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Gavilán J, Mardones C, Oyarce G, Triviño S, Espinoza-Rubilar N, Ramírez-Molina O, Pérez C, Becerra J, Varas P, Duran-Arcos R, Muñoz-Montesino C, Moraga-Cid G, Yévenes GE, Fuentealba J. Elephant Black Garlic's Beneficial Properties for Hippocampal Neuronal Network, Chemical Characterization and Biological Evaluation. Foods 2023; 12:3968. [PMID: 37959086 PMCID: PMC10650549 DOI: 10.3390/foods12213968] [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: 09/10/2023] [Revised: 10/11/2023] [Accepted: 10/13/2023] [Indexed: 11/15/2023] Open
Abstract
Garlic has been used for decades as an important food and additionally for its beneficial properties in terms of nutrition and ancestral therapeutics. In this work, we compare the properties of fresh (WG) and aged (BG) extract obtained from elephant garlic, harvested on Chiloe Island, Chile. BG was prepared from WG with a 20-day aging process under controlled temperature and humidity conditions. We observed that in BG, compounds such as diallyl disulfide decrease, and compounds of interest such as 5-hydroxymethylfurfural (69%), diallyl sulfide (17%), 3H-1,2-Dithiole (22%) and 4-Methyl-1,2,3-trithiolane (16%) were shown to be increased. Using 2,2-diphenyl-1-picrylhydrazyl (DPPH, BG: 51 ± 5.7%, WG: 12 ± 2.6%) and 2,20-azino-bis-(3-ethylbenzothiazoline-6 sulfonate) diammonium salt (ABTS, BG: 69.4 ± 2.3%, WG: 21 ± 3.9%) assays, we observed that BG possesses significantly higher antioxidant activity than WG and increased cell viability in hippocampal slices (41 ± 9%). The effects of WG and BG were shown to improve the neuronal function through an increased in intracellular calcium transients (189 ± 4%). In parallel, BG induced an increase in synaptic vesicle protein 2 (SV-2; 75 ± 12%) and brain-derived neurotrophic factor (BDNF; 32 ± 12%) levels. Thus, our study provides the initial scientific bases to foster the use of BG from Chiloe Island as a functional food containing a mixture of bioactive compounds that may contribute to brain health and well-being.
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Affiliation(s)
- Javiera Gavilán
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
| | - Claudia Mardones
- Facultad de Farmacia, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile;
| | - Gabriela Oyarce
- Laboratorio de Quimica de Productos Naturales, Facultas de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (G.O.); (S.T.); (C.P.); (J.B.)
| | - Sergio Triviño
- Laboratorio de Quimica de Productos Naturales, Facultas de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (G.O.); (S.T.); (C.P.); (J.B.)
| | - Nicole Espinoza-Rubilar
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
| | - Oscar Ramírez-Molina
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
| | - Claudia Pérez
- Laboratorio de Quimica de Productos Naturales, Facultas de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (G.O.); (S.T.); (C.P.); (J.B.)
| | - José Becerra
- Laboratorio de Quimica de Productos Naturales, Facultas de Ciencias Naturales y Oceanograficas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (G.O.); (S.T.); (C.P.); (J.B.)
| | | | - Robinson Duran-Arcos
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
| | - Carola Muñoz-Montesino
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
| | - Gustavo Moraga-Cid
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
| | - Gonzalo E. Yévenes
- MinusPain, Facultad de Ciencias Biológicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile
| | - Jorge Fuentealba
- Departmento de Fisiologia, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepción P.O. Box 160-C, Chile; (J.G.); (N.E.-R.); (O.R.-M.); (R.D.-A.); (C.M.-M.); (G.M.-C.)
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Panes-Fernandez J, Godoy PA, Gavilan J, Ramírez-Molina O, Burgos CF, Marileo A, Flores-Núñez O, Castro PA, Moraga-Cid G, Yévenes GE, Muñoz-Montesino C, Fuentealba J. TG2 promotes amyloid beta aggregates: Impact on ER-mitochondria crosstalk, calcium homeostasis and synaptic function in Alzheimer’s disease. Biomed Pharmacother 2023; 162:114596. [PMID: 36989728 DOI: 10.1016/j.biopha.2023.114596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/20/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by cognitive impairment that increasingly affects the elderly. AD's main features have been related to cellular and molecular events, including the aberrant aggregation of the amyloid beta peptide (Aβ), Ca2+ dyshomeostasis, and increased mitochondria-associated membranes (MAMs). Transglutaminase type 2 (TG2) is a ubiquitous enzyme whose primary role is the Ca2+-dependent proteins transamidation, including the Aβ peptide. TG2 activity has been closely related to cellular damage and death. We detected increased TG2 levels in neuronal cells treated with Aβ oligomers (AβOs) and hippocampal slices from J20 mice using cellular and molecular approaches. In this work, we characterized the capacity of TG2 to interact and promote Aβ toxic aggregates (AβTG2). AβTG2 induced an acute increase in intracellular Ca2+, miniature currents, and hiperexcitability, consistent with an increased mitochondrial Ca2+ overload, IP3R-VDAC tethering, and mitochondria-endoplasmic reticulum contacts (MERCs). AβTG2 also decreased neuronal viability and excitatory postsynaptic currents, reinforcing the idea of synaptic failure associated with MAMs dysregulation mediated by TG2. Z-DON treatment, TG2 inhibitor, reduced calcium overload, mitochondrial membrane potential loss, and synaptic failure, indicating an involvement of TG2 in a toxic cycle which increases Aβ aggregation, Ca2+ overload, and MAMs upregulation. These data provide novel information regarding the role TG2 plays in synaptic function and contribute additional evidence to support the further development of TG2 inhibitors as a disease-modifying strategy for AD.
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3
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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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4
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Castro PA, Pinto-Borguero I, Yévenes GE, Moraga-Cid G, Fuentealba J. Antiseizure medication in early nervous system development. Ion channels and synaptic proteins as principal targets. Front Pharmacol 2022; 13:948412. [PMID: 36313347 PMCID: PMC9614143 DOI: 10.3389/fphar.2022.948412] [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: 05/19/2022] [Accepted: 09/05/2022] [Indexed: 12/04/2022] Open
Abstract
The main strategy for the treatment of epilepsy is the use of pharmacological agents known as antiseizure medication (ASM). These drugs control the seizure onset and improves the life expectancy and quality of life of patients. Several ASMs are contraindicated during pregnancy, due to a potential teratogen risk. For this reason, the pharmacological treatments of the pregnant Women with Epilepsy (WWE) need comprehensive analyses to reduce fetal risk during the first trimester of pregnancy. The mechanisms by which ASM are teratogens are still under study and scientists in the field, propose different hypotheses. One of them, which will be addressed in this review, corresponds to the potential alteration of ASM on ion channels and proteins involved in relevant signaling and cellular responses (i.e., migration, differentiation) during embryonic development. The actual information related to the action of ASM and its possible targets it is poorly understood. In this review, we will focus on describing the eventual presence of some ion channels and synaptic proteins of the neurotransmitter signaling pathways present during early neural development, which could potentially interacting as targets of ASM. This information leads to elucidate whether these drugs would have the ability to affect critical signaling during periods of neural development that in turn could explain the fetal malformations observed by the use of ASM during pregnancy.
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Affiliation(s)
- Patricio A. Castro
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
- *Correspondence: Patricio A. Castro,
| | - Ingrid Pinto-Borguero
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E. Yévenes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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5
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San Martín VP, Sazo A, Utreras E, Moraga-Cid G, Yévenes GE. Glycine Receptor Subtypes and Their Roles in Nociception and Chronic Pain. Front Mol Neurosci 2022; 15:848642. [PMID: 35401105 PMCID: PMC8984470 DOI: 10.3389/fnmol.2022.848642] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 01/28/2022] [Indexed: 01/23/2023] Open
Abstract
Disruption of the inhibitory control provided by the glycinergic system is one of the major mechanisms underlying chronic pain. In line with this concept, recent studies have provided robust proof that pharmacological intervention of glycine receptors (GlyRs) restores the inhibitory function and exerts anti-nociceptive effects on preclinical models of chronic pain. A targeted regulation of the glycinergic system requires the identification of the GlyR subtypes involved in chronic pain states. Nevertheless, the roles of individual GlyR subunits in nociception and in chronic pain are yet not well defined. This review aims to provide a systematic outline on the contribution of GlyR subtypes in chronic pain mechanisms, with a particular focus on molecular pathways of spinal glycinergic dis-inhibition mediated by post-translational modifications at the receptor level. The current experimental evidence has shown that phosphorylation of synaptic α1β and α3β GlyRs are involved in processes of spinal glycinergic dis-inhibition triggered by chronic inflammatory pain. On the other hand, the participation of α2-containing GlyRs and of β subunits in pain signaling have been less studied and remain undefined. Although many questions in the field are still unresolved, future progress in GlyR research may soon open new exciting avenues into understanding and controlling chronic pain.
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Affiliation(s)
- Victoria P. San Martín
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Anggelo Sazo
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Elías Utreras
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
- Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile
| | - Gustavo Moraga-Cid
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Gonzalo E. Yévenes
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
- *Correspondence: Gonzalo E. Yévenes,
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6
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Panes JD, Saavedra P, Pineda B, Escobar K, Cuevas ME, Moraga-Cid G, Fuentealba J, Rivas CI, Rezaei H, Muñoz-Montesino C. PrP C as a Transducer of Physiological and Pathological Signals. Front Mol Neurosci 2021; 14:762918. [PMID: 34880726 PMCID: PMC8648500 DOI: 10.3389/fnmol.2021.762918] [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: 08/23/2021] [Accepted: 10/18/2021] [Indexed: 11/13/2022] Open
Abstract
After the discovery of prion phenomenon, the physiological role of the cellular prion protein (PrP C ) remained elusive. In the past decades, molecular and cellular analysis has shed some light regarding interactions and functions of PrP C in health and disease. PrP C , which is located mainly at the plasma membrane of neuronal cells attached by a glycosylphosphatidylinositol (GPI) anchor, can act as a receptor or transducer from external signaling. Although the precise role of PrP C remains elusive, a variety of functions have been proposed for this protein, namely, neuronal excitability and viability. Although many issues must be solved to clearly define the role of PrP C , its connection to the central nervous system (CNS) and to several misfolding-associated diseases makes PrP C an interesting pharmacological target. In a physiological context, several reports have proposed that PrP C modulates synaptic transmission, interacting with various proteins, namely, ion pumps, channels, and metabotropic receptors. PrP C has also been implicated in the pathophysiological cell signaling induced by β-amyloid peptide that leads to synaptic dysfunction in the context of Alzheimer's disease (AD), as a mediator of Aβ-induced cell toxicity. Additionally, it has been implicated in other proteinopathies as well. In this review, we aimed to analyze the role of PrP C as a transducer of physiological and pathological signaling.
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Affiliation(s)
- Jessica D Panes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Paulina Saavedra
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Benjamin Pineda
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Kathleen Escobar
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Magdalena E Cuevas
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Coralia I Rivas
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Human Rezaei
- Virologie et Immunologie Moléculaires (VIM), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Jouy-en-Josas, France.,Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Versailles, France.,Université Paris-Saclay, Jouy-en-Josas, France
| | - Carola Muñoz-Montesino
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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7
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Muñoz B, Mariqueo T, Murath P, Peters C, Yevenes GE, Moraga-Cid G, Peoples RW, Aguayo LG. Modulatory Actions of the Glycine Receptor β Subunit on the Positive Allosteric Modulation of Ethanol in α2 Containing Receptors. Front Mol Neurosci 2021; 14:763868. [PMID: 34867189 PMCID: PMC8637530 DOI: 10.3389/fnmol.2021.763868] [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: 08/24/2021] [Accepted: 10/18/2021] [Indexed: 01/23/2023] Open
Abstract
Alpha1-containing glycine receptors (GlyRs) are major mediators of synaptic inhibition in the spinal cord and brain stem. Recent studies reported the presence of α2-containing GlyRs in other brain regions, such as nucleus accumbens and cerebral cortex. GlyR activation decreases neuronal excitability associated with sensorial information, motor control, and respiratory functions; all of which are significantly altered during ethanol intoxication. We evaluated the role of β GlyR subunits and of two basic amino acid residues, K389 and R390, located in the large intracellular loop (IL) of the α2 GlyR subunit, which are important for binding and functional modulation by Gβγ, the dimer of the trimeric G protein conformation, using HEK-293 transfected cells combined with patch clamp electrophysiology. We demonstrate a new modulatory role of the β subunit on ethanol sensitivity of α2 subunits. Specifically, we found a differential allosteric modulation in homomeric α2 GlyRs compared with the α2β heteromeric conformation. Indeed, while α2 was insensitive, α2β GlyRs were substantially potentiated by ethanol, GTP-γ-S, propofol, Zn2+ and trichloroethanol. Furthermore, a Gβγ scavenger (ct-GRK2) selectively attenuated the effects of ethanol on recombinant α2β GlyRs. Mutations in an α2 GlyR co-expressed with the β subunit (α2AAβ) specifically blocked ethanol sensitivity, but not propofol potentiation. These results show a selective mechanism for low ethanol concentration effects on homomeric and heteromeric conformations of α2 GlyRs and provide a new mechanism for ethanol pharmacology, which is relevant to upper brain regions where α2 GlyRs are abundantly expressed.
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Affiliation(s)
- Braulio Muñoz
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Trinidad Mariqueo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Pablo Murath
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Christian Peters
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E Yevenes
- Laboratory of Neuropharmacology, Department of Physiology, Universidad de Concepción, Concepción, Chile
| | | | - Robert W Peoples
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, United States
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Concepción, Chile
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8
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Vásquez PA, San Martín L, Argel Y, Riquelme C, Torres J, Vidal F, Cayuman F, Castro P, Fuentealba J, Moraga-Cid G, Yevenes G, Jin C, Jiménez VA, Guzmán L. Stereospecific Inhibition of Ethanol Potentiation on Glycine Receptor by M554 Stereoisomers. J Chem Inf Model 2020; 60:6634-6641. [PMID: 33259207 DOI: 10.1021/acs.jcim.0c00943] [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] [Indexed: 11/29/2022]
Abstract
Blocking the interaction between the Gβγ protein and the glycine receptor (GlyR) has emerged as a promising pharmacological strategy to treat acute alcohol intoxication by inhibiting ethanol potentiation on GlyR. M554 is a recently discovered small molecule capable of binding to Gβγ with potent in vitro and in vivo inhibitory activity. This compound has been tested as a mixture of diastereomers, and no information is available concerning the stereospecific activity of each species, which is critical to pursue efforts on lead optimization and drug development. In this work, we explored the differential activity of four M554 stereoisomers by in silico molecular dynamics simulations and electrophysiological experiments. Our results revealed that the (R,R)-M554 stereoisomer is a promising lead compound that inhibits ethanol potentiation of GlyR.
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Affiliation(s)
- Pilar A Vásquez
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Loreto San Martín
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Yenifer Argel
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Camila Riquelme
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Josefa Torres
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Felipe Vidal
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Francisca Cayuman
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Patricio Castro
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Jorge Fuentealba
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Gonzalo Yevenes
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
| | - Chunyang Jin
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
| | - Verónica A Jiménez
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Sede Concepción, Autopista Concepción-Talcahuano 7100, Talcahuano, Región del Bio Bio 4300866, Chile
| | - Leonardo Guzmán
- Departamento de Fisiología, Edificio Arco de Ciencias Biológicas, Universidad de Concepción, Victor Lamas 1290, Concepción, Región del Bio Bio 4030000, Chile
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9
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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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10
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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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11
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Benavides-Rivas C, Tovar LM, Zúñiga N, Pinto-Borguero I, Retamal C, Yévenes GE, Moraga-Cid G, Fuentealba J, Guzmán L, Coddou C, Bascuñán-Godoy L, Castro PA. Altered Glutaminase 1 Activity During Neurulation and Its Potential Implications in Neural Tube Defects. Front Pharmacol 2020; 11:900. [PMID: 32636743 PMCID: PMC7316894 DOI: 10.3389/fphar.2020.00900] [Citation(s) in RCA: 3] [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: 11/29/2019] [Accepted: 06/02/2020] [Indexed: 01/04/2023] Open
Abstract
The neurulation process is regulated by a large amount of genetic and environmental factors that determine the establishment, folding, and fusion of the neural plate to form the neural tube, which develops into the main structure of the central nervous system. A recently described factor involved in this process is glutamate. Through NMDA ionotropic receptor, glutamate modifies intracellular Ca2+ dynamics allowing the oriented cell migration and proliferation, essentials processes in neurulation. Glutamate synthesis depends on the mitochondrial enzyme known as glutaminase 1 (GLS1) that is widely expressed in brain and kidney. The participation of GLS 1 in prenatal neurogenic processes and in the adult brain has been experimentally established, however, its participation in early stages of embryonic development has not been described. The present investigation describes for the first time the presence and functionality of GLS1 in Xenopus laevis embryos during neurulation. Although protein expression levels remains constant, the catalytic activity of GLS1 increases significantly (~66%) between early (stage 12) and middle to late (stages 14–19) neurulation process. Additionally, the use of 6-diazo-5-oxo-L-norleucine (L-DON, competitive inhibitor of glutamine-depend enzymes), reduced significantly the GLS1 specific activity during neurulation (~36%) and induce the occurrence of neural tube defects involving its possible participation in the neural tube closure in Xenopus laevis embryos.
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Affiliation(s)
- Camila Benavides-Rivas
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Lina Mariana Tovar
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Nicolás Zúñiga
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Ingrid Pinto-Borguero
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Claudio Retamal
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E Yévenes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Claudio Coddou
- Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Luisa Bascuñán-Godoy
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Patricio A Castro
- Laboratory of Physiology and Pharmacology for Neural Development, LAND, Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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12
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Panes JD, Godoy PA, Silva-Grecchi T, Celis MT, Ramirez-Molina O, Gavilan J, Muñoz-Montecino C, Castro PA, Moraga-Cid G, Yévenes GE, Guzmán L, Salisbury JL, Trushina E, Fuentealba J. Changes in PGC-1α/SIRT1 Signaling Impact on Mitochondrial Homeostasis in Amyloid-Beta Peptide Toxicity Model. Front Pharmacol 2020; 11:709. [PMID: 32523530 PMCID: PMC7261959 DOI: 10.3389/fphar.2020.00709] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [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: 09/25/2019] [Accepted: 04/29/2020] [Indexed: 01/16/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive impairment that increasingly afflicts the elderly population. Soluble oligomers (AβOs) has been implicated in AD pathogenesis: however, the molecular events underlying a role for Aβ are not well understood. We studied the effects of AβOs on mitochondrial function and on key proteins that regulate mitochondrial dynamics and biogenesis in hippocampal neurons and PC-12 cells. We find that AβOs treatment caused a reduction in total Mfn1 after a 2 h exposure (42 ± 11%); while DRP1 increased at 1 and 2 h (205 ± 22% and 198 ± 27%, respectively), correlating to changes in mitochondrial morphology. We also observed that SIRT1 levels were reduced after acute and chronic AβOs treatment (68 ± 7% and 77 ± 6%, respectively); while PGC-1α levels were reduced with the same time treatments (68 ± 8% and 67 ± 7%, respectively). Interestingly, we found that chronic treatment with AβOs increased the levels of pSIRT1 (24 h: 157 ± 18%), and we observed changes in the PGC-1α and p-SIRT1 nucleus/cytosol ratio and SIRT1-PGC-1α interaction pattern after chronic exposure to AβOs. Our data suggest that AβOs induce important changes in the level and localization of mitochondrial proteins related with the loss of mitochondrial function that are mediated by a fast and sustained SIRT1/PGC-1α complex disruption promoting a “non-return point” to an irreversible synaptic failure and neuronal network disconnection.
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Affiliation(s)
- Jessica D Panes
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Pamela A Godoy
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Tiare Silva-Grecchi
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - María T Celis
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Oscar Ramirez-Molina
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Javiera Gavilan
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Carola Muñoz-Montecino
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Patricio A Castro
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E Yévenes
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
| | | | - Eugenia Trushina
- Neurology Research, Mayo Clinic Foundation, Rochester, MN, United States
| | - Jorge Fuentealba
- Laboratory of Screening of Neuroactive Compound, Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile.,Center for Advanced Research on Biomedicine (CIAB-UdeC), Physiology Department, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
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13
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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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14
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Roa FJ, Peña E, Gatica M, Escobar-Acuña K, Saavedra P, Maldonado M, Cuevas ME, Moraga-Cid G, Rivas CI, Muñoz-Montesino C. Therapeutic Use of Vitamin C in Cancer: Physiological Considerations. Front Pharmacol 2020; 11:211. [PMID: 32194425 PMCID: PMC7063061 DOI: 10.3389/fphar.2020.00211] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [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: 11/29/2019] [Accepted: 02/14/2020] [Indexed: 12/13/2022] Open
Abstract
Since the early studies of William J. McCormick in the 1950s, vitamin C has been proposed as a candidate for the treatment of cancer. A number of reports have shown that pharmacological concentrations of vitamin C selectively kill cancer cells in vitro and decrease the growth rates of a number of human tumor xenografts in immunodeficient mice. However, up to the date there is still doubt regarding this possible therapeutic role of vitamin C in cancer, mainly because high dose administration in cancer patients has not showed a clear antitumor activity. These apparent controversial findings highlight the fact that we lack information on the interactions that occurs between cancer cells and vitamin C, and if these transformed cells can uptake, metabolize and compartmentalize vitamin C like normal human cells do. The role of SVCTs and GLUTs transporters, which uptake the reduced form and the oxidized form of vitamin C, respectively, has been recently highlighted in the context of cancer showing that the relationship between vitamin C and cancer might be more complex than previously thought. In this review, we analyze the state of art of the effect of vitamin C on cancer cells in vitro and in vivo, and relate it to the capacity of cancer cells in acquiring, metabolize and compartmentalize this nutrient, with its implications on the potential therapeutic role of vitamin C in cancer.
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Affiliation(s)
- Francisco J Roa
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Eduardo Peña
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Marcell Gatica
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Kathleen Escobar-Acuña
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Paulina Saavedra
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Mafalda Maldonado
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Magdalena E Cuevas
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Coralia I Rivas
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Carola Muñoz-Montesino
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
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15
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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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16
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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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17
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Roa FJ, Peña E, Inostroza E, Sotomayor K, González M, Gutierrez-Castro FA, Maurin M, Sweet K, Labrousse C, Gatica M, Aylwin CF, Mendoza P, Maldonado M, Delgado C, Madariaga J, Panes J, Silva-Grecchi T, Concha II, Moraga-Cid G, Reyes AM, Muñoz-Montesino C, Vera JC, Rivas CI. Data on SVCT2 transporter expression and localization in cancer cell lines and tissues. Data Brief 2019; 25:103972. [PMID: 31249848 PMCID: PMC6586595 DOI: 10.1016/j.dib.2019.103972] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 03/16/2019] [Revised: 04/12/2019] [Accepted: 04/26/2019] [Indexed: 12/05/2022] Open
Abstract
The data presented in this article are related to the research paper entitled “Increased expression of mitochondrial sodium-coupled ascorbic acid transporter-2 (mitSVCT2) as a central feature in breast cancer”, available in Free Radical Biology and Medicine Journal [1]. In this article, we examined the SVCT2 transporter expression in various breast cancer cell lines using RT-PCR and Western blot assays. In addition, we analyzed the subcellular localization of SVCT2 by immunofluorescence colocalization assays and cellular fractionation experiments. Finally, an analysis of different cancer tissue microarrays immunostained for SVCT2 and imaged by The Human Protein Atlas (https://www.proteinatlas.org) is presented.
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Affiliation(s)
- Francisco J Roa
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Eduardo Peña
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Eveling Inostroza
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Kirsty Sotomayor
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Mauricio González
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Francisco A Gutierrez-Castro
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Michelle Maurin
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Karen Sweet
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Claire Labrousse
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Marcell Gatica
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Carlos F Aylwin
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Pamela Mendoza
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Mafalda Maldonado
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Carolina Delgado
- Departamento de Especialidades Médicas, Facultad de Medicina, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Jaime Madariaga
- Departamento de Especialidades Médicas, Facultad de Medicina, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Jessica Panes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Tiare Silva-Grecchi
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Ilona I Concha
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, PO Box 567, Valdivia, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Alejandro M Reyes
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, PO Box 567, Valdivia, Chile
| | - Carola Muñoz-Montesino
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Juan Carlos Vera
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Coralia I Rivas
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
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Peña E, Roa FJ, Inostroza E, Sotomayor K, González M, Gutierrez-Castro FA, Maurin M, Sweet K, Labrousse C, Gatica M, Aylwin CF, Mendoza P, Maldonado M, Delgado C, Madariaga J, Panes J, Silva-Grecchi T, Concha II, Moraga-Cid G, Reyes AM, Muñoz-Montesino C, Vera JC, Rivas CI. Increased expression of mitochondrial sodium-coupled ascorbic acid transporter-2 (mitSVCT2) as a central feature in breast cancer. Free Radic Biol Med 2019; 135:283-292. [PMID: 30902760 DOI: 10.1016/j.freeradbiomed.2019.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/07/2019] [Accepted: 03/12/2019] [Indexed: 12/20/2022]
Abstract
The potential role of vitamin C in cancer prevention and treatment remains controversial. While normal human cells obtain vitamin C as ascorbic acid, the prevalent form of vitamin C in vivo, the uptake mechanisms by which cancer cells acquire vitamin C has remained unclear. The aim of this study is to characterize how breast cancer cells acquire vitamin C. For this, we determined the expression of vitamin C transporters in normal and breast cancer tissue samples, and in ZR-75, MCF-7, MDA-231 and MDA-468 breast cancer cell lines. At the same time, reduced (AA) and oxidized (DHA) forms of vitamin C uptake experiments were performed in all cell lines. We show here that human breast cancer tissues differentially express a form of SVCT2 transporter, that is systematically absent in normal breast tissues and it is increased in breast tumors. In fact, estrogen receptor negative breast cancer tissue, exhibit the most elevated SVCT2 expression levels. Despite this, our analysis in breast cancer cell lines showed that these cells are not able to uptake ascorbic acid and depend on glucose transporter for the acquisition of vitamin C by a bystander effect. This is consistent with our observations that this form of SVCT2 is completely absent from the plasma membrane and is overexpressed in mitochondria of breast cancer cells, where it mediates ascorbic acid transport. This work shows that breast cancer cells acquire vitamin C in its oxidized form and are capable of accumulated high concentrations of the reduced form. Augmented expression of an SVCT2 mitochondrial form appears to be a common hallmark across all human cancers and might have implications in cancer cells survival capacity against pro-oxidant environments.
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Affiliation(s)
- Eduardo Peña
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Francisco J Roa
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Eveling Inostroza
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Kirsty Sotomayor
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Mauricio González
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Francisco A Gutierrez-Castro
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Michelle Maurin
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Karen Sweet
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Claire Labrousse
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Marcell Gatica
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Carlos F Aylwin
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Pamela Mendoza
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Mafalda Maldonado
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Carolina Delgado
- Departamento de Especialidades Médicas, Facultad de Medicina, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Jaime Madariaga
- Departamento de Especialidades Médicas, Facultad de Medicina, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Jessica Panes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Tiare Silva-Grecchi
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Ilona I Concha
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, PO Box 567, Valdivia, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Alejandro M Reyes
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, PO Box 567, Valdivia, Chile
| | - Carola Muñoz-Montesino
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile.
| | - Juan Carlos Vera
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile
| | - Coralia I Rivas
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Barrio Universitario s/n, PO Box 160C, Concepción, Chile.
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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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20
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Gavilan J, Mennickent D, Ramirez-Molina O, Triviño S, Perez C, Silva-Grecchi T, Godoy PA, Becerra J, Aguayo LG, Moraga-Cid G, Martin VS, Yevenes GE, Castro PA, Guzman L, Fuentealba J. 17 Oxo Sparteine and Lupanine, Obtained from Cytisus scoparius, Exert a Neuroprotection against Soluble Oligomers of Amyloid-β Toxicity by Nicotinic Acetylcholine Receptors. J Alzheimers Dis 2019; 67:343-356. [DOI: 10.3233/jad-180945] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Javiera Gavilan
- Laboratorio de Screening de Compuestos Neuroactivos, Universidad de Concepción, Chile
| | - Daniela Mennickent
- Laboratorio de Screening de Compuestos Neuroactivos, Universidad de Concepción, Chile
| | - Oscar Ramirez-Molina
- Laboratorio de Screening de Compuestos Neuroactivos, Universidad de Concepción, Chile
| | - Sergio Triviño
- Departamento de Botánica, Laboratorio de Química de Productos Naturales, Universidad de Concepción, Chile
| | - Claudia Perez
- Departamento de Botánica, Laboratorio de Química de Productos Naturales, Universidad de Concepción, Chile
| | - Tiare Silva-Grecchi
- Laboratorio de Screening de Compuestos Neuroactivos, Universidad de Concepción, Chile
| | - Pamela A. Godoy
- Laboratorio de Screening de Compuestos Neuroactivos, Universidad de Concepción, Chile
| | - Jose Becerra
- Departamento de Botánica, Laboratorio de Química de Productos Naturales, Universidad de Concepción, Chile
| | - Luis G. Aguayo
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Gustavo Moraga-Cid
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Victoria San Martin
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Gonzalo E. Yevenes
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Patricio A. Castro
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Leonardo Guzman
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile
| | - Jorge Fuentealba
- Laboratorio de Screening de Compuestos Neuroactivos, Universidad de Concepción, Chile
- Centro de Investigaciones Avanzadas en Biomedicina-U. de Concepcion (CIAB UdeC), Chile
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21
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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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22
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Förstera B, Castro PA, Moraga-Cid G, Aguayo LG. Potentiation of Gamma Aminobutyric Acid Receptors (GABAAR) by Ethanol: How Are Inhibitory Receptors Affected? Front Cell Neurosci 2016; 10:114. [PMID: 27199667 PMCID: PMC4858537 DOI: 10.3389/fncel.2016.00114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [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: 01/25/2016] [Accepted: 04/20/2016] [Indexed: 01/10/2023] Open
Abstract
In recent years there has been an increase in the understanding of ethanol actions on the type A γ-aminobutyric acid chloride channel (GABAAR), a member of the pentameric ligand gated ion channels (pLGICs). However, the mechanism by which ethanol potentiates the complex is still not fully understood and a number of publications have shown contradictory results. Thus many questions still remain unresolved requiring further studies for a better comprehension of this effect. The present review concentrates on the involvement of GABAAR in the acute actions of ethanol and specifically focuses on the immediate, direct or indirect, synaptic and extra-synaptic modulatory effects. To elaborate on the immediate, direct modulation of GABAAR by acute ethanol exposure, electrophysiological studies investigating the importance of different subunits, and data from receptor mutants will be examined. We will also discuss the nature of the putative binding sites for ethanol based on structural data obtained from other members of the pLGICs family. Finally, we will briefly highlight the glycine gated chloride channel (GlyR), another member of the pLGIC family, as a suitable target for the development of new pharmacological tools.
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Affiliation(s)
- Benjamin Förstera
- Laboratory of Neurophysiology, Department of Physiology, University of Concepcion Concepcion, Chile
| | - Patricio A Castro
- Laboratory of Environmental Neurotoxicology, Department of Biomedical Sciences, Faculty of Medicine, Universidad Católica del Norte Coquimbo, Chile
| | - Gustavo Moraga-Cid
- Hindbrain Integrative Neurobiology Laboratory, Institut de Neurobiologie Alfred Fessard Gif-Sur-Yvette, France
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, University of Concepcion Concepcion, Chile
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23
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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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24
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Sauguet L, Poitevin F, Murail S, Van Renterghem C, Moraga-Cid G, Malherbe L, Thompson A, Corringer PJ, Baaden M, Delarue M. Structural Basis for Ion Permeation Mechanism in Pentameric Ligand-Gated Ion Channels. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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25
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Yévenes GE, Moraga-Cid G, Romo X, Aguayo LG. Activated G protein α s subunits increase the ethanol sensitivity of human glycine receptors. J Pharmacol Exp Ther 2011; 339:386-93. [PMID: 21821696 DOI: 10.1124/jpet.111.184408] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is well known that ethanol modulates the function of the Cys loop ligand-gated ion channels, which include the inhibitory glycine receptors (GlyRs). Previous studies have consistently shown that transmembrane and extracellular sites are essential for ethanol actions in GlyRs. In addition, recent evidence has shown that the ethanol modulation of GlyRs is also affected by G protein activation through Gβγ subunits. However, more specific roles of G protein α subunits on ethanol actions are unknown. Here, we show that the allosteric effect of ethanol on the human α(1) GlyR is selectively enhanced by the expression of Gα(s) Q-L. For example, constitutively active Gα(s), but not Gα(q) or Gα(i), was able to displace the alcohol sensitivity of GlyRs toward low millimolar concentrations (17 ± 4 versus 48 ± 5% at 100 mM). Experiments under conditions that increased cAMP and protein kinase A (PKA)-mediated signaling, on the contrary, did not produce the same enhancement in sensitivity, suggesting that the Gα(s) Q-L effect was not dependent on cAMP/PKA-dependent signaling. On the other hand, the effect of Gα(s) Q-L was blocked by a Gβγ scavenger (9 ± 3% of control). Furthermore, two mutant receptors previously shown to have impaired interactions with Gβγ were not affected by Gα(s) Q-L, suggesting that Gβγ is needed for enhancing ethanol sensitivity. These results support the conclusion that activated Gα(s) can facilitate the Gβγ interaction with GlyRs in presence of ethanol, independent of increases in cAMP signaling. Thus, these data indicate that the activated form of Gα(s) is able to positively influence the effect of ethanol on a type of inhibitory receptor important for motor control, pain, and respiration.
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Affiliation(s)
- Gonzalo E Yévenes
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile
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Fuentealba J, Muñoz B, Yévenes G, Moraga-Cid G, Pérez C, Guzmán L, Rigo JM, Aguayo LG. Potentiation and inhibition of glycine receptors by tutin. Neuropharmacology 2011; 60:453-9. [DOI: 10.1016/j.neuropharm.2010.10.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 10/21/2010] [Accepted: 10/25/2010] [Indexed: 11/28/2022]
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27
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Yevenes GE, Moraga-Cid G, Avila A, Guzmán L, Figueroa M, Peoples RW, Aguayo LG. Molecular requirements for ethanol differential allosteric modulation of glycine receptors based on selective Gbetagamma modulation. J Biol Chem 2010; 285:30203-13. [PMID: 20647311 PMCID: PMC2943258 DOI: 10.1074/jbc.m110.134676] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [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: 04/19/2010] [Revised: 07/19/2010] [Indexed: 12/18/2022] Open
Abstract
It is now believed that the allosteric modulation produced by ethanol in glycine receptors (GlyRs) depends on alcohol binding to discrete sites within the protein structure. Thus, the differential ethanol sensitivity of diverse GlyR isoforms and mutants was explained by the presence of specific residues in putative alcohol pockets. Here, we demonstrate that ethanol sensitivity in two ligand-gated ion receptor members, the GlyR adult α(1) and embryonic α(2) subunits, can be modified through selective mutations that rescued or impaired Gβγ modulation. Even though both isoforms were able to physically interact with Gβγ, only the α(1) GlyR was functionally modulated by Gβγ and pharmacological ethanol concentrations. Remarkably, the simultaneous switching of two transmembrane and a single extracellular residue in α(2) GlyRs was enough to generate GlyRs modulated by Gβγ and low ethanol concentrations. Interestingly, although we found that these TM residues were different to those in the alcohol binding site, the extracellular residue was recently implicated in conformational changes important to generate a pre-open-activated state that precedes ion channel gating. Thus, these results support the idea that the differential ethanol sensitivity of these two GlyR isoforms rests on conformational changes in transmembrane and extracellular residues within the ion channel structure rather than in differences in alcohol binding pockets. Our results describe the molecular basis for the differential ethanol sensitivity of two ligand-gated ion receptor members based on selective Gβγ modulation and provide a new mechanistic framework for allosteric modulations of abuse drugs.
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Affiliation(s)
| | | | - Ariel Avila
- From the Laboratory of Neurophysiology, Department of Physiology, and
| | - Leonardo Guzmán
- From the Laboratory of Neurophysiology, Department of Physiology, and
| | - Maximiliano Figueroa
- the Department of Biochemistry and Molecular Biology, University of Concepción, Concepción, Chile and
| | - Robert W. Peoples
- the Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Luis G. Aguayo
- From the Laboratory of Neurophysiology, Department of Physiology, and
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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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29
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Guzman L, Moraga-Cid G, Avila A, Figueroa M, Yevenes GE, Fuentealba J, Aguayo LG. Blockade of ethanol-induced potentiation of glycine receptors by a peptide that interferes with Gbetagamma binding. J Pharmacol Exp Ther 2009; 331:933-9. [PMID: 19773530 PMCID: PMC2784719 DOI: 10.1124/jpet.109.160440] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [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: 08/14/2009] [Accepted: 09/21/2009] [Indexed: 01/09/2023] Open
Abstract
The large intracellular loop (IL) of the glycine receptor (GlyR) interacts with various signaling proteins and plays a fundamental role in trafficking and regulation of several receptor properties, including a direct interaction with Gbetagamma. In the present study, we found that mutation of basic residues in the N-terminal region of the IL reduced the binding of Gbetagamma to 21 +/- 10% of control. Two basic residues in the C-terminal region, on the other hand, contributed to a smaller extent to Gbetagamma binding. Using docking analysis, we found that both basic regions of the IL bind in nearby regions to the Gbetagamma dimer, within an area of high density of amino acids having an electronegative character. Thereafter, we generated a 17-amino acid peptide with the N-terminal sequence of the wild-type IL (RQH) that was able to inhibit the in vitro binding of Gbetagamma to GlyRs to 57 +/- 5% of control in glutathione S-transferase pull-down assays using purified proteins. More interestingly, when the peptide was intracellularly applied to human embryonic kidney 293 cells, it inhibited the Gbetagamma-mediated modulations of G protein-coupled inwardly rectifying potassium channel by baclofen (24 +/- 14% of control) and attenuated the GlyR potentiation by ethanol (51 +/- 10% versus 10 +/- 3%).
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Affiliation(s)
- Leonardo Guzman
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile
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30
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Godoy A, Ormazabal V, Moraga-Cid G, Zúñiga FA, Sotomayor P, Barra V, Vasquez O, Montecinos V, Mardones L, Guzmán C, Villagrán M, Aguayo LG, Oñate SA, Reyes AM, Cárcamo JG, Rivas CI, Vera JC. Mechanistic Insights and Functional Determinants of the Transport Cycle of the Ascorbic Acid Transporter SVCT2. J Biol Chem 2007; 282:615-24. [PMID: 17012227 DOI: 10.1074/jbc.m608300200] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We characterized the human Na(+)-ascorbic acid transporter SVCT2 and developed a basic model for the transport cycle that challenges the current view that it functions as a Na(+)-dependent transporter. The properties of SVCT2 are modulated by Ca(2+)/Mg(2+) and a reciprocal functional interaction between Na(+) and ascorbic acid that defines the substrate binding order and the transport stoichiometry. Na(+) increased the ascorbic acid transport rate in a cooperative manner, decreasing the transport K(m) without affecting the V(max), thus converting a low affinity form of the transporter into a high affinity transporter. Inversely, ascorbic acid affected in a bimodal and concentration-dependent manner the Na(+) cooperativity, with absence of cooperativity at low and high ascorbic acid concentrations. Our data are consistent with a transport cycle characterized by a Na(+):ascorbic acid stoichiometry of 2:1 and a substrate binding order of the type Na(+):ascorbic acid:Na(+). However, SVCT2 is not electrogenic. SVCT2 showed an absolute requirement for Ca(2+)/Mg(2+) for function, with both cations switching the transporter from an inactive into an active conformation by increasing the transport V(max) without affecting the transport K(m) or the Na(+) cooperativity. Our data indicate that SVCT2 may switch between a number of states with characteristic properties, including an inactive conformation in the absence of Ca(2+)/Mg(2+). At least three active states can be envisioned, including a low affinity conformation at Na(+) concentrations below 20 mM and two high affinity conformations at elevated Na(+) concentrations whose Na(+) cooperativity is modulated by ascorbic acid. Thus, SVCT2 is a Ca(2+)/Mg(2+)-dependent transporter.
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Affiliation(s)
- Alejandro Godoy
- Departamento de Fisiopatología, Universidad de Concepción, Concepción, Casilla 160C, Chile
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31
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Yevenes GE, Moraga-Cid G, Guzmán L, Haeger S, Oliveira L, Olate J, Schmalzing G, Aguayo LG. Molecular determinants for G protein betagamma modulation of ionotropic glycine receptors. J Biol Chem 2006; 281:39300-7. [PMID: 17040914 DOI: 10.1074/jbc.m608272200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [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] [Indexed: 11/06/2022] Open
Abstract
The ligand-gated ion channel superfamily plays a critical role in neuronal excitability. The functions of glycine receptor (GlyR) and nicotinic acetylcholine receptor are modulated by G protein betagamma subunits. The molecular determinants for this functional modulation, however, are still unknown. Studying mutant receptors, we identified two basic amino acid motifs within the large intracellular loop of the GlyR alpha(1) subunit that are critical for binding and functional modulation by Gbetagamma. Mutations within these sequences demonstrated that all of the residues detected are important for Gbetagamma modulation, although both motifs are necessary for full binding. Molecular modeling predicts that these sites are alpha-helixes near transmembrane domains 3 and 4, near to the lipid bilayer and highly electropositive. Our results demonstrate for the first time the sites for G protein betagamma subunit modulation on GlyRs and provide a new framework regarding the ligand-gated ion channel superfamily regulation by intracellular signaling.
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Affiliation(s)
- Gonzalo E Yevenes
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile
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Orrego R, Burgos A, Moraga-Cid G, Inzunza B, Gonzalez M, Valenzuela A, Barra R, Gavilán JF. Effects of pulp and paper mill discharges on caged rainbow trout (Oncorhynchus mykiss): biomarker responses along a pollution gradient in the Biobio River, Chile. Environ Toxicol Chem 2006; 25:2280-7. [PMID: 16986781 DOI: 10.1897/05-385r.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Caging experiments were conducted using hatchery-reared, immature, female rainbow trout (Oncorhynchus mykiss) in three previously defined areas of the Biobio River (south central Chile) representing a pollution gradient from the pulp and paper mill discharges area: a pre-impact area (upstream area, reference location), an impact area (area directly influenced), and a postimpact area (downstream area, less influenced). No significant changes were observed in the physiological index as represented by condition factor (K) and liver somatic index during different sampling times (after 11, 21, and 30 d of exposure). Ethoxyresorufin-O-deethylase activities were significantly higher in trout caged at the impact and postimpact discharges areas (two- to fourfold) compared with the reference (pre-impact) area, and a strong inhibition of acetylcholinesterase activity, reaching 50%, was observed mainly in fish caged at the impact area. A significant endocrine-disrupting effect (reproductive level) was evidenced by significant increments in gonad somatic index and plasma vitellogenin levels combined with an induction of gonad maturation (presence of vitellogenic oocytes) in trout caged at the impact and postimpact areas. These results, generated by an in situ approach, confirmed our group's findings for trout exposed to sediment in the laboratory: discharges of pulp mill effluent in the Biobio River are associated with the effects evaluated at different biological levels.
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Affiliation(s)
- Rodrigo Orrego
- Aquatic Systems Research Unit EULA-Chile Environmental Sciences Centre, University of Concepción, Chile.
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33
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Orrego R, Moraga-Cid G, González M, Barra R, Valenzuela A, Burgos A, Gavilán JF. Reproductive, physiological, and biochemical responses in juvenile female rainbow trout (Oncorhynchus mykiss) exposed to sediment from pulp and paper mill industrial discharge areas. Environ Toxicol Chem 2005; 24:1935-43. [PMID: 16152965 DOI: 10.1897/04-251r1.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Four pulp and paper mills discharge their effluents in the same section of the Biobio River in central southern Chile. Pulp mill effluents are a very complex mixture with characteristics that depend on the type of raw material, the process technology, and the effluent treatment. To investigate the effect of pulp mill effluent discharges, immature Oncorhynchus mykiss were exposed to river sediments in the laboratory for 29 d. Three sampling areas were defined in a spatial gradient in the river: Preimpact, impact, and postimpact zones relative to the pulp and paper mill discharge areas. Ethoxyresorufin-O-deethylase activities were significantly higher in fish exposed to impact and postimpact sediments when compared to those exposed to preimpact sediments, and higher levels of vitellogenin were observed in the plasma of female fish exposed to impact and postimpact sediments. Histological analysis of the gonadal tissue showed an induction of gonadal maturation in fish exposed to sediment coming from the impact and postimpact zones (oocytes in a vitellogenic state). No site differences were observed in erythrocytes, although differences were noted in the leukocytes in the exposure areas. Finally, the biomarker approach showed evidence that the sediment associated with pulp mill effluent discharges produces some effects in fish under laboratory conditions.
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Affiliation(s)
- Rodrigo Orrego
- Aquatic Systems Research Unit, EULA-Chile Environmental Sciences Centre, University of Concepción, P.O. Box 160-C, Concepción, Chile.
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Oñate AA, Donoso G, Moraga-Cid G, Folch H, Céspedes S, Andrews E. An RNA vaccine based on recombinant Semliki Forest virus particles expressing the Cu,Zn superoxide dismutase protein of Brucella abortus induces protective immunity in BALB/c mice. Infect Immun 2005; 73:3294-300. [PMID: 15908354 PMCID: PMC1111843 DOI: 10.1128/iai.73.6.3294-3300.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We constructed infectious but replication-deficient Semliki Forest virus (SFV) particles carrying recombinant RNA encoding Brucella abortus Cu,Zn superoxide dismutase (SOD). The recombinant SFV particles (SFV-SOD particles) were then evaluated for their ability to induce a T-cell immune response and to protect BALB/c mice against a challenge with B. abortus 2308. Intraperitoneal injection of mice with recombinant SFV-SOD particles did not lead to the induction of SOD-specific antibodies, at least until week 6 after immunization (the end of the experiment). In vitro stimulation of splenocytes from the vaccinated mice with either recombinant Cu,Zn SOD (rSOD) or crude Brucella protein resulted in a T-cell proliferative response and the induction of gamma interferon secretion but not interleukin-4. In addition, the splenocytes exhibited significant levels of cytotoxic T-lymphocyte activity against Brucella-infected cells. The SFV-SOD particles, but not the control virus particles, induced a significant level of protection in BALB/c mice against challenge with B. abortus virulent strain 2308. These findings indicated that an SFV-based vector carrying the SOD gene has potential for use as a vaccine to induce resistance against B. abortus infections.
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Affiliation(s)
- Angel A Oñate
- Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, P.O. Box 152-C, Concepción, Chile.
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Muñoz-Montesino C, Andrews E, Rivers R, González-Smith A, Moraga-Cid G, Folch H, Céspedes S, Oñate AA. Intraspleen delivery of a DNA vaccine coding for superoxide dismutase (SOD) of Brucella abortus induces SOD-specific CD4+ and CD8+ T cells. Infect Immun 2004; 72:2081-7. [PMID: 15039330 PMCID: PMC375181 DOI: 10.1128/iai.72.4.2081-2087.2004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the development of vaccines capable of providing immunity against brucellosis, Cu-Zn superoxide dismutase (SOD) has been demonstrated to be one of the protective immunogens of Brucella abortus. In an earlier study, we provided strong evidence that intramuscular injection with a plasmid DNA carrying the SOD gene (pcDNA-SOD) was able to induce a protective immune response. The present study was designed to characterize T-cell immune responses after an intraspleen (i.s.) vaccination of BALB/c mice with pcDNA-SOD. Animals vaccinated with pcDNA-SOD did not develop SOD-specific antibodies, at least until week 4 after immunization (the end of the experiment), and in vitro stimulation of their splenocytes with either recombinant Cu-Zn SOD or crude Brucella protein induced the secretion of gamma interferon (IFN-gamma), but not interleukin-4, and elicited the induction of cytotoxic-T-lymphocyte activity. Upon analyzing the SOD-specific T-cell responses, the pcDNA-SOD vaccination was found to be stimulating both CD4(+)- and CD8(+)-T-cell populations. However, only the CD4(+) population was able to produce IFN-gamma and only the CD8(+) population was able to induce cytotoxic activity. Nevertheless, although i.s. route vaccination induces a significant level of protection in BALB/c mice against challenge with the virulent B. abortus strain 2308, vaccination by the intramuscular route with a similar amount of plasmid DNA does not protect. Based on these results, we conclude that i.s. immunization with pcDNA-SOD vaccine efficiently induced a Th1 type of immune response and a protective response that could be related to IFN-gamma production and cytotoxic activity against infected cells by SOD-specific CD4(+) and CD8(+) T cells, respectively.
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Affiliation(s)
- Carola Muñoz-Montesino
- Molecular Immunology Laboratory, Department of Microbiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción, Chile
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