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Marileo AM, Gavilán J, San Martín VP, Lara CO, Sazo A, Muñoz-Montesino C, Castro PA, Burgos CF, Leiva-Salcedo E, Aguayo LG, Moraga-Cid G, Fuentealba J, Yévenes GE. Modulation of GABA A receptors and of GABAergic synapses by the natural alkaloid gelsemine. Front Mol Neurosci 2023; 15:1083189. [PMID: 36733271 PMCID: PMC9887029 DOI: 10.3389/fnmol.2022.1083189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/30/2022] [Indexed: 01/18/2023] Open
Abstract
The Gelsemium elegans plant preparations have shown beneficial activity against common diseases, including chronic pain and anxiety. Nevertheless, their clinical uses are limited by their toxicity. Gelsemine, one of the most abundant alkaloids in the Gelsemium plants, have replicated these therapeutic and toxic actions in experimental behavioral models. However, the molecular targets underlying these biological effects remain unclear. The behavioral activity profile of gelsemine suggests the involvement of GABAA receptors (GABAARs), which are the main biological targets of benzodiazepines (BDZs), a group of drugs with anxiolytic, hypnotic, and analgesic properties. Here, we aim to define the modulation of GABAARs by gelsemine, with a special focus on the subtypes involved in the BDZ actions. The gelsemine actions were determined by electrophysiological recordings of recombinant GABAARs expressed in HEK293 cells, and of native receptors in cortical neurons. Gelsemine inhibited the agonist-evoked currents of recombinant and native receptors. The functional inhibition was not associated with the BDZ binding site. We determined in addition that gelsemine diminished the frequency of GABAergic synaptic events, likely through a presynaptic modulation. Our findings establish gelsemine as a negative modulator of GABAARs and of GABAergic synaptic function. These pharmacological features discard direct anxiolytic or analgesic actions of gelsemine through GABAARs but support a role of GABAARs on the alkaloid induced toxicity. On the other hand, the presynaptic effects of the alkaloid provide an additional mechanism to explain their beneficial effects. Collectively, our results contribute novel information to improve understanding of gelsemine actions in the mammalian nervous system.
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Affiliation(s)
- Ana M. Marileo
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile,Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Javiera Gavilán
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Victoria P. San Martín
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile,Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Cesar O. Lara
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile,Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Anggelo Sazo
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile,Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Carola Muñoz-Montesino
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Patricio A. Castro
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Carlos F. Burgos
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Elías Leiva-Salcedo
- Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile, Santiago, Chile
| | - Luis G. Aguayo
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E. Yévenes
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile,Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile,*Correspondence: Gonzalo E. Yévenes, ✉
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Castillo C, Bravo-Arrepol G, Wendt A, Saez-Orellana F, Millar C, Burgos CF, Gavilán J, Pacheco C, Ahumada-Rudolph R, Napiórkowska M, Pérez C, Becerra J, Fuentealba J, Cabrera-Pardo JR. Neuroprotective Properties of Eudesmin on a Cellular Model of Amyloid-β Peptide Toxicity. J Alzheimers Dis 2023; 94:S97-S108. [PMID: 36463456 PMCID: PMC10473145 DOI: 10.3233/jad-220935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive impairment and memory loss. One of the hallmarks in AD is amyloid-β peptide (Aβ) accumulation, where the soluble oligomers of Aβ (AβOs) are the most toxic species, deteriorating the synaptic function, membrane integrity, and neuronal structures, which ultimately lead to apoptosis. Currently, there are no drugs to arrest AD progression, and current scientific efforts are focused on searching for novel leads to control this disease. Lignans are compounds extracted from conifers and have several medicinal properties. Eudesmin (Eu) is an extractable lignan from the wood of Araucaria araucana, a native tree from Chile. This metabolite has shown a range of biological properties, including the ability to control inflammation and antibacterial effects. OBJECTIVE In this study, the neuroprotective abilities of Eu on synaptic failure induced by AβOs were analyzed. METHODS Using neuronal models, PC12 cells, and in silico simulations we evaluated the neuroprotective effect of Eu (30 nM) against the toxicity induced by AβOs. RESULTS In primary cultures from mouse hippocampus, Eu preserved the synaptic structure against AβOs toxicity, maintaining stable levels of the presynaptic protein SV2 at the same concentration. Eu also averted synapsis failure from the AβOs toxicity by sustaining the frequencies of cytosolic Ca2+ transients. Finally, we found that Eu (30 nM) interacts with the Aβ aggregation process inducing a decrease in AβOs toxicity, suggesting an alternative mechanism to explain the neuroprotective activity of Eu. CONCLUSION We believe that Eu represents a novel lead that reduces the Aβ toxicity, opening new research venues for lignans as neuroprotective agents.
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Affiliation(s)
- Carolina Castillo
- Laboratory of Screening of Neuroactive Compounds, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gastón Bravo-Arrepol
- Unidad de Desarrollo Tecnológico, Parque Industrial Coronel, Universidad de Concepción, Concepción, Chile
| | - Aline Wendt
- Laboratory of Screening of Neuroactive Compounds, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Francisco Saez-Orellana
- Laboratory of Screening of Neuroactive Compounds, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Camila Millar
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Carlos F. Burgos
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Javiera Gavilán
- Laboratory of Screening of Neuroactive Compounds, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Carla Pacheco
- Departamento de Bioquímica Clínica, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Ramón Ahumada-Rudolph
- Laboratorio de Química Aplicada y Sustentable (LabQAS), Departamento de Química, Universidad del Bío-Bío, Concepción, Chile
| | - Mariola Napiórkowska
- Chair and Department of Biochemistry, Medical University of Warsaw, Warsaw, Poland
| | - Claudia Pérez
- Unidad de Desarrollo Tecnológico, Parque Industrial Coronel, Universidad de Concepción, Concepción, Chile
- Laboratorio de Química de Productos Naturales, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - José Becerra
- Unidad de Desarrollo Tecnológico, Parque Industrial Coronel, Universidad de Concepción, Concepción, Chile
- Laboratorio de Química de Productos Naturales, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Laboratory of Screening of Neuroactive Compounds, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jaime R. Cabrera-Pardo
- Laboratorio de Química Aplicada y Sustentable (LabQAS), Departamento de Química, Universidad del Bío-Bío, Concepción, Chile
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Burgos CF, Cikutovic R, Alarcón M. MicroRNA expression in male infertility. Reprod Fertil Dev 2022; 34:805-818. [PMID: 35760398 DOI: 10.1071/rd21131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 05/25/2022] [Indexed: 11/23/2022] Open
Abstract
Male infertility is a multifactorial disorder that involves different physiopathological mechanisms and multiple genes. In this sense, we analyse the role of miRNAs in this pathology. Gene expression analysis can provide relevant information to detect biomarkers, signalling pathways, pathologic mechanisms, and potential therapeutic targets for the disease. In this review, we describe four miRNA microarrays related to patients who present infertility diseases, including azoospermia, asthenozoospermia, and oligoasthenozoospermic. We selected 13 miRNAs with altered expressions in testis tissue (hsa-miR-122-5p, hsa-miR-145-5p, hsa-miR-16-5p, hsa-miR-193a-3p, hsa-miR-19a-3p, hsa-miR-23a-3p, hsa-miR-30b-5p, hsa-miR-34b-5p, hsa-miR-34c-5p, hsa-miR-374b-5p, hsa-miR-449a, hsa-miR-574-3p and hsa-miR-92a-3p), and systematically examine the mechanisms of four relevant miRNAs (hsa-miR-16-5p, hsa-miR-19a-3p, hsa-miR-92a-3p and hsa-miR-30b-5p) which we found that regulated a large number of proteins. An interaction network was generated, and its connections allowed us to identify signalling pathways and interactions between proteins associated with male infertility. In this way, we confirm that the most affected and relevant pathway is the PI3K-Akt signalling.
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Affiliation(s)
- C F Burgos
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepcion, Chile
| | - R Cikutovic
- Universidad de Talca, Talca, 360000 Maule, Chile
| | - M Alarcón
- Department of Clinical Biochemistry and Immunohaematology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile
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Ramirez AE, Fernández-Pérez EJ, Olivos N, Burgos CF, Boopathi S, Armijo-Weingart L, Pacheco CR, González W, Aguayo LG. The Stimulatory Effects of Intracellular α-Synuclein on Synaptic Transmission Are Attenuated by 2-Octahydroisoquinolin-2(1H)-ylethanamine. Int J Mol Sci 2021; 22:ijms222413253. [PMID: 34948050 PMCID: PMC8705949 DOI: 10.3390/ijms222413253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
α-Synuclein (αSyn) species can be detected in synaptic boutons, where they play a crucial role in the pathogenesis of Parkinson's Disease (PD). However, the effects of intracellular αSyn species on synaptic transmission have not been thoroughly studied. Here, using patch-clamp recordings in hippocampal neurons, we report that αSyn oligomers (αSynO), intracellularly delivered through the patch electrode, produced a fast and potent effect on synaptic transmission, causing a substantial increase in the frequency, amplitude and transferred charge of spontaneous synaptic currents. We also found an increase in the frequency of miniature synaptic currents, suggesting an effect located at the presynaptic site of the synapsis. Furthermore, our in silico approximation using docking analysis and molecular dynamics simulations showed an interaction between a previously described small anti-amyloid beta (Aβ) molecule, termed M30 (2-octahydroisoquinolin-2(1H)-ylethanamine), with a central hydrophobic region of αSyn. In line with this finding, our empirical data aimed to obtain oligomerization states with thioflavin T (ThT) and Western blot (WB) indicated that M30 interfered with αSyn aggregation and decreased the formation of higher-molecular-weight species. Furthermore, the effect of αSynO on synaptic physiology was also antagonized by M30, resulting in a decrease in the frequency, amplitude, and charge transferred of synaptic currents. Overall, the present results show an excitatory effect of intracellular αSyn low molecular-weight species, not previously described, that are able to affect synaptic transmission, and the potential of a small neuroactive molecule to interfere with the aggregation process and the synaptic effect of αSyn, suggesting that M30 could be a potential therapeutic strategy for synucleinopathies.
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Affiliation(s)
- Alejandra E. Ramirez
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Eduardo J. Fernández-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
- Correspondence: (E.J.F.-P.); (L.G.A.)
| | - Nicol Olivos
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Carlos F. Burgos
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Subramanian Boopathi
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico;
- Center for Bioinformatics, Simulations and Modeling, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile;
| | - Lorena Armijo-Weingart
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Carla R. Pacheco
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Wendy González
- Center for Bioinformatics, Simulations and Modeling, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile;
- Millennium Nucleus of Ion Channels-Associated Diseases, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile
| | - Luis G. Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
- Programa de Neurociencia, Psiquiatría y Salud Mental, Anatomy Building,
Faculty of Medicine, Universidad de Concepción, Concepción 4030000, Chile
- Correspondence: (E.J.F.-P.); (L.G.A.)
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5
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Toledo JP, Fernández-Pérez EJ, Ferreira IL, Marinho D, Riffo-Lepe NO, Pineda-Cuevas BN, Pinochet-Pino LF, Burgos CF, Rego AC, Aguayo LG. Boldine Attenuates Synaptic Failure and Mitochondrial Deregulation in Cellular Models of Alzheimer's Disease. Front Neurosci 2021; 15:617821. [PMID: 33679301 PMCID: PMC7933475 DOI: 10.3389/fnins.2021.617821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/25/2021] [Indexed: 11/18/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of senile dementia worldwide, characterized by both cognitive and behavioral deficits. Amyloid beta peptide (Aβ) oligomers (AβO) have been found to be responsible for several pathological mechanisms during the development of AD, including altered cellular homeostasis and synaptic function, inevitably leading to cell death. Such AβO deleterious effects provide a way for identifying new molecules with potential anti-AD properties. Available treatments minimally improve AD symptoms and do not extensively target intracellular pathways affected by AβO. Naturally-derived compounds have been proposed as potential modifiers of Aβ-induced neurodysfunction and cytotoxicity based on their availability and chemical diversity. Thus, the aim of this study was to evaluate boldine, an alkaloid derived from the bark and leaves of the Chilean tree Peumus boldus, and its capacity to block some dysfunctional processes caused by AβO. We examined the protective effect of boldine (1–10 μM) in primary hippocampal neurons and HT22 hippocampal-derived cell line treated with AβO (24–48 h). We found that boldine interacts with Aβ in silico affecting its aggregation and protecting hippocampal neurons from synaptic failure induced by AβO. Boldine also normalized changes in intracellular Ca2+ levels associated to mitochondria or endoplasmic reticulum in HT22 cells treated with AβO. In addition, boldine completely rescued the decrease in mitochondrial membrane potential (ΔΨm) and the increase in mitochondrial reactive oxygen species, and attenuated AβO-induced decrease in mitochondrial respiration in HT22 hippocampal cells. We conclude that boldine provides neuroprotection in AD models by both direct interactions with Aβ and by preventing oxidative stress and mitochondrial dysfunction. Additional studies are required to evaluate the effect of boldine on cognitive and behavioral deficits induced by Aβ in vivo.
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Affiliation(s)
- Juan P Toledo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
| | - Eduardo J Fernández-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
| | - Ildete L Ferreira
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,IIIUC-Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Daniela Marinho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,IIIUC-Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Nicolas O Riffo-Lepe
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
| | - Benjamin N Pineda-Cuevas
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
| | - Luis F Pinochet-Pino
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
| | - Carlos F Burgos
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
| | - A Cristina Rego
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Barrio Universitario, Concepción, Chile
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6
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Sánchez A, Bustos P, Honorato P, Burgos CF, Barriga N, Jannes CE, Sáez K, Alonso R, Asenjo S, Radojkovic C. Phenotypic characterization and predictive analysis of p.Asp47Asn LDL receptor mutation associated with Familial Hypercholesterolemia in a Chilean population. J Clin Lipidol 2021; 15:366-374.e1. [PMID: 33547002 DOI: 10.1016/j.jacl.2021.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/22/2020] [Accepted: 01/11/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Familial hypercholesterolemia (FH) is an inherited disorder mainly caused by mutations in the LDL receptor (LDL-R) and characterized by elevation of low-density lipoprotein cholesterol (LDL-C) levels and premature cardiovascular disease. OBJECTIVE In this study, we evaluated the clinical phenotype of the p.Asp47Asn, described as an uncertain pathogenic variant, and its effect on the structure of LDL-R and ligand interactions with apolipoproteins. METHODS 27 children and adolescents with suspected FH diagnosis were recruited from a pediatric endocrinology outpatient clinic. Blood samples were collected after 12 h fasting for lipid profile analysis. DNA sequencing was performed for six FH-related genes by Ion Torrent PGM platform and copy number variation by MLPA. For index cases, a familial cascade screening was done restricted to the same mutation found in the index case. In silico analysis were developed to evaluate the binding capacity of LDL-R to apolipoproteins B100 and E. RESULTS Lipid profile in children and adolescents demonstrated higher LDL-C levels in p.Asp47Asn carriers compared to the wild type genotype. In silico analysis predicted a reduction in the binding capacity of the ligand-binding modules LA1-2 of p.Asp47Asn LDL-R for ApoB100 and ApoE, which was not produced by local structural changes or folding defects but as a consequence of a decreased apparent affinity for both apolipoproteins. CONCLUSION The clinical phenotype and the structural effects of p.Asp47Asn LDL-R mutation suggest that this variant associates to FH.
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Affiliation(s)
- Andrea Sánchez
- Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Paulina Bustos
- Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Paula Honorato
- Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Carlos F Burgos
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Natalia Barriga
- Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile
| | - Cinthia E Jannes
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor), University of São Paulo Medical School Hospital, São Paulo, Brazil
| | - Katia Sáez
- Departamento de Estadística, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile
| | - Rodrigo Alonso
- Center for Advanced Metabolic Medicine and Nutrition, Santiago de Chile. Fundación Hipercolesterolemia Familiar, Madrid, Spain
| | - Sylvia Asenjo
- Departamento de Pediatría, Facultad de Medicina, Universidad de Concepción, Concepción, Chile
| | - Claudia Radojkovic
- Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile.
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González-Sanmiguel J, Burgos CF, Bascuñán D, Fernández-Pérez EJ, Riffo-Lepe N, Boopathi S, Fernández-Pérez A, Bobadilla-Azócar C, González W, Figueroa M, Vicente B, Aguayo LG. Gabapentin Inhibits Multiple Steps in the Amyloid Beta Toxicity Cascade. ACS Chem Neurosci 2020; 11:3064-3076. [PMID: 32886489 DOI: 10.1021/acschemneuro.0c00414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Oligomeric β-amyloid peptide (Aβ) is one of the main neurotoxic agents of Alzheimer's disease (AD). Oligomers associate to neuronal membranes, forming "pore-like" structures that cause intracellular calcium and neurotransmitter dyshomeostasis, leading to synaptic failure and death. Through molecular screening targeting the C terminal region of Aβ, a region involved in the toxic properties of the peptide, we detected an FDA approved compound, gabapentin (GBP), with neuroprotective effects against Aβ toxicity. At micromolar concentrations, GBP antagonized peptide aggregation over time and reduced the Aβ absorbance plateau to 28% of control. In addition, GBP decreased Aβ association to membranes by almost half, and the effects of Aβ on intracellular calcium in hippocampal neurons were antagonized without causing effects on its own. Finally, we found that GBP was able to block the synaptotoxicity induced by Aβ in hippocampal neurons, increasing post-synaptic currents from 1.7 ± 0.9 to 4.2 ± 0.7 fC and mean relative fluorescence intensity values of SV2, a synaptic protein, from 0.7 ± 0.09 to 1.00 ± 0.08. The results show that GBP can interfere with Aβ-induced toxicity by blocking multiple steps, resulting in neuroprotection, which justifies advancing toward additional animal and human studies.
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Affiliation(s)
- Juliana González-Sanmiguel
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
| | - Carlos F. Burgos
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
| | - Denisse Bascuñán
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
| | - Eduardo J. Fernández-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
| | - Nicolás Riffo-Lepe
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
| | - Subramanian Boopathi
- The Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca 3460000, Chile
| | | | - Catalina Bobadilla-Azócar
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
| | - Wendy González
- The Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca 3460000, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
| | - Maximiliano Figueroa
- Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology, Universidad de Concepción, Concepción 4030000, Chile
| | - Benjamín Vicente
- Department of Psychiatry and Mental Health, Universidad de Concepcion, Concepción 4030000, Chile
- Program on Neuroscience, Psychiatry and Mental Health, Universidad de Concepcion, Concepción 4030000, Chile
| | - Luis G. Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción 4030000, Chile
- Program on Neuroscience, Psychiatry and Mental Health, Universidad de Concepcion, Concepción 4030000, Chile
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Muñoz-Montesino C, Burgos CF, Lara CO, Riquelme CR, Flaig D, San Martin VP, Aguayo LG, Fuentealba J, Castro PA, Guzmán L, Yévenes GE, Moraga-Cid G. Inhibition of the Glycine Receptor alpha 3 Function by Colchicine. Front Pharmacol 2020; 11:1143. [PMID: 32903667 PMCID: PMC7438739 DOI: 10.3389/fphar.2020.01143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 07/13/2020] [Indexed: 11/22/2022] Open
Abstract
Colchicine is a plant alkaloid that is widely used as a therapeutic agent. It is widely accepted that colchicine reduces the production of inflammatory mediators mainly by altering cytoskeleton dynamics due to its microtubule polymerization inhibitory activity. However, other lines of evidence have shown that colchicine exerts direct actions on the function of ion channels, which are independent of cytoskeleton alterations. Colchicine is able to modify the function of several pentameric ligand-gated ion channels, including glycine receptors (GlyRs). Previous electrophysiological studies have shown that colchicine act as an antagonist of GlyRs composed by the α1 subunit. In addition, it was recently demonstrated that colchicine directly bind to the α3 subunit of GlyRs. Interestingly, other studies have shown a main role of α3GlyRs on chronic inflammatory pain. Nevertheless, the functional effects of colchicine on the α3GlyR function are still unknown. Here, by using electrophysiological techniques and bioinformatics, we show that colchicine inhibited the function of the α3GlyRs. Colchicine elicited concentration-dependent inhibitory effects on α3GlyRs at micromolar range and decreased the apparent affinity for glycine. Single-channel recordings show that the colchicine inhibition is associated with a decrease in the open probability of the ion channel. Molecular docking assays suggest that colchicine preferentially bind to the orthosteric site in the closed state of the ion channel. Altogether, our results suggest that colchicine is a competitive antagonist of the α3GlyRs.
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9
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Avila ME, Sepúlveda FJ, Burgos CF, Moraga-Cid G, Parodi J, Moon RT, Aguayo LG, Opazo C, De Ferrari GV. Correction: Canonical Wnt3a modulates intracellular calcium and enhances excitatory neurotransmission in hippocampal neurons. J Biol Chem 2020; 295:9265. [PMID: 32620693 DOI: 10.1074/jbc.aac120.014663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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10
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Peters C, Bascuñán D, Burgos CF, Bobadilla C, González-Sanmiguel J, Boopathi S, Riffo N, Fernández-Pérez EJ, Tarnok ME, Aguilar LF, Gonzalez W, Aguayo LG. Characterization of a new molecule capable of inhibiting several steps of the amyloid cascade in Alzheimer's disease. Neurobiol Dis 2020; 141:104938. [PMID: 32434047 DOI: 10.1016/j.nbd.2020.104938] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/04/2020] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in elderly people. Existent therapies are directed at alleviating some symptoms, but are not effective in altering the course of the disease. METHODS Based on our previous study that showed that an Aβ-interacting small peptide protected against the toxic effects of amyloid-beta peptide (Aβ), we carried out an array of in silico, in vitro, and in vivo assays to identify a molecule having neuroprotective properties. RESULTS In silico studies showed that the molecule, referred to as M30 (2-Octahydroisoquinolin-2(1H)-ylethanamine), was able to interact with the Aβ peptide. Additionally, in vitro assays showed that M30 blocked Aβ aggregation, association to the plasma membrane, synaptotoxicity, intracellular calcium, and cellular toxicity, while in vivo experiments demonstrated that M30 induced a neuroprotective effect by decreasing the toxicity of Aβ in the dentate gyrus of the hippocampus and improving the alteration in spatial memory in behavior assays. DISCUSSION Therefore, we propose that this new small molecule could be a useful candidate for the additional development of a treatment against AD since it appears to block multiple steps in the amyloid cascade. Overall, since there are no drugs that effectively block the progression of AD, this approach represents an innovative strategy. SIGNIFICANCE Currently, there is no effective treatment for AD and the expectations to develop an effective therapy are low. Using in silico, in vitro, and in vivo experiments, we identified a new compound that is able to inhibit Aβ-induced neurotoxicity, specifically aggregation, association to neurons, synaptic toxicity, calcium dyshomeostasis and memory impairment induced by Aβ. Because Aβ toxicity is central to AD progression, the inhibition mediated by this new molecule might be useful as a therapeutic tool.
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Affiliation(s)
- Christian Peters
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Denisse Bascuñán
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Carlos F Burgos
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Catalina Bobadilla
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | | | - Subramanian Boopathi
- The Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca, Chile
| | - Nicolás Riffo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Eduardo J Fernández-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - María Elena Tarnok
- Laboratory of Photophysics and Molecular Spectroscopy, Chemistry, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Luis Felipe Aguilar
- Laboratory of Photophysics and Molecular Spectroscopy, Chemistry, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Wendy Gonzalez
- The Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile.
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11
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Moraga-Cid G, San Martín VP, Lara CO, Muñoz B, Marileo AM, Sazo A, Muñoz-Montesino C, Fuentealba J, Castro PA, Guzmán L, Burgos CF, Zeilhofer HU, Aguayo LG, Corringer PJ, Yévenes GE. Modulation of glycine receptor single-channel conductance by intracellular phosphorylation. Sci Rep 2020; 10:4804. [PMID: 32179786 PMCID: PMC7076024 DOI: 10.1038/s41598-020-61677-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/12/2020] [Indexed: 01/05/2023] Open
Abstract
Glycine receptors (GlyRs) are anion-permeable pentameric ligand-gated ion channels (pLGICs). The GlyR activation is critical for the control of key neurophysiological functions, such as motor coordination, respiratory control, muscle tone and pain processing. The relevance of the GlyR function is further highlighted by the presence of abnormal glycinergic inhibition in many pathophysiological states, such as hyperekplexia, epilepsy, autism and chronic pain. In this context, previous studies have shown that the functional inhibition of GlyRs containing the α3 subunit is a pivotal mechanism of pain hypersensitivity. This pathway involves the activation of EP2 receptors and the subsequent PKA-dependent phosphorylation of α3GlyRs within the intracellular domain (ICD), which decrease the GlyR-associated currents and enhance neuronal excitability. Despite the importance of this mechanism of glycinergic dis-inhibition associated with dysfunctional α3GlyRs, our current understanding of the molecular events involved is limited. Here, we report that the activation of PKA signaling pathway decreases the unitary conductance of α3GlyRs. We show in addition that the substitution of the PKA-targeted serine with a negatively charged residue within the ICD of α3GlyRs and of chimeric receptors combining bacterial GLIC and α3GlyR was sufficient to generate receptors with reduced conductance. Thus, our findings reveal a potential biophysical mechanism of glycinergic dis-inhibition and suggest that post-translational modifications of the ICD, such as phosphorylation, may shape the conductance of other pLGICs.
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Affiliation(s)
- Gustavo Moraga-Cid
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile.
| | - Victoria P San Martín
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Cesar O Lara
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Braulio Muñoz
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Ana M Marileo
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Anggelo Sazo
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Carola Muñoz-Montesino
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Patricio A Castro
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Carlos F Burgos
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Hanns U Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland.,Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zurich, Vladimir-Prelog-Weg 1-5/10, CH-8090, Zurich, Switzerland
| | - Luis G Aguayo
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | | | - Gonzalo E Yévenes
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile.
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12
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Lara CO, Burgos CF, Moraga-Cid G, Carrasco MA, Yévenes GE. Pentameric Ligand-Gated Ion Channels as Pharmacological Targets Against Chronic Pain. Front Pharmacol 2020; 11:167. [PMID: 32218730 PMCID: PMC7079299 DOI: 10.3389/fphar.2020.00167] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 02/07/2020] [Indexed: 12/31/2022] Open
Abstract
Chronic pain is a common detrimental condition that affects around 20% of the world population. The current drugs to treat chronic pain states, especially neuropathic pain, have a limited clinical efficiency and present significant adverse effects that complicates their regular use. Recent studies have proposed new therapeutic strategies focused on the pharmacological modulation of G-protein-coupled receptors, transporters, enzymes, and ion channels expressed on the nociceptive pathways. The present work intends to summarize recent advances on the pharmacological modulation of pentameric ligand-gated ion channels, which plays a key role in pain processing. Experimental data have shown that novel allosteric modulators targeting the excitatory nicotinic acetylcholine receptor, as well as the inhibitory GABAA and glycine receptors, reverse chronic pain-related behaviors in preclinical assays. Collectively, these evidences strongly suggest the pharmacological modulation of pentameric ligand-gated ion channels is a promising strategy towards the development of novel therapeutics to treat chronic pain states in humans.
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Affiliation(s)
- César O Lara
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
| | - Carlos F Burgos
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
| | - Gustavo Moraga-Cid
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
| | - Mónica A Carrasco
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Talca, Talca, Chile
| | - Gonzalo E Yévenes
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
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13
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Lara CO, Burgos CF, Silva-Grecchi T, Muñoz-Montesino C, Aguayo LG, Fuentealba J, Castro PA, Guzmán JL, Corringer PJ, Yévenes GE, Moraga-Cid G. Large Intracellular Domain-Dependent Effects of Positive Allosteric Modulators on Glycine Receptors. ACS Chem Neurosci 2019; 10:2551-2559. [PMID: 30893555 DOI: 10.1021/acschemneuro.9b00050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Glycine receptors (GlyRs) are members of the pentameric ligand-gated ionic channel family (pLGICs) and mediate fast inhibitory neurotransmission in the brain stem and spinal cord. The function of GlyRs can be modulated by positive allosteric modulators (PAMs). So far, it is largely accepted that both the extracellular (ECD) and transmembrane (TMD) domains constitute the primary target for many of these PAMs. On the other hand, the contribution of the intracellular domain (ICD) to the PAM effects on GlyRs remains poorly understood. To gain insight about the role of the ICD in the pharmacology of GlyRs, we examined the contribution of each domain using a chimeric receptor. Two chimeras were generated, one consisting of the ECD of the prokaryotic homologue Gloeobacter violaceus ligand-gated ion channel (GLIC) fused to the TMD of the human α1GlyR lacking the ICD (Lily) and a second with the ICD (Lily-ICD). The sensitivity to PAMs of both chimeric receptors was studied using electrophysiological techniques. The Lily receptor showed a significant decrease in the sensitivity to four recognized PAMs. Remarkably, the incorporation of the ICD into the Lily background was sufficient to restore the wild-type α1GlyR sensitivity to these PAMs. Based on these data, we can suggest that the ICD is necessary to form a pLGIC having full sensitivity to positive allosteric modulators.
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Affiliation(s)
- Cesar O. Lara
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Carlos F. Burgos
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Tiare Silva-Grecchi
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Carola Muñoz-Montesino
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Luis G. Aguayo
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Jorge Fuentealba
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Patricio A. Castro
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Jose L. Guzmán
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | | | - Gonzalo E. Yévenes
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiologı́a, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
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14
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San Martín VP, Burgos CF, Marileo AM, Lara CO, Sazo A, Fuentealba J, Guzmán L, Castro PA, Aguayo LG, Moraga-Cid G, Yévenes GE. Inhibitory Actions of Tropeines on the α3 Glycine Receptor Function. Front Pharmacol 2019; 10:331. [PMID: 31024303 PMCID: PMC6465966 DOI: 10.3389/fphar.2019.00331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 03/19/2019] [Indexed: 01/15/2023] Open
Abstract
Glycine receptors (GlyRs) are chloride-permeable pentameric ligand-gated ion channels. The inhibitory activity of GlyRs is essential for many physiological processes, such as motor control and respiration. In addition, several pathological states, such as hyperekplexia, epilepsy, and chronic pain, are associated with abnormal glycinergic inhibition. Recent studies have pointed out that positive allosteric modulators targeting the GlyR α3 subunit (α3GlyR) displayed beneficial effects in chronic pain models. Interestingly, previous electrophysiological studies have shown that tropeines, which are a family of synthetic antagonists of the serotonin type 3 receptors (5-HT3Rs), potentiate the activity of GlyRs conformed by α1 subunits. However, despite its importance as a pharmacological target in chronic pain, it is currently unknown whether the α3GlyR function is modulated by tropeines. Using electrophysiological techniques and molecular docking simulations, here we show that tropeines are inhibitors of the α3GlyR function. Tropisetron, a prototypical tropeine, exerted concentration-dependent inhibitory effects on α3GlyRs at the low micromolar range. In addition, three other tropeines showed similar effects. Single-channel recordings show that tropisetron inhibition is associated with a decrease in the open probability of the ion channel. Molecular docking assays suggest that tropeines preferentially bind to an agonist-free, closed state of the ion channel. The tropeine binding occurs in a discrete pocket around the vicinity of the orthosteric site within the extracellular domain of α3GlyR. Thus, our results describe the pharmacological modulation of tropeines on α3GlyRs. These findings may contribute to the development of GlyR-selective tropeine derivatives for basic and/or clinical applications.
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Affiliation(s)
- Victoria P San Martín
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Carlos F Burgos
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Ana M Marileo
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Cesar O Lara
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Anggelo Sazo
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Patricio A Castro
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Luis G Aguayo
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
| | - Gonzalo E Yévenes
- Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
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15
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Burgos CF, Sanchéz C, Sepúlveda C, Fuentes E, Palomo I, Alarcón M. Anti-aggregation effect on platelets of Indiplon a hypnotic sedative non-benzodiazepine drug. Biomed Pharmacother 2018; 111:378-385. [PMID: 30594050 DOI: 10.1016/j.biopha.2018.12.087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 12/04/2018] [Accepted: 12/19/2018] [Indexed: 10/27/2022] Open
Abstract
Cardiovascular diseases are one of the main public health problems, and many of them, their pathophysiology involves alterations in platelet activity. Platelet activation is an essential event that is regulated by the intracellular concentrations of Ca2+ and cAMP. Interestingly, it has been shown that the activation of adenosine A2A receptors increases cAMP levels and produces the inhibition of platelet aggregation, which appears as a potential target for regulation of platelet activity. Therefore, we tried to activate A2A receptors using Indiplon, a drug developed for the treatment of insomnia, and analyze its effect on platelet activity in vitro. Our results indicate that Indiplon is able to interact in silico with the adenosine A2A receptor (ΔGbind of -73.321 kcal/mol, similar to that obtained with adenosine), which is involved in the regulation of platelet cAMP levels. In functional studies using PRP, a reduction in platelet aggregation induced by ADP was observed in the presence of Indiplon at 500 μM with a percentage of inhibition 70%, where the use of specific inhibitors (ZM241385 and MSX-2) of the A2A receptor also blocked these effects reducing the percentage of inhibition to 41% and 34.1%, respectively. Also, the use of Indiplon produced a decrease in the expression in the membrane of P-selectin. Thus, Indiplon acts as an A2A receptor agonist and whose activation results in inhibition of platelet aggregation and activation, showing a possible cardiovascular protective role.
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Affiliation(s)
- C F Burgos
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Chile
| | - C Sanchéz
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile
| | - C Sepúlveda
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - E Fuentes
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - I Palomo
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - M Alarcón
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile.
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16
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Sepúlveda C, Hernández B, Burgos CF, Fuentes E, Palomo I, Alarcón M. The cAMP/PKA Pathway Inhibits Beta-amyloid Peptide Release from Human Platelets. Neuroscience 2018; 397:159-171. [PMID: 30496824 DOI: 10.1016/j.neuroscience.2018.11.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/30/2018] [Accepted: 11/15/2018] [Indexed: 12/12/2022]
Abstract
The main component of Alzheimer's disease (AD) is the amyloid-beta peptide (Aβ), the brain of these patients is characterized by deposits in the parenchyma and cerebral blood vessels known as cerebral amyloid angiopathy (CAA). On the other hand, the platelets are the major source of the Aβ peptide in circulation and once secreted can activate the platelets and endothelial cells producing the secretion of several inflammatory mediators that finally end up unchaining the CAA and later AD. In the present study we demonstrate that cAMP/PKA pathway plays key roles in the regulation of calpain activation and secretion of Aβ in human platelets. We confirmed that inhibition of platelet functionality occurred when platelets were incubated with forskolin (molecule that rapidly increased cAMP levels). In this sense we found that platelets pre-incubated with forskolin (20 μM) present a complete inhibition of calpain activity and this effect is reversed using an inhibitor of protein kinase A. Consequentially, when platelets were inhibited by forskolin a reduction in the processing of the APP with the consequent decrease in the Aβ peptide secretion was observed. Therefore our study provides novel insight in relation to the mechanism of processing and release of the Aβ peptide from human platelets.
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Affiliation(s)
- C Sepúlveda
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - B Hernández
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - C F Burgos
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Chile
| | - E Fuentes
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - I Palomo
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - M Alarcón
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile.
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17
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Castillo C, Zaror S, Gonzalez M, Hidalgo A, Burgos CF, Cabezas OI, Hugues F, Jiménez SP, González-Horta E, González-Chavarría I, Gavilán J, Montesino R, Sánchez O, Lopez MG, Fuentealba J, Toledo JR. Neuroprotective effect of a new variant of Epo nonhematopoietic against oxidative stress. Redox Biol 2018; 14:285-294. [PMID: 28987867 PMCID: PMC5975214 DOI: 10.1016/j.redox.2017.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/05/2017] [Accepted: 09/18/2017] [Indexed: 12/19/2022] Open
Abstract
Human erythropoietin is mainly recognized for its hematopoietic function; however, by binding to its receptor (EpoR), it can activate different signaling pathways as STAT, PI3K, MAPK and RAS to increase cellular differentiation or provide neuroprotective effects, among others. A recombinant human erythropoietin variant with low glycosylation and without hematopoietic effect (EpoL) was purified from skimmed goat milk. Recombinant human erythropoietin (Epo) was obtained from CHO cell line and used as control to compare EpoL effects. Neuroprotection studies were performed in PC12 cells and rat hippocampal slices. Cells were pretreated during 1h with EpoL or Epo and exposed to oxidative agents (H2O2 or FCCP); cell viability was assayed at the end of the experiment by the MTT method. Hippocampal slices were exposed to 15min of oxygen and glucose deprivation (OGD) and the neuroprotective drugs EpoL or Epo were incubated for 2h post-OGD in re-oxygenated medium. Cell cultures stressed with oxidative agents, and pretreated with EpoL, showed neuroprotective effects of 30% at a concentration 10 times lower than that of Epo. Moreover, similar differences were observed in OGD ex vivo assays. Neuroprotection elicited by EpoL was lost when an antibody against EpoR was present, indicating that its effect is EpoR-dependent. In conclusion, our results suggest that EpoL has a more potent neuroprotective profile than Epo against oxidative stress, mediated by activation of EpoR, thus EpoL represents an important target to develop a potential biopharmaceutical to treat different central nervous system pathologies related to oxidative stress such as stroke or neurodegenerative diseases.
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Affiliation(s)
- C Castillo
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - S Zaror
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - M Gonzalez
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - A Hidalgo
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - C F Burgos
- Laboratory of Screening of Neuroactive Compound, Physiology Department. School of Biological Sciences, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - O I Cabezas
- Clinical Sciences Department, School of Veterinary Sciences, Universidad de Concepción, Avenida Vicente Méndez 595, Chillan, Chile
| | - F Hugues
- Clinical Sciences Department, School of Veterinary Sciences, Universidad de Concepción, Avenida Vicente Méndez 595, Chillan, Chile
| | - S P Jiménez
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - E González-Horta
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - I González-Chavarría
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - J Gavilán
- Laboratory of Screening of Neuroactive Compound, Physiology Department. School of Biological Sciences, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - R Montesino
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - O Sánchez
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Manuela G Lopez
- Department of Pharmacology and Therapeutics, "Instituo Teófilo Hernando", Universidad Autónoma de Madrid, Spain
| | - J Fuentealba
- Laboratory of Screening of Neuroactive Compound, Physiology Department. School of Biological Sciences, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - J R Toledo
- Biotechnology and Biopharmaceutical Laboratory, Pathophysiology Department, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile.
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Burgos CF, Yévenes GE, Aguayo LG. Structure and Pharmacologic Modulation of Inhibitory Glycine Receptors. Mol Pharmacol 2016; 90:318-25. [PMID: 27401877 DOI: 10.1124/mol.116.105726] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 07/08/2016] [Indexed: 01/08/2023] Open
Abstract
Glycine receptors (GlyR) are inhibitory Cys-loop ion channels that contribute to the control of excitability along the central nervous system (CNS). GlyR are found in the spinal cord and brain stem, and more recently they were reported in higher regions of the CNS such as the hippocampus and nucleus accumbens. GlyR are involved in motor coordination, respiratory rhythms, pain transmission, and sensory processing, and they are targets for relevant physiologic and pharmacologic modulators. Several studies with protein crystallography and cryoelectron microscopy have shed light on the residues and mechanisms associated with the activation, blockade, and regulation of pentameric Cys-loop ion channels at the atomic level. Initial studies conducted on the extracellular domain of acetylcholine receptors, ion channels from prokaryote homologs-Erwinia chrysanthemi ligand-gated ion channel (ELIC), Gloeobacter violaceus ligand-gated ion channel (GLIC)-and crystallized eukaryotic receptors made it possible to define the overall structure and topology of the Cys-loop receptors. For example, the determination of pentameric GlyR structures bound to glycine and strychnine have contributed to visualizing the structural changes implicated in the transition between the open and closed states of the Cys-loop receptors. In this review, we summarize how the new information obtained in functional, mutagenesis, and structural studies have contributed to a better understanding of the function and regulation of GlyR.
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Affiliation(s)
- Carlos F Burgos
- Laboratory of Neurophysiology (C.F.B., L.G.A.), and Laboratory of Neuropharmacology (G.E.Y.), Department of Physiology, University of Concepción, Concepción, Chile
| | - Gonzalo E Yévenes
- Laboratory of Neurophysiology (C.F.B., L.G.A.), and Laboratory of Neuropharmacology (G.E.Y.), Department of Physiology, University of Concepción, Concepción, Chile
| | - Luis G Aguayo
- Laboratory of Neurophysiology (C.F.B., L.G.A.), and Laboratory of Neuropharmacology (G.E.Y.), Department of Physiology, University of Concepción, Concepción, Chile
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Lara CO, Murath P, Muñoz B, Marileo AM, Martín LS, San Martín VP, Burgos CF, Mariqueo TA, Aguayo LG, Fuentealba J, Godoy P, Guzman L, Yévenes GE. Functional modulation of glycine receptors by the alkaloid gelsemine. Br J Pharmacol 2016; 173:2263-77. [PMID: 27128379 DOI: 10.1111/bph.13507] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/12/2016] [Accepted: 04/18/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Gelsemine is one of the principal alkaloids produced by the Gelsemium genus of plants belonging to the Loganiaceae family. The extracts of these plants have been used for many years, for a variety of medicinal purposes. Coincidentally, recent studies have shown that gelsemine exerts anxiolytic and analgesic effects on behavioural models. Several lines of evidence have suggested that these beneficial actions were dependent on glycine receptors, which are inhibitory neurotransmitter-gated ion channels of the CNS. However, it is currently unknown whether gelsemine can directly modulate the function of glycine receptors. EXPERIMENTAL APPROACH We examined the functional effects of gelsemine on glycine receptors expressed in transfected HEK293 cells and in cultured spinal neurons by electrophysiological techniques. KEY RESULTS Gelsemine directly modulated recombinant and native glycine receptors and exerted conformation-specific and subunit-selective effects. Gelsemine modulation was voltage-independent and was associated with differential changes in the apparent affinity for glycine and in the open probability of the ion channel. In addition, the alkaloid preferentially targeted glycine receptors in spinal neurons and showed only minor effects on GABAA and AMPA receptors. Furthermore, gelsemine significantly diminished the frequency of glycinergic and glutamatergic synaptic events without altering the amplitude. CONCLUSIONS AND IMPLICATIONS Our results provide a pharmacological basis to explain, at least in part, the glycine receptor-dependent, beneficial and toxic effects of gelsemine in animals and humans. In addition, the pharmacological profile of gelsemine may open new approaches to the development of subunit-selective modulators of glycine receptors.
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Affiliation(s)
- Cesar O Lara
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Pablo Murath
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Braulio Muñoz
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Ana M Marileo
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Loreto San Martín
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Victoria P San Martín
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Carlos F Burgos
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | | | - Luis G Aguayo
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Jorge Fuentealba
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Patricio Godoy
- IfADo-Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, Dortmund, Germany
| | - Leonardo Guzman
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
| | - Gonzalo E Yévenes
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Chile
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20
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Acuña MA, Yévenes GE, Ralvenius WT, Benke D, Di Lio A, Lara CO, Muñoz B, Burgos CF, Moraga-Cid G, Corringer PJ, Zeilhofer HU. Phosphorylation state-dependent modulation of spinal glycine receptors alleviates inflammatory pain. J Clin Invest 2016; 126:2547-60. [PMID: 27270175 DOI: 10.1172/jci83817] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 04/14/2016] [Indexed: 01/10/2023] Open
Abstract
Diminished inhibitory neurotransmission in the superficial dorsal horn of the spinal cord is thought to contribute to chronic pain. In inflammatory pain, reductions in synaptic inhibition occur partially through prostaglandin E2- (PGE2-) and PKA-dependent phosphorylation of a specific subtype of glycine receptors (GlyRs) that contain α3 subunits. Here, we demonstrated that 2,6-di-tert-butylphenol (2,6-DTBP), a nonanesthetic propofol derivative, reverses inflammation-mediated disinhibition through a specific interaction with heteromeric αβGlyRs containing phosphorylated α3 subunits. We expressed mutant GlyRs in HEK293T cells, and electrophysiological analyses of these receptors showed that 2,6-DTBP interacted with a conserved phenylalanine residue in the membrane-associated stretch between transmembrane regions 3 and 4 of the GlyR α3 subunit. In native murine spinal cord tissue, 2,6-DTBP modulated synaptic, presumably αβ heteromeric, GlyRs only after priming with PGE2. This observation is consistent with results obtained from molecular modeling of the α-β subunit interface and suggests that in α3βGlyRs, the binding site is accessible to 2,6-DTBP only after PKA-dependent phosphorylation. In murine models of inflammatory pain, 2,6-DTBP reduced inflammatory hyperalgesia in an α3GlyR-dependent manner. Together, our data thus establish that selective potentiation of GlyR function is a promising strategy against chronic inflammatory pain and that, to our knowledge, 2,6-DTBP has a unique pharmacological profile that favors an interaction with GlyRs that have been primed by peripheral inflammation.
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21
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Burgos CF, Muñoz B, Guzman L, Aguayo LG. Ethanol effects on glycinergic transmission: From molecular pharmacology to behavior responses. Pharmacol Res 2015; 101:18-29. [PMID: 26158502 DOI: 10.1016/j.phrs.2015.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 07/01/2015] [Accepted: 07/01/2015] [Indexed: 10/23/2022]
Abstract
It is well accepted that ethanol is able to produce major health and economic problems associated to its abuse. Because of its intoxicating and addictive properties, it is necessary to analyze its effect in the central nervous system. However, we are only now learning about the mechanisms controlling the modification of important membrane proteins such as ligand-activated ion channels by ethanol. Furthermore, only recently are these effects being correlated to behavioral changes. Current studies show that the glycine receptor (GlyR) is a susceptible target for low concentrations of ethanol (5-40mM). GlyRs are relevant for the effects of ethanol because they are found in the spinal cord and brain stem where they primarily express the α1 subunit. More recently, the presence of GlyRs was described in higher regions, such as the hippocampus and nucleus accumbens, with a prevalence of α2/α3 subunits. Here, we review data on the following aspects of ethanol effects on GlyRs: (1) direct interaction of ethanol with amino acids in the extracellular or transmembrane domains, and indirect mechanisms through the activation of signal transduction pathways; (2) analysis of α2 and α3 subunits having different sensitivities to ethanol which allows the identification of structural requirements for ethanol modulation present in the intracellular domain and C-terminal region; (3) Genetically modified knock-in mice for α1 GlyRs that have an impaired interaction with G protein and demonstrate reduced ethanol sensitivity without changes in glycinergic transmission; and (4) GlyRs as potential therapeutic targets.
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Affiliation(s)
- Carlos F Burgos
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Chile
| | - Braulio Muñoz
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Chile
| | - Leonardo Guzman
- Laboratory of Molecular Neurobiology, Department of Physiology, University of Concepción, Chile
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Chile.
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22
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Sánchez A, Yévenes GE, San Martin L, Burgos CF, Moraga-Cid G, Harvey RJ, Aguayo LG. Control of ethanol sensitivity of the glycine receptor α3 subunit by transmembrane 2, the intracellular splice cassette and C-terminal domains. J Pharmacol Exp Ther 2015; 353:80-90. [PMID: 25589412 DOI: 10.1124/jpet.114.221143] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Previous studies have shown that the effect of ethanol onglycine receptors (GlyRs) containing the a1 subunit is affected by interaction with heterotrimeric G proteins (Gβγ). GlyRs containing the α3 subunit are involved in inflammatory pain sensitization and rhythmic breathing and have received much recent attention. For example, it is unknown whether ethanol affects the function of this important GlyR subtype. Electrophysiologic experiments showed that GlyR α3 subunits were not potentiated by pharmacologic concentrations of ethanol or by Gβγ. Thus, we studied GlyR α1–α3 chimeras and mutants to determine the molecular properties that confer ethanol insensitivity. Mutation of corresponding glycine 254 in transmembrane domain 2 (TM2) found in a1 in the α3(A254G) –α1 chimera induced a glycine-evoked current that displayed potentiation during application of ethanol (46 ± 5%, 100 mM) and Gβγ activation (80 ± 17%). Interestingly,insertion of the intracellular α3L splice cassette into GlyR α1 abolished the enhancement of the glycine-activated current by ethanol (5 ± 6%) and activation by Gβγ (21 6 7%). In corporation of the GlyR α1 C terminus into the ethanol-resistant α3S(A254G) mutant produced a construct that displayed potentiation of the glycine-activated current with 100 mM ethanol (40 ± 6%)together with a current enhancement after G protein activation (68 ± 25%). Taken together, these data demonstrate that GlyRα3 subunits are not modulated by ethanol. Residue A254 in TM2, the α3L splice cassette, and the C-terminal domain of α3GlyRs are determinants for low ethanol sensitivity and form the molecular basis of subtype-selective modulation of GlyRs by alcohol.
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Affiliation(s)
- Andrea Sánchez
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile
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23
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Muñoz G, Urrutia JC, Burgos CF, Silva V, Aguilar F, Sama M, Yeh HH, Opazo C, Aguayo LG. Low concentrations of ethanol protect against synaptotoxicity induced by Aβ in hippocampal neurons. Neurobiol Aging 2015; 36:845-56. [DOI: 10.1016/j.neurobiolaging.2014.10.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 09/23/2014] [Accepted: 10/08/2014] [Indexed: 12/27/2022]
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Burgos CF, Castro PA, Mariqueo T, Bunster M, Guzmán L, Aguayo LG. Evidence for α-helices in the large intracellular domain mediating modulation of the α1-glycine receptor by ethanol and Gβγ. J Pharmacol Exp Ther 2015; 352:148-55. [PMID: 25339760 PMCID: PMC4279101 DOI: 10.1124/jpet.114.217976] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 10/21/2014] [Indexed: 12/19/2022] Open
Abstract
The α1-subunit containing glycine receptors (GlyRs) is potentiated by ethanol, in part, by intracellular Gβγ actions. Previous studies have suggested that molecular requirements in the large intracellular domain are involved; however, the lack of structural data about this region has made it difficult to describe a detailed mechanism. Using circular dichroism and molecular modeling, we generated a full model of the α1-GlyR, which includes the large intracellular domain and provides new information on structural requirements for allosteric modulation by ethanol and Gβγ. The data strongly suggest the existence of an α-helical conformation in the regions near transmembrane (TM)-3 and TM4 of the large intracellular domain. The secondary structure in the N-terminal region of the large intracellular domain near TM3 appeared critical for ethanol action, and this was tested using the homologous domain of the γ2-subunit of the GABAA receptor predicted to have little helical conformation. This region of γ2 was able to bind Gβγ and form a functional channel when combined with α1-GlyR, but it was not sensitive to ethanol. Mutations in the N- and C-terminal regions introduced to replace corresponding amino acids of the α1-GlyR sequence restored the ability to be modulated by ethanol and Gβγ. Recovery of the sensitivity to ethanol was associated with the existence of a helical conformation similar to α1-GlyR, thus being an essential secondary structural requirement for GlyR modulation by ethanol and G protein.
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Affiliation(s)
- Carlos F Burgos
- Laboratory of Neurophysiology, Department of Physiology (C.F.B., .P.A.C., T.M., L.G.A.), Laboratory of Molecular Neurobiology, Department of Physiology (L.G.), Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology (M.B.), and Ph.D. program in Pharmacology (T.M.), University of Concepción, Concepción, Chile
| | - Patricio A Castro
- Laboratory of Neurophysiology, Department of Physiology (C.F.B., .P.A.C., T.M., L.G.A.), Laboratory of Molecular Neurobiology, Department of Physiology (L.G.), Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology (M.B.), and Ph.D. program in Pharmacology (T.M.), University of Concepción, Concepción, Chile
| | - Trinidad Mariqueo
- Laboratory of Neurophysiology, Department of Physiology (C.F.B., .P.A.C., T.M., L.G.A.), Laboratory of Molecular Neurobiology, Department of Physiology (L.G.), Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology (M.B.), and Ph.D. program in Pharmacology (T.M.), University of Concepción, Concepción, Chile
| | - Marta Bunster
- Laboratory of Neurophysiology, Department of Physiology (C.F.B., .P.A.C., T.M., L.G.A.), Laboratory of Molecular Neurobiology, Department of Physiology (L.G.), Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology (M.B.), and Ph.D. program in Pharmacology (T.M.), University of Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Laboratory of Neurophysiology, Department of Physiology (C.F.B., .P.A.C., T.M., L.G.A.), Laboratory of Molecular Neurobiology, Department of Physiology (L.G.), Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology (M.B.), and Ph.D. program in Pharmacology (T.M.), University of Concepción, Concepción, Chile
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology (C.F.B., .P.A.C., T.M., L.G.A.), Laboratory of Molecular Neurobiology, Department of Physiology (L.G.), Laboratory of Molecular Biophysics, Department of Biochemistry and Molecular Biology (M.B.), and Ph.D. program in Pharmacology (T.M.), University of Concepción, Concepción, Chile
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Zurita MP, Muñoz G, Sepúlveda FJ, Gómez P, Castillo C, Burgos CF, Fuentealba J, Opazo C, Aguayo LG. Ibuprofen inhibits the synaptic failure induced by the amyloid-β peptide in hippocampal neurons. J Alzheimers Dis 2013; 35:463-73. [PMID: 23455989 DOI: 10.3233/jad-122314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Epidemiological studies have reported a decrease in the prevalence of Alzheimer's disease in individuals who chronically use non-steroidal anti-inflammatory drugs (NSAIDs). Clinical trials, on the other hand, have been less positive. Nevertheless, it has been proposed that NSAIDs exert part of their effects by reducing long-term cerebral neuroinflammation, although this mechanism has not been proven. In this study, we report that ibuprofen, one of the more widely used non-steroidal anti-inflammatory drugs, was able to alter the ultrastructure of amyloid-β peptide (Aβ) and significantly decrease its association to neuronal membranes, and consequently, its synaptotoxic effect in rat primary hippocampal and cortical cultures at 24 h incubation. In agreement with these results, we found that the decrease in the frequency of calcium transients with Aβ was partly recovered by addition of ibuprofen (8.0 × 10-2 Hz in control; 3.4 × 10-2 Hz in 5 μM Aβ, and 5.9 × 10-2 Hz in the presence of Aβ and 200 μM ibuprofen). Additionally, this effect correlated well with the increment and recovery of miniature spontaneous currents (47 ± 5% of control in 1 μM Aβ alone and 104 ± 14% in the presence of Aβ and ibuprofen). Our results suggest that ibuprofen could be exerting its neuroprotective effect by directly interacting with Aβ and altering its toxic aggregated forms. We postulate that other ibuprofen analogs with better pharmacological properties might have a higher efficacy in AD.
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Affiliation(s)
- Maria Paz Zurita
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, University of Concepción, Concepción, Chile
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26
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Peters C, Fernandez-Perez EJ, Burgos CF, Espinoza MP, Castillo C, Urrutia JC, Streltsov VA, Opazo C, Aguayo LG. Inhibition of amyloid beta-induced synaptotoxicity by a pentapeptide derived from the glycine zipper region of the neurotoxic peptide. Neurobiol Aging 2013; 34:2805-14. [PMID: 23855983 DOI: 10.1016/j.neurobiolaging.2013.06.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 05/29/2013] [Accepted: 06/04/2013] [Indexed: 10/26/2022]
Abstract
A major characteristic of Alzheimer's disease is the presence of amyloid beta (Aβ) oligomers and aggregates in the brain. Aβ oligomers interact with the neuronal membrane inducing perforations, causing an influx of calcium ions and increasing the release of synaptic vesicles that leads to a delayed synaptic failure by vesicle depletion. Here, we identified a neuroprotective pentapeptide anti-Aβ compound having the sequence of the glycine zipper region of the C-terminal of Aβ (G33LMVG37). Docking and Förster resonance energy transfer experiments showed that G33LMVG37 interacts with Aβ at the C-terminal region, which is important for Aβ association and insertion into the lipid membrane. Furthermore, this pentapeptide interfered with Aβ aggregation, association, and perforation of the plasma membrane. The synaptotoxicity induced by Aβ after acute and chronic applications were abolished by G33LMVG37. These results provide a novel rationale for drug development against Alzheimer's disease.
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Affiliation(s)
- Christian Peters
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile; Laboratory of Neurobiometals, Department of Physiology, University of Concepción, Concepción, Chile
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27
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Avila ME, Sepúlveda FJ, Burgos CF, Moraga-Cid G, Parodi J, Moon RT, Aguayo LG, Opazo C, De Ferrari GV. Canonical Wnt3a modulates intracellular calcium and enhances excitatory neurotransmission in hippocampal neurons. J Biol Chem 2010; 285:18939-47. [PMID: 20404321 PMCID: PMC2881816 DOI: 10.1074/jbc.m110.103028] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 04/16/2010] [Indexed: 11/06/2022] Open
Abstract
A role for Wnt signal transduction in the development and maintenance of brain structures is widely acknowledged. Recent studies have suggested that Wnt signaling may be essential for synaptic plasticity and neurotransmission. However, the direct effect of a Wnt protein on synaptic transmission had not been demonstrated. Here we show that nanomolar concentrations of purified Wnt3a protein rapidly increase the frequency of miniature excitatory synaptic currents in embryonic rat hippocampal neurons through a mechanism involving a fast influx of calcium from the extracellular space, induction of post-translational modifications on the machinery involved in vesicle exocytosis in the presynaptic terminal leading to spontaneous Ca(2+) transients. Our results identify the Wnt3a protein and a member of its complex receptor at the membrane, the low density lipoprotein receptor-related protein 6 (LRP6) coreceptor, as key molecules in neurotransmission modulation and suggest cross-talk between canonical and Wnt/Ca(2+) signaling in central neurons.
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Affiliation(s)
- Miguel E. Avila
- From the Departments of Biochemistry and Molecular Biology and
| | - Fernando J. Sepúlveda
- Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción P.O. Box 4070386, Chile
| | | | - Gustavo Moraga-Cid
- Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción P.O. Box 4070386, Chile
| | - Jorge Parodi
- Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción P.O. Box 4070386, Chile
| | - Randall T. Moon
- Howard Hughes Medical Institute, Department of Pharmacology and Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, Washington 98195, and
| | - Luis G. Aguayo
- Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción P.O. Box 4070386, Chile
| | - Carlos Opazo
- Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción P.O. Box 4070386, Chile
| | - Giancarlo V. De Ferrari
- From the Departments of Biochemistry and Molecular Biology and
- the Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andrés Bello, Santiago P.O. Box 8370134, Chile
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