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Prasanth MI, Verma K, Brimson S, Tencomnao T, Brimson JM. Simple ammonium salt and sigma-1 receptor ligand dipentylammonium provides neuroprotective effects in cell culture and Caenorhabditis elegans models of Alzheimer's disease. Biomed Pharmacother 2024; 173:116455. [PMID: 38503234 DOI: 10.1016/j.biopha.2024.116455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 03/21/2024] Open
Abstract
The sigma-1 receptor (σ-1R), a chaperone protein located at the mitochondria-associated membrane (MAM) of the endoplasmic reticulum, can interact with and modify the signaling pathways of various proteins, thereby modulating many disease pathologies, including Alzheimer's disease (AD). The σ-1R ligand dipentylammonium (DPA) was analyzed for its anti-AD properties using PC12 cells (in vitro) and Caenorhabditis elegans (in vivo) models along with molecular docking (in silico) analysis. DPA at 1 and 10 µM concentrations was able to significantly potentiate NGF-induced neurite growth length by 137.7 ± 12.0 and 187.8 ± 16.4, respectively, when compared to the control 76.9 ± 7.4. DPA also regulated neurite damage caused by Aβ(25-35) treatment in differentiated PC12 cells by improving cell viability and neurite length. In C. elegans, DPA could significantly extend the median and maximum lifespan of Aβ transgenic strain CL2006 without impacting wild-type nematodes. Additionally, it could significantly reduce the paralysis phenotype of another Aβ transgenic strain, CL4176, thereby improving the overall health in AD pathogenesis. This effect depended on σ-1R, as DPA could not modulate the lifespan of σ-1R mutant TM3443. This was further confirmed using agonist PRE084 and antagonist BD1047, wherein the agonist alone could extend the lifespan of CL2006, while the antagonist suppressed the effect of DPA in CL2006. Interestingly, neither had an TM3443. Further, molecular docking analysis showed that DPA had a similar binding affinity as that of PRE084, BD1047 and pentazocine against the σ-1R receptor in humans and C. elegans, which collectively suggests the anti-AD properties of DPA.
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Affiliation(s)
- Mani Iyer Prasanth
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand; Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kanika Verma
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand; Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand; Department of Molecular Epidemiology, ICMR-National Institute of Malaria Research (NIMR), New Delhi 110077, India
| | - Sirikalaya Brimson
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tewin Tencomnao
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand; Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
| | - James Michael Brimson
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand; Research Unit for Innovation and International Affairs, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
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Malar DS, Thitilertdecha P, Ruckvongacheep KS, Brimson S, Tencomnao T, Brimson JM. Targeting Sigma Receptors for the Treatment of Neurodegenerative and Neurodevelopmental Disorders. CNS Drugs 2023; 37:399-440. [PMID: 37166702 PMCID: PMC10173947 DOI: 10.1007/s40263-023-01007-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/18/2023] [Indexed: 05/12/2023]
Abstract
The sigma-1 receptor is a 223 amino acid-long protein with a recently identified structure. The sigma-2 receptor is a genetically unrelated protein with a similarly shaped binding pocket and acts to influence cellular activities similar to the sigma-1 receptor. Both proteins are highly expressed in neuronal tissues. As such, they have become targets for treating neurological diseases, including Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), multiple sclerosis (MS), Rett syndrome (RS), developmental and epileptic encephalopathies (DEE), and motor neuron disease/amyotrophic lateral sclerosis (MND/ALS). In recent years, there have been many pre-clinical and clinical studies of sigma receptor (1 and 2) ligands for treating neurological disease. Drugs such as blarcamesine, dextromethorphan and pridopidine, which have sigma-1 receptor activity as part of their pharmacological profile, are effective in treating multiple aspects of several neurological diseases. Furthermore, several sigma-2 receptor ligands are under investigation, including CT1812, rivastigmine and SAS0132. This review aims to provide a current and up-to-date analysis of the current clinical and pre-clinical data of drugs with sigma receptor activities for treating neurological disease.
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Affiliation(s)
- Dicson S Malar
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand
| | - Premrutai Thitilertdecha
- Siriraj Research Group in Immunobiology and Therapeutic Sciences, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Kanokphorn S Ruckvongacheep
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Sirikalaya Brimson
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Tewin Tencomnao
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand
| | - James M Brimson
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand.
- Research, Innovation and International Affairs, Faculty of Allied Health Sciences, Chulalongkorn University, Room 409, ChulaPat-1 Building, 154 Rama 1 Road, Bangkok, 10330, Thailand.
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Li J, Satyshur KA, Guo LW, Ruoho AE. Sphingoid Bases Regulate the Sigma-1 Receptor-Sphingosine and N, N'-Dimethylsphingosine Are Endogenous Agonists. Int J Mol Sci 2023; 24:3103. [PMID: 36834510 PMCID: PMC9962145 DOI: 10.3390/ijms24043103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/28/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
Both bioactive sphingolipids and Sigma-1 receptor (S1R) chaperones occur ubiquitously in mammalian cell membranes. Endogenous compounds that regulate the S1R are important for controlling S1R responses to cellular stress. Herein, we interrogated the S1R in intact Retinal Pigment Epithelial cells (ARPE-19) with the bioactive sphingoid base, sphingosine (SPH), or the pain-provoking dimethylated SPH derivative, N,N'-dimethylsphingosine (DMS). As informed by a modified native gel approach, the basal and antagonist (BD-1047)-stabilized S1R oligomers dissociated to protomeric forms in the presence of SPH or DMS (PRE-084 as control). We, thus, posited that SPH and DMS are endogenous S1R agonists. Consistently, in silico docking of SPH and DMS to the S1R protomer showed strong associations with Asp126 and Glu172 in the cupin beta barrel and extensive van der Waals interactions of the C18 alkyl chains with the binding site including residues in helices 4 and 5. Mean docking free energies were 8.73-8.93 kcal/mol for SPH and 8.56-8.15 kcal/mol for DMS, and calculated binding constants were ~40 nM for SPH and ~120 nM for DMS. We hypothesize that SPH, DMS, and similar sphingoid bases access the S1R beta barrel via a membrane bilayer pathway. We further propose that the enzymatic control of ceramide concentrations in intracellular membranes as the primary sources of SPH dictates availability of endogenous SPH and DMS to the S1R and the subsequent control of S1R activity within the same cell and/or in cellular environments.
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Affiliation(s)
- Jing Li
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Kenneth A. Satyshur
- Small Molecule Screening Facility, Carbone Cancer Center, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA
| | - Lian-Wang Guo
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA
| | - Arnold E. Ruoho
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705, USA
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Dvorácskó S, Lázár L, Fülöp F, Palkó M, Zalán Z, Penke B, Fülöp L, Tömböly C, Bogár F. Novel High Affinity Sigma-1 Receptor Ligands from Minimal Ensemble Docking-Based Virtual Screening. Int J Mol Sci 2021; 22:8112. [PMID: 34360878 PMCID: PMC8347176 DOI: 10.3390/ijms22158112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 02/07/2023] Open
Abstract
Sigma-1 receptor (S1R) is an intracellular, multi-functional, ligand operated protein that also acts as a chaperone. It is considered as a pluripotent drug target in several pathologies. The publication of agonist and antagonist bound receptor structures has paved the way for receptor-based in silico drug design. However, recent studies on this subject payed no attention to the structural differences of agonist and antagonist binding. In this work, we have developed a new ensemble docking-based virtual screening protocol utilizing both agonist and antagonist bound S1R structures. This protocol was used to screen our in-house compound library. The S1R binding affinities of the 40 highest ranked compounds were measured in competitive radioligand binding assays and the sigma-2 receptor (S2R) affinities of the best S1R binders were also determined. This way three novel high affinity S1R ligands were identified and one of them exhibited a notable S1R/S2R selectivity.
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Affiliation(s)
- Szabolcs Dvorácskó
- Biological Research Centre, Institute of Biochemistry, Eötvös Loránd Research Network (ELKH), H-6726 Szeged, Hungary; (S.D.); (C.T.)
| | - László Lázár
- Institute of Pharmaceutical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (L.L.); (F.F.); (M.P.); (Z.Z.)
| | - Ferenc Fülöp
- Institute of Pharmaceutical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (L.L.); (F.F.); (M.P.); (Z.Z.)
| | - Márta Palkó
- Institute of Pharmaceutical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (L.L.); (F.F.); (M.P.); (Z.Z.)
| | - Zita Zalán
- Institute of Pharmaceutical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (L.L.); (F.F.); (M.P.); (Z.Z.)
| | - Botond Penke
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary;
| | - Lívia Fülöp
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary;
| | - Csaba Tömböly
- Biological Research Centre, Institute of Biochemistry, Eötvös Loránd Research Network (ELKH), H-6726 Szeged, Hungary; (S.D.); (C.T.)
| | - Ferenc Bogár
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary;
- MTA-SZTE Biomimetic Systems Research Group, Eötvös Loránd Research Network (ELKH), H-6720 Szeged, Hungary
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Aishwarya R, Abdullah CS, Morshed M, Remex NS, Bhuiyan MS. Sigmar1's Molecular, Cellular, and Biological Functions in Regulating Cellular Pathophysiology. Front Physiol 2021; 12:705575. [PMID: 34305655 PMCID: PMC8293995 DOI: 10.3389/fphys.2021.705575] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/07/2021] [Indexed: 12/11/2022] Open
Abstract
The Sigma 1 receptor (Sigmar1) is a ubiquitously expressed multifunctional inter-organelle signaling chaperone protein playing a diverse role in cellular survival. Recessive mutation in Sigmar1 have been identified as a causative gene for neuronal and neuromuscular disorder. Since the discovery over 40 years ago, Sigmar1 has been shown to contribute to numerous cellular functions, including ion channel regulation, protein quality control, endoplasmic reticulum-mitochondrial communication, lipid metabolism, mitochondrial function, autophagy activation, and involved in cellular survival. Alterations in Sigmar1’s subcellular localization, expression, and signaling has been implicated in the progression of a wide range of diseases, such as neurodegenerative diseases, ischemic brain injury, cardiovascular diseases, diabetic retinopathy, cancer, and drug addiction. The goal of this review is to summarize the current knowledge of Sigmar1 biology focusing the recent discoveries on Sigmar1’s molecular, cellular, pathophysiological, and biological functions.
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Affiliation(s)
- Richa Aishwarya
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
| | - Chowdhury S Abdullah
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
| | - Mahboob Morshed
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
| | - Naznin Sultana Remex
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
| | - Md Shenuarin Bhuiyan
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States.,Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
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Brimson JM, Prasanth MI, Malar DS, Brimson S, Thitilertdecha P, Tencomnao T. Drugs that offer the potential to reduce hospitalization and mortality from SARS-CoV-2 infection: The possible role of the sigma-1 receptor and autophagy. Expert Opin Ther Targets 2021; 25:435-449. [PMID: 34236922 PMCID: PMC8290373 DOI: 10.1080/14728222.2021.1952987] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023]
Abstract
Introduction: Despite the availability of new vaccines for SARS-CoV-2, there has been slow uptake and problems with supply in some parts of the world. Hence, there is still a necessity for drugs that can prevent hospitalization of patients and reduce the strain on health care systems. Drugs with sigma affinity potentially provide protection against the most severe symptoms of SARS-COV-2 and could prevent mortality via interactions with the sigma-1 receptor.Areas covered: This review examines the role of the sigma-1 receptor and autophagy in SARS-CoV-2 infections and how they may be linked. The authors reveal how sigma ligands may reduce the symptoms, complications, and deaths resulting from SARS-CoV-2 and offer insights on those patient cohorts that may benefit most from these drugs.Expert opinion: Drugs with sigma affinity potentially offer protection against the most severe symptoms of SARS-CoV-2 via interactions with the sigma-1 receptor. Agonists of the sigma-1 receptor may provide protection of the mitochondria, activate mitophagy to remove damaged and leaking mitochondria, prevent ER stress, manage calcium ion transport, and induce autophagy to prevent cell death in response to infection.
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Affiliation(s)
- James Michael Brimson
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Mani Iyer Prasanth
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Dicson Sheeja Malar
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Sirikalaya Brimson
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Premrutai Thitilertdecha
- Siriraj Research Group in Immunobiology and Therapeutic Sciences, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Tewin Tencomnao
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
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Brimson JM, Brimson S, Chomchoei C, Tencomnao T. Using sigma-ligands as part of a multi-receptor approach to target diseases of the brain. Expert Opin Ther Targets 2020; 24:1009-1028. [PMID: 32746649 DOI: 10.1080/14728222.2020.1805435] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The sigma receptors are found abundantly in the central nervous system and are targets for the treatment of various diseases, including Alzheimer's (AD), Parkinson's (PD), Huntington's disease (HD), depression, amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). However, for many of these diseases, other receptors and targets have been the focus of the most, such as acetylcholine esterase inhibitors in Alzheimer's and dopamine replacement in Parkinson's. The currently available drugs for these diseases have limited success resulting in the requirement of an alternative approach to their treatment. AREAS COVERED In this review, we discuss the potential role of the sigma receptors and their ligands as part of a multi receptor approach in the treatment of the diseases mentioned above. The literature reviewed was obtained through searches in databases, including PubMed, Web of Science, Google Scholar, and Scopus. EXPERT OPINION Given sigma receptor agonists provide neuroprotection along with other benefits such as potentiating the effects of other receptors, further development of multi-receptor targeting ligands, and or the development of multi-drug combinations to target multiple receptors may prove beneficial in the future treatment of degenerative diseases of the CNS, especially when coupled with better diagnostic techniques.
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Affiliation(s)
- James Michael Brimson
- Age-related Inflammation and Degeneration Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University , Bangkok, Thailand
| | - Sirikalaya Brimson
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University , Bangkok, Thailand
| | - Chanichon Chomchoei
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University , Bangkok, Thailand
| | - Tewin Tencomnao
- Age-related Inflammation and Degeneration Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University , Bangkok, Thailand
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Aydar E, Cobos EJ, Maurice T, Murell-Lagnado RD, Safrany ST. Editorial: Sigma Receptors. Front Pharmacol 2020; 11:590519. [PMID: 33013426 PMCID: PMC7493683 DOI: 10.3389/fphar.2020.590519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 08/12/2020] [Indexed: 12/11/2022] Open
Affiliation(s)
- Ebru Aydar
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Enrique J Cobos
- Instituto de Investigación Biosanitaria ibs.GRANADA and Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Tangui Maurice
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
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Brimson JM, Akula KK, Abbas H, Ferry DR, Kulkarni SK, Russell ST, Tisdale MJ, Tencomnao T, Safrany ST. Simple ammonium salts acting on sigma-1 receptors yield potential treatments for cancer and depression. Sci Rep 2020; 10:9251. [PMID: 32514120 PMCID: PMC7280195 DOI: 10.1038/s41598-020-65849-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 05/06/2020] [Indexed: 01/11/2023] Open
Abstract
Sigma-1 and sigma-2 receptors are emerging therapeutic targets. We have identified that simple ammonium salts bind to these receptors and are effective in vivo. Radioligand binding assays were used to obtain structure-activity relationships of these salts. MTS assays were performed to determine their effect on growth in MCF7 and MDA-MB-486 cells. Anticancer properties were tested in NMRI mice transplanted with a fragment of mouse adenocarcinoma (MAC13). Antidepressant activity was tested using the forced-swim test and tail suspension tests. Dipentylammonium (Ki 43 nM), tripentylammonium (Ki 15 nM) and trihexylammonium (Ki 9 nM) showed high affinity for the sigma-1 receptor. Dioctanoylammonium had the highest affinity (K50 0.05 nM); this also showed the highest affinity for sigma-2 receptors (Ki 13 nM). Dipentylammonium was found to have antidepressant activity in vivo. Branched-chain ammonium salts showed lower affinity. Bis(2-ethylhexyl)ammonium (K50 29 µM), triisopentylammonium (K50 196 µM) and dioctanoylammonium showed a low Hill slope, and fitted a 2-site binding model for the sigma-1 receptor. We propose this two-site binding can be used to biochemically define a sigma-1 receptor antagonist. Bis(2-ethylhexyl)ammonium and triisopentylammonium were able to inhibit the growth of tumours in vivo. Cheap, simple ammonium salts act as sigma-1 receptor agonists and antagonists in vivo and require further investigation.
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Affiliation(s)
- James M Brimson
- Age-Related Inflammation and Degeneration Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Kiran K Akula
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
- Ultragenyx Pharmaceuticals Inc, Novato, California, CA94949, USA
| | - Haider Abbas
- Department of Pharmacy, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1LY, UK
- New Cross Hospital, Wolverhampton, WV10 0QP, UK
- University Hospital Birmingham NHS Foundation Trust, Mindelsohn Way, Birmingham, B15 2TH, UK
| | - David R Ferry
- Eli Lilly, 893 S Delaware Street, Indianapolis, IN, 46225, USA
| | - Shrinivas K Kulkarni
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
| | - Steven T Russell
- School of Health and Life Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Michael J Tisdale
- School of Health and Life Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Tewin Tencomnao
- Age-Related Inflammation and Degeneration Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Stephen T Safrany
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
- Department of Pharmacy, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1LY, UK.
- RCSI-Bahrain, PO Box 15503, Adliya, Kingdom of Bahrain.
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Abbas H, Borde P, Willars GB, Ferry DR, Safrany ST. Hazards of Using Masking Protocols When Performing Ligand Binding Assays: Lessons From the Sigma-1 and Sigma-2 Receptors. Front Pharmacol 2020; 11:309. [PMID: 32231573 PMCID: PMC7082753 DOI: 10.3389/fphar.2020.00309] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 03/02/2020] [Indexed: 11/13/2022] Open
Abstract
Sigma-1 and sigma-2 receptors are emerging therapeutic targets. Although the molecular identity of the sigma-2 receptor has recently been determined, receptor quantitation has used, and continues to use, the sigma-1 selective agents (+) pentazocine or dextrallorphan to mask the sigma-1 receptor in radioligand binding assays. Here, we have assessed the suitability of currently established saturation and competition binding isotherm assays that are used to quantify parameters of the sigma-2 receptor. We show that whilst the sigma-1 receptor mask (+) pentazocine has low affinity for the sigma-2 receptor (Ki 406 nM), it can effectively compete at this site with [³H] di-O-tolyl guanidine (DTG) at the concentrations frequently used to mask the sigma-1 receptor (100 nM and 1 µM). This competition influences the apparent affinity of DTG and other ligands tested in this system. A more troublesome issue is that DTG can displace (+) pentazocine from the sigma-1 receptor, rendering it partly unmasked. Indeed, commonly used concentrations of (+) pentazocine, 100 nM and 1 µM, allowed 37 and 11% respectively of sigma-1 receptors to be bound by DTG (300 nM), which could result in an overestimation of sigma-2 receptor numbers in assays where sigma-1 receptors are also present. Similarly, modelled data for 1 µM dextrallorphan show that only 71–86% of sigma-1 receptors would be masked in the presence of 300 nM DTG. Therefore, the use of dextrallorphan as a masking agent would also lead to the overestimation of sigma-2 receptors in systems where sigma-1 receptors are present. These data highlight the dangers of using masking agents in radioligand binding studies and we strongly recommend that currently used masking protocols are not used in the study of sigma-2 receptors. In order to overcome these problems, we recommend the use of a cell line apparently devoid of sigma-1 receptors [e.g., MCF7 (ATCC HTB-22)] in the absence of any masking agent when determining the affinity of agents for the sigma-2 receptor. In addition, assessing the relative levels of sigma-1 and sigma-2 receptors can be achieved using [³H] DTG saturation binding followed by two-site analysis of (+) pentazocine competition binding with [³H] DTG.
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Affiliation(s)
- Haider Abbas
- School of Pharmacy, University of Wolverhampton, Wolverhampton, United Kingdom.,Oncology Department, New Cross Hospital, Wolverhampton, United Kingdom
| | - Preeti Borde
- School of Medicine, RCSI-Bahrain, Adliya, Bahrain
| | - Gary B Willars
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - David R Ferry
- Gastrointestinal Oncology Strategy, Eli Lilly, Indianapolis, IN, United States
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Oyer HM, Sanders CM, Kim FJ. Small-Molecule Modulators of Sigma1 and Sigma2/TMEM97 in the Context of Cancer: Foundational Concepts and Emerging Themes. Front Pharmacol 2019; 10:1141. [PMID: 31695608 PMCID: PMC6816035 DOI: 10.3389/fphar.2019.01141] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/04/2019] [Indexed: 12/17/2022] Open
Abstract
There are two known subtypes of the so-called sigma receptors, Sigma1 and Sigma2. Sigma1 (encoded by the SIGMAR1 gene and also known as Sigma-1 receptor, S1R) is a unique pharmacologically regulated integral membrane chaperone or scaffolding protein that allosterically modulates the activity of its associated proteins. Sigma2, recently identified as transmembrane protein 97 (TMEM97), is an integral membrane protein implicated in cellular cholesterol homeostasis. A number of publications over the past two decades have suggested a role for both sigma proteins in tumor biology. Although there is currently no clinically used anti-cancer drug that targets Sigma1 or Sigma2/TMEM97, a growing body of evidence supports the potential of small-molecule compounds with affinity for these proteins, putative sigma ligands, as therapeutic agents to treat cancer. In preclinical models, these compounds have been reported to inhibit cancer cell proliferation, survival, adhesion, and migration; furthermore, they have been demonstrated to suppress tumor growth, to alleviate cancer-associated pain, and to exert immunomodulatory properties. Here, we will address the known knowns and the known unknowns of Sigma1 and Sigma2/TMEM97 ligand actions in the context of cancer. This review will highlight key discoveries and published evidence in support of a role for sigma proteins in cancer and will discuss several fundamental questions regarding the physiological roles of sigma proteins in cancer and sigma ligand mechanism of action.
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Affiliation(s)
- Halley M Oyer
- Department of Cancer Biology, Sidney Kimmel Cancer Center at Thomas Jefferson University, Philadelphia, PA, United States
| | - Christina M Sanders
- Department of Cancer Biology, Sidney Kimmel Cancer Center at Thomas Jefferson University, Philadelphia, PA, United States
| | - Felix J Kim
- Department of Cancer Biology, Sidney Kimmel Cancer Center at Thomas Jefferson University, Philadelphia, PA, United States
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Brimson JM, Safrany ST, Qassam H, Tencomnao T. Dipentylammonium Binds to the Sigma-1 Receptor and Protects Against Glutamate Toxicity, Attenuates Dopamine Toxicity and Potentiates Neurite Outgrowth in Various Cultured Cell Lines. Neurotox Res 2018; 34:263-272. [PMID: 29589276 DOI: 10.1007/s12640-018-9883-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/14/2018] [Accepted: 02/19/2018] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease is a neurodegenerative disease that affects 44 million people worldwide, costing the world $605 billion to care for those affected not taking into account the physical and psychological costs for those who care for Alzheimer's patients. Dipentylammonium is a simple amine, which is structurally similar to a number of other identified sigma-1 receptor ligands with high affinities such as (2R-trans)-2butyl-5-heptylpyrrolidine, stearylamine and dodecylamine. This study investigates whether dipentylammonium is able to provide neuroprotective effects similar to those of sigma-1 receptor agonists such as PRE-084. Here we identify dipentylammonium as a sigma-1 receptor ligand with nanomolar affinity. We have found that micromolar concentrations of dipentylammonium protect from glutamate toxicity and prevent NFκB activation in HT-22 cells. Micromolar concentrations of dipentylammonium also protect stably expressing amyloid precursor protein Swedish mutant (APP/Swe) Neuro2A cells from toxicity induced by 150 μM dopamine, suggesting that dipentylammonium may be useful for the treatment of Parkinsonian symptoms in Alzheimer's patients which are often associated with a more rapid deterioration of cognitive and physical ability. Finally, we found that low micromolar concentrations of dipentylammonium could out preform known sigma-1 receptor agonist PRE-084 in potentiating neurite outgrowth in Neuro2A cells, further suggesting that dipentylammonium has a potential use in the treatment of neurodegenerative diseases and could be acting through the sigma-1 receptor.
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Affiliation(s)
- James M Brimson
- Age-related Inflammation and Degeneration Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10230, Thailand
| | - Stephen T Safrany
- Royal College of Surgeons in Ireland, Medical University of Bahrain, P.O. Box 15503, Adliya, Bahrain
| | - Heider Qassam
- Department of Molecular and Cell Biology, University in Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 7RH, UK
| | - Tewin Tencomnao
- Age-related Inflammation and Degeneration Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10230, Thailand.
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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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14
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Dalwadi DA, Kim S, Schetz JA. Activation of the sigma-1 receptor by haloperidol metabolites facilitates brain-derived neurotrophic factor secretion from human astroglia. Neurochem Int 2017; 105:21-31. [PMID: 28188803 PMCID: PMC5375023 DOI: 10.1016/j.neuint.2017.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/31/2017] [Accepted: 02/06/2017] [Indexed: 02/07/2023]
Abstract
Glial cells play a critical role in neuronal support which includes the production and release of the neurotrophin brain-derived neurotrophic factor (BDNF). Activation of the sigma-1 receptor (S1R) has been shown to attenuate inflammatory stress-mediated brain injuries, and there is emerging evidence that this may involve a BDNF-dependent mechanism. In this report we studied S1R-mediated BDNF release from human astrocytic glial cells. Astrocytes express the S1R, which mediates BDNF release when stimulated with the prototypical S1R agonists 4-PPBP and (+)-SKF10047. This effect could be antagonized by a selective concentration of the S1R antagonist BD1063. Haloperidol is known to have high affinity interactions with the S1R, yet it was unable to facilitate BDNF release. Remarkably, however, two metabolites of haloperidol, haloperidol I and haloperidol II (reduced haloperidol), were discovered to facilitate BDNF secretion and this effect was antagonized by BD1063. Neither 4-PPBP, nor either of the haloperidol metabolites affected the level of BDNF mRNA as assessed by qPCR. These results demonstrate for the first time that haloperidol metabolites I and II facilitate the secretion of BDNF from astrocytes by acting as functionally selective S1R agonists.
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Affiliation(s)
- Dhwanil A Dalwadi
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas, 76107, United States
| | - Seongcheol Kim
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas, 76107, United States
| | - John A Schetz
- Department of Pharmacology & Neuroscience, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas, 76107, United States; Institute for Healthy Aging, Center for Neuroscience Discovery, United States.
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Abstract
Sigma1 (also known as sigma-1 receptor, Sig1R, σ1 receptor) is a unique pharmacologically regulated integral membrane chaperone or scaffolding protein. The majority of publications on the subject have focused on the neuropharmacology of Sigma1. However, a number of publications have also suggested a role for Sigma1 in cancer. Although there is currently no clinically used anti-cancer drug that targets Sigma1, a growing body of evidence supports the potential of Sigma1 ligands as therapeutic agents to treat cancer. In preclinical models, compounds with affinity for Sigma1 have been reported to inhibit cancer cell proliferation and survival, cell adhesion and migration, tumor growth, to alleviate cancer-associated pain, and to have immunomodulatory properties. This review will highlight that although the literature supports a role for Sigma1 in cancer, several fundamental questions regarding drug mechanism of action and the physiological relevance of aberrant SIGMAR1 transcript and Sigma1 protein expression in certain cancers remain unanswered or only partially answered. However, emerging lines of evidence suggest that Sigma1 is a component of the cancer cell support machinery, that it facilitates protein interaction networks, that it allosterically modulates the activity of its associated proteins, and that Sigma1 is a selectively multifunctional drug target.
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Affiliation(s)
- Felix J Kim
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 North 15th Street, Philadelphia, PA, USA.
- Sidney Kimmel Cancer Center, Philadelphia, PA, USA.
| | - Christina M Maher
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 North 15th Street, Philadelphia, PA, USA
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Lee JK, Nam DOH, Lee J. Repurposing antipsychotics as glioblastoma therapeutics: Potentials and challenges. Oncol Lett 2016; 11:1281-1286. [PMID: 26893731 DOI: 10.3892/ol.2016.4074] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 05/29/2015] [Indexed: 12/30/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the most common and most lethal primary brain tumor, with tragically little therapeutic progress over the last 30 years. Surgery provides a modest benefit, and GBM cells are resistant to radiation and chemotherapy. Despite significant development of the molecularly targeting strategies, the clinical outcome of GBM patients remains dismal. The challenges inherent in developing effective GBM treatments have become increasingly clear, and include resistance to standard treatments, the blood-brain barrier, resistance of GBM stem-like cells, and the genetic complexity and molecular adaptability of GBM. Recent studies have collectively suggested that certain antipsychotics harbor antitumor effects and have potential utilities as anti-GBM therapeutics. In the present review, the anti-tumorigenic effects and putative mechanisms of antipsychotics, and the challenges for the potential use of antipsychotic drugs as anti-GBM therapeutics are reviewed.
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Affiliation(s)
- Jin-Ku Lee
- Cancer Stem Cell Research Center, Department of Neurosurgery, Samsung Medical Center and Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea
| | - DO-Hyun Nam
- Cancer Stem Cell Research Center, Department of Neurosurgery, Samsung Medical Center and Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea
| | - Jeongwu Lee
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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van Waarde A, Rybczynska AA, Ramakrishnan NK, Ishiwata K, Elsinga PH, Dierckx RAJO. Potential applications for sigma receptor ligands in cancer diagnosis and therapy. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1848:2703-14. [PMID: 25173780 DOI: 10.1016/j.bbamem.2014.08.022] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/04/2014] [Accepted: 08/19/2014] [Indexed: 01/03/2023]
Abstract
Sigma receptors (sigma-1 and sigma-2) represent two independent classes of proteins. Their endogenous ligands may include the hallucinogen N,N-dimethyltryptamine (DMT) and sphingolipid-derived amines which interact with sigma-1 receptors, besides steroid hormones (e.g., progesterone) which bind to both sigma receptor subpopulations. The sigma-1 receptor is a ligand-regulated molecular chaperone with various ion channels and G-protein-coupled membrane receptors as clients. The sigma-2 receptor was identified as the progesterone receptor membrane component 1 (PGRMC1). Although sigma receptors are over-expressed in tumors and up-regulated in rapidly dividing normal tissue, their ligands induce significant cell death only in tumor tissue. Sigma ligands may therefore be used to selectively eradicate tumors. Multiple mechanisms appear to underlie cell killing after administration of sigma ligands, and the signaling pathways are dependent both on the type of ligand and the type of tumor cell. Recent evidence suggests that the sigma-2 receptor is a potential tumor and serum biomarker for human lung cancer and an important target for inhibiting tumor invasion and cancer progression. Current radiochemical efforts are focused on the development of subtype-selective radioligands for positron emission tomography (PET) imaging. Right now, the mostpromising tracers are [18F]fluspidine and [18F]FTC-146 for sigma-1 receptors and [11C]RHM-1 and [18F]ISO-1 for the sigma-2 subtype. Nanoparticles coupled to sigma ligands have shown considerable potential for targeted delivery of antitumor drugs in animal models of cancer, but clinical studies exploring this strategy in cancer patients have not yet been reported. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
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Affiliation(s)
- Aren van Waarde
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
| | - Anna A Rybczynska
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Nisha K Ramakrishnan
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Kiichi Ishiwata
- Tokyo Metropolitan Institute of Gerontology, Research Team for Neuroimaging, 35-2 Sakae-Cho, Itabashi-Ku, Tokyo 173-0015, Japan
| | - Philip H Elsinga
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Rudi A J O Dierckx
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Ghent, University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
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18
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Abstract
This review compares the biological and physiological function of Sigma receptors [σRs] and their potential therapeutic roles. Sigma receptors are widespread in the central nervous system and across multiple peripheral tissues. σRs consist of sigma receptor one (σ1R) and sigma receptor two (σ2R) and are expressed in numerous regions of the brain. The sigma receptor was originally proposed as a subtype of opioid receptors and was suggested to contribute to the delusions and psychoses induced by benzomorphans such as SKF-10047 and pentazocine. Later studies confirmed that σRs are non-opioid receptors (not an µ opioid receptor) and play a more diverse role in intracellular signaling, apoptosis and metabolic regulation. σ1Rs are intracellular receptors acting as chaperone proteins that modulate Ca2+ signaling through the IP3 receptor. They dynamically translocate inside cells, hence are transmembrane proteins. The σ1R receptor, at the mitochondrial-associated endoplasmic reticulum membrane, is responsible for mitochondrial metabolic regulation and promotes mitochondrial energy depletion and apoptosis. Studies have demonstrated that they play a role as a modulator of ion channels (K+ channels; N-methyl-d-aspartate receptors [NMDAR]; inositol 1,3,5 triphosphate receptors) and regulate lipid transport and metabolism, neuritogenesis, cellular differentiation and myelination in the brain. σ1R modulation of Ca2+ release, modulation of cardiac myocyte contractility and may have links to G-proteins. It has been proposed that σ1Rs are intracellular signal transduction amplifiers. This review of the literature examines the mechanism of action of the σRs, their interaction with neurotransmitters, pharmacology, location and adverse effects mediated through them.
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Affiliation(s)
- Colin G Rousseaux
- a Department of Pathology and Laboratory Medicine , University of Ottawa , Ottawa , ON , Canada and
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20
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Pan B, Guo Y, Kwok WM, Hogan Q, Wu HE. Sigma-1 receptor antagonism restores injury-induced decrease of voltage-gated Ca2+ current in sensory neurons. J Pharmacol Exp Ther 2014; 350:290-300. [PMID: 24891452 PMCID: PMC4109486 DOI: 10.1124/jpet.114.214320] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/29/2014] [Indexed: 01/01/2023] Open
Abstract
Sigma-1 receptor (σ1R), an endoplasmic reticulum-chaperone protein, can modulate painful response after peripheral nerve injury. We have demonstrated that voltage-gated calcium current is inhibited in axotomized sensory neurons. We examined whether σ1R contributes to the sensory dysfunction of voltage-gated calcium channel (VGCC) after peripheral nerve injury through electrophysiological approach in dissociated rat dorsal root ganglion (DRG) neurons. Animals received either skin incision (Control) or spinal nerve ligation (SNL). Both σ1R agonists, (+)pentazocine (PTZ) and DTG [1,3-di-(2-tolyl)guanidine], dose dependently inhibited calcium current (ICa) with Ba(2+) as charge carrier in control sensory neurons. The inhibitory effect of σ1R agonists on ICa was blocked by σ1R antagonist, BD1063 (1-[2-(3,4-dichlorophenyl)ethyl]-4-methylpiperazine dihydrochloride) or BD1047 (N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino)ethylamine dihydrobromide). PTZ and DTG showed similar effect on ICa in axotomized fifth DRG neurons (SNL L5). Both PTZ and DTG shifted the voltage-dependent activation and steady-state inactivation of VGCC to the left and accelerated VGCC inactivation rate in both Control and axotomized L5 SNL DRG neurons. The σ1R antagonist, BD1063 (10 μM), increases ICa in SNL L5 neurons but had no effect on Control and noninjured fourth lumbar neurons in SNL rats. Together, the findings suggest that activation of σR1 decreases ICa in sensory neurons and may play a pivotal role in pain generation.
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Affiliation(s)
- Bin Pan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin (B.P., Y.G., W.-M.K., Q.H., H.-e.W.); and Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin (Q.H.)
| | - Yuan Guo
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin (B.P., Y.G., W.-M.K., Q.H., H.-e.W.); and Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin (Q.H.)
| | - Wai-Meng Kwok
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin (B.P., Y.G., W.-M.K., Q.H., H.-e.W.); and Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin (Q.H.)
| | - Quinn Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin (B.P., Y.G., W.-M.K., Q.H., H.-e.W.); and Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin (Q.H.)
| | - Hsiang-en Wu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin (B.P., Y.G., W.-M.K., Q.H., H.-e.W.); and Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin (Q.H.)
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21
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Schrock JM, Spino CM, Longen CG, Stabler SM, Marino JC, Pasternak GW, Kim FJ. Sequential cytoprotective responses to Sigma1 ligand-induced endoplasmic reticulum stress. Mol Pharmacol 2013; 84:751-62. [PMID: 24006496 DOI: 10.1124/mol.113.087809] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Sigma1 receptor (Sigma1) is an endoplasmic reticulum (ER) integral membrane protein that is highly expressed in a number of cancer cell lines. Small molecule compounds targeting Sigma1 (Sigma1 ligands) inhibit cancer cell proliferation and induce apoptotic cell death in vitro and inhibit tumor growth in xenograft experiments. However, the cellular pathways activated by Sigma1 protein-ligand interaction are not well defined. Here, we find that treatment with some Sigma1 ligands induces ER stress and activates the unfolded protein response (UPR) in a dose- and time-responsive manner in a range of adenocarcinoma cell lines. Autophagy is engaged after extended treatment with Sigma1 ligands, which suggests that protracted UPR results in autophagy as a secondary response. Inhibition of UPR by RNAi-mediated knockdown of inositol-requiring enzyme 1α and activating transcription factor 4 abrogates autophagosome formation, as does knockdown of essential autophagy gene products Beclin1 and autophagy protein 5. Knockdown of Sigma1 also suppresses IPAG [1-(4-iodophenyl)-3-(2-adamantyl) guanidine] induced UPR marker and autophagosome levels, indicating that this response is indeed Sigma1-mediated. We find that UPR activation precedes autophagosome formation and autophagy precedes apoptosis in Sigma1 ligand-treated cells. These processes are reversible, and washout of IPAG before cell death results in a return of autophagosomes and UPR markers toward basal levels. However, inhibition of Sigma1 ligand-induced UPR or autophagy accelerates apoptotic cell death. Together, these data suggest that UPR and autophagy are engaged as primary and secondary cytoprotective responses, respectively, to Sigma1 ligand-induced disruption of cancer cell protein homeostasis.
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Affiliation(s)
- Joel M Schrock
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania (C.M.S., C.G.L., F.J.K.); and Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York (J.M.S., S.M.S., J.C.M., G.W.P.)
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Laurini E, Marson D, Dal Col V, Fermeglia M, Mamolo MG, Zampieri D, Vio L, Pricl S. Another brick in the wall. Validation of the σ1 receptor 3D model by computer-assisted design, synthesis, and activity of new σ1 ligands. Mol Pharm 2012; 9:3107-26. [PMID: 23020867 DOI: 10.1021/mp300233y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Originally considered an enigmatic polypeptide, the σ(1) receptor has recently been identified as a unique ligand-regulated protein. Many studies have shown the potential of σ(1) receptor ligands for the treatment of various diseases of the central nervous system (CNS); nevertheless, almost no information about the 3D structure of the receptor and/or the possible modes of interaction of the σ(1) protein with its ligands have been unveiled so far. With the present work we validated our σ(1) 3D homology model and assessed its reliability as a platform for σ(1) ligand structure-based drug design. To this purpose, the 3D σ(1) model was exploited in the design of 33 new σ(1) ligands and in their ranking for receptor affinity by extensive molecular dynamics simulation-based free energy calculations. Also, the main interactions involved in receptor/ligand binding were analyzed by applying a per residue free energy deconvolution and in silico alanine scanning mutagenesis calculations. Subsequently, all compounds were synthesized in our laboratory and tested for σ(1) binding activity in vitro. The agreement between in silico and in vitro results confirms the reliability of the proposed σ(1) 3D model in the a priori prediction of the affinity of new σ(1) ligands. Moreover, it also supports and corroborates the currently available biochemical data concerning the σ(1) protein residues considered essential for σ(1) ligand binding and activity.
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Affiliation(s)
- Erik Laurini
- Molecular Simulation Engineering Laboratory, Department of Industrial Engineering and Information Technology, University of Trieste, Via Valerio 10, 34127 Trieste, Italy
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