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Shmal D, Mantero G, Floss T, Benfenati F, Maya-Vetencourt JF. Restoring vision in adult amblyopia by enhancing plasticity through deletion of the transcriptional repressor REST. iScience 2024; 27:109507. [PMID: 38591011 PMCID: PMC11000024 DOI: 10.1016/j.isci.2024.109507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/30/2024] [Accepted: 03/13/2024] [Indexed: 04/10/2024] Open
Abstract
Visual cortical plasticity is high during early life, but gradually decreases with development. This is due to the Otx2-driven maturation of intracortical inhibition that parallels the condensation of extracellular matrix components into perineuronal nets mainly around parvalbumin-positive GABAergic neurons. Repressor Element 1 Silencing Transcription (REST) epigenetically controls the expression of a plethora of neuron-specific genes. We demonstrate that the conditional knockout of REST in the primary visual cortex of adult mice induces a shift of ocular dominance after short-term monocular deprivation and promotes the recovery of vision in long-term deprived animals after reverse suture. These phenomena paralleled a reduction of perineuronal net density and increased expression of REST target genes, but not of the homeoprotein Otx2 in the visual cortex contralateral to the deprived eye. This shows that REST regulates adult visual cortical plasticity and is a potential therapeutic target to restore vision in adult amblyopia by enhancing V1 plasticity.
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Affiliation(s)
- Dmytro Shmal
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Giulia Mantero
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Thomas Floss
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Neuherberg, Germany
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - José Fernando Maya-Vetencourt
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Biology, University of Pisa, Pisa, Italy
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Huang H, Chen M, Liu X, Xiong X, Zhou L, Su Z, Lu Y, Liang B. A novel variant in the GJB6 gene in a large Chinese family with a unique phenotype of Clouston syndrome. Front Med 2023; 17:330-338. [PMID: 36645631 DOI: 10.1007/s11684-022-0933-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/21/2022] [Indexed: 01/17/2023]
Abstract
Clouston syndrome (OMIM #129500), also known as hidrotic ectodermal dysplasia type 2, is a rare autosomal dominant skin disorder. To date, four mutations in the GJB6 gene, G11R, V37E, A88V, and D50N, have been confirmed to cause this condition. In previous studies, the focus has been mainly on gene sequencing, and there has been a lack of research on clinical manifestations and pathogenesis. To confirm the diagnosis of this pedigree at the molecular level and summarize and analyse the clinical phenotype of patients and to provide a basis for further study of the pathogenesis of the disease, we performed whole-exome and Sanger sequencing on a large Chinese Clouston syndrome pedigree. Detailed clinical examination included histopathology, hair microscopy, and scanning electron microscopy. We found a novel heterozygous missense variant (c.134G>C:p.G45A) for Clouston syndrome. We identified a new clinical phenotype involving all nail needling pain in all patients and found a special honeycomb hole structure in the patients' hair under scanning electron microscopy. Our data reveal that a novel variant (c.134G>C:p.G45A) plays a likely pathogenic role in this pedigree and highlight that genetic testing is necessary for the diagnosis of Clouston syndrome.
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Affiliation(s)
- Hequn Huang
- Institute of Dermatology and Department of Dermatology, the First Affiliated Hospital, Anhui Medical University, Hefei, 230000, China
- Key Laboratory of Dermatology (Anhui Medical University), Ministry of Education, Hefei, 230000, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Hefei, 230000, China
| | - Mengyun Chen
- Institute of Dermatology and Department of Dermatology, the First Affiliated Hospital, Anhui Medical University, Hefei, 230000, China
- Key Laboratory of Dermatology (Anhui Medical University), Ministry of Education, Hefei, 230000, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Hefei, 230000, China
| | - Xia Liu
- Huai'an District Skin Disease Prevention and Treatment Hospital, Huai'an, 223000, China
| | - Xixi Xiong
- Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210000, China
| | - Lanbo Zhou
- Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210000, China
| | - Zhonglan Su
- Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210000, China
| | - Yan Lu
- Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210000, China.
| | - Bo Liang
- Institute of Dermatology and Department of Dermatology, the First Affiliated Hospital, Anhui Medical University, Hefei, 230000, China.
- Key Laboratory of Dermatology (Anhui Medical University), Ministry of Education, Hefei, 230000, China.
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Hefei, 230000, China.
- Department of Clinical Laboratory, The First Affiliated Hospital, Anhui Medical University, Hefei, 230000, China.
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Borodinova AA, Balaban PM, Bezprozvanny IB, Salmina AB, Vlasova OL. Genetic Constructs for the Control of Astrocytes' Activity. Cells 2021; 10:cells10071600. [PMID: 34202359 PMCID: PMC8306323 DOI: 10.3390/cells10071600] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/20/2021] [Accepted: 06/23/2021] [Indexed: 12/20/2022] Open
Abstract
In the current review, we aim to discuss the principles and the perspectives of using the genetic constructs based on AAV vectors to regulate astrocytes’ activity. Practical applications of optogenetic approaches utilizing different genetically encoded opsins to control astroglia activity were evaluated. The diversity of astrocytic cell-types complicates the rational design of an ideal viral vector for particular experimental goals. Therefore, efficient and sufficient targeting of astrocytes is a multiparametric process that requires a combination of specific AAV serotypes naturally predisposed to transduce astroglia with astrocyte-specific promoters in the AAV cassette. Inadequate combinations may result in off-target neuronal transduction to different degrees. Potentially, these constraints may be bypassed with the latest strategies of generating novel synthetic AAV serotypes with specified properties by rational engineering of AAV capsids or using directed evolution approach by searching within a more specific promoter or its replacement with the unique enhancer sequences characterized using modern molecular techniques (ChIP-seq, scATAC-seq, snATAC-seq) to drive the selective transgene expression in the target population of cells or desired brain regions. Realizing these strategies to restrict expression and to efficiently target astrocytic populations in specific brain regions or across the brain has great potential to enable future studies.
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Affiliation(s)
- Anastasia A. Borodinova
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485 Moscow, Russia;
| | - Pavel M. Balaban
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117485 Moscow, Russia;
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (I.B.B.); (A.B.S.); (O.L.V.)
- Correspondence:
| | - Ilya B. Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (I.B.B.); (A.B.S.); (O.L.V.)
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Alla B. Salmina
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (I.B.B.); (A.B.S.); (O.L.V.)
- Research Institute of Molecular Medicine and Pathobiochemistry, V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, 660022 Krasnoyarsk, Russia
- Research Center of Neurology, 125367 Moscow, Russia
| | - Olga L. Vlasova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (I.B.B.); (A.B.S.); (O.L.V.)
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Sánchez OF, Rodríguez AV, Velasco-España JM, Murillo LC, Sutachan JJ, Albarracin SL. Role of Connexins 30, 36, and 43 in Brain Tumors, Neurodegenerative Diseases, and Neuroprotection. Cells 2020; 9:E846. [PMID: 32244528 PMCID: PMC7226843 DOI: 10.3390/cells9040846] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/15/2020] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Gap junction (GJ) channels and their connexins (Cxs) are complex proteins that have essential functions in cell communication processes in the central nervous system (CNS). Neurons, astrocytes, oligodendrocytes, and microglial cells express an extraordinary repertory of Cxs that are important for cell to cell communication and diffusion of metabolites, ions, neurotransmitters, and gliotransmitters. GJs and Cxs not only contribute to the normal function of the CNS but also the pathological progress of several diseases, such as cancer and neurodegenerative diseases. Besides, they have important roles in mediating neuroprotection by internal or external molecules. However, regulation of Cx expression by epigenetic mechanisms has not been fully elucidated. In this review, we provide an overview of the known mechanisms that regulate the expression of the most abundant Cxs in the central nervous system, Cx30, Cx36, and Cx43, and their role in brain cancer, CNS disorders, and neuroprotection. Initially, we focus on describing the Cx gene structure and how this is regulated by epigenetic mechanisms. Then, the posttranslational modifications that mediate the activity and stability of Cxs are reviewed. Finally, the role of GJs and Cxs in glioblastoma, Alzheimer's, Parkinson's, and Huntington's diseases, and neuroprotection are analyzed with the aim of shedding light in the possibility of using Cx regulators as potential therapeutic molecules.
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Affiliation(s)
- Oscar F. Sánchez
- Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, 110911 Bogota, Colombia; (A.V.R.); (J.M.V.-E.); (L.C.M.); (J.-J.S.)
| | | | | | | | | | - Sonia-Luz Albarracin
- Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, 110911 Bogota, Colombia; (A.V.R.); (J.M.V.-E.); (L.C.M.); (J.-J.S.)
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Bussini A, Righi R, Pessina C, Genoni A, Cristofari E, Meli A, Granata P, Meroni E, Broccolo F, Casalone R. The p.Gly130Val mutation in the GJB2 gene: A familiar case of autosomal dominant non-syndromic hearing loss. Int J Pediatr Otorhinolaryngol 2019; 127:109653. [PMID: 31472357 DOI: 10.1016/j.ijporl.2019.109653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 08/01/2019] [Accepted: 08/20/2019] [Indexed: 11/27/2022]
Abstract
Several forms of sensorineural hearing loss (SNHL) have been imputated to connexins mutations and prevalently to connexin 26 (Cx26), codified by the GJB2 gene (gap junction protein, beta 2). Here, we report the first familiar case (heterozygous p. G130V mutation) of non-syndromic (without any dermatological manifestation) dominant profound SNHL. Proband was a 6-years-old male with post-lingual bilateral profound SNHL, clinically identified at the age of 3 with diagnosis of severe SNHL. We confirm that the p. G130V variant of the GJB2 gene is causative of autosomal dominant form of SNHL, although it is not always associated with the presence of skin diseases.
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Affiliation(s)
- Adelaide Bussini
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy
| | - Rossana Righi
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy
| | - Chiara Pessina
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy
| | - Angelo Genoni
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy
| | | | | | - Paola Granata
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy
| | - Emanuela Meroni
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy
| | - Francesco Broccolo
- Department of Medicine and Surgery (School of Medicine), University of Milano-Bicocca, Monza, Italy.
| | - Rosario Casalone
- Unit of Cytogenetics and Medical Genetic, ASST Settelaghi, Varese, Italy.
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Aasen T, Johnstone S, Vidal-Brime L, Lynn KS, Koval M. Connexins: Synthesis, Post-Translational Modifications, and Trafficking in Health and Disease. Int J Mol Sci 2018; 19:ijms19051296. [PMID: 29701678 PMCID: PMC5983588 DOI: 10.3390/ijms19051296] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/20/2018] [Accepted: 04/21/2018] [Indexed: 02/06/2023] Open
Abstract
Connexins are tetraspan transmembrane proteins that form gap junctions and facilitate direct intercellular communication, a critical feature for the development, function, and homeostasis of tissues and organs. In addition, a growing number of gap junction-independent functions are being ascribed to these proteins. The connexin gene family is under extensive regulation at the transcriptional and post-transcriptional level, and undergoes numerous modifications at the protein level, including phosphorylation, which ultimately affects their trafficking, stability, and function. Here, we summarize these key regulatory events, with emphasis on how these affect connexin multifunctionality in health and disease.
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Affiliation(s)
- Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
| | - Scott Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VI 22908, USA.
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TT, UK.
| | - Laia Vidal-Brime
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
| | - K Sabrina Lynn
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Juszczak GR, Stankiewicz AM. Glucocorticoids, genes and brain function. Prog Neuropsychopharmacol Biol Psychiatry 2018; 82:136-168. [PMID: 29180230 DOI: 10.1016/j.pnpbp.2017.11.020] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/18/2017] [Accepted: 11/23/2017] [Indexed: 01/02/2023]
Abstract
The identification of key genes in transcriptomic data constitutes a huge challenge. Our review of microarray reports revealed 88 genes whose transcription is consistently regulated by glucocorticoids (GCs), such as cortisol, corticosterone and dexamethasone, in the brain. Replicable transcriptomic data were combined with biochemical and physiological data to create an integrated view of the effects induced by GCs. The most frequently reported genes were Errfi1 and Ddit4. Their up-regulation was associated with the altered transcription of genes regulating growth factor and mTORC1 signaling (Gab1, Tsc22d3, Dusp1, Ndrg2, Ppp5c and Sesn1) and progression of the cell cycle (Ccnd1, Cdkn1a and Cables1). The GC-induced reprogramming of cell function involves changes in the mRNA level of genes responsible for the regulation of transcription (Klf9, Bcl6, Klf15, Tle3, Cxxc5, Litaf, Tle4, Jun, Sox4, Sox2, Sox9, Irf1, Sall2, Nfkbia and Id1) and the selective degradation of mRNA (Tob2). Other genes are involved in the regulation of metabolism (Gpd1, Aldoc and Pdk4), actin cytoskeleton (Myh2, Nedd9, Mical2, Rhou, Arl4d, Osbpl3, Arhgef3, Sdc4, Rdx, Wipf3, Chst1 and Hepacam), autophagy (Eva1a and Plekhf1), vesicular transport (Rhob, Ehd3, Vps37b and Scamp2), gap junctions (Gjb6), immune response (Tiparp, Mertk, Lyve1 and Il6r), signaling mediated by thyroid hormones (Thra and Sult1a1), calcium (Calm2), adrenaline/noradrenaline (Adcy9 and Adra1d), neuropeptide Y (Npy1r) and histamine (Hdc). GCs also affected genes involved in the synthesis of polyamines (Azin1) and taurine (Cdo1). The actions of GCs are restrained by feedback mechanisms depending on the transcription of Sgk1, Fkbp5 and Nr3c1. A side effect induced by GCs is increased production of reactive oxygen species. Available data show that the brain's response to GCs is part of an emergency mode characterized by inactivation of non-core activities, restrained inflammation, restriction of investments (growth), improved efficiency of energy production and the removal of unnecessary or malfunctioning cellular components to conserve energy and maintain nutrient supply during the stress response.
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Affiliation(s)
- Grzegorz R Juszczak
- Department of Animal Behavior, Institute of Genetics and Animal Breeding, Jastrzebiec, ul. Postepu 36A, 05-552 Magdalenka, Poland.
| | - Adrian M Stankiewicz
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Jastrzebiec, ul. Postepu 36A, 05-552 Magdalenka, Poland
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Berman JW, Carvallo L, Buckner CM, Luers A, Prevedel L, Bennett MV, Eugenin EA. HIV-tat alters Connexin43 expression and trafficking in human astrocytes: role in NeuroAIDS. J Neuroinflammation 2016; 13:54. [PMID: 26934876 PMCID: PMC4774036 DOI: 10.1186/s12974-016-0510-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/14/2016] [Indexed: 11/16/2022] Open
Abstract
Background HIV-associated neurocognitive disorders (HAND) are a major complication in at least half of the infected population despite effective antiretroviral treatment and immune reconstitution. HIV-associated CNS damage is not correlated with active viral replication but instead is associated with mechanisms that regulate inflammation and neuronal compromise. Our data indicate that one of these mechanisms is mediated by gap junction channels and/or hemichannels. Normally, gap junction channels shutdown under inflammatory conditions, including viral diseases. However, HIV infection upregulates Connexin43 (Cx43) expression and maintains gap junctional communication by unknown mechanism(s). Methods Human primary astrocytes were exposed to several HIV proteins as well as to HIV, and expression and function of Connexin43- and Connexin30-containing channels were determined by western blot, immunofluorescence, microinjection of a fluorescent tracer and chromatin immunoprecipitation (ChIP). Results Here, we demonstrate that HIV infection increases Cx43 expression in vivo. HIV-tat, the transactivator of the virus, and no other HIV proteins tested, increases Cx43 expression and maintains functional gap junctional communication in human astrocytes. Cx43 upregulation is mediated by binding of the HIV-tat protein to the Cx43 promoter, but not to the Cx30 promoter, resulting in increased Cx43 messenger RNA (mRNA) and protein as well as gap junctional communication. Conclusions We propose that HIV-tat contributes to the spread of intracellular toxic signals generated in a few HIV-infected cells into surrounding uninfected cells by upregulating gap junctional communication. In the current antiretroviral era, where HIV replication is often completely suppressed, viral factors such as HIV-tat are still produced and released from infected cells. Thus, blocking the effects of HIV-tat could result in new strategies to reduce the damaging consequences of HIV infection of the CNS.
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Affiliation(s)
- Joan W Berman
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA. .,Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Loreto Carvallo
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Clarisa M Buckner
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA. .,Current address: Laboratory of Immunoregulation, NIAID, Bethesda, MD, USA.
| | - Aimée Luers
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Lisa Prevedel
- Public Health Research Institute (PHRI), 225 Warren Street, Newark, NJ, 07103, USA.,Department of Microbiology and Molecular Genetics, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA
| | - Michael V Bennett
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Eliseo A Eugenin
- Public Health Research Institute (PHRI), 225 Warren Street, Newark, NJ, 07103, USA. .,Department of Microbiology and Molecular Genetics, Rutgers University, 225 Warren Street, Newark, NJ, 07103, USA.
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Churko JM, Laird DW. Gap junction remodeling in skin repair following wounding and disease. Physiology (Bethesda) 2013; 28:190-8. [PMID: 23636264 DOI: 10.1152/physiol.00058.2012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the present review, we provide an overview of connexin expression during skin development and remodeling in wound healing, and reflect on how loss- or gain-of-function connexin mutations may change cellular phenotypes and lead to diseases of the skin. We also consider the therapeutic value of targeting connexins in wound healing.
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Affiliation(s)
- Jared M Churko
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
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Fujimoto A, Kurban M, Nakamura M, Farooq M, Fujikawa H, Kibbi AG, Ito M, Dahdah M, Matta M, Diab H, Shimomura Y. GJB6, of which mutations underlie Clouston syndrome, is a potential direct target gene of p63. J Dermatol Sci 2012; 69:159-66. [PMID: 23219093 DOI: 10.1016/j.jdermsci.2012.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 11/06/2012] [Accepted: 11/08/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Clouston syndrome is a rare autosomal dominant condition characterized by hypotrichosis, nail dystrophy, and occasionally palmoplantar keratoderma. The disease is caused by mutations in GJB6 gene, which encodes a gap junction protein connexin 30 (Cx30). OBJECTIVE To disclose the molecular basis of Clouston syndrome in a Lebanese-German family, and also to determine precise expression of Cx30 in normal skin of humans and mice, as well as transcriptional regulation for the GJB6 expression. METHODS We searched for mutations in the GJB6 gene using DNA of the family members with Clouston syndrome. We performed immunostaining to localize the Cx30 expression in normal human skin and mouse embryos. In addition, we did a series of in vitro studies to investigate if the GJB6 could be a direct transcriptional target gene of p63. RESULTS We identified a recurrent heterozygous mutation c.31G>C (p.Gly11Arg) in the GJB6 gene in the Lebanese-German family with Clouston syndrome. Immunostaining in normal human skin sections demonstrated predominant expression of Cx30 in hair follicles, nails, and palmoplantar epidermis, which partially overlapped with p63 expression. We also showed co-expression of Cx30 and p63 in developing mouse hair follicles and nail units. In cultured cells, the GJB6 expression was significantly upregulated by ΔNp63α isoform. Further in vitro analyses suggested that ΔNp63α was potentially involved in the GJB6 expression via binding to the sequences in intron 1 of the GJB6 gene. CONCLUSION Our data further underscore the crucial roles of Cx30 in morphogenesis and development of skin and its appendages.
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Affiliation(s)
- Atsushi Fujimoto
- Laboratory of Genetic Skin Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Iossa S, Marciano E, Franzé A. GJB2 Gene Mutations in Syndromic Skin Diseases with Sensorineural Hearing Loss. Curr Genomics 2012; 12:475-785. [PMID: 22547955 PMCID: PMC3219843 DOI: 10.2174/138920211797904098] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 07/27/2011] [Accepted: 08/10/2011] [Indexed: 01/10/2023] Open
Abstract
The GJB2 gene is located on chromosome 13q12 and it encodes the connexin 26, a transmembrane protein involved in cell-cell attachment of almost all tissues. GJB2 mutations cause autosomal recessive (DFNB1) and sometimes dominant (DFNA3) non-syndromic sensorineural hearing loss. Moreover, it has been demonstrated that connexins are involved in regulation of growth and differentiation of epidermis and, in fact, GJB2 mutations have also been identified in syndromic disorders with hearing loss associated with various skin disease phenotypes. GJB2 mutations associated with skin disease are, in general, transmitted with a dominant inheritance pattern. Nonsyndromic deafness is caused prevalently by a loss-of-function, while literature evidences suggest for syndromic deafness a mechanism based on gain-of-function. The spectrum of skin manifestations associated with some mutations seems to have a very high phenotypic variability. Why some mutations can lead to widely varying cutaneous manifestations is poorly understood and in particular, the reason why the skin disease-deafness phenotypes differ from each other thus remains unclear. This review provides an overview of recent findings concerning pathogenesis of syndromic deafness imputable to GJB2 mutations with an emphasis on relevant clinical genotype-phenotype correlations. After describing connexin 26 fundamental characteristics, the most relevant and recent information about its known mutations involved in the syndromic forms causing hearing loss and skin problems are summarized. The possible effects of the mutations on channel expression and function are discussed.
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Oyamada M, Takebe K, Oyamada Y. Regulation of connexin expression by transcription factors and epigenetic mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:118-33. [PMID: 22244842 DOI: 10.1016/j.bbamem.2011.12.031] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 12/17/2011] [Accepted: 12/27/2011] [Indexed: 01/24/2023]
Abstract
Gap junctions are specialized cell-cell junctions that directly link the cytoplasm of neighboring cells. They mediate the direct transfer of metabolites and ions from one cell to another. Discoveries of human genetic disorders due to mutations in gap junction protein (connexin [Cx]) genes and experimental data on connexin knockout mice provide direct evidence that gap junctional intercellular communication is essential for tissue functions and organ development, and that its dysfunction causes diseases. Connexin-related signaling also involves extracellular signaling (hemichannels) and non-channel intracellular signaling. Thus far, 21 human genes and 20 mouse genes for connexins have been identified. Each connexin shows tissue- or cell-type-specific expression, and most organs and many cell types express more than one connexin. Connexin expression can be regulated at many of the steps in the pathway from DNA to RNA to protein. In recent years, it has become clear that epigenetic processes are also essentially involved in connexin gene expression. In this review, we summarize recent knowledge on regulation of connexin expression by transcription factors and epigenetic mechanisms including histone modifications, DNA methylation, and microRNA. This article is part of a Special Issue entitled: The communicating junctions, roles and dysfunctions.
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Affiliation(s)
- Masahito Oyamada
- Department of Food Science and Human Nutrition, Fuji Women's University, Ishikarishi, Japan.
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Ru B, Han N, He G, Brayer K, Zhang S, Wang Z. Molecular cloning and evolutionary analysis of GJB6 in mammals. Biochem Genet 2011; 50:213-26. [PMID: 21948254 DOI: 10.1007/s10528-011-9463-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Accepted: 04/07/2011] [Indexed: 11/29/2022]
Abstract
GJB6 plays a crucial role in hearing. In mammals, bats use ultrasonic echolocation for orientation and locating prey. To investigate the evolution of GJB6 in mammals, we cloned the full-length coding region of GJB6 from 16 species of bats and 4 other mammal species and compared them with orthologous sequences in 11 other mammals. The results show purifying selection on GJB6 in mammals, as well as in the bat lineage, which indicates an important role for GJB6 in mammal hearing. We also found one unique amino acid substitution shared by 16 species of bats and 10 shared by two species of artiodactyls. This positioned the artiodactyls at an abnormal location in the gene tree. In addition, the cytoplasmic loop and carboxy terminus were more variable than other domains in all the mammals. These results demonstrate that GJB6 is basically conserved in mammals but has undergone relatively rapid evolution in particular lineages and domains.
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Affiliation(s)
- Binghua Ru
- Institute of Molecular Ecology and Evolution, Institutes for Advanced Interdisciplinary Research, East China Normal University, Shanghai, China.
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Tandem alternative splicing of zebrafish connexin45.6. Genomics 2010; 96:112-8. [PMID: 20466054 DOI: 10.1016/j.ygeno.2010.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 04/19/2010] [Accepted: 05/04/2010] [Indexed: 11/24/2022]
Abstract
Early studies suggested that most connexin genes share a relatively simple structure with a single intron of variable length interrupting the 5' untranslated region (UTR). Here we report that zebrafish cx45.6 shows six isoforms of alternative 5'UTRs which are generated from multiple promoter usage and alternative pre-mRNA splicing. Interestingly, cx45.6 undergoes tandem alternative splicing, which produces transcripts only differing by 3 nucleotides. This is the first study that has demonstrated tandem alternative pre-mRNA splicing in the connexin gene family. Expression patterns of cx45.6 alternative transcripts were demonstrated by real-time RT-PCR during zebrafish embryonic development and in adult tissues. The complexity of 5'UTR diversity suggests complicated regulatory mechanisms for cx45.6 gene expression at both transcriptional and post-transcriptional levels, and we propose that tandem alternative splicing in cx45.6 5'UTRs could play a role in translational control. These results lay groundwork for further investigations on the regulation and function of cx45.6 gene expression.
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Lemaître G, Sivan V, Lamartine J, Cosset JM, Cavelier-Balloy B, Salomon D, Waksman G, Martin MT. Connexin 30, a new marker of hyperproliferative epidermis. Br J Dermatol 2006; 155:844-6. [PMID: 16965443 DOI: 10.1111/j.1365-2133.2006.07439.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wilch E, Zhu M, Burkhart KB, Regier M, Elfenbein JL, Fisher RA, Friderici KH. Expression of GJB2 and GJB6 is reduced in a novel DFNB1 allele. Am J Hum Genet 2006; 79:174-9. [PMID: 16773579 PMCID: PMC1474119 DOI: 10.1086/505333] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Accepted: 04/20/2006] [Indexed: 11/04/2022] Open
Abstract
In a large kindred of German descent, we found a novel allele that segregates with deafness when present in trans with the 35delG allele of GJB2. Qualitative polymerase chain reaction-based allele-specific expression assays showed that expression of both GJB2 and GJB6 from the novel allele is dramatically reduced. This is the first evidence of a deafness-associated regulatory mutation of GJB2 and of potential coregulation of GJB2 and GJB6.
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Affiliation(s)
- Ellen Wilch
- Genetics Program, Michigan State University, East Lansing, 48824, USA
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Oyamada M, Oyamada Y, Takamatsu T. Regulation of connexin expression. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1719:6-23. [PMID: 16359940 DOI: 10.1016/j.bbamem.2005.11.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 10/29/2005] [Accepted: 11/02/2005] [Indexed: 01/22/2023]
Abstract
Gap junctions contain cell-cell communicating channels that consist of multimeric proteins called connexins and mediate the exchange of low-molecular-weight metabolites and ions between contacting cells. Gap junctional communication has long been hypothesized to play a crucial role in the maintenance of homeostasis, morphogenesis, cell differentiation, and growth control in multicellular organisms. The recent discovery that human genetic disorders are associated with mutations in connexin genes and experimental data on connexin knockout mice have provided direct evidence that gap junctional communication is essential for tissue functions and organ development. Thus far, 21 human genes and 20 mouse genes for connexins have been identified. Each connexin shows tissue- or cell-type-specific expression, and most organs and many cell types express more than one connexin. Cell coupling via gap junctions is dependent on the specific pattern of connexin gene expression. This pattern of gene expression is altered during development and in several pathological conditions resulting in changes of cell coupling. Connexin expression can be regulated at many of the steps in the pathway from DNA to RNA to protein. However, transcriptional control is one of the most important points. In this review, we summarize recent knowledge on transcriptional regulation of connexin genes by describing the structure of connexin genes and transcriptional factors that regulate connexin expression.
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Affiliation(s)
- Masahito Oyamada
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
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