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Pertusa M, Solorza J, Madrid R. Molecular determinants of TRPM8 function: key clues for a cool modulation. Front Pharmacol 2023; 14:1213337. [PMID: 37388453 PMCID: PMC10301734 DOI: 10.3389/fphar.2023.1213337] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 05/30/2023] [Indexed: 07/01/2023] Open
Abstract
Cold thermoreceptor neurons detect temperature drops with highly sensitive molecular machinery concentrated in their peripheral free nerve endings. The main molecular entity responsible for cold transduction in these neurons is the thermo-TRP channel TRPM8. Cold, cooling compounds such as menthol, voltage, and osmolality rises activate this polymodal ion channel. Dysregulation of TRPM8 activity underlies several physiopathological conditions, including painful cold hypersensitivity in response to axonal damage, migraine, dry-eye disease, overactive bladder, and several forms of cancer. Although TRPM8 could be an attractive target for treating these highly prevalent diseases, there is still a need for potent and specific modulators potentially suitable for future clinical trials. This goal requires a complete understanding of the molecular determinants underlying TRPM8 activation by chemical and physical agonists, inhibition by antagonists, and the modulatory mechanisms behind its function to guide future and more successful treatment strategies. This review recapitulates information obtained from different mutagenesis approaches that have allowed the identification of specific amino acids in the cavity comprised of the S1-S4 and TRP domains that determine modulation by chemical ligands. In addition, we summarize different studies revealing specific regions within the N- and C-terminus and the transmembrane domain that contribute to cold-dependent TRPM8 gating. We also highlight the latest milestone in the field: cryo-electron microscopy structures of TRPM8, which have provided a better comprehension of the 21 years of extensive research in this ion channel, shedding light on the molecular bases underlying its modulation, and promoting the future rational design of novel drugs to selectively regulate abnormal TRPM8 activity under pathophysiological conditions.
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Affiliation(s)
- María Pertusa
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
| | - Jocelyn Solorza
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Talca, Chile
| | - Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
- Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago, Chile
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Gomez-Pinedo U, Matías-Guiu JA, Torre-Fuentes L, Montero-Escribano P, Hernández-Lorenzo L, Pytel V, Maietta P, Alvarez S, Sanclemente-Alamán I, Moreno-Jimenez L, Ojeda-Hernandez D, Villar-Gómez N, Benito-Martin MS, Selma-Calvo B, Vidorreta-Ballesteros L, Madrid R, Matías-Guiu J. Variant rs4149584 (R92Q) of the TNFRSF1A gene in patients with familial multiple sclerosis. Neurologia 2022:S2173-5808(22)00087-6. [PMID: 35963536 DOI: 10.1016/j.nrleng.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 07/15/2022] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION Genomic studies have identified numerous genetic variants associated with susceptibility to multiple sclerosis (MS); however, each one explains only a small percentage of the risk of developing the disease. These variants are located in genes involved in specific pathways, which supports the hypothesis that the risk of developing MS may be linked to alterations in these pathways, rather than in specific genes. We analyzed the role of the TNFRSF1A gene, which encodes one of the TNF-α receptors involved in a signaling pathway previously linked to autoimmune disease. METHODS We included 138 individuals from 23 families including at least 2 members with MS, and analyzed the presence of exonic variants of TNFRSF1A through whole-exome sequencing. We also conducted a functional study to analyze the pathogenic mechanism of variant rs4149584 (-g.6442643C > G, NM_001065.4:c.362 G > A, R92Q) by plasmid transfection into human oligodendroglioma (HOG) cells, which behave like oligodendrocyte lineage cells; protein labeling was used to locate the protein within cells. We also analyzed the ability of transfected HOG cells to proliferate and differentiate into oligodendrocytes. RESULTS Variant rs4149584 was found in 2 patients with MS (3.85%), one patient with another autoimmune disease (7.6%), and in 5 unaffected individuals (7.46%). The 2 patients with MS and variant rs4149584 were homozygous carriers and belonged to the same family, whereas the remaining individuals presented the variant in heterozygosis. The study of HOG cells transfected with the mutation showed that the protein does not reach the cell membrane, but rather accumulates in the cytoplasm, particularly in the endoplasmic reticulum and near the nucleus; this suggests that, in the cells presenting the mutation, TNFRSF1 does not act as a transmembrane protein, which may alter its signaling pathway. The study of cell proliferation and differentiation found that transfected cells continue to be able to differentiate into oligodendrocytes and are probably still capable of producing myelin, although they present a lower rate of proliferation than wild-type cells. CONCLUSIONS Variant rs4149584 is associated with risk of developing MS. We analyzed its functional role in oligodendrocyte lineage cells and found an association with MS in homozygous carriers. However, the associated molecular alterations do not influence the differentiation into oligodendrocytes; we were therefore unable to confirm whether this variant alone is pathogenic in MS, at least in heterozygosis.
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Affiliation(s)
- U Gomez-Pinedo
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain.
| | - J A Matías-Guiu
- Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - L Torre-Fuentes
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - P Montero-Escribano
- Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - L Hernández-Lorenzo
- Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - V Pytel
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain; Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | | | | | - I Sanclemente-Alamán
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - L Moreno-Jimenez
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - D Ojeda-Hernandez
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - N Villar-Gómez
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - M S Benito-Martin
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - B Selma-Calvo
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | - L Vidorreta-Ballesteros
- Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
| | | | - J Matías-Guiu
- Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain; Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain
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Arredondo C, Cefaliello C, Dyrda A, Jury N, Martinez P, Díaz I, Amaro A, Tran H, Morales D, Pertusa M, Stoica L, Fritz E, Corvalán D, Abarzúa S, Méndez-Ruette M, Fernández P, Rojas F, Kumar MS, Aguilar R, Almeida S, Weiss A, Bustos FJ, González-Nilo F, Otero C, Tevy MF, Bosco DA, Sáez JC, Kähne T, Gao FB, Berry JD, Nicholson K, Sena-Esteves M, Madrid R, Varela D, Montecino M, Brown RH, van Zundert B. Excessive release of inorganic phosphate by ALS/FTD astrocytes causes non-cell-autonomous toxicity to motoneurons. Neuron 2022; 110:1656-1670.e12. [PMID: 35276083 DOI: 10.1016/j.neuron.2022.02.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/01/2021] [Accepted: 02/15/2022] [Indexed: 12/13/2022]
Abstract
Non-cell-autonomous mechanisms contribute to neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), in which astrocytes release unidentified factors that are toxic to motoneurons (MNs). We report here that mouse and patient iPSC-derived astrocytes with diverse ALS/FTD-linked mutations (SOD1, TARDBP, and C9ORF72) display elevated levels of intracellular inorganic polyphosphate (polyP), a ubiquitous, negatively charged biopolymer. PolyP levels are also increased in astrocyte-conditioned media (ACM) from ALS/FTD astrocytes. ACM-mediated MN death is prevented by degrading or neutralizing polyP in ALS/FTD astrocytes or ACM. Studies further reveal that postmortem familial and sporadic ALS spinal cord sections display enriched polyP staining signals and that ALS cerebrospinal fluid (CSF) exhibits increased polyP concentrations. Our in vitro results establish excessive astrocyte-derived polyP as a critical factor in non-cell-autonomous MN degeneration and a potential therapeutic target for ALS/FTD. The CSF data indicate that polyP might serve as a new biomarker for ALS/FTD.
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Affiliation(s)
- Cristian Arredondo
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Carolina Cefaliello
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Agnieszka Dyrda
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Nur Jury
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Pablo Martinez
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Iván Díaz
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Armando Amaro
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Helene Tran
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Danna Morales
- Program of Physiology and Biophysics, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago 9160000, Chile
| | - Maria Pertusa
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago 9160000, Chile; Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago 9160000, Chile; Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Lorelei Stoica
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA; Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Elsa Fritz
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Daniela Corvalán
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Sebastián Abarzúa
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile; FONDAP Center for Genome Regulation, Santiago 8370146, Chile
| | - Maxs Méndez-Ruette
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Paola Fernández
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Fabiola Rojas
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Meenakshi Sundaram Kumar
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Rodrigo Aguilar
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile
| | - Sandra Almeida
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Alexandra Weiss
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Fernando J Bustos
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile
| | - Fernando González-Nilo
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso 2340000, Chile; Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile
| | - Carolina Otero
- School of Chemistry and Pharmacy, Faculty of Medicine, Universidad Andres Bello, Santiago 8320000, Chile
| | - Maria Florencia Tevy
- Cell Biology Laboratory, INTA, University of Chile and GEDIS Biotech, Santiago 7810000, Chile
| | - Daryl A Bosco
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Juan C Sáez
- Instituto de Neurociencias, Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Thilo Kähne
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University Magdeburg, Magdeburg 39120, Germany
| | - Fen-Biao Gao
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - James D Berry
- Massachusetts General Hospital Neurological Clinical Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Katharine Nicholson
- Massachusetts General Hospital Neurological Clinical Research Institute and Harvard Medical School, Boston, MA 02114, USA
| | - Miguel Sena-Esteves
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA; Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Rodolfo Madrid
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago 9160000, Chile; Millennium Nucleus for the Study of Pain (MiNuSPain), Santiago 9160000, Chile; Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Diego Varela
- Program of Physiology and Biophysics, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago 9160000, Chile
| | - Martin Montecino
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; FONDAP Center for Genome Regulation, Santiago 8370146, Chile
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Brigitte van Zundert
- Institute of Biomedical Sciences (ICB), Faculty of Medicine & Faculty of Life Sciences, Universidad Andres Bello, Santiago 8370186, Chile; CARE Biomedical Research Center, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile; Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA.
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Cornejo VH, González C, Campos M, Vargas-Saturno L, Juricic MDLÁ, Miserey-Lenkei S, Pertusa M, Madrid R, Couve A. Non-conventional Axonal Organelles Control TRPM8 Ion Channel Trafficking and Peripheral Cold Sensing. Cell Rep 2020; 30:4505-4517.e5. [DOI: 10.1016/j.celrep.2020.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 10/07/2019] [Accepted: 03/05/2020] [Indexed: 12/31/2022] Open
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Wigdahl B, Allen A, Worell S, Nwaozo G, Madrid R, Dampier W, Nonnemacher M. Broad-spectrum gRNAs abolish HIV-1 LTR-mediated transcription in cells that receive CRISPR/Cas9 therapy. J Virus Erad 2019. [DOI: 10.1016/s2055-6640(20)30217-x] [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: 11/24/2022] Open
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Pertusa M, Rivera B, González A, Ugarte G, Madrid R. Critical role of the pore domain in the cold response of TRPM8 channels identified by ortholog functional comparison. J Biol Chem 2018; 293:12454-12471. [PMID: 29880642 DOI: 10.1074/jbc.ra118.002256] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/30/2018] [Indexed: 11/06/2022] Open
Abstract
In mammals, the main molecular entity involved in innocuous cold transduction is TRPM8. This polymodal ion channel is activated by cold, cooling compounds such as menthol and voltage. Despite its relevance, the molecular determinants involved in its activation by cold remain elusive. In this study we explored the use of TRPM8 orthologs with different cold responses as a strategy to identify new molecular determinants related with their thermosensitivity. We focused on mouse TRPM8 (mTRPM8) and chicken TRPM8 (cTRPM8), which present complementary thermosensitive and chemosensitive phenotypes. Although mTRPM8 displays larger responses to cold than cTRPM8 does, the avian ortholog shows a higher sensitivity to menthol compared with the mouse channel, in both HEK293 cells and primary somatosensory neurons. We took advantage of these differences to build multiple functional chimeras between these orthologs, to identify the regions that account for these discrepancies. Using a combination of calcium imaging and patch clamping, we identified a region encompassing positions 526-556 in the N terminus, whose replacement by the cTRPM8 homolog sequence potentiated its response to agonists. More importantly, we found that the characteristic cold response of these orthologs is due to nonconserved residues located within the pore loop, suggesting that TRPM8 has evolved by increasing the magnitude of its cold response through changes in this region. Our results reveal that these structural domains are critically involved in cold sensitivity and functional modulation of TRPM8, and support the idea that the pore domain is a key molecular determinant in temperature responses of this thermo-transient receptor potential (TRP) channel.
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Affiliation(s)
- María Pertusa
- From the Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, 9160000 Santiago, Chile
| | - Bastián Rivera
- From the Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, 9160000 Santiago, Chile
| | - Alejandro González
- From the Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, 9160000 Santiago, Chile
| | - Gonzalo Ugarte
- From the Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, 9160000 Santiago, Chile
| | - Rodolfo Madrid
- From the Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, 9160000 Santiago, Chile
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Affiliation(s)
- María Pertusa
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000 Santiago, Chile and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD)
| | - Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000 Santiago, Chile and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD)
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8
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González A, Herrera G, Ugarte G, Restrepo C, Piña R, Pertusa M, Orio P, Madrid R. IKD Current in Cold Transduction and Damage-Triggered Cold Hypersensitivity. Adv Exp Med Biol 2017; 1015:265-277. [PMID: 29080031 DOI: 10.1007/978-3-319-62817-2_14] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In primary sensory neurons of the spinal and trigeminal somatosensory system, cold-sensitivity is strongly dependent on the functional balance between TRPM8 channels, the main molecular entity responsible for the cold-activated excitatory current, and Shaker-like Kv1.1-1.2 potassium channels, the molecular counterpart underlying the excitability brake current IKD. This slow-inactivating outward K+ current reduces the excitability of cold thermoreceptor neurons increasing their thermal threshold, and prevents unspecific activation by cold of neurons of other somatosensory modalities. Here we examine the main biophysical properties of this current in primary sensory neurons, its central role in cold thermotransduction, and its contribution to alterations in cold sensitivity triggered by peripheral nerve damage.
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Affiliation(s)
- Alejandro González
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Gaspar Herrera
- Centro Interdisciplinario de Neurociencia de Valparaíso and Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, 2340000, Valparaíso, Chile
| | - Gonzalo Ugarte
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Carlos Restrepo
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Ricardo Piña
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - María Pertusa
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso and Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, 2340000, Valparaíso, Chile
| | - Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, and Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Santiago de Chile, Alameda L. Bdo. O'Higgins 3363, 9160000, Santiago, Chile.
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Gallay P, Tosi E, Madrid R, Tirado M, Comedi D. Glucose biosensor based on functionalized ZnO nanowire/graphite films dispersed on a Pt electrode. Nanotechnology 2016; 27:425501. [PMID: 27622391 DOI: 10.1088/0957-4484/27/42/425501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present a glucose biosensor based on ZnO nanowire self-sustained films grown on compacted graphite flakes by the vapor transport method. Nanowire/graphite films were fragmented in water, filtered to form a colloidal suspension, subsequently functionalized with glucose oxidase and finally transferred to a metal electrode (Pt). The obtained devices were evaluated using scanning electron microscopy, energy-dispersive x-ray spectroscopy, cyclic voltammetry and chronoamperometry. The electrochemical responses of the devices were determined in buffer solutions with successive glucose aggregates using a tripolar electrode system. The nanostructured biosensors showed excellent analytical performance, with linear response to glucose concentrations, high sensitivity of up to ≈17 μA cm(-2) mM(-1) in the 0.03-1.52 mM glucose concentration range, relatively low Michaelis-Menten constant, excellent reproducibility and a fast response. The detection limits are more than an order of magnitude lower than those achievable in commercial biosensors for glucose control, which is promising for the development of glucose monitoring methods that do not require blood extraction from potentially diabetic patients. The strong detection enhancements provided by the functionalized nanostructures are much larger than the electrode surface-area increase and are discussed in terms of the physical and chemical mechanisms involved in the detection and transduction processes.
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Affiliation(s)
- P Gallay
- NanoProject and Laboratorio de Física del Sólido, Dep. Fisica, Facultad de Ciencias Exactas y Tecnología, Universidad Nacional de Tucumán, Av. Independencia 1800, 4000 San Miguel de Tucumán, Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET, Argentina
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Rozas P, Lazcano P, Piña R, Cho A, Terse A, Pertusa M, Madrid R, Gonzalez-Billault C, Kulkarni AB, Utreras E. Targeted overexpression of tumor necrosis factor-α increases cyclin-dependent kinase 5 activity and TRPV1-dependent Ca2+ influx in trigeminal neurons. Pain 2016; 157:1346-1362. [PMID: 26894912 PMCID: PMC4868804 DOI: 10.1097/j.pain.0000000000000527] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [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: 01/30/2023]
Abstract
We reported earlier that TNF-α, a proinflammatory cytokine implicated in many inflammatory disorders causing orofacial pain, increases the activity of Cdk5, a key kinase involved in brain development and function and recently found to be involved in pain signaling. To investigate a potential mechanism underlying inflammatory pain in trigeminal ganglia (TGs), we engineered a transgenic mouse model (TNF) that can conditionally overexpresses TNF-α upon genomic recombination by Cre recombinase. TNF mice were bred with Nav1.8-Cre mouse line that expresses the Cre recombinase in sensory neurons to obtain TNF-α:Nav1.8-Cre (TNF-α cTg) mice. Although TNF-α cTg mice appeared normal without any gross phenotype, they displayed a significant increase in TNF-α levels after activation of NFκB signaling in the TG. IL-6 and MCP-1 levels were also increased along with intense immunostaining for Iba1 and GFAP in TG, indicating the presence of infiltrating macrophages and the activation of satellite glial cells. TNF-α cTg mice displayed increased trigeminal Cdk5 activity, and this increase was associated with elevated levels of phospho-T407-TRPV1 and capsaicin-evocated Ca influx in cultured trigeminal neurons. Remarkably, this effect was prevented by roscovitine, an inhibitor of Cdk5, which suggests that TNF-α overexpression induced sensitization of the TRPV1 channel. Furthermore, TNF-α cTg mice displayed more aversive behavior to noxious thermal stimulation (45°C) of the face in an operant pain assessment device as compared with control mice. In summary, TNF-α overexpression in the sensory neurons of TNF-α cTg mice results in inflammatory sensitization and increased Cdk5 activity; therefore, this mouse model would be valuable for investigating the mechanism of TNF-α involved in orofacial pain.
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Affiliation(s)
- Pablo Rozas
- Laboratory of Molecular and Cellular Mechanisms of Pain, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Pablo Lazcano
- Laboratory of Molecular and Cellular Mechanisms of Pain, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Ricardo Piña
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago de Chile, Santiago, Chile
| | - Andrew Cho
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Anita Terse
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Maria Pertusa
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago de Chile, Santiago, Chile
| | - Rodolfo Madrid
- Department of Biology, Faculty of Chemistry and Biology, University of Santiago de Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Ashok B. Kulkarni
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Elias Utreras
- Laboratory of Molecular and Cellular Mechanisms of Pain, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
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11
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Madrid R. Beta sarcoglycanopathy caused by a novel mutation in the SGCB gene in a Palestinian family. J Neurol Sci 2015. [DOI: 10.1016/j.jns.2015.08.259] [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: 10/22/2022]
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12
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Olivares E, Salgado S, Maidana JP, Herrera G, Campos M, Madrid R, Orio P. TRPM8-Dependent Dynamic Response in a Mathematical Model of Cold Thermoreceptor. PLoS One 2015; 10:e0139314. [PMID: 26426259 PMCID: PMC4591370 DOI: 10.1371/journal.pone.0139314] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/11/2015] [Indexed: 11/30/2022] Open
Abstract
Cold-sensitive nerve terminals (CSNTs) encode steady temperatures with regular, rhythmic temperature-dependent firing patterns that range from irregular tonic firing to regular bursting (static response). During abrupt temperature changes, CSNTs show a dynamic response, transiently increasing their firing frequency as temperature decreases and silencing when the temperature increases (dynamic response). To date, mathematical models that simulate the static response are based on two depolarizing/repolarizing pairs of membrane ionic conductance (slow and fast kinetics). However, these models fail to reproduce the dynamic response of CSNTs to rapid changes in temperature and notoriously they lack a specific cold-activated conductance such as the TRPM8 channel. We developed a model that includes TRPM8 as a temperature-dependent conductance with a calcium-dependent desensitization. We show by computer simulations that it appropriately reproduces the dynamic response of CSNTs from mouse cornea, while preserving their static response behavior. In this model, the TRPM8 conductance is essential to display a dynamic response. In agreement with experimental results, TRPM8 is also needed for the ongoing activity in the absence of stimulus (i.e. neutral skin temperature). Free parameters of the model were adjusted by an evolutionary optimization algorithm, allowing us to find different solutions. We present a family of possible parameters that reproduce the behavior of CSNTs under different temperature protocols. The detection of temperature gradients is associated to a homeostatic mechanism supported by the calcium-dependent desensitization.
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Affiliation(s)
- Erick Olivares
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Simón Salgado
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Jean Paul Maidana
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Gaspar Herrera
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Matías Campos
- Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Rodolfo Madrid
- Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- * E-mail:
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13
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Arias-Darraz L, Cabezas D, Colenso CK, Alegría-Arcos M, Bravo-Moraga F, Varas-Concha I, Almonacid DE, Madrid R, Brauchi S. A transient receptor potential ion channel in Chlamydomonas shares key features with sensory transduction-associated TRP channels in mammals. Plant Cell 2015; 27:177-88. [PMID: 25595824 PMCID: PMC4330573 DOI: 10.1105/tpc.114.131862] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Sensory modalities are essential for navigating through an ever-changing environment. From insects to mammals, transient receptor potential (TRP) channels are known mediators for cellular sensing. Chlamydomonas reinhardtii is a motile single-celled freshwater green alga that is guided by photosensory, mechanosensory, and chemosensory cues. In this type of alga, sensory input is first detected by membrane receptors located in the cell body and then transduced to the beating cilia by membrane depolarization. Although TRP channels seem to be absent in plants, C. reinhardtii possesses genomic sequences encoding TRP proteins. Here, we describe the cloning and characterization of a C. reinhardtii version of a TRP channel sharing key features present in mammalian TRP channels associated with sensory transduction. In silico sequence-structure analysis unveiled the modular design of TRP channels, and electrophysiological experiments conducted on Human Embryonic Kidney-293T cells expressing the Cr-TRP1 clone showed that many of the core functional features of metazoan TRP channels are present in Cr-TRP1, suggesting that basic TRP channel gating characteristics evolved early in the history of eukaryotes.
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Affiliation(s)
- Luis Arias-Darraz
- Physiology Department, Faculty of Medicine, Universidad Austral de Chile, Campus Isla Teja, Valdivia 5110566, Chile
| | - Deny Cabezas
- Physiology Department, Faculty of Medicine, Universidad Austral de Chile, Campus Isla Teja, Valdivia 5110566, Chile
| | - Charlotte K Colenso
- Physiology Department, Faculty of Medicine, Universidad Austral de Chile, Campus Isla Teja, Valdivia 5110566, Chile
| | - Melissa Alegría-Arcos
- Universidad Andres Bello, Center for Bioinformatics and Integrative Biology, Faculty of Biological Sciences, Santiago 8370146, Chile
| | - Felipe Bravo-Moraga
- Universidad Andres Bello, Center for Bioinformatics and Integrative Biology, Faculty of Biological Sciences, Santiago 8370146, Chile
| | - Ignacio Varas-Concha
- Universidad Andres Bello, Center for Bioinformatics and Integrative Biology, Faculty of Biological Sciences, Santiago 8370146, Chile
| | - Daniel E Almonacid
- Universidad Andres Bello, Center for Bioinformatics and Integrative Biology, Faculty of Biological Sciences, Santiago 8370146, Chile CINV, Faculty of Sciences, Universidad de Valparaíso, Valparaíso 2366103, Chile
| | - Rodolfo Madrid
- Biology Department, Faculty of Chemistry and Biology, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Sebastian Brauchi
- Physiology Department, Faculty of Medicine, Universidad Austral de Chile, Campus Isla Teja, Valdivia 5110566, Chile
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14
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Pertusa M, González A, Hardy P, Madrid R, Viana F. Bidirectional modulation of thermal and chemical sensitivity of TRPM8 channels by the initial region of the N-terminal domain. J Biol Chem 2014; 289:21828-43. [PMID: 24917670 DOI: 10.1074/jbc.m114.565994] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [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: 01/17/2023] Open
Abstract
TRPM8, a nonselective cation channel activated by cold, voltage, and cooling compounds such as menthol, is the principal molecular detector of cold temperatures in primary sensory neurons of the somatosensory system. The N-terminal domain of TRPM8 consists of 693 amino acids, but little is known about its contribution to channel function. Here, we identified two distinct regions within the initial N terminus of TRPM8 that contribute differentially to channel activity and proper folding and assembly. Deletion or substitution of the first 40 residues yielded channels with augmented responses to cold and menthol. The thermal threshold of activation of these mutants was shifted 2 °C to higher temperatures, and the menthol dose-response curve was displaced to lower concentrations. Site-directed mutagenesis screening revealed that single point mutations at positions Ser-26 or Ser-27 by proline caused a comparable increase in the responses to cold and menthol. Electrophysiological analysis of the S27P mutant revealed that the enhanced sensitivity to agonists is related to a leftward shift in the voltage dependence of activation, increasing the probability of channel openings at physiological membrane potentials. In addition, we found that the region encompassing positions 40-60 is a key element in the proper folding and assembly of TRPM8. Different deletions and mutations within this region rendered channels with an impaired function that are retained within the endoplasmic reticulum. Our results suggest a critical contribution of the initial region of the N-terminal domain of TRPM8 to thermal and chemical sensitivity and the proper biogenesis of this polymodal ion channel.
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Affiliation(s)
- María Pertusa
- From the Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, 9160000 Santiago, Chile and the Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, 03550 Alicante, Spain
| | - Alejandro González
- From the Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, 9160000 Santiago, Chile and
| | - Paulina Hardy
- From the Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, 9160000 Santiago, Chile and
| | - Rodolfo Madrid
- From the Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, 9160000 Santiago, Chile and
| | - Félix Viana
- the Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, 03550 Alicante, Spain
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15
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Abstract
The detection of environmental temperature is critical for the survival of the most diverse organisms. Thermosensitive transient receptor potential (thermoTRP) channels have evolved as a class of ion channels activated by a wide range of temperatures. These molecular thermal sensors are spread through the different TRP channel subfamilies. Among the Melastatin subfamily of TRP channels, the eighth member, TRPM8, is a calcium-permeable cationic ion channel activated by cold, by substances that evoke cold sensation such as menthol, and by voltage. This channel is considered the main molecular entity responsible for the sensitivity to cold of primary sensory neurons of the somatosensory system. Here we present to the readers a summary of some the most relevant biophysical properties, physiological role, and molecular intimacies of this polymodal thermoTRP channel.
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Affiliation(s)
- Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - María Pertusa
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
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16
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Briz V, Serramía MJ, Madrid R, Hameau A, Caminade AM, Majoral JP, Muñoz-Fernández MA. Validation of a generation 4 phosphorus-containing polycationic dendrimer for gene delivery against HIV-1. Curr Med Chem 2013; 19:5044-51. [PMID: 22963636 DOI: 10.2174/0929867311209025044] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/28/2012] [Accepted: 08/26/2012] [Indexed: 11/22/2022]
Abstract
Gene therapy, in which oligomeric genetic material is carried into cells by nano-sized gene delivery vehicles to interfere with gene expression, represents a promising approach for preventive therapy against HIV/AIDS pandemic. Herein, we evaluate the usefulness of a phosphorus-containing dendrimer G4(NH+Et2Cl-)96 as a delivery agent of ODNs and siRNAs. G4(NH+Et2Cl-)96 formed stable complexes with ODNs or siRNAs and exhibited very low cytotoxicity in Sup T1 cells or PBMC. Functional validation was performed by using specific siRNA against HIV-1 Nef, siNEF to interfere in HIV-1 replication. G4(NH+Et2Cl-)96/siNEF dendriplex showed a high efficiency in Nef silencing. Furthermore, in vitro treatment of HIV-infected PBMC with G4(NH+Et2Cl-)96/siNEF dendriplex significantly reduced the viral replication. Our results prove the usefulness of phosphorus-containing dendrimers to deliver and transfect siRNA into CD4-T cells as a potential alternative therapy in the HIV-1 infection.
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Affiliation(s)
- V Briz
- Laboratorio Inmuno-Biologia Molecular, Instituto de Investigacion Sanitaria Gregorio Maranon (IiSGM); Hospital General Universitario Gregorio Maranon, C/Doctor Esquerdo 46, 28007 Madrid, Spain
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17
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Fritz E, Izaurieta P, Weiss A, Mir FR, Rojas P, Gonzalez D, Rojas F, Brown RH, Madrid R, van Zundert B. Mutant SOD1-expressing astrocytes release toxic factors that trigger motoneuron death by inducing hyperexcitability. J Neurophysiol 2013; 109:2803-14. [PMID: 23486205 DOI: 10.1152/jn.00500.2012] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by dysfunction and degeneration of motoneurons starting in adulthood. Recent studies using cell or animal models document that astrocytes expressing disease-causing mutations of human superoxide dismutase 1 (hSOD1) contribute to the pathogenesis of ALS by releasing a neurotoxic factor(s). Neither the mechanism by which this neurotoxic factor induces motoneuron death nor its cellular site of action has been elucidated. Here we show that acute exposure of primary wild-type spinal cord cultures to conditioned medium derived from astrocytes expressing mutant SOD1 (ACM-hSOD1(G93A)) increases persistent sodium inward currents (PC(Na)), repetitive firing, and intracellular calcium transients, leading to specific motoneuron death days later. In contrast to TTX, which paradoxically increased twofold the amplitude of calcium transients and killed motoneurons, reduction of hyperexcitability by other specific (mexiletine) and nonspecific (spermidine and riluzole) blockers of voltage-sensitive sodium (Na(v)) channels restored basal calcium transients and prevented motoneuron death induced by ACM-hSOD1(G93A). These findings suggest that riluzole, the only FDA-approved drug with known benefits for ALS patients, acts by inhibiting hyperexcitability. Together, our data document that a critical element mediating the non-cell-autonomous toxicity of ACM-hSOD1(G93A) on motoneurons is increased excitability, an observation with direct implications for therapy of ALS.
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Affiliation(s)
- Elsa Fritz
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Ave Republica 217, Santiago, Chile
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18
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Orio P, Parra A, Madrid R, González O, Belmonte C, Viana F. Role of Ih in the firing pattern of mammalian cold thermoreceptor endings. J Neurophysiol 2012; 108:3009-23. [DOI: 10.1152/jn.01033.2011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [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
Mammalian peripheral cold thermoreceptors respond to cooling of their sensory endings with an increase in firing rate and modification of their discharge pattern. We recently showed that cultured trigeminal cold-sensitive (CS) neurons express a prominent hyperpolarization-activated current ( Ih), mainly carried by HCN1 channels, supporting subthreshold resonance in the soma without participating in the response to acute cooling. However, peripheral pharmacological blockade of Ih, or characterization of HCN1−/− mice, reveals a deficit in acute cold detection. Here we investigated the role of Ih in CS nerve endings, where cold sensory transduction actually takes place. Corneal CS nerve endings in mice show a rhythmic spiking activity at neutral skin temperature that switches to bursting mode when the temperature is lowered. Ih blockers ZD7288 and ivabradine alter firing patterns of CS nerve endings, lengthening interspike intervals and inducing bursts at neutral skin temperature. We characterized the CS nerve endings from HCN1−/− mouse corneas and found that they behave similar to wild type, although with a lower slope in the firing frequency vs. temperature relationship, thus explaining the deficit in cold perception of HCN1−/− mice. The firing pattern of nerve endings from HCN1−/− mice was also affected by ZD7288, which we attribute to the presence of HCN2 channels in the place of HCN1. Mathematical modeling shows that the firing phenotype of CS nerve endings from HCN1−/− mice can be reproduced by replacing HCN1 channels with the slower HCN2 channels rather than by abolishing Ih. We propose that Ih carried by HCN1 channels helps tune the frequency of the oscillation and the length of bursts underlying regular spiking in cold thermoreceptors, having important implications for neural coding of cold sensation.
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Affiliation(s)
- Patricio Orio
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV) and Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Andrés Parra
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Alicante, Spain
| | - Rodolfo Madrid
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile; and
| | - Omar González
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Alicante, Spain
- Fundación de Investigación Oftalmológica, Instituto Fernandez-Vega, Oviedo, Spain
| | - Carlos Belmonte
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Alicante, Spain
| | - Félix Viana
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Alicante, Spain
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19
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Pertusa M, Madrid R, Morenilla-Palao C, Belmonte C, Viana F. N-glycosylation of TRPM8 ion channels modulates temperature sensitivity of cold thermoreceptor neurons. J Biol Chem 2012; 287:18218-29. [PMID: 22493431 DOI: 10.1074/jbc.m111.312645] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
TRPM8 is a member of the transient receptor potential ion channel superfamily, which is expressed in sensory neurons and is activated by cold and cooling compounds, such as menthol. Activation of TRPM8 by agonists takes place through shifts in its voltage activation curve, allowing channel opening at physiological membrane potentials. Here, we studied the role of the N-glycosylation occurring at the pore loop of TRPM8 on the function of the channel. Using heterologous expression of recombinant channels in HEK293 cells we found that the unglycosylated TRPM8 mutant (N934Q) displays marked functional differences compared with the wild type channel. These differences include a shift in the threshold of temperature activation and a reduced response to menthol and cold stimuli. Biophysical analysis indicated that these modifications are due to a shift in the voltage dependence of TRPM8 activation toward more positive potentials. By using tunicamycin, a drug that prevents N-glycosylation of proteins, we also evaluated the effect of the N-glycosylation on the responses of trigeminal sensory neurons expressing TRPM8. These experiments showed that the lack of N-glycosylation affects the function of native TRPM8 ion channels in a similar way to heterologously expressed ones, causing an important shift of the temperature threshold of cold-sensitive thermoreceptor neurons. Altogether, these results indicate that post-translational modification of TRPM8 is an important mechanism modulating cold thermoreceptor function, explaining the marked differences in temperature sensitivity observed between recombinant and native TRPM8 ion channels.
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Affiliation(s)
- María Pertusa
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Alicante, Spain
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20
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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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21
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Parra A, Madrid R, Echevarria D, del Olmo S, Morenilla-Palao C, Acosta MC, Gallar J, Dhaka A, Viana F, Belmonte C. Ocular surface wetness is regulated by TRPM8-dependent cold thermoreceptors of the cornea. Nat Med 2010; 16:1396-9. [DOI: 10.1038/nm.2264] [Citation(s) in RCA: 222] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 10/19/2010] [Indexed: 01/03/2023]
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22
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Orio P, Madrid R, de la Peña E, Parra A, Meseguer V, Bayliss DA, Belmonte C, Viana F. Characteristics and physiological role of hyperpolarization activated currents in mouse cold thermoreceptors. J Physiol 2009; 587:1961-76. [PMID: 19273581 PMCID: PMC2689336 DOI: 10.1113/jphysiol.2008.165738] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [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: 10/31/2008] [Accepted: 03/05/2009] [Indexed: 01/12/2023] Open
Abstract
Hyperpolarization-activated currents (I(h)) are mediated by the expression of combinations of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channel subunits (HCN1-4). These cation currents are key regulators of cellular excitability in the heart and many neurons in the nervous system. Subunit composition determines the gating properties and cAMP sensitivity of native I(h) currents. We investigated the functional properties of I(h) in adult mouse cold thermoreceptor neurons from the trigeminal ganglion, identified by their high sensitivity to moderate cooling and responsiveness to menthol. All cultured cold-sensitive (CS) neurons expressed a fast activating I(h), which was fully blocked by extracellular Cs(+) or ZD7288 and had biophysical properties consistent with those of heteromeric HCN1-HCN2 channels. In CS neurons from HCN1(-/-) animals, I(h) was greatly reduced but not abolished. We find that I(h) activity is not essential for the transduction of cold stimuli in CS neurons. Nevertheless, I(h) has the potential to shape the excitability of CS neurons. First, I(h) blockade caused a membrane hyperpolarization in CS neurons of about 5 mV. Furthermore, impedance power analysis showed that all CS neurons had a prominent subthreshold membrane resonance in the 5-7 Hz range, completely abolished upon blockade of I(h) and absent in HCN1 null mice. This frequency range matches the spontaneous firing frequency of cold thermoreceptor terminals in vivo. Behavioural responses to cooling were reduced in HCN1 null mice and after peripheral pharmacological blockade of I(h) with ZD7288, suggesting that I(h) plays an important role in peripheral sensitivity to cold.
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Affiliation(s)
- Patricio Orio
- Universidad Miguel Hernández, Instituto de Neurociencias de Alicante, Alicante, Spain
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23
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Mälkiä A, Madrid R, Meseguer V, de la Peña E, Valero M, Belmonte C, Viana F. Bidirectional shifts of TRPM8 channel gating by temperature and chemical agents modulate the cold sensitivity of mammalian thermoreceptors. J Physiol 2007; 581:155-74. [PMID: 17317754 PMCID: PMC2075222 DOI: 10.1113/jphysiol.2006.123059] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [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: 01/23/2023] Open
Abstract
TRPM8, a member of the melastatin subfamily of transient receptor potential (TRP) cation channels, is activated by voltage, low temperatures and cooling compounds. These properties and its restricted expression to small sensory neurons have made it the ion channel with the most advocated role in cold transduction. Recent work suggests that activation of TRPM8 by cold and menthol takes place through shifts in its voltage-activation curve, which cause the channel to open at physiological membrane potentials. By contrast, little is known about the actions of inhibitors on the function of TRPM8. We investigated the chemical and thermal modulation of TRPM8 in transfected HEK293 cells and in cold-sensitive primary sensory neurons. We show that cold-evoked TRPM8 responses are effectively suppressed by inhibitor compounds SKF96365, 4-(3-chloro-pyridin-2-yl)-piperazine-1-carboxylic acid (4-tert-butyl-phenyl)-amide (BCTC) and 1,10-phenanthroline. These antagonists exert their effect by shifting the voltage dependence of TRPM8 activation towards more positive potentials. An opposite shift towards more negative potentials is achieved by the agonist menthol. Functionally, the bidirectional shift in channel gating translates into a change in the apparent temperature threshold of TRPM8-expressing cells. Accordingly, in the presence of the antagonist compounds, the apparent response-threshold temperature of TRPM8 is displaced towards colder temperatures, whereas menthol sensitizes the response, shifting the threshold in the opposite direction. Co-application of agonists and antagonists produces predictable cancellation of these effects, suggesting the convergence on a common molecular process. The potential for half maximal activation of TRPM8 activation by cold was approximately 140 mV more negative in native channels compared to recombinant channels, with a much higher open probability at negative membrane potentials in the former. In functional terms, this difference translates into a shift in the apparent temperature threshold for activation towards higher temperatures for native currents. This difference in voltage-dependence readily explains the high threshold temperatures characteristic of many cold thermoreceptors. The modulation of TRPM8 activity by different chemical agents unveils an important flexibility in the temperature-response curve of TRPM8 channels and cold thermoreceptors.
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Affiliation(s)
- Annika Mälkiä
- Alicante Institute of Neuroscience, University Miguel Hernández-CSIC, Spain.
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Treo E, Felice C, Madrid R. Non linear dielectric properties of microbiological suspensions at electrode-electrolyte interfaces. Conf Proc IEEE Eng Med Biol Soc 2007; 2005:4588-91. [PMID: 17281261 DOI: 10.1109/iembs.2005.1615491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Nonlinear properties of biological suspensions have been previously presented as a bulk phenomenon, however, some authors consider that they are generated at the electrode-electrolyte interface and are reflected as a bulk property phenomenon. They were mainly ascribed to the H<sup>+</sup>-ATPase present in the plasma membrane of these cells. In this paper, we describe the construction of a dual-cell nonlinear dielectric spectrometer. The system is applied to the study of interfaces with resting cell suspensions of Saccharomyces cerevisiae. Substantial harmonics are generated at the interface when a sinusoidal current is applied and altered by the presence of yeast. When a second interface with yeast and enzyme inhibitor is used as reference, a decrease in the magnitude response of the third harmonic can be observed. As it was already described for the solution bulk, we obtained a similar behavior at the interface. Besides, we also found optimal intervals, respectively, for frequency and voltage to reach maximal response. This result would support the contention that biological nonlinearity is an interface-based phenomenon.
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Affiliation(s)
- E Treo
- Department of Bioengineering, Universidad Nacional de Tucumán, Tucumán, Argentina, also with Consejo Nacional de Investigaciones Científicas y Tecnológicas
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Madrid R, Donovan-Rodríguez T, Meseguer V, Acosta MC, Belmonte C, Viana F. Contribution of TRPM8 channels to cold transduction in primary sensory neurons and peripheral nerve terminals. J Neurosci 2006; 26:12512-25. [PMID: 17135413 PMCID: PMC6674899 DOI: 10.1523/jneurosci.3752-06.2006] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [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: 01/22/2023] Open
Abstract
Transient receptor potential melastatin 8 (TRPM8) is the best molecular candidate for innocuous cold detection by peripheral thermoreceptor terminals. To dissect out the contribution of this cold- and menthol-gated, nonselective cation channel to cold transduction, we identified BCTC [N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl)piperazine-1-carboxamide] as a potent and full blocker of recombinant TRPM8 channels. In cold-sensitive trigeminal ganglion neurons of mice and guinea pig, responses to menthol were abolished by BCTC. In contrast, the effect of BCTC on cold-evoked responses was variable but showed a good correlation with the presence or lack of menthol sensitivity in the same neuron, suggesting a specific blocking action of BCTC on TRPM8 channels. The biophysical properties of native cold-gated currents (I(cold)), and the currents blocked by BCTC were nearly identical, consistent with a role of this channel in cold sensing at the soma. The temperature activation threshold of native TRPM8 channels was significantly warmer than those reported in previous expression studies. The effect of BCTC on native I(cold) was characterized by a dose-dependent shift in the temperature threshold of activation. The role of TRPM8 in transduction was further investigated in the guinea pig cornea, a peripheral territory densely innervated with cold thermoreceptors. All cold-sensitive terminals were activated by menthol, suggesting the functional expression of TRPM8 channels in their membrane. However, the spontaneous activity and firing pattern characteristic of cold thermoreceptors was totally immune to TRPM8 channel blockade with BCTC or SKF96365 (1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole hydrochloride). Cold-evoked responses in corneal terminals were also essentially unaffected by these drugs, whereas responses to menthol were completely abolished. The minor impairment in the ability to transduce cold stimuli by peripheral corneal thermoreceptors during TRPM8 blockade unveils an overlapping functional role for various thermosensitive mechanisms in these nerve terminals.
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Affiliation(s)
- Rodolfo Madrid
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain
| | - Tansy Donovan-Rodríguez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain
| | - Victor Meseguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain
| | - Mari Carmen Acosta
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain
| | - Carlos Belmonte
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain
| | - Félix Viana
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Spain
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Abstract
Odor stimulation may excite or inhibit olfactory receptor neurons (ORNs). It is well established that the excitatory response involves a cyclic AMP (cAMP) transduction mechanism that activates a nonselective cationic cyclic nucleotide-gated (CNG) conductance, accompanied by the activation of a Ca2+-dependent Cl(-) conductance, both causing a depolarizing receptor potential. In contrast, odor inhibition is attributed to a hyperpolarizing receptor potential. It has been proposed that a Ca2+-dependent K+ (K(Ca)) conductance plays a key role in odor inhibition, both in toad and rat isolated olfactory neurons. The mechanism underlying odor inhibition has remained elusive. We assessed its study using various pharmacological agents and caged compounds for cAMP, Ca2+, and inositol 1,4,5-triphosphate (InsP3) on isolated toad ORNs. The odor-triggered K(Ca) current was reduced on exposing the cell either to the CNG channel blocker LY83583 (20 microM) or to the adenylyl cyclase inhibitor SQ22536 (100 microM). Photorelease of caged Ca2+ activated a Cl- current sensitive to niflumic acid (10 microM) and a K+ current blockable by charybdotoxin (20 nM) and iberiotoxin (20 nM). In contrast, photoreleased Ca2+ had no effect on cells missing their cilia, indicating that these conductances are confined to the cilia. Photorelease of cAMP induced a charybdotoxin-sensitive K+ current in intact ORNs. Photorelease of InsP3 did not increase the membrane conductance of olfactory neurons, arguing against a direct role of InsP3 in chemotransduction. We conclude that a cAMP cascade mediates the activation of the ciliary Ca2+-dependent K+ current and that the Ca2+ ions that activate the inhibitory current enter the cilia through CNG channels.
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Affiliation(s)
- Rodolfo Madrid
- Department of Biology, Faculty of Sciences, University of Chile, P.O. Box 653, Santiago, Chile
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Hawley RJ, Madrid R. Post-infectious central and peripheral nervous system diseases in patient with Devic's disease and Guillain-Barre syndrome. Eur J Neurol 2003; 10:600. [PMID: 12940848 DOI: 10.1046/j.1468-1331.2003.00659.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Olfactory receptor neurons (ORNs) respond to odorants with characteristic patterns of action potentials that are relevant for odor coding. Prolonged odorant exposures revealed three populations of dissociated toad ORNs, which were mimicked by depolarizing currents: tonic (TN, displaying sustained firing, 49% of 102 cells), phasic (PN, exhibiting brief action potential trains, 36%) and intermediate neurons (IN, generating trains longer than PN, 15%). We studied the biophysical properties underlying the differences between TNs and PNs, the most extreme cases among ORNs. TNs and PNs possessed similar membrane capacitances (approximately 4 pF), but they differed in resting potential (-82 versus -64 mV), input resistance (4.2 versus 2.9 G(Omega)) and unspecific current, I(u) (TNs: 0 < I(u) <or= 1 pA/pF; and PNs: I(u) > 1 pA/pF). Firing behavior did not correlate with differences in voltage-gated conductances. We developed a mathematical model that accurately simulates tonic and phasic patterns. Whole cell recordings from rat ORNs in fragments (approximately 4 mm(2)) of olfactory epithelium showed that such a tissue normally contains tonic and phasic receptor neurons, suggesting that this feature is common across a wide range of vertebrates. Our findings show that the individual passive electrical properties can govern the firing patterns of ORNs.
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Affiliation(s)
- Rodolfo Madrid
- Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
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Serrano M, Amoros A, Pretel MT, Martinez-Madrid MC, Madrid R, Romojaro F. Effect of Calcium Deficiency on Melon (Cucumis melo L.) Texture and Glassiness Incidence During Ripening. FOOD SCI TECHNOL INT 2002. [DOI: 10.1177/1082013202008003117] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
We have cloned the gene encoding the TRK transporter of the soil yeast Schwanniomyces occidentalis and obtained the HAK1 trk1 delta and the hak1 delta TRK1 mutant strains. Analyses of the transport capacities of these mutants have shown that (i) the HAK1 and the TRK1 potassium transporters are the only transporters operating at low and medium K+ concentrations (< 1 mM); (ii) the HAK1 transporter is functional at low pH but fails at high pH; and (iii) the TRK1 transporter functions at neutral and high pH and fails at low pH. At neutral pH, both transporters are functional, but HAK1 is not expressed, except at very low K+ concentrations (< 50 microM) where HAK1 is very effective. TRK1 is also involved in the control of the membrane potential.
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Affiliation(s)
- M A Bañuelos
- Departamento de Biotecnología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
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Ayala F, Murillo H, Lepe L, Solorio S, Almazán A, Enciso R, Madrid R, Antonio L, Martínez O, García Manzano A. [Low molecular weight heparin in pregnancy. Report of three cases with pure mitral stenosis]. Arch Inst Cardiol Mex 1999; 69:344-9. [PMID: 10553191] [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: 02/14/2023]
Abstract
Three pregnant women with 5 +/- 1.7 weeks of pregnancy and mitral stenosis are described. Their valve area were < 1.0 cm2. They received medical treatment with little improvement and were included in our valvotomy percutaneous mitral (VPM) program with Inoue technique before their 30th week of pregnancy. Before they were treated with low molecular weight heparin (LMWH), Enoxiparin) as prophylaxis of intracavitary thrombus formation transthoracic and transesophageal echocardiogram demonstrated the absence of thrombus. We used 40 mgs. subcutaneous injection once a day during 16 weeks. Repeated transthoracic and transesophageal echocardiogram during VPM showed no evidence of intracavitary thrombus. Complete blood count and coagulation parameters remained within normal limits. The three cases delivered a healthy products. In conclusion, although this series is small, we show that the LMWH can be used in the first trimester of pregnancy as prophylactic treatment instead of oral anticoagulant treatment.
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Affiliation(s)
- F Ayala
- Hospital de Especialidades, Centro Médico La Raza, Instituto Mexicano del Seguro Social, México, D.F
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Ocampo S, Solorio S, Rangel A, León FJ, Lepe L, Ayala F, Madrid R, Romero MA, Carrillo AM. [Low-molecular-weight heparin in unstable angina pectoris]. Arch Inst Cardiol Mex 1999; 69:222-7. [PMID: 10529855] [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: 02/14/2023]
Abstract
We studied the therapeutic effect of standard heparin (HS) compared with low-molecular-weight (HBPM) in two homogeneous groups of 14 patients heparin selected at random, with clinical history and electrocardiographic signs of unstable angina pectoris. Patients received the conventional treatment with platelets' inhibitors, nitrates, adrenergic beta-blockers or calcium antagonists. Both heparins, separately, showed statistical therapeutic effect on the symptoms and signs of unstable angina pectoris. They decreased to zero the number and duration of symptomatic myocardial ischemic events observed by ambulatory electrocardiogram (EKG-Holter). The symptoms of the angina pectoris disappeared at the same elapsed time: in 51.9 +/- 20.2 min. for the HS, and in 48.14 +/- 20.7 min. for the HBPM. They decreased the frequency of the silent myocardial ischemia observed at the EKG-Holter: 9 events decreased to 4 with the HS, and 8 events decreased to 3 with the HBPM. They decreased the total elapsed time of the silent ischemia from 52 min. to 15 min., and the mean elapsed time of the silent ischemia decreased from 3.71 +/- 3.29 min. to 1.07 +/- 1.81 min. with the HS (P < 0.001). With HBPM it decreased the total elapsed time of the silent ischemia from 60 min to 10 min, and the mean elapsed time of the silent ischemia decreased from 4.28 +/- 4.49 min. to 0.71 +/- 1.43 min. (P < 0.02). Both heparins considerably decreased the frequency of the lethal arrhythmias. Although in this study we did not find statistical differences in the therapeutic action of either heparins, HBPM reduced rapidly angina symptoms and the events associated to angina pectoris, cardiac arrhythmias, specially lethal extrasystolia, conduction defects and atrial paroxysmal tachycardia. Compared to HS, HBPM is easily applied, does not produce side effects on coagulation or bleeding time.
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Affiliation(s)
- S Ocampo
- Departamento de Cardiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México, D.F
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Murillo H, Ayala F, Lepe L, Madrid R, Solorio S, Lara A, Enciso R, Chávez E, Rangel A. [Percutaneous mitral commissurotomy in patients with mitral valve stenosis and thrombosis of the left atrium]. Arch Inst Cardiol Mex 1999; 69:134-8. [PMID: 10478291] [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: 02/13/2023]
Abstract
UNLABELLED Mitral percutaneous valvotomy (MPV) is an effective therapeutic alternative in the treatment of patients with mitral stenosis (MS) and thrombus in the left atrium have been an absolute contraindication to this procedure. The aim of our study is to evaluate the safety of MPV in patients with MS and thrombus in the appendix of the left atrium (ALA). Between September 1996 and April 1997, we performed ten procedures of MPV with Inoue's technique in patients with MS and thrombus in ALA. Nine females and 1 male were included. Their were 41 +/- 7.6 years old. The Wilkins score in our patients were 8 +/- 1.2. All were treated with oral anticoagulants between three and twelve months but the thrombus did not resolved. With transesophagic echocardiogram and fluoroscopic control we avoided the contact between wires and Inoue's catheter with ALA. Results were positive. Mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.95 +/- 0.3 cm2. There was no case of systemic embolism or others major complications during the MVP and during following one year. CONCLUSION MPV is a safe and efficient therapeutic alternative in the treatment of selected patients with MS and thrombus in ALA.
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Affiliation(s)
- H Murillo
- Servicio de Cardiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México D. F
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Madrid R, Gómez MJ, Ramos J, Rodríguez-Navarro A. Ectopic potassium uptake in trk1 trk2 mutants of Saccharomyces cerevisiae correlates with a highly hyperpolarized membrane potential. J Biol Chem 1998; 273:14838-44. [PMID: 9614085 DOI: 10.1074/jbc.273.24.14838] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.2] [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
Null trk1 trk2 mutants of Saccharomyces cerevisiae exhibit a low-affinity uptake of K+ and Rb+. We show that this low-affinity Rb+ uptake is mediated by several independent transporters, and that trk1Delta cells and especially trk1Delta trk2Delta cells are highly hyperpolarized. Differences in the membrane potentials were assessed for sensitivity to hygromycin B and by flow cytometric analyses of cellular DiOC6(3) fluorescence. On the basis of the latter analyses, it is proposed that Trk1p and Trk2p are involved in the control of the membrane potential, preventing excessive hyperpolarizations. K+ starvation and nitrogen starvation hyperpolarize both TRK1 TRK2 and trk1Delta trk2Delta cells, thus suggesting that other proteins, in addition to Trk1p and Trk2p, participate in the control of the membrane potential. The HAK1 K+ transporter from Schwanniomyces occidentalis suppresses the K+-defective transport of trk1Delta trk2Delta cells but not the high hyperpolarization, and the HKT1 K+ transporter from wheat suppresses both defects, in the presence of Na+. We discuss the mechanism involved in the control of the membrane potential by Trk1p and Trk2p and the causal relationship between the high membrane potential (negative inside) of trk1Delta trk2Delta cells and its ectopic transport of alkali cations.
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Affiliation(s)
- R Madrid
- Departamento de Biotecnología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
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Abstract
In toad olfactory neurons, a putrid odorant mixture inducing inhibitory responses increases Ca2+-activated K+ conductance, developing a hyperpolarizing receptor potential. Removal of extracellular Ca2+ or exposure to nifedipine reversibly reduced the inhibitory response, suggesting that odorants induce a Ca2+ influx. We show evidence for an odorant-induced Ca2+ current. Using confocal microscopy, it is shown that odorants induce a nifedipine-sensitive elevation of Ca2+ in the apical end of the cell. These results suggest an inhibitory mechanism in which an apical Ca2+ influx causes an increase in internal Ca2+, opening Ca2+-activated K2+ channels that lead to membrane hyperpolarization.
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Affiliation(s)
- B Morales
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago
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Espinosa de los Monteros A, Yuan J, McCartney D, Madrid R, Cole R, Kanfer JN, deVellis J. Acceleration of the maturation of oligodendroblasts into oligodendrocytes and enhancement of their myelinogenic properties by a chemically defined medium. Dev Neurosci 1997; 19:297-311. [PMID: 9215875 DOI: 10.1159/000111226] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [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: 02/04/2023] Open
Abstract
Because of the importance of oligodendrocytes (OL) in forming and maintaining myelin in the CNS and the fact that the remyelination in the CNS is very limited in contrast to the peripheral nervous system, we investigated the effect of a chemically defined medium OLDEM, previously characterized by the maintenance of mature myelinating OL, on oligodendroblasts (or OL progenitors) in culture. The effect of each component of this medium as well as different combinations of them were also examined. Cultures were examined at different developmental stages immunocytochemically for developmental markers, such as transferrin, sulfatides, myelin basic protein and proteolipid protein. OLDEM accelerated the appearance of developmental markers and concomitant morphological changes. Furthermore, myelin-specific enzymes such as glycerophosphorylcholine phosphodiesterase; p-nitro-phenolphosphocholine phosphodiesterase; 2'3'-cyclic nucleotide 3'-phosphodiesterase and UDP galactose: ceramide galactosyltransferase had enzymatic activities similar to values found in pure myelin, indicating that OLDEM allows the optimal expression of myelin-related genes. The effect of each OLDEM constituent was evaluated by immunocytochemistry and by measurement of enzymatic activities. With each single additive or multiple combinations, oligodendrocytes displayed different degrees of maturation. Deletion of selenium, glucose, and galactose severely affected cell survival as well as enzymes expression in young cultures. However, older cultures were more resistant to these deletions. Putrescine and insulin did not cause such effects on survival, but their absence affected cell maturation. None of the OLDEM additives individually supported survival and/or maturation. Enzyme assays performed on isolated myelin-like membranes or the cells soma revealed a redistribution of the activity between these fractions as the cell matured. The biological role of each of these constituents on the maturation of the oligodendroglial cells is discussed. These observations indicate that OLDEM constituents have a powerful effect on OL progenitor maturation, and membrane formation. This medium will be used for investigating the remyelination potential of adult OL progenitors.
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Murillo H, Ayala F, Badui E, Almazán A, Solorio S, Enciso R, Madrid R, Lepe L, Rangel Abundis A, Chávez E. [Percutaneous mitral commissurotomy using Inoue's balloon during pregnancy]. Arch Inst Cardiol Mex 1996; 66:350-5. [PMID: 8984957] [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: 02/03/2023]
Abstract
The authors present three cases of pregnant women with symptomatic severe mitral stenosis with a mean age of 28.6 +/- 2.3 years, and during 27.6 +/- 1.52 weeks of pregnancy. Two patients were in class III and one in class IV of the New York Heart Association (NYHA). All patients had a mitral valvular area equal or less than 1 cm2, with a Wilkins score of 7 to 9 and mitral insufficiency grade I in two cases; two, had severe pulmonary arterial hypertension (mean > 50 mm Hg). After Percutaneous Mitral Valvuloplasty (PMV) the mitral valve measured by 2D echocardiography increased form 0.83 +/- 0.2 cm2 to 1.8 +/- 0.15 cm2; the mean transmitral gradient diminished from 13 +/- 3.4 mm Hg to 3.6 +/- 1.15 mm Hg; the degree of mitral insufficiency was no modified in neither case. Hemodynamic results revealed increasing of the mitral valve from 0.83 +/- 0.18 cm2 to 2.23 +/- 0.3 cm2; the mean mitral gradient decreased from 21.6 +/- 9 to 4.3 +/- 0.5 mm Hg; the mean left atrial pressure from 30 +/- 12 to 12.3 +/- 4 mm Hg; the mean pressure of the pulmonary artery diminished suddenly from 44.3 +/- 16 to 25.6 +/- 11 mm Hg. The average fluoroscopic time was 15.3 +/- 3 minutes. There were no complications. The patients were discharged 48 hours after the procedure and continued their pregnancies in class I NYHA, which resolved in a non complicated vaginal delivery with normal products. We conclude that PMV is a safe and useful therapy in pregnant patient with severe mitral stenosis refractory to medical treatment.
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Affiliation(s)
- H Murillo
- División de Cardiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México, D.F
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Ayala F, Badui E, Murillo H, Madrid R, Almazan A, Rangel A, Gutierrez-Vogel S. Right coronary ostium agenesis with anomalous origin of the right coronary artery from an ectasic circumflex artery. A case report. Angiology 1995; 46:637-9. [PMID: 7618769 DOI: 10.1177/000331979504600713] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In this report the authors present a case with right coronary ostium agenesis with anomalous origin of the right coronary artery from an ectasic circumflex artery, which, according to the literature review, they consider to be a unique case.
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Affiliation(s)
- F Ayala
- Division of Cardiology, Hospital de Especialidades, IMSS, Mexico, D.F
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39
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Abstract
A sixty-two-year-old white woman with a 14.5 cm (145 mm) silent giant left atrial enlargement secondary probably to rheumatic heart disease is presented. Aside from mild progressive shortness of breath during the past year, the patient had been asymptomatic all her life. Her clinical picture was manifested for the first time by syncope secondary to slow atrial fibrillation, for which a permanent pacemaker was required. The correct diagnosis of the enlarged chamber was not possible through the routine chest roentgenogram. In this case, the echocardiogram, nuclear angiogram, and computed tomography were the pertinent studies needed to reach the diagnosis.
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Affiliation(s)
- E Badui
- Division of Cardiology, Hospital de Especialidades, Mexico, D.F
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40
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Abstract
This study describes the physiological changes in the activities of the hepatic antioxidant enzymes superoxide dismutase isoenzymes (Cu/Zn-and Mn-superoxide dismutase) and catalase, in the glutathione content and in the lipid peroxidation levels in fetal (20 and 21 days of gestation) and neonatal rat liver (Days 1, 8, 15, and 22 post partum). The catalase and superoxide dismutase activities decreased before birth and increased after birth. The oxidized:reduced glutathione (GSSG:GSH) ratio declined before birth, but it increased between Days 1 and 15 post partum and then remained stable. Finally, newborn rat liver from the 1st day of life shows the highest susceptibility to lipid peroxidation. These results suggest that the changes in antioxidant defences could be related mainly to the beginning of diet intake after birth, which entails a higher hepatic metabolism rate, as well as a higher oxygen consumption.
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Affiliation(s)
- M M Gonzalez
- Departmento de Biologia Animal II, Facultad de Biologia, Universidad Complutense, Madrid, Spain
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41
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Sierra E, Maganto P, González M, Madrid R, Codesal J, Castillo-Olivares JL, Arahuetes RM. Antioxidant enzymatic activities in fetal hepatocytes transplanted into the spleen. Transplant Proc 1994; 26:3501-3. [PMID: 7998248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- E Sierra
- Clínica Puerta de Hierro, Madrid, Spain
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Valdespino A, Solorio S, Badui E, Ocaña J, Lepe L, Ayala F, León F, Madrid R, Campos A, Graef A. [The first myocardial infarct in the elderly patient]. Arch Inst Cardiol Mex 1994; 64:531-5. [PMID: 7726688] [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: 01/26/2023]
Abstract
UNLABELLED Acute myocardial infarction (AMI) in patients over 65 years of age represent more than half of the patients with AMI. Among them, between 60 and 80% represent the first AMI. The objective of this study is to evaluate the behavior of AMI in this group of patients. The clinical charts of patients over 65 years of age with ischemic heart disease admitted into the hospital during the past two years, were reviewed. We used the international criteria (clinical, ECG, enzymatic, echocardiographic and scintigraphic studies) for the diagnosis of AMI. Patients with previous AMI were excluded. We included 274 patients (68% males and 32% females). The age varied from 65 to 91 years with an average of 71.7 +/- 5.3 years. Typical symptoms were present in 90.5% and atypical in 9.5% of the cases, being the latest most frequent in those over 75 years of age. RISK FACTORS cigarette smoking was present in 60% of the patients, hypertension in 52% and diabetes mellitus in 37%. Both of them were associated in 21%. In 144 cases (52.5%) the MI localization was anterior and in 130 (47.5%) inferior; among them 47 patients (36%) had extension to the right ventricle and 7 (2.5%) had a non Q AMI. COMPLICATIONS Type I-II VPCs of Bernard Lown were present in 18% and type V 10.2%. Compete AV block in 14.2% (all of them with inferior wall MI); bifascicular block in 55 and mitral insufficiency due to papillary muscle dysfunction in 6.5%.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Valdespino
- División de Cardiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México D.F
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Caballero R, Solorio S, Badui E, Almazán A, Madrid R, Rangel A, Lepe L, Ayala F, Murillo H. [The echo-dobutamine pharmacological stress test in ischemic cardiopathy]. Arch Inst Cardiol Mex 1994; 64:355-360. [PMID: 7840719] [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: 05/22/2023]
Abstract
We report our experience with Echo-Dobutamine stress test. In order to evaluate the sensitivity, specificity and the safety, of the pharmacologic echo-dobutamine stress test, we studied 30 patients with ischemic heart disease based on clinical history, 2D echocardiogram, standard exercise stress test and cardiac catheterization. The test was started under continuous videotape of the segmental left ventricular motility on the conventional views. Dobutamine was administer intravenously 2.5 to 40 micrograms/kg/min every 3 minutes, the mean higher dobutamine dose was 19 +/- 14.3 micrograms/kg/min, having a continuous electrocardiographic monitoring of the heart rate as well as blood pressure. The myocardial motility was recorded with each increment in the dobutamine dose. Among the cases, 22 were males and 8 females with an average age of 55 +/- 9 years. Twenty two patients had history of remote myocardial infarction and were asymptomatic at the moment of the test; 8, who had angina pectoris were on a functional class I-II of the CCS. The mean basal ejection fraction was 62.6 +/- 11.7% by echo vs 64.4 +/- 16.8% obtained by cardiac catheterization (p no significant). There were no arrhythmias in any case. The heart rate increased from 68.7 +/- 10.1 to 85.5 +/- 15.7 beats per minute (p < 0.001). The systolic B/P was increased from a mean of 124 +/- 14.5 to 138.3 +/- 14.4 mmHg (p < 0.0005) while the diastolic pressure varied from 82.3 +/- 8.2 to 90.8 +/- 9.6 mmHg (p < 0.001). There were no severe complications.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R Caballero
- División de Cardiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México, D.F
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Solorio S, Sánchez H, Madrid R, Badui E, Valdespino A, Murillo H, Rangel A, Enciso R. [Thrombolysis in mechanical prosthetic valve thrombosis. Its management with streptokinase]. Arch Inst Cardiol Mex 1994; 64:51-5. [PMID: 8179437] [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: 01/29/2023]
Abstract
We present the first experience in Mexico in 10 patients, 9 female and 1 male with an average age of 42.5 years. All patients had clinical, echocardiographic and fluoroscopic criteria of dysfunctioning mechanical valvular prosthesis due to thrombosis (9 Sorin type and 1 Starr-Edwards). None of the patients had contraindications for thrombolytic therapy. All cases were treated with intravenous streptokinase: 250,000 U in 30 minutes followed by an infusion of 100,000 U per hour, always under clinical, echocardiographic and fluoroscopic control every 2 and 24 hours respectively until the normalization of the clinical and hemodynamic parameters with a top limit of 72 hour. The average duration of the thrombolysis was 54 +/- 6.1 hours with an average total doses of 5' 200,000 U of streptokinase. In 90% of the cases there was an increase in the valvular area: mitral (n = 7), from 1.02 +/- 0.21 to 1.75 +/- 0.36 cm2 (p < 0.001), while the mean transvalvular gradient decreased from 10.42 +/- 3.77 to 3.42 +/- 0.975 mmHg (p < 0.001); the systolic pulmonary artery pressure also decreased from 53.7 +/- 15.29 to 35 +/- 2 mmHg (p < 0.001). In the tricuspid prosthesis (n = 2) the average valvular area was increased from 0.8 +/- 0.44 to 1.55 +/- 0.77 cm2, decreasing proportionally the mean transvalvular gradient from 12.5 +/- 2 to 4.5 +/- 3.5 mmHg with no changes in the systolic pressure of the pulmonary artery. In the Starr-Edwards prosthesis in aortic position (n = 1), no hemodynamic changes were observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S Solorio
- División de Cardiología y Angiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México, D.F
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Murillo H, Ayala F, Almazán A, Madrid R, Rangel A, Valdespino A, Solorio S, Lepe L, Badui E. [Percutaneous transluminal coronary angioplasty. The experience of the Hospital de Especialidades of the La Raza Medical Center, IMSS]. Arch Inst Cardiol Mex 1993; 63:523-7. [PMID: 8135594] [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: 01/29/2023]
Abstract
UNLABELLED We analyzed the initial results of the PTCA program at the Hospital de Especialidades CMR, IMSS. During the last year we studied 33 patients in whom we performed 35 PTCA procedures with total of 45 lesions. The age of the patients varied from 27 to 75 years of age (average 57 year +/- 10.9). Among them, 84.8% were males and 15.2% females. In 54.5% of the patients, stable angina was present, whereas in 45.5% unstable angina was observed. Multivessel disease was detected in 39.4% of the cases. In 17.8% the coronary lesions were type "A", in 77.8% type "B" and in 4.4% type C. The most frequent lesions were present at the left anterior descending artery in 46.6%, right coronary artery in 40% and circumflex in 13.4%. The global procedural success was 88.5% (32/35 procedure) whereas the procedural success by isolated lesion was 88.8% (40/45 lesions). The average artery stenosis was decreased from 85 +/- 10.4% to 23 +/- 16%. A procedural failure occurred in 4 instances (11.4%), among them, 2 (5.71%) without complications and 2 more, associated to acute myocardial infarction. In the present study there were no emergency operation neither deaths. CONCLUSIONS Although the number of PTCA performed in our hospital is limited, we consider that the initial results are good, with a success rate of 88.5% with a minimal complications.
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Affiliation(s)
- H Murillo
- División de Cardiología-Angiología, Hospital de Especialidades, Centro Médico La Raza, IMSS, México, D.F
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Arahuetes RM, Madrid R, Cadenas S, Rojas C, Pérez-Campo R, López-Torres M, Barja G. Effect of early maternal adrenalectomy on antioxidant enzymes, GSH, ascorbate, and uric acid in the rat fetal lung at term. Exp Lung Res 1993; 19:533-43. [PMID: 8253057 DOI: 10.3109/01902149309031726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 01/29/2023]
Abstract
Previous studies have shown that the increase of the enzymatic antioxidant defense that takes place in the fetal rat lung at the end of gestation can be accelerated by the synthetic glucocorticoid dexamethasone and diminished by metyrapone, a blocker of glucocorticoid synthesis. Since it is known that the fetal adrenal does not start to synthesize corticosterone until the last 20% of gestation, pregnant rats were bilaterally adrenalectomized on the first day of gestation in order to clarify the role of the endogenous maternal hormone on the development of the enzymatic and nonenzymatic antioxidant systems of fetal lung. This early adrenalectomy did not change fetal lung catalase, glutathione peroxidase, glutathione reductase, cytochrome oxidase, GSH, ascorbate, and uric acid at term. The presence of the maternal glands is not essential for lung antioxidant development in the fetus and that the stimulus of fetal corticosterone during the last 20% of gestation is enough to achieve a normal maturation of the fetal lung enzymatic and nonenzymatic antioxidant systems.
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Affiliation(s)
- R M Arahuetes
- Department of Animal Biology-II (Animal Physiology), Faculty of Biology, Complutense University, Madrid, Spain
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Abstract
A 24-year-old white man had a knife chest wound, and four months after this event, manifested progressive dyspnea. A false aneurysm of the left ventricle was diagnosed by 2D echocardiogram. Surgical resection of the aneurysmal sac with closure of the orifice of the lateral wall of the left ventricle was performed successfully.
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Affiliation(s)
- E Badui
- Department of Cardiology, Hospital de Especialidades, Centro Medico la Raza, Instituto Mexicano del Seguro Social, Mexico City
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Abstract
Myocardial infarction secondary to nonpenetrating chest trauma is rare. We present the case of a sportsman who developed an acute transmural posteroinferior wall myocardial infarction due to chest trauma by a football. The angiographic study revealed total obstruction of the proximal right coronary artery.
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Abstract
The presence of isolate-specific Trypanosoma cruzi minicircles has been shown in the kinetoplast DNA of this parasite. This led to the rapid identification of isolates and clones of trypanosomes by means of 'dot-spot' hybridizations with molecularly cloned minicircle probes. Unexpectedly, whole kDNAs were also suitable as probes for this purpose, provided that filters were washed under stringent conditions. This was attributed to the presence of the above-mentioned isolate-specific minicircle sequences. The fact that parasites could be directly spotted onto nitrocellulose filters simplified the rapid routine screening of a large number of samples.
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Bradley WG, Madrid R, Davis CJ. The peroneal muscular atrophy syndrome. Clinical genetic, electrophysiological and nerve biopsy studies. Part 3. Clinical, electrophysiological and pathological correlations. J Neurol Sci 1977; 32:123-36. [PMID: 864488 DOI: 10.1016/0022-510x(77)90043-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This report analyses correlations between clinical, electrophysiological and pathological data derived from a series of families with peroneal muscular atrophy. It was found that the observed differences between families in median nerve forearm motor conduction velocity were unlikely to be due to differences in the age or severity of the cases. Similarly it it was unlikely that the pathological differences between cases were due to age or severity of the case. The conduction velocity in the Hypertrophic Neuropathy Group tended to increase slightly with age, while that in other cases tended to fall slightly. The conduction velocity and total myelinated fibre counts were inversely related to the degree of segmental demyelination. The Hypertrophic Neuropathy Group and the Intermediate Group of cases were found to behave differently in a number of correlative analyses, thus supporting the suggestion that they represent different disease entities.
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