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Couly S, Yasui Y, Foncham S, Grammatikakis I, Lal A, Shi L, Su TP. Benzomorphan and non-benzomorphan agonists differentially alter sigma-1 receptor quaternary structure, as does types of cellular stress. Cell Mol Life Sci 2024; 81:14. [PMID: 38191696 PMCID: PMC10774196 DOI: 10.1007/s00018-023-05023-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 01/10/2024]
Abstract
Sigma-1 receptor (S1R) is a calcium-sensitive, ligand-operated receptor chaperone present on the endoplasmic reticulum (ER) membrane. S1R plays an important role in ER-mitochondrial inter-organelle calcium signaling and cell survival. S1R and its agonists confer resilience against various neurodegenerative diseases; however, the molecular mechanism of S1R is not yet fully understood. At resting state, S1R is either in a monomeric or oligomeric state but the ratio of these concentrations seems to change upon activation of S1R. S1R is activated by either cellular stress, such as ER-calcium depletion, or ligands. While the effect of ligands on S1R quaternary structure remains unclear, the effect of cellular stress has not been studied. In this study we utilize cellular and an in-vivo model to study changes in quaternary structure of S1R upon activation. We incubated cells with cellular stressors (H2O2 and thapsigargin) or exogenous ligands, then quantified monomeric and oligomeric forms. We observed that benzomorphan-based S1R agonists induce monomerization of S1R and decrease oligomerization, which was confirmed in the liver tissue of mice injected with (+)-Pentazocine. Antagonists block this effect but do not induce any changes when used alone. Oxidative stress (H2O2) increases the monomeric/oligomeric S1R ratio whereas ER calcium depletion (thapsigargin) has no effect. We also analyzed the oligomerization ability of various truncated S1R fragments and identified the fragments favorizing oligomerization. In this publication we demonstrate that quaternary structural changes differ according to the mechanism of S1R activation. Therefore, we offer a novel perspective on S1R activation as a nuanced phenomenon dependent on the type of stimulus.
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Affiliation(s)
- Simon Couly
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute On Drug Abuse, NIH/DHHS, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Yuko Yasui
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute On Drug Abuse, NIH/DHHS, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Semnyonga Foncham
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute On Drug Abuse, NIH/DHHS, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Ioannis Grammatikakis
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), Bethesda, MD, 20892, USA
| | - Ashish Lal
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), Bethesda, MD, 20892, USA
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute On Drug Abuse, NIH/DHHS, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute On Drug Abuse, NIH/DHHS, 333 Cassell Drive, Baltimore, MD, 21224, USA.
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Wang J, Barwick SR, Xiao H, Smith SB. Evaluation of the role of Sigma 1 receptor and Cullin3 in retinal photoreceptor cells. Free Radic Biol Med 2023; 205:214-223. [PMID: 37328017 PMCID: PMC10527355 DOI: 10.1016/j.freeradbiomed.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/24/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
Sigma 1 receptor (Sig1R), a pluripotent modulator of cell survival, is neuroprotective in models of retinal degeneration when activated by the high-affinity, high-specificity ligand (+)-pentazocine ((+)-PTZ). The molecular mechanisms of Sig1R-mediated retinal neuroprotection are under investigation. We previously reported that the antioxidant regulatory transcription factor Nrf2 may be involved in Sig1R-mediated retinal photoreceptor cell (PRC) rescue. Cullin 3 (Cul3) is a component of the Nrf2-Keap1 antioxidant pathway and facilitates Nrf2 ubiquitination. Our earlier transcriptome analysis revealed decreased Cul3 in retinas lacking Sig1R. Here, we asked whether Sig1R activation can modulate Cul3 expression in 661 W cone PRCs. Proximity ligation and co-immunoprecipitation (co-IP) showed that Cul3 resides closely to and co-IPs with Sig1R. Activation of Sig1R using (+)-PTZ significantly increased Cul3 at the gene/protein level; silencing Sig1R decreased Cul3 gene/protein levels. Experiments in which Cul3 was silenced in cells exposed to tBHP resulted in increased oxidative stress, which was not attenuated with Sig1R activation by (+)-PTZ, whereas cells transfected with scrambled siRNA (and incubated with tBHP) responded to (+)-PTZ treatment by decreasing levels of oxidative stress. Assessment of mitochondrial respiration and glycolysis revealed significantly improved maximal respiration, spare capacity and glycolytic capacity in oxidatively-stressed cells transfected with scrambled siRNA and treated with (+)-PTZ, but not in (+)-PTZ treated, oxidatively-stressed cells in which Cul3 had been silenced. The data provide the first evidence that Sig1R co-localizes/interacts with Cul3, a key player in the Nrf2-Keap1 antioxidant pathway. The data suggest that the preservation of mitochondrial respiration/glycolytic function and reduction of oxidative stress observed upon activation of Sig1R occur in part in a Cul3-dependent manner.
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Affiliation(s)
- Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Shannon R Barwick
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Haiyan Xiao
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, USA.
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Wang T, Jia H. The Sigma Receptors in Alzheimer's Disease: New Potential Targets for Diagnosis and Therapy. Int J Mol Sci 2023; 24:12025. [PMID: 37569401 PMCID: PMC10418732 DOI: 10.3390/ijms241512025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/14/2023] [Accepted: 07/16/2023] [Indexed: 08/13/2023] Open
Abstract
Sigma (σ) receptors are a class of unique proteins with two subtypes: the sigma-1 (σ1) receptor which is situated at the mitochondria-associated endoplasmic reticulum (ER) membrane (MAM), and the sigma-2 (σ2) receptor, located in the ER-resident membrane. Increasing evidence indicates the involvement of both σ1 and σ2 receptors in the pathogenesis of Alzheimer's disease (AD), and thus these receptors represent two potentially effective biomarkers for emerging AD therapies. The availability of optimal radioligands for positron emission tomography (PET) neuroimaging of the σ1 and σ2 receptors in humans will provide tools to monitor AD progression and treatment outcomes. In this review, we first summarize the significance of both receptors in the pathophysiology of AD and highlight AD therapeutic strategies related to the σ1 and σ2 receptors. We then survey the potential PET radioligands, with an emphasis on the requirements of optimal radioligands for imaging the σ1 or σ2 receptors in humans. Finally, we discuss current challenges in the development of PET radioligands for the σ1 or σ2 receptors, and the opportunities for neuroimaging to elucidate the σ1 and σ2 receptors as novel biomarkers for early AD diagnosis, and for monitoring of disease progression and AD drug efficacy.
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Affiliation(s)
- Tao Wang
- Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China;
- Department of Nuclear Medicine, Xinqiao Hospital, Army Medical University, Chongqing 400037, China
| | - Hongmei Jia
- Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China;
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Zhao J, Veeranan-Karmegam R, Baker FC, Mysona BA, Bagchi P, Liu Y, Smith SB, Gonsalvez GB, Bollinger KE. Defining the ligand-dependent proximatome of the sigma 1 receptor. Front Cell Dev Biol 2023; 11:1045759. [PMID: 37351276 PMCID: PMC10284605 DOI: 10.3389/fcell.2023.1045759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 05/16/2023] [Indexed: 06/24/2023] Open
Abstract
Sigma 1 Receptor (S1R) is a therapeutic target for a wide spectrum of pathological conditions ranging from neurodegenerative diseases to cancer and COVID-19. S1R is ubiquitously expressed throughout the visceral organs, nervous, immune and cardiovascular systems. It is proposed to function as a ligand-dependent molecular chaperone that modulates multiple intracellular signaling pathways. The purpose of this study was to define the S1R proximatome under native conditions and upon binding to well-characterized ligands. This was accomplished by fusing the biotin ligase, Apex2, to the C terminus of S1R. Cells stably expressing S1R-Apex or a GFP-Apex control were used to map proximal proteins. Biotinylated proteins were labeled under native conditions and in a ligand dependent manner, then purified and identified using quantitative mass spectrometry. Under native conditions, S1R biotinylates over 200 novel proteins, many of which localize within the endomembrane system (endoplasmic reticulum, Golgi, secretory vesicles) and function within the secretory pathway. Under conditions of cellular exposure to either S1R agonist or antagonist, results show enrichment of proteins integral to secretion, extracellular matrix formation, and cholesterol biosynthesis. Notably, Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) displays increased binding to S1R under conditions of treatment with Haloperidol, a well-known S1R antagonist; whereas Low density lipoprotein receptor (LDLR) binds more efficiently to S1R upon treatment with (+)-Pentazocine ((+)-PTZ), a classical S1R agonist. Furthermore, we demonstrate that the ligand bound state of S1R correlates with specific changes to the cellular secretome. Our results are consistent with the postulated role of S1R as an intracellular chaperone and further suggest important and novel functionalities related to secretion and cholesterol metabolism.
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Affiliation(s)
- Jing Zhao
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Culver Vision Discovery Institute, Augusta, GA, United States
| | - Rajalakshmi Veeranan-Karmegam
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Frederick C. Baker
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Barbara A. Mysona
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Culver Vision Discovery Institute, Augusta, GA, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Pritha Bagchi
- Emory Integrated Proteomics Core, Emory University, Atlanta, GA, United States
| | - Yutao Liu
- Culver Vision Discovery Institute, Augusta, GA, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Sylvia B. Smith
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Culver Vision Discovery Institute, Augusta, GA, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Graydon B. Gonsalvez
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Kathryn E. Bollinger
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Culver Vision Discovery Institute, Augusta, GA, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States
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Couly S, Yasui Y, Su TP. SIGMAR1 Confers Innate Resilience against Neurodegeneration. Int J Mol Sci 2023; 24:ijms24097767. [PMID: 37175473 PMCID: PMC10178636 DOI: 10.3390/ijms24097767] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023] Open
Abstract
The sigma-1 receptor (SIGMAR1) is one of a kind: a receptor chaperone protein. This 223 amino acid-long protein is enriched at the mitochondria-associated endoplasmic reticulum membrane (MAM), a specialized microdomain of the endoplasmic reticulum that is structurally and functionally connected to the mitochondria. As a receptor, SIGMAR1 binds a wide spectrum of ligands. Numerous molecules targeting SIGMAR1 are currently in pre-clinical or clinical development. Interestingly, the range of pathologies covered by these studies is broad, especially with regard to neurodegenerative disorders. Upon activation, SIGMAR1 can translocate and interact with other proteins, mostly at the MAM but also in other organelles, which allows SIGMAR1 to affect many cellular functions. During these interactions, SIGMAR1 exhibits chaperone protein behavior by participating in the folding and stabilization of its partner. In this short communication, we will shed light on how SIGMAR1 confers protection against neurodegeneration to the cells of the nervous system and why this ability makes SIGMAR1 a multifunctional therapeutic prospect.
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Affiliation(s)
- Simon Couly
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - Yuko Yasui
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD 21224, USA
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Overview of Sigma-1R Subcellular Specific Biological Functions and Role in Neuroprotection. Int J Mol Sci 2023; 24:ijms24031971. [PMID: 36768299 PMCID: PMC9916267 DOI: 10.3390/ijms24031971] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
For the past several years, fundamental research on Sigma-1R (S1R) protein has unveiled its necessity for maintaining proper cellular homeostasis through modulation of calcium and lipid exchange between the endoplasmic reticulum (ER) and mitochondria, ER-stress response, and many other mechanisms. Most of these processes, such as ER-stress response and autophagy, have been associated with neuroprotective roles. In fact, improving these mechanisms using S1R agonists was beneficial in several brain disorders including neurodegenerative diseases. In this review, we will examine S1R subcellular localization and describe S1R-associated biological activity within these specific compartments, i.e., the Mitochondrion-Associated ER Membrane (MAM), ER-Lipid Droplet (ER-LD) interface, ER-Plasma Membreane (ER-PM) interface, and the Nuclear Envelope (NE). We also discussed how the dysregulation of these pathways contributes to neurodegenerative diseases, while highlighting the cellular mechanisms and key binding partners engaged in these processes.
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Munguia-Galaviz FJ, Miranda-Diaz AG, Cardenas-Sosa MA, Echavarria R. Sigma-1 Receptor Signaling: In Search of New Therapeutic Alternatives for Cardiovascular and Renal Diseases. Int J Mol Sci 2023; 24:ijms24031997. [PMID: 36768323 PMCID: PMC9916216 DOI: 10.3390/ijms24031997] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
Cardiovascular and renal diseases are among the leading causes of death worldwide, and regardless of current efforts, there is a demanding need for therapeutic alternatives to reduce their progression to advanced stages. The stress caused by diseases leads to the activation of protective mechanisms in the cell, including chaperone proteins. The Sigma-1 receptor (Sig-1R) is a ligand-operated chaperone protein that modulates signal transduction during cellular stress processes. Sig-1R interacts with various ligands and proteins to elicit distinct cellular responses, thus, making it a potential target for pharmacological modulation. Furthermore, Sig-1R ligands activate signaling pathways that promote cardioprotection, ameliorate ischemic injury, and drive myofibroblast activation and fibrosis. The role of Sig-1R in diseases has also made it a point of interest in developing clinical trials for pain, neurodegeneration, ischemic stroke, depression in patients with heart failure, and COVID-19. Sig-1R ligands in preclinical models have significantly beneficial effects associated with improved cardiac function, ventricular remodeling, hypertrophy reduction, and, in the kidney, reduced ischemic damage. These basic discoveries could inform clinical trials for heart failure (HF), myocardial hypertrophy, acute kidney injury (AKI), and chronic kidney disease (CKD). Here, we review Sig-1R signaling pathways and the evidence of Sig-1R modulation in preclinical cardiac and renal injury models to support the potential therapeutic use of Sig-1R agonists and antagonists in these diseases.
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Affiliation(s)
- Francisco Javier Munguia-Galaviz
- Departamento de Fisiologia, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, Jalisco, Mexico
- Division de Ciencias de la Salud, Centro Universitario del Sur, Universidad de Guadalajara, Ciudad Guzman 49000, Jalisco, Mexico
| | - Alejandra Guillermina Miranda-Diaz
- Departamento de Fisiologia, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, Jalisco, Mexico
| | - Miguel Alejandro Cardenas-Sosa
- Departamento de Fisiologia, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, Jalisco, Mexico
| | - Raquel Echavarria
- CONACYT-Centro de Investigacion Biomedica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara 44340, Jalisco, Mexico
- Correspondence:
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Wang SM, Wu HE, Yasui Y, Geva M, Hayden M, Maurice T, Cozzolino M, Su TP. Nucleoporin POM121 signals TFEB-mediated autophagy via activation of SIGMAR1/sigma-1 receptor chaperone by pridopidine. Autophagy 2023; 19:126-151. [PMID: 35507432 PMCID: PMC9809944 DOI: 10.1080/15548627.2022.2063003] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 01/09/2023] Open
Abstract
Macroautophagy/autophagy is an essential process for cellular survival and is implicated in many diseases. A critical step in autophagy is the transport of the transcription factor TFEB from the cytosol into the nucleus, through the nuclear pore (NP) by KPNB1/importinβ1. In the C9orf72 subtype of amyotrophic lateral sclerosis-frontotemporal lobar degeneration (ALS-FTD), the hexanucleotide (G4C2)RNA expansion (HRE) disrupts the nucleocytoplasmic transport of TFEB, compromising autophagy. Here we show that a molecular chaperone, the SIGMAR1/Sigma-1 receptor (sigma non-opioid intracellular receptor 1), facilitates TFEB transport into the nucleus by chaperoning the NP protein (i.e., nucleoporin) POM121 which recruits KPNB1. In NSC34 cells, HRE reduces TFEB transport by interfering with the association between SIGMAR1 and POM121, resulting in reduced nuclear levels of TFEB, KPNB1, and the autophagy marker LC3-II. Overexpression of SIGMAR1 or POM121, or treatment with the highly selective and potent SIGMAR1 agonist pridopidine, currently in phase 2/3 clinical trials for ALS and Huntington disease, rescues all of these deficits. Our results implicate nucleoporin POM121 not merely as a structural nucleoporin, but also as a chaperone-operated signaling molecule enabling TFEB-mediated autophagy. Our data suggest the use of SIGMAR1 agonists, such as pridopidine, for therapeutic development of diseases in which autophagy is impaired.Abbreviations: ALS-FTD, amyotrophic lateral sclerosis-frontotemporal dementiaC9ALS-FTD, C9orf72 subtype of amyotrophic lateral sclerosis-frontotemporal dementiaCS, citrate synthaseER, endoplasmic reticulumGSS, glutathione synthetaseHRE, hexanucleotide repeat expansionHSPA5/BiP, heat shock protein 5LAMP1, lysosomal-associated membrane protein 1MAM, mitochondria-associated endoplasmic reticulum membraneMAP1LC3/LC3, microtubule-associated protein 1 light chain 3NP, nuclear poreNSC34, mouse motor neuron-like hybrid cell lineNUPs, nucleoporinsPOM121, nuclear pore membrane protein 121SIGMAR1/Sigma-1R, sigma non-opioid intracellular receptor 1TFEB, transcription factor EBTMEM97/Sigma-2R, transmembrane protein 97.
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Affiliation(s)
- Shao-Ming Wang
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, DHHS, 333 Cassell Drive, Baltimore, Maryland21224, USA
- China Medical University, Graduate Institute of Biomedical Sciences, Taiwan
- Neuroscience and Brain Disease Center, China Medical University, No.91, Hsueh-Shih Road, Taichung city, 404333, Taiwan
- Department of Neurology, China Medical University Hospital, No.2, Yude Road, North District, Taichung city, 404333, Taiwan
| | - Hsiang-En Wu
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, DHHS, 333 Cassell Drive, Baltimore, Maryland21224, USA
| | - Yuko Yasui
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, DHHS, 333 Cassell Drive, Baltimore, Maryland21224, USA
| | - Michal Geva
- Prilenia Therapeutics Development Ltd, Herzliya, Israel
| | - Michael Hayden
- Prilenia Therapeutics Development Ltd, Herzliya, Israel
- The Centre for Molecular Medicine and Therapeutics, BC Children’s Hospital Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tangui Maurice
- MMDN, University of Montpellier, EPHE, INSERM, Montpellier, France
| | - Mauro Cozzolino
- Institute of Translational Pharmacology, CNR, Via del Fosso del Cavaliere 100, 00133, Rome, Italy
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, DHHS, 333 Cassell Drive, Baltimore, Maryland21224, USA
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9
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Mysona BA, Zhao J, De Greef O, Beisel A, Patel PA, Berman L, Smith SB, Bollinger K. Sigma-1 receptor agonist, (+)-pentazocine, is neuroprotective in a Brown Norway rat microbead model of glaucoma. Exp Eye Res 2023; 226:109308. [PMID: 36400283 PMCID: PMC9839578 DOI: 10.1016/j.exer.2022.109308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/23/2022] [Accepted: 11/08/2022] [Indexed: 11/17/2022]
Abstract
PURPOSE Glaucoma is a worldwide leading cause of irreversible blindness. Standard treatments lower intraocular pressure (IOP). Novel treatments to prevent optic nerve (ON) degeneration are needed. Here, we investigate the hypothesis that sigma-1 receptor (S1R) agonist (+)-pentazocine (PTZ) is neuroprotective in a Brown Norway (BN) rat, microbead model of glaucoma. METHODS BN rats (9-11 weeks, male and female) were treated by intraperitoneal injection, 3 times per week with (+)-PTZ (2 mg/kg) or vehicle (VEH) alone. Treatment started 1 week prior to intraocular injection of polystyrene microbeads to elevate IOP. IOP was measured 2-3 times per week. Five weeks post microbead injection, rats were euthanized. ONs were removed, then fixed and processed for 63x oil, light microscope imaging of toluidine blue stained ON cross sections. To facilitate comparison of ON morphology from VEH and (+)-PTZ treated rats with similar ocular hypertensive insults, rats were assigned to low (IOP ≤15.8 mmHg), moderate (15.8 < IOP <28.0 mmHg), and high (IOP ≥28.0 mmHg) groups based on average IOP in the microbead injected eye. Axon numbers, axon density, axonal and glial areas, axon loss, and axon size distributions of naïve, bead, and contralateral ONs were assessed using QuPath program for automated image analysis. RESULTS (+)-PTZ treatment of BN rats protected ONs from damage caused by moderate IOP elevation. Treatment with (+)-PTZ significantly reduced axon loss and glial areas, and increased axon density and axonal areas compared to ONs from VEH treated rats with moderate IOP. (+)-PTZ-mediated neuroprotection was independent of IOP lowering effects. At average IOP ≥28.0 mmHg, (+)-PTZ treatment did not provide measurable neuroprotection. ONs from contralateral eyes exhibited subtle, complex changes in response to conditions in the bead eyes. CONCLUSIONS S1R agonist (+)-PTZ shows promise as a neuroprotective treatment for glaucoma. Future studies to understand the complex molecular mechanisms by which (+)-PTZ provides this neuroprotection are needed.
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Affiliation(s)
- Barbara A Mysona
- Department of Cellular Biology and Anatomy CB-2304, Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA; James and Jean Culver Vision Discovery Institute, Department of Ophthalmology, Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
| | - Jing Zhao
- James and Jean Culver Vision Discovery Institute, Department of Ophthalmology, Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
| | - Oceane De Greef
- Student Training and Research Program, Graduate School, Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
| | - August Beisel
- Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
| | - Parth A Patel
- Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
| | - Lindsay Berman
- Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy CB-2304, Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA.
| | - Kathryn Bollinger
- James and Jean Culver Vision Discovery Institute, Department of Ophthalmology, Medical College of Georgia at Augusta University, 1120 15th Street, Augusta, GA, 30912, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
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10
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Wang YM, Xia CY, Jia HM, He J, Lian WW, Yan Y, Wang WP, Zhang WK, Xu JK. Sigma-1 receptor: A potential target for the development of antidepressants. Neurochem Int 2022; 159:105390. [PMID: 35810915 DOI: 10.1016/j.neuint.2022.105390] [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: 02/22/2022] [Revised: 06/10/2022] [Accepted: 07/05/2022] [Indexed: 10/17/2022]
Abstract
Though a great many of studies on the development of antidepressants for the therapy of major depression disorder (MDD) and the development of antidepressants have been carried out, there still lacks an efficient approach in clinical practice. The involvement of Sigma-1 receptor in the pathological process of MDD has been verified. In this review, recent research focusing on the role of Sigma-1 receptor in the etiology of MDD were summarized. Preclinical studies and clinical trials have found that stress induce the variation of Sigma-1 receptor in the blood, brain and heart. Dysfunction and absence of Sigma-1 receptor result in depressive-like behaviors in rodent animals. Agonists of Sigma-1 receptor show not only antidepressant-like activities but also therapeutical effects in complications of depression. The mechanisms underlying antidepressant-like effects of Sigma-1 receptor may include suppressing neuroinflammation, regulating neurotransmitters, ameliorating brain-derived neurotrophic factor and N-Methyl-D-Aspartate receptor, and alleviating the endoplasmic reticulum stress and mitochondria damage during stress. Therefore, Sigma-1 receptor represents a potential target for antidepressants development.
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Affiliation(s)
- Yu-Ming Wang
- School of Life Sciences & School of Chinese Medicine Sciences, Beijing University of Chinese Medicine, Beijing, 100029, PR China; Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China
| | - Cong-Yuan Xia
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China
| | - Hong-Mei Jia
- Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, PR China
| | - Jun He
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China
| | - Wen-Wen Lian
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China
| | - Yu Yan
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China
| | - Wen-Ping Wang
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China
| | - Wei-Ku Zhang
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, PR China.
| | - Jie-Kun Xu
- School of Life Sciences & School of Chinese Medicine Sciences, Beijing University of Chinese Medicine, Beijing, 100029, PR China.
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11
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Xu Z, Lei Y, Qin H, Zhang S, Li P, Yao K. Sigma-1 Receptor in Retina: Neuroprotective Effects and Potential Mechanisms. Int J Mol Sci 2022; 23:ijms23147572. [PMID: 35886921 PMCID: PMC9321618 DOI: 10.3390/ijms23147572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/03/2022] [Accepted: 07/05/2022] [Indexed: 02/04/2023] Open
Abstract
Retinal degenerative diseases are the major factors leading to severe visual impairment and even irreversible blindness worldwide. The therapeutic approach for retinal degenerative diseases is one extremely urgent and hot spot in science research. The sigma-1 receptor is a novel, multifunctional ligand-mediated molecular chaperone residing in endoplasmic reticulum (ER) membranes and the ER-associated mitochondrial membrane (ER-MAM); it is widely distributed in numerous organs and tissues of various species, providing protective effects on a variety of degenerative diseases. Over three decades, considerable research has manifested the neuroprotective function of sigma-1 receptor in the retina and has attempted to explore the molecular mechanism of action. In the present review, we will discuss neuroprotective effects of the sigma-1 receptor in retinal degenerative diseases, mainly in aspects of the following: the localization in different types of retinal neurons, the interactions of sigma-1 receptors with other molecules, the correlated signaling pathways, the influence of sigma-1 receptors to cellular functions, and the potential therapeutic effects on retinal degenerative diseases.
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12
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Zhao J, Gonsalvez GB, Mysona BA, Smith SB, Bollinger KE. Sigma 1 Receptor Contributes to Astrocyte-Mediated Retinal Ganglion Cell Protection. Invest Ophthalmol Vis Sci 2022; 63:1. [PMID: 35103752 PMCID: PMC8819349 DOI: 10.1167/iovs.63.2.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/28/2021] [Indexed: 01/22/2023] Open
Abstract
Purpose Sigma 1 receptor (S1R) is expressed in retinal ganglion cells (RGCs) and astrocytes, and its activation is neuroprotective. We evaluated the contribution of S1R within optic nerve head astrocytes (ONHAs) to growth and survival of RGCs in vitro. Methods Wild-type (WT) RGCs and WT or S1R knockout (S1R KO) ONHAs were cocultured for 2, 4, or 7 days. Total and maximal neurite length, neurite root, and extremity counts were measured. Cell death was measured using a TUNEL assay. Signal transducer and activator of transcription 3 phosphorylation levels were evaluated in ONHA-derived lysates by immunoblotting. Results The coculture of WT RGCs with WT or S1R KO ONHAs increased the total and maximal neurite length. Neurite root and extremity counts increased at 4 and 7 days when WT RGCs were cocultured with WT or S1R KO ONHAs. At all timepoints, the total and maximal neurite length decreased for WT RGCs in coculture with S1R KO ONHAs compared with WT ONHAs. Root and extremity counts decreased for WT RGCs in coculture with S1R KO ONHAs compared with WT ONHAs at 2 and 7, but not 4 days. RGC apoptosis increased in S1R KO ONHA coculture and S1R KO-conditioned medium, compared with WT ONHA coculture or WT-conditioned medium. S1R KO ONHA-derived lysates showed decreased phosphorylated signal transducer and activator of transcription 3 levels compared with WT ONHA-derived lysates. Conclusions The absence of S1R within ONHAs has a deleterious effect on RGC neurite growth and RGC survival, reflected in analysis of WT RGC + S1R KO ONHA indirect cocultures. The data suggest that S1R may enhance ganglion cell survival via glia-mediated mechanisms.
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Affiliation(s)
- Jing Zhao
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | | | - Barbara A. Mysona
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | - Sylvia B. Smith
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | - Kathryn E. Bollinger
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
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13
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Shin SM, Wang F, Qiu C, Itson-Zoske B, Hogan QH, Yu H. Sigma-1 receptor activity in primary sensory neurons is a critical driver of neuropathic pain. Gene Ther 2022; 29:1-15. [PMID: 32424233 PMCID: PMC7671947 DOI: 10.1038/s41434-020-0157-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/21/2020] [Accepted: 05/04/2020] [Indexed: 12/15/2022]
Abstract
The Sigma-1 receptor (σ1R) is highly expressed in the primary sensory neurons (PSNs) that are the critical site of initiation and maintenance of pain following peripheral nerve injury. By immunoblot and immunohistochemistry, we observed increased expression of both σ1R and σ1R-binding immunoglobulin protein (BiP) in the lumbar (L) dorsal root ganglia (DRG) ipsilateral to painful neuropathy induced by spared nerve injury (SNI). To evaluate the therapeutic potential of PSN-targeted σ1R inhibition at a selected segmental level, we designed a recombinant adeno-associated viral (AAV) vector expressing a small hairpin RNA (shRNA) against rat σ1R. Injection of this vector into the L4/L5 DRGs induced downregulation of σ1R in DRG neurons of all size groups, while expression of BiP was not affected. This was accompanied by attenuation of SNI-induced cutaneous mechanical and thermal hypersensitivity. Whole-cell current-clamp recordings of dissociated neurons showed that knockdown of σ1R suppressed neuronal excitability, suggesting that σ1R silencing attenuates pain by reversal of injury-induced neuronal hyperexcitability. These findings support a critical role of σ1R in modulating PSN nociceptive functions, and that the nerve injury-induced elevated σ1R activity in the PSNs can be a significant driver of neuropathic pain. Further understanding the role of PSN-σ1R in pain pathology may open routes to exploit this system for DRG-targeted pain therapy.
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Affiliation(s)
- Seung Min Shin
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Zablocki Veterans Affairs Medical Center, Milwaukee, WI, 53295, USA
| | - Fei Wang
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Medical Experiment Center, Shaanxi University of Chinese Medicine, Xianyang, 712046, Shaanxi, PR China
| | - Chensheng Qiu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Department of Orthopedic Surgery, Affiliated Hospital of Qingdao University, Qingdao, 266000, PR China
| | - Brandon Itson-Zoske
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Quinn H Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Zablocki Veterans Affairs Medical Center, Milwaukee, WI, 53295, USA
| | - Hongwei Yu
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
- Zablocki Veterans Affairs Medical Center, Milwaukee, WI, 53295, USA.
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14
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Abdullah CS, Aishwarya R, Alam S, Remex NS, Morshed M, Nitu S, Miriyala S, Panchatcharam M, Hartman B, King J, Alfrad Nobel Bhuiyan M, Traylor J, Kevil CG, Orr AW, Bhuiyan MS. The molecular role of Sigmar1 in regulating mitochondrial function through mitochondrial localization in cardiomyocytes. Mitochondrion 2022; 62:159-175. [PMID: 34902622 PMCID: PMC8790786 DOI: 10.1016/j.mito.2021.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 01/03/2023]
Abstract
Sigmar1 is a widely expressed molecular chaperone protein in mammalian cell systems. Accumulating research demonstrated the cardioprotective roles of pharmacologic Sigmar1 activation by ligands in preclinical rodent models of cardiac injury. Extensive biochemical and immuno-electron microscopic research demonstrated Sigmar1's sub-cellular localization largely depends on cell and organ types. Despite comprehensive studies, Sigmar1's direct molecular role in cardiomyocytes remains elusive. In the present study, we determined Sigmar1's subcellular localization, transmembrane topology, and function using complementary microscopy, biochemical, and functional assays in cardiomyocytes. Quantum dots in transmission electron microscopy showed Sigmar1 labeled quantum dots on the mitochondrial membranes, lysosomes, and sarcoplasmic reticulum-mitochondrial interface. Subcellular fractionation of heart cell lysates confirmed Sigmar1's localization in purified mitochondria fraction and lysosome fraction. Immunocytochemistry confirmed Sigmar1 colocalization with mitochondrial proteins in isolated adult mouse cardiomyocytes. Sigmar1's mitochondrial localization was further confirmed by Sigmar1 colocalization with Mito-Tracker in isolated mouse heart mitochondria. A series of biochemical experiments, including alkaline extraction and proteinase K treatment of purified heart mitochondria, demonstrated Sigmar1 as an integral mitochondrial membrane protein. Sigmar1's structural requirement for mitochondrial localization was determined by expressing FLAG-tagged Sigmar1 fragments in cells. Full-length Sigmar1 and Sigmar1's C terminal-deletion fragments were able to localize to the mitochondrial membrane, whereas N-terminal deletion fragment was unable to incorporate into the mitochondria. Finally, functional assays using extracellular flux analyzer and high-resolution respirometry showed Sigmar1 siRNA knockdown significantly altered mitochondrial respiration in cardiomyocytes. Overall, we found that Sigmar1 localizes to mitochondrial membranes and is indispensable for maintaining mitochondrial respiratory homeostasis in cardiomyocytes.
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Affiliation(s)
- Chowdhury S Abdullah
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Richa Aishwarya
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Shafiul Alam
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Naznin Sultana Remex
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Mahboob Morshed
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Sadia Nitu
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Sumitra Miriyala
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Manikandan Panchatcharam
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Brandon Hartman
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Judy King
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | | | - James Traylor
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Christopher G Kevil
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA; Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA; Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - A Wayne Orr
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA; Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA; Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA
| | - Md Shenuarin Bhuiyan
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA; Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71103, USA.
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15
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Li L, He S, Liu Y, Yorio T, Ellis DZ. Sigma-1R Protects Retinal Ganglion Cells in Optic Nerve Crush Model for Glaucoma. Invest Ophthalmol Vis Sci 2021; 62:17. [PMID: 34406331 PMCID: PMC8375012 DOI: 10.1167/iovs.62.10.17] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/28/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to determine the effects of the Sigma-1R (σ-1r) on retinal ganglion cell (RGC) survival following optic nerve crush (ONC) and the signaling mechanism involved in the σ-1r protection. Methods The overall strategy was to induce injury by ONC and mitigate RGC death by increasing σ-1r expression and/or activate σ-1r activity in σ-1r K/O mice and wild type (WT) mice. AAV2-σ-1r vector was used to increase σ-1r expression and σ-1r agonist used to activate the σ-1r and RGCs were counted. Immunohistochemical and Western blot analysis determined phosphorylated (p)-c-Jun, c-Jun, and Caspase-3. Pattern electroretinography (PERG) determined RGC activity. Results RGC counts and function were similar in pentazocine-treated WT mice when compared to untreated mice and in WT mice when compared with σ-1r K/O mice. Pentazocine-induced effects and the effects of σ-1r K/O were only observable after ONC. ONC resulted in decreased RGC counts and activity in both WT and σ-1r K/O mice, with σ-1r K/O mice experiencing significant decreases compared with WT mice. The σ-1r transgenic expression resulted in increased RGC counts and activity following ONC. In WT mice, treatment with σ-1r agonist pentazocine resulted in increased RGC counts and increased activity when compared with untreated WT mice. There were time-dependent increases in c-jun, p-c-jun, and caspase-3 expression in ONC mice that were mitigated with pentazocine-treatment. Conclusions These findings suggest that the apoptotic pathway is involved in RGC losses seen in an ONC model. The σ-1r offers neuroprotection, as activation and/or transgenic expression of σ-1r attenuated the apoptotic pathway and restored RGCs number and function following ONC.
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Affiliation(s)
- Linya Li
- Department of Pharmacology and Neuroscience University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Shaoqing He
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Yang Liu
- Department of Pharmacology and Neuroscience University of North Texas Health Science Center, Fort Worth, Texas, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Thomas Yorio
- Department of Pharmacology and Neuroscience University of North Texas Health Science Center, Fort Worth, Texas, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Dorette Z Ellis
- Department of Pharmaceutical Sciences, University of North Texas Systems College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
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16
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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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17
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Barwick SR, Siddiq MS, Wang J, Xiao H, Marshall B, Perry E, Smith SB. Sigma 1 Receptor Co-Localizes with NRF2 in Retinal Photoreceptor Cells. Antioxidants (Basel) 2021; 10:antiox10060981. [PMID: 34205384 PMCID: PMC8234060 DOI: 10.3390/antiox10060981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/10/2021] [Accepted: 06/18/2021] [Indexed: 12/25/2022] Open
Abstract
Sigma 1 receptor (Sig1R), a modulator of cell survival, has emerged as a novel target for retinal degenerative disease. Studies have shown that activation of Sig1R, using the high affinity ligand (+)-pentazocine ((+)-PTZ), improves cone function in a severe retinopathy model. The rescue is accompanied by normalization of levels of NRF2, a key transcription factor that regulates the antioxidant response. The interaction of Sig1R with a number of proteins has been investigated; whether it interacts with NRF2, however, is not known. We used co-immunoprecipitation (co-IP), proximity ligation assay (PLA), and electron microscopy (EM) immunodetection methods to investigate this question in the 661W cone photoreceptor cell line. For co-IP experiments, immune complexes were precipitated by protein A/G agarose beads and immunodetected using anti-NRF2 antibody. For PLA, cells were incubated with anti-Sig1R polyclonal and anti-NRF2 monoclonal antibodies, then subsequently with (−)-mouse and (+)-rabbit PLA probes. For EM analysis, immuno-EM gold labeling was performed using nanogold-enhanced labeling with anti-NRF2 and anti-Sig1R antibodies, and data were confirmed using colloidal gold labeling. The co-IP experiment suggested that NRF2 was bound in a complex with Sig1R. The PLA assays detected abundant orange fluorescence in cones, indicating that Sig1R and NRF2 were within 40 nm of each other. EM immunodetection confirmed co-localization of Sig1R with NRF2 in cells and in mouse retinal tissue. This study is the first to report co-localization of Sig1R-NRF2 and supports earlier studies implicating modulation of NRF2 as a mechanism by which Sig1R mediates retinal neuroprotection.
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Affiliation(s)
- Shannon R. Barwick
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA
| | - Mevish S. Siddiq
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
| | - Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA
| | - Haiyan Xiao
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA
| | - Brendan Marshall
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
| | - Elizabeth Perry
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
| | - Sylvia B. Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; (S.R.B.); (M.S.S.); (J.W.); (H.X.); (B.M.); (E.P.)
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
- Correspondence: ; Tel.: +1-706-721-7392; Fax: +1-706-721-6120
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18
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Zhao J, Gonsalvez G, Bartoli M, Mysona BA, Smith SB, Bollinger KE. Sigma 1 Receptor Modulates Optic Nerve Head Astrocyte Reactivity. Invest Ophthalmol Vis Sci 2021; 62:5. [PMID: 34086045 PMCID: PMC8185400 DOI: 10.1167/iovs.62.7.5] [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: 11/26/2020] [Accepted: 05/03/2021] [Indexed: 12/04/2022] Open
Abstract
Purpose Stimulation of Sigma 1 Receptor (S1R) is neuroprotective in retina and optic nerve. S1R is expressed in both neurons and glia. The purpose of this work is to evaluate the ability of S1R to modulate reactivity responses of optic nerve head astrocytes (ONHAs) by investigating the extent to which S1R activation alters ONHA reactivity under conditions of ischemic cellular stress. Methods Wild type (WT) and S1R knockout (KO) ONHAs were derived and treated with vehicle or S1R agonist, (+)-pentazocine ((+)-PTZ). Cells were subjected to six hours of oxygen glucose deprivation (OGD) followed by 18 hours of re-oxygenation (OGD/R). Astrocyte reactivity responses were measured. Molecules that regulate ONHA reactivity, signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa B (NF-kB), were evaluated. Results Baseline glial fibrillary acidic protein (GFAP) levels were increased in nonstressed KO ONHAs compared with WT cultures. Baseline cellular migration was also increased in nonstressed KO ONHAs compared with WT. Treatment with (+)-PTZ increased cellular migration in nonstressed WT ONHAs but not in KO ONHAs. Exposure of both WT and KO ONHAs to ischemia (OGD/R), increased GFAP levels and cellular proliferation. However, (+)-PTZ treatment of OGD/R-exposed ONHAs enhanced GFAP levels, cellular proliferation, and cellular migration in WT but not KO cultures. The (+)-PTZ treatment of WT ONHAs also enhanced the OGD/R-induced increase in cellular pSTAT3 levels. However, treatment of WT ONHAs with (+)-PTZ abrogated the OGD/R-induced rise in NF-kB(p65) activation. Conclusions Under ischemic stress conditions, S1R activation enhanced ONHA reactivity characteristics. Future studies should address effects of these responses on RGC survival.
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Affiliation(s)
- Jing Zhao
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | - Graydon Gonsalvez
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
| | - Manuela Bartoli
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | - Barbara A. Mysona
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | - Sylvia B. Smith
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
| | - Kathryn E. Bollinger
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- Culver Vision Discovery Institute, Augusta, Georgia, United States
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Maurice T. Bi-phasic dose response in the preclinical and clinical developments of sigma-1 receptor ligands for the treatment of neurodegenerative disorders. Expert Opin Drug Discov 2021; 16:373-389. [PMID: 33070647 DOI: 10.1080/17460441.2021.1838483] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/14/2020] [Indexed: 12/19/2022]
Abstract
Introduction: The sigma-1 receptor (S1R) is attracting much attention for disease-modifying therapies in neurodegenerative diseases. It is a conserved protein, present in plasma and endoplasmic reticulum (ER) membranes and enriched in mitochondria-associated ER membranes (MAMs). It modulates ER-mitochondria Ca2+ transfer and ER stress pathways. Mitochondrial and MAM dysfunctions contribute to neurodegenerative processes in diseases such as Alzheimer, Parkinson, Huntington or Amyotrophic Lateral Sclerosis. Interestingly, the S1R can be activated by small druggable molecules and accumulating preclinical data suggest that S1R agonists are effective protectants in these neurodegenerative diseases.Area covered: In this review, we will present the data showing the high therapeutic potential of S1R drugs for the treatment of neurodegenerative diseases, focusing on pridopidine as a potent and selective S1R agonist under clinical development. Of particular interest is the bi-phasic (bell-shaped) dose-response effect, representing a common feature of all S1R agonists and described in numerous preclinical models in vitro, in vivo and in clinical trials.Expert opinion: S1R agonists modulate inter-organelles communication altered in neurodegenerative diseases and activate intracellular survival pathways. Research will continue growing in the future. The particular cellular nature of this chaperone protein must be better understood to facilitate the clinical developement of promising molecules.
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Affiliation(s)
- Tangui Maurice
- MMDN, Univ Montpellier, EPHE, INSERM, UMR_S1198, Montpellier, France
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20
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Vavers E, Zvejniece B, Stelfa G, Svalbe B, Vilks K, Kupats E, Mezapuke R, Lauberte L, Dambrova M, Zvejniece L. Genetic inactivation of the sigma-1 chaperone protein results in decreased expression of the R2 subunit of the GABA-B receptor and increased susceptibility to seizures. Neurobiol Dis 2021; 150:105244. [PMID: 33385516 DOI: 10.1016/j.nbd.2020.105244] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/07/2020] [Accepted: 12/27/2020] [Indexed: 02/02/2023] Open
Abstract
There is a growing body of evidence demonstrating the significant involvement of the sigma-1 chaperone protein in the modulation of seizures. Several sigma-1 receptor (Sig1R) ligands have been demonstrated to regulate the seizure threshold in acute and chronic seizure models. However, the mechanism by which Sig1R modulates the excitatory and inhibitory pathways in the brain has not been elucidated. The aim of this study was to compare the susceptibility to seizures of wild type (WT) and Sig1R knockout (Sig1R-/-) mice in intravenous pentylenetetrazol (PTZ) and (+)-bicuculline (BIC) infusion-induced acute seizure and Sig1R antagonist NE-100-induced seizure models. To determine possible molecular mechanisms, we used quantitative PCR, Western blotting and immunohistochemistry to assess the possible involvement of several seizure-related genes and proteins. Peripheral tissue contractile response of WT and Sig1R-/- mice was studied in an isolated vasa deferentia model. The most important finding was the significantly decreased expression of the R2 subunit of the GABA-B receptor in the hippocampus and habenula of Sig1R-/- mice. Our results demonstrated that Sig1R-/- mice have decreased thresholds for PTZ- and BIC-induced tonic seizures. In the NE-100-induced seizure model, Sig1R-/- animals demonstrated lower seizure scores, shorter durations and increased latency times of seizures compared to WT mice. Sig1R-independent activities of NE-100 included downregulation of the gene expression of iNOS and GABA-A γ2 and inhibition of KCl-induced depolarization in both WT and Sig1R-/- animals. In conclusion, the results of this study indicate that the lack of Sig1R resulted in decreased expression of the R2 subunit of the GABA-B receptor and increased susceptibility to seizures. Our results confirm that Sig1R is a significant molecular target for seizure modulation and warrants further investigation for the development of novel anti-seizure drugs.
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Affiliation(s)
- Edijs Vavers
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia.
| | - Baiba Zvejniece
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia; University of Latvia, Riga LV-1586, Latvia
| | - Gundega Stelfa
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia; Latvia University of Life Sciences and Technologies, Jelgava LV-3001, Latvia
| | - Baiba Svalbe
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia
| | - Karlis Vilks
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia; University of Latvia, Riga LV-1586, Latvia
| | - Einars Kupats
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia; Riga Stradins University, Riga LV-1007, Latvia
| | | | - Lasma Lauberte
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia
| | - Maija Dambrova
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia; Riga Stradins University, Riga LV-1007, Latvia
| | - Liga Zvejniece
- Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia
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21
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Wang J, Xiao H, Barwick S, Liu Y, Smith SB. Optimal timing for activation of sigma 1 receptor in the Pde6b rd10/J (rd10) mouse model of retinitis pigmentosa. Exp Eye Res 2021; 202:108397. [PMID: 33310057 PMCID: PMC7808329 DOI: 10.1016/j.exer.2020.108397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/24/2020] [Accepted: 12/07/2020] [Indexed: 11/18/2022]
Abstract
Sigma 1 Receptor (Sig1R), a pluripotent modulator of cell survival, is a promising target for treatment of retinal degenerative diseases. Previously, we reported that administration of the high-affinity, high-specificity Sig1R ligand (+)-pentazocine, ((+)-PTZ) beginning at post-natal day 14 (P14) and continuing every other day improves visual acuity and delays loss of photoreceptor cells (PRCs) in the Pde6βrd10/J (rd10) mouse model of retinitis pigmentosa. Whether administration of (+)-PTZ, at time points concomitant with (P18) or following (P21, P24) onset of PRC death, would prove neuroprotective was investigated in this study. Rd10 mice were administered (+)-PTZ intraperitoneally [0.5 mg/kg], starting at either P14, P18, P21 or P24. Injections continued every other day through P42. Visual acuity was assessed using the optokinetic tracking response (OKR). Rd10 mice treated with (+)-PTZ beginning at P14 retained visual acuity for the duration of the study (~0.33 c/d at P21, ~0.38 c/d at P28, ~0.32 c/d at P35, ~0.32 c/d at P42), whereas mice injected beginning at P18, P21, P24 showed a decline in acuity when tested at P35 and P42. Their acuity was only slightly better than rd10-non-treated mice. Electrophysiologic function was assessed using scotopic and photopic electroretinography (ERG) to assess rod and cone function, respectively. Photopic a- and b-wave amplitudes were significantly greater in rd10 mice treated with (+)-PTZ beginning at P14 compared with non-treated mice and those in the later-onset (+)-PTZ injection groups. Retinal architecture was visualized in living mice using spectral domain-optical coherence tomography (SD-OCT) allowing measurement of the total retinal thickness, the inner retina and the outer retina (the area most affected in rd10 mice). The outer retina measured ~35 μm in rd10 mice treated with (+)-PTZ beginning at P14, which was significantly greater than mice in the later-onset (+)-PTZ injection groups (~25 μm) and non-treated rd10 mice (~25 μm). Following the visual function studies performed in the living mice, eyes were harvested at P42 for histologic analysis. While the inner retina was largely intact in all (+)-PTZ-injection groups, there was a marked reduction in the outer retina of non-treated rd10 mice (e.g. in the outer nuclear layer there were ~10 PRCs/100 μm retinal length). The rd10 mice treated with (+)-PTZ beginning at P14 had ~20 PRCs/100 μm retinal length, whereas the mice in groups beginning P18, P21 and P24 had ~16 PRCs/100 μm retinal length. In conclusion, the data indicate that delaying (+)-PTZ injection past the onset of PRC death in rd10 mice - even by a few days - can negatively impact the long-term preservation of retinal function. Our findings suggest that optimizing the administration of Sig1R ligands is critical for retinal neuroprotection.
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Affiliation(s)
- Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Haiyan Xiao
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Shannon Barwick
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, United States; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, United States.
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22
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Lee PT, Liévens JC, Wang SM, Chuang JY, Khalil B, Wu HE, Chang WC, Maurice T, Su TP. Sigma-1 receptor chaperones rescue nucleocytoplasmic transport deficit seen in cellular and Drosophila ALS/FTD models. Nat Commun 2020; 11:5580. [PMID: 33149115 PMCID: PMC7642387 DOI: 10.1038/s41467-020-19396-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
In a subgroup of patients with amyotrophic lateral sclerosis (ALS)/Frontotemporal dementia (FTD), the (G4C2)-RNA repeat expansion from C9orf72 chromosome binds to the Ran-activating protein (RanGAP) at the nuclear pore, resulting in nucleocytoplasmic transport deficit and accumulation of Ran in the cytosol. Here, we found that the sigma-1 receptor (Sig-1R), a molecular chaperone, reverses the pathological effects of (G4C2)-RNA repeats in cell lines and in Drosophila. The Sig-1R colocalizes with RanGAP and nuclear pore proteins (Nups) and stabilizes the latter. Interestingly, Sig-1Rs directly bind (G4C2)-RNA repeats. Overexpression of Sig-1Rs rescues, whereas the Sig-1R knockout exacerbates, the (G4C2)-RNA repeats-induced aberrant cytoplasmic accumulation of Ran. In Drosophila, Sig-1R (but not the Sig-1R-E102Q mutant) overexpression reverses eye necrosis, climbing deficit, and firing discharge caused by (G4C2)-RNA repeats. These results on a molecular chaperone at the nuclear pore suggest that Sig-1Rs may benefit patients with C9orf72 ALS/FTD by chaperoning the nuclear pore assembly and sponging away deleterious (G4C2)-RNA repeats.
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Affiliation(s)
- Pin-Tse Lee
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD, 21224, USA
- The Ph.D Program for Neural Regenerative Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan
- Taiwan Biomaterial Company, 6F, No. 26-1, Sec. 2, Shengyi Rd., Zhubei City, Hsin-Chu County, 30261, Taiwan
| | | | - Shao-Ming Wang
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Jian-Ying Chuang
- The Ph.D Program for Neural Regenerative Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan
| | - Bilal Khalil
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Hsiang-En Wu
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Wen-Chang Chang
- The Ph.D Program for Neural Regenerative Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 11031, Taiwan
| | - Tangui Maurice
- MMDN, University of Montpellier, EPHE, INSERM, Montpellier, France
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, 333 Cassell Drive, Baltimore, MD, 21224, USA.
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Acute cocaine treatment enhances the antagonistic allosteric adenosine A2A-dopamine D2 receptor-receptor interactions in rat dorsal striatum without increasing significantly extracellular dopamine levels. Pharmacol Rep 2020; 72:332-339. [PMID: 32124388 DOI: 10.1007/s43440-020-00069-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 01/13/2023]
Abstract
BACKGROUND Antagonistic adenosine A2A receptor (A2AR)-dopamine D2 receptor (D2R) receptor-receptor interactions have previously been demonstrated in A2AR-D2R heteroreceptor complexes in the rat dorsal striatum. They mainly involve a reduction of affinity in the high-affinity component of the D2R agonist binding site upon activation in vivo of the A2AR by an A2AR agonist. Upon cocaine self-administration, this antagonistic A2AR-D2R interaction disappeared in the dorsal striatum. METHODS In the current experiments, it was tested whether such modifications in the antagonistic A2AR-D2R receptor-receptor interactions can develop also after an acute systemic injection of a low cocaine dose (1 mg/kg; sc). RESULTS Microdialysis experiments indicated that acute cocaine did not significantly alter the extracellular dopamine levels in the dorsal striatum of the awake Wistar rats. Competition dopamine receptor binding experiments demonstrated that in the acute cocaine group, the A2AR agonist CGS-21680 produced significantly larger increases in the D2R Ki, High values (reduction of high-affinity) versus the saline-injected (i.e. control) group. Furthermore, in the dorsal striatum membrane preparation from acute cocaine-injected rats, CGS-21680 also produced significant increases in the D2R Ki, Low values (reduction of low-affinity) and in the proportion of D2Rs in the high-affinity state (RH). Such significant effects were not observed with CGS-21680 in the control group. CONCLUSIONS The molecular mechanism involved in the acute cocaine-induced increase in the antagonistic allosteric A2AR-D2R receptor-receptor interactions may be an increased formation of higher-order complexes A2AR-D2R-sigma1R in which cocaine by binding to the sigma1R protomer also allosterically enhances the inhibitory A2AR-D2R interaction in this receptor complex.
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Arun AS, Eddings CR, Wilson KL. Novel missense alleles of SIGMAR1 as tools to understand emerin-dependent gene silencing in response to cocaine. Exp Biol Med (Maywood) 2019; 244:1354-1361. [PMID: 31324122 PMCID: PMC6880142 DOI: 10.1177/1535370219863444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/23/2019] [Indexed: 12/18/2022] Open
Abstract
Sigma-1 receptor (Sigma1R; SIGMAR1 ), an integral membrane protein of the endoplasmic reticulum and nuclear envelope, has a hydrophobic drug-binding pocket that binds with high affinity to addictive drugs (cocaine, methamphetamine) and therapeutics used to treat a wide spectrum of neurological disorders. Cocaine enhances Sigma1R association with three nuclear lamina proteins (emerin, lamin A/C, BANF1), causing Sigma1R-dependent and emerin-dependent recruitment and transcriptional repression of a gene, MAOB1 , involved in dopamine removal from neural synapses. The mechanism of Sigma1R association with emerin and the molecular impact of cocaine on their association are unknown. Mutations in Sigma1R, as a proposed regulator or mis-regulator of the nuclear lamina, have the potential to alter nuclear lamina function in brain or other tissues. We examined the frequency of SIGMAR1 missense alleles among 60,706 unrelated individuals in the ExAC database. We identified two novel SIGMAR1 missense variants of particular interest due to their frequency and potential to impact molecular association with emerin or other nuclear lamina proteins. Variant p.Q2P was widespread in ExAC (overall allele frequency 18.4%) with broad ethnic distribution among non-Finnish Europeans, Africans, South Asians, Latinx (allele frequencies ∼15% to 23%), and East Asians (∼38%). The p.R208W allele was identified in ∼0.78% of individuals overall with enrichment in Africans, Latinx, and East Asians (∼1.9–2.9%). These and other novel Sigma1R variants provide tools for future studies to determine the molecular basis of Sigma1R association with emerin and the mechanism of nuclear lamina misregulation by cocaine and potentially other Sigma1R agonists.
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Affiliation(s)
- Adith S Arun
- Department of Cell Biology, Johns Hopkins University
School of Medicine, Baltimore, MD 21205, USA
| | - Chelsy R Eddings
- Department of Cell Biology, Johns Hopkins University
School of Medicine, Baltimore, MD 21205, USA
| | - Katherine L Wilson
- Department of Cell Biology, Johns Hopkins University
School of Medicine, Baltimore, MD 21205, USA
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Wang J, Saul A, Smith SB. Activation of Sigma 1 Receptor Extends Survival of Cones and Improves Visual Acuity in a Murine Model of Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2019; 60:4397-4407. [PMID: 31639826 PMCID: PMC6808049 DOI: 10.1167/iovs.19-27709] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/21/2019] [Indexed: 01/02/2023] Open
Abstract
Purpose Retinitis pigmentosa (RP), a retinal photoreceptor degeneration, typically affects rod function and subsequently cones. Activation of sigma 1 receptor (Sig1R) has been shown to preserve cone function through 6 weeks in the rd10 mouse model of RP, when mice were treated systemically with the Sig1R ligand (+)-pentazocine (PTZ). This study determined the extent to which cone function is preserved in rd10 mice when Sig1R is activated. Methods Rd10 mice were administered (+)-PTZ (alternate days beginning at postnatal day [P]14) over a period of 180 days. Mouse visual function and structure were measured in vivo using optokinetic tracking response, scotopic and photopic electroretinography plus photopic assessment using "natural" noise stimuli, and optical coherence tomography (OCT). Immunofluorescent methods were used to detect cones in retinal cryosections. Results Visual acuity was maintained in rd10(+)-PTZ-treated mice through P56, whereas rd10 nontreated mice showed marked decline by P28. Cone responses were detected in (+)-PTZ-treated mice through P60, which were more robust when tested with natural noise stimuli; cone responses were minimal in nontreated rd10 mice. OCT revealed significantly thicker retinas in (+)-PTZ-treated rd10 mice through P60 compared to nontreated mice. Cones were detected by immunofluorescence in (+)-PTZ-treated rd10 retinas through P120. Conclusions The extent to which cone rescue could be sustained in (+)-PTZ-treated rd10 mice was evaluated comprehensively, showing that activation of Sig1R is associated with prolonged visual acuity, extended detection of cone function, and detection of cones in retinal histologic sections. The data reflect promising long-term neuroprotection when Sig1R is activated.
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Affiliation(s)
- Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Alan Saul
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Sylvia B. Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
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Yang H, Shen H, Li J, Guo LW. SIGMAR1/Sigma-1 receptor ablation impairs autophagosome clearance. Autophagy 2019; 15:1539-1557. [PMID: 30871407 PMCID: PMC6693456 DOI: 10.1080/15548627.2019.1586248] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 01/30/2019] [Accepted: 02/06/2019] [Indexed: 12/14/2022] Open
Abstract
Autophagosome-lysosome fusion is a common critical step in various forms of macroautophagy/autophagy including mitophagy, the selective degradation of mitochondria. Regulations of this fusion process remain poorly defined. Here we have determined the role of SIGMAR1, a unique endoplasmic reticulum membrane protein. Knockout of Sigmar1 impaired mitochondrial clearance without altering the PINK1-PRKN/Parkin signaling, in mouse retinal explants and cultured cells treated with carbonyl cyanide m-chlorophenyl hydrazone (CCCP) for induction of mitophagy. SIGMAR1 depletion also caused accumulation of autophagosome markers LC3-II and SQSTM1, but did not change the levels of BECN1 and ATG7, proteins associated with autophagosome biogenesis. Lysosomal pH and protease activities were not negatively affected. However, sigmar1 knockout partially compromised autophagosome-lysosome fusion in CCCP-treated NSC34 cells, as revealed by reduced GFP fluorescence quenching of GFP-RFP-LC3-II puncta and co-localization of lysosomes with mitochondria. Furthermore, SIGMAR1 co-immunoprecipitated with ATG14, STX17, and VAMP8 (but not SNAP29), proteins key to autophagosome-lysosome membrane fusion. Re-expressing SIGMAR1 in the null background rescued clearance of mitochondria and autophagosomes. In summary, we started out finding that sigmar1 knockout impaired the clearance of mitochondria and autophagosomes, and then narrowed down the SIGMAR1 modulation to the autophagosome-lysosome fusion step. This study may shed new light on understanding autophagy-associated cyto-protection and disease mechanisms. Abbreviations: APEX2, a genetically engineered peroxidase; BiFC, bimolecule fluorescence complementation; CCCP, a mitophagy inducing compound; CRISPR, clustered regularly interspaced short palindromic repeats; EM, electron microscopy; ER, endoplasmic reticulum; MAP1LC3/LC3, microtubule-associated protein 1 light chain 3; SIGMAR1, sigma non-opioid intracellular receptor 1.
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Affiliation(s)
- Huan Yang
- Department of Surgery and Departemnt of Physiology & Cell Biology, College of Medicine, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH USA
| | - Hongtao Shen
- Department of Surgery and Departemnt of Physiology & Cell Biology, College of Medicine, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH USA
| | - Jing Li
- Department of Surgery and Departemnt of Physiology & Cell Biology, College of Medicine, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH USA
| | - Lian-Wang Guo
- Department of Surgery and Departemnt of Physiology & Cell Biology, College of Medicine, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH USA
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI
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Ryskamp DA, Korban S, Zhemkov V, Kraskovskaya N, Bezprozvanny I. Neuronal Sigma-1 Receptors: Signaling Functions and Protective Roles in Neurodegenerative Diseases. Front Neurosci 2019; 13:862. [PMID: 31551669 PMCID: PMC6736580 DOI: 10.3389/fnins.2019.00862] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/31/2019] [Indexed: 12/12/2022] Open
Abstract
Sigma-1 receptor (S1R) is a multi-functional, ligand-operated protein situated in endoplasmic reticulum (ER) membranes and changes in its function and/or expression have been associated with various neurological disorders including amyotrophic lateral sclerosis/frontotemporal dementia, Alzheimer's (AD) and Huntington's diseases (HD). S1R agonists are broadly neuroprotective and this is achieved through a diversity of S1R-mediated signaling functions that are generally pro-survival and anti-apoptotic; yet, relatively little is known regarding the exact mechanisms of receptor functioning at the molecular level. This review summarizes therapeutically relevant mechanisms by which S1R modulates neurophysiology and implements neuroprotective functions in neurodegenerative diseases. These mechanisms are diverse due to the fact that S1R can bind to and modulate a large range of client proteins, including many ion channels in both ER and plasma membranes. We summarize the effect of S1R on its interaction partners and consider some of the cell type- and disease-specific aspects of these actions. Besides direct protein interactions in the endoplasmic reticulum, S1R is likely to function at the cellular/interorganellar level by altering the activity of several plasmalemmal ion channels through control of trafficking, which may help to reduce excitotoxicity. Moreover, S1R is situated in lipid rafts where it binds cholesterol and regulates lipid and protein trafficking and calcium flux at the mitochondrial-associated membrane (MAM) domain. This may have important implications for MAM stability and function in neurodegenerative diseases as well as cellular bioenergetics. We also summarize the structural and biochemical features of S1R proposed to underlie its activity. In conclusion, S1R is incredibly versatile in its ability to foster neuronal homeostasis in the context of several neurodegenerative disorders.
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Affiliation(s)
- Daniel A Ryskamp
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States
| | - Svetlana Korban
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg State Polytechnic University, Saint Petersburg, Russia
| | - Vladimir Zhemkov
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States
| | - Nina Kraskovskaya
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg State Polytechnic University, Saint Petersburg, Russia
| | - Ilya Bezprozvanny
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States.,Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg State Polytechnic University, Saint Petersburg, Russia
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Su TP. Non-canonical Targets Mediating the Action of Drugs of Abuse: Cocaine at the Sigma-1 Receptor as an Example. Front Neurosci 2019; 13:761. [PMID: 31396041 PMCID: PMC6664055 DOI: 10.3389/fnins.2019.00761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/09/2019] [Indexed: 11/13/2022] Open
Abstract
In addition to acting on traditionally recognized receptors or transporters on the plasma membrane, several drugs of abuse, including amphetamine, methamphetamine, nicotine, opioid, cocaine, ketamine, and cannabinoid, have been shown to exert their effects by acting on additional molecular targets either on the plasma membrane or inside a cell. These targets are usually nascent receptors or proteins that can cause downstream signaling or molecular events, leading to altered physiological outcomes favoring addictive processes. However, those "non-canonical" targets of drugs of abuse, in general, have not been widely recognized in drug abuse research. This perspective diverts attention to those underrecognized targets, in the hope of promoting a more complete understanding of the action of drugs of abuse.
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Affiliation(s)
- Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, DHHS, Baltimore, MD, United States
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Abraham MJ, Fleming KL, Raymond S, Wong AYC, Bergeron R. The sigma-1 receptor behaves as an atypical auxiliary subunit to modulate the functional characteristics of Kv1.2 channels expressed in HEK293 cells. Physiol Rep 2019; 7:e14147. [PMID: 31222975 PMCID: PMC6586770 DOI: 10.14814/phy2.14147] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/17/2019] [Accepted: 05/25/2019] [Indexed: 12/11/2022] Open
Abstract
Expression of Kv1.2 within Kv1.x potassium channel complexes is critical in maintaining appropriate neuronal excitability and determining the threshold for action potential firing. This is attributed to the interaction of Kv1.2 with a hitherto unidentified protein that confers bimodal channel activation gating, allowing neurons to adapt to repetitive trains of stimulation and protecting against hyperexcitability. One potential protein candidate is the sigma-1 receptor (Sig-1R), which regulates other members of the Kv1.x channel family; however, the biophysical nature of the interaction between Sig-1R and Kv1.2 has not been elucidated. We hypothesized that Sig-1R may regulate Kv1.2 and may further act as the unidentified modulator of Kv1.2 activation. In transiently transfected HEK293 cells, we found that ligand activation of the Sig-1R modulates Kv1.2 current amplitude. More importantly, Sig-1R interacts with Kv1.2 in baseline conditions to influence bimodal activation gating. These effects are abolished in the presence of the auxiliary subunit Kvβ2 and when the Sig-1R mutation underlying ALS16 (Sig-1R-E102Q), is expressed. These data suggest that Kvβ2 occludes the interaction of Sig-1R with Kv1.2, and that E102 may be a residue critical for Sig-1R modulation of Kv1.2. The results of this investigation describe an important new role for Sig-1R in the regulation of neuronal excitability and introduce a novel mechanism of pathophysiology in Sig-1R dysfunction.
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Affiliation(s)
- Madelyn J. Abraham
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
| | - Kayla L. Fleming
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
| | - Sophie Raymond
- NeuroscienceOttawa Hospital Research InstituteOttawaOntarioCanada
| | | | - Richard Bergeron
- Department of Cellular and Molecular MedicineUniversity of OttawaOttawaOntarioCanada
- NeuroscienceOttawa Hospital Research InstituteOttawaOntarioCanada
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Wang J, Zhao J, Cui X, Mysona BA, Navneet S, Saul A, Ahuja M, Lambert N, Gazaryan IG, Thomas B, Bollinger KE, Smith SB. The molecular chaperone sigma 1 receptor mediates rescue of retinal cone photoreceptor cells via modulation of NRF2. Free Radic Biol Med 2019; 134:604-616. [PMID: 30743048 PMCID: PMC6619428 DOI: 10.1016/j.freeradbiomed.2019.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 01/11/2023]
Abstract
Sigma 1 receptor (Sig1R), a putative molecular chaperone, has emerged as a novel therapeutic target for retinal degenerative disease. Earlier studies showed that activation of Sig1R via the high-affinity ligand (+)-pentazocine ((+)-PTZ) induced profound rescue of cone photoreceptor cells in the rd10 mouse model of retinitis pigmentosa; however the mechanism of rescue is unknown. Improved cone function in (+)-PTZ-treated mice was accompanied by reduced oxidative stress and normalization of levels of NRF2, a transcription factor that activates antioxidant response elements (AREs) of hundreds of cytoprotective genes. Here, we tested the hypothesis that modulation of NRF2 is central to Sig1R-mediated cone rescue. Activation of Sig1R in 661W cone cells using (+)-PTZ induced dose-dependent increases in NRF2-ARE binding activity and NRF2 gene/protein expression, whereas silencing Sig1R significantly decreased NRF2 protein levels and increased oxidative stress, although (+)-PTZ did not disrupt NRF2-KEAP1 binding. In vivo studies were conducted to investigate whether, in the absence of NRF2, activation of Sig1R rescues cones. (+)-PTZ was administered systemically for several weeks to rd10/nrf2+/+ and rd10/nrf2-/- mice. Through post-natal day 42, cone function was significant in rd10/nrf2+/+, but minimal in rd10/nrf2-/- mice as indicated by electroretinographic recordings using natural noise stimuli, optical coherence tomography and retinal histological analyses. Immunodetection of cones was limited in (+)-PTZ-treated rd10/nrf2-/-, though considerable in (+)-PTZ-treated rd10/nrf2+/+mice. The data suggest that Sig1R-mediated cone rescue requires NRF2 and provide evidence for a previously-unrecognized relationship between these proteins.
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Affiliation(s)
- J Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - J Zhao
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - X Cui
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - B A Mysona
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - S Navneet
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - A Saul
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - M Ahuja
- Department of Pharmacology/Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - N Lambert
- Department of Pharmacology/Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - I G Gazaryan
- Department of Anatomy and Cell Biology, New York Medical College, Valhalla, NY, USA
| | - B Thomas
- Department of Pharmacology/Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - K E Bollinger
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - S B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, USA.
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31
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Vavers E, Zvejniece L, Maurice T, Dambrova M. Allosteric Modulators of Sigma-1 Receptor: A Review. Front Pharmacol 2019; 10:223. [PMID: 30941035 PMCID: PMC6433746 DOI: 10.3389/fphar.2019.00223] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 02/22/2019] [Indexed: 11/13/2022] Open
Abstract
Allosteric modulators of sigma-1 receptor (Sig1R) are described as compounds that can increase the activity of some Sig1R ligands that compete with (+)-pentazocine, one of the classic prototypical ligands that binds to the orthosteric Sig1R binding site. Sig1R is an endoplasmic reticulum membrane protein that, in addition to its promiscuous high-affinity ligand binding, has been shown to have chaperone activity. Different experimental approaches have been used to describe and validate the activity of allosteric modulators of Sig1R. Sig1R-modulatory activity was first found for phenytoin, an anticonvulsant drug that primarily acts by blocking the voltage-gated sodium channels. Accumulating evidence suggests that allosteric Sig1R modulators affect processes involved in the pathophysiology of depression, memory and cognition disorders as well as convulsions. This review will focus on the description of selective and non-selective allosteric modulators of Sig1R, including molecular structure properties and pharmacological activity both in vitro and in vivo, with the aim of providing the latest overview from compound discovery approaches to eventual clinical applications. In this review, the possible mechanisms of action will be discussed, and future challenges in the development of novel compounds will be addressed.
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Affiliation(s)
- Edijs Vavers
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Liga Zvejniece
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Tangui Maurice
- MMDN, University of Montpellier, INSERM, EPHE, UMR-S1198, Montpellier, France
| | - Maija Dambrova
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Riga, Latvia
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Smith SB, Wang J, Cui X, Mysona BA, Zhao J, Bollinger KE. Sigma 1 receptor: A novel therapeutic target in retinal disease. Prog Retin Eye Res 2018; 67:130-149. [PMID: 30075336 PMCID: PMC6557374 DOI: 10.1016/j.preteyeres.2018.07.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/27/2018] [Accepted: 07/30/2018] [Indexed: 02/08/2023]
Abstract
Retinal degenerative diseases are major causes of untreatable blindness worldwide and efficacious treatments for these diseases are sorely needed. A novel target for treatment of retinal disease is the transmembrane protein Sigma 1 Receptor (Sig1R). This enigmatic protein is an evolutionary isolate with no known homology to any other protein. Sig1R was originally thought to be an opioid receptor. That notion has been dispelled and more recent pharmacological and molecular studies suggest that it is a pluripotent modulator with a number of biological functions, many of which are relevant to retinal disease. This review provides an overview of the discovery of Sig1R and early pharmacologic studies that led to the cloning of the Sig1R gene and eventual elucidation of its crystal structure. Studies of Sig1R in the eye were not reported until the late 1990s, but since that time there has been increasing interest in the potential role of Sig1R as a target for retinal disease. Studies have focused on elucidating the mechanism(s) of Sig1R function in retina including calcium regulation, modulation of oxidative stress, ion channel regulation and molecular chaperone activity. Mechanistic studies have been performed in isolated retinal cells, such as Müller glial cells, microglial cells, optic nerve head astrocytes and retinal ganglion cells as well as in the intact retina. Several compelling studies have provided evidence of powerful in vivo neuroprotective effects against ganglion cell loss as well as photoreceptor cell loss. Also described are studies that have examined retinal structure/function in various models of retinal disease in which Sig1R is absent and reveal that these phenotypes are accelerated compared to retinas of animals that express Sig1R. The collective evidence from analysis of studies over the past 20 years is that Sig1R plays a key role in modulating retinal cellular stress and that it holds great promise as a target in retinal neurodegenerative disease.
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Affiliation(s)
- Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University 30912, Augusta, GA, USA.
| | - Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Barbara A Mysona
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Jing Zhao
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University 30912, Augusta, GA, USA
| | - Kathryn E Bollinger
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia at Augusta University 30912, Augusta, GA, USA
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Abdullah CS, Alam S, Aishwarya R, Miriyala S, Panchatcharam M, Bhuiyan MAN, Peretik JM, Orr AW, James J, Osinska H, Robbins J, Lorenz JN, Bhuiyan MS. Cardiac Dysfunction in the Sigma 1 Receptor Knockout Mouse Associated With Impaired Mitochondrial Dynamics and Bioenergetics. J Am Heart Assoc 2018; 7:e009775. [PMID: 30371279 PMCID: PMC6474981 DOI: 10.1161/jaha.118.009775] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/10/2018] [Indexed: 12/21/2022]
Abstract
Background The Sigma 1 receptor (Sigmar1) functions as an interorganelle signaling molecule and elicits cytoprotective functions. The presence of Sigmar1 in the heart was first reported on the basis of a ligand-binding assay, and all studies to date have been limited to pharmacological approaches using less-selective ligands for Sigmar1. However, the physiological function of cardiac Sigmar1 remains unknown. We investigated the physiological function of Sigmar1 in regulating cardiac hemodynamics using the Sigmar1 knockout mouse (Sigmar1-/-). Methods and Results Sigmar1-/- hearts at 3 to 4 months of age showed significantly increased contractility as assessed by left ventricular catheterization with stimulation by increasing doses of a β1-adrenoceptor agonist. Noninvasive echocardiographic measurements were also used to measure cardiac function over time, and the data showed the development of cardiac contractile dysfunction in Sigmar1 -/- hearts as the animals aged. Histochemistry demonstrated significant cardiac fibrosis, collagen deposition, and increased periostin in the Sigmar1 -/- hearts compared with wild-type hearts. Ultrastructural analysis of Sigmar1-/- cardiomyocytes revealed an irregularly shaped, highly fused mitochondrial network with abnormal cristae. Mitochondrial size was larger in Sigmar1-/- hearts, resulting in decreased numbers of mitochondria per microscopic field. In addition, Sigmar1-/- hearts showed altered expression of mitochondrial dynamics regulatory proteins. Real-time oxygen consumption rates in isolated mitochondria showed reduced respiratory function in Sigmar1-/- hearts compared with wild-type hearts. Conclusions We demonstrate a potential function of Sigmar1 in regulating normal mitochondrial organization and size in the heart. Sigmar1 loss of function led to mitochondrial dysfunction, abnormal mitochondrial architecture, and adverse cardiac remodeling, culminating in cardiac contractile dysfunction.
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Affiliation(s)
- Chowdhury S. Abdullah
- Department of Pathology and Translational PathobiologyLouisiana State University Health Sciences CenterShreveportLA
| | - Shafiul Alam
- Department of Pathology and Translational PathobiologyLouisiana State University Health Sciences CenterShreveportLA
| | - Richa Aishwarya
- Department of Molecular and Cellular PhysiologyLouisiana State University Health Sciences CenterShreveportLA
| | - Sumitra Miriyala
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLA
| | - Manikandan Panchatcharam
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLA
| | | | - Jonette M. Peretik
- Department of Pathology and Translational PathobiologyLouisiana State University Health Sciences CenterShreveportLA
| | - A. Wayne Orr
- Department of Pathology and Translational PathobiologyLouisiana State University Health Sciences CenterShreveportLA
- Department of Molecular and Cellular PhysiologyLouisiana State University Health Sciences CenterShreveportLA
- Department of Cellular Biology and AnatomyLouisiana State University Health Sciences CenterShreveportLA
| | - Jeanne James
- Division of Pediatric CardiologyMedical College of WisconsinMilwaukeeWI
| | - Hanna Osinska
- Division of Molecular Cardiovascular BiologyCincinnati Children's HospitalCincinnatiOH
| | - Jeffrey Robbins
- Division of Molecular Cardiovascular BiologyCincinnati Children's HospitalCincinnatiOH
| | - John N. Lorenz
- Department of Molecular and Cellular PhysiologyUniversity of Cincinnati College of MedicineCincinnatiOH
| | - Md. Shenuarin Bhuiyan
- Department of Pathology and Translational PathobiologyLouisiana State University Health Sciences CenterShreveportLA
- Department of Molecular and Cellular PhysiologyLouisiana State University Health Sciences CenterShreveportLA
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Mavylutov T, Chen X, Guo L, Yang J. APEX2- tagging of Sigma 1-receptor indicates subcellular protein topology with cytosolic N-terminus and ER luminal C-terminus. Protein Cell 2018; 9:733-737. [PMID: 28929457 PMCID: PMC6053353 DOI: 10.1007/s13238-017-0468-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Timur Mavylutov
- Department of Anesthesiology, University of Wisconsin SMPH, Madison, WI, 53705, USA
| | - Xi Chen
- Department of Anesthesiology, University of Wisconsin SMPH, Madison, WI, 53705, USA
| | - Lianwang Guo
- Department of Surgery and Physiology & Cell Biology, Ohio State University, Columbus, OH, 43210, USA
| | - Jay Yang
- Department of Anesthesiology, University of Wisconsin SMPH, Madison, WI, 53705, USA.
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Sambo DO, Lebowitz JJ, Khoshbouei H. The sigma-1 receptor as a regulator of dopamine neurotransmission: A potential therapeutic target for methamphetamine addiction. Pharmacol Ther 2018; 186:152-167. [PMID: 29360540 PMCID: PMC5962385 DOI: 10.1016/j.pharmthera.2018.01.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Methamphetamine (METH) abuse is a major public health issue around the world, yet there are currently no effective pharmacotherapies for the treatment of METH addiction. METH is a potent psychostimulant that increases extracellular dopamine levels by targeting the dopamine transporter (DAT) and alters neuronal activity in the reward centers of the brain. One promising therapeutic target for the treatment of METH addiction is the sigma-1 receptor (σ1R). The σ1R is an endoplasmic reticulum-localized chaperone protein that is activated by cellular stress, and, unique to this chaperone, its function can also be induced or inhibited by different ligands. Upon activation of this unique "chaperone receptor", the σ1R regulates a variety of cellular functions and possesses neuroprotective activity in the brain. Interestingly, a variety of σ1R ligands modulate dopamine neurotransmission and reduce the behavioral effects of METH in animal models of addictive behavior, suggesting that the σ1R may be a viable therapeutic target for the treatment of METH addiction. In this review, we provide background on METH and the σ1R as well as a literature review regarding the role of σ1Rs in modulating both dopamine neurotransmission and the effects of METH. We aim to highlight the complexities of σ1R pharmacology and function as well as the therapeutic potential of the σ1R as a target for the treatment of METH addiction.
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Affiliation(s)
- Danielle O Sambo
- University of Florida, College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States
| | - Joseph J Lebowitz
- University of Florida, College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States
| | - Habibeh Khoshbouei
- University of Florida, College of Medicine, Department of Neuroscience, Gainesville, FL 32611, United States.
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Sambo DO, Lin M, Owens A, Lebowitz JJ, Richardson B, Jagnarine DA, Shetty M, Rodriquez M, Alonge T, Ali M, Katz J, Yan L, Febo M, Henry LK, Bruijnzeel AW, Daws L, Khoshbouei H. The sigma-1 receptor modulates methamphetamine dysregulation of dopamine neurotransmission. Nat Commun 2017; 8:2228. [PMID: 29263318 PMCID: PMC5738444 DOI: 10.1038/s41467-017-02087-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 11/05/2017] [Indexed: 12/16/2022] Open
Abstract
Dopamine neurotransmission is highly dysregulated by the psychostimulant methamphetamine, a substrate for the dopamine transporter (DAT). Through interactions with DAT, methamphetamine increases extracellular dopamine levels in the brain, leading to its rewarding and addictive properties. Methamphetamine also interacts with the sigma-1 receptor (σ1R), an inter-organelle signaling modulator. Using complementary strategies, we identified a novel mechanism for σ1R regulation of dopamine neurotransmission in response to methamphetamine. We found that σ1R activation prevents methamphetamine-induced, DAT-mediated increases in firing activity of dopamine neurons. In vitro and in vivo amperometric measurements revealed that σ1R activation decreases methamphetamine-stimulated dopamine efflux without affecting basal dopamine neurotransmission. Consistent with these findings, σ1R activation decreases methamphetamine-induced locomotion, motivated behavior, and enhancement of brain reward function. Notably, we revealed that the σ1R interacts with DAT at or near the plasma membrane and decreases methamphetamine-induced Ca2+ signaling, providing potential mechanisms. Broadly, these data provide evidence for σ1R regulation of dopamine neurotransmission and support the σ1R as a putative target for the treatment of methamphetamine addiction.
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Affiliation(s)
- Danielle O Sambo
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Min Lin
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Anthony Owens
- Department of Cellular & Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Joseph J Lebowitz
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Ben Richardson
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Darin A Jagnarine
- Department of Psychiatry, University of Florida, Gainesville, FL, 32611, USA
| | - Madhur Shetty
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, 58203, USA
| | - Meghan Rodriquez
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, 58203, USA
| | - Taiwo Alonge
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Mishaal Ali
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA
| | - Jonathan Katz
- Psychobiology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Long Yan
- Max Plank Institute for Neuroscience Jupiter, Jupiter, FL, 33458, USA
| | - Marcelo Febo
- Department of Psychiatry, University of Florida, Gainesville, FL, 32611, USA
| | - L Keith Henry
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND, 58203, USA
| | | | - Lynette Daws
- Department of Cellular & Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida, Gainesville, FL, 32611, USA.
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Yang H, Fu Y, Liu X, Shahi PK, Mavlyutov TA, Li J, Yao A, Guo SZW, Pattnaik BR, Guo LW. Role of the sigma-1 receptor chaperone in rod and cone photoreceptor degenerations in a mouse model of retinitis pigmentosa. Mol Neurodegener 2017; 12:68. [PMID: 28927431 PMCID: PMC5606113 DOI: 10.1186/s13024-017-0202-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 08/09/2017] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Retinitis pigmentosa (RP) is the most common inherited retinal degenerative disease yet with no effective treatment available. The sigma-1 receptor (S1R), a ligand-regulated chaperone, emerges as a potential retina-protective therapeutic target. In particular, pharmacological activation of S1R was recently shown to rescue cones in the rd10 mouse, a rod Pde6b mutant that recapitulates the RP pathology of autonomous rod degeneration followed by secondary death of cones. The mechanisms underlying the S1R protection for cones are not understood in detail. METHODS By rearing rd10/S1R-/- and rd10/S1R+/+ mice in dim light to decelerate rapid rod/cone degeneration, we were able to compare their retinal biochemistry, histology and functions throughout postnatal 3-6 weeks (3 W-6 W). RESULTS The receptor-interacting protein kinases (RIP1/RIP3) and their interaction (proximity ligation) dramatically up-regulated after 5 W in rd10/S1R-/- (versus rd10/S1R+/+) retinas, indicative of intensified necroptosis activation, which was accompanied by exacerbated loss of cones. Greater rod loss in rd10/S1R-/- versus rd10/S1R+/+ retinas was evidenced by more cleaved Caspase3 (4 W) and lower rod electro-retinographic a-waves (4 W-6 W), concomitant with reduced LC3-II and CHOP (4 W-6 W), markers of autophagy and endoplasmic reticulum stress response, respectively. However, the opposite occurred at 3 W. CONCLUSION This study reveals previously uncharacterized S1R-associated mechanisms during rd10 photoreceptor degeneration, including S1R's influences on necroptosis and autophagy as well as its biphasic role in rod degeneration upstream of cone death.
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Affiliation(s)
- Huan Yang
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
| | - Yingmei Fu
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping Nan Road, Shanghai, 200030 People’s Republic of China
| | - Xinying Liu
- Department of Pediatrics, Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, SMI 112, Madison, WI 53706 USA
| | - Pawan K. Shahi
- Department of Pediatrics, Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, SMI 112, Madison, WI 53706 USA
| | - Timur A. Mavlyutov
- Department of Anesthesiology, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
| | - Jun Li
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
- Department of Ophthalmology, the First Hospital of China Medical University, Shenyang, 110001 People’s Republic of China
- Department of Ophthalmology, the 3rd People’s Hospital of Dalian, Dalian, 116033 People’s Republic of China
| | - Annie Yao
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
| | - Steven Z.-W. Guo
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
| | - Bikash R. Pattnaik
- Department of Pediatrics, Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, SMI 112, Madison, WI 53706 USA
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705 USA
| | - Lian-Wang Guo
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 USA
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705 USA
- Department of Surgery and Department of Physiology &Cell Biology, the Ohio State University, Columbus, OH 43210 USA
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Wang J, Saul A, Cui X, Roon P, Smith SB. Absence of Sigma 1 Receptor Accelerates Photoreceptor Cell Death in a Murine Model of Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2017; 58:4545-4558. [PMID: 28877319 PMCID: PMC5586962 DOI: 10.1167/iovs.17-21947] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/31/2017] [Indexed: 02/06/2023] Open
Abstract
Purpose Sigma 1 Receptor (Sig1R) is a novel therapeutic target in neurodegenerative diseases, including retinal disease. Sig1R-/- mice have late-onset retinal degeneration with ganglion cell loss that worsens under stress. Whether Sig1R plays a role in maintaining other retinal neurons is unknown, but was investigated here using rd10 mice, a model of severe photoreceptor degeneration. Methods Wild-type, rd10, and rd10/Sig1R-/- mice were subjected to ERG and spectral-domain optical coherence tomography (SD-OCT) to assess visual function/structure in situ. Retinas imaged microscopically were subjected to morphometric analysis, immunodetection of cones, and analysis of gliosis. Oxidative and endoplasmic reticulum (ER) stress was evaluated at mRNA/protein levels. Results Photopic ERG responses were reduced significantly in rd10/Sig1R-/- versus rd10 mice at P28 (31 ± 6 vs. 56 ± 7 μV), indicating accelerated cone loss when Sig1R was absent. At P28, SD-OCT revealed reduced retinal thickness in rd10/Sig1R-/- mice (60% of WT) versus rd10 (80% of WT). Morphometric analysis disclosed profound photoreceptor nuclei loss in rd10/Sig1R-/- versus rd10 mice. rd10/Sig1R-/- mice had 35% and 60% fewer photoreceptors, respectively, at P28 and P35, than rd10. Peanut agglutinin cone labeling decreased significantly; gliosis increased significantly in rd10/Sig1R-/- versus rd10 mice. At P21, NRF2 levels increased in rd10/Sig1R-/- mice versus rd10 and downstream antioxidants increased indicating oxidative stress. At P28, ER stress genes/proteins, especially XBP1, a potent transcriptional activator of the unfolded protein response and CHOP, a proapoptotic transcription factor, increased significantly in rd10/Sig1R-/- mice versus rd10. Conclusions Photoreceptor cell degeneration accelerates and cone function diminishes much earlier in rd10/Sig1R-/- than rd10 mice emphasizing the importance of Sig1R as a modulator of retinal cell survival.
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Affiliation(s)
- Jing Wang
- Department of Cellular Biology and Anatomy, The Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Alan Saul
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Department of Ophthalmology, Augusta University, Augusta, Georgia, United States
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy, The Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Penny Roon
- Department of Cellular Biology and Anatomy, The Medical College of Georgia at Augusta University, Augusta, Georgia, United States
| | - Sylvia B. Smith
- Department of Cellular Biology and Anatomy, The Medical College of Georgia at Augusta University, Augusta, Georgia, United States
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Department of Ophthalmology, Augusta University, Augusta, Georgia, United States
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He S, Stankowska DL, Ellis DZ, Krishnamoorthy RR, Yorio T. Targets of Neuroprotection in Glaucoma. J Ocul Pharmacol Ther 2017; 34:85-106. [PMID: 28820649 DOI: 10.1089/jop.2017.0041] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Progressive neurodegeneration of the optic nerve and the loss of retinal ganglion cells is a hallmark of glaucoma, the leading cause of irreversible blindness worldwide, with primary open-angle glaucoma (POAG) being the most frequent form of glaucoma in the Western world. While some genetic mutations have been identified for some glaucomas, those associated with POAG are limited and for most POAG patients, the etiology is still unclear. Unfortunately, treatment of this neurodegenerative disease and other retinal degenerative diseases is lacking. For POAG, most of the treatments focus on reducing aqueous humor formation, enhancing uveoscleral or conventional outflow, or lowering intraocular pressure through surgical means. These efforts, in some cases, do not always lead to a prevention of vision loss and therefore other strategies are needed to reduce or reverse the progressive neurodegeneration. In this review, we will highlight some of the ocular pharmacological approaches that are being tested to reduce neurodegeneration and provide some form of neuroprotection.
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Affiliation(s)
- Shaoqing He
- North Texas Eye Research Institute, University of North Texas Health Science Center , Fort Worth, Texas
| | - Dorota L Stankowska
- North Texas Eye Research Institute, University of North Texas Health Science Center , Fort Worth, Texas
| | - Dorette Z Ellis
- North Texas Eye Research Institute, University of North Texas Health Science Center , Fort Worth, Texas
| | - Raghu R Krishnamoorthy
- North Texas Eye Research Institute, University of North Texas Health Science Center , Fort Worth, Texas
| | - Thomas Yorio
- North Texas Eye Research Institute, University of North Texas Health Science Center , Fort Worth, Texas
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Potential independent action of sigma receptor ligands through inhibition of the Kv2.1 channel. Oncotarget 2017; 8:59345-59358. [PMID: 28938641 PMCID: PMC5601737 DOI: 10.18632/oncotarget.19581] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/16/2017] [Indexed: 12/14/2022] Open
Abstract
The sigma-1 receptor (σ1-R) and sigma-2 receptor (σ2-R) are potential drug targets for treatment of cancer, pain, depression, retinal degeneration and other neuronal diseases. Previous reports show that sigma-1 receptor modulates the activities of multiple channels. We are interested in possible sigma receptor modulation of Kv2.1, a K+ channel abundant in retinal photoreceptors. We tested the effect of established sigma receptor ligands on Kv2.1 channels which were stably expressed in HEK293 cells. Surprisingly, σ1-R antagonists inhibited Kv2.1 currents in both wild type and σ1-R knockout HEK293 cells that we engineered using the CRISPR/Cas9 technology. Moreover, PB28, a σ1-R antagonist and also σ2-R agonist, inhibited Kv2.1 in σ1-R knockout cells, but this action was not blocked by the σ2-R antagonists that did not have an effect on Kv2.1. We also observed inhibition of electroretinogram by PB28 in wild type as well as σ1-R knockout mice. Thus, the results in this study indicate that the Kv2.1-inhibiting function of the sigma ligands is not sigma receptor dependent, suggesting a direct effect of these ligands on the Kv2.1 channel.
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Mavlyutov TA, Yang H, Epstein ML, Ruoho AE, Yang J, Guo LW. APEX2-enhanced electron microscopy distinguishes sigma-1 receptor localization in the nucleoplasmic reticulum. Oncotarget 2017; 8:51317-51330. [PMID: 28881650 PMCID: PMC5584251 DOI: 10.18632/oncotarget.17906] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/04/2017] [Indexed: 12/03/2022] Open
Abstract
The sigma-1 receptor (Sig1R) is an endoplasmic reticulum chaperonin that is attracting tremendous interest as a potential anti-neurodegenerative target. While this membrane protein is known to reside in the inner nuclear envelope (NE) and influences transcription, apparent Sig1R presence in the nucleoplasm is often observed, seemingly contradicting its NE localization. We addressed this confounding issue by applying an antibody-free approach of electron microscopy (EM) to define Sig1R nuclear localization. We expressed APEX2 peroxidase fused to Sig1R-GFP in a Sig1R-null NSC34 neuronal cell line generated with CRISPR-Cas9. APEX2-catalyzed gold/silver precipitation markedly improved EM clarity and confirmed an apparent intra-nuclear presence of Sig1R. However, serial sectioning combined with APEX2-enhanced EM revealed that Sig1R actually resided in the nucleoplasmic reticulum (NR), a specialized nuclear compartment formed via NE invagination into the nucleoplasm. NR cross-sections also indicated Sig1R in ring-shaped NR membranes. Thus, this study distinguishes Sig1R in the NR which could otherwise appear localized in the nucleoplasm if detected with low-resolution methods. Our finding is important for uncovering potential Sig1R regulations in the nucleus.
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Affiliation(s)
- Timur A Mavlyutov
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin, Madison, WI 53705, USA
| | - Huan Yang
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin, Madison, WI 53705, USA
| | - Miles L Epstein
- Department of Neuroscience, University of Wisconsin, Madison, WI 53706, USA
| | - Arnold E Ruoho
- Department of Neuroscience, University of Wisconsin, Madison, WI 53706, USA
| | - Jay Yang
- Department of Anesthesiology, Wisconsin Institute for Medical Research, University of Wisconsin, Madison, WI 53705, USA
| | - Lian-Wang Guo
- Department of Surgery, Wisconsin Institute for Medical Research, University of Wisconsin, Madison, WI 53705, USA.,McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705, USA.,Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.,Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
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Epigenetic intervention with a BET inhibitor ameliorates acute retinal ganglion cell death in mice. Mol Vis 2017; 23:149-159. [PMID: 28356707 PMCID: PMC5360452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/18/2017] [Indexed: 10/26/2022] Open
Abstract
PURPOSE The bromo and extraterminal (BET) epigenetic "reader" family is becoming an appealing new therapeutic target for several common diseases, yet little is known of its role in retinal neurodegeneration. We explored the potential of BET inhibition in the protection of retinal ganglion cells (RGCs). METHODS To test the therapeutic effect of JQ1, an inhibitor highly selective for the BET family of proteins, we used an acute RGC damage model induced by N-methyl-D-aspartic acid (NMDA) excitotoxicity. Adult C57BL/6 mice received an intravitreal injection of NMDA with (or without) JQ1 in one eye and vehicle control in the contralateral eye; RGC loss was assessed on retinal sections and whole mounts. Gene expression and apoptosis were analyzed by quantitative real time (RT)-PCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), respectively. For counting RGCs, immunostaining of the marker protein BRN3A was performed on whole mounts. RESULTS NMDA treatment eliminated RGCs (day 7 and day 14 post injection) and diminished the expression (mRNAs) of RGC-selective genes, including Thy1, Nrn1, Sncg, and Nfl (day 3 and day 7). In contrast, co-injection with JQ1 maintained the number and gene expression of RGCs at ~2 fold of the control (NMDA only, no JQ1), and it decreased NMDA-induced TUNEL-positive cells in the RGC layer by 35%. While NMDA treatment dramatically upregulated mRNAs of inflammatory cytokines (TNFα, IL-1β, MCP-1, RANTES) in retinal homogenates, co-injection with JQ1 suppressed their upregulation by ~50%. CONCLUSIONS Intravitreal injection of a BET inhibitor (JQ1) ameliorates NMDA-induced RGC death, revealing the RGC-protective potential of pharmacological blockage of the BET family. This new strategy of epigenetic intervention may be extended to other retinal degenerative conditions.
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Zhao L, Chen G, Li J, Fu Y, Mavlyutov TA, Yao A, Nickells RW, Gong S, Guo LW. An intraocular drug delivery system using targeted nanocarriers attenuates retinal ganglion cell degeneration. J Control Release 2017; 247:153-166. [PMID: 28063892 PMCID: PMC5323250 DOI: 10.1016/j.jconrel.2016.12.038] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/08/2016] [Accepted: 12/29/2016] [Indexed: 02/03/2023]
Abstract
Glaucoma is a common blinding disease characterized by loss of retinal ganglion cells (RGCs). To date, there is no clinically available treatment directly targeting RGCs. We aim to develop an RGC-targeted intraocular drug delivery system using unimolecular micelle nanoparticles (unimNPs) to prevent RGC loss. The unimNPs were formed by single/individual multi-arm star amphiphilic block copolymer poly(amidoamine)-polyvalerolactone-poly(ethylene glycol) (PAMAM-PVL-PEG). While the hydrophobic PAMAM-PVL core can encapsulate hydrophobic drugs, the hydrophilic PEG shell provides excellent water dispersity. We conjugated unimNPs with the cholera toxin B domain (CTB) for RGC-targeting and with Cy5.5 for unimNP-tracing. To exploit RGC-protective sigma-1 receptor (S1R), we loaded unimNPs with an endogenous S1R agonist dehydroepiandrosterone (DHEA) as an FDA-approved model drug. These unimNPs produced a steady DHEA release in vitro for over two months at pH7.4. We then co-injected (mice, intraocular) unimNPs with the glutamate analog N-methyl-d-aspartate (NMDA), which is excito-toxic and induces RGC death. The CTB-conjugated unimNPs (i.e., targeted NPs) accumulated at the RGC layer and effectively preserved RGCs at least for 14days, whereas the unimNPs without CTB (i.e., non-targeted NPs) showed neither accumulation at nor protection of NMDA-treated RGCs. Consistent with S1R functions, targeted NPs relative to non-targeted NPs showed markedly better inhibitory effects on apoptosis and oxidative/inflammatory stresses in the RGC layer. Hence, the DHEA-loaded, CTB-conjugated unimNPs represent an RGC/S1R dual-targeted nanoplatform that generates an efficacious template for further development of a sustainable intraocular drug delivery system to protect RGCs, which may be applicable to treatments directed at glaucomatous pathology.
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Affiliation(s)
- Lei Zhao
- Department of Surgery, 5151 Wisconsin Institute for Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA
| | - Guojun Chen
- Department of Materials Science and Engineering, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Jun Li
- Department of Surgery, 5151 Wisconsin Institute for Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA; Department of Ophthalmology, The First Hospital of China Medical University, Shenyang 110001, China.; Department of Ophthalmology, The 3rd People's Hospital of Dalian, Dalian 116033, China
| | - Yingmei Fu
- Department of Surgery, 5151 Wisconsin Institute for Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wanping Nan Road, Shanghai 200030, China
| | - Timur A Mavlyutov
- Department of Surgery, 5151 Wisconsin Institute for Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA
| | - Annie Yao
- Department of Surgery, 5151 Wisconsin Institute for Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA
| | - Robert W Nickells
- Department of Ophthalmology and Vision Sciences, University of Wisconsin-Madison, 1300 University Ave, Madison, WI 53706, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Shaoqin Gong
- Department of Materials Science and Engineering, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53715, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA.
| | - Lian-Wang Guo
- Department of Surgery, 5151 Wisconsin Institute for Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA.
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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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Photoreceptor protection via blockade of BET epigenetic readers in a murine model of inherited retinal degeneration. J Neuroinflammation 2017; 14:14. [PMID: 28103888 PMCID: PMC5248448 DOI: 10.1186/s12974-016-0775-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 12/07/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The bromodomain and extraterminal domain (BET) family proteins (BET2, BET3, and BET4) "read" (bind) histone acetylation marks via two distinct bromodomains (Brom1 and Brom2) facilitating transcriptional activation. These epigenetic "readers" play crucial roles in pathogenic processes such as inflammation. The role of BETs in influencing the degenerative process in the retina is however unknown. METHODS We employed the rd10 mouse model (Pde6b rd10 mutation) of retinitis pigmentosa (RP) to examine the involvement of BET proteins in retinal neurodegeneration. RESULTS Inhibition of BET activity by intravitreal delivery of JQ1, a BET-specific inhibitor binding both Brom1 and Brom2, ameliorated photoreceptor degeneration and improved electroretinographic function. Rescue effects of JQ1 were related to the suppression of retinal microglial activation in vivo, as determined by decreased immunostaining of activation markers (IBA1, CD68, TSPO) and messenger RNA (mRNA) levels of inflammatory cytokines in microglia purified from rd10 retinas. JQ1 pre-treatment also suppressed microglial activation in vitro, decreasing microglial proliferation, migration, and mRNA expression of inflammatory cytokines (TNFα, MCP-1, IL-1β, IL-6, and RANTES). Expression of BET2, but not BET3 and BET4, was significantly elevated during photoreceptor degeneration at postnatal day (PN)24 in retinas of rd10 mice relative to age-matched wild-type controls. siRNA knockdown of BET2 but not BET4, and the inhibitor of Brom2 (RVX208) but not of Brom1 (Olinone), decreased microglial activation. CONCLUSIONS These findings indicate that BET inhibition rescues photoreceptor degeneration likely via the suppression of microglial activation and implicates BET interference as a potential therapeutic strategy for the treatment of degenerative retinal diseases.
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Kerkhofs M, Giorgi C, Marchi S, Seitaj B, Parys JB, Pinton P, Bultynck G, Bittremieux M. Alterations in Ca 2+ Signalling via ER-Mitochondria Contact Site Remodelling in Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:225-254. [PMID: 28815534 DOI: 10.1007/978-981-10-4567-7_17] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inter-organellar contact sites establish microdomains for localised Ca2+-signalling events. One of these microdomains is established between the ER and the mitochondria. Importantly, the so-called mitochondria-associated ER membranes (MAMs) contain, besides structural proteins and proteins involved in lipid exchange, several Ca2+-transport systems, mediating efficient Ca2+ transfer from the ER to the mitochondria. These Ca2+ signals critically control several mitochondrial functions, thereby impacting cell metabolism, cell death and survival, proliferation and migration. Hence, the MAMs have emerged as critical signalling hubs in physiology, while their dysregulation is an important factor that drives or at least contributes to oncogenesis and tumour progression. In this book chapter, we will provide an overview of the role of the MAMs in cell function and how alterations in the MAM composition contribute to oncogenic features and behaviours.
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Affiliation(s)
- Martijn Kerkhofs
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| | - Carlotta Giorgi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Saverio Marchi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Bruno Seitaj
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| | - Jan B Parys
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| | - Paolo Pinton
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Geert Bultynck
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium.
| | - Mart Bittremieux
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
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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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Mavlyutov TA, Baker EM, Losenegger TM, Kim JR, Torres B, Epstein ML, Ruoho AE. The Sigma-1 Receptor-A Therapeutic Target for the Treatment of ALS? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 964:255-265. [PMID: 28315276 DOI: 10.1007/978-3-319-50174-1_17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The membrane bound 223 amino acid Sigma-1 Receptor (S1R) serves as a molecular chaperone and functional regulator of many signaling proteins. Spinal cord motor neuron activation occurs, in part, via large ventral horn cholinergic synapses called C-boutons/C-terminals. Chronic excitation of motor neurons and alterations in C-terminals has been associated with Amyotrophic Lateral Sclerosis (ALS ). The S1R has an important role in regulating motor neuron function. High levels of the S1R are localized in postsynaptic endoplasmic reticulum (ER) subsurface cisternae within 10-20 nm of the plasma membrane that contain muscarinic type 2 acetylcholine receptors (M2AChR), calcium activated potassium channels (Kv2.1) and slow potassium (SK) channels. An increase in action potentials in the S1R KO mouse motor neurons indicates a critical role for the S1R as a "brake" on motor neuron function possibly via calcium dependent hyperpolarization mechanisms involving the aforementioned potassium channels. The longevity of SOD-1/S1R KO ALS mice is significantly reduced compared to SOD-1/WT ALS controls. The S1R colocalizes in C-terminals with Indole(ethyl)amine-N-methyl transferase (INMT ), the enzyme that produces the S1R agonist , N,N'- dimethyltryptamine (DMT). INMT methylation can additionally neutralize endogenous toxic sulfur and selenium derivatives thus providing functional synergism with DMT to reduce oxidative stress in motor neurons . Small molecule activation of the S1R and INMT thus provides a possible therapeutic strategy to treat ALS .
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Affiliation(s)
- Timur A Mavlyutov
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Erin M Baker
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Tasher M Losenegger
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Jaimie R Kim
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Brian Torres
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Miles L Epstein
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Arnold E Ruoho
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.
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Wang J, Cui X, Roon P, Saul A, Smith SB. The Role of Sigma1R in Mammalian Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 964:267-284. [PMID: 28315277 DOI: 10.1007/978-3-319-50174-1_18] [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: 01/08/2023]
Abstract
This review article focuses on studies of Sigma 1 Receptor (Sigma1R) and retina . It provides a brief overview of the earliest pharmacological studies performed in the late 1990s that provided evidence of the presence of Sigma1R in various ocular tissues. It then describes work from a number of labs concerning the location of Sigma1R in several retinal cell types including ganglion, Müller glia , and photoreceptors . The role of Sigma1R ligands in retinal neuroprotection is emphasized. Early studies performed in vitro clearly showed that targeting Sigma1R could attenuate stress-induced retinal cell loss. These studies were followed by in vivo experiments. Data about the usefulness of targeting Sigma1R to prevent ganglion cell loss associated with diabetic retinopathy are reviewed. Mechanisms of Sigma1R-mediated retinal neuroprotection involving Müller cells , especially in modulating oxidative stress are described along with information about the retinal phenotype of mice lacking Sigma1R (Sigma1R -/- mice). The retina develops normally in Sigma1R -/- mice, but after many months there is evidence of apoptosis in the optic nerve head, decreased ganglion cell function and eventual loss of these cells. Additional studies using the Sigma1R -/- mice provide strong evidence that in the retina, Sigma1R plays a key role in modulating cellular stress. Recent work has shown that targeting Sigma1R may extend beyond protection of ganglion cells to include photoreceptor cell degeneration as well.
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Affiliation(s)
- Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Penny Roon
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
| | - Alan Saul
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1120 15th Street, CB 1114, Augusta, GA, 30912-2000, USA
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Sylvia B Smith
- 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.
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Mavlyutov TA, Guo LW. Peeking into Sigma-1 Receptor Functions Through the Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 964:285-297. [PMID: 28315278 PMCID: PMC6283661 DOI: 10.1007/978-3-319-50174-1_19] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review discusses recent advances towards understanding the sigma-1 receptor (S1R) as an endogenous neuro-protective mechanism in the retina , a favorable experimental model system. The exquisite architecture of the mammalian retina features layered and intricately wired neurons supported by non-neuronal cells. Ganglion neurons, photoreceptors , as well as the retinal pigment epithelium, are susceptible to degeneration that leads to major retinal diseases such as glaucoma , diabetic retinopathy , and age-related macular degeneration (AMD), and ultimately, blindness. The S1R protein is found essentially in every retinal cell type, with high abundance in the ganglion cell layer. Ultrastructural studies of photoreceptors, bipolar cells, and ganglion cells show a predominant localization of S1R in the nuclear envelope. A protective role of S1R for ganglion and photoreceptor cells is supported by in vitro and in vivo experiments. Most recently, studies suggest that S1R may also protect retinal neurons via its activities in Müller glia and microglia. The S1R functions in the retina may be attributed to a reduction of excitotoxicity, oxidative stress , ER stress response, or inflammation. S1R knockout mice are being used to delineate the S1R-specific effects. In summary, while significant progress has been made towards the objective of establishing a S1R-targeted paradigm for retinal neuro-protection , critical questions remain. In particular, context-dependent effects and potential side effects of interventions targeting S1R need to be studied in more diverse and more clinically relevant animal models.
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Affiliation(s)
- Timur A Mavlyutov
- Department of Surgery and McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, 5151 Wisconsin Institute for Medical Research, 1111 Highland Ave, 53705, Madison, WI, USA
| | - Lian-Wang Guo
- Department of Surgery and McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, 5151 Wisconsin Institute for Medical Research, 1111 Highland Ave, 53705, Madison, WI, USA
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