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Gentile G, Paciello F, Zorzi V, Spampinato AG, Guarnaccia M, Crispino G, Tettey-Matey A, Scavizzi F, Raspa M, Fetoni AR, Cavallaro S, Mammano F. miRNA and mRNA Profiling Links Connexin Deficiency to Deafness via Early Oxidative Damage in the Mouse Stria Vascularis. Front Cell Dev Biol 2021; 8:616878. [PMID: 33569381 PMCID: PMC7868390 DOI: 10.3389/fcell.2020.616878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022] Open
Abstract
Pathogenic mutations in the non-syndromic hearing loss and deafness 1 (DFNB1) locus are the primary cause of monogenic inheritance for prelingual hearing loss. To unravel molecular pathways involved in etiopathology and look for early degeneration biomarkers, we used a system biology approach to analyze Cx30−/− mice at an early cochlear post-natal developmental stage. These mice are a DFNB1 mouse model with severely reduced expression levels of two connexins in the inner ear, Cx30, and Cx26. Integrated analysis of miRNA and mRNA expression profiles in the cochleae of Cx30−/− mice at post-natal day 5 revealed the overexpression of five miRNAs (miR-34c, miR-29b, miR-29c, miR-141, and miR-181a) linked to apoptosis, oxidative stress, and cochlear degeneration, which have Sirt1 as a common target of transcriptional and/or post-transcriptional regulation. In young adult Cx30−/− mice (3 months of age), these alterations culminated with blood barrier disruption in the Stria vascularis (SV), which is known to have the highest aerobic metabolic rate of all cochlear structures and whose microvascular alterations contribute to age-related degeneration and progressive decline of auditory function. Our experimental validation of selected targets links hearing acquisition failure in Cx30−/− mice, early oxidative stress, and metabolic dysregulation to the activation of the Sirt1–p53 axis. This is the first integrated analysis of miRNA and mRNA in the cochlea of the Cx30−/− mouse model, providing evidence that connexin downregulation determines a miRNA-mediated response which leads to chronic exhaustion of cochlear antioxidant defense mechanisms and consequent SV dysfunction. Our analyses support the notion that connexin dysfunction intervenes early on during development, causing vascular damage later on in life. This study identifies also early miRNA-mediated biomarkers of hearing impairment, either inherited or age related.
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Affiliation(s)
- Giulia Gentile
- Department of Biomedical Sciences, National Research Council (CNR) Institute for Biomedical Research and Innovation, Catania, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Veronica Zorzi
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy.,Department of Biomedical Sciences, National Research Council (CNR) Institute of Biochemistry and Cell Biology, Rome, Italy
| | - Antonio Gianmaria Spampinato
- Department of Biomedical Sciences, National Research Council (CNR) Institute for Biomedical Research and Innovation, Catania, Italy.,Department of Mathematics and Computer Science, University of Catania, Catania, Italy
| | - Maria Guarnaccia
- Department of Biomedical Sciences, National Research Council (CNR) Institute for Biomedical Research and Innovation, Catania, Italy
| | - Giulia Crispino
- Department of Biomedical Sciences, National Research Council (CNR) Institute of Biochemistry and Cell Biology, Rome, Italy
| | - Abraham Tettey-Matey
- Department of Biomedical Sciences, National Research Council (CNR) Institute of Biochemistry and Cell Biology, Rome, Italy
| | - Ferdinando Scavizzi
- Department of Biomedical Sciences, National Research Council (CNR) Institute of Biochemistry and Cell Biology, Rome, Italy
| | - Marcello Raspa
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Anna Rita Fetoni
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy.,Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Sebastiano Cavallaro
- Department of Biomedical Sciences, National Research Council (CNR) Institute for Biomedical Research and Innovation, Catania, Italy
| | - Fabio Mammano
- Department of Biomedical Sciences, National Research Council (CNR) Institute of Biochemistry and Cell Biology, Rome, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padua, Padua, Italy
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2
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Fetoni AR, Zorzi V, Paciello F, Ziraldo G, Peres C, Raspa M, Scavizzi F, Salvatore AM, Crispino G, Tognola G, Gentile G, Spampinato AG, Cuccaro D, Guarnaccia M, Morello G, Van Camp G, Fransen E, Brumat M, Girotto G, Paludetti G, Gasparini P, Cavallaro S, Mammano F. Cx26 partial loss causes accelerated presbycusis by redox imbalance and dysregulation of Nfr2 pathway. Redox Biol 2018; 19:301-317. [PMID: 30199819 PMCID: PMC6129666 DOI: 10.1016/j.redox.2018.08.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/26/2018] [Accepted: 08/05/2018] [Indexed: 11/29/2022] Open
Abstract
Mutations in GJB2, the gene that encodes connexin 26 (Cx26), are the most common cause of sensorineural hearing impairment. The truncating variant 35delG, which determines a complete loss of Cx26 protein function, is the prevalent GJB2 mutation in several populations. Here, we generated and analyzed Gjb2+/- mice as a model of heterozygous human carriers of 35delG. Compared to control mice, auditory brainstem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) worsened over time more rapidly in Gjb2+/- mice, indicating they were affected by accelerated age-related hearing loss (ARHL), or presbycusis. We linked causally the auditory phenotype of Gjb2+/- mice to apoptosis and oxidative damage in the cochlear duct, reduced release of glutathione from connexin hemichannels, decreased nutrient delivery to the sensory epithelium via cochlear gap junctions and deregulated expression of genes that are under transcriptional control of the nuclear factor erythroid 2-related factor 2 (Nrf2), a pivotal regulator of tolerance to redox stress. Moreover, a statistically significant genome-wide association with two genes (PRKCE and TGFB1) related to the Nrf2 pathway (p-value < 4 × 10-2) was detected in a very large cohort of 4091 individuals, originating from Europe, Caucasus and Central Asia, with hearing phenotype (including 1076 presbycusis patients and 1290 healthy matched controls). We conclude that (i) elements of the Nrf2 pathway are essential for hearing maintenance and (ii) their dysfunction may play an important role in the etiopathogenesis of human presbycusis.
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Affiliation(s)
- Anna Rita Fetoni
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy; Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy; Institute of Otolaryngology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168 Rome, Italy
| | - Veronica Zorzi
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy; Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Fabiola Paciello
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy; Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Gaia Ziraldo
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy; Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy
| | - Chiara Peres
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy
| | - Marcello Raspa
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy
| | | | | | - Giulia Crispino
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy
| | - Gabriella Tognola
- CNR Institute of Electronics, Computer and Telecommunication Engineering, 20133 Milano, Italy
| | - Giulia Gentile
- CNR Institute of Neurological Sciences, 95126 Catania, Italy
| | | | - Denis Cuccaro
- CNR Institute of Neurological Sciences, 95126 Catania, Italy
| | | | | | - Guy Van Camp
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - Erik Fransen
- Department of Biomedical Sciences, University of Antwerp, 2650 Antwerp, Belgium
| | - Marco Brumat
- Dept Med Surg & Hlth Sci, University of Trieste, Trieste, Italy; IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Trieste, Italy
| | - Giorgia Girotto
- Dept Med Surg & Hlth Sci, University of Trieste, Trieste, Italy; IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Trieste, Italy
| | - Gaetano Paludetti
- Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168 Rome, Italy; Institute of Otolaryngology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo F. Vito 1, 00168 Rome, Italy
| | - Paolo Gasparini
- Dept Med Surg & Hlth Sci, University of Trieste, Trieste, Italy; IRCCS Burlo Garofolo, Inst Maternal & Child Hlth, Trieste, Italy.
| | | | - Fabio Mammano
- CNR Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy; University of Padova, Department of Physics and Astronomy "G. Galilei", Padova, Italy.
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3
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Zonta F, Buratto D, Crispino G, Carrer A, Bruno F, Yang G, Mammano F, Pantano S. Cues to Opening Mechanisms From in Silico Electric Field Excitation of Cx26 Hemichannel and in Vitro Mutagenesis Studies in HeLa Transfectans. Front Mol Neurosci 2018; 11:170. [PMID: 29904340 PMCID: PMC5990870 DOI: 10.3389/fnmol.2018.00170] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/04/2018] [Indexed: 01/06/2023] Open
Abstract
Connexin channels play numerous essential roles in virtually every organ by mediating solute exchange between adjacent cells, or between cytoplasm and extracellular milieu. Our understanding of the structure-function relationship of connexin channels relies on X-ray crystallographic data for human connexin 26 (hCx26) intercellular gap junction channels. Comparison of experimental data and molecular dynamics simulations suggests that the published structures represent neither fully-open nor closed configurations. To facilitate the search for alternative stable configurations, we developed a coarse grained (CG) molecular model of the hCx26 hemichannel and studied its responses to external electric fields. When challenged by a field of 0.06 V/nm, the hemichannel relaxed toward a novel configuration characterized by a widened pore and an increased bending of the second transmembrane helix (TM2) at the level of the conserved Pro87. A point mutation that inhibited such transition in our simulations impeded hemichannel opening in electrophysiology and dye uptake experiments conducted on HeLa tranfectants. These results suggest that the hCx26 hemichannel uses a global degree of freedom to transit between different configuration states, which may be shared among the whole connexin family.
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Affiliation(s)
- Francesco Zonta
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.,CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Damiano Buratto
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.,CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padua, Padua, Italy
| | - Giulia Crispino
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padua, Padua, Italy.,Venetian Institute of Molecular Medicine, Padua, Italy
| | - Andrea Carrer
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padua, Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Fabio Mammano
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.,CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padua, Padua, Italy.,Venetian Institute of Molecular Medicine, Padua, Italy
| | - Sergio Pantano
- Group of Biomolecular Simulations, Institut Pasteur de Montevideo, Montevideo, Uruguay
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4
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Carrer A, Leparulo A, Crispino G, Ciubotaru CD, Marin O, Zonta F, Bortolozzi M. Cx32 hemichannel opening by cytosolic Ca2+ is inhibited by the R220X mutation that causes Charcot-Marie-Tooth disease. Hum Mol Genet 2018; 27:80-94. [PMID: 29077882 DOI: 10.1093/hmg/ddx386] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/17/2017] [Indexed: 11/15/2022] Open
Abstract
Mutations of the GJB1 gene encoding connexin 32 (Cx32) cause the X-linked form of Charcot-Marie-Tooth disease (CMTX1), a demyelinating peripheral neuropathy for which there is no cure. A growing body of evidence indicates that ATP release through Cx32 hemichannels in Schwann cells could be critical for nerve myelination, but it is unknown if CMTX1 mutations alter the cytosolic Ca2+-dependent gating mechanism that controls Cx32 hemichannel opening and ATP release. The current study uncovered that loss of the C-terminus in Cx32 (R220X mutation), which causes a severe CMTX1 phenotype, inhibits hemichannel opening during a canonical IP3-mediated increase in cytosolic Ca2+ in HeLa cells. Interestingly, the gating function of R220X hemichannels was completely restored by both the intracellular and extracellular application of a peptide that mimics the Cx32 cytoplasmic loop. All-atom molecular dynamics simulations suggest that loss of the C-terminus in the mutant hemichannel triggers abnormal fluctuations of the cytoplasmic loop which are prevented by binding to the mimetic peptide. Experiments that stimulated R220X hemichannel opening by cell depolarization displayed reduced voltage sensitivity with respect to wild-type hemichannels which was explained by loss of subconductance states at the single channel level. Finally, experiments of intercellular diffusion mediated by wild-type or R220X gap junction channels revealed similar unitary permeabilities to ions, signalling molecules (cAMP) or larger solutes (Lucifer yellow). Taken together, our findings support the hypothesis that paracrine signalling alteration due to Cx32 hemichannel dysfunction underlies CMTX1 pathogenesis and suggest a candidate molecule for novel studies investigating a therapeutic approach.
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Affiliation(s)
- Andrea Carrer
- Venetian Institute of Molecular Medicine (VIMM), Padua 35129, Italy
- Department of Physics and Astronomy "G. Galilei", University of Padua, Padua 35131, Italy
| | - Alessandro Leparulo
- Venetian Institute of Molecular Medicine (VIMM), Padua 35129, Italy
- Department of Physics and Astronomy "G. Galilei", University of Padua, Padua 35131, Italy
| | - Giulia Crispino
- Venetian Institute of Molecular Medicine (VIMM), Padua 35129, Italy
- Department of Physics and Astronomy "G. Galilei", University of Padua, Padua 35131, Italy
| | | | - Oriano Marin
- Department of Biomedical Sciences, University of Padua, Padua 35131, Italy
| | - Francesco Zonta
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
- Italian National Research Council (CNR), Institute of Cell Biology and Neurobiology, Monterotondo 00015, Italy
| | - Mario Bortolozzi
- Venetian Institute of Molecular Medicine (VIMM), Padua 35129, Italy
- Department of Physics and Astronomy "G. Galilei", University of Padua, Padua 35131, Italy
- Italian National Research Council (CNR), Institute of Protein Biochemistry, Naples 80131, Italy
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5
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Zorzi V, Paciello F, Ziraldo G, Peres C, Mazzarda F, Nardin C, Pasquini M, Chiani F, Raspa M, Scavizzi F, Carrer A, Crispino G, Ciubotaru CD, Monyer H, Fetoni AR, M Salvatore A, Mammano F. Mouse Panx1 Is Dispensable for Hearing Acquisition and Auditory Function. Front Mol Neurosci 2017; 10:379. [PMID: 29234270 PMCID: PMC5712377 DOI: 10.3389/fnmol.2017.00379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 10/30/2017] [Indexed: 11/13/2022] Open
Abstract
Panx1 forms plasma membrane channels in brain and several other organs, including the inner ear. Biophysical properties, activation mechanisms and modulators of Panx1 channels have been characterized in detail, however the impact of Panx1 on auditory function is unclear due to conflicts in published results. To address this issue, hearing performance and cochlear function of the Panx1−/− mouse strain, the first with a reported global ablation of Panx1, were scrutinized. Male and female homozygous (Panx1−/−), hemizygous (Panx1+/−) and their wild type (WT) siblings (Panx1+/+) were used for this study. Successful ablation of Panx1 was confirmed by RT-PCR and Western immunoblotting in the cochlea and brain of Panx1−/− mice. Furthermore, a previously validated Panx1-selective antibody revealed strong immunoreactivity in WT but not in Panx1−/− cochleae. Hearing sensitivity, outer hair cell-based “cochlear amplifier” and cochlear nerve function, analyzed by auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) recordings, were normal in Panx1+/− and Panx1−/− mice. In addition, we determined that global deletion of Panx1 impacts neither on connexin expression, nor on gap-junction coupling in the developing organ of Corti. Finally, spontaneous intercellular Ca2+ signal (ICS) activity in organotypic cochlear cultures, which is key to postnatal development of the organ of Corti and essential for hearing acquisition, was not affected by Panx1 ablation. Therefore, our results provide strong evidence that, in mice, Panx1 is dispensable for hearing acquisition and auditory function.
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Affiliation(s)
- Veronica Zorzi
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,School of Medicine, Institute of Otolaryngology, Catholic University, Rome, Italy
| | - Fabiola Paciello
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Gaia Ziraldo
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,School of Medicine, Institute of Otolaryngology, Catholic University, Rome, Italy
| | - Chiara Peres
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Flavia Mazzarda
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Science, Roma Tre University, Rome, Italy
| | - Chiara Nardin
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Science, Roma Tre University, Rome, Italy
| | - Miriam Pasquini
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, Rome, Italy
| | - Francesco Chiani
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Marcello Raspa
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | | | - Andrea Carrer
- Department of Physics and Astronomy G. Galilei, University of Padua, Padua, Italy
| | - Giulia Crispino
- Department of Physics and Astronomy G. Galilei, University of Padua, Padua, Italy
| | | | - Hannah Monyer
- Department of Clinical Neurobiology, Deutches Krebforschungzentrum, University of Heidelberg, Heidelberg, Germany
| | - Anna R Fetoni
- School of Medicine, Institute of Otolaryngology, Catholic University, Rome, Italy
| | - Anna M Salvatore
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Fabio Mammano
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy G. Galilei, University of Padua, Padua, Italy.,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
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6
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Xu L, Carrer A, Zonta F, Qu Z, Ma P, Li S, Ceriani F, Buratto D, Crispino G, Zorzi V, Ziraldo G, Bruno F, Nardin C, Peres C, Mazzarda F, Salvatore AM, Raspa M, Scavizzi F, Chu Y, Xie S, Yang X, Liao J, Liu X, Wang W, Wang S, Yang G, Lerner RA, Mammano F. Design and Characterization of a Human Monoclonal Antibody that Modulates Mutant Connexin 26 Hemichannels Implicated in Deafness and Skin Disorders. Front Mol Neurosci 2017; 10:298. [PMID: 29018324 PMCID: PMC5615210 DOI: 10.3389/fnmol.2017.00298] [Citation(s) in RCA: 26] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/05/2017] [Indexed: 12/21/2022] Open
Abstract
Background: Mutations leading to changes in properties, regulation, or expression of connexin-made channels have been implicated in 28 distinct human hereditary diseases. Eight of these result from variants of connexin 26 (Cx26), a protein critically involved in cell-cell signaling in the inner ear and skin. Lack of non-toxic drugs with defined mechanisms of action poses a serious obstacle to therapeutic interventions for diseases caused by mutant connexins. In particular, molecules that specifically modulate connexin hemichannel function without affecting gap junction channels are considered of primary importance for the study of connexin hemichannel role in physiological as well as pathological conditions. Monoclonal antibodies developed in the last three decades have become the most important class of therapeutic biologicals. Recombinant methods permit rapid selection and improvement of monoclonal antibodies from libraries with large diversity. Methods: By screening a combinatorial library of human single-chain fragment variable (scFv) antibodies expressed in phage, we identified a candidate that binds an extracellular epitope of Cx26. We characterized antibody action using a variety of biochemical and biophysical assays in HeLa cells, organotypic cultures of mouse cochlea and human keratinocyte-derived cells. Results: We determined that the antibody is a remarkably efficient, non-toxic, and completely reversible inhibitor of hemichannels formed by connexin 26 and does not affect direct cell-cell communication via gap junction channels. Importantly, we also demonstrate that the antibody efficiently inhibits hyperative mutant Cx26 hemichannels implicated in autosomal dominant non-syndromic hearing impairment accompanied by keratitis and hystrix-like ichthyosis-deafness (KID/HID) syndrome. We solved the crystal structure of the antibody, identified residues that are critical for binding and used molecular dynamics to uncover its mechanism of action. Conclusions: Although further studies will be necessary to validate the effect of the antibody in vivo, the methodology described here can be extended to select antibodies against hemichannels composed by other connexin isoforms and, consequently, to target other pathologies associated with hyperactive hemichannels. Our study highlights the potential of this approach and identifies connexins as therapeutic targets addressable by screening phage display libraries expressing human randomized antibodies.
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Affiliation(s)
- Liang Xu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China.,Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of SciencesShanghai, China
| | - Andrea Carrer
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy
| | - Francesco Zonta
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China.,CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy
| | - Zhihu Qu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Peixiang Ma
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Sheng Li
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Federico Ceriani
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy
| | - Damiano Buratto
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy
| | - Giulia Crispino
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy.,Venetian Institute of Molecular MedicinePadova, Italy
| | - Veronica Zorzi
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Institute of Otolaryngology, Catholic University School of MedicineRome, Italy
| | - Gaia Ziraldo
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy.,Institute of Otolaryngology, Catholic University School of MedicineRome, Italy
| | - Francesca Bruno
- Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy.,Venetian Institute of Molecular MedicinePadova, Italy
| | - Chiara Nardin
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Science, Roma Tre UniversityRome, Italy
| | - Chiara Peres
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy
| | - Flavia Mazzarda
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Science, Roma Tre UniversityRome, Italy
| | - Anna M Salvatore
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy
| | - Marcello Raspa
- CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy
| | | | - Youjun Chu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Sichun Xie
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Xuemei Yang
- School of Life Science and Technology, Shanghai Tech UniversityShanghai, China
| | - Jun Liao
- School of Life Science and Technology, Shanghai Tech UniversityShanghai, China
| | - Xiao Liu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China.,Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of SciencesShanghai, China.,University of Chinese Academy of SciencesBeijing, China
| | - Wei Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Shanshan Wang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China
| | - Richard A Lerner
- Department of Cell and Molecular Biology, The Scripps Research InstituteLa Jolla, CA, United States
| | - Fabio Mammano
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech UniversityShanghai, China.,CNR Institute of Cell Biology and NeurobiologyMonterotondo, Italy.,Department of Physics and Astronomy "G. Galilei,", University of PadovaPadova, Italy.,Venetian Institute of Molecular MedicinePadova, Italy
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7
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Sulaiman I, Mokoka MC, MacHale E, Seheult J, Hughes C, Holmes M, D’arcy S, Taylor T, Rapcan V, Murphy D, Hunt E, Lane SJ, Sahadevan A, Crispino G, Diette GB, Sartini-Bhreathnach A, Cushen B, Killane I, Reilly RB, Costello RW. P208 Behavioural feed-back education intervention to enhance adherence in patients with severe uncontrolled asthma, a randomised clinical trial. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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8
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Zonta F, Girotto G, Buratto D, Crispino G, Morgan A, Abdulhadi K, Alkowari M, Badii R, Gasparini P, Mammano F. The p.Cys169Tyr variant of connexin 26 is not a polymorphism. Hum Mol Genet 2015; 24:2641-8. [PMID: 25628337 PMCID: PMC4383868 DOI: 10.1093/hmg/ddv026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/21/2015] [Indexed: 12/31/2022] Open
Abstract
Mutations in the GJB2 gene, which encodes the gap junction protein connexin 26 (Cx26), are the primary cause of hereditary prelingual hearing impairment. Here, the p.Cys169Tyr missense mutation of Cx26 (Cx26C169Y), previously classified as a polymorphism, has been identified as causative of severe hearing loss in two Qatari families. We have analyzed the effect of this mutation using a combination of confocal immunofluorescence microscopy and molecular dynamics simulations. At the cellular level, our results show that the mutant protein fails to form junctional channels in HeLa transfectants despite being correctly targeted to the plasma membrane. At the molecular level, this effect can be accounted for by disruption of the disulfide bridge that Cys169 forms with Cys64 in the wild-type structure (Cx26WT). The lack of the disulfide bridge in the Cx26C169Y protein causes a spatial rearrangement of two important residues, Asn176 and Thr177. In the Cx26WT protein, these residues play a crucial role in the intra-molecular interactions that permit the formation of an intercellular channel by the head-to-head docking of two opposing hemichannels resident in the plasma membrane of adjacent cells. Our results elucidate the molecular pathogenesis of hereditary hearing loss due to the connexin mutation and facilitate the understanding of its role in both healthy and affected individuals.
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Affiliation(s)
- Francesco Zonta
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy
| | - Giorgia Girotto
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy
| | - Damiano Buratto
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy
| | - Giulia Crispino
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy, Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
| | - Anna Morgan
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy
| | - Khalid Abdulhadi
- Audiology and Balance Unit, National Program for Early Detection of Hearing Loss, WH, Hamad Medical Corporation (HMC) Doha, Doha, Qatar
| | - Moza Alkowari
- Molecular Genetics Laboratory, Department of Laboratory of Medicine and Pathology, Hamad Medical Corporation (HMC), Doha, Qatar
| | - Ramin Badii
- Molecular Genetics Laboratory, Department of Laboratory of Medicine and Pathology, Hamad Medical Corporation (HMC), Doha, Qatar
| | - Paolo Gasparini
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy, Medical Genetics, Institute for Maternal and Child Health-IRCCS 'Burlo Garofolo', Trieste, Italy and
| | - Fabio Mammano
- Dipartimento di Fisica e Astronomia 'G. Galilei', Università di Padova, 35131 Padova, Italy, Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy, CNR Institute of Cell Biology and Neurobiology, 00015 Monterotondo, Rome, Italy
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9
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Crispino G, Di Pasquale G, Scimemi P, Rodriguez L, Galindo Ramirez F, De Siati RD, Santarelli RM, Arslan E, Bortolozzi M, Chiorini JA, Mammano F. BAAV mediated GJB2 gene transfer restores gap junction coupling in cochlear organotypic cultures from deaf Cx26Sox10Cre mice. PLoS One 2011; 6:e23279. [PMID: 21876744 PMCID: PMC3158073 DOI: 10.1371/journal.pone.0023279] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 07/11/2011] [Indexed: 11/24/2022] Open
Abstract
The deafness locus DFNB1 contains GJB2, the gene encoding connexin26 and GJB6, encoding connexin30, which appear to be coordinately regulated in the inner ear. In this work, we investigated the expression and function of connexin26 and connexin30 from postnatal day 5 to adult age in double transgenic Cx26(Sox10Cre) mice, which we obtained by crossing connexin26 floxed mice with a deleter Sox10-Cre line. Cx26(Sox10Cre) mice presented with complete connexin26 ablation in the epithelial gap junction network of the cochlea, whereas connexin30 expression was developmentally delayed; immunolabeling patterns for both connexins were normal in the cochlear lateral wall. In vivo electrophysiological measurements in Cx26(Sox10Cre) mice revealed profound hearing loss accompanied by reduction of endocochlear potential, and functional experiments performed in postnatal cochlear organotypic cultures showed impaired gap junction coupling. Transduction of these cultures with a bovine adeno associated virus vector restored connexin26 protein expression and rescued gap junction coupling. These results suggest that restoration of normal connexin levels by gene delivery via recombinant adeno associated virus could be a way to rescue hearing function in DFNB1 mouse models and, in future, lead to the development of therapeutic interventions in humans.
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Affiliation(s)
- Giulia Crispino
- Fondazione per la Ricerca Biomedica Avanzata, Istituto Veneto di Medicina Molecolare, Padova, Italy
- Dipartimento di Fisica “G. Galilei”, Università di Padova, Padova, Italy
| | - Giovanni Di Pasquale
- Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Pietro Scimemi
- Dipartimento di Specialità Medico–Chirurgiche e Servizio di Audiologia, Università di Padova, Padova, Italy
| | - Laura Rodriguez
- Fondazione per la Ricerca Biomedica Avanzata, Istituto Veneto di Medicina Molecolare, Padova, Italy
- Dipartimento di Fisica “G. Galilei”, Università di Padova, Padova, Italy
| | - Fabian Galindo Ramirez
- Fondazione per la Ricerca Biomedica Avanzata, Istituto Veneto di Medicina Molecolare, Padova, Italy
| | - Romolo Daniele De Siati
- Dipartimento di Specialità Medico–Chirurgiche e Servizio di Audiologia, Università di Padova, Padova, Italy
| | - Rosa Maria Santarelli
- Dipartimento di Specialità Medico–Chirurgiche e Servizio di Audiologia, Università di Padova, Padova, Italy
| | - Edoardo Arslan
- Dipartimento di Specialità Medico–Chirurgiche e Servizio di Audiologia, Università di Padova, Padova, Italy
| | - Mario Bortolozzi
- Fondazione per la Ricerca Biomedica Avanzata, Istituto Veneto di Medicina Molecolare, Padova, Italy
- Dipartimento di Fisica “G. Galilei”, Università di Padova, Padova, Italy
- Istituto CNR di Neuroscienze, Padova, Italy
| | - John A. Chiorini
- Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Fabio Mammano
- Fondazione per la Ricerca Biomedica Avanzata, Istituto Veneto di Medicina Molecolare, Padova, Italy
- Dipartimento di Fisica “G. Galilei”, Università di Padova, Padova, Italy
- Istituto CNR di Neuroscienze, Padova, Italy
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10
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Schütz M, Scimemi P, Majumder P, De Siati RD, Crispino G, Rodriguez L, Bortolozzi M, Santarelli R, Seydel A, Sonntag S, Ingham N, Steel KP, Willecke K, Mammano F. The human deafness-associated connexin 30 T5M mutation causes mild hearing loss and reduces biochemical coupling among cochlear non-sensory cells in knock-in mice. Hum Mol Genet 2010; 19:4759-73. [PMID: 20858605 PMCID: PMC2989887 DOI: 10.1093/hmg/ddq402] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 08/18/2010] [Accepted: 09/14/2010] [Indexed: 12/11/2022] Open
Abstract
Mutations in the GJB2 and GJB6 genes, respectively, coding for connexin26 (Cx26) and connexin30 (Cx30) proteins, are the most common cause for prelingual non-syndromic deafness in humans. In the inner ear, Cx26 and Cx30 are expressed in different non-sensory cell types, where they largely co-localize and may form heteromeric gap junction channels. Here, we describe the generation and characterization of a mouse model for human bilateral middle/high-frequency hearing loss based on the substitution of an evolutionarily conserved threonine by a methionine residue at position 5 near the N-terminus of Cx30 (Cx30T5M). The mutation was inserted in the mouse genome by homologous recombination in mouse embryonic stem cells. Expression of the mutated Cx30T5M protein in these transgenic mice is under the control of the endogenous Cx30 promoter and was analysed via activation of the lacZ reporter gene. When probed by auditory brainstem recordings, Cx30(T5M/T5M) mice exhibited a mild, but significant increase in their hearing thresholds of about 15 dB at all frequencies. Immunolabelling with antibodies to Cx26 or Cx30 suggested normal location of these proteins in the adult inner ear, but western blot analysis showed significantly down-regulated the expression levels of Cx26 and Cx30. In the developing cochlea, electrical coupling, probed by dual patch-clamp recordings, was normal. However, transfer of the fluorescent tracer calcein between cochlear non-sensory cells was reduced, as was intercellular Ca(2+) signalling due to spontaneous ATP release from connexin hemichannels. Our findings link hearing loss to decreased biochemical coupling due to the point-mutated Cx30 in mice.
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Affiliation(s)
- Melanie Schütz
- Institut fuer Genetik, Rheinische Friedrich-Wilhelms-Universitaet Bonn, Roemerstrasse 164, D-53117 Bonn, Germany
| | - Pietro Scimemi
- Dipartimento di Specialità Medico Chirurgiche, Università di Padova, via Giustiniani 2, 35129 Padova, Italy
- Servizio di Audiologia, Ospedale ‘Ca’ Foncello’, Treviso, Italy
| | - Paromita Majumder
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
| | - Romolo Daniele De Siati
- Dipartimento di Specialità Medico Chirurgiche, Università di Padova, via Giustiniani 2, 35129 Padova, Italy
- Servizio di Audiologia, Ospedale ‘Ca’ Foncello’, Treviso, Italy
| | - Giulia Crispino
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
| | - Laura Rodriguez
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
| | - Mario Bortolozzi
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
- Dipartimento di Fisica ‘G. Galilei’, Università di Padova, 35131 Padova, Italy
- Istituto CNR di Neuroscienze, Padova, Italy and
| | - Rosamaria Santarelli
- Dipartimento di Specialità Medico Chirurgiche, Università di Padova, via Giustiniani 2, 35129 Padova, Italy
- Servizio di Audiologia, Ospedale ‘Ca’ Foncello’, Treviso, Italy
| | - Anke Seydel
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
| | - Stephan Sonntag
- Institut fuer Genetik, Rheinische Friedrich-Wilhelms-Universitaet Bonn, Roemerstrasse 164, D-53117 Bonn, Germany
| | - Neil Ingham
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Karen P. Steel
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Klaus Willecke
- Institut fuer Genetik, Rheinische Friedrich-Wilhelms-Universitaet Bonn, Roemerstrasse 164, D-53117 Bonn, Germany
| | - Fabio Mammano
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, 35129 Padova, Italy
- Dipartimento di Fisica ‘G. Galilei’, Università di Padova, 35131 Padova, Italy
- Istituto CNR di Neuroscienze, Padova, Italy and
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11
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Bortolozzi M, Brini M, Parkinson N, Crispino G, Scimemi P, De Siati RD, Di Leva F, Parker A, Ortolano S, Arslan E, Brown SD, Carafoli E, Mammano F. The novel PMCA2 pump mutation Tommy impairs cytosolic calcium clearance in hair cells and links to deafness in mice. J Biol Chem 2010; 285:37693-703. [PMID: 20826782 PMCID: PMC2988374 DOI: 10.1074/jbc.m110.170092] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The mechanotransduction process in hair cells in the inner ear is associated with the influx of calcium from the endolymph. Calcium is exported back to the endolymph via the splice variant w/a of the PMCA2 of the stereocilia membrane. To further investigate the role of the pump, we have identified and characterized a novel ENU-induced mouse mutation, Tommy, in the PMCA2 gene. The mutation causes a non-conservative E629K change in the second intracellular loop of the pump that harbors the active site. Tommy mice show profound hearing impairment from P18, with significant differences in hearing thresholds between wild type and heterozygotes. Expression of mutant PMCA2 in CHO cells shows calcium extrusion impairment; specifically, the long term, non-stimulated calcium extrusion activity of the pump is inhibited. Calcium extrusion was investigated directly in neonatal organotypic cultures of the utricle sensory epithelium in Tommy mice. Confocal imaging combined with flash photolysis of caged calcium showed impairment of calcium export in both Tommy heterozygotes and homozygotes. Immunofluorescence studies of the organ of Corti in homozygous Tommy mice showed a progressive base to apex degeneration of hair cells after P40. Our results on the Tommy mutation along with previously observed interactions between cadherin-23 and PMCA2 mutations in mouse and humans underline the importance of maintaining the appropriate calcium concentrations in the endolymph to control the rigidity of cadherin and ensure the function of interstereocilia links, including tip links, of the stereocilia bundle.
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Affiliation(s)
- Mario Bortolozzi
- Department of Physics G Galilei, University of Padua, Padua 35131, Italy
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12
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Majumder P, Crispino G, Rodriguez L, Ciubotaru CD, Anselmi F, Piazza V, Bortolozzi M, Mammano F. ATP-mediated cell-cell signaling in the organ of Corti: the role of connexin channels. Purinergic Signal 2010; 6:167-87. [PMID: 20806010 PMCID: PMC2912995 DOI: 10.1007/s11302-010-9192-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 05/31/2010] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Connexin 26 (Cx26) and connexin 30 (Cx30) form hemichannels that release ATP from the endolymphatic surface of cochlear supporting and epithelial cells and also form gap junction (GJ) channels that allow the concomitant intercellular diffusion of Ca(2+) mobilizing second messengers. Released ATP in turn activates G-protein coupled P2Y(2) and P2Y(4) receptors, PLC-dependent generation of IP(3), release of Ca(2+) from intracellular stores, instigating the regenerative propagation of intercellular Ca(2+) signals (ICS). The range of ICS propagation is sensitive to the concentration of extracellular divalent cations and activity of ectonucleotidases. Here, the expression patterns of Cx26 and Cx30 were characterized in postnatal cochlear tissues obtained from mice aged between P5 and P6. The expression gradient along the longitudinal axis of the cochlea, decreasing from the basal to the apical cochlear turn (CT), was more pronounced in outer sulcus (OS) cells than in inner sulcus (IS) cells. GJ-mediated dye coupling was maximal in OS cells of the basal CT, inhibited by the nonselective connexin channel blocker carbenoxolone (CBX) and absent in hair cells. Photostimulating OS cells with caged inositol (3,4,5) tri-phosphate (IP(3)) resulted in transfer of ICS in the lateral direction, from OS cells to IS cells across the hair cell region (HCR) of medial and basal CTs. ICS transfer in the opposite (medial) direction, from IS cells photostimulated with caged IP(3) to OS cells, occurred mostly in the basal CT. In addition, OS cells displayed impressive rhythmic activity with oscillations of cytosolic free Ca(2+) concentration ([Ca(2+)](i)) coordinated by the propagation of Ca(2+) wavefronts sweeping repeatedly through the same tissue area along the coiling axis of the cochlea. Oscillations evoked by uncaging IP(3) or by applying ATP differed greatly, by as much as one order of magnitude, in frequency and waveform rise time. ICS evoked by direct application of ATP propagated along convoluted cellular paths in the OS, which often branched and changed dynamically over time. Potential implications of these findings are discussed in the context of developmental regulation and cochlear pathophysiology. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (doi:10.1007/s11302-010-9192-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paromita Majumder
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
| | - Giulia Crispino
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
| | - Laura Rodriguez
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
| | - Catalin Dacian Ciubotaru
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
| | - Fabio Anselmi
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
| | - Valeria Piazza
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
| | - Mario Bortolozzi
- Dipartimento di Fisica “G. Galilei”, Università di Padova, via Marzolo 8, 35129 Padova, Italy
- Istituto di Neuroscienze, CNR, Padova, Italy
| | - Fabio Mammano
- Istituto Veneto di Medicina Molecolare, Fondazione per la Ricerca Biomedica Avanzata, via G. Orus 2, 35129 Padova, Italy
- Dipartimento di Fisica “G. Galilei”, Università di Padova, via Marzolo 8, 35129 Padova, Italy
- Istituto di Neuroscienze, CNR, Padova, Italy
- Centro Interdipartimentale per lo Studio dei Segnali Cellulari, Università di Padova, via G. Orus 2, 35129 Padova, Italy
- VIMM, Via G. Orus 2, 35129 Padova, Italy
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13
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Marconato L, Crispino G, Finotello R, Mazzotti S, Salerni F, Zini E. Serum lactate dehydrogenase activity in canine malignancies. Vet Comp Oncol 2009; 7:236-43. [DOI: 10.1111/j.1476-5829.2009.00196.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Anselmi F, Hernandez VH, Crispino G, Seydel A, Ortolano S, Roper SD, Kessaris N, Richardson W, Rickheit G, Filippov MA, Monyer H, Mammano F. ATP release through connexin hemichannels and gap junction transfer of second messengers propagate Ca2+ signals across the inner ear. Proc Natl Acad Sci U S A 2008; 105:18770-5. [PMID: 19047635 PMCID: PMC2596208 DOI: 10.1073/pnas.0800793105] [Citation(s) in RCA: 262] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Indexed: 11/18/2022] Open
Abstract
Extracellular ATP controls various signaling systems including propagation of intercellular Ca(2+) signals (ICS). Connexin hemichannels, P2x7 receptors (P2x7Rs), pannexin channels, anion channels, vesicles, and transporters are putative conduits for ATP release, but their involvement in ICS remains controversial. We investigated ICS in cochlear organotypic cultures, in which ATP acts as an IP(3)-generating agonist and evokes Ca(2+) responses that have been linked to noise-induced hearing loss and development of hair cell-afferent synapses. Focal delivery of ATP or photostimulation with caged IP(3) elicited Ca(2+) responses that spread radially to several orders of unstimulated cells. Furthermore, we recorded robust Ca(2+) signals from an ATP biosensor apposed to supporting cells outside the photostimulated area in WT cultures. ICS propagated normally in cultures lacking either P2x7R or pannexin-1 (Px1), as well as in WT cultures exposed to blockers of anion channels. By contrast, Ca(2+) responses failed to propagate in cultures with defective expression of connexin 26 (Cx26) or Cx30. A companion paper demonstrates that, if expression of either Cx26 or Cx30 is blocked, expression of the other is markedly down-regulated in the outer sulcus. Lanthanum, a connexin hemichannel blocker that does not affect gap junction (GJ) channels when applied extracellularly, limited the propagation of Ca(2+) responses to cells adjacent to the photostimulated area. Our results demonstrate that these connexins play a dual crucial role in inner ear Ca(2+) signaling: as hemichannels, they promote ATP release, sustaining long-range ICS propagation; as GJ channels, they allow diffusion of Ca(2+)-mobilizing second messengers across coupled cells.
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Affiliation(s)
- Fabio Anselmi
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Victor H. Hernandez
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Giulia Crispino
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Anke Seydel
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
| | - Saida Ortolano
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
- Department of Physics “G. Galilei,” University of Padua, 35129 Padua, Italy
| | - Stephen D. Roper
- Department of Physiology and Biophysics and Program in Neurosciences, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Nicoletta Kessaris
- Wolfson Institute for Biomedical Research and Department of Biology, University College London, London WC1E 6BT, United Kingdom
| | - William Richardson
- Wolfson Institute for Biomedical Research and Department of Biology, University College London, London WC1E 6BT, United Kingdom
| | - Gesa Rickheit
- Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), D-13125 Berlin, Germany; and
| | - Mikhail A. Filippov
- Department of Clinical Neurobiology, University Hospital of Neurology, Heidelberg, Germany
| | - Hannah Monyer
- Department of Clinical Neurobiology, University Hospital of Neurology, Heidelberg, Germany
| | - Fabio Mammano
- Foundation for Advanced Biomedical Research, Venetian Institute of Molecular Medicine, 35129 Padua, Italy
- Department of Physics “G. Galilei,” University of Padua, 35129 Padua, Italy
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15
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Ortolano S, Di Pasquale G, Crispino G, Anselmi F, Mammano F, Chiorini JA. Coordinated control of connexin 26 and connexin 30 at the regulatory and functional level in the inner ear. Proc Natl Acad Sci U S A 2008; 105:18776-81. [PMID: 19047647 PMCID: PMC2596232 DOI: 10.1073/pnas.0800831105] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Indexed: 11/18/2022] Open
Abstract
Connexin 26 (Cx26) and connexin 30 (Cx30) are encoded by two genes (GJB2 and GJB6, respectively) that are found within 50 kb in the same complex deafness locus, DFNB1. Immunocytochemistry and quantitative PCR analysis of Cx30 KO mouse cultures revealed that Cx26 is downregulated at the protein level and at the mRNA level in nonsensory cells located between outer hair cells and the stria vascularis. To explore connexin coregulation, we manipulated gene expression using the bovine adeno-associated virus. Overexpression of Cx30 in the Cx30 KO mouse by transduction with bovine adeno-associated virus restored Cx26 expression, permitted the formation of functional gap junction channels, and rescued propagating Ca(2+) signals. Ablation of Cx26 by transduction of Cx26(loxP/loxP) cultures with a Cre recombinase vector caused concurrent downregulation of Cx30 and impaired intercellular communication. The coordinated regulation of Cx26 and Cx30 expression appears to occur as a result of signaling through PLC and the NF-kappaB pathway, because activation of IP(3)-mediated Ca(2+) responses by stimulation of P2Y receptors for 20 min with 20 nM ATP increased the levels of Cx26 transcripts in Cx30 KO cultures. This effect was inhibited by expressing a stable form of the IkappaB repressor protein that prevents activation/translocation of NF-kappaB. Thus, our data reveal a Ca(2+)-dependent control in the expression of inner ear connexins implicated in hereditary deafness as well as insight into the hitherto unexplained observation that some deafness-associated DFNB1 alleles are characterized by hereditable reduction of both GJB2 and GJB6 expression.
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Affiliation(s)
- Saida Ortolano
- Venetian Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padua, Italy
- Department of Physics “G.Galilei,” University of Padua, 35129 Padua, Italy; and
| | - Giovanni Di Pasquale
- Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
| | - Giulia Crispino
- Venetian Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padua, Italy
| | - Fabio Anselmi
- Venetian Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padua, Italy
| | - Fabio Mammano
- Venetian Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35129 Padua, Italy
- Department of Physics “G.Galilei,” University of Padua, 35129 Padua, Italy; and
| | - John A. Chiorini
- Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
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Perretti A, Crispino G, Marcantonio L, Lenta S, Caropreso M, Manganelli F, Scianguetta S, Iorio R, Iolascon A, Vajro P. Clinical utility of electrophysiological evaluation in Crigler-Najjar syndrome. Neuropediatrics 2007; 38:173-8. [PMID: 18058623 DOI: 10.1055/s-2007-991147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
We evaluated the neurological and neurophysiological features in ten patients with genetically characterized Crigler-Najjar (CN) syndrome: four with typical type I CN had undergone orthotopic liver transplantation (OLT); six had type II CN, and three of them developed severe hyperbilirubinemia with a limited response to phenobarbital leading to an intermediate phenotype I/II. Clinical neurological and multimodal electrophysiological evaluations [electroencephalogram (EEG), visual (VEPs), motor (MEPs) and brainstem auditory (BAEPs) evoked potentials] were performed. Neurological examinations showed mild hand tremor in four patients (one pre-OLT and one post-OLT type I, two type I/II). EEG revealed high voltage paroxysmal discharges in four patients (three type I/II, and one type I with a marked improvement after OLT). VEPs showed P100 wave increased latency in five patients (three type I, and two type I/II considered for OLT evaluation). MEPs showed prolonged central motor conduction time in five patients (two type I; one type I/II; two type II). Only EEG and VEPs findings showed a correlation with high bilirubin levels. BAEPs were normal. In conclusion, VEPs and EEG contribute to identify and monitor bilirubin neurotoxic effects, and may play a decisional role in some cases of severe hyperbilirubinemia without overt neurologic damage.
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Affiliation(s)
- A Perretti
- Department of Neurological Sciences, University of Naples Federico II, Naples, Italy
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17
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Vajro P, Migliaro F, Ruggeri C, Di Cosmo N, Crispino G, Caropreso M, Vecchione R. Life saving cyclophosphamide treatment in a girl with giant cell hepatitis and autoimmune haemolytic anaemia: case report and up-to-date on therapeutical options. Dig Liver Dis 2006; 38:846-50. [PMID: 16266839 DOI: 10.1016/j.dld.2005.09.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 09/05/2005] [Accepted: 09/15/2005] [Indexed: 12/11/2022]
Abstract
We report the case of a girl affected by giant cell hepatitis associated with autoimmune haemolytic anaemia. Both conditions were severe with a number of life-threatening episodes of liver failure and anaemia unresponsive to several immunosuppressant drugs but cyclophosphamide. After a low-dose long-term treatment with this drug the patient is stably well without any therapy. A review of therapeutical options in this condition is also presented.
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Affiliation(s)
- P Vajro
- Department of Pediatrics, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy.
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18
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Faa G, Crispino G. Molecular interactions in copper metabolism. Adv Clin Path 2000; 4:195-201. [PMID: 11436158] [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] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- G Faa
- Dipartimento di Citomorfologia, Divisione di Anatomia Patologica. Universitá di Cagliari, Cagliari, Italy
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19
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Molica S, Vitelli G, Levato D, Crispino G, Dell'Olio M, Dattilo A, Matera R, Gandolfo GM, Musto P. CD27 in B-cell chronic lymphocytic leukemia. Cellular expression, serum release and correlation with other soluble molecules belonging to nerve growth factor receptors (NGFr) superfamily. Haematologica 1998; 83:398-402. [PMID: 9658722] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND AND OBJECTIVE CD27, a transmembrane homodimer belonging to the nerve growth factor (NGF) receptor superfamily, is typically expressed on leukemic CD5+ cells in B-cell chronic lymphocytic leukemia (CLL) and found in soluble form in the serum of CLL patients. Therefore, we investigated clinico-biological implications of increased serum levels of sCD27 in an unselected series of B-CLL patients. DESIGN AND METHODS Serum CD27 (sCD27) levels were determined at the time of diagnosis in 82 previously untreated B-CLL patients using a sandwich enzyme-linked immunoassay (ELISA). Results were correlated with either clinico-hematological or biological features. Finally, quantitative flow cytometric analyses of membrane CD27 (mCD27) expression were carried out on peripheral blood (PB) cells of 22 B-CLL patients and 5 healthy controls, respectively. RESULTS CD27 was found to be expressed on the surface of both resting normal and leukemic B cells. sCD27 levels were significantly higher in B-CLL patients (median value 2150 U/mL) than in healthy controls (median value 220 U/mL) (p < 0.0001). There was a close relationship between sCD27 and soluble TNF-alpha, another molecule belonging to the NGF receptor superfamily. Changes in sCD27 level correlated with clinical stage, beta 2 microglobulin and LDH. INTERPRETATION AND CONCLUSIONS These findings indicate that sCD27 is a reliable marker of tumor mass in B-CLL. Its potential prognostic value should be tested in prospective studies.
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Affiliation(s)
- S Molica
- Divisione Ematologia, Azienda Ospedaliera Pugliese-Ciaccio, Catanzaro, Italy
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20
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Molica S, Mannella A, Crispino G, Dattilo A, Levato D. Comparative flow cytometric evaluation of bcl-2 oncoprotein in CD5+ and CD5- B-cell lymphoid chronic leukemias. Haematologica 1997; 82:555-9. [PMID: 9407720] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Levels of intracellular bcl-2 oncoprotein have been found to be increased in leukemic cells of CD5+ B-chronic lymphocytic leukemia (CLL) patients. However, it is not clear whether bcl-2 overexpression is a peculiar feature of CD5+ B-CLL. Based on this background we carried out a quantitative flow cytometric evaluation of intracellular bcl-2 levels on leukemic cells of CD5+ and CD5- B-CLL. METHODS We assessed in flow cytometry levels of bcl-2 protein using a quantitative indirect immunofluorescence assay (QIFI kit) on samples from 46 previously untreated CD5+ B-CLL patients. Results were compared with those obtained on either normal peripheral blood B-lymphocytes or leukemic cells from 7 CD5- B-CLL patients intentionally selected for statistical comparison. RESULTS A relatively homogeneous amount of bcl-2 protein which did not reflect either clinical-biological features at the time of diagnosis nor in vivo response to therapy was found. Results expressed as antibody binding capacity (ABC) accounted for a mean value of 12.2 +/- 1.5 x 10(3) molecules/cell (range, 6.4-13 x 10(3) molecules/cell). Levels of bcl-2 detected on CD5+ B-CLL leukemic cells were significantly lower than those of B peripheral blood lymphocytes from healthy donors (p = 0.0001). The same applied when comparing CD5+ and CD5- B-CLL patients (bcl-2 ABC, 8.07 +/- 0.26 x 10(3) molecules/cell vs. 12.2 +/- 1.5 x 10(9) molecules/cell; p = 0.0001). INTERPRETATION AND CONCLUSIONS According to the role of bcl-2 in preventing apoptosis, our results indicate that differences in the pattern of expression of such an oncoprotein, might, at least in part, explain the more aggressive clinical course of CD5- B-CLL forms.
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Affiliation(s)
- S Molica
- Divisione Ematologia, Azienda Ospedaliera, Pugliese-Ciaccio, Catanzaro, Italy
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21
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Angeletti G, Crispino G, Bracaccia M, Rosi G, Caputo N, Lupidi G, Sbordone GB. Precocious puberty and neurofibromatosis of von Recklinghausen. A clinical report. Recenti Prog Med 1990; 81:806-8. [PMID: 2127464] [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: 12/30/2022]
Abstract
A case of a 9-year-old boy with neurofibromatosis of von Recklinghausen and precocious puberty is reported. The patient was referred to us because of an unexplained onset of precocious puberty. Clinical manifestations of neurofibromatosis included multiple café-au-lait spots, skeletal anomalies, progressive impairment of vision and precocious sexual development. CT scan and NMR demonstrated the presence of optic gliomas. The correlation between the lesions of retino-hypothalamic projection and production of the neuroendocrinology mechanism of sexual changes is discussed.
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Affiliation(s)
- G Angeletti
- Istituto di Patologia speciale medica, Facoltà di Medicina e Chirurgia, Università, Perugia
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De Feo P, Gallai V, Mazzotta G, Crispino G, Torlone E, Perriello G, Ventura MM, Santeusanio F, Brunetti P, Bolli GB. Modest decrements in plasma glucose concentration cause early impairment in cognitive function and later activation of glucose counterregulation in the absence of hypoglycemic symptoms in normal man. J Clin Invest 1988; 82:436-44. [PMID: 3403713 PMCID: PMC303532 DOI: 10.1172/jci113616] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.7] [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: 01/05/2023] Open
Abstract
To establish the glycemic threshold for onset of neuroglycopenia (impaired cognitive function, measured by the latency of the P300 wave), activation of hormonal counterregulation and hypoglycemic symptoms, 12 normal subjects were studied either under conditions of insulin-induced, glucose-controlled plasma glucose decrements, or during maintenance of euglycemia. A decrement in plasma glucose concentration from 88 +/- 3 to 80 +/- 1 mg/dl for 150 min did not result in changes in the latency of the P300 wave nor in an activation of counterregulatory hormonal response. In contrast, a greater decrement in plasma glucose concentration from 87 +/- 3 to 72 +/- 1 mg/dl for 120 min caused an increase in the latency of the P300 wave (from 301 +/- 12 to 348 +/- 20 ms, P less than 0.01), a subsequent increase in all counterregulatory hormones but no hypoglycemic symptoms. Finally, when plasma glucose concentration was decreased in a stepwise manner from 88 +/- 2 to 50 +/- 1 mg/dl within 75 min, the increase in the latency of the P300 wave was correlated with the corresponding plasma glucose concentration (r = -0.76, P less than 0.001). The glycemic threshold for hypoglycemic symptoms was 49 +/- 2 mg/dl. Thus, in normal man the glycemic threshold for neuroglycopenia (72 +/- 1 mg/dl) is greater than currently thought; the hormonal counterregulation follows the onset of neuroglycopenia; the hypoglycemic symptoms are a late indicator of advanced neuroglycopenia.
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Affiliation(s)
- P De Feo
- Istituto di Patologia Medica, Unviersity of Perugia, Italy
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