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Peña-Münzenmayer G, George AT, Llontop N, Mazola Y, Apablaza N, Spichiger C, Brauchi S, Sarmiento J, Zúñiga L, González W, Catalán MA. K +-Driven Cl -/HCO 3- Exchange Mediated by Slc4a8 and Slc4a10. Int J Mol Sci 2024; 25:4575. [PMID: 38674160 PMCID: PMC11050268 DOI: 10.3390/ijms25084575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Slc4a genes encode various types of transporters, including Na+-HCO3- cotransporters, Cl-/HCO3- exchangers, or Na+-driven Cl-/HCO3- exchangers. Previous research has revealed that Slc4a9 (Ae4) functions as a Cl-/HCO3- exchanger, which can be driven by either Na+ or K+, prompting investigation into whether other Slc4a members facilitate cation-dependent anion transport. In the present study, we show that either Na+ or K+ drive Cl-/HCO3- exchanger activity in cells overexpressing Slc4a8 or Slc4a10. Further characterization of cation-driven Cl-/HCO3- exchange demonstrated that Slc4a8 and Slc4a10 also mediate Cl- and HCO3--dependent K+ transport. Full-atom molecular dynamics simulation on the recently solved structure of Slc4a8 supports the coordination of K+ at the Na+ binding site in S1. Sequence analysis shows that the critical residues coordinating monovalent cations are conserved among mouse Slc4a8 and Slc4a10 proteins. Together, our results suggest that Slc4a8 and Slc4a10 might transport K+ in the same direction as HCO3- ions in a similar fashion to that described for Na+ transport in the rat Slc4a8 structure.
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Affiliation(s)
- Gaspar Peña-Münzenmayer
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile; (G.P.-M.); (N.A.); (C.S.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia 5090000, Chile
| | - Alvin T. George
- Secretory Mechanisms and Dysfunction Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nuria Llontop
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
| | - Yuliet Mazola
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca 3460000, Chile (W.G.)
| | - Natalia Apablaza
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile; (G.P.-M.); (N.A.); (C.S.)
| | - Carlos Spichiger
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile; (G.P.-M.); (N.A.); (C.S.)
| | - Sebastián Brauchi
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Valdivia 5090000, Chile
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
| | - José Sarmiento
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
| | - Leandro Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, Talca 3460000, Chile;
| | - Wendy González
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, Talca 3460000, Chile (W.G.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Talca 3460000, Chile
| | - Marcelo A. Catalán
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia 5090000, Chile; (N.L.); (J.S.)
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2
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Peña-Münzenmayer G, Kondo Y, Salinas C, Sarmiento J, Brauchi S, Catalán MA. Activation of the Ae4 (Slc4a9) cation-driven Cl -/HCO 3- exchanger by the cAMP-dependent protein kinase in salivary gland acinar cells. Am J Physiol Gastrointest Liver Physiol 2021; 321:G628-G638. [PMID: 34585968 PMCID: PMC8887885 DOI: 10.1152/ajpgi.00145.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 01/31/2023]
Abstract
Ae4 transporters are critical for Cl- uptake across the basolateral membrane of acinar cells in the submandibular gland (SMG). Although required for fluid secretion, little is known about the physiological regulation of Ae4. To investigate whether Ae4 is regulated by the cAMP-dependent signaling pathway, we measured Cl-/HCO3- exchanger activity in SMG acinar cells from Ae2-/- mice, which only express Ae4, and found that the Ae4-mediated activity was increased in response to β-adrenergic receptor stimulation. Moreover, pretreatment with H89, an inhibitor of the cAMP-activated kinase (PKA), prevented the stimulation of Ae4 exchangers. We then expressed Ae4 in CHO-K1 cells and found that the Ae4-mediated activity was increased when Ae4 is coexpressed with the catalytic subunit of PKA (PKAc), which is constitutively active. Ae4 sequence analysis showed two potential PKA phosphorylation serine residues located at the intracellular NH2-terminal domain according to a homology model of Ae4. NH2-terminal domain Ser residues were mutated to alanine (S173A and S273A, respectively), where the Cl-/HCO3- exchanger activity displayed by the mutant S173A was not activated by PKA. Conversely, S273A mutant kept the PKA dependency. Together, we conclude that Ae4 is stimulated by PKA in SMG acinar cells by a mechanism that probably depends on the phosphorylation of S173.NEW & NOTEWORTHY We found that Ae4 exchanger activity in secretory salivary gland acinar cells is increased upon β-adrenergic receptor stimulation. The activation of Ae4 was prevented by H89, a nonselective PKA inhibitor. Protein sequence analysis revealed two residues (S173 and S273) that are potential targets of cAMP-dependent protein kinase (PKA). Experiments in CHO-K1 cells expressing S173A and S273A mutants showed that S173A, but not S273A, is not activated by PKA.
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Affiliation(s)
- Gaspar Peña-Münzenmayer
- Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Yusuke Kondo
- Division of Oral Reconstruction and Rehabilitation, Kyushu Dental University, Fukuoka, Japan
| | - Constanza Salinas
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
| | - José Sarmiento
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
| | - Sebastián Brauchi
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Valdivia, Chile
| | - Marcelo A Catalán
- Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique, Chile
- Facultad de Medicina, Instituto de Fisiología, Universidad Austral de Chile, Valdivia, Chile
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3
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Vásquez-Navarrete J, Martínez AD, Ory S, Baéz-Matus X, González-Jamett AM, Brauchi S, Caviedes P, Cárdenas AM. RCAN1 Knockdown Reverts Defects in the Number of Calcium-Induced Exocytotic Events in a Cellular Model of Down Syndrome. Front Cell Neurosci 2018; 12:189. [PMID: 30034324 PMCID: PMC6043644 DOI: 10.3389/fncel.2018.00189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 02/06/2018] [Accepted: 06/12/2018] [Indexed: 12/15/2022] Open
Abstract
In humans, Down Syndrome (DS) is a condition caused by partial or full trisomy of chromosome 21. Genes present in the DS critical region can result in excess gene dosage, which at least partially can account for DS phenotype. Although regulator of calcineurin 1 (RCAN1) belongs to this region and its ectopic overexpression in neurons impairs transmitter release, synaptic plasticity, learning and memory, the relative contribution of RCAN1 in a context of DS has yet to be clarified. In the present work, we utilized an in vitro model of DS, the CTb neuronal cell line derived from the brain cortex of a trisomy 16 (Ts16) fetal mouse, which reportedly exhibits acetylcholine release impairments compared to CNh cells (a neuronal cell line established from a normal littermate). We analyzed single exocytotic events by using total internal reflection fluorescence microscopy (TIRFM) and the vesicular acetylcholine transporter fused to the pH-sensitive green fluorescent protein (VAChT-pHluorin) as a reporter. Our analyses showed that, compared with control CNh cells, the trisomic CTb cells overexpress RCAN1, and they display a reduced number of Ca2+-induced exocytotic events. Remarkably, RCAN1 knockdown increases the extent of exocytosis at levels comparable to those of CNh cells. These results support a critical contribution of RCAN1 to the exocytosis process in the trisomic condition.
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Affiliation(s)
- Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Stéphane Ory
- Centre National de la Recherche Scientifique (CNRS UPR 3212), Institut des Neurosciences Cellulaires et Intégratives (INCI), Strasbourg, France
| | - Ximena Baéz-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Arlek M González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Sebastián Brauchi
- Department of Physiology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Centro de Biotecnología y Bioingeniería (CeBiB), Departamento de Ingeniería Química, Biotecnología y Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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Flores Aldama L, Bustos D, Opazo JG, González W, Brauchi S. Evolutionary Variations in HLH Domain Modulate the Fast Inactivation Phase in Calcium Selective TRP Channels. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.2660] [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: 11/29/2022] Open
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5
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Kadala A, Sotelo-Hitschfeld P, Ahmad Z, Tripal P, Schmid B, Mueller A, Bernal L, Winter Z, Brauchi S, Lohbauer U, Messlinger K, Lennerz JK, Zimmermann K. Fluorescent Labeling and 2-Photon Imaging of Mouse Tooth Pulp Nociceptors. J Dent Res 2017; 97:460-466. [PMID: 29130364 DOI: 10.1177/0022034517740577] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Retrograde fluorescent labeling of dental primary afferent neurons (DPANs) has been described in rats through crystalline fluorescent DiI, while in the mouse, this technique was achieved with only Fluoro-Gold, a neurotoxic fluorescent dye with membrane penetration characteristics superior to the carbocyanine dyes. We reevaluated this technique in the rat with the aim to transfer it to the mouse because comprehensive physiologic studies require access to the mouse as a model organism. Using conventional immunohistochemistry, we assessed in rats and mice the speed of axonal dye transport from the application site to the trigeminal ganglion, the numbers of stained DPANs, and the fluorescence intensity via 1) conventional crystalline DiI and 2) a novel DiI formulation with improved penetration properties and staining efficiency. A 3-dimensional reconstruction of an entire trigeminal ganglion with 2-photon laser scanning fluorescence microscopy permitted visualization of DPANs in all 3 divisions of the trigeminal nerve. We quantified DPANs in mice expressing the farnesylated enhanced green fluorescent protein (EGFPf) from the transient receptor potential cation channel subfamily M member 8 (TRPM8EGFPf/+) locus in the 3 branches. We also evaluated the viability of the labeled DPANs in dissociated trigeminal ganglion cultures using calcium microfluorometry, and we assessed the sensitivity to capsaicin, an agonist of the TRPV1 receptor. Reproducible DiI labeling of DPANs in the mouse is an important tool 1) to investigate the molecular and functional specialization of DPANs within the trigeminal nociceptive system and 2) to recognize exclusive molecular characteristics that differentiate nociception in the trigeminal system from that in the somatic system. A versatile tool to enhance our understanding of the molecular composition and characteristics of DPANs will be essential for the development of mechanism-based therapeutic approaches for dentine hypersensitivity and inflammatory tooth pain.
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Affiliation(s)
- A Kadala
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - P Sotelo-Hitschfeld
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
- 2 Instituto de Fisiología, Facultad de Medicina, Escuela de Graduados, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Z Ahmad
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - P Tripal
- 3 Optical Imaging Centre Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - B Schmid
- 3 Optical Imaging Centre Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - A Mueller
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - L Bernal
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Z Winter
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - S Brauchi
- 2 Instituto de Fisiología, Facultad de Medicina, Escuela de Graduados, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - U Lohbauer
- 4 Klinik für Zahnerhaltung und Parodontologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - K Messlinger
- 5 Institut für Physiologie und Pathophysiologie, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - J K Lennerz
- 6 Center for Integrated Diagnostics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - K Zimmermann
- 1 Klinik für Anästhesiologie, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
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6
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Covarrubias-Pinto A, Moll P, Solís-Maldonado M, Acuña AI, Riveros A, Miró MP, Papic E, Beltrán FA, Cepeda C, Concha II, Brauchi S, Castro MA. Beyond the redox imbalance: Oxidative stress contributes to an impaired GLUT3 modulation in Huntington's disease. Free Radic Biol Med 2015; 89:1085-96. [PMID: 26456058 PMCID: PMC4840472 DOI: 10.1016/j.freeradbiomed.2015.09.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 11/29/2022]
Abstract
Failure in energy metabolism and oxidative damage are associated with Huntington's disease (HD). Ascorbic acid released during synaptic activity inhibits use of neuronal glucose, favouring lactate uptake to sustain brain activity. Here, we observe a decreased expression of GLUT3 in STHdhQ111 cells (HD cells) and R6/2 mice (HD mice). Localisation of GLUT3 is decreased at the plasma membrane in HD cells affecting the modulation of glucose uptake by ascorbic acid. An ascorbic acid analogue without antioxidant activity is able to inhibit glucose uptake in HD cells. The impaired modulation of glucose uptake by ascorbic acid is directly related to ROS levels indicating that oxidative stress sequesters the ability of ascorbic acid to modulate glucose utilisation. Therefore, in HD, a decrease in GLUT3 localisation at the plasma membrane would contribute to an altered neuronal glucose uptake during resting periods while redox imbalance should contribute to metabolic failure during synaptic activity.
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Affiliation(s)
- Adriana Covarrubias-Pinto
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Pablo Moll
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Macarena Solís-Maldonado
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Aníbal I Acuña
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Andrea Riveros
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - María Paz Miró
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Eduardo Papic
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Felipe A Beltrán
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, The David Geffen School of Medicine, UCLA, Los Angeles, USA and
| | - Ilona I Concha
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Sebastián Brauchi
- Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile; Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Maite A Castro
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Center for Interdisciplinary Studies on the Nervous system (CISNe), Universidad Austral de Chile, Valdivia, Chile.
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7
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Acuña AI, Esparza M, Kramm C, Beltrán FA, Parra AV, Cepeda C, Toro CA, Vidal RL, Hetz C, Concha II, Brauchi S, Levine MS, Castro MA. A failure in energy metabolism and antioxidant uptake precede symptoms of Huntington's disease in mice. Nat Commun 2014; 4:2917. [PMID: 24336051 PMCID: PMC3905737 DOI: 10.1038/ncomms3917] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [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: 05/27/2013] [Accepted: 11/12/2013] [Indexed: 01/22/2023] Open
Abstract
Huntington's disease has been associated with a failure in energy metabolism and oxidative damage. Ascorbic acid is a powerful antioxidant highly concentrated in the brain where it acts as a messenger, modulating neuronal metabolism. Using an electrophysiological approach in R6/2 HD slices, we observe an abnormal ascorbic acid flux from astrocytes to neurons, which is responsible for alterations in neuronal metabolic substrate preferences. Here using striatal neurons derived from knock-in mice expressing mutant huntingtin (STHdhQ cells), we study ascorbic acid transport. When extracellular ascorbic acid concentration increases, as occurs during synaptic activity, ascorbic acid transporter 2 (SVCT2) translocates to the plasma membrane, ensuring optimal ascorbic acid uptake for neurons. In contrast, SVCT2 from cells that mimic HD symptoms (dubbed HD cells) fails to reach the plasma membrane under the same conditions. We reason that an early impairment of ascorbic acid uptake in HD neurons could lead to early metabolic failure promoting neuronal death.
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Affiliation(s)
- Aníbal I Acuña
- 1] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [3] Escuela de Graduados, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [4]
| | - Magdalena Esparza
- 1] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [3]
| | - Carlos Kramm
- 1] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [3]
| | - Felipe A Beltrán
- 1] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [3] Escuela de Graduados, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile
| | - Alejandra V Parra
- 1] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile
| | - Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, The David Geffen School of Medicine, 760 Westwood Plaza, University of California Los Angeles, Los Angeles, California 90095-1759, USA
| | - Carlos A Toro
- 1] Escuela de Graduados, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile
| | - René L Vidal
- Instituto de Ciencias Biomédicas, Universidad de Chile, Avda, Independencia 1027, Santiago, Chile
| | - Claudio Hetz
- Neurounion Biomedical Foundation, Independencia 1027, Santiago, Chile
| | - Ilona I Concha
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile
| | - Sebastián Brauchi
- 1] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile
| | - Michael S Levine
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Brain Research Institute, The David Geffen School of Medicine, 760 Westwood Plaza, University of California Los Angeles, Los Angeles, California 90095-1759, USA
| | - Maite A Castro
- 1] Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile [2] Centro de Investigación Sur-Austral en Enfermedades del Sistema Nervioso (CISNe), Universidad Austral de Chile, Campus Isla Teja s/n, Valdivia, 5090000 Chile
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8
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Rebolledo CL, Sotelo-Hitschfeld P, Brauchi S, Olavarría MZ. Design and synthesis of conformationally restricted capsaicin analogues based in the 1, 3, 4-thiadiazole heterocycle reveal a novel family of transient receptor potential vanilloid 1 (TRPV1) antagonists. Eur J Med Chem 2013; 66:193-203. [PMID: 23796768 DOI: 10.1016/j.ejmech.2013.05.001] [Citation(s) in RCA: 9] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 04/12/2013] [Accepted: 05/01/2013] [Indexed: 11/26/2022]
Abstract
4-hydroxy-3-methoxybenzaldehyde was used as starting material to obtain a number of 1, 3, 4-thiadiazole alkylamide derivatives. The pharmacological properties of these conformationally restricted capsaicin analogues were evaluated on HEK-293T cells transiently expressing TRPV1 receptor. By means of a highthroughput calcium imaging assay we find that 1, 3, 4-thiadiazoles (compounds 8-15) act as potent antagonists of the capsaicin receptor, inhibiting both, the capsaicin- and temperature-dependent activation. Docking studies suggested a different binding orientation on the vanilloid binding site when compared with capsaicin analogues, such as 5-iodononivamide. Overall, our studies suggest that 1, 3, 4-thiadiazoles interact with capsaicin's binding region of the receptor, although using a different set of interactions within the vanilloid binding pocket.
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Affiliation(s)
- Carolyne Lespay Rebolledo
- Department of Organic Chemistry, Faculty of Chemical Sciences, University of Concepcion, Edmundo Larenas 160C, Concepción 1430000, Chile
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Abstract
Transient receptor potential melastatin 8 (TRPM8), a calcium-permeable cation channel activated by cold, cooling compounds and voltage, is the main molecular entity responsible for detection of cold temperatures in the somatosensory system. Here, we review the biophysical properties, physiological role, and near-membrane trafficking of this exciting polymodal ion channel.
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Affiliation(s)
- Ramón Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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10
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Abstract
In this review, we discuss a novel function of ascorbic acid in brain energetics. It has been proposed that during glutamatergic synaptic activity neurons preferably consume lactate released from glia. The key to this energetic coupling is the metabolic activation that occurs in astrocytes by glutamate and an increase in extracellular [K(+)]. Neurons are cells well equipped to consume glucose because they express glucose transporters and glycolytic and tricarboxylic acid cycle enzymes. Moreover, neuronal cells express monocarboxylate transporters and lactate dehydrogenase isoenzyme 1, which is inhibited by pyruvate. As glycolysis produces an increase in pyruvate concentration and a decrease in NAD(+)/NADH, lactate and glucose consumption are not viable at the same time. In this context, we discuss ascorbic acid participation as a metabolic switch modulating neuronal metabolism between rest and activation periods. Ascorbic acid is highly concentrated in CNS. Glutamate stimulates ascorbic acid release from astrocytes. Ascorbic acid entry into neurons and within the cell can inhibit glucose consumption and stimulate lactate transport. For this switch to occur, an ascorbic acid flow is necessary between astrocytes and neurons, which is driven by neural activity and is part of vitamin C recycling. Here, we review the role of glucose and lactate as metabolic substrates and the modulation of neuronal metabolism by ascorbic acid.
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Affiliation(s)
- Maite A Castro
- Instituto de Bioquímica, Universidad Austral de Chile, Valdivia, Chile.
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Puñal A, Brauchi S, Reyes JG, Chamy R. Dynamics of extracellular polymeric substances in UASB and EGSB reactors treating medium and low concentrated wastewaters. Water Sci Technol 2003; 48:41-49. [PMID: 14640198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this work the dynamic study of EPS (Extracellular Polymeric Substances) concentration and distribution during the operation of two different reactor configurations (UASB and EGSB) is presented, treating medium (5 g COD/l) and low-concentrated (0.5 g COD/l) wastewater. Medium-concentrated wastewater was supplied for granules maturation as well as for stabilisation of the process. The effect of substrate change on granule characteristics was followed in both reactors. Total concentration of EPS associated to steady operation, was higher in the UASB reactor. The change to a low-concentrated substrate led to an increased difference, promoting a sharp destabilisation of the EGSB reactor, observing an increment in filamentous structures, causing biomass flotation and wash out. Although total concentration of EPS remained almost constant in the UASB reactor, their composition and distribution presented significant differences. The ratio of protein/polysaccharides as well as acidic-polysaccharides/total (neutral + acidic) polysaccharides decreased drastically in the EGSB reactor, while in the UASB reactor, the decrease was not so important and not enough for destabilisation of granule structure. Moreover, polysaccharides distribution seemed to have an important role in granule stability being enough to maintain granule cohesion only in the case of the UASB reactor. These observations point to composition and distribution of EPS rather than their total concentration as key parameters for granule stability and settleability.
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Affiliation(s)
- A Puñal
- Escuela de Ingeniería Bioquímica, Universidad Católica de Valparaíso, Avda. Brasil 2950, Casilla 4059, Valparaíso, Chile.
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