at higher doses. Percentages of the saturable binding of [(3)H](+)-pentazocine was much lower than that of [(11)C]SA4503. The brain uptake of [(3)H](+)-pentazocine was greatly blocked by SA4503 at a dose of 2 micromol/kg, while that of [(11)C]SA4503 was blocked by (+)-pentazocine at a dose of 20 micromol/kg and over. When mice were treated with cyclosporin A, a P-glycoprotein modulator, the uptake of [(3)H](+)-pentazocine was enhanced, but that of [(11)C]SA4503 was not. Under control and P-glycoprotein-modulated conditions, the brain uptake of both radioligands was reduced by haloperidol, another representative sigma receptor ligand, to a different extent. We concluded that the P-glycoprotein modulation resulted in the different brain kinetics of the two radioligands. The radiolabeled SA4503 is suitable as an in vivo probe, but radiolabeled (+)-pentazocine is not.
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Affiliation(s)
- Kazunori Kawamura
- Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0022, Japan.
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32
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Klouz A, Sapena R, Liu J, Maurice T, Tillement JP, Papadopoulos V, Morin D. Evidence for sigma-1-like receptors in isolated rat liver mitochondrial membranes. Br J Pharmacol 2002; 135:1607-15. [PMID: 11934800 PMCID: PMC1573292 DOI: 10.1038/sj.bjp.0704626] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2001] [Accepted: 01/23/2002] [Indexed: 11/08/2022] Open
Abstract
1. Sigma (sigma) receptors have generated a great deal of interest on the basis of their possible roles in various pathologies, including cytoprotection. Although the exact function of sigma-1 (sigma(1)) receptors is not yet known, their role in the regulation of intracellular Ca(2+) levels and sterol biosynthesis, functions that could be assigned to mitochondria, are the only mechanisms described. 2. Using preparations of purified rat liver and brain mitochondria we demonstrate herein the presence of sigma-like binding sites. [(3)H](+)-pentazocine, a sigma(1) radioligand was used to label these sites. 3. In the liver, [(3)H](+)-pentazocine labelled one class of binding sites with high affinity (K(d)=3 nM), similar to that observed in liver microsomes and synaptic membranes. These sites were located on the outer mitochondrial membranes and displayed high affinity for other sigma(1) ligands namely, haloperidol, ifenprodil, carbetapentane or 1,3-di(2-tolyl)guanidine (DTG). 4. The presence of sigma(1) receptors on liver mitochondria was confirmed using double fluorescence immunostaining. 5. [(3)H](+)-pentazocine binding sites were also found on brain mitochondria but they appeared pharmacologically distinct to the liver ones as [(3)H](+)-pentazocine and typical sigma(1) ligands displayed lower affinities for these sites. Nevertheless, [(3)H](+)-pentazocine binding on both liver and brain mitochondria was modulated by progesterone, a putative endogenous ligand for sigma receptors. 6. Our data demonstrates the presence of [(3)H](+)-pentazocine binding sites with pharmacological characteristics identical to sigma(1) receptors on rat liver mitochondrial membranes. The pharmacological significance of these sites and their role on mitochondrial function remain unknown.
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Affiliation(s)
- Anis Klouz
- Département de Pharmacologie, Faculté de Médecine de Paris XII, F-94010 Créteil, France
| | - Rosa Sapena
- Département de Pharmacologie, Faculté de Médecine de Paris XII, F-94010 Créteil, France
| | - Jun Liu
- Division of Hormone Research, Department of Cell Biology, Georgetown University Medical Center, Washington DC 20007, U.S.A
| | | | - Jean-Paul Tillement
- Département de Pharmacologie, Faculté de Médecine de Paris XII, F-94010 Créteil, France
| | - Vassilios Papadopoulos
- Division of Hormone Research, Department of Cell Biology, Georgetown University Medical Center, Washington DC 20007, U.S.A
| | - Didier Morin
- Département de Pharmacologie, Faculté de Médecine de Paris XII, F-94010 Créteil, France
- CNRS, Faculté de Médecine de Paris XII, F-94010 Créteil, France
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33
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Höfner G, Wanner KT. [3H]ifenprodil binding to NMDA receptors in porcine hippocampal brain membranes. Eur J Pharmacol 2000; 394:211-9. [PMID: 10771286 DOI: 10.1016/s0014-2999(00)00084-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
(+/-)-2-(4-Benzylpiperidino)-1-(4-hydroxyphenyl)propan-1-ol ([3H]ifenprodil) binding to a subcellular fraction of porcine hippocampus, which was obtained by centrifugation on a discontinuous sucrose gradient, was investigated with the objective to label selectively the ifenprodil recognition site of native NMDA receptors. Saturation experiments revealed high-affinity sites for [3H]ifenprodil in this membrane fraction which could be characterised by a K(d) value of 23.0+/-1.8 nM using a one-site model. Calculation of saturation isotherms on the basis of a two-site model yielded a K(d1) value of 10.4+/-2.4 nM and a K(d2) value of 2200+/-1300 nM, respectively. Inhibition of [3H]ifenprodil binding by NR2B subunit-selective NMDA receptor antagonists, by polyamines, by sigma receptor ligands, by a variety of ligands acting at different NMDA receptor recognition sites and by several cations was studied and compared with the effects of these compounds on (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5, 10-imine ([3H]MK-801) binding under non-equilibrium conditions. It turned out that sigma receptor ligands such as 1, 3-di(2-tolyl)-guanidine (DTG), (+)-3-(3-hydroxyphenyl)-N-propylpiperidine (R)-3-PPP, (S)-3-PPP and (1-¿2-[bis(4-fluorophenyl)methoxy]ethyl¿)(-4-[3-phenylpropyl]piperazi ne) (GBR-12909) did not affect [3H]ifenprodil binding in the nanomolar range or only slightly. In contrast, ifenprodil, eliprodil, nylidrin and haloperidol inhibited [3H]ifenprodil binding in the nanomolar range and in the same rank order and with the same potency as observed for the inhibition of the high-affinity fraction of [3H]MK-801 binding. The polyamines, which activate NMDA receptors, inhibited [3H]ifenprodil binding in a biphasic manner. Their potency to inhibit the high-affinity fraction of [3H]ifenprodil binding was found to be in the same range as their potency to enhance [3H]MK-801 binding. In the presence of 10 microM spermine a significantly enhanced (P=0.0097) rate of dissociation of [3H]ifenprodil binding was found, suggesting that inhibition of [3H]ifenprodil binding by spermine is not, or at least not exclusively mediated by a competitive interaction.
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Affiliation(s)
- G Höfner
- Institut für Pharmazie, Zentrum für Pharmaforschung, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, D-81377, München, Germany.
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34
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Ahmed MS, Mather A, Enna SJ. Binding of [3H]desglycinyl remacemide to rat brain membranes: association with the benzomorphan attachment site of the N-methyl-D-aspartic acid receptor channel. Brain Res 1999; 827:46-50. [PMID: 10320692 DOI: 10.1016/s0006-8993(99)01263-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Desglycinyl remacemide (DGR), a biologically active metabolite of remacemide, was radiolabeled in an attempt to develop a ligand binding assay to identify its site of action. Incubation of the radioligand with membranes obtained from P2 fractions of whole rat brain revealed a single population of specific [3H]-DGR binding sites having a Kd of 290 nM and a Bmax of 1.3 pmole/mg protein. The specific binding of [3H]-DGR is most enriched in the P2 subcellular fraction and is heterogeneously distributed throughout the brain. The binding of [3H]-DGR to rat brain membranes was inhibited most potently by MK-801 and SKF-10,047. In contrast, haloperidol, and other sigma receptor-active agents, were relatively inactive at this site. These data suggest that DGR interacts with a channel blocking site on the NMDA receptor.
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Affiliation(s)
- M S Ahmed
- Schools of Pharmacy and Medicine, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO, 64108, USA
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35
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Bhardwaj A, Sawada M, London ED, Koehler RC, Traystman RJ, Kirsch JR. Potent ς
1
-Receptor Ligand 4-Phenyl-1-(4-Phenylbutyl) Piperidine Modulates Basal and
N
-Methyl-
d
-Aspartate–Evoked Nitric Oxide Production In Vivo. Stroke 1998. [DOI: 10.1161/01.str.29.11.2404] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose
—ς-Receptor ligands ameliorate ischemic neuronal injury and modulate neuronal responses to
N
-methyl-
d
-aspartate (NMDA) receptor stimulation. Because NMDA-evoked synthesis of nitric oxide (NO) may play an important role in excitotoxic-mediated injury, we tested the hypothesis that ς-receptor ligands attenuate basal and NMDA-evoked NO production in the striatum in vivo.
Methods
—Microdialysis probes were placed bilaterally into the striatum of halothane-anesthetized adult Wistar rats. Rats were divided into 7 treatment groups and perfused with artificial cerebrospinal fluid (aCSF) containing 3 μmol/L [
14
C]
l
-arginine for 2 to 3 hours followed by NMDA in various combinations with the following drugs:
l
-nitroarginine (L-NNA); the ς
1
-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine (PPBP); the selective ς
1
-receptor antagonist 1-(cyclopropylmethyl)-4-(2′-oxoethyl) piperidine hydrobromide (DuP 734); and the noncompetitive NMDA receptor blocker MK-801 in aCSF. Right-left differences between [
14
C]
l
-citrulline in the effluent from rats treated with different drug combinations were assumed to reflect differences in NO production.
Results
—After a 3-hour loading period with [
14
C]
l
-arginine, addition of 1 mmol/L NMDA increased [
14
C]
l
-citrulline recovery compared with aCSF alone. This NMDA-evoked increase was inhibited by 1 mmol/L of L-NNA and PPBP. Perfusion of 1 mmol/L of the ς
1
-receptor antagonist DuP 734 with 1 mmol/L PPBP augmented NMDA-evoked [
14
C]
l
-citrulline recovery compared with perfusion with PPBP and NMDA. MK-801 attenuated the basal as well as NMDA-evoked [
14
C]
l
-citrulline recovery. PPBP did not cause any further attenuation in the basal and NMDA-evoked [
14
C]
l
-citrulline recovery in the presence of MK-801.
Conclusions
—These data indicate that a ς
1
-receptor ligand attenuates basal as well as NMDA-evoked NO production. Because the attenuated NO production was reversed by DuP 734, PPBP appears to act as an agonist at the ς
1
-receptor. Attenuated NO production by ς
1
-receptor agonists provides one possible mechanism for focal ischemic neuroprotection.
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Affiliation(s)
- Anish Bhardwaj
- From the Departments of Neurology (A.B.) and Anesthesiology and Critical Care Medicine (A.B., M.S., R.C.K., R.J.T., J.R.K.), Johns Hopkins University School of Medicine, and National Institute on Drug Abuse (E.D.L.), Baltimore, Md
| | - Masahiko Sawada
- From the Departments of Neurology (A.B.) and Anesthesiology and Critical Care Medicine (A.B., M.S., R.C.K., R.J.T., J.R.K.), Johns Hopkins University School of Medicine, and National Institute on Drug Abuse (E.D.L.), Baltimore, Md
| | - Edythe D. London
- From the Departments of Neurology (A.B.) and Anesthesiology and Critical Care Medicine (A.B., M.S., R.C.K., R.J.T., J.R.K.), Johns Hopkins University School of Medicine, and National Institute on Drug Abuse (E.D.L.), Baltimore, Md
| | - Raymond C. Koehler
- From the Departments of Neurology (A.B.) and Anesthesiology and Critical Care Medicine (A.B., M.S., R.C.K., R.J.T., J.R.K.), Johns Hopkins University School of Medicine, and National Institute on Drug Abuse (E.D.L.), Baltimore, Md
| | - Richard J. Traystman
- From the Departments of Neurology (A.B.) and Anesthesiology and Critical Care Medicine (A.B., M.S., R.C.K., R.J.T., J.R.K.), Johns Hopkins University School of Medicine, and National Institute on Drug Abuse (E.D.L.), Baltimore, Md
| | - Jeffrey R. Kirsch
- From the Departments of Neurology (A.B.) and Anesthesiology and Critical Care Medicine (A.B., M.S., R.C.K., R.J.T., J.R.K.), Johns Hopkins University School of Medicine, and National Institute on Drug Abuse (E.D.L.), Baltimore, Md
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36
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Meyer C, Schmieding K, Falkenstein E, Wehling M. Are high-affinity progesterone binding site(s) from porcine liver microsomes members of the sigma receptor family? Eur J Pharmacol 1998; 347:293-9. [PMID: 9653896 DOI: 10.1016/s0014-2999(98)00103-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Membrane progesterone binding sites have been purified recently from pig liver. Since progesterone is considered as an endogenous sigma (sigma) receptor ligand, these sites were characterized pharmacologically by ligands selective for sigma receptor and dopamine receptor binding sites, and by other drugs from distinct pharmacological classes. Binding studies using the radioligand [3H]progesterone were done in crude membrane preparations and solubilized fractions to determine half-maximal inhibitory concentration (IC50) values, from which inhibitory constants (Ki values) were calculated. Radioligand binding was inhibited by the sigma receptor ligands haloperidol, carbetapentane citrate, 1,3-Di(2-tolyl)guanidine (DTG), R(-)-N-(3-phenyl-1-propyl)-1-phenyl-2 aminopropane HCl (R(-)-PPAAP HCl), or sigma receptor antagonists like (+)-3-(3-hydroxyphenyl)-N-propylpiperidine HCl (R(+)-PPP HCl) and cis-9-[3-(3,5-dimethyl-1-piperazinyl)propyl]-9H-carbazole dihydrochloride (rimcazole 2HCl). The hierarchy of inhibitory action was not fully compatible with either sigma receptor class I (moderate affinity of pentazocine, diphenylhydantoin (phenytoin) insensitivity) or II sites (high affinity of carbetapentane). The data thus suggest that progesterone binding sites in porcine liver membranes are related to the sigma receptor binding site superfamily, but may represent a particular species with progesterone specificity.
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Affiliation(s)
- C Meyer
- Division of Clinical Pharmacology, Medizinische Klinik, Klinikum Innenstadt, University of Munich, Germany
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37
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Senda T, Mita S, Kaneda K, Kikuchi M, Akaike A. Effect of SA4503, a novel sigma1 receptor agonist, against glutamate neurotoxicity in cultured rat retinal neurons. Eur J Pharmacol 1998; 342:105-11. [PMID: 9544798 DOI: 10.1016/s0014-2999(97)01450-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We examined the effects of sigma1 receptor agonists against glutamate-induced neurotoxicity in cultured retinal neurons. Primary cultures obtained from fetal rat retinas (16-19 d gestation) were used. The neurotoxic effect of glutamate was quantitatively assessed using the trypan blue exclusion method. A brief exposure of retinal cultures to glutamate (500 microM) led to delayed neuronal cell death. The glutamate-induced neurotoxicity was inhibited by (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo-[a,b]-cyclohepten-5 ,10-imine hydrogen maleate (MK-801). The sigma1 receptor agonists, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)-piperazine dihydrochloride (SA4503) and (+)-pentazocine at a concentration range of 0.1 approximately 100 microM reduced the glutamate-induced neurotoxicity in a dose-dependent manner. In addition, the neuroprotective effects of both SA4503 and (+)-pentazocine were antagonized by co-treatment with N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]ethylamine monohydrochloride (NE-100), a putative sigma1 receptor antagonist. These findings suggest that sigma1 receptor agonists protect retinal cells against glutamate-induced neurotoxicity.
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Affiliation(s)
- T Senda
- Discovery Research Division, Santen Pharmaceutical Co., Ltd., Osaka, Japan
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38
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Takahashi H, Traystman RJ, Hashimoto K, London ED, Kirsch JR. Postischemic brain injury is affected stereospecifically by pentazocine in rats. Anesth Analg 1997; 85:353-7. [PMID: 9249113 DOI: 10.1097/00000539-199708000-00020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We tested whether rats treated with the sigma1-receptor ligand, (+)-pentazocine, during transient focal ischemia would have a smaller volume of postischemic brain infarction than rats treated with the nonspecific opioid-receptor ligand (-)-pentazocine. Rats underwent focal cerebral ischemia using the filament occlusion technique for 2 h, followed by 22 h of reperfusion. Rats received (+) or (-)-pentazocine (n = 9 each group) at a dose of 2 mg x kg(-1) x h(-1) by continuous intravenous infusion from 1 h of ischemia to 22 h of reperfusion. Triphenyltetrazolium-determined infarction volume of ipsilateral striatum ([+]-pentazocine, 19 +/- 4 mm3, mean +/- SEM; [-]-pentazocine, 44 +/- 5 mm3) and cerebral cortex ([+]-pentazocine, 26 +/- 12 mm3; [-]-pentazocine, 134 +/- 29 mm3) was smaller in rats treated with (+) compared with (-)-pentazocine. Infarction volume in rats treated with (-)-pentazocine was also very similar to the infarction volume in saline-treated control rats from our previous study (striatum 44 +/- 4 mm3; hemisphere 136 +/- 27 mm3). These data indicate that sigma1-receptors may play an important role in the mechanism of injury both in cortex and striatum after 2 h of transient focal ischemia in rat.
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Affiliation(s)
- H Takahashi
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287-4963, USA
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39
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Takahashi H, Traystman RJ, Hashimoto K, London ED, Kirsch JR. Postischemic Brain Injury Is Affected Stereospecifically by Pentazocine in Rats. Anesth Analg 1997. [DOI: 10.1213/00000539-199708000-00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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40
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Moebius FF, Reiter RJ, Hanner M, Glossmann H. High affinity of sigma 1-binding sites for sterol isomerization inhibitors: evidence for a pharmacological relationship with the yeast sterol C8-C7 isomerase. Br J Pharmacol 1997; 121:1-6. [PMID: 9146879 PMCID: PMC1564641 DOI: 10.1038/sj.bjp.0701079] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
1. The sigma-drug binding site of guinea-pig liver is carried by a protein which shares significant amino acid sequence similarities with the yeast sterol C8-C7 isomerase (ERG2 protein). Pharmacologically-but not structurally-the sigma 1-site is also related to the emopamil binding protein, the mammalian sterol C8-C7 isomerase. We therefore investigated if sterol C8-C7 isomerase inhibitors are high affinity ligands for the (+)-[3H]-pentazocine labelled sigma 1-binding site. 2. Among the compounds which bound with high affinity to native hepatic and cerebral as well as to yeast expressed sigma 1-binding sites were the agricultural fungicide fenpropimorph (Ki 0.005 nM), the antihypocholesterinaemic drugs triparanol (Ki 7.0 nM), AY-9944 (Ki, 0.46 nM) and MDL28,815 (Ki 0.16 nM), the enantiomers of the ovulation inducer clomiphene (Ki 5.5 and 12 nM, respectively) and the antioestrogene tamoxifen (Ki 26 nM). 3. Except for tamoxifen these affinities are essentially identical with those for the [3H]-ifenprodil labelled sterol C8-C7 isomerase of S. cerevisiae. This demonstrates that sigma 1-binding protein and yeast isomerase are not only structurally but also pharmacologically related. Because of its affiliations with yeast and mammalian sterol isomerases we propose that the sigma 1-binding site is localized on a sterol isomerase related protein, involved in postsqualene sterol biosynthesis.
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MESH Headings
- Animals
- Binding Sites
- Brain/drug effects
- Brain/metabolism
- Calcium Channel Blockers/metabolism
- Clomiphene/metabolism
- Clomiphene/pharmacology
- Estrogen Antagonists/metabolism
- Estrogen Antagonists/pharmacology
- Excitatory Amino Acid Antagonists/metabolism
- Fertility Agents, Female/metabolism
- Fertility Agents, Female/pharmacology
- Fungicides, Industrial/metabolism
- Fungicides, Industrial/toxicity
- Guinea Pigs
- Hypolipidemic Agents/metabolism
- Hypolipidemic Agents/pharmacology
- Isoquinolines/metabolism
- Isoquinolines/pharmacology
- Isotope Labeling
- Microsomes/metabolism
- Microsomes, Liver/drug effects
- Microsomes, Liver/metabolism
- Morpholines/metabolism
- Morpholines/toxicity
- Pentazocine/metabolism
- Piperidines/metabolism
- Receptors, sigma/drug effects
- Receptors, sigma/metabolism
- Saccharomyces cerevisiae/enzymology
- Saccharomyces cerevisiae/metabolism
- Stereoisomerism
- Steroid Isomerases/antagonists & inhibitors
- Steroid Isomerases/metabolism
- Tamoxifen/metabolism
- Tamoxifen/pharmacology
- Triparanol/metabolism
- Triparanol/pharmacology
- Verapamil/analogs & derivatives
- Verapamil/metabolism
- trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride/metabolism
- trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride/pharmacology
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Affiliation(s)
- F F Moebius
- Institut für Biochemische Pharmakologie, Universität Innsbruck, Austria
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41
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Bouchard P, Quirion R. [3H]1,3-di(2-tolyl)guanidine and [3H](+)pentazocine binding sites in the rat brain: autoradiographic visualization of the putative sigma1 and sigma2 receptor subtypes. Neuroscience 1997; 76:467-77. [PMID: 9015331 DOI: 10.1016/s0306-4522(96)00221-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Sigma (sigma) receptors have generated a great deal of interest on the basis of their possible role in psychosis and on locomotor behaviors. The effects of sigma drugs on these various functions are apparently mediated by different sigma receptor subtypes (sigma1 and sigma2). However, little information is currently available on the discrete anatomical distribution of these putative sigma receptor subtypes in the rat brain. The aim of the present study was to investigate, by quantitative autoradiography, the respective distribution of purported sigma1 and sigma2 receptor subtypes in the rat brain using [3H]1,3-di(2-tolyl)guanidine, a universal sigma ligand, and [3H](+)pentazocine, a selective sigma1 ligand. Putative sigma2 receptor sites were visualized using [3H]1,3-di(2-tolyl)guanidine in presence of a saturating concentration of (+)pentazocine. Specific [3H]1,3-di(tolyl)guanidine and [3H](+)pentazocine binding sites were found to be widely but discretely distributed in the rat brain. The highest densities of specific labeling were seen in various cranial nerve nuclei, followed by certain hippocampal sub-fields and laminae, the red nucleus, the interpeduncular nucleus and mid-layers of primary and secondary motor cortices. Lower amounts of specific binding were present in various other structures including most thalamic and hypothalamic nuclei, and the cerebellum. Interestingly, [3H]1,3-di(2-tolyl)guanidine binding in the motor cortex was found to be particularly resistant to a saturating concentration of (+)pentazocine suggesting an enrichment in the putative sigma2 receptor subtype. This also applies for a few other structures such as the nucleus accumbens, substantia nigra pars reticulata, central gray matter, occulomotor nucleus and cerebellum. On the other hand, the sigma1 subtype is more abundant in most other regions with the highest densities seen in the dentate gyrus of the hippocampal formation, facial nucleus, and various thalamic and hypothalamic nuclei. The comparative localization of the sigma1 and sigma2 receptor binding sites probably relates to the differential effects of sigma1 and sigma2 drugs in the rat brain.
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Affiliation(s)
- P Bouchard
- Douglas Hospital Research Center, Verdun, Québec, Canada
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42
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Berardi F, Giudice G, Perrone R, Tortorella V, Govoni S, Lucchi L. Novel potent sigma 1 ligands: N-[omega-(tetralin-1-yl)alkyl]piperidine derivatives. J Med Chem 1996; 39:4255-60. [PMID: 8863803 DOI: 10.1021/jm9508898] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A series of substituted N-[(tetralin-1-yl)alkyl]piperidines and a number of related N-di-n-propyl-[(tetralin-1-yl)alkyl]amines were prepared. Structural modifications such as piperidine substitutions, intermediate chain lengthening, and the nature of the aromatic ring were explored in order to identify structural requirements for selective sigma 1 affinity. They were tested in radioligand binding assays on sigma 1, 5-HT1A and 5-HT2 serotonergic, PCP (phencyclidine), and D-2 dopaminergic receptors. Almost all the compounds reported here showed a high to superpotent sigma 1 affinity, and some compounds also demonstrated a widespread selectivity over the other receptors. In [3H]-(+)-pentazocine binding, 3,3-dimethyl-1-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)-n- propyl] piperidine (24) and 3,3-dimethyl-1-[4-(1,2,3,4-tetrahydronaphthalen-1-yl)-n- butyl]piperidine (26) reached the lowest Ki values (0.4 and 0.8 nM, respectively); compound 24 also demonstrated a considerable PCP affinity (Ki = 34.2 nM), whereas compound 26 was suitably selective. Furthermore the presence of a 4-benzyl substituent on the piperidine ring (compound 16, Ki = 3.9 nM on sigma 1 sites) caused an increase in 5-HT1A affinity (Ki < 0.14 nM).
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Affiliation(s)
- F Berardi
- Dipartimento Farmaco-chimico, Università di Bari, Italy
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43
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DeHaven-Hudkins DL, Daubert JD, Sawutz DG, Tiberio L, Baine Y. [3H]1,3-di(2-tolyl) guanidine binds to a sigma 2 receptor on Jurkat cell membranes, but sigma compounds fail to influence immunomodulatory events in human peripheral blood lymphocytes. IMMUNOPHARMACOLOGY 1996; 35:27-39. [PMID: 8913792 DOI: 10.1016/0162-3109(96)00107-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The binding characteristics of the sigma ligand [3H]1.3-di(2-tolyl)guanidine (DTG) were investigated in membranes prepared from the Jurkat T cell line. Binding was saturable with a KD of 56 +/- 3 nM and a Bmax of 11706 +/- 3173 fmol/mg protein (n = 3). The rank order of potency for sigma reference compounds to inhibit binding in the Jurkat cell line was ifenprodil > 1,3-di(2-tolyl)guanidine > haloperidol > carbetapentane > (+)3-(3-hydroxyphenyl)-N-propylpiperidine ((+)3-PPP) > (-)pentazocine > caramiphen > (+)pentazocine, and significantly correlated with potency at sigma 2 binding sites in guinea pig brain (r = 0.90, p < 0.01). The immunomodulatory activities of the sigma ligands 1,3-di(2-tolyl)guanidine, haloperidol. (-)pentazocine and (+)pentazocine on CD3-induced proliferation, IL-2 production and Ca2+ flux in human lymphocytes did not reveal any consistent pharmacology that could be ascribed to potency of these compounds at sigma binding sites. Collectively the data demonstrate that the [3H]1,3-di(2-tolyl)guanidine binding site on Jurkat cell membranes has a pharmacology consistent with sigma receptors, but no modulation of functional activity or intracellular events in human peripheral blood lymphocytes correlating with sigma receptors was found.
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Affiliation(s)
- D L DeHaven-Hudkins
- Department of Biochemistry, Sterling Winthrop Pharmaceuticals Research Division, Collegeville, PA 19426, USA
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44
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Hanner M, Moebius FF, Flandorfer A, Knaus HG, Striessnig J, Kempner E, Glossmann H. Purification, molecular cloning, and expression of the mammalian sigma1-binding site. Proc Natl Acad Sci U S A 1996; 93:8072-7. [PMID: 8755605 PMCID: PMC38877 DOI: 10.1073/pnas.93.15.8072] [Citation(s) in RCA: 724] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Sigma-ligands comprise several chemically unrelated drugs such as haloperidol, pentazocine, and ditolylguanidine, which bind to a family of low molecular mass proteins in the endoplasmic reticulum. These so-called sigma-receptors are believed to mediate various pharmacological effects of sigma-ligands by as yet unknown mechanisms. Based on their opposite enantioselectivity for benzomorphans and different molecular masses, two subtypes are differentiated. We purified the sigma1-binding site as a single 30-kDa protein from guinea pig liver employing the benzomorphan(+)[3H]pentazocine and the arylazide (-)[3H]azidopamil as specific probes. The purified (+)[3H]pentazocine-binding protein retained its high affinity for haloperidol, pentazocine, and ditolylguanidine. Partial amino acid sequence obtained after trypsinolysis revealed no homology to known proteins. Radiation inactivation of the pentazocine-labeled sigma1-binding site yielded a molecular mass of 24 +/- 2 kDa. The corresponding cDNA was cloned using degenerate oligonucleotides and cDNA library screening. Its open reading frame encoded a 25.3-kDa protein with at least one putative transmembrane segment. The protein expressed in yeast cells transformed with the cDNA showed the pharmacological characteristics of the brain and liver sigma1-binding site. The deduced amino acid sequence was structurally unrelated to known mammalian proteins but it shared homology with fungal proteins involved in sterol synthesis. Northern blots showed high densities of the sigma1-binding site mRNA in sterol-producing tissues. This is also in agreement with the known ability of sigma1-binding sites to interact with steroids, such as progesterone.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding Sites
- Binding, Competitive
- Brain/metabolism
- Chromatography, Affinity
- Chromatography, Ion Exchange
- Cloning, Molecular
- DNA Primers
- DNA, Complementary
- DNA-Binding Proteins/chemistry
- Guinea Pigs
- Intracellular Membranes/metabolism
- Kinetics
- Ligands
- Mammals
- Microsomes/metabolism
- Microsomes, Liver/metabolism
- Molecular Sequence Data
- Pentazocine/metabolism
- Polymerase Chain Reaction
- Receptors, sigma/chemistry
- Receptors, sigma/isolation & purification
- Receptors, sigma/metabolism
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/chemistry
- Recombinant Proteins/isolation & purification
- Saccharomyces cerevisiae
- Sequence Homology, Amino Acid
- Trans-Activators/chemistry
- Transcriptional Regulator ERG
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Affiliation(s)
- M Hanner
- Instit für Biochemische Pharmakologie, Universität Innsbruck, Austria
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45
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Sagi N, Yamamoto H, Yamamoto T, Okuyama S, Moroji T. Possible expression of a sigma 1 site in rat pheochromocytoma (PC12) cells. Eur J Pharmacol 1996; 304:185-90. [PMID: 8813601 DOI: 10.1016/0014-2999(96)00115-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To examine the functional interaction between the sigma binding sites and nicotinic acetylcholine receptors, we investigated the effects of various sigma receptor ligands on nicotine-evoked Ca2+ uptake in differentiated PC12 cells. The IC50 values of sigma receptor ligands tested in this uptake study did not correlate with their Ki values in the [3H]1, 3-di(2-tolyl) guanidine ([3H]DTG) binding to guinea pig brain reported by Rothman et al. (1991). To clarify further the binding characteristics of the sigma binding sites on PC12 cells, we examined the effects of sigma receptor ligands on [3H]N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]-ethylamine HCl ([3H]NE-100) binding to PC12 membranes. The Ki values of the various drugs tested for [3H]NE-100 binding site closely correlated with their Ki values for the DTG site-1 reported by Rothman et al. (1991). This study showed that PC12 cells express sigma 1-like sites and the inhibitory effect of sigma receptor ligands on the nicotine-evoked Ca2+ uptake was not directly coupled with either the sigma 1 or sigma 2 sites.
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Affiliation(s)
- N Sagi
- Department of Psychopharmacology, Tokyo Institute of Psychiatry, Japan
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46
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Berardi F, Colabufo NA, Giudice G, Perrone R, Tortorella V, Govoni S, Lucchi L. New sigma and 5-HT1A receptor ligands: omega-(tetralin-1-yl)-n-alkylamine derivatives. J Med Chem 1996; 39:176-82. [PMID: 8568804 DOI: 10.1021/jm950409c] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Two series of compounds that are structurally related to benzomorphans, derived by structural modification of arylpiperazines with high 5-HT1A affinity and moderate sigma affinity, were prepared in order to increase sigma affinity and selectivity. All new compounds are N-substituted-omega-(1,2,3,4-tetrahydronaphthalen-1-yl)- or -omega-(1,2-dihydronaphthalen-4-yl)-n-alkylamines with, in some cases, a methoxy group on the tetralin moiety. They were tested in radioligand binding assays on sigma ([3H]DTG and [3H]-(+)-pentazocine), D-2 dopaminergic, 5-HT1A and 5-HT2 serotonergic, and PCP (phencyclidine) receptors. A first set of compounds bearing a 4-(1-substituted)piperazine moiety as terminal fragment on the alkyl chain showed moderate to high sigma affinity (Ki = 5.3-139 nM), the most active and selective being 1-cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)-n- propyl ]piperazine (14), with probable pronounced sigma 2 affinity (Ki = 5.3 nM on [3H]DTG and Ki = 71 nM on [3H]-(+)-pentazocine). Moreover, compound 13, a 1-benzylpiperazine analogue of 14, preserved a dual high 5-HT1A and sigma affinity (Ki = 3.6 nM on [3H]-5-HT and Ki = 7.0 nM on [3H]DTG). The second set of compounds includes some N-phenylalkyl derivatives of 3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)- n-propylamine that can be considered to be open-chain derivatives of 4-substituted-1-arylpiperazines. Among these compounds that had a lower activity toward sigma binding sites, a high 5-HT1A affinity was found for the N-(3-phenylpropyl) derivative 21 (Ki = 4.4 nM) which demonstrated very good selectivity.
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Affiliation(s)
- F Berardi
- Dipartimento Farmaco-chimico, Università di Bari, Italy
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47
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Kornhuber J, Schoppmeyer K, Bendig C, Riederer P. Characterization of [3H]pentazocine binding sites in post-mortem human frontal cortex. J Neural Transm (Vienna) 1996; 103:45-53. [PMID: 9026376 DOI: 10.1007/bf01292615] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We investigated binding characteristics of [3H](+)-pentazocine in homogenates of post-mortem human frontal cortex. At equilibrium, specific binding was linear with protein concentration, was saturable, reversible, stereoselective, heat-labile and was nearly absent in the white matter. Saturation experiments revealed a KD of 3.68 +/- 0.46nM and a B(max) of 0.636 +/- 0.107 pmol/mg protein. The rank order of Ki values of competing substances was: haloperidol < N,N'-di(o-tolyl)guanidine (DTG) < (+)-SKF 10,047 < (-)-SKF 10,047. We also examined the influence of age, gender, hemisphere, post-mortem time and storage time of brain tissue at -80 degrees C on [3H](+)-pentazocine binding sites. Of these variables, only age was significantly related to [3H](+)-pentazocine binding (diminished binding with increasing age). Together, our results demonstrate the presence of specific [3H](+)-pentazocine binding sites in post-mortem human brain tissue. Furthermore, the binding sites decrease with increasing age and are apparently independent of gender, hemisphere, post-mortem time and storage time of brain tissue.
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Affiliation(s)
- J Kornhuber
- Department of Psychiatry, University of Würzburg, Federal Republic of Germany
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48
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Church J, Fletcher EJ. Blockade by sigma site ligands of high voltage-activated Ca2+ channels in rat and mouse cultured hippocampal pyramidal neurones. Br J Pharmacol 1995; 116:2801-10. [PMID: 8680709 PMCID: PMC1909231 DOI: 10.1111/j.1476-5381.1995.tb15929.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
1. The effects of a series of structurally-dissimilar sigma site ligands were examined on high voltage-activated Ca2+ channel activity in two preparations of cultured hippocampal pyramidal neurones. 2. In mouse hippocampal neurones under whole-cell voltage-clamp, voltage-activated Ca2+ channel currents carried by barium ions (IBa) were reduced with the rank order (IC50 values in microM): 1S,2R-(-)-cis-N-methyl-N-[2-(3,4-dichlorophenyl)ethyl]- 2-(1-pyrrolidinyl)cyclohexylamine (7.8) > rimcazole (13) > haloperidol (16) > ifenprodil (18) > opipramol (32) > carbetapentane (40) = 1-benzylspiro[1,2,3,4-tetrahydronaphthalene-1,4-piperidine] (42) > caramiphen (47) > dextromethorphan (73). At the highest concentrations tested, the compounds almost abolished IBa in the absence of any other pharmacological agent. 3. The current-voltage characteristics of the whole-cell IBa were unaffected by the test compounds. The drug-induced block was rapid in onset and offset, with the exceptions of carbetapentane and caramiphen where full block was achieved only after two to three voltage-activated currents and was associated with an apparent increase in the rate of inactivation of IBa. 4. In rat hippocampal neurones loaded with the Ca(2+)-sensitive dye Fura-2, rises in intracellular free Ca2+ concentration evoked by transient exposure to 50 mM K(+)-containing medium, either in the absence or in the presence of 10 microM nifedipine (to block L-type high voltage-activated Ca2+ channels), were also reversibly attenuated by the sigma ligands. The rank order potencies for the compounds in these experimental paradigms were similar to that observed for blockade of IBa in the electrophysiological studies. 5. These results indicate that, at micromolar concentrations, the compounds tested block multiple subtypes of high voltage-activated Ca2+ channels. These actions, which do not appear to be mediated by high-affinity sigma binding sites, may play a role in some of the functional effects previously described for the compounds.
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Affiliation(s)
- J Church
- Department of Anatomy, University of British Columbia, Vancouver, Canada
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49
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Kovács KJ, Larson AA. Discrepancies in characterization of sigma sites in the mouse central nervous system. Eur J Pharmacol 1995; 285:127-34. [PMID: 8566130 DOI: 10.1016/0014-2999(95)00383-v] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The characteristics of [3H](+)-pentazocine and [3H]1,3-di(2-tolyl) guanidine (DTG) binding to mouse whole brain, cortex, cerebellum and spinal cord membranes were investigated in radioreceptor assays. [3H](+)-Pentazocine bound to a single, high affinity site (Kd = 1.2-1.6 nM) with increasing density along the neuraxis from the cortex (Bmax = 543 fmol/mg protein) to the spinal cord (Bmax = 886 fmol/mg protein). Hot saturation studies resolved the presence of one binding site for [3H]DTG showing no tissue variations in terms of density (Bmax = 1075-1264 fmol/mg protein) or affinity (Kd = 16.6-22.3 nM). Incubation with 100 nM (+)-pentazocine revealed two classes of high affinity [3H]DTG labeled binding sites corresponding to sigma 1 and sigma 2 subtypes. A preponderance of sigma 2 sites was revealed in all investigated tissues. Different pharmacological profiles were demonstrated for the sigma 2 sites in mouse whole bain compared to mouse spinal cord. However, competition studies indicated that the whole brain and spinal [3H](+)-pentazocine labeled sigma 1 binding sites exhibited similar pharmacological properties. The density of [3H](+)-pentazocine labeled sigma 1 population was found not to match that of [3H]DTG labeled sigma 1 site throughout the mouse central nervous system. The presence of low affinity [3H]DTG labeled sites was demonstrated in cold saturation experiments. Equilibrium binding data for the low affinity [3H]DTG binding site resulted in an increasing density (Bmax = 1973-11,369 fmol/mg protein) with a decreasing affinity (Kd = 242-943 nM) in mouse cortex through the spinal cord.
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Affiliation(s)
- K J Kovács
- Department of Veterinary Pathobiology, University of Minnesota, St. Paul 55108, USA
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50
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Sircar R, He HJ, Li CS. Chronic postnatal phencyclidine treatment on [3H](+) pentazocine binding in juvenile rat brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1995; 88:224-6. [PMID: 8665670 DOI: 10.1016/0165-3806(95)00093-s] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chronic phencyclidine (PCP) administrations in postnatal rats produce long-term behavioral changes. Here we report the effects of repeated postnatal PCP treatment on [3H](+)pentazocine binding in juvenile rats. Saturation analyses of the binding data showed no significant difference in any of the binding characteristics between chronic PCP-related rats and saline-treated controls suggesting that mechanisms other than alterations in sigma1 binding underlie the behavioral effects of repeated postnatal PCP administration in immature rats.
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Affiliation(s)
- R Sircar
- Department of Psychiatry and Neurology, Albert Einstein College of Medicine, Bronx, NY, USA
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